Abstract: In the present study, a procedure was developed to
determine the optimum reaction rate constants in generalized
Arrhenius form and optimized through the Nelder-Mead method. For
this purpose, a comprehensive mathematical model of a fixed bed
reactor for dehydrogenation of heavy paraffins over Pt–Sn/Al2O3
catalyst was developed. Utilizing appropriate kinetic rate expressions
for the main dehydrogenation reaction as well as side reactions and
catalyst deactivation, a detailed model for the radial flow reactor was
obtained. The reactor model composed of a set of partial differential
equations (PDE), ordinary differential equations (ODE) as well as
algebraic equations all of which were solved numerically to
determine variations in components- concentrations in term of mole
percents as a function of time and reactor radius. It was demonstrated
that most significant variations observed at the entrance of the bed
and the initial olefin production obtained was rather high. The
aforementioned method utilized a direct-search optimization
algorithm along with the numerical solution of the governing
differential equations. The usefulness and validity of the method was
demonstrated by comparing the predicted values of the kinetic
constants using the proposed method with a series of experimental
values reported in the literature for different systems.
Abstract: The mechanism of microwave heating is essentially
that of dielectric heating. After exposing the emulsion to the
microwave Electromagnetic (EM) field, molecular rotation and ionic
conduction due to the penetration of (EM) into the emulsion are
responsible for the internal heating. To determine the capability of
microwave technology in demulsification of crude oil emulsions,
microwave demulsification method was applied in a 50-50 % and 20-
80 % water-in-oil emulsions with microwave exposure time varied
from 20-180 sec. Transient temperature profiles of water-in-oil
emulsions inside a cylindrical container were measured. The
temperature rise at a given location was almost horizontal (linear).
The average rates of temperature increase of 50-50 % and 20-80 %
water-in-oil emulsions are 0.351 and 0.437 oC/sec, respectively. The
rate of temperature increase of emulsions decreased at higher
temperature due to decreasing dielectric loss of water. These results
indicate that microwave demulsification of water-in-oil emulsions
does not require chemical additions. Microwave has the potential to
be used as an alternative way in the demulsification process.
Abstract: Static synchronous compensator (STATCOM) is a shunt connected voltage source converter (VSC), which can affect rapid control of reactive flow in the transmission line by controlling the generated a.c. voltage. The main aim of the paper is to design a power system installed with a Static synchronous compensator (STATCOM) and demonstrates the application of the linearised Phillips-heffron model in analyzing the damping effect of the STATCOM to improve power system oscillation stability. The proposed PI controller is designed to coordinate two control inputs: Voltage of the injection bus and capacitor voltage of the STATCOM, to improve the Dynamic stability of a SMIB system .The power oscillations damping (POD) control and power system stabilizer (PSS) and their coordinated action with proposed controllers are tested. The simulation result shows that the proposed damping controllers provide satisfactory performance in terms of improvements of dynamic stability of the system.
Abstract: Cryptographic algorithms play a crucial role in the
information society by providing protection from unauthorized
access to sensitive data. It is clear that information technology will
become increasingly pervasive, Hence we can expect the emergence
of ubiquitous or pervasive computing, ambient intelligence. These
new environments and applications will present new security
challenges, and there is no doubt that cryptographic algorithms and
protocols will form a part of the solution. The efficiency of a public
key cryptosystem is mainly measured in computational overheads,
key size and bandwidth. In particular the RSA algorithm is used in
many applications for providing the security. Although the security
of RSA is beyond doubt, the evolution in computing power has
caused a growth in the necessary key length. The fact that most chips
on smart cards can-t process key extending 1024 bit shows that there
is need for alternative. NTRU is such an alternative and it is a
collection of mathematical algorithm based on manipulating lists of
very small integers and polynomials. This allows NTRU to high
speeds with the use of minimal computing power. NTRU (Nth degree
Truncated Polynomial Ring Unit) is the first secure public key
cryptosystem not based on factorization or discrete logarithm
problem. This means that given sufficient computational resources
and time, an adversary, should not be able to break the key. The
multi-party communication and requirement of optimal resource
utilization necessitated the need for the present day demand of
applications that need security enforcement technique .and can be
enhanced with high-end computing. This has promoted us to develop
high-performance NTRU schemes using approaches such as the use
of high-end computing hardware. Peer-to-peer (P2P) or enterprise
grids are proven as one of the approaches for developing high-end
computing systems. By utilizing them one can improve the
performance of NTRU through parallel execution. In this paper we
propose and develop an application for NTRU using enterprise grid
middleware called Alchemi. An analysis and comparison of its
performance for various text files is presented.
