Physical Sciences and Mathematics Commons^™

Education In The Environment: A Strategy For Continued Interagency Outdoor Education Programming: Quarterly Progress Report: Period Ending November 30, 2008, Environmental Education Strategy For Nevada

Reports (PLI Education)

Highlights of the university’s focused efforts during the past three months include the following:

• Fourteen people are near completion of the Fall Cohort workshop sessions toward partial achievement of the Nevada State Certification in Environmental and Interpretation Certification Program.
• Participation in the Michoacán Cultural Festival (500 people in attendance).
• Participation in the Day of the Dead: Life in Death Festival (over 11,000 in attendance).
• Development planning is near completion for the mobile exhibit program to support and deliver SNAP messages.
• Forever Earth was scheduled for 32 days and benefited 1077 individuals.
• Sixteen Discover Mojave Outdoor World events were conducted for …

In Memoriam

Studia UBB Geologia

No abstract provided.

Events, Bogdan P. Onac, Corina Ionescu

Studia UBB Geologia

No abstract provided.

Thermo-Mineral Waters From The Cerna Valley Basin (Romania), Ioan Povara, Georgel Simion, Constantin Marin

Studia UBB Geologia

In the south-west of the Southern Carpathians, upstream from the confluence of Cerna with Belareca, an aquifer complex has developed, strongly influenced by hydrogeothermal phenomena, acting within two major geological structures, the Cerna Syncline and the Cerna Graben. The complex consists mainly in Jurassic and Cretaceous carbonate rocks, as well as in the upper part of the Cerna Granite, highly fractured, tectonically sunken into the graben. As a result of the tectonic processes which occurred after the end of the Jurassic-Cretaceous sedimentation cycle, limestones may be encountered at 1100 m altitude in the Mehedinţi Mountains, at 150 ¬¬600 m in …

Examples Of Weathering And Deterioration Of Tertiary Building Stones At St. Michaels Cathedral In Cluj-Napoca (Romania), Roman Koch, Paul Calin Racataianu, Ioan I. Bucur

Studia UBB Geologia

St. Michaels Cathedral is one of the oldest Gothic architectural monuments in Cluj. It is built predominantly of Cenozoic (Eocene) limestones which were deposited on a shallow carbonate platform. They are composed of different facies and microfacies types with varying amounts of particles, matrix and cement. Limestones from the Baci quarry (Cluj Limestone), which is situated about 3 km from the centre of Cluj, were commonly used. The weathering features correspond to the microfacies types, to the position of the stones in the walls and to the exposure (east, south, west, and north), which controls the moisture/dry cycles. This interrelationship …

Microfacies Analysis Of Upper Eocene Shallow-Water Carbonates From The Rodnei Mountains (N Romania), Diana Sahy, Emanoil Sasaran, Tudor Tamas

Studia UBB Geologia

A Priabonian carbonate ramp developed in the NW Rodnei Mountains as a part of a Paleogene sedimentary cover which overlies the metamorphic basement of the Eastern Carpathians. Two sections were sampled at different locations along the carbonate ramp. The deposits accumulated in a shallow environment, in which relative sea level change is seen as the main controlling factor of facies distribution. A shoreface → middle ramp → inner ramp transition was recorded in both sections. Associations of large benthic foraminifers and high siliciclastic input are the dominant features in the northern part of the ramp, while in the south corals …

Lower Cretaceous Calcareous Nannofossils From The Southern Apuseni Mountains, Romania, Ana-Maria Vulc

Studia UBB Geologia

We investigated Lower Cretaceous calcareous nannofossils from Southern Apuseni Mts. The studied section from Bucium Cerbu quarry is characterized by flysch deposits (rhythmical interbedded marls and sandstones), which were assigned to the Căbeşti Formation. The studied nannofossil assemblages yielded a high diversity. The Early Aptian age of the studied deposits was assigned based on both the Tethyan and Boreal calcareous nannofossil zonations. Several reworked Valanginian nannofossils were also observed in the Early Aptian in situ nannofloras. The nannofloras are dominated by tethyan and cosmopolitan species. Besides Boreal species are also present. The presence of boreal taxa (e.g. Kokia borealis, K. …

Search For Neutral Higgs Bosons In Multi-B-Jet Events In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

Data recorded by the D0 experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. This production mode can be enhanced in the minimal supersymmetric standard model (MSSM). The search is performed in the three b quark channel using multijet triggered events corresponding to an integrated luminosity of 1 fb^-1. No statistically significant excess of events with respect to the predicted background is observed and limits are set in the MSSM parameter space.

