Shape dependent energy optimization in quantum dots

In this paper, we investigate a minimization problem related to the principal eigenvalue of the Schrödinger operator. The optimized solution can be applied to design new electronic and photonic devices based on the quantum dots.     

Vesicle deformations by clusters of transmembrane proteins

We carry out a coarse-grained molecular dynamics simulation of phospholipid vesicles with transmembrane proteins. We measure the mean and Gaussian curvatures of our protein-embedded vesicles and quantitatively show how protein clusters change the shapes of their host vesicles. The effects of depletion force and vesiculation on protein clustering are also investigated. By increasing the protein concentration, clusters are fragmented to smaller bundles, which are then redistributed to form more symmetric structures corresponding to lower bending energies. Big clusters and highly aspherical vesicles cannot be formed when the fraction of protein to lipid molecules is large.     

Selective Oxidation of Sulfides to Sulfoxides and Sulfones Using n -Butyltriphenylphosphonium Dichromate (Bu n PPh3)2Cr2O7 in the Presence of Aluminium Chloride in Solution and Under Microwave Irradiation

A wide variety of sulfides are efficiently oxidized to their corresponding sulfoxides and sulfones in excellent yields using n-butyltriphenylphosphonium dichromate (BTPPDC) in the presence of aluminium chloride in acetonitrile solution and under microwave irradiation. In addition, selective oxidation of sulfides in the presence of functional groups such as a carbon–carbon double bond, ketone, oxime, aldehyde, ether, and acetal can be considered as a noteworthy advantage of this method.     

The topological structure of a certain Menger space

In this paper we will reconsider the topological structure of Menger probabilistic normed spaces (briefly PN-spaces) under the t-norm M. We will prove that this topology is compatible with the topology induced by a countable and separating family of semi-norms, and hence the well-known theorems of classical functional analysis (such as the principle of uniform boundedness, open mapping and closed graph theorems) are valid in this context also. We will meanwhile obtain a method by which one may construct easily a large class of PN-spaces. Finally, using this method, we see that a certain subspace of bounded linear operators between PN-spaces, i.e. the class of strongly bounded linear operators, has a natural PN structure.     

Gamma-spectrum of241Am

The γ-ray spectrum of²⁴¹Am was reinvestigated by using intense sources. A purified solution source was used to make sure that the γ-lines presents in the spectrum come from the α-decay of²⁴¹Am. The γ-spectrometer consists of 40% relative efficiency HPGe detector and 8192-channel ADC. Out of 137 γ-lines that are presents in the spectrum 46 are new.     

Development of a needle trap device packed with titanium‐based metal‐organic framework sorbent for extraction of phenolic derivatives in air

We developed a novel method of needle trap device packed with titanium‐based metal‐organic framework for the extraction of phenolic derivatives in air followed by gas chromatography‐flame ionization detector analysis. The synthetized adsorbent was packed inside a 22‐gauge spinal needle. This method was first tested at laboratory scale, and then was used for field sampling of phenolic derivatives in air. A glass chamber placed on a heater at 60°C was used to provide different concentrations of phenolic derivatives. The desorption conditions and breakthrough volume were optimized using response surface methodology. The limit of detection and limit of quantitation of the proposed method were estimated to be in the range of 0.001–0.12 and 0.003–0.62 ng/mL, respectively, indicating a high sensitivity for the suggested sampler. Storing the packed needle trap device in a refrigerator at 4?C for 60 days did not dramatically affect the storage stability. Our findings indicated that there was a high correlation coefficient (R² = 0.99) between the measurement results of this method and the NIOSH recommended method (XAD‐7 sorbent tube). Therefore, it can be concluded that the needle trap device packed with titanium‐based metal‐organic framework can be used as a efficient method for extraction of phenolic derivatives in air.     

Synthesis of 1-amidoalkyl-2-naphthol derivatives using a magnetic nano-Fe3O4@SiO2@Hexamethylenetetramine-supported ionic liquid as a catalyst under solvent-free conditions

Hexamethylenetetramine-functionalized silica-coated nano-Fe₃O₄ particles (MNPs@Hexamethylenetetramine) were prepared as a reusable heterogeneous catalyst using a facile process. The catalyst was synthesized and characterized using infrared, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometer. This magnetic nanocatalyst was employed as an efficient, reusable, and environmentally benign heterogeneous catalyst for the synthesis of amidoalkylnaphthol derivatives from a one-pot three-component condensation reaction of beta-naphthol, aldehydes, and amides in good to excellent yields, Moreover, this catalyst can be easily recovered by using a magnetic field and directly reused for at least seven runs without sign ificant loss of its activity.     

Synthesis of antimicrobial agents of tetra-substituted thiophenes from ethyl 5-(2-bromoacetyl)-4-phenyl-2-(phenylamino)thiophene-3-carboxylate

5-(2-Bromoacetyl)-2,3,4-trisubstituted-thiophene was used as a synthetic intermediate to prepare a series of thiophene derivatives and thiophene incorporating oxazole, imidazole, thiazole, pyrrole, and pyridine rings via substitution and cyclo-condensation reactions. The data were extracted from the spectra of the resulting products confirmed their suggested structures. The newly synthesized compounds were screened to evaluate their in vitro antimicrobial activity vs several positive and negative gram bacteria and fungi. The screening data revealed that the thiophene derivative 7a , incorporating a thiazole ring, displayed strong activity against all tested microorganisms when compared with the antibiotics used.