Tumor-Triggered Geometrical Shape Switch of Chimeric Peptide for Enhanced in Vivo Tumor Internalization and Photodynamic Therapy.

Science.gov (United States)

Han, Kai; Zhang, Jin; Zhang, Weiyun; Wang, Shibo; Xu, Luming; Zhang, Chi; Zhang, Xianzheng; Han, Heyou

2017-03-28

Geometrical shape of nanoparticles plays an important role in cellular internalization. However, the applicability in tumor selective therapeutics is still scarcely reported. In this article, we designed a tumor extracellular acidity-responsive chimeric peptide with geometrical shape switch for enhanced tumor internalization and photodynamic therapy. This chimeric peptide could self-assemble into spherical nanoparticles at physiological condition. While at tumor extracellular acidic microenvironment, chimeric peptide underwent detachment of acidity-sensitive 2,3-dimethylmaleic anhydride groups. The subsequent recovery of ionic complementarity between chimeric peptides resulted in formation of rod-like nanoparticles. Both in vitro and in vivo studies demonstrated that this acidity-triggered geometrical shape switch endowed chimeric peptide with accelerated internalization in tumor cells, prolonged accumulation in tumor tissue, enhanced photodynamic therapy, and minimal side effects. Our results suggested that fusing tumor microenvironment with geometrical shape switch should be a promising strategy for targeted drug delivery.

Time and Frequency Localized Pulse Shape for Resolution Enhancement in STFT-BOTDR

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Linqing Luo

2016-01-01

Full Text Available Short-Time Fourier Transform-Brillouin Optical Time-Domain Reflectometry (STFT-BOTDR implements STFT over the full frequency spectrum to measure the distributed temperature and strain along the optic fiber, providing new research advances in dynamic distributed sensing. The spatial and frequency resolution of the dynamic sensing are limited by the Signal to Noise Ratio (SNR and the Time-Frequency (T-F localization of the input pulse shape. T-F localization is fundamentally important for the communication system, which suppresses interchannel interference (ICI and intersymbol interference (ISI to improve the transmission quality in multicarrier modulation (MCM. This paper demonstrates that the T-F localized input pulse shape can enhance the SNR and the spatial and frequency resolution in STFT-BOTDR. Simulation and experiments of T-F localized different pulses shapes are conducted to compare the limitation of the system resolution. The result indicates that rectangular pulse should be selected to optimize the spatial resolution and Lorentzian pulse could be chosen to optimize the frequency resolution, while Gaussian shape pulse can be used in general applications for its balanced performance in both spatial and frequency resolution. Meanwhile, T-F localization is proved to be useful in the pulse shape selection for system resolution optimization.

Enhancement of intermediate-field two-photon absorption by rationally shaped femtosecond pulses

International Nuclear Information System (INIS)

Chuntonov, Lev; Rybak, Leonid; Gandman, Andrey; Amitay, Zohar

2008-01-01

We extend the powerful frequency-domain analysis of femtosecond two-photon absorption to the intermediate-field regime of considerable absorption yields, where additionally to the weak-field nonresonant two-photon transitions also four-photon transitions play a role. Consequently, we rationally find that the absorption is enhanced over the transform-limited pulse by any shaped pulse having a spectral phase that is antisymmetric around one-half of the transition frequency and a spectrum that is asymmetric around it (red or blue detuned according to the system). The enhancement increases as the field strength increases. The theoretical results for Na are verified experimentally

Effects of Ag Nanocubes with Different Corner Shape on the Absorption Enhancement in Organic Solar Cells

Directory of Open Access Journals (Sweden)

Feng Shan

2014-01-01

Full Text Available The effects of corner shape of silver (Ag nanocubes (NCs on optical absorptions of organic solar cells (OSCs are theoretically investigated by finite element method (FEM calculations. The absorption of sun light in the active layer is calculated. Significant absorption enhancements have been demonstrated in metallic region with different shapes of Ag NCs, among them corner radius (R is zero result in the best light absorption performance of up to 55% enhancement with respect to bare OSCs. The origins of increased absorption are believed to be the effects of the huge electric field enhancement and increased scattering upon the excitation of localized surface plasmon resonance (LSPR. Apart from using R=0, we show that R=3, 6, and 11.29 of Ag NCs in metallic region of active layer may also result in the maximum comparable absorption enhancement of 49%, 41%, and 28%, respectively. In addition, a significant effect of the period of NCs is observed.

Enhanced cognitive Radio Resource Management for LTE systems

KAUST Repository

Alqerm, Ismail

2013-10-01

The explosive growth in mobile Internet and related services has increased the need for more bandwidth in cellular networks. The Long-Term Evolution (LTE) technology is an attractive solution for operators and subscribers to meet such need since it provides high data rates and scalable bandwidth. Radio Resource Management (RRM) is essential for LTE to provide better communication quality and meet the application QoS requirements. Cognitive resource management is a promising solution for LTE RRM as it improves network efficiency by exploiting radio environment information, intelligent optimization algorithms to configure transmission parameters, and mitigate interference. In this paper, we propose a cognitive resource management scheme to adapt LTE network parameters to the environment conditions. The scheme optimizes resource blocks assignment, modulation selection and bandwidth selection to maximize throughput and minimize interference. The scheme uses constrained optimization for throughput maximization and interference control. It is also enhanced by learning mechanism to reduce the optimization complexity and improve the decision-making quality. Our evaluation results show that our scheme achieved significant improvements in throughput and LTE system capacity. Results also show the improvement in the user satisfaction over other techniques in LTE RRM.

Human Resource Management in the Enhancement Processes of Knowledge Management

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Didi Sundiman

2017-11-01

Full Text Available This research explored Human Resource Management (HRM in enhancement processes of knowledge management. This research explored how HRM practice enhanced the operational of knowledge management. Data were collected by a survey by interviewing 12 informants from Small and Medium Enterprise (SME. The results show that HRM practice gives initiative in the enhancement process of the knowledge management strategy applied to the company. It can be concluded that each sub-component of HRM affects the components of knowledge management, and HRM is highly influential and has a positive effect on quality management processes and vice versa in the work environment.

Star-shaped ZnO/Ag hybrid nanostructures for enhanced photocatalysis and antibacterial activity

Energy Technology Data Exchange (ETDEWEB)

Andrade, George R.S., E-mail: grsandrade@hotmail.com [Postgraduate Program in Materials Science and Engineering, Federal University of Sergipe, São Cristóvão, SE (Brazil); Nascimento, Cristiane C. [Postgraduate Program in Materials Science and Engineering, Federal University of Sergipe, São Cristóvão, SE (Brazil); Federal Institute of Education, Science and Technology of Sergipe, Glória Campus, Nossa Senhora da Glória, SE (Brazil); Lima, Zenon M. [Postgraduate Program in Industrial Biochemistry, Tiradentes University, Aracaju, SE (Brazil); Teixeira-Neto, Erico [LNNano − Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP (Brazil); Costa, Luiz P. [Postgraduate Program in Industrial Biochemistry, Tiradentes University, Aracaju, SE (Brazil); ITPS − Technological and Research Institute of Sergipe, Aracaju, SE (Brazil); Gimenez, Iara F. [Postgraduate Program in Materials Science and Engineering, Federal University of Sergipe, São Cristóvão, SE (Brazil); Department of Chemistry, Federal University of Sergipe, São Cristóvão, SE (Brazil)

2017-03-31

Highlights: • A new and simple one-pot method for preparing star-shaped ZnO particles was reported. • ZnO particles were decorated with Ag nanoparticles (SNPs) by a photodeposition method. • The presence of SNC{sup −} ions on ZnO surface prevented uncontrollable growth of SNPs. • ZnO/Ag particles showed plasmon-enhanced photocatalytic activity toward an AZO dye. • SNP improved 16 times the antibacterial activity of ZnO toward 4 bacterial strains. - Abstract: Zinc oxide (ZnO) particles with a star-shaped morphology have been synthesized by a novel and simple room-temperature method and decorated with silver nanoparticles (SNPs) for enhanced photocatalysis and bactericide applications. The presence of thiourea during the precipitation of ZnO in alkaline conditions allowed the control of morphological features (e.g. average size and shape) and the surface functionalization with thiocyanate ions (SCN{sup −}). SNPs were deposited into the ZnO surface by a photoreduction method and their sizes could be easily controlled by changing the ZnO/AgNO{sub 3} ratio. The presence of SCN{sup −} on the semiconductor surface prevents uncontrollable growth of Ag nanoparticles into different morphologies and high degrees of polydispersity. XRD, SEM, TEM, FTIR, UV-vis-NIR and PL were employed for characterizing the structure, morphology and optical properties of the as-obtained pure and hybrid nanostructures. Finally, the hybrid ZnO/Ag particles have shown plasmon-enhanced performance for applications in photocatalysis and antibacterial activity compared to the pure ZnO counterpart. In this work, evaluation of the photodegradation of an aqueous methylene blue solution under UV-A irradiation and the antibacterial activity toward 4 bacterial strains, including Gram-positive bacteria Staphylococcus aureus (ATCC 43300, ATCC 25923 and ATCC 33591) and Gram-negative bacteria Pseudomonas aeruginosa (ATCC 27853).

Therapeutic-Ultrasound-Triggered Shape Memory of a Melamine-Enhanced Poly(vinyl alcohol) Physical Hydrogel.

Science.gov (United States)

Li, Guo; Yan, Qiang; Xia, Hesheng; Zhao, Yue

2015-06-10

Therapeutic-ultrasound-triggered shape memory was demonstrated for the first time with a melamine-enhanced poly(vinyl alcohol) (PVA) physical hydrogel. The addition of a small amount of melamine (up to 1.5 wt %) in PVA results in a strong hydrogel due to the multiple H-bonding between the two constituents. A temporary shape of the hydrogel can be obtained by deformation of the hydrogel (∼65 wt % water) at room temperature, followed by fixation of the deformation by freezing/thawing the hydrogel under strain, which induces crystallization of PVA. We show that the ultrasound delivered by a commercially available device designed for the patient's pain relief could trigger the shape recovery process as a result of ultrasound-induced local heating in the hydrogel that melts the crystallized PVA cross-linking. This hydrogel is thus interesting for potential applications because it combines many desirable properties, being mechanically strong, biocompatible, and self-healable and displaying the shape memory capability triggered by a physiological stimulus.

Geography and major host evolutionary transitions shape the resource use of plant parasites.

Science.gov (United States)

Calatayud, Joaquín; Hórreo, José Luis; Madrigal-González, Jaime; Migeon, Alain; Rodríguez, Miguel Á; Magalhães, Sara; Hortal, Joaquín

2016-08-30

The evolution of resource use in herbivores has been conceptualized as an analog of the theory of island biogeography, assuming that plant species are islands separated by phylogenetic distances. Despite its usefulness, this analogy has paradoxically led to neglecting real biogeographical processes in the study of macroevolutionary patterns of herbivore-plant interactions. Here we show that host use is mostly determined by the geographical cooccurrence of hosts and parasites in spider mites (Tetranychidae), a globally distributed group of plant parasites. Strikingly, geography accounts for most of the phylogenetic signal in host use by these parasites. Beyond geography, only evolutionary transitions among major plant lineages (i.e., gymnosperms, commelinids, and eudicots) shape resource use patterns in these herbivores. Still, even these barriers have been repeatedly overcome in evolutionary time, resulting in phylogenetically diverse parasite communities feeding on similar hosts. Therefore, our results imply that patterns of apparent evolutionary conservatism may largely be a byproduct of the geographic cooccurrence of hosts and parasites.

r-Shaped hybrid nanogenerator with enhanced piezoelectricity.

Science.gov (United States)

Han, Mengdi; Zhang, Xiao-Sheng; Meng, Bo; Liu, Wen; Tang, Wei; Sun, Xuming; Wang, Wei; Zhang, Haixia

2013-10-22

Piezoelectric and triboelectric nanogenerators (NGs) have been proposed in the past few years to effectively harvest mechanical energy from the environment. Here, a polydimethylsiloxane (PDMS) layer is placed under the aluminum electrode of polyvinylidene fluoride (PVDF), thus forming an r-shaped hybrid NG. Micro/nanostructures have been fabricated on the PDMS surface and the aluminum electrodes of PVDF to enhance the output performance. Power densities of the piezoelectric part and the triboelectric part are 10.95 and 2.04 mW/cm(3), respectively. Moreover, influence of the triboelectric charges on the piezoelectric output voltage is investigated. Both finite element method simulations and experimental measurements are conducted to verify this phenomenon. The novel hybrid NG is also demonstrated as a power source for consumer electronics. Through one cycle of electric generation, 10 light-emitting diodes are lighted up instantaneously, and a 4-bit liquid crystal display can display continuously for more than 15 s. Besides, the device is integrated into a keyboard to harvest energy in the typing process.

Performance comparisons of enhanced tubes with discrete and wavy disruption shapes

Energy Technology Data Exchange (ETDEWEB)

Arman, B.; Rabas, T.J.

1993-08-01

This paper presents comparisons of the friction factors and heat-transfer coefficients obtained with enhanced tubes with transverse discrete and almost transverse wavy two-dimensional disruptions. Both experimental data and numerical predictions were used for the comparisons. For the latter a two-layer turbulence model incorporated in a body-fitted, finite-volume method was used. The disruption shape, discrete or wavy, depends on the manufacturing process. If an extrusion process is used, discrete disruptions (ribs) of various profiles are obtained that are separated from each other by a flat or unaltered inside diameter. If a spirally indenting process is used, a wavy proflie is obtained with a continuously varying inside diameter between two adjacent disruption peaks. These disruptions are transverse or almost transverse to the tube axis and separated by a distance that exceeds the reattachment length. Based on these comparisons, the following conclusions are obtained: (1) the disruption shape is not an important correlating parameter for discrete disruptions, (2) only the friction factor is influenced by the shape for wavy disruptions, and (3) there are major differences between both the friction-factor and heat-transfer performance of discrete and wavy disruptions with the same maximum disruption height and spacing. However, the most important finding is that the groove radius of spirally indented tubes should be increased because of the substantial reduction of the friction factor but only a small decrease in the thermal performance. Additional comparisons of predicted results were made to obtain a fundamental understanding of the influence of these different shapes.

Health capabilities and diabetes self-management: the impact of economic, social, and cultural resources.

Science.gov (United States)

Weaver, Robert R; Lemonde, Manon; Payman, Naghmeh; Goodman, William M

2014-02-01

While the "social determinants of health" view compels us to explore how social structures shape health outcomes, it often ignores the role individual agency plays. In contrast, approaches that focus on individual choice and personal responsibility for health often overlook the influence of social structures. Amartya Sen's "capabilities" framework and its derivative the "health capabilities" (HC) approach attempts to accommodate both points of view, acknowledging that individuals function under social conditions over which they have little control, while also acting as agents in their own health and well-being. This paper explores how economic, social, and cultural resources shape the health capability of people with diabetes, focusing specifically on dietary practices. Health capability and agency are central to dietary practices, while also being shaped by immediate and broader social conditions that can generate habits and a lifestyle that constrain dietary behaviors. From January 2011 to December 2012, we interviewed 45 people with diabetes from a primary care clinic in Ontario (Canada) to examine how their economic, social, and cultural resources combine to influence dietary practices relative to their condition. We classified respondents into low, medium, and high resource groups based on economic circumstances, and compared how economic resources, social relationships, health-related knowledge and values combine to enhance or weaken health capability and dietary management. Economic, social, and cultural resources conspired to undermine dietary management among most in the low resource group, whereas social influences significantly influenced diet among many in the medium group. High resource respondents appeared most motivated to maintain a healthy diet, and also had the social and cultural resources to enable them to do so. Understanding the influence of all three types of resources is critical for constructing ways to enhance health capability, chronic

Enhanced magnetoelectric effects in composite of piezoelectric ceramics, rare-earth iron alloys, and shape-optimized nanocrystalline alloys.

Science.gov (United States)

Zhang, Jitao; Li, Ping; Wen, Yumei; He, Wei; Yang, Aichao; Lu, Caijiang

2014-03-01

An enhancement for magnetoelectric (ME) effects is studied in a three-phase ME architecture consisting of two magnetostrictive Terfenol-D (Tb(0.3)Dy(0.7)Fe(1.92)) plates, a piezoelectric PZT (Pb(Zr,Ti)O3) plate, and a pair of shape-optimized FeCuNbSiB nanocrystalline alloys. By modifying the conventional shape of the magnetic flux concentrator, the shape-optimized flux concentrator has an improved effective permeability (μ(eff)) due to the shape-induced demagnetizing effect at its end surface. The flux concentrator concentrates and amplifies the external magnetic flux into Terfenol-D plate by means of changing its internal flux concentrating manner. Consequently, more flux lines can be uniformly concentrated into Terfenol-D plates. The effective piezomagnetic coefficients (d(33m)) of Terfenol-D plate and the ME voltage coefficients (α(ME)) can be further improved under a lower magnetic bias field. The dynamic magneto-elastic properties and the effective magnetic induction of Terfenol-D are taken into account to derive the enhanced effective ME voltage coefficients (α(ME,eff)), the consistency of experimental results and theoretical analyses verifies this enhancement. The experimental results demonstrate that the maximum d(33m) in our proposed architecture achieves 22.48 nm/A under a bias of 114 Oe. The maximum α(ME) in the bias magnetic range 0-900 Oe reaches 84.73 mV/Oe under the low frequency of 1 kHz, and 2.996 V/Oe under the resonance frequency of 102.3 kHz, respectively. It exhibits a 1.43 times larger piezomagnetic coefficient and a 1.87 times higher ME voltage coefficient under a smaller magnetic bias of 82 Oe than those of a conventional Terfenol-D/PZT/Terfenol-D composite. These shape-induced magnetoelectric behaviors provide the possibility of using this ME architecture in ultra-sensitive magnetic sensors.

Going beyond "it depends:" the role of context in shaping participation in natural resource management

Directory of Open Access Journals (Sweden)

Susan Baker

2018-03-01

Full Text Available Public participation is increasingly advocated in natural resource management to meet a spectrum of instrumental to normative goals. However, the success of participation in achieving these goals is highly variable, depending on both societal and institutional contexts. Whether participation realises its benefits or succumbs to its pitfalls is shaped by dynamic interactions operating among three contextual dimensions: participatory rationales (instrumental to normative, institutional fit of different levels (types of participation (information delivery to partnership to delegation, and social structures (such as cultural context, social capital, and power distribution. Some levels of participation may support the existing power hierarchy, others benefit organized stakeholder groups and special interests, and still others foster deliberative democratic outcomes. We argue that wise choice of levels of participation in particular contexts shapes the balance of participation's benefits and pitfalls.

Shape-Enhanced Photocatalytic Activities of Thoroughly Mesoporous ZnO Nanofibers

KAUST Repository

Ren, Xiaolong

2016-06-24

1D mesoporous materials have attracted extensive interest recently, owning to their fascinating properties and versatile applications. However, it remains as a grand challenge to develop a simple and efficient technique to produce oxide nanofibers with mesoporous architectures, controlled morphologies, large surface areas, and optimal performances. In this work, a facile foaming-assisted electrospinning strategy with foaming agent of tea saponin is used to produce thoroughly mesoporous ZnO nanofibers with high purity and controlled morphology. Interestingly, mesoporous fibers with elliptical cross-section exhibit the significantly enhanced photocatalytic activity for hydrogen production, as compared to the counterparts with circular and rectangular cross-sections, and they also perform better than the commercial ZnO nanopowders. The unexpected shape dependence of photocatalytic activities is attributed to the different stacking modes of the mesoporous fibers, and a geometrical model is developed to account for the shape dependence. This work represents an important step toward producing thoroughly mesoporous ZnO nanofibers with tailored morphologies, and the discovery that fibers with elliptical cross-section render the best performance provides a valuable guideline for improving the photocatalytic performance of such mesoporous nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization.

Science.gov (United States)

Linguraru, Marius George; Pura, John A; Chowdhury, Ananda S; Summers, Ronald M

2010-01-01

The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. An automated method optimized for medical image data is presented for the simultaneous segmentation of four abdominal organs from 4D CT data using graph cuts. Contrast-enhanced CT scans were obtained at two phases: non-contrast and portal venous. Intra-patient data were spatially normalized by non-linear registration. Then 4D erosion using population historic information of contrast-enhanced liver, spleen, and kidneys was applied to multi-phase data to initialize the 4D graph and adapt to patient specific data. CT enhancement information and constraints on shape, from Parzen windows, and location, from a probabilistic atlas, were input into a new formulation of a 4D graph. Comparative results demonstrate the effects of appearance and enhancement, and shape and location on organ segmentation.

Shape-assisted body reorientation enhances trafficability through cluttered terrain

Science.gov (United States)

Li, Chen; Pullin, Andrew; Haldane, Duncan; Fearing, Ronald; Full, Robert

2014-11-01

Many birds and fishes have slender, streamlined bodies that reduce fluid dynamic drag and allow fast and efficient locomotion. Similarly, numerous terrestrial animals run through cluttered terrain where 3-D, multi-component obstacles like grass, bushes, trees, walls, doors, and pillars also resist motion, but it is unknown whether their body shape plays a major role. Here, we challenged discoid cockroaches that possess a rounded, thin, nearly ellipsoidal body to run through tall, narrowly spaced, grass-like beams. The animals primarily rolled their body to the side to maneuver through the obstacle gaps. Reduction of body roundness by artificial shells inhibited this side roll maneuver, resulting in a lower traversal probability and a longer traversal time (P exoskeleton shell to a legged robot of a nearly cuboidal body. The rounded shell enabled the robot to use passive side rolling to maneuver through beams. To explain the mechanism, we developed a simple physics model to construct an energy landscape of the body-terrain interaction, which allowed estimation of body forces and torques exerted by the beams. Our model revealed that, by passive interaction with the terrain, a rounded body (ellipsoid) rolled more easily than an angular body (cuboid) to access energy valleys between energy barriers caused by obstacles. Our study is the first to demonstrate that a terradynamically ``streamlined'' shape can reduce terrain resistance and enhance trafficability by assisting body reorientation.

Access to resources shapes maternal decision making: evidence from a factorial vignette experiment.

Directory of Open Access Journals (Sweden)

Geoff Kushnick

Full Text Available The central assumption of behavioral ecology is that natural selection has shaped individuals with the capacity to make decisions that balance the fitness costs and benefits of behavior. A number of factors shape the fitness costs and benefits of maternal care, but we lack a clear understanding how they, taken together, play a role in the decision-making process. In animal studies, the use of experimental methods has allowed for the tight control of these factors. Standard experimentation is inappropriate in human behavioral ecology, but vignette experiments may solve the problem. I used a confounded factorial vignette experiment to gather 640 third-party judgments about the maternal care decisions of hypothetical women and their children from 40 female karo Batak respondents in rural Indonesia. This allowed me to test hypotheses derived from parental investment theory about the relative importance of five binary factors in shaping maternal care decisions with regard to two distinct scenarios. As predicted, access to resources--measured as the ability of a woman to provide food for her children--led to increased care. A handful of other factors conformed to prediction, but they were inconsistent across scenarios. The results suggest that mothers may use simple heuristics, rather than a full accounting for costs and benefits, to make decisions about maternal care. Vignettes have become a standard tool for studying decision making, but have made only modest inroads to evolutionarily informed studies of human behavior.

Access to resources shapes maternal decision making: evidence from a factorial vignette experiment.

Science.gov (United States)

Kushnick, Geoff

2013-01-01

The central assumption of behavioral ecology is that natural selection has shaped individuals with the capacity to make decisions that balance the fitness costs and benefits of behavior. A number of factors shape the fitness costs and benefits of maternal care, but we lack a clear understanding how they, taken together, play a role in the decision-making process. In animal studies, the use of experimental methods has allowed for the tight control of these factors. Standard experimentation is inappropriate in human behavioral ecology, but vignette experiments may solve the problem. I used a confounded factorial vignette experiment to gather 640 third-party judgments about the maternal care decisions of hypothetical women and their children from 40 female karo Batak respondents in rural Indonesia. This allowed me to test hypotheses derived from parental investment theory about the relative importance of five binary factors in shaping maternal care decisions with regard to two distinct scenarios. As predicted, access to resources--measured as the ability of a woman to provide food for her children--led to increased care. A handful of other factors conformed to prediction, but they were inconsistent across scenarios. The results suggest that mothers may use simple heuristics, rather than a full accounting for costs and benefits, to make decisions about maternal care. Vignettes have become a standard tool for studying decision making, but have made only modest inroads to evolutionarily informed studies of human behavior.

Automatic gallbladder segmentation using combined 2D and 3D shape features to perform volumetric analysis in native and secretin-enhanced MRCP sequences.

Science.gov (United States)

Gloger, Oliver; Bülow, Robin; Tönnies, Klaus; Völzke, Henry

2017-11-24

We aimed to develop the first fully automated 3D gallbladder segmentation approach to perform volumetric analysis in volume data of magnetic resonance (MR) cholangiopancreatography (MRCP) sequences. Volumetric gallbladder analysis is performed for non-contrast-enhanced and secretin-enhanced MRCP sequences. Native and secretin-enhanced MRCP volume data were produced with a 1.5-T MR system. Images of coronal maximum intensity projections (MIP) are used to automatically compute 2D characteristic shape features of the gallbladder in the MIP images. A gallbladder shape space is generated to derive 3D gallbladder shape features, which are then combined with 2D gallbladder shape features in a support vector machine approach to detect gallbladder regions in MRCP volume data. A region-based level set approach is used for fine segmentation. Volumetric analysis is performed for both sequences to calculate gallbladder volume differences between both sequences. The approach presented achieves segmentation results with mean Dice coefficients of 0.917 in non-contrast-enhanced sequences and 0.904 in secretin-enhanced sequences. This is the first approach developed to detect and segment gallbladders in MR-based volume data automatically in both sequences. It can be used to perform gallbladder volume determination in epidemiological studies and to detect abnormal gallbladder volumes or shapes. The positive volume differences between both sequences may indicate the quantity of the pancreatobiliary reflux.

Calculated shape dependence of electromagnetic field in tip-enhanced Raman scattering by using a monopole antenna model

Science.gov (United States)

Kitahama, Yasutaka; Itoh, Tamitake; Suzuki, Toshiaki

2018-05-01

To evaluate the shape of an Ag tip with regard to tip-enhanced Raman scattering (TERS) signal, the enhanced electromagnetic (EM) field and scattering spectrum, arising from surface plasmon resonance at the apex of the tip, were calculated using a finite-difference time domain (FDTD) method. In the calculated forward scattering spectra from the smooth Ag tip, the band appeared within the visible region, similar to the experimental results and calculation for a corrugated Ag cone. In the FDTD calculation of TERS, the Ag tip acting as a monopole antenna was adopted by insertion of a perfect electric conductor between the root of the tip and a top boundary surface of the calculation space. As a result, the EM field was only enhanced at the apex. The shape dependence i.e. the EM field calculated at the apex with various curvatures on the different tapered tips, obtained using the monopole antenna model, was different from that simulated using a conventional dipole antenna model.

Synthesis of spindle-shaped AgI/TiO{sub 2} nanoparticles with enhanced photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Yang, Liu; Gao, Minggang; Dai, Bin; Guo, Xuhong; Liu, Zhiyong; Peng, Banghua, E-mail: banghuapeng@hotmail.com

2016-11-15

Highlights: • Nanoporous spindle-shaped AgI/TiO{sub 2} was synthesized by the solvothermal approach. • The spindle-shaped TiO{sub 2} was an excellent support for loading nanoparticles, such as AgI, transferring electrons quickly from AgI, which is beneficial for stabilizing the AgI. • AgI/TiO{sub 2} nanoparticles showed enhanced absorption intensity in the visible region and exhibited excellent photocatalytic activity. - Abstract: A novel synthetic route has been developed to prepare silver iodide (AgI) loaded spindle-shaped TiO{sub 2} nanoparticles (NPs). The morphology and crystallinity characterization revealed that small AgI NPs, with an average diameter of 15 nm were dispersed on the surface and interior of nanoporous anatase TiO{sub 2} support. High-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) surface area, Raman and X-ray photoelectron spectroscopy (XPS) were used to identify the nanoporous structure of TiO{sub 2} and the existence of AgI NPs. Diffuse reflectance spectra (DRS) showed that AgI/TiO{sub 2} composite exhibited a remarkable enhancement of visible light absorption, which is ascribed to the addition of AgI. For illustrating the superior property of this hybrid as photocatalyst, the degradation experiments were carried out for processing rhodamine B (RhB) solution under visible light irradiation and it was found that the photocatalytic activity was dramatically improved for AgI/TiO{sub 2} compared with nanoporous TiO{sub 2} and commercial P25 TiO{sub 2}. The enhanced photocatalytic properties could be attributed to the large surface area of porous TiO{sub 2}, good stability of AgI particles, and the effective charge separation due to the synergetic effect between AgI and TiO{sub 2} that can facilitate the separation of electron-hole pairs. Our novel composite based on nanoporous spindle-shaped TiO{sub 2} represents a promising new pathway for the design of high-performance photocatalysts for environmental

Electromagnetic field enhancement and spectrum shaping through plasmonically integrated optical vortices.

Science.gov (United States)

Ahn, Wonmi; Boriskina, Svetlana V; Hong, Yan; Reinhard, Björn M

2012-01-11

We introduce a new design approach for surface-enhanced Raman spectroscopy (SERS) substrates that is based on molding the optical powerflow through a sequence of coupled nanoscale optical vortices "pinned" to rationally designed plasmonic nanostructures, referred to as Vortex Nanogear Transmissions (VNTs). We fabricated VNTs composed of Au nanodiscs by electron beam lithography on quartz substrates and characterized their near- and far-field responses through combination of computational electromagnetism, and elastic and inelastic scattering spectroscopy. Pronounced dips in the far-field scattering spectra of VNTs provide experimental evidence for an efficient light trapping and circulation within the nanostructures. Furthermore, we demonstrate that VNT integration into periodic arrays of Au nanoparticles facilitates the generation of high E-field enhancements in the VNTs at multiple defined wavelengths. We show that spectrum shaping in nested VNT structures is achieved through an electromagnetic feed-mechanism driven by the coherent multiple scattering in the plasmonic arrays and that this process can be rationally controlled by tuning the array period. The ability to generate high E-field enhancements at predefined locations and frequencies makes nested VNTs interesting substrates for challenging SERS applications. © 2011 American Chemical Society

Achieving resource sustainability and enhancing economic development through biomass utilization

Science.gov (United States)

Jerrold E. Winandy

2005-01-01

As the problems associated with sustaining and enhancing the world's forest and agricultural resources compete with the needs of a rapidly increasing and affluent population, the management of our land becomes a much more complex and important issue. One of the most important environmental features of wood and other woody-like fibers is that they are renewable and...

Assessing the prospective resource base for enhanced geothermal systems in Europe

NARCIS (Netherlands)

Limberger, Jon; Calcagno, Philippe; Manzella, Adelle; Trumpy, Eugenio; Boxem, Thijs; Pluymaekers, Maarten; van Wees, Jan-Diederik

2014-01-01

In this study the resource base for EGS (enhanced geothermal systems) in Europe was quantified and economically constrained, applying a discounted cash-flow model to different techno-economic scenarios for future EGS in 2020, 2030, and 2050. Temperature is a critical parameter that controls the

Suppressive and Enhancing Effects in Early Visual Cortex during Illusory Shape Perception: A Comment on Kok and de Lange (2014

Directory of Open Access Journals (Sweden)

Pieter Moors

2015-02-01

Full Text Available In a recent functional magnetic resonance imaging study, Kok and de Lange (2014 observed that BOLD activity for a Kanizsa illusory shape stimulus, in which pacmen-like inducers elicit an illusory shape percept, was either enhanced or suppressed relative to a nonillusory control configuration depending on whether the spatial profile of BOLD activity in early visual cortex was related to the illusory shape or the inducers, respectively. The authors argued that these findings fit well with the predictive coding framework, because top-down predictions related to the illusory shape are not met with bottom-up sensory input and hence the feedforward error signal is enhanced. Conversely, for the inducing elements, there is a match between top-down predictions and input, leading to a decrease in error. Rather than invoking predictive coding as the explanatory framework, the suppressive effect related to the inducers might be caused by neural adaptation to perceptually stable input due to the trial sequence used in the experiment.

Numerical study of heat transfer enhancement due to the use of fractal-shaped design for impingement cooling

Directory of Open Access Journals (Sweden)

Cai Lin

2017-01-01

Full Text Available This paper describes a numerical analysis of a heat transfer enhancement technique that introduces fractal-shaped design for impingement cooling. Based on the gas turbine combustion chamber cooling, a fractal-shaped nozzle is designed for the constant flow area in a single impingement cooling model. The incompressible Reynolds-averaged Navier-Stokes equations are applied to the system using CFD software. The numerical results are compared with the experiment results for array impingement cooling.

Enhanced depth imaging optical coherence tomography of the sclera in dome-shaped macula.

Science.gov (United States)

Imamura, Yutaka; Iida, Tomohiro; Maruko, Ichiro; Zweifel, Sandrine A; Spaide, Richard F

2011-02-01

To examine the posterior anatomic structure of eyes with dome-shaped macula using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Retrospective observational case series. Patients with dome-shaped macula, a condition defined as convex elevation of the macula as compared with the surrounding staphylomatous region in a highly myopic eye, were identified through routine examinations using optical coherence tomography (OCT). EDI-OCT was used to examine their posterior anatomic changes. The scleral thickness was measured from the outer border of the choroid to the outer scleral border under the fovea and 3000 μm temporal to the fovea. The mean age of the 15 patients (23 eyes) was 59.3 (± 12.2) years, and the mean refractive error was -13.6 (± 5.0) diopters. The best-corrected visual acuity ranged from 20/15 to 20/800 (median: 20/30). Eight patients (53%) had dome-shaped macula bilaterally. The mean subfoveal scleral thickness in 23 eyes with dome-shaped macula was 570 (± 221) μm, and that in 25 eyes of 15 myopic patients with staphyloma but without dome-shaped macula was 281 (± 85) μm (P macula is the result of a relative localized thickness variation of the sclera under the macula in highly myopic patients, and it cannot be categorized into any of the known types of staphyloma. This finding suggests the ocular expansion in myopia may be more complex than previously thought. Copyright © 2011 Elsevier Inc. All rights reserved.

Nanostructured Tip-Shaped Biosensors: Application of Six Sigma Approach for Enhanced Manufacturing.

Science.gov (United States)

Kahng, Seong-Joong; Kim, Jong-Hoon; Chung, Jae-Hyun

2016-12-23

Nanostructured tip-shaped biosensors have drawn attention for biomolecule detection as they are promising for highly sensitive and specific detection of a target analyte. Using a nanostructured tip, the sensitivity is increased to identify individual molecules because of the high aspect ratio structure. Various detection methods, such as electrochemistry, fluorescence microcopy, and Raman spectroscopy, have been attempted to enhance the sensitivity and the specificity. Due to the confined path of electrons, electrochemical measurement using a nanotip enables the detection of single molecules. When an electric field is combined with capillary action and fluid flow, target molecules can be effectively concentrated onto a nanotip surface for detection. To enhance the concentration efficacy, a dendritic nanotip rather than a single tip could be used to detect target analytes, such as nanoparticles, cells, and DNA. However, reproducible fabrication with relation to specific detection remains a challenge due to the instability of a manufacturing method, resulting in inconsistent shape. In this paper, nanostructured biosensors are reviewed with our experimental results using dendritic nanotips for sequence specific detection of DNA. By the aid of the Six Sigma approach, the fabrication yield of dendritic nanotips increases from 20.0% to 86.6%. Using the nanotips, DNA is concentrated and detected in a sequence specific way with the detection limit equivalent to 1000 CFU/mL. The pros and cons of a nanotip biosensor are evaluated in conjunction with future prospects.

Enhanced mechanical properties of linear segmented shape memory poly(urethane-urea) by incorporating flexible PEG400 and rigid piperazine

Science.gov (United States)

Zhang, Xiao-Yan; Ma, Yu-Fei; Li, Yong-Gang; Wang, Pin-Pin; Wang, Yuan-Liang; Luo, Yan-Feng

2012-12-01

The goal of this study is to design and synthesize a linear segmented shape memory poly(urethane-urea) (SMPUU) that possesses near-body-temperature shape memory temperature ( T tran) and enhanced mechanical properties by incorporating flexible poly(ethylene glycol) 400 (PEG400) to form poly(D,L-lactic acid)-based macrodiols (PDLLA-PEG400-PDLLA) and then rigid piperazine (PPZ) as a chain extender to form the desired SMPUUs (PEG400-PUU-PPZ). PEG400 increased M n while maintaining a lower T g of PDLLA-PEG400-PDLLA, which together with PPZ improved the mechanical properties of PEG400-PUU-PPZ. The obtained optimum SMPUU with enhanced mechanical properties ( σ y = 24.28 MPa; ɛ f = 698%; U f = 181.5 MJ/m3) and a T g of 40.62°C exhibited sound shape memory properties as well, suggesting a promising SMPUU for in vivo biomedical applications.

Overview of Trends Shaping Human Resource Management for ...

African Journals Online (AJOL)

Human Resource Management (HRM) is a strategic and coherent approach to the ... effectively, human resources will make a substantial impact on firm.s performance used. ... resource managers do and the models for engagement of human capital. ... education, training, skills, and expertise of an organization.s employees.

Automatized spleen segmentation in non-contrast-enhanced MR volume data using subject-specific shape priors

Science.gov (United States)

Gloger, Oliver; Tönnies, Klaus; Bülow, Robin; Völzke, Henry

2017-07-01

To develop the first fully automated 3D spleen segmentation framework derived from T1-weighted magnetic resonance (MR) imaging data and to verify its performance for spleen delineation and volumetry. This approach considers the issue of low contrast between spleen and adjacent tissue in non-contrast-enhanced MR images. Native T1-weighted MR volume data was performed on a 1.5 T MR system in an epidemiological study. We analyzed random subsamples of MR examinations without pathologies to develop and verify the spleen segmentation framework. The framework is modularized to include different kinds of prior knowledge into the segmentation pipeline. Classification by support vector machines differentiates between five different shape types in computed foreground probability maps and recognizes characteristic spleen regions in axial slices of MR volume data. A spleen-shape space generated by training produces subject-specific prior shape knowledge that is then incorporated into a final 3D level set segmentation method. Individually adapted shape-driven forces as well as image-driven forces resulting from refined foreground probability maps steer the level set successfully to the segment the spleen. The framework achieves promising segmentation results with mean Dice coefficients of nearly 0.91 and low volumetric mean errors of 6.3%. The presented spleen segmentation approach can delineate spleen tissue in native MR volume data. Several kinds of prior shape knowledge including subject-specific 3D prior shape knowledge can be used to guide segmentation processes achieving promising results.

Riparian Forest Buffers - Function for Protection and Enhancement of Water Resources

Science.gov (United States)

David J. Welsch

1991-01-01

Streamside forests are crucial to the protection and enhancement of the water resources of the Eastern United States. They are extremely complex ecosystems that help provide optimum food and habitat for stream communities as well as being useful in mitigating or controlling nonpoint source pollution (NPS). Used as a component of an integrated management system...

Population Genetic Structure of Glycyrrhiza inflata B. (Fabaceae) Is Shaped by Habitat Fragmentation, Water Resources and Biological Characteristics.

Science.gov (United States)

Yang, Lulu; Chen, Jianjun; Hu, Weiming; Yang, Tianshun; Zhang, Yanjun; Yukiyoshi, Tamura; Zhou, Yanyang; Wang, Ying

2016-01-01

Habitat fragmentation, water resources and biological characteristics are important factors that shape the genetic structure and geographical distribution of desert plants. Analysis of the relationships between these factors and population genetic variation should help to determine the evolutionary potential and conservation strategies for genetic resources for desert plant populations. As a traditional Chinese herb, Glycyrrhiza inflata B. (Fabaceae) is restricted to the fragmented desert habitat in China and has undergone a dramatic decline due to long-term over-excavation. Determining the genetic structure of the G. inflata population and identifying a core collection could help with the development of strategies to conserve this species. We investigated the genetic variation of 25 G. inflata populations based on microsatellite markers. A high level of population genetic divergence (FST = 0.257), population bottlenecks, reduced gene flow and moderate genetic variation (HE = 0.383) were detected. The genetic distances between the populations significantly correlated with the geographical distances, and this suggests that habitat fragmentation has driven a special genetic structure of G. inflata in China through isolation by distance. STRUCTURE analysis showed that G. inflata populations were structured into three clusters and that the populations belonged to multiple water systems, which suggests that water resources were related to the genetic structure of G. inflata. In addition, the biological characteristics of the perennial species G. inflata, such as its long-lived seeds, asexual reproduction, and oasis ecology, may be related to its resistance to habitat fragmentation. A core collection of G. inflata, that included 57 accessions was further identified, which captured the main allelic diversity of G. inflata. Recent habitat fragmentation has accelerated genetic divergence. The population genetic structure of G. inflata has been shaped by habitat

A LINEAR PROGRAMMING METHOD TO ENHANCE RESOURCE UTILIZATION CASE OF ETHIOPIAN APPAREL SECTOR

Directory of Open Access Journals (Sweden)

Gezahegn Tesfaye

2016-06-01

Full Text Available The Ethiopian industrial development strategy is characterized by export-led and labor intensive industrialization. The country is emerging as the most important investment destination in its apparel sector. Thought this sector is expected to generate more income from the export market, its export earnings remain trivial mainly due to the inefficient organizational resource utilization. One of the competent techniques that help companies to efficiently improve the use of their resources to increase their profit is linear programming. In apparel manufacturing firms, efficient use of materials such as fabrics and sewing threads and processing time at different stages of production as well as minimization of labor and materials cost are necessary to enhance their profitability. Cutting, sewing, and finishing operations deserve more attention for apparel process optimization. However, the issue of proper resource allocation remains an unsolved problem within the Ethiopian apparel industry. The aim of this research is to devise efficient resource utilization mechanism for Ethiopian apparel sector to improve their resource utilization and profitability, taking one of the garment factories engaged in the export market as a case study. Five types of products the company is currently producing, the amount of resources employed to produce each unit of the products, and the value of profit per unit from the sale of each products have been collected from the case company. The monthly availability of resources utilized and the monthly production volume of the five products have also been collected from the company. The data gathered was mathematically modeled using a linear programming technique, and solved using MS-Excel solver. The findings of the study depicts that all of the organizational resources are severely underutilized. This research proved that the resource utilization of the case company can be improved from 46.41% of the current resource

Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

Directory of Open Access Journals (Sweden)

Shuzhi Sam Ge

2011-09-01

Full Text Available One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects’ shapes and, more specifically, the objects’ surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB, Artificial Neural Networks (ANN, and Support Vector Machines (SVM were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

Beam shaping optics to enhance performance of interferometry techniques in grating manufacture

Science.gov (United States)

Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

2018-02-01

Improving of industrial holographic and interferometry techniques is of great importance in interference lithography, computer-generated holography, holographic data storage, interferometry recording of Bragg gratings as well as gratings of various types in semiconductor industry. Performance of mentioned techniques is essentially enhanced by providing a light beam with flat phase front and flat-top irradiance distribution. Therefore, transformation of Gaussian distribution of a TEM00 laser to flat-top (top hat, uniform) distribution is an important optical task. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. As a solution it is suggested to apply refractive field mapping beam shaping optics πShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. High optical quality of resulting flat-top beam allows applying additional optical components to build various imaging optical systems for variation of beam size and shape to fulfil requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holography and laser interference lithography. Examples of real implementations and experimental results will be presented as well.

The greenscape shapes surfing of resource waves in a large migratory herbivore.

Science.gov (United States)

Aikens, Ellen O; Kauffman, Matthew J; Merkle, Jerod A; Dwinnell, Samantha P H; Fralick, Gary L; Monteith, Kevin L

2017-06-01

The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e. green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that migratory routes are more than a link between seasonal ranges, and they provide an important, but often overlooked, foraging habitat. In addition, the spatiotemporal configuration of forage resources that propagate along migratory routes shape animal movement and presumably, energy gains during migration. © 2017 John Wiley & Sons Ltd/CNRS.

Resource Structuring and Ambidexterity

DEFF Research Database (Denmark)

Ma, Yucheng; Li, Peter Ping

-shaped effect on organizational ambidexterity in new ventures. Further, because of the traditional culture and economic transition characteristics, new ventures actively leverage managerial ties as key social relations to obtain special resources or nurture business transactions. We propose that ties with other......Focusing on how resource structuring mechanisms and managerial ties influence organizational ambidexterity of new ventures in emerging economy, this study explores the effects of resource structuring mechanisms (i.e., resource acquiring and resource accumulating) on organizational ambidexterity....... It further examines the moderating effects of managerial ties, (i.e., ties with other firms and ties with the government) on the above relationships. Survey data from China¡¯s 202 new ventures demonstrates that the resource acquiring has an inverted U-shaped effect whereas the resource accumulating has a U...

Integrating ergonomics knowledge into business-driven design projects: The shaping of resource constraints in engineering consultancy.

Science.gov (United States)

Hall-Andersen, Lene Bjerg; Neumann, Patrick; Broberg, Ole

2016-10-17

The integration of ergonomics knowledge into engineering projects leads to both healthier and more efficient workplaces. There is a lack of knowledge about integrating ergonomic knowledge into the design practice in engineering consultancies. This study explores how organizational resources can pose constraints for the integration of ergonomics knowledge into engineering design projects in a business-driven setting, and how ergonomists cope with these resource constraints. An exploratory case study in an engineering consultancy was conducted. A total of 27 participants were interviewed. Data were collected applying semi-structured interviews, observations, and documentary studies. Interviews were transcribed, coded, and categorized into themes. From the analysis five overall themes emerged as major constituents of resource constraints: 1) maximizing project revenue, 2) payment for ergonomics services, 3) value of ergonomic services, 4) role of the client, and 5) coping strategies to overcome resource constraints. We hypothesize that resource constraints were shaped due to sub-optimization of costs in design projects. The economical contribution of ergonomics measures was not evaluated in the entire life cycle of a designed workplace. Coping strategies included teaming up with engineering designers in the sales process or creating an alliance with ergonomists in the client organization.

Management Strategy for Hydroelectric Project Toro 2: Knowing and enhancing natural resources sustainably

Directory of Open Access Journals (Sweden)

José Pereira Chaves

2014-01-01

Full Text Available The aim of this article is to understand and sustainably enhance the biological and ecological resources of the Hydroelectric Project of Toro 2, thus; a research was carried out to inventory the presence of birds, mammals and plants, in order to know if the site qualifies as a biological tourist attraction, as well as to know the opinion of local people. It is proposed the sustainable uses of natural resources, through a strategy of use, management and conservation of the ecosystems.

Empowering public service workers to face bystander conflict : Enhancing resources through a training intervention

NARCIS (Netherlands)

van Erp, K.J.P.M.; Gevers, J.M.P.; Rispens, S.; Demerouti, E.

2018-01-01

Public service employees work in occupations that are accompanied with high psychosocial risks. Police, firefighters, and paramedics are increasingly being confronted with argumentative, conflicting bystanders that frustrate them in executing their task. We developed a resource-enhancement

Micropore Geometry Manipulation by Macroscopic Deformation Based on Shape Memory Effect in Porous PLLA Membrane and its Enhanced Separation Performance.

Science.gov (United States)

Zhao, Jingxin; Yang, Qiucheng; Wang, Tao; Wang, Lian; You, Jichun; Li, Yongjin

2017-12-20

An effective strategy to tailor the microporous structures has been developed based on the shape memory effect in porous poly(l-lactic acid) membranes in which tiny crystals and amorphous matrix play the roles of shape-fixed phase and reversible-phase, respectively. Our results indicate that not only PLLA membranes but micropores exhibit shape memory properties. The proportional deformations on two scales have been achieved by uniaxial or biaxial tension, providing a facile way to manipulate continuously the size and the orientation degree of pores on microscale. The enhanced separation performance has been validated by taking polystyrene colloids with varying diameters as an example.

Enhanced photomechanical response of a Ni-Ti shape memory alloy coated with polymer-based photothermal composites

Science.gov (United States)

Perez-Zúñiga, M. G.; Sánchez-Arévalo, F. M.; Hernández-Cordero, J.

2017-10-01

A simple way to enhance the activation of shape memory effects with light in a Ni-Ti alloy is demonstrated. Using polydimethylsiloxane-carbon nanopowder (PDMS+CNP) composites as coatings, the one-way shape memory effect (OWSME) of the alloy can be triggered using low power IR light from a laser diode. The PDMS+CNP coatings serve as photothermal materials capable to absorb light, and subsequently generate and dissipate heat in a highly efficient manner, thereby reducing the optical powers required for triggering the OWSME in the Ni-Ti alloy. Experimental results with a cantilever flexural test using both, bare Ni-Ti and coated samples, show that the PDMS+CNP coatings perform as thermal boosters, and therefore the temperatures required for phase transformation in the alloy can be readily obtained with low laser powers. It is also shown that the two-way shape memory effect (TWSME) can be set in the Ni-Ti alloy through cycling the TWSME by simply modulating the laser diode signal. This provides a simple means for training the material, yielding a light driven actuator capable to provide forces in the mN range. Hence, the use of photothermal coatings on Ni-Ti shape memory alloys may offer new possibilities for developing light-controlled smart actuators.

Enhance heat transfer in the channel with V-shaped wavy lower plate using liquid nanofluids

Directory of Open Access Journals (Sweden)

Azher M. Abed

2015-03-01

Full Text Available The heat transfer and flow characteristics in corrugated with V-shape lower plate using nanofluids are numerically studied. The computations are performed on uniform heat flux over a range of Reynolds number (Re 8000–20,000. The governing equations are numerically solved in the domain by a finite volume method (FVM using the k–ε standard turbulent model. Studies are carried out for different types of nanoparticles Al2O3,CuO, SiO2 and ZnO with different volume fractions in the range of 0–4%. Three different types of base fluid (water, glycerin, ethylene glycol are also examined. Results indicated that the average Nusselt number for nanofluids is greater than that of the base liquid. The SiO2 nanofluid yields the best heat transfer enhancement among all other type of nanofluids. Heat transfer enhancement increase with increases the volumetric concentration, but it is accompanied by increasing pressure drop values. Moreover, the average Nusselt number increases with an increase in Reynolds number and volume concentration. The SiO2–glycerin nanofluid has the highest Nusselt number compared with other base fluids. The present study shows that these V-shaped wavy channels have advantages by using nanofluids and thus serve as promising candidates for incorporation into efficient heat transfer devices.

Research in Shape Analysis

CERN Document Server

Leonard, Kathryn; Tari, Sibel; Hubert, Evelyne; Morin, Geraldine; El-Zehiry, Noha; Chambers, Erin

2018-01-01

Based on the second Women in Shape (WiSH) workshop held in Sirince, Turkey in June 2016, these proceedings offer the latest research on shape modeling and analysis and their applications. The 10 peer-reviewed articles in this volume cover a broad range of topics, including shape representation, shape complexity, and characterization in solving image-processing problems. While the first six chapters establish understanding in the theoretical topics, the remaining chapters discuss important applications such as image segmentation, registration, image deblurring, and shape patterns in digital fabrication. The authors in this volume are members of the WiSH network and their colleagues, and most were involved in the research groups formed at the workshop. This volume sheds light on a variety of shape analysis methods and their applications, and researchers and graduate students will find it to be an invaluable resource for further research in the area.

Allocating Resources to Enhance Resilience, with Application to Superstorm Sandy and an Electric Utility.

Science.gov (United States)

MacKenzie, Cameron A; Zobel, Christopher W

2016-04-01

This article constructs a framework to help a decisionmaker allocate resources to increase his or her organization's resilience to a system disruption, where resilience is measured as a function of the average loss per unit time and the time needed to recover full functionality. Enhancing resilience prior to a disruption involves allocating resources from a fixed budget to reduce the value of one or both of these characteristics. We first look at characterizing the optimal resource allocations associated with several standard allocation functions. Because the resources are being allocated before the disruption, however, the initial loss and recovery time may not be known with certainty. We thus also apply the optimal resource allocation model for resilience to three models of uncertain disruptions: (1) independent probabilities, (2) dependent probabilities, and (3) unknown probabilities. The optimization model is applied to an example of increasing the resilience of an electric power network following Superstorm Sandy. © 2015 Society for Risk Analysis.

Chromosomal inversions effect body size and shape in different breeding resources in Drosophila buzzatii.

Science.gov (United States)

Fernández Iriarte, P J; Norry, F M; Hasson, E R

2003-07-01

The cactophilic Drosophila buzzatii provides an excellent model for the study of reaction norms across discrete environments because it breeds on rotting tissues (rots) of very different cactus species. Here we test the possible effects of second chromosome inversions on body size and shape (wing loading) across suitable natural breeding substrates. Using homokaryotypic stocks derived from several lines homozygous for four naturally occurring chromosomal inversions, we show that arrangements significantly affect size-related traits and wing loading. In addition, karyotypes show differing effects, across natural breeding resources, for wing loading. The 2st and 2jz(3) arrangements decrease and the 2j arrangement increases wing loading. For thorax length and wing loading, karyotypic correlations across host plants are slightly lower in females than in males. These results support the hypothesis that these traits have a genetic basis associated with the inversion polymorphism.

Localized surface plasmon resonance enhanced photoluminescence of CdSe QDs in PMMA matrix on silver colloids with different shapes

International Nuclear Information System (INIS)

Lu Liu; Xu Xiaoliang; Shi Chaoshu; Ming Hai

2010-01-01

Localized surface plasmon resonance (LSPR) enhanced photoluminescences (PL) from CdSe quantum dots (QDs) on worm-like or quasi-spherical silver colloids have been investigated. The shape of silver colloid film is controlled by annealing temperature (200 o C∼350 o C). Strong PL enhancements of CdSe QDs on both as-grown and annealed silver colloid films are observed. The results show that the PL enhancement factor of CdSe QDs on worm-like silver colloid film reaches as high as 15-fold. Moreover, the enhancement factor is 5 times larger than that obtained from the quasi-spherical silver colloids. The superiority of worm-like silver nanostructure on LSPR enhanced photoluminescence is attributed to its larger size, hot spots and multiple dipole resonance modes coupling, which are induced by aggregation effect.

