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The work aims at developing fluorimetric methods used for bioassay to expand the range of the determined low-molecular-weight organic analytes and cut down sample preparation operations using available fluorophores, reagents, and identical fluorimetric systems for qualitative and quantitative analysis. We proposed using the reaction of carbocyanine fluorophore oxidation by hydrogen peroxide, catalyzed by copper(II), changing fluorescence intensity in the near-IR region (700 nm). Several organic compounds of different nature accelerate or slow down the indicator reaction, to varying degrees, and at different times of the process. The model analytes were eight sulfonamides, which can be distinguished qualitatively using the kinetic factor in data processing by principal component analysis. We demonstrated on an example of phthalylsulfathiazole that the signal could be obtained not only in an aqueous solution but also in the presence of a turkey muscle homogenate at a level of 0.08-0.5 mM (RSD = 9%) without separation. The prospects for the development of such fluorescence platforms are discussed., Author(s): I. A. Stepanova [sup.1], A. N. Lebedeva [sup.1], A. V. Shik [sup.1], E. V. Skorobogatov [sup.1], M. K. Beklemishev [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Department [...]

Many studies have focused on the effect of fusion plasma particles onto the structural materials of future nuclear fusion reactors. In this paper, the effect of the products of the first-generation fuel reaction on structural fusion materials, such as copper and 316-stainless steel target materials, was studied. Firstly, the effect of 14.1 MeV neutrons produced from D-T neutron generator for different irradiation times, 10, 20, 30, 50, and 60 min, was investigated. Hence, this effect was analyzed and characterized by X-ray diffraction analysis, surface roughness test, scanning electron microscope, and Vickers hardness. Secondly, the effect of 3.5 MeV [alpha]-particles on these target materials by different incident angles, 00, 300, 450, 600 and 850, using SRIM code was studied. Also, SRIM code was used to calculate [alpha]-particles' trajectories, projected and straggle ranges, skewness, kurtosis, target ionization/phonons, and total displacements for copper and 316-stainless steel target materials. Key words: D-T neutrons generator, copper and 316-stainless steel, surface roughness, SRIM, Vickers hardness. Plusieurs etudes se sont focalisees sur l'effet des particules du plasma de fusion impactant les materiaux formant la structure du futur reacteur de fusion nucleaire. Nous examinons ici l'effet du combustible de reaction de premiere generation sur les materiaux de structure cibles, comme le cuivre et l'acier inoxydable 316. D'abord, nous etudions l'effet des neutrons de 14,1 MeV provenant de la reaction D-T pour differents temps d'irradiation de 10, 20, 30, 50 et 60 minutes. L'effet est analyse et caracterise par differents moyens, la diffraction-X, un test de rugosite de surface, la microscopie electronique a balayage et la durete de Vickers. Ensuite, nous etudions l'effet des particules de 3,5 MeV a des angles d'incidence de 00, 300, 450, 600 et 850 en utilisant le logiciel SRIM. Ce meme code est utilise pour calculer les trajectoires des particules, la distance parcourue, leur inclinaison, leur aplatissement, l'ionisation des materiaux cibles avec la generation de phonons, ainsi que le deplacement total des noyaux de cuivre et d'acier inoxydable 316. [Traduit par la Redaction.] Mots-cles : generateur de neutrons D-T, cuivre et acier inoxydable 316, rugosite de surface, durete Vickers, logiciel SRIM., 1. Introduction Plasma interactions with plasma-facing components (PFCs) is one subject of intensive research in tokamaks, such as International Thermonuclear Experimental Reactor (ITER), and fusion reactors. The most important issue [...]