Abstract: In this paper, the notion of Hyperbolic Klingenberg
plane is introduced via a set of axioms like as Affine Klingenberg
planes and Projective Klingenberg planes. Models of such planes are
constructed by deleting a certain number m of equivalence classes
of lines from a Projective Klingenberg plane. In the finite case, an
upper bound for m is established and some combinatoric properties
are investigated.
Abstract: Employees commonly encounter unpredictable and
unavoidable work related stressors. Exposure to such stressors can
evoke negative appraisals and associated adverse mental, physical,
and behavioral responses. Because Acceptance and Commitment
Therapy (ACT) emphasizes acceptance of unavoidable stressors and
diffusion from negative appraisals, it may be particularly beneficial
for work stress. Forty-five workers were randomly assigned to an
ACT intervention for work stress (n = 21) or a waitlist control group
(n = 24). The intervention consisted of two 3-hour sessions spaced
one week apart. An examination of group process and outcomes was
conducted using the Revised Sessions Rating Scale. Results indicated
that the ACT participants reported that they perceived the
intervention to be supportive, task focused, and without adverse
therapist behaviors (e.g., feelings of being criticized or discounted).
Additionally, the second session (values clarification and
commitment to action) was perceived to be more supportive and task
focused than the first session (mindfulness, defusion). Process ratings
were correlated with outcomes. Results indicated that perceptions of
therapy supportiveness and task focus were associated with reduced
psychological distress and improved perceived physical health.
Abstract: Groundwater is an essential and vital component of our life support system. The groundwater resources are being utilized for drinking, irrigation and industrial purposes. There is growing concern on deterioration of groundwater quality due to geogenic and anthropogenic activities. Groundwater, being a fragile must be carefully managed to maintain its purity within standard limits. So, quality assessment and management are to be carried out hand-in-hand to have a pollution free environment and for a sustainable use. In order to assess the quality for consumption by human beings and for use in agriculture, the groundwater from the shallow aquifers (dug well) in the Palakkad and Chittur taluks of Bharathapuzha river basin - a paddy dominated agricultural basin (order=8th; L= 209 Km; Area = 6186 Km2), Kerala, India, has been selected. The water samples (n= 120) collected for various seasons, viz., monsoon-MON (August, 2005), postmonsoon-POM (December, 2005) and premonsoon-PRM (April, 2006), were analyzed for important physico-chemical attributes. Spatial and temporal variation of attributes do exist in the study area, and based on major cations and anions, different hydrochemical facies have been identified. Using Gibbs'diagram, rock dominance has been identified as the mechanism controlling groundwater chemistry. Further, the suitability of water for irrigation was determined by analyzing salinity hazard indicated by sodium adsorption ratio (SAR), residual sodium carbonate (RSC) and sodium percent (%Na). Finally, stress zones in the study area were delineated using Arc GIS spatial analysis and various management options were recommended to restore the ecosystem.
Abstract: The case study deals with the semi-quantitative risk
assessment of water resource earmarked for the emergency supply
of population with drinking water. The risk analysis has been based
on previously identified hazards/sensitivities of the elements
of hydrogeological structure and technological equipment of ground
water resource as well as on the assessment of the levels of hazard,
sensitivity and criticality of individual resource elements in the form
of point indexes. The following potential sources of hazard have
been considered: natural disasters caused by atmospheric and
geological changes, technological hazards, and environmental
burdens. The risk analysis has proved that the assessed risks are
acceptable and the water resource may be integrated into a crisis plan
of a given region.
Abstract: Burnishing is a method of finishing and hardening
machined parts by plastic deformation of the surface. Experimental
work based on central composite second order rotatable design has
been carried out on a lathe machine to establish the effects of ball
burnishing parameters on the surface roughness of brass material.
Analysis of the results by the analysis of variance technique and the
F-test show that the parameters considered, have significant effects
on the surface roughness.
