Abstract: It is well-known that, using principal weak flatness
property, some important monoids are characterized, such as regular
monoids, left almost regular monoids, and so on. In this article, we
define a generalization of principal weak flatness called GP-Flatness,
and will characterize monoids by this property of their right (Rees
factor) acts. Also we investigate new classes of monoids called
generally regular monoids and generally left almost regular monoids.
Abstract: In the last decade the emergence of new social needs
as an effect of the economic crisis has stimulated the flourishing of
business endeavours characterised by explicit social goals. Social
start-ups, social enterprises or Corporate Social Responsibility
operations carried out by traditional companies are quintessential
examples in this regard. This paper analyses these kinds of initiatives
in order to discover the main characteristics of social business models
and to provide insights to social entrepreneurs for developing or
improving their strategies. The research is conducted through the
integration of literature review and case study analysis and, thanks to
the recognition of the importance of both profits and social impacts
as the key success factors for a social business model, proposes a
framework for identifying indicators suitable for measuring the social
impacts generated.
Abstract: Rapid prototyping is a new group of manufacturing
processes, which allows fabrication of physical of any complexity
using a layer by layer deposition technique directly from a computer
system. The rapid prototyping process greatly reduces the time and
cost necessary to bring a new product to market. The prototypes
made by these systems are used in a range of industrial application
including design evaluation, verification, testing, and as patterns for
casting processes. These processes employ a variety of materials and
mechanisms to build up the layers to build the part. The present work
was to build a FDM prototyping machine that could control the X-Y
motion and material deposition, to generate two-dimensional and
three-dimensional complex shapes. This study focused on the
deposition of wax material. This work was to find out the properties
of the wax materials used in this work in order to enable better
control of the FDM process. This study will look at the integration of
a computer controlled electro-mechanical system with the traditional
FDM additive prototyping process. The characteristics of the wax
were also analysed in order to optimise the model production process.
These included wax phase change temperature, wax viscosity and
wax droplet shape during processing.
Abstract: Analytical formula for the optical gain based on a
simple parabolic-band by introducing theoretical expressions for the
quantized energy is presented. The model used in this treatment take
into account the effects of intraband relaxation. It is shown, as a
result, that the gain for the TE mode is larger than that for TM mode
and the presence of acceptor impurity increase the peak gain.
Abstract: The reheating furnace is used to reheat the steel slabs
before the hot-rolling process. The supported system includes the
stationary/moving beams, and the skid buttons which block some
thermal radiation transmitted to the bottom of the slabs. Therefore, it is
important to analyze the steel slab temperature distribution during the
heating period. A three-dimensional mathematical transient heat
transfer model for the prediction of temperature distribution within the
slab has been developed. The effects of different skid button height
(H=60mm, 90mm, and 120mm) and different gap distance between
two slabs (S=50mm, 75mm, and 100mm) on the slab skid mark
formation and temperature profiles are investigated. Comparison with
the in-situ experimental data from Steel Company in Taiwan shows
that the present heat transfer model works well for the prediction of
thermal behavior of the slab in the reheating furnace. It is found that
the skid mark severity decreases with an increase in the skid button
height. The effect of gap distance is important only for the slab edge
planes, while it is insignificant for the slab central planes.
Abstract: Wicking and evaporation of water in porous knitted fabrics is investigated by combining experimental and analytical approaches: The standard wicking model from Lucas and Washburn is enhanced to account for evaporation and gravity effects. The goal is to model the effect of gravity and evaporation on wicking using simple analytical expressions and investigate the influence of fabrics geometrical parameters, such as porosity and thickness on evaporation impact on maximum reachable height values. The results show that fabric properties have a significant influence on evaporation effect. In this paper, an experimental study of determining water kinetics from different knitted fabrics were gravimetrically investigated permitting the measure of the mass and the height of liquid rising in fabrics in various atmospheric conditions. From these measurements, characteristic pore parameters (capillary radius and permeability) can be determined.
