Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

2002

Discipline
Institution
Keyword
Publication
Publication Type

Articles 121 - 150 of 429

Full-Text Articles in Chemistry

Effect Of Cl- On The Transition Current Density Of Zn During The Electrodeposition Of Zn-Ni Alloys, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao May 2002

Effect Of Cl- On The Transition Current Density Of Zn During The Electrodeposition Of Zn-Ni Alloys, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao

Journal of Electrochemistry

There exists a transition current density of Zn when the normal co-deposition of Zn-Ni alloys at chloride baths turns to anomalous type. The value increases with Cl- concentration, but is independent of pH, this is because the existence of Cl- decreases the evolution overpotential of Ni metal and has a catalytic effect on it.

Go to article

Electrocatalytic Oxidation Of Formaldehyde On The Proline Film Modified Electrode, Yu-Rong Ma, Qiu-Xia Yang, Guo-Bao Li, Zheng-Kai Xi, Xue-Lin Wang May 2002

Electrocatalytic Oxidation Of Formaldehyde On The Proline Film Modified Electrode, Yu-Rong Ma, Qiu-Xia Yang, Guo-Bao Li, Zheng-Kai Xi, Xue-Lin Wang

Journal of Electrochemistry

The proline film modified electrode and its electrochemical behavior was studied by cyclic voltammetry and spectroelectrochemistry. After incorporation of Ni(Ⅱ), the cyclic voltammograms of the proline Ni(Ⅱ) film electrode exhibited a typical redox peak, which appeared at potential of 0.52 V anodic and 0.44 V cathodic in NaOH. The formal potentials E' were linearly dependent on the pH, and the peak currents ip were linearly dependent on the square root of the scan rates, thus charge transfer in the film was controlled by diffusion. The diffusion coefficient is figured out to be 2×10-10 cm2·s-1. The …

Go to article

Effect Of Precondition On Porous Silicon Formation, Xuan Cheng, Guang-Feng Luo May 2002

Effect Of Precondition On Porous Silicon Formation, Xuan Cheng, Guang-Feng Luo

Journal of Electrochemistry

In this work, effect of precondition on porous silicon formation was investigated by performing electrochemical polarization measurements. The surface morphologies and optical properties of the samples were also studied by scanning electron microscopy (SEM) and Raman spectrometer. It was demonstrated that precondition enhanced the chemical/electrochemical reactions occurred at Si/solution interface and the growth of porous silicon, which ultimately resulted in a red shift in photoluminescence. However, the thickness of porous silicon decreased with the increase of precondition time. More broad bands were observed with prolonged precondition.

Go to article

Preparation,Structure And Properties Of Electrochromic Rhodium Oxide Films, Hai-Hong Wang, Tao Wang, Man-Ming Yan, Zhi-Yu Jiang May 2002

Preparation,Structure And Properties Of Electrochromic Rhodium Oxide Films, Hai-Hong Wang, Tao Wang, Man-Ming Yan, Zhi-Yu Jiang

Journal of Electrochemistry

Electrochromic rhodium oxide films were prepared on ITO substrate by sol-gel method. The films exhibited reversible two-color (bright yellow at reduction and dark green at oxidation) electrochromic behavior in alkaline solution with good cycle stability. In-situ XRD, TGA-DTA, IR, XPS methods were used for studying the structure and chemical process of the films. The diffusion coefficient during the electrochromic process was measured by electrochemical impedance spectra method. It was found that the rhodium oxide films may be suitable for the use in electrochromic devices.

