Abstract: Hydrogen is an important chemical in many industries and it is expected to become one of the major fuels for energy generation in the future. Unfortunately, hydrogen does not exist in its elemental form in nature and therefore has to be produced from hydrocarbons, hydrogen-containing compounds or water.
Above its critical point (374.8oC and 22.1MPa), water has lower density and viscosity, and a higher heat capacity than those of ambient water. Mass transfer in supercritical water (SCW) is enhanced due to its increased diffusivity and transport ability. The reduced dielectric constant makes supercritical water a better solvent for organic compounds and gases. Hence, due to the aforementioned desirable properties, there is a growing interest toward studies regarding the gasification of organic matter containing biomass or model biomass solutions in supercritical water.
In this study, hydrogen and biofuel production by the catalytic gasification of 2-Propanol in supercritical conditions of water was investigated. Ru/Al2O3 was the catalyst used in the gasification reactions. All of the experiments were performed under a constant pressure of 25 MPa. The effects of five reaction temperatures (400, 450, 500, 550 and 600oC) and five reaction times (10, 15, 20, 25 and 30 s) on the gasification yield and flammable component content were investigated.
Abstract: In this article we research on the drivers’ behavior at intersections. Some significant behaviors are chosen and designed a questionnaire which was about 2 pages. In this questionnaire, samples were being asked to answer by checking the box. The answers have been from always to never. This questionnaire related to our selection’s behaviors. Finally it has been resulted that most of aggressive behaviors were being common in them. Also it has been suggested some solutions for each of them.
Abstract: In this paper, we present some formulas of symbolic operator summation, which involving Generalization well-know number sequences or polynomial sequences, and mean while we obtain some identities about the sequences by employing M-R‘s substitution rule.
Abstract: Nowadays, in most radiotherapy departments, the commercial treatment planning systems (TPS) used to calculate dose distributions needs to be verified; therefore, quick, easy-to-use and low cost dose distribution algorithms are desirable to test and verify the performance of the TPS. In this paper, we put forth an analytical method to calculate the phantom scatter contribution and depth dose on the central axis based on the equivalent square concept. Then, this method was generalized to calculate the profiles at any depth and for several field shapes regular or irregular fields under symmetry and asymmetry photon beam conditions. Varian 2100 C/D and Siemens Primus Plus Linacs with 6 and 18 MV photon beam were used for irradiations. Percentage depth doses (PDDs) were measured for a large number of square fields for both energies, and for 45º wedges which were employed to obtain the profiles in any depth. To assess the accuracy of the calculated profiles, several profile measurements were carried out for some treatment fields. The calculated and measured profiles were compared by gamma-index calculation. All γ–index calculations were based on a 3% dose criterion and a 3 mm dose-to-agreement (DTA) acceptance criterion. The γ values were less than 1 at most points. However, the maximum γ observed was about 1.10 in the penumbra region in most fields and in the central area for the asymmetric fields. This analytical approach provides a generally quick and fairly accurate algorithm to calculate dose distribution for some treatment fields in conventional radiotherapy.
Abstract: The purpose of this paper is to simulate the production process of a metal stamping industry and to evaluate the utilization of the production line by using ARENA simulation software. The process time and the standard time for each process of the production line is obtained from data given by the company management. Other data are collected through direct observation of the line. There are three work stations performing ten different types of processes in order to produce a single product type. Arena simulation model is then developed based on the collected data. Verification and validation are done to the Arena model, and finally the result of Arena simulation can be analyzed. It is found that utilization at each workstation will increase if batch size is increased although throughput rate remains/is kept constant. This study is very useful for the company because the company needs to improve the efficiency and utilization of its production lines.
Abstract: The aim of the study is evaluation of absorbed doses for thyroids by using neck phantoms. For this purpose, it was arranged the irradiation set with different phantoms. Three different materials were used for phantom materials as, water, parafine and wood. The phantoms were three different dimensions for simulation of different ages and human race for each material. Co-60 gammao source was used for irradiation and the experimental procedure applied rigorously with narrow beam geometry. As the results of the experiments the relative radiation doses are evaluated for therapic applications for thyroids and backscattering factors were calculated and shown that water, parafine and wood can appropriate for phantom material with the converge values of backscattering factors.
