Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 6

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Prediction of Inner Grooved Circular Jet Flow with Artificial Neural Networks

100%
Inan A.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 3
403-405
EN
In this study, an artificial neural network model was established by using experimental measurement values obtained from a low-speed subsonic wind tunnel, with the length of 75 cm and experiment test section of 32× 32 cm². Model results were compared with experimental values and then, the prediction was made for the unmeasured tunnel stream values. In the wind tunnel, the jet velocity of 25 m/s and four tunnel velocities of 0, 5, 10 and 20 m/s were used. At four measurement stations x/D=0.3, x/D=12.5, x/D=31.2 and x/D=50, experimental measurements were made using a hot wire anemometer. This study is the continuation of the work done by Inan and Sisman [T. Inan, T. Sisman, Acta Phys. Pol. A 127, 1145 (2015)]. Inner grooved circular jet flows at x/D=0.3 and x/D=50 stations with average tunnel flow velocities of 7.5 m/s and 15 m/s were studied by using artificial neural networks.
2
Content available remote

Investigation of Grooved Circular Jet Flow Experimentally and Using Computational Fluid Dynamics

63%
Inan A., Sisman T.
|
EN
This study is the investigation of grooved circular jet flow experimentally and using computational fluid dynamics (CFD). Experimental studies were conducted by using straight circular and grooved circular tubes in a multi-purpose low-range subsonic wind tunnel. Single channel hot wire anemometer was used in turbulence measurements. Numerical studies for the solution of jet flow were performed through FLUENT program (ANSYS 14.5). Jet flow profiles at different velocities were formed by using the data generated at predetermined stations in the experiment room for the straight circular tubes and grooved circular tubes. After transferring the experimental data to Fluent, jet exit points of the circular tubes were placed in the quarter model to coincide with the initial coordinates of experimental room. CFD Calculations were done by implementing different velocities in the experimental room and the jet. Jet flow structures obtained from both computational and experimental calculations are shown in graphs and the data is presented in Tables. The obtained parameters are as follows: axis velocity (U_{e}), root mean square velocity (U_{rms}), turbulence velocity (U_{turb}), jet half width (b) and Reynolds numbers (Re_{D} and Re_{b}). These parameters were calculated with reference to jet radius and jet half width. Graphics formed by the generated non-dimensional data were compared to the previous studies.
3
Content available remote

Coaxial Circular Jet Flows with Conical Attachments

51%
Inan A., Gul M., Isikan M.
Acta Physica Polonica A
|
2015
|
vol. 127
|
issue 4
1373-1379
EN
This study is devoted to experiments on jet flows, which have many application areas. It shows the obtained jet flow structure. The experiments were carried out in a subsonic sucking wind tunnel having cross-section of 32×32 cm², length of 75 cm, and turbulence densities of 0.5%. One-channel hot-wire anemometer (HWA) was used in measurements. For circular jet, a steel pipe was used with a length of 120 cm and a diameter of 8 mm. Air generator was used for generating air into the jet flow and measurements were done at different jet flow velocities. Moreover, a conical diffuser with a length of 21 cm and 6° slope was attached to the nozzle exit and effect of this diffuser on jet flow was examined. Seven types of measurement in three different categories were carried out. In experimental studies, velocity and turbulence distribution, axial velocity variation, jet half widths and, using these, jet diffusion rates and angles were measured. Moreover, flow analyses were done by drawing moment and frequency distribution for measurement sensitivity. These experimental results were compared with the studies on jet flow.
4
Content available remote

Hydroxyapatite Synthesis from Fish Bones: Atlantic Salmon (Salmon Salar)

33%
Komur B., Altun E., Aydogdu M., Bilgiç D., Gokce H., Ekren N., Salman S., Inan A., Oktar F., Gunduz O.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 3
400-402
EN
Production of the bioceramics on the market is presently conducted from typical precipitation method by using reagent grade raw chemicals or through calcination of natural sources like animal bones (especially bovine bone) and fish bones. Usually fish bones were damped near or in the water sources, which can lead to serious environmental pollution. Those were regarded as a trash, even though they still bear economic value, including conjugates. In this study bones of Atlantic Salmon (Salmo salar) were used as a bioceramic material source. Bones of Atlantic Salmon were collected from Besiktas Fish Market. Those were cleaned from possible flesh with reagent grade NaOH. Cleaned parts were washed with demineralized water very neatly. Dry fish bones were calcinated at 850°C for 4 hours. The obtained hydroxyapatite material was characterized with scanning electron microscopy and X-ray diffraction methods. It was found that the bioceramic material consisted of hydroxyapatite and various related phases. Scanning electron microscopy studies have revealed nano-structured bioceramic particles. The aim of this study is to obtain nano-structured bioceramics from bones of Atlantic Salmon in an environmentally friendly and economic way.
5
Content available remote

Characterization of Cu/Ag/Eu/Hydroxyapatite Composites Produced by Wet Chemical Precipitation

33%
Komur B., Ozturk E., Ekren N., Inan A., Gunduz O., Andronescu E., Ficai A., Oktar F.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 3
392-396
EN
In the first part of this study hydroxyapatite was prepared synthetically through classical wet precipitation, using Ca(NO₃)₂·4H₂O (calcium nitrate tetrahydrate) as calcium source and HgN₂O4P as phosphate source. In the second part of the study HA compounds were prepared with different ratios (0.5, 1, 2, 5, 10 and 25 wt.%) of antibacterial materials like copper (Cu), silver (Ag) and europium (Eu), using the same wet precipitation method. The prepared pure HA material was utilized as the control group for comparison with Cu/Ag/Eu/HA composites. Studies of X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, equipped with energy dispersive X-ray analysis were performed. The aim of this study was to investigate Cu/Ag/Eu/HA composites and the effect of metals on HA biomaterials, used as scaffold materials in bone disease treatment.
6
Content available remote

Physical Characterization of Turbot (Psetta Maxima) Originated Natural Hydroxyapatite

33%
Inan A., Komur B., Ekren N., Aydogdu M., Gokce H., Ficai A., Salman S., Oktar F., Gunduz O.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 3
397-399
EN
Nowadays hydroxyapatite is one of the most popular biomaterials, which is used in various medical and dental applications areas as graft material. Bovine bone is the biggest source for natural hydroxyapatite production, but its production can lead to very dangerous disease, like mad cow disease, without high degree calcination. Hydroxyapatite produced from marine sources is much safer and easier to produce than bovine hydroxyapatite. Here in this study natural hydroxyapatite and related phases were produced from a local source turbot (Psetta maxima). Beside the main bony internal structure, there are koshers (cycloid scale) on its skin. Koshers are bulky bumps, looking like flat, small and rounded structures. Internal bones and those bulky bumps were cleaned from flesh with chemicals and calcined at 850°C for 4 hours. After calcinations, especially those bulky bumps, were formed into mesoporous structures with very light bluish color. Those mesoporous structures can be used as natural mesoporous hydroxyapatite structures for bone grafting purposes. The internal bones have also formed hydroxyapatite. Scanning electron microscope and X-ray diffraction studies were performed. I this study it is found that the bones of turbot consist of hydroxyapatite and TCP related phases. The aim of this study is to produce natural hydroxyapatite structures from turbot scale with low carbon footprint, without harming the environment and without using complex chemicals.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.