Abstract: This analysis of Kuosheng nuclear power plant (NPP)
was performed mainly by TRACE, assisted with FRAPTRAN and
FRAPCON. SNAP v2.2.1 and TRACE v5.0p3 are used to develop the
Kuosheng NPP SPU TRACE model which can simulate the turbine
trip without bypass transient. From the analysis of TRACE, the
important parameters such as dome pressure, coolant temperature and
pressure can be determined. Through these parameters, comparing
with the criteria which were formulated by United States Nuclear
Regulatory Commission (U.S. NRC), we can determine whether the
Kuoshengnuclear power plant failed or not in the accident analysis.
However, from the data of TRACE, the fuel rods status cannot be
determined. With the information from TRACE and burn-up analysis
obtained from FRAPCON, FRAPTRAN analyzes more details about
the fuel rods in this transient. Besides, through the SNAP interface, the
data results can be presented as an animation. From the animation, the
TRACE and FRAPTRAN data can be merged together that may be
realized by the readers more easily. In this research, TRACE showed
that the maximum dome pressure of the reactor reaches to 8.32 MPa,
which is lower than the acceptance limit 9.58 MPa. Furthermore,
FRAPTRAN revels that the maximum strain is about 0.00165, which
is below the criteria 0.01. In addition, cladding enthalpy is 52.44 cal/g
which is lower than 170 cal/g specified by the USNRC NUREG-0800
Standard Review Plan.
Abstract: An experimental study has been done to investigate the flame acceleration in a closed pipe. A horizontal steel pipe, 2m long and 0.1m in diameter (L/D of 20), was used in this work. For tests with 90 degree bends, the bend had a radius of 0.1m and thus, the pipe was lengthened 1m (based on the centreline length of the segment). Ignition was affected at one end of the vessel while the other end was closed. Only stoichiometric concentration (Ф, = 1.0) of natural gas/air mixtures will be reported in this paper. It was demonstrated that bend pipe configuration gave three times higher in maximum overpressure (5.5 bars) compared to straight pipe (2.0 bars). From the results, the highest flame speed, of 63ms-1, was observed in a gas explosion with bent pipe; greater by a factor of ~3 as compared with straight pipe (23ms-1). This occurs because bending acts similar to an obstacle, in which this mechanism can induce more turbulence, initiating combustion in an unburned pocket at the corner region and causing a high mass burning rate, which increases the flame speed.
Abstract: Open burning of sugarcane fields is recognized to have a negative impact on soil by degrading its properties, especially soil organic carbon (SOC) content. Better understating the effect of open burning on soil carbon dynamics is crucial for documenting the carbon sequestration capacity of agricultural soils. In this study, experiments to investigate soil carbon stocks under burned and unburned sugarcane plantation systems in Thailand were conducted. The results showed that cultivation fields without open burning during 5 consecutive years enabled to increase the SOC content at a rate of 1.37 Mg ha-1y-1. Also it was found that sugarcane fields burning led to about 15% reduction of the total carbon stock in the 0-30 cm soil layer. The overall increase in SOC under unburned practice is mainly due to the large input of organic material through the use of sugarcane residues.
Abstract: The functional performance of machined components, often, depends on surface topography, hardness, nature of stress and strain induced on the surface, etc. Invariably, surfaces of metallic components obtained by turning, milling, etc., consist of irregularities such as machining marks are responsible for the above. Surface finishing/coating processes used to produce improved surface quality/textures are classified as chip-removal and chip-less processes. Burnishing is chip-less cold working process carried out to improve surface finish, hardness and resistance to fatigue and corrosion; not obtainable by other surface coating and surface treatment processes. It is a very simple, but effective method which improves surface characteristics and is reported to introduce compressive stresses.
Of late, considerable attention is paid to post-machining, finishing operations, such as burnishing. During burnishing the micro-irregularities start to deform plastically, initially the crests are gradually flattened and zones of reduced deformation are formed. When all the crests are deformed, the valleys between the micro-irregularities start moving in the direction of the newly formed surface. The grain structure is then condensed, producing a smoother and harder surface with superior load-carrying and wear-resistant capabilities.
