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Articles 5401 - 5430 of 8621

Full-Text Articles in Physical Sciences and Mathematics

Characteristics Of Mongolian Wild Ass Hooves (Equus Hemionus Hemionus), Jan Gahsche, Michael Stubbe, Matthias Oppermann, N. Batsajchan, Annegret Stubbe Jan 2010

Characteristics Of Mongolian Wild Ass Hooves (Equus Hemionus Hemionus), Jan Gahsche, Michael Stubbe, Matthias Oppermann, N. Batsajchan, Annegret Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Measurements of hoof angles, hoof length, toe length, etc., and non-metrical hoof characters of Mongolian Wild Ass carcasses collected in in the South Gobi and in Bordzongijn-Gobi desert are presented. Khulan hooves are flat, wide and look big in relation to the animal’s dimensions. Remarkably is the wide variability in size, angles, in non metric characteristics like shape, color and the occurrence of particularly prolonged hoof wall and flaring walls. For example, toe angles are 52° for front and 54° for hind hooves on average. This measures and the suggested graphical model of the „ideal hoof shape“ can assist to …


Challenges And Prospects Of Sustainable Groundwater Management In The Indus Basin, Pakistan, Asad Sarwar Qureshi, Peter G. Mccornick, A. Sarwar, Bharat R. Sharma Jan 2010

Challenges And Prospects Of Sustainable Groundwater Management In The Indus Basin, Pakistan, Asad Sarwar Qureshi, Peter G. Mccornick, A. Sarwar, Bharat R. Sharma

Daugherty Water for Food Global Institute: Faculty Publications

In Pakistan, on-demand availability of groundwater has transformed the concept of low and uncertain crop yields into more assured crop production. Increased crop yields have resulted in food security and improved rural livelihoods. However, this growth has also led to problems of overdraft, falling water tables, and degradation of groundwater quality, and yields generally remain well below potential levels. Over the last three decades, Pakistan has tried several direct and indirect management strategies for groundwater management. However the success has been limited. This paper argues that techno-institutional approaches such as introducing water rights, direct or indirect pricing, and permit systems …


The Challenges Of Wastewater Irrigation In Developing Countries, M. Qadir, D. Wichelns, L. Raschid-Sally, Peter G. Mccornick, P. Drechsel, A. Bahri, P. S. Minhas Jan 2010

The Challenges Of Wastewater Irrigation In Developing Countries, M. Qadir, D. Wichelns, L. Raschid-Sally, Peter G. Mccornick, P. Drechsel, A. Bahri, P. S. Minhas

Daugherty Water for Food Global Institute: Faculty Publications

The volume of wastewater generated by domestic, industrial, and commercial sources has increased with population, urbanization, improved living conditions, and economic development. The productive use of wastewater has also increased, as millions of small-scale farmers in urban and peri-urban areas of developing countries depend on wastewater or wastewater-polluted water sources to irrigate high-value edible crops for urban markets, often as they have no alternative sources of irrigation water. Undesirable constituents in wastewater can harm human health and the environment. Hence, wastewater irrigation is an issue of concern to public agencies responsible for maintaining public health and environmental quality. For diverse …


Ni Doping Of Semiconducting Boron Carbide, Nina Hong, Marjorie Langell, Jing Liu, Orhan Kizilkaya, Shireen Adenwalla Jan 2010

Ni Doping Of Semiconducting Boron Carbide, Nina Hong, Marjorie Langell, Jing Liu, Orhan Kizilkaya, Shireen Adenwalla

Marjorie A. Langell Publications

The wide band gap, temperature stability, high resistivity, and robustness of semiconducting boron carbide make it an attractive material for device applications. Undoped boron carbide is p type; Ni acts as a n-type dopant. Here we present the results of controlled doping of boron carbide with Ni on thin film samples grown using plasma enhanced chemical vapor deposition. The change in the dopant concentration within the thin film as a function of the dopant flow rate in the precursor gas mixture was confirmed by x-ray photoelectron spectroscopy measurements; with increasing dopant concentration, current-voltage (I-V) curves clearly establish the trend from …


Interlayer Exchange Coupling Across A Ferroelectric Barrier, M Ye Zhuravlev, A V. Vedyayev, Evgeny Y. Tsymbal Jan 2010

