Epitaxial growth and transport properties of Nb-doped SrTiO3_{3} thin films

Nb-doped SrTiO$_{3}$ epitaxial thin films have been prepared on (001) SrTiO$_{3}$ substrates using pulsed laser deposition. A high substrate temperature ($>1000^{\circ}{C}$) was found to be necessary to achieve 2-dimensional growth. Atomic force microscopy reveals atomically flat surfaces with 3.9 \AA $$ steps. The films show a metallic behavior, residual resistivity ratios between 10 and 100, and low residual resistivity of the order of 10$^{-4}$$\Omega$cm. At 0.3 K, a sharp superconducting transition, reaching zero resistance, is observed.Comment: 4 pages, 4 figure

Biostratigraphic and magnetostratigraphic synthesis of the Celebes and Sulu Seas, Leg 124

During ODP Leg 124, late middle Eocene to Quaternary sediment sequences were recovered from 13 holes drilled at five sites in the Celebes and Sulu basins. Paleomagnetic measurements and biostratigraphic studies using calcareous nannofossils, planktonic and benthic foraminifers, radiolarians, and diatoms were completed and summarized here. Two Neogene sediment sections recovered in the Sulu Basin yielded excellent core recoveries and magnetic reversal records, allowing direct magnetobiostratigraphic correlations for the Pliocene and Quaternary at Site 768 and for the middle Miocene to Quaternary at Site 769. The interpolated ages of biohorizons are not consistent between sites and only a few of them are in good agreement with previous calibrations. The differences may be the results of redeposition by turbidity currents and selective dissolution of key fossils

Global and regional estimates of cancer mortality and incidence by site: I. Application of regional cancer survival model to estimate cancer mortality distribution by site

BACKGROUND: The Global Burden of Disease 2000 (GBD 2000) study starts from an analysis of the overall mortality envelope in order to ensure that the cause-specific estimates add to the total all cause mortality by age and sex. For regions where information on the distribution of cancer deaths is not available, a site-specific survival model was developed to estimate the distribution of cancer deaths by site. METHODS: An age-period-cohort model of cancer survival was developed based on data from the Surveillance, Epidemiology, and End Results (SEER). The model was further adjusted for the level of economic development in each region. Combined with the available incidence data, cancer death distributions were estimated and the model estimates were validated against vital registration data from regions other than the United States. RESULTS: Comparison with cancer mortality distribution from vital registration confirmed the validity of this approach. The model also yielded the cancer mortality distribution which is consistent with the estimates based on regional cancer registries. There was a significant variation in relative interval survival across regions, in particular for cancers of bladder, breast, melanoma of the skin, prostate and haematological malignancies. Moderate variations were observed among cancers of colon, rectum, and uterus. Cancers with very poor prognosis such as liver, lung, and pancreas cancers showed very small variations across the regions. CONCLUSIONS: The survival model presented here offers a new approach to the calculation of the distribution of deaths for areas where mortality data are either scarce or unavailable

A Case Study of Assessing Button Bits Failure through Wavelet Transform Using Rock Drilling Induced Noise Signals

Finding the precise moment of button breakage of bits during drilling, with the experience of drill rig operators is a serious concern for modern vibrant mining industry. This research proposed a new methodology to find the failure of button using the sound generated by rock-bit interactions. The experiment is conducted by the video and sound data recorded during a drilling process in an underground mine, that uses a Sandvik AXERA7 twin boom jumbo drill rig and Polycrystalline diamond (PCD) tapered button bits. Signal analysis techniques such as Fourier transform and Wavelet transform are utilised to analyse the hectic noise signal recorded. The analysed results are shown that Wavelet Transform is much more effective in finding singularity points such as chipping or breakage of a button in compared to the Fourier Transform. The outcome of this analysis, which is the peak intensity at the breakage point, was correlated to the average intensity of the sound wave using moving average method. The results suggest that the noise generated during the drilling process can be used to detect the condition of the drill bit

Photoluminescence, recombination induced luminescence and electroluminescence in epoxy resin

Dielectric breakdown of epoxies is preceded by light emission, or so-called electroluminescence, from the solid-state material. Very little is known about the luminescence properties of epoxies. The aim of this paper is to derive information that can be used as a basis to understand the nature of the excited states and their involvement in electrical degradation processes. Three different kinds of stimulation were used to excite the material luminescence. Photoluminescence was performed on the base resin, the hardener and the cured resin. Luminescence excited by a silent discharge has been analysed to identify which of the luminescent centres are optically active upon the recombination of electrical charges and could therefore act as charge traps. Finally, the electroluminescence spectrum has been acquired and compared with the previous ones. Although the identification of the origin of these emissions is far from being complete, it has been found that the photoluminescence from the cured resin is due to in-chain chromophores, which acts as trapping centres. The excited states involved in photoluminescence also seems to be involved in electroluminescence, but other components are detected as well, which could be due to the degradation of the resin molecule under the effect of the electric stress

Comparison of Bond Character in Hydrocarbons and Fullerenes

We present a comparison of the bond polarizabilities for carbon-carbon bonds in hydrocarbons and fullerenes, using two different models for the fullerene Raman spectrum and the results of Raman measurements on ethane and ethylene. We find that the polarizabilities for single bonds in fullerenes and hydrocarbons compare well, while the double bonds in fullerenes have greater polarizability than in ethylene.Comment: 7 pages, no figures, uses RevTeX. (To appear in Phys. Rev. B.

The first year of Antarctic VLBI observations

We are undertaking a series of geodetic VLBI observations between the Syowa Station 11-m antenna in Antarctica, and the 26-m antennas in Hobart Tasmania and Hartebeesthoek South Africa. These observations are the beginning of our campaign to monitor the motion and stability of the Antarctic plate. We describe here the results of the first year\u27s observations made during the southern summer and winter of 1998. Two mutually incompatible recording systems, K4 and S2, are used. The Mitaka FX Correlator was used to correlate these data. By using software called CALC3/MSOLV, the mean position of the antenna\u27s geodetic reference point was found to be X=1766194.152±0.006m, Y=1460410.923±0.005m and Z=- 5932273.329±0.015m at the epoch of 1998.9 in the International Terrestrial Reference Frame 2000 (ITRF2000) system. From a comparison with measurements made with other space geodetic techniques we estimate that our results have typical uncertainties of no more than 2 to 3cm in each coordinate