Go to article

Studies On Sulfate Reducing Bacteria Influenced Corrosion Of 90/10 Cu/Ni Alloy, Guang-Zhou Liu, Jian-Hua Qian, Yan Ma, Jian-Hua Wu May 2002

Studies On Sulfate Reducing Bacteria Influenced Corrosion Of 90/10 Cu/Ni Alloy, Guang-Zhou Liu, Jian-Hua Qian, Yan Ma, Jian-Hua Wu

Journal of Electrochemistry

Electrochemical techniques such as measurements of corrosion potential,the polarization resistance, and potentiodynamic scanning technique were used to investigate the electrochemical behavior of 90/10 Cu/Ni alloy in Postgate C medium containing sulfate reducing bacteria(SRB). The results showed that the corrosion potential of the alloy changed from -0.20 to -0.75 V(SCE) when bacteria inocula was added, and the polarization resistance Rp decreased obviously, which corresponds to an increased corrosion rate. The shape ofthe anodic polarization curves was drastically changed in the presence of SRB, and an active-passive transition was observed. Electron probe microanalyzer was used to investigate the morphology and chemical …

Go to article

Determination Of Novalgin With Second Order Differential Simple Oscillographic Voltammetry, Fu-Fang Tao, Hong-Fang Zhang, Xun-Yu Xiong, Jian-Bin Zheng May 2002

Determination Of Novalgin With Second Order Differential Simple Oscillographic Voltammetry, Fu-Fang Tao, Hong-Fang Zhang, Xun-Yu Xiong, Jian-Bin Zheng

Journal of Electrochemistry

Based on the oscillographic characteristic of novalgin that incision can be caused at -1.2 V (vs .SCE) in 0.1 mol·L-1 KNO3, a new electronanlytical method, second order differential simple oscillographic voltammetry for the determination of novalgin was found. The method was applied to the determination of novalgin in tablet. The calibration graph is linear from 5.0×10-6 to 5.0×10-5 mol·L-1 with a detection limit of 2×10-6 mol·L-1. The relative standard deviation of the method is 2.1% for 3.00×10-5 mol·L-1 novalgin. The determination results showed that the simple oscillographic voltammetry is …

Go to article

Recent Developments In The Electrolyte For Lic6/Electrolyte/Cathode Battery, Cui-Ying Wang, Sheng-Liang Zhao, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin May 2002

Recent Developments In The Electrolyte For Lic6/Electrolyte/Cathode Battery, Cui-Ying Wang, Sheng-Liang Zhao, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

We present a reviewed the development and status of electrolyte for LiC 6/electrolyte/cathode battery. The effect of the salt, solvent, additive and impurity on the conductivity of the electrolyte, formation of the solid-electrolyte-interphase (SEI) and cycle life of the battery were described.

Go to article

Syntheses And Photoluminescence Of Zinc Oxide Polyaniline Coaxial Nanowires And Their Array, Zhi-Xin Zheng, Yan-Yan Xi, Ping Dong, Huai-Guo Huang, Jian-Zhang Zhou, Lin-Lin Wu, Zhong-Hua Lin May 2002

Syntheses And Photoluminescence Of Zinc Oxide Polyaniline Coaxial Nanowires And Their Array, Zhi-Xin Zheng, Yan-Yan Xi, Ping Dong, Huai-Guo Huang, Jian-Zhang Zhou, Lin-Lin Wu, Zhong-Hua Lin

Journal of Electrochemistry

A novel nanomaterial, zinc oxide (ZnO) and polyaniline (PANI) coaxial nanowires and their array in the template, was synthesized using anodic aluminum oxide (AAO) membrane as template. The morphology of these coaxial nanowires was observed with transmission electron microscope (TEM). The experiments on photoluminescence (PL) of coaxial nanowires and their array in AAO membrane show that the visible emission band of ZnO shifts from 530 nm to 400 nm and the luminescence is enhanced for the coaxial nanowires array in AAO membrane,and the visible emission band shifts to a lower wavelergth (385 nm) for coatial nanowires in NaOH solution. Possible …

Go to article

Electrochemical Properties Of Mixed Metal Oxide Coated Titanium Anodes In Seawater, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen May 2002