Interlayer Exchange Coupling Across A Ferroelectric Barrier, M Ye Zhuravlev, A V. Vedyayev, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

A new magnetoelectric effect is predicted originating from the interlayer exchange coupling between two ferromagnetic layers separated by an ultrathin ferroelectric barrier. It is demonstrated that ferroelectric polarization switching driven by an external electric field leads to a sizable change in the interlayer exchange coupling. The effect occurs in asymmetric ferromagnet/ferroelectric/ferromagnet junctions due to a change in the electrostatic potential profile across the junction affecting the interlayer coupling. The predicted phenomenon indicates the possibility of switching the magnetic configuration by reversing the polarization of the ferroelectric barrier layer.


Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal Jan 2010

Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Using first-principles density-functional calculations, we demonstrate that ferromagnetism can be induced and modulated on an otherwise paramagnetic Pd metal thin-film surface through application of an external electric field. As free charges are either accumulated or depleted at the Pd surface to screen the applied electric field, there is a corresponding change in the surface density of states. This change can be made sufficient for the Fermi-level density of states to satisfy the Stoner criterion, driving a transition locally at the surface from a paramagnetic state to an itinerant ferromagnetic state above a critical applied electric field, Ec. Furthermore, …


Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal Jan 2010

Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

First-principles calculations demonstrate the evolution of the band alignment at La0.7A0.3MnO3 / La1−xAxO / TiO2 / SrTiO3 (001) heterointerfaces, where A=Ca, Sr, or Ba, as the interfacial A-site composition, La1−xAx, is varied from x=0.5 to x=1.0. This variation leads to a linear change in the SrTiO3 valence-band offset with respect to the Fermi level of the La0.7A0.3MnO3 metal electrode and hence to a linear change in the Schottky barrier height at this interface. The effect arises due to electrostatic …


Dissociative Electron Attachment In Nonplanar Chlorocarbons With Π**-Coupled Molecular Orbitals, Kayvan Aflatooni, Gordon A. Gallup, Paul Burrow Jan 2010

Dissociative Electron Attachment In Nonplanar Chlorocarbons With Π*/Σ*-Coupled Molecular Orbitals, Kayvan Aflatooni, Gordon A. Gallup, Paul Burrow

Paul Burrow Publications

Total absolute cross sections for the dissociative electron attachment (DEA) process are reported for a series of nonplanar ethylenic and phenylic compounds monosubstituted with (CH2)nCl groups, where n=1–4. Coupling between the local π* molecular orbitals provided by the unsaturated moieties and the σ* (C-Cl) orbital is thus examined as a function of the separation of these groups. In particular, the coupling is viewed from the perspective of the interacting temporary negative ions formed by short lived occupation of these orbitals and their decay into the DEA channel. A theoretical treatment of “remote” bond breaking, …


Fuel Consumption And Smoke Emissions From Landscape-Scale Burns In Eastern Hardwoods, Matthew Dickinson, Ann Acheson, Robert Kremens Jan 2010

Fuel Consumption And Smoke Emissions From Landscape-Scale Burns In Eastern Hardwoods, Matthew Dickinson, Ann Acheson, Robert Kremens

JFSP Research Project Reports

Our project used remotely-sensed infrared radiation measurements to estimate fuel consumption in eastern mixed-oak forests and facilitated the development of smoke management expertise and processes for complying with EPA regulations in Ohio and Kentucky. As a result of two workshops, Ohio developed a Smoke Management Plan designed to ensure that best management practices were being used across land ownerships and to facilitate mandated information sharing with the Ohio EPA and US EPA. Ohio also established a Prescribed Fire Council as a result of this process. Kentucky opted for a less formal response to EPA regulations, establishing a Prescribed Fire Council …


Developing And Using Fire Scar Histories In The Southern And Eastern United States, Richard P. Guyette, Martin Spetich, Daniel C. Dey Jan 2010

Developing And Using Fire Scar Histories In The Southern And Eastern United States, Richard P. Guyette, Martin Spetich, Daniel C. Dey

JFSP Research Project Reports

Land managers developing fire management plans in the eastern and southern United States lack quantitative information on historic fire regimes. Twelve new fire histories were developed from dated fire scars on trees from regions where no fire scar history data had existed before in the states of Alabama, Louisiana, Kentucky, Iowa, Wisconsin, and Michigan. Sites represent highly variable climates from extreme cold (with long snow cover duration) to subtropical. All sites utilized oak or pine recorder species that were collected from closed forest to open savanna structures. Pre-industrial mean fire intervals ranged from 3 to more than 35 years at …


