The 43GHz SiO maser in the circumstellar envelope of the AGB star R Cassiopeiae

We present multi-epoch, total intensity, high-resolution images of 43GHz, v=1, J=1-0 SiO maser emission toward the Mira variable R Cas. In total we have 23 epochs of data for R Cas at approximate monthly intervals over an optical pulsation phase range from 0.158 to 1.78. These maps show a ring-like distribution of the maser features in a shell, which is assumed to be centred on the star at a radius of 1.6 to 2.3 times the stellar radii. It is clear from these images that the maser emission is significantly extended around the star. At some epochs a faint outer arc can be seen at 2.2 stellar radii. The intensity of the emission waxes and wanes during the stellar phase. Some maser features are seen infalling as well as outflowing. We have made initial comparisons of our data with models by Gray et. al. (2009).Comment: 12 pages, 14 figure

Facies analysis and stratigraphic development of the Albian Succession in Nasiriyah Oil Field, Southern Iraq

The Carbonate - Clastic succession in this study is represented by the Nahr Uamr and Mauddud Formations deposited during the Albian Sequence. This study includes facies analysis and stratigraphic development for this succession in 5 boreholes within Nasiriyah oil field. There are several types of microfacies were recognized in the succession of the Mauddud Formation. Their characteristic grain types and depositional texture enabled the recognition of six facies associations (depositional environments) were distinguished in the Mauddud Formation, they are: shallow open marine, restricted, reef, slope, deep open marine and basinal. Two types of rocks are observed within the Nahr Umr Formation; the first is the upper part which characterized by shale dominated rocks and the second (lower part) is characterized by sand dominated rocks. Four facies associations (depositional environments) were distinguished in the Nahr Umr Formation, they are: delta plain, prodelta, bay fill, and distributary channels. The microfacies analysis and reconstructed the paleoenvironments of the Albain basin in the studied area; there are three stages of the deposition: - during the first stage the sea level was rise which led to progress prodelta facies (retrogradation) and onlapping the unconformity. This part is represented by TST stage in all studied boreholes. The prodelta facies was changed to distributary channel facies up-wared to mark the mfs between these two facies. This refers to deposition during the high stand period as two cycles. The sea level was reactivated to progress after the last step of Nahr Umr deposition, to start the Mauddud Formation deposition. At second stage the facies change was shown three steps of the sea level rise (TST) to deposition the restricted, reef-back reef and shallow open marine/slope. Overlying the slope facies to the shallow marine and then deposited the shallow marine refer to maximum flooding surfaces after deposition the last ones. Therefore, the shallowing up-ward succession which deposition later was represented the high stand stage (HST). The final stage is represented by reactivated the sea level rise to deposition the basinal facies within the Mauddud Formation. The continued rise in sea level during the period of transgression (TST) is a preparation for the Ahmadi basin, which is characterized by deposition in a deep environment and conformable lower contact with the Mauddud Formation

Experimental Study Of Natural Convection Heat Transfer In An Enclosed Vibration Cavity

Experimental study has been implemented to elucidate an affect of mechanical vibration at  normal gravity on natural convection in cubic enclosure  side (L=120mm) filled with air ( 14Pr=0.71)">  at two amount of heat flux (. The enclosure was comprised of two vertical and opposed surfaces. The right wall was heated at uniform heat flux where the left wall cooled was maintained at 14Tc"> , surrounded by four other adiabatic surfaces. Vibration stresses were applied to this heat transfer cell by mounting it vertically on the armature of electrodynamic vibratior. The experiments were carried out at for Rayleigh number range ( 147*107-4*108)"> and aspect ratio equal (1), frequencies from 2to 8 Hertz at 14q""> =85 14Wm2">  and from 3 to 9 Hertz at 946.017 14Wm2"> ). In the high Rayleih number case (Ra=4* 14108"> ), the gravitional thermal convection dominates, and the vibration motion does not enhances the heat transfer remarkably. In contrast, in low Rayleigh (Ra=7* 14107"> ), the vibration thermal convection is dominant, and the vibration enhaces the heat transfer rate significantly. In addition, the higher the vibration frequency is, the quicker the steady stateis reached and for two cases of Rayeigh number at ascending frequencies is in general higher than that descending frequencies. Keywords: Cubic Enclosure, Mechanical Vibration

Optimization of thermoluminescence response of copper doped zinc lithium borate glass co-doped with Na2O