Abstract: This study aims at improving the urban hydrological
cycle of the Orléans agglomeration (France) and understanding the
relationship between physical and chemical parameters of urban
surface runoff and the hydrological conditions. In particular water
quality parameters such as pH, conductivity, total dissolved solids,
major dissolved cations and anions, and chemical and biological
oxygen demands were monitored for three types of urban water
discharges (wastewater treatment plant output (WWTP), storm
overflow and stormwater outfall) under two hydrologic scenarios (dry
and wet weather). The first results were obtained over a period of five
months. Each investigated (Ormes, l’Egoutier and La Corne) outfall
represents an urban runoff source that receives water from runoff
roads, gutters, the irrigation of gardens and other sources of flow over
the Earth’s surface that drains in its catchments and carries it to the
Loire River. In wet weather conditions there is rain water runoff and
an additional input from the roof gutters that have entered the
stormwater system during rainfall. For the comparison the results La
Chilesse is a storm overflow that was selected in our study as a
potential source of waste water which is located before the (WWTP). The comparison of the physical-chemical parameters (total
dissolved solids, turbidity, pH, conductivity, dissolved organic
carbon (DOC), concentration of major cations and anions) together
with the chemical oxygen demand (COD) and biological oxygen
demand (BOD) helped to characterize sources of runoff waters in the
different watersheds. It also helped to highlight the infiltration of
wastewater in some stormwater systems that reject directly in the
Loire River. The values of the conductivity measured in the outflow
of Ormes were always higher than those measured in the other two
outlets. The results showed a temporal variation for the Ormes outfall
of conductivity from 1465 μS cm-1 in the dry weather flow to 650 μS
cm-1 in the wet weather flow and also a spatial variation in the wet
weather flow from 650 μS cm-1 in the Ormes outfall to 281 μS cm-1
in L’Egouttier outfall. The ultimate BOD (BOD28) showed a
significant decrease in La Corne outfall from 181 mg L-1 in the wet
weather flow to 95 mg L-1 in the dry weather flow because of the
nutrient load that was transported by the runoff.
Abstract: Processing of high-silicon bauxite on the base of the
traditional clinkering method is related to high power consumption
and capital investments, which makes production of alumina from
those ores non-competitive in terms of basic economic showings. For
these reasons, development of technological solutions enabling to
process bauxites with various chemical and mineralogical structures
efficiently with low level of thermal power consumption is important.
Flow sheet of the studies on washability of ores from the Timanskoe
and the Severo-Onezhskoe deposits is on the base of the flotation
method.
Abstract: Zinc borate is an important inorganic hydrate borate
material, which can be used as a flame retardant agent and corrosion
resistance material. This compound can loss its structural water
content at higher than 290°C. Due to thermal stability; Zinc Borate
can be used as flame retardant at high temperature process of plastic
and gum. In this study, the ultrasonic reaction of zinc borates were
studied using hydrozincite (Zn5(CO3)2·(OH)6) and boric acid
(H3BO3) raw materials. Before the synthesis raw materials were
characterized by X-Ray Diffraction (XRD) and Fourier Transform
Infrared Spectroscopy (FT-IR). Ultrasonic method is a new
application on the zinc borate synthesis. The synthesis parameters
were set to 90°C reaction temperature and 55 minutes of reaction
time, with 1:1, 1:2, 1:3, 1:4 and 1:5 molar ratio of starting materials
(Zn5(CO3)2·(OH)6 : H3BO3). After the zinc borate synthesis, the
products were analyzed by XRD and FT-IR. As a result, optimum
molar ratio of 1:5 is determined for the synthesis of zinc borates with
ultrasonic method.
Abstract: Lyophilization, also called freeze-drying, is an
important dehydration technique mainly used for pharmaceuticals.
Food industry also uses lyophilization when it is important to retain
most of the nutritional quality, taste, shape and size of dried products
and to extend their shelf life. Vacuum-Induced during freezing cycle
(VI) has been used in order to control ice nucleation and,
consequently, to reduce the time of primary drying cycle of
pharmaceuticals preserving quality properties of the final product.
This procedure has not been applied in freeze drying of foods. The
present work aims to investigate the effect of VI on the lyophilization
drying time, final moisture content, density and reconstitutional
properties of mango (Mangifera indica L.) slices (MS) and mango
pulp-maltodextrin dispersions (MPM) (30% concentration of total
solids). Control samples were run at each freezing rate without using
induced vacuum. The lyophilization endpoint was the same for all
treatments (constant difference between capacitance and Pirani
vacuum gauges). From the experimental results it can be concluded
that at the high freezing rate (0.4°C/min) reduced the overall process
time up to 30% comparing process time required for the control and
VI of the lower freeze rate (0.1°C/min) without affecting the quality
characteristics of the dried product, which yields a reduction in costs
and energy consumption for MS and MPM freeze drying. Controls
and samples treated with VI at freezing rate of 0.4°C/min in MS
showed similar results in moisture and density parameters.
Furthermore, results from MPM dispersion showed favorable values
when VI was applied because dried product with low moisture
content and low density was obtained at shorter process time
compared with the control. There were not found significant
differences between reconstitutional properties (rehydration for MS
and solubility for MPM) of freeze dried mango resulting from
controls, and VI treatments.
Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: In the present study we have investigated axial
buckling characteristics of nanocomposite beams reinforced by
single-walled carbon nanotubes (SWCNTs). Various types of beam
theories including Euler-Bernoulli beam theory, Timoshenko beam
theory and Reddy beam theory were used to analyze the buckling
behavior of carbon nanotube-reinforced composite beams.