Do Annual Prescribed Fires Enhance Or Slow The Loss Of Coastal Marsh Habitat At Blackwater National Wildlife Refuge?, Donald R. Cahoon, Glenn Guntenspergen, Suzanne Baird Jan 2010

Do Annual Prescribed Fires Enhance Or Slow The Loss Of Coastal Marsh Habitat At Blackwater National Wildlife Refuge?, Donald R. Cahoon, Glenn Guntenspergen, Suzanne Baird

JFSP Research Project Reports

The rate of estuarine marsh loss at Blackwater NWR has been high (up to 2,000 ha) during the past 80 years because the vertical buildup of the marsh surface has lagged behind the local rate of relative sea-level rise. In this mineral sediment-poor estuary, marsh vertical development is driven primarily by the accumulation of plant matter in the soil (roots and rhizomes). Thus any activity that affects plant productivity can affect the ability of these marshes to keep pace with sea-level rise. Blackwater NWR has employed an annual prescribed fire regime since the 1970’s to achieve multiple management objectives. However, …


Effect Of Season And Interval Of Prescribed Burns In A Ponderosa Pine Ecosystem On Tree Growth And Understory Vegetation., W. G. Thies, Becky K. Kerns, Douglas J. Westlind Jan 2010

Effect Of Season And Interval Of Prescribed Burns In A Ponderosa Pine Ecosystem On Tree Growth And Understory Vegetation., W. G. Thies, Becky K. Kerns, Douglas J. Westlind

JFSP Research Project Reports

After decades of fire exclusion many stands now have historically unprecedented (high) levels of fuels and overstocking. As a result these stands have developed a variety of health issues. In response to these problems land managers are using prescribed fire to restore fuel loads and stand stocking to pre-fire exclusion levels. The impacts of season of prescribed burn as well as burn interval are not well understood. Managers need the ability to better predict these impacts on such things as tree mortality from fire, associated insect attack and disease development, tree growth, and plant communities. The “Season of Burn” study …


Do Fuel Treatments Reduce Fire Severity? Evaluating Treatment Effectiveness In The 2006 Tripod Complex Fires, Susan J. Prichard, David L. Peterson Jan 2010

Do Fuel Treatments Reduce Fire Severity? Evaluating Treatment Effectiveness In The 2006 Tripod Complex Fires, Susan J. Prichard, David L. Peterson

JFSP Research Project Reports

The 2006 Tripod Complex fires burned over 70,000 ha of dry mixed conifer forests in north-central Washington State. Recent fuel treatments burned in the wildfire offered an opportunity to quantitatively evaluate if fuel treatment effectively mitigated fire severity. We quantified the relative effect of two common fuel treatments: mechanical thinning only (thin) and mechanical thinning followed by prescribed burning (thinRx). Fire severity was markedly different between the two treatments. Over 57% of trees survived in thinRx units versus 19% in thin and 14% in control units. Considering only large-diameter trees (> 20 cm dbh), 73% survived in thinRx units versus …


Effects Of Prescribed Burning, Mechanical, And Chemical Treatments To Curtail Rhododendron Dominance And Reduce Urban Interface Fuel Loads, Shepard M. Zedaker, Charles W. Harrell Iii, Christopher D. Pearce Jan 2010

Effects Of Prescribed Burning, Mechanical, And Chemical Treatments To Curtail Rhododendron Dominance And Reduce Urban Interface Fuel Loads, Shepard M. Zedaker, Charles W. Harrell Iii, Christopher D. Pearce

JFSP Research Project Reports

One-half-acre treatment areas were delineated within prescribed burns. Cutting treatments consisted of chainsaw or brushsaw severing of all rhododendron stems within 6 in of the ground surface. Herbicide and herbicide followed by fire treatments consisted of basal applications of triclopyr or imazapyr in methylated seed oil on each plot. Cutting and burning treatments followed by herbicides utilized foliar applications of triclopyr or imazapyr in emulsions to all resprouting rhododendron. All herbicide plots were randomly split in half for the application of imazapyr or triclopyr on different halves. Analyses of variance and mean separation by LSD were used to compare treatment …


