181 research outputs found
Good and bad muslims, real and fake seculars: center-periphery relations and hegomony in Turkey through the February 28 and April 27 processes
The dissertation is about the media role during February 28 and April 27 military intervention ProcessesLEI Universiteit LeidenMiddle Eastern Studie
Mechanics of milling 48-2-2 gamma titanium aluminide
Accurate and fast prediction of cutting forces is important in high-performance cutting in the aerospace industry. Gamma titanium aluminide (gamma-TiAl) is a material of choice for aerospace and automotive applications due to its superior thermo-mechanical properties. Nevertheless, it is a difficult to machine material. This article presents the prediction of cutting forces for Ti-48Al-2Cr-2Nb (48-2-2) gamma-TiAl in milling process using orthogonal to oblique transformation technique. The novelty of this paper lies in reporting the orthogonal database of 48-2-2 gamma-TiAl. Fundamental cutting parameters such as shear stress, friction angle and shear angle are calculated based on experimental measurements. Friction coefficients are identified for two different coating conditions which are AlTiN, and AlCrN on carbide tools. Predicted results are validated with the experimental cutting forces during end milling and ball-end milling operations for different cutting conditions. The simulated results showed good agreement with the experimental results, which confirms the validity of the force modelWOS:000568177300002Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ2ArticleUluslararası işbirliği ile yapılan - EVETAğustos2020YÖK - 2019-2
A novel approach for skin infections: Controlled release topical mats of poly (lactic acid)/poly(ethylene succinate) blends containing Voriconazole
WOS: 000438500700010The oral and injectable formulations of Voriconazole (VRZ), a known antifungal agent with low solubility, seem to cause severe side effects. Consequently, topical application of VRZ could be advantageous for skin fungal infections. In this study, VRZ embedded in a polymeric matrix composed of biocompatible poly(lactic acid) (PLA) and poly(ethylene succinate) (PESu). The mats were prepared via solvent evaporation and fully characterized by Fourier-Transformed Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), in vitro hydrolysis and release studies. The prepared blends defined as immiscible by DSC and SEM while FTIR spectroscopy did not disclose noticeable interactions between the polymers. It was found that hydrolysis was improved by increasing PESu content into the blend. VRZ loaded blends spectra exhibit slight differentiation compared to neat blends while the absence of VRZ melting peak, as DSC illustrated, indicated drug amorphization. Lastly, in vitro release studies depicted a controlled release pattern dependent on mats' hydrolysis degree. An improved antifungal activity of mats was detected by disc diffusion method against various microorganisms. Ex vivo studies of VRZ did not determine high permeation while histopathology results using mice were profitable. The irritation experiments displayed that the mats did not induce any skin irritation
Existence of Hamiltonians for Some Singular Interactions on Manifolds
The existence of the Hamiltonians of the renormalized point interactions in
two and three dimensional Riemannian manifolds and that of a relativistic
extension of this model in two dimensions are proven. Although it is much more
difficult, the proof of existence of the Hamiltonian for the renormalized
resolvent for the non-relativistic Lee model can still be given. To accomplish
these results directly from the resolvent formula, we employ some basic tools
from the semigroup theory.Comment: 33 pages, no figure
Protein and gene delivery systems for neurodegenerative disorders: Where do we stand today?
