Abstract: This paper aims at to develop a robust optimization methodology for the mechatronic modules of machine tools by considering all important characteristics from all structural and control domains in one single process. The relationship between these two domains is strongly coupled. In order to reduce the disturbance caused by parameters in either one, the mechanical and controller design domains need to be integrated. Therefore, the concurrent integrated design method Design For Control (DFC), will be employed in this paper. In this connect, it is not only applied to achieve minimal power consumption but also enhance structural performance and system response at same time. To investigate the method for integrated optimization, a mechatronic feed drive system of the machine tools is used as a design platform. Pro/Engineer and AnSys are first used to build the 3D model to analyze and design structure parameters such as elastic deformation, nature frequency and component size, based on their effects and sensitivities to the structure. In addition, the robust controller,based on Quantitative Feedback Theory (QFT), will be applied to determine proper control parameters for the controller. Therefore, overall physical properties of the machine tool will be obtained in the initial stage. Finally, the technology of design for control will be carried out to modify the structural and control parameters to achieve overall system performance. Hence, the corresponding productivity is expected to be greatly improved.
Abstract: The objective of the research was to evaluate the
quality of milk pomade sweet – sherbet packed in different packaging
materials (Multibarrier 60, met.BOPET/PE, Aluthen), by several
packaging technologies – active and modified atmosphere (MAP)
(consisting of 100% CO2), and control – in air ambiance.
Experiments were carried out at the Faculty of Food Technology of
Latvia University of Agriculture. Samples were stored at the room
temperature +21±1 °C. The physiochemical properties – weight
losses, moisture, hardening, colour and changes in headspace
atmosphere concentration (CO2 and O2) of packs were analysed
before packaging and after 2, 4, 6, 8, 10 and 12 storage weeks.
Abstract: In order to study the effect of plant density and
competition of wheat with field bindweed (Convolvulus arvensis) on
yield and agronomical properties of wheat(Triticum Sativum) in
irrigated conditions, a factorial experiment as the base of complete
randomize block design in three replication was conducted at the
field of Kamalvand in khoramabad (Lorestan) region of Iran during
2008-2009. Three plant density (Factor A=200, 230 and 260kg/ha)
three cultivar (Factor B=Bahar,Pishtaz and Alvand) and weed control
(Factor C= control and no control of weeds)were assigned in
experiment. Results show that: Plant density had significant effect
(statistically) on seed yield, 1000 seed weight, weed density and dry
weight of weeds, seed yield and harvest index had been meaningful
effect for cultivars. The interaction between plant density and
cultivars for weed density, seed yield, thousand seed weight and
harvest index were significant. 260 kg/ha (plant density) of wheat had
more effect on increasing of seed yield in Bahar cultivar wheat in
khoramabad region of Iran.
Abstract: In recent years, Radio Frequency Identification (RFID)
is followed with interest by many researches, especially for the
purpose of indoor positioning as the innate properties of RFID are
profitable for achieving it. A lot of algorithms or schemes are proposed
to be used in the RFID-based positioning system, but most of them are
lack of environmental consideration and it induces inaccuracy of
application. In this research, a lot of algorithms and schemes of RFID
indoor positioning are discussed to see whether effective or not on
application, and some rules are summarized for achieving accurate
positioning. On the other hand, a new term “Noise Factor" is involved
to describe the signal loss between the target and the obstacle. As a
result, experimental data can be obtained but not only simulation; and
the performance of the positioning system can be expressed
substantially.
Abstract: Meat and meat products for human consumption are one of main sources of protein, amino acids, fatty acids, vitamins, and minerals. Popular variety of meat product is meatballs, which can be enriched with valuable product – Jerusalem artichoke powder, made from dried and grinded Jerusalem artichoke tubers, it is raw material with low-calorie, low fat, rich in dietary fibres, minerals, and vitamins. The results of this study indicate that that people could accept the new product - meatballs with Jerusalem artichoke powder and Jerusalem artichoke powder is suitable for meatballs preparation, in result them is possible to improve meatballs sensory and physical properties.