Burnishing can be performed on a lathe with a highly polished ball or roller type tool which is traversed under force over a rotating/stationary work piece. Often, several passes are used to obtain the work piece surface with the desired finish and hardness.
This paper presents the findings of an experimental investigation on the effect of ball burnishing parameters such as, burnishing speed, feed, force and number of passes; on surface roughness (Ra) and micro-hardness (Hv) of a 60/40 copper/zinc alloy, using a 2-level fractional factorial design of experiments (DoE). Mathematical models were developed to predict surface roughness and hardness generated by burnishing in terms of the above process parameters. A ball-type tool, designed and constructed from a high chrome steel material (HRC=63 and Ra=0.012 µm), was used for burnishing of fine-turned cylindrical bars (0.68-0.78µm and 145Hv). They are given by,
Ra= 0.305-0.005X1 - 0.0175X2 + 0.0525X4 + 0.0125X1X4 -0.02X2X4 - 0.0375X3X4
Hv=160.625 -2.37 5X1 + 5.125X2 + 1.875X3 + 4.375X4 - 1.625X1X4 + 4.375X2X4 - 2.375X3X4
High surface microhardness (175HV) was obtained at 400rpm, 2passes, 0.05mm/rev and 15kgf., and high surface finish (0.20µm) was achieved at 30kgf, 0.1mm/rev, 112rpm and single pass. In other words, surface finish improved by 350% and microhardness improved by 21% compared to as machined conditions.
Abstract: In order to determine the performance and key design parameters of rocket, the erosion of nozzle throat during solid rocket motor burning have to be calculated. This study aims to predict the nozzle throat erosion in solid rocket motors according to the thrust profile of motor in operating conditions and develop a model for optimum performance of rocket. We investigate the throat radius change in the static test programs. The standard method and thrust coefficient are used for adjusting into the ideal performance for conical nozzles. Pressure and thrust data acquired from the tests are analyzed to determine the instantaneous nozzle throat diameter variation throughout the test duration. The result shows good agreement of calculated correlation comparing with measured erosion rate data showing agreement within 1.6 mm/s. Nozzle thrust coefficient loss is found approximately 24% form nozzle throat erosion during burning.
Abstract: The ongoing effort to develop an in-house
compressible solver with multi-disciplinary physics is presented in
this paper. Basic compressible solver combined with IBM technique
provides us an effective numerical tool able to tackle the physics
phenomena and especially physic phenomena involved in Solid
Rocket Motors (SRMs). Main principles are introduced step by step
describing its implementation. This paper sheds light on the whole
potentiality of our proposed numerical model and we strongly believe
a way to introduce multi-physics mechanisms strongly coupled is
opened to ablation in nozzle, fluid/structure interaction and burning
propellant surface with time.
Abstract: In this paper, we have presented a new multivariate fuzzy time series forecasting method. This method assumes mfactors with one main factor of interest. History of past three years is used for making new forecasts. This new method is applied in forecasting total number of car accidents in Belgium using four secondary factors. We also make comparison of our proposed method with existing methods of fuzzy time series forecasting. Experimentally, it is shown that our proposed method perform better than existing fuzzy time series forecasting methods. Practically, actuaries are interested in analysis of the patterns of causalities in road accidents. Thus using fuzzy time series, actuaries can define fuzzy premium and fuzzy underwriting of car insurance and life insurance for car insurance. National Institute of Statistics, Belgium provides region of risk classification for each road. Thus using this risk classification, we can predict premium rate and underwriting of insurance policy holders.
Abstract: Increased energy demand and the concern about
environment friendly technology, renewable bio-fuels are better
alternative to petroleum products. In the present study linseed oil was
used as alternative source for diesel engine fuel and the results were
compared with baseline data of neat diesel. Performance parameters
such as brake thermal efficiency (BTE) and brake specific fuel
consumption (BSFC) and emissions parameters such as CO,
unburned hydro carbon (UBHC), NOx, CO2 and exhaust temperature
were compared. BTE of the engine was lower and BSFC was higher
when the engine was fueled with Linseed oil compared to diesel fuel.