Search For Anomalous Wtb Couplings In Single Top Quark Production, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

In 0.9 fb^{-1 of pp collisions, the D0 Collaboration presented evidence for single top quark production in events with an isolated lepton, missing transverse momentum, and two to four jets. We examine these data to study the Lorentz structure of the Wtb coupling. The standard model predicts a left-handed vector coupling at the Wtb vertex. The most general lowest dimension, CP-conserving Lagrangian admits right-handed vector and left- or right-handed tensor couplings as well. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. These are the first direct constraints on …}

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 1 - Operazioni Di Base (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Higher Order Corrections To H± Production, Nikolaos Kidonakis

Faculty Articles

I discuss recent calculations of higher-order corrections to charged Higgs production through various partonic subprocesses. Particular attention is paid to H⁻ production in association with a top quark at the LHC.

Study On The Texturization Of C-Si Wafers By Different Kinds Of Alkaline For Heterojunction Solar Cells, Yu-Hua Dou, Yu-Qin Zhou, Mei-Fang Zhu, Shuang Song, Feng-Zhen Liu, Jin-Long Liu, Zhan-Jun Zhang

Journal of Electrochemistry

The texturization of(100) crystalline silicon(c-Si) wafer was studied by field-emission scanning electron microscope using different kinds of etchant: sodium hydroxide,sodium carbonate and tribasic sodium phosphate.By optimizing the etching parameters,the lowest values of averaged reflectance(Rav) were obtained to be 9.70% for NaOH,9.76% for Na2CO3 and 8.63% for Na3PO4·12H2O,which is comparable to that of the wafer with textured surface covered with an anti-reflection coating of either silicon nitride or thermally grown silicon dioxide.The relation of Rav and surface morphology of textured wafer was analyzed.Moreover,special emphasis was put on the role of isopropyl alcohol(IPA) and sodium bicarbonate for texturization.It is proved that IPA …

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work.The outer CL was Nafion-free,while the inner CL was Nafion-bonded.The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated.Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL.The polarization curves showed that the output voltage of the …

Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang

Journal of Electrochemistry

The combustion products of thermal battery used iron-heated powders have been studied.It is identified by X-ray diffraction(XRD) analysis that the main compositions of the combustion products are Fe、FeO and KCl.The transmission electron microscopy(TEM) shows a typical core-shell structure with un-reacted Fe particle core coated by FeO shell with a shell thickness of around 200 nm.The combusted iron-heated powders exhibit no metal property,which is contrast to previous assumption.Further measurement indicates that at the ambient temperature the combustion products show semiconductor property of the p-type with conductivity in the order of 103 S·cm-1,which is five order lower than that of the iron …

Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang

Journal of Electrochemistry

The Ir/C catalyst with 30%(by mass) Ir was prepared in the CH3CH2OH and H2O binary system.The X-ray diffraction(XRD) data showed that the average sizes of the Ir particles in the Ir/C catalyst was about 2.2 nm.The results of the electrochemical measurements indicated that the electrocatalytic activity of the Ir/C catalyst for the ammonia oxidation in the neutral NaClO4 solution was similar to the Ir catalyst,while electrocatalytic stability was much better than that of the Ir catalyst.Furthermore,the peak current density of the ammonia oxidation at the Ir/C catalyst electrode showed a good linear relationship with the ammonia concentration,illustrating that the Ir/C …

Direct Electrochemistry Of Chloroperoxidase At Gc Electrode Modified With Swnts, Hong-Xia Zhang, Xia-Qin Wu, Wen-Jing Hou, Wen Xie, Zhong-Qing Lu, Rong Wang, He-Xing Li

Journal of Electrochemistry

The chloroperoxidase(CPO) was immobilized onto the surface of SWNTs modified electrodes.The electrochemical behaviors of modified electrode have been investigated by cyclic voltammetry.The appearance of a pair of well-defined redox peaks in the CV curve indicated that SWNTs can promote the electron transfer reaction of CPO.The results of cyclic voltammetry in PBS of different pH,from 3~9,showed that the reaction of CPO on the modified electrode was with equal numbers of electron and protein.This readily prepared SWNTs modified electrode showed excellent stability and good catalysis to O2.