Generalized differential quadrature (GDQ) method was utilized to
discretize the governing differential equations along with four
commonly used boundary conditions. The material properties of the
nanocomposite beams were obtained using molecular dynamic (MD)
simulation corresponding to both short-(10,10) SWCNT and long-
(10,10) SWCNT composites which were embedded by amorphous
polyethylene matrix. Then the results obtained directly from MD
simulations were matched with those calculated by the mixture rule
to extract appropriate values of carbon nanotube efficiency
parameters accounting for the scale-dependent material properties.
The selected numerical results were presented to indicate the
influences of nanotube volume fractions and end supports on the
critical axial buckling loads of nanocomposite beams relevant to
long- and short-nanotube composites.
Abstract: Si-Ge solid solutions (bulk poly- and mono-crystalline
samples, thin films) are characterized by high perspectives for
application in semiconductor devices, in particular, optoelectronics
and microelectronics. From this point of view, complex studying of
structural state of the defects and structural-sensitive physical
properties of Si-Ge solid solutions depending on the contents of Si
and Ge components is very important. Present work deals with the
investigations of microstructure, microhardness, internal friction and
shear modulus of Si1-xGex(x≤0,02) bulk monocrystals conducted at
room temperature. Si-Ge bulk crystals were obtained by Czochralski
method in [111] crystallographic direction. Investigated
monocrystalline Si-Ge samples are characterized by p-type
conductivity and carriers’ concentration 5.1014-1.1015cm-3.
Microhardness was studied on Dynamic Ultra Micro hardness Tester
DUH-201S with Berkovich indenter. Investigate samples are characterized with 0,5x0,5x(10-15)mm3
sizes, oriented along [111] direction at torsion oscillations ≈1Hz,
multistage changing of internal friction and shear modulus has been
revealed in an interval of strain amplitude of 10-5-5.10-3. Critical
values of strain amplitude have been determined at which hysteretic
changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also
determined. Dynamic mechanical characteristics decreasing trend is
shown with increasing Ge content in Si-Ge solid solutions. Observed
changes are discussed from the point of view of interaction of various
dislocations with point defects and their complexes in a real structure
of Si-Ge solid solutions.
Abstract: Urinary Tract Infections are considered as one of the
most common bacterial infections with an estimated annual global
incidence of 150 million. Antimicrobial drug resistance is one of the
major threats due to wide spread usage of uncontrolled antibiotics. In
this study, a total number of 9149 urine samples were collected from
R.H Patiala and processed in the Department of Microbiology G. M.
C Patiala (January 2013 to December 2013). Urine samples were
inoculated on MacConkey’s and blood agar plates and incubated at
370C for 24 hrs. The organisms were identified by colony characters,
Gram’s staining, and biochemical reactions. Antimicrobial
susceptibility of the isolates was determined against various
antimicrobial agents (Hi – Media Mumbai India) by Kirby Bauer
DISK diffusion method on Muller Hinton agar plates. Maximum patients were in the age group of 21-30 yrs followed by
31-40 yrs. Males (34%) are less prone to urinary tract infections than
females (66%). Culture was positive in 25% of the samples.
Escherichia coli was the most common isolate 60.3% followed by
Klebsiella pneumoniae 13.5%, Proteus spp. 9% and Staphylococcus
aureus 7.6%. Most of the urinary isolates were sensitive to,
carbepenems, Aztreonam, Amikacin, and Piperacillin + Tazobactum.
All the isolates showed a good sensitivity towards Nitrofurantoin
(82%). ESBL production was found to be 70.6% in Escherichia coli
and 29.4% in Klebsiella pneumonia. Susceptibility of ESBL
producers to Imipenem, Nitrofurantoin and Amikacin were found to
be 100%, 76%, and 75% respectively. Uropathogens are increasingly
showing resistance to many antibiotics making empiric management
of outpatient UTIs challenging. Ampicillin, Cotrimoxazole and
Ciprofloxacin should not be used in empiric treatment. Nitrofurantoin
could be used in lower urinary tract infection. Knowledge of
uropathogens and their antimicrobial susceptibility pattern in a
geographical region will help in appropriate and judicious antibiotic
usage in a health care setup.
Abstract: It has been known that a characteristic
Burst-Suppression (BS) pattern appears in EEG during the early
recovery period following Cardiac Arrest (CA). Here, to explore the
relationship between cortical and subcortical neural activities
underlying BS, extracellular activity in the parietal cortex and the
centromedian nucleus of the thalamus and extradural EEG were
recorded in a rodent CA model. During the BS, the cortical firing rate
is extraordinarily high, and that bursts in EEG correlate to dense spikes
in cortical neurons. Newly observed phenomena are that 1) thalamic
activity reemerges earlier than cortical activity following CA, and 2)
the correlation coefficient of cortical and thalamic activities rises
during BS period. These results would help elucidate the underlying
mechanism of brain recovery after CA injury.