First principles calculations in the context of density functional theory (DFT) provides a platform to investigate the material's properties in a way to explain the physics of solids. Electronic, structural, and optical properties for pure and Cu-doped LaAl[O.sub.3] are investigated. The study reveals that the band structure of LaAl[O.sub.3] after the inclusion of Cu at the La site is affected significantly. Due to the substitution of Cu, there is a decrease in the band gap from 3.02 eV to 2.95 eV. Furthermore, the partial density of states of LaAl[O.sub.3] changes significantly after Cu doping, which has confirmed the doping effect on intrinsic LaAl[O.sub.3]. The p and d states play a vital role on top of the valence band. The range in which the top of a valence band lies is from 0 eV to -9 eV having a significant effect and it is because of Cu-d states. The optical properties of both pure and doped systems were analyzed. Redshift was observed as absorption edge shifted from 4.5 eV to 4.0 eV and even the refractive index reduces from 2.25 to 1.0, which means the Cu inclusion significantly play its role to tailor optical properties. Hence Cu-doping affects the properties of LaAl[O.sub.3] and makes it a suitable candidate for use in different optical devices. Key words: doping, density functional theory, and gap, density of states, optical properties, refractive index. Des calculs bases sur les principes premiers, dans le cadre de la theorie de la fonctionnelle de densite (TFD/DFT), nous fournissent une plateforme pour examiner les proprietes des materiaux en physique du solide. Nous analysons les proprietes electroniques, structurelles et optiques du LaAl[O.sub.3] pur et dope au Cu. L'etude revele que la structure de bande du LaAl[O.sub.3] est affectee de facon significative apres l'inclusion de Cu sur les sites de La. Suite a cette substitution, la bande interdite (gap) est diminuee de 3.02 eV a 2.95 eV. De plus, la densite partielle d'etats (DPE/PDOS) du LaAl[O.sub.3] change de facon marquee apres le dopage au Cu, ce qui confirme l'effet du dopage sur le LaAl[O.sub.3]. Les etats p et d jouent un role crucial sur le haut de la bande de valence. Le domaine dans lequel se trouve le haut de la bande de valence se situe entre 0 eV et -9 eV, un effet significatif cause par les etats d du Cu. Nous analysons les proprietes optiques des systemes purs et dopes. Un decalage vers le rouge est observe suite au deplacement du seuil d'absorption de 4.5 eV a 4.0 eV et meme l'indice de refraction est reduit de 2.25 a 1.0, ce qui signifie que l'inclusion du Cu joue son role pour ajuster les proprietes optiques. Par consequent, les effets du dopage par le Cu affectent les proprietes du LaAl[O.sub.3] et en font un bon candidat pour utilisation dans les dispositifs optiques. [Traduit par la Redaction] Mots-cles : dopage, theorie de la fonctionnelle de densite, bande interdite, densite d'etats, proprietes optiques, indice de refraction., 1. Introduction The power and energy crises demand that humans establish new ideas and perceptions; therefore different theoretical and experimental methods in research have been developed in the materials field. [...]

Multicomponent reactions are relied on in both academic and industrial synthetic organic chemistry owing to their step- and atom-economy advantages over traditional synthetic sequences.sup.1. Recently, bicyclo[1.1.1]pentane (BCP) motifs have become valuable as pharmaceutical bioisosteres of benzene rings, and in particular 1,3-disubstituted BCP moieties have become widely adopted in medicinal chemistry as para-phenyl ring replacements.sup.2. These structures are often generated from [1.1.1]propellane via opening of the internal C-C bond through the addition of either radicals or metal-based nucleophiles.sup.3-13. The resulting propellane-addition adducts are then transformed to the requisite polysubstituted BCP compounds via a range of synthetic sequences that traditionally involve multiple chemical steps. Although this approach has been effective so far, a multicomponent reaction that enables single-step access to complex and diverse polysubstituted drug-like BCP products would be more time efficient compared to current stepwise approaches. Here we report a one-step three-component radical coupling of [1.1.1]propellane to afford diverse functionalized bicyclopentanes using various radical precursors and heteroatom nucleophiles via a metallaphotoredox catalysis protocol. This copper-mediated reaction operates on short timescales (five minutes to one hour) across multiple (more than ten) nucleophile classes and can accommodate a diverse array of radical precursors, including those that generate alkyl, [alpha]-acyl, trifluoromethyl and sulfonyl radicals. This method has been used to rapidly prepare BCP analogues of known pharmaceuticals, one of which is substantially more metabolically stable than its commercial progenitor. A one-step, three-component radical coupling of [1.1.1]propellane by a photoredox reaction mediated by a copper catalyst produces drug-like bicyclopentanes., Author(s): Xiaheng Zhang [sup.1] , Russell T. Smith [sup.1] , Chip Le [sup.1] , Stefan J. McCarver [sup.2] , Brock T. Shireman [sup.2] , Nicholas I. Carruthers [sup.2] , David [...]

