Abstract: It is well known that in recent years magnetic
materials have received increased attention due to their properties.
For this reason a significant number of patents that were published
during the last decade are oriented towards synthesis and study of
such materials. The aim of this work is to create and study ferrite
nanocrystalline materials with spinel structure, using sol-gel
technology with participation of auto-combustion. This method is
perspective in that it is a cheap and low-temperature technique that
allows for the fine control on the product’s chemical composition.
Abstract: Specific leaf area (SLA; cm2leaf g-1leaf) the ratio of leaf
area to leaf dry mass is a key ecophysiological parameter influencing
leaf physiology, photosynthesis, and whole plant carbon gain and
also can be used as a rapid and diagnostic tool. In this study, two
species of soluble inorganic selenium forms, selenite (Se^IV) and
selenate (Se^VI) at different concentrations were investigated on maize
plants that were growing in nutrient solutions during 2 weeks and at
the end of the experiment, amounts of SLA for first and second
leaves of maize were measured. In accordance with the results we
observed that our regarded Se concentrations in both forms of Se^IV
and Se^VI were not effective on maize plants’ SLA significantly
although high level of 3 mg.kg-1 Se^IV had negative affect on growth
of the samples that had been treated by it but about Se^VI samples we
did not observe this state and our different considered Se^VI
concentrations were not toxic for maize plants.
Abstract: The paper discusses mineral water consumer market
and development policy in Georgia, the tools and measures, which
will contribute to production of mineral waters and increase its
export.
The paper studies and analyses current situation in mineral water
production sector as well as the factors affecting increase and
reduction of its export. It’s noted that in order to gain and maintain
competitive advantage, it’s necessary to provide continuous supply of
high quality goods with modern design, open new distribution
channels to enter new markets, carry out broad promotional activities,
organize e-commerce. Economic policy plays an important role in
protecting markets from counterfeit goods. The state also plays an
important role in attracting foreign direct investments. Stable
business environment and export oriented strategy is the basis for the
country’s economic growth.
Based on the research, the paper suggests the strategy for
improving competitiveness of Georgian mineral waters; relevant
conclusions and recommendations are provided.
Abstract: This article discusses event monitoring options for
heterogeneous event sources as they are given in nowadays
heterogeneous distributed information systems. It follows the central
assumption, that a fully generic event monitoring solution cannot
provide complete support for event monitoring; instead, event source
specific semantics such as certain event types or support for certain
event monitoring techniques have to be taken into account.
Following from this, the core result of the work presented here is
the extension of a configurable event monitoring (Web) service for a
variety of event sources. A service approach allows us to trade
genericity for the exploitation of source specific characteristics. It
thus delivers results for the areas of SOA, Web services, CEP and
EDA.
Abstract: In this study, polycaprolactone (PCL) was dissolved
in chloroform:ethanol solvent system at a concentration of 18 w/v %.
1, 2, 4, and 6 droplets of formic acid were added to the prepared 10ml
PCL-chloroform:ethanol solutions separately. Fibrous webs were
produced by electrospinning technique based on the horizontal
working principle. Morphology of the webs was investigated by
using scanning electron microscopy (SEM) whereas fiber diameters
were measured by Image J Software System. The effect of formic
acid addition to the mostly used chloroform solvent on fiber
morphology was examined.
Results indicate that there is a distinct fall in fiber diameter with
the addition of formic acid drops. The average fiber diameter was
measured as 2.22μm in PCL /chloroform:ethanol solution system. On
the other hand, 328nm and 256 nm average fiber diameters were
measured for the samples of 4 drops and 6 drops formic acid added.
This study offers alternative solvent systems to produce nanoscaled,
nontoxic PCL fibrous webs by electrospinning technique.
Abstract: The problem of toughening in brittle materials
reinforced by fibers is complex, involving all of the mechanical
properties of fibers, matrix and the fiber/matrix interface, as well as
the geometry of the fiber. Development of new numerical methods
appropriate to toughening simulation and analysis is necessary. In
this work, we have performed simulations and analysis of toughening
in brittle matrix reinforced by randomly distributed fibers by means
of the discrete elements method. At first, we put forward a
mechanical model of toughening contributed by random fibers. Then
with a numerical program, we investigated the stress, damage and
bridging force in the composite material when a crack appeared in the
brittle matrix. From the results obtained, we conclude that: (i) fibers
of high strength and low elasticity modulus are beneficial to
toughening; (ii) fibers of relatively high elastic modulus compared to
the matrix may result in substantial matrix damage due to spalling
effect; (iii) employment of high-strength synthetic fibers is a good
option for toughening. We expect that the combination of the discrete
element method (DEM) with the finite element method (FEM) can
increase the versatility and efficiency of the software developed. The
present work can guide the design of ceramic composites of high
performance through the optimization of the parameters.
