Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Environmental Sciences (498)
- Computer Sciences (410)
- Physics (373)
- Chemistry (351)
- Earth Sciences (300)
-
- Engineering (296)
- Life Sciences (261)
- Mathematics (254)
- Education (148)
- Social and Behavioral Sciences (145)
- Oceanography and Atmospheric Sciences and Meteorology (133)
- Science and Mathematics Education (127)
- Geology (113)
- Astrophysics and Astronomy (103)
- Environmental Health and Protection (88)
- Water Resource Management (84)
- Arts and Humanities (83)
- Natural Resources Management and Policy (83)
- Natural Resources and Conservation (79)
- Hydrology (78)
- Physical Chemistry (78)
- Statistics and Probability (73)
- Applied Mathematics (72)
- Computer Engineering (68)
- Soil Science (65)
- History (63)
- Materials Science and Engineering (60)
- Environmental Indicators and Impact Assessment (58)
- History of Science, Technology, and Medicine (56)
- Institution
-
- University of Nebraska - Lincoln (328)
- Utah State University (138)
- TÜBİTAK (124)
- Selected Works (81)
- Old Dominion University (78)
-
- William & Mary (71)
- Air Force Institute of Technology (69)
- Chinese Chemical Society | Xiamen University (67)
- Missouri University of Science and Technology (62)
- University of New Hampshire (59)
- Purdue University (52)
- Dartmouth College (48)
- University of Northern Iowa (48)
- University of Kentucky (45)
- Claremont Colleges (44)
- Syracuse University (43)
- Wright State University (40)
- Washington University in St. Louis (39)
- Portland State University (35)
- Singapore Management University (33)
- University of South Florida (33)
- California Polytechnic State University, San Luis Obispo (32)
- University of Colorado Law School (30)
- Western Michigan University (30)
- New Jersey Institute of Technology (29)
- University of Wollongong (29)
- Cleveland State University (27)
- Department of Primary Industries and Regional Development, Western Australia (27)
- Nova Southeastern University (24)
- University of Massachusetts Amherst (23)
- Keyword
-
- United States (25)
- Western Australia (23)
- Environmental (16)
- Geology (16)
- Impact (15)
-
- Geochemistry (14)
- Mathematics (14)
- Algorithms (13)
- Groundwater (13)
- History of Polymer Science (13)
- Otto Vogl (13)
- Statement (13)
- Climate Change (12)
- Cryology (12)
- Final (12)
- Glaciogeology (12)
- Glaciology (12)
- Research and Technical Reports (12)
- 04. Personalities in Polymer Science (11)
- Biographies (11)
- Management (11)
- Polymer scientists (11)
- Water quality (11)
- West (11)
- College of Engineering and Computer Science (10)
- Computer Science (10)
- Ecology (10)
- Engineering (10)
- Glaciochemistry (10)
- Nebraska (10)
- Publication
-
- Theses and Dissertations (75)
- Journal of Electrochemistry (67)
- Turkish Journal of Chemistry (62)
- Turkish Journal of Mathematics (62)
- Department of Computer Science Technical Reports (52)
-
- Faculty Publications (46)
- Nebraska Tractor Tests (41)
- All Computer Science and Engineering Research (38)
- Physics Faculty Publications (38)
- Journal of the Iowa Academy of Science: JIAS (37)
- Dissertations, Theses, and Masters Projects (36)
- Eighth Eastern Wildlife Damage Management Conference (1997) (36)
- Great Plains Wildlife Damage Control Workshop Proceedings (33)
- Research Collection School Of Computing and Information Systems (33)
- Wildlife Damage Management Conference (32)
- Dissertations (31)
- Humanistic Mathematics Network Journal (30)
- Masters Theses (29)
- Theses (27)
- Honors Theses (26)
- Faculty of Informatics - Papers (Archive) (25)
- Dams: Water and Power in the New West (Summer Conference, June 2-4) (24)
- Dartmouth Scholarship (24)
- RISK: Health, Safety & Environment (1990-2002) (24)
- Conference on Applied Statistics in Agriculture (21)
- Physics Faculty Research & Creative Works (20)
- Reports (19)
- Computer Science Technical Reports (18)
- Space Science Center (18)
- All Physics Faculty Publications (17)
- Publication Type
- File Type
Articles 2221 - 2250 of 2472
Full-Text Articles in Physical Sciences and Mathematics
A Chemical Extraction Study Of Lead Contaminated Soil From Granite City, Il, Yan Zhang
A Chemical Extraction Study Of Lead Contaminated Soil From Granite City, Il, Yan Zhang
Masters Theses
Granite City, IL, surface soil ( 0-10 cm ) contaminated with lead was studied by both single- and a four-step sequential chemical extraction procedures designed to establish the partitioning, mobility and availability of lead in soil. The five fractions corresponding to the selected extractants were exchangeable, carbonates-bound, Fe-Mn oxides bound, organic matter and residual. Lead contamination of the soil was determined as a function of particle size and soil depth.