Electrochemical Properties Of Mixed Metal Oxide Coated Titanium Anodes In Seawater, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Mixed metal oxide coated titanium anodes prepared by thermal decomposition were characterized by scanning electron microscopy and electrochemical measurement, while the consumption rate of an anode was also measured in seawater. In order to examine the practical performances of mixed metal oxide-coated anodes, a simulating test on floating dock in seawater has also been carried out. The SEM results indicate that oxide layers exhibited a cracked-mud morphology which endows the anode with good electrocatalytic activity. The electrochemical measurements showed that mixed metal oxide-coated anodes exhibit excellent electrochemical activity and electrochemical stability in seawater. Owing to good corrosion resistance and low …

Go to article

A Blend Conducting Membranes For Direct Methanol Fuel Cells, Lei Li, Jun Zhang, Hong Wu, Yu-Xin Wang May 2002

A Blend Conducting Membranes For Direct Methanol Fuel Cells, Lei Li, Jun Zhang, Hong Wu, Yu-Xin Wang

Journal of Electrochemistry

An attempt was made to modify membranes for direct methanol fuel cells by blending Nafion or polystyrene sulfonic acid (PSSA) with polyvinylidene fluoride (PVDF) from their solutions. The proton conductivity and methanol barrier property as a function of the membrane compositions are discussed. Compared with the Nafion 117 membrane, the PVDF-Nafion blend membranes with 25 wt% of Nafion showed a decrease in the conductivity by about 2 orders of magnitude, and the methanol barrier properties increased about 3 orders of magnitude. If the ratio (σ/P) is adopted to characterize the performance of the membrane, the PVDF-PSSA and PVDF-Nafiion blend membranes …

Go to article

Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Ngocnga Dao, Scott L. Whittenburg, Y. Hao, Leszek M. Malkinski, Jian Qing Wang, C. A. Ross May 2002

Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Ngocnga Dao, Scott L. Whittenburg, Y. Hao, Leszek M. Malkinski, Jian Qing Wang, C. A. Ross

Chemistry and Biochemistry Faculty Publications

We present our recent simulated results on Cr (5 nm)/ Cu (5 nm)/ Co (5 nm)/ Cu (3 nm)/ Co (2 nm) pseudo-spin valve dots. The simulated results agree qualitatively with the experimental results. Three different sizes of elliptical dots, and were simulated. Our simulations show that in these types of dots magnetization reversal occurs by the formation of domain walls: for and for No domain wall was observed in the reversal of the dots. For such dots, the simulated loops show a small two-step reversal pattern with the thin upper layer partially reversing followed by complete reversal of both …

Go to article

Magnetic And Mössbauer Studies On Oxygen Deficient Perovskite, La₀.₆Sr₀.₄Feo3-Δ, Jinbo Yang, William B. Yelon, William Joseph James, X.-D. Zhou, Yixiang Xie, Harlan U. Anderson, Zili Chu May 2002

Magnetic And Mössbauer Studies On Oxygen Deficient Perovskite, La₀.₆Sr₀.₄Feo3-Δ, Jinbo Yang, William B. Yelon, William Joseph James, X.-D. Zhou, Yixiang Xie, Harlan U. Anderson, Zili Chu

Physics Faculty Research & Creative Works

Samples of La0.6Sr0.4Fe3-δ with varying oxygen vacancy contents were prepared by heating them in different gas flows. Magnetization measurement showed that samples with low oxygen vacancies have a magnetic ordering temperature in the range of 300-325 K while those with 9%-12% oxygen vacancies have a magnetic ordering temperature of 800 K and higher. Mössbauer spectra at 300 K exhibit paramagnetic or weak magnetic characteristics for the N2, O2, and air-quenched samples, whereas an average hyperfine field of 52 T is found for the CO/CO2 reduced samples. The heat treatment in …

Go to article

Magnetic And Neutron Diffraction Studies On Prmnsb₂, Satish K. Malik, Zili Chu, Amish G. Joshi, Jinbo Yang, William B. Yelon, Qingsheng Cai, William Joseph James, Kishore Kamaraju May 2002

Magnetic And Neutron Diffraction Studies On Prmnsb₂, Satish K. Malik, Zili Chu, Amish G. Joshi, Jinbo Yang, William B. Yelon, Qingsheng Cai, William Joseph James, Kishore Kamaraju