Abstract: The aim of the present study was to examine whether
increasing molybdenum (Mo) concentration affects the growth and
Mo concentration of maize (Zea mays L. cv Norma SC) and
sunflower (Helianthus annuus L. cv Arena PR) seedlings within
laboratory conditions.
In this experiment, calcareous chernozem soil was used and Mo
was supplemented into the soil as ammonium molybdate
[(NH4)6Mo7O24.4H2O] in four different concentrations as follow: 0
(control), 30, 90 and 270 mg·kg-1.
In this study, we found that molybdenum in small amount (30
mg·kg-1) affects positively on growth of maize and sunflower
seedlings, however, higher concentration of Mo reduces the dry
weights of shoots and roots. In the case of maize the highest Mo
treatment (270 mg·kg-1) and in sunflower 90 mg·kg-1 treatment
caused significant reduction in plant growth.
In addition, we observed that molybdenum contents in the roots
and shoots were very low in case of control soil but were
significantly elevated with increasing concentration of Mo treatment.
Only in case of sunflower the highest 270 mg·kg-1 Mo treatment
caused decrease in Mo concentration.
Abstract: For optimal unbiased filter as mean-square and in the
case of functioning anomalous noises in the observation memory
channel, we have proved insensitivity of filter to inaccurate
knowledge of the anomalous noise intensity matrix and its
equivalence to truncated filter plotted only by non anomalous
components of an observation vector.
Abstract: Dengue outbreaks are affected by biological,
ecological, socio-economic and demographic factors that vary over
time and space. These factors have been examined separately and still
require systematic clarification. The present study aimed to investigate
the spatial-temporal clustering relationships between these factors and
dengue outbreaks in the northern region of Sri Lanka. Remote sensing
(RS) data gathered from a plurality of satellites were used to develop
an index comprising rainfall, humidity and temperature data. RS data
gathered by ALOS/AVNIR-2 were used to detect urbanization, and a
digital land cover map was used to extract land cover information.
Other data on relevant factors and dengue outbreaks were collected
through institutions and extant databases. The analyzed RS data and
databases were integrated into geographic information systems,
enabling temporal analysis, spatial statistical analysis and space-time
clustering analysis. Our present results showed that increases in the
number of the combination of ecological factor and socio-economic
and demographic factors with above the average or the presence
contribute to significantly high rates of space-time dengue clusters.
Abstract: Nanofibers are effective materials which have
frequently been investigated to produce high quality air filters. As an
environmental approach our aim is to achieve nanofibers by melting.
In spun-bond systems extruder, spin-pump, nozzle package and
attenuator are used. Molten polymer which flows from extruder is
made steady by spin-pump. Regular melt passes through nozzle holes
and forms fibers under high pressure. The fibers pulled from nozzle
are shrunk to micron size by an attenuator; after solidification, they
are collected on a conveyor. In this research different designs of
attenuator system have been studied; and also CFD analysis has been
done on these different designs. Afterwards, one of these designs
tested and finally some optimizations have been done to reduce
pressure loss and increase air velocity.
Abstract: The development of active and stable catalysts
without noble metals for low temperature oxidation of exhaust gases
remains a significant challenge. The purpose of this study is to
determine the influence of the preparation method on the catalytic
activity of the supported copper-manganese mixed oxides in terms of
VOCs oxidation. The catalysts were prepared by impregnation of γ-
Al2O3 with copper and manganese nitrates and acetates and the
possibilities for CO, CH3OH and dimethyl ether (DME) oxidation
were evaluated using continuous flow equipment with a four-channel
isothermal stainless steel reactor. Effect of the support, Cu/Mn mole
ratio, heat treatment of the precursor and active component loading
were investigated. Highly active alumina supported Cu-Mn catalysts
for CO and VOCs oxidation were synthesized. The effect of
preparation conditions on the activity behavior of the catalysts was
discussed.
The synergetic interaction between copper and manganese species
increases the activity for complete oxidation over mixed catalysts.
Type of support, calcination temperature and active component
loading along with catalyst composition are important factors,
determining catalytic activity. Cu/Mn molar ratio of 1:5, heat
treatment at 450oC and 20 % active component loading are the best
compromise for production of active catalyst for simultaneous
combustion of CO, CH3OH and DME.
Abstract: In review the generalized data about biological
activity of anthraquinone-containing plants and specimens on their
basis is presented. Data of traditional medicine, results of
bioscreening and clinical researches of specimens are analyzed.
Abstract: Properties of Portland cement mixtures with various
fractions of metakaolin were studied. 10% of Portland cement CEM I
42.5 R was replaced by different fractions of high reactivity
metakaolin with defined chemical and mineralogical properties.