Abstract: In this paper, we proposed a method for detecting consistency violation between state machine diagrams and a sequence diagram defined in UML 2.0 using SMV. We extended a method expressing these diagrams defined in UML 1.0 with boolean formulas so that it can express a sequence diagram with combined fragments introduced in UML 2.0. This extension made it possible to represent three types of combined fragment: alternative, option and parallel. As a result of experiment, we confirmed that the proposed method could detect consistency violation correctly with SMV.
Abstract: Proxy signature helps the proxy signer to sign
messages on behalf of the original signer. It is very useful when
the original signer (e.g. the president of a company) is not
available to sign a specific document. If the original signer can
not forge valid proxy signatures through impersonating the proxy
signer, it will be robust in a virtual environment; thus the original
signer can not shift any illegal action initiated by herself to the
proxy signer. In this paper, we propose a new proxy signature
scheme. The new scheme can prevent the original signer from
impersonating the proxy signer to sign messages. The proposed
scheme is based on the regular ElGamal signature. In addition,
the fair privacy of the proxy signer is maintained. That means,
the privacy of the proxy signer is preserved; and the privacy can
be revealed when it is necessary.
Abstract: This paper proposes a novel system for monitoring the
health of underground pipelines. Some of these pipelines transport
dangerous contents and any damage incurred might have catastrophic
consequences. However, most of these damage are unintentional and
usually a result of surrounding construction activities. In order to
prevent these potential damages, monitoring systems are
indispensable. This paper focuses on acoustically recognizing road
cutters since they prelude most construction activities in modern
cities. Acoustic recognition can be easily achieved by installing a
distributed computing sensor network along the pipelines and using
smart sensors to “listen" for potential threat; if there is a real threat,
raise some form of alarm. For efficient pipeline monitoring, a novel
monitoring approach is proposed. Principal Component Analysis
(PCA) was studied and applied. Eigenvalues were regarded as the
special signature that could characterize a sound sample, and were
thus used for the feature vector for sound recognition. The denoising
ability of PCA could make it robust to noise interference. One class
SVM was used for classifier. On-site experiment results show that the
proposed PCA and SVM based acoustic recognition system will be
very effective with a low tendency for raising false alarms.
Abstract: This paper presents the development of analysis tools
for Home Agriculture project. The tools are required for monitoring
the condition of greenhouse which involves two components:
measurement hardware and data analysis engine. Measurement
hardware is functioned to measure environment parameters such as
temperature, humidity, air quality, dust and etc while analysis tool is
used to analyse and interpret the integrated data against the condition
of weather, quality of health, irradiance, quality of soil and etc. The
current development of the tools is completed for off-line data
recorded technique. The data is saved in MMC and transferred via
ZigBee to Environment Data Manager (EDM) for data analysis.
EDM converts the raw data and plot three combination graphs. It has
been applied in monitoring three months data measurement for
irradiance, temperature and humidity of the greenhouse..
Abstract: This paper describes the development of a control
system model using a graphical software tool. This control system is
part of an operator training simulator developed for the National
Training Center for Operators of Ixtapantongo (CNCAOI, acronym
according to its name in Spanish language) of the Mexico-s Federal
Commission of Electricity, CFE). The Department of Simulation of
the Electrical Research Institute (IIE) developed this simulator using
as reference the Unit I of the Combined Cycle Power Plant El Sauz,
located at the centre of Mexico. The first step in the project was the
developing of the Gas Turbine System and its control system
simulator. The Turbo Gas simulator was finished and delivered to
CNCAOI in March 2007 for commercial operation. This simulator is
a high-fidelity real time dynamic simulator built and tested for
accurate operation over the entire load range. The simulator was used
primarily for operator training although it has been used for
procedure development and evaluation of plant transients.
Abstract: Ligula intestinalis is a three-host life-cycle
Pseudophyllidean Cestode which in its plerocercoid stage infests a
range of fresh water species. The objective of the present study was
the worm occurrence within planctonic copepods, fishes and
piscivorous birds and examine of parasite-hosts samples in the Lake
of Sattarkhan Dam (near the city of Ahar, East Azerbaijan, Iran).