Synthesis Of The Lifepo_4 By Co Reduction:Reaction Mechanism And Kinetics, Yun-Hua Chen, Yong Yang

Journal of Electrochemistry

LiFePO4 cathode material was synthesized by CO reducing FePO4 and LiOH precursors.The structure,morphology and electrochemical performances of such LiFePO4 material were characterized by XRD,SEM and charge-discharge tests.It was shown that the particle size of the LiFePO4 synthesized with 5% excess of LiOH in the precursor was about 200 nm.By carbon coating,the LiFePO4 electrode was able to deliver a reversible capacity of 158 mAh·g-1 at 0.1C discharge rate.Temperature-programmed X-ray diffraction was employed to monitor the reaction during the formation of LiFePO4,and Li3Fe2(PO4)3 was found to be an intermediate by analyzing the time-resolved XRD patterns.Kinetic study indicates that nucleation and their growth …

Preparation And Optical Transmission Of The Zno Nanorod Array Films, Feng Ye, Jing-Jing Li, Tong-Tao Wang, Yong-Liang Wang, Yun Liu, Xin-Dong Wang

Journal of Electrochemistry

By using a galvaostatic electrodeposition method in the ZnCl2 solution,the highly oriented ZnO nanorod array films have been successfully prepared on ITO substrate after the pretreatment with ZnO nanoparticles.And they were characterized by scanning electron microscope,X-ray diffraction and transmittance spectra.The results indicated that the ZnO nanorod arrays grew along(001) direction with an orientation perpendicular to the substrate.When the wavelength of incident was over 380 nm,the ZnO nanorod arrays showed high optical transmission of above 95%.Furthermore,the band gap became narrower.

Effect Of Ch_2cl_2 On The Redox Behavior Of Ferrocene In Ionic Liquid Bmimpf6, Wei-Wei Ji, Li-Qun Xu, Dong-Mei Li, Rong Wang, Xia-Qin Wu, Zong-Rang Zhang

Journal of Electrochemistry

The effects of CH2Cl2 on the room temperature redox behaviors of ferrocene in ionic liquid,BmimPF6,were studied by cyclic voltammetry and AC Impedance.The results suggested that the presence of CH2Cl2,accelerated the dissociation of ionic liquid,leading to lower viscosity and larger ionic conductovity,hence,the diffusions of ferrocence in BmimPF6 were enhanced and the peak currents of redox reactions were increased.The changes in the double-layer structure at the electrode interface resulted in larger capacitance,which reduced the electrode recution resistances,accordirgly,the reaction kinetics of ferrocene were enhanced.

Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang

Journal of Electrochemistry

The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was …

Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu

Journal of Electrochemistry

A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10-10 ～ 5.0×10-8 mol/L and 1.0×10-7 ～ 3.0×10-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was 1.0 × 10-11 mol/L.This …

Electrochemical Behavior And Determination Of Paracetamol On Activated Glassy Carbon Electrode, Bao-Yu Tan, Fang Liao, Xiao-Ying He, Qing-Tao Zhu, Jun Hua, Xiao-Li Jiang

Journal of Electrochemistry

The electrochemical behavior of paracetamol(PCT) was studied at glassy carbon electrode activated by cyclic voltammetry.In HAc-NaAc buffer solution(pH=4.00),a couple of sensitive redox peaks were recorded about 0.54 V in the cyclic voltammograms.The result indicated that the process was controlled by adsorption and nearly reversible.The reaction electron and proton numbers were estimated,respectively,to be two.Excllent linearity was observed in the correlation between the oxidation peak current and the concentration of PCT in the range of 8.00×10-6～2.00×10-4 mol·L-1.The correlative coefficient was-0.999 18.The detection limit was 6.34×10-6 mol·L-1.This method can be used for the determination of PCT real samples.

Application Of Self-Assembly Technique In The Process Of Metallized Fabric, Yue-Hui Ma, Wei Wang, Dan Yu, Jin-Xin He

Journal of Electrochemistry

After the pretreatment of nylon fabric by functional chitosan,the self-assembly technique was used in the process of activation before electroless plating to produce the CS-Pd membrane.The nanosized palladium particles with nanoscal have large relative surface and high catalyzed activity.Electromagnetic wave shielding fabric was prepared by electroless plating of Ni-P alloy with the activated fabric.The optimal process condition of CS finishing was given with the orthogonal and single factor experiments.The variation of fabric surface structure was characterized by SPM,SEM.Based on the Schelkunoff theory.The electromagnetic shielding effectiveness comes above 30 dB,which corresponds to shielding 96.0 percent of the electromagnetic wave or more.