Abstract: Hydrogen fuel is a zero-emission fuel which uses electrochemical cells or combustion in internal engines, to power vehicles and electric devices. Methods of hydrogen storage for subsequent use span many approaches, including high pressures, cryogenics and chemical compounds that reversibly release H2 upon heating. Most research into hydrogen storage is focused on storing hydrogen as a lightweight, compact energy carrier for mobile applications. With the accelerating demand for cleaner and more efficient energy sources, hydrogen research has attracted more attention in the scientific community. Until now, full implementation of a hydrogen-based energy system has been hindered in part by the challenge of storing hydrogen gas, especially onboard an automobile. New techniques being researched may soon make hydrogen storage more compact, safe and efficient. In this overview, few hydrogen storage methods and mechanism of hydrogen uptake in carbon nanotubes are summarized.
Abstract: In this paper, an energy efficient digital baseband circuit for piezoelectric (PE) harvester powered batteryless remote control system is presented. Pulse mode PE harvester, which provides short duration of energy, is adopted to replace conventional chemical battery in wireless remote controller. The transmitter digital baseband repeats the control command transmission once the digital circuit is initiated by the power-on-reset. A power efficient data frame format is proposed to maximize the transmission repetition time. By using the proposed frame format and receiver clock and data recovery method, the receiver baseband is able to decode the command even when the received data has 20% error. The proposed transmitter and receiver baseband are implemented using FPGA and simulation results are presented.
Abstract: This experiment aims to demonstrate the efficacy of ceramic powder derived from various sources to inactivate avian influenza virus and its possibility to use in the environment. The ceramics used in the present experiment were derived from chicken feces (CF), scallop shell (SS), polyvinyl chloride (PVC) and soybean (SB). All ceramics were mixed with low pathogenic AIV (LPAIV) H7N1, and then kept at room temperature. The recovered virus was titrated onto Madin-Darby canine kidney (MDCK) cells. All ceramics were assessed the inactivation stability in the environment by keeping under sunlight and under wet-dry condition until reached 7 week or 7 resuspension times respectively. The results indicate that all ceramics have excellent efficacy to inactivate LPAIV. This efficacy can be maintained under the simulated condition. The ceramics are expected to be the good materials for application in the biosecurity system at farms.
Abstract: Different vegetable oil based biodiesel (FAMES) were prepared by alkaline transesterification using refined oils as well as waste frying oil (WFO). Methanol and sodium hydroxide are used as catalyst under similar reaction conditions. To ensure the quality of biodiesel produced, a series of different ASTM Standard tests were carried out. In this context, various testwere done including viscosity, carbon residue, specific gravity, corrosion test, flash point, cloud point and pour point. Results revealed that characteristics of biodiesel depend on the feedstock and it is far better than petroleum diesel.
Abstract: This study presents a new method for detecting the
cutting tool wear based on the measured cutting force signals using
the regression model and I-kaz method. The detection of tool wear
was done automatically using the in-house developed regression
model and 3D graphic presentation of I-kaz 3D coefficient during
machining process. The machining tests were carried out on a CNC
turning machine Colchester Master Tornado T4 in dry cutting
condition, and Kistler 9255B dynamometer was used to measure the
cutting force signals, which then stored and displayed in the DasyLab
software. The progression of the cutting tool flank wear land (VB)
was indicated by the amount of the cutting force generated. Later, the
I-kaz was used to analyze all the cutting force signals from beginning
of the cut until the rejection stage of the cutting tool. Results of the IKaz
analysis were represented by various characteristic of I-kaz 3D
coefficient and 3D graphic presentation. The I-kaz 3D coefficient
number decreases when the tool wear increases. This method can be
used for real time tool wear monitoring.