Emission characteristics are better than diesel fuel. NOx formation by
using linseed oil during the experiment was lower than diesel fuel.
Linseed oil is non edible oil, so it can be used as an extender of diesel
fuel energy source for small and medium energy needs.
Abstract: Hypericum perforatum L. is a member of the Hypericaceae (Guttiferae) family and commonly known as St. John’s wort. There is a growing interest in this medicinal plant because of the constituents of this genus. A number of species have been shown to possess various biological activities such as antiviral, wound healing, analgesic, hepatoprotective, antimicrobial and antioxidant activities and also have therapeutic effects on burns, bruises, swelling, anxiety and mild to moderate depression.
In this study, the aerial parts of Hypericum perforatum L. are extracted and the main and effective constituents are determined. The analysis of the extracts was performed by GC-MS and LC-MS. As a next step, it is aimed to investigate the usage of the main constituents of the medicinal plant.
Abstract: High-velocity oxygen fuel (HVOF) thermal spraying
uses a combustion process to heat the gas flow and coating material.
A computational fluid dynamics (CFD) model has been developed to
predict gas dynamic behavior in a HVOF thermal spray gun in which
premixed oxygen and propane are burnt in a combustion chamber
linked to a parallel-sided nozzle. The CFD analysis is applied to
investigate axisymmetric, steady-state, turbulent, compressible,
chemically reacting, subsonic and supersonic flow inside and outside
the gun. The gas velocity, temperature, pressure and Mach number
distributions are presented for various locations inside and outside
the gun. The calculated results show that the most sensitive
parameters affecting the process are fuel-to-oxygen gas ratio and
total gas flow rate. Gas dynamic behavior along the centerline of the
gun depends on both total gas flow rate and fuel-to-oxygen gas ratio.
The numerical simulations show that the axial gas velocity and Mach
number distribution depend on both flow rate and ratio; the highest
velocity is achieved at the higher flow rate and most fuel-rich ratio.
In addition, the results reported in this paper illustrate that the
numerical simulation can be one of the most powerful and beneficial
tools for the HVOF system design, optimization and performance
analysis.
Abstract: The presented work is motivated by a French law
regarding nuclear waste management. A new conceptual Accelerator
Driven System (ADS) designed for the Minor Actinides (MA)
transmutation has been assessed by numerical simulation. The
MUltiple Spallation Target (MUST) ADS combines high thermal power (up to 1.4 GWth) and high specific power. A 30 mA and 1
GeV proton beam is divided into three secondary beams transmitted on three liquid lead-bismuth spallation targets. Neutron and thermalhydraulic
simulations have been performed with the code MURE, based on the Monte-Carlo transport code MCNPX. A methodology has been developed to define characteristic of the MUST ADS concept according to a specific transmutation scenario. The reference
scenario is based on a MA flux (neptunium, americium and curium)
providing from European Fast Reactor (EPR) and a plutonium multireprocessing
strategy is accounted for. The MUST ADS reference
concept is a sodium cooled fast reactor. The MA fuel at equilibrium is mixed with MgO inert matrix to limit the core reactivity and
improve the fuel thermal conductivity. The fuel is irradiated over five
years. Five years of cooling and two years for the fuel fabrication are
taken into account. The MUST ADS reference concept burns about 50% of the initial MA inventory during a complete cycle. In term of
mass, up to 570 kg/year are transmuted in one concept. The methodology to design the MUST ADS and to calculate fuel
composition at equilibrium is precisely described in the paper. A detailed fuel evolution analysis is performed and the reference scenario is compared to a scenario where only americium transmutation is performed.