Fish sample were collected with fyke and gill nets and the abdominal
cavity was examined for the presence of ligula. Zooplanktons were
captured using a planktonic net and occurrence of parasitic larval
form in the body cavity was determined. Piscivorous birds were
selected by telescope, they hunted and dissected for presence of
parasite eggs in their gut. Results indicated that prevalence of
infection was 16% for cyclopid copepoda and majority of infected
cyclopid were female Cyclops. Investigation of 310 fishes specimens
were indicated to infection of five species of cyprinid fishes. In
addition, results indicated to manipulation of six species of migratory
aquatic and semi aquatic birds by ligula. Obtained results are in
agreement by previous studies. Its definite in this study that all of
fishes in Sattarkhan Lake capable to infection, its important for
health because they capture by native people and it is documented
that ligula can be introduce as a zoonose. It's seemed that to prevent
from disperses of parasite and restricted of infection, biological
elimination can be effective and it's necessary to inform native
people about sanitation.
Abstract: This paper proposes a methodology for mitigating the occurrence of cascading failure in stressed power systems. The methodology is essentially based on predicting voltage instability in the power system using a voltage stability index and then devising a corrective action in order to increase the voltage stability margin. The paper starts with a brief description of the cascading failure mechanism which is probable root cause of severe blackouts. Then, the voltage instability indices are introduced in order to evaluate stability limit. The aim of the analysis is to assure that the coordination of protection, by adopting load shedding scheme, capable of enhancing performance of the system after the major location of instability is determined. Finally, the proposed method to generate instability prediction is introduced.
Abstract: In this paper, the differential quadrature method is applied to simulate natural convection in an inclined cubic cavity using velocity-vorticity formulation. The numerical capability of the present algorithm is demonstrated by application to natural convection in an inclined cubic cavity. The velocity Poisson equations, the vorticity transport equations and the energy equation are all solved as a coupled system of equations for the seven field variables consisting of three velocities, three vorticities and temperature. The coupled equations are simultaneously solved by imposing the vorticity definition at boundary without requiring the explicit specification of the vorticity boundary conditions. Test results obtained for an inclined cubic cavity with different angle of inclinations for Rayleigh number equal to 103, 104, 105 and 106 indicate that the present coupled solution algorithm could predict the benchmark results for temperature and flow fields. Thus, it is convinced that the present formulation is capable of solving coupled Navier-Stokes equations effectively and accurately.
Abstract: Natural gas is defined as gas obtained from a natural underground reservoir. It generally contains a large quantity of methane along with heavier hydrocarbons such as ethane, propane, isobutene, normal butane; also in the raw state it often contains a considerable amount of non hydrocarbons, such as nitrogen and the acid gases (carbon dioxide and hydrogen sulfide). The acid gases must be removed from natural gas before use. One of the processes witch are use in the industry to remove the acid gases from natural gas is the use of alkanolamine process. In this present paper, a simulation study for an industrial gas sweetening plant has been investigated. The aim of the study is to investigate the effect of using mixing amines as solvent on the gas treatment process using the software Hysys.
Abstract: The increasing industrialization and motorization of the world has led to a steep rise for the demand of petroleum-based fuels. Petroleum-based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain regions of the world. Therefore, those countries not having these resources are facing energy/foreign exchange crisis, mainly due to the import of crude petroleum. Hence, it is necessary to look for alternative fuels which can be produced from resources available locally within the country such as alcohol, biodiesel, vegetable oils etc. Biodiesel is a renewable, domestically produced fuel that has been shown to reduce particulate, hydrocarbon, and carbon monoxide emissions from combustion. In the present study an experimental investigation on emission characteristic of a liquid burner system operating on several percentage of biodiesel and gas oil is carried out. Samples of exhaust gas are analysed with Testo 350 Xl. The results show that biodiesel can lower some pollutant such as CO, CO2 and particulate matter emissions while NOx emission would increase in comparison with gas oil. The results indicate there may be benefits to using biodiesel in industrial processes.
Abstract: An artificial neural network (ANN) model is
presented for the prediction of kinematic viscosity of binary mixtures
of poly (ethylene glycol) (PEG) in water as a function of temperature,
number-average molecular weight and mass fraction. Kinematic
viscosities data of aqueous solutions for PEG (0.55419×10-6 –
9.875×10-6 m2/s) were obtained from the literature for a wide range
of temperatures (277.15 - 338.15 K), number-average molecular
weight (200 -10000), and mass fraction (0.0 – 1.0). A three layer
feed-forward artificial neural network was employed. This model
predicts the kinematic viscosity with a mean square error (MSE) of
0.281 and the coefficient of determination (R2) of 0.983. The results
show that the kinematic viscosity of binary mixture of PEG in water
could be successfully predicted using an artificial neural network
model.