Determination of sodium hyaluronate in pharmaceutical formulations by HPLC–UV

A liquid chromatography （HPLC） method with UV detection was developed for determination of sodium hyaluronate in pharmaceutical formulation. Sodium hyaluronate is a polymer of disaccharides, composed of D-glucuronic acid and D-N-acetylglucosamine, linked via alternating 13-1, 4 and D-l, 3 glycosidic bonds. Being a polymer compound it lacks a UV absorbing chromophore. In the absence of a UV absorbing chromophore and highly polar nature of compound, the analysis becomes a major challenge. To overcome these problems a novel method for the determination of sodium hyaluronate was developed and validated based on size exclusion liquid chromatography （SEC） with UV detection. An isocratic mobile phase consisting of buffer 0.05 M potassium dihydrogen phosphate, pH adjusted to 7.0 using potassium hydroxide （10%） was used. Chromatography was carried out at 25 ~C on a BioSep SEC $2000, 300 mm ~ 7.8 mm column. The detection was carded out using variable wavelength UV-vis detector set at 205 nm. The compounds were eluted isocratically at a steady flow rate of 1.0 mL/min. Sodium hyaluronate retention time was about 4.9 min with an asymmetry factor of 1.93. A calibration curve was obtained from 1 to 38 g/mL （r〉0.9998）. Within-day % RSD was 1.0 and between-day % RSD was 1.10. Specificity/selectivity experiments revealed the absence of interference from excipients, recovery from spiked samples for sodium hyaluronate was 99-102. The developed method was applied to the determination of sodium hyaluronate in pharmaceutical drug substance and product.

Crystal Growth and Characterization of Potassium Manganese Nickel Sulphate Hexahydrate—A New UV Filter

Potassium Manganese Nickel Sulphate Hexahydrate (KMNSH) crystals have been successfully grown by using traditional slow evaporation method. The empirical formula of KMNNSH is K2Mn0.1Ni0.9 (SO4)2?6H2O with formula weight 430.7698. KMNNSH crystal revealed monoclinic space group P2(1)/c, a = 6.12(4) ?, b = 12.19(9) ?, c = 8.96(7) ?, α = γ = 90?, β = 105.3(2), V = 645(1)?3, Z = 2, Dc = 2.2281 g/cm3 with deep green color. IR confirms that there is strong interaction between free water molecules. The thermal analysis indicates that the water molecules are present in the KMNNSH crystals. The transmission spectrometry of KMNNSH in the range from UV to near IR wavelengths is reported. Atomic Absorption Spectroscopy also have been studied and discussed.

Effect of Heat Treatment Processes on the Mechanical Properties of Medium Carbon Steel

The importance of various form of heat treatment operations on medium carbon steel in order to forester the problem that may arise in making a wrong choice of these steel materials or faulty heat treatment operations which may give rise to serious disruption in terms of human safety, higher cost and untimely failure of the machine components is of great concern. The mechanical properties such as ductility, toughness, strength, hardness and tensile strength can easily be modified by heat treating the medium carbon steel to suit a particular design purpose. Tensile specimens were produced from medium carbon steel and were subjected to various forms of heat treatment processes like annealing, normalizing, hardening and tempering. The stiffness, ductility, ultimate tensile strength, yield strength and hardness of the heat treated samples were observed from their stress-strain curve. The value of the yield strength (σy) was observed to be higher for the tempered specimen possibly as a result of the grain re-arrangement, followed by the hardened, normalized and annealed specimens. The value of the ultimate tensile strength (σu) were also observed to be in the order;hardened> tempered>normalized>annealed.

Design and Performance Analysis of an Innovative Single Basin Solar NanoStill

The provision of fresh water is becoming an increasingly important issue in many areas of the world. Clean water is a basic human necessity, and without water life will be impossible. The rapid international developments, the industrial growth, agriculture and population explosion all over the world have resulted in a large escalation of demand for fresh water. The solar still is the most economical way to accomplish this objective. The sun’s energy heats water to the point of evaporation. When water evaporates, water vapour rises leaving the impurities like salts, heavy metals and condensate on the underside of the glass cover. Solar distillation has low yield, but safe and pure supplies of water in remote areas. The attempts are made to increase the productivity of solar still by using nanofluids and also by black paint coat- ing inside the still basin. Heat transfer enhancement in solar still is one of the key issues of energy saving and compact designs. The essential initiative is to seek the solid particles having thermal conductivity of several hundred times higher than those of conventional fluids. Recently, as an innovative material, nanosized particles have been used in sus- pension in conventional solar still water. The fluids with nanosized solid particles suspended in them are called “nanofluids”. The suspended metallic or nonmetallic nanoparticles change the transport properties, heat transfer characteristics and evaporative properties of the base fluid, The aim of this paper is to analyze and compare the enhanced performance of a single basin solar still using nanofluids with the conventional water. They greatly improve the rate of evaporation and hence the increase in efficiency.