Physics Faculty Research & Creative Works

Magnetic and neutron diffraction studies have been carried out on PrMnSb2. Magnetization data in the temperature range of 5-400 K show two magnetic transitions: one at ∼175 K attributed to the antiferromagnetic ordering of the Mn moments, and the other at ∼35 K possibly due to the antiferromagnetic ordering of the Pr moments. The magnetization-field isotherms at various temperatures are consistent with the above. Neutron diffraction data obtained at various temperatures can be fitted with a nearly antiferromagnetically coupled Mn moment of ∼3μB at 70 K. At 10 K, moments both on Mn (∼3.5μB) and …

Go to article

Magnetic Properties Of Iron-Rich Mixed Rare-Earth Sm₂-ₓtbₓfe17-YSiY Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, William Joseph James, Ph. I'Héritier May 2002

Magnetic Properties Of Iron-Rich Mixed Rare-Earth Sm₂-ₓtbₓfe17-YSiY Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, William Joseph James, Ph. I'Héritier

Physics Faculty Research & Creative Works

A series of Sm2-xTbxFe17-ySiy solid solutions with x = 0, 1, and 1.5 and y = 1, 2, and 3 were prepared by induction melting stoichiometric amounts of high purity elements. The x-ray diffraction data confirm that the postannealed samples are 2:17 intermetallics of the R3 space group. The lattice parameters and the unit cell volumes were calculated using a modified Rietveld program. The fitted intensities showed behavior related to a disordered rhombohedral structure as inferred from neutron data. It was observed that for a particular y, the unit cell volume decreased almost …

Go to article

Possible Ordering Of Ru And Cu In The Charge-Reservoir Of Magneto-Superconductor Rusr₂Gdcu₂O₈ (Ru-1212): Magnetic, Transport, And Tem Microstructural Studies, V. P. S. Awana, S. Ichihara, J. Nakamura, M. Karppinen, H. Yamauchi, Jinbo Yang, William B. Yelon, William Joseph James, Satish K. Malik May 2002

Possible Ordering Of Ru And Cu In The Charge-Reservoir Of Magneto-Superconductor Rusr₂Gdcu₂O₈ (Ru-1212): Magnetic, Transport, And Tem Microstructural Studies, V. P. S. Awana, S. Ichihara, J. Nakamura, M. Karppinen, H. Yamauchi, Jinbo Yang, William B. Yelon, William Joseph James, Satish K. Malik

Physics Faculty Research & Creative Works

Magnetization vs temperature behavior of RuSr2GdCu2O8-δ (Ru-1212) measured in an field of 5 Oe, shows a clear branching of zero-field-cooled (ZFC) and field-cooled (FC) curves around 140 K, a cusp at 135 K, and a diamagnetic transition around 20 K (in the ZFC branch). The cusp at 135 K is due to the antiferromagnetic ordering of the Ru moments. The magnetization-field isotherms, below 50 K, show a nonlinear contribution from a ferromagnetic component. The resistance vs temperature behavior of the compound, in applied fields of 0, 3, and 7 T, confirms that the sample is …

Go to article

Observation Of Novel Disordered Rhombohedral R₂Fe₁₇ (R=Rare Earth) Based Compounds, William B. Yelon, William Joseph James, Jinbo Yang, Kishore Kamaraju, Qingsheng Cai, Zili Chu, Satish K. Malik May 2002

Observation Of Novel Disordered Rhombohedral R₂Fe₁₇ (R=Rare Earth) Based Compounds, William B. Yelon, William Joseph James, Jinbo Yang, Kishore Kamaraju, Qingsheng Cai, Zili Chu, Satish K. Malik

