40 research outputs found
Quantum walk on distinguishable non-interacting many-particles and indistinguishable two-particle
We present an investigation of many-particle quantum walks in systems of
non-interacting distinguishable particles. Along with a redistribution of the
many-particle density profile we show that the collective evolution of the
many-particle system resembles the single-particle quantum walk evolution when
the number of steps is greater than the number of particles in the system. For
non-uniform initial states we show that the quantum walks can be effectively
used to separate the basis states of the particle in position space and
grouping like state together. We also discuss a two-particle quantum walk on a
two- dimensional lattice and demonstrate an evolution leading to the
localization of both particles at the center of the lattice. Finally we discuss
the outcome of a quantum walk of two indistinguishable particles interacting at
some point during the evolution.Comment: 8 pages, 7 figures, To appear in special issue: "quantum walks" to be
published in Quantum Information Processin
PETROLEUM REFINERY RESIDUALS AND WASTES MANAGEMENT -A REVIEW
Residuals and wastes are produced in crude oil refineries. Intermediate residuals are
waterborne, airborne and solids. Waterborne residuals are treated by API separators. The
reductionof H2Sand S02 to elemental sulfur is desirable in airborne residuals. US Environmental
ProtectionAgency (EPA) has characterized hazardous wastes based on ignitability, corrosivity.,
r,eactivity or toxicity
Recent Trends in Production of Hydrogen from Biomass
Biomass is a potential source to accelerate realization of hydrogen as a
major fuel of the future. In the present paper different routes of hydrogen
production from biomass are discussed that includes direct production
routes as well as conversion of storable intermediates formed during
various processes. The direct routes mainly comprise thermal
gasification, solar gasification and other direct processes. The
intermediate products like syn gas, bio oil are converted to hydrogen.
The co-production of hydrogen and methanol is an attractive option
CORROSION INHIBITION IN HYDROCARBON HANDLING SYSTEMS
Corrosion inhibitors are chemicals that react with a metallic surface or the corrosive environment to which metallic
surface is exposed, giving the metal surface a certain level of protection. Most of the corrosion inhibitors, used in
petroleum industry, are either inorganic or organic compounds depending on the type of corrosion problems faced
by the specific system. The composition and structure of the organic corrosion inhibitors change according to the
applications in the petroleum industry which vary from purely aqueous to hydrocarbon rich media. Present article
highlights the utility of the corrosion inhibitors used during hydrocarbon handling which are either nitrogen containing
organic compounds or their derivatives. Th~ action of specific corrosion inhibitors used in hydrocarbon handling
systems has been explained on the basis of experimental work carried out in authors' laboratory. The
emphasis has been laid on the crude oil characteristics, nitrogen containing organic corrosion inhibitors, hydrophobic
interaction during inhibition and the dependence of the inhibitor performance on the type of the test
method used for its evaluation.
KEYWORDS: Corrosion Inhibition, Hydrocarbon Handling System
Naphthenic Acid Corrosion in Petroleum Refineries
Present review article aims to highlight corrosion problems in refinery processing environment due to low
molecular weight carboxylic acids commonly known as naphthenic acids. Various components like
vacuum unit distillation column, pumps, transfer lines and exchangers are affected due to naphthenic acid
corrosion in refinery environment. Naphthenic acids cause more severe corrosion in vapor phase when
compared to liquid phase and velocity has an effect on the corrosion rate through wall shear stress.
Corrosion intensity also depends on the physical state of the acids present in the operating system.
Suitable corrosion monitoring is invariably required to check the effectiveness of any corrosion control
measure. Various modern instrumental techniques for the determination of the nature of the naphthenic
acids present can provide vital information such as acids' sizes and composition, which may be used in
the battle against corrosion and also used to fingerprint samples from different oil fields. Different
corrosion preventive measures like blending, material up gradation, use of resistant alloys and chemical
treatment using corrosion inhibitors have been taken into account while discussing the problem in detail.
Keywords: Corrosion, Naphthenic acids and Refinery
THERMODYNAMIC PROPERTIES OF OXYGEN COMPOUNDS I. VINYL ACETATE
A complete vibrational assignment is made and ideal gas thermodynamic
properties of vinyl acetate have been reported from 100-1500 K. Internal rotational
contributions have been calculated using Pitzer and Gwinn's tables
Biomass-based energy fuel through biochemical routes: A review
Energy demand is increasing continuously due to rapid growth in population and industrialization development. The development of
energy sources is not keeping pace with spiraling consumption. Even developed countries are not able to compensate even after
increasing the energy production multifold. The major energy demand is provided from the conventional energy sources such as coal, oil,
natural gas, etc. Two major problems, which every country is facing with these conventional fuels, are depletion of fossil fuels and
deterioration of environment.
The present review article aims to highlight various biochemical processes for conversion of biomass into biological hydrogen gas and
ethanol. The present discussion focuses on hydrogen production through various routes viz. fermentative, photosynthesis and biological
water gas shift reaction. In addition, emphasis has been laid on ethanol as biomass-based energy fuel. The discussion has been focused on
the technology for ethanol production from various biomass sources such as molasses, lignocellulosic feedstock and starch. Various
biochemical processes and their major steps involved during the ethanol production from biomass have been discussed in detail.
Keywords: Hydrogen; Ethanol; Biomass; Biochemica