A holistic model for evaluating the impact of individual technology-enhanced learning resources.

Science.gov (United States)

Pickering, James D; Joynes, Viktoria C T

2016-12-01

The use of technology within education has now crossed the Rubicon; student expectations, the increasing availability of both hardware and software and the push to fully blended learning environments mean that educational institutions cannot afford to turn their backs on technology-enhanced learning (TEL). The ability to meaningfully evaluate the impact of TEL resources nevertheless remains problematic. This paper aims to establish a robust means of evaluating individual resources and meaningfully measure their impact upon learning within the context of the program in which they are used. Based upon the experience of developing and evaluating a range of mobile and desktop based TEL resources, this paper outlines a new four-stage evaluation process, taking into account learner satisfaction, learner gain, and the impact of a resource on both the individual and the institution in which it has been adapted. A new multi-level model of TEL resource evaluation is proposed, which includes a preliminary evaluation of need, learner satisfaction and gain, learner impact and institutional impact. Each of these levels are discussed in detail, and in relation to existing TEL evaluation frameworks. This paper details a holistic, meaningful evaluation model for individual TEL resources within the specific context in which they are used. It is proposed that this model is adopted to ensure that TEL resources are evaluated in a more meaningful and robust manner than is currently undertaken.

Nitride coating enhances endothelialization on biomedical NiTi shape memory alloy

Energy Technology Data Exchange (ETDEWEB)

Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Luculescu, Catalin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, P.O. Box MG-36, 077125 Magurele-Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Marx, Philippe [AMF Company, Route de Quincy, 18120 Lury-sur-Arnon (France); Gordin, Doina-Margareta; Gloriant, Thierry [INSA Rennes, UMR CNRS 6226 ISCR, 20 Avenue des Buttes de Coësmes, 35708 Rennes Cedex 7 (France)

2016-05-01

Surface nitriding was demonstrated to be an effective process for improving the biocompatibility of implantable devices. In this study, we investigated the benefits of nitriding the NiTi shape memory alloy for vascular stent applications. Results from cell experiments indicated that, compared to untreated NiTi, a superficial gas nitriding treatment enhanced the adhesion of human umbilical vein endothelial cells (HUVECs), cell spreading and proliferation. This investigation provides data to demonstrate the possibility of improving the rate of endothelialization on NiTi by means of nitride coating. - Highlights: • Gas nitriding process of NiTi is competent to promote cell spreading. • Surface nitriding of NiTi is able to stimulate focal adhesion formation and cell proliferation. • Similar expression pattern of vWf and eNOS was exhibited by bare and nitrided NiTi. • Gas nitriding treatment of NiTi shows promise for better in vivo endothelialization.

Enhancement of nonlinear optical response of weakly confined excitons in GaAs thin films by spectrally rectangle-shape-pulse-excitation

International Nuclear Information System (INIS)

Kojima, O; Isu, T; Ishi-Hayase, J; Sasaki, M; Tsuchiya, M

2007-01-01

We report the enhancement of the nonlinear optical response of the weakly confined excitons with use of spectrally rectangular pulse. The nonlinear optical response was investigated as a function of excitation energy by a degenerate four-wave-mixing (DFWM) technique. In the case that the laser pulse with the controlled spectral shape excites the plural exciton states simultaneously, the DFWM signal intensity is enhanced by a factor of two in comparison with the intensity under the excitation of a single exciton state. This enhancement is caused by the superposition of the nonlinear optical responses from the plural exciton states

Donut-shaped Co_3O_4 nanoflakes grown on nickel foam with enhanced supercapacitive performances

International Nuclear Information System (INIS)

Han, Zhicheng; Zheng, Xin; Yao, Shunyu; Xiao, Huanhao; Qu, Fengyu; Wu, Xiang

2016-01-01

Graphical abstract: The as-synthesized product exhibits a high initial discharge capacitance of 518 mF/cm"2 at a current density of 1 mA cm"−"2 and can maintain 75% capacitance retention even after 6000 charge–discharge cycles. Electrochemical results revealed that the prepared Co_3O_4 nanoflakes possess a remarkable performance in supercapacitor applications. - Highlights: • Donut-shaped Co_3O_4 nanoflakes were first fabricated by a solution approach. • The tests show high discharge areal capacitance and long cycle life stability. • Co_3O_4 nanoflakes might be promising supercapacitor electrode materials. - Abstract: Donut-shaped Co_3O_4 nanoflakes grown on nickel foam were successfully fabricated by a simple one-pot hydrothermal approach. The prepared products were functionalized as the supercapacitors electrodes. Electrochemical performance of the as-prepared products demonstrated high specific capacitance (518 mF cm"−"2) and excellent cycling stability (∼25% loss) after 6000 repetitive cycles at a charge–discharge current density of 1 mA cm"−"2. The superior electrochemical performance may be ascribed into two reasons: one is the unique spatial structures which possess many active sites and provide enhanced combination between the electrode and nickel foam to support fast ion and electron transfer, the other is that donut-shaped Co_3O_4 nanoflakes electrodes show relatively lower resistances. It is expected that the as-obtained donut-shaped Co_3O_4 nanoflakes could have potential applications in portable electronics and electrical vehicles.

Social Web Content Enhancement in a Distance Learning Environment: Intelligent Metadata Generation for Resources

Science.gov (United States)

García-Floriano, Andrés; Ferreira-Santiago, Angel; Yáñez-Márquez, Cornelio; Camacho-Nieto, Oscar; Aldape-Pérez, Mario; Villuendas-Rey, Yenny

2017-01-01

Social networking potentially offers improved distance learning environments by enabling the exchange of resources between learners. The existence of properly classified content results in an enhanced distance learning experience in which appropriate materials can be retrieved efficiently; however, for this to happen, metadata needs to be present.…

Biopolymer coated gold nanocrystals prepared using the green chemistry approach and their shape-dependent catalytic and surface-enhanced Raman scattering properties.

Science.gov (United States)

Chou, Chih-Wei; Hsieh, Hui-Hsuan; Hseu, You-Cheng; Chen, Ko-Shao; Wang, Gou-Jen; Chang, Hsien-Chang; Pan, Yong-Li; Wei, Yi-Syuan; Chang, Ko Hsin; Harn, Yeu-Wei

2013-07-21

This study deals with the preparation of multi-shaped nanoscale gold crystals under synthetically simple, green, and efficient conditions using a seed-mediated growth approach in the presence of hyaluronic acid (HA). These highly biocompatible multi-shaped gold nanocrystals were examined to evaluate their catalytic and surface enhanced Raman scattering (SERS) properties. The results show that the size and shape of the nanocrystals are mainly correlated to the amount of seed, seed size, HA concentration, and reaction temperature. Gold seeds accelerate the reduction of the gold precursor to form gold nanocrystals using HA. The HA serves as a reducing agent and a growth template for the reduction of Au(III) and nanocrystal stabilization. The multi-shaped gold nanocrystals showed superior catalytic properties and higher SERS performance. The simple, green approach efficiently controls the nanocrystals and creates many opportunities for future applications.

Formation of polyhedral ceria nanoparticles with enhanced catalytic CO oxidation activity in thermal plasma via a hydrogen mediated shape control mechanism

International Nuclear Information System (INIS)

Zheng Jie; Zhang Yaohua; Song Xubo; Li Xingguo

2011-01-01

Ceria nanoparticles with well defined facets are prepared in argon–hydrogen thermal plasma followed by controlled oxidation. With increasing hydrogen fraction in the plasma, a clear sphere-to-polyhedron shape transition is observed. The heat released during the hydrogenation of cerium, which significantly enhances the species mobility on the surface, favors the growth of well defined facets. The polyhedron ceria nanoparticles, though lower in specific surface area, exhibit superior catalytic performance for CO oxidation over the round particles, which is attributed to the higher density of the reactive {200} and {220} facets on the surface. The hydrogen mediated shape control mechanism provides new insights into the shape control of nanoparticles during thermal plasma processing.

Anchor enhanced capsulorraphy in bunionectomies using an L-shaped capsulotomy.

Science.gov (United States)

Gould, John S; Ali, Sheriff; Fowler, Rachel; Fleisig, Glenn S

2003-01-01

The objective of this study was to investigate potential benefit of a suture anchor-enhanced capsulorraphy in the early maintenance of correction in bunionectomies. We compared, retrospectively, in successive series, the loss of correction of the Hallux Valgus (HV) and intermetatarsal (IM) angle, in those repaired with an L-shaped capsulorraphy enhanced with anchors to those without. Intraoperative and second week postoperative simulated weightbearing anterior posterior (AP) X-rays were used to evaluate results. By using only intraoperative and early postoperative X-rays, we should have effectively eliminated extraneous factors that might have influenced our results. A Total of 106 cases were investigated, 65 of which were repaired using anchors, the remaining 41 without. In the anchor group, 38 underwent a proximal metatarsal concentric shelf osteotomy (CSO)/modified McBride procedure, while the remaining 27 had a distal Chevron correction. In the without-anchor group, 21 had a CSO/modified McBride procedure while 20 underwent the Chevron procedure. In the without-anchor group, the average HV and IM loss of correction was 4.60 degrees (range, -2 to 21 degrees) and 0.6 degrees (range, -1 to 9 degrees) respectively. In the anchor group, the corresponding loss was 2.8 degrees (range, -3 to 17 degrees) and 0.6 degrees (range, -2 to 14 degrees) respectively. These results, when statistically analyzed, demonstrated that while the IM angle change was not statistically significant, the HV angle change was statistically significant, implying that the anchor plays a significant role in maintaining the surgical correction in both the distal Chevron and CSO/ modified McBride bunionectomies.

Morphology modification of gold nanoparticles from nanoshell to C-shape: Improved surface enhanced Raman scattering

International Nuclear Information System (INIS)

Xing, Ting-Yang; Zhu, Jian; Li, Jian-Jun; Zhao, Jun-Wu

2016-01-01

Morphology modification of nanostructures is of great interest, because it can be used to fabricate nanostructures which are hard to be done using other methods. Different from traditional lithographic technique which is slow and expensive, morphology modification is easy, cheap, and reproducible. In this paper, modification of the optical and morphological properties of a hollow gold nanoshell (HGNS) is achieved by using H 2 O 2 as an oxidizer. The reshaping of these nanostructures has been demonstrated as a consequence of an oxidation process in which HGNSs are dissolved by H 2 O 2 under the acidic conditions provided by HCl. We investigate the oxidation process by a transmission electron microscope and propose a reshaping model involving four different shapes (HGNS, HGNS with hole, gold nanoring, and C-shaped gold nanoparticle) which are corresponding to the oxidation products of HGNSs at different pH values. Besides, the surface enhanced Raman scattering (SERS) activity of each oxidation product has been evaluated by using rhodamine 6G as the Raman active probe. It has been observed that the C-shaped gold nanoparticles which are corresponding to the oxidation products at the minimum pH value have the highest SERS activity and this result can also be interpreted by discrete-dipole approximation simulations. We demonstrate that the morphology modification of HGNSs becomes possible in a controlled manner using wet chemistry and can be used in preparation of gold nanoparticles such as HGNS with hole, gold nanoring, and C-shaped gold nanoparticle with large SERS activity. These nanostructures must have potential use in many plasmonic areas, including sensing, catalysis, and biomedicine.

Morphology modification of gold nanoparticles from nanoshell to C-shape: Improved surface enhanced Raman scattering

Energy Technology Data Exchange (ETDEWEB)

Xing, Ting-Yang; Zhu, Jian; Li, Jian-Jun; Zhao, Jun-Wu, E-mail: nanoptzhao@163.com [The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China)

2016-06-28

Morphology modification of nanostructures is of great interest, because it can be used to fabricate nanostructures which are hard to be done using other methods. Different from traditional lithographic technique which is slow and expensive, morphology modification is easy, cheap, and reproducible. In this paper, modification of the optical and morphological properties of a hollow gold nanoshell (HGNS) is achieved by using H{sub 2}O{sub 2} as an oxidizer. The reshaping of these nanostructures has been demonstrated as a consequence of an oxidation process in which HGNSs are dissolved by H{sub 2}O{sub 2} under the acidic conditions provided by HCl. We investigate the oxidation process by a transmission electron microscope and propose a reshaping model involving four different shapes (HGNS, HGNS with hole, gold nanoring, and C-shaped gold nanoparticle) which are corresponding to the oxidation products of HGNSs at different pH values. Besides, the surface enhanced Raman scattering (SERS) activity of each oxidation product has been evaluated by using rhodamine 6G as the Raman active probe. It has been observed that the C-shaped gold nanoparticles which are corresponding to the oxidation products at the minimum pH value have the highest SERS activity and this result can also be interpreted by discrete-dipole approximation simulations. We demonstrate that the morphology modification of HGNSs becomes possible in a controlled manner using wet chemistry and can be used in preparation of gold nanoparticles such as HGNS with hole, gold nanoring, and C-shaped gold nanoparticle with large SERS activity. These nanostructures must have potential use in many plasmonic areas, including sensing, catalysis, and biomedicine.

A Drosophila LexA Enhancer-Trap Resource for Developmental Biology and Neuroendocrine Research

Directory of Open Access Journals (Sweden)

Lutz Kockel

2016-10-01

Full Text Available Novel binary gene expression tools like the LexA-LexAop system could powerfully enhance studies of metabolism, development, and neurobiology in Drosophila. However, specific LexA drivers for neuroendocrine cells and many other developmentally relevant systems remain limited. In a unique high school biology course, we generated a LexA-based enhancer trap collection by transposon mobilization. The initial collection provides a source of novel LexA-based elements that permit targeted gene expression in the corpora cardiaca, cells central for metabolic homeostasis, and other neuroendocrine cell types. The collection further contains specific LexA drivers for stem cells and other enteric cells in the gut, and other developmentally relevant tissue types. We provide detailed analysis of nearly 100 new LexA lines, including molecular mapping of insertions, description of enhancer-driven reporter expression in larval tissues, and adult neuroendocrine cells, comparison with established enhancer trap collections and tissue specific RNAseq. Generation of this open-resource LexA collection facilitates neuroendocrine and developmental biology investigations, and shows how empowering secondary school science can achieve research and educational goals.

Thermoplastic shape-memory polyurethanes based on natural oils

International Nuclear Information System (INIS)

Saralegi, Ainara; Eceiza, Arantxa; Corcuera, Maria Angeles; Johan Foster, E; Weder, Christoph

2014-01-01

A new family of segmented thermoplastic polyurethanes with thermally activated shape-memory properties was synthesized and characterized. Polyols derived from castor oil with different molecular weights but similar chemical structures and a corn-sugar-based chain extender (propanediol) were used as starting materials in order to maximize the content of carbon from renewable resources in the new materials. The composition was systematically varied to establish a structure–property map and identify compositions with desirable shape-memory properties. The thermal characterization of the new polyurethanes revealed a microphase separated structure, where both the soft (by convention the high molecular weight diol) and the hard phases were highly crystalline. Cyclic thermo-mechanical tensile tests showed that these polymers are excellent candidates for use as thermally activated shape-memory polymers, in which the crystalline soft segments promote high shape fixity values (close to 100%) and the hard segment crystallites ensure high shape recovery values (80–100%, depending on the hard segment content). The high proportion of components from renewable resources used in the polyurethane formulation leads to the synthesis of bio-based polyurethanes with shape-memory properties. (paper)

Dominance of Plasmonic Resonant Energy Transfer over Direct Electron Transfer in Substantially Enhanced Water Oxidation Activity of BiVO4 by Shape-Controlled Au Nanoparticles.

Science.gov (United States)

Lee, Mi Gyoung; Moon, Cheon Woo; Park, Hoonkee; Sohn, Woonbae; Kang, Sung Bum; Lee, Sanghan; Choi, Kyoung Jin; Jang, Ho Won

2017-10-01

The performance of plasmonic Au nanostructure/metal oxide heterointerface shows great promise in enhancing photoactivity, due to its ability to confine light to the small volume inside the semiconductor and modify the interfacial electronic band structure. While the shape control of Au nanoparticles (NPs) is crucial for moderate bandgap semiconductors, because plasmonic resonance by interband excitations overlaps above the absorption edge of semiconductors, its critical role in water splitting is still not fully understood. Here, first, the plasmonic effects of shape-controlled Au NPs on bismuth vanadate (BiVO 4 ) are studied, and a largely enhanced photoactivity of BiVO 4 is reported by introducing the octahedral Au NPs. The octahedral Au NP/BiVO 4 achieves 2.4 mA cm -2 at the 1.23 V versus reversible hydrogen electrode, which is the threefold enhancement compared to BiVO 4 . It is the highest value among the previously reported plasmonic Au NPs/BiVO 4 . Improved photoactivity is attributed to the localized surface plasmon resonance; direct electron transfer (DET), plasmonic resonant energy transfer (PRET). The PRET can be stressed over DET when considering the moderate bandgap semiconductor. Enhanced water oxidation induced by the shape-controlled Au NPs is applicable to moderate semiconductors, and shows a systematic study to explore new efficient plasmonic solar water splitting cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shape Recovery with Concomitant Mechanical Strengthening of Amphiphilic Shape Memory Polymers in Warm Water

International Nuclear Information System (INIS)

Zhang, Ben; DeBartolo, Janae E.; Song, Jie

2017-01-01

Maintaining adequate or enhancing mechanical properties of shape memory polymers (SMPs) after shape recovery in an aqueous environment are greatly desired for biomedical applications of SMPs as self-fitting tissue scaffolds or minimally invasive surgical implants. Here we report stable temporary shape fixing and facile shape recovery of biodegradable triblock amphiphilic SMPs containing a poly(ethylene glycol) (PEG) center block and flanking poly(lactic acid) or poly(lactic-co-glycolic acid) blocks in warm water, accompanied with concomitant enhanced mechanical strengths. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WXRD) and small-angle X-ray scattering (SAXS) analyses revealed that the unique stiffening of the amphiphilic SMPs upon hydration was due to hydration-driven microphase separation and PEG crystallization. We further demonstrated that the chemical composition of degradable blocks in these SMPs could be tailored to affect the persistence of hydration-induced stiffening upon subsequent dehydration. These properties combined open new horizons for these amphiphilic SMPs for smart weight-bearing in vivo applications (e.g. as self-fitting intervertebral discs). In conclusion, this study also provides a new material design strategy to strengthen polymers in aqueous environment in general.

Critical disease windows shaped by stress exposure alter allocation trade-offs between development and immunity.

Science.gov (United States)

Kirschman, Lucas J; Crespi, Erica J; Warne, Robin W

2018-01-01

Ubiquitous environmental stressors are often thought to alter animal susceptibility to pathogens and contribute to disease emergence. However, duration of exposure to a stressor is likely critical, because while chronic stress is often immunosuppressive, acute stress can temporarily enhance immune function. Furthermore, host susceptibility to stress and disease often varies with ontogeny; increasing during critical developmental windows. How the duration and timing of exposure to stressors interact to shape critical windows and influence disease processes is not well tested. We used ranavirus and larval amphibians as a model system to investigate how physiological stress and pathogenic infection shape development and disease dynamics in vertebrates. Based on a resource allocation model, we designed experiments to test how exposure to stressors may induce resource trade-offs that shape critical windows and disease processes because the neuroendocrine stress axis coordinates developmental remodelling, immune function and energy allocation in larval amphibians. We used wood frog larvae (Lithobates sylvaticus) to investigate how chronic and acute exposure to corticosterone, the dominant amphibian glucocorticoid hormone, mediates development and immune function via splenocyte immunohistochemistry analysis in association with ranavirus infection. Corticosterone treatments affected immune function, as both chronic and acute exposure suppressed splenocyte proliferation, although viral replication rate increased only in the chronic corticosterone treatment. Time to metamorphosis and survival depended on both corticosterone treatment and infection status. In the control and chronic corticosterone treatments, ranavirus infection decreased survival and delayed metamorphosis, although chronic corticosterone exposure accelerated rate of metamorphosis in uninfected larvae. Acute corticosterone exposure accelerated metamorphosis increased survival in infected larvae. Interactions

Enhancement of environment and resources engineering studies through an international cooperation network

Science.gov (United States)

Caporali, E.; Tuneski, A.

2012-12-01

Higher education plays a very important role in the modern societies development, enhancing social, cultural and economic development for a sustainable growth, environment respectful. In this framework, the European Commission promotes the TEMPUS-Trans European Mobility Programme for University Studies. Curricula harmonization and lifelong learning programme development in higher education are among the focused aspects of the TEMPUS programme. The DEREL-Development of Environment and Resources Engineering Learning, is a three years TEMPUS project coordinated by the University of Firenze, in cooperation with colleagues of the Ss Cyril and Methodius University, Skopje financed and activated since October 2010. The DEREL Project Consortium consists of 4 EU Universities (from Italy, Greece, Germany and Austria), 7 Partner Countries (PC) Universities (from FYR of Macedonia, Serbia and Albania), and 1 PC Ministry, 4 PC National Agencies, 1 PC non governmental organization and 1 PC enterprise. In cooperation with the same 4 EU Universities and the same Macedonian Institutions, in the period 2005-2008 also a TEMPUS JEP entitled DEREC-Development of Environmental and Resources Engineering Curriculum, was also carried out by the University of Firenze in cooperation with colleagues of the Ss Cyril and Methodius University. Within DEREC a new three-years first cycle curriculum in Environmental and Resources Engineering was opened at the University Ss Cyril and Methodius, Skopje, and the necessary conditions for offering a Joint Degree Title, on the basis of an agreement between the Ss. Cyril and Methodius University and the University of Firenze, were fulfilled. The running DEREL project, as a continuation of DEREC, is aimed to introduce a new, up-to-date, postgraduate second cycle curriculum in Environment and Resources Engineering at the Ss Cyril and Methodius University in Skopje, FYR of Macedonia, University of Novi Sad, Serbia and Polytechnic University of Tirana, Albania

A saw-tooth plasma actuator for film cooling efficiency enhancement of a shaped hole

Science.gov (United States)

Li, Guozhan; Yu, Jianyang; Liu, Huaping; Chen, Fu; Song, Yanping

2017-08-01

This paper reports the large eddy simulations of the effects of a saw-tooth plasma actuator and the laidback fan-shaped hole on the film cooling flow characteristics, and the numerical results are compared with a corresponding standard configuration (cylindrical hole without the saw-tooth plasma actuator). For this numerical research, the saw-tooth plasma actuator is installed just downstream of the cooling hole and a phenomenological plasma model is employed to provide the 3D plasma force vectors. The results show that thanks to the downward force and the momentum injection effect of the saw-tooth plasma actuator, the cold jet comes closer to the wall surface and extends further downstream. The saw-tooth plasma actuator also induces a new pair of vortex which weakens the strength of the counter-rotating vortex pair (CRVP) and entrains the coolant towards the wall, and thus the diffusion of the cold jet in the crossflow is suppressed. Furthermore, the laidback fan-shaped hole reduces the vertical jet velocity causing the disappearance of downstream spiral separation node vortices, this compensates for the deficiency of the saw-tooth plasma actuator. Both effects of the laidback fan-shaped hole and the saw-tooth plasma actuator effectively control the development of the CRVP whose size and strength are smaller than those of the anti-counter rotating vortex pair in the far field, thus the centerline and the spanwise-averaged film cooling efficiency are enhanced. The average film cooling efficiency is the biggest in the Fan-Dc = 1 case, which is 80% bigger than that in the Fan-Dc = 0 case and 288% bigger than that in the Cyl-Dc = 0 case.

AC Electric Field Activated Shape Memory Polymer Composite

Science.gov (United States)

Kang, Jin Ho; Siochi, Emilie J.; Penner, Ronald K.; Turner, Travis L.

2011-01-01

Shape memory materials have drawn interest for applications like intelligent medical devices, deployable space structures and morphing structures. Compared to other shape memory materials like shape memory alloys (SMAs) or shape memory ceramics (SMCs), shape memory polymers (SMPs) have high elastic deformation that is amenable to tailored of mechanical properties, have lower density, and are easily processed. However, SMPs have low recovery stress and long response times. A new shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive fillers to enhance its thermo-mechanical characteristics. A new composition of shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive functionalized graphene sheets (FGS) to enhance its thermo-mechanical characteristics. The elastic modulus of LaRC-SMPC is approximately 2.7 GPa at room temperature and 4.3 MPa above its glass transition temperature. Conductive FGSs-doped LaRC-SMPC exhibited higher conductivity compared to pristine LaRC SMP. Applying an electric field at between 0.1 Hz and 1 kHz induced faster heating to activate the LaRC-SMPC s shape memory effect relative to applying DC electric field or AC electric field at frequencies exceeding1 kHz.

Efficiency enhancement of slow-wave electron-cyclotron maser by a second-order shaping of the magnetic field in the low-gain limit

Energy Technology Data Exchange (ETDEWEB)

Liu, Si-Jia; Zhang, Yu-Fei; Wang, Kang [School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Yong-Ming [Information Science and Engineering College, XinJiang University, Urumqi XinJiang 830046 (China); Jing, Jian, E-mail: jingjian@mail.buct.edu.cn [School of Science, Beijing University of Chemical Technology, Beijing 100029 (China)

2017-03-15

Based on the anomalous Doppler effect, we put forward a proposal to enhance the conversion efficiency of the slow-wave electron cyclotron masers (ECM) under the resonance condition. Compared with previous studies, we add a second-order shaping term in the guild magnetic field. Theoretical analyses and numerical calculations show that it can enhance the conversion efficiency in the low-gain limit. The case of the initial velocity spread of electrons satisfying the Gaussian distribution is also analysed numerically.

Enhancing Cloud Resource Utilisation using Statistical Analysis

OpenAIRE

Sijin He; Li Guo; Yike Guo

2014-01-01

Resource provisioning based on virtual machine (VM) has been widely accepted and adopted in cloud computing environments. A key problem resulting from using static scheduling approaches for allocating VMs on different physical machines (PMs) is that resources tend to be not fully utilised. Although some existing cloud reconfiguration algorithms have been developed to address the problem, they normally result in high migration costs and low resource utilisation due to ignoring the multi-dimens...

Comparison of Power Versus Manual Injection in Bolus Shape and Image Quality on Contrast-Enhanced Magnetic Resonance Angiography: An Experimental Study in a Swine Model.

Science.gov (United States)

Tsuboyama, Takahiro; Jost, Gregor; Pietsch, Hubertus; Tomiyama, Noriyuki

2017-09-01

The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA). Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks. Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to

Low-Dose Contrast-Enhanced Breast CT Using Spectral Shaping Filters: An Experimental Study.

Science.gov (United States)

Makeev, Andrey; Glick, Stephen J

2017-12-01

Iodinated contrast-enhanced X-ray imaging of the breast has been studied with various modalities, including full-field digital mammography (FFDM), digital breast tomosynthesis (DBT), and dedicated breast CT. Contrast imaging with breast CT has a number of advantages over FFDM and DBT, including the lack of breast compression, and generation of fully isotropic 3-D reconstructions. Nonetheless, for breast CT to be considered as a viable tool for routine clinical use, it would be desirable to reduce radiation dose. One approach for dose reduction in breast CT is spectral shaping using X-ray filters. In this paper, two high atomic number filter materials are studied, namely, gadolinium (Gd) and erbium (Er), and compared with Al and Cu filters currently used in breast CT systems. Task-based performance is assessed by imaging a cylindrical poly(methyl methacrylate) phantom with iodine inserts on a benchtop breast CT system that emulates clinical breast CT. To evaluate detectability, a channelized hoteling observer (CHO) is used with sums of Laguerre-Gauss channels. It was observed that spectral shaping using Er and Gd filters substantially increased the dose efficiency (defined as signal-to-noise ratio of the CHO divided by mean glandular dose) as compared with kilovolt peak and filter settings used in commercial and prototype breast CT systems. These experimental phantom study results are encouraging for reducing dose of breast CT, however, further evaluation involving patients is needed.

Effects of particle shape and size on nanofluid properties for potential Enhanced Oil Recovery (EOR

Directory of Open Access Journals (Sweden)

Tengku Mohd Tengku Amran

2016-01-01

Full Text Available Application of Enhanced Oil Recovery (EOR in oil and gas industry is very important to increase oil recovery and prolong the lifetime of a reservoir but it has been very costly and losing properties of EOR agent due to harsh condition. Nanoparticles have been used in EOR application since they are not degradable in reservoir condition and used in smaller amount compared to polymer usage. Commonly, EOR techniques are focusing on increasing the sweep efficiency by controlling the mobility ratio between reservoir fluid and injected fluid. Thus, this research aimed to analyze the nanofluid viscosity at different particle size and shape, volumetric concentration and types of dispersing fluid, as well as to determine the oil recovery performance at different nanofluid concentration. The nanofluid viscosity was investigated at nanoparticle sizes of 15nm and 60nm and shapes of 15nm spherical-solid and porous. Five nanofluid samples with concentration ranging from 0.1wt.% to 7wt.% were used to investigate the effect of volumetric concentration. Distilled water, ethanol, ethylene glycol (EG and brine were used for the effect of dispersing fluids. Oil recovery was investigated at five different concentrations of nanofluid samples through flooding test. It was found that viscosity of nanofluid increased with decreasing particle size and increasing volumetric concentration. Solid shape particle and increasing dispersing fluid viscosity resulted in higher nanofluid viscosity. The higher the nanofluid concentration, the higher the oil recovery obtained. It can be concluded that nanofluid properties have been significantly affected by the environment and the particle used for potential EOR application.

Time to Talk? How the Structure of Dialog Processes Shapes Stakeholder Learning in Participatory Water Resources Management

Directory of Open Access Journals (Sweden)

Melanie Muro

2012-03-01

Full Text Available Public participation is increasingly viewed as a means to initiate social learning among stakeholders, resource managers, and policy makers rather than to ensure democratic representation. This growing understanding of participatory activities as learning platforms can be seen as a direct response to shifts in how natural resources management is framed, namely as uncertain, non-linear, and interlinked with the human dimensions. Social learning as it is discussed within the natural resources management (NRM context features a process of collective and communicative learning that is thought to enable stakeholders to arrive at a shared understanding of a specific environmental situation and to develop new solutions as well as ways of acting together in pursuit of a shared ambition. Yet, although case-study research on social-learning processes provides multiple accounts of positive experiences, there are also reports of mistaken learning, the intensification of tensions or conflict, and failure to reach agreement or verifiable consensus. Based on results of a postal survey of stakeholder experiences in two involvement initiatives, we can draw two main conclusions: First, social learning is a multidimensional and dynamic process and, as such, evolves in stages and to various degrees. Second, stakeholder processes are shaped and affected by a multitude of factors that constrain the occurrence of learning processes and eventually limit the extent to which these can contribute to sustainable NRM. Foremost, the fact that the intensity of stakeholder learning differed in the two investigated initiatives reinforces the role organizational arrangements play in encouraging the type of communicative process necessary for stakeholder learning.

Integrated resource planning-concepts and principles

Energy Technology Data Exchange (ETDEWEB)

Atkinson, S.

1994-12-31

The concepts and principles of integrated resource planning (IRP) are outlined. The following topics are discussed: utility opportunities and methodologies, application considerations, ambitious energy-efficient programs, the future of IRP, three methods to study resource alternatives, the load adjustment method, simultaneous optimization, static analysis, utility profile data, load forecasts and shapes, load data, conversion, variable costs, external analysis, internal analysis, DSM objectives, supply-side prescreening, DSM screening analysis, DSM evaluation, the IRP process, risk analysis, collaborative planning process, and load shape objectives.

How do Resource Structuring and Strategic Flexibility Interact to Shape Radical Innovation?

DEFF Research Database (Denmark)

Li, Yuan; Li, Peter Ping; Wang, Haifeng

2017-01-01

flexibility could be complementary or substitutive, and the effective utilization of these two organizational dimensions as a joint force should be well aligned to achieve scientific breakthroughs. Specifically, this study explores how two different types of strategic flexibility (i.e., resource flexibility......As high resource consumption and high uncertainty are two of the most critical challenges to radical innovation, it is imperative to adopt resource structuring for an active management of resource portfolios, and also to adopt strategic flexibility for active management of contextual uncertainties......, especially for firms in the emerging economies characterized by serious resource deficiency and high contextual uncertainty. Though firms engaging in resource structuring and strategic flexibility separately could foster radical innovation, the interaction effect of resource structuring and strategic...

Shared access protocol (SAP) in femtocell channel resources for cellular coverage enhancement

KAUST Repository

Magableh, Amer M.

2012-12-01

Femtocells are promising techniques employed in cellular systems to enhance the indoor coverage, especially in areas with high density and high traffic rates. In this paper, we propose an efficient resource utilization protocol, named shared access protocol (SAP), that enables the unlicensed macro-cell user equipments (MC-UE) to communicate with partially closed access femtocell base stations and hence, improves and enhances the overall system performance in closed environments. For the proposed system model, we obtain, in closed-form, the main signal-to-interference plus noise ratio (SINR) characteristics, including the probability density function (PDF) and the cumulative distribution function (CDF). In addition, these expressions are further used to derive several performance metrics in closed-form, such as, the average bit error rate (BER), outage probability, and the average channel capacity for the proposed SAP herein. Furthermore, Monte-carlo simulations as well as numerical results are provided showing a good match that ensures and confirms the correctness of the derived expressions. © 2012 IEEE.

Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

Science.gov (United States)

Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

2012-10-23

An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

Social Support and Social Anxiety in Use and Perceptions of Online Mental Health Resources: Exploring Social Compensation and Enhancement.

Science.gov (United States)

Ruppel, Erin K; McKinley, Christopher J

2015-08-01

This study used the frameworks of social compensation and social enhancement to examine how social anxiety and social support were related to college students' (N=443) use and perceptions of online mental health resources (Web sites and online support groups). Potential interactions between social support and social anxiety were also examined. Consistent with the social compensation hypothesis, perceived usefulness of Web sites was positively associated with social support. Perceived usefulness of online support groups was positively associated with social support when participants reported average or high, but not low, social anxiety. In contrast, previous use of Web sites was consistent with the social compensation hypothesis. Participants who reported less social support were more likely to have used a Web site for a mental or emotional problem. These findings suggest that college students' use and perceptions of online mental health resources vary as a function of social support and social anxiety, and that patterns suggestive of social compensation and social enhancement depend on whether perceptions or actual use of resources are examined. Combined with the significant interaction between social support and social anxiety on perceived usefulness of online support groups, these findings highlight the potential complexity of social compensation and enhancement phenomena.

The concept of ensuring a hydride moderator resource for enhanced power NPF

International Nuclear Information System (INIS)

Volkov, S.P.; Glushkov, E.S.; Degal'tsev, IU.G.; Pliukhov, A.D.; Ponomarev-Stepnoi, N.N.; Usov, V.A.; Boiko, E.B.; Izhvanov, L.A.; Frolov, V.L.; Ivanov, A.S.

1991-01-01

The nuclear power systems of enhanced power and resource use zirconium hydride having a composition ZrH(1.85-1.92) as a moderator material. The products (disk with openings) work over a temperature range of (460-630) C and neutron flux of about 2.10 exp 21 n/sq cm. A reduction of hydrogen loss to a permissible level is reached due to special protective coatings applied to the moderator disks and power unit vessel as well as by means of a number constructive decisions. Specific attention is paid to the conditions of sustaining these coatings' operability

Enhanced lubricant film formation through micro-dimpled hard-on-hard artificial hip joint: An in-situ observation of dimple shape effects.

Science.gov (United States)

Choudhury, Dipankar; Rebenda, David; Sasaki, Shinya; Hekrle, Pavel; Vrbka, Martin; Zou, Min

2018-05-01

This study evaluates the impact of dimple shapes on lubricant film formation in artificial hip joints. Micro-dimples with 20-50 µm lateral size and 1 ± 0.2 µm depths were fabricated on CrCoMo hip joint femoral heads using a picosecond laser. Tribological studies were performed using a pendulum hip joint simulator to apply continuous swing flexion-extension motions. The results revealed a significantly enhanced lubricant film thickness (≥ 500 nm) with micro-dimpled prosthesis heads at equilibrium position after the lubricant film has fully developed. The average lubricant film thickness of dimpled prostheses with square- and triangular-shaped dimple arrays over time is about 3.5 that of the non-dimpled prosthesis (204 nm). Remarkably, the prosthesis with square-shaped dimple arrays showed a very fast lubricant film formation reaching their peak values within 0.5 s of pendulum movement, followed by prosthesis with triangular-shaped dimple arrays with a transition period of 42.4 s. The fully developed lubricant film thicknesses (≥ 700 nm) are significantly higher than the surface roughness (≈ 25 nm) demonstrating a hydrodynamic lubrication. Hardly any scratches appeared on the post-experimental prosthesis with square-shaped dimple array and only a few scratches were found on the post-experimental prosthesis with triangular-shaped dimple arrays. Thus, prostheses with square-shaped dimple arrays could be a potential solution for durable artificial hip joints. Copyright © 2018 Elsevier Ltd. All rights reserved.

Accelerating Innovation that Enhances Resource Recovery in the Wastewater Sector: Advancing a National Testbed Network.

Science.gov (United States)

Mihelcic, James R; Ren, Zhiyong Jason; Cornejo, Pablo K; Fisher, Aaron; Simon, A J; Snyder, Seth W; Zhang, Qiong; Rosso, Diego; Huggins, Tyler M; Cooper, William; Moeller, Jeff; Rose, Bob; Schottel, Brandi L; Turgeon, Jason

2017-07-18

This Feature examines significant challenges and opportunities to spur innovation and accelerate adoption of reliable technologies that enhance integrated resource recovery in the wastewater sector through the creation of a national testbed network. The network is a virtual entity that connects appropriate physical testing facilities, and other components needed for a testbed network, with researchers, investors, technology providers, utilities, regulators, and other stakeholders to accelerate the adoption of innovative technologies and processes that are needed for the water resource recovery facility of the future. Here we summarize and extract key issues and developments, to provide a strategy for the wastewater sector to accelerate a path forward that leads to new sustainable water infrastructures.

OPAC Design Enhancements and Their Effects on Circulation and Resource Sharing within the Library Consortium Environment

Directory of Open Access Journals (Sweden)

Michael J. Bennett

2007-03-01

Full Text Available A longitudinal study of three discrete online public access catalog (OPAC design enhancements examined the possible effects such changes may have on circulation and resource sharing within the automated library consortium environment. Statistical comparisons were made of both circulation and interlibrary loan (ILL figures from the year before enhancement to the year after implementation. Data from sixteen libraries covering a seven-year period were studied in order to determine the degree to which patrons may or may not utilize increasingly broader OPAC ILL options over time. Results indicated that while ILL totals increased significantly after each OPAC enhancement, such gains did not result in significant corresponding changes in total circulation.

Shape-dependent surface-enhanced Raman scattering in gold–Raman-probe–silica sandwiched nanoparticles for biocompatible applications

International Nuclear Information System (INIS)

Li Ming; Cushing, Scott K; Lankford, Jessica; Wu, Nianqiang; Zhang Jianming; Ma Dongling; Aguilar, Zoraida P

2012-01-01

To meet the requirement of Raman probes (labels) for biocompatible applications, a synthetic approach has been developed to sandwich the Raman-probe (malachite green isothiocyanate, MGITC) molecules between the gold core and the silica shell in gold–SiO 2 composite nanoparticles. The gold–MGITC–SiO 2 sandwiched structure not only prevents the Raman probe from leaking out but also improves the solubility of the nanoparticles in organic solvents and in aqueous solutions even with high ionic strength. To amplify the Raman signal, three types of core, gold nanospheres, nanorods and nanostars, have been chosen as the substrates of the Raman probe. The effect of the core shape on the surface-enhanced Raman scattering (SERS) has been investigated. The colloidal nanostars showed the highest SERS enhancement factor while the nanospheres possessed the lowest SERS activity under excitation with 532 and 785 nm lasers. Three-dimensional finite-difference time domain (FDTD) simulation showed significant differences in the local electromagnetic field distributions surrounding the nanospheres, nanorods, and nanostars, which were induced by the localized surface plasmon resonance (LSPR). The electromagnetic field was enhanced remarkably around the two ends of the nanorods and around the sharp tips of the nanostars. This local electromagnetic enhancement made the dominant contribution to the SERS enhancement. Both the experiments and the simulation revealed the order nanostars > nanorods > nanospheres in terms of the enhancement factor. Finally, the biological application of the nanostar–MGITC–SiO 2 nanoparticles has been demonstrated in the monitoring of DNA hybridization. In short, the gold–MGITC–SiO 2 sandwiched nanoparticles can be used as a Raman probe that features high sensitivity, good water solubility and stability, low-background fluorescence, and the absence of photobleaching for future biological applications. (paper)

Donut-shaped Co{sub 3}O{sub 4} nanoflakes grown on nickel foam with enhanced supercapacitive performances

Energy Technology Data Exchange (ETDEWEB)

Han, Zhicheng; Zheng, Xin; Yao, Shunyu; Xiao, Huanhao; Qu, Fengyu; Wu, Xiang, E-mail: wuxiang05@163.com

2016-03-01

Graphical abstract: The as-synthesized product exhibits a high initial discharge capacitance of 518 mF/cm{sup 2} at a current density of 1 mA cm{sup −2} and can maintain 75% capacitance retention even after 6000 charge–discharge cycles. Electrochemical results revealed that the prepared Co{sub 3}O{sub 4} nanoflakes possess a remarkable performance in supercapacitor applications. - Highlights: • Donut-shaped Co{sub 3}O{sub 4} nanoflakes were first fabricated by a solution approach. • The tests show high discharge areal capacitance and long cycle life stability. • Co{sub 3}O{sub 4} nanoflakes might be promising supercapacitor electrode materials. - Abstract: Donut-shaped Co{sub 3}O{sub 4} nanoflakes grown on nickel foam were successfully fabricated by a simple one-pot hydrothermal approach. The prepared products were functionalized as the supercapacitors electrodes. Electrochemical performance of the as-prepared products demonstrated high specific capacitance (518 mF cm{sup −2}) and excellent cycling stability (∼25% loss) after 6000 repetitive cycles at a charge–discharge current density of 1 mA cm{sup −2}. The superior electrochemical performance may be ascribed into two reasons: one is the unique spatial structures which possess many active sites and provide enhanced combination between the electrode and nickel foam to support fast ion and electron transfer, the other is that donut-shaped Co{sub 3}O{sub 4} nanoflakes electrodes show relatively lower resistances. It is expected that the as-obtained donut-shaped Co{sub 3}O{sub 4} nanoflakes could have potential applications in portable electronics and electrical vehicles.

Three-Dimensional Cellular Structures Enhanced By Shape Memory Alloys

Science.gov (United States)

Nathal, Michael V.; Krause, David L.; Wilmoth, Nathan G.; Bednarcyk, Brett A.; Baker, Eric H.

2014-01-01

This research effort explored lightweight structural concepts married with advanced smart materials to achieve a wide variety of benefits in airframe and engine components. Lattice block structures were cast from an aerospace structural titanium alloy Ti-6Al-4V and a NiTi shape memory alloy (SMA), and preliminary properties have been measured. A finite element-based modeling approach that can rapidly and accurately capture the deformation response of lattice architectures was developed. The Ti-6-4 and SMA material behavior was calibrated via experimental tests of ligaments machined from the lattice. Benchmark testing of complete lattice structures verified the main aspects of the model as well as demonstrated the advantages of the lattice structure. Shape memory behavior of a sample machined from a lattice block was also demonstrated.

Report: Enhanced EPA Oversight and Action Can Further Protect Water Resources From the Potential Impacts of Hydraulic Fracturing

Science.gov (United States)

Report #15-P-0204, July 16, 2015. Enhanced EPA oversight of the permitting process for diesel fuel use during hydraulic fracturing can further EPA efforts to protect water resources, and establishment of a plan for determining whether to propose a chemical

Model-based, semiquantitative and time intensity curve shape analysis of dynamic contrast-enhanced MRI: a comparison in patients undergoing antiangiogenic treatment for recurrent glioma

NARCIS (Netherlands)

Lavini, Cristina; Verhoeff, Joost J. C.; Majoie, Charles B.; Stalpers, Lukas J. A.; Richel, Dick J.; Maas, Mario

2011-01-01

To compare time intensity curve (TIC)-shape analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data with model-based analysis and semiquantitative analysis in patients with high-grade glioma treated with the antiangiogenic drug bevacizumab. Fifteen patients had a pretreatment

Automated mode shape estimation in agent-based wireless sensor networks

Science.gov (United States)

Zimmerman, Andrew T.; Lynch, Jerome P.

2010-04-01

Recent advances in wireless sensing technology have made it possible to deploy dense networks of sensing transducers within large structural systems. Because these networks leverage the embedded computing power and agent-based abilities integral to many wireless sensing devices, it is possible to analyze sensor data autonomously and in-network. In this study, market-based techniques are used to autonomously estimate mode shapes within a network of agent-based wireless sensors. Specifically, recent work in both decentralized Frequency Domain Decomposition and market-based resource allocation is leveraged to create a mode shape estimation algorithm derived from free-market principles. This algorithm allows an agent-based wireless sensor network to autonomously shift emphasis between improving mode shape accuracy and limiting the consumption of certain scarce network resources: processing time, storage capacity, and power consumption. The developed algorithm is validated by successfully estimating mode shapes using a network of wireless sensor prototypes deployed on the mezzanine balcony of Hill Auditorium, located on the University of Michigan campus.

Experimental evidence for shape changes at high spin

International Nuclear Information System (INIS)

Twin, P.J.

1985-01-01

Recent experimental evidence obtained with TESSA for shape changes at high spin is presented. Continuum γ-ray spectroscopy data indicates the co-existence of both prolate and oblate shapes in N = 90 nuclei and lifetime data in 152 Dy shows that the super deformed decays are very enhanced. (orig.)

The better you feel the better you learn: do warm colours and rounded shapes enhance learning outcome in multimedia learning?

OpenAIRE

Münchow, Hannes; Mengelkamp, Christoph; Bannert, Maria

2018-01-01

The aim of the present study was to examine whether fostering positive activating affect during multimedia learning enhances learning outcome. University students were randomly assigned to either a multimedia learning environment designed to induce positive activating affect through the use of “warm” colours and rounded shapes (n=61) or an affectively neutral environment that used achromatic colours and sharp edges (n=50). Participants learned about the topic of functional neuroanatomy for 20...

Determining the functional form of density dependence: deductive approaches for consumer-resource systems having a single resource.

Science.gov (United States)

Abrams, Peter A

2009-09-01

Consumer-resource models are used to deduce the functional form of density dependence in the consumer population. A general approach to determining the form of consumer density dependence is proposed; this involves determining the equilibrium (or average) population size for a series of different harvest rates. The relationship between a consumer's mortality and its equilibrium population size is explored for several one-consumer/one-resource models. The shape of density dependence in the resource and the shape of the numerical and functional responses all tend to be "inherited" by the consumer's density dependence. Consumer-resource models suggest that density dependence will very often have both concave and convex segments, something that is impossible under the commonly used theta-logistic model. A range of consumer-resource models predicts that consumer population size often declines at a decelerating rate with mortality at low mortality rates, is insensitive to or increases with mortality over a wide range of intermediate mortalities, and declines at a rapidly accelerating rate with increased mortality when mortality is high. This has important implications for management and conservation of natural populations.

Daily physical activity enhances resilient resources for symptom management in middle-aged women.

Science.gov (United States)

Kishida, Moé; Elavsky, Steriani

2015-07-01

The aim of the present study was to evaluate the direct and indirect associations between physical activity and menopausal symptoms. Community-dwelling middle-aged women (N = 103; age range 40-60 years) completed daily Internet surveys at the end of the day and wore an accelerometer for the objective assessment of physical activity for 21-days. 1-1-1 multilevel mediation models were estimated to test whether resilient resources (i.e., positive affect and coping efficacy) mediated the association between physical activity and symptom burden at the between- and within-person level. Analyses demonstrated physical activity had an indirect effect (-0.16) on symptom burden through the enhancement of positive affect at the within-person level (p physical activity on symptom burden at the within-person level was -0.08 (p physical activity may help a woman to cope with her symptoms is through the enhancement of positive affect and coping efficacy on a day-to-day basis. (c) 2015 APA, all rights reserved.

Shape-morphing composites with designed micro-architectures.

Science.gov (United States)

Rodriguez, Jennifer N; Zhu, Cheng; Duoss, Eric B; Wilson, Thomas S; Spadaccini, Christopher M; Lewicki, James P

2016-06-15

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designed for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. The ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.

Guide wire extension for shape memory polymer occlusion removal devices

Science.gov (United States)

Maitland, Duncan J [Pleasant Hill, CA; Small, IV, Ward; Hartman, Jonathan [Sacramento, CA

2009-11-03

A flexible extension for a shape memory polymer occlusion removal device. A shape memory polymer instrument is transported through a vessel via a catheter. A flexible elongated unit is operatively connected to the distal end of the shape memory polymer instrument to enhance maneuverability through tortuous paths en route to the occlusion.

Environmental and thermodynamic evaluation of CO2 capture, transport and storage with and without enhanced resource recovery

International Nuclear Information System (INIS)

Iribarren, Diego; Petrakopoulou, Fontina; Dufour, Javier

2013-01-01

This study evaluates the environmental and thermodynamic performance of six coal-fired power plants with CO 2 capture and storage. The technologies examined are post-combustion capture using monoethanolamine, membrane separation, cryogenic fractionation and pressure swing adsorption, pre-combustion capture through coal gasification, and capture performing conventional oxy-fuel combustion. The incorporation of CO 2 capture is evaluated both on its own and in combination with CO 2 transport and geological storage, with and without beneficial use. Overall, we find that pre-combustion CO 2 capture and post-combustion through membrane separation present relatively low life-cycle environmental impacts and high exergetic efficiencies. When accounting for transport and storage, the environmental impacts increase and the efficiencies decrease. However, a better environmental performance can be achieved for CO 2 capture, transport and storage when incorporating beneficial use through enhanced oil recovery. The performance with enhanced coal-bed methane recovery, on the other hand, depends on the impact categories evaluated. The incorporation of methane recovery results in a better thermodynamic performance, when compared to the incorporation of oil recovery. The cumulative energy demand shows that the integration of enhanced resource recovery strategies is necessary to attain favourable life-cycle energy balances. - Highlights: ► Evaluation of six different CO 2 capture technologies for coal-fired power plants. ► Calculation of life-cycle environmental impacts and exergetic efficiencies. ► Suitability of post-combustion capture with membrane separation. ► Suitability of pre-combustion capture through coal gasification. ► Improved performance when incorporating enhanced resource recovery

Liquid mixing enhanced by pulse width modulation in a Y-shaped jet configuration

Science.gov (United States)

Xia, Qingfeng; Zhong, Shan

2013-04-01

In this paper, mixing between two fluid streams, which are injected into a planar mixing channel via a Y-shaped confluence section at the same volume flow rate, is studied experimentally. The injection of the two fluid streams is controlled by two separate solenoid valves, which are operated with a phase difference of 180°, using pulse width modulation. The experiments are conducted using water at a mean Reynolds number between 83 and 250, a range of pulsation frequencies and two duty cycles (25 and 50%). Both particle-image velocimetry and planar laser-induced fluorescence technique are used to visualize the flow patterns and to quantify the mixing degree in the mixing channel. This experiment shows that the pulsation of each jet produces vortical structures, which promotes mixing via vortex entrainment and vortex breakup, and at the same time the mixing is also greatly enhanced by sequential segmentation produced by a 180° out-of-phase pulsation of the two jets. This mixing enhancement method is effective at a Reynolds number greater than 125 with a mixing degree of 0.9 being achieved. For the Reynolds numbers studied in the present experiments, an optimal frequency exists, which corresponds to a Strouhal number in the range of 0.5-2. Furthermore, at a given mean Reynolds number a lower duty cycle is found to produce a better mixing due to the resultant higher instantaneous Reynolds number in the jet flow. It is also found that pulsation of only one jet can produce a similar mixing effect.

Liquid mixing enhanced by pulse width modulation in a Y-shaped jet configuration

Energy Technology Data Exchange (ETDEWEB)

Xia Qingfeng; Zhong Shan, E-mail: shan.zhong@manchester.ac.uk [School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

2013-04-15

In this paper, mixing between two fluid streams, which are injected into a planar mixing channel via a Y-shaped confluence section at the same volume flow rate, is studied experimentally. The injection of the two fluid streams is controlled by two separate solenoid valves, which are operated with a phase difference of 180 Degree-Sign , using pulse width modulation. The experiments are conducted using water at a mean Reynolds number between 83 and 250, a range of pulsation frequencies and two duty cycles (25 and 50%). Both particle-image velocimetry and planar laser-induced fluorescence technique are used to visualize the flow patterns and to quantify the mixing degree in the mixing channel. This experiment shows that the pulsation of each jet produces vortical structures, which promotes mixing via vortex entrainment and vortex breakup, and at the same time the mixing is also greatly enhanced by sequential segmentation produced by a 180 Degree-Sign out-of-phase pulsation of the two jets. This mixing enhancement method is effective at a Reynolds number greater than 125 with a mixing degree of 0.9 being achieved. For the Reynolds numbers studied in the present experiments, an optimal frequency exists, which corresponds to a Strouhal number in the range of 0.5-2. Furthermore, at a given mean Reynolds number a lower duty cycle is found to produce a better mixing due to the resultant higher instantaneous Reynolds number in the jet flow. It is also found that pulsation of only one jet can produce a similar mixing effect. (paper)

How comprehensive are research studies investigating the efficacy of technology-enhanced learning resources in anatomy education? A systematic review.

