First test of an enriched 116^{116}CdWO4_4 scintillating bolometer for neutrinoless double-beta-decay searches

For the first time, a cadmium tungstate crystal scintillator enriched in $^{116}$Cd has been succesfully tested as a scintillating bolometer. The measurement was performed above ground at a temperature of 18 mK. The crystal mass was 34.5 g and the enrichment level ~82 %. Despite a substantial pile-up effect due to above-ground operation, the detector demonstrated a high energy resolution (2-7 keV FWHM in 0.2-2.6 MeV $\gamma$ energy range), a powerful particle identification capability and a high level of internal radiopurity. These results prove that cadmium tungstate is an extremely promising detector material for a next-generation neutrinoless double-beta decay bolometric experiment, like that proposed in the CUPID project (CUORE Upgrade with Particle IDentification)

Static Cylindrical Matter Shells

Static cylindrical shells composed of massive particles arising from matching of two different Levi-Civita space-times are studied for the shell satisfying either isotropic or anisotropic equation of state. We find that these solutions satisfy the energy conditions for certain ranges of the parameters.Comment: 9 pages, 3 figures, Latex; Final version, To appear in General Relativity and Gravitatio

Notes on static cylindrical shells

Static cylindrical shells made of various types of matter are studied as sources of the vacuum Levi-Civita metrics. Their internal physical properties are related to the two essential parameters of the metrics outside. The total mass per unit length of the cylinders is always less than 1/4. The results are illustrated by a number of figures.Comment: 14 pages, 8 figure

Exact Relativistic Static Charged Dust Disks and Non-axisymmetric Structures

The well-known ``displace, cut and reflect'' method used to generate disks from given solutions of Einstein field equations is applied to the superposition of twoextreme Reissner-Nordstrom black holes to construct disks made of charged dust and alsonon-axisymmetric planar distributions of charged dust on the z=0 plane. They are symmetric with respect to twoor one coordinate axes, depending whether the black holes have equal or unequal masses, respectively.For these non-axisymmetric distributions of matter we also study the effective potential for geodesic motion of neutral test particles.Comment: Classical and Quantum Gravity (in press). 15 pages, LaTex, 8 .eps fig

Algebraically special axisymmetric solutions of the higher-dimensional vacuum Einstein equation

A d-dimensional spacetime is "axisymmetric" if it possesses an SO(d-2) isometry group whose orbits are (d-3)-spheres. In this paper, algebraically special, axisymmetric solutions of the higher dimensional vacuum Einstein equation (with cosmological constant) are investigated. Necessary and sufficient conditions for static axisymmetric solutions to belong to different algebraic classes are presented. Then general (possibly time-dependent) axisymmetric solutions are discussed. All axisymmetric solutions of algebraic types II, D, III and N are obtained.Comment: 28 page

Prediction of Asphalt Creep Compliance Using Artificial Neural Networks

Creep compliance of the hot-mix asphalt (HMA) is a primary input of the pavement thermal cracking prediction model in the recently developed Mechanistic-Empirical Pavement Design Guide (M-EPDG) in the US. The HMA creep compliance is typically determined from the Indirect Tension (IDT) tests and requires complex experimental setup. On the other hand, creep compliance of asphalt binders is determined from a relatively simple three- point bending test performed in the Bending Beam Rheometer (BBR) device. This paper discusses a process of training an Artificial Neural Network (ANN) to correlate the creep compliance values obtained from the IDT with those from an innovative approach of testing HMA beams in the BBR. In addition, ANNs are also trained to predict HMA creep compliance from the creep compliance of asphalt binder and vice versa using the BBR setup. All trained ANNs exhibited a very high correlation of 97 to 99 percent between predicted and measured values. The binder creep compliance curves built on the ANN-predicted values also exhibited good correlation with those obtained from laboratory experiments. However, the simulation of trained ANNs on the independent dataset produced a significant deviation from the expected values which was most likely caused by the differences in material composition, such as aggregate type and gradation, presence of recycled additives, and binder type

Prediction of asphalt creep compliance using artificial neural networks

Creep compliance of the hot-mix asphalt (HMA) is a primary input of the current pavement thermal cracking prediction model used in the US. This paper discusses a process of training an Artificial Neural Network (ANN) to correlate the creep compliance values obtained from the Indirect Tension (IDT) with similar values obtained on small HMA beams from the Bending Beam Rheometer (BBR). In addition, ANNs are also trained to predict HMA creep compliance from the creep compliance of asphalt binder and vice versa using the BBR setup. All trained ANNs exhibited a very high correlation of 97 to 99 percent between predicted and measured values. The binder creep compliance functions built on the ANN-predicted discrete values also exhibited a good correlation when compared with the laboratory experiments. However, the simulation of trained ANNs on the independent dataset produced a significant deviation from the measured values which was most likely caused by the differences in material composition, such as aggregate type and gradation, presence of recycled additives, and binder type

Application of FT-IR technique to bituminous materials

Spektroskopia to podstawowa metoda oceny struktury związków chemicznych na podstawie ich widm, czyli wykresów zależności transmisji od długości fali z zakresu podczerwieni. Spektroskopia w podczerwieni IR umożliwia np. identyfikację substancji i zanieczyszczeń w tej substancji. W szczególności urządzenia FT-IR pozwalają na analizę złożonych mieszanin bez uprzedniego ich rozdzielania. Spektrometry FT-IR rejestrują pochłanianie energii elektromagnetycznej przez określone wiązania międzyatomowe w cząsteczkach. Wyniki są zwykle naniesione na spektrogramie i pokazują miarę pochłaniania w funkcji długości fali elektromagnetycznej. Poszczególne maksima są identyfikowalne w spektrogramie i mogą być wykorzystywane do identyfikacji np. związku chemicznego w zmienionej mieszance, gdy jej wykres podczerwieni jest znany z analizy w stanie czystym. W ostatnich latach metodę FT-IR stosuje się coraz częściej do oceny i kontroli materiałów budowlanych, np. cementu portlandzkiego, asfaltu, itd.Spectroscopy is a fundamental method used in the material science that relies on the interaction of the electromagnetic radiation with a matter. Infrared spectroscopy allows for material fingerprinting as well as detection and quantification of compounds in a sample. In principle, IR spectrometers record the absorption of electromagnetic energy by chemical bounds in a sample as a function of wavelength. Chemical bounds have unique spectra bands at specific wavelengths regardless of the composition of the remaining molecular structure. The absorbance at these specific wavelengths can be used to quantify a particular functional group in the analyzed material. Absorbance peaks are easily identified on the IR spectra and can be used to fingerprint a compound in a mixture, especially when compared to the original unmodified IR spectra. In the recent years, the FT-IR method has become a popular tool for the quality assurance in the practical applications as well as it became a very useful tool in studying various construction materials, e.g. portland cement, bitumen, etc