Evaluating Postfire Seeding Treatments Designed To Suppress Cheatgrass (Bromus Tectorum) In A Ponderosa Pine Forest On The Colorado Plateau, Matthew L. Brooks, Robert Klinger, Jennifer Chase, Curt Deuser Jan 2010

Evaluating Postfire Seeding Treatments Designed To Suppress Cheatgrass (Bromus Tectorum) In A Ponderosa Pine Forest On The Colorado Plateau, Matthew L. Brooks, Robert Klinger, Jennifer Chase, Curt Deuser

JFSP Research Project Reports

The restoration of historical fuel conditions and fire regimes is one of the primary land management goals in the Shivwits Plateau region of northwestern Arizona. Fire is the primary tool used in this region to reduce fuel loads and shift landscapes back to historical conditions of a low intensity, 8- 15 year return interval, surface fire regime. However, the invasive plant cheatgrass has become the dominant understory vegetation and fuel type following initial fire treatments in many areas. There is significant concern that repeated burning at historically appropriate fire return intervals for ponderosa pine forest will benefit this invasive plant …


Evaluating Approaches To Mapping Burn Probabilities For A Quantitative Wildland Fire Risk Analysis Framework., Carol Miller, Marc Parisien, Alan Ager, Mark Finney Jan 2010

Evaluating Approaches To Mapping Burn Probabilities For A Quantitative Wildland Fire Risk Analysis Framework., Carol Miller, Marc Parisien, Alan Ager, Mark Finney

JFSP Research Project Reports

This final report summarizes a collaboration that brought together experts in burn probability (BP) modeling and wildland fire risk analysis to compare and evaluate BP models, and ultimately incorporate these into a risk analysis framework. The project built on and extended the work from JFSP project #01-1-1-05. This project evaluated and tested three different independent models that generate BP maps as output for their operational use in risk analysis. The project quantified the relative sensitivity of the three BP models to different inputs, enhanced our understanding of the factors that affect BP at the landscape scale, and yielded concrete improvements …


Evaluating Postfire Seeding Treatments Designed To Suppress Cheatgrass (Bromus Tectorum) In A Ponderosa Pine Forest On The Colorado Plateau, Matthew L. Brooks, Robert Klinger, Jennifer Chase, Curt Deuser Jan 2010

Evaluating Postfire Seeding Treatments Designed To Suppress Cheatgrass (Bromus Tectorum) In A Ponderosa Pine Forest On The Colorado Plateau, Matthew L. Brooks, Robert Klinger, Jennifer Chase, Curt Deuser

JFSP Research Project Reports

The restoration of historical fuel conditions and fire regimes is one of the primary land management goals in the Shivwits Plateau region of northwestern Arizona. Fire is the primary tool used in this region to reduce fuel loads and shift landscapes back to historical conditions of a low intensity, 8- 15 year return interval, surface fire regime. However, the invasive plant cheatgrass has become the dominant understory vegetation and fuel type following initial fire treatments in many areas. There is significant concern that repeated burning at historically appropriate fire return intervals for ponderosa pine forest will benefit this invasive plant …


Land Conservation And Energy Infrastructure: Threats And Opportunities, Bradford Gentry, Casey Pickett, Livia Demarchis Jan 2010

Land Conservation And Energy Infrastructure: Threats And Opportunities, Bradford Gentry, Casey Pickett, Livia Demarchis

Yale School of the Environment Publications Series

2009 Berkley Conference Summary


Two Particle Correlations And The Ridge In Relativistic Heavy Ion Collisions, George Stevens Moschelli Jan 2010

Two Particle Correlations And The Ridge In Relativistic Heavy Ion Collisions, George Stevens Moschelli

Wayne State University Dissertations

Measurements at the Relativistic Heavy Ion Collider (RHIC) find an enhancement of two particle correlations in relativistic heavy ion collisions, not present in proton-proton collisions. Because the correlation structure is wide in relative pseudorapidity and narrow in relative azimuthal angle, it is known as the ridge. The most striking feature of the ridge is that it seems to extend to a long range in relative pseudorapidity where causality limits interaction. Similar ridge structures are observed in correlations of particles associated with and without a jet trigger. We argue that the untriggered ridge arises when particles formed in an early Glasma …


