I
n this study, the influence of grinding parameters of talc sample in the conventional ball
mill on water-based paint properties was investigated, and the results obtained from the
experiments were statistically modeled. The regression analysis were designed to reveal the
correlation between grinding parameters of the talc and the opacity and brightness of the
paint with the recipes containing prepared mineral. In multivariate regression analysis, the
differential grinding parameters were used to determine the change on opacity and brightness of the paint with a linear model between the change of the grinding parameters as the
variables. Therefore, developed analysis includes a numerical model which could foresee the
changes on final paint properties due to parameter changes (ball charge, material charge and
time) in the grinding process. At the end of the experimental studies, the results indicated
that the changes on brightness and opacity of a water-based paint are very dependant to the
characteristics of talc mineral used as a filler in the same recipe. In other words, it was possible to foresee the changes on opacity and brightness of the paint due to changing grinding
parameters of talc used as mineral filler in paint by using multivariate multiple regression
analysis
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I
n the present study, the effects of inlet air cooling on compound cycle performance in a
diesel gas turbine engine system where waste heat is used in the composite power system
in the sustainable energy system were investigated thermodynamically. The effects of the
inlet air cooling the system that enhances power production and the resulting thermal efficiency values were analyzed based on various operational variables (gas turbine pressure
ratio, diesel engine compression ratio, gas turbine inlet and fresh air inlet temperatures,
etc.). The energy losses in each system component were determined and the second law
efficiency of the system was determined based on the introduced operational parameters.
The gas turbine unit in the model included a gas generator with two compressors and a
high-pressure turbine, and a low-pressure power turbine running on a separate shaft. The
diesel engine and gas-generator exhaust gases were mixed and expanded in a low-pressure
turbine, leading to the production of power with the waste energy. In the cycle, an intake
air cooler, an intercooler and a recuperative air pre-heater were used. In the intake air cooling cycle, the power increase was around 15% when the pressure rate of the low-pressure
compressor was 3.5. Natural gas was used as fuel in the thermodynamic model. The cycle
irreversibilitywas used in the calculations based onthe thermodynamic concepts
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I
n concentrated photovoltaic thermal (CPVT) systems, sunlight is directly converted into
electricity and during this conversion waste heat is generated on the photovoltaic module.
The resulting waste heat can be used for heating the fluids. In this study, the effect of using
a low concentrating photovoltaic thermal system as a pre-heater before the evaporator in
the organic Rankine cycle (ORC) was investigated. Thermodynamic analyzes were performed for different solar radiation values, concentration ratio values and various photovoltaic module (PV) materials. The increase in solar radiation and concentration increased
the electricity production in the photovoltaic module and the thermal efficiency of the
system but led to a decrease in exergy efficiency. In the analyzes, four different PV module
materials were examined and M-Si and P-Si module materials showed better performance
in terms of system efficiency and electricity production.
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This study presents an energy study of an Organic Rankine Cycle (ORC) by comparing
three organic fluids. The latter is considered as a promising cycle for the conversion of
heat into mechanical energy adapted to low-temperature heat sources; it uses more volatile
organic fluids than water, which generally has high molecular weights, thus allowing operating pressures at temperatures lower than those of the traditional Rankine cycle. This study
devoted to the energy analysis of the ORC cycle, taking into account the effect of the operating temperatures and the choice of the organic fluid on the cycle performance. The utilized
three fluids were Toluene, R245fa and R123. The results obtained show that the Toluene
organic fluid has the best energy efficiency of the cycle with 7.45%.
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VEGF has the positive effect on wound healing. In this study, the effect of VEGF application on some serum parameters during wound healing process were investigated. 36
female normoglycemic Wistar rats were used (200–250 g). Dorsolateral incisional wounds
(length: 4 cm) were made on the two sides of the medulla spinalis in rats. They were divided into 3 groups: untreated group (n=12), chitosan group (n=12) and chitosan+VEGF
group (n=12). The rats were sacrificed on the 3rd and 7th days of post wounding. NOx,
TBARs and RSH levels were determined spectrophotometrically in serum. Results were
compared by one-way ANOVA (p<0.05). Serum TBARs levels both the chitosan treated
group and the VEGF application group was found decreased when compared with untreated groups (3rd and 7th days) (p <0.05). Chitosan and VEGF application were effective
increasing antioxidant capacity of serum on the 7th day. Serum NOx levels decreased in
the VEGF treated groups on 3rd and on 7th days (p<0.05). It can be considered that VEGF
administration has a more positive systemic effect to eliminate increased oxidative damage
in the serum of normoglycemic rats.
