Linear solvation energy relationship of the solubility of very polar gases: Sulfur dioxide,hydrogen chloride,hydrogen bromide,and ammonia

A linear free energy relationship was found for the log (mole fraction) of solutes in a wide variety of organic solvents with the solvatochromic parameters and the Hildebrand solubility parameter. The solutes were the highly dipolar gases sulfur dioxide, hydrogen chloride, hydrogen bromide, and ammonia at 25°C and 1 atm. partial pressure of the solute. It was found that correlations were greatly improved if solvatochromic parameters for the solvent as a monomer were used rather than the values for the bulk solvent. In solutions with these very dipolar gases, the mole ratio of solute to solvents approaches unity in many of the solutions, so a molecule of solute is interacting primarily with a particular molecule of the solvent. Therefore, the use of the solvatochromic parameters for the solvent as monomer is physically reasonable.     

Role of coordinated metal ions on the orientation of phthalocyanine based coatings

In the present work, we have investigated the molecular orientation of phthalocyanine films deposited on polycrystalline gold. Three films built from the following molecules are investigated: phthalocyanine (H(2)Pc), cobalt phthalocyanine (CoPc) and copper phthalocyanine (CuPc). The films are prepared by spin coating and drop casting methods. Orientation analysis has been performed using polarization dependent Fourier transform infrared (FTIR) spectroscopy using transmission and grazing angle reflectance mode. The FTIR study suggests that each phthalocyanine film contains both alpha- and beta-phases. H(2)Pc based films demonstrate deposition method dependence on the molecular orientation, while the CuPc and CoPc films preserve their molecular orientation independent of deposition method. Grazing angle analysis also suggests that CoPc films show negligible preferred orientation irrespective of film deposition methods. In literature, the band at 878cm(-1) in CuPc has been assigned to out-of-plane bending of C-H. Our grazing angle experiments suggest that this band cannot be assigned to out-of-plane bending vibrations of C-H. Accurate band assignments are also described here for the phthalocyanine system.     

ZnS/SnS/Ag2S photocatalyst with enhanced photocatalytic activity under visible light illumination towards wastewater treatment

Research on Chemical Intermediates - In this study, various compositions of ternary ZnS/SnS/Ag2S nanocatalysts were prepared for the first time through a wet chemical method. The as-prepared...     

Effect of hydrocarbons and other parameters on hydrocarbon-utilizing Pichia angusta MTCC-225

Pichia angusta MTCC-225, a catalase-positive yeast that utilizes methanol and lighter hydrocarbons, is the subject of this investigation. An orthogonal experimental design L₁₆ was used to investigate the effects of methanol, a gas mixture, zero air, temperature, agitation, and salts solution on hydrocarbon utilizing P. angusta. QUALITEK-4 Software was used for automatic design and analysis of the experimental results. Among the various parameters tested, agitation contributed the highest influence (56.5%). Zero air, methanol concentration, and gas mixture showed a moderate influence on the growth of P. angusta. Methanol concentration and gas mixture showed a 10.91 and 10.12% influence, respectively, on yeast growth. Zero air played an important role, with a 15.19% influence on the utilization of hydrocarbon.     

An alternate approach to solve two-level hierarchical time minimization transportation problem

This paper discusses a two-level hierarchical time minimization transportation problem, which is an important class of transportation problems arising in industries. This problem has been studied by various researchers (Sharma et al. in Eur J Oper Res 246:700–707, 2015; Sonia and Puri in TOP 12(2):301–330, 2004; Xie et al. in Comput Oper Res 86:124–139, 2017) and therefore, a number of polynomial time iterative algorithms are available to find its solution. All the existing algorithms, though efficient, have some shortcomings. The current study proposes an alternate solution algorithm for the problem that is more efficient in terms of computational time than the existing algorithms. The results justifying the underlying theory of the proposed algorithm are given. Further, a detailed comparison of the computational behaviour of all the algorithms for randomly generated instances of this problem, of different sizes validates the efficiency of the proposed algorithm.

     

In vitro measurement of attenuation and nonlinear scattering from echogenic liposomes

Echogenic liposomes (ELIP) are an excellent candidate for concurrent imaging and drug delivery applications. They combine the advantages of liposomes-biocompatibility and ability to encapsulate both hydrophobic and hydrophilic drugs-with strong reflections of ultrasound. The objective of this study is to perform a detailed in vitro acoustic characterization - including nonlinear scattering that has not been studied before - along with an investigation of the primary mechanism of echogenicity. Both components are critical for developing viable clinical applications of ELIP. Mannitol, a cryoprotectant, added during the preparation of ELIP is commonly believed to be critical in making them echogenic. Accordingly, here ELIP prepared with varying amount of mannitol concentration are investigated for their pressure dependent linear and non-linear scattered responses. The average diameter of these liposomes is measured to be 125-185 nm. But they have a broad size distribution including liposomes with diameters over a micro-meter as observed by TEM and AFM. These larger liposomes are critical for the overall echogenicity. Attenuation through liposomal solution is measured with four different transducers (central frequencies 2.25, 3.5, 5, 10 MHz). Measured attenuation increases linearly with liposome concentration indicating absence of acoustic interactions between liposomes. Due to the broad size distribution, the attenuation shows a flat response without a distinct peak in the range of frequencies (1-12 MHz) investigated. A 15-20 dB enhancement with 1.67 μg/ml of lipids is observed both for the scattered fundamental and the second harmonic responses at 3.5 MHz excitation frequency and 50-800 kPa amplitude. It demonstrates the efficacy of ELIP for fundamental as well as harmonic ultrasound imaging. The scattered response however does not show any distinct subharmonic peak for the acoustic excitation parameters studied. Small amount of mannitol proves critical for echogenicity. However, mannitol concentration above 100 mM shows no effect.     

具有精准结构Zr-O及Zr/Ti-O纳米团簇的深共熔溶剂热合成

近年来,深共熔溶剂热作为一种绿色合成方法被广泛用于多种杂化功能材料的合成。在本研究中,这一合成方法被引入到多核Zr-和Zr/Ti-O纳米团簇的制备,成功获得被邻菲罗啉、苯酚等共轭配体修饰的Zr₆以及Ti₁₁Zr₄团簇。此方法将为具有精准结构信息的被较多发色团包覆的纳米团簇的合成开辟新的技术路线。此外,光催化分解水产氢实验结果表明,由于具有不同的簇核环境,这两种纳米团簇表现出不同的分散性及与之相关的产氢活性。因此,该研究也为探索金属氧簇材料的结构–性能关系以及结构设计原则提供了借鉴。     

Electronic structure and physical properties of bcc selenium under high pressure

Abstract

Here we report a theoretical calculation of the band structure and superconductivity of Se in the bcc phase. The energy band structure and the effect of pressure on the band structure is obtained by means of the Linear Muffin-Tin Orbital method within the atomic sphere approximation. The superconducting transition temperature (T_c) is calculated using McMillan's formula and we predict the value of T_c at 115.3 Gpa as 2.3 K. Further increase in presssure decreases the T_c values. The normal state electrical resistivity at 115.3 Gpa is 1.43 fl cm, with further increase in pressure the resistivity decreases, which is a typical behaviour of number of elemental metals under pressure.     

Structural, magnetic and electrochemical studies on LiCo0.5Fe0.5O2

LiCo_0.5Fe_0.5O₂ was prepared by sol–gel method. The sample had spinel, cubic and hexagonal phases up to 873 K and a single hexagonal phase above 1,073 K. The magnetic properties were studied at room temperature and at 77 K. The large coercivities observed for the samples annealed at 1,073 and 1,273 K show that these samples do not exhibit a simple antiferromagnetic ordering. From the Mössbauer and magnetization measurements, it is concluded that the hexagonal phase is only an antiferromagnet. The above results clearly demonstrate that the simple aqueous-based sol–gel process developed in this work provides a viable method to synthesize the fine cuboidal particles that display discharge capacity as high as ≈165 mAh/g, which is higher than the value obtained by M. Holzapfel et al. (Holzapfel M, Schreiner R, Ott A, Electrochim Acta 46:1063, 2001) for their samples synthesized by using the ion exchange method. This work suggests that the approaches based on solution chemistry are viable processes for synthesizing good quality electrode material.     

Linear matrix inequality approach for synchronization control of fuzzy cellular neural networks with mixed time delays

Fuzzy cellular neural networks (FCNNs) are special kinds of cellular neural networks (CNNs). Each cell in an FCNN contains fuzzy operating abilities. The entire network is governed by cellular computing laws. The design of FCNNs is based on fuzzy local rules. In this paper, a linear matrix inequality (LMI) approach for synchronization control of FCNNs with mixed delays is investigated. Mixed delays include discrete time-varying delays and unbounded distributed delays. A dynamic control scheme is proposed to achieve the synchronization between a drive network and a response network. By constructing the Lyapunov–Krasovskii functional which contains a triple-integral term and the free-weighting matrices method an improved delay-dependent stability criterion is derived in terms of LMIs. The controller can be easily obtained by solving the derived LMIs. A numerical example and its simulations are presented to illustrate the effectiveness of the proposed method.