Abstract: Swedish truck industry is investigating the possibility
for implementing the use of Compacted Graphite Iron (CGI) in their
heavy duty diesel engines. Compared to the alloyed gray iron used
today, CGI has superior mechanical properties but not as good
machinability. Another issue that needs to be addressed when
implementing CGI is the inhomogeneous microstructure when the
cast component has different section thicknesses, as in cylinder
blocks. Thinner sections results in finer pearlite, in the material, with
higher strength. Therefore an investigation on its influence on
machinability was needed. This paper focuses on the effect that
interlamellar distance in pearlite has on CGI machinability and
material physical properties. The effect of pearlite content and
nodularity is also examined. The results showed that interlamellar
distance in pearlite did not have as large effect on the material
physical properties or machinability as pearlite content. The paper
also shows the difficulties of obtaining a homogeneous
microstructure in inhomogeneous workpieces.
Abstract: Indium-tin oxide films are deposited by low plasma
temperature RF sputtering on highly flexible modification of glycol
polyethyleneterephtalate substrates. The produced layers are
characterized with transparency over 82 % and sheet resistance of
86.9 Ω/square. The film’s conductivity was further improved by
additional UV illumination from light source (365 nm), having power
of 250 W. The influence of the UV exposure dose on the structural
and electro-optical properties of ITO was investigated. It was
established that the optimum time of illumination is 10 minutes and
further UV treatment leads to polymer substrates degradation.
Structural and bonds type analysis show that at longer treatment
carbon atoms release and diffuse into ITO films, which worsen their
electrical behavior. For the optimum UV dose the minimum sheet
resistance was measured to be 19.2 Ω/square, and the maximum
transparency remained almost unchanged – above 82 %.
Abstract: In the article there have been revealed the properties
of designing the research teaching the military masters and in the context it has been offered the program of mastering by the masters
military men the methodology of research work, in the course of practical teaching activity there has been considered the developed
and approbated model of organization of the process of mastering by the masters the methodology of research work. As a whole, the research direction of master preparation leaves its
sign to the content of education, forms of organization of educational
process, scientific work of masters. In this connection the offered in
the article properties of organization of research teaching and a model
of organization of mastering by the masters military men the methodology of research work can be taken into account when
designing the content of master preparation.
Abstract: In this study, it is investigated the stability boundary of
Functionally Graded (FG) panel under the heats and supersonic
airflows. Material properties are assumed to be temperature
dependent, and a simple power law distribution is taken. First-order
shear deformation theory (FSDT) of plate is applied to model the
panel, and the von-Karman strain- displacement relations are
adopted to consider the geometric nonlinearity due to large
deformation. Further, the first-order piston theory is used to model the
supersonic aerodynamic load acting on a panel and Rayleigh damping
coefficient is used to present the structural damping. In order to find a
critical value of the speed, linear flutter analysis of FG panels is
performed. Numerical results are compared with the previous works,
and present results for the temperature dependent material are
discussed in detail for stability boundary of the panel with various
volume fractions, and aerodynamic pressures.
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: Noble metal participation in nanostructured
semiconductor catalysts has drawn much interest because of their
improved properties. Recently, it has been discussed by many
researchers that Ag participation in TiO2, CuO, ZnO semiconductors
showed improved photocatalytic and optical properties. In this
research, Ag/ZnO nanocomposite particles were prepared by
Ultrasonic Spray Pyrolysis(USP) Method. 0.1M silver and zinc
nitrate aqueous solutions were used as precursor solutions. The
Ag:Zn atomic ratio of the solution was selected 1:1. Experiments
were taken place under constant air flow of 400 mL/min at 800°C
furnace temperature. Particles were characterized by X-Ray
Diffraction (XRD), Scanning Electron Microscope (SEM) and
Energy Dispersive Spectroscopy (EDS). The crystallite sizes of Ag
and ZnO in composite particles are 24.6 nm, 19.7 nm respectively.
Although, spherical nanocomposite particles are in a range of 300-
800 nm, these particles are formed by the aggregation of primary
particles which are in a range of 20-60 nm.