Physics Faculty Research & Creative Works

A recent study of (SmGd)Fe 14Si3 showed an anomalous x-ray diffraction pattern [P. C. Ezekwenna, G. K. Marasinghe, J.-H. Nam, W. J. James, W. B. Yelon, M. Ellouze, and Ph. I'Héritier, J. Appl. Phys. 87, 6716 (2000)]. Although all observed peaks could be indexed to the rhombohedral 2:17 phase (R-3m) many lines were strongly reduced in intensity. Subsequently, the same phenomenon was seen in neutron diffraction patterns from Nd2-xDysFe17-ySiy alloys and conventional refinement using the rhombohedral phase left significant residuals. Fourier mapping revealed additional density along the c-axis chains of Fe dumbbells …

Go to article

Structure And Magnetic Properties Of The Mnbi Low Temperature Phase, Jinbo Yang, William B. Yelon, William Joseph James, Qingsheng Cai, Samit Roy, Naushad Ali May 2002

Structure And Magnetic Properties Of The Mnbi Low Temperature Phase, Jinbo Yang, William B. Yelon, William Joseph James, Qingsheng Cai, Samit Roy, Naushad Ali

Physics Faculty Research & Creative Works

High purity MnBi low temperature phase has been prepared and analyzed using magnetic measurements and neutron diffraction. The low-temperature phase of the MnBi alloy has a coercivity μ0iHc of 2.0 T at 400 K, and exhibits a positive temperature coefficient from 0 to at least 400 K. The neutron data refinement indicated that the Mn atom changes its spin direction from c axis above room temperature to nearly perpendicular to the c axis at 50 K. A canted magnetic structure has been observed below 200 K. The anisotropy field increases with increasing temperature which gives rise to …

Go to article

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/02- 5/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper May 2002

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/02- 5/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to …

Go to article

Footprinting, Circular Dichroism And Uv Melting Studies On Neomycin B Binding To The Packaging Region Of Human Immunodeficiency Virus Type-1 Rna, Mark P. Mcpike, Julie M. Sullivan, Jerry Goodisman, James C. Dabrowiak May 2002

Footprinting, Circular Dichroism And Uv Melting Studies On Neomycin B Binding To The Packaging Region Of Human Immunodeficiency Virus Type-1 Rna, Mark P. Mcpike, Julie M. Sullivan, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

We have studied the binding of neomycin to a 171mer RNA (Ψ-RNA) from the packaging region of the LAI strain of human immunodeficiency virus type-1, HIV-1 (LAI). The RNase I footprinting studies reveal that the primary binding site for the drug is in stem-loop 1, which contains the dimer initiation site of HIV-1. Loading this site with neomycin causes a structural change in the RNA, allowing nucleotides in the neighboring stem-loop 2 to participate in the drug site. Drug binding to secondary sites induces structural changes in other stem-loops of the RNA. Footprinting plots, showing cutting at a site as …

Go to article

Communicator-In-Chief: Presidential Use Of Television Past, Present, And Future, Jenna Wasson May 2002

Communicator-In-Chief: Presidential Use Of Television Past, Present, And Future, Jenna Wasson

Honors Theses

This thesis seeks to determine how television has changed as a communication medium for presidents over the past half century. An evaluation of the evolving ways presidents use television to communicate with and to build support from the American people has been conducted. Presidential communication strategies have been identified by drawing primarily from primary sources written by presidents and White House staff. Television technology and the television audience have changed over the years. Presidents have taken a more pro-active, aggressive role in their efforts to harness television for their own purposes. Why have these changes occurred? What impact have these …

Go to article

Synthesis And Dna Binding Of Cis And Trans-Rucl2 (Dmso)4, Thomas Curran May 2002

Synthesis And Dna Binding Of Cis And Trans-Rucl2 (Dmso)4, Thomas Curran

Honors Theses

The synthesis of both cis and trans-RuCl?(DMSO)? has been reported in literature, and is currently the only way of acquiring these compounds. Because these metallodrugs have shown similar antitumor properties to cisplatin, they are currently under investigation for use in clinical trials as potential chemotherapeutics. It is believed that these drugs act in a way similar to cisplatin by causing intrastrand crosslinking of adjacent guanine residues in DNA. In an attempt to better understand any Ru/DNA interaction for these compounds, both cis and trans-RuCl?(DMSO)? were synthesized with reasonable yields (~40%). The compounds were then characterized by nuclear magnetic resonance (NMR), …

