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Abstract The descriptive distribution and phylogeny of feline coronaviruses (FCoVs) were studied in cats suspected of having feline infectious peritonitis (FIP) in Malaysia. Ascitic fluids and/or biopsy samples were subjected to a reverse transcription polymerase chain reaction (RT-PCR) targeted for a conserved region of 3'untranslated region (3'UTR) of the FCoV genome. Eighty nine percent of the sampled animals were positive for the presence of FCoV. Among the FCoV positive cats, 80% of cats were males and 64% were below 2 years of age. The FCoV positive cases included 56% domestic short hair (DSH), 40% Persian, and 4% Siamese cats. The nucleotide sequences of 10 selected amplified products from FIP cases were determined. The sequence comparison revealed that the field isolates had 96% homology with a few point mutations. The extent of homology decreased to 93% when compared with reference strains. The overall branching pattern of phylogenetic tree showed two distinct clusters, where all Malaysian isolates fall into one main genetic cluster. These findings provided the first genetic information of FCoV in Malaysia.

Ferromagnetic and highly conductive copper doped ZnO (ZnO:Cu) films were prepared by filtered cathodic vacuum arc technique. By employing a biasing technique during growth, the electron concentration and resistivity of the ZnO:Cu films can be as high as 1020 cm-3 and 5.2×10-3 Ω cm, respectively. The ferromagnetic behavior is observed in all the conductive films, but its magnetization is quenched with an increment in carrier concentration, suggesting that carrier induced exchange is not directly responsible for the ferromagnetism. Heterojunction light emitting diodes have been fabricated using the conductive ZnO:Cu layer as an electron injector and a p-type GaN as hole injector. Electroluminescence can be detected from the devices. [ABSTRACT FROM AUTHOR]

The use of combined filtered cathodic vacuum arc (FCVA) technique and laser ablation to fabricate high-quality As doped ZnO (ZnO:As) films at room temperature is proposed. This is possible because FCVA technique is capable of realizing high-quality undoped ZnO films with extremely high resistivity (i.e., extremely low concentration of Zn interstitials) at low deposition temperature. In addition, laser ablation allows the generation of As plume to react with Zn ion species and O2 inside the FCVA chamber to form ZnO:As films. It was shown that high-quality p-type ZnO:As film with a resistivity of 0.05 Ω cm, a mobility of 2 cm2/V s, and a hole concentration of 4×1019 cm-3 was obtained at room temperature by using the proposed deposited technique. X-ray photoemission spectroscopy analysis has indicated that complex of As substitutional Zn induces two Zn vacancies (i.e., AsZn–2VZn complex), which is likely to be the defect contributing to the formation of shallow acceptor lever inside the ZnO:As films. Furthermore, In/Au Ohmic contacts deposited on p-type ZnO:As films and p-n ZnO based homojunction have been fabricated using plastic as the substrate. [ABSTRACT FROM AUTHOR]

Nanoforest carbon nanotubes (CNTs) were synthesized by biased thermal chemical vapor deposition on cobalt-containing amorphous carbon composite films. The composite films were deposited on silicon by filtered cathodic vacuum arc using a Co-containing graphite target and then CNTs were grown at 580 °C using the composite film as a catalyst layer. The nanoforest multiwalled CNTs have thin diameters between 10 and 20 nm. Their tips point upwards while the rest is densely tangled. They exhibit good field emission properties with a low threshold field of 1.6 V/μm and a high current density of 2.1 mA/cm2 at 3 V/μm. [ABSTRACT FROM AUTHOR]

Room temperature deposition of high crystal quality zinc oxide (ZnO) films was realized by the filtered cathodic vacuum arc (FCVA) technique. Detrimental macroparticles in the plasma as byproducts of arcing process are removed with an off-plane double bend magnetic filter. The influence of oxygen pressure on the structural, electrical and optical properties of ZnO films were investigated in detail. The crystal structure of ZnO is hexagonal with highly c-axis orientation. Intrinsic stress decreases with an increase of chamber pressure, and near stress-free film was obtained at 1 × 10[sup -3] Torr. Films with optical transmittance above 90% in the visible range and resistivity as low as 4.1 × 10[sup -3] Ω cm were prepared at pressure of 5 × 10[sup -4] Torr. Energetic zinc particles in the cathodic plasma and low substrate temperature enhance the probability of formation of zinc interstitials in the ZnO films. The observation of strong ultraviolet photoluminescence and weak deep level emission at room temperature manifest the high crystal quality of the ZnO films prepared by FCVA. Enlargement of the band gap is observed in the absorption and photoluminescence spectra, the band gap shifts towards lower energy with an increase of oxygen pressure. This phenomenon is attributed to the Burstein-Moss effect. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) films were synthesized by thermal oxidation of metallic zinc films in air. The influence of annealing temperatures ranging from 320 to 1000°C on the structural and optical properties of ZnO films is investigated systematically using x-ray diffraction and room temperature photoluminescence (PL). The films show a polycrystalline hexagonal wurtzite structure without preferred orientation. Room temperature PL spectra of the ZnO films display two emission bands, predominant excitonic ultraviolet (UV) emission and weak deep level visible emission. It is observed that the ZnO film annealed at 410 °C exhibits the strongest UV emission intensity and narrowest full width at half maximum (81 meV) among the temperature ranges studied. The excellent UV emission from the film annealed at 410 °C is attributed to the good crystalline quality of the ZnO film and the low rate of formation of intrinsic defects at such low temperature. The visible emission consists of two components in the green and yellow range, and they show different temperature dependent behavior from UV emission. Their possible origins are discussed. [ABSTRACT FROM AUTHOR]

The light scattering properties of boron doped diamond film have been investigated by Raman spectroscopy using ultraviolet (325 and 244 nm) and visible (514 nm) excitations. The relative intensity of electronic Raman scattering to phonon scattering decreases with the increase of the excitation energies, while the Fano-type interference between discrete phonon scattering and continuum electronic scattering becomes weak and phonon scattering peak shifts to higher Raman shift. The decoupling zone center phonon frequency is estimated based on the ultraviolet (UV) Raman scattering; the result indicates that boron induced phonon "softening" in diamond is smaller than that estimated based on the visible Raman spectra. The two broad peaks located at about 500 and 1200 cm[sup -1] on the visible Raman spectrum cannot be detected when it is excited by the UV lasers. [ABSTRACT FROM AUTHOR]