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Articles 43501 - 43530 of 304318

Full-Text Articles in Physical Sciences and Mathematics

A Preliminary Study On Graphene Film-Metal Composites Prepared By Electrodeposition, Shuang-Juan Liu, Hai-Jing Wang, Jing Guo, Peng-Cheng Wang, Hao Zhou, Cai Meng, Han-Jie Guo Aug 2021

A Preliminary Study On Graphene Film-Metal Composites Prepared By Electrodeposition, Shuang-Juan Liu, Hai-Jing Wang, Jing Guo, Peng-Cheng Wang, Hao Zhou, Cai Meng, Han-Jie Guo

Journal of Electrochemistry

Graphene film (GF) has excellent electrical and thermal conductivity, but low strength and hardness. In order to obtain good comprehensive mechanical properties to improve the practical value of GF, the concept of preparing GF-metal composite materials was proposed. This work was conducted to preliminarily study the feasibility of using electrodeposition method to prepare GF-metal composites. Two kinds of composites, GF-Cu and GF-Cr, were successfully prepared by using GF as the cathode, and pure Cu and DSA (Dimensionally Stable Anode) as the anodes, respectively, with applying DC power externally. Employing certain electrochemical parameters, the cation in the electrolyte moved towards the …

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Preparation And Characterization Of Thermoplastic Polyurethane-Based Polymer Electrolyte, Li Zhou, Lie Wu, Zhao-Ming Xue Aug 2021

Preparation And Characterization Of Thermoplastic Polyurethane-Based Polymer Electrolyte, Li Zhou, Lie Wu, Zhao-Ming Xue

Journal of Electrochemistry

Electrolyte still has to be improved to satisfy the increasingly rigid demands of lithium ion batteries that have higher energy densities. Thermoplastic polyurethane (TPU) has two phase structures of soft segments and hard segments, which can guarantee the electrochemical and physical performances of electrolyte for lithium ion battery. It is now creatively applied to the gel polymer electrolyte matrix of lithium ion batteries. In this paper, a novel polymer membrane based on thermoplastic polyurethane/cellulose acetate (TPU/CA) was prepared by non-solvent induced phase separation (NIPS) method. Further, the TPU/CA blending gel polymer electrolyte (GPE) was prepared by absorbing liquid electrolyte. The …

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Commuting Isometries And Invariant Subspaces In Several Variables., Sankar T. R. Dr. Aug 2021

Commuting Isometries And Invariant Subspaces In Several Variables., Sankar T. R. Dr.

Doctoral Theses

A very general and fundamental problem in the theory of bounded linear operators on Hilbert spaces is to find invariants and representations of commuting families of isometries.In the case of single isometries this question has a complete and explicit answer: If V is an isometry on a Hilbert space â„‹, then there exists a Hilbert space Hu and a unitary operator U on â„‹u such that V on â„‹u and[ S ⊗ IW 0 0 U] ∈ B((l 2 (ℤ+) ⊗ W) ⊕ â„‹u),are unitarily equivalent, whereW = ker V∗ ,is the wandering subspace for V and S is the …

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“Surviving And Growing Up With Illegal Status”: The Analysis Of Socio–Economic Household, Potential Conflict, The Environmental Damage, And Vulnerability Of Local Community To Disaster, Sofyan Syahnur, Yossi Diantimala Aug 2021

“Surviving And Growing Up With Illegal Status”: The Analysis Of Socio–Economic Household, Potential Conflict, The Environmental Damage, And Vulnerability Of Local Community To Disaster, Sofyan Syahnur, Yossi Diantimala

Journal of Sustainable Mining

This study aims to analyze, from social-economics and environmental perspectives, how illegal gold mining survives and grows with its illegal status. Generally, illegal mining has a positive impact on the socio-economy of all parties involved. However, mining activities cause environmental damage and pollution so that the local community is vulnerable to disaster and potential conflict. This research was conducted at an illegal mining site in Aceh, the western province of Indonesia. To describe the primary data, it employs a descriptive qualitative method. The purposive sampling method is used to select key informants. The results show an increasing income of all …

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Seed Production And Quality Of Buffelgrass (Cenchrus Ciliaris) Selections, N. F. G. Rethman, W. H. Boshoff Aug 2021

Seed Production And Quality Of Buffelgrass (Cenchrus Ciliaris) Selections, N. F. G. Rethman, W. H. Boshoff

IGC Proceedings (1993-2023)

As seed production and quality are critical considerations in the commercialization of new cultivars, an evaluation programme of promising Cenchrus ciliaris (Buffelgrass) accessions placed particular emphasis on these parameters. Accessions identified for registration proved to be superior in both respects, although storage of seed or cleaning of fresh seed reduced the differences in germination between accessions. The refinement of seed cleaning processes should receive greater emphasis by commercial concerns.