Establishing the basic procedures that will influence the enhancement of the TL yield of a phosphor is paramount in the issue of dosimetry. Melt quenching method was adopted in synthesizing lithium borate glass modified with ZnO, doped with CuO and codoped with Na2O. The structural and optical properties of zinc lithium borate and some TL properties of copper doped zinc lithium borate were reported in our previous works. The amorphous nature of the prepared glasses was confirmed by x-ray diffraction analysis (XRD). Physical properties of the glass were obtained via Archimedes principle. The copper doped zinc lithium borate was co-doped with different concentration of Na2O (0.025 mol % to 0.1 mol %). The glasses were irradiated with 4 Gy dose of gamma rays using 60Co gamma cell. The highest TL response was recorded against 0.05 mol% concentration of Na2O. The best settings for TLD reading of the proposed TLD were determined. The optimal annealing temperature and time for this composition was found to be 300 oC and 50 min respectively. The best heating rate at which the new TLD can be readout was 3 oC S-1

Improvement of Gasoline Octane Number by Using Organic Compounds

The toxic lead additives to gasoline are no longer used in many countries around the world. Many other countries are now phasing out the lead in gasoline. Although the lead fuel is still in use in Iraq, several plans are considered to phase out the lead. The use of organic compounds to replace the lead additives in gasoline is considered now as an option in Iraqi refineries. The main objective of this project was preparation of premium gasoline, by blending of gasoline with Alternative additives (alcohol, aromatic) to enhancing octane number of Al-Doura gasoline pool. Improved gasoline was tested by ASTM standard method which includes octane number measuring by CFR engine analyzer. Gasoline pool RON (80) was used and selective components were added to the gasoline pool (1-3%) to improving it octane, such as ethanol, methanol,isopropanol,isobutanol, benzene, nitrobenzene, Aniline, and nitro aniline. Octane number of blends was measured by CFR engine. Mixture of alternative additives was prepared and adding in 1-3%vol to the gasoline pool. It was found that the additives show significant improvement of octane number of gasoline but the important increasing of RON was shown on use mixture of alcohols and aniline

Potentiometric determination of nickel (II) with sodium diethyldithiocarbamate (NaDEDC)

The article presents the results of potentiometric titration of the solution containing Ni (II) by the solution of sodium diethylditheocarbamate (NaDEDC). The possibilities of carbon composite electrode (CCE) and certain ion-selective and metal electrodes as the sensors for potentiometric determination of ions were investigated. The conditions for potentiometric titration of nickel (reagent, pH, composition of supporting solution, efficient electrode, effect of interfering ions) using sensors have been studied and optimized. The titration curves were processed by the linearization method which provide determination of equivalence point with high accuracy

Borotellurite glasses for gamma-ray shielding: an exploration of photon attenuation coefficients, structural, and thermal properties

Gamma-ray attenuation characteristics and vibrational and thermal features have been studied for singly doped erbium (Er), dysprosium (Dy), and Er/Dycodoped sodium lithium zinc lead borotellurite glasses. For all glasses, the amorphous nature was confirmed from the x-ray diffraction profiles, and BO3, BO4, TeO4, TeO3 +1, and TeO3 structural units were identified by both Fourier transform infrared spectroscopy and Raman spectroscopy. Glass transition (Tg), onset crystallization (Tx), peak crystallization (Tc), and melting (Tm) temperatures including thermal stabilities (DT) were evaluated following the glass differential scanning calorimetry profiles. An enhancement in Tg (359 fi 399C) and DT variation at 131–169C with Er2O3, Dy2O3, and Er2O3/ Dy2O3 incorporation suggested that the prepared glasses possess good thermal stability. The radiation shielding properties within the 0.356–1.33-MeV photon energy range were assessed for all the glasses. The mass attenuation coefficient (l/q) values have been calculated using Monte Carlo simulation code. Further, photon interaction parameters like effective atomic number (Zeff), half-value layer (HVL), and mean free path (MFP) were also computed. The host and 1.0 Er/1.0 Dy (mol.%)-codoped glasses possess the lowest and highest Zeff values and their magnitudes are varied within the range 11.40–15.99 and 12.14–17.26, respectively. For the host glass, exposure buildup factor values were calculated by the geometric progression (GP) fitting method within the 0.015–15-MeV energy range and up to a penetration depth of 40 MFP. The removal cross sections RR (cm1) for fast neutrons were calculated to evaluate the attenuation of neutrons through the prepared glasses