The contaminated sample had the highest lead content of 573.1 mg/kg at the 4 cm soil depth level, and on average was about 8.8 times that of background soil. Most …
Constancy Of Bond Dissociation Energy Ratios For Ab₂/Ab Systems, Danyu Xu
Constancy Of Bond Dissociation Energy Ratios For Ab₂/Ab Systems, Danyu Xu
Masters Theses
G2 and G2(MP2) theories have been used to study the bond dissociation energies D0m of a series of AB2, AB2+, AB2-, AB, AB+ and AB- systems. A total of fifty-four molecules and ions have been examined, for which B = O, S or Se and A = C, S, Ge, N+, P+, As+, B-, Al- or Ga-. Each triatomic system has sixteen valence electrons and each diatomic system has ten valence electrons. Both triplet and singlet spin …
An Expeditious Synthesis Of Β,Γ-Unsaturated Δ-Lactones: Useful Pharmacological Synthetic Intermediates, Li Xiong
Masters Theses
Two-carbon ring expansions of vinyl β-lactones, were carried out by Lewis acids (BF3-Et2O or Et2AlCl) via an ionization/cation rearrangement. β,γ-unsaturated δ-lactones were produced as efficient protocols for the synthesis of bioactive substances.
Vinyl β-lactones were prepared via ring closure of corresponding unsaturated β-hydroxy acids. Differently structured substrates were examined to study the influence of the substituents on the rearrangement. Other factors, such as temperature, solvent and catalyst were also studied in search of suitable reaction conditions.
This method is moderately successful in providing fused-ring δ-lactones, but higher yields (so far total yield of 24.8%) …
A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen
A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen
Masters Theses
This thesis is aimed at developing and applying advanced modeling tools in the prediction of risk to the general public from transportation of chemical waste on public highways. The modeling tools developed can then be used to compare alternative waste management scenarios. The application considered is related to the transport of hazardous waste generated by the United States Department of Energy (DOE) to current treatment, storage, and disposal facilities. DOE is currently considering four different scenarios.
The application considered can be more specifically defined as an analysis of the risk to the general public from transporting the 63 shipments of …
Identification Of Organosulfur Compounds In Illinois Coal, Mandy N. Amin
Identification Of Organosulfur Compounds In Illinois Coal, Mandy N. Amin
Masters Theses
The goal of this research was to identify representative organosulfur compounds in Illinois coal which are removed by a mild, chemical desulfurization procedure. Pyridine was used to extract three raw Illinois coals. Coal with a significant amount of elemental sulfur was treated with 1:1 HCl/HF followed by lithium aluminum hydride before pyridine extraction. Pyridine soluble extracts were extracted with tetrahydrofuran. Nickel boride desulfurization was performed on the soluble extracts of the three coals. The before and after desulfurized THF soluble extracts were fractionated and purified by liquid chromatography and the eluents were anlyzed by gas chromatography/mass spectrometry to characterize the …
Azo Dyes Based On 1,10-Phenanthroline, Minchong Mao
Azo Dyes Based On 1,10-Phenanthroline, Minchong Mao
Masters Theses
A series of new phenanthroline based azo-dye ligands, produced by diazotizing 5-amino-1,10-phenanthroline (5-NH2-phen) and then coupling this intermediate to a variety of coupling components, has been synthesized and characterized. The coupling components used were β-naphthol, phenol, and 2,6-dimethylphenol, and the three dye ligands were named phen-azo-β-naphthol, phen-azo-p-phenol, and phen-azo-2,6-dimethylphenol, respectively. 1H-NMR and IR spectra showed that the dyes exist primarily in the azo form in DMSO solution and as solids. UV-Vis spectra (in MeOH) showed intense (ε ≅ 104 M-1cm-1) absorptions ranging from 380 nm to 500 nm for these ligands.