Go to article

Analysis Of Fuel Additives And Impurities In Gasoline, Nicholas Lentz May 2002

Analysis Of Fuel Additives And Impurities In Gasoline, Nicholas Lentz

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Go to article

Conformational Analysis Of Small Peptides By Circular Dichroism, Toni Bowie May 2002

Conformational Analysis Of Small Peptides By Circular Dichroism, Toni Bowie

Electronic Dissertations and Theses

Reports on peptides that are rich in D-alanine indicate that peptides with this structural motif adopt a specific secondary structure. In this study, two cyclic tetrapeptides cyclo[Leu-D-Ala], where Xaa is Glu or Lys, was studied by circular dichroism (CD). The conformational stability of these peptides was investigated by varying the temperature, solvent, pH, and concentration of the peptide solutions. When these conditions were varied, the CD measurements in each condition did not produce any significant changes. The CD of both peptides exhibits two positive CD bands at 211 nm and 222 nm and a third positive CD band below 190 …

Go to article

Modulation Of Oxidative Stress Via Benzodiazepines, Chauncey D. Daniels May 2002

Modulation Of Oxidative Stress Via Benzodiazepines, Chauncey D. Daniels

Electronic Dissertations and Theses

Oxidative damage resulting from generation of oxygen-derived free radicals is thought to be the cause of age-related dysfunction in key organs and tissues. Recent studies suggest that the GABA neurotransmitter system modulates the extent of oxidative damage. If this is true, then a drug that alters GABA neurotransmission, such as diazepam, a drug that facilitates GABA neurotransmission, was tested for its efficacy to lessen oxidative damage to the brain tissue. A total of sixteen Swiss Webster mice were implanted subcutaneously with osmotic mini pumps that provided a constant delivery (3.5 mg/Kg/day) of either diazepam (n=8) or vehicle (50% dimethyl sulfoxide/ …

Go to article

Rnaml: A Standard Syntax For Exchanging Rna Information, Neocles B. Leontis, Allison Waugh, Patrick Gendron, Russ Altman, James W. Brown, David Case, Daniel Gautheret, Stephen C. Harvey, John Westbrook, Eric Westhof, Michael Zuker, François Major May 2002

Rnaml: A Standard Syntax For Exchanging Rna Information, Neocles B. Leontis, Allison Waugh, Patrick Gendron, Russ Altman, James W. Brown, David Case, Daniel Gautheret, Stephen C. Harvey, John Westbrook, Eric Westhof, Michael Zuker, François Major

Chemistry Faculty Publications

Analyzing a single data set using multiple RNA informatics programs often requires a file format conversion between each pair of programs, significantly hampering productivity. To facilitate the interoperation of these programs, we propose a syntax to exchange basic RNA molecular information. This RNAML syntax allows for the storage and the exchange of information about RNA sequence and secondary and tertiary structures. The syntax permits the description of higher level information about the data including, but not restricted to, base pairs, base triples, and pseudoknots. A class-oriented approach allows us to represent data common to a given set of RNA molecules, …

Go to article

Direct Haplotyping Of Kilobase-Size Dna Using Carbon Nanotube Probes, Adam T. Woolley, Chantal Guillemette, Chin Li Cheung, David E. Housman, Charles M. Lieber May 2002

Direct Haplotyping Of Kilobase-Size Dna Using Carbon Nanotube Probes, Adam T. Woolley, Chantal Guillemette, Chin Li Cheung, David E. Housman, Charles M. Lieber

