A Density Functional Theory Investigation of Carboranethiol Self-Assembled Monolayer on Au(111)

Isolated and full monolayer adsorption of various carboranethiol (C$_2$B$_{10}$H$_{12}$S) isomers on gold (111) surface have been investigated using both the standard and van der Waals density functional theoretical calculations. The effect of differing molecular dipole moment orientations on the low energy adlayer geometries, the binding characteristics and the electronic properties of the self-assembled monolayers of these isomers have been studied. Specifically, the binding energy and work function changes associated with different molecules show a correlation with their dipole moments. The adsorption is favored for the isomers with dipole moments parallel to the surface. Of the two possible unit cell structures, the (5$\times$5) was found to be more stable than the ($\sqrt{19}\times\sqrt{19}$)R23.4$^o$ one.Comment: 22 pages, 6 figures and 3 table

Joint Channel Estimation and Decoding with Low-Complexity Iterative Structures in Time-Varying Fading Channels

A low-complexity iterative channel estimation (ICE) algorithm is proposed with the promise of improved error performance. The new algorithm operates the LMS filter both in the forward and the backward directions along a block. The feedback from the decoder to the estimator is in the form of soft decisions. The pilot symbol assisted modulation (PSAM) is used as the transmission technique. The effect of code choice on various ICE algorithms is also explored by considering the blockwise concatenated codes initially offered for block-fading channels. The performance of the new estimation algorithm with the proposed coding is shown to outperform the conventional estimation algorithms over a fast time-varying Rayleigh fading channel beside its low complexity structure

Building a constructivist social learning environment through talk in the mathematics classroom

This study aimed to create a constructivist learning environment wherein third grade students talk to problem solve, which is different from traditional approaches to math learning. The study focused on the group talk and discussions to understand the students’ actions and interactions during the process of problem solving. Fifteen students and their teacher participated in the study, which was conducted within a collaborative action study design. Different types of problems were constructed including addition, subtraction, multiplication and division. Students were divided into four groups and observed for four weeks as they solved the different types of problems through group discussion. In the study, it was observed that the students who took leadership roles in the groups during the problem solving activities lead discussions. Additionally, the study found that the students, who could not solve the problems individually, were able to contribute more to the problem solving activity in the group works

Investigation of the Effect of Climate Change on Extreme Precipitation: Capital Ankara Case

This study examines the potential impacts of climate change on extreme precipitation. Rainfall analysis with stationary and nonstationary approach for observed and future conditions is performed for (1950-2015 period) observed data of 5, 10, 15, 30 minutes and 1, 2, 3, 6 hour and projections (2015-2098 period) of 10, 15 minutes and 1, 6 hour for Ankara province, Turkey. Daily projections are disaggregated to finer scales, 5 minutes storm durations, then five minutes time series aggregated to the storm durations that are subject of interest. Nonstationary Generalized Extreme Value (GEV) models and stationary GEV models for observed and future data are obtained. Nonstationary model results are in general exhibited smaller return level values with respect to stationary model results of each storm duration for observed data driven model results. Considering the projected data driven model results; on average nonstationary models produce mostly lower return levels for mid and longer return periods for all storm durations and return periods except one hour storm duration. Depending on the models and Representative Concentration Pathways (RCP), there are different results for the future extreme rainfall input; yet all results indicate a decreasing extreme trend

Impact of dietary calcium tetraborate supplementation on the mineral content of egg and eggshell of laying quails

Boron (B) is a trace element that plays an important role in the mineral, cell membrane, hormone, and enzyme metabolism of animals and humans. The aim of this study was to examine the effect of dietary calcium tetraborate (CaB4O7) supplementation on the mineral composition of egg content and eggshell of laying quails. For this purpose, a total of 20 male and 40 female quails, 6-week-old, were equally divided into 2 groups (control and additive groups) in 5 replicates (6 birds/replicate) and given CaB4O7 300 mg/kg feed in additive group. The experiment was conducted for 56 days. The eggs were collected and the mineral composition [B, calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), potassium (K), manganese (Mn), copper (Cu), zinc (Zn)] of egg content and eggshell samples were determined at the end of the experiment in randomly collected 6 eggs per group. Results of this study indicated dietary supplementation of CaB4O7 increased Mg (P<0.01), Na (P<0.01), and K (P<0.05) contents of edible parts of eggs compared to the control group, but B concentration were not determined in edible parts of eggs in both groups. Moreover, B (P<0.01), Mg (P<0.01), Na (P<0.01), Fe (P<0.01), K (P<0.05), Cu (P<0.05) and Zn (P<0.01) of eggshell were higher in the additive group than control. There were also significant correlations between examined minerals both edible and eggshell parts of the eggs. It may be concluded that supplementing diets with CaB4O7 could improve Ca metabolism, producing eggs enriched in minerals, promoting B, Mg, Na, Fe, K, Cu, and Zn deposition in eggshells, and improving eggshells quality. The effective B supplementation doses for functional egg production could be determined and B could be advantageous in terms of beneficial physiological effects

Antimicrobial activity of extracts of chemical races of the lichen Pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents

Chloroatranorin and olivetoric acid were active against the same microorganisms with few exceptions. Physodic acid was active against about the same bacteria and yeasts and inactive against all of the filamentous fungi tested. Also no activity of atranorin against the filamentous fungi was observed

Dithiooxamide Modified Glassy Carbon Electrode for the Studies of Non-Aqueous Media: Electrochemical Behaviors of Quercetin on the Electrode Surface

Electrochemical oxidation of quercetin, as an important biological molecule, has been studied in non-aqueous media using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. To investigate the electrochemical properties of quercetin, an important flavonoid derivative, on a different surface, a new glassy carbon electrode has been developed using dithiooxamide as modifier in non-aqueous media. The surface modification of glassy carbon electrode has been performed within the 0.0 mV and +800 mV potential range with 20 cycles using 1 mM dithioxamide solution in acetonitrile. However, the modification of quercetin to both bare glassy carbon and dithiooxamide modified glassy carbon electrode surface was carried out in a wide +300 mV and +2,800 mV potential range with 10 cycles. Following the modification process, cyclic voltammetry has been used for the surface characterization in aqueous and non-aqueous media whereas electrochemical impedance spectroscopy has been used in aqueous media. Scanning electron microscopy has also been used to support the surface analysis. The obtained data from the characterization and modification studies of dithioxamide modified and quercetin grafted glassy carbon electrode showed that the developed electrode can be used for the quantitative determination of quercetin and antioxidant capacity determination as a chemical sensor electrode

Characteristics of food allergy in children: National multicenter study

Conference: Congress of the European-Academy-of-Allergy-and-Clinical-Immunology (EAACI) Location: Lisbon, PORTUGAL Date: JUN 01-05, 2019Background : Food allergies impose a significant burden on the life of the child and the family. In this study, to determine the demographic characteristics of food allergies, we investigated the characteristics of patients with food allergies in different regions of Pediatric Allergy- Immunology departments in Turkey. Method : Turkey ' s National Study of Allergy and Clinical Immunology Society has conducted a Study Group on Food Allergies. 25 centers participated in this multicenter, cross- sectional and descriptive study.European Academy of Allergy and Clinical Immunolog

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

Structural, photo, optical and thermal luminescent properties of beta barium metaborate

Barium borate compounds (BaB4O7-beta-BaB2O4) were produced by different synthesis methods, which include solution assisted solid state synthesis method (SAS), microwave assisted solid state synthesis method (MAS) and high temperature solid state synthesis method (HTS). These different synthesis methods were carried out in air atmosphere (AA) and nitrogen atmosphere (NA). Luminescence emission spectra of barium borate compounds exhibited a broad band around 400 nm (similar to 310 nm excitation). X- ray induced luminescence measurements have shown a similar emission band, supporting the PL measurements. Photoluminescence decay curve of beta-BaB2O4 compound (excited with 365 nm) is well fitted with a double exponential function with lifetimes tau(1) = 3, 69 ms and tau(2) = 29, 45 ms. At around 365 nm, Quantum Efficiency (QE) of the luminescence emission from beta-BaB2O4 was calculated as 8 +/- 1 percent. In order to test the possibility of using in radiation dosimetry, Optically Stimulated Luminescence (OSL) properties of beta-BaB2O4 were investigated by determining radiation dose response, fading and repeatability of response. The OSL signal intensity was observed to increase linearly with increasing beta dose from 5 Gy to 1000 Gy. Thermoluminescence (TL) glow curve of beta-BaB2O4 phosphor consist of broad glow peak with an apparent maximum at around 240 degrees C; which is also growing with radiation dose. The results presented here are of preliminary in nature and for a better understanding of the luminescence properties of beta-BaB2O4 deserves more attention with possible applications as a phosphor and optical and dosimeter material