Does Internet use reflect your personality? Relationship between Eysenck’s personality dimensions and Internet use

The aim of this study was to investigate the relationship between three Eysenckian personality dimensions – psychoticism, extroversion and neuroticism – and the Internet use. A sample of 427 Turkish university students completed the Eysenck’s Personality Questionnaire, an Internet survey which contained questions about interpersonal motives for Internet use and a scale for measuring the tendency for expressing one’s “true” self on the Internet. The results indicated that psychoticism was the only personality dimension related to establishing new relationships and having “Internet only” friends; and extroversion was the only personality dimension that is related to maintaining long-distance relationships, and supporting daily face-to-face relationships. The results supported the idea that for some individuals, Internet can be used as social substitute for face-to-face social interactions while for some others it can be used as a tool of social extension, depending on the user’s personality characteristics. Also, psychoticism and neuroticism were found to be positively associated with the expressing “true self” on the Internet, and it was shown that the relationship between psychoticism and Internet uses as social substitute is mediated by the tendency to express one’s true self on the Internet.     

Computing minimum distortion embeddings into a path for bipartite permutation graphs and threshold graphs

The problem of computing minimum distortion embeddings of a given graph into a line (path) was introduced in 2004 and has quickly attracted significant attention with subsequent results appearing at recent stoc and soda conferences. So far, all such results concern approximation algorithms or exponential-time exact algorithms. We give the first polynomial-time algorithms for computing minimum distortion embeddings of graphs into a path when the input graphs belong to specific graph classes. In particular, we solve this problem in polynomial time for bipartite permutation graphs and threshold graphs. For both graph classes, the distortion can be arbitrarily large. The graphs that we consider are unweighted.     

Automatic tag expansion using visual similarity for photo sharing websites

In this paper we present an automatic photo tag expansion method designed for photo sharing websites. The purpose of the method is to suggest tags that are relevant to the visual content of a given photo at upload time. Both textual and visual cues are used in the process of tag expansion. When a photo is to be uploaded, the system asks for a couple of initial tags from the user. The initial tags are used to retrieve relevant photos together with their tags. These photos are assumed to be potentially content related to the uploaded target photo. The tag sets of the relevant photos are used to form the candidate tag list, and visual similarities between the target photo and relevant photos are used to give weights to these candidate tags. Tags with the highest weights are suggested to the user. The method is applied on Flickr (). Results show that including visual information in the process of photo tagging increases accuracy with respect to text-based methods.     

Geometry dependence of the electrostatic and thermal response of a carbon nanotube during field emission

In this paper we present an analysis to simulate heating within an isolated carbon nanotube (CNT) attached to an etched tungsten tip during field emission of an electron beam. The length, radius, wall thickness and shape of the tip (closed with a hemispherical shape or open and flat) of the CNT and its separation distance from the flat surface are considered as variables. Using a finite element method, we predict the field enhancement, emission current and temperature of the CNT as a function of these parameters. The electrostatic and transient thermal analyses are integrated with the field-emission models based on the Fowler-Nordheim approximation and heating/cooling due to emitting energetic electrons (the Nottingham effect). These simulations suggest that the main mechanism responsible for heating of the CNT is Joule heating, which is significantly larger than the Nottingham effect. Results also indicate that the electrostatic characteristics of CNTs are very sensitive to the considered parameters whereas the transient thermal response is only a function of the CNT radius and wall thickness. Further, the thermal response of the CNT is independent of its geometry, meaning that, as long as a given set of geometrical conditions are present that result in a given emission current, the maximum temperature a CNT attains will be the same.     

Optimization of counter flow Ranque–Hilsch vortex tube performance using Taguchi method

This study discusses the application of Taguchi method in assessing maximum temperature gradient for the Ranque–Hilsch counter flow vortex tube performance. The experiments were planned based on Taguchi's L27 orthogonal array with each trial performed under different conditions of inlet pressure, nozzle number and fluid type. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression analysis were carried out in order to determine the effects of process parameters and optimal factor settings. Finally, confirmation tests verified that Taguchi method achieved optimization of counter flow Ranque–Hilsch vortex tube performance with sufficient accuracy.     

Ethidium bromide binding to DNA cryogels

The interaction of the classical intercalator ethidium bromide (EtBr) with the double helical network strands of DNA cryogels was investigated. The cryogels were prepared starting from aqueous solutions of DNA (about 2000 base pairs long) at ?18 °C using 1,4-butanediol diglycidyl ether crosslinker under various reaction conditions. In contrast to the solubilization of DNA hydrogels in aqueous EtBr solutions, DNA cryogels remain stable even after complete saturation of their EtBr binding sites. The total binding capacity of the cryogels is 0.6 ± 0.1 EtBr per nucleotide, which is close to the theoretical maximum number of EtBr molecules that can bind to DNA. Even in very dilute solutions (down to 3 μM), cryogels remove EtBr from aqueous solutions with an efficiency of 90%. The equilibrium binding constant and the maximum number of EtBr binding sites of the cryogels almost coincide with the reported values for the secondary binding process of EtBr by DNA in aqueous solutions. At low mole ratios of bound EtBr to DNA, the cryogels swell with increasing amount of bound EtBr, most likely caused by the lengthening of DNA due to the intercalated EtBr. The response of DNA cryogels to changes in EtBr concentration between 3 and 300 μM also suggests that they can be used to detect DNA binding substrates in aqueous solutions.     

Thermoresponsive hydrogels based on renewable resources

This work aims to synthesize novel thermoresponsive hydrogels from renewable resources, bacterial cellulose (BC), and castor oil (CO), and to investigate the effect of CO on physical and thermal behaviors of BC/Poly(N-isopropylacrylamide) (PNIPAM) hydrogels. The structural properties of the hydrogels are analyzed by Fourier-transform infrared (FTIR) spectroscopy. Differential scanning calorimeter (DSC) technique and thermogravimetric analysis (TGA) are also performed to examine the thermal properties of the hydrogels. The morphological differences of the hydrogels are analyzed by scanning electron microscope (SEM). The thermoresponsive performances of the hydrogels are examined by swelling and deswelling behaviors. The hydrogel with CO is found to be more sensitive to temperature changes than the one without CO. Deswelling study demonstrates 91 and 25% of water loss for hydrogels with and without CO, respectively. The present study shows a novel approach to synthesize thermoresponsive hydrogels with renewable resources for biomedical applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48861.     

Multiresponsive polymeric particles with tunable morphology and properties based on acrylonitrile (AN) and 4-vinylpyridine (4-VP)

We report the synthesis of amphiphilic, pH and magnetic field sensitive polymeric particles obtained from the modification of poly(acrylonitrile-co-4-vinylpyridine) (p(AN-c-4-VP)) core-shell nanoparticles. The magnetic metal nanoparticles were encapsulated in the microemulsion during the polymerization to achieve magnetic-p(AN-c-4-VP)-composites with various morphology. We further chemically modified each component of p(AN-c-4-VP) particles and its composite to tune the hydrophilicity of the particles. Modification of nitrile (hydrophobic) groups to amidoxime (hydrophilic) groups by amidoximation reaction on AN, and quarternization of nitrogen on pyridine ring of 4-VP were carried out to tune the hydrophilicity and the charge of the particles. The modification also performed on magnetic responsive composites after inclusion of separately prepared magnetic Fe₃O₄ nanoparticles. It was further demonstrated that these multiresponsive particles can be used as drug carrier. A nonsteroidal and anti-inflammatory drug Naproxen was used as a model active agent for drug loading and the release studies from (p(AN-c-4-VP) based particles in phosphate buffer solution (pH = 7.4) at ambient temperature.