A simple and low cost colorimetric procedure using an Android smartphone was developed for determination of copper(II) in copper supported silica catalysts. The developed software was installed in a smartphone for measuring the intensity of the blue color produced by the reaction between copper(II) and 2-carboxy-2'-hydroxy-5'-sulfoformazyl-benzene in an acidic solution. More than one sample can be measured by taking only one photo shot. Under the selected conditions, the linear range from 0 to 5 mg/L was obtained with the detection and quantitation limits of 0.04 and 0.13 mg/L, respectively. The method provided a good precision with the percent relative standard deviation values less than 5%. The percent recoveries were in the range of 97-104%. The results corresponded well with those obtained by atomic absorption spectrophotometry. This developed method is convenient, rapid and simple with an uncomplicated device., Author(s): Nuntaporn Moonrungsee [sup.1], Somkid Pencharee [sup.2], Jaroon Junsomboon [sup.3], Jaroon Jakmunee [sup.4], Nipat Peamaroon [sup.1] Author Affiliations: (1) grid.443781.d, Department of Chemistry, Faculty of Science and Technology, Rambhai Barni [...]

COPPER NANOMESH MURDERS MICROBES Scientists from the University of Tokyo, the Korea Research Institute of Bioscience and Biotechnology, and the RIKEN Center for Emergent Matter Science, Japan, developed a wearable [...]

Copper (Cu) has been successfully cold spray deposited on carbon fiber-reinforced polymer (CFRP) by a hybrid fabrication process. In this study, the feasibility of Cu coating build-up on a Cu [...]

The Cypro-Minoan script was in regular use on the island of Cyprus, and by Cypriot merchants overseas, during the Late Bronze Age. Although still undeciphered, sign-sequences inscribed on miniature copper 'oxhide' ingots and on associated clay labels may hold a clue to their purpose. The ingots were previously interpreted as votive offerings inscribed with dedications. Here, it is suggested instead that these extremely pure copper miniatures were produced as commercial samples, and were marked with a brand denoting their high quality and provenance, such as 'pure Cypriot copper'. Keywords: Cyprus, Late Bronze Age, writing, epigraphy, copper, ingot, Tracing writing on Cyprus Cypro-Minoan writing, a syllabic script, was used on the island of Cyprus during the Late Bronze Age (c. 1550-1050 BC). Despite several attempts at decipherment, the [...]

A new, selective and accurate direct spectrophotometric procedure was developed for the determination of L-ascorbic acid (AA) in pharmaceuticals. Background correction was based on the oxidation of AA by potassium peroxodisulfate in the presence of Cu(II) as a catalyst. The molar absorptivity of the proposed procedure was 1.04 x [10.sup.4] L/(mol cm) at 262 nm. Beer's law was obeyed in the concentration range of 0.68-16.00 µg/mL for AA. The detection limit was 0.20 µg/mL, and the relative standard deviation was 0.91% (n = 7) for 8.00 µg/mL AA. Other compounds commonly found in pharmaceutical preparations did not interfere with the detection of AA. The proposed procedure was successfully applied to the determination of AA in pharmaceuticals, and the results obtained agreed with those obtained by iodine titration. Keywords: ascorbic acid, oxidation, peroxodisulfate, spectrophotometry, pharmaceutical preparations DOI: 10.1134/S1061934816020088, L-Ascorbic acid (vitamin C) is the dienol form of γ-lactone of 2-desoxy-2-keto-L-gulonic acid, which is a relatively strong reducing agent. AA is a constituent of multivitamin preparations, food additives, and [...]

IMPROVING MICROMETERS Manufacturers are working with fibers and wires much thinner than they had even a decade ago for optical communications and on-chip electrical networks. This has driven the need [...]

Copper and palladium catalysts are critically important in numerous commercial chemical processes. Improvements in the activity, selectivity and scope of these catalysts could drastically reduce the environmental impact, and increase the sustainability, of chemical reactions. One rapidly developing strategy for achieving these goals is to use 'high- valent' organometallic copper and palladium intermediates in catalysis. Here we describe recent advances involving both the fundamental chemistry and the applications of these high-valent metal complexes in numerous synthetically useful catalytic transformations., Homogeneous copper- and palladium-catalysed reactions are widely used for the construction of important organic molecules, including pharmaceuticals (1-3), commodity chemicals (4) and polymers5. The development of copper and palladium catalysis [...]