Science.gov (United States)

Clunie, Lauren; Morris, Neil P; Joynes, Viktoria C T; Pickering, James D

2018-05-06

Anatomy education is at the forefront of integrating innovative technologies into its curricula. However, despite this rise in technology numerous authors have commented on the shortfall in efficacy studies to assess the impact such technology-enhanced learning (TEL) resources have on learning. To assess the range of evaluation approaches to TEL across anatomy education, a systematic review was conducted using MEDLINE, the Educational Resources Information Centre (ERIC), Scopus, and Google Scholar, with a total of 3,345 articles retrieved. Following the PRISMA method for reporting items, 153 articles were identified and reviewed against a published framework-the technology-enhanced learning evaluation model (TELEM). The model allowed published reports to be categorized according to evaluations at the level of (1) learner satisfaction, (2) learning gain, (3) learner impact, and (4) institutional impact. The results of this systematic review reveal that most evaluation studies into TEL within anatomy curricula were based on learner satisfaction, followed by module or course learning outcomes. Randomized controlled studies assessing learning gain with a specific TEL resource were in a minority, with no studies reporting a comprehensive assessment on the overall impact of introducing a specific TEL resource (e.g., return on investment). This systematic review has provided clear evidence that anatomy education is engaged in evaluating the impact of TEL resources on student education, although it remains at a level that fails to provide comprehensive causative evidence. Anat Sci Educ 11: 303-319. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

Science.gov (United States)

Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

2016-03-01

Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

Pressure Enhancement in Confined Fluids: Effect of Molecular Shape and Fluid-Wall Interactions.

Science.gov (United States)

Srivastava, Deepti; Santiso, Erik E; Gubbins, Keith E

2017-10-24

Recently, several experimental and simulation studies have found that phenomena that normally occur at extremely high pressures in a bulk phase can occur in nanophases confined within porous materials at much lower bulk phase pressures, thus providing an alternative route to study high-pressure phenomena. In this work, we examine the effect on the tangential pressure of varying the molecular shape, strength of the fluid-wall interactions, and pore width, for carbon slit-shaped pores. We find that, for multisite molecules, the presence of additional rotational degrees of freedom leads to unique changes in the shape of the tangential pressure profile, especially in larger pores. We show that, due to the direct relationship between the molecular density and the fluid-wall interactions, the latter have a large impact on the pressure tensor. The molecular shape and pore size have a notable impact on the layering of molecules in the pore, greatly influencing both the shape and scale of the tangential pressure profile.

Enhanced machine learning scheme for energy efficient resource allocation in 5G heterogeneous cloud radio access networks

KAUST Repository

Alqerm, Ismail

2018-02-15

Heterogeneous cloud radio access networks (H-CRAN) is a new trend of 5G that aims to leverage the heterogeneous and cloud radio access networks advantages. Low power remote radio heads (RRHs) are exploited to provide high data rates for users with high quality of service requirements (QoS), while high power macro base stations (BSs) are deployed for coverage maintenance and low QoS users support. However, the inter-tier interference between the macro BS and RRHs and energy efficiency are critical challenges that accompany resource allocation in H-CRAN. Therefore, we propose a centralized resource allocation scheme using online learning, which guarantees interference mitigation and maximizes energy efficiency while maintaining QoS requirements for all users. To foster the performance of such scheme with a model-free learning, we consider users\\' priority in resource blocks (RBs) allocation and compact state representation based learning methodology to enhance the learning process. Simulation results confirm that the proposed resource allocation solution can mitigate interference, increase energy and spectral efficiencies significantly, and maintain users\\' QoS requirements.

ALLOCATION OF FINANCIAL RESOURCE TO ENHANCE ...

African Journals Online (AJOL)

GRACE

This study examines the allocation of financial resource to the education industry and ..... This should check all books of account at least once a month to reconcile ... All cash advance request must be supported with relevant documents vii.

Questions of quality in repositories of open educational resources: a literature review

Directory of Open Access Journals (Sweden)

Javiera Atenas

2014-07-01

Full Text Available Open educational resources (OER are teaching and learning materials which are freely available and openly licensed. Repositories of OER (ROER are platforms that host and facilitate access to these resources. ROER should not just be designed to store this content – in keeping with the aims of the OER movement, they should support educators in embracing open educational practices (OEP such as searching for and retrieving content that they will reuse, adapt or modify as needed, without economic barriers or copyright restrictions. This paper reviews key literature on OER and ROER, in order to understand the roles ROER are said or supposed to fulfil in relation to furthering the aims of the OER movement. Four themes which should shape repository design are identified, and the following 10 quality indicators (QI for ROER effectiveness are discussed: featured resources; user evaluation tools; peer review; authorship of the resources; keywords of the resources; use of standardised metadata; multilingualism of the repositories; inclusion of social media tools; specification of the creative commons license; availability of the source code or original files. These QI form the basis of a method for the evaluation of ROER initiatives which, in concert with considerations of achievability and long-term sustainability, should assist in enhancement and development.

Contact Resistance Reduction of ZnO Thin Film Transistors (TFTs) with Saw-Shaped Electrode

KAUST Repository

Park, Woojin

2018-05-15

We report a saw-shaped electrode architecture ZnO thin film transistor (TFT) for effectively increase channel width. Such a saw-shaped electrode has ~2 times longer contact line at the contact metal/ZnO channel junction. We experimentally observed an enhancement in the output drive current by 50% and reduction in the contact resistance by over 50%, when compared to a typical shaped electrode ZnO TFT consuming the same chip area. This performance enhancement is attributed to extension of channel width. This technique can contribute to device performance enhancement and especially reduction in the contact resistance which is a serious challenge.

Enhancing well-being at work: The role of emotion regulation skills as personal resources.

Science.gov (United States)

Buruck, Gabriele; Dörfel, Denise; Kugler, Joachim; Brom, Sarah Susanne

2016-10-01

Dealing with negative emotions is a crucial work demand, particularly for employees in health care. Job resources (e.g., autonomy, social support, or reward) but also personal resources (such as emotion regulation strategies) might reduce job stress and support well-being. Following this, the present study focused on strengthening emotion regulation as 1 way of dealing with high job demands. The aim of this study was to evaluate the impact of a standardized emotion regulation training (Affect Regulation Training [ART]; Berking, 2010) to improve emotion regulation skills and well-being of employees in elderly health care. Therefore, 96 elderly care workers filled out an established questionnaire of emotion regulation skills as well as a measure of well-being at pretreatment, posttreatment and at 6-month follow-up. The findings show that the ART fosters emotion regulation skills. In particularly, acceptance, tolerance, and modification of negative emotions was enhanced in the training groups in comparison to a control-group. Modification, meaning the ability to actively change emotions, improved even more over the follow-up-period. Simultaneously, well-being of participants increased over all measurement time points in the ART-group compared with the control-group. Additionally, the improvement in emotion regulation skills from pre to posttreatment was related to well-being at follow-up. In summary, our results support the ART as an effective intervention for dealing with negative emotions and to enhance well-being among employees in elderly care. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

Energy Technology Data Exchange (ETDEWEB)

Philippe, F.; Villette, B. [CEA, DAM, DIF, F-91297 Arpajon (France); Michel, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Petrasso, R. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Giraldez, E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; and others

2014-07-15

A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

Science.gov (United States)

Philippe, F.; Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Villette, B.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; Michel, P.; Frenje, J.; Gatu-Johnson, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Sorce, C.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

2014-07-01

A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

International Nuclear Information System (INIS)

Philippe, F.; Villette, B.; Michel, P.; Petrasso, R.; Stoeckl, C.; Giraldez, E.; Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.

2014-01-01

A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results

Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

Energy Technology Data Exchange (ETDEWEB)

Philippe, F. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Tassin, V. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Depierreux, S. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Gauthier, P. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Masson-Laborde, P. E. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Monteil, M. C. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Seytor, P. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Villette, B. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Lasinski, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, H. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ross, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Amendt, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doeppner, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hinkel, D. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wallace, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Michel, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Frenje, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Gatu-Johnson, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Li, C. K. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Petrasso, R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Glebov, V. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Sorce, C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Stoeckl, C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Nikroo, A. [General Atomics, San Diego, CA (United States); Giraldez, E. [General Atomics, San Diego, CA (United States)

2014-07-25

A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

The decomposition of deformation: New metrics to enhance shape analysis in medical imaging.

Science.gov (United States)

Varano, Valerio; Piras, Paolo; Gabriele, Stefano; Teresi, Luciano; Nardinocchi, Paola; Dryden, Ian L; Torromeo, Concetta; Puddu, Paolo E

2018-05-01

In landmarks-based Shape Analysis size is measured, in most cases, with Centroid Size. Changes in shape are decomposed in affine and non affine components. Furthermore the non affine component can be in turn decomposed in a series of local deformations (partial warps). If the extent of deformation between two shapes is small, the difference between Centroid Size and m-Volume increment is barely appreciable. In medical imaging applied to soft tissues bodies can undergo very large deformations, involving large changes in size. The cardiac example, analyzed in the present paper, shows changes in m-Volume that can reach the 60%. We show here that standard Geometric Morphometrics tools (landmarks, Thin Plate Spline, and related decomposition of the deformation) can be generalized to better describe the very large deformations of biological tissues, without losing a synthetic description. In particular, the classical decomposition of the space tangent to the shape space in affine and non affine components is enriched to include also the change in size, in order to give a complete description of the tangent space to the size-and-shape space. The proposed generalization is formulated by means of a new Riemannian metric describing the change in size as change in m-Volume rather than change in Centroid Size. This leads to a redefinition of some aspects of the Kendall's size-and-shape space without losing Kendall's original formulation. This new formulation is discussed by means of simulated examples using 2D and 3D platonic shapes as well as a real example from clinical 3D echocardiographic data. We demonstrate that our decomposition based approaches discriminate very effectively healthy subjects from patients affected by Hypertrophic Cardiomyopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

Human resources in innovation systems

DEFF Research Database (Denmark)

Nielsen, René Nesgaard

2007-01-01

Human resources in innovation systems: With focus on introduction of highly educated labour in small Danish firms This thesis has two purposes: (1) a ‘general' purpose to enhance our knowledge on the relationship between innovation, technological and organisational change, and human resources......, including knowledge and skills embodied in human resources, and (2) a more ‘specific' purpose to enhance our knowledge on introduction of highly educated labour, innovation, and upgrading changes in small Danish firms. Chapter 1 establishes the relevance of this research interest, and it also states...... stemming from human resources - such as insight, understanding, creativity, and action - are inherently important to all innovation processes. The chapter also suggests a tentative conceptual and analytical framework for studying human resources and their development within a system of innovation approach...

Shape anisotropy and hybridization enhanced magnetization in nanowires of Fe/MgO/Fe encapsulated in carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Aryee, Dennis [Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, MD 21005 (United States); Department of Physics and Engineering Physics, Morgan State University, Baltimore, MD 21251 (United States); Seifu, Dereje, E-mail: dereje.seifu@morgan.edu [Department of Physics and Engineering Physics, Morgan State University, Baltimore, MD 21251 (United States)

2017-05-01

Arrays of tunneling magnetoresistance (TMR) nanowires were synthesized for the first time by filling Fe/MgO/Fe inside vertically grown and substrate supported carbon nanotubes. The magnetic properties of nanowires and planar nanoscale thin films of Fe/MgO/Fe showed several similarities, such as two-fold magnetic symmetry and ratio of orbital moment to spin moment. Nanowires of Fe/MgO/Fe showed higher saturation magnetization by a factor of 2.7 compared to planar thin films of Fe/MgO/Fe at 1.5 kOe. The enhanced magnetic properties likely resulted from shape anisotropy of the nanowires and as well as the hybridization that occur between the π- electronic states of carbon and 3d-bands of the Fe-surface.

Shape-induced anisotropy in antiferromagnetic nanoparticles

International Nuclear Information System (INIS)

Gomonay, O.; Kondovych, S.; Loktev, V.

2014-01-01

High fraction of the surface atoms considerably enhances the influence of size and shape on the magnetic and electronic properties of nanoparticles. Shape effects in ferromagnetic nanoparticles are well understood and allow us to set and control the parameters of a sample that affect its magnetic anisotropy during production. In the present paper we study the shape effects in the other widely used magnetic materials – antiferromagnets, – which possess vanishingly small or zero macroscopic magnetization. We take into account the difference between the surface and bulk magnetic anisotropy of a nanoparticle and show that the effective magnetic anisotropy depends on the particle shape and crystallographic orientation of its faces. The corresponding shape-induced contribution to the magnetic anisotropy energy is proportional to the particle volume, depends on magnetostriction, and can cause formation of equilibrium domain structure. Crystallographic orientation of the nanoparticle surface determines the type of domain structure. The proposed model allows us to predict the magnetic properties of antiferromagnetic nanoparticles depending on their shape and treatment. - Highlights: • We demonstrate that the shape effects in antiferromagnetic nanoparticles stem from the difference of surface and bulk magnetic properties combined with strong magnetoelastic coupling. • We predict shape-induced anisotropy in antiferromagnetic particles with large aspect ratio. • We predict different types of domain structures depending on the orientation of the particle faces

Conflicts Over Water as a Resource

National Research Council Canada - National Science Library

Cooksey, James

2008-01-01

.... A specific element that operational planners must consider when assessing political and military objectives of belligerents, and how those objectives may shape military operations, is water as a natural resource...

2D double-layer-tube-shaped structure Bi2S3/ZnS heterojunction with enhanced photocatalytic activities

International Nuclear Information System (INIS)

Gao, Xiaoming; Wang, Zihang; Fu, Feng; Li, Xiang; Li, Wenhong

2015-01-01

Bi 2 S 3 /ZnS heterojunction with 2D double-layer-tube-shaped structures was prepared by the facile synthesis method. The corresponding relationship was obtained among loaded content to phase, morphology, and optical absorption property of Bi 2 S 3 /ZnS composite. The results shown that Bi 2 S 3 loaded could evidently change the crystallinity of ZnS, enhance the optical absorption ability for visible light of ZnS, and improve the morphologies and microstructure of ZnS. The photocatalytic activities of the Bi 2 S 3 /ZnS sample were evaluated for the photodegradation of phenol and desulfurization of thiophene under visible light irradiation. The results showed that Bi 2 S 3 loaded greatly improved the photocatalytic activity of ZnS, and the content of loaded Bi 2 S 3 had an impact on the catalytic activity of ZnS. Moreover, the mechanism of enhanced photocatalytic activity was also investigated by analysis of relative band positions of Bi 2 S 3 and ZnS, and photo-generated hole was main active radicals during photocatalytic oxidation process

2D double-layer-tube-shaped structure Bi2S3/ZnS heterojunction with enhanced photocatalytic activities

Science.gov (United States)

Gao, Xiaoming; Wang, Zihang; Fu, Feng; Li, Xiang; Li, Wenhong

2015-10-01

Bi2S3/ZnS heterojunction with 2D double-layer-tube-shaped structures was prepared by the facile synthesis method. The corresponding relationship was obtained among loaded content to phase, morphology, and optical absorption property of Bi2S3/ZnS composite. The results shown that Bi2S3 loaded could evidently change the crystallinity of ZnS, enhance the optical absorption ability for visible light of ZnS, and improve the morphologies and microstructure of ZnS. The photocatalytic activities of the Bi2S3/ZnS sample were evaluated for the photodegradation of phenol and desulfurization of thiophene under visible light irradiation. The results showed that Bi2S3 loaded greatly improved the photocatalytic activity of ZnS, and the content of loaded Bi2S3 had an impact on the catalytic activity of ZnS. Moreover, the mechanism of enhanced photocatalytic activity was also investigated by analysis of relative band positions of Bi2S3 and ZnS, and photo-generated hole was main active radicals during photocatalytic oxidation process.

Even-Odd Differences and Shape Deformation of Metal Clusters

OpenAIRE

Hidetoshi, Nishioka; Yoshio, Takahashi; Department of Physics, Konan University; Faculty of General Education, Yamagata University

1994-01-01

The relation between even-odd difference of metal cluster and the deformation of equilibrium shape is studied in terms of two different models; (i) tri-axially deformed harmonic oscillator model, (ii) rectangular box model. Having assumed the matter density ρ kept constant for different shapes of a cluster, we can determine the equilibrium shape both for the two models. The enhancement of HOMO-LUMO gap is obtained and it is ascribed to Jahn-Teller effect. Good agreement of the calculated resu...

Quality in Human Resource Practice

DEFF Research Database (Denmark)

Nielsen, Kjeld

Abstract: Quality in Human Resource Practice – a process perspective The purpose of this article is to establish criteria for what quality in human resource practice (HRP) actually means. The general thesis is that quality in human resource practices is shaped within social processes in the HRM...... areas (recruitment, training, work environment etc.). Initially the concept of quality is defined in general on the basis of selections from the HRM literature, and then related to human resource practice. The question posed in the article is then answered using examples from case studies of human...... resource practice in industrial and service-related work processes. The focus in these studies is directed at behavioural processes between managers and employees, especially at individual and group level. The conclusion is that quality in human resource practice can be considered to be a social process...

Web-Enhanced Instruction and Learning: Findings of a Short- and Long-Term Impact Study and Teacher Use of NASA Web Resources

Science.gov (United States)

McCarthy, Marianne C.; Grabowski, Barbara L.; Koszalka, Tiffany

2003-01-01

Over a three-year period, researchers and educators from the Pennsylvania State University (PSU), University Park, Pennsylvania, and the NASA Dryden Flight Research Center (DFRC), Edwards, California, worked together to analyze, develop, implement and evaluate materials and tools that enable teachers to use NASA Web resources effectively for teaching science, mathematics, technology and geography. Two conference publications and one technical paper have already been published as part of this educational research series on Web-based instruction and learning. This technical paper, Web-Enhanced Instruction and Learning: Findings of a Short- and Long-Term Impact Study, is the culminating report in this educational research series and is based on the final report submitted to NASA. This report describes the broad spectrum of data gathered from teachers about their experiences using NASA Web resources in the classroom. It also describes participating teachers responses and feedback about the use of the NASA Web-Enhanced Learning Environment Strategies reflection tool on their teaching practices. The reflection tool was designed to help teachers merge the vast array of NASA resources with the best teaching methods, taking into consideration grade levels, subject areas and teaching preferences. The teachers described their attitudes toward technology and innovation in the classroom and their experiences and perceptions as they attempted to integrate Web resources into science, mathematics, technology and geography instruction.

Enhancing Resources at the Workplace with Health-Promoting Leadership.

Science.gov (United States)

Jiménez, Paul; Bregenzer, Anita; Kallus, K Wolfgang; Fruhwirth, Bianca; Wagner-Hartl, Verena

2017-10-20

Leaders engaging in health-promoting leadership can influence their employees' health directly by showing health awareness or indirectly by changing working conditions. With health-promoting leadership, leaders are able to support a healthy working environment by providing resource-oriented working conditions for their employees to support their health. Changing working conditions in a health-supportive way can prevent possible negative consequences from critical working conditions (e.g., burnout risk). The present study examined the relationship between health-promoting leadership and the employees' resources, stress and burnout. To analyze our proposed model, structural equation modelling was conducted in two samples. The resulting model from the first sample of 228 Austrian workers was cross-validated and could be verified with the second sample (N = 263 Austrian workers). The results supported a model in which health-promoting leadership has a strong direct effect on the employees' resources and an indirect effect on stress and burnout, which was mediated by resources. The results indicate that health-promoting leadership describes the leaders' capability and dedication creating the right working conditions for their employees by increasing the employees' resources at the workplace. This in turn minimizes the risk of experiencing burnout.

Enhancing Resources at the Workplace with Health-Promoting Leadership

Directory of Open Access Journals (Sweden)

Paul Jiménez

2017-10-01

Full Text Available Leaders engaging in health-promoting leadership can influence their employees’ health directly by showing health awareness or indirectly by changing working conditions. With health-promoting leadership, leaders are able to support a healthy working environment by providing resource-oriented working conditions for their employees to support their health. Changing working conditions in a health-supportive way can prevent possible negative consequences from critical working conditions (e.g., burnout risk. The present study examined the relationship between health-promoting leadership and the employees’ resources, stress and burnout. To analyze our proposed model, structural equation modelling was conducted in two samples. The resulting model from the first sample of 228 Austrian workers was cross-validated and could be verified with the second sample (N = 263 Austrian workers. The results supported a model in which health-promoting leadership has a strong direct effect on the employees’ resources and an indirect effect on stress and burnout, which was mediated by resources. The results indicate that health-promoting leadership describes the leaders’ capability and dedication creating the right working conditions for their employees by increasing the employees’ resources at the workplace. This in turn minimizes the risk of experiencing burnout.

Entrepreneurship, transaction costs, and resource attributes

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

2006-01-01

transaction costs shape the process of entrepreneurial discovery. We provide a sketch of the mechanisms that link entrepreneurship, property rights, and transaction costs in a resource-based setting, contributing further to the attempt to take the RBV in a more dynamic direction.......This paper responds to Kim and Mahoney's "How Property Rights Economics Furthers the Resource-Based View: Resources, Transaction Costs and Entrepreneurial Discovery" (a comment on Foss and Foss, 2005). While we agree with many of their arguments, we argue that they fail to recognise how exactly...

Entrepreneurship, transaction costs, and resource attributes

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

2006-01-01

This paper responds to Kim and Mahoney's "How Property Rights Economics Furthers the Resource-Based View: Resources, Transaction Costs and Entrepreneurial Discovery" (a comment on Foss and Foss, 2005). While we agree with many of their arguments, we argue that they fail to recognise how exactly t...... transaction costs shape the process of entrepreneurial discovery. We provide a sketch of the mechanisms that link entrepreneurship, property rights, and transaction costs in a resource-based setting, contributing further to the attempt to take the RBV in a more dynamic direction....

Resource-enhancing group intervention against depression at workplace: who benefits? A randomised controlled study with a 7-month follow-up.

Science.gov (United States)

Ahola, Kirsi; Vuori, Jukka; Toppinen-Tanner, Salla; Mutanen, Pertti; Honkonen, Teija

2012-12-01

The aim of the present study was to investigate whether participation in a structured resource-enhancing group intervention at work would act as primary prevention against depression. The authors analysed whether the intervention resulted in universal, selected or indicated prevention. A total of 566 persons participated in a prospective, within-organisation, randomly assigned field experimental study, which consisted of 34 workshops in 17 organisations. The participants filled in a questionnaire, were randomly assigned to either intervention (n=296) or comparison (n=324) groups and returned another questionnaire 7 months later. The intervention, lasting four half-day sessions, was delivered by trainers from occupational health services and human resources. The aim of the structured programme was to enhance participants' career management preparedness by strengthening self-efficacy and inoculation against setbacks. The comparison group received a literature package. The authors measured depressive symptoms using the short version of the Beck Depression Inventory. A high number of depressive symptoms (over 9 points) were used as a proxy for depression. At follow-up, the odds of depression were lower in the intervention group (OR=0.40, 95% CI 0.19 to 0.85) than in the comparison group when adjusted for baseline depressive symptoms, job strain and socio-demographics. In addition, the odds of depression among those with job strain (OR=0.15, 95% CI 0.03-0.81) at baseline were lower after the intervention. The intervention had no statistically significant effect on those with depressive symptoms (over 4 points) at baseline. The resource-enhancing group intervention appeared to be successful as universal and selective prevention of potential depression.

Shape Memory Characteristics of Ti(sub 49.5)Ni(sub 25)Pd(sub 25)Sc(sub 0.5) High-Temperature Shape Memory Alloy After Severe Plastic Deformation

Science.gov (United States)

Atli, K. C.; Karaman, I.; Noebe, R. D.; Garg, A.; Chumlyakov, Y. I.; Kireeva, I. V.

2011-01-01

A Ti(49.5)Ni25Pd25Sc(0.5) high-temperature shape memory alloy is thermomechanically processed to obtain enhanced shape-memory characteristics: in particular, dimensional stability upon repeated thermal cycles under constant loads. This is accomplished using severe plastic deformation via equal channel angular extrusion (ECAE) and post-processing annealing heat treatments. The results of the thermomechanical experiments reveal that the processed materials display enhanced shape memory response, exhibiting higher recoverable transformation and reduced irrecoverable strain levels upon thermal cycling compared with the unprocessed material. This improvement is attributed to the increased strength and resistance of the material against defect generation upon phase transformation as a result of the microstructural refinement due to the ECAE process, as supported by the electron microscopy observations.

Automatic focusing of attention on object size and shape

Directory of Open Access Journals (Sweden)

Cesar Galera

2005-01-01

Full Text Available In two experiments we investigated the automatic adjusting of the attentional focus to simple geometric shapes. The participants performed a visual search task with four stimuli (the target and three distractors presented always around the fixation point, inside an outlined frame not related to the search task. A cue informed the subject only about the possible size and shape of the frame, not about the target. The results of the first experiment showed faster target detection in the valid cue trials, suggesting that attention was captured automatically by the cue shape. In the second experiment, we introduced a flanker stimulus (compatible or incompatible with the target in order to determine if attentional resources spread homogenously inside and outside the frame. The results showed that performance depended both on cue validity and frame orientation. The flanker effect was dependent on compatibility and flanker position (vertical or horizontal meridian. The results of both experiments suggest that the form of an irrelevant object can capture attention despite participants’ intention and the results of the second experiment suggest that the attentional resources are more concentrated along the horizontal meridian.

Shaping the Curriculum: The Power of a Library's Digital Resources

Science.gov (United States)

Kirkwood, Patricia

2011-01-01

Researchers were the first adopters of digital resources available through the library. Online journals and databases make finding research articles much easier than when this author started as a librarian more than 20 years ago. Speedier interlibrary loan due to digital delivery means research materials are never far away. Making it easier for…

The Future of Electricity Resource Planning

Energy Technology Data Exchange (ETDEWEB)

Kahrl, Fredrich [Energy and Environmental Economics, Inc., San Francisco, CA (United States); Mills, Andrew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lavin, Luke [Energy and Environmental Economics, Inc., San Francisco, CA (United States); Ryan, Nancy [Energy and Environmental Economics, Inc., San Francisco, CA (United States); Olsen, Arne [Energy and Environmental Economics, Inc., San Francisco, CA (United States); Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-09-14

Electricity resource planning is the process of identifying longer-term investments to meet electricity reliability requirements and public policy goals at a reasonable cost. Resource planning processes provide a forum for regulators, electric utilities, and electricity industry stakeholders to evaluate the economic, environmental, and social benefits and costs of different investment options. By facilitating a discussion on future goals, challenges and strategies, resource planning processes often play an important role in shaping utility business decisions. Resource planning emerged more than three decades ago in an era of transition, where declining electricity demand and rising costs spurred fundamental changes in electricity industry regulation and structure. Despite significant changes in the industry, resource planning continues to play an important role in supporting investment decision making. Over the next two decades, the electricity industry will again undergo a period of transition, driven by technological change, shifting customer preferences and public policy goals. This transition will bring about a gradual paradigm shift in resource planning, requiring changes in scope, approaches and methods. Even as it changes, resource planning will continue to be a central feature of the electricity industry. Its functions — ensuring the reliability of high voltage (“bulk”) power systems, enabling oversight of regulated utilities and facilitating low-cost compliance with public policy goals — are likely to grow in importance as the electricity industry enters a new period of technological, economic and regulatory change. This report examines the future of electricity resource planning in the context of a changing electricity industry. The report examines emerging issues and evolving practices in five key areas that will shape the future of resource planning: (1) central-scale generation, (2) distributed generation, (3) demand-side resources, (4

Gastropod shells: a dynamic resource that helps shape benthic community structure. [Calliactis tricolor; Pagurus pollicaris; Calappa flammea; Octopus joubini; Panulirus argus

Energy Technology Data Exchange (ETDEWEB)

McLean, R

1983-01-01

Empty gastropod shells are an important resource for many animals in shallow benthic marine communities. Shells provide shelter for hermit crabs, octopuses, and fishes, provide attachment substratum for hermit crab symbionts, and directly or indirectly modify hermit crab predation. Creation of an empty shell due to predation of one gastropod on another and acquisition of that shell by a hermit crab are two key events in the subsequent use of that shell. Shells of different gastropod species and the species of hermit crab acquiring them affect the symbiont complement that attaches to the shell, which in turn may affect future shell use by other symbionts. Certain shell types worn by the hermit crab, Pagurus pollicaris Say, are positively associated with the symbiotic sea anemone, Calliactis tricolor (Lesueur), which protects the hermit crab from predation by the crab, Calappa flammea (Herbst), and possibly from the octopus, Octopus joubini Robson. Shells of other species of gastropods are resistant to being crushed by the spiny lobster, Panulirus argus (Latreille). The inter- and intraspecific interactions centered on the gastropod shell are termed a ''habitat web.'' The potential of the shell to limit the size and distribution of animal populations demonstrates how this resource helps shape community structure.

Business groups' outward FDI: A managerial resources perspective

OpenAIRE

Tan, D C; Meyer, Klaus E

2010-01-01

Outward FDI strategies are driven by firms' resource endowments, which in turn are conditioned by their home environment. In emerging economies, thus, the pattern of outward FDI is shaped by local firms' idiosyncratic contexts and the resources that these firms developed to fit the contexts. This includes business groups, a dominant organizational form in many emerging economies, competing with context-bound resources. When they wish to transcend their home context, they need internationally ...

Experimental Comparison of Probabilistic Shaping Methods for Unrepeated Fiber Transmission

DEFF Research Database (Denmark)

Renner, Julian; Fehenberger, Tobias; Yankov, Metodi Plamenov

2017-01-01

This paper studies the impact of probabilistic shaping on effective signal-to-noise ratios (SNRs) and achievable information rates (AIRs) in a back-to-back configuration and in unrepeated nonlinear fiber transmissions. For back-to-back, various shaped quadrature amplitude modulation (QAM......) distributions are found to have the same implementation penalty as uniform input. By demonstrating in transmission experiments that shaped QAM input leads to lower effective SNR than uniform input at a fixed average launch power, we experimentally confirm that shaping enhances the fiber nonlinearities. However......, shaping is ultimately found to increase the AIR, which is the most relevant figure of merit as it is directly related to spectral efficiency. In a detailed study of these shaping gains for the nonlinear fiber channel, four strategies for optimizing QAM input distributions are evaluated and experimentally...

Ultrathin Shape Change Smart Materials.

Science.gov (United States)

Xu, Weinan; Kwok, Kam Sang; Gracias, David H

2018-02-20

With the discovery of graphene, significant research has focused on the synthesis, characterization, and applications of ultrathin materials. Graphene has also brought into focus other ultrathin materials composed of organics, polymers, inorganics, and their hybrids. Together, these ultrathin materials have unique properties of broad significance. For example, ultrathin materials have a large surface area and high flexibility which can enhance conformal contact in wearables and sensors leading to improved sensitivity. When porous, the short transverse diffusion length in these materials allows rapid mass transport. Alternatively, when impermeable, these materials behave as an ultrathin barrier. Such controlled permeability is critical in the design of encapsulation and drug delivery systems. Finally, ultrathin materials often feature defect-free and single-crystal-like two-dimensional atomic structures resulting in superior mechanical, optical, and electrical properties. A unique property of ultrathin materials is their low bending rigidity, which suggests that they could easily be bent, curved, or folded into 3D shapes. In this Account, we review the emerging field of 2D to 3D shape transformations of ultrathin materials. We broadly define ultrathin to include materials with a thickness below 100 nm and composed of a range of organic, inorganic, and hybrid compositions. This topic is important for both fundamental and applied reasons. Fundamentally, bending and curving of ultrathin films can cause atomistic and molecular strain which can alter their physical and chemical properties and lead to new 3D forms of matter which behave very differently from their planar precursors. Shape change can also lead to new 3D architectures with significantly smaller form factors. For example, 3D ultrathin materials would occupy a smaller space in on-chip devices or could permeate through tortuous media which is important for miniaturized robots and smart dust applications. Our

Digital Cadavers: Online 2D Learning Resources Enhance Student Learning in Practical Head and Neck Anatomy within Dental Programs

Directory of Open Access Journals (Sweden)

Mahmoud M. Bakr

2016-01-01

Full Text Available Head and neck anatomy provides core concepts within preclinical dental curricula. Increased student numbers, reduced curricula time, and restricted access to laboratory-based human resources have increased technology enhanced learning approaches to support student learning. Potential advantages include cost-effectiveness, off-campus access, and self-directed review or mastery opportunities for students. This study investigated successful student learning within a first-year head and neck anatomy course at the School of Dentistry and Oral Health, Griffith University, Australia, taught by the same teaching team, between 2010 and 2015. Student learning success was compared, for cohorts before and after implementation of a supplementary, purpose-designed online digital library and quiz bank. Success of these online resources was confirmed using overall students’ performance within the course assessment tasks and Student Evaluation of Course surveys and online access data. Engagement with these supplementary 2D online resources, targeted at improving laboratory study, was positively evaluated by students (mean 85% and significantly increased their laboratory grades (mean difference 6%, P<0.027, despite being assessed using cadaveric resources. Written assessments in final exams were not significantly improved. Expanded use of supplementary online resources is planned to support student learning and success in head and neck anatomy, given the success of this intervention.

Resource management for sustainable development : The application of a methodology to support resource management for the adequate application of Construction Systems to enhance sustainability in the lower income dwelling construction industry in Costa Rica

NARCIS (Netherlands)

Egmond - de Wilde De Ligny, van E.L.C.; Erkelens, P.A.; Jonge, de S.; Vliet, van A.A.M.

2000-01-01

This paper describes the results of the application of a methodology to support resource management for the enhancement of sustainability in the construction industry. Particular emphasis is given to the sustainability of manufacturing and application of construction systems for low income housing

ISOGEOMETRIC SHAPE OPTIMIZATION FOR ELECTROMAGNETIC SCATTERING PROBLEMS

DEFF Research Database (Denmark)

Nguyen, D. M.; Evgrafov, Anton; Gravesen, Jens

2012-01-01

We consider the benchmark problem of magnetic energy density enhancement in a small spatial region by varying the shape of two symmetric conducting scatterers. We view this problem as a prototype for a wide variety of geometric design problems in electromagnetic applications. Our approach...

Ductile shape memory alloys of the Cu-Al-Mn system

International Nuclear Information System (INIS)

Kainuma, R.; Takahashi, S.; Ishida, K.

1995-01-01

Cu-Al-Mn shape memory alloys with enhanced ductility have been developed by decreasing the degree of order in the β parent phase. Cu-Al-Mn alloys with Al contents lower than 18% exhibit good ductility with elongations of about 15% and excellent cold-workability arising from a lower degree of order in the Heusler (L21) β 1 parent phase, without any loss in their shape memory behavior. In this paper the mechanical and shape memory characteristics, such as the cold-workability, the Ms temperatures, the shape memory effect and the pseudo-elasticity of such ductile Cu-Al-Mn alloys are presented. (orig.)

Shape optimization and sensitivity of compliant beams for prescribed load-displacement response

NARCIS (Netherlands)

Radaelli, G.; Herder, J.L.

2016-01-01

This paper presents the shape optimization of a compliant beam for prescribed load-displacements response. The analysis of the design is based on the isogeometric analysis framework for an enhanced fidelity between designed and analysed shape. The sensitivities used for an improved optimization

[Application of job demands-resources model in research on relationships between job satisfaction, job resources, individual resources and job demands].

Science.gov (United States)

Potocka, Adrianna; Waszkowska, Małgorzata

2013-01-01

The aim of this study was to explore the relationships between job demands, job resourses, personal resourses and job satisfaction and to assess the usefulness of the Job Demands-Resources (JD-R) model in the explanation of these phenomena. The research was based on a sample of 500 social workers. The "Psychosocial Factors" and "Job satisfaction" questionnaires were used to test the hypothesis. The results showed that job satisfaction increased with increasing job accessibility and personal resources (r = 0.44; r = 0.31; p job resources and job demands [F(1.474) = 4.004; F(1.474) = 4.166; p job satisfaction. Moreover, interactions between job demands and job resources [F(3,474) = 2.748; p job demands and personal resources [F(3.474) = 3.021; p job satisfaction. The post hoc tests showed that 1) in low job demands, but high job resources employees declared higher job satisfaction, than those who perceived them as medium (p = 0.0001) or low (p = 0.0157); 2) when the level of job demands was perceived as medium, employees with high personal resources declared significantly higher job satisfaction than those with low personal resources (p = 0.0001). The JD-R model can be used to investigate job satisfaction. Taking into account fundamental factors of this model, in organizational management there are possibilities of shaping job satisfaction among employees.

Implementation of intra-cavity beam shaping technique to enhance pump efficiency

CSIR Research Space (South Africa)

Litvin, IA

2012-02-01

Full Text Available In this work the author proposes an implementation of a new intra-cavity beam shaping technique to vary the intensity distribution of the fundamental mode in a resonator cavity while maintaining a constant intensity distribution at the output...

Lead, zinc and copper fine powder with controlled size and shape

Directory of Open Access Journals (Sweden)

Mahmoud A Rabah

2017-12-01

Full Text Available This study describes the preparation of lead, zinc and copper powders by hydrometallurgy from secondary resources. Chloride, sulphate and acetate salts of zinc, copper and lead were prepared. The powders were prepared by reducing the ionic species of these metals by hydrazine hydrate or ascorbic acid. The effect of addition of some water soluble polar organic solvents to the aqueous salt solutions on the morphology and particle size of the prepared powder was studied. Findings were explained on the basis of the transition state theory and according to the Hughes and Ingold’s rule. Aqueous solutions alone produce metal powder having different size and irregular shape. The presence of polar organic solvents with high molecular weight and polarity produce powders having controlled size and regular morphology. The reason was because solvent polarity enhances the rate of red-ox reactions between metal ions and the reducing agent. The mean particle size of the powder was 60 um with zinc, 80 um with copper, and 90 um with lead. The extent of productivity was ≥98%. Results highlighted that the chemical reduction of the ionic species took place in a sequence steps. The first is a diffusion of the reactants across a boundary layer established at the polar site of the organic solvent molecules. The next step is the direct contact of the reactants. The third step involved reduction to yield powder. The last is the backward diffusion of the powder outside the boundary layer. Results showed that addition of water-miscible solvents having high dielectric constant increased the polarity of the medium. This energizes and enhances the one or more t step of the model to be more rapid to yield particles with small size and symmetrical shape.

Yield impact for wafer shape misregistration-based binning for overlay APC diagnostic enhancement

Science.gov (United States)

Jayez, David; Jock, Kevin; Zhou, Yue; Govindarajulu, Venugopal; Zhang, Zhen; Anis, Fatima; Tijiwa-Birk, Felipe; Agarwal, Shivam

2018-03-01

The importance of traditionally acceptable sources of variation has started to become more critical as semiconductor technologies continue to push into smaller technology nodes. New metrology techniques are needed to pursue the process uniformity requirements needed for controllable lithography. Process control for lithography has the advantage of being able to adjust for cross-wafer variability, but this requires that all processes are close in matching between process tools/chambers for each process. When this is not the case, the cumulative line variability creates identifiable groups of wafers1 . This cumulative shape based effect is described as impacting overlay measurements and alignment by creating misregistration of the overlay marks. It is necessary to understand what requirements might go into developing a high volume manufacturing approach which leverages this grouping methodology, the key inputs and outputs, and what can be extracted from such an approach. It will be shown that this line variability can be quantified into a loss of electrical yield primarily at the edge of the wafer and proposes a methodology for root cause identification and improvement. This paper will cover the concept of wafer shape based grouping as a diagnostic tool for overlay control and containment, the challenges in implementing this in a manufacturing setting, and the limitations of this approach. This will be accomplished by showing that there are identifiable wafer shape based signatures. These shape based wafer signatures will be shown to be correlated to overlay misregistration, primarily at the edge. It will also be shown that by adjusting for this wafer shape signal, improvements can be made to both overlay as well as electrical yield. These improvements show an increase in edge yield, and a reduction in yield variability.

Porous-shaped silicon carbide ultraviolet photodetectors on porous silicon substrates

Energy Technology Data Exchange (ETDEWEB)

Naderi, N., E-mail: naderi.phd@gmail.com [Nano-Optoelectronics Research Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Hashim, M.R. [Nano-Optoelectronics Research Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

2013-03-05

Highlights: ► Porous-shaped silicon carbide thin film was deposited on porous silicon substrate. ► Thermal annealing was followed to enhance the physical properties of samples. ► Metal–semiconductor-metal ultraviolet detectors were fabricated on samples. ► The effect of annealing temperature on electrical performance of devices was studied. ► The efficiency of photodetectors was enhanced by annealing at elevated temperatures. -- Abstract: A metal–semiconductor-metal (MSM) ultraviolet photodetector was fabricated based on a porous-shaped structure of silicon carbide (SiC). For increasing the surface roughness of SiC and hence enhancing the light absorption effect in fabricated devices, porous silicon (PS) was chosen as a template; SiC was deposited on PS substrates via radio frequency magnetron sputtering. Therefore, the deposited layers followed the structural pattern of PS skeleton and formed a porous-shaped SiC layer on PS substrate. The structural properties of samples showed that the as-deposited SiC was amorphous. Thus, a post-deposition annealing process with elevated temperatures was required to convert its amorphous phase to crystalline phase. The morphology of the sputtered samples was examined via scanning electron and atomic force microscopies. The grain size and roughness of the deposited layers clearly increased upon an increase in the annealing temperature. The optical properties of sputtered SiC were enhanced due to applying high temperatures. The most intense photoluminescence peak was observed for the sample with 1200 °C of annealing temperature. For the metallization of the SiC substrates to fabricate MSM photodetectors, two interdigitated Schottky contacts of Ni with four fingers for each electrode were deposited onto all the porous substrates. The optoelectronic characteristics of MSM UV photodetectors with porous-shaped SiC substrates were studied in the dark and under UV illumination. The electrical characteristics of fabricated

Porous-shaped silicon carbide ultraviolet photodetectors on porous silicon substrates

International Nuclear Information System (INIS)

Naderi, N.; Hashim, M.R.

2013-01-01

Highlights: ► Porous-shaped silicon carbide thin film was deposited on porous silicon substrate. ► Thermal annealing was followed to enhance the physical properties of samples. ► Metal–semiconductor-metal ultraviolet detectors were fabricated on samples. ► The effect of annealing temperature on electrical performance of devices was studied. ► The efficiency of photodetectors was enhanced by annealing at elevated temperatures. -- Abstract: A metal–semiconductor-metal (MSM) ultraviolet photodetector was fabricated based on a porous-shaped structure of silicon carbide (SiC). For increasing the surface roughness of SiC and hence enhancing the light absorption effect in fabricated devices, porous silicon (PS) was chosen as a template; SiC was deposited on PS substrates via radio frequency magnetron sputtering. Therefore, the deposited layers followed the structural pattern of PS skeleton and formed a porous-shaped SiC layer on PS substrate. The structural properties of samples showed that the as-deposited SiC was amorphous. Thus, a post-deposition annealing process with elevated temperatures was required to convert its amorphous phase to crystalline phase. The morphology of the sputtered samples was examined via scanning electron and atomic force microscopies. The grain size and roughness of the deposited layers clearly increased upon an increase in the annealing temperature. The optical properties of sputtered SiC were enhanced due to applying high temperatures. The most intense photoluminescence peak was observed for the sample with 1200 °C of annealing temperature. For the metallization of the SiC substrates to fabricate MSM photodetectors, two interdigitated Schottky contacts of Ni with four fingers for each electrode were deposited onto all the porous substrates. The optoelectronic characteristics of MSM UV photodetectors with porous-shaped SiC substrates were studied in the dark and under UV illumination. The electrical characteristics of fabricated

Power, Conflict and Natural Resources

DEFF Research Database (Denmark)

Jaime Macuane, José; Buur, Lars; Monjane, Celso Marcos

2017-01-01

This article explores how the present socio-economic crisis in Mozambique is linked to the prospects of natural resource windfalls for the country. Drawing on the political settlement approach, it explores how the distribution of power both within and outside the ruling elite is structured...... and consequently how the underlying political processes have been shaped by the expectations of natural resource windfalls. The article argues that the present socio-economic crisis in Mozambique is not due to national resource assets in themselves. Instead, the political and economic downturn in Mozambique should...... be understood as a manifestation of how the political settlement has been organized and rent mobilization controlled by the ruling elite. To understand how the prospect of rents from natural resource sectors have influenced the political settlement, we have argued that one has to look at the dynamics of power...

Enhanced Resource Descriptions Help Learning Matrix Users.

Science.gov (United States)

Roempler, Kimberly S.

2003-01-01

Describes the Learning Matrix digital library which focuses on improving the preparation of math and science teachers by supporting faculty who teach introductory math and science courses in two- and four-year colleges. Suggests it is a valuable resource for school library media specialists to support new science and math teachers. (LRW)

Developing theological tools for a strategic engagement with Human Enhancement.

Science.gov (United States)

Tomkins, Justin

2014-01-01

The literature on Human Enhancement may indeed have reached a critical mass yet theological engagement with the subject is still thin. Human Enhancement has already been established as a key topic within research and captivating visions of the future have been allied with a depth of philosophical analysis. Some Transhumanists have pointed to a theological dimension to their position and some who have warned against enhancement might be seen as having done so from a perspective shaped by a Judeo-Christian worldview. Nonetheless, in neither of these cases has theology been central to engagement with the enhancement quest.Christian theologians who have begun to open up such an engagement with Human Enhancement include Brent Waters, Robert Song and Celia Deane-Drummond. The work they have already carried out is insightful and important yet due to the scale of the possible engagement, the wealth of Christian theology which might be applied to Human Enhancement remains largely untapped. This paper explores how three key aspects of Christian theology, eschatology, love of God and love of neighbour, provide valuable tools for a theological engagement with Human Enhancement. It is proposed that such theological tools need to be applied to Human Enhancement if the debate is to be resourced with the Christian theological perspective of what it means to be human in our contemporary technological context and if society is to have the choice of maintaining its Christian foundations.

EPA Participates in Energy Roundtable with States, Tribes, Businesses and Environmental Groups to Enhance Coordination and Promote Responsible Domestic Production of Oil and Gas Resources

Science.gov (United States)

EPA News Release: EPA Participates in Energy Roundtable with States, Tribes, Businesses and Environmental Groups to Enhance Coordination and Promote Responsible Domestic Production of Oil and Gas Resources

When are stakeholder pressures effective? An extension of slack resources theory

NARCIS (Netherlands)

Xiao, Chengyong; Wang, Qian; van Donk, Dirk Pieter; van der Vaart, T.

There has been an intense debate on when stakeholder pressures are effective in driving firms to contribute to sustainable development. Drawing upon institutional theory and slack resources theory, we theorize that country-level sustainability performance interacts with slack resources in shaping

A New Artificial Neural Network Enhanced by the Shuffled Complex Evolution Optimization with Principal Component Analysis (SP-UCI) for Water Resources Management

Science.gov (United States)

Hayatbini, N.; Faridzad, M.; Yang, T.; Akbari Asanjan, A.; Gao, X.; Sorooshian, S.

2016-12-01

The Artificial Neural Networks (ANNs) are useful in many fields, including water resources engineering and management. However, due to the non-linear and chaotic characteristics associated with natural processes and human decision making, the use of ANNs in real-world applications is still limited, and its performance needs to be further improved for a broader practical use. The commonly used Back-Propagation (BP) scheme and gradient-based optimization in training the ANNs have already found to be problematic in some cases. The BP scheme and gradient-based optimization methods are associated with the risk of premature convergence, stuck in local optimums, and the searching is highly dependent on initial conditions. Therefore, as an alternative to BP and gradient-based searching scheme, we propose an effective and efficient global searching method, termed the Shuffled Complex Evolutionary Global optimization algorithm with Principal Component Analysis (SP-UCI), to train the ANN connectivity weights. Large number of real-world datasets are tested with the SP-UCI-based ANN, as well as various popular Evolutionary Algorithms (EAs)-enhanced ANNs, i.e., Particle Swarm Optimization (PSO)-, Genetic Algorithm (GA)-, Simulated Annealing (SA)-, and Differential Evolution (DE)-enhanced ANNs. Results show that SP-UCI-enhanced ANN is generally superior over other EA-enhanced ANNs with regard to the convergence and computational performance. In addition, we carried out a case study for hydropower scheduling in the Trinity Lake in the western U.S. In this case study, multiple climate indices are used as predictors for the SP-UCI-enhanced ANN. The reservoir inflows and hydropower releases are predicted up to sub-seasonal to seasonal scale. Results show that SP-UCI-enhanced ANN is able to achieve better statistics than other EAs-based ANN, which implies the usefulness and powerfulness of proposed SP-UCI-enhanced ANN for reservoir operation, water resources engineering and management

3D shape decomposition and comparison for gallbladder modeling

Science.gov (United States)

Huang, Weimin; Zhou, Jiayin; Liu, Jiang; Zhang, Jing; Yang, Tao; Su, Yi; Law, Gim Han; Chui, Chee Kong; Chang, Stephen

2011-03-01

This paper presents an approach to gallbladder shape comparison by using 3D shape modeling and decomposition. The gallbladder models can be used for shape anomaly analysis and model comparison and selection in image guided robotic surgical training, especially for laparoscopic cholecystectomy simulation. The 3D shape of a gallbladder is first represented as a surface model, reconstructed from the contours segmented in CT data by a scheme of propagation based voxel learning and classification. To better extract the shape feature, the surface mesh is further down-sampled by a decimation filter and smoothed by a Taubin algorithm, followed by applying an advancing front algorithm to further enhance the regularity of the mesh. Multi-scale curvatures are then computed on the regularized mesh for the robust saliency landmark localization on the surface. The shape decomposition is proposed based on the saliency landmarks and the concavity, measured by the distance from the surface point to the convex hull. With a given tolerance the 3D shape can be decomposed and represented as 3D ellipsoids, which reveal the shape topology and anomaly of a gallbladder. The features based on the decomposed shape model are proposed for gallbladder shape comparison, which can be used for new model selection. We have collected 19 sets of abdominal CT scan data with gallbladders, some shown in normal shape and some in abnormal shapes. The experiments have shown that the decomposed shapes reveal important topology features.

Stuff- The Materials that Shape our World - Experimental Learning Opportunities

Energy Technology Data Exchange (ETDEWEB)

Rosenstein, Pam

2012-04-30

Making Stuff is a four-part series that explores how materials changed history and are shaping the future. To further enhance public engagement in and understanding of materials science, the project convened an extensive network of community coalitions across the country that hosted Making Stuff outreach activities and events, science cafes, and educator workshops in their local areas. Department Of Energy funding enabled us to increase the number of communities formally involved in the project, from 10 to 20 community hubs. Department of Energy funding also made it possible to develop a collection of materials science resources, activities and hands-on demonstrations for use in a variety of formal and informal settings, and Making Stuff activities were presented at science conferences and festivals around the country. The design, printing and national dissemination of the Making Stuff afterschool activity guide were also developed with DOE funding, as well as professional webinar trainings for scientists and educators to help facilitate many of the community activities and other online and print materials. Thanks to additional funding from the Department of Energy, we were able to expand the reach and scope of the project's outreach plan, specifically in the areas of: 1) content development, 2) training/professional development, 3) educational activities and 4) community partnerships. This report documents how the following DOE project goals were met: (1) Train scientists and provide teachers and informal educators with resources to engage youth with age appropriate information about materials science; (2) Provide activities and resources to five selected communities with ties to DOE researchers; (3) Increase interest in STEM.

Entrepreneurship, Transaction Costs, and Resource Attributes

DEFF Research Database (Denmark)

Foss, Kirsten; Foss, Nicolai Juul

transaction costs and property rights shape the process of entrepreneurial discovery. We provide a sketch of the mechanisms that link entrepreneurship, property rights, and transaction costs in a resource-based setting, contributing further to the attempt to take the RBV in a more dynamic direction....

Laser beam welding of titanium nitride coated titanium using pulse-shaping

Directory of Open Access Journals (Sweden)

Milton Sergio Fernandes de Lima

2005-09-01

Full Text Available A new welding method which allows the assembly of two titanium nitride coated titanium parts is proposed. The welding procedure utilizes the possibility for pulse-shaping in order to change the energy distribution profile during the laser pulse. The pulse-shaping is composed of three elements: a a short high power pulse for partial ablation at the surface; b a long pulse for thermal penetration; and c a quenching slope for enhanced weldability. The combination of these three elements produces crack-free welds. The weld microstructure is changed in comparison to normal welding, i.e. with a rectangular pulse, as the nitrogen and the microhardness are more homogenously distributed in the weld under pulse-shaping conditions. This laser pulse dissolves the TiN layer and allows nitrogen to diffuse into the melt pool, also contributing to an enhanced weldability by providing suitable thermal conditions.

Enhanced optical transmission through a star-shaped bull's eye at dual resonant-bands in UV and the visible spectral range.

Science.gov (United States)

Nazari, Tavakol; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Kong, Byung-Joo; Oh, Kyunghwan

2015-07-13

Dual resonant bands in UV and the visible range were simultaneously observed in the enhanced optical transmission (EOT) through star-shaped plasmonic structures. EOTs through four types of polygonal bull's eyes with a star aperture surrounded by the concentric star grooves were analyzed and compared for 3, 4, 5, and 6 corners, using finite difference time domain (FDTD) method. In contrast to plasmonic resonances in the visible range, the UV-band resonance intensity was found to scale with the number of corners, which is related with higher order multipole interactions. Spectral positions and relative intensities of the dual resonances were analyzed parametrically to find optimal conditions to maximize EOT in UV-visible dual bands.

Lunar resource base

Science.gov (United States)

Pulley, John; Wise, Todd K.; Roy, Claude; Richter, Phil

A lunar base that exploits local resources to enhance the productivity of a total SEI scenario is discussed. The goals were to emphasize lunar science and to land men on Mars in 2016 using significant amounts of lunar resources. It was assumed that propulsion was chemical and the surface power was non-nuclear. Three phases of the base build-up are outlined, the robotic emplacement of the first elements is detailed and a discussion of future options is included.

How river rocks round: resolving the shape-size paradox.