喷雾热解法在硅衬底上生长定向碳纳米管阵列(英文)

以向日葵油的甲基酯为碳源,二茂铁为催化剂前驱体,Ar为载气,通过喷雾热解法在硅衬底上合成定向碳纳米管阵列。结果表明,在硅衬底上原位形成Fe催化剂纳米颗粒。由拉曼光谱、透射电镜图和X-射线衍射谱图显示所制定向碳纳米管阵列具有较好的石墨化程度,其直径为1 0～3 0 nm,管壁约为1 0 nm。所制定向碳纳米管阵列中残留的催化剂含量可以忽略。

High-Performance Multipath Routing Algorithm Using CPEGASIS Protocol in Wireless Sensor Cloud Environment

The current IT cloud computing is playing a vital role in most of the areas such as Education, Research, Health care, etc. The cloud computing technology involving in sensor networks embedded system and IOT (Internet of Things). At present scenario, the sensors collected the information from the particular environment, where the sensors are fixed and transfer the collected information to cloud storage, here the challenge is the data transmission i.e. data that traverse from sensor to cloud environment are the big issue and maximum number of data loss is very high especially in dynamic routing environment. If data loss is identified in any routing path then automatically the information will transfer to alternate routing path. In this paper, we introduce a new algorithm for automatic routing path selection that can be integrated with cloud technology. This algorithm supports when data loss is found in the particular path of a network, then it selects an alternate route to transfer the data. The proposed model is comparatively more efficient than the prior methodologies. The implementation of the proposed work is done on NS3 simulator, and the performance metric is analyzed.

Seed Extract of Psidium guajava as Ecofriendly Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Medium

The anticorrosion characteristics of the seeds of Psidium guajava （P. guajava） fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of ad- sorption of the inhibitor on the metal surface （Q）, change in entropy （ΔS）, change in flee energy of the reaction （ΔG）, corrosion rate （CR） and energy of activation for corrosion reaction of carbon steel （E） were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investi- gated using Fourier transform infrared （FT-IR） spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy （SEM） micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.

A Shoreline Change Analysis Along the Coast Between Kanyakumari and Tuticorin, India, Using Digital Shoreline Analysis System

The shoreline is one of the rapidly changing landforms in coastal areas. They are the key element in coastal GIS and provide the most information on coastal land form dynamics. Therefore, accurate detection and frequent monitoring of shorelines is very essential to understand the coastal processes and dynamics of various coastal features. The present study is to investigate the shoreline changes along the coast between Kanyakumari and Tuticorin of south India （where hydrodynamic and morphologic changes occur continuously after the December 2004 tsunami） by using Digital Shoreline Analysis System （DSAS）, an extension of ArcGIS. Multidate 1RS and Landsat Satellite data （1999, 2001, 2003, 2005, 2007, and 2009） are used to extract the shorelines. The data is processed by using the ERDAS IMAGINE 9.1 software and analyzed by ArcGIS 9.2 workstation. The rates of shoreline changes are estimated by three statistical methods, namely, End Point Rate （EPR）, Linear Regression Rate （LRR）, and Least Median of Squares （LMS） by using DSAS. The study reveals that most of the study area has undergoing erosion. Both natural and anthropogenic processes along the coast modify the shoreline configuration and control the erosion and accretion of the coastal zones. The coastal zones along the estuary have experienced accretion due to the littoral processes. The zones with headlands have more eroded than other zones along the study area. The study also shows that the coastal zones where sand is mined have relatively more rate of erosion than that of the other zones. Improper and unsustainable sand mining may also lead to severe erosion problem along this area. The shoreline change rates are altered by various geological processes along the coast. Thus, the present study implies that proper beach filling and nourishment projects should be made in the study area to save from hazards. It also indicates the advantage and suitability of DSAS to assess the shoreline changes compared with the traditional manual shoreline change analysis and promising its applications for coastal zone management in other regions.