The …
The Resolution Of Chiral Dialkylarylsufonium Ions By 1h Nmr Spectroscopy, Johnathan Whetstine
The Resolution Of Chiral Dialkylarylsufonium Ions By 1h Nmr Spectroscopy, Johnathan Whetstine
Mahurin Honors College Capstone Experience/Thesis Projects
The goal of this research was to design a rapid Nuclear Magnetic Resonance method to measure enantiomeric excess of chiral sulfonium ions by using chiral lanthanide shift reagents. The sulfonium ions studied were dialkylarylsulfonium ions. The shift reagent that was employed was Europium (III) surrounded by chiral ligands of 3-trifluoroacetyl-d-camphor (tfc), which is derived from (+)-camphor. Ethylmcthylphenylsulfonium ion was synthesized for study as a racemic and enantiomerically enriched mixture. The sulfonium ion was then ion-paired with the shift reagent for resolution of R and S enantiomers. The best resolution was obtained with the Eu(fod)4- shift reagent, with nearly baseline resolution …
Small Mammal Habitat Uses Of Two Natural And Created Wetlands In Southeastern Virginia, Amanda Mckenney Mueller
Small Mammal Habitat Uses Of Two Natural And Created Wetlands In Southeastern Virginia, Amanda Mckenney Mueller
Dissertations, Theses, and Masters Projects
No abstract provided.
Les Deux Faces De La Pensée De E. A. Martel, Jacques Choppy
Les Deux Faces De La Pensée De E. A. Martel, Jacques Choppy
International Journal of Speleology
Réunion de textes de Martel: 1 - Extraits du Nouveau Traité des Eaux Souterraines (1921), donnant l’essentiel de la pensée de l’auteur sur l’hydraulique et la morphologie du karst. 2 - En opposition à cette vision, rappelée de nombreuses fois par l’auteur, extraits de diverses publications (de 1894 à 1930), admettant qu’un fonctionnement en régime noyé était possible: Martel est donc l’un des tout premiers ayant observé des formes de creusement en régime noyé, et les ayant interprétées comme telles.
Distribution Of Freshwater Amphipoda In The Lake Matoaka/College Woods Area, Williamsburg, Virginia, Susan Alexandra Mahon
Distribution Of Freshwater Amphipoda In The Lake Matoaka/College Woods Area, Williamsburg, Virginia, Susan Alexandra Mahon
Dissertations, Theses, and Masters Projects
No abstract provided.
Suprachiasmatic Nucleus Neurons Are Glucose Sensitive, Adam C. Hall, Roselle M. Hoffmaster, Edra L. Stern, Mary E. Harrington, David Bickar
Suprachiasmatic Nucleus Neurons Are Glucose Sensitive, Adam C. Hall, Roselle M. Hoffmaster, Edra L. Stern, Mary E. Harrington, David Bickar
Chemistry: Faculty Publications
The suprachiasmatic nucleus (SCN) in the hypothalamus serves as the pacemaker for mammalian circadian rhythms. In a hamster brain slice preparation, the authors were able to record spontaneous activity from SCN cells for up to 4 days in vitro and verify a self-sustained rhythm in firing. The phase of this rhythm was altered by the concentration of glucose in the bathing medium, with time of peak firing advanced for a 20 mM glucose condition and slightly delayed for a 5 mM glucose condition, relative to 10 mM. The advancing effect of 20 mM glucose and the delaying effect of 5 …
The Effects Of User Interface Metaphors On The Learnability Of Computer Systems By Field Dependent And Field Independent Computer Users, Robert N. Urwiler Jr.