Directory of Open Access Journals (Sweden)

Gabor Domokos

Full Text Available River-bed sediments display two universal downstream trends: fining, in which particle size decreases; and rounding, where pebble shapes evolve toward ellipsoids. Rounding is known to result from transport-induced abrasion; however many researchers argue that the contribution of abrasion to downstream fining is negligible. This presents a paradox: downstream shape change indicates substantial abrasion, while size change apparently rules it out. Here we use laboratory experiments and numerical modeling to show quantitatively that pebble abrasion is a curvature-driven flow problem. As a consequence, abrasion occurs in two well-separated phases: first, pebble edges rapidly round without any change in axis dimensions until the shape becomes entirely convex; and second, axis dimensions are then slowly reduced while the particle remains convex. Explicit study of pebble shape evolution helps resolve the shape-size paradox by reconciling discrepancies between laboratory and field studies, and enhances our ability to decipher the transport history of a river rock.

Enhanced cognitive Radio Resource Management for LTE systems

KAUST Repository

Alqerm, Ismail; Shihada, Basem; Shin, Kang G.

2013-01-01

as it improves network efficiency by exploiting radio environment information, intelligent optimization algorithms to configure transmission parameters, and mitigate interference. In this paper, we propose a cognitive resource management scheme to adapt LTE

Climate change adaptation among Tibetan pastoralists: challenges in enhancing local adaptation through policy support.

Science.gov (United States)

Fu, Yao; Grumbine, R Edward; Wilkes, Andreas; Wang, Yun; Xu, Jian-Chu; Yang, Yong-Ping

2012-10-01

While researchers are aware that a mix of Local Ecological Knowledge (LEK), community-based resource management institutions, and higher-level institutions and policies can facilitate pastoralists' adaptation to climate change, policy makers have been slow to understand these linkages. Two critical issues are to what extent these factors play a role, and how to enhance local adaptation through government support. We investigated these issues through a case study of two pastoral communities on the Tibetan Plateau in China employing an analytical framework to understand local climate adaptation processes. We concluded that LEK and community-based institutions improve adaptation outcomes for Tibetan pastoralists through shaping and mobilizing resource availability to reduce risks. Higher-level institutions and policies contribute by providing resources from outside communities. There are dynamic interrelationships among these factors that can lead to support, conflict, and fragmentation. Government policy could enhance local adaptation through improvement of supportive relationships among these factors. While central government policies allow only limited room for overt integration of local knowledge/institutions, local governments often have some flexibility to buffer conflicts. In addition, government policies to support market-based economic development have greatly benefited adaptation outcomes for pastoralists. Overall, in China, there are still questions over how to create innovative institutions that blend LEK and community-based institutions with government policy making.

H-shaped supra-amphiphiles based on a dynamic covalent bond.

Science.gov (United States)

Wang, Guangtong; Wang, Chao; Wang, Zhiqiang; Zhang, Xi

2012-10-16

The imine bond, a kind of dynamic covalent bond, is used to bind two bolaform amphiphiles together with spacers, yielding H-shaped supra-amphiphiles. Micellar aggregates formed by the self-assembly of the H-shaped supra-amphiphiles are observed. When pH is tuned down from basic to slightly acidic, the benzoic imine bond can be hydrolyzed, leading to the dissociation of H-shaped supra-amphiphiles. Moreover, H-shaped supra-amphiphiles have a lower critical micelle concentration than their building blocks, which is very helpful in enhancing the stability of the benzoic imine bond being hydrolyzed by acid. The surface tension isotherms of the H-shaped supra-amphiphiles with different spacers indicate their twisty conformation at a gas-water interface. The study of H-shaped supra-amphiphiles can enrich the family of amphiphiles, and moreover, the pH-responsiveness may make them apply to controlled or targetable drug delivery in a biological environment.

Coupling and power transfer efficiency enhancement of modular and array of planar coils using in-plane ring-shaped inner ferrites for inductive heating applications

Science.gov (United States)

Kilic, V. T.; Unal, E.; Demir, H. V.

2017-07-01

We propose and demonstrate a highly effective method of enhancing coupling and power transfer efficiency in inductive heating systems composed of planar coils. The proposed method is based on locating ring-shaped ferrites in the inner side of the coils in the same plane. Measurement results of simple inductive heating systems constructed with either a single or a pair of conventional circular coils show that, with the in-plane inner ferrites, the total dissipated power of the system is increased by over 65%. Also, with three-dimensional full electromagnetic solutions, it is found that power transfer efficiency of the system is increased up to 92% with the inner ferrite placement. The proposed method is promising to be used for efficiency enhancement in inductive heating applications, especially in all-surface induction hobs.

Hardware-Efficient Design of Real-Time Profile Shape Matching Stereo Vision Algorithm on FPGA

Directory of Open Access Journals (Sweden)

Beau Tippetts

2014-01-01

Full Text Available A variety of platforms, such as micro-unmanned vehicles, are limited in the amount of computational hardware they can support due to weight and power constraints. An efficient stereo vision algorithm implemented on an FPGA would be able to minimize payload and power consumption in microunmanned vehicles, while providing 3D information and still leaving computational resources available for other processing tasks. This work presents a hardware design of the efficient profile shape matching stereo vision algorithm. Hardware resource usage is presented for the targeted micro-UV platform, Helio-copter, that uses the Xilinx Virtex 4 FX60 FPGA. Less than a fifth of the resources on this FGPA were used to produce dense disparity maps for image sizes up to 450 × 375, with the ability to scale up easily by increasing BRAM usage. A comparison is given of accuracy, speed performance, and resource usage of a census transform-based stereo vision FPGA implementation by Jin et al. Results show that the profile shape matching algorithm is an efficient real-time stereo vision algorithm for hardware implementation for resource limited systems such as microunmanned vehicles.

Resources that promote positive youth development

Directory of Open Access Journals (Sweden)

Martha Frías Armenta

2016-12-01

Full Text Available Adolescence is a crucial developmental phase that shapes people´s futures. Positive psychology investigates the variables that promote the optimal development of human beings. It recognizes that all children and adolescents have strengths that will develop once these strengths match the resources needed to achieve this in the various settings in which they live. The aim of this study was to analyze from a multidisciplinary perspective (e.g. psychological, sociological, and economic the effect of resources that promote positive youth development. The sample consisted of 200 middle school students (15 to 19 years. EQS statistical software was used to analyse a structural equation model in which the study variables comprised 4 factors: one for each resource (economic, psychological, sociological, and one for positive youth development. The results showed a direct association between psychological and social resources and positive development, and between social resources and psychological assets. However, no association was found between economic resources and positive youth development. These results suggest that the main influences on positive youth development are psychological and social resources.

Mutual Coupling Reduction of E-Shaped MIMO Antenna with Matrix of C-Shaped Resonators

Directory of Open Access Journals (Sweden)

Raghad Ghalib Saadallah Alsultan

2018-01-01

Full Text Available E-shaped multiple-input-multiple-output (MIMO microstrip antenna systems operating in WLAN and WiMAX bands (between 5 and 7.5 GHz are proposed with enhanced isolation features. The systems are comprised of two antennas that are placed parallel and orthogonal to each other, respectively. According to the simulation results, the operating frequency of the MIMO antenna system is 6.3 GHz, and mutual coupling is below −18 dB in a parallel arrangement, whereas they are 6.4 GHz and −25 dB, respectively, in the orthogonal arrangement. The 2 × 3 matrix of C-shaped resonator (CSR is proposed and placed between the antenna elements over the substrate, to reduce the mutual coupling and enhance the isolation between the antennas. More than 30 dB isolation between the array elements is achieved at the resonant frequency for both of the configurations. The essential parameters of the MIMO array such as mutual coupling, surface current distribution, envelop correlation coefficient (ECC, diversity gain (DG, and the total efficiency have been simulated to verify the reliability and the validity of the MIMO system in both parallel and orthogonal configurations. The experimental results are also provided and compared for the mutual coupling with simulated results. An adequate match between the measured and simulated results is achieved.

Modeling students’ instrumental (mis-) use of substances to enhance cognitive performance: Neuroenhancement in the light of job demands-resources theory

Science.gov (United States)

2014-01-01

Background Healthy university students have been shown to use psychoactive substances, expecting them to be functional means for enhancing their cognitive capacity, sometimes over and above an essentially proficient level. This behavior called Neuroenhancement (NE) has not yet been integrated into a behavioral theory that is able to predict performance. Job Demands Resources (JD-R) Theory for example assumes that strain (e.g. burnout) will occur and influence performance when job demands are high and job resources are limited at the same time. The aim of this study is to investigate whether or not university students’ self-reported NE can be integrated into JD-R Theory’s comprehensive approach to psychological health and performance. Methods 1,007 students (23.56 ± 3.83 years old, 637 female) participated in an online survey. Lifestyle drug, prescription drug, and illicit substance NE together with the complete set of JD-R variables (demands, burnout, resources, motivation, and performance) were measured. Path models were used in order to test our data’s fit to hypothesized main effects and interactions. Results JD-R Theory could successfully be applied to describe the situation of university students. NE was mainly associated with the JD-R Theory’s health impairment process: Lifestyle drug NE (p model NE as a means to reach an end (i.e. performance enhancement) rather than a target behavior itself. This is necessary to provide a deeper understanding of the behavioral roots and consequences of the phenomenon. PMID:24904687

Histological image classification using biologically interpretable shape-based features

International Nuclear Information System (INIS)

Kothari, Sonal; Phan, John H; Young, Andrew N; Wang, May D

2013-01-01

Automatic cancer diagnostic systems based on histological image classification are important for improving therapeutic decisions. Previous studies propose textural and morphological features for such systems. These features capture patterns in histological images that are useful for both cancer grading and subtyping. However, because many of these features lack a clear biological interpretation, pathologists may be reluctant to adopt these features for clinical diagnosis. We examine the utility of biologically interpretable shape-based features for classification of histological renal tumor images. Using Fourier shape descriptors, we extract shape-based features that capture the distribution of stain-enhanced cellular and tissue structures in each image and evaluate these features using a multi-class prediction model. We compare the predictive performance of the shape-based diagnostic model to that of traditional models, i.e., using textural, morphological and topological features. The shape-based model, with an average accuracy of 77%, outperforms or complements traditional models. We identify the most informative shapes for each renal tumor subtype from the top-selected features. Results suggest that these shapes are not only accurate diagnostic features, but also correlate with known biological characteristics of renal tumors. Shape-based analysis of histological renal tumor images accurately classifies disease subtypes and reveals biologically insightful discriminatory features. This method for shape-based analysis can be extended to other histological datasets to aid pathologists in diagnostic and therapeutic decisions

Resource availability and competition shape the evolution of survival and growth ability in a bacterial community.

Directory of Open Access Journals (Sweden)

Minna Pekkonen

Full Text Available Resource availability is one of the main factors determining the ecological dynamics of populations or species. Fluctuations in resource availability can increase or decrease the intensity of resource competition. Resource availability and competition can also cause evolutionary changes in life-history traits. We studied how community structure and resource fluctuations affect the evolution of fitness related traits using a two-species bacterial model system. Replicated populations of Serratia marcescens (copiotroph and Novosphingobium capsulatum (oligotroph were reared alone or together in environments with intergenerational, pulsed resource renewal. The comparison of ancestral and evolved bacterial clones with 1 or 13 weeks history in pulsed resource environment revealed species-specific changes in life-history traits. Co-evolution with S. marcescens caused N. capsulatum clones to grow faster. The evolved S. marcescens clones had higher survival and slower growth rate then their ancestor. The survival increased in all treatments after one week, and thereafter continued to increase only in the S. marcescens monocultures that experienced large resource pulses. Though adaptive radiation is often reported in evolution studies with bacteria, clonal variation increased only in N. capsulatum growth rate. Our results suggest that S. marcescens adapted to the resource renewal cycle whereas N. capsulatum was more affected by the interspecific competition. Our results exemplify species-specific evolutionary response to both competition and environmental variation.

SHAPE selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data

DEFF Research Database (Denmark)

Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R

2015-01-01

transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES...

ElectroAcoustic Resource Site (EARS)

OpenAIRE

Atkinson, Simon; Landy, Leigh

2002-01-01

Central to the MTIRC’s electroacoustic music studies focus, EARS is supported by the AHRC’s resource enhancement scheme (ca. £170k) and Unesco (£3k). Beyond its initial goal to create the glossary (~500 entries) and related index (providing a coherent hyperlink structure for the bibliography – ~3000 entries) there are further methodological research imperatives – to offer a web-based resource that: a) Realises an accessible research resource (glossary, keyword index and bibliography) to co...

Resource Disambiguator for the Web: Extracting Biomedical Resources and Their Citations from the Scientific Literature.

Directory of Open Access Journals (Sweden)

Ibrahim Burak Ozyurt

Full Text Available The NIF Registry developed and maintained by the Neuroscience Information Framework is a cooperative project aimed at cataloging research resources, e.g., software tools, databases and tissue banks, funded largely by governments and available as tools to research scientists. Although originally conceived for neuroscience, the NIF Registry has over the years broadened in the scope to include research resources of general relevance to biomedical research. The current number of research resources listed by the Registry numbers over 13K. The broadening in scope to biomedical science led us to re-christen the NIF Registry platform as SciCrunch. The NIF/SciCrunch Registry has been cataloging the resource landscape since 2006; as such, it serves as a valuable dataset for tracking the breadth, fate and utilization of these resources. Our experience shows research resources like databases are dynamic objects, that can change location and scope over time. Although each record is entered manually and human-curated, the current size of the registry requires tools that can aid in curation efforts to keep content up to date, including when and where such resources are used. To address this challenge, we have developed an open source tool suite, collectively termed RDW: Resource Disambiguator for the (Web. RDW is designed to help in the upkeep and curation of the registry as well as in enhancing the content of the registry by automated extraction of resource candidates from the literature. The RDW toolkit includes a URL extractor from papers, resource candidate screen, resource URL change tracker, resource content change tracker. Curators access these tools via a web based user interface. Several strategies are used to optimize these tools, including supervised and unsupervised learning algorithms as well as statistical text analysis. The complete tool suite is used to enhance and maintain the resource registry as well as track the usage of individual

Heat transfer with geometric shape of micro-fin tubes (I) - Condensing heat transfer

Energy Technology Data Exchange (ETDEWEB)

Kwak, K M; Chang, J S; Bai, C H; Chung, M [Yeungnam University, Kyungsan (Korea)

1999-11-01

To examine the enhancement mechanism of condensing heat transfer through microfin tube, the condensation experiments with refrigerant HCFC 22 are performed using 4 and 6 kinds of microfin tubes with outer diameter of 9.52 mm and 7.0 mm, respectively. Used microfin tubes have different shape and number of fins with each other. The main heat transfer enhancement mechanism is known to be the enlargement of heat transfer area and turbulence promotion. Together with these main factors, we can find other enhancement factors by the experimental data, which are the overflow of the refrigerant over the microfin and microfin arrangement. The overflow of the refrigerant over the microfin can be analyzed by the geometric shape of the microfin. microfin tubes having a shape which can give much overflow over the microfin show large condensing heat transfer coefficients. The effect of microfin arrangement is related to the heat transfer resistance of liquid film of refrigerant. The condensing heat transfer coefficients are high for the microfin tube with even distribution of liquid film. 17 refs., 14 figs., 3 tabs.

Management of agroforestry systems for enhancing resource use efficiency and crop productivity

International Nuclear Information System (INIS)

2008-11-01

Agroforestry is a low-input system which combines trees with crops in various combinations or sequences. It is an alternative to intensive cropping systems, which rely on large inputs of manufactured fertilizers and other external inputs to sustain production. Agroforestry also has the potential to reduce risk through diversification of a variety of products, including food, fuelwood and animal fodder. Other perceived benefits include enhanced nutrient and water use efficiencies, reduced nutrient leaching to groundwater and improved soil physical and biological properties. The use of leguminous or actinorhizal trees may further enhance these benefits because of their capacity to fix atmospheric nitrogen. Depending on the type of agroforestry system and the management practices employed, a substantial portion of this fixed nitrogen can be transferred to companion crops and to the soil. In considering the overall productivity of agroforestry systems, it is essential to investigate the competition or complementarity in the capture and partitioning of resources between tree and crop components. This is especially true for nutrients and water, usually the two most limiting factors influencing crop growth. The focus of this coordinated research project (CRP) was to evaluate the efficacy of various agroforestry systems used in Member States in terms of crop productivity, resource use efficiency and improvements in soil properties. The use of isotopes and nuclear techniques was essential for understanding the dynamics of nutrients and water in agroforestry systems. The contribution of nitrogen from fertilizers and leguminous trees to soil and crops was studied using both direct and indirect 15 N labelling techniques. The cycling of carbon from trees or crops to soil was studied using natural variations in the 13 C signatures of the soils and the different species. The soil moisture neutron probe in conjunction with tensionics was used to monitor soil water status and

Strategic Resource Use for Learning: A Self-Administered Intervention That Guides Self-Reflection on Effective Resource Use Enhances Academic Performance.

Science.gov (United States)

Chen, Patricia; Chavez, Omar; Ong, Desmond C; Gunderson, Brenda

2017-06-01

Many educational policies provide learners with more resources (e.g., new learning activities, study materials, or technologies), but less often do they address whether students are using these resources effectively. We hypothesized that making students more self-reflective about how they should approach their learning with the resources available to them would improve their class performance. We designed a novel Strategic Resource Use intervention that students could self-administer online and tested its effects in two cohorts of a college-level introductory statistics class. Before each exam, students randomly assigned to the treatment condition strategized about which academic resources they would use for studying, why each resource would be useful, and how they would use their resources. Students randomly assigned to the treatment condition reported being more self-reflective about their learning throughout the class, used their resources more effectively, and outperformed students in the control condition by an average of one third of a letter grade in the class.

Alternative modes for optical trapping and manipulation using counter-propagating shaped beams

International Nuclear Information System (INIS)

Palima, D; Tauro, S; Glückstad, J; Lindballe, T B; Kristensen, M V; Stapelfeldt, H; Keiding, S R

2011-01-01

Counter-propagating beams have enabled the first stable three-dimensional optical trapping of microparticles and this procedure has been enhanced and developed over the years to achieve independent and interactive manipulation of multiple particles. In this work, we analyse counter-propagating shaped-beam traps that depart from the conventional geometry based on symmetric, coaxial counter-propagating beams. We show that projecting shaped beams with separation distances previously considered axially unstable can, in fact, enhance the axial and transverse trapping stiffnesses. We also show that deviating from using perfectly counter-propagating beams to use oblique beams can improve the axial stability of the traps and improve the axial trapping stiffness. These alternative geometries can be particularly useful for handling larger particles. These results hint at a rich potential for light shaping for optical trapping and manipulation using patterned counter-propagating beams, which still remains to be fully tapped

Effects of Plasma Shaping on Nonlinear Gyrokinetic Turbulence

Energy Technology Data Exchange (ETDEWEB)

Belli, E. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Hammett, G. W. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Dorland, W. [Univ. of Maryland, College Park, MD (United States)

2008-08-01

The effects of flux surface shape on the gyrokinetic stability and transport of tokamak plasmas are studied using the GS2 code [M. Kotschenreuther, G. Rewoldt, and W.M. Tang, Comput. Phys. Commun. 88, 128 (1995); W. Dorland, F. Jenko, M. Kotschenreuther, and B.N. Rogers, Phys. Rev. Lett. 85, 5579 (2000)]. Studies of the scaling of nonlinear turbulence with shaping parameters are performed using analytic equilibria based on interpolations of representative shapes of the Joint European Torus (JET) [P.H. Rebut and B.E. Keen, Fusion Technol. 11, 13 (1987)]. High shaping is found to be a stabilizing influence on both the linear ion-temperature-gradient (ITG) instability and the nonlinear ITG turbulence. For the parameter regime studied here, a scaling of the heat flux with elongation of χ ~ κ^-1.5 or κ^-2.0, depending on the triangularity, is observed at fixed average temperature gradient. While this is not as strong as empirical elongation scalings, it is also found that high shaping results in a larger Dimits upshift of the nonlinear critical temperature gradient due to an enhancement of the Rosenbluth-Hinton residual zonal flows.

Effects of Plasma Shaping on Nonlinear Gyrokinetic Turbulence

International Nuclear Information System (INIS)

E.A. Belli, G.W. Hammett and W. Dorland

2008-01-01

The effects of flux surface shape on the gyrokinetic stability and transport of tokamak plasmas are studied using the GS2 code [M. Kotschenreuther, G. Rewoldt, and W.M. Tang, Comput. Phys. Commun. 88, 128 (1995); W. Dorland, F. Jenko, M. Kotschenreuther, and B.N. Rogers, Phys. Rev. Lett. 85, 5579 (2000)]. Studies of the scaling of nonlinear turbulence with shaping parameters are performed using analytic equilibria based on interpolations of representative shapes of the Joint European Torus (JET) [P.H. Rebut and B.E. Keen, Fusion Technol. 11, 13 (1987)]. High shaping is found to be a stabilizing influence on both the linear ion-temperature-gradient (ITG) instability and the nonlinear ITG turbulence. For the parameter regime studied here, a scaling of the heat flux with elongation of χ ∼ κ -1.5 or κ -2.0 , depending on the triangularity, is observed at fixed average temperature gradient. While this is not as strong as empirical elongation scalings, it is also found that high shaping results in a larger Dimits upshift of the nonlinear critical temperature gradient due to an enhancement of the Rosenbluth-Hinton residual zonal flows

Nonlinear microscopy of localized field enhancements in fractal shaped periodic metal nanostructures

DEFF Research Database (Denmark)

Beermann, I.; Evlyukhin, A.; Boltasseva, Alexandra

2008-01-01

Fractal shaped periodic nanostructures formed with a 100 nm period square lattice of gold nanoparticles placed on a gold film are characterized using far-field nonlinear scanning optical microscopy, in which two-photon photoluminescence (TPL) excited with a strongly focused femtosecond laser beam...

Young people and ICT – materials shaping resource-intensive practices?

DEFF Research Database (Denmark)

Christensen, Toke Haunstrup; Rommes, Els

2016-01-01

The extensive use of information and communication technology (ICT) in everyday practices results in increasing levels of consumption of energy and materials. Academics, NGOs and policymakers are beginning to address this issue and develop policies and campaigns to promote “sustainable” use of ICT....... The use of ICT is particularly widespread among young people, and this paper investigates the practices related to young people’s use of ICT. More specifically, we focus on the use of smart phones and laptops. The paper focuses on how the material qualities of smart phones, laptops and their related...... of ICT. Theoretically, the paper will apply a practice theoretical approach with STS concepts that bring the role of materials in shaping practices to the fore. In particular, we will draw on the Madeline Akrichs (1992) concept of (design) scripts. The analysis is based on focus groups with young people...

improvisation and utilization of resources in the teaching

African Journals Online (AJOL)

resources are inevitable in enhancing the teaching and learning of science and mathematics generally ... poor performance and low achievement in science and mathematics. Therefore these ..... Learning Resources for Primary science.

The Blueprint for Change: A National Strategy to Enhance Access to Earth and Space Science Education Resources

Science.gov (United States)

Geary, E. E.; Barstow, D.

2001-12-01

Enhancing access to high quality science education resources for teachers, students, and the general public is a high priority for the earth and space science education communities. However, to significantly increase access to these resources and promote their effective use will require a coordinated effort between content developers, publishers, professional developers, policy makers, and users in both formal and informal education settings. Federal agencies, academic institutions, professional societies, informal science centers, the Digital Library for Earth System Education, and other National SMETE Digital Library Projects are anticipated to play key roles in this effort. As a first step to developing a coordinated, national strategy for developing and delivering high quality earth and space science education resources to students, teachers, and the general public, 65 science educators, scientists, teachers, administrators, policy makers, and business leaders met this June in Snowmass, Colorado to create "Earth and Space Science Education 2010: A Blueprint for Change". The Blueprint is a strategy document that will be used to guide Earth and space science education reform efforts in grades K-12 during the next decade. The Blueprint contains specific goals, recommendations, and strategies for coordinating action in the areas of: Teacher Preparation and Professional Development, Curriculum and Materials, Equity and Diversity, Assessment and Evaluation, Public Policy and Systemic Reform, Public and Informal Education, Partnerships and Collaborations, and Technology. If you develop, disseminate, or use exemplary earth and space science education resources, we invite you to review the Blueprint for Change, share it with your colleagues and local science educators, and join as we work to revolutionize earth and space science education in grades K-12.

Enhancing faba bean (Vicia faba L.) genome resources

NARCIS (Netherlands)

Cooper, James W.; Wilson, Michael H.; Derks, M.F.L.; Smit, Sandra; Kunert, Karl J.; Cullis, Christopher; Foyer, C.H.

2017-01-01

Grain legume improvement is currently impeded by a lack of genomic resources. The paucity of genome information for faba bean can be attributed to the intrinsic difficulties of assembling/annotating its giant (~13 Gb) genome. In order to address this challenge, RNA-sequencing analysis was performed

Enhanced recovery pathways optimize health outcomes and resource utilization: A meta-analysis of randomized controlled trials in colorectal surgery

DEFF Research Database (Denmark)

Adamina, Michel; Kehlet, Henrik; Tomlinson, George A

2011-01-01

in costs that threatens the stability of health care systems. Enhanced recovery pathways (ERP) have been proposed as a means to reduce morbidity and improve effectiveness of care. We have reviewed the evidence supporting the implementation of ERP in clinical practice. Methods Medline, Embase...... of health care processes. Thus, while accelerating recovery and safely reducing hospital stay, ERPs optimize utilization of health care resources. ERPs can and should be routinely used in care after colorectal and other major gastrointestinal procedures....

Modeling students' instrumental (mis-) use of substances to enhance cognitive performance: Neuroenhancement in the light of job demands-resources theory.

Science.gov (United States)

Wolff, Wanja; Brand, Ralf; Baumgarten, Franz; Lösel, Johanna; Ziegler, Matthias

2014-01-01

Healthy university students have been shown to use psychoactive substances, expecting them to be functional means for enhancing their cognitive capacity, sometimes over and above an essentially proficient level. This behavior called Neuroenhancement (NE) has not yet been integrated into a behavioral theory that is able to predict performance. Job Demands Resources (JD-R) Theory for example assumes that strain (e.g. burnout) will occur and influence performance when job demands are high and job resources are limited at the same time. The aim of this study is to investigate whether or not university students' self-reported NE can be integrated into JD-R Theory's comprehensive approach to psychological health and performance. 1,007 students (23.56 ± 3.83 years old, 637 female) participated in an online survey. Lifestyle drug, prescription drug, and illicit substance NE together with the complete set of JD-R variables (demands, burnout, resources, motivation, and performance) were measured. Path models were used in order to test our data's fit to hypothesized main effects and interactions. JD-R Theory could successfully be applied to describe the situation of university students. NE was mainly associated with the JD-R Theory's health impairment process: Lifestyle drug NE (p performance. From a public health perspective, intervention strategies should address these costs of non-supervised NE. With regard to future research we propose to model NE as a means to reach an end (i.e. performance enhancement) rather than a target behavior itself. This is necessary to provide a deeper understanding of the behavioral roots and consequences of the phenomenon.

Memory color of natural familiar objects: effects of surface texture and 3-D shape.

Science.gov (United States)

Vurro, Milena; Ling, Yazhu; Hurlbert, Anya C

2013-06-28

Natural objects typically possess characteristic contours, chromatic surface textures, and three-dimensional shapes. These diagnostic features aid object recognition, as does memory color, the color most associated in memory with a particular object. Here we aim to determine whether polychromatic surface texture, 3-D shape, and contour diagnosticity improve memory color for familiar objects, separately and in combination. We use solid three-dimensional familiar objects rendered with their natural texture, which participants adjust in real time to match their memory color for the object. We analyze mean, accuracy, and precision of the memory color settings relative to the natural color of the objects under the same conditions. We find that in all conditions, memory colors deviate slightly but significantly in the same direction from the natural color. Surface polychromaticity, shape diagnosticity, and three dimensionality each improve memory color accuracy, relative to uniformly colored, generic, or two-dimensional shapes, respectively. Shape diagnosticity improves the precision of memory color also, and there is a trend for polychromaticity to do so as well. Differently from other studies, we find that the object contour alone also improves memory color. Thus, enhancing the naturalness of the stimulus, in terms of either surface or shape properties, enhances the accuracy and precision of memory color. The results support the hypothesis that memory color representations are polychromatic and are synergistically linked with diagnostic shape representations.

Influences on Employee Perceptions of Organizational Work-Life Support: Signals and Resources

Science.gov (United States)

Valcour, Monique; Ollier-Malaterre, Ariane; Matz-Costa, Christina; Pitt-Catsouphes, Marcie; Brown, Melissa

2011-01-01

This study examined predictors of employee perceptions of organizational work-life support. Using organizational support theory and conservation of resources theory, we reasoned that workplace demands and resources shape employees' perceptions of work-life support through two mechanisms: signaling that the organization cares about their work-life…

Application of Job Demands-Resources model in research on relationships between job satisfaction, job resources, individual resources and job demands

Directory of Open Access Journals (Sweden)

Adrianna Potocka

2013-04-01

Full Text Available Background: The aim of this study was to explore the relationships between job demands, job resourses, personal resourses and job satisfaction and to assess the usefulness of the Job Demands-Resources (JD-R model in the explanation of these phenomena. Materials and Methods: The research was based on a sample of 500 social workers. The "Psychosocial Factors" and "Job satisfaction" questionnaires were used to test the hypothesis. Results: The results showed that job satisfaction increased with increasing job accessibility and personal resources (r = 0.44; r = 0.31; p < 0.05. The analysis of variance (ANOVA indicated that job resources and job demands [F(1.474 = 4.004; F(1.474 = 4.166; p < 0.05] were statistically significant sources of variation in job satisfaction. Moreover, interactions between job demands and job resources [F(3,474 = 2.748; p < 0.05], as well as between job demands and personal resources [F(3.474 = 3.021; p < 0.05] had a significant impact on job satisfaction. The post hoc tests showed that 1 in low job demands, but high job resources employees declared higher job satisfaction, than those who perceived them as medium (p = 0.0001 or low (p = 0.0157; 2 when the level of job demands was perceived as medium, employees with high personal resources declared significantly higher job satisfaction than those with low personal resources (p = 0.0001. Conclusion: The JD-R model can be used to investigate job satisfaction. Taking into account fundamental factors of this model, in organizational management there are possibilities of shaping job satisfaction among employees. Med Pr 2013;64(2:217–225

Satellite-observed cold-ring-shaped features atop deep convective clouds

Czech Academy of Sciences Publication Activity Database

Setvák, M.; Lindsey, D. T.; Novák, P.; Wang, P. K.; Radová, Michaela; Kerkmann, J.; Grasso, L.; Su, S.-H.; Rabin, R. M.; Šťástka, J.; Charvát, Z.

2010-01-01

Roč. 97, 1-2 (2010), s. 80-96 ISSN 0169-8095 R&D Projects: GA ČR GA205/07/0905; GA MŠk ME09033 Institutional research plan: CEZ:AV0Z30420517 Keywords : convective storm * storm top * cloud top height * cold-ring shape * cold-U shape * enhanced-V feature * overshooting top * lower stratosphere * Meteosat second generation Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.597, year: 2010 http://www.sciencedirect.com/science/article/pii/S016980951000058X

Mechanism of information resources knowledge

Directory of Open Access Journals (Sweden)

A. M. Izmailov

2016-01-01

Full Text Available Modern vector of development of the economy is quite different from previous periods, which in it turn is reflected in the strategic state documents generated including the Government of Russia. In particular, it should be noted that to date, the state defined the vector of development defined as an innovative and socially oriented. Given the level of technical and technological progress and its impact on the realities of the present time it is necessary to pay attention to enhance the relevance and significance of information in the development of modern society. The article analyzes the degree of influence of information and knowledge in modern economic processes taking place in society. The analysis is based on the study of scientific works of modern scientists specializing in the study of information problems and knowledge economy. The main trends in the development of the information society status related primarily to the expansion of data, as well as strengthening the role of progressive information technologies to reduce the role of the geographical factor of resistance in sharing knowledge. The authors defined the essence of information knowledge environment, as well as the marked characteristics form the spectrum of features inherent to the modern information environment. The analysis of the concept of «information knowledge resource» (IKR, which is a synthesis of three terms: information, knowledge, resources, and refined his interpretation. IKR designated role in shaping the knowledge economy. Presents specific features which have knowledge information and resources, among which stands out: intangibility, immeasurable, non-exclusive use. The paper presents a model of the PSI, based on the transformation of information into knowledge under the influence of certain factors that could affect the quality of the resulting knowledge. Also in the proposed IKR management mechanism as a central element of organizational change

Optimization of L-shaped tunneling field-effect transistor for ambipolar current suppression and Analog/RF performance enhancement

Science.gov (United States)

Li, Cong; Zhao, Xiaolong; Zhuang, Yiqi; Yan, Zhirui; Guo, Jiaming; Han, Ru

2018-03-01

L-shaped tunneling field-effect transistor (LTFET) has larger tunnel area than planar TFET, which leads to enhanced on-current ION . However, LTFET suffers from severe ambipolar behavior, which needs to be further optimized for low power and high-frequency applications. In this paper, both hetero-gate-dielectric (HGD) and lightly doped drain (LDD) structures are introduced into LTFET for suppression of ambipolarity and improvement of analog/RF performance of LTFET. Current-voltage characteristics, the variation of energy band diagrams, distribution of band-to-band tunneling (BTBT) generation and distribution of electric field are analyzed for our proposed HGD-LDD-LTFET. In addition, the effect of LDD on the ambipolar behavior of LTFET is investigated, the length and doping concentration of LDD is also optimized for better suppression of ambipolar current. Finally, analog/RF performance of HGD-LDD-LTFET are studied in terms of gate-source capacitance, gate-drain capacitance, cut-off frequency, and gain bandwidth production. TCAD simulation results show that HGD-LDD-LTFET not only drastically suppresses ambipolar current but also improves analog/RF performance compared with conventional LTFET.

Soil fertility shapes belowground food webs across a regional climate gradient.

Science.gov (United States)

Laliberté, Etienne; Kardol, Paul; Didham, Raphael K; Teste, François P; Turner, Benjamin L; Wardle, David A

2017-10-01

Changes in soil fertility during pedogenesis affect the quantity and quality of resources entering the belowground subsystem. Climate governs pedogenesis, yet how climate modulates responses of soil food webs to soil ageing remains unexplored because of the paucity of appropriate model systems. We characterised soil food webs along each of four retrogressive soil chronosequences situated across a strong regional climate gradient to show that belowground communities are predominantly shaped by changes in fertility rather than climate. Basal consumers showed hump-shaped responses to soil ageing, which were propagated to higher-order consumers. There was a shift in dominance from bacterial to fungal energy channels with increasing soil age, while the root energy channel was most important in intermediate-aged soils. Our study highlights the overarching importance of soil fertility in regulating soil food webs, and indicates that belowground food webs will respond more strongly to shifts in soil resources than climate change. © 2017 John Wiley & Sons Ltd/CNRS.

Contact Resistance Reduction of ZnO Thin Film Transistors (TFTs) with Saw-Shaped Electrode

KAUST Repository

Park, Woojin; Shaikh, Sohail F.; Min, Jungwook; Lee, Sang Kyung; Lee, Byoung Hun; Hussain, Muhammad Mustafa

2018-01-01

an enhancement in the output drive current by 50% and reduction in the contact resistance by over 50%, when compared to a typical shaped electrode ZnO TFT consuming the same chip area. This performance enhancement is attributed to extension of channel width

Stochastic Prediction of Wind Generating Resources Using the Enhanced Ensemble Model for Jeju Island’s Wind Farms in South Korea

OpenAIRE

Deockho Kim; Jin Hur

2017-01-01

Due to the intermittency of wind power generation, it is very hard to manage its system operation and planning. In order to incorporate higher wind power penetrations into power systems that maintain secure and economic power system operation, an accurate and efficient estimation of wind power outputs is needed. In this paper, we propose the stochastic prediction of wind generating resources using an enhanced ensemble model for Jeju Island’s wind farms in South Korea. When selecting the poten...

Impact of Market-Based Disturbance on the Composition of West Virginia's Forest Resource

Science.gov (United States)

William G. Luppold; John E. Baumgras; John E. Baumgras

2000-01-01

The eastern hardwood resource has been shaped by a combination of human and natural disturbances. This impact on the forest resources of West Virginia has been especially dramatic. This resource has changed from a virgin forest dominated white oak, chestnut, spruce, white pine, and hemlock in the late 19th century, to one dominated by red oak in the 1950's, to...

A biodegradable shape-memory nanocomposite with excellent magnetism sensitivity

International Nuclear Information System (INIS)

Yu Xiongjun; Zhou Shaobing; Zheng Xiaotong; Guo Tao; Xiao Yu; Song Botao

2009-01-01

This paper reports a kind of biodegradable nanocomposite which can show an excellent shape-memory property in hot water or in an alternating magnetic field with f = 20 kH and H = 6.8 kA m -1 . The nanocomposite is composed of crosslinked poly(ε-caprolactone) (c-PCL) and Fe 3 O 4 nanoparticles. The crosslinking reaction in PCL with linear molecular structure was realized using benzoyl peroxide (BPO) as an initiator. The biocompatible Fe 3 O 4 magnetite nanoparticles with an average size of 10 nm were synthesized according to a chemical coprecipitation method. The initial results from c-PCL showed crosslinking modification had brought about a large enhancement in shape-memory effect for PCL. Then a series of composites made of Fe 3 O 4 nanoparticles and c-PCL were prepared and their morphological properties, mechanical properties, thermodynamic properties and shape-memory effect were investigated in succession. Significantly, the photos of the shape-memory process confirmed the anticipatory magnetically responsive shape-recovery effect of the nanocomposites because inductive heat from Fe 3 O 4 can be utilized to actuate the c-PCL vivification from their frozen temporary shape. All the results imply a very feasible method to fabricate shape-memory PCL-based nanocomposites since just a simple modification is required. Additionally, this modification would endow an excellent shape-memory effect to all other kinds of polymers so that they could broadly serve in various fields, especially in medicine.

Evidence-based human resource management: a study of nurse leaders' resource allocation.

Science.gov (United States)

Fagerström, Lisbeth

2009-05-01

The aims were to illustrate how the RAFAELA system can be used to facilitate evidence-based human resource management. The theoretical framework of the RAFAELA system is based on a holistic view of humankind and a view of leadership founded on human resource management. Nine wards from three central hospitals in Finland participated in the study. The data, stemming from 2006-2007, were taken from the critical indicators (ward-related and nursing intensity information) for national benchmarking used in the RAFAELA system. The data were analysed descriptively. The daily nursing resources per classified patient ratio is a more specific method of measurement than the nurse-to-patient ratio. For four wards, the nursing intensity per nurse surpassed the optimal level 34% to 62.2% of days. Resource allocation was clearly improved in that a better balance between patients' care needs and available nursing resources was maintained. The RAFAELA system provides a rational, systematic and objective foundation for evidence-based human resource management. Data from a systematic use of the RAFAELA system offer objective facts and motives for evidence-based decision making in human resource management, and will therefore enhance the nurse leaders' evidence and scientific based way of working.

Phylogeny and adaptation shape the teeth of insular mice.

Science.gov (United States)

Ledevin, Ronan; Chevret, Pascale; Ganem, Guila; Britton-Davidian, Janice; Hardouin, Emilie A; Chapuis, Jean-Louis; Pisanu, Benoit; da Luz Mathias, Maria; Schlager, Stefan; Auffray, Jean-Christophe; Renaud, Sabrina

2016-02-10

By accompanying human travels since prehistorical times, the house mouse dispersed widely throughout the world, and colonized many islands. The origin of the travellers determined the phylogenetic source of the insular mice, which encountered diverse ecological and environmental conditions on the various islands. Insular mice are thus an exceptional model to disentangle the relative role of phylogeny, ecology and climate in evolution. Molar shape is known to vary according to phylogeny and to respond to adaptation. Using for the first time a three-dimensional geometric morphometric approach, compared with a classical two-dimensional quantification, the relative effects of size variation, phylogeny, climate and ecology were investigated on molar shape diversity across a variety of islands. Phylogeny emerged as the factor of prime importance in shaping the molar. Changes in competition level, mostly driven by the presence or absence of the wood mouse on the different islands, appeared as the second most important effect. Climate and size differences accounted for slight shape variation. This evidences a balanced role of random differentiation related to history of colonization, and of adaptation possibly related to resource exploitation. © 2016 The Author(s).

Light-dependent governance of cell shape dimensions in cyanobacteria

Directory of Open Access Journals (Sweden)

Beronda L Montgomery

2015-05-01

Full Text Available The regulation of cellular dimension is important for the function and survival of cells. Cellular dimensions, such as size and shape, are regulated throughout the life cycle of bacteria and can be adapted in response to environmental changes to fine-tune cellular fitness. Cell size and shape are generally coordinated with cell growth and division. Cytoskeletal regulation of cell shape and cell wall biosynthesis and/or deposition occurs in a range of organisms. Photosynthetic organisms, such as cyanobacteria, particularly exhibit light-dependent regulation of morphogenes and generation of reactive oxygen species and other signals that can impact cellular dimensions. Environmental signals initiate adjustments of cellular dimensions, which may be vitally important for optimizing resource acquisition and utilization or for coupling the cellular dimensions with the regulation of subcellular organization to maintain optimal metabolism. Although the involvement of cytoskeletal components in the regulation of cell shape is widely accepted, the signaling factors that regulate cytoskeletal and other distinct components involved in cell shape control, particularly in response to changes in external light cues, remain to be fully elucidated. In this review, factors impacting the inter-coordination of growth and division, the relationship between the regulation of cellular dimensions and central carbon metabolism, and consideration of the effects of specific environment signals, primarily light, on cell dimensions in cyanobacteria will be discussed. Current knowledge about the molecular bases of the light-dependent regulation of cellular dimensions and cell shape in cyanobacteria will be highlighted.

Spiral-shaped reactor for water disinfection

KAUST Repository

Soukane, Sofiane

2016-04-20

Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria. The hydrodynamic behavior of contact tanks of different shapes, each with an approximate total volume of 50,000 m3, was analyzed by solving turbulent momentum transport equations with a computational fluid dynamics code, namely ANSYS fluent. Numerical experiments of a tracer pulse were performed for each design to generate flow through curves and investigate species residence time distribution for different inlet flow rates, ranging from 3 to 12 m3 s−1. A new nature-inspired Conch tank design whose shape follows an Archimedean spiral was then developed. The spiral design is shown to strongly outperform the other tanks’ designs for all the selected plug flow criteria with an enhancement in efficiency, less short circuiting, and an order of magnitude improvement in mixing and dispersion. Moreover, following the intensification philosophy, after 50% reduction in its size, the new design retains its properties and still gives far better results than the classical shapes.

Natural resource trust funds : a comparison of Alberta and Alaska resource funds

Energy Technology Data Exchange (ETDEWEB)

Warrack, A.A.; Keddie, R.R. [Alberta Univ., Edmonton, AB (Canada)

2002-09-01

Alberta and Alaska both have an economy based largely on natural resources. The cyclical nature of their economies poses a challenge to stability and sustained prosperity. During the oil crisis of 1973-1974, Alberta and Alaska began receiving oil and gas royalties. The idea of an endowment-type fund began taking shape. This fund would assist in the gradual transition from dependence on non-renewable resources to the responsible management of these resources. Both the Alberta Heritage Savings Trust Fund and the Alaska Permanent Fund were created in 1976. The governments of both jurisdictions set aside revenues from natural resource royalties to provide economic stability. Both jurisdictions followed different policies in terms of management, structure, governance, and objectives. In this paper, the authors compared both funds, examining the policy options which had an impact on their growth and successes. The results showed that in Alaska, monies are paid directly to eligible persons, while allocation decisions in Alberta have been made by the government. The government manages the fund in Alberta, while in Alaska, the fund is managed by a separate entity. The Alaskan fund continues to grow, while the the size of the Alberta fund has remained unchanged for a number of years and is not growing. 21 refs., 5 figs.

Enhancing New Product Development (NPD Portfolio Performance by Shaping the Development Funnel

Directory of Open Access Journals (Sweden)

Paulo Soares Figueiredo

2012-12-01

Full Text Available New product development (NPD projects are typically managed through a series of screens, or gates, where ideas compete for resources. Ideas are carved into projects, and these projects are reviewed, and approved or terminated through the screening process so that only the best performing projects continue to subsequent stages of design, development and testing, and are released into the market place (Krishnan and Ulrich 2001; Terwiesch and Ulrich 2009. Most large innovative organizations deal with more than one NPD project at a time and typically engage in product pipeline management (PPM, where a set of active projects are evaluated together while they traverse through a sequence of such screens. Key decisions in a R&D pipeline are: screen thresholds, complexity of projects, resource allocation and capacity adjustment biases. We explore the impact of structural and behavioral aspects of these decisions through a simulation based analysis of a pharmaceutical dataset. Results establish concave relationships between value created at the end of pipeline and the resource allocation and complexity allocation biases, indicating optimizability and a limit for front loading practices.

Job Demands-Resources Interventions

NARCIS (Netherlands)

J. Van Wingerden (Jessica)

2016-01-01

markdownabstractThe main aim of this dissertation was to examine whether positive organizational interventions based on JD-R theory can enhance employees’ work engagement and performance. This thesis presented five empirical intervention studies from different perspectives; (a) a personal resources

Tunable shape memory behaviors of poly(ethylene vinyl acetate) achieved by adding poly(L-lactide)

International Nuclear Information System (INIS)

Zhang, Zhi-xing; Liao, Fei; He, Zhen-zhen; Yang, Jing-hui; Huang, Ting; Zhang, Nan; Wang, Yong; Gao, Xiao-ling

2015-01-01

In this work, different contents of poly(L-lactide) (PLLA) (20–50 wt%) were introduced into poly(ethylene vinyl acetate) (EVA) to prepare the samples with a tunable shape memory behavior. Morphological characterization demonstrated that with increasing PLLA content from 20 to 50 wt%, the blend morphology changed from sea-island structure to cocontinuous structure. In all the samples, PLLA was amorphous and it did not affect the crystallization of polyethylene part in the EVA component. The presence of PLLA greatly enhanced the storage modulus of samples, especially at relatively low temperatures. The shape memory behaviors of samples were systematically investigated and the results demonstrated that the EVA/PLLA blends exhibited a tunable shape memory effect. On one hand, PLLA accelerated the shape fixation and enhanced the fixity ratio of samples. On the other hand, PLLA reduced the dependence of shape fixity of samples on fixity temperatures. Specifically, for the first time, a critical recovery temperature was observed for the immiscible shape memory polymer blends. In this work, the critical recovery temperature was about 53 °C. At recovery temperature below the critical value, the blends exhibited smaller recovery ratios compared with the pure EVA, however, at recovery temperature above 53 °C, the blends exhibited higher recovery ratios. (paper)

The Food and Wine Tourism: A Resource for a New Local Development Model

Directory of Open Access Journals (Sweden)

Grazia Calabrò

2016-11-01

Full Text Available Any human activity needs to realize conditions purposeful to the economic objectives to be pursued and to do this, needs to modify the original environmental equilibrium. These situations are clearly observable in agricultural activities, whose development has often determined an “artificialisation” so intense to change the original appearance of entire areas. The evolution of the territorial role of agriculture has implicated the coexistence among various economic activities, some of which have gained benefits from the “artificialisation” realized by farmers. It is the case of touristic activities and food services which take advantages from the beauty and from the attractiveness of landscapes shaped by agricultural activities. The purpose of this paper is to verify how, for territorial realities where tourist offer found its main basis on contexts realized by agriculture, the set of economic activities can take advantages from the sustainable use of the same resource and, therefore, it can contribute to its development. To this aim, we’ll take as an example the recent development of food and wine tourism, in Italy, as an important expression of tangible socio-economic systems based on the enhancement of local resources.

Shape descriptors for mode-shape recognition and model updating

International Nuclear Information System (INIS)

Wang, W; Mottershead, J E; Mares, C

2009-01-01

The most widely used method for comparing mode shapes from finite elements and experimental measurements is the Modal Assurance Criterion (MAC), which returns a single numerical value and carries no explicit information on shape features. New techniques, based on image processing (IP) and pattern recognition (PR) are described in this paper. The Zernike moment descriptor (ZMD), Fourier descriptor (FD), and wavelet descriptor (WD), presented in this article, are the most popular shape descriptors having properties that include efficiency of expression, robustness to noise, invariance to geometric transformation and rotation, separation of local and global shape features and computational efficiency. The comparison of mode shapes is readily achieved by assembling the shape features of each mode shape into multi-dimensional shape feature vectors (SFVs) and determining the distances separating them.

Watsonville Sloughs watershed resource conservation and enhancement plan

Data.gov (United States)

Department of the Interior — This document identifies feasible projects that address the long-term protection and enhancement of the Watsonville Sloughs system’s ecological values and the needs...

Wetland Resources Action Planning (WRAP) toolkit

DEFF Research Database (Denmark)

Bunting, Stuart W.; Smith, Kevin G.; Lund, Søren

2013-01-01

The Wetland Resources Action Planning (WRAP) toolkit is a toolkit of research methods and better management practices used in HighARCS (Highland Aquatic Resources Conservation and Sustainable Development), an EU-funded project with field experiences in China, Vietnam and India. It aims to communi......The Wetland Resources Action Planning (WRAP) toolkit is a toolkit of research methods and better management practices used in HighARCS (Highland Aquatic Resources Conservation and Sustainable Development), an EU-funded project with field experiences in China, Vietnam and India. It aims...... to communicate best practices in conserving biodiversity and sustaining ecosystem services to potential users and to promote the wise-use of aquatic resources, improve livelihoods and enhance policy information....

Electrochemically shape-controlled synthesis in deep eutectic solvents of Pt nanoflowers with enhanced activity for ethanol oxidation

International Nuclear Information System (INIS)

Wei Lu; Fan Youjun; Wang Honghui; Tian Na; Zhou Zhiyou; Sun Shigang

2012-01-01

Highlights: ► The electrochemically shape-controlled synthesis in deep eutectic solvents (DESs) has been applied to produce the uniform Pt nanoflowers with sharp single crystal petals and high density of atomic steps. ► The as-prepared Pt nanoflowers exhibit higher electrocatalytic activity and stability than commercial Pt black catalyst toward ethanol electrooxidation. ► The growth of Pt nanoflowers in DESs by the simple electrochemical route is straightforward and controllable in terms of nanoflowers’ shape and size. - Abstract: The electrochemically shape-controlled synthesis in deep eutectic solvents (DESs) has been applied to produce the electrocatalyst of Pt nanoflowers. The uniform Pt nanoflowers with sharp single crystal petals and high density of atomic steps were characterized by SEM, TEM, XRD, XPS and electrochemical tests. The results illustrated that the as-prepared Pt nanoflowers exhibit higher electrocatalytic activity and stability than commercial Pt black catalyst toward ethanol electrooxidation. The growth of Pt nanoflowers in DESs by the simple electrochemical route is straightforward and controllable in terms of nanoflowers’ shape and size, which can be applied in shape-controlled synthesis of other noble metal nanoparticles with high catalytic activity.

Sphere-shaped hierarchical cathode with enhanced growth of nanocrystal planes for high-rate and cycling-stable li-ion batteries.

Science.gov (United States)

Zhang, Linjing; Li, Ning; Wu, Borong; Xu, Hongliang; Wang, Lei; Yang, Xiao-Qing; Wu, Feng

2015-01-14

High-energy and high-power Li-ion batteries have been intensively pursued as power sources in electronic vehicles and renewable energy storage systems in smart grids. With this purpose, developing high-performance cathode materials is urgently needed. Here we report an easy and versatile strategy to fabricate high-rate and cycling-stable hierarchical sphered cathode Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O2, by using an ionic interfusion method. The sphere-shaped hierarchical cathode is assembled with primary nanoplates with enhanced growth of nanocrystal planes in favor of Li(+) intercalation/deintercalation, such as (010), (100), and (110) planes. This material with such unique structural features exhibits outstanding rate capability, cyclability, and high discharge capacities, achieving around 70% (175 mAh g(-1)) of the capacity at 0.1 C rate within about 2.1 min of ultrafast charging. Such cathode is feasible to construct high-energy and high-power Li-ion batteries.

Shaping Social Work Science: What Should Quantitative Researchers Do?

Science.gov (United States)

Guo, Shenyang

2015-01-01

Based on a review of economists' debates on mathematical economics, this article discusses a key issue for shaping the science of social work--research methodology. The article describes three important tasks quantitative researchers need to fulfill in order to enhance the scientific rigor of social work research. First, to test theories using…

Electronic human resource management: Enhancing or entrancing?

Directory of Open Access Journals (Sweden)

Paul Poisat

2017-07-01

Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

Utilisation of Electronic Information Resources By Lecturers in ...

African Journals Online (AJOL)

This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

Linear shaped charge

Energy Technology Data Exchange (ETDEWEB)

Peterson, David; Stofleth, Jerome H.; Saul, Venner W.

2017-07-11

Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.

Natural resource workshop: Public/private partnership for sustainable use of natural resources

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

As part of an effort to shape Federal policy for environmentally sound, sustainable economic development, the White House Office of Science and Technology Policy sponsored a workshop in Boise, Idaho on February 1--2, 1995. The Boise Idaho workshop focused on the sustainable use of natural resources, a topic of considerable interest in Idaho. The workshop gave representatives from industry, academia, research, the public, and local and state government an opportunity to provide input to lawmakers and policymakers for establishing a National Environmental Technology Strategy to be issued by Earth Day, 1995.

Legal, regulatory & institutional issues facing distributed resources development

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-01

This report describes legal, regulatory, and institutional considerations likely to shape the development and deployment of distributed resources. It is based on research co-sponsored by the National Renewable Energy Laboratory (NREL) and four investor-owned utilities (Central & South West Services, Cinergy Corp., Florida Power Corporation, and San Diego Gas & Electric Company). The research was performed between August 1995 and March 1996 by a team of four consulting firms experienced in energy and utility law, regulation, and economics. It is the survey phase of a project known as the Distributed Resources Institutional Analysis Project.

Empirical Analysis of Resource-Use Conflicts Between Smallholder ...