Abstract: Bangla Vowel characterization determines the spectral properties of Bangla vowels for efficient synthesis as well as recognition of Bangla vowels. In this paper, Bangla vowels in isolated word have been analyzed based on speech production model within the framework of Analysis-by-Synthesis. This has led to the extraction of spectral parameters for the production model in order to produce different Bangla vowel sounds. The real and synthetic spectra are compared and a weighted square error has been computed along with the error in the formant bandwidths for efficient representation of Bangla vowels. The extracted features produced good representation of targeted Bangla vowel. Such a representation also plays essential role in low bit rate speech coding and vocoders.
Abstract: This study investigated the effect of germination on chemical compositions, physio-chemical properties of malted (germinated) red sorghum flours and evaluated characteristics of gluten free breads from sorghum flour. Results showed that germinated sorghum flour had higher amylase activity, swelling power and solubility at 95°C, but lower in the peak, break down, final and set back viscosities than ungerminated sample (p≤0.05). Five gluten free breads made from sorghum flour blends, with different ratios of ungerminated and germinated sorghum flour, were compared for the physical properties with those made from wheat flour. Crumb hardness, cohesiveness, gumminess and chewiness of sorghum breads were found significantly higher than those of wheat bread. With increasing of ungerminated flour proportion, the bread hardness increased while the cohesiveness declined. Sorghum breads appeared red to human eyes with a*values of 10.41-15.77.Their crust and crumb colors differed significantly from those of wheat bread.
Abstract: Biomechanical properties of infantile aorta in vitro in
cases of different standard anastomoses: end-to-end (ETE), extended
anastomosis end-to-end (EETE) and subclavian flap aortoplasty
(SFA) used for surgical correction of coarctation were analyzed to
detect the influence of the method on the biomechanics of infantile
aorta and possible changes in haemodinamics. 10 specimens of native
aorta, 3 specimens with ETE, 4 EEET and 3 SFA were investigated.
The experiments showed a non-linear relationship between stress and
strain in the infantile aorta, the modulus of elasticity of the aortic wall
increased with the increase of inner pressure. In the case of
anastomosis end-to-end the modulus was almost constant, relevant to
the modulus of elasticity of the aorta with the inner pressure 100-120
mmHg. The anastomoses EETE and SFA showed elastic properties
closer to native aorta, the stiffness of ETE did not change with the
changes in inner pressure.
Abstract: This paper presents the experimental results of the
investigation of various properties related to the durability and longterm
performance of mortars made of Fly Ash blended cement, FA
and Ordinary Portland cement, OPC. The properties that were
investigated in an experimental program include; equilibration of
specimen in different relative humidity, determination of total
porosity, compressive strength, chloride permeability index, and
electrical resistivity. Fly Ash blended cement mortar specimens
exhibited 10% to 15% lower porosity when measured at equilibrium
conditions in different relative humidities as compared to the
specimens made of OPC mortar, which resulted in 6% to 8% higher
compressive strength of FA blended cement mortar specimens. The
effects of ambient relative humidity during sample equilibration on
porosity and strength development were also studied. For specimens
equilibrated in higher relative humidity conditions, such as 75%, the
total porosity of different mortar specimens was between 35% to 50%
less than the porosity of samples equilibrated in 12% relative
humidity, consequently leading to higher compressive strengths of
these specimens.A valid statistical correlation between values of
compressive strength, porosity and the degree of saturation was
obtained. Measured values of chloride permeability index of fly ash
blended cement mortar were obtained as one fourth to one sixth of
those measured for OPC mortar specimens, which indicates high
resistance against chloride ion penetration in FA blended cement
specimens, hence resulting in a highly durable mortar.
Abstract: Efficient luminescence is reported for the first time in Eu2+ activated double Chlorides A2BCl4 (A=Alkali metal, B=Alkaline earth element). A simple wet-chemical preparation is described. Emission intensities are comparable to that of the commercial phosphor. Excitation covers near UV region. These phosphors may be useful for applications like solid state lighting, scintillation detectors and X-ray storage using photo-stimulable phosphors.
