Phacomatosis pigmentovascularis Type IIa – A case report

Phacomatosis pigmentovascularis (PPV) is a rare syndrome characterized by capillary vascular malformation and pigmentary nevus but with a wide variability in clinical presentation. A case of a 9-month-old patient is reported, who presented with capillary malformation and hemihypertrophy. These features typically are seen in Klippel–Trenaunay (KT) syndrome, a syndromic type of congenital vascular malformation. However, in addition, this child had large persistent Mongolian spots, the presence of which allowed us to classify this case as PPV, type II. This is a condition with a clinical course not always benign as KT syndrome

Optimal Design of a Trickle Bed Reactor for Light Fuel Oxidative Desulfurization based on Experiments and Modelling

YesIn this work, the performance of oxidative desulfurization (ODS) of dibenzothiophene (DBT) in light gas oil (LGO) is evaluated with a homemade manganese oxide (MnO2/γ-Al2O3) catalyst. The catalyst is prepared by Incipient Wetness Impregnation (IWI) method with air under moderate operating conditions. The effect of different reaction parameters such as reaction temperature, liquid hour space velocity and initial concentration of DBT are also investigated experimentally. Developing a detailed and a validated trickle bed reactor (TBR) process model that can be employed for design and optimization of the ODS process, it is important to develop kinetic models for the relevant reactions with high accuracy. Best kinetic model for the ODS process taking into account hydrodynamic factors (mainly, catalyst effectiveness factor, catalyst wetting efficiency and internal diffusion) and the physical properties affecting the oxidation process is developed utilizing data from pilot plant experiments. An optimization technique based upon the minimization of the sum of the squared error between the experimental and predicted composition of oxidation process is used to determine the best parameters of the kinetic models. The predicted product conversion showed very good agreement with the experimental data for a wide range of the operating condition with absolute average errors less than 5%

Memory of 6 Transistors SRAM Cell Using

Abstract: Semiconductor memory arrays capable of storing large quantities of digital information are essential to all digital systems. The amount of memory required in a particular system depends on the type of application, but, in general, the number of transistors utilized for the information (data) storage function is much larger than the number of transistors used in logic operations and for other purposes. The ever-increasing demand for larger data storage capacity has driven the fabrication technology and memory development towards more compact design rules and, consequently, toward higher data storage densities. The trend towards higher memory density and larger storage capacity will continue to push the leading edge of digital system design. The Microwind 3.1 software will allow designing and simulating an integrated circuit at physical description level. The main novelties related to the 45 nm technology are the high-k gate oxide, metal gate and very low-k interconnect dielectric. The effective gate length required for 45 nm technology is 25nm. Low Power (0.211mwatt), high speed static RAM area efficient chip is designed using 45 nm CMOS technology

LIQUID-LIQUID EQUILIBRIUM STUDIES ON HYDROCARBON (ClO-C2o)-SULFOLANE SYSTEMS

Masohan, A., Nanoti, S.M., Sharma, K.G., Puri, S.N., Gupta, P. and Rawat, B.S., 1990. Liquid-liquid equilibrium studies on hydrocarbon (ClO-C20)-sulfolane systems. Fluid Phase Equilibria, 61: 89-98. Equilibrium tie line data have been determined at 60 and 1000 C with sulfolane and five model hydrocarbon mixtures consisting of butylbenzene-dodecane, hexylbenzene-dodecane, hexylbenzene-cetane, octylbenzene-dodecane and octylbenzene-cetane. The data so obtained have been predicted by UNIFAC and correlated by NRTL and UNIQUAC model equations. The alkylbenzenes used in the study were prepared in the laboratory

Ultra low sulfur diesel by oxidative desulfuriztion of HDS diesel

Due to increasing environmental concerns developed countries have put stringent limits on sulfur levels in fuel and now these limits are being implemented in the developing countries also. The US EPA released new regulation limiting sulfur in diesel to 15ppm by 2006. In India diesel fuel with 50 ppm sulfur is to be used in 11 major cities and 350 ppm in rest of the country by 2010. The pressing needs to reduce sulfur levels to ultra low in diesel have aggressively accelerated the research and development activities in the area of diesel desulfurization. The most targeted deep hydrodesulfurization processes have inherent problems like high capital and operational costs, high energy requirements difficult to justify it for small refiners on one hand and limitations of the catalyst to desulfurize sulfur species like 4,6-dimethyl dibenzothiophene (4,6-DMDBT) on the other hand. Owing to these difficulties, alternative methods like oxidative desulfurization, biodesulfurization, liquid-liquid extraction, and selective adsorption are being investigated worldwide for desulfurization of diesel fuel. Among the alternative approaches oxidative desulfurization, which involves oxidation of sulfur compounds present in diesel to more polar sulphones/ sulphoxides followed by their removal by solvent extraction/ adsorption has attracted worldwide attention. Oxidation of sulfur compounds present in HDS diesel containing about 500ppm sulfur was extensively studied first in mixer settler and then in a continuous counter current oxidation reactor with a oxidizing solution consisting of carboxylic P-16 XII RTM, 14th – 16th NOVEMBER, 2005 HYDERABAD 540 acid (CA) and active oxygen containing species to achieve their quantitative oxidation to sulphones/ sulfoxides. This was followed by counter current extraction of sulphones/ sulphoxides from oxidized diesel with N-methyl pyrolidinone - antisolvent mixture and final finishing by passing through a bed of silica/ alumina to obtain ultra low sulfur diesel (ULSD). Oxidation of sulfur compounds present in HDS diesel was also studied in a continuous down flow fixed bed laboratory reactor with organic hydroperoxide in presence of transition metal containing heterogeneous catalyst to achieve their quantitative oxidation to sulphones/ sulphoxides. The sulphones/sulphoxides thus formed could be removed from oxidized diesel by adsorption on solid alumina / silica to obtain ultra low sulfur diesel (ULSD). Both these approaches for oxidative desulfurization (ODS) of HDS diesel were found to be efficient to obtain ultra low sulfur diesel (ULSD) with less than 10 ppm sulfur content and are discussed in detail in this article