African Journals Online (AJOL)

Key factors significantly enhancing resource-use conflicts were increasing herd size, market integration, and increase in household wealthy differentiation. A key factor likely to significantly minimize the conflicts was strong local leadership. The mechanism employed to resolving resource use-conflicts was formation of ...

Resources for our Future. Key issues and best practices in resource efficiency

Energy Technology Data Exchange (ETDEWEB)

Weterings, R.; Bastein, T.; Tukker, A. [TNO, Delft (Netherlands); Rademaker, M.; De Ridder, M. [The Hague Centre for Strategic studies HCSS, Den Haag (Netherlands)

2013-08-15

This book provides an analysis of the issues surrounding international resources and inspiring accounts of industrial best practices. The book consists of two distinct parts. The first part of the book brings together the results of years of research into the geopolitical, economic and ecological dimensions of material scarcity and resource efficiency. Chapter 2 discusses the main challenges and constraints related to the use of energy resources, water and land, industrial and metallic minerals, construction minerals and biotic resources, including water use and ecosystem degradation. The chapter also addresses important linkages between these various resources. Chapter 3 describes the international trends that are shaping the geopolitics of natural resources and looks at the implications for Europe and the Netherlands. Chapter 4 presents a wide range of strategies by which governments, producers and consumers may contribute to the more sustainable use of natural resources. The second part of the book describes 21 inspiring best practices in resource efficiency in a variety of industrial sectors. Based on a series of interviews with industrial pioneers, these chapters relate their first-hand experiences in improving resource efficiency. These business cases demonstrate that innovation and entrepreneurship can result in substantial improvements in resource efficiency. Chapter 5 focuses on best practices in the built environment, where substantial amounts of energy and minerals are used. Chapter 6 presents four ambitious strategies to promote sustainable food production and consumption. Chapter 7 describes recent developments in the chemical process industry, which produces most of the ingredients, compounds and semi-products for the vast range of products used by society. Chapter 8 provides four examples of the state-of-the-art in resource efficiency in the metal and high-tech industries. This chapter presents four business cases highlighting the benefits of the

Enhanced visual statistical learning in adults with autism

Science.gov (United States)

Roser, Matthew E.; Aslin, Richard N.; McKenzie, Rebecca; Zahra, Daniel; Fiser, József

2014-01-01

Individuals with autism spectrum disorder (ASD) are often characterized as having social engagement and language deficiencies, but a sparing of visuo-spatial processing and short-term memory, with some evidence of supra-normal levels of performance in these domains. The present study expanded on this evidence by investigating the observational learning of visuospatial concepts from patterns of covariation across multiple exemplars. Child and adult participants with ASD, and age-matched control participants, viewed multi-shape arrays composed from a random combination of pairs of shapes that were each positioned in a fixed spatial arrangement. After this passive exposure phase, a post-test revealed that all participant groups could discriminate pairs of shapes with high covariation from randomly paired shapes with low covariation. Moreover, learning these shape-pairs with high covariation was superior in adults with ASD than in age-matched controls, while performance in children with ASD was no different than controls. These results extend previous observations of visuospatial enhancement in ASD into the domain of learning, and suggest that enhanced visual statistical learning may have arisen from a sustained bias to attend to local details in complex arrays of visual features. PMID:25151115

Working memory can enhance unconscious visual perception.

Science.gov (United States)

Pan, Yi; Cheng, Qiu-Ping; Luo, Qian-Ying

2012-06-01

We demonstrate that unconscious processing of a stimulus property can be enhanced when there is a match between the contents of working memory and the stimulus presented in the visual field. Participants first held a cue (a colored circle) in working memory and then searched for a brief masked target shape presented simultaneously with a distractor shape. When participants reported having no awareness of the target shape at all, search performance was more accurate in the valid condition, where the target matched the cue in color, than in the neutral condition, where the target mismatched the cue. This effect cannot be attributed to bottom-up perceptual priming from the presentation of a memory cue, because unconscious perception was not enhanced when the cue was merely perceptually identified but not actively held in working memory. These findings suggest that reentrant feedback from the contents of working memory modulates unconscious visual perception.

Understanding the Shape of the Land and Watersheds Using Simple Models in the Classroom

Science.gov (United States)

Gardiner, L.; Johnson, R.; Russell, R.; Bergman, J.; Genyuk, J.; Lagrave, M.

2006-12-01

Middle school students can gain essential understandings of the Earth and its processes in the classroom by making and manipulating simple models. While no substitute for field experiences, simple models made of easily-obtained materials can foster student understanding of natural environments. Through this collection of hands-on activities, students build and manipulate simple models that demonstrate (1) tectonic processes that shape the land, (2) the shape of the land surface, (3) how the shape of the land influences the distribution of waterways and watersheds, and (4) how the human communities within a watershed are interconnected through use of surface water. The classroom activities described in this presentation are available on Windows to the Universe (www.windows.ucar.edu), a project of the University Corporation for Atmospheric Research Office of Education and Outreach. Windows to the Universe, a long-standing Web resource supporting Earth and space science education, provides users with content about the Earth and space sciences at three levels (beginner, intermediate, and advanced) in English and Spanish. Approximately 80 hands-on classroom activities appropriate for K-12 classrooms are available within the teacher resources section of the Windows to the Universe.

Body shape shifting during growth permits tests that distinguish between competing geometric theories of metabolic scaling

DEFF Research Database (Denmark)

Hirst, Andrew G.; Glazier, Douglas S.; Atkinson, David

2014-01-01

Metabolism fuels all of life’s activities, from biochemical reactions to ecological interactions. According to two intensely debated theories, body size affects metabolism via geometrical influences on the transport of resources and wastes. However, these theories differ crucially in whether...... the size dependence of metabolism is derived from material transport across external surfaces, or through internal resource-transport networks. We show that when body shape changes during growth, these models make opposing predictions. These models are tested using pelagic invertebrates, because...... these animals exhibit highly variable intraspecific scaling relationships for metabolic rate and body shape. Metabolic scaling slopes of diverse integument-breathing species were significantly positively correlated with degree of body flattening or elongation during ontogeny, as expected from surface area...

Shape representation modulating the effect of motion on visual search performance.

Science.gov (United States)

Yang, Lindong; Yu, Ruifeng; Lin, Xuelian; Liu, Na

2017-11-02

The effect of motion on visual search has been extensively investigated, but that of uniform linear motion of display on search performance for tasks with different target-distractor shape representations has been rarely explored. The present study conducted three visual search experiments. In Experiments 1 and 2, participants finished two search tasks that differed in target-distractor shape representations under static and dynamic conditions. Two tasks with clear and blurred stimuli were performed in Experiment 3. The experiments revealed that target-distractor shape representation modulated the effect of motion on visual search performance. For tasks with low target-distractor shape similarity, motion negatively affected search performance, which was consistent with previous studies. However, for tasks with high target-distractor shape similarity, if the target differed from distractors in that a gap with a linear contour was added to the target, and the corresponding part of distractors had a curved contour, motion positively influenced search performance. Motion blur contributed to the performance enhancement under dynamic conditions. The findings are useful for understanding the influence of target-distractor shape representation on dynamic visual search performance when display had uniform linear motion.

Attractor neural networks with resource-efficient synaptic connectivity

Science.gov (United States)

Pehlevan, Cengiz; Sengupta, Anirvan

Memories are thought to be stored in the attractor states of recurrent neural networks. Here we explore how resource constraints interplay with memory storage function to shape synaptic connectivity of attractor networks. We propose that given a set of memories, in the form of population activity patterns, the neural circuit choses a synaptic connectivity configuration that minimizes a resource usage cost. We argue that the total synaptic weight (l1-norm) in the network measures the resource cost because synaptic weight is correlated with synaptic volume, which is a limited resource, and is proportional to neurotransmitter release and post-synaptic current, both of which cost energy. Using numerical simulations and replica theory, we characterize optimal connectivity profiles in resource-efficient attractor networks. Our theory explains several experimental observations on cortical connectivity profiles, 1) connectivity is sparse, because synapses are costly, 2) bidirectional connections are overrepresented and 3) are stronger, because attractor states need strong recurrence.

Tailoring consumer resources to enhance self-care in chronic heart failure.

Science.gov (United States)

Driscoll, Andrea; Davidson, Patricia; Clark, Robyn; Huang, Nancy; Aho, Zoe

2009-08-01

Chronic heart failure (CHF) is associated with high hospitalisation and mortality rates and debilitating symptoms. In an effort to reduce hospitalisations and improve symptoms individuals must be supported in managing their condition. Patients who can effectively self-manage their symptoms through lifestyle modification and adherence to complex medication regimens will experience less hospitalisations and other adverse events. The purpose of this paper is to explain how providing evidence-based information, using patient education resources, can support self-care. Self-care relates to the activities that individuals engage in relation to health seeking behaviours. Supporting self-care practices through tailored and relevant information can provide patients with resources and advice on strategies to manage their condition. Evidence-based approaches to improve adherence to self-care practices in patients with heart failure are not often reported. Low health literacy can result in poor understanding of the information about CHF and is related to adverse health outcomes. Also a lack of knowledge can lead to non-adherence with self-care practices such as following fluid restriction, low sodium diet and daily weighing routines. However these issues need to be addressed to improve self-management skills. Recently the Heart Foundation CHF consumer resource was updated based on evidence-based national clinical guidelines. The aim of this resource is to help consumers improve understanding of the disease, reduce uncertainty and anxiety about what to do when symptoms appear, encourage discussions with local doctors, and build confidence in self-care management. Evidence-based CHF patient education resources promote self-care practices and early detection of symptom change that may reduce hospitalisations and improve the quality of life for people with CHF.

Using Immersive Visualizations to Improve Decision Making and Enhancing Public Understanding of Earth Resource and Climate Issues

Science.gov (United States)

Yu, K. C.; Raynolds, R. G.; Dechesne, M.

2008-12-01

New visualization technologies, from ArcGIS to Google Earth, have allowed for the integration of complex, disparate data sets to produce visually rich and compelling three-dimensional models of sub-surface and surface resource distribution patterns. The rendering of these models allows the public to quickly understand complicated geospatial relationships that would otherwise take much longer to explain using traditional media. We have impacted the community through topical policy presentations at both state and city levels, adult education classes at the Denver Museum of Nature and Science (DMNS), and public lectures at DMNS. We have constructed three-dimensional models from well data and surface observations which allow policy makers to better understand the distribution of groundwater in sandstone aquifers of the Denver Basin. Our presentations to local governments in the Denver metro area have allowed resource managers to better project future ground water depletion patterns, and to encourage development of alternative sources. DMNS adult education classes on water resources, geography, and regional geology, as well as public lectures on global issues such as earthquakes, tsunamis, and resource depletion, have utilized the visualizations developed from these research models. In addition to presenting GIS models in traditional lectures, we have also made use of the immersive display capabilities of the digital "fulldome" Gates Planetarium at DMNS. The real-time Uniview visualization application installed at Gates was designed for teaching astronomy, but it can be re-purposed for displaying our model datasets in the context of the Earth's surface. The 17-meter diameter dome of the Gates Planetarium allows an audience to have an immersive experience---similar to virtual reality CAVEs employed by the oil exploration industry---that would otherwise not be available to the general public. Public lectures in the dome allow audiences of over 100 people to comprehend

Enhancing agricultural productivity and rural incomes through sustainable use of natural resources in the semi arid tropics.

Science.gov (United States)

Wani, Suhas P; Dixin, Yin; Li, Zhong; Dar, William D; Chander, Girish

2012-03-30

A participatory watershed management approach is one of the tested, sustainable and eco-friendly options to upgrade rain-fed agriculture to meet growing food demand along with additional multiple benefits in terms of improving livelihoods, addressing equity issues and biodiversity concerns. Watershed interventions at study sites in Thailand (Tad Fa and Wang Chai) and India (Kothapally) effectively reduced runoff and the associated soil loss. Such interventions at Xiaoxincun (China) and Wang Chai improved groundwater recharging and availability. Enhanced productive transpiration increased rainwater use efficiency for crop production by 13-29% at Xiaoxincun; 13-160% at Lucheba (China), 32-37% at Tad Fa and 23-46% at Wang Chai and by two to five times at Kothapally. Watershed interventions increased significantly the additional net returns from crop production as compared with the pre-watershed intervention period. Increased water availability opened up options for crop diversification with high-value crops, including increased forage production and boosted livestock-based livelihoods. In dryland tropics, integrated watershed management approach enabled farmers to diversify the systems along with increasing agricultural productivity through increased water availability, while conserving the natural resource base. Household incomes increased substantially, leading to improved living and building the resilience of the community and natural resources. Copyright © 2011 Society of Chemical Industry.

Morphological image processing for quantitative shape analysis of biomedical structures: effective contrast enhancement

International Nuclear Information System (INIS)

Kimori, Yoshitaka

2013-01-01

A contrast enhancement approach utilizing a new type of mathematical morphology called rotational morphological processing is introduced. The method is quantitatively evaluated and then applied to some medical images. Image processing methods significantly contribute to visualization of images captured by biomedical modalities (such as mammography, X-ray computed tomography, magnetic resonance imaging, and light and electron microscopy). Quantitative interpretation of the deluge of complicated biomedical images, however, poses many research challenges, one of which is to enhance structural features that are scarcely perceptible to the human eye. This study introduces a contrast enhancement approach based on a new type of mathematical morphology called rotational morphological processing. The proposed method is applied to medical images for the enhancement of structural features. The effectiveness of the method is evaluated quantitatively by the contrast improvement ratio (CIR). The CIR of the proposed method is 12.1, versus 4.7 and 0.1 for two conventional contrast enhancement methods, clearly indicating the high contrasting capability of the method

Shape memory polymers

Energy Technology Data Exchange (ETDEWEB)

Wilson, Thomas S.; Bearinger, Jane P.

2017-08-29

New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

Shape memory polymers

Science.gov (United States)

Wilson, Thomas S.; Bearinger, Jane P.

2015-06-09

New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

Cu-based shape memory alloys with enhanced thermal stability and mechanical properties

International Nuclear Information System (INIS)

Chung, C.Y.; Lam, C.W.H.

1999-01-01

Cu-based shape memory alloys were developed in the 1960s. They show excellent thermoelastic martensitic transformation. However the problems in mechanical properties and thermal instability have inhibited them from becoming promising engineering alloys. A new Cu-Zn-Al-Mn-Zr Cu-based shape memory alloy has been developed. With the addition of Mn and Zr, the martensitic transformation behaviour and the grain size ca be better controlled. The new alloys demonstrates good mechanical properties with ultimate tensile strenght and ductility, being 460 MPa and 9%, respectively. Experimental results revealed that the alloy has better thermal stability, i.e. martensite stabilisation is less serious. In ordinary Cu-Zn-Al alloys, martensite stabilisation usually occurs at room temperature. The new alloy shows better thermal stability even at elevated temperature (∝150 C, >A f =80 C). A limited small amount of martensite stabilisation was observed upon ageing of the direct quenched samples as well as the step quenched samples. This implies that the thermal stability of the new alloy is less dependent on the quenching procedure. Furthermore, such minor martensite stabilisation can be removed by subsequent suitable parent phase ageing. The new alloy is ideal for engineering applications because of its better thermal stability and better mechanical properties. (orig.)

Electrochemical synthesis of SnCo alloy shells on orderly rod-shaped Cu current collectors as anode materials for lithium-ion batteries with enhanced performance

Energy Technology Data Exchange (ETDEWEB)

Zhan, Fangwei; Zhang, Hui, E-mail: meszhanghui@zju.edu.cn; Qi, Yue; Wang, Jiazheng; Du, Ning; Yang, Deren

2013-09-05

Highlights: •Nanostructured SnCo/Cu electrodes have been successfully fabricated. •A simple electrodeposition approach was employed. •The Cu arrays offer large surface area and improve electronic/ionic conductivity. •The electrodes show improved performance as anode for Li-ion batteries. •The improved performance was attributed to the nanostructured current collectors. -- Abstract: In this article, we report a two-step electrodeposition method for the synthesis of Cu/SnCo core–shell rod-shaped arrays as anodes of lithium-ion batteries. Firstly, the arrayed Cu nanorods with diameters of 200 nm were fabricated on a Cu foil through an electrodeposition method with alumina oxide membrane (AAO) as the template. Secondly, the SnCo alloy shells were subsequently electrodeposited on the surface of the rod-shaped Cu arrays to form the hybrid nanostructures. These hybrid electrodes delivered the enhanced cyclic performance and high rate capability serving as the anode materials for lithium-ion batteries. The improved electrochemical performance might be attributed to the large surface-to-volume area, sufficient buffering space, and high electronic conductivity associated with these 3-dimensional (3D) nanostructures.

Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

International Nuclear Information System (INIS)

Kim, Tae Yun; Kim, Sung Hun; Kang, Bong Joo; Kim, Hyeon Sook; Cha, Eun Suk; Kim, Ji Youn; Song, Byung Joo

2013-01-01

Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Yun [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Sung Hun, E-mail: rad-ksh@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kang, Bong Joo [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Hyeon Sook [Department of Radiology, St. Paul Hospital, The Catholic University of Korea (Korea, Republic of); Cha, Eun Suk [Department of Radiology, Ewha Womans University, School of Medicine, Mokdong Hospital (Korea, Republic of); Kim, Ji Youn [Department of Radiology, Yeouido St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Song, Byung Joo [Department of Surgery, Seoul St. Mary' s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of)

2013-12-01

Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

Shape recovery and irrecoverable strain control in polyurethane shape-memory polymer

International Nuclear Information System (INIS)

Tobushi, Hisaaki; Ejiri, Yoshihiro; Hayashi, Syunichi; Hoshio, Kazumasa

2008-01-01

In shape-memory polymers, large strain can be fixed at a low temperature and thereafter recovered at a high temperature. If the shape-memory polymer is held at a high temperature for a long time, the irrecoverable strain can attain a new intermediate shape between the shape under the maximum stress and the primary shape. Irrecoverable strain control can be applied to the fabrication of a shape-memory polymer element with a complex shape in a simple method. In the present study, the influence of the strain-holding conditions on the shape recovery and the irrecoverable strain control in polyurethane shape-memory polymer is investigated by tension test of a film and three-point bending test of a sheet. The higher the shape-holding temperature and the longer the shape-holding time, the higher the irrecoverable strain rate. The equation that expresses the characteristics of the irrecoverable strain control is formulated

Environmentally friendly synthesis of highly monodisperse biocompatible gold nanoparticles with urchin-like shape.

Science.gov (United States)

Lu, Lehui; Ai, Kelong; Ozaki, Yukihiro

2008-02-05

We report a facile and environmentally friendly strategy for high-yield synthesis of highly monodisperse gold nanoparticles with urchin-like shape. A simple protein, gelatin, was first used for the control over shape and orientation of the gold nanoparticles. These nanoparticles, ready to use for biological systems, are promising in the optical imaging-based disease diagnostics and therapy because of their tunable surface plasmon resonance (SPR) and excellent surface-enhanced Raman scattering (SERS) activity.

The changing shape of U.S. licensing philosophy

International Nuclear Information System (INIS)

Remick, F.J.

1992-01-01

The shape of U.S. nuclear licensing and regulatory philosophy and process has already changed. The new process requires NRC review and approval of the vendor designs before a prospective utility license applicant purchases the design and begins construction. The new philosophy has resulted from the lessons learned from extensive operating experience accumulated in the United States. New criteria established for judging reactor designs include the capability of future designs to be more tolerant of accidents beyond the traditional design basis events. Qualitative and quantitative goals have been chosen as a guide for allocating resources for regulation of the currently operating plants. The changing shape of nuclear licensing and regulatory philosophy is also a result of economic circumstances in the United States. All will have a better opportunity to take part in the process which is most likely to encourage further development of safe nuclear energy in the United States. (author)

The University Council for Workforce and Human Resource Education: Its History, Purpose, and Activities

Science.gov (United States)

Johnson, Scott D.; Martinez, Reynaldo L., Jr.

2009-01-01

This article features the University Council for Workforce and Human Resource Education, a nonprofit organization representing leading United States universities that offer graduate programs in career and technical education (CTE) and human resource development (HRD). The mission of the Council is to be a recognized force in shaping the future of…

BNFL Magnox - Upgrades and enhancements

International Nuclear Information System (INIS)

Udbinac, M.J.

2006-01-01

In the past, generic models, restrictive budgets,and general shortages of resources have limited the scope of the UK's older Magnox simulators. Nevertheless, the simulators evolved slowly over time, becoming more like their reference plants, as resources became available. Three years ago, the Training and Development Branch of Magnox Electric plc took a giant leap, investing significant resources into the modernization of their training simulators. New hardware was built, including a new simulator room. The simulator software was ported from Unix running on outdated servers to new servers running Microsoft Windows NT. Perhaps most significantly, major model enhancements were made to key plant systems to significantly increase the likeness of each simulator to its reference plant. The upgrade to NT, the addition of state-of-the-art instructor stations, and some of the model enhancements were achieved with SimPort, an all-inclusive simulation package provided by DS and S. This paper will provide a more detailed view of the Magnox modular simulators, including how they are used and how they have benefited from the enhancements and upgrades implemented during the project. (author)

Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

Energy Technology Data Exchange (ETDEWEB)

Tavana, Nariman Roshandel, E-mail: nroshandel@ee.iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Shoulaie, Abbas, E-mail: shoulaie@iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of)

2011-01-15

In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

International Nuclear Information System (INIS)

Tavana, Nariman Roshandel; Shoulaie, Abbas

2011-01-01

In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

Improved Management of Water and Natural Resources Requires Open, Cognizant, Adaptive Science and Policy

Science.gov (United States)

Glynn, P. D.; Voinov, A. A.; Shapiro, C. D.; Jenni, K. E.

2017-12-01

Water issues impact the availability and use of other natural resources as well as environmental conditions. In an increasingly populated hyper-connected world, water issues are increasingly "wicked problems": complex problems with high uncertainties and no independent observers. Water is essential to life, and life affects water quality and availability. Scientists, managers, decision-makers, and the greater public all have a stake in improving the management of water resources. In turn, they are part of the systems that they are studying, deciding on, affecting, or trying to improve. Governance of water issues requires greater accessibility, traceability, and accountability (ATA) in science and policy. Water-related studies and decision-making need transdisciplinary science, inclusive participatory processes, and consideration and acceptance of multiple perspectives. Biases, Beliefs, Heuristics, and Values (BBHV) shape much of our perceptions and knowledge, and inevitably, affect both science and policy. Understanding the role of BBHV is critical to (1) understanding individual and group judgments and choices, (2) recognizing potential differences between societal "wants" and societal "needs", and (3) identifying "winners" and "losers" of policy decisions. Societal acceptance of proposed policies and actions can be fostered by enhancing participatory processes and by providing greater ATA in science, in policy, and in development of the laws, rules, and traditions that constrain decision-making. An adaptive science-infused governance framework is proposed that seeks greater cognizance of the role of BBHV in shaping science and policy choices and decisions, and that also seeks "Open Traceable Accountable Policy" to complement "Open Science". We discuss the limitations of the governance that we suggest, as well as tools and approaches to help implementation.

Infrastructure resources for clinical research in amyotrophic lateral sclerosis.

Science.gov (United States)

Sherman, Alexander V; Gubitz, Amelie K; Al-Chalabi, Ammar; Bedlack, Richard; Berry, James; Conwit, Robin; Harris, Brent T; Horton, D Kevin; Kaufmann, Petra; Leitner, Melanie L; Miller, Robert; Shefner, Jeremy; Vonsattel, Jean Paul; Mitsumoto, Hiroshi

2013-05-01

Clinical trial networks, shared clinical databases, and human biospecimen repositories are examples of infrastructure resources aimed at enhancing and expediting clinical and/or patient oriented research to uncover the etiology and pathogenesis of amyotrophic lateral sclerosis (ALS), a rapidly progressive neurodegenerative disease that leads to the paralysis of voluntary muscles. The current status of such infrastructure resources, as well as opportunities and impediments, were discussed at the second Tarrytown ALS meeting held in September 2011. The discussion focused on resources developed and maintained by ALS clinics and centers in North America and Europe, various clinical trial networks, U.S. government federal agencies including the National Institutes of Health (NIH), the Agency for Toxic Substances and Disease Registry (ATSDR) and the Centers for Disease Control and Prevention (CDC), and several voluntary disease organizations that support ALS research activities. Key recommendations included 1) the establishment of shared databases among individual ALS clinics to enhance the coordination of resources and data analyses; 2) the expansion of quality-controlled human biospecimen banks; and 3) the adoption of uniform data standards, such as the recently developed Common Data Elements (CDEs) for ALS clinical research. The value of clinical trial networks such as the Northeast ALS (NEALS) Consortium and the Western ALS (WALS) Consortium was recognized, and strategies to further enhance and complement these networks and their research resources were discussed.

Microbial enhancement of crop resource use efficiency.

Science.gov (United States)

Dodd, Ian C; Ruiz-Lozano, Juan Manuel

2012-04-01

Naturally occurring soil microbes may be used as inoculants to maintain crop yields despite decreased resource (water and nutrient) inputs. Plant symbiotic relationships with mycorrhizal fungi alter root aquaporin gene expression and greatly increase the surface area over which plant root systems take up water and nutrients. Soil bacteria on the root surface alter root phytohormone status thereby increasing growth, and can make nutrients more available to the plant. Combining different classes of soil organism within one inoculant can potentially take advantage of multiple plant growth-promoting mechanisms, but biological interactions between inoculant constituents and the plant are difficult to predict. Whether the yield benefits of such inocula allow modified nutrient and water management continues to challenge crop biotechnologists. Copyright © 2011 Elsevier Ltd. All rights reserved.

Resource regulation by a twig-girdling beetle has implications for desertification

Science.gov (United States)

1. Resource regulation by insects is the phenomenon by which herbivory enhances resources for the progeny of the herbivore. This report provides an example of resource regulation with implications for desertification in the Chihuahuan Desert of North America. 2. Female Oncideres rhodosticta beetles...

Interoperability of Demand Response Resources Demonstration in NY

Energy Technology Data Exchange (ETDEWEB)

Wellington, Andre

2014-03-31

The Interoperability of Demand Response Resources Demonstration in NY (Interoperability Project) was awarded to Con Edison in 2009. The objective of the project was to develop and demonstrate methodologies to enhance the ability of customer sited Demand Response resources to integrate more effectively with electric delivery companies and regional transmission organizations.

A simple interpretation of Hubbert's model of resource exploitation

Energy Technology Data Exchange (ETDEWEB)

Bardi, U.; Lavacchi, A. [Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 3, Sesto Fiorentino FI (Italy); Bardi, U.; Lavacchi, A. [ASPO - Association for the Study of Peak Oil and Gas, Italian section, c/o Dipartimento di Chimica, Universita di Firenze, 50019 Sesto Fiorentino (Italy)

2009-07-01

The well known 'Hubbert curve' assumes that the production curve of a crude oil in a free market economy is 'bell shaped' and symmetric. The model was first applied in the 1950s as a way of forecasting the production of crude oil in the US lower 48 states. Today, variants of the model are often used for describing the worldwide production of crude oil, which is supposed to reach a global production peak ('peak oil') and to decline afterwards. The model has also been shown to be generally valid for mineral resources other than crude oil and also for slowly renewable biological resources such as whales. Despite its widespread use, Hubbert's model sometimes criticized for being arbitrary and its underlying assumptions are rarely examined. In the present work, we use a simple model to generate the bell shaped curve using the smallest possible number of assumptions, taking also into account the 'Energy Return to Energy Invested' (EROI or EROEI) parameter. We show that this model can reproduce several historical cases, even for resources other than crude oil, and provide a useful tool for understanding the general mechanisms of resource exploitation and the future of energy production in the world's economy. (author)

Biodegradable toughened nanohybrid shape memory polymer for smart biomedical applications.

Science.gov (United States)

Biswas, Arpan; Singh, Akhand Pratap; Rana, Dipak; Aswal, Vinod K; Maiti, Pralay

2018-05-17

A polyurethane nanohybrid has been prepared through the in situ polymerization of an aliphatic diisocyanate, ester polyol and a chain extender in the presence of two-dimensional platelets. Polymerization within the platelet galleries helps to intercalate, generate diverse nanostructure and improve the nano to macro scale self-assembly, which leads to a significant enhancement in the toughness and thermal stability of the nanohybrid in comparison to pure polyurethane. The extensive interactions, the reason for property enhancement, between nanoplatelets and polymer chains are revealed through spectroscopic measurements and thermal studies. The nanohybrid exhibits significant improvement in the shape memory phenomena (91% recovery) at the physiological temperature, which makes it suitable for many biomedical applications. The structural alteration, studied through temperature dependent small angle neutron scattering and X-ray diffraction, along with unique crystallization behavior have extensively revealed the special shape memory behavior of this nanohybrid and facilitated the understanding of the molecular flipping in the presence of nanoplatelets. Cell line studies and subsequent imaging testify that this nanohybrid is a superior biomaterial that is suitable for use in the biomedical arena. In vivo studies on albino rats exhibit the potential of the shape memory effect of the nanohybrid as a self-tightening suture in keyhole surgery by appropriately closing the lips of the wound through the recovery of the programmed shape at physiological temperature with faster healing of the wound and without the formation of any scar. Further, the improved biodegradable nature along with the rapid self-expanding ability of the nanohybrid at 37 °C make it appropriate for many biomedical applications including a self-expanding stent for occlusion recovery due to its tough and flexible nature.

Self-erecting shapes

Science.gov (United States)

Reading, Matthew W.

2017-07-04

Technologies for making self-erecting structures are described herein. An exemplary self-erecting structure comprises a plurality of shape-memory members that connect two or more hub components. When forces are applied to the self-erecting structure, the shape-memory members can deform, and when the forces are removed the shape-memory members can return to their original pre-deformation shape, allowing the self-erecting structure to return to its own original shape under its own power. A shape of the self-erecting structure depends on a spatial orientation of the hub components, and a relative orientation of the shape-memory members, which in turn depends on an orientation of joining of the shape-memory members with the hub components.

Dynamic contrast-enhanced magnetic resonance imaging of the wrist in children with juvenile idiopathic arthritis

Energy Technology Data Exchange (ETDEWEB)

Nusman, Charlotte M. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Lavini, Cristina; Hemke, Robert; Caan, Matthan W.A.; Maas, Mario [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Dolman, Koert M. [Sint Lucas Andreas Hospital, Department of Pediatrics, Amsterdam (Netherlands); Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Rossum, Marion A.J. van [Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Emma Children' s Hospital, Department of Pediatrics, Academic Medical Center, Amsterdam (Netherlands)

2017-02-15

Dynamic contrast-enhanced MRI provides information on the heterogeneity of the synovium, the primary target of disease in children with juvenile idiopathic arthritis (JIA). To evaluate the feasibility of dynamic contrast-enhanced MRI in the wrist of children with JIA using conventional descriptive measures and time-intensity-curve shape analysis. To explore the association between enhancement characteristics and clinical disease status. Thirty-two children with JIA and wrist involvement underwent dynamic contrast-enhanced MRI with movement-registration and were classified using validated criteria as clinically active (n = 27) or inactive (n = 5). Outcome measures included descriptive parameters and the classification into time-intensity-curve shapes, which represent the patterns of signal intensity change over time. Differences in dynamic contrast-enhanced MRI outcome measures between clinically active and clinically inactive disease were analyzed and correlation with the Juvenile Arthritis Disease Activity Score was determined. Comprehensive evaluation of disease status was technically feasible and the quality of the dynamic dataset was improved by movement registration. The conventional descriptive measure maximum enhancement differed significantly between clinically active and inactive disease (P = 0.019), whereas time-intensity-curve shape analysis showed no differences. Juvenile Arthritis Disease Activity Score correlated moderately with enhancing volume (P = 0.484). Dynamic contrast-enhanced MRI is a promising biomarker for evaluating disease status in children with JIA and wrist involvement. Conventional descriptive dynamic contrast-enhanced MRI measures are better associated with clinically active disease than time-intensity-curve shape analysis. (orig.)

Site determination of Ni atoms in Cu-Al-Ni shape memory alloys by electron channelling enhanced microanalysis

International Nuclear Information System (INIS)

Nakata, Yoshiyuki; Tadaki, Tsugio; Shimizu, Ken-ichi

1990-01-01

The crystallographic site of Ni atoms in the parent phase of differently heat-treated Cu-28.6Al-3.7Ni (at.%) shape memory alloys has been examined by electron channelling enhanced microanalysis (ALCHEMI) in order to clarify effects of heat-treatments on the Ni atom site and M s temperature. The heat-treatments were as follows: (a) Quenching into a 10% NaOH solution at 263 K, (b) Quenching into hot water at 363 K and (c) Aging at 523 K for 3.6 ks after treatment (b). The M s temperatures of specimens (a), (b) and (c) were 158, 185 and 259 K, respectively, increasing with lowering quenching rate or aging. ALCHEMI revealed that Ni atoms occupied an identical site in all the three kinds of specimens: The Ni atoms were located at the nearest neighbor sites around Al atoms. This preferential occupation of Ni atoms was attributed to the strong binding force between Ni and Al atoms. Thus, the change in M s temperature due to different heat-treatments was not directly related to the crystallographic site of Ni atoms, but might be caused by the ordering between the next nearest neighbor Cu and Al atoms. (author)

Planning and Resource Allocation Management.

Science.gov (United States)

Coleman, Jack W.

1986-01-01

Modern scientific management techniques provide college administrators with valuable planning and resource allocation insights and enhances the decision process. The planning model should incorporate assessment, strategic planning, dynamic and long-term budgeting, operational planning, and feedback and control for actual operations. (MSE)

Silica-covered star-shaped Au-Ag nanoparticles as new electromagnetic nanoresonators for Raman characterisation of surfaces

Science.gov (United States)

Krajczewski, Jan; Kołątaj, Karol; Pietrasik, Sylwia; Kudelski, Andrzej

2018-03-01

One of the tools used for determining the composition of surfaces of various materials is shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). SHINERS is a modification of "standard" surface-enhanced Raman spectroscopy (SERS), in which, before Raman spectra are recorded, the surfaces analysed are covered with a layer of plasmonic nanoparticles protected by a very thin layer of a transparent dielectric. The plasmonic cores of the core-shell nanoparticles used in SHINERS measurements generate a local enhancement of the electric field of the incident electromagnetic radiation, whereas the transparent coatings prevent the metal cores from coming into direct contact with the material being analysed. In this contribution, we propose a new type of SHINERS nanoresonators that contain spiky, star-shaped metal cores (produced from a gold/silver alloy). These spiky, star-shaped Au-Ag nanoparticles have been covered by a layer of silica. The small radii of the ends of the tips of the spikes of these plasmonic nanostructures make it possible to generate a very large enhancement of the electromagnetic field there, with the result that such SHINERS nanoresonators are significantly more efficient than the standard semi-spherical nanostructures. The Au-Ag alloy nanoparticles were synthesised by the reduction of a solution containing silver nitrate and chloroauric acid by ascorbic acid. The final geometry of the nanostructures thus formed was controlled by changing the ratio between the concentrations of AuCl4- and Ag+ ions. The shape of the synthesised star-shaped Au-Ag nanoparticles does not change significantly during the two standard procedures for depositing a layer of silica (by the decomposition of sodium silicate or the decomposition of tetraethyl orthosilicate).

Shape-changing interfaces:

DEFF Research Database (Denmark)

Rasmussen, Majken Kirkegård; Pedersen, Esben Warming; Petersen, Marianne Graves

2015-01-01

Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address these shortc......Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address...... these shortcomings. We identify eight types of shape that are transformed in various ways to serve both functional and hedonic design purposes. Interaction with shape-changing interfaces is simple and rarely merges input and output. Three questions are discussed based on the review: (a) which design purposes may...

A DOUBLE E SHAPED MICROSTRIP PATCH ANTENNA FOR MULTIBAND APPLICATIONS

Directory of Open Access Journals (Sweden)

Pristin K Mathew

2014-06-01

Full Text Available This paper presents a dual band Compact double E shaped Microstrip Patch antenna with enhanced gain for Worldwide Interoperability for Microwave Access (WI-MAX, Universal Mobile Telecommunication Systems (UMTS and Satellite applications. The modified E shaped patch antenna is designed using CADFEKO and the results of return loss, Voltage Standing Wave Ratio (VSWR, gain of the proposed antenna are compared with a conventional E shaped patch antenna. The results show that the double E shaped wideband patch antenna has an impedance bandwidth of 10.7 % with a return loss of -13.6dB, -12.4 dB, -12.1dB and -14.2dB at resonant frequencies of 1.96 GHz, 3.62 GHz, 5.76 GHz and 6.82 GHz, whereas a conventional E shaped patch antenna operates at 2.5 GHz, 3.4 GHz and 5.5 GHz with a return loss of -16 dB each and impedance bandwidth of 10.6 %. Both the antennas uses Coaxial Probe feeding technique and Flame Retardant 4 (FR-4 as the substrate material with a thickness of 2.87 mm. A parametric study has been done so as to understand the effect of each parameter to obtain a better performance and optimised results.

Efficiency Enhancement of an Envelope Tracking Power Amplifier Combining Supply Shaping and Dynamic Biasing

DEFF Research Database (Denmark)

Tafuri, Felice Francesco; Sira, Daniel; Jensen, Ole Kiel

2013-01-01

This paper presents a new method to improve the performance of envelope tracking (ET) power amplifiers (PAs). The method consists of combining the supply modulation that characterizes the envelope tracking architecture with supply shaping and dynamic biasing. The inclusion of dynamic biasing allo...

Multi-Shaped Ag Nanoparticles in the Plasmonic Layer of Dye-Sensitized Solar Cells for Increased Power Conversion Efficiency

Directory of Open Access Journals (Sweden)

Da Hyun Song

2017-06-01

Full Text Available The use of dye-sensitized solar cells (DSSCs is widespread owing to their high power conversion efficiency (PCE and low cost of manufacturing. We prepared multi-shaped Ag nanoparticles (NPs and introduced them into DSSCs to further enhance their PCE. The maximum absorption wavelength of the multi-shaped Ag NPs is 420 nm, including the shoulder with a full width at half maximum (FWHM of 121 nm. This is a broad absorption wavelength compared to spherical Ag NPs, which have a maximum absorption wavelength of 400 nm without the shoulder of 61 nm FWHM. Therefore, when multi-shaped Ag NPs with a broader plasmon-enhanced absorption were coated on a mesoporous TiO2 layer on a layer-by-layer structure in DSSCs, the PCE increased from 8.44% to 10.22%, equivalent to an improvement of 21.09% compared to DSSCs without a plasmonic layer. To confirm the plasmon-enhanced effect on the composite film structure in DSSCs, the PCE of DSSCs based on the composite film structure with multi-shaped Ag NPs increased from 8.58% to 10.34%, equivalent to an improvement of 20.51% compared to DSSCs without a plasmonic layer. This concept can be applied to perovskite solar cells, hybrid solar cells, and other solar cells devices.

Self-healing polyurethane/attapulgite nanocomposites based on disulfide bonds and shape memory effect

Energy Technology Data Exchange (ETDEWEB)

Xu, Yurun; Chen, Dajun, E-mail: cdj@dhu.edu.cn

2017-07-01

Nanocomposites with remarkable enhanced mechanical properties have attracted great research efforts recently. In this work, a series of self-healing polyurethane/attapulgite nanocomposites were prepared by solution blending. Introducing self-healing ability and attapulgite (AT) reinforcement simultaneously led to prolonged material lifetime and enhanced mechanical properties. Scanning electron microscope (SEM) observation indicated that AT could achieve a uniform dispersion in polyurethane matrix when AT content was relatively low. The influences on mechanical properties were evaluated by tensile test. Results showed that incorporating an appropriate content of AT would lead to an enhanced tensile properties. The interactions between AT and polyurethane matrix were studied by effective cross-linking density calculation and Fourier transform infrared (FTIR) analysis. Results indicated that rich hydrogen bonds were formed between AT and polyurethane matrix. Displacement data was utilized to evaluate the influence on shape memory effect. With the incorporation of AT, deformation of the sample under external force was restrained. Meanwhile, closure of the scratches still can be accomplished during healing process. Results of healing test suggested that incorporating 1% of AT would also promote self-healing property. - Highlights: • Composites with both self-healing and enhanced mechanical property are prepared. • Healing mechanism relies on disulfide exchange reaction and shape memory effect. • Mechanical enhancement is caused by rich hydrogen bonds introduced by attapulgite.

Self-healing polyurethane/attapulgite nanocomposites based on disulfide bonds and shape memory effect

International Nuclear Information System (INIS)

Xu, Yurun; Chen, Dajun

2017-01-01

Nanocomposites with remarkable enhanced mechanical properties have attracted great research efforts recently. In this work, a series of self-healing polyurethane/attapulgite nanocomposites were prepared by solution blending. Introducing self-healing ability and attapulgite (AT) reinforcement simultaneously led to prolonged material lifetime and enhanced mechanical properties. Scanning electron microscope (SEM) observation indicated that AT could achieve a uniform dispersion in polyurethane matrix when AT content was relatively low. The influences on mechanical properties were evaluated by tensile test. Results showed that incorporating an appropriate content of AT would lead to an enhanced tensile properties. The interactions between AT and polyurethane matrix were studied by effective cross-linking density calculation and Fourier transform infrared (FTIR) analysis. Results indicated that rich hydrogen bonds were formed between AT and polyurethane matrix. Displacement data was utilized to evaluate the influence on shape memory effect. With the incorporation of AT, deformation of the sample under external force was restrained. Meanwhile, closure of the scratches still can be accomplished during healing process. Results of healing test suggested that incorporating 1% of AT would also promote self-healing property. - Highlights: • Composites with both self-healing and enhanced mechanical property are prepared. • Healing mechanism relies on disulfide exchange reaction and shape memory effect. • Mechanical enhancement is caused by rich hydrogen bonds introduced by attapulgite.

Neural - levelset shape detection segmentation of brain tumors in dynamic susceptibility contrast enhanced and diffusion weighted magnetic resonance images

International Nuclear Information System (INIS)

Vijayakumar, C.; Bhargava, Sunil; Gharpure, Damayanti Chandrashekhar

2008-01-01

A novel Neuro - level set shape detection algorithm is proposed and evaluated for segmentation and grading of brain tumours. The algorithm evaluates vascular and cellular information provided by dynamic contrast susceptibility magnetic resonance images and apparent diffusion coefficient maps. The proposed neural shape detection algorithm is based on the levels at algorithm (shape detection algorithm) and utilizes a neural block to provide the speed image for the level set methods. In this study, two different architectures of level set method have been implemented and their results are compared. The results show that the proposed Neuro-shape detection performs better in differentiating the tumor, edema, necrosis in reconstructed images of perfusion and diffusion weighted magnetic resonance images. (author)

Coherent enhancement of resonance-mediated multiphoton absorption

International Nuclear Information System (INIS)

Zhang, Shian; Zhang, Hui; Jia, Tianqing; Wang, Zugeng; Sun, Zhenrong

2010-01-01

In this paper, we theoretically investigate the coherent enhancement of resonance-mediated (2+2) four-photon absorption. It is found that by shaping the spectral phase with a π phase step, the resonance-mediated (2+2) four-photon transition probability can be enhanced. Furthermore, the coherent enhancement dependences on the detuning between the two two-photon absorptions, laser spectral bandwidth and laser centre frequency are explicitly discussed and analysed. We believe these theoretical results may play an important role in enhancing more complex resonance-mediated multiphoton absorption processes.

Beam shaping as an enabler for new applications

Science.gov (United States)

Guertler, Yvonne; Kahmann, Max; Havrilla, David

2017-02-01

For many years, laser beam shaping has enabled users to achieve optimized process results as well as manage challenging applications. The latest advancements in industrial lasers and processing optics have taken this a step further as users are able to adapt the beam shape to meet specific application requirements in a very flexible way. TRUMPF has developed a wide range of experience in creating beam profiles at the work piece for optimized material processing. This technology is based on the physical model of wave optics and can be used with ultra short pulse lasers as well as multi-kW cw lasers. Basically, the beam shape can be adapted in all three dimensions in space, which allows maximum flexibility. Besides adaption of intensity profile, even multi-spot geometries can be produced. This approach is very cost efficient, because a standard laser source and (in the case of cw lasers) a standard fiber can be used without any special modifications. Based on this innovative beam shaping technology, TRUMPF has developed new and optimized processes. Two of the most recent application developments using these techniques are cutting glass and synthetic sapphire with ultra-short pulse lasers and enhanced brazing of hot dip zinc coated steel for automotive applications. Both developments lead to more efficient and flexible production processes, enabled by laser technology and open the door to new opportunities. They also indicate the potential of beam shaping techniques since they can be applied to both single-mode laser sources (TOP Cleave) and multi-mode laser sources (brazing).

Simulation Analysis of Tilted Polyhedron-Shaped Thermoelectric Elements

Science.gov (United States)

Meng, Xiangning; Suzuki, Ryosuke O.

2015-06-01

The generation of thermoelectricity is considered a promising approach to harness the waste heat generated in industries, automobiles, gas fields, and other man-made processes. The waste heat can be converted to electricity via a thermoelectric (TE) generator. In this light, the generator performance depends on the geometric configuration of its constituent elements as well as their material properties. Our previous work reported TE behaviors for modules consisting of parallelogram-shaped elements, because elements with tilted laminate structures provide increased mechanical stability and efficient heat-transferring ability from the hot surface to the cold surface. Here, we study TE elements in the shape of a polyhedron that is obtained by mechanically truncating the edges of a parallelogram element in order to further enhance the generator performance and reduce TE material usage. The TE performance of the modules consisting of these polyhedron elements is numerically simulated by using the finite-volume method. The output power, voltage, and current of the polyhedral TE module are greater than those of the parallelogram-element module. The polyhedron shape positively affects heat transfer and the flow of electric charges in the light of increasing the efficiency of conversion from heat to electricity. By varying the shape of the truncated portions, we determine the optimal shape that enables homogeneous heat flux distribution and slow diffusion of thermal energy to obtain the better efficiency of conversion of heat into electricity. We believe that the findings of our study can significantly contribute to the design policy in TE generation.

Rod-Shaped Magnetite Nano/Microparticles Synthesis at Ambient Temperature

Directory of Open Access Journals (Sweden)

Balaprasad Ankamwar

2013-01-01

Full Text Available Here, we reported room temperature synthesis of Fe3O4 rod-shaped nano/microparticles by chemical reduction method from FeCl3 precursor and NaBH4 as the reducing agent in the presence of the pyrrole as a capping agent. The magnetic Fe3O4 particles were characterized by several methods, such as SEM, XRD, FTIR, and TGA. The average aspect ratio of Fe3O4 rod-shaped particles was ~2.8. These particles were redispersed in deionised water to form a colloidal solution and showed magnetic properties. This economical synthesis route is scalable, and Fe3O4 particles can be exploited for various applications such as MRI contrast enhancement, biodiseperations, Ni-Fe batteries, and as a catalyst.

human resources management and lecturer's job satisfaction

African Journals Online (AJOL)

PROF EKWUEME

The study revealed that administrators' human resources management effectiveness has a significant influence on ... opportunity for academic publication and administrators' staff relationship. .... enhance professional development. This is true ...

Shape up or ship out: can we enhance productivity in coastal aquaculture to compete with other uses?

Science.gov (United States)

Schrobback, Peggy; Pascoe, Sean; Coglan, Louisa

2014-01-01

Coastal resources are coming under increasing pressure from competition between recreational, commercial and conservation uses. This is particularly so in coastal areas adjacent to major population centres. Given high recreational and conservation values in such areas, economic activities need to be highly efficient in order to persist. Management of these industries must therefore also encourage efficient production and full utilisation of the areas available. In order to achieve this, managers must first understand the level and drivers of productivity, and how these can be influenced. In this study, by way of illustration, the focus was on the Sydney rock oyster industry within Queensland's Moreton Bay, a multiple use marine park with high recreational and conservation value adjacent to Australia's third largest city. Productivity of the oyster industry in Moreton Bay is currently low compared to historic levels, and management has an objective of reversing this trend. It is unclear whether this difference is due to oyster farmers' business choices and personal characteristics or whether varying environmental conditions in the Moreton Bay limit the capacity of the oyster industry. These require different management responses in order to enhance productivity. The study examined different productivity measures of the oyster industry using data envelopment analysis (DEA) to determine where productivity gains can be made and by how much. The findings suggest that the industry is operating at a high level of capacity utilisation, but a low level of efficiency. The results also suggest that both demographic and environmental conditions affect technical efficiency in the Bay, with water characteristics improvements and appropriate training potentially providing the greatest benefits to the industry. Methods used in this study are transferable to other industries and provide a means by which coastal aquaculture may be managed to ensure it remains competitive with other

Shape up or ship out: can we enhance productivity in coastal aquaculture to compete with other uses?

Directory of Open Access Journals (Sweden)

Peggy Schrobback

Full Text Available Coastal resources are coming under increasing pressure from competition between recreational, commercial and conservation uses. This is particularly so in coastal areas adjacent to major population centres. Given high recreational and conservation values in such areas, economic activities need to be highly efficient in order to persist. Management of these industries must therefore also encourage efficient production and full utilisation of the areas available. In order to achieve this, managers must first understand the level and drivers of productivity, and how these can be influenced. In this study, by way of illustration, the focus was on the Sydney rock oyster industry within Queensland's Moreton Bay, a multiple use marine park with high recreational and conservation value adjacent to Australia's third largest city. Productivity of the oyster industry in Moreton Bay is currently low compared to historic levels, and management has an objective of reversing this trend. It is unclear whether this difference is due to oyster farmers' business choices and personal characteristics or whether varying environmental conditions in the Moreton Bay limit the capacity of the oyster industry. These require different management responses in order to enhance productivity. The study examined different productivity measures of the oyster industry using data envelopment analysis (DEA to determine where productivity gains can be made and by how much. The findings suggest that the industry is operating at a high level of capacity utilisation, but a low level of efficiency. The results also suggest that both demographic and environmental conditions affect technical efficiency in the Bay, with water characteristics improvements and appropriate training potentially providing the greatest benefits to the industry. Methods used in this study are transferable to other industries and provide a means by which coastal aquaculture may be managed to ensure it remains

Enhanced heat transfer with corrugated flow channel in anode side of direct methanol fuel cells

International Nuclear Information System (INIS)

Heidary, H.; Abbassi, A.; Kermani, M.J.

2013-01-01

Highlights: • Effect of corrugated flow channel on the heat exchange of DMFC is studied. • Corrugated boundary (except rectangular type) increase heat transfer up to 90%. • Average heat transfer in rectangular-corrugated boundary is less than straight one. • In Re > 60, wavy shape boundary has highest heat transfer. • In Re < 60, triangular shape boundary has highest heat transfer. - Abstract: In this paper, heat transfer and flow field analysis in anode side of direct methanol fuel cells (DMFCs) is numerically studied. To enhance the heat exchange between bottom cold wall and core flow, bottom wall of fluid delivery channel is considered as corrugated boundary instead of straight (flat) one. Four different shapes of corrugated boundary are recommended here: rectangular shape, trapezoidal shape, triangular shape and wavy (sinusoidal) shape. The top wall of the channel (catalyst layer boundary) is taken as hot boundary, because reaction occurs in catalyst layer and the bottom wall of the channel is considered as cold boundary due to coolant existence. The governing equations are numerically solved in the domain by the control volume approach based on the SIMPLE technique (1972). A wide spectrum of numerical studies is performed over a range of various shape boundaries, Reynolds number, triangle block number, and the triangle block amplitude. The performed parametric studies show that corrugated channel with trapezoidal, triangular and wavy shape enhances the heat exchange up to 90%. With these boundaries, cooling purpose of reacting flow in anode side of DMFCs would be better than straight one. Also, from the analogy between the heat and mass transfer problems, it is expected that the consumption of reacting species within the catalyst layer of DMFCs enhance. The present work provides helpful guidelines to the bipolar plate manufacturers of DMFCs to considerably enhance heat transfer and performance of the anode side of DMFC

Thermoinduced plastic flow and shape memory effects

Directory of Open Access Journals (Sweden)

Xiao Heng

2011-01-01

Full Text Available We propose an enhanced form of thermocoupled J2-flow models of finite deformation elastoplasticity with temperature-dependent yielding and hardening behaviour. The thermomechanical constitutive structure of these models is rendered free and explicit in the rigorous sense of thermodynamic consistency. Namely, with a free energy function explicitly introduced in terms of almost any given form of the thermomechanical constitutive functions, the requirements from the second law are identically fulfilled with positive internal dissipation. We study the case when a dependence of yielding and hardening on temperature is given and demonstrate that thermosensitive yielding with anisotropic hardening may give rise to appreciable plastic flow either in a process of heating or in a cyclic process of heating/cooling, thus leading to the findings of one- and two-way thermoinduced plastic flow. We then show that such theoretical findings turn out to be the effects found in shape memory materials, such as one- and two-way memory effects. Thus, shape memory effects may be explained to be thermoinduced plastic flow resulting from thermosensitive yielding and hardening behaviour. These and other relevant facts may suggest that, from a phenomenological standpoint, thermocoupled elastoplastic J2-flow models with thermosensitive yielding and hardening may furnish natural, straightforward descriptions of thermomechanical behaviour of shape memory materials.

South-South exchanges enhance resource management and biodiversity conservation at various scales

Directory of Open Access Journals (Sweden)

William D Heyman

2011-01-01

Full Text Available International conservation organisations have invested considerable resources in fostering biodiversity conservation programs in the humid tropics, the most biologically diverse areas on earth. Recent approaches to conservation have centered on integrated conservation and development projects and participatory resource management programs, co-managed between governments and local communities. But these programs have had only mixed success and often suffer from insufficient quantity or quality of participation by local communities. We pose that participatory resource management is more likely to succeed when community members, 1 gain a global perspective on how their social, economic and environmental conditions compare with peer communities in other similar areas of the world, and thus better understand issues of relative scarcity and the benefits of sustainable resource management, and 2 engage as decision-makers at every stage of the conservation process up to reflective program evaluation. This paper examines the role of South-South exchanges as a tool to achieve these intermediate goals that ultimately foster more effective and participatory conservation and support sustainable local livelihoods. The data are extracted from the initiatives of the authors in two different environments- marine and coastal communities in Central America and the Caribbean, and lowland rainforest communities in the western Amazon of South America. We conclude that the exchanges are effective ways to build stakeholder comprehension about, and meaningful engagement in, resource management. South-South exchanges may also help build multi-local coalitions from various remote areas that together support biodiversity conservation at regional and global scales.