A Study Of Structure-Property Correlation In V2o5 And Tio2 Based Thin Films As Functional Materials, Chandra Thapa Jan 2010

A Study Of Structure-Property Correlation In V2o5 And Tio2 Based Thin Films As Functional Materials, Chandra Thapa

Wayne State University Dissertations

ABSTRACT

A STUDY OF STRUCTURE-PROPERTY CORRELATION IN V2O5 AND TiO2 BASED THIN FILMS AS FUNCTIONAL MATERIALS

by

CHANDRA THAPA

June 2010

Advisor: Dr. Ratna Naik

Co-Advisor: Dr. K. R. Padmanabhan

Major: Physics (Condensed Matter)

Degree: Doctor of Philosophy

The focus of this thesis is to study the structure-property correlation in thin films of V2O5 and TiO2 based transition metal oxides as functional materials. V2O5 is investigated as a cathode material for lithium ion battery and TiO2 as a high-K dielectric material.

We studied V2O5 thin films prepared by spin coating using three different types of precursors, MOD precursor, sol-gel organic …


Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian Jan 2010

Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian

Wayne State University Dissertations

This thesis describes investigations directed at the development of methods for the selenosulfide and disulfide rearrangements for the permanent functionalization of thiols, and in particular of cysteine and carbohydrate based thiols. Emphasis is placed on the newly invented silver mediated allylic desulfurative rearrangement for the primary modification of thiols and the synthesis of complex oligosaccharide mimics.

Chapter one introduces the concept of chemoselective ligations for the modification of macromolecules like carbohydrates and proteins. It overviews the native and non-native ligation techniques for their modification of such entities with a attention focusing on thiol based ligation techniques. The later part of …


Metal Chalcogenide Nanocrystal Assembly: From Synthesis To Applications, Qinghong Yao Jan 2010

Metal Chalcogenide Nanocrystal Assembly: From Synthesis To Applications, Qinghong Yao

Wayne State University Dissertations

This dissertation study is focused on (1) the application of an oxidation-induced sol-gel assembly method to formation of CdTe aerogels; (2) extension of existing aerogel compositions and properties by an alternative synthetic approach: cation-exchange reactions; and (3) probing the functionality of CdSe aerogels as optical sensors of Lewis base analytes.

Highly porous CdTe aerogels were successfully synthesized by sol-gel assembly of CdTe nanocrystals with thiolate or nonthiolate (phosphine oxide) ligated surfaces by treatment with tetranitromethane. Both phosphine oxide-capped and the thiolate-capped aerogels exhibit similar structure, morphology and porosimetry properties, suggesting that precursor ligation does not have a no major effect …


Synthesis And Characterization Of Metal Complexes Containing Tetrazolate, Poly(Tetrazolyl)Borate, And Aryl Pentazole Ligands As High Energy Density Materials, Dongmei Lu Jan 2010

Synthesis And Characterization Of Metal Complexes Containing Tetrazolate, Poly(Tetrazolyl)Borate, And Aryl Pentazole Ligands As High Energy Density Materials, Dongmei Lu

Wayne State University Dissertations

Heavier alkaline earth metal tetrazolates have been prepared as cryatals contain aqua ligands and as anhydrous powders, and were characterized by spectral and analytical methods. Potassium bis(tetrazolyl)borate complexes K(BH2(RCN4)2)(H2O)n (R = H, Me, NMe2, and NiPr2) and their 18-crown-6 adducts have been synthesized. In the solid state, complexes where R = H and Me have B-N bonds to the nitrogen atoms proximal to the carbon atom, whereas those with R = NMe2 and NiPr2 possess isomeric B-N bonds to the nitrogen atoms distal to the …


Identification Of Neuroblastoma And Its Prognostic Markers Using Raman Spectroscopy, Rachel Kast Jan 2010

Identification Of Neuroblastoma And Its Prognostic Markers Using Raman Spectroscopy, Rachel Kast

Wayne State University Dissertations

Introduction: Neuroblastoma is the most common cancer of infancy. It is one of several peripheral nervous system tumors, including ganglioneuroma, peripheral nerve sheath tumor, and pheochromocytoma. It is commonly situated on the adrenal gland. It displays similar histology to other small round blue cell tumors, including non-Hodgkin lymphoma, rhabdomyosarcoma, and Ewing sarcoma. One method of judging neuroblastoma aggressiveness uses tumor histology factors, including mitosis-karyorrhexis index, Schwannian stromal development, degree of differentiation, and patient age. Tumor aggressiveness can also be judged based on the amplification of certain genes, including MYCN. Raman spectroscopy is a physics-based method which identifies the biochemical …