Abstract: The current-voltage (I-V) characteristics of Pd/n-GaN Schottky barrier were studied at temperatures over room temperature (300-470K). The values of ideality factor (n), zero-bias barrier height (φB0), flat barrier height (φBF) and series resistance (Rs) obtained from I-V-T measurements were found to be strongly temperature dependent while (φBo) increase, (n), (φBF) and (Rs) decrease with increasing temperature. The apparent Richardson constant was found to be 2.1x10-9 Acm-2K-2 and mean barrier height of 0.19 eV. After barrier height inhomogeneities correction, by assuming a Gaussian distribution (GD) of the barrier heights, the Richardson constant and the mean barrier height were obtained as 23 Acm-2K-2 and 1.78eV, respectively. The corrected Richardson constant was very closer to theoretical value of 26 Acm-2K-2.
Abstract: In this work, we attempt to associate firm
characteristics with innovative activity. We collect microdata from
listed firms of selected Eurozone Country-members, after the
beginning of 2007 financial crisis. The following literature, several
indicators of growth and performance were selected and tested for
their ability to interpret innovative activity. The main scope is to
examine the possible differences in performance and growth between
innovative and non-innovative firms, during a severe recession.
Additionally to that, a special focus will be held on whether
macroeconomic performance and national innovation system,
determines the extent of innovators' performance. Preliminary
findings, through correlation matrices and non-parametric tests,
strongly indicate the positive relation between innovative activity and
most of the measures used (profitability, size, employment),
confirming that even during a recessionary period, innovative firms
not only survive but also seem to succeed better economic results in
almost all indexes relative to non-innovative. However, even though
innovators seem to perform better in all economies examined, the
extent of that performance seems to be strongly affected by the
supportive mechanisms (financial and structural) that their country
provides. Thus, it is clear, that the technologically intensive 'gap'
between European South and North, during the economic crisis,
became chaotic, due to the harsh austerity measures and reduced
budgets in those countries, even in sectors with high potentials in
economic activity and employment, impairing the effects of crisis and
enhancing the vicious circle of recession.
Abstract: This paper reports the viability of developing Zn-27Al
alloy matrix hybrid composites reinforced with alumina, graphite and
fly ash (solid waste bye product of coal in thermal power plants).
This research work was aimed at developing low cost-high
performance Zn-27Al matrix composite with low density. Alumina
particulates (Al2O3), graphite added with 0, 2, 3, 4 and 5 wt% fly ash
were utilized to prepare 10wt% reinforcing phase with Zn-27Al alloy
as matrix using two-step stir casting method. Density measurement,
estimated percentage porosity, tensile testing, micro hardness
measurement and optical microscopy were used to assess the
performance of the composites produced. The results show that the
hardness, ultimate tensile strength, and percent elongation of the
hybrid composites decrease with increase in fly ash content. The
maximum decrease in hardness and ultimate tensile strength of
13.72% and 15.25% respectively were observed for composite grade
containing 5wt% fly ash. The percentage elongation of composite
sample without fly ash is 8.9% which is comparable with that of the
sample containing 2wt% fly ash with percentage elongation of 8.8%.
The fracture toughness of the fly ash containing composites was
however superior to those of composites without fly ash with 5wt%
fly ash containing composite exhibiting the highest fracture
toughness. The results show that fly ash can be utilized as
complementary reinforcement in ZA-27 alloy matrix composite to
reduce cost.
Abstract: In view of the requirements of the current industrial
processes, the instrumentation plays a critical role. In this context,
this work aims to raise some the operating characteristics of the level
and flow transmitters, in addition to observing their similarities and
possible limitations configurations.
Abstract: Structural failure is caused mainly by damage that
often occurs on structures. Many researchers focus on to obtain very
efficient tools to detect the damage in structures in the early state. In
the past decades, a subject that has received considerable attention in
literature is the damage detection as determined by variations in the
dynamic characteristics or response of structures. The study presents
a new damage identification technique. The technique detects the
damage location for the incomplete structure system using output
data only. The method indicates the damage based on the free
vibration test data by using ‘Two Points Condensation (TPC)
technique’. This method creates a set of matrices by reducing the
structural system to two degrees of freedom systems. The current
stiffness matrices obtain from optimization the equation of motion
using the measured test data. The current stiffness matrices compare
with original (undamaged) stiffness matrices. The large percentage
changes in matrices’ coefficients lead to the location of the damage. TPC technique is applied to the experimental data of a simply
supported steel beam model structure after inducing thickness change
in one element, where two cases consider. The method detects the
damage and determines its location accurately in both cases. In
addition, the results illustrate these changes in stiffness matrix can be
a useful tool for continuous monitoring of structural safety using
ambient vibration data. Furthermore, its efficiency proves that this
technique can be used also for big structures.