Abstract: We have investigated statistical properties of the defect turbulence in 1D CGLE wherein many body interaction is involved between local depressing wave (LDW) and local standing wave (LSW). It is shown that the counting number fluctuation of LDW is subject to the sub-Poisson statistics (SUBP). The physical origin of the SUBP can be ascribed to pair extinction of LDWs based on the master equation approach. It is also shown that the probability density function (pdf) of inter-LDW distance can be identified by the hyper gamma distribution. Assuming a superstatistics of the exponential distribution (Poisson configuration), a plausible explanation is given. It is shown further that the pdf of amplitude of LDW has a fattail. The underlying mechanism of its fluctuation is examined by introducing a generalized fractional Poisson configuration.
Abstract: In order to Study the efficacy application of green
manure as chickpea pre plant, field experiments were carried out in
2007 and 2008 growing seasons. In this research the effects of
different strategies for soil fertilization were investigated on grain
yield and yield component, minerals, organic compounds and
cooking time of chickpea. Experimental units were arranged in splitsplit
plots based on randomized complete blocks with three
replications. Main plots consisted of (G1): establishing a mixed
vegetation of Vicia panunica and Hordeum vulgare and (G2):
control, as green manure levels. Also, five strategies for obtaining the
base fertilizer requirement including (N1): 20 t.ha-1 farmyard manure;
(N2): 10 t.ha-1 compost; (N3): 75 kg.ha-1 triple super phosphate;
(N4): 10 t.ha-1 farmyard manure + 5 t.ha-1 compost and (N5): 10 t.ha-1
farmyard manure + 5 t.ha-1 compost + 50 kg.ha-1 triple super
phosphate were considered in sub plots. Furthermoree four levels of
biofertilizers consisted of (B1): Bacillus lentus + Pseudomonas
putida; (B2): Trichoderma harzianum; (B3): Bacillus lentus +
Pseudomonas putida + Trichoderma harzianum; and (B4): control
(without biofertilizers) were arranged in sub-sub plots. Results
showed that integrating biofertilizers (B3) and green manure (G1)
produced the highest grain yield. The highest amounts of yield were
obtained in G1×N5 interaction. Comparison of all 2-way and 3-way
interactions showed that G1N5B3 was determined as the superior
treatment. Significant increasing of N, P2O5, K2O, Fe and Mg content
in leaves and grains emphasized on superiority of mentioned
treatment because each one of these nutrients has an approved role in
chlorophyll synthesis and photosynthesis abilities of the crops. The
combined application of compost, farmyard manure and chemical
phosphorus (N5) in addition to having the highest yield, had the best
grain quality due to high protein, starch and total sugar contents, low
crude fiber and reduced cooking time.
Abstract: An accurate prediction of the minimum fluidization
velocity is a crucial hydrodynamic aspect of the design of fluidized
bed reactors. Common approaches for the prediction of the minimum
fluidization velocities of binary-solid fluidized beds are first
discussed here. The data of our own careful experimental
investigation involving a binary-solid pair fluidized with water is
presented. The effect of the relative composition of the two solid
species comprising the fluidized bed on the bed void fraction at the
incipient fluidization condition is reported and its influence on the
minimum fluidization velocity is discussed. In this connection, the
capability of packing models to predict the bed void fraction is also
examined.
Abstract: One of the major features of hypermedia learning is its non-linear structure, allowing learners, the opportunity of flexible navigation to accommodate their own needs. Nevertheless, such flexibility can also cause problems such as insufficient navigation and disorientation for some learners, especially those with Field Dependent cognitive styles. As a result students learning performance can be deteriorated and in turn, they can have negative attitudes with hypermedia learning systems. It was suggested that visual elements can be used to compensate dilemmas. However, it is unclear whether these visual elements improve their learning or whether problems still exist. The aim of this study is to investigate the effect of students cognitive styles and visual elements on students learning performance and attitudes in hypermedia learning environment. Cognitive Style Analysis (CSA), Learning outcome in terms of pre and post-test, practical task, and Attitude Questionnaire (AQ) were administered to a sample of 60 university students. The findings revealed that FD students preformed equally to those of FI. Also, FD students experienced more disorientation in the hypermedia learning system where they depend a lot on the visual elements for navigation and orientation purposes. Furthermore, they had more positive attitudes towards the visual elements which escape them from experiencing navigation and disorientation dilemmas. In contrast, FI students were more comfortable, did not get disturbed or did not need some of the visual elements in the hypermedia learning system.