It has been estimated that every year, millions of people are affected by neurodegenerative disorders, which complicate their lives and their caregivers’ lives. To date, there has not been an approved pharmacological approach to provide the complete treatment of neurodegenerative disorders. The only available drugs may only relieve the symptoms or slow down the progression of the disease. The absence of any treatment is quite rational given that neurodegeneration occurs by the progressive loss of the function or structure of the nerve cells of the brain or the peripheral nervous system, which eventually leads to their death either by apoptosis or necrotic cell death. According to a recent study, even though adult brain cells are injured, they can revert to an embryonic state, which may help to restore their function. These interesting findings might open a new path for the development of more efficient therapeutic strategies to combat devastating neurodegenerative disorders. Gene and protein therapies have emerged as a rapidly growing field for various disorders, especially neurodegenerative diseases. Despite these promising therapies, the complete treatment of neurodegenerative disorders has not yet been achieved. Therefore, the aim of this review is to address the most up-to-date data for neurodegenerative diseases, but most importantly, to summarize the available delivery systems incorporating proteins, peptides, and genes that can potentially target such diseases and pass into the blood–brain barrier. The authors highlight the advancements, at present, on delivery based on the carrier, i.e., lipid, polymeric, and inorganic, as well as the recent studies on radiopharmaceutical theranostics
CAPP Axion Search Experiments with Quantum Noise Limited Amplifiers
The axion is expected to solve the strong CP problem of quantum
chromodynamics and is one of the leading candidates for dark matter. CAPP in
South Korea has several axion search experiments based on cavity haloscopes in
the frequency range of 1-6 GHz. The main effort focuses on operation of the
experiments with the highest possible sensitivity. It requires maintenance of
the haloscopes at the lowest physical temperature in the range of mK and usage
of low noise components to amplify the weak axion signal. We report development
and operation of low noise amplifiers for 5 haloscope experiments targeting at
different frequency ranges. The amplifiers show noise temperatures approaching
the quantum limit.Comment: 6 pages, 7 figures, 29th International Conference on Low Temperature
Physics, August 18-24, 2022, Sapporo, Japa
Four-channel System for Characterization of Josephson Parametric Amplifiers
The axion search experiments based on haloscopes at the Center for Axion and
Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in
South Korea are performed in the frequency range from 1 GHz to 6 GHz. In order
to perform the experiments in a strong magnetic field of 12 T and a
large-volume cavity of close to 40 liters, we use He wet dilution refrigerators
with immersed superconducting magnets. The measurements require continuous
operation for months without interruptions for microwave component
replacements. This is achieved by using different cryogenic engineering
approaches including microwave RF-switching. The critical components, defining
the scanning rate and the sensitivity of the setup, are the Josephson
parametric amplifiers (JPA) and cryogenic low noise amplifiers (cLNA) based on
high-electron-mobility-transistor (HEMT) technology. It is desirable for both
devices to have a wide frequency range and low noise close to the quantum limit
for the JPA. In this paper, we show a recent design of a 4-channel measurement
setup for JPA and HEMT measurements. The setup is based on a 4-channel wideband
noise source (NS) and is used for both JPA and HEMT gain and noise
measurements. The setup is placed at 20 mK inside the dry dilution
refrigerator. The NS is thermally decoupled from the environment using plastic
spacers, superconducting wires and superconducting coaxial cables. We show the
gain and noise temperature curves measured for 4 HEMT amplifiers and 2 JPAs in
one cool-downComment: to be published in JPS Conference Proceedings (LT29
Josephson Parametric Amplifier in Axion Experiments
The axion is a hypothetical particle, a promising candidate for dark matter,
and a solution to the strong CP problem. Axion haloscope search experiments
deal with a signal power comparable to noise uncertainty at millikelvin
temperature. We use a flux-driven Josephson parametric amplifier (JPA) with the
aim of approaching a noise level near the theoretically allowed limit of half
quanta. In our measurements to characterize the JPA we have found the added
noise to the system with a JPA as the first-stage amplifier to be lower than
110 mK at the frequencies from 0.938 GHz to 0.963 GHz.Comment: to be published in JPS Conference Proceedings (LT29
Search for the Sagittarius Tidal Stream of Axion Dark Matter around 4.55 eV
We report the first search for the Sagittarius tidal stream of axion dark
matter around 4.55 eV using CAPP-12TB haloscope data acquired in March of
2022. Our result excluded the Sagittarius tidal stream of
Dine-Fischler-Srednicki-Zhitnitskii and Kim-Shifman-Vainshtein-Zakharov axion
dark matter densities of and GeV/cm,
respectively, over a mass range from 4.51 to 4.59 eV at a 90% confidence
level.Comment: 6 pages, 7 Figures, PRD Letter accepte
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