Abstract: Nowadays, the importance of energy saving is clearance to everyone. By attention to increasing price of fuels and also the problems of environment pollutions, there are the most efforts for using fuels littler and more optimum in everywhere. This essay studies optimizing of gas consumption in gas-burner space heaters. In oven of each gas-burner space heaters there is two snags to prevent the hot air (the result of combustion of natural gas) to go out of oven of the gas-burner space heaters directly without delivering its heat to the space of favorite environment like a room. These snags cause a excess circulating that helps hot air deliver its heat to the space of favorite environment. It means the exhaust air temperature will be decreased then when there are no snags. This is the aim of this essay to use maximum potential energy of the natural gas to make heat. In this study, by the help of a finite volume software (FLUENT) consumption of the gas-burner space heaters is simulated and optimized. At the end of this writing, by comparing the results of software and experimental results, it will be proved the authenticity of this method.
Abstract: Palm methyl ester (PME) is one of the alternative
biomass fuels to liquid fossil fuels. To investigate the combustion
characteristics of PME as an alternative fuel for gas turbines, combustion experiments using two types of burners under atmospheric
pressure were performed. One of the burners has a configuration
making strong non-premixed flame, whereas the other has a
configuration promoting prevaporization of fuel droplets. The results
show that the NOx emissions can be reduced by employing the latter burner without accumulation of soot when PME is used as a fuel. A
burner configuration promoting prevaporzation of fuel droplets is
recommended for PME.
Abstract: This study focuses on emission of black carbon (BC)
from field open burning of corn residues. Real-time BC
concentration was measured by Micro Aethalometer from field
burning and simulated open burning in a chamber (SOC)
experiments. The average concentration of BC was 1.18±0.47 mg/m3
in the field and 0.89±0.63 mg/m3 in the SOC. The deduced emission
factor from field experiments was 0.50±0.20 gBC/kgdm, and 0.56±0.33
gBC/kgdm from SOC experiment, which are in good agreement with
other studies. In 2007, the total burned area of corn crop was 8,000
ha, resulting in an emission load of BC 20 ton corresponding to 44.5
million kg CO2 equivalent. Therefore, the control of open burning in
corn field represents a significant global warming reduction option.
Abstract: In recent years in Kazakhstan, as well as in all countries, we have been talking not only about the professional stress, but also professional Burnout Syndrome of employees. Burnout is essentially a response to chronic emotional stress – manifests itself in the form of chronic fatigue, despondency, unmotivated aggression, anger, and others. This condition is due to mental fatigue among teachers as a sort of payment for overstrain when professional commitments include the impact of “heat your soul", emotional investment. The emergence of professional Burnout among teachers is due to the system of interrelated and mutually reinforcing factors relating to the various levels of the personality: individually-psychological level is psychodynamic special subject characteristics of valuemotivational sphere and formation of skills and habits of selfregulation; the socio-psychological level includes especially the Organization and interpersonal interaction of a teacher. Signs of the Burnout were observed in 15 testees, and virtually a symptom could be observed in every teacher. As a result of the diagnosis 48% of teachers had the signs of stress (phase syndrome), resulting in a sense of anxiety, mood, heightened emotional susceptibility. The following results have also been got:-the fall of General energy potential – 14 pers. -Psychosomatic and psycho vegetative syndrome – 26 pers. -emotional deficit-34 pers. -emotional Burnout Syndrome-6 pers. The problem of professional Burnout of teachers in the current conditions should become not only meaningful, but particularly relevant. The quality of education of the younger generation depends on professional development; teachers- training level, and how “healthy" teachers are. That is why the systematic maintenance of pedagogic-professional development for teachers (including disclosure of professional Burnout Syndrome factors) takes on a special meaning.
Abstract: Time series models have been used to make predictions of academic enrollments, weather, road accident, casualties and stock prices, etc. Based on the concepts of quartile regression models, we have developed a simple time variant quantile based fuzzy time series forecasting method. The proposed method bases the forecast using prediction of future trend of the data. In place of actual quantiles of the data at each point, we have converted the statistical concept into fuzzy concept by using fuzzy quantiles using fuzzy membership function ensemble. We have given a fuzzy metric to use the trend forecast and calculate the future value. The proposed model is applied for TAIFEX forecasting. It is shown that proposed method work best as compared to other models when compared with respect to model complexity and forecasting accuracy.