Barry Chin Li Cheung Publications

We have implemented a method for multiplexed detection of polymorphic sites and direct determination of haplotypes in 10-kilobasesize DNA fragments using single-walled carbon nanotube (SWNT) atomic force microscopy (AFM) probes. Labeled oligonucleotides are hybridized specifically to complementary target sequences in template DNA, and the positions of the tagged sequences are detected by direct SWNT tip imaging. We demonstrated this concept by detecting streptavidin and IRD800 labels at two different sequences in M13mp18. Our approach also permits haplotype determination from simple visual inspection of AFM images of individual DNA molecules, which we have done on UGT1A7, a gene under study as …

Go to article

Chemical Imaging Comes Of Age, John F. Turner Ii May 2002

Chemical Imaging Comes Of Age, John F. Turner Ii

Chemistry Faculty Publications

Sophisticated analysis techniques allow researchers to extract meaningful results from spectral imaging data.

Go to article

The Relationship Between Magnetic Interactions And Near Neighbor Interatomic Distances In The Transition Metal Sublattice Of R(Mn/Fe)₆A₆(R=Nd Or Sm, A=Ge Or Sn), G. K. Marasinghe, J. Han, William Joseph James, William B. Yelon, Naushad Ali May 2002

The Relationship Between Magnetic Interactions And Near Neighbor Interatomic Distances In The Transition Metal Sublattice Of R(Mn/Fe)₆A₆(R=Nd Or Sm, A=Ge Or Sn), G. K. Marasinghe, J. Han, William Joseph James, William B. Yelon, Naushad Ali

Chemistry Faculty Research & Creative Works

The magnetic and crystallographic structures of R(Fe/Mn)6A6 (R=Nd or Sm and A = Ge or Sn) intermetallics have been investigated using x-ray and neutron diffraction techniques and superconducting quantum interference device magnetic measurements. For both stannides (A = Sn) and germanides (A = Ge), the lattice contracts with increasing iron content. In the case of the stannides, substitution of manganese by iron enhances the saturation magnetization and Curie temperature at low iron concentrations (x ≤2 ) suggesting the presence of an extremely rare occurrence, positive coupling between iron and manganese magnetic moments. In contrast, the magnetic properties …

Go to article

Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Scott Whittenburg May 2002

Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Scott Whittenburg

Chemistry Faculty Publications

We present our recent simulated results on Cr (5 nm)/ Cu (5 nm)/ Co (5 nm)/ Cu (3 nm)/ Co (2 nm) pseudo-spin valve dots. The simulated results agree qualitatively with the experimental results. Three different sizes of elliptical dots, 150 nm3105 nm, 175 nm370 nm, and 200 nm360 nm, were simulated. Our simulations show that in these types of dots magnetization reversal occurs by the formation of domain walls: 90° for 175 nm370 nm and 360° for 200 nm360 nm. No domain wall was observed in the reversal of the 150 nm3105 nm dots. For such dots, the simulated …

Go to article

Atmospheric Chemistry Of Aromatic Compounds, Bernadette Duffy May 2002

Atmospheric Chemistry Of Aromatic Compounds, Bernadette Duffy

Masters

Rate constants (in units of 10-11 cm3 molecule-1s-1) were measured for the following reactions at 298+-2K and 1 atmosphere pressure using a relative rate technique. k(OH+Benzene)= 1.42+-0.1; k(OH+p-Xylene)= 15.9 +-2.5 k(OH+Toluene)=6.30+-0.15; k(OH+o-Ethyltoluene)=14.1+-1.1; k(OH+Ethylbenzene)=7.50+-0.72:k(OH+m-Ethyltoluene)=23.0+-1.5; k(OH+o-Xylene)=14.5+-3.1; k(OH+p-Ethyltoluene)=14.2+-1.0; k(OH+m-Xylene=23.1+-2.2: k(OH+1,3,5-Rimethylbenzene= 69.7+-4.3 The increase in reactivity with increasing degree of alkyl substitution on the aromatic ring supports the conclusions of previous studies that the dominant reaction pathway at room temperature for reaction of hydroxyl radicals with aromatic compounds is addition to the benzene rig. The rate data are compared with previous measurements and discusses in terms of structure-activity relationships The Photochemical Ozone Creation Potentials …

Go to article

First Prev Next Last