The Effects Of User Interface Metaphors On The Learnability Of Computer Systems By Field Dependent And Field Independent Computer Users, Robert N. Urwiler Jr.
CCE Theses and Dissertations
This study was designed to assess the differences in the learning performance (speed and accuracy) with which field dependent and field independent subjects could complete a set of checkbook management tasks using software employing a user interface making strong use of common checkbook management metaphors versus software employing an interface adhering to a defacto industry standard-based graphical user interface design guideline. It was hypothesized that both field dependent and field independent users would complete tasks more quickly and accurately using both user interface types.
From a population of traditional and non-traditional college students, 64 individuals volunteered to participate in the …
Keyboardless Visual Programming Using Voice, Handwriting, And Gesture, Jennifer Leopold, A. Ambler
Keyboardless Visual Programming Using Voice, Handwriting, And Gesture, Jennifer Leopold, A. Ambler
Computer Science Faculty Research & Creative Works
Visual programming languages have facilitated the application development process, improving our ability to express programs, as well as our ability to view, edit and interact with them. Yet even in programming environments, productivity is restricted by the primary input sources: the mouse and the keyboard. As an alternative, we investigate a program development interface which responds to the most natural human communication technologies: voice, handwriting and gesture. Speech- and pen-based systems have yet to find broad acceptance in everyday life because they are insufficiently advantageous to overcome problems with reliability. However, we believe that a visual programming environment with a …
User Defined Prewrites For Increasing Concurrency In Design Databases, Sanjay Kumar Madria, A. Embong
User Defined Prewrites For Increasing Concurrency In Design Databases, Sanjay Kumar Madria, A. Embong
Computer Science Faculty Research & Creative Works
We introduce a prewrite operation before a write operation is performed on design databases, a database that consists of objects as engineering designs. A prewrite operation does not actually make a design but it only makes available the model of the design that the transaction will produce in future. Once the prewrite design by a transaction is announced, the transaction executes a pre-commit operation. After the pre-commit, read operations can access the prewrite design even before the pre-committed transaction has finally made the design and committed. Therefore, our algorithm increases the potential concurrency as compared to the algorithms that permit …
A Concurrency Control Algorithm For An Open And Safe Nested Transaction Model, Sanjay Kumar Madria
A Concurrency Control Algorithm For An Open And Safe Nested Transaction Model, Sanjay Kumar Madria
Computer Science Faculty Research & Creative Works
We present a concurrency control algorithm for an open and safe nested transaction model. We use prewrite operations in our model to increase the concurrency. Prewrite operations are modeled as subtransactions in the nested transaction tree. The subtransaction which initiates prewrite subtransactions are modelled as recovery point subtransaction. The recovery point subtransaction can release their locks before its ancestors commit. Thus, our model increases the concurrency in comparison to other nested transaction models. Our model is useful an environment of long-running transactions common in object oriented databases, computer aided design and in the software development process
High-Order Object Model Based Software Analysis, Xiaoqing Frank Liu, Hungwen Lin
High-Order Object Model Based Software Analysis, Xiaoqing Frank Liu, Hungwen Lin
Computer Science Faculty Research & Creative Works
The integration of object oriented modeling and structured analysis (SA) for developing a well structured object oriented software system is a challenge for requirements analysts and software designers. Some of the existing object oriented modeling techniques adopt approaches that are very different from SA, and others have clumsily stayed with SA after a few modifications. Our High Order Object Modeling Technique (HOOMT) however, attempts to strike a mean between both extremes while at the same time provides an effective modeling method. HOOMT consists of two models, the High Order Object Model and the Object Information Flow Model. By using the …
Climatic Fluctuations And Tropical Troglobitic Evolution, Pedro Gnaspini
Climatic Fluctuations And Tropical Troglobitic Evolution, Pedro Gnaspini
International Journal of Speleology
No abstract provided.