The copper(I) iodide/1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine (CuI-L2) system catalyzed the cross-coupling reactions between aryl halides and aqueous ammonia in water to produce primary aromatic amines in good yields. The protocol was simple and efficient, avoiding the need for inert atmosphere, additional base, or other additives. Key words: copper, catalysis, cross coupling, water chemistry, aqueous ammonia, primary arylamine. Le systeme iodure de cuivre(I)/1,4-bis(2-hydroxy-3,5-di-ieri-butylbenzyl)piperazine (CuI-L2) catalyse les reactions de couplages croisees entre les halogenures d'aryles et une solution aqueuse d'ammoniaque pour conduire a la formation d'amines aromatiques primaires avec de bons rendements. Le protocole est simple et efficace, il ne necessite pas d'atmosphere inerte, de base additionnelle ou d'autres additifs. Mots-cles : cuivre, catalyse, couplage croise, chimie dans l'eau, solution aqueuse d'ammoniaque, arylamine primaire., Introduction Ammonia is an attractive source of nitrogen in organic synthesis owing to its great abundance and low cost. (1) In recent years, the palladium- or copper-catalyzed coupling of aryl [...]

Preparation of a Cu (II) chelate of bis(salicylaldehyde)ethylenediamine was carried out directly in epoxidized rape oil via a water/oil microemulsion reactor. Detailed characterization of the friction of boundary lubrication produced by epoxidized rape oil with and without the Cu (I1) chelate of bis(salicylaldehyde)ethylenediamine was performed in reciprocating sliding tests with a microtribometer. In the presence of a modification of the epoxidized rape oil with 2 wt % of the Cu (II) chelate of bis(salicylaldehyde)ethylenediamine, the friction coefficient decreased by 15%. The Cu (II) chelate of bis(salicylaldehyde)ethylenediamine served as the additive in the epoxidized rape oil and self-assembled on the surface of 100Cr6 steel. The self-assembled monolayer was detected with atomic force microscopy and scanning electron microscopy, and characterized with cyclic voltammetry. It was verified by energy dispersive spectroscopy and X-ray photoelectron spectroscopy analyses that steel/steel rubbing pairs underwent a selective transfer of organic substance and copper, as a result of lubrication with the modified lubricant. It indicated that the modification of epoxidized rape oil with Cu (II) chelate of bis(salicylaldehyde)ethylenediamine led to wear self-repair on the steel surface, with selective transfer of a film of organic substance and copper metal [DOI: 10.1115/1.4001963] Keywords: W/O microemulsion reactor, Cu (11) chelate of bis(salicylaldehyde)ethylenediamine, epoxidized rape oil, wear self-repairing

In this research, the microwave (MW) energy is used to generate heat directly inside the nanoscale copper particles that are suspended in aqueous chlorobenzene (CB) solution. The heat will reduce CB activation energy so that the CB can be more efficiently decomposed by the heat generated. Because the copper particle surface has pointed protuberances, more MW energy can be absorbed to result in higher solution temperature and lower CB activation energy. Laboratory results indicate that without MW irradiation, the CB solution temperature varies from 25 to 60[degrees]C with 19.5 to 41.3% removal of CB that has 21.4 kJ/mol activation energy. In the presence of 250-W MW, the CB activation energy is reduced to 15.8 kJ/mol, and the CB removal efficiency is raised by 1.8 times. Using MW energy to generate heat directly in nanoscale copper particles suspended in aqueous CB solution for reducing the activation energy of CB and enhancing its removal is a novel and efficient method for treating toxic organic substances. DOI: 10.1061/(ASCE)EE. 1943-7870.0000163 CE Database subject headings: Copper; Particles; Microwave; Energy; Degradation; Waste treatment. Author keywords: Chlorobenzene; Nanoscale copper; Microwave; Activation energy (Ea).

Cadmium telluride (CdTe) thin film photovoltaic devices fabricated in a-line process developed at Colorado State University (CSU) have shown stability during long-term (over a 5 year period) accelerated stress testing. These devices have a copper (Cu) containing back contact. The Cu profile as measured by secondary, ion mass spectrometry. characterization shows, for the maximum stressed device (23,399 h), that there is a significant (two times) change in the concentration of secondary Cu ions in the bulk of the material; however, the Cu concentration gradient at the back of the device has no significant change, and the CdS layer has no significant Cu concentration increase at open-circuit bias and 65[degrees]C temperature conditions. This indicates that with a proper Cd[Cl.sub.2] treatment, Cu can be used to form the back contact for CdTe devices with acceptable stability: These devices have a projected field lifetime of greater than 60 years. [DOI: 10.1115/1.3090820] Keywords: cadmium telluride, multicrystalline, device testing, oxide, surface treatments

Stabilizing the copper interconnect process is the key to improving yield and reliability. A stable process for forming adequate grains in a copper film is important, but there is no proper method for monitoring the grains in that film. We introduce the micro-haze method, an advanced method for monitoring grain size using scattering light. We experimentally verified the effectiveness of the method and concluded that the method enables the monitoring the grains in a copper film. Index Terms--Design of experiment, grain size of copper, micro-haze method, surface roughness.