Abstract: The present project was conducted with the
circumferential-fuel-jets inverse diffusion flame (CIDF) burner
burning liquefied petroleum gas (LPG) enriched with 50% of
hydrogen fuel (H2). The range of stable operation of the CIDF burner
in terms of Reynolds number (from laminar to turbulent flow regions),
equivalence ratio and fuel jet velocity of LPG of the 50% H2-LPG
mixed fuel was identified. Experiments were also carried out to
investigate the flame structures of the LPG flame and LPG enriched H2
flame. Experimental results obtained from these two flames were
compared to fully explore the influence of hydrogen addition on flame
stability. Flame heights obtained by burning these two kinds of fuels at
various equivalence ratios were compared and correlated with the
Global Momentum Ratio (GMR).
Abstract: Numerical studies have been carried out using a two
dimensional code to examine the influence of pressure / thrust
transient of solid propellant rockets at liftoff. This code solves
unsteady Reynolds-averaged thin-layer Navier–Stokes equations by
an implicit LU-factorization time-integration method. The results
from the parametric study indicate that when the port is narrow there
is a possibility of increase in pressure / thrust-rise rate due to
relatively high flame spread rate. Parametric studies further reveal
that flame spread rate can be altered by altering the propellant
properties, igniter jet characteristics and nozzle closure burst pressure
without altering the grain configuration and/or the mission
demanding thrust transient. We observed that when the igniter
turbulent intensity is relatively low the vehicle could liftoff early due
to the early flow choking of the rocket nozzle. We concluded that the
high pressurization-rate has structural implications at liftoff in
addition to transient burning effect. Therefore prudent selection of the
port geometry and the igniter, for meeting the mission requirements,
within the given envelop are meaningful objectives for any designer
for the smooth liftoff of solid propellant rockets.
Abstract: A mathematical model based on a mass and energy
balance for the combustion in a cement rotary kiln was developed.
The model was used to investigate the impact of replacing about
45 % of the primary coal energy by different alternative fuels.
Refuse derived fuel, waste wood, solid hazardous waste and liquid
hazardous waste were used in the modeling. The results showed that
in order to keep the kiln temperature unchanged, and thereby
maintain the required clinker quality, the production capacity had to
be reduced by 1-15 %, depending on the fuel type. The reason for the
reduction is increased exhaust gas flow rates caused by the fuel
characteristics. The model, which has been successfully validated in a
full-scale experiment, was also used to show that the negative impact
on the production capacity can be avoided if a relatively small part of
the combustion air is replaced by pure oxygen.
Abstract: Generation of electricity from coal has increased over
the years in the United States and around the world. Burning of coal
results in annual production of upwards of 100 millions tons (United
States only) of coal combustion products (CCPs). Only about a third
of these products are being used to create new products while the
remainder goes to landfills. Application of CCPs mixed with
composted organic materials onto soil can improve the soil-s
physico-chemical conditions and provide essential plant nutritients.
Our objective was to create plant growth media utilizing CCPs and
compost in way which maximizes the use of these products and, at
the same time, maintain good plant growth. Media were formulated
by adding composted organic matter (COM) to CCPs at ratios
ranging from 2:8 to 8:2 (v/v). The quality of these media was
evaluated by measuring their physical and chemical properties and
their effect on plant growth. We tested the media by 1) measuring
their physical and chemical properties and 2) the growth of three
plant species in the experimental media: wheat (Triticum sativum),
tomato (Lycopersicum esculentum) and marigold (Tagetes patula).
We achieved significantly (p < 0.001) higher growth (7-130%) in the
experimental media containing CCPs compared to a commercial mix.
The experimental media supplied adequate plant nutrition as no
fertilization was provided during the experiment. Based on the
results, we recommend the use of CCPs and composts for the
creation of plant growth media.