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In this study, the hairs of the badger (Meles meles) in the collection and various museums were examined and was tried to determine whether there were variations. For the
morphological analysis of the guard hair samples taken from the middle part of the ridge,
the guard hairs were examined by both light microscopy and scanning electron microscopy
(SEM). The root of the guard hairs on the back and sides was dirty white, the body was
brownish black and the tip was white. The length of the hairs on the back and sides was
determined to be about 75 mm. It was determined that 21 of the samples had summer fur,
the dorsal part had brown and transition tones had dark brown hairs, and 4 had winter fur,
the dorsal part had grayish brown hairs and the ventral part had blackish light brown hairs.
In addition, winter fur was found to be covered more frequently and with long guard hairs
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The DNA binding activity of previously synthesized and characterized 2(3), 9(10), 16(17), 23(24) –Tetrakis 4-(4-(2-phenylprop-2-yl) phenoxy) phthalocyanine compound (PcF) with CT-DNA was studied using UV/Vis, emission spectroscopic titrations,
the melting temperature, viscosity measurement, and agarose gel electrophoresis methods
in a Tris-HCl buffer solution at a pH of 7.1 at room temperature. The absorption titration
spectra studies of PcF showed that absorbance intensities were decreased with increasing of
concentrations of CT-DNA and the finding proved that the compound interacts with the
DNA. Addition to absorption titration study, emission spectroscopic titration, the melting
temperature, viscosity measurement, and agarose gel electrophoresis methods were also
performed to investigate the binding activities of PcF with the DNA. The results of these
methods confirmed the findings of absorption spectra study that the compound interacts
with the DNA
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In this study, gold nanoparticles (AuNPs) were deposited onto graphene oxide (GO) modified pencil graphite electrode (PGE) in order to construct a disposable sensor platform for the electrochemical detection of ceftizoxime (CFX). Initially, electrode surface was
covered with GO by physical adsorption and then AuNPs were deposited on the surface by
electro-deposition method. Morphological feature of the developed sensor was investigated
by scanning electron microscope. The parameters effecting the experimental conditions
such as adsorption time of graphene oxide, deposition time of gold nanoparticles, supporting electrolyte pH, pre-concentrating potential/time were optimized. Under optimum experimental conditions, good linearity was obtained for CFX response in the range between
0.02-2.0 μM of CFX concentrations with a low detection limit (0.442 nM) by stripping
voltammetry. The AuNPs/GO modified PGE was implemented to pharmaceutical samples
with good recovery values. This study results proved that developed disposable sensor is a
good alternative for the practical application of CFX analysis.
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One of the main problems of our country is inability to select the right materials of high quality in production. Decision making based on multiple criteria has an important role to do the right selections in each sector. One of these sectors is construction. Construction
sector develops rapidly and using the right material is an important issue. Using the right
material in this period when construction sector develops rapidly has a great importance. In
the construction sector, the building material which has been used the most widely from past
to present is concrete. In this study, a knowledge-based system via TOPSIS approach was
proposed to generalize the multi-criteria decision making problems of fine aggregate material selection in concrete production. In addition, six different mortar series were produced
by using the fine aggregates which were obtained from various plants used in the production
of ready-mixed concrete in Kütahya and CEN Standard sand. The methylene blue, physical
and mechanical tests were carried out on the produced mortars in order to get an idea for the
strength and durability of concrete. The purpose of the study was to determine which of the
five different fine aggregates had characteristics that are the closest to those of CEN Standard sand based on defined these multi criteria. It was found that the best fine aggregate series
was A based on the defined criteria by considering the results of the experiments, assigning
weights based on importance and analyzing these with TOPSIS approach.
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In the last decade, unmanned aerial vehicle gained popularity and started to be used in different tasks most of which are performed in outdoor environments. Still, there is a great potential to use quadrotors in indoor tasks such as urban relief and disaster
operations. In this paper, we developed a framework and a novel target-based navigation
algorithm for mapping of an unknown 2D environment with a quadrotor using an ultrawideband system. The target-based navigation algorithm aims to explore map of the environment by moving the border between the discovered and undiscovered areas. It uses
A* search algorithm for path planning if there is an obstacle present in the environment.
The target-based navigation algorithm is implemented on Gazebo simulator and its performance is compared with the well-known wall following algorithm and exploration algorithm in terms of task completion time and distance travelled. The target-based navigation
algorithm outperforms the other two algorithms especially in environments with obstacles.
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