Martel's Voyage To Russia In 1903, Arrigo A. Cigna
Martel's Voyage To Russia In 1903, Arrigo A. Cigna
International Journal of Speleology
The news concerning caves and karst reported in a Martel’s book on his voyage to Russia in 1903 are here listed and the cave maps are reproduced.
Edouard-Alfred Martel Et Les Cavernes De La Belgique, Daniel André
Edouard-Alfred Martel Et Les Cavernes De La Belgique, Daniel André
International Journal of Speleology
An exhaustive report on the activity of Martel in Belgium is here given. In particular some relevant passages of Martel’s letters and papers are also included.
Classical Interpretation Of The Quantum Description Of H- Photodetachment In Parallel E And B Fields, Qiaoling Wang, Anthony F. Starace
Classical Interpretation Of The Quantum Description Of H- Photodetachment In Parallel E And B Fields, Qiaoling Wang, Anthony F. Starace
Anthony F. Starace Publications
Total quantum mechanical cross sections for photodetachment of H- in parallel E and B fields are examined both analytically and numerically to extract information which has a classical interpretation, thereby complementing recent classical and semiclassical periodic orbit studies.
Development Of Monitoring Protocol For Created Wetlands : Project Summary For 1997, James E. Perry
Development Of Monitoring Protocol For Created Wetlands : Project Summary For 1997, James E. Perry
Reports
Appx. 1. Annotated bibliography -- Appx. 2. Field data sheet - Appx. 3.Monitoring protocol manual for created wetlands: draft manual.
Distribution Of Submerged Aquatic Vegetation In The Chesapeake Bay And Tributaries And The Coastal Bays - 1996, Robert J. Orth, Judith F. Nowak, David J. Wilcox, Jennifer R. Whiting, Leah S. Nagy
Distribution Of Submerged Aquatic Vegetation In The Chesapeake Bay And Tributaries And The Coastal Bays - 1996, Robert J. Orth, Judith F. Nowak, David J. Wilcox, Jennifer R. Whiting, Leah S. Nagy
Reports
SA V distribution data in this report are presented and discussed based on the segmentation scheme adopted by the Chesapeake Bay Program (Flemer et al., 1983) and described briefly in the Methods section of this report. This zonation scheme (Upper, Middle, and Lower zones) for Chesapeake Bay, which accommodates the Chesapeake Bay Program segmentation boundaries, was adapted from that used in previous SAV distribution reports (i.e., Orth et al., 1994) and established by Orth and Moore ( 1982), then modified by Orth et al., ( 1989). The 1996 data were edgematched using ARC/INFO GIS software, as were all the historical …
Limiting Spheroid Size As A Function Of Growth Factor Source Location, J. A. Adam, K. Y. Ward
Limiting Spheroid Size As A Function Of Growth Factor Source Location, J. A. Adam, K. Y. Ward
Mathematics & Statistics Faculty Publications
Solutions C(r) of the time-independent nonhomogeneous diffusion equation for three different piecewise-uniform source terms are used to examine the limiting size of multicell spheroids using a simple model which reproduces concentration-dependent mitotic behavior. A condition is derived under which nontrivial solutions do not exist (in all three cases), and a condition for the existence of a unique nontrivial solution is established for the case of growth-modifying factor (GMF) production throughout the spheroid. Qualitative behavior of the limiting size is established as a function of various physiological parameters. Of fundamental importance is the assumed GMF concentration threshold θ, …
An Introduction To Topological Quantum Field Theories, Michael Atiyah
An Introduction To Topological Quantum Field Theories, Michael Atiyah
Turkish Journal of Mathematics
No abstract provided.
Augmented Graded Rings, Mashhoor Refai
Augmented Graded Rings, Mashhoor Refai
Turkish Journal of Mathematics
In this paper we study the augmented graded rings and give the ralationship between these rings and stronger properties of graded rings.