Metal-based microchannel heat exchangers (MHEs) are of current interest due to the combination of high heat transfer performance and improved mechanical integrity. Efficient methods for fabrication and assembly of functional metal-based MHEs are essential to ensure the economic viability of such devices. In this paper, the results on fabrication, assembly, and heat transfer testing of Cu- and Al-based MHE prototypes are reported. Efficient fabrication of Cu- and Al-based high-aspect-ratio microscale structures (HARMSs) has been achieved through molding replication using surface-engineered metallic mold inserts. Replicated metallic HARMSs were assembled through eutectic bonding to form entirely Cu- and Al-based MHE prototypes, on which heat transfer tests were conducted to determine the average rate of heat transfer from electrically heated Cu blocks placed outside the MHEs to water flowing within the molding replicated microchannel arrays. Experimentally observed heat transfer rates are higher as compared to those from previous studies on microchannel devices with similar geometries. The potential influence of microchannel surface profile on heat transfer rates is discussed. The present results illustrate the potential of metal-based MHEs in wide-ranging applications. Index Terms--Heat transfer characteristics, metal-based microchannel heat exchangers (MHEs), molding replication.

High current-carrying capacity and low resistivity are key parameters for power devices. In this paper a copper based terminal metallurgy scheme for wire- and wedge-bonding is described, which improves these properties. The method of choice for depositing thick copper wires is pattern plating. However the plating process has to be optimized in order to get a homogeneous thickness distribution. An electroless coating of NiP, Pd and Au on top of the Cu layers is used as bond interface. This process provides high reliable gold-wire and aluminum-wedge bonds. Index Terms--Copper, electroless plating, electroplating, texture.

A study to examine if neonatal diagnosis of Menkes disease, a fatal degenerative disorder in infancy and treatment with copper injections can help prevent fatalities is conducted. Results confirm the hypothesis showing neurochemical profiles to have high sensitivity and specificity for detecting disease.

A new standard detector for high-accuracy measurements of [F.sub.2] laser radiation at 157 nm is presented. This gold-coated copper cone detector permits the measurement of average powers up to 2 W with an uncertainty of ~1%. To the best of our knowledge, this is the first highly accurate standard detector for [F.sub.2] laser radiation for this power level. It is fully characterized according to Guide to the Expression of Uncertainty in Measurement of the International Organization for Standardization and is connected to the calibration chain for laser radiation established by the German National Metrology Institute.

Three different kinds of Ti additions were evaluated in order to improve the via reliability such as the SIV and the electromigration (EM) in multilevel Cu interconnects. The improvement of adhesiveness at the interface between the via and the lower Cu line, and the oxygen gettering from Cu by Ti play an important role in suppressing the SIV and the EM.

An investigation was conducted on the FTIR spectral changes of bovine cytochrome c oxidase (CcO) upon the ligand dissociation from heme a(sub 3) and redox change of the Cu(sub A)-heme a moiety (Cu(sub A)Fe(sub a). The results indicate that an oxidation state of the (Cu(sub A)Fe(sub a)) moeity determines the carboxyl stretching spectra.

Adsorption and thermal decomposition of alkanethiols (RSH, R=CH3, C2H5 and C4H9) on a Cu(110) surface is studied with the help of temperature-programmed desorption (TPD) and X-ray photoemission spectroscopy (XPS) with synchrotron radiation. The distribution of desorption products depends on the nature of the adsorption site of a particular alkanethiolate.

Selective detection of o-diphenols (e.g., catechol, dopamine, and pyrogallol) in the presence of simple phenols, m- and p- derivative diphenols, and ascorbic acid has been demonstrated on copper-plated screen-printed electrodes (CuSPEs) in pH 7.4 phosphate buffer solution. The CuSPE showed an unusual catalytic response at -0.05 V versus Ag/AgCl selectively to o-diphenolic compounds. The o-diphenols can thus be determined amperometrically through direct electrochemical oxidation in low potentials (~0 V), where the CuSPE is much less subject to interfering reactions. Such a catalytic phenomenon cannot be observed on conventional Pt and glassy carbon electrodes. The selective mechanism is explained in terms of the formation of cyclic five-member complex intermediate (Cu(II)-o-quinolate). Most important of all, the common drawbacks of electrode fouling through polymerization were completely overcome in this system.

