8 research outputs found
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/Îł-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%
Remote Sensing and GIS Technologies for Management of Soil and Land Resources for Ecorestoration of Watershed
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
Crystallographic and electrical study of the chromium substituted ferrous zinc copper ferrites
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
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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