Methods Of Variational Analysis In Pessimistic Bilevel Programming, Samarathunga M. Dassanayaka Jan 2010

Methods Of Variational Analysis In Pessimistic Bilevel Programming, Samarathunga M. Dassanayaka

Wayne State University Dissertations

Bilevel programming problems are of growing interest both from theoretical and practical points of view. These models are used in various applications, such as economic planning, network design, and so on. The purpose of this dissertation is to study the pessimistic (or strong) version of bilevel programming problems in finite-dimensional spaces. Problems of this type are intrinsically nonsmooth (even for smooth initial data) and can be treated by using appropriate tools of modern variational analysis and generalized differentiation developed by B. Mordukhovich.

This dissertation begins with analyzing pessimistic bilevel programs, formulation of the problems, literature review, practical application, existence of …


Spectral Methods For The Hamiltonian Systems, Nairat Kanyamee Jan 2010

Spectral Methods For The Hamiltonian Systems, Nairat Kanyamee

Wayne State University Dissertations

We conduct a systematic comparison of spectral methods with some

symplectic methods in solving Hamiltonian dynamical systems. Our

main emphasis is on the non-linear problems. Numerical evidence has

demonstrated that the proposed spectral collocation method preserves

both energy and symplectic structure up to the machine error in each

time (large) step, and therefore has a better long time behavior.


I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta Jan 2010

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta

Wayne State University Dissertations

ABSTRACT

I-KINETIC AND MECHANISTIC INVESTIGATIONS OF AMINO ACID SUBSTRATES REACTIVITIES WITH FERRYL SPECIES

II-SYNTHESIS AND CHARACTERIZATION OF DERIVATIVES OF THE BN-TPEN LIGAND AND THEIR METAL COMPLEXES

by

AHMED IBRAHIM YOUSSEF ABOUELATTA

MAY 2011

Advisor: Dr. Jeremy Jacob Kodanko

Major: Chemistry (Organic)

Degree: Doctor of philosophy

The reactivity of tryptophan, methionine, aspartic acid, glutamic acid, histidine and hydrochloride salt of lysine amino acid substrates with the N4Py ferryl species was studied by UV-vis spectroscopy and product characterization. Based on kinetic isotope effect studies and product analysis, an ET-PT mechanism was proposed for the reaction of tryptophan substrate with N4Py ferryl and …


Measuring The Nanomechanics Of Nanoconfined Water Layers, Shah Haidar Khan Jan 2010

Measuring The Nanomechanics Of Nanoconfined Water Layers, Shah Haidar Khan

Wayne State University Dissertations

Nanoconfined water has been the subject of special interest due to its applications in various fields such as biology, geology, medicine, and engineering tribology. While there is a general agreement on the layering of water molecules along atomically smooth surfaces, the behavior and properties of nanoconfined water is still poorly understood. A significant controversy exists whether there is a phase transformation imposed by confinement. We have measured the stiffness and damping coefficient of nanoconfined water using a small amplitude (0.5-1 Å) atomic force microscope. The results were analyzed with the help of two viscoelastic models, the Kelvin model and the …


Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit Jan 2010

Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit

Wayne State University Dissertations

ABSTRACT

Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties.

Thin …


The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly Jan 2010

The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly

Wayne State University Dissertations

A series of heavy alkaline earth complexes containing TpR2-based ligands has been synthesized, structurally characterized, and their properties were investigated. Salt metathesis routes involving MI2 (M = Ca, Sr, Ba) with either KTpEt2 or KTpnPr2 afforded MTpEt22 or MTpnPr22 in good to moderate yields. All of these complexes are volatile and exceptionally thermally stable, and have acceptable properties for use as group 2 atomic layer deposition (ALD) precursors. In addition, a series of group 2 complexes containing BpR2-based ligand systems were synthesized. Treatment of MI2 (M = Ca, Sr, Ba) with two equivalents of TlBptBu2, KBp, and KBpiPr2 in tetrahydrofuran …