The magnetic interactions in Mn(II)(hfac)2{di(4-pyridyl)phenylcarbene}(1a) and Cu(II)(hfac)2{di(4-pyridyl)phenylcarbene}(2a) are studied. The two complexes are regarded as the new d-pi-p conjugated systems containing transition metal ion and carbene as spin sources.

Ultraviolet (UV) excitation for laser-induced native fluorescence (LINF) detection in capillary electrophoresis (CE) offers impressive performance figures of merit when assaying peptides containing tyrosine or tryptophan residues, catecholamines, indolamines, and a number of other classes of analytes with appreciable fluorescence when excited by IN radiation. One of the largest drawbacks of native fluorescence detection schemes in CELINF systems has been the expense and the complexity of the lasers required for excitation in the deep UV wavelength range of 200-300 nm. An improved 'turnkey' NeCu laser operating at 248.6 nm interfaced to a sheath flow-based CE system obtains a performance similar to that of large frame frequency-doubled Ar ion lasers. The detection limits for serotonin and dopamine (27 nM and 8 [micro]M, respectively, for ~3-nL injection) are similar to those obtained using a frequency-doubled Ar ion laser at 257 nm (21 nM and 8 [micro]M, respectively). An example of the detection of serotonin-related analytes from a single-cell electropherogram demonstrates the performance of such a system for mass-limited measurements.

On squirrel-cage induction motors, there is an important choice between utilizing a lower cost die-cast or fabricated aluminum rotor versus the more expensive copper bar rotor. Utilizing the wrong rotor construction for the application can either increase costs unnecessarily or lead to catastrophic failure. This paper will provide the background necessary to assist in making the proper choice. The fundamentals of rotor construction and basic information on how the induction motor works will be discussed. Additionally, the effects of various materials and types of rotor construction on motor performance will be analyzed. Index Terms--Aluminum die cast, copper, motors, rotor construction, rotors.

Cu/Ti/TiN/Sio2 was annealed to obtain self passivated copper as a gate electrode in the form of TiO/CuTiO/TiN/Sio2.

Research has been conducted on the dioxygen adduct of the binuclear heme iron-copper center. The results of the reaction of reduced cytochrome c oxidase with O (sub)2 that produced this adduct are discussed.

Deuterium implantation and its effects on stresses in Cu and CuA12 phases in Cu coatings deposited on A1 alloy substrates, were studied.

Copper and copper alloys have proven to be highly effective in preventing zebra mussel biofouling. The present laboratory measurements reveal that the rate of copper release (mg/m2/day) from surfaces in flowing lake water is inversely proportional to the number of zebra mussels adhering to similar surfaces in Lake Erie. Data are shown for copper, copper-nickel alloys (90:10, 80:20, and 70:30), a copper-epoxy coating, and galvanic couples of copper connected to zinc or aluminum.

Restoration mechanisms observed during wire drawing of OFHC copper are reported, were found to play a part in strengthening but had little effect on resistivity.

Research was conducted to examine the photorefractive characteristics of Cu-doped (K0.5Na0.5)0.2(Sr0.75Ba0.25)0.9Nb2O6 crystals with different doping levels. Two-wave mixing, self-pumped phase conjugation, the growth conditions and absorption properties were the characteristics studied. Results revealed that the doping levels have much influence on the photorefractive properties.

Research was conducted to examine the superconducting properties of niobium films deposited on the inner wall of copper radiofrequency cavities. A few cavities were cut to analyze in more detail the film properties. Characterizations included SEM and TEM observations, AES and SIMS elemental composition studies, XRD analyses and RRR and T(sub c) measurements. Results show that all the variables that influence the BCS surface resistance have no reproducible effect on the residual resistance.

A feasibility study of the seamless Nb/Cu clad cavity was conducted. The purpose of the study was to investigate the mechanical properties of Nb/Cu clad material. Findings show that the workability of the clad material was as good as copper itself which indicate that there will be no problem with fabrication of seamless cavities. To analyze the cavity performance, three L-band single cell cavities using a spinning technology were also fabricated.

Research was conducted to examine the dependence of the exchange bias field on the in-plane direction of the external field. It was observed that the exchange bias field depends in a very sensitive manner on all contributing in-plane anisotropies and on the direction of the external field. The unidirectional, uniaxial and fourfold anisotropy contributions were determined with high precision from the measurement of the exchange bias field as a function of the in-plane angle of the applied field.