Cyber victim and bullying scale: A study of validity and reliability

The purpose of this study is to develop a reliable and valid scale, which determines cyber victimization and bullying behaviors of high school students. Research group consisted of 404 students (250 male, 154 male) in Sakarya, in 2009–2010 academic years. In the study sample, mean age is 16.68. Content validity and face validity of the scale was provided via field specialists’ judgment. Confirmatory and exploratory factor analyses were performed for investigation of the factor structure of the scale. As a result of principal component analysis of cyber victim subscale three factors emerged which accounted for the 46.38% of the total variance. Also for cyber bullying subscale, same three factors emerged accounting for the 49.18% of the total variance. Scales with 22 items under 3 factors were tested with confirmatory factor analysis for each victim and bullying variables. Three factors were named as cyber verbal bullying, hiding identity and cyber forgery. Three factors model of scales were found theoretically and statistically fitted after confirmatory factor analysis. For criterion related validity the correlation between cyber victim and bullying scale and Aggression Scale was calculated as .27 and .36, respectively. The internal consistency coefficients calculated for reliability. Cyber victim and bullying scales’ internal consistency coefficients were .89 and split-half coefficients were .79. for both scales. Test-retest reliability for cyber victim .85, for cyber bullying respectively .90 was found. These results demonstrate that the Cyber Victim and Bullying Scale’ is a valid and reliable instrument.     

Note on transport equation and fractional Sumudu transform

In this paper, the Chebyshev polynomials to solve analytically the fractional neutron transport equation in one-dimensional plane geometry are used. The procedure is based on the expansion of the angular flux in terms of the Chebyshev polynomials. The obtained system of fractional linear differential equation is solved analytically by using fractional Sumudu transform.     

Neutronic analysis of a high power density hybrid reactor using innovative coolants

In this study, neutronic investigation of a deuterium-tritium (DT) driven hybrid reactor using ceramic uranium fuels, namely UC, UO₂ or UN under a high neutron wall load (NWL) of 10MW/m² at the first wall is conducted over a period of 24 months for fissile fuel breeding for light water reactors (LWRs). New substances, namely, Flinabe or Li₂₀Sn₈₀ are used as coolants in the fuel zone to facilitate heat transfer out of the blanket. Natural lithium is also utilized for comparison to these two innovative coolants. Neutron transport calculations are performed on a simple experimental hybrid blanket with cylindrical geometry with the help of the SCALE 4.3 System by solving the Boltzmann transport equation with the XSDRNPM code in 238 neutron groups and an S₈-P₃ approximation. The investigated blanket using Flinabe or Li₂₀Sn₈₀ shows better fissile fuel breeding and fuel enrichment characteristics compared to that with natural lithium which shows that these two innovative coolants can be used in hybrid reactors for higher fissile fuel breeding performance. Furthermore, using a high NWL of 10MW/m² at the first wall of the investigated blanket can decrease the time for fuel rods to reach the level for charging in LWRs.     

A new MILP model proposal in feed formulation and using a hybrid-linear binary PSO (H-LBP) approach for alternative solutions

Large-scale feed factories may have multiple production and storage facilities. Any production facility uses its own available raw materials while performing feed formulation. However, ensuring a reasonable cost is achieved, and the desired quality criteria are met, may require obtaining a certain amount of raw material from other facilities. Selecting a specific amount of raw materials among many raw materials in different facilities requires many combinations to be tried out. Providing solutions, especially when there is a large amount of the raw material, may be costly and take more time. A new mixed-integer linear programming (MILP) model that specifies the type of material and the amount of the material to be selected from external facilities has been proposed in this study. When deterministic methods like MILP are used, only one solution result is obtained. However, when the decision-maker would like to see alternative results, solution constraints can be mitigated and a solution provided within the same or similar time. A new method named hybrid-linear binary PSO (H-LBP) has been proposed in this study for the problems that the decision-maker had limited time for and for which the solution results were required in a shorter time. Continuous particle swarm optimization, which works as a hybrid with linear programming, has been used in this method. The new model proposed in this study was tested on the mixed feeds for sheep, cattle and rabbit species by using both MILP and the proposed H-LBP methods. Raw materials determined by the model were added to the mixture, and the cost in each of the three species was observed to go down. In addition, different alternative solutions at reasonable cost and similar quality were presented to the producer/decision-maker in a shorter time.

     

Preparation and properties of multi-walled carbon nanotube/poly(organophosphazene) composites

Carbon nanotubes (CNTs) are promising materials because of their unique properties. However, the poor solubility in solvents limits the function of CNTs and hinders their applications in many fields. Surface modification of CNTs with polymers is an efficient method to solve this problem. Several polymers were tested for the preparation of CNT dispersions. In comparison with organic polymers, poly(organophosphazenes) are highly stable macromolecules with adjustable properties which depend on the side groups. This article is to describe the synthesis of thermally stable and soluble multi-walled CNT/poly(organophosphazene) composites. The poly(organophosphazene)s substituted with (a) 100 % quaternary protonated pyridinoxy (PPY), (b) 50 % quaternary protonated pyridinoxy and 50 % a long aliphatic chain alcohol (1-dodecanol) (PDK), and (c) 50 % quaternary protonated pyridinoxy and 50 % a glycol ether [(2-(2-methoxyethoxy)ethanol] (PET) have been synthesized. f-MWCNT/poly(organophosphazene) composites have been prepared by the treatment of the functionalized multi-walled carbon nanotubes (f-MWCNT) with the protonated polyphosphazenes (PPY, PDK, and PET) using different feed ratios [R _feed = 1:1, 1:3, 1:5, 1:10 (w:w)]. The thermal stability of prepared composites (f-MWCNT/PPY, f-MWCNT/PDK, and f-MWCNT/PET) have been investigated by TGA. By considering thermal stabilities and solubility of all prepared composites, f-MWCNT/PPY_1:5, f-MWCNT/PDK_1:5, and f-MWCNT/PET_1:5 have been chosen as optimum composite composition and characterized by ³¹P NMR, ¹H NMR, XRD, Raman spectroscopy, and EDX analysis. The morphologic characterizations of the f-MWCNT/PPY_1:5, f-MWCNT/PDK_1:5, f-MWCNT/PET_1:5 nanocomposites have been carried out by HRTEM. Excellent dispersions of the nanocomposites in water and common organic solvents have been achieved. The solubility and thermal stability of nanocomposites depend on the side groups on poly(organophosphazene).     

WSe2 Nanotubes: Their Formation by Electron Irradiation

The discovery of multi-walled carbon nanotubes¹ and single-walled carbon nanotubes² has prompted numerous studies of the structure, properties^3,4, and potential applications^5,6of these materials. For example, nanotubes are expected to have a high strength-to-weight ratio⁶, which is advantageous in advanced composites to be used in high performance materials such as aircraft frames. The small dimensions of the tubes show promise for use as a gas absorption medium⁷, a field emitter for use in flat-panel displays⁸, and nanoscale electronic devices⁹.