Abstract: A numerical study on the effect of side-dump angle on
fuel droplets sizing and effective mass fraction have been
investigated in present paper. The mass of fuel vapor inside the
flammability limit is named as the effective mass fraction. In the first
step we have considered a side-dump combustor with dump angle of
0o (acrossthe cylinder) and by increasing the entrance airflow velocity
from 20 to 30, 40 and 50 (m/s) respectively, the mean diameter of
fuel droplets sizing and effective mass fraction have been studied.
After this step, we have changed the dump angle from 0o to 30o,45o
and finally 60o in direction of cylinderand also we have increased the
entrance airflow velocity from 20 up to 50 (m/s) with the amount of
growth of 10(m/s) in each step, to examine its effects on fuel droplets
sizing as well as effective mass fraction. With rise of entrance airflow
velocity, these calculations are repeated in each step too. The results
show, with growth of dump-angle the effective mass fraction has
been decreased and the mean diameter of droplets sizing has been
increased. To fulfill the calculations a modified version of KIVA-3V
code which is a transient, three-dimensional, multiphase,
multicomponent code for the analysis of chemically reacting flows
with sprays, is used.
Abstract: In this article, we are dealing with a model consisting of a classical Van der Pol oscillator coupled gyroscopically to a linear oscillator. The major problem is analyzed. The regular dynamics of the system is considered using analytical methods. In this case, we provide an approximate solution for this system using parameter-expansion method. Also, we find approximate values for frequencies of the system. In parameter-expansion method the solution and unknown frequency of oscillation are expanded in a series by a bookkeeping parameter. By imposing the non-secularity condition at each order in the expansion the method provides different approximations to both the solution and the frequency of oscillation. One iteration step provides an approximate solution which is valid for the whole solution domain.
Abstract: The conventional assessment of human semen is a
highly subjective assessment, with considerable intra- and interlaboratory
variability. Computer-Assisted Sperm Analysis (CASA)
systems provide a rapid and automated assessment of the sperm
characteristics, together with improved standardization and quality
control. However, the outcome of CASA systems is sensitive to the
method of experimentation. While conventional CASA systems use
digital microscopes with phase-contrast accessories, producing
higher contrast images, we have used raw semen samples (no
staining materials) and a regular light microscope, with a digital
camera directly attached to its eyepiece, to insure cost benefits and
simple assembling of the system. However, since the accurate finding
of sperms in the semen image is the first step in the examination and
analysis of the semen, any error in this step can affect the outcome of
the analysis. This article introduces and explains an algorithm for
finding sperms in low contrast images: First, an image enhancement
algorithm is applied to remove extra particles from the image. Then,
the foreground particles (including sperms and round cells) are
segmented form the background. Finally, based on certain features
and criteria, sperms are separated from other cells.
Abstract: Biometrics, which refers to identifying an individual
based on his or her physiological or behavioral characteristics, has
the capability to reliably distinguish between an authorized person
and an imposter. Signature verification systems can be categorized as
offline (static) and online (dynamic). This paper presents a neural
network based recognition of offline handwritten signatures system
that is trained with low-resolution scanned signature images.
Abstract: Debates on residential satisfaction topic have been
vigorously discussed in family house setting. Nonetheless, less or
lack of attention was given to survey on student residential
satisfaction in the campus house setting. This study, however, tried to
fill in the gap by focusing more on the relationship between students-
socio-economic backgrounds and student residential satisfaction with
their on-campus student housing facilities. Two-stage cluster
sampling method was employed to classify the respondents. Then,
self-administered questionnaires were distributed face-to-face to the
students. In general, it was confirmed that the students- socioeconomic
backgrounds have significantly influence the students-
satisfaction with their on-campus student housing facilities. The main
influential factors were revealed as the economic status, sense of
sharing, and the ethnicity of roommates. Likewise, this study could
also provide some useful feedback for the universities administration
in order to improve their student housing facilities.