On Some Bounds For The Solutions Of The Semi-Discretized Time-Dependent Ginzburg-Landau Equations, Erhan Coşkun
On Some Bounds For The Solutions Of The Semi-Discretized Time-Dependent Ginzburg-Landau Equations, Erhan Coşkun
Turkish Journal of Mathematics
We study the two-dimensional system of Time-Dependent Ginzburg-Landau Equations (TDGL) for modeling a thin film of superconductor subject to a uniform magnetic field. We discretize the TDGL for the space variables using bond variables and staggered grid partitioning technique. By investigating the temporal evolution of semi-discrete Helmholtz enery functional and that of Semi-discretized TDGL, we provide bounds for some observable physical quantities of interest such as superelectron density, supercurrent density, charge density, electric field, and induced magnetic field.
Polymer Light Emitting Diodes, Frank E. Karasz, Bin Hu, Zhou Yang
Polymer Light Emitting Diodes, Frank E. Karasz, Bin Hu, Zhou Yang
Turkish Journal of Chemistry
Polyphenylene vinylene-based conjugated-nonconjugated alternating block copolymers form the active chromophores in a series of light emitting diodes (LEDs). The quantum efficiency and brightness of these devices can be improved by several orders of magnitude by incorporation of appropriate carrier transport layers and by rational choice of electrodes. Further improvements can be gained by blending of the active chromophores with high or low molecular weight species.
Novel Architectures Of Macromolecular Systems, Gerhard Wegner
Novel Architectures Of Macromolecular Systems, Gerhard Wegner
Turkish Journal of Chemistry
An important thrust in modern macromolecular chemistry is to construct complex architectures either directly from monomer units, or to design macromolecules capable of forming a desired superstructure by self-organization. Chain-rigidity is an example of a structural principle leading to self organization depending on the aspect ratio of the molecular objects and their mutual interactions. These molecularly defined objects serve as the building blocks of systems for which ultrathin layers composed of hairy rod macromolecules (HRM) are an example. Depending on architectural details layered architectures of HRM are models for molecular nanocomposites, exhibit interesting optical, electrochemical, dielectric or barrier properties. They …
Analytical Applications Of Organic Conducting Polymer Electrodes, Nada F. Atta, George C. Russell, Z. Wang, N. Akmal, J.F. Rubinson, S.K. Lunsford, E. Karagözler, O. Y. Ataman, H. Zimmer, H.B. (Jr.) Mark, Ahmed Galal
Analytical Applications Of Organic Conducting Polymer Electrodes, Nada F. Atta, George C. Russell, Z. Wang, N. Akmal, J.F. Rubinson, S.K. Lunsford, E. Karagözler, O. Y. Ataman, H. Zimmer, H.B. (Jr.) Mark, Ahmed Galal
Turkish Journal of Chemistry
Electrodes modified by he electrodeposition of conducting polymers were used for the detection and quantitative determination of some inorganic, organic, and biological molecules. Monomers used were five membered ring heterocycles or crown ethers and their derivatives. The polymer films were deposited on glassy carbon or platinum substrates. The resulting electrodes were used in the amperometric mode or in the potentiometric mode for flow injection and chromatographic analyses. The results showed that the proposed modified surface catalyzes the oxidation of organic and biological compounds. The detection of electroinactive inorganic anions, such as F^-, Cl^-, Br^-, NO_2^- and NO^-_3 was also possible …
Reduction Of Combustion Generated Pollution: Process Modifications And Energy Efficient Power Cycles, Janos M. Beer
Reduction Of Combustion Generated Pollution: Process Modifications And Energy Efficient Power Cycles, Janos M. Beer
Turkish Journal of Chemistry
Theoretical bases of combustion process modifications aimed at the reduction of pollutant emission are examined. It is shown, as an example, of how the minimization of emissions of nitrogen oxides leads to a design protocol that translates results of modeling and of bench scale experiments into guidelines for industrial design. The formation and emission of polycyclic aromatic compounds is also considered, because their formation is strongly favored in "low NO_x flames". In power generation the pollutant emission can be reduced effectively by the improvement of the ``heat rate,"i.e., the thermodynamic efficiency of the power cycle. Combined gas turbine-steam cycles which …