Exclusive production of π+π−\pi^+\pi^- and π0π0\pi^0\pi^0 pairs in photon-photon and in ultrarelativistic heavy ion collisions

The $\gamma\gamma\to\pi\pi$ reactions are discussed. To describe those processes, we include dipion continuum, resonances, high-energy pion-pion rescatterings, $\rho$ meson exchange and pQCD Brodsky-Lepage mechanisms. The cross section for the production of pion pairs in photon-photon collisions in peripheral heavy ion collisions is calculated with the help of Equivalent Photon Approximaption (EPA) in the impact parameter space. We show predictions at $\sqrt{s_{NN}}=3.5$ TeV which could be measured e.g. by the ALICE collaboration at the LHC.Comment: 4 pages, 7 figures, 1 table, talk by M. Klusek-Gawenda at MESON2012, 31 May - 5 June 2012, Krakow, Polan

Determination of optimum combination of voxel size and b-value for brain diffusion tensor imaging

Optimum combination of voxel size resolution and b-value for whole brain imaging has been determined. Data images were acquired using a 1.5T magnetic resonance imaging (MRI) system (GE Signa HDxt). Diffusion tensor imaging (DTI) scan was performed on phantom and a human volunteer. Six protocols which consist of various combination of voxel size and b-value were evaluated. Measurement of signal-to-noise ratio (SNR) and DTI parameter indices were carried out for both phantom and in-vivo studies. Due consideration was given to a combination of parameters yielding sufficient SNR with DTI values comparable to those obtained from previous reported studies. For the phantom study, SNR ≥ 20 was found in all of the protocols except for a combination of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1200 s/mm2 (V2.0 B1200) and that of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1000 s/mm2 (V2.0 B1000). For in-vivo study, all protocols presented SNR > 20. It was found that a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 1000 s/mm2 (V2.5 B1000) and that of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 (V2.5 B700) displayed the most comparable ADC and FA values with references. In terms of anatomic coverage, V2.5 B700 was found better than V2.5 B1000 as it assures coverage of the whole brain. In conclusion, a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 was considered as optimum parameters for brain DTI

Studi Deformasi Waduk Pendidikan Diponegoro Tahun 2016

According to SNI No. 1731-1989 dam is any artificial barrier, urugan type or any other type that can hold or store water both natural and artificial. In addition to benefits are very much dams also have a high risk because has the potential danger of collapse that could result in the loss of life and material losses, therefore it needs to be observed deformation to determine the condition of the dam.In this research will be observation of the deformation of Pendidikan Diponegoro dam, with GPS (Global Positioning System) observation methods will be observed of 9 monitoring points deformation (bench mark) spread around the body of the dam, the GPS observed data will be processing using scientific software GAMIT 10.6, deformation monitoring points were also observed changes in distance and height from the control points are placed outside the body of the dam, deformation observations carried out from April to June 2016, with twice the period of observation.The results of GPS observations during the observation period showed deformation monitoring points change the coordinate value with ranging from 0.06 cm to 1.4 cm for the X axis, 0.03 cm to 1.9 cm for the Y axis, and 0.4 cm to 1.3 cm for the Z axis. Distance and height changes based on total station and waterpass measurement during the observation period ranging from 0.09 mm to 1.7 mm and 0.15 mm to 1.8 mm. From the result of the dam deformation observation by GPS observation methods, total station, and waterpass shows deformation of the deformation monitoring points during the observation period, but based on the statistical test with 95% confidence level showed that there is no deformation of all the deformation monitoring points

A Differential X-Ray Gunn-Peterson Test Using a Giant Cluster Filament

Using CCD detectors onboard the forthcoming X-ray observatories Chandra and XMM, it is possible to devise a measurement of the absolute density of heavy elements in the hypothetical warm gas filling intercluster space. This gas may be the largest reservoir of baryonic matter in the Universe, but even its existence has not been proven observationally at low redshifts. The proposed measurement would make use of a unique filament of galaxy clusters spanning over 700 Mpc (0.1<z<0.2) along the line of sight in a small area of the sky in Aquarius. The surface density of Abell clusters there is more than 6 times the sky average. It is likely that the intercluster matter column density is enhanced by a similar factor, making its detection feasible under certain optimistic assumptions about its density and elemental abundances. One can compare photoabsorption depth, mostly in the partially ionized oxygen edges, in the spectra of clusters at different distances along the filament, looking for a systematic increase of depth with the distance. The absorption can be measured by the same detector and through the same Galactic column, hence the differential test. A CCD moderate energy resolution (about 100 eV) is adequate for detecting an absorption edge at a known redshift.Comment: Latex, 4 pages, 3 figures, uses emulateapj.sty. ApJ Letters in pres

