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Articles 4051 - 4080 of 4447
Full-Text Articles in Physical Sciences and Mathematics
Effect Of Iron Concentrations On Some Physical Properties Of The System Li_{0.5}Fe_{X}Ga_{2.5 - X}O_{4}, Abd El-Raouf Tawfik, N. Tashtoush, O.M. Hemeda
Effect Of Iron Concentrations On Some Physical Properties Of The System Li_{0.5}Fe_{X}Ga_{2.5 - X}O_{4}, Abd El-Raouf Tawfik, N. Tashtoush, O.M. Hemeda
Turkish Journal of Physics
A series of Li_{0.5} Fe_{x} Ga_{2.5 - x} O_{4} systems were prepared for x = 0, 0.25, 0.5, 0.75 and 1 by the general ceramic method. X-ray diffraction showed that all compositions have single phase Spinel cubic structure. The lattice parameter increased with enhancing iron concentration. The thermoelectric coefficient decreased with increasing x, and the majority carriers are holes. The increase of the jump length of hole increased the electrical conductivity. Jump-length increased with iron concentration and the rate of jumping gave rise to the electrical conductivity. The concentration of Fe^{3 +} ions in Lithium gallate is important, for such …
Ac Conductivity And Dielectric Study Of Chalcogenide Glasses Of Se-Te-Ge System, Fathy Salman
Ac Conductivity And Dielectric Study Of Chalcogenide Glasses Of Se-Te-Ge System, Fathy Salman
Turkish Journal of Physics
The ac conductivity and dielectric properties of glassy system Se_{x}Te_{79 - x}Ge_{21}, with x = 11, 14, 17 at.%, has been studied at temperatures 300 to 450 K and over a wide range of frequencies (50 Hz to 500 kHz). Experimental results indicate that the ac conductivity and the dielectric constants depend on temperature, frequency and Se content. The conductivity as a function of frequency exhibited two components: dc conductivity \sigma _{dc}, and ac conductivity \sigma _{ac}, where \sigma _{ac} \sim \omega ^{s}. The mechanism of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping model …
Quantum Statistical Entropy Of Sen Black Hole, Zhao Ren, Wu Yueqin, Zhang Lichun
Quantum Statistical Entropy Of Sen Black Hole, Zhao Ren, Wu Yueqin, Zhang Lichun
Turkish Journal of Physics
In this paper, by using quantum statistical methods, we directly obtain the partition function of Bose field and Fermi field on the background of the axisymmetrical Sen black hole. The difficult-to-solve wave equation is avoided. Then via the improved brick-wall method and membrane model, we calculate the entropy of Bose field and Fermi field of the black hole. We find that the entropy of the black hole is proportional to the area of the horizon. In our results, we do not encounter the left out term nor the divergent logarithmic term that appears in the original brick-wall method. The question …
Structural And Magnetic Properties Of Co_{0.6}Znn_{0.4}Mn_{X}Fe_{2 - X}O_{4}, O.M. Hemeda
Structural And Magnetic Properties Of Co_{0.6}Znn_{0.4}Mn_{X}Fe_{2 - X}O_{4}, O.M. Hemeda
Turkish Journal of Physics
A series of Co-Zn ferrite samples substituted by Mn were prepared by the usual double sintering ceramic technique. The x-ray diffraction patterns of the samples confirmed the formation of single-phase spinel structure, and x-ray analysis supply data that suggests the cation distribution of the material. The tetrahedral and octahedral radius permits one to calculate the theoretical lattice parameter and the bond lengths Fe-O at A and B sites. The particle size of the given samples was measured from the Scherer equation and a correlation was found between particle size, and structural and magnetic properties. The XRF confirmed the presence of …
The Normal And Inverted Meyer-Neldel Rule In The Ac Conductivity, Fouad Abdel-Wahab
The Normal And Inverted Meyer-Neldel Rule In The Ac Conductivity, Fouad Abdel-Wahab
Turkish Journal of Physics
Recently, a new approach has been proposed for the correlated barrier hopping (CBH) model where the ac relaxation time is thought to obey the Meyer-Neldel (MN) rule. This approach gives quantitative agreement with some reliable published experimental data. We report on an experiment involving the characterization of the ac conductivity of Se-Te thin films over a wide range of frequencies and temperatures, carried out in order to confirm applicability of the MN rule to the ac conductivity. In addition to the normal MN rule, the inverted MN rule was observed.
The Riemann Zeta Function Applied On Glassy Systems And Neural Networks, Viorel L. Cartas
The Riemann Zeta Function Applied On Glassy Systems And Neural Networks, Viorel L. Cartas
Turkish Journal of Physics
Glassy systems and Neural networks share a simple model of study: the model of a set of N non interacting harmonic oscillators with energy. In this paper the author tries to describe these complex systems in order to find the energy involved. The mathematical method used is described in detail.
Exceptionaly Low Amplitude Anisotropic Wave Train Events In Cosmic Ray Intensity, Rajesh K. Mishra, Rekha Agarwal Mishra
Exceptionaly Low Amplitude Anisotropic Wave Train Events In Cosmic Ray Intensity, Rajesh K. Mishra, Rekha Agarwal Mishra
Turkish Journal of Physics
The unusually low amplitude anisotropic wave train events (LAEs) in cosmic ray intensity using the ground-based Deep River neutron monitor data has been studied during the period 1991--94. It has been observed that the phase of the diurnal anisotropy for majority of the LAE events remains in the corotational direction. However, for some of the LAE events the phase of the diurnal anisotropy shifts towards earlier hours. On the other hand, the amplitude of the semi-diurnal anisotropy remains statistically the same whereas, phase shift towards later hours; similar trend has also been found in case of tri-diurnal anisotropy. The interplanetary …
Raman Scattering In Layered Cdingas_4, Aydin Kulibekov
Raman Scattering In Layered Cdingas_4, Aydin Kulibekov
Turkish Journal of Physics
Raman scattering spectra of CdInGaS_4 crystals grown by the chemical transport method were measured at room and liquid-nitrogen temperatures. Band pairs at 29-38, 43-48 and 60-65 cm^{-1} are reported for the first time. The origin of these bands is attributed to the Davydov doublets, arising due to a small interlayer interaction. Seventeen bands observed in the Raman spectra are assigned to normal modes on the basis of the C_{3v}^1 space group. This modification contains two layers per unit cell and do not have inversion symmetry. It is shown that the crystals grown from the vapor phase and by the Bridgman …
On Hamiltonian Formulation Of Non-Conservative Systems, Eqab M. Rabei, Tareq S. Alhalholy, A. A. Taani
On Hamiltonian Formulation Of Non-Conservative Systems, Eqab M. Rabei, Tareq S. Alhalholy, A. A. Taani
Turkish Journal of Physics
Fractional derivatives are used to construct the Lagrangian and the Hamiltonian formulation for non-conservative systems. To clarify the theory of Riewe two interesting examples are given. The potentials are obtained using the Laplace transform operator for fractional derivatives and the Lagrangian and Hamiltonian formulations are constructed for the two systems. Besides, it is shown that the Hamilton equations of motion are in agreement with the Euler-Lagrange equations for these systems.
The Hypervirial-Padé Summation Method Applied To The Anharmonic Oscillator, Altuğ Arda
The Hypervirial-Padé Summation Method Applied To The Anharmonic Oscillator, Altuğ Arda
Turkish Journal of Physics
The energy eigenvalues of the anharmonