X-Ray Diffraction – The Magic Wand

This review paper covers one of the most important discoveries of the last century, viz. X-ray diffraction. It has made enormous contribution to chemistry, physics, engineering, materials science, crystallography and above all medical sciences. The review covers the history of X-rays detection and production, its uses/ applications. The scientific and medical community will forever be indebted to Röntgen for this invaluable discovery and to those who perfected its application.read more

Iqra Zubair Awan

Dielectric Properties of MWNTs/HDPE Composites in Terahertz Region Studied with Reverse Effective Medium Approach

Optical properties of composites MWNTs/HDPE were explored by terahertz time-domain spectroscopy (THz-TDS). It was found that with the increasing of frequency from 0.4 to 2 THz the absorption coefficient increases gradually whereas the refractive index decreases. Furthermore, composites with thick MWNTs possesses larger absorption coefficient and index of refraction compared to that with the thin MWNTs at the same concentration. The dielectric properties of the MWNTs were extracted with reverse effective medium approach (REMA) from that of the composites. The results of the absorption coefficient and refractive index for MWNTs calculated from different concentrations coincides well with each other. The extracted results were then analyzed with the Drude model combined with a localized Lorentz absorption.read more

Wang Zhenqiang, Chen Xiliang , Liu Wei

New Synthesis of Solid-Solution Lead Hydroxyapatite (PbHAP) by Ceramic and Semi-Ceramic Methods

The synthesis of solid solutions lead hydroxyapatite, Pb10(PO4)6*y(OH)2, were successfully synthesized by solid-state reaction (ceramic method) (y= 0.95; 0.96; 0.97; 0.98; 0.99 and 1.00) and precipitation (semi ceramic method) (y= 0.97; 0.98; 0.99 and 1.00) methods at 800 ºC for 50 hours. The X-ray powder diffraction (DRON-3m diffractometer), electron microscopy scanning (SEM) and energy dispersive X-ray micro-analysis which characterized all samples. It has been established that Pb10(PO4)5.82(OH)2 and Pb10(PO4)5.88(OH)2 are the best synthesis for lead hydroxyapatite in the solid-state reaction method, and Pb10(PO4)5.88(OH)2 is the precipitation method.read more

Mohammed A.B. Abdul jabar and Ignatov A.V

The Difference of Serum Protein Transport between Echinosides and Verbascoside

Verbascoside (VER) is the enzymatic hydrolysis product of echinacoside (ECH). The molecular structures of ECH and VER have different glucosyl groups so they bind to serum albumin in different ways, resulting in different pharmacological actions. In this report, we have examined the binding characteristics between human serum albumin (HSA) and ECH/VER by molecular modeling and spectroscopic approaches. Molecular modeling revealed that VER bound to HSA mainly through hydrogen bonds, van der Waals forces and hydrophobic forces. The spectroscopic results showed that the interactions between HSA and VER/ECH involved a static binding process, and the bonding strength of the VER-HSA complex was stronger than that of the ECH-HSA complex. The value of the binding distances (r) was low, which indicated the occurrence of energy transfer. The reaction conformational pattern of HSA-VER and HSA-ECH gave a “two-state model” based on fluorescent phase diagram analysis. According to the thermodynamic model, the main forces between interaction of VER and HSA were hydrogen bonds and van der Waals forces, whereas the interaction between ECH and HSA was hydrophobic force. The fluorescence polarization analysis demonstrated that the interaction between HSA and VER or ECH generated a non-covalent complex. Compared with ECH, VER was more likely to bind with HSA because of its smaller molecular size and low polarity. The results of the spectral analysis concurred with the molecular modeling data, which provides a helpful reference for the study of the molecular reaction mechanism of VER/ECH binding to HSA.read more

Ming Guo, Xiaoxue Zhao, Peter. E. Brodelius, Ling Fang, Zhihong Sun and Rui Wang

A 1H-Benzotriazole Derivative Nucleated Poly(L-lactic acid):Thermal Behavior and Physical Properties

In this study, a 1H-benzotriazole derivative, N, N'-bis(1H-benzotriazole) succinic acid acethydrazide (SABHA), was synthesized to nucleate Poly(L-lactic acid) (PLLA). A series of comparative studies on the melt-crystallization, the cold-crystallization, the melting behavior, the thermal stability, as well as the fluidity between the pure PLLA and PLLA/SABHA were performed. The melt-crystallization behavior revealed that the SABHA as a heterogeneous nucleating agent could significantly facilitate the crystallization of PLLA, and a larger amount of SABHA concentration exhibited the better nucleation effect. However, for the cold-crystallization process, the crystallization peak shifted toward the lower temperature with increasing of SABHA concentration. The melting behavior after crystallization at different crystallization temperatures showed that the melting process of PLLA/SABHA samples depended on the crystallization temperature, and the appearance of the double melting peaks was attributed to the melt-recrystallization. The thermal decomposition profile of PLLA was not affected by SABHA, but the addition of SABHA reduced the thermal stability of PLLA. Fortunately, the presence of SABHA improved the fluidity of PLLA, and the effect of SABHA concentration on the fluidity was positive.read more

Li-Sha Zhao and Yan-Hua Cai

Application of Modified PANI-ZnO Composites for NH3Gas Sensor at Ambient Temperature

Polyaniline and zinc oxide nanoparticles were successfully synthesized through inverse emulsion polymerization method and hydrothermal method respectively. For ammonia gas sensing using LCR meter thin film of the composite was fabricated by using spin coater. The functional groups, morphological, optical, structural properties of zinc oxide nanoparticles, polyaniline (emeraldine salt) and composites were investigated by FTIR spectroscopy, Scanning electron microscopy (SEM), UV- Visible spectroscopy and XRD analysis. The formation of ZnO particles of different shapes in the nano range was confirmed from UV-visible and XRD analysis. UV visible spectrum shows the formation of nanoparticles of ZnO. Thin film of Polyaniline/zinc oxide composites were deposited on the surface of copper interdigitated electrode. The fabricated device showed sensitivity to ammonia gas (NH3) at ambient temperature (300 K). It was observed that the resistance is decreases with the increase of volume of ammonia gas. The electrical properties were also investigated of the different concentration of nanocomposite. Optimum sensing response was achieved with PANI in the presence of 50 wt% ZnO nanoparticles. It may also be inferred from this study that the solution mixing process to produce composites has promising future if handled carefully.read more

Naimat Ullah, Anwar -Ul-Haq Ali Shah, Fazal Akbar Jan, Rotaba Ansir, Wali Muhammad

Investigation of the Magnetic and Electronic Properties of Copper Nanocluster Cu14 Contaminated with Fe, Ni and Co

We have presented density functional calculations of the electronic structures and magnetic properties of bimetallics nanoclusters Cu14-nMn (n=1-3) (M=Fe, Ni and Co) in the FCC crystal structure. For the calculations of the physical properties of the compounds, we have used the full potential linearized augmented plane wave method. The magnetic nature, semiconducting, half metallicity and metalloid of transition metals clusters in the FCC crystal structure are investigated. Results show that studied systems have ferromagnetic properties against Cu14Cluster. It is found that band gap of the clusters decreases with doping of atoms compared to pure cluster Cu14, Particularly for Fe. These calculations show that Cu14 and Cu12Co2 are metals, while Cu13Fe, Cu12Fe2, Cu13Co, Cu11Co3 and Cu11Ni3 are half-metals and Cu11Fe3 and Cu12Ni2 are metalloid. Between these clusters, Cu13Ni is semiconductor. The spin polarization and the magnetic moment of the systems are dependent on number and type of the host transition metal atoms. The Cu13Ni has maximum spin polarization and stability. These results provide a new candidate for applications this series of compounds as dilute magnetic clusters and half-metal in spintronic devices.read more

Maryam Darvishpour, Mohammad Hossein Fekri

Optimization of Ultrasound-Assisted Extraction of Polyphenols from Xanthoceras sorbifolia Husks and their Determination using HPLC

X. sorbifolia can be used as both food material and medicinal plant. In this study, ultrasound-assisted extraction (UAE) was firstly used to optimize the extraction process of total polyphenols from X. sorbifolia husks. Ultrasonic time, ultrasonic temperature, ratio of solvent to material and volume fraction of ethanol were investigated and optimized by orthogonal experiments. Then, High Performance Liquid Chromatography (HPLC) was applied to analyze the polyphenols of the extract under the optimal extraction process. The optimized results for UAE was 40 min of ultrasonic time, 40 ℃ of ultrasonic temperature, 100:1 mL/g of solvent to material ratio and 60% aqueous ethanol. Under the optimal extraction process, the total polyphenol content (TPC) of the extract was 23.16 mg GAE/g DW. Furthermore, the most abundant polyphenols in X. sorbifolia husks extract, such as gallic acid, protocatechuic acid, epicatechin, myricetin-3-O-β-D-rutinoside, rutin and quercetin, were analysed using HPLC. In addition, UAE extract showed antioxidant activity in a concentration-dependent manner. Accordingly, X. sorbifolia husks can be used as a rich source of natural antioxidants. To sum up, these results provided a solid chemical basis underlying the future research and application of Xanthoceras sorbifolia husks.read more

Xue Mei, Guoqian Li, Yong Lin, Bin Yuan, Ying Wei, Chunyan Yang and Chunyang Zhou

Sorption of Uranium (VI) Ions by a Sorbent Based on a Copolymer of Maleic Anhydride with Styrene Modified by N, N'-diphenylguanidine

In this paper the results of a study on the extraction and concentration of micro-quantities of uranium (VI) with a polymeric chelating sorbent with fragments of N, N 'diphenylguanidine is discussed. There was studied a static sorption capacity on K+ ions ((SSC = 9.3 mmol / g) and there were determined the ionization constants of ionogenic groups ( =3.97; =8.47) by potentiometric titration. The optimal conditions of the sorption of elements (pHopt, sorption time - τ, the influence of ionic strength - μ) were determined by the dependence of the sorption capacity (SC, mg/g) on the parameter being studied; the sorption capacity of the sorbent (SC) was determined from the saturation curve constructed under optimal sorption conditions. The maximum degree of extraction of uranium by sorbents is achieved from solutions with pH 5. Sorption equilibrium is achieved within 2 hours of contact of the solution with the sorbent. With an increase in the concentration of the uranyl ion in the solution, the amount of the sorbed metal increases, and at a concentration of 8•10–3 mol/l, it becomes maximal (pH = 5, = 8•10–3 mol/l, Vgen = 20 ml, msorb. = 0.05 g, SC = 1258 mg/g). Limits of detection (3, n=20) are 13.9 ng/ml. The effect of various mineral acids(HClО4, H2SО4, HNО3, HCl) with the same concentrations on the desorption of uranium (VI) from the sorbent was studied. The developed technique was applied to determine uranium in oil sludge.read more

Fidan Bahmanova, Sevinj Hajiyeva, Elnara Alirzaeva, Nazim Shamilov and Famil Chyragov

Discrimination of Mungbean Cultivars/Varieties Based on Minor Saccharides Composition by HPLC Coupled with Multivariate Statistical Analysis

Present study reports the potential use of HPLC coupled with principle component analysis (PCA) and partial least squares discriminant analysis (PLSDA), for differentiation of approved mungbean variety from the promising lines based on minor saccharides profiles. A total of 48 mungbean samples from one approved variety and seven promising lines were analyzed for minor saccharides using HPLC and multivariate statistical analysis. PCA showed a clear separation among the classes. PLSDA was conducted to extract the variables that were responsible for the separation of mungbean approved variety from the lines. Maltoheptaose, maltohexaose, maltopentaose, maltotretraose, maltitol, maltose, mannitole, betaine varied significantly while stachyose, raffinose, sucrose, lectitol, dulcitol, xylitol, galactose showed non-significant differences. Maltoheptaose, maltohexaose, maltotretraose, maltitol, mannitole and galactose were found as the most abundant compounds while stachyose, raffinose, sucrose, lectitol and betaine were found less abundant in all lines and approved variety of V. radiata. The study highlights metabolic variation among mungbean variety and lines for minor saccharides profiles and its usefulness for consumers to choose for their desired variety or line as well as for breeders to look into the genetic factors responsible for this variation.read more

Mudasir Majeed, Abdullah Ijaz Hussain, Shahzad Ali Shahid Chatha, Ghulam Mustafa Kamal and Qasim Ali