Abstract: Let S be an ordered semigroup. In this paper we first introduce the concepts of (∈,∈ ∨q)-fuzzy ideals, (∈,∈ ∨q)-fuzzy bi-ideals and (∈,∈ ∨q)-fuzzy generalized bi-ideals of an ordered semigroup S, and investigate their related properties. Furthermore, we also define the upper and lower parts of fuzzy subsets of an ordered semigroup S, and investigate the properties of (∈,∈ ∨q)-fuzzy ideals of S. Finally, characterizations of regular ordered semigroups and intra-regular ordered semigroups by means of the lower part of (∈ ,∈ ∨q)-fuzzy left ideals, (∈,∈ ∨q)-fuzzy right ideals and (∈,∈ ∨q)- fuzzy (generalized) bi-ideals are given.
Abstract: Saturated hydraulic conductivity is one of the soil
hydraulic properties which is widely used in environmental studies
especially subsurface ground water. Since, its direct measurement is
time consuming and therefore costly, indirect methods such as
pedotransfer functions have been developed based on multiple linear
regression equations and neural networks model in order to estimate
saturated hydraulic conductivity from readily available soil
properties e.g. sand, silt, and clay contents, bulk density, and organic
matter. The objective of this study was to develop neural networks
(NNs) model to estimate saturated hydraulic conductivity from
available parameters such as sand and clay contents, bulk density,
van Genuchten retention model parameters (i.e. r
θ , α , and n) as well
as effective porosity. We used two methods to calculate effective
porosity: : (1) eff s FC φ =θ -θ , and (2) inf φ =θ -θ eff s , in which s
θ is
saturated water content, FC θ is water content retained at -33 kPa
matric potential, and inf θ is water content at the inflection point.
Total of 311 soil samples from the UNSODA database was divided
into three groups as 187 for the training, 62 for the validation (to
avoid over training), and 62 for the test of NNs model. A commercial
neural network toolbox of MATLAB software with a multi-layer
perceptron model and back propagation algorithm were used for the
training procedure. The statistical parameters such as correlation
coefficient (R2), and mean square error (MSE) were also used to
evaluate the developed NNs model. The best number of neurons in
the middle layer of NNs model for methods (1) and (2) were
calculated 44 and 6, respectively. The R2 and MSE values of the test
phase were determined for method (1), 0.94 and 0.0016, and for
method (2), 0.98 and 0.00065, respectively, which shows that method
(2) estimates saturated hydraulic conductivity better than method (1).
Abstract: Waste problem is becoming a future problem all over the world. Magnesium wastes which can be used in recycling processes are produced by many industrial activities. Magnesium borates which have useful properties such as; high heat resistance, corrosion resistance, supermechanical strength, superinsulation, light weight, high coefficient of elasticity and so on. Addition, magnesium borates have great potential in the development of ceramic and detergents industry, whisker-reinforced composites, antiwear, and reducing friction additives.
In this study, using the starting materials of waste magnesium and H3BO3 the hydrothermal method was applied at a moderate temperature of 70oC with different reaction times. Several reaction times of waste magnesium to H3BO3 were selected as; 30, 60, 120, 240 minutes. After the synthesis, X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques were applied to products. As a result, the forms of Admontite [MgO(B2O3)3.7(H2O)] and Mcallisterite [Mg2(B6O7(OH)6)2.9(H2O)] were synthesized.
Abstract: Thermoplastic starch, polylactic acid glycerol and
maleic anhydride (MA) were compounded with natural
montmorillonite (MMT) through a twin screw extruder to investigate
the effects of different loading of MMT on structure, thermal and
absorption behavior of the nanocomposites. X-ray diffraction analysis
(XRD) showed that sample with MMT loading 4phr exhibited
exfoliated structure while sample that contained MMT 8 phr
exhibited intercalated structure. FESEM images showed big lump
when MMT loading was at 8 phr. The thermal properties were
characterized by using differential scanning calorimeter (DSC). The
results showed that MMT increased melting temperature and
crystallization temperature of matrix but reduction in glass transition
temperature was observed Meanwhile the addition of MMT has
improved the water barrier property. The nanosize MMT particle is
also able to block a tortuous pathway for water to enter the starch
chain, thus reducing the water uptake and improved the physical
barrier of nanocomposite.