Various fractions of metakaolin were prepared by jet mill classifying
system. There is a clear trend between fineness of metakaolin and
hydration heat development. Due to metakaolin presence in mixtures
the compressive strength development of mortars is rather slower for
coarser fractions but 28-day flexural strengths are improved for all
fractions of metakaoline used in mixtures compared to reference
sample of pure Portland cement. Yield point, plastic viscosity and
adhesion of fresh pastes are considerably influenced by fineness of
metakaolin used in cement pastes.
Abstract: Interaction of Schiff base complexes of Iron and
Manganese: Iron [N, N’ Bis (5- (triphenyl phosphonium methyl)
salicylidene) -1, 2 ethanediamine) chloride, [Fe Salen]Cl; Manganese
[N, N’ Bis (5- (triphenyl phosphonium methyl) salicylidene) -1, 2
ethanediamine) acetate, were investigated by spectroscopic and
isothermal titration calorimetry techniques (ITC).
The absorbance spectra of complexes have shown hyper and
hypochromism in the presence of DNA that is indication of
interaction of complexes with DNA. The linear dichroism (LD)
measurements confirmed the bending of DNA in the presence of
complexes.
Furthermore, Isothermal titration calorimetry experiments
approved that complexes bound to DNA on the base of both
electrostatic and hydrophobic interactions. More, ITC profile exhibits
the existence of two binding phases for the complexes. Antibacterial
activity of ligand and complexes were tested in vitro to evaluate their
activity against the gram positive and negative bacteria.
Abstract: In review the generalized data about biosynthetic routs
formation anthraquinone molecules in natural cells. The basic
possibilities of various ways of biosynthesis of different quinoid
substances are shown.
Abstract: Ionic liquids consisting of a phosphonium cationic
moiety and a saccharinate anion are synthesized and compared with
their precursors, phosphonium chlorides, in reference to their
extraction efficiency towards L-lactic acid. On the base of
measurements of the acid and the water partitioning in the
equilibrium biphasic systems, the molar ratios between acid, water
and ionic liquid are estimated which allows to deduce the lactic acid
extractive pathway. The effect of a salting-out addition that
strengthens hydrophobicity in both phases is studied in view to reveal
the best biphasic system with respect to IL low toxicity and high
extraction efficiency.
Abstract: Modern Portfolio Theory (MPT) according to
Markowitz states that investors form mean-variance efficient
portfolios which maximizes their utility. Markowitz proposed the
standard deviation as a simple measure for portfolio risk and the
lower semi-variance as the only risk measure of interest to rational
investors. This paper uses a third volatility estimator based on
intraday data and compares three efficient frontiers on the Croatian
Stock Market. The results show that range-based volatility estimator
outperforms both mean-variance and lower semi-variance model.
Abstract: We assessed the ecology of the organic and mineral soil
layers of laurel-leaved (BB-1) and Cryptomeria japonica (BB-2 and Pw)
forests in the Kasugayama Hill Primeval Forest (Nara, Japan). The soil
respiration rate was higher in the deeper horizons (F and H) of organic
layers than in those of mineral soil layers, suggesting organic layers
may be where active microbial metabolism occurs. Respiration rates in
the soil of BB-1, BB-2 and Pw forests were closely similar at 5 and 10°C.
However, the soil respiration rate increased in proportion to
temperatures of 15°C or above. We therefore consider the activity of
soil microorganisms to markedly decrease at temperatures below 10°C.
At a temperature of 15°C or above, the soil respiration rate in the BB-1
organic layers was higher than in those of the BB-2 and Pw organic
layers, due to differences in forest vegetation that appeared to
influence several salient soil properties, particularly pH and the carbon
(C) and nitrogen (N) content of the F and H horizons.
Abstract: In this work, we begin with the presentation of the
Tθ family of usual similarity measures concerning multidimensional
binary data. Subsequently, some properties of these measures are
proposed. Finally the impact of the use of different inter-elements
measures on the results of the Agglomerative Hierarchical Clustering
Methods is studied.
Abstract: In the present work, fly ash geopolymer based
composites including polyester (PES) waste were studied. Specimens
of three compositions were prepared: (a) fly ash geopolymer with 5%
PES waste; (b) fly ash geopolymer mortar with 5% PES waste; (c) fly
ash geopolymer mortar with 6.25% PES waste. Compressive and
bending strength measurements, water absorption test and
determination of thermal conductivity coefficient were performed.
The results showed that the addition of sand in a mixture of
geopolymer with 5% PES content led to higher compressive strength,
while it increased water absorption and reduced thermal conductivity
coefficient. The increase of PES addition in geopolymer mortars
resulted in a more dense structure, indicated by the increase of
strength and thermal conductivity and the decrease of water
absorption.