Corrosion Inhibition Of Magnesium Alloy In 3.5% Nacl Medium By Tungstate, Ling-Jie Li, Zhi-Ming Yao, Jing-Lei Lei, Dong-Hai He, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

Electrochemical impedance spectroscopy(EIS),Tafel polarization curves and scanning electron microscopy(SEM) were used to study the corrosion inhibition of AZ61 magnesium alloy in 3.5% NaCl medium with tungstate.Results showed that tungstate demonstrates strong inhibition to the corrosion of AZ61 magnesium alloy.At the concentration of 0.01 mol/L,tungstate has a high inhibition efficiency 75.5%.Tungstate is an anodic inhibitor that mainly inhibited the anodic reactions of magnesium alloy through forming a compact protective layer that covered the magnesium alloy surface active sites.

Voltammetric Determination Of L-Cysteine At Bipyrine Bridged Copper(Ⅱ) Complex Modified Glassy Carbon Electrode, Ming-Yan Wang, Fan Yang, Sheng-Yu Zhang, Xing-You Xu, Xu-Jie Yang

Journal of Electrochemistry

A modified electrode has been constructed by depositing a novel copper(Ⅱ) complex 2biPy(ClO4)4 on the glassy carbon electrode through the method of cyclic voltammetry(CV).It was found that the modified electrode exhibited high electrocatalytic activity toward L-Cysteine oxidation with good reproducibility and high sensitivity.The peak current of semi-derivative linear scan was proportional to the concentration of L-cys in the range of 1×10-6～3×10-4 mol·L-1.The detection limit was 5×10-7 mol·L-1.

Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie

Journal of Electrochemistry

Effects of solution pH on the electrochemical behavior of tiron(sodium 4,5-dihydroxy-1,3-benzendisulfonic) couple(on a graphite electrode) were studied by cyclic voltammetry in aqueous solutions.It is shown that at pH<4,tiron exhibited a redox process at a relatively high potential with a good reversibility.A redox flow battery was formed employing tiron as the positive active species and V(III)/V(II) as the negative redox couple.In sulfuric acid medium,the coulombic efficiency of the tiron-V redox flow cell was more than 90% with a good cycle life.The decay in the cycle performance was minimal.Therefore,the feasibility of tiron as active materials for redox flow battery application is demonstrated.

Preparations Of Composite Electrodes Of Pt With H_Xwo_3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li

Journal of Electrochemistry

Three composite electrodes of platinum with hydrogen tungsten bronze(HxWO3)were prepared by voltammetry: hydrogen tungsten bronze deposited on platinum(HxWO3/Pt);platinum deposited on hydrogen tungsten bronze(Pt/HxWO3) and codeposited platinum and hydrogen tungsten bronze(Pt-HxWO3).The eletro-catalytic activities of three electrodes toward oxygen reduction reaction were studied.It is found that the catalytic activity of platinum can be improved by introducing with hydrogen tungsten bronze.Among these composite electrodes Pt/HxWO3,and the electrode shows the best eletro-catalytic activity toward oxygen reduction reaction,hence,provides a new way for reducing loading of noble metal in the application for fuel cell.

Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu

Journal of Electrochemistry

Hydrophilic aluminum oxide is popularly used for heat exchanger of air-condition.Herein,we developed a simple method to prepare superhydrophilic aluminum oxide on the surface of aluminum through single-step electrochemical oxidization.The morphologies and water contact angles on surfaces of alumina fabricated under different electrochemical conditions were investgated.Superhydrophilic surfaces fabricated by this method have good stability and high mechanical strength with water contact angle almost 0°.Coated with low surface energy materials,superhydrophilc alumina will be converted to superhydrophobic.

The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode materials of nanosiged LiFePO4 were prepared by hydrothermal templating synthesis.The grain sizes and electrochemical performance of LiFePO4 were controlled by surfactant.It was shown that the grain sizes varied from less than a hundred to hundreds nanometers by the SEM images.In the charge/discharge tests,the discharge capacities of the sample as a lithium ion battery were achieved to 150 mAh/g at 0.1C,140 mAh/g at 1C,and 126 mAh/g at 2C,with good cycling performance.

High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao

Journal of Electrochemistry

The Pt/C catalyst with high dispersion and high performance was prepared successfully by an organic colloidal method and small batch production(10g) of Pt/C catalyst has been realized.The particle sizes of the active components in the catalyst could be as small as 2.8 nm and the active surface area was up to 450 m2/g.A high performance membrane-electrode assembly(MEA) with surface area of 275 cm2 has been prepared by using the home-made catalyst with a catalyst coated membrane method invented in the lab,and a 5 kW stack has been assembled.The stack showed working 10 h at room temperature,atmosphere and without humidification.