Processing and Characterization of NiTi Shape Memory Alloy Particle Reinforced Sn-In Solders

National Research Council Canada - National Science Library

Chung, Kohn C

2006-01-01

.... In previous work, it was proposed that reinforcement of solder by NiTi shape memory alloy particles to form smart composite solder reduces the inelastic strain of the solder and hence, may enhance...

Shape-Dependent Electrocatalytic Reduction of CO2 to CO on Triangular Silver Nanoplates.

Science.gov (United States)

Liu, Subiao; Tao, Hongbiao; Zeng, Li; Liu, Qi; Xu, Zhenghe; Liu, Qingxia; Luo, Jing-Li

2017-02-15

Electrochemical reduction of CO 2 (CO 2 RR) provides great potential for intermittent renewable energy storage. This study demonstrates a predominant shape-dependent electrocatalytic reduction of CO 2 to CO on triangular silver nanoplates (Tri-Ag-NPs) in 0.1 M KHCO 3 . Compared with similarly sized Ag nanoparticles (SS-Ag-NPs) and bulk Ag, Tri-Ag-NPs exhibited an enhanced current density and significantly improved Faradaic efficiency (96.8%) and energy efficiency (61.7%), together with a considerable durability (7 days). Additionally, CO starts to be observed at an ultralow overpotential of 96 mV, further confirming the superiority of Tri-Ag-NPs as a catalyst for CO 2 RR toward CO formation. Density functional theory calculations reveal that the significantly enhanced electrocatalytic activity and selectivity at lowered overpotential originate from the shape-controlled structure. This not only provides the optimum edge-to-corner ratio but also dominates at the facet of Ag(100) where it requires lower energy to initiate the rate-determining step. This study demonstrates a promising approach to tune electrocatalytic activity and selectivity of metal catalysts for CO 2 RR by creating optimal facet and edge site through shape-control synthesis.

How the mach phenomenon and shape affect the radiographic appearance of skeletal structures

International Nuclear Information System (INIS)

Papageorges, M.

1991-01-01

The shape of skeletal structures and their position relative to the x-ray beam have a considerable effect on their radiographic appearance. Depending on the thickness of the cortical or subchondral bone, skeletal structures display the characteristics of either homogeneous or compound lamellar structures. Convex homogeneous structures are associated with a negative Mach line, and concave homogeneous structures are associated with a positive Mach line. Convex compound lamellar structures are associated with a negative Mach band and visualization of the lamina (subchondral or cortical bone) is reduced. Concave compound lamellar structures are associated with a positive Mach band and visualization of the lamina is enhanced. The combined effect of Mach phenomenon, shape, and thickness enhances visualization of some skeletal surfaces and make others imperceptible. These principles are very useful to correctly identify complex skeletal structures and avoid misinterpretations

Precipitation-induced of partial annealing of Ni-rich NiTi shape memory alloy

Science.gov (United States)

Nashrudin, Muhammad Naqib; Mahmud, Abdus Samad; Mohamad, Hishamiakim

2018-05-01

NiTi shape memory alloy behavior is very sensitive to alloy composition and heat treatment processes. Thermomechanical behavior of near-equiatomic alloy is normally enhanced by partial anneal of a cold-worked specimen. The shape memory behavior of Ni-rich alloy can be enhanced by ageing precipitation. This work studied the effect of simultaneous partial annealing and ageing precipitation of a Ni-rich cold drawn Ti-50.9at%Ni wire towards martensite phase transformation behavior. Ageing treatment of a non-cold worked specimen was also done for comparison. It was found that the increase of heat treatment temperature caused the forward transformation stress to decrease for the cold worked and non-cold worked specimens. Strain recovery on the reverse transformation of the cold worked wire improved compared to the non-cold worked wire as the temperature increased.

Implementation of a real-time adaptive digital shaping for nuclear spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Regadío, Alberto, E-mail: aregadio@srg.aut.uah.es [Department of Computer Engineering, Space Research Group, Universidad de Alcalá, 28805 Alcalá de Henares (Spain); Electronic Technology Area, Instituto Nacional de Técnica Aeroespacial, 28850 Torrejón de Ardoz (Spain); Sánchez-Prieto, Sebastián, E-mail: ssanchez@srg.aut.uah.es [Department of Computer Engineering, Space Research Group, Universidad de Alcalá, 28805 Alcalá de Henares (Spain); Prieto, Manuel, E-mail: mprieto@srg.aut.uah.es [Department of Computer Engineering, Space Research Group, Universidad de Alcalá, 28805 Alcalá de Henares (Spain); Tabero, Jesús, E-mail: taberogj@inta.es [Electronic Technology Area, Instituto Nacional de Técnica Aeroespacial, 28850 Torrejón de Ardoz (Spain)

2014-01-21

This paper presents the structure, design and implementation of a new adaptive digital shaper for processing the pulses generated in nuclear particle detectors. The proposed adaptive algorithm has the capacity to automatically adjust the coefficients for shaping an input signal with a desired profile in real-time. Typical shapers such as triangular, trapezoidal or cusp-like ones can be generated, but more exotic unipolar shaping could also be performed. A practical prototype was designed, implemented and tested in a Field Programmable Gate Array (FPGA). Particular attention was paid to the amount of internal FPGA resources required and to the sampling rate, making the design as simple as possible in order to minimize power consumption. Lastly, its performance and capabilities were measured using simulations and a real benchmark.

Implementation of a real-time adaptive digital shaping for nuclear spectroscopy

International Nuclear Information System (INIS)

Regadío, Alberto; Sánchez-Prieto, Sebastián; Prieto, Manuel; Tabero, Jesús

2014-01-01

This paper presents the structure, design and implementation of a new adaptive digital shaper for processing the pulses generated in nuclear particle detectors. The proposed adaptive algorithm has the capacity to automatically adjust the coefficients for shaping an input signal with a desired profile in real-time. Typical shapers such as triangular, trapezoidal or cusp-like ones can be generated, but more exotic unipolar shaping could also be performed. A practical prototype was designed, implemented and tested in a Field Programmable Gate Array (FPGA). Particular attention was paid to the amount of internal FPGA resources required and to the sampling rate, making the design as simple as possible in order to minimize power consumption. Lastly, its performance and capabilities were measured using simulations and a real benchmark

Mapping cultural resource sites for the Prince William Sound Graphical Resource Database

International Nuclear Information System (INIS)

Wooley, C. B.; O'Brien, D. K.; Hillman, S. O.

1997-01-01

A software package for mapping digital data 'layers' of environmentally and/or culturally sensitive areas such as seabird colonies, seal haulouts, and sea otter concentrations in Prince William Sound and adjoining areas of southern Alaska has been developed by the Alyeska Pipeline Service Company. The data is to be added to an environmental computer mapping database. More than 1,800 known and reported coastal cultural resource sites have been identified. The database is part of the Prince William Sound Tanker Oil Discharge Prevention and Contingency Plan. The mappable data layers can be used to plan and execute whatever site protection program may be necessary, thus enhancing effective cultural resource protection during an oil spill response. 22 refs., 4 figs

Reversibility in martensitic transformation and shape memory in high Mn ferrous alloys

International Nuclear Information System (INIS)

Tomota, Y.

2000-01-01

The reversibility of austenite (γ : fcc) epsilon (ε : hcp) martensitic transformation and shape memory effect in high Mn ferrous alloys are discussed. A particular emphasis is put on the ε → γ reverse transformation behavior in two poly-crystalline alloys, Fe-24Mn and Fe-24Mn-6Si, where the latter exhibits excellent shape memory while the former shows poor memory although their forward γ → ε transformation behavior is quite similar. TEM in situ observations have revealed that the motion of Shockley partial dislocations during ε → γ reverse transformation is different from each other in these two alloys. The influence of alloying elements on the shape memory effect can be related to solid solution hardening of austenite, suggesting an important role of internal stress. The effect of training on enhancing the shape memory is explained by such an internal stress distribution associated with the formation of very thin, i.e., nano-scale ε/γ lamellae. (orig.)

On ad valorem taxation of nonrenewable resource production

International Nuclear Information System (INIS)

Rowse, John

1997-01-01

Taxing a nonrenewable resource typically shifts production through time, compresses the economically recoverable resource base and shrinks social welfare. But by how much? In this paper a computational model of natural gas use, representing numerous demand and supply features believed important for shaping efficient intertemporal allocations, is utilized to answer this question under different ad valorem royalty taxes on wellhead production. Proportionate social welfare losses from fixed royalties up to 30% are found to be small and the excess burden stands at less than 6.5% for a 30% royalty. This result replicates findings of several earlier studies and points to a general conclusion

Training method for enhancement of safety attitude in nuclear power plant based on crew resource management

International Nuclear Information System (INIS)

Ishibashi, Akira; Karikawa, Daisuke; Takahashi, Makoto; Wakabayashi, Toshio; Kitamura, Masaharu

2010-01-01

A conventional training program for nuclear power plant operators has been developed with emphasis on improvement of knowledge and skills of individual operators. Although it has certainly contributed to safety operation of nuclear power plants, some recent incidents have indicated the necessity of an improved training program aiming at improvement of the performance of operators working as a team. In the aviation area, crew resource management (CRM) training has shown the effect of resolving team management issues of flight crews, aircraft maintenance crews, and so on. In the present research, we attempted to introduce the CRM concept into operator training in nuclear power plants as training for conceptual skill enhancement. In this paper, a training method specially customized for nuclear power plant operators based on CRM is proposed. The proposed method has been practically utilized in the management training course of Japan Nuclear Technology Institute. The validity of the proposed method has been evaluated by means of a questionnaire survey. (author)

Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

Science.gov (United States)

Zhang, Ying; Whitfield-Gabrieli, Susan; Christodoulou, Joanna A.; Gabrieli, John D. E.

2013-01-01

Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading. PMID:23825653

Shape-memory effect of nanocomposites based on liquid-crystalline elastomers

Science.gov (United States)

Marotta, A.; Lama, G. C.; Gentile, G.; Cerruti, P.; Carfagna, C.; Ambrogi, V.

2016-05-01

In this work, nanocomposites based on liquid crystalline (LC) elastomers were prepared and characterized in their shape memory properties. For the synthesis of materials, p-bis(2,3-epoxypropoxy)-α-methylstilbene (DOMS) was used as mesogenic epoxy monomer, sebacic acid (SA) as curing agent and multi-walled carbon nanotubes (MWCNT) and graphene oxide (GO) as fillers. First, an effective compatibilization methodology was set up to improve the interfacial adhesion between the matrix and the carbonaceous nanofillers, thus obtaining homogeneous distribution and dispersion of the nanofillers within the polymer phase. Then, the obtained nanocomposite films were characterized in their morphological and thermal properties. In particular, the effect of the addition of the nanofillers on liquid crystalline behavior, as well as on shape-memory properties of the realized materials was investigated. It was found that both fillers were able to enhance the thermomechanical response of the LC elastomers, making them good candidates as shape memory materials.

Silica-covered star-shaped Au-Ag nanoparticles as new electromagnetic nanoresonators for Raman characterisation of surfaces.

Science.gov (United States)

Krajczewski, Jan; Kołątaj, Karol; Pietrasik, Sylwia; Kudelski, Andrzej

2018-03-15

One of the tools used for determining the composition of surfaces of various materials is shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). SHINERS is a modification of "standard" surface-enhanced Raman spectroscopy (SERS), in which, before Raman spectra are recorded, the surfaces analysed are covered with a layer of plasmonic nanoparticles protected by a very thin layer of a transparent dielectric. The plasmonic cores of the core-shell nanoparticles used in SHINERS measurements generate a local enhancement of the electric field of the incident electromagnetic radiation, whereas the transparent coatings prevent the metal cores from coming into direct contact with the material being analysed. In this contribution, we propose a new type of SHINERS nanoresonators that contain spiky, star-shaped metal cores (produced from a gold/silver alloy). These spiky, star-shaped Au-Ag nanoparticles have been covered by a layer of silica. The small radii of the ends of the tips of the spikes of these plasmonic nanostructures make it possible to generate a very large enhancement of the electromagnetic field there, with the result that such SHINERS nanoresonators are significantly more efficient than the standard semi-spherical nanostructures. The Au-Ag alloy nanoparticles were synthesised by the reduction of a solution containing silver nitrate and chloroauric acid by ascorbic acid. The final geometry of the nanostructures thus formed was controlled by changing the ratio between the concentrations of AuCl 4 - and Ag + ions. The shape of the synthesised star-shaped Au-Ag nanoparticles does not change significantly during the two standard procedures for depositing a layer of silica (by the decomposition of sodium silicate or the decomposition of tetraethyl orthosilicate). Copyright © 2017 Elsevier B.V. All rights reserved.

Wind Resource Estimation using QuikSCAT Ocean Surface Winds

DEFF Research Database (Denmark)

Xu, Qing; Zhang, Guosheng; Cheng, Yongcun

2011-01-01

In this study, the offshore wind resources in the East China Sea and South China Sea were estimated from over ten years of QuikSCAT scatterometer wind products. Since the errors of these products are larger close to the coast due to the land contamination of radar backscatter signal...... and the complexity of air-sea interaction processes, an empirical relationship that adjusts QuikSCAT winds in coastal waters was first proposed based on vessel measurements. Then the shape and scale parameters of Weibull function are determined for wind resource estimation. The wind roses are also plotted. Results...

Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients

International Nuclear Information System (INIS)

Hemke, Robert; Lavini, Cristina; Maas, Mario; Nusman, Charlotte M.; Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W.; Dolman, Koert M.; Rossum, Marion A.J. van

2014-01-01

To compare DCE-MRI parameters and the relative number of time-intensity curve (TIC) shapes as derived from pixel-by-pixel DCE-MRI TIC shape analysis between knees of clinically active and inactive juvenile idiopathic arthritis (JIA) patients. DCE-MRI data sets were prospectively obtained. Patients were classified into two clinical groups: active disease (n = 43) and inactive disease (n = 34). Parametric maps, showing seven different TIC shape types, were created per slice. Statistical measures of different TIC shapes, maximal enhancement (ME), maximal initial slope (MIS), initial area under the curve (iAUC), time-to-peak (TTP), enhancing volume (EV), volume transfer constant (K trans ), extravascular space fractional volume (V e ) and reverse volume transfer constant (k ep ) of each voxel were calculated in a three-dimensional volume-of-interest of the synovial membrane. Imaging findings from 77 JIA patients were analysed. Significantly higher numbers of TIC shape 4 (P = 0.008), median ME (P = 0.015), MIS (P = 0.001) and iAUC (P = 0.002) were observed in clinically active compared with inactive patients. TIC shape 5 showed higher presence in the clinically inactive patients (P = 0.036). The pixel-by-pixel DCE-MRI TIC shape analysis method proved capable of differentiating clinically active from inactive JIA patients by the difference in the number of TIC shapes, as well as the descriptive parameters ME, MIS and iAUC. (orig.)

Shape memory alloys

International Nuclear Information System (INIS)

Kaszuwara, W.

2004-01-01

Shape memory alloys (SMA), when deformed, have the ability of returning, in certain circumstances, to their initial shape. Deformations related to this phenomenon are for polycrystals 1-8% and up to 15% for monocrystals. The deformation energy is in the range of 10 6 - 10 7 J/m 3 . The deformation is caused by martensitic transformation in the material. Shape memory alloys exhibit one directional or two directional shape memory effect as well as pseudoelastic effect. Shape change is activated by temperature change, which limits working frequency of SMA to 10 2 Hz. Other group of alloys exhibit magnetic shape memory effect. In these alloys martensitic transformation is triggered by magnetic field, thus their working frequency can be higher. Composites containing shape memory alloys can also be used as shape memory materials (applied in vibration damping devices). Another group of composite materials is called heterostructures, in which SMA alloys are incorporated in a form of thin layers The heterostructures can be used as microactuators in microelectromechanical systems (MEMS). Basic SMA comprise: Ni-Ti, Cu (Cu-Zn,Cu-Al, Cu-Sn) and Fe (Fe-Mn, Fe-Cr-Ni) alloys. Shape memory alloys find applications in such areas: automatics, safety and medical devices and many domestic appliances. Currently the most important appears to be research on magnetic shape memory materials and high temperature SMA. Vital from application point of view are composite materials especially those containing several intelligent materials. (author)

Pyramid shape of polymer solar cells: a simple solution to triple efficiency

International Nuclear Information System (INIS)

Xia, Yuxin; Hou, Lintao; Ma, Kaijie; Wang, Biao; Xiong, Kang; Liu, Pengyi; Liao, Jihai; Wen, Shangsheng; Wang, Ergang

2013-01-01

Pyramid-shaped polymer solar cells fabricated on flexible substrates were investigated. Effective light trapping can be realized due to light reflection in all 360° directions, and 100% space utilization is achieved when assembled into arrays. The power conversion efficiency is enhanced by 200% ([60]PCBM as the acceptor) and 260% ([70]PCBM as the acceptor) with a dihedral angle of 30° between the opposite sides of the pyramid compared with a planar device, and a high V oc of 3.5 V in series connection is obtained. Considering the material utilization, an angle of 90° for pyramid-shaped polymer solar cells is proposed. Pyramid-shaped polymer solar cells are particularly suitable for installation on roof of vehicles and houses, which have limited surface area. (paper)

Valuation of Human Resource During the Implementation of Resource Strategy of Sport Club

Directory of Open Access Journals (Sweden)

Polyakov Konstantin, L

2017-06-01

Full Text Available This study deals with the practice of human resource valuation in the professional command football during the implementation of sport club resource strategy. The choice of the direction of research is not random. Resource view in the analysis of strategy and strategy shaping (Barney, 1991 is an effective long term success tool. There are many costs in the process of resource allocation, in particular during resource valuation, in the market economy in connection, e.g. costs related to information collection and negotiating. Costs rise with the globalization of the economy. Therefore, it is important to create and maintain various institutions to control the level of costs and to study the most common practice of the resource strategy implementation. Particularly, it is important to study resource valuation in the context of institutional environment given the heterogeneity of markets. Human resource is the most important strategic resource on the market of professional command sport. At the same time, solving the problem of human resource allocation on this market leads to serious practical problems. Specifics of economic component of command sport results in the inevitability of labor market failure (Downward, Dawson, 2002 for sustainable development of the sector. Therefore, the need for institution which is to regulate the labor market occurs. Institute of transfer plays this role in some kinds of command sport, such as football. It is the system of concepts and rules, which regulate the transfer of athlete from one sport club to another prior to the expiration of the contract. The number of requirements exist due to the institute of transfer to the practice of athlete’s valuation, which determine the sum and the order of payment of compensation for prior sporting club management. The latter should correlate with the value of the athletes, which they are interest in, with the existing restrictions, which is the reason of the strongly

Interventions and Interactions: Understanding Coupled Human-Water Dynamics for Improved Water Resources Management in the Himalayas

Science.gov (United States)

Crootof, A.

2017-12-01

Understanding coupled human-water dynamics offers valuable insights to address fundamental water resources challenges posed by environmental change. With hydropower reshaping human-water interactions in mountain river basins, there is a need for a socio-hydrology framework—which examines two-way feedback loops between human and water systems—to more effectively manage water resources. This paper explores the cross-scalar interactions and feedback loops between human and water systems in river basins affected by run-of-the-river hydropower and highlights the utility of a socio-hydrology perspectives to enhance water management in the face of environmental change. In the Himalayas, the rapid expansion of run-of-the-river hydropower—which diverts streamflow for energy generation—is reconfiguring the availability, location, and timing of water resources. This technological intervention in the river basin not only alters hydrologic dyanmics but also shapes social outcomes. Using hydropower development in the highlands of Uttarakhand, India as a case study, I first illustrate how run-of-the-river projects transform human-water dynamics by reshaping the social and physical landscape of a river basin. Second, I emphasize how examining cross-scalar feedbacks among structural dynamics, social outcomes, and values and norms in this coupled human-water system can inform water management. Third, I present hydrological and social literature, raised separately, to indicate collaborative research needs and knowledge gaps for coupled human-water systems affected by run-of-the-river hydropower. The results underscore the need to understand coupled human-water dynamics to improve water resources management in the face of environmental change.

A New 3D Object Pose Detection Method Using LIDAR Shape Set.

Science.gov (United States)

Kim, Jung-Un; Kang, Hang-Bong

2018-03-16

In object detection systems for autonomous driving, LIDAR sensors provide very useful information. However, problems occur because the object representation is greatly distorted by changes in distance. To solve this problem, we propose a LIDAR shape set that reconstructs the shape surrounding the object more clearly by using the LIDAR point information projected on the object. The LIDAR shape set restores object shape edges from a bird's eye view by filtering LIDAR points projected on a 2D pixel-based front view. In this study, we use this shape set for two purposes. The first is to supplement the shape set with a LIDAR Feature map, and the second is to divide the entire shape set according to the gradient of the depth and density to create a 2D and 3D bounding box proposal for each object. We present a multimodal fusion framework that classifies objects and restores the 3D pose of each object using enhanced feature maps and shape-based proposals. The network structure consists of a VGG -based object classifier that receives multiple inputs and a LIDAR-based Region Proposal Networks (RPN) that identifies object poses. It works in a very intuitive and efficient manner and can be extended to other classes other than vehicles. Our research has outperformed object classification accuracy (Average Precision, AP) and 3D pose restoration accuracy (3D bounding box recall rate) based on the latest studies conducted with KITTI data sets.

Bio-based hyperbranched thermosetting polyurethane/triethanolamine functionalized multi-walled carbon nanotube nanocomposites as shape memory materials.

Science.gov (United States)

Kalita, Hemjyoti; Karak, Niranjan

2014-07-01

Here, bio-based shape memory polymers have generated immense interest in recent times. Here, Bio-based hyperbranched polyurethane/triethanolamine functionalized multi-walled carbon nanotube (TEA-f-MWCNT) nanocomposites were prepared by in-situ pre-polymerization technique. The Fourier transform infrared spectroscopy and the transmission electron microscopic studies showed the strong interfacial adhesion and the homogeneous distribution of TEA-f-MWCNT in the polyurethane matrix. The prepared epoxy cured thermosetting nanocomposites exhibited enhanced tensile strength (6.5-34.5 MPa), scratch hardness (3.0-7.5 kg) and thermal stability (241-288 degrees C). The nanocomposites showed excellent shape fixity and shape recovery. The shape recovery time decreases (24-10 s) with the increase of TEA-f-MWCNT content in the nanocomposites. Thus the studied nanocomposites have potential to be used as advanced shape memory materials.

Thermomechanical behavior of Fe-Mn-Si-Cr-Ni shape memory alloys modified with samarium

International Nuclear Information System (INIS)

Shakoor, R.A.; Khalid, F. Ahmad

2009-01-01

The deformation and training behavior of Fe-14Mn-3Si-10Cr-5Ni (wt.%) shape memory alloys containing samarium addition has been studied in the iron-based shape memory alloys. It is noticed that thermomechanical treatment (training) has significant influence on proof stress, critical stress and shape memory behavior of the alloys. The improvement in shape memory behavior can be attributed to the decrease in the proof stress and critical stress which facilitates the formation of ε (hcp martensite). It is also observed that alloy 2 containing samarium undergoes less softening as compared to alloy 1 with training which inhibits the formation of α (bcc martensite) and thus enhances the shape memory behavior. The excessive thermomechanical treatment with increase in the training cycle has led to the formation of α (bcc martensite) along with ε (hcp martensite) in the alloy 1 which appeared to have decline in the shape memory effect. This has been demonstrated by the examination of microstructure and identification of α (bcc martensite) martensite in the alloy 1 as compared to alloy 2

Chinese wine classification system based on micrograph using combination of shape and structure features

Science.gov (United States)

Wan, Yi

2011-06-01

Chinese wines can be classification or graded by the micrographs. Micrographs of Chinese wines show floccules, stick and granule of variant shape and size. Different wines have variant microstructure and micrographs, we study the classification of Chinese wines based on the micrographs. Shape and structure of wines' particles in microstructure is the most important feature for recognition and classification of wines. So we introduce a feature extraction method which can describe the structure and region shape of micrograph efficiently. First, the micrographs are enhanced using total variation denoising, and segmented using a modified Otsu's method based on the Rayleigh Distribution. Then features are extracted using proposed method in the paper based on area, perimeter and traditional shape feature. Eight kinds total 26 features are selected. Finally, Chinese wine classification system based on micrograph using combination of shape and structure features and BP neural network have been presented. We compare the recognition results for different choices of features (traditional shape features or proposed features). The experimental results show that the better classification rate have been achieved using the combinational features proposed in this paper.

Shape memory materials

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Compared with piezoelectric ceramics and magnetostrictive materials, the shape memory materials possess larger recoverable strain and recovery stress but slower response to external field. It is expected that the magneto-shape memory materials may develop considerable strain as well as rapid and precise shape control. Pseudoelasticity and shape memory effect (SME) resulted from martensitic transformation and its reverse transformation in shape memory materials were generally described. The requirements of appearing the shape memory effect in materials and the criteria for thermoelastic martensitic transformation were given. Some aspects concerning characteristics of martensitic transformation, and factors affecting SME in Ni-Ti, Cu-Zn-Al and Fe-Mn-Si based alloys as well as ZrO2 containing ceramics were briefly reviewed. Thermodynamic calculation of Ms temperature as function of grain size and parent ordering in Cu-Zn-Al was presented. The works on prediction of Ms in Fe-Mn-Si based alloys and in ZrO2-CeO2 were mentioned. Magnetic shape memory materials were briefly introduced.

Shape anisotropy enhanced optomagnetic measurement for prostate-specific antigen detection via magnetic chain formation

DEFF Research Database (Denmark)

Tian, Bo; Wetterskog, Erik; Qiu, Zhen

2017-01-01

anisotropy), and directly increasing the optomagnetic signal (via optical shape anisotropy). We achieve a limit of detection (LOD) of 5.5 pM (0.82 ng/mL) for the detection of a model multivalent molecule, biotinylated anti-streptavidin, in PBS. For the measurements of prostate-specific antigen (PSA) in 50...

The Better You Feel the Better You Learn: Do Warm Colours and Rounded Shapes Enhance Learning Outcome in Multimedia Learning?

Directory of Open Access Journals (Sweden)

Hannes Münchow

2017-01-01

Full Text Available The aim of the present study was to examine whether fostering positive activating affect during multimedia learning enhances learning outcome. University students were randomly assigned to either a multimedia learning environment designed to induce positive activating affect through the use of “warm” colours and rounded shapes (n=61 or an affectively neutral environment that used achromatic colours and sharp edges (n=50. Participants learned about the topic of functional neuroanatomy for 20 minutes and had to answer several questions for comprehension and transfer afterwards. Affective states as well as achievement goal orientations were investigated before and after the learning phase using questionnaires. The results show that participants in the affectively positive environment were superior in comprehension as well as transfer when initial affect was strong. Preexperimental positive affect was therefore a predictor of comprehension and a moderator for transfer. Goal orientations did not influence these effects. The findings support the idea that positive affect, induced through the design of the particular multimedia learning environment, can facilitate performance if initial affective states are taken into account.

U-Shaped Interest in U-Shaped Development--and What It Means

Science.gov (United States)

Siegler, Robert S.

2004-01-01

Interest in U-shaped development has itself undergone a U-shaped progression. Twenty-five years ago, interest in U-shaped development was high. This interest was evident at a 1978 conference in Tel Aviv on "U-shaped Behavioral Growth" that resulted in the publication of a book of the same title 4 years later (Strauss, 1982). The breadth…

Silver Nanoparticle-Decorated Shape-Memory Polystyrene Sheets as Highly Sensitive Surface-Enhanced Raman Scattering Substrates with a Thermally Inducible Hot Spot Effect.

Science.gov (United States)

Mengesha, Zebasil Tassew; Yang, Jyisy

2016-11-15

In this study, an active surface-enhanced Raman scattering (SERS) substrate with a thermally inducible hot spot effect for sensitive measurement of Raman-active molecules was successfully fabricated from silver nanoparticle (AgNP)-decorated shape-memory polystyrene (SMP) sheets. To prepare the SERS substrate, SMP sheets were first pretreated with n-octylamine for effective decoration with AgNPs. By varying the formulation and condition of the reduction reaction, AgNP-decorated SMP (Ag@SMP) substrates were successfully prepared with optimized particle gaps to produce inducible hot spot effects on thermal shrink. High-quality SERS spectra were easily obtained with enhancement factors higher than 10 8 by probing with aromatic thiols. Several Ag@SMP substrates produced under different reaction conditions were explored for the creation of inducible hot spot effects. The results indicated that AgNP spacing is crucial for strong hot spot effects. The suitability of Ag@SMP substrates for quantification was also evaluated according to the detection of adenine. Results confirmed that prepared Ag@SMP substrates were highly suitable for quantitative analysis because they yielded an estimated limit of detection as low as 120 pg/cm 2 , a linear range of up to 7 ng/cm 2 , and a regression coefficient (R 2 ) of 0.9959. Ag@SMP substrates were highly reproducible; the average relative standard deviation for all measurements was less than 10%.

Optical tracking of contrast medium bolus to optimize bolus shape and timing in dynamic computed tomography

International Nuclear Information System (INIS)

Eisa, Fabian; Brauweiler, Robert; Peetz, Alexander; Hupfer, Martin; Nowak, Tristan; Kalender, Willi A

2012-01-01

One of the biggest challenges in dynamic contrast-enhanced CT is the optimal synchronization of scan start and duration with contrast medium administration in order to optimize image contrast and to reduce the amount of contrast medium. We present a new optically based approach, which was developed to investigate and optimize bolus timing and shape. The time-concentration curve of an intravenously injected test bolus of a dye is measured in peripheral vessels with an optical sensor prior to the diagnostic CT scan. The curves can be used to assess bolus shapes as a function of injection protocols and to determine contrast medium arrival times. Preliminary results for phantom and animal experiments showed the expected linear behavior between dye concentration and absorption. The kinetics of the dye was compared to iodinated contrast medium and was found to be in good agreement. The contrast enhancement curves were reliably detected in three mice with individual bolus shapes and delay times of 2.1, 3.5 and 6.1 s, respectively. The optical sensor appears to be a promising approach to optimize injection protocols and contrast enhancement timing and is applicable to all modalities without implying any additional radiation dose. Clinical tests are still necessary. (note)

The state of human dimensions capacity for natural resource management: needs, knowledge, and resources

Science.gov (United States)

Sexton, Natalie R.; Leong, Kirsten M.; Milley, Brad J.; Clarke, Melinda M.; Teel, Tara L.; Chase, Mark A.; Dietsch, Alia M.

2013-01-01

The social sciences have become increasingly important in understanding natural resource management contexts and audiences, and are essential in design and delivery of effective and durable management strategies. Yet many agencies and organizations do not have the necessary resource management. We draw on the textbook definition of HD: how and why people value natural resources, what benefits people seek and derive from those resources, and how people affect and are affected by those resources and their management (Decker, Brown, and Seimer 2001). Clearly articulating how HD information can be used and integrated into natural resource management planning and decision-making is an important challenge faced by the HD field. To address this challenge, we formed a collaborative team to explore the issue of HD capacity-building for natural resource organizations and to advance the HD field. We define HD capacity as activities, efforts, and resources that enhance the ability of HD researchers and practitioners and natural managers and decision-makers to understand and address the social aspects of conservation.Specifically, we sought to examine current barriers to integration of HD into natural resource management, knowledge needed to improve HD capacity, and existing HD tools, resources, and training opportunities. We conducted a needs assessment of HD experts and practitioners, developed a framework for considering HD activities that can contribute both directly and indirectly throughout any phase of an adaptive management cycle, and held a workshop to review preliminary findings and gather additional input through breakout group discussions. This paper provides highlights from our collaborative initiative to help frame and inform future HD capacity-building efforts and natural resource organizations and also provides a list of existing human dimensions tools and resources.

Early-enhancing non-neoplastic lesions on gadolinium-enhanced MRI of the liver

Energy Technology Data Exchange (ETDEWEB)

Kanematsu, M. E-mail: masa-gif@umin.ac.jp; Kondo, H.; Semelka, R.C.; Matsuo, M.; Goshima, S.; Hoshi, H.; Moriyama, N.; Itai, Y

2003-10-01

AIM: To assess the frequency, cause, and significance of early-enhancing, non-neoplastic (EN) lesions on gadolinium-enhanced magnetic resonance imaging (MRI) of the liver performed for the detection of malignant hepatic tumours. MATERIALS AND METHODS: From September 1997 to September 2000, we reviewed the images of 125 patients, suspected of having hepatic tumours, in whom (1) gadolinium-enhanced triphasic dynamic gradient-recalled-echo (GRE) imaging in addition to unenhanced T1- and T2-weighted MRI was performed, (2) conventional angiography and combination computed tomography (CT) hepatic arteriography and CT during arterial portography were performed within 2 weeks of the MRI, and (3) definitive surgery within 2 weeks of the MRI or follow-up study by means of intravenously contrast-enhanced CT or MRI in 10 months or more was performed. Angiographic studies were correlated to determine the underlying causes of the EN lesions. RESULTS: We found 78 EN lesions in 36 patients (29%), ranging in size from 4 and 50 mm (mean, 12.2 mm). From the MR reports, our radiologists had prospectively diagnosed EN lesions as probable malignant tumours in eight (10%), possible malignant tumours in 36 (46%), and probable non-neoplastic lesion in 34 (44%). EN lesions were found in 27 of 81 (33%) cirrhotic patients and in nine of 44 (20%) non-cirrhotic patients. Fifty-one EN lesions (65%) were located along the liver edge. The shape was circular in 42 (54%), oval in 14 (18%), irregular in 12 (15%), wedge-shaped in seven (9%), and fan-shaped in three (4%). Twenty EN lesions (26%) appeared slightly hyperintense on T2-weighted images. The causes were non-neoplastic arterio-portal shunting in 48 (62%), cystic venous drainage in four (5%), rib compression in four (5%), aberrant right gastric venous drainage in two (3%), and unknown in 20 (26%). CONCLUSION: Over half the number of EN lesions were caused by non-neoplastic arterio-portal shunting, occasionally showing slight hyperintensity on

Whole-body bone segmentation from MRI for PET/MRI attenuation correction using shape-based averaging

DEFF Research Database (Denmark)

Arabi, Hossein; Zaidi, H.

2016-01-01

Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine it with stati......Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine...... it with statistical atlas fusion techniques. Moreover, a fast and efficient shape comparisonbased atlas selection scheme was developed and incorporated into the SBA method. Methods: Clinical studies consisting of PET/CT and MR images of 21 patients were used to assess the performance of the SBA method. In addition...... voting (MV) atlas fusion scheme was also evaluated as a conventional and commonly used method. MRI-guided attenuation maps were generated using the different segmentation methods. Thereafter, quantitative analysis of PET attenuation correction was performed using CT-based attenuation correction...

Resource management and nonmarket valuation research

Science.gov (United States)

Douglas, A.J.; Taylor, J.G.

1999-01-01

Survey based nonmarket valuation research is often regarded as economics research. However, resource economists need to be aware of and acknowledge the manifold information sources that they employ in order to enhance the policy credibility of their studies. Communication between resource economists and practitioners of allied disciplines including chemistry, civil engineering, sociology, and anthropology are often neglected. Recent resource allocation policy debates have given rise to an extensive discussion of methodological issues that narrow the scope of the subject. The present paper provides a format for the presentation of nonmarket valuation research results that emphasizes the manifold links between economics studies that employ different methodologies to estimate nonmarket resource values. A more robust emphasis on the interlocking features of the different approaches for estimating nonmarket benefits should foster appreciation of the transdisciplinary aspects of the subject.

Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture

Energy Technology Data Exchange (ETDEWEB)

Zachritz, W.H., II; Polka, R.; Schoenmackers

1996-04-01

A demonstration high rate aquaculture production system utilizing a cascaded geothermal resource was designed, constructed and operated to fulfill the objectives of this project. Analysis of the energy and water balances for the system indicated that the addition of an Aquaculture Facility expanded the use of the existing resource. This expanded use in no way affected the up- stream processes. Analysis of the system`s energy and water requirements indicated that the present resource was under-utilized and could be expanded. Energy requirements appeared more limiting than water use, but the existing system could be expanded to a culture volume of 72,000 gal. This system would have a potential production capacity of 93,600 lb/yr with a potential market value of $280,00/yr. Based on the results of this study, the heat remaining in the geothermal fluid from one square foot of operating greenhouse is sufficient to support six gallons of culture water for a high density aquaculture facility. Thus, the over 1.5M ft{sup 2} of existing greenhouse space in New Mexico, has the potential to create an aquaculture industry of nearly 9M gal. This translates to an annual production potential of 11.7M lb with a market value of $35.lM.

Connecting empowerment-focused HRM and labor productivity to work engagement : The mediating role of job demands and resources

NARCIS (Netherlands)

van de Voorde, F.C.; Veld, M.; van Veldhoven, M.J.P.M.

2016-01-01

Integrating the strategic HRM literature with key aspects of the job demands-resources (JDR) model, we propose in this study that empowerment-focused HRM and labour productivity influence work engagement of employees by shaping task-related resources and demands. A total of 311 employees nested

Connecting empowerment-focused HRM and labour productivity to work engagement: the mediating role of job demands and resources

NARCIS (Netherlands)

van de Voorde, Karina; Veld, M.F.A.; van Veldhoven, Marc

2016-01-01

Integrating the strategic HRM literature with key aspects of the job demands-resources (JDR) model, we propose in this study that empowerment-focused HRM and labour productivity influence work engagement of employees by shaping task-related resources and demands. A total of 311 employees nested

Optimal resource states for local state discrimination

Science.gov (United States)

Bandyopadhyay, Somshubhro; Halder, Saronath; Nathanson, Michael

2018-02-01

We study the problem of locally distinguishing pure quantum states using shared entanglement as a resource. For a given set of locally indistinguishable states, we define a resource state to be useful if it can enhance local distinguishability and optimal if it can distinguish the states as well as global measurements and is also minimal with respect to a partial ordering defined by entanglement and dimension. We present examples of useful resources and show that an entangled state need not be useful for distinguishing a given set of states. We obtain optimal resources with explicit local protocols to distinguish multipartite Greenberger-Horne-Zeilinger and graph states and also show that a maximally entangled state is an optimal resource under one-way local operations and classical communication to distinguish any bipartite orthonormal basis which contains at least one entangled state of full Schmidt rank.

Nuclear shape evolution starting from superdeformed state. Role of two-body collision and rotation

International Nuclear Information System (INIS)

Liu, Yu-xin; Sakata, Fumihiko

1999-01-01

With the nuclear density distribution being simulated by the Boltzmann Uehling-Uhlenbeck equation and Vlasov equation with several rotational frequencies, the time evolution of the quadrupole moment of nucleus 86 Zr starting with superdeformed shape is studied. The contribution of two-body collisions and the effects of collective rotation to the shape evolution is investigated. The numerical results indicate that the two-body collisions play a role of damping on the evolution from a superdeformed shape to a normal deformed one in a case without rotation. In a case of rotation with lower frequency, the two-body collisions accelerate the evolution process. A new role of the collective rotation to enhance the nuclear fission is proposed. (author)

Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

Directory of Open Access Journals (Sweden)

Fengming Wang

2012-12-01

Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

Access to electronic resources by visually impaired people

Directory of Open Access Journals (Sweden)

Jenny Craven

2003-01-01

Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

NOTION, ELEMENTS AND EVALUATION OF HUMAN RESOURCES MANAGMENT IN SPORT

Directory of Open Access Journals (Sweden)

Milorad M. Drobac

2009-11-01

Full Text Available Principal object of the author’s research in work is identification of notion, cru- cial elements and evaluation of human resources management in general and apart in sport. From the beginning of usage of term “human resources management”, we use foretoken “strategic” that has especially signified meaning. Strategic approach to the exploration of this problem points to the fact that human resources are from particularly significance for all forms of human organization (firms, associations, institutions etc., regardless are we talking about economy, social activity, politics, science, sport or any other area of human activity. Experience shows that, in our society, we mainly considered human resources management from the aspect of formulation and implementation of strategy in any shape and segment of altogether human activity, but we pay a little interest to the control, or in other words evaluation of human resources performance. What is attained in world rela- tions, on the human resources management plan, admonish and binds that we must ac- cept employees in our environment (it implies sport as an equal partner in management

Refining teacher design capacity: mathematics teachers' interactions with digital curriculum resources

NARCIS (Netherlands)

Pepin, B.; Gueudet, G.; Trouche, L.

2017-01-01

The goal of this conceptual paper is to develop enhanced understandings of mathematics teacher design and design capacity when interacting with digital curriculum resources. We argue that digital resources in particular offer incentives and increasing opportunities for mathematics teachers’ design,

Enhanced photocurrent in thin-film amorphous silicon solar cells via shape controlled three-dimensional nanostructures

International Nuclear Information System (INIS)

Hilali, Mohamed M; Banerjee, Sanjay; Sreenivasan, S V; Yang Shuqiang; Miller, Mike; Xu, Frank

2012-01-01

In this paper, we have explored manufacturable approaches to sub-wavelength controlled three-dimensional (3D) nano-patterns with the goal of significantly enhancing the photocurrent in amorphous silicon solar cells. Here we demonstrate efficiency enhancement of about 50% over typical flat a-Si thin-film solar cells, and report an enhancement of 20% in optical absorption over Asahi textured glass by fabricating sub-wavelength nano-patterned a-Si on glass substrates. External quantum efficiency showed superior results for the 3D nano-patterned thin-film solar cells due to enhancement of broadband optical absorption. The results further indicate that this enhanced light trapping is achieved with minimal parasitic absorption losses in the deposited transparent conductive oxide for the nano-patterned substrate thin-film amorphous silicon solar cell configuration. Optical simulations are in good agreement with experimental results, and also show a significant enhancement in optical absorption, quantum efficiency and photocurrent. (paper)

Effect of Si on the reversibility of stress-induced martensite in Fe-Mn-Si shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

Stanford, N. [Centre for Material and Fibre Innovation, Deakin University, Geelong, Victoria 3217 (Australia); Dunne, D.P., E-mail: druce_dunne@uow.edu.au [Faculty of Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia)

2010-12-15

Fe-Mn-Si is a well-characterized ternary shape memory alloy. Research on this alloy has consistently shown that the addition of 5-6 wt.% Si is desirable to enhance the reversibility of stress-induced martensite vis-a-vis shape memory. This paper examines the effect of Si on the morphology and the crystallography of the martensite in the Fe-Mn-Si system. It is concluded that the addition of Si increases the c/a ratio of the martensite, reduces the transformation volume change and decreases the atomic spacing difference between the parallel close-packed directions in the austenite-martensite interface (habit) plane. It is proposed that, in addition to austenite strengthening, Si enhances reversibility by reducing the volume change and the interfacial atomic mismatch between the martensite and the austenite. Although shape memory is improved, transformation reversibility remains limited by the necessary misfit dislocations that accommodate the atomic spacing differences in the interface.

Effect of Si on the reversibility of stress-induced martensite in Fe-Mn-Si shape memory alloys

International Nuclear Information System (INIS)

Stanford, N.; Dunne, D.P.

2010-01-01

Fe-Mn-Si is a well-characterized ternary shape memory alloy. Research on this alloy has consistently shown that the addition of 5-6 wt.% Si is desirable to enhance the reversibility of stress-induced martensite vis-a-vis shape memory. This paper examines the effect of Si on the morphology and the crystallography of the martensite in the Fe-Mn-Si system. It is concluded that the addition of Si increases the c/a ratio of the martensite, reduces the transformation volume change and decreases the atomic spacing difference between the parallel close-packed directions in the austenite-martensite interface (habit) plane. It is proposed that, in addition to austenite strengthening, Si enhances reversibility by reducing the volume change and the interfacial atomic mismatch between the martensite and the austenite. Although shape memory is improved, transformation reversibility remains limited by the necessary misfit dislocations that accommodate the atomic spacing differences in the interface.

Measurement of b-quark Jet Shapes at CDF

Energy Technology Data Exchange (ETDEWEB)

Lister, Alison [Univ. of Oxford (United Kingdom)

2006-01-01

The main topic of this thesis is the measurement of b-quark jet shapes at CDF. CDF is an experiment located at Fermilab, in the United States, which studies proton-antiproton collisions at a center of mass energy of 1.96TeV. To reach this energy, the particles are accelerated using the Tevatron accelerator which is currently the highest energy collider in operation. The data used for this analysis were taken between February 2002 and September 2004 and represent an integrated luminosity of about 300 pb^-1. This is the first time that b-quark jet shapes have been measured at hadron colliders. The basis of this measurement lies in the possibility of enhancing the b-quark jet content of jet samples by requiring the jets to be identified as having a displaced vertex inside the jet cone. Such jets are called tagged. This enhances the b-quark jet fraction from about 5% before tagging to 20-40% after tagging, depending on the transverse momentum of the jets. I verified that it is possible to apply this secondary vertex tagging algorithm to different cone jet algorithms (MidPoint and JetClu) and different cone sizes (0.4 and 0.7). I found that the performance of the algorithm does not change significantly, as long as the sub-cone inside which tracks are considered for the tagging is kept at the default value of 0.4. Because the b-quark purity of the jets is still relatively low, it is necessary to extract the shapes of b-quark jets in a statistical manner from the jet shapes both before and after tagging. The other parameters that enter into the unfolding equation used to extract the b-quark jet shapes are the b-jet purities, the biases due to the tagging requirement both for b- and nonbjets and the hadron level corrections. The last of these terms corrects the measured b-jet shapes back to the shapes expected at hadron level which makes comparisons with theoretical models and other experimental results possible. This measurement shows that, despite relatively

Shape Perception and Navigation in Blind Adults

Science.gov (United States)

Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

2017-01-01

Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development. PMID:28144226

Investigation of high frequency external perturbation effects on flow in a T-shape microchannel by μLIF technique

Science.gov (United States)

Kravtsova, A. Yu; Meshalkin, Yu E.; Bilsky, A. V.

2017-11-01

Investigation of high frequency external perturbation effect on flow inside T-shape microchannel was examined. In-phase pulsations of different frequencies were added to both inlets of the T-shaped microchannel to study mixing by means of Micro Laser Induced Fluorescence (μLIF) technique. For all flow regimes studied, mixing enhancement was obtained. Significant enhancement can be achieved at the beginning of the outlet channel operating in steady asymmetric regime (Re=186) by forcing at certain frequency ranges (f = 500Hz, f = 800Hz). Mixing suppression was also observed for two flow regimes (Re = 400, f = 1000Hz) and (Re = 120, f = 700Hz).

The zebrafish world of colors and shapes: preference and discrimination.

Science.gov (United States)

Oliveira, Jessica; Silveira, Mayara; Chacon, Diana; Luchiari, Ana

2015-04-01

Natural environment imposes many challenges to animals, which have to use cognitive abilities to cope with and exploit it to enhance their fitness. Since zebrafish is a well-established model for cognitive studies and high-throughput screening for drugs and diseases that affect cognition, we tested their ability for ambient color preference and 3D objects discrimination to establish a protocol for memory evaluation. For the color preference test, zebrafish were observed in a multiple-chamber tank with different environmental color options. Zebrafish showed preference for blue and green, and avoided yellow and red. For the 3D objects discrimination, zebrafish were allowed to explore two equal objects and then observed in a one-trial test in which a new color, size, or shape of the object was presented. Zebrafish showed discrimination for color, shape, and color+shape combined, but not size. These results imply that zebrafish seem to use some categorical system to discriminate items, and distracters affect their ability for discrimination. The type of variables available (color and shape) may favor zebrafish objects perception and facilitate discrimination processing. We suggest that this easy and simple memory test could serve as a useful screening tool for cognitive dysfunction and neurotoxicological studies.

Achieving competitive advantage through strategic human resource management.

Science.gov (United States)

Fottler, M D; Phillips, R L; Blair, J D; Duran, C A

1990-01-01

The framework presented here challenges health care executives to manage human resources strategically as an integral part of the strategic planning process. Health care executives should consciously formulate human resource strategies and practices that are linked to and reinforce the broader strategic posture of the organization. This article provides a framework for (1) determining and focusing on desired strategic outcomes, (2) identifying and implementing essential human resource management actions, and (3) maintaining or enhancing competitive advantage. The strategic approach to human resource management includes assessing the organization's environment and mission; formulating the organization's business strategy; assessing the human resources requirements based on the intended strategy; comparing the current inventory of human resources in terms of numbers, characteristics, and human resource management practices with respect to the strategic requirements of the organization and its services or product lines; formulating the human resource strategy based on the differences between the assessed requirements and the current inventory; and implementing the appropriate human resource practices to reinforce the strategy and attain competitive advantage.

Update of the FANTOM web resource

DEFF Research Database (Denmark)

Lizio, Marina; Harshbarger, Jayson; Abugessaisa, Imad

2017-01-01

Upon the first publication of the fifth iteration of the Functional Annotation of Mammalian Genomes collaborative project, FANTOM5, we gathered a series of primary data and database systems into the FANTOM web resource (http://fantom.gsc.riken.jp) to facilitate researchers to explore...... transcriptional regulation and cellular states. In the course of the collaboration, primary data and analysis results have been expanded, and functionalities of the database systems enhanced. We believe that our data and web systems are invaluable resources, and we think the scientific community will benefit...... for this recent update to deepen their understanding of mammalian cellular organization. We introduce the contents of FANTOM5 here, report recent updates in the web resource and provide future perspectives....

Influence of Au Nanoparticle Shape on Au@Cu2O Heterostructures

Directory of Open Access Journals (Sweden)

Jie Zhu

2015-01-01

Full Text Available Synthesis of metal-semiconductor heterostructures may allow the combination of function of the corresponding components and/or the enhanced performance resulting from the interactions between all the components. In this paper, Au@Cu2O core-shell heterostructures are prepared by a seed-growth method, using different-shaped Au nanocrystals as the seeds such as nanorods, octahedra, decahedra, dots, and nanocubes. The results revealed that the final structure of Au@Cu2O was greatly influenced by the shape of the seeds used. Exposure of Cu2O{111} and Cu2O{001} favored when the overgrowth happened on Au{111} and Au{001} surface, respectively. The size of the product can also be tuned by the amount of the seeds. The results reported here provide a thinking clue to modulate the shape and size of core-shell nanocrystals, which is useful in developing new materials with desired performance.

The Development of the Flat-Knitted Shaped Uppers based on Ergonomics

Directory of Open Access Journals (Sweden)

Lu Zhiwen

2016-06-01

Full Text Available To achieve the efficiency and specification of the flat-knitted uppers design, the basic patterns of uppers are made from shoe lasts based on the research on the characteristics of human’s feet and wearability requirements on uppers. The knitting technology for half-shaped and fully shaped uppers was formed after the shear deformation of basic pattern and combination with flat knitting technology. As regards to the functional requirements on key parts of uppers, the structures of flat-knitted shaped uppers were intensively analysed and studied, dividing them into two categories (functional structure and decorative structure, discussing the knitting methods and advantages of different structure, and finally experimentally proving that the planar pattern of flat knitted uppers can apply to the design of flat-knitted uppers and achieve the combination of functionality and artistry of sneakers after combining with structural changes, with a great significance on the achievement of the efficient production of uppers and the enhancement of its commercial value.

Polydopamine Particle-Filled Shape-Memory Polyurethane Composites with Fast Near-Infrared Light Responsibility.

Science.gov (United States)

Yang, Li; Tong, Rui; Wang, Zhanhua; Xia, Hesheng

2018-03-25

A new kind of fast near-infrared (NIR) light-responsive shape-memory polymer composites was prepared by introducing polydopamine particles (PDAPs) into commercial shape-memory polyurethane (SMPU). The toughness and strength of the polydopamine-particle-filled polyurethane composites (SMPU-PDAPs) were significantly enhanced with the addition of PDAPs due to the strong interface interaction between PDAPs and polyurethane segments. Owing to the outstanding photothermal effect of PDAPs, the composites exhibit a rapid light-responsive shape-memory process in 60 s with a PDAPs content of 0.01 wt%. Due to the excellent dispersion and convenient preparation method, PDAPs have great potential to be used as high-efficiency and environmentally friendly fillers to obtain novel photoactive functional polymer composites. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Post-study caffeine administration enhances memory consolidation in humans.

Science.gov (United States)

Borota, Daniel; Murray, Elizabeth; Keceli, Gizem; Chang, Allen; Watabe, Joseph M; Ly, Maria; Toscano, John P; Yassa, Michael A

2014-02-01

It is currently not known whether caffeine has an enhancing effect on long-term memory in humans. We used post-study caffeine administration to test its effect on memory consolidation using a behavioral discrimination task. Caffeine enhanced performance 24 h after administration according to an inverted U-shaped dose-response curve; this effect was specific to consolidation and not retrieval. We conclude that caffeine enhanced consolidation of long-term memories in humans.

Complementary resources and capabilities for an ethical and environmental management: a qual/quan study

OpenAIRE

López-Gamero, María D.; Claver Cortés, Enrique; Molina-Azorín, José F.

2008-01-01

Managers’ commitment to contribute to sustainable development holds the key to their long-term business success and may be a source of competitive advantage. The managerial perception of business ethics is influenced by the level of moral development and personal characteristics of managers. These perceptions are also shaped by forces existing in the environment of the firm, including available resources, societal expectations, sector, and regulations. The resource-based perspective can th...

Information resources

Science.gov (United States)

Friend, Milton; Franson, J. Christian; Friend, Milton; Gibbs, Samantha E.J.; Wild, Margaret A.

2015-10-19

During recent decades, natural resources agency personnel and others involved with the management and stewardship of wildlife have experienced an increasing need to access information and obtain technical assistance for addressing a diverse array of wildlife disease issues. This Chapter provides a broad overview of selected sources for obtaining supplemental information and technical assistance for addressing wildlife disease issues in North America. Specifically, examples of existing major wildlife disease programs focusing on free-ranging wildlife populations are highlighted; training opportunities for enhancing within-agency wildlife disease response are identified; a selected reading list of wildlife disease references is provided; and selected Web sites providing timely information on wildlife disease are highlighted. No attempt is made to detail all the North American programs and capabilities that address disease in free-ranging wildlife populations. Instead, this Chapter is focused on enhancing awareness of the types of capabilities that exist as potential sources for assistance and collaboration between wildlife conservation agency personnel and others in addressing wildlife disease issues.

What factors mediate the relationship between global self-worth and weight and shape concerns?

Science.gov (United States)

Murphy, Edel; Dooley, Barbara; Menton, Aoife; Dolphin, Louise

2016-04-01

The primary aim of this study was to investigate whether the relationship between global self-worth and weight concerns and global self-worth and shape concerns was mediated by pertinent body image factors, while controlling for gender and estimated BMI. Participants were 775 adolescents (56% male) aged 12-18years (M=14.6; SD=1.50). Mediation analysis revealed a direct and a mediated effect between global self-worth and two body image models: 1) weight concerns and 2) shape concerns. The strongest mediators in both models were physical appearance, restrained eating, and depression. Partial mediation was observed for both models, indicating that body image factors which span cognitive, affective, and behavioral constructs, explain the association between global self-worth and weight and shape concerns. Implications for future research, weight and shape concern prevention and global self-worth enhancement programs are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can we apply the MRI BI-RADS lexicon morphology descriptors on contrast-enhanced spectral mammography?

Science.gov (United States)

Kamal, Rasha M; Helal, Maha H; Mansour, Sahar M; Haggag, Marwa A; Nada, Omniya M; Farahat, Iman G; Alieldin, Nelly H

2016-07-12

To assess the feasibility of using the MRI breast imaging reporting and data system (BI-RADS) lexicon morphology descriptors to characterize enhancing breast lesions identified on contrast-enhanced spectral mammography (CESM). The study is a retrospective analysis of the morphology descriptors of 261 enhancing breast lesions identified on CESM in 239 patients. We presented the morphological categorization of the included lesions into focus, mass and non-mass. Further classifications included (1) the multiplicity for "focus" category, (2) the shape, margin and internal enhancement for "mass" category and (3) the distribution and internal enhancement for "non-mass" category. Each morphology descriptor was evaluated individually (irrespective of all other descriptors) by calculating its sensitivity, specificity, positive-predictive value (PPV) and negative-predictive value (NPV) and likelihood ratios (LRs). The study included 68/261 (26.1%) benign lesions and 193/261 (73.9%) malignant lesions. Intensely enhancing foci, whether single (7/12, 58.3%) or multiple (2/12, 16.7%), were malignant. Descriptors of "irregular"-shape (PPV: 92.4%) and "non-circumscribed" margin (odds ratio: 55.2, LR positive: 4.77; p-value: <0.001) were more compatible with malignancy. Internal mass enhancement patterns showed a very low specificity (58.0%) and NPV (40.0%). Non-mass enhancement (NME) was detected in 81/261 lesions. Asymmetrical NME in 81% (n = 52/81) lesions was malignant lesions and internal enhancement patterns indicative of malignancy were the heterogeneous and clumped ones. We can apply the MRI morphology descriptors to characterize lesions on CESM, but with few expectations. In many situations, irregular-shaped, non-circumscribed masses and NME with focal, ductal or segmental distribution and heterogeneous or clumped enhancement are the most suggestive descriptors of malignant pathologies. (1) The MRI BI-RADS lexicon morphology descriptors can be applied in the

The Researches on I-beam of different web’s shapes

Science.gov (United States)

Shuang, Chao; Zhou, Dong Hua

2018-05-01

When the ratio of height to thickness of girder web is relatively high, generally the local stability of web is enhanced by setting up stiffeners. But setting up stiffeners not only increase the use of material, but also increases the welding work. Therefore, the web can be processed into trapezoid, curve, triangles and rectangle to improve its stability. In order to study the mechanical behavior of the web with different shapes and its local stable bearing capacity, the finite element analysis software ANSYS was used to analyze the six I-beam, and the stress characteristics under different web forms were obtained. The results show that the local stability bearing capacity of the I-beam is improved, especially the shape of the trapezoidal web and the shape of the curved web have a significant effect on the local stability of the I-beam. Finally, based on the study of the local stability of the trapezoidal web and the curved web, the influence of their geometrical dimensions on the local stable bearing capacity is also studied.

Web-based resources for critical care education.

Science.gov (United States)

Kleinpell, Ruth; Ely, E Wesley; Williams, Ged; Liolios, Antonios; Ward, Nicholas; Tisherman, Samuel A

2011-03-01

reviews of the benefits of utilizing e-learning. Review of the Web sites of relevant critical care organizations revealed the existence of a number of e-learning resources, including online critical care courses, tutorials, podcasts, webcasts, slide sets, and continuing medical education resources, some requiring membership or a fee to access. Respondents to listserve queries (>100) and critical care medicine fellowship director and advanced practice nursing educator e-mail queries (>50) identified the use of a number of tutorials, self-directed learning modules, and video-enhanced programs for critical care education and practice. In all, >135 Web-based education resources exist, including video Web resources for critical care education in a variety of e-learning formats, such as tutorials, self-directed learning modules, interactive case studies, webcasts, podcasts, and video-enhanced programs. As identified by critical care educators and practitioners, e-learning is actively being integrated into critical care medicine and nursing training programs for continuing medical education and competency training purposes. Knowledge of available Web-based educational resources may enhance critical care practitioners' ongoing learning and clinical competence, although this has not been objectively measured to date.

Femtosecond pulse shaping using the geometric phase.

Science.gov (United States)

Gökce, Bilal; Li, Yanming; Escuti, Michael J; Gundogdu, Kenan

2014-03-15

We demonstrate a femtosecond pulse shaper that utilizes polarization gratings to manipulate the geometric phase of an optical pulse. This unique approach enables circular polarization-dependent shaping of femtosecond pulses. As a result, it is possible to create coherent pulse pairs with orthogonal polarizations in a 4f pulse shaper setup, something until now that, to our knowledge, was only achieved via much more complex configurations. This approach could be used to greatly simplify and enhance the functionality of multidimensional spectroscopy and coherent control experiments, in which multiple coherent pulses are used to manipulate quantum states in materials of interest.

Body shape helps legged robots climb and turn in complex 3-D terrains

Science.gov (United States)

Han, Yuanfeng; Wang, Zheliang; Li, Chen

Analogous to streamlined shapes that reduce drag in fluids, insects' ellipsoid-like rounded body shapes were recently discovered to be ``terradynamically streamlined'' and enhance locomotion in cluttered terrain by facilitating body rolling. Here, we hypothesize that there exist more terradynamic shapes that facilitate other modes of locomotion like climbing and turning in complex 3-D terrains by facilitating body pitching and yawing. To test our hypothesis, we modified the body shape of a legged robot by adding an elliptical and a rectangular shell and tested how it negotiated with circular and square vertical pillars. With a rectangular shell the robot always pitched against square pillars in an attempt to climb, whereas with an elliptical shell it always yawed and turned away from circular pillars given a small initial lateral displacement. Square / circular pillars facilitated pitching / yawing, respectively. To begin to reveal the contact physics, we developed a locomotion energy landscape model. Our model revealed that potential energy barriers to transition from pitching to yawing are high for angular locomotor and obstacle shapes (rectangular / square) but vanish for rounded shapes (elliptical / circular). Our study supports the plausibility of locomotion energy landscapes for understanding the rich locomotor transitions in complex 3-D terrains.

Trainees' reactions to training: shaping groups and courses for happier trainees

DEFF Research Database (Denmark)

Giangreco, Antonio; Carugati, Andrea; Sebastiano, Antonio

2010-01-01

The extensive use of training demands more extensive evaluations of its real effects. Human resource scholars attempt to develop multi-dimensional training evaluation models, often ignored by practitioners, whereas training managers tend to evaluate only reaction evaluations, the first dimension ...... (which is also a moderator variable), the length of the course and the type of target audience influence trainees’ OST. These results provide useful implications for practitioners in shaping their courses and audiences to maximise the trainees’ reactions....

Impact of Grain Shape and Multiple Black Carbon Internal Mixing on Snow Albedo: Parameterization and Radiative Effect Analysis

Science.gov (United States)

He, Cenlin; Liou, Kuo-Nan; Takano, Yoshi; Yang, Ping; Qi, Ling; Chen, Fei

2018-01-01

We quantify the effects of grain shape and multiple black carbon (BC)-snow internal mixing on snow albedo by explicitly resolving shape and mixing structures. Nonspherical snow grains tend to have higher albedos than spheres with the same effective sizes, while the albedo difference due to shape effects increases with grain size, with up to 0.013 and 0.055 for effective radii of 1,000 μm at visible and near-infrared bands, respectively. BC-snow internal mixing reduces snow albedo at wavelengths external mixing, internal mixing enhances snow albedo reduction by a factor of 1.2-2.0 at visible wavelengths depending on BC concentration and snow shape. The opposite effects on albedo reductions due to snow grain nonsphericity and BC-snow internal mixing point toward a careful investigation of these two factors simultaneously in climate modeling. We further develop parameterizations for snow albedo and its reduction by accounting for grain shape and BC-snow internal/external mixing. Combining the parameterizations with BC-in-snow measurements in China, North America, and the Arctic, we estimate that nonspherical snow grains reduce BC-induced albedo radiative effects by up to 50% compared with spherical grains. Moreover, BC-snow internal mixing enhances the albedo effects by up to 30% (130%) for spherical (nonspherical) grains relative to external mixing. The overall uncertainty induced by snow shape and BC-snow mixing state is about 21-32%.

Prolate non-collective shape- a rare shape phase around Z = 50

International Nuclear Information System (INIS)

Aggarwal, Mamta

2009-01-01

The search for rare shape-phase transition in hot and rotating nuclei is one of the very active field in nuclear physics research. According to universally known features of the evolution of equilibrium shapes with temperature and spin, heating a deformed nonrotating nucleus leads to a shape transition from deformed to spherical at a certain temperature. At high temperatures T≅ 2 MeV, the shell effects melt and the nucleus resembles a classical liquid drop. Rotation of the hot nucleus generates an oblate shape rotating noncollectively. But it has been shown by A. Goodman that nuclei with two critical temperatures can rotate with a rare non-collective prolate shape phase which has been caused directly by rotation at angular momentum values around (5-30h) which creates a residual quantum shell effect as shown by A. L. Goodman. Search for such exotic shape-phase around Z = 50 region is the aim of present work. We consider N = 60 isotones 108 Cd, 109 In, 110 Sn

Shape Effects in Nanoparticle-Based Imaging Agents

Science.gov (United States)

Culver, Kayla Shani Brook

At the nanoscale, material properties become highly size and shape dependent. These properties can be manipulated and exploited for a variety of biomedical applications, including sensing, drug delivery, diagnostics, and imaging. In particular, nanoparticles of different materials, sizes and shapes have been developed as high-performance contrast agents for optical, electron, and medical imaging. In this thesis, I focus on gold nanoparticles because they are widely used as contrast agents in multiple types of imaging modalities. Additionally, the surface of gold can be readily functionalized with ligands and the structure of the particles can be manipulated to modulate their performance as imaging agents. The properties of nanoparticles can generate contrast directly. For example, the light scattering properties of gold particles can be visualized in optical microscopy, the high electron density of gold produces contrast in electron microscopy, and the x-ray absorption properties of gold can be detected in medical x-ray and computed tomography imaging. Alternatively, the properties of the nanomaterial can be exploited to modulate the signal produced by other molecules that are bound to the particle surface. The light emission of molecular fluorophores can be quenched or dramatically increased by coupling to the optical field enhancements of gold nanoparticles, and the performance of gadolinium (Gd(III))-based magnetic resonance imaging (MRI) contrast agents can be increased by coupling to the rotational motion of nanoparticles. In this dissertation, I focus specifically on how the structure of star-shaped gold particles (nanostars) can be exploited as single-particle optical probes and to dramatically enhance the relaxivity of Gd(III) bound to the surface. Differential interference contrast (DIC) is a type of wide-field diffraction-limited optical microscopy that is commonly used by biologists to image cells without labels. Here, I demonstrate the DIC can be used

Thermoviscoelastic shape memory behavior for epoxy-shape memory polymer

International Nuclear Information System (INIS)

Chen, Jianguo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2014-01-01

There are various applications for shape memory polymer (SMP) in the smart materials and structures field due to its large recoverable strain and controllable driving method. The mechanical shape memory deformation mechanism is so obscure that many samples and test schemes have to be tried in order to verify a final design proposal for a smart structure system. This paper proposes a simple and very useful method to unambiguously analyze the thermoviscoelastic shape memory behavior of SMP smart structures. First, experiments under different temperature and loading conditions are performed to characterize the large deformation and thermoviscoelastic behavior of epoxy-SMP. Then, a rheological constitutive model, which is composed of a revised standard linear solid (SLS) element and a thermal expansion element, is proposed for epoxy-SMP. The thermomechanical coupling effect and nonlinear viscous flowing rules are considered in the model. Then, the model is used to predict the measured rubbery and time-dependent response of the material, and different thermomechanical loading histories are adopted to verify the shape memory behavior of the model. The results of the calculation agree with experiments satisfactorily. The proposed shape memory model is practical for the design of SMP smart structures. (paper)

Macroecological factors shape local-scale spatial patterns in agriculturalist settlements.

Science.gov (United States)

Tao, Tingting; Abades, Sebastián; Teng, Shuqing; Huang, Zheng Y X; Reino, Luís; Chen, Bin J W; Zhang, Yong; Xu, Chi; Svenning, Jens-Christian

2017-11-15

Macro-scale patterns of human systems ranging from population distribution to linguistic diversity have attracted recent attention, giving rise to the suggestion that macroecological rules shape the assembly of human societies. However, in which aspects the geography of our own species is shaped by macroecological factors remains poorly understood. Here, we provide a first demonstration that macroecological factors shape strong local-scale spatial patterns in human settlement systems, through an analysis of spatial patterns in agriculturalist settlements in eastern mainland China based on high-resolution Google Earth images. We used spatial point pattern analysis to show that settlement spatial patterns are characterized by over-dispersion at fine spatial scales (0.05-1.4 km), consistent with territory segregation, and clumping at coarser spatial scales beyond the over-dispersion signals, indicating territorial clustering. Statistical modelling shows that, at macroscales, potential evapotranspiration and topographic heterogeneity have negative effects on territory size, but positive effects on territorial clustering. These relationships are in line with predictions from territory theory for hunter-gatherers as well as for many animal species. Our results help to disentangle the complex interactions between intrinsic spatial processes in agriculturalist societies and external forcing by macroecological factors. While one may speculate that humans can escape ecological constraints because of unique abilities for environmental modification and globalized resource transportation, our work highlights that universal macroecological principles still shape the geography of current human agricultural societies. © 2017 The Author(s).

An in situ neutron diffraction study of shape setting shape memory NiTi

International Nuclear Information System (INIS)

Benafan, O.; Padula, S.A.; Noebe, R.D.; Brown, D.W.; Clausen, B.; Vaidyanathan, R.

2013-01-01

A bulk polycrystalline Ni 49.9 Ti 50.1 (at.%) shape memory alloy specimen was shape set while neutron diffraction spectra were simultaneously acquired. The objective was to correlate internal stress, phase volume fraction, and texture measurements (from neutron diffraction spectra) with the macroscopic stress and shape changes (from load cell and extensometry measurements) during the shape setting procedure and subsequent shape recovery. Experimental results showed the evolution of the martensitic transformation (lattice strains, phase fractions and texture) against external constraints during both heating and cooling. Constrained heating resulted in a build-up of stresses during the martensite to austenite transformation, followed by stress relaxation due to thermal expansion, final conversion of retained martensite, and recovery processes. Constrained cooling also resulted in stress build-up arising from thermal contraction and early formation of martensite, followed by relaxation as the austenite fully transformed to martensite. Comparisons were also made between specimens pre-shape set and post-shape set with and without external constraints. The specimens displayed similar shape memory behavior consistent with the microstructure of the shape set sample, which was mostly unchanged by the shape setting process and similar to that of the as-received material

Electron pulse shaping in the FELIX RF accelerator

International Nuclear Information System (INIS)

Weits, H.H.; Geer, C.A.J. van der; Oepts, D.; Meer, A.F.G. van der

1999-01-01

The FELIX free-electron laser uses short pulses of relativistic electrons produced by an RF accelerator. The design target for the duration of these electron bunches was around 3 ps. In experiments we observed that the bunches emit coherently enhanced spontaneous emission (CSE) when they travel through an undulator. It was demonstrated that the power level of the CSE critically depends on the settings of the accelerator. In this article we seek to explain these observations by studying the length and shape of the electron bunches as a function of the settings of the accelerator. A particle-tracking model was used to simulate the acceleration and transport processes. These include bunch compression in a 14-cell travelling wave buncher cavity, acceleration in a travelling wave linear accelerator, and passage through a (dispersive) chicane structure. The effect of the phase setting of the RF accelerating field with respect to the arrival time of the electron bunch in each accelerator structure was studied. The parameter range of the simulations is related to that of an actual free-electron laser experiment using these bunches. We find that, for specific settings of the accelerating system, electron pulses with a length of 350 μm FWHM (1 ps) are produced. The charge in the bunch rises steeply within a distance of 25 μm. This bunch shape explains the high level of coherently enhanced spontaneous emission observed in the FELIX laser. (author)

Rogue waves and W-shaped solitons in the multiple self-induced transparency system.

Science.gov (United States)

Wang, Xin; Liu, Chong; Wang, Lei

2017-09-01

We study localized nonlinear waves on a plane wave background in the multiple self-induced transparency (SIT) system, which describes an important enhancement of the amplification and control of optical waves compared to the single SIT system. A hierarchy of exact multiparametric rational solutions in a compact determinant representation is presented. We demonstrate that this family of solutions contain known rogue wave solutions and unusual W-shaped soliton solutions. State transitions between the fundamental rogue waves and W-shaped solitons as well as higher-order nonlinear superposition modes are revealed in the zero-frequency perturbation region by the suitable choice for the background wavenumber of the electric field component. Particularly, it is found that the multiple SIT system can admit both stationary and nonstationary W-shaped solitons in contrast to the stationary results in the single SIT system. Moreover, the W-shaped soliton complex which is formed by a certain number of fundamental W-shaped solitons with zero phase parameters and its decomposition mechanism in the case of the nonzero phase parameters are shown. Meanwhile, some important characteristics of the nonlinear waves including trajectories and spectrum are discussed through the numerical and analytical methods.

Effect of the Network Structure and Programming Temperature on the Shape-Memory Response of Thiol-Epoxy “Click” Systems

Directory of Open Access Journals (Sweden)

Alberto Belmonte

2015-10-01

Full Text Available This paper presents a new methodology to develop “thiol-epoxy” shape-memory polymers (SMPs with enhanced mechanical properties in a simple and efficient manner via “click” chemistry by using thermal latent initiators. The shape-memory response (SMR, defined by the mechanical capabilities of the SMP (high ultimate strength and strain, the shape-fixation and the recovery of the original shape (shape-recovery, was analyzed on thiol-epoxy systems by varying the network structure and programming temperature. The glass transition temperature (Tg and crosslinking density were modified using 3- or 4- functional thiol curing agents and different amounts of a rigid triglycidyl isocyanurate compound. The relationship between the thermo-mechanical properties, network structure and the SMR was evidenced by means of qualitative and quantitative analysis. The influence of the programming temperature (Tprog on the SMR was also analyzed in detail. The results demonstrate the possibility of tailoring SMPs with enhanced mechanical capabilities and excellent SMR, and intend to provide a better insight into the relationship between the network structure properties, programming temperature and the SMR of unconstrained (stress-free systems; thus, making it easier to decide between different SMP and to define the operative parameters in the useful life.

The guidance of visual search by shape features and shape configurations.

Science.gov (United States)

McCants, Cody W; Berggren, Nick; Eimer, Martin

2018-03-01

Representations of target features (attentional templates) guide attentional object selection during visual search. In many search tasks, targets objects are defined not by a single feature but by the spatial configuration of their component shapes. We used electrophysiological markers of attentional selection processes to determine whether the guidance of shape configuration search is entirely part-based or sensitive to the spatial relationship between shape features. Participants searched for targets defined by the spatial arrangement of two shape components (e.g., hourglass above circle). N2pc components were triggered not only by targets but also by partially matching distractors with one target shape (e.g., hourglass above hexagon) and by distractors that contained both target shapes in the reverse arrangement (e.g., circle above hourglass), in line with part-based attentional control. Target N2pc components were delayed when a reverse distractor was present on the opposite side of the same display, suggesting that early shape-specific attentional guidance processes could not distinguish between targets and reverse distractors. The control of attention then became sensitive to spatial configuration, which resulted in a stronger attentional bias for target objects relative to reverse and partially matching distractors. Results demonstrate that search for target objects defined by the spatial arrangement of their component shapes is initially controlled in a feature-based fashion but can later be guided by templates for spatial configurations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

Energy Technology Data Exchange (ETDEWEB)

Rasselet, Benjamin [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Larbi, Ahmed; Viala, Pierre [Medical Imaging Department, Nimes University Hospital, 4 rue du Professeur Robert Debré, 30029 Nîmes (France); Molinari, Nicolas [Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Tetreau, Raphael [Medical Imaging Department, Montpellier Cancer Institute (ICM), 208 Avenue des Apothicaires, 34298 Montpellier Cedex 5 (France); Faruch-Bilfeld, Marie [Medical Imaging Department, Toulouse University Hospital, Place du Docteur Baylac, 31059 Toulouse Cedex 9 (France); Taourel, Patrice [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Cyteval, Catherine, E-mail: c-cyteval@chu-montpellier.fr [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France)

2017-01-15

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

International Nuclear Information System (INIS)

Rasselet, Benjamin; Larbi, Ahmed; Viala, Pierre; Molinari, Nicolas; Tetreau, Raphael; Faruch-Bilfeld, Marie; Taourel, Patrice; Cyteval, Catherine

2017-01-01

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Southern Forest Resource Assessment and Linkages to the National RPA

Science.gov (United States)

Fredrick Cubbage; Jacek Siry; Steverson Moffat; David N. Wear; Robert Abt

1998-01-01

We developed a Southern Forest Resource Assessment Consortium (SOFAC) in 1994, which is designed to enhance our capabilities to analyze and model the southern forest and timber resources. Southern growth and yield analyses prepared for the RPA via SOFAC indicate that substantial increases in timber productivity can occur given current technology. A survey about NIPF...

Reinforced Airfoil Shaped Body

DEFF Research Database (Denmark)

2011-01-01

The present invention relates to an airfoil shaped body with a leading edge and a trailing edge extending along the longitudinal extension of the body and defining a profile chord, the airfoil shaped body comprising an airfoil shaped facing that forms the outer surface of the airfoil shaped body...

Biomass energy resource enhancement: the move to modern secondary energy forms

Energy Technology Data Exchange (ETDEWEB)

Craig, K; Overend, R P [National Renewable Energy Laboratory, Golden, CO (United States)

1995-12-01

Income growth and industrialization in developing countries is driving their economies towards the use of secondary energy forms that deliver high efficiency energy and environmentally more benignant-uses for biomass. Typical of these secondary energy forms are electricity, distributed gas systems and liquid fuels. This trend suggests that the hitherto separate pathways taken by biomass energy technology development in developing and industrialized countries will eventually share common elements. While in the United States and the European Union the majority of the bioenergy applications are in medium- and large-scale industrial uses of self-generated biomass residues, the characteristic use in developing countries is in rural cook-stoves. Increasing urbanization and investment in transportation infrastructure may allow increasing the operational scale in developing countries. One factor driving this trend is diminishing individual and household biomass resource demands as rural incomes increase and households ascend the energy ladder towards clean and efficient fuels and appliances. Scale increases and end-user separation from the biomass resource require that the biomass be converted at high efficiency into secondary energy forms that serve as energy carriers. In middle-income developing country economies such as Brazil, secondary energy transmission is increasingly in the form of gas and electricity in addition to liquid transportation fuels. Unfortunately, the biomass resource is finite, and in the face of competing food and fibre uses and land constraints, it is difficult to substantially increase the amount of biomass available. As a result, development must emphasize conversion efficiency and the applications of bioenergy. Moreover, as a consequence of economic growth, biomass resources are increasingly to be found in the secondary and tertiary waste streams of cities and industrial operations. If not used for energy production, this potential resource needs

Biomass energy resource enhancement: the move to modern secondary energy forms

International Nuclear Information System (INIS)

Craig, K.; Overend, R.P.

1995-01-01

Income growth and industrialization in developing countries is driving their economies towards the use of secondary energy forms that deliver high efficiency energy and environmentally more benignant-uses for biomass. Typical of these secondary energy forms are electricity, distributed gas systems and liquid fuels. This trend suggests that the hitherto separate pathways taken by biomass energy technology development in developing and industrialized countries will eventually share common elements. While in the United States and the European Union the majority of the bioenergy applications are in medium- and large-scale industrial uses of self-generated biomass residues, the characteristic use in developing countries is in rural cook-stoves. Increasing urbanization and investment in transportation infrastructure may allow increasing the operational scale in developing countries. One factor driving this trend is diminishing individual and household biomass resource demands as rural incomes increase and households ascend the energy ladder towards clean and efficient fuels and appliances. Scale increases and end-user separation from the biomass resource require that the biomass be converted at high efficiency into secondary energy forms that serve as energy carriers. In middle-income developing country economies such as Brazil, secondary energy transmission is increasingly in the form of gas and electricity in addition to liquid transportation fuels. Unfortunately, the biomass resource is finite, and in the face of competing food and fibre uses and land constraints, it is difficult to substantially increase the amount of biomass available. As a result, development must emphasize conversion efficiency and the applications of bioenergy. Moreover, as a consequence of economic growth, biomass resources are increasingly to be found in the secondary and tertiary waste streams of cities and industrial operations. If not used for energy production, this potential resource needs

The Effects of Resource Bundling on Third-party Logistics Providers’ Performance

Directory of Open Access Journals (Sweden)

Noorliza Karia

2015-03-01

resource bundling (excluding advanced technology is required to achieve cost leadership. The effects of other resources on performance are mediated mainly by the demand management interface capability and knowledge resources. This is a novel attempt to justify the interaction and mediation effects of resources and capabilities on performance. The research highlights the needs for 3PL managers to focus on developing and bundling their demand management interface capability and knowledge resources in order to achieve cost leadership, and further combine advanced technology into such bundling of resources and capabilities to achieve innovation in customer service. It advances the application of resource-based view (RBV theory in logistics research by identifying resources that play supporting roles and examining the capabilities for enhancing 3PLs’ competitive performance.

Shapes of interacting RNA complexes

DEFF Research Database (Denmark)

Fu, Benjamin Mingming; Reidys, Christian

2014-01-01

Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

Job Demand and Job Resources related to the turnover intention of public health nurses: An analysis using a Job Demands-Resources model.

Science.gov (United States)

Iguchi, Aya

2016-01-01

Objectives The purpose of this study was to investigate the job demands and job resources of public health nurses based on the Job Demands-Resources (JD-R) model, and to build a model that can estimate turnover intention based on job demands and job resources.Method By adding 12 items to the existing questionnaire, the author created a questionnaire consisting of 10 factors and 167 items, and used statistical analysis to examine job demands and job resources in relation to turnover intention.Results Out of 2,668 questionnaires sent, 1993 (72.5%) were returned. Considering sex-based differences in occupational stress, I analyzed women's answers in 1766 (66.2%) mails among the 1798 valid responses. The average age of respondents was 41.0±9.8 years, and the mean service duration was 17.0±10.0 years. For public health nurses, there was a turnover intention of 9.2%. The "job demands" section consisted of 29 items and 10 factors, while the "job resources" section consisted of 54 items and 22 factors. The result of examining the structure of job demands and job resources, leading to turnover intention was supported by the JD-R model. Turnover intention was strong and the Mental Component Summary (MCS) is low in those who had many job demands and few job resources (experiencing 'burn-out'). Enhancement of work engagement and turnover intention was weak in those who had many job resources. This explained approximately 60% of the dispersion to "burn-out", and approximately 40% to "work engagement", with four factors: work suitability, work significance, positive work self-balance, and growth opportunity of job resources.Conclusion This study revealed that turnover intention is strong in those who are burned out because of many job demands. Enhancement of work engagement and turnover intention is weak in those with many job resources. This suggests that suitable staffing and organized efforts to raise awareness of job significance are effective in reducing

The Role of Human Resource Management in Employee Motivation

Directory of Open Access Journals (Sweden)

Muhammed Kürşad ÖZLEN

2014-05-01

Full Text Available The main objectives of this study are to present the condition of Human resources management in Bosnian and Herzegovinian companies. Therefore, the developed survey questionnaire is conducted through the employees of Bosnian companies. Data was obtained from surveyed 193 employees, and descriptively analyzed using SPSS software. The results identified low level of human resources management in Bosnia and Herzegovina. It can be suggested that Bosnian companies should develop their human resources strategies and functions and enhance the motivation of their employees in order to get more benefit.

Work Engagement: Investigating the Role of Transformational Leadership, Job Resources, and Recovery.

Science.gov (United States)

Hawkes, Amy J; Biggs, Amanda; Hegerty, Erin

2017-08-18

While the relationship between job resources and engagement has been well established, a greater understanding of the upstream factors that shape job resources is required to develop strategies to promote work engagement. The current study addresses this need by exploring transformational leadership as an upstream job resource, and the moderating role of recovery experiences. It was hypothesized that job resources would mediate the relationship between transformational leadership and engagement. Recovery experiences were expected to moderate the relationship between resources and engagement. A sample of 277 employees from a variety of organizations and industries was obtained. Analysis showed direct relationships between: transformational leadership and engagement, and transformational leadership and job resources. Mediation analysis using bootstrapping found a significant indirect path between transformational leadership and engagement via job resources. Recovery experiences did not significantly moderate the relationship between job resources and engagement. To date, the majority of published literature on recovery has focused on job demands; hence the nonsignificant result offers insight of a potentially more complex relationship for recovery with resources and engagement. Overall, the current study extends the JD-R model and provides evidence for broadening the model to include upstream organizational variables such as transformational leadership.

A water-responsive shape memory ionomer with permanent shape reconfiguration ability

Science.gov (United States)

Bai, Yongkang; Zhang, Jiwen; Tian, Ran; Chen, Xin

2018-04-01

In this work, a water-responsive shape memory ionomer with high toughness was fabricated by cross-linking hyaluronic acid sodium (HAS) and polyvinyl alcohol (PVA) through coordination interactions. The strong Fe3+-carboxyl (from HAS) coordination interactions served as main physical cross-linking points for the performance of water-responsive shape memory, which associated with the flexibility of PVA chain producing excellent mechanical properties of this ionomer. The optimized ionomer was not only able to recover to its original shape within just 22 s by exposing to water, but exhibited high tensile strength up to 35.4 MPa and 4 times higher tractility than the ionomer without PVA. Moreover, the ionomers can be repeatedly programed to various new permanent shapes on demand due to the reversible physical interactions, which still performed complete and fast geometric recovery under stimuli even after 4 cycles of reprograming with 3 different shapes. The excellent shape memory and strong mechanical behaviors make our ionomers significant and promising smart materials for variety of applications.

Customized shaping of vibration modes by acoustic metamaterial synthesis

Science.gov (United States)

Xu, Jiawen; Li, Shilong; Tang, J.

2018-04-01

Acoustic metamaterials have attractive potential in elastic wave guiding and attenuation over specific frequency ranges. The vast majority of related investigations are on transient waves. In this research we focus on stationary wave manipulation, i.e., shaping of vibration modes. Periodically arranged piezoelectric transducers shunted with inductive circuits are integrated to a beam structure to form a finite-length metamaterial beam. We demonstrate for the first time that, under a given operating frequency of interest, we can facilitate a metamaterial design such that this frequency becomes a natural frequency of the integrated system. Moreover, the vibration mode corresponding to this natural frequency can be customized and shaped to realize tailored/localized response distribution. This is fundamentally different from previous practices of utilizing geometry modification and/or feedback control to achieve mode tailoring. The metamaterial design is built upon the combinatorial effects of the bandgap feature and the effective resonant cavity feature, both attributed to the dynamic characteristics of the metamaterial beam. Analytical investigations based on unit-cell dynamics and modal analysis of the metamaterial beam are presented to reveal the underlying mechanism. Case illustrations are validated by finite element analyses. Owing to the online tunability of circuitry integrated, the proposed mode shaping technique can be online adjusted to fit specific requirements. The customized shaping of vibration modes by acoustic metamaterial synthesis has potential applications in vibration suppression, sensing enhancement and energy harvesting.

Information empowerment: predeparture resource training for students in global health.

Science.gov (United States)

Rana, Gurpreet K

2014-04-01

The Taubman Health Sciences Library (THL) collaborates with health sciences schools to provide information skills instruction for students preparing for international experiences. THL enhances students' global health learning through predeparture instruction for students who are involved in global health research, clinical internships, and international collaborations. This includes teaching international literature searching skills, providing country-specific data sources, building awareness of relevant mobile resources, and encouraging investigation of international news. Information skills empower creation of stronger global partnerships. Use of information resources has enhanced international research and training experiences, built lifelong learning foundations, and contributed to the university's global engagement. THL continues to assess predeparture instruction.

Ultrafast responses of dipolar and V-shaped dipicolinate derivatives with potential applications in the labeling of biomolecules

Science.gov (United States)

Wang, Yaochuan; Liu, Siyuan; Liu, Dajun; Wang, Guiqiu; Xiao, Haibo

2016-02-01

A dipolar dipicolinate derivative, trans-dimethyl-4-[4'-(N,N-diphenylamino)-styry1]-pyridin-2,6-dicarboxylate (P-1), and a P-1based V-shaped compound, {4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl) vinyl]}-N-phenyl-N-{4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl)vinylphenyl]}aniline (P-2), with intense two-photon fluorescence emission properties were systematically investigated by using steady-state absorption and fluorescence spectroscopy, open-aperture Z-scans, and two-photon excited fluorescence (TPF). The two-photon absorption cross-section of the V-shaped compound P-2 in tetrahydrofuran (THF) was determined to be 208 GM, which represents a 6.5-fold enhancement compared with its dipolar counterpart P-1 (32 GM). Extension of the intramolecular charge transfer (ICT) in the V-shaped dipicolinate derivative has been suggested as the mechanism of enhancement. The excited state dynamics from transient absorption spectroscopy were analyzed and discussed. The formation and relaxation lifetimes of the ICT state for these dipicolinate derivatives in THF solutions were found to be several picoseconds and several hundred picoseconds, respectively. The results show an increased ICT character of the V-shaped compound and a potential application for this compound in two-photon fluorescence imaging fields.

Ultrafast responses of dipolar and V-shaped dipicolinate derivatives with potential applications in the labeling of biomolecules

Directory of Open Access Journals (Sweden)

Yaochuan Wang

2016-02-01

Full Text Available A dipolar dipicolinate derivative, trans-dimethyl-4-[4′-(N,N-diphenylamino-styry1]-pyridin-2,6-dicarboxylate (P-1, and a P-1based V-shaped compound, {4-[(E-2-(2,6-dimethoxycarbonylpyridin-4-yl vinyl]}-N-phenyl-N-{4-[(E-2-(2,6-dimethoxycarbonylpyridin-4-ylvinylphenyl]}aniline (P-2, with intense two-photon fluorescence emission properties were systematically investigated by using steady-state absorption and fluorescence spectroscopy, open-aperture Z-scans, and two-photon excited fluorescence (TPF. The two-photon absorption cross-section of the V-shaped compound P-2 in tetrahydrofuran (THF was determined to be 208 GM, which represents a 6.5-fold enhancement compared with its dipolar counterpart P-1 (32 GM. Extension of the intramolecular charge transfer (ICT in the V-shaped dipicolinate derivative has been suggested as the mechanism of enhancement. The excited state dynamics from transient absorption spectroscopy were analyzed and discussed. The formation and relaxation lifetimes of the ICT state for these dipicolinate derivatives in THF solutions were found to be several picoseconds and several hundred picoseconds, respectively. The results show an increased ICT character of the V-shaped compound and a potential application for this compound in two-photon fluorescence imaging fields.

Constructing and Using Broad-coverage Lexical Resource for Enhancing Morphological Analysis of Arabic

OpenAIRE

Sawalha, M.; Atwell, E.S.

2010-01-01

Broad-coverage language resources which provide prior linguistic knowledge must improve the accuracy and the performance of NLP applications. We are constructing a broad-coverage lexical resource to improve the accuracy of morphological analyzers and part-of-speech taggers of Arabic text. Over the past 1200 years, many different kinds of Arabic language lexicons were constructed; these lexicons are different in ordering, size and aim or goal of construction. We collected 23 machine-readable l...

Systems and methods for enhancing optical information

Science.gov (United States)

DeVore, Peter Thomas Setsuda; Chou, Jason T.

2018-01-02

An Optical Information Transfer Enhancer System includes a first system for producing an information bearing first optical wave that is impressed with a first information having a first information strength wherein the first optical wave has a first shape. A second system produces a second optical wave. An information strength enhancer module receives the first and said second optical waves and impresses the first optical wave upon the second optical wave via cross-phase modulation (XPM) to produce an information-strength-enhanced second optical wave having a second information strength that is greater than the first information strength of the first optical wave. Following a center-wavelength changer by an Optical Information Transfer Enhancer System improves its performance.

Nuclear quantum shape-phase transitions in odd-mass systems

Science.gov (United States)

Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

2018-03-01

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

Tunable plasmon-induced transparency with graphene-based T-shaped array metasurfaces

Science.gov (United States)

Niu, Yuying; Wang, Jicheng; Hu, Zhengda; Zhang, Feng

2018-06-01

The frequency tunable Plasmonic induced transparency (PIT) effect is researched with a periodically patterned T-shaped graphene array in mid-infrared region. We adjust the geometrical parameters to obtain the optimized combination for the realization of the PIT response and use the coupled Lorentz oscillator model to analysis the physical mechanism. Due to the properties of graphene, the PIT effect can be easily and markedly enhanced with the increase of chemical potential and carrier mobility. The frequency of PIT effect is also insensitive with the angle of incident light. In addition, we also propose the π shaped structure to realizing the double-peak PIT effect. The results offer a flexible approach for the development of tunable graphene-based photonic devices.

Alpha Shapes and Proteins

DEFF Research Database (Denmark)

Winter, Pawel; Sterner, Henrik; Sterner, Peter

2009-01-01

We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

Napa River Sediment TMDL Implementation and Habitat Enhancement Project

Science.gov (United States)

Information about the SFBWQP Napa River Sediment TMDL Implementation and Habitat Enhancement Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Investigation of novel fractal shape of the nano-aperture as a metasurface for bio sensing application

Energy Technology Data Exchange (ETDEWEB)

Heydari, Samaneh [Sama Technical and Vocational Training College, Islamic Azad University, Isfahan Branch, Khorasgan (Iran, Islamic Republic of); Rastan, Iman; Parvin, Amin [Faculty of Eng., Science and Research Branch, Islamic Azad University, Shiraz (Iran, Islamic Republic of); Pirooj, Azadeh [Faculty of Eng., Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Zarrabi, Ferdows B., E-mail: ferdows.zarrabi@yahoo.com [Young Researchers and Elite Club, Babol Branch, Islamic Azad University, Babol (Iran, Islamic Republic of)

2017-01-23

Recently, nano-aperture is noticed due to its good transmission in the optical regime. Also, the nano-apertures are developed at the metasurface design for circular polarization; for this aim, various shapes of the nano-aperture are suggested. To reach this objective, we have developed a novel Jerusalem cross fractal shape for a mid-infrared application. We have simulated various formations of the nano-fractal Jerusalem cross based on a simple cross to show the effect of nano-aperture shape on electrical field enhancement in the near-field which is important in spectroscopy and optical imaging. In addition, we have used a single layer graphene over the aperture as a coat for making reconfigurable characteristic also creating a membrane for placement of nano-particle over the aperture. Implementation of the graphene is an amendment to the transfer of the nano-apertures. The biological materials with a thickness of 80 nm have been placed over the graphene layer and the Figures of Merits (FOM) have been obtained. Additionally, the prototype of nano-antenna is independent from incident wave polarization. The Finite Difference Time Domain (FDTD) calculations have been implemented in the simulation and modeling the nano-apertures. - Highlights: • Nano-apertures are developed at the metasurface design for circular polarization. • We have developed a novel Jerusalem cross fractal shape for a mid-infrared application. • Effect of nano-aperture shape on near-field enhancement is noticed which is important in spectroscopy and optical imaging. • Single layer graphene over the aperture as a coat for making reconfigurable characteristic.

Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

Science.gov (United States)

Peterchev, Angel V.; DʼOstilio, Kevin; Rothwell, John C.; Murphy, David L.

2014-10-01

Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with a lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (\\lt 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in ten healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool.

Surface-enhanced Raman scattering from metal and transition metal nano-caped arrays

Science.gov (United States)

Sun, Huanhuan; Gao, Renxian; Zhu, Aonan; Hua, Zhong; Chen, Lei; Wang, Yaxin; Zhang, Yongjun

2018-03-01

The metal and transition metal cap-shaped arrays on polystyrene colloidal particle (PSCP) templates were fabricated to study the surface-enhanced Raman scattering (SERS) effect. We obtained the Ag and Fe complex film by a co-sputtering deposition method. The size of the deposited Fe particle was changed by the sputtering power. We also study the SERS enhancement mechanism by decorating the PATP probe molecule on the different films. The SERS signals increased firstly, and then decreased as the size of Fe particles grows gradually. The finite-difference time domain (FDTD) simulation and experimental Raman results manifest that SERS enhancement was mainly attributed to surface plasma resonance (SPR) between Ag and Ag nanoparticles. The SERS signals of PATP molecule were enhanced to reach a lowest detectable concentration of 10-8 mol/L. The research demonstrates that the SERS substrates with Ag-Fe cap-shaped arrays have a high sensitivity.

The Influence of Human Resource Practices on Internal Customer Satisfaction and Organizational Effectiveness

Directory of Open Access Journals (Sweden)

Irfan Ullah

2013-08-01

Full Text Available It is generally believed that the impact of Human Resource Practices on internal customer satisfaction can create comparative advantage for the organizational performance. The main objective of this study was to find out the impact of Human Resource Practices on internal customer satisfaction and organizational effectiveness. The impact of human resource practices on the overall performance of organizations has been a leading subject of research and the results have been encouraging, indicative of positive relationship between Human Resource practices and organizational effectiveness. Data was collected through personally administered questionnaire-based survey from 290 banking personnel of Pakistan. Structural equation modeling was used to examine the anticipated model. The results showed that some Human Resource Practices appear to be linked to internal customer satisfaction and organizational effectiveness. The implications for practitioners were to modify and emphasize certain human resource practices, and to emphasize the role of internal customers for organizational effectiveness enhancement. These findings revealed the importance of internal customers in enhancing employee morale, organizational commitment, employee productivity, turnover rate and the organization’s ability to attract talent.

[Research on resources chemistry of Chinese medicinal materials and resources recycling utilization ways and goals and tasks].

Science.gov (United States)

Duan, Jin-ao; Su, Shu-lan; Guo, Sheng; Jiang, Shu; Liu, Pei; Yan, Hui; Qian, Da-wei; Zhu, Hua-xu; Tang, Yu-ping; Wu, Qi-nan

2015-09-01

The objects of research on the resources chemistry of Chinese medicinal materials (RCCMM) are promotion of efficient production, rational utilization and improving quality of CMM and natural products. The development of TCM cause depends on the efficient utilization and sustainable development of CMM, hinges on the technologies and methods for using and discovering medicinal biological resources, stand or fall on the extension of industy chains, detailed utilizaion of resource chemical components by multi-way, multi-level. All of these may help to the recycling utilization and sound development of RCMM. In this article, five respects were discussed to the RCCMM researches and resources recycling utilization ways and goals and tasks. First, based on the principle of resource scarcity, discovering or replacing CMM resources, protecting the rare or endangered species or resources. Second, based on the multifunctionality of CMM, realizing the value-added and value compensation, and promoting the utilization efficiency through systermatic and detailed exploitation and utilization. Third, based on the resource conservation and environment-friendly, reducing raw material consumption, lowering cost, promoting recycling utilization and elevating utilization efficiency. Fourth, based on the stratege of turning harm into good, using the invasive alien biological resources by multi-ways and enriching the medicial resources. Fifth, based on the method of structure modification of chemical components, exploring and enhancing the utility value of resouces chemical substances. These data should provide references and attention for improving the utilization efficiency, promoting the development of recycling economy, and changing the mode of economic growth of agriculture and industry of CMM fundamentally.

Assured Resource Sharing in Ad-Hoc Collaboration

Energy Technology Data Exchange (ETDEWEB)

Ahn, Gail-Joon [Arizona State Univ., Tempe, AZ (United States)

2015-12-19

The project seeks an innovative framework to enable users to access and selectively share resources in distributed environments, enhancing the scalability of information sharing. We have investigated secure sharing & assurance approaches for ad-hoc collaboration, focused on Grids, Clouds, and ad-hoc network environments.

Consolidation of Hierarchy-Structured Nanopowder Agglomerates and Its Application to Net-Shaping Nanopowder Materials

Science.gov (United States)

Lee, Jai-Sung; Choi, Joon-Phil; Lee, Geon-Yong

2013-01-01

This paper provides an overview on our recent investigations on the consolidation of hierarchy-structured nanopowder agglomerates and related applications to net-shaping nanopowder materials. Understanding the nanopowder agglomerate sintering (NAS) process is essential to processing of net-shaped nanopowder materials and components with small and complex shape. The key concept of the NAS process is to enhance material transport through controlling the powder interface volume of nanopowder agglomerates. Based upon this concept, we have suggested a new idea of full density processing for fabricating micro-powder injection molded part using metal nanopowder agglomerates produced by hydrogen reduction of metal oxide powders. Studies on the full density sintering of die compacted- and powder injection molded iron base nano-agglomerate powders are introduced and discussed in terms of densification process and microstructure. PMID:28788317

Consolidation of Hierarchy-Structured Nanopowder Agglomerates and Its Application to Net-Shaping Nanopowder Materials

Directory of Open Access Journals (Sweden)

Geon-Yong Lee

2013-09-01

Full Text Available This paper provides an overview on our recent investigations on the consolidation of hierarchy-structured nanopowder agglomerates and related applications to net-shaping nanopowder materials. Understanding the nanopowder agglomerate sintering (NAS process is essential to processing of net-shaped nanopowder materials and components with small and complex shape. The key concept of the NAS process is to enhance material transport through controlling the powder interface volume of nanopowder agglomerates. Based upon this concept, we have suggested a new idea of full density processing for fabricating micro-powder injection molded part using metal nanopowder agglomerates produced by hydrogen reduction of metal oxide powders. Studies on the full density sintering of die compacted- and powder injection molded iron base nano-agglomerate powders are introduced and discussed in terms of densification process and microstructure.

Designing a New Ni-Mn-Sn Ferromagnetic Shape Memory Alloy with Excellent Performance by Cu Addition

Directory of Open Access Journals (Sweden)

Kun Zhang

2018-02-01

Full Text Available Both magnetic-field-induced reverse martensitic transformation (MFIRMT and a high working temperature are crucial for the application of Ni-Mn-Sn magnetic shape memory alloys. Here, by first-principles calculations, we demonstrate that the substitution of Cu for Sn is effective not only in enhancing the MFIRMT but also in increasing martensitic transformation, which is advantageous for its application. Large magnetization difference (ΔM in Ni-Mn-Sn alloy is achieved by Cu doping, which arises from the enhancement of magnetization of austenite due to the change of Mn-Mn interaction from anti-ferromagnetism to ferromagnetism. This directly leads to the enhancement of MFIRMT. Meanwhile, the martensitic transformation shifts to higher temperature, owing to the energy difference between the austenite L21 structure and the tetragonal martensite L10 structure increases by Cu doping. The results provide the theoretical data and the direction for developing a high temperature magnetic-field-induced shape memory alloy with large ΔM in the Ni-Mn-Sn Heusler alloy system.

Two-way shape memory behavior of shape memory polyurethanes with a bias load

International Nuclear Information System (INIS)

Hong, Seok Jin; Yu, Woong-Ryeol; Youk, Ji Ho

2010-01-01

Thermo-responsive shape memory polyurethane (SMPU) is a smart material that can respond to external heat by changing its macroscopic shape from a temporary configuration to a memorized permanent one. The temporary shape can be processed using mechanical forces above a certain temperature (the transition temperature) and can be maintained until the material acquires a certain thermal energy. Thereafter, the material will recover its memorized permanent shape. However, it is unclear what will occur if the thermal energy is then dissipated, i.e., the material temperature decreases. There are two possibilities: the material will respond to the dissipated energy, resulting in another macroscopic shape change; or nothing will happen beyond the thermal contraction. The former is called two-way shape memory (TWSM) behavior and the latter is called one-way shape memory behavior. This paper reports novel findings showing that TWSM behavior can be imparted to SMPUs using a thermo-mechanical treatment, i.e., imposing a constant stress on them after their temporary shaping. A series of experiments were carried out to characterize the TWSM behavior of SMPUs and to explain its mechanism

Double-tailed acyl glycoside niosomal nanocarrier for enhanced oral bioavailability of Cefixime.

Science.gov (United States)

Imran, Muhammad; Shah, Muhammad Raza; Ullah, Farhat; Ullah, Shafi; Sadiq, Abdul; Ali, Imdad; Ahmed, Farid; Nawaz, Waqas

2017-11-01

Novel, safe, efficient, and cost effective surfactants from renewable resources has attracted attention for enhancing solubility and bioavailability of hydrophobic dugs. We report the synthesis, characterization, and biocompatibility of a novel non-ionic acyl glycoside double-tailed surfactant for niosomal drug delivery system. Structure of the surfactant was confirmed by 1 H NMR and mass spectroscopy. Applications of surfactant in niosomal drug delivery were explored using Cefixime as model. The shape, size, and polydispersity index (PDI) of drug loaded vesicles were investigated with atomic force microscope (AFM) and dynamic light scattering (DLS). Drug entrapping efficiency (EE%) was determined using HPLC. Biocompatibility of the surfactant was evaluated by in vitro cytotoxicity, blood hemolysis, and in vivo acute toxicity. Bioavailability of the surfactant based formulation was investigated in rabbits using HPLC. Vesicles were found to be 159.76 ± 6.54 nm with narrow size distribution and spherical shape. EE% was found to be 71.39 ± 3.52%. Novel surfactant was non-cytotoxicity and hemo-compatible even at 1000 μg/mL concentration and was safe up to 2000 mg/kg body weight. The in vivo bioavailability of niosomal formulation showed elevated plasma concentration and decreased clearance of Cefixime. Current findings reveal that this novel surfactant is biocompatible and could be employed for niosomal drug delivery.

Crescent shaped Fabry-Perot fiber cavity for ultra-sensitive strain measurement

Science.gov (United States)

Liu, Ye; Wang, D. N.; Chen, W. P.

2016-12-01

Optical Fabry-Perot interferometer sensors based on inner air-cavity is featured with compact size, good robustness and high strain sensitivity, especially when an ultra-thin air-cavity is adopted. The typical shape of Fabry-Perot inner air-cavity with reflection mode of operation is elliptic, with minor axis along with and major axis perpendicular to the fiber length. The first reflection surface is diverging whereas the second one is converging. To increase the visibility of the output interference pattern, the length of major axis should be large for a given cavity length. However, the largest value of the major axis is limited by the optical fiber diameter. If the major axis length reaches the fiber diameter, the robustness of the Fabry-Perot cavity device would be decreased. Here we demonstrate an ultra-thin crescent shaped Fabry-Perot cavity for strain sensing with ultra-high sensitivity and low temperature cross-sensitivity. The crescent-shape cavity consists of two converging reflection surfaces, which provide the advantages of enhanced strain sensitivity when compared with elliptic or D-shaped FP cavity. The device is fabricated by fusion splicing an etched multimode fiber with a single mode fiber, and hence is simple in structure and economic in cost.

Heat and mass transfer intensification and shape optimization a multi-scale approach

CERN Document Server

2013-01-01

Is the heat and mass transfer intensification defined as a new paradigm of process engineering, or is it just a common and old idea, renamed and given the current taste? Where might intensification occur? How to achieve intensification? How the shape optimization of thermal and fluidic devices leads to intensified heat and mass transfers? To answer these questions, Heat & Mass Transfer Intensification and Shape Optimization: A Multi-scale Approach clarifies  the definition of the intensification by highlighting the potential role of the multi-scale structures, the specific interfacial area, the distribution of driving force, the modes of energy supply and the temporal aspects of processes.   A reflection on the methods of process intensification or heat and mass transfer enhancement in multi-scale structures is provided, including porous media, heat exchangers, fluid distributors, mixers and reactors. A multi-scale approach to achieve intensification and shape optimization is developed and clearly expla...

Teachers as Designers of Technology Enhanced Learning

NARCIS (Netherlands)

Kali, Yael; McKenney, Susan; Sagy, Ornit

2015-01-01

While the benefits of teacher involvement in designing technology enhanced learning are acknowledged in the literature, far less is known about shaping that involvement to yield those benefits. Research is needed to understand how teachers learn through design; how teacher design activities may be

Teachers as Designers of Technology Enhanced Learning

NARCIS (Netherlands)

Kali, Yael; McKenney, Susan; Sagy, Ornit

2016-01-01

While the benefits of teacher involvement in designing technology enhanced learning are acknowledged in the literature, far less is known about shaping that involvement to yield those benefits. Research is needed to understand how teachers learn through design; how teacher design activities may be

30 CFR 206.265 - Value enhancement of marketable coal.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Value enhancement of marketable coal. 206.265... MANAGEMENT PRODUCT VALUATION Federal Coal § 206.265 Value enhancement of marketable coal. If, prior to use, sale, or other disposition, the lessee enhances the value of coal after the coal has been placed in...

30 CFR 206.464 - Value enhancement of marketable coal.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Value enhancement of marketable coal. 206.464... MANAGEMENT PRODUCT VALUATION Indian Coal § 206.464 Value enhancement of marketable coal. If, prior to use, sale, or other disposition, the lessee enhances the value of coal after the coal has been placed in...

Analyses on Water Vapor Resource in Chengdu City

Science.gov (United States)

Liu, B.; Xiao, T.; Wang, C.; Chen, D.

2017-12-01

Chengdu is located in the Sichuan basin, and it is the most famous inland city in China. With suitable temperatures and rainfall, Chengdu is the most livable cities in China. With the development of urban economy and society, the population has now risen to 16 million, and it will up to 22 million in 2030. This will cause the city water resources demand, and the carrying capacity of water resources become more and more serious. In order to improve the contradiction between urban waterlogging and water shortage, sponge city planning was proposed by Chengdu government, and this is of great practical significance for promoting the healthy development of the city. Base on the reanalysis data from NCEP during 2007-2016, the characters of Water Vapor Resources was analyzed, and the main contents of this research are summarized as follows: The water vapor resource in Chengdu plain is more than that in Southeast China and less in Northwest China. The annual average water vapor resource is approximately 160 mm -320 mm, and the water vapor resource in summer can reach 3 times in winter. But the annual average precipitation in Chengdu is about 800 mm -1200 mm and it is far greater than the water vapor resource, this is because of the transport of water vapor. Using the formula of water vapor flux, the water vapor in Chengdu is comes from the west and the south, and the value is around 50kg/(ms). Base on the calculation of boundary vapor budget, the water vapor transport under 500hPa accounted for 97% of the total. Consider the water vapor transport, transformation and urban humidification effect, the Water Vapor Resource in Chengdu is 2500mm, and it can be used by artificial precipitation enhancement. Therefore, coordinated development of weather modification and sponge city construction, the shortage of water resources in Chengdu plain can be solved. Key words: Chengdu; Sponge city; Water vapor resource; Precipitation; Artificial precipitation enhancement Acknowledgements

An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States

Energy Technology Data Exchange (ETDEWEB)

Mullane, Michelle; Gleason, Michael; Reber, Tim; McCabe, Kevin; Mooney, Meghan; Young, Katherine R.

2017-05-01

Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

A Regions of Confidence Based Approach to Enhance Segmentation with Shape Priors.

Science.gov (United States)

Appia, Vikram V; Ganapathy, Balaji; Abufadel, Amer; Yezzi, Anthony; Faber, Tracy

2010-01-18

We propose an improved region based segmentation model with shape priors that uses labels of confidence/interest to exclude the influence of certain regions in the image that may not provide useful information for segmentation. These could be regions in the image which are expected to have weak, missing or corrupt edges or they could be regions in the image which the user is not interested in segmenting, but are part of the object being segmented. In the training datasets, along with the manual segmentations we also generate an auxiliary map indicating these regions of low confidence/interest. Since, all the training images are acquired under similar conditions, we can train our algorithm to estimate these regions as well. Based on this training we will generate a map which indicates the regions in the image that are likely to contain no useful information for segmentation. We then use a parametric model to represent the segmenting curve as a combination of shape priors obtained by representing the training data as a collection of signed distance functions. We evolve an objective energy functional to evolve the global parameters that are used to represent the curve. We vary the influence each pixel has on the evolution of these parameters based on the confidence/interest label. When we use these labels to indicate the regions with low confidence; the regions containing accurate edges will have a dominant role in the evolution of the curve and the segmentation in the low confidence regions will be approximated based on the training data. Since our model evolves global parameters, it improves the segmentation even in the regions with accurate edges. This is because we eliminate the influence of the low confidence regions which may mislead the final segmentation. Similarly when we use the labels to indicate the regions which are not of importance, we will get a better segmentation of the object in the regions we are interested in.

Influence of hexadecapole deformations of the nuclear shape of subbarrier fusion reactions

International Nuclear Information System (INIS)

Fernandez Niello, J.

1989-01-01

A systematic study of the contribution of hexadecapole deformations to the enhancement of subbarrier fusion cross reactions is carried out. The analysis is based on calculations that cover the full range of values of hexadecapole deformations found in actual nuclear systems. The interplay of this shape degree of freedom with the presence of prolate quadrupole deformations is also contemplated. (Author) [es

Shape memory polymer medical device

Science.gov (United States)

Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

2010-06-29

A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

Cervical lymph node metastasis of oral squamous cell carcinomas. CT enhancement and histopathological evaluations

Energy Technology Data Exchange (ETDEWEB)

Etoh, Yohei; Kimura, Takuji; Sasaki, Akira; Kishimoto, Koji; Matsumura, Tomohiro; Kishi, Kanji [Okayama Univ. (Japan). Dental School

2000-06-01

A comparison of the results of histopathological and enhanced CT examinations were carried out for 88 patients with oral squamous cell carcinomas who underwent neck dissection. CT scanning (5-mm thick section) images obtained during bolus/drip injection of Iopamidol were routinely taken through the neck. Ninety-two of 1634 nodes were histologically diagnosed as metastatic. Low density areas surrounding enhancement rims were metastatic nodal central necrosis or keratinization. Enhanced areas in many metastatic nodes were considered to be lymphatic architecture, not metastatic masses especially in the avascular keratinization. Enhanced CT produced accurate information of lymph node size, location, shape, grouping and spread from nodes to adjacent structures. However, it was considered that not every metastatic lymph node should show enlargement and/or enhancement. Improved assessment of solid metastatic features of lymph nodes (shape, size, and involvement) may be achieved with the aid of thin-thickness CT. (author)

Cervical lymph node metastasis of oral squamous cell carcinomas. CT enhancement and histopathological evaluations

International Nuclear Information System (INIS)

Etoh, Yohei; Kimura, Takuji; Sasaki, Akira; Kishimoto, Koji; Matsumura, Tomohiro; Kishi, Kanji

2000-01-01

A comparison of the results of histopathological and enhanced CT examinations were carried out for 88 patients with oral squamous cell carcinomas who underwent neck dissection. CT scanning (5-mm thick section) images obtained during bolus/drip injection of Iopamidol were routinely taken through the neck. Ninety-two of 1634 nodes were histologically diagnosed as metastatic. Low density areas surrounding enhancement rims were metastatic nodal central necrosis or keratinization. Enhanced areas in many metastatic nodes were considered to be lymphatic architecture, not metastatic masses especially in the avascular keratinization. Enhanced CT produced accurate information of lymph node size, location, shape, grouping and spread from nodes to adjacent structures. However, it was considered that not every metastatic lymph node should show enlargement and/or enhancement. Improved assessment of solid metastatic features of lymph nodes (shape, size, and involvement) may be achieved with the aid of thin-thickness CT. (author)

Practicing natural resource management with a policy orientation

Science.gov (United States)

Clark, Tim W.

1992-07-01

All natural resource managers want to contribute to successful conservation programs. Having and applying an explicit policy orientation is indispensable. The policy sciences are described and a case is made that, if natural resource managers utilize this set of conceptual and applied tools in their natural resource work, their effectiveness could be enhanced. The policy sciences offer a contextual, problem-oriented, and multimethod approach to meeting complex problems. Two kinds of knowledge are needed to solve problems—substantive knowledge about the resource and process knowledge about the decision and policy processes used to derive courses of management action. The interplay of science, analysis, and politics are examined. The wildlife management community is used to illustrate many points, including the important role implementation plays in the overall policy process.

Shape memory nanocomposite of poly(L-lactic acid/graphene nanoplatelets triggered by infrared light and thermal heating

Directory of Open Access Journals (Sweden)

S. Lashgari

2016-04-01

Full Text Available In this study, the effect of graphene nanoplatelets (GNPs on the shape memory properties of poly(L-lactic acid (PLLA was studied. In addition to thermal activation, the possibility of infrared actuating of thermo-responsive shape memory PLLA/GNPs nanocomposite was investigated. The incorporated GNPs were expected to absorb infrared wave’s energy and activate shape memory PLLA/GNPs. Different techniques such as differential scanning calorimetry (DSC, wide-angle X-ray diffraction (WAXD, field emission gun scanning electron microscope (FEG-SEM and dynamic mechanical thermal analysis (DMTA were used to characterize samples. DSC and WAXD results indicated that GNPs augmented crystallinity due to nucleating effect of graphene particles. GNPs improved both thermal and infrared activating shape memory properties along with faster response. Pure shape memory PLLA was slightly responsive to infrared light and its infrared actuated shape recovery ratio was 86% which increased to more than 95% with loading of GNPs. Drastic improvement in the crystallinity was obtained in nanocomposites with lower GNPs contents (0.5 and 1 wt% due to finer dispersion of graphene which resulted in more prominent mechanical and shape memory properties enhancement. Infrared activated shape memory PLLA/GNPs nanocomposites can be developed for wireless remote shape control of smart medical and bio-systems.

Jorum: The UK’s national repository for open educational resources

OpenAIRE

Burke , Shiobhan; Egan, Louise

2014-01-01

Members of the Open Education Special Interest Group have collected a selection of short case studies on Open Education. View all of the case studies at http://repository.alt.ac.uk/view/divisions/CaseStudies/ Jorum: The UK’s national repository for open educational resources: With a collection of over 15,000 free resources, which is growing daily, Jorum can offer those who teach in FE or HE the chance to find and share resources from a broad range of topics to enhance teaching and save ti...

SOLVENT-BASED ENHANCED OIL RECOVERY PROCESSES TO DEVELOP WEST SAK ALASKA NORTH SLOPE HEAVY OIL RESOURCES

Energy Technology Data Exchange (ETDEWEB)

David O. Ogbe; Tao Zhu

2004-01-01

A one-year research program is conducted to evaluate the feasibility of applying solvent-based enhanced oil recovery processes to develop West Sak and Ugnu heavy oil resources found on the Alaska North Slope (ANS). The project objective is to conduct research to develop technology to produce and market the 300-3000 cp oil in the West Sak and Ugnu sands. During the first phase of the research, background information was collected, and experimental and numerical studies of vapor extraction process (VAPEX) in West Sak and Ugnu are conducted. The experimental study is designed to foster understanding of the processes governing vapor chamber formation and growth, and to optimize oil recovery. A specially designed core-holder and a computed tomography (CT) scanner was used to measure the in-situ distribution of phases. Numerical simulation study of VAPEX was initiated during the first year. The numerical work completed during this period includes setting up a numerical model and using the analog data to simulate lab experiments of the VAPEX process. The goal was to understand the mechanisms governing the VAPEX process. Additional work is recommended to expand the VAPEX numerical study using actual field data obtained from Alaska North Slope.

Shear Capacity of C-Shaped and L-Shaped Angle Shear Connectors.

Directory of Open Access Journals (Sweden)

Farzad Tahmasbi

Full Text Available This paper investigates the behaviour of C-shaped and L-shaped angle shear connectors embedded in solid concrete slabs. An effective finite element model is proposed to simulate the push out tests of these shear connectors that encompass nonlinear material behaviour, large displacement and damage plasticity. The finite element models are validated against test results. Parametric studies using this nonlinear model are performed to investigate the variations in concrete strength and connector dimensions. The finite element analyses also confirm the test results that increasing the length of shear connector increases their shear strength proportionately. It is observed that the maximum stress in L-shaped angle connectors takes place in the weld attachment to the beam, whereas in the C-shaped angle connectors, it is in the attached leg. The location of maximum concrete compressive damage is rendered in each case. Finally, a new equation for prediction of the shear capacity of C-shaped angle connectors is proposed.

Shear Capacity of C-Shaped and L-Shaped Angle Shear Connectors

Science.gov (United States)

Tahmasbi, Farzad; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N. H.; Tahir, M. M.

2016-01-01

This paper investigates the behaviour of C-shaped and L-shaped angle shear connectors embedded in solid concrete slabs. An effective finite element model is proposed to simulate the push out tests of these shear connectors that encompass nonlinear material behaviour, large displacement and damage plasticity. The finite element models are validated against test results. Parametric studies using this nonlinear model are performed to investigate the variations in concrete strength and connector dimensions. The finite element analyses also confirm the test results that increasing the length of shear connector increases their shear strength proportionately. It is observed that the maximum stress in L-shaped angle connectors takes place in the weld attachment to the beam, whereas in the C-shaped angle connectors, it is in the attached leg. The location of maximum concrete compressive damage is rendered in each case. Finally, a new equation for prediction of the shear capacity of C-shaped angle connectors is proposed. PMID:27478894

An Untapped Resource: Patient and Public Involvement in Implementation Comment on "Knowledge Mobilization in Healthcare Organizations: A View From the Resource-Based View of the Firm".

Science.gov (United States)

Burton, Christopher; Rycroft-Malone, Jo

2015-08-07

This commentary considers the potential role of patient and public involvement in implementation. Developing an analytical thread from the resource-based view of the Firm, we argue that this involvement may create unique resources that have the capacity to enhance the impact of implementation activity for healthcare organisations. © 2015 by Kerman University of Medical Sciences.

The shape of nuclei

International Nuclear Information System (INIS)

Mackintosh, R.S.

1977-01-01

For the class of nuclei which are 'strongly deformed' it is possible to introduce the idea of an empirically measurable static nuclear shape. The limitations of this concept as applied to nuclei (fundamentally quantum-mechanical objects) are discussed. These are basically the limitations of the rotational model which must be introduced in order to define and measure nuclear shape. A unified discussion of the ways in which the shape has been parametrized is given with emphasis on the fact that different parametrizations correspond to different nuclear structures. Accounts of the various theoretical procedures for calculating nuclear shapes and of the interaction between nuclear shapes and nuclear spectroscopy are given. A coherent account of a large subset of nuclei (strongly deformed nuclei) can be given by means of a model in which the concept of nuclear shape plays a central role. (author)

Conservatism and adaptability during squirrel radiation: what is mandible shape telling us?

Directory of Open Access Journals (Sweden)

Isaac Casanovas-Vilar

Full Text Available Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing shape and size variation in the mandible of extant squirrels using landmark-based geometric morphometrics in combination with a comparative phylogenetic analysis. Dietary specialization and locomotion were found to be reliable predictors of mandible shape, with the prediction by locomotion probably reflecting the underlying diet. In addition a weak but significant allometric effect could be demonstrated. Our results found a strong phylogenetic signal in the family as a whole as well as in the main clades, which is in agreement with the general notion of squirrels being a conservative group. This fact does not preclude functional explanations for mandible shape, but rather indicates that ancient adaptations kept a prominent role, with most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous adaptations that allow them to specialize on unique dietary resources. Such adaptations mostly occurred in the Callosciurinae and probably reflect their radiation into the numerous ecological niches of the tropical and subtropical forests of Southeastern Asia. Our dietary reconstruction for the oldest known fossil squirrels (Eocene, 36 million years ago show a specialization on nuts and seeds, implying that the development from protrogomorphous to sciuromorphous skulls was not necessarily related to a change in diet.

Properties and medical applications of shape memory alloys.

Science.gov (United States)

Tarniţă, Daniela; Tarniţă, D N; Bîzdoacă, N; Mîndrilă, I; Vasilescu, Mirela

2009-01-01

One of the most known intelligent material is nitinol, which offers many functional advantages over conventional implantable alloys. Applications of SMA to the biomedical field have been successful because of their functional qualities, enhancing both the possibility and the execution of less invasive surgeries. The biocompatibility of these alloys is one of their most important features. Different applications exploit the shape memory effect (one-way or two-way) and the super elasticity, so that they can be employed in orthopedic and cardiovascular applications, as well as in the manufacture of new surgical tools. Therefore, one can say that smart materials, especially SMA, are becoming noticeable in the biomedical field. Super elastic NiTi has become a material of strategic importance as it allows to overcome a wide range of technical and design issues relating to the miniaturization of medical devices and the increasing trend for less invasive and therefore less traumatic procedures. This paper will consider just why the main properties of shape memory alloys hold so many opportunities for medical devices and will review a selection of current applications.

Metabolic and demographic feedbacks shape the emergent spatial structure and function of microbial communities.

Directory of Open Access Journals (Sweden)

Sylvie Estrela

Full Text Available Microbes are predominantly found in surface-attached and spatially structured polymicrobial communities. Within these communities, microbial cells excrete a wide range of metabolites, setting the stage for interspecific metabolic interactions. The links, however, between metabolic and ecological interactions (functional relationships, and species spatial organization (structural relationships are still poorly understood. Here, we use an individual-based modelling framework to simulate the growth of a two-species surface-attached community where food (resource is traded for detoxification (service and investigate how metabolic constraints of individual species shape the emergent structural and functional relationships of the community. We show that strong metabolic interdependence drives the emergence of mutualism, robust interspecific mixing, and increased community productivity. Specifically, we observed a striking and highly stable emergent lineage branching pattern, generating a persistent lineage mixing that was absent when the metabolic exchange was removed. These emergent community properties are driven by demographic feedbacks, such that aid from neighbouring cells directly enhances focal cell growth, which in turn feeds back to neighbour fecundity. In contrast, weak metabolic interdependence drives conflict (exploitation or competition, and in turn greater interspecific segregation. Together, these results support the idea that species structural and functional relationships represent the net balance of metabolic interdependencies.

Self-constructed tree-shape high thermal conductivity nanosilver networks in epoxy.

Science.gov (United States)

Pashayi, Kamyar; Fard, Hafez Raeisi; Lai, Fengyuan; Iruvanti, Sushumna; Plawsky, Joel; Borca-Tasciuc, Theodorian

2014-04-21

We report the formation of high aspect ratio nanoscale tree-shape silver networks in epoxy, at low temperatures (thermal conductivity (κ) of the nanocomposite compared to the polymer matrix. The networks form through a three-step process comprising of self-assembly by diffusion limited aggregation of polyvinylpyrrolidone (PVP) coated nanoparticles, removal of PVP coating from the surface, and sintering of silver nanoparticles in high aspect ratio networked structures. Controlling self-assembly and sintering by carefully designed multistep temperature and time processing leads to κ of our silver nanocomposites that are up to 300% of the present state of the art polymer nanocomposites at similar volume fractions. Our investigation of the κ enhancements enabled by tree-shaped network nanocomposites provides a basis for the development of new polymer nanocomposites for thermal transport and storage applications.

Life cycle assessment and sustainable engineering in the context of near net shape grown components: striving towards a sustainable way of future production.

Science.gov (United States)

Kämpfer, Christoph; Seiler, Thomas-Benjamin; Beger, Anna-Lena; Jacobs, Georg; Löwer, Manuel; Moser, Franziska; Reimer, Julia; Trautz, Martin; Usadel, Björn; Wormit, Alexandra; Hollert, Henner

2017-01-01

Technical product harvesting (TEPHA) is a newly developing interdisciplinary approach in which bio-based production is investigated from a technical and ecological perspective. Society's demand for ecologically produced and sustainably operable goods is a key driver for the substitution of conventional materials like metals or plastics through bio-based alternatives. Technical product harvesting of near net shape grown components describes the use of suitable biomass for the production of technical products through influencing the natural shape of plants during their growth period. The use of natural materials may show positive effects on the amount of non-renewable resource consumption. This also increases the product recyclability at the end of its life cycle. Furthermore, through the near net shape growth of biomass, production steps can be reduced. As a consequence such approaches may save energy and the needed resources like crude oil, coal or gas. The derived near net shape grown components are not only considered beneficial from an environmental point of view. They can also have mechanical advantages through an intrinsic topology optimization in contrast to common natural materials, which are influenced in their shape after harvesting. In order to prove these benefits a comprehensive, interdisciplinary scientific strategy is needed. Here, both mechanical investigations and life cycle assessment as a method of environmental evaluation are used.

Shape perception simultaneously up- and downregulates neural activity in the primary visual cortex.

Science.gov (United States)

Kok, Peter; de Lange, Floris P

2014-07-07

An essential part of visual perception is the grouping of local elements (such as edges and lines) into coherent shapes. Previous studies have shown that this grouping process modulates neural activity in the primary visual cortex (V1) that is signaling the local elements [1-4]. However, the nature of this modulation is controversial. Some studies find that shape perception reduces neural activity in V1 [2, 5, 6], while others report increased V1 activity during shape perception [1, 3, 4, 7-10]. Neurocomputational theories that cast perception as a generative process [11-13] propose that feedback connections carry predictions (i.e., the generative model), while feedforward connections signal the mismatch between top-down predictions and bottom-up inputs. Within this framework, the effect of feedback on early visual cortex may be either enhancing or suppressive, depending on whether the feedback signal is met by congruent bottom-up input. Here, we tested this hypothesis by quantifying the spatial profile of neural activity in V1 during the perception of illusory shapes using population receptive field mapping. We find that shape perception concurrently increases neural activity in regions of V1 that have a receptive field on the shape but do not receive bottom-up input and suppresses activity in regions of V1 that receive bottom-up input that is predicted by the shape. These effects were not modulated by task requirements. Together, these findings suggest that shape perception changes lower-order sensory representations in a highly specific and automatic manner, in line with theories that cast perception in terms of hierarchical generative models. Copyright © 2014 Elsevier Ltd. All rights reserved.

Shape analysis in medical image analysis

CERN Document Server

Tavares, João

2014-01-01

This book contains thirteen contributions from invited experts of international recognition addressing important issues in shape analysis in medical image analysis, including techniques for image segmentation, registration, modelling and classification, and applications in biology, as well as in cardiac, brain, spine, chest, lung and clinical practice. This volume treats topics such as, anatomic and functional shape representation and matching; shape-based medical image segmentation; shape registration; statistical shape analysis; shape deformation; shape-based abnormity detection; shape tracking and longitudinal shape analysis; machine learning for shape modeling and analysis; shape-based computer-aided-diagnosis; shape-based medical navigation; benchmark and validation of shape representation, analysis and modeling algorithms. This work will be of interest to researchers, students, and manufacturers in the fields of artificial intelligence, bioengineering, biomechanics, computational mechanics, computationa...

Manufacturing of mushroom-shaped structures and its hydrophobic robustness analysis based on energy minimization approach

Science.gov (United States)

Wang, Li; Yang, Xiaonan; Wang, Quandai; Yang, Zhiqiang; Duan, Hui; Lu, Bingheng

2017-07-01

The construction of stable hydrophobic surfaces has increasingly gained attention owing to its wide range of potential applications. However, these surfaces may become wet and lose their slip effect owing to insufficient hydrophobic stability. Pillars with a mushroom-shaped tip are believed to enhance hydrophobicity stability. This work presents a facile method of manufacturing mushroom-shaped structures, where, compared with the previously used method, the modulation of the cap thickness, cap diameter, and stem height of the structures is more convenient. The effects of the development time on the cap diameter and overhanging angle are investigated and well-defined mushroom-shaped structures are demonstrated. The effect of the microstructure geometry on the contact state of a droplet is predicted by taking an energy minimization approach and is experimentally validated with nonvolatile ultraviolet-curable polymer with a low surface tension by inspecting the profiles of liquid-vapor interface deformation and tracking the trace of the receding contact line after exposure to ultraviolet light. Theoretical and experimental results show that, compared with regular pillar arrays having a vertical sidewall, the mushroom-like structures can effectively enhance hydrophobic stability. The proposed manufacturing method will be useful for fabricating robust hydrophobic surfaces in a cost-effective and convenient manner.

A multiobjective module-order model for software quality enhancement

NARCIS (Netherlands)

Khoshgoftaar, TM; Liu, Y; Seliya, N

2004-01-01

The knowledge, prior to system operations, of which program modules are problematic is valuable to a software quality assurance team, especially when there is a constraint on software quality enhancement resources. A cost-effective approach for allocating such resources is to obtain a prediction in

Assessing innovation in emerging energy technologies: Socio-technical dynamics of carbon capture and storage (CCS) and enhanced geothermal systems (EGS) in the USA

International Nuclear Information System (INIS)

Stephens, Jennie C.; Jiusto, Scott

2010-01-01

This study applies a socio-technical systems perspective to explore innovation dynamics of two emerging energy technologies with potential to reduce greenhouse gas emissions from electrical power generation in the United States: carbon capture and storage (CCS) and enhanced geothermal systems (EGS). The goal of the study is to inform sustainability science theory and energy policy deliberations by examining how social and political dynamics are shaping the struggle for resources by these two emerging, not-yet-widely commercializable socio-technical systems. This characterization of socio-technical dynamics of CCS and EGS innovation includes examining the perceived technical, environmental, and financial risks and benefits of each system, as well as the discourses and actor networks through which the competition for resources - particularly public resources - is being waged. CCS and EGS were selected for the study because they vary considerably with respect to their social, technical, and environmental implications and risks, are unproven at scale and uncertain with respect to cost, feasibility, and life-cycle environmental impacts. By assessing the two technologies in parallel, the study highlights important social and political dimensions of energy technology innovation in order to inform theory and suggest new approaches to policy analysis.

Women in Shape Modeling Workshop

CERN Document Server

Tari, Sibel

2015-01-01

Presenting the latest research from the growing field of mathematical shape analysis, this volume is comprised of the collaborations of participants of the Women in Shape Modeling (WiSh) workshop, held at UCLA's Institute for Pure and Applied Mathematics in July 2013. Topics include: Simultaneous spectral and spatial analysis of shape Dimensionality reduction and visualization of data in tree-spaces, such as classes of anatomical trees like airways and blood vessels Geometric shape segmentation, exploring shape segmentation from a Gestalt perspective, using information from the Blum medial axis of edge fragments in an image Representing and editing self-similar details on 3D shapes, studying shape deformation and editing techniques Several chapters in the book directly address the problem of continuous measures of context-dependent nearness and right shape models. Medical and biological applications have been a major source of motivation in shape research, and key topics are examined here in detail. All...

Liver hemangioma : comparison of echogenecity and contrast-enhancement on dynamic MRI

International Nuclear Information System (INIS)

Seong, Chang Kyu; Han, Joon Koo; Choi, Byung Ihn; Kim, Seog Joon; Yeon, Kyung Mo; Han, Man Chung

1998-01-01

To evaluate the differences in sonographic appearance and hemodynamics between hypoechoic and hyperechoic hemangioma Material and Method : We retrospectively reviewed the sonographic appearance and MRI findings of 23 hypoechoic hepatic hemangiomas in 16 consecutive patients. Nine were men and seven were women, witha mean age of 50 years(range, 40-72). We analyzed the sonographic appearance such as size, shape, border,echogenecity, posterior acoustic enhancement and the presence of fatty liver, and MRI findings such as signal intensity, enhancement pattern. For comparison, we also reviewed the sonographic appearance and MRI findings of 23 hyperechoic hemangiomas in 16 randomly selected patients. Results : There were no differences in size, shape,incidence of posterior acoustic enhancement, MR signal intensity or enhancement pattern between hypoechoic and hyperechoic hemangiomas(p>0.05, Chi-square). However, fatty infiltration of the liver and echogenic rim of the masses were more commonly seen in hypoechoic hemangiomas(9:1, 5:0, respectively, p<0.05). Conclusions : There we reno differences in MR enhomcement pattern or incidence of posterior acoustic enhancement between hypoechoic hyperechoic hemangioma. The vascularity of a mass therefore seems to contribute little to its echogenecity

Shape memory polymer hybrids of SBS/dl-PLA and their shape memory effects

International Nuclear Information System (INIS)

Zhang, Heng; Chen, Zhi; Zheng, Zheng; Zhu, Xiaomin; Wang, Haitao

2013-01-01

The hybrids of styrene-butadiene-styrene tri-block copolymer (SBS) and amorphous poly(dl-lactic acid) (dl-PLA) are found to exhibit shape memory effects, which gives an example of a dual-domain shape memory system consisting of an elastic domain and a thermo-switch domain. The dual-domain manner in this hybrid is studied by means of differential scanning calorimetry (DSC) and scanning electron microscope (SEM). Subsequently, the tensile test clarifies the interactions of the two domains on shape memory effects. As an elastic domain, SBS offers good shape recovery when its content exceeds 50 wt%. As a thermo-switch domain, dl-PLA triggers the shape memory effect at ca. 55 °C and offers good shape fixing when the content exceeds 30 wt%. An easy-to-do and easy-to-know feature of the hybrid is that the optimization of shape memory effect can be achieved by generating bicontinous phases of SBS and dl-PLA, in which the dl-PLA content ranges from 30 to 70 wt%. -- Highlights: ► The composite materials of SBS and amorphous dl-PLA were prepared by blending. ► A continuous domain was observed with the increasing content of dl-PLA. ► The composites exhibited shape memory effects.

Perspectives in shape analysis

CERN Document Server

Bruckstein, Alfred; Maragos, Petros; Wuhrer, Stefanie

2016-01-01

This book presents recent advances in the field of shape analysis. Written by experts in the fields of continuous-scale shape analysis, discrete shape analysis and sparsity, and numerical computing who hail from different communities, it provides a unique view of the topic from a broad range of perspectives. Over the last decade, it has become increasingly affordable to digitize shape information at high resolution. Yet analyzing and processing this data remains challenging because of the large amount of data involved, and because modern applications such as human-computer interaction require real-time processing. Meeting these challenges requires interdisciplinary approaches that combine concepts from a variety of research areas, including numerical computing, differential geometry, deformable shape modeling, sparse data representation, and machine learning. On the algorithmic side, many shape analysis tasks are modeled using partial differential equations, which can be solved using tools from the field of n...

Examining Container Port Resources and Environments to Enhance Competitiveness: A Cross-Country Study from Resource-Based and Institutional Perspectives1

Directory of Open Access Journals (Sweden)

Hyuksoo CHO

2015-09-01

Full Text Available This study aims to analyze the competitiveness of container ports using a cross-country analysis with theoretical foundations. Tangible and intangible resources are discussed as determinants of container port competitiveness using the resource-based view and the institutional theory. This study analyzes the relationships among six variables: container port competitiveness, traffic volume, quality of infrastructure, linear shipping connectivity, operating efficiency, and institutional influence. This study retrieved country-level data on different indicators and countries from several trade and maritime databases. Structural Equation Modeling (SEM is used to test various hypotheses and to evaluate the casual relationships among six variables. Additionally, Ordinary Least Squares (OLS regression is used to test the moderating effects of institutional influence.

Polymorphic Ring-Shaped Molecular Clusters Made of Shape-Variable Building Blocks

Directory of Open Access Journals (Sweden)

Keitel Cervantes-Salguero

2015-02-01

Full Text Available Self-assembling molecular building blocks able to dynamically change their shapes, is a concept that would offer a route to reconfigurable systems. Although simulation studies predict novel properties useful for applications in diverse fields, such kinds of building blocks, have not been implemented thus far with molecules. Here, we report shape-variable building blocks fabricated by DNA self-assembly. Blocks are movable enough to undergo shape transitions along geometrical ranges. Blocks connect to each other and assemble into polymorphic ring-shaped clusters via the stacking of DNA blunt-ends. Reconfiguration of the polymorphic clusters is achieved by the surface diffusion on mica substrate in response to a monovalent salt concentration. This work could inspire novel reconfigurable self-assembling systems for applications in molecular robotics.

Utilization of bio-resources by low energy electron beam

International Nuclear Information System (INIS)

Kume, Tamikazu

2003-01-01

Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

Free and Innovative Teaching Resources for STEM Educators

Science.gov (United States)

Weber, W. J.; McWhirter, J.; Dirks, D.

2014-12-01

The Unidata Program Center has implemented a teaching resource facility that allows educators to create, access, and share collections of resource material related to atmospheric, oceanic, and other earth system phenomena. While the facility can manage almost any type of electronic resource, it is designed with scientific data and products, teaching tools such as lesson plans and guided exercises, and tools for displaying data in mind. In addition to being very easy for educators and students to access, the facility makes it simple for other educators and scientists to contribute content related to their own areas of expertise to the collection. This allows existing teaching resources to grow in depth and breadth over time, enhancing their relevance and providing insights from multiple disciplines. Based on the open-source RAMADDA content/data management framework, the teaching resource facility provides a variety of built-in services to analyze and display data, as well as support for Unidata's rich 3D client, the Interactive Data Viewer (IDV).

Shaping-lathe headrig will convert small hardwoods into pallet cants plus flakes for structural exterior flakeboard

Science.gov (United States)

Peter Koch

1975-01-01

Virtually all nations have an under-utilized resource of small-diameter, low-grade hardwoods of mixed species in a range of densities. The shaping-lathe headrig, now in the final stages of commercialization, is a key to utilizing these hardwoods for pallets, industrial lumber, and-with further development-railroad crossties. Lathe residues in the form of flakes can be...

Photochemical synthesis of shape-selective palladium nanocubes in aqueous solution

International Nuclear Information System (INIS)

Kundu, Subrata; Wang Ke; Lau, Sean; Liang Hong

2010-01-01

We have developed a seedless, citrateless one-step synthetic process for the formation of shape controlled monodisperse Pd nanoparticles (NPs) in 4 h of UV-photoirradiation. The synthesis was done in cetyl trimethylammonium bromide (CTAB) surfactant media in the presence of ascorbic acid as a reducing agent. The size and shape of the particles can be tuned easily by varying the molar ratio of the CTAB with the Pd salt and by controlling the UV-photoirradiation time. The preferential binding of CTAB to the (100) facets of Pd leads to the formation of Pd nanorods and nanocubes. The approach developed here would reduce the use of seed particles and tri-sodium citrate for the fast synthesis of faceted Pd NPs. The synthesized particles were found to be stable for at least 3 months under ambient conditions at room temperature. This newly developed process might find potential applications in the formation of other materials like Au, Ag, and CdS NPs and applicable in surface enhanced Raman scattering, and different catalysis reactions.Graphical AbstractWe have developed a seedless, citrateless one-step synthetic process for the formation of shape controlled monodisperse Pd nanoparticles (NPs) in 4 h of UV-photoirradiation. The synthesis was done in cetyl trimethylammonium bromide (CTAB) surfactant media in the presence of ascorbic acid as a reducing agent. The size and shape of the particles can be tuned easily by varying the molar ratio of the CTAB with the Pd salt and by controlling the UV-photoirradiation time. The preferential binding of CTAB to the (100) facets of Pd leads to the formation of Pd nanorods and nanocubes. The approach developed here would reduce the use of seed particles and tri-sodium citrate for the fast synthesis of faceted Pd NPs. The synthesized particles were found to be stable for at least 3 months under ambient conditions at room temperature. This newly developed process might find potential applications in the formation of other materials like

Photochemical synthesis of shape-selective palladium nanocubes in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Kundu, Subrata, E-mail: skundu@tamu.edu; Wang Ke; Lau, Sean; Liang Hong, E-mail: hliang@tamu.ed [Texas A and M University, Materials Science and Mechanical Engineering (United States)

2010-10-15

We have developed a seedless, citrateless one-step synthetic process for the formation of shape controlled monodisperse Pd nanoparticles (NPs) in 4 h of UV-photoirradiation. The synthesis was done in cetyl trimethylammonium bromide (CTAB) surfactant media in the presence of ascorbic acid as a reducing agent. The size and shape of the particles can be tuned easily by varying the molar ratio of the CTAB with the Pd salt and by controlling the UV-photoirradiation time. The preferential binding of CTAB to the (100) facets of Pd leads to the formation of Pd nanorods and nanocubes. The approach developed here would reduce the use of seed particles and tri-sodium citrate for the fast synthesis of faceted Pd NPs. The synthesized particles were found to be stable for at least 3 months under ambient conditions at room temperature. This newly developed process might find potential applications in the formation of other materials like Au, Ag, and CdS NPs and applicable in surface enhanced Raman scattering, and different catalysis reactions.Graphical AbstractWe have developed a seedless, citrateless one-step synthetic process for the formation of shape controlled monodisperse Pd nanoparticles (NPs) in 4 h of UV-photoirradiation. The synthesis was done in cetyl trimethylammonium bromide (CTAB) surfactant media in the presence of ascorbic acid as a reducing agent. The size and shape of the particles can be tuned easily by varying the molar ratio of the CTAB with the Pd salt and by controlling the UV-photoirradiation time. The preferential binding of CTAB to the (100) facets of Pd leads to the formation of Pd nanorods and nanocubes. The approach developed here would reduce the use of seed particles and tri-sodium citrate for the fast synthesis of faceted Pd NPs. The synthesized particles were found to be stable for at least 3 months under ambient conditions at room temperature. This newly developed process might find potential applications in the formation of other materials like

A Community Assessment Tool for Education Resources

Science.gov (United States)

Hou, C. Y.; Soyka, H.; Hutchison, V.; Budden, A. E.

2016-12-01

In order to facilitate and enhance better understanding of how to conserve life on earth and the environment that sustains it, Data Observation Network for Earth (DataONE) develops, implements, and shares educational activities and materials as part of its commitment to the education of its community, including scientific researchers, educators, and the public. Creating and maintaining educational materials that remain responsive to community needs is reliant on careful evaluations in order to enhance current and future resources. DataONE's extensive collaboration with individuals and organizations has informed the development of its educational resources and through these interactions, the need for a comprehensive, customizable education evaluation instrument became apparent. In this presentation, the authors will briefly describe the design requirements and research behind a prototype instrument that is intended to be used by the community for evaluation of its educational activities and resources. We will then demonstrate the functionality of a web based platform that enables users to identify the type of educational activity across multiple axes. This results in a set of structured evaluation questions that can be included in a survey instrument. Users can also access supporting documentation describing the types of question included in the output or simply download a full editable instrument. Our aim is that by providing the community with access to a structured evaluation instrument, Earth/Geoscience educators will be able to gather feedback easily and efficiently in order to help maintain the quality, currency/relevancy, and value of their resources, and ultimately, support a more data literate community.

Building the Nanoplasmonics Toolbox Through Shape Modeling and Single Particle Optical Studies

Science.gov (United States)

Ringe, Emilie

Interest in nanotechnology is driven by unprecedented properties tailorability, achievable by controlling particle structure and composition. Unlike bulk components, minute changes in size and shape affect the optical and electronic properties of nanoparticles. Characterization of such structure-function relationships and better understanding of structure control mechanisms is crucial to the development of applications such as plasmonic sensors and devices. The objective of the current research is thus twofold: to theoretically predict and understand how shape is controlled by synthesis conditions, and to experimentally unravel, through single particle studies, how shape, composition, size, and surrounding environment affect plasmonic properties in noble metal particles. Quantitative, predictive rules and fundamental knowledge obtained from this research contributes to the "nanoplasmonics toolbox", a library designed to provide scientists and engineers the tools to create and optimize novel nanotechnology applications. In this dissertation, single particle approaches are developed and used to unravel the effects of size, shape, substrate, aggregation state and surrounding environment on the optical response of metallic nanoparticles. Ag and Au nanocubes on different substrates are first presented, followed by the discussion of the concept of plasmon length, a universal parameter to describe plasmon energy for a variety of particle shapes and plasmon modes. Plasmonic sensing (both refractive index sensing and surface-enhanced Raman spectroscopy) and polarization effects are then studied at the single particle level. In the last two Chapters, analytical shape models based on the Wulff construction provide unique modeling tools for alloy and kinetically grown nanoparticles. The former reveals a size-dependence of the shape of small alloy particles (such as those used in catalysis) because of surface segregation, while the latter uniquely models the shape of many

The RISE Framework: Using Learning Analytics to Automatically Identify Open Educational Resources for Continuous Improvement

Science.gov (United States)

Bodily, Robert; Nyland, Rob; Wiley, David

2017-01-01

The RISE (Resource Inspection, Selection, and Enhancement) Framework is a framework supporting the continuous improvement of open educational resources (OER). The framework is an automated process that identifies learning resources that should be evaluated and either eliminated or improved. This is particularly useful in OER contexts where the…

Enhanced Input in LCTL Pedagogy

Directory of Open Access Journals (Sweden)

Marilyn S. Manley

2009-08-01

Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

Enhanced Input in LCTL Pedagogy

Directory of Open Access Journals (Sweden)

Marilyn S. Manley

2010-08-01

Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

Shape control in wafer-based aperiodic 3D nanostructures

International Nuclear Information System (INIS)

Jeong, Hyeon-Ho; Mark, Andrew G; Gibbs, John G; Fischer, Peer; Reindl, Thomas; Waizmann, Ulrike; Weis, Jürgen

2014-01-01

Controlled local fabrication of three-dimensional (3D) nanostructures is important to explore and enhance the function of single nanodevices, but is experimentally challenging. We present a scheme based on e-beam lithography (EBL) written seeds, and glancing angle deposition (GLAD) grown structures to create nanoscale objects with defined shapes but in aperiodic arrangements. By using a continuous sacrificial corral surrounding the features of interest we grow isolated 3D nanostructures that have complex cross-sections and sidewall morphology that are surrounded by zones of clean substrate. (papers)

Pairwise harmonics for shape analysis

KAUST Repository

Zheng, Youyi

2013-07-01

This paper introduces a simple yet effective shape analysis mechanism for geometry processing. Unlike traditional shape analysis techniques which compute descriptors per surface point up to certain neighborhoods, we introduce a shape analysis framework in which the descriptors are based on pairs of surface points. Such a pairwise analysis approach leads to a new class of shape descriptors that are more global, discriminative, and can effectively capture the variations in the underlying geometry. Specifically, we introduce new shape descriptors based on the isocurves of harmonic functions whose global maximum and minimum occur at the point pair. We show that these shape descriptors can infer shape structures and consistently lead to simpler and more efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.

Integrating ergonomics knowledge into business-driven design projects: The shaping of resource constraints in engineering consultancy

DEFF Research Database (Denmark)

Hall-Andersen, Lene Bjerg; Neumann, W. Patrick; Broberg, Ole

2016-01-01

participants were interviewed. METHODS: Data were collected applying semi-structured interviews, observations, and documentary studies. Interviews were transcribed, coded, and categorized into themes. RESULTS: From the analysis five overall themes emerged as major constituents of resource constraints: 1...

Airfoil Shape Optimization based on Surrogate Model

Science.gov (United States)

Mukesh, R.; Lingadurai, K.; Selvakumar, U.

2018-02-01

Engineering design problems always require enormous amount of real-time experiments and computational simulations in order to assess and ensure the design objectives of the problems subject to various constraints. In most of the cases, the computational resources and time required per simulation are large. In certain cases like sensitivity analysis, design optimisation etc where thousands and millions of simulations have to be carried out, it leads to have a life time of difficulty for designers. Nowadays approximation models, otherwise called as surrogate models (SM), are more widely employed in order to reduce the requirement of computational resources and time in analysing various engineering systems. Various approaches such as Kriging, neural networks, polynomials, Gaussian processes etc are used to construct the approximation models. The primary intention of this work is to employ the k-fold cross validation approach to study and evaluate the influence of various theoretical variogram models on the accuracy of the surrogate model construction. Ordinary Kriging and design of experiments (DOE) approaches are used to construct the SMs by approximating panel and viscous solution algorithms which are primarily used to solve the flow around airfoils and aircraft wings. The method of coupling the SMs with a suitable optimisation scheme to carryout an aerodynamic design optimisation process for airfoil shapes is also discussed.

Shape: automatic conformation prediction of carbohydrates using a genetic algorithm

Directory of Open Access Journals (Sweden)

Rosen Jimmy

2009-09-01

Full Text Available Abstract Background Detailed experimental three dimensional structures of carbohydrates are often difficult to acquire. Molecular modelling and computational conformation prediction are therefore commonly used tools for three dimensional structure studies. Modelling procedures generally require significant training and computing resources, which is often impractical for most experimental chemists and biologists. Shape has been developed to improve the availability of modelling in this field. Results The Shape software package has been developed for simplicity of use and conformation prediction performance. A trivial user interface coupled to an efficient genetic algorithm conformation search makes it a powerful tool for automated modelling. Carbohydrates up to a few hundred atoms in size can be investigated on common computer hardware. It has been shown to perform well for the prediction of over four hundred bioactive oligosaccharides, as well as compare favourably with previously published studies on carbohydrate conformation prediction. Conclusion The Shape fully automated conformation prediction can be used by scientists who lack significant modelling training, and performs well on computing hardware such as laptops and desktops. It can also be deployed on computer clusters for increased capacity. The prediction accuracy under the default settings is good, as it agrees well with experimental data and previously published conformation prediction studies. This software is available both as open source and under commercial licenses.

Calculation of Added Mass for Submerged Reactor with Complex Shape

Energy Technology Data Exchange (ETDEWEB)

Sun, Jong-Oh; Kim, Gyeongho; Choo, Yeon-Seok; Yoo, Yeon-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Kijang Research Reactor (KJRR) is currently under construction. Its reactor is located on the bottom of a reactor pool which is filled with water to a depth of 12m. Some components are installed on or inside the reactor and their structural integrity and safety performance need to be verified under seismic situations. For the verification, time history data or Floor Response Spectrum (FRS) on their support location, which is the reactor, should be obtained. A Finite Element (FE) model with fluid elements can give very accurate results for the matter; however, it costs too many resources and takes too much time for the transient analyses. In order to make the model more efficient and simple, added masses are often used to simulate the effect of water instead of the fluid elements. Many literatures introduce methods to calculate the added mass according to the exterior shape of structures. In this paper, how to calculate added masses for complex shaped structure was suggested. The proposed method was applied to RSA for KJRR and its accuracy was verified through comparison of the natural frequencies of RSA with fluid elements and the added masses. They showed the differences less than 1.5% between two models. Finally, it is concluded that the proposed method is quite useful to obtain added masses for complex shaped structure.

Modeling efficient resource allocation patterns for arable crop ...

African Journals Online (AJOL)

optimum plans. This should be complemented with strong financial support, farm advisory services and adequate supply of modern inputs at fairly competitive prices would enhance the prospects of the small holder farmers. Keywords: efficient, resource allocation, optimization, linear programming, gross margin ...

Relational Resources of a University as a Source of Education Quality Assurance

Science.gov (United States)

Bagdasaryan, Irina; Vasilyeva, Zoya; Almabekova, Olga

2015-01-01

This paper considers high quality educational services provided by a university being the highest priority and assumes relational resources as valuable sources that can facilitate and enhance quality assurance. Each university with a unique resource base is connected with a variety of entities--other universities, non-profit and for-profit…

Shape Memory Properties and Enzymatic Degradability of Poly(ε-caprolactone)-Based Polyurethane Urea Containing Phenylalanine-Derived Chain Extender.

Science.gov (United States)

Wang, Rong; Zhang, Fanjun; Lin, Weiwei; Liu, Wenkai; Li, Jiehua; Luo, Feng; Wang, Yaning; Tan, Hong

2018-04-24

Biodegradable shape memory polymers are promising biomaterials for minimally invasive surgical procedures. Herein, a series of linear biodegradable shape memory poly(ε-caprolactone) (PCL)-based polyurethane ureas (PUUs) containing a novel phenylalanine-derived chain extender is synthesized. The phenylalanine-derived chain extender, phenylalanine-hexamethylenediamine-phenylalanine (PHP), contains two chymotrypsin cleaving sites to enhance the enzymatic degradation of PUUs. The degradation rate, the crystallinity, and mechanical properties of PUUs are tailored by the content of PHP. Meanwhile, semicrystalline PCL is not only hydrolytically degradable but also vital for shape memory. Good shape memory ability under body temperature is achieved for PUUs due to the strong interactions in hard segments for permanent crosslinking and the crystallization-melt transition of PCL to switch temporary shape. The PUUs would have a great potential in application as implanting stent. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dependence of the shape of graphene nanobubbles on trapped substance

Science.gov (United States)

Ghorbanfekr-Kalashami, H.; Vasu, K. S.; Nair, R. R.; Peeters, François M.; Neek-Amal, M.

2017-06-01

Van der Waals (vdW) interaction between two-dimensional crystals (2D) can trap substances in high pressurized (of order 1 GPa) on nanobubbles. Increasing the adhesion between the 2D crystals further enhances the pressure and can lead to a phase transition of the trapped material. We found that the shape of the nanobubble can depend critically on the properties of the trapped substance. In the absence of any residual strain in the top 2D crystal, flat nanobubbles can be formed by trapped long hydrocarbons (that is, hexadecane). For large nanobubbles with radius 130 nm, our atomic force microscopy measurements show nanobubbles filled with hydrocarbons (water) have a cylindrical symmetry (asymmetric) shape which is in good agreement with our molecular dynamics simulations. This study provides insights into the effects of the specific material and the vdW pressure on the microscopic details of graphene bubbles.

Water Intensity of Electricity from Geothermal Resources

Science.gov (United States)

Mishra, G. S.; Glassley, W. E.

2010-12-01

BACKGROUND Electricity from geothermal resources could play a significant role in the United States over the next few decades; a 2006 study by MIT expects a capacity of 100GWe by 2050 as feasible; approximately 10% of total electricity generating capacity up from less than 1% today. However, there is limited research on the water requirements and impacts of generating electricity from geothermal resources - conventional as well as enhanced. To the best of our knowledge, there is no baseline exists for water requirements of geothermal electricity. Water is primarily required for cooling and dissipation of waste heat in the power plants, and to account for fluid losses during heat mining of enhanced geothermal resources. MODEL DESCRIPTION We have developed a model to assess and characterize water requirements of electricity from hydrothermal resources and enhanced geothermal resources (EGS). Our model also considers a host of factors that influence cooling water requirements ; these include the temperature and chemical composition of geothermal resource; installed power generation technology - flash, organic rankine cycle and the various configurations of these technologies; cooling technologies including air cooled condensers, wet recirculating cooling, and hybrid cooling; and finally water treatment and recycling installations. We expect to identify critical factors and technologies. Requirements for freshwater, degraded water and geothermal fluid are separately estimated. METHODOLOGY We have adopted a lifecycle analysis perspective that estimates water consumption at the goethermal field and power plant, and accounts for transmission and distribution losses before reaching the end user. Our model depends upon an extensive literature review to determine various relationships necessary to determine water usage - for example relationship between thermal efficiency and temperature of a binary power plant, or differences in efficiency between various ORC configurations

An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States: Preprint

Energy Technology Data Exchange (ETDEWEB)

Mullane, Michelle; Gleason, Michael; McCabe, Kevin; Mooney, Meghan; Reber, Timothy; Young, Katherine R.

2016-10-01

Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

Magnetic properties of elliptical and stadium-shaped nanoparticles: Effect of the shape anisotropy

International Nuclear Information System (INIS)

Corona, R.M.; Altbir, D.; Escrig, J.

2012-01-01

Elliptical and stadium-shaped nanoparticles as a function of their geometry have been investigated using numerical simulations. The effect of the shape anisotropy of the particles on coercivity and remanence together with the angular dependence of the remanence and coercivity are addressed. Our results demonstrate that the stadium-shaped particles have many of the outstanding properties of elliptical particles, but also have unique properties, such that the coercivity and remanence remain stable for a wide range of geometry parameters, and exhibit a peculiar angular dependence in the coercivity. These properties suggest that they can be useful for applications in the area of magnetic recording systems. - Highlights: ► Coercivity and remanence are strongly affected by the shape anisotropy of the particles. ► Coercivities for ellipses are nearly three times the obtained for stadium-shaped particles. ►Elliptical particles with δ≤0.6, the hystereses resemble the square loops of wires. ► An anhisteretic behavior appears for θ=90° for elliptical particles, which do not appear in stadium-shaped particles. ► Stadium-shaped particles have unique properties that allow us to suggest them for applications.

Optimal sensor configuration for flexible structures with multi-dimensional mode shapes

International Nuclear Information System (INIS)

Chang, Minwoo; Pakzad, Shamim N

2015-01-01

A framework for deciding the optimal sensor configuration is implemented for civil structures with multi-dimensional mode shapes, which enhances the applicability of structural health monitoring for existing structures. Optimal sensor placement (OSP) algorithms are used to determine the best sensor configuration for structures with a priori knowledge of modal information. The signal strength at each node is evaluated by effective independence and modified variance methods. Euclidean norm of signal strength indices associated with each node is used to expand OSP applicability into flexible structures. The number of sensors for each method is determined using the threshold for modal assurance criterion (MAC) between estimated (from a set of observations) and target mode shapes. Kriging is utilized to infer the modal estimates for unobserved locations with a weighted sum of known neighbors. A Kriging model can be expressed as a sum of linear regression and random error which is assumed as the realization of a stochastic process. This study presents the effects of Kriging parameters for the accurate estimation of mode shapes and the minimum number of sensors. The feasible ranges to satisfy MAC criteria are investigated and used to suggest the adequate searching bounds for associated parameters. The finite element model of a tall building is used to demonstrate the application of optimal sensor configuration. The dynamic modes of flexible structure at centroid are appropriately interpreted into the outermost sensor locations when OSP methods are implemented. Kriging is successfully used to interpolate the mode shapes from a set of sensors and to monitor structures associated with multi-dimensional mode shapes. (paper)

How Structure-Directing Agents Control Nanocrystal Shape: Polyvinylpyrrolidone-Mediated Growth of Ag Nanocubes.

Science.gov (United States)

Qi, Xin; Balankura, Tonnam; Zhou, Ya; Fichthorn, Kristen A

2015-11-11

The importance of structure-directing agents (SDAs) in the shape-selective synthesis of colloidal nanostructures has been well documented. However, the mechanisms by which SDAs actuate shape control are poorly understood. In the polyvinylpyrrolidone (PVP)-mediated growth of {100}-faceted Ag nanocrystals, this capability has been attributed to preferential binding of PVP to Ag(100). We use molecular dynamics simulations to probe the mechanisms by which Ag atoms add to Ag(100) and Ag(111) in ethylene glycol solution with PVP. We find that PVP induces kinetic Ag nanocrystal shapes by regulating the relative Ag fluxes to these facets. Stronger PVP binding to Ag(100) leads to a larger Ag flux to Ag(111) and cubic nanostructures through two mechanisms: enhanced Ag trapping by more extended PVP films on Ag(111) and a reduced free-energy barrier for Ag to cross lower-density films on Ag(111). These flux-regulating capabilities depend on PVP concentration and chain length, consistent with experiment.