Diversity of culturable moderately halophilic and halotolerant bacteria in a marsh and two salterns a protected ecosystem of Lower Loukkos (Morocco)

To study the biodiversity of halophilic bacteria in a protected wetland located in Loukkos (Northwest, Morocco), a total of 124 strains were recovered from sediment samples from a marsh and salterns. 120 isolates (98%) were found to be moderately halophilic bacteria; growing in salt ranges of 0.5 to 20%. Of 124 isolates, 102 were Gram-positive while 22 were Gram negative. All isolates were identified based on 16S rRNA gene phylogenetic analysis and characterized phenotypically and by screening for extracellular hydrolytic enzymes. The Gram-positive isolates were dominated by the genus Bacillus (89%) and the others were assigned to Jeotgalibacillus, Planococcus, Staphylococcus and Thalassobacillus. The Gram negative isolates were dominated by the genus Vibrio (41%) and the others were assigned to Halomonas, Psychrobacter, Marinobacterium, Pseudoalteromonas, Salinivibrio and Photobacterium. The growth of strains obtained under different physico-chemical conditions and the screening for hydrolytic enzymes showed a high diversity even within the same species

Lightweight Concrete Produced Using a Two-Stage Casting Process

The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregates in a frame and then filling in the remaining interstitial voids with cementitious grout. The casting process results in the lowest density of lightweight concrete, which consequently has low compressive strength. The irregularly shaped aggregates compensate for the weak point in terms of strength while the round-shape aggregates provide a strength of 20 MPa. Therefore, the proposed casting process can be applied for manufacturing non-structural elements and structural composites requiring a very low density and a strength of at most 20 MPaopen0

Novel Technique of Transepithelial Corneal Cross-Linking Using Iontophoresis in Progressive Keratoconus

In this work, the authors presented the techniques and the preliminary results at 6 months of a randomized controlled trial (NCT02117999) comparing a novel transepithelial corneal cross-linking protocol using iontophoresis with the Dresden protocol for the treatment of progressive keratoconus. At 6months, there was a significant average improvement with an average flattening of themaximum simulated keratometry reading of 0.72\ub11.20D(P = 0.01); in addition, corrected distance visual acuity improved significantly (P = 0.08) and spherical equivalent refraction was significantly lessmyopic (P = 0.02) 6months a\u17fter transepithelial corneal cross-linkingwith iontophoresis. The novel protocol using iontophoresis showed comparable resultswith standard corneal cross-linking to halt progression of keratoconus during 6-month follow-up. Investigation of the long-term RCT outcomes are ongoing to verify the efficacy of this transepithelial corneal cross-linking protocol and to determine if it may be comparable with standard corneal cross-linking in themanagement of progressive keratoconus

Solr Total

Lightning Talks (June 8), video recording is available at: http://repozitar.techlib.cz/record/1275Lightning Talks (June 8), video záznam je k dispozici na: http://repozitar.techlib.cz/record/127

CO2 gasification reactivity of char from high-ash biomass

Biomass char produced from pyrolysis processes is of great interest to be utilized as renewable solid fuels or materials. Forest byproducts and agricultural wastes are low-cost and sustainable biomass feedstocks. These biomasses generally contain high amounts of ash-forming elements, generally leading to high char reactivity. This study elaborates in detail how chemical and physical properties affect CO2 gasification rates of high-ash biomass char, and it also targets the interactions between these properties. Char produced from pine bark, forest residue, and corncobs (particle size 4–30 mm) were included, and all contained different relative compositions of ash-forming elements. Acid leaching was applied to further investigate the influence of inorganic elements in these biomasses. The char properties relevant to the gasification rate were analyzed, that is, elemental composition, specific surface area, and carbon structure. Gasification rates were measured at an isothermal condition of 800 °C with 20% (vol.) of CO2 in N2. The results showed that the inorganic content, particularly K, had a stronger effect on gasification reactivity than specific surface area and aromatic cluster size of the char. At the gasification condition utilized in this study, K could volatilize and mobilize through the char surface, resulting in high gasification reactivity. Meanwhile, the mobilization of Ca did not occur at the low temperature applied, thus resulting in its low catalytic effect. This implies that the dispersion of these inorganic elements through char particles is an important reason behind their catalytic activity. Upon leaching by diluted acetic acid, the K content of these biomasses substantially decreased, while most of the Ca remained in the biomasses. With a low K content in leached biomass char, char reactivity was determined by the active carbon surface area.publishedVersio