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Effect Of The Hierarchical Position Of Individuals In A Medicago Sativa Stand On Shoot Respiration, M. Lötscher, Hans Schnyder Aug 2021

Effect Of The Hierarchical Position Of Individuals In A Medicago Sativa Stand On Shoot Respiration, M. Lötscher, Hans Schnyder

IGC Proceedings (1993-2023)

The influence of the hierarchical position on the relationship between C gains and C losses (respiration) of individuals was investigated in a alfalfa (Medicago sativa) stand. The hierarchical position that an individual occupied was defined by its height relative to the stand height. Stands were established by arranging potted individual plants at a density of 400 plants m-2. Stands were grown in growth cabinets. 13C steady-state labelling was used to assess C fixation (Cnew) by individuals during a photoperiod of 16 h. Respiration of shoots was measured during the following 8 h dark …

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Patterns Of Development And Nitrogen Reserves Mobilization During Regrowth Of Defoliated Clover, F. Le Dily, E. Goulas, P. Lainé, E. Le Deunff Aug 2021

Patterns Of Development And Nitrogen Reserves Mobilization During Regrowth Of Defoliated Clover, F. Le Dily, E. Goulas, P. Lainé, E. Le Deunff

IGC Proceedings (1993-2023)

Contribution of nitrogen reserves to regrowth following defoliation was studied in white clover plants (Trifolium repens) according to the morphological pattern of differentiation of the aerial parts during the same period. Low temperature and short day lengths were used as a pre-treatment in order to increase branching and enhance new sites of leaf production during a further 25 d period of regrowth. Pre-treated plants exhibited a large reduction in leaf area largely counterbalanced with a high increase in leaf pool size during the first 10 d of regrowth. The mobilization of nitrogen reserves during regrowth of defoliated clover …

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Resistance To Drought In Shore Elurope (Aeluropus Litoralis) And Weeping Alkaligrass (Puccinellia Distans), Mohammad Jafari, A. G. Firouzabadi Aug 2021

Resistance To Drought In Shore Elurope (Aeluropus Litoralis) And Weeping Alkaligrass (Puccinellia Distans), Mohammad Jafari, A. G. Firouzabadi

IGC Proceedings (1993-2023)

Two rangeland grass species, Shore Elurope (Aeluropus litoralis) and Weeping Alkaligrass (Puccinellia distans) were studied. The research was done under a split plot experiment and completely randomized design. Plants were grown under two irrigation treatments (seven and fourteen day periods of irrigation treatments). Morphological response included determination of wilting percentage, leaf water potential, production of yield, root dry weight, weight ratio of root/stem and finally total dry weight of species. Anatomical studies included leaf descriptive structure such as comparison of stomata and their density in area unit, study of vascular structure, mesophyl tissues and epiderm. Results …

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Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor Aug 2021

Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor

School of Natural Resources: Faculty Publications

Effective measurement of seasonal variations in the timing and amount of production is critical to managing spatially heterogeneous agroecosystems in a changing climate. Although numerous technologies for such measurements are available, their relationships to one another at a continental extent are unknown. Using data collected from across the Long-Term Agroecosystem Research (LTAR) network and other networks, we investigated correlations among key metrics representing primary production, phenology, and carbon fluxes in croplands, grazing lands, and crop-grazing integrated systems across the continental U.S. Metrics we examined included gross primary productivity (GPP) estimated from eddy covariance (EC) towers and modelled from the Landsat …

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Computer Vision Applications For Autonomous Aerial Vehicles, Burak Kakillioglu Aug 2021

Computer Vision Applications For Autonomous Aerial Vehicles, Burak Kakillioglu

Dissertations - ALL

Undoubtedly, unmanned aerial vehicles (UAVs) have experienced a great leap forward over the last decade. It is not surprising anymore to see a UAV being used to accomplish a certain task, which was previously carried out by humans or a former technology. The proliferation of special vision sensors, such as depth cameras, lidar sensors and thermal cameras, and major breakthroughs in computer vision and machine learning fields accelerated the advance of UAV research and technology. However, due to certain unique challenges imposed by UAVs, such as limited payload capacity, unreliable communication link with the ground stations and data safety, UAVs …

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Binary Neutron Star Mergers: Gravitational-Wave Measurements Of Their Parameters And The Nuclear Equation Of State, Daniel Roger Finstad Aug 2021

Binary Neutron Star Mergers: Gravitational-Wave Measurements Of Their Parameters And The Nuclear Equation Of State, Daniel Roger Finstad

Dissertations - ALL

Since making the first direct detection of gravitational waves in 2015, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) together with the Virgo observatory has detected an additional 51 confirmed signals from binary mergers. Two of these signals, GW170817 and GW190425, were identified as binary neutron star mergers. As detector sensitivity improves we expect to see many more binary neutron star merger events, both from future observing runs of the LIGO-Virgo network and from planned third-generation detectors. These new detections will provide an exquisite look at the nature of these systems and of neutron stars themselves. This thesis describes how gravitational-wave …

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Mgrre_Pureoilscouttickets_Kinster_1_21127005020000, Mgrre Aug 2021

Mgrre_Pureoilscouttickets_Kinster_1_21127005020000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

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Analysis Of Rock Varnish From The Mojave Desert By Handheld Laser-Induced Breakdown Spectroscopy, Russell S. Harmon, Daria Khashchevskaya, Michelle Morency, Lewis A. Owen, Morgan Jennings, Jeffrey R. Knott, Jason M. Dortch Aug 2021

Analysis Of Rock Varnish From The Mojave Desert By Handheld Laser-Induced Breakdown Spectroscopy, Russell S. Harmon, Daria Khashchevskaya, Michelle Morency, Lewis A. Owen, Morgan Jennings, Jeffrey R. Knott, Jason M. Dortch

Faculty, Staff, and Affiliated Publications--KGS

Laser-induced breakdown spectroscopy (LIBS) is a form of optical emission spectroscopy that can be used for the rapid analysis of geological materials in the field under ambient environmental conditions. We describe here the innovative use of handheld LIBS for the in situ analysis of rock varnish. This thinly laminated and compositionally complex veneer forms slowly over time on rock surfaces in dryland regions and is particularly abundant across the Mojave Desert climatic region of east-central California (USA). Following the depth profiling examination of a varnished clast from colluvial gravel in Death Valley in the laboratory, our in situ analysis of …

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Elucidating The Effects Of Oxygen- And Nitrogen-Containing Functional Groups In Graphene Nanomaterials For Applied Electrochemistry By Density Functional Theory, Sanju Gupta, N. Dimakis Aug 2021

Elucidating The Effects Of Oxygen- And Nitrogen-Containing Functional Groups In Graphene Nanomaterials For Applied Electrochemistry By Density Functional Theory, Sanju Gupta, N. Dimakis

Physics and Astronomy Faculty Publications and Presentations

Graphene nanomaterials functionalized with oxygen groups [graphene oxide (GO) and reduced GO (rGO)] are either doped with element nitrogen or nitrogen-containing aromatic moieties followed by the investigation of electrochemical properties that generally show enhanced electroanalytical performance. We studied structural, morphological, and physical–chemical properties using correlative techniques. While we attribute their improved properties promoted simultaneously by topologically interconnected mesoporous network morphology, the presence of heteroatom species, and lattice vibrational structure, the complex interpretation requires the need to supplement the experimental observations with theoretical calculations for further insights. The complex interplay of pore size and redox properties revealing distinctive supercapacitive (ion-adsorption controlled) …

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Control Technology And Supervision Of Sulfur Oxide Emission From Ships, Keshun Li Aug 2021

Control Technology And Supervision Of Sulfur Oxide Emission From Ships, Keshun Li

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Analysis And Suggestions On Development Of China’S Coastal Lng Bunkering Industry, Ren Tang Aug 2021

Analysis And Suggestions On Development Of China’S Coastal Lng Bunkering Industry, Ren Tang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Improved Ships Course-Keeping Robust Control Algorithm Based On Backstepping And Nonlinear Feedback, Sirui Wang Aug 2021

Improved Ships Course-Keeping Robust Control Algorithm Based On Backstepping And Nonlinear Feedback, Sirui Wang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Research On Black Carbon Emission Of Ships In Arctic And Analysis Of Emission Abatement Solutions, Ye Tao Aug 2021

Research On Black Carbon Emission Of Ships In Arctic And Analysis Of Emission Abatement Solutions, Ye Tao

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Analytical Review Of Countermeasures For The Effective Implementation Of Marine Greenhouse Gas Regulations By The Member States Of Imo, Junjie Wei Aug 2021

Analytical Review Of Countermeasures For The Effective Implementation Of Marine Greenhouse Gas Regulations By The Member States Of Imo, Junjie Wei

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Economic Analysis Of Measures For Shipowners Under Sulfur Emission Control, Luyao Yu Aug 2021

Economic Analysis Of Measures For Shipowners Under Sulfur Emission Control, Luyao Yu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Research On Legal Problems In And Countermeasures For Prevention And Control Marine Environment Pollution By Ships, Dapeng Sun Aug 2021

Research On Legal Problems In And Countermeasures For Prevention And Control Marine Environment Pollution By Ships, Dapeng Sun

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Data-Driven Based Automatic Routing Planning For Mass, Qingwu Wang Aug 2021

Data-Driven Based Automatic Routing Planning For Mass, Qingwu Wang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Evaluation On Navigation Environment Of Luoyu Port Area For 400,000-Dwt Uloc, Lijiao Wen Aug 2021

Evaluation On Navigation Environment Of Luoyu Port Area For 400,000-Dwt Uloc, Lijiao Wen

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Study On Emergency Response Mechanism And Treatment Technology Of Lng Releasing On/Under Water, Bin Zhang Aug 2021

Study On Emergency Response Mechanism And Treatment Technology Of Lng Releasing On/Under Water, Bin Zhang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Optimal Scheme Of Ships’ Routeing System In The Yangtze Estuary Based On Analytical Hierarchy Process, Yixiang Zhang Aug 2021

Optimal Scheme Of Ships’ Routeing System In The Yangtze Estuary Based On Analytical Hierarchy Process, Yixiang Zhang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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Self-Organization In Models Of Cyclically Sheared Suspensions, Jikai Wang Aug 2021

Self-Organization In Models Of Cyclically Sheared Suspensions, Jikai Wang

Dissertations - ALL

This thesis presents a study of random self-organized systems using computer-simulated models inspired by cyclically-sheared non-Brownian suspensions of monodisperse spherical particles in a density-matched fluid. When driven at low Reynolds number, such systems have vanishing thermal fluctuations and only short-range interactions between individual particles. Nevertheless, they show intriguing collective behaviors at large length scales, such as a strong suppression of fluctuations in the number density. Such self-organized "hyperuniform" states can useful in industrial applications where well-controlled states can ease the processing of such materials.In Chapter 2, we propose a new way of generating hyperuniform suspensions, by incorporating slow gravity-driven sedimentation …

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Computational Methodologies For The Simulation And Analysis Of Low-Frequency Vibrations In Molecular Crystals, Sara Jean Dampf Aug 2021

Computational Methodologies For The Simulation And Analysis Of Low-Frequency Vibrations In Molecular Crystals, Sara Jean Dampf

Dissertations - ALL

Quantum mechanical models are used to calculate a host of physical phenomena in molecular solids ranging from mechanical elasticity to the energetic stability ordering of polymorphs. However, with the many software packages and methodologies available, it can be difficult to select the most suitable model for the problem at hand without prior knowledge. A promising approach for evaluating the performance of solid-state models is the comparison of the simulations to experimentally measured low-frequency (sub-200 cm-1) vibrational spectra. As this region is dominated by weak intermolecular forces and shallow potential energy surfaces, even slight miscalculations in the solid-state packing arrangements can …

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Investigations Of Trace Element Titanium In Silica Minerals, Zachary Robert Osborne Aug 2021

Investigations Of Trace Element Titanium In Silica Minerals, Zachary Robert Osborne

Dissertations - ALL

Quartz is a common mineral in many igneous, metamorphic, and sedimentary rocks because it is stable over a wide range of pressure (P) and temperature (T) conditions; therefore, quartz is an excellent mineral to target for thermobarometric uses. Thermobarometry is the quantitative determination of the pressure (baro-) and temperature (thermo-) conditions at which a natural rock sample reached chemical equilibrium. This dissertation contains three chapters describing mineral synthesis experiments that quantify and define the trace-element solubility behavior of titanium (Ti) in the silica minerals quartz and coesite, to advance the understanding and application of trace-element thermobarometry.Chapter 1 details the experiments …

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Molecular Interfaces And Heterogeneous Bubble Nucleation From Heated Surfaces At Nanoscale, Manish Gupta Aug 2021

Molecular Interfaces And Heterogeneous Bubble Nucleation From Heated Surfaces At Nanoscale, Manish Gupta

Dissertations - ALL

Heat transfer from a solid surface to fluid occurs in numerous applications, such as boilers, refrigerators, power electronics, etc., and include various underlying phenomena of thin-film evaporation, boiling, condensation, surface wetting, and droplet evaporation. Several studies show that heat transfer can be enhanced significantly by incorporating micro and nanoscale features onto surfaces. Phase change heat transfer plays an important role in dissipating energy from hot surfaces and distributing it to bulk liquid due to high latent heat of liquids. Boiling, a phase change heat transfer phenomenon, happens when the surface is heated to a temperature above the saturation temperature of …

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Multimode Circuit Quantum Electrodynamics With Superconducting Metamaterial Resonators, . Indrajeet Aug 2021

Multimode Circuit Quantum Electrodynamics With Superconducting Metamaterial Resonators, . Indrajeet

Dissertations - ALL

Superconducting devices in circuit quantum electrodynamics (cQED) systems are one of the leading approaches for realizing scalable quantum information processors. The combination of cQED architectures with multimode resonator systems can provide a flexible platform for performing analog quantum simulations, storing quantum information, and generating complex entangled states. Metamaterial resonant structures made from arrays of superconducting lumped circuit elements can exhibit microwave mode spectra with left-handed dispersion, resulting in a high density of modes in the same frequency range where superconducting qubits are typically operated, as well as a bandgap at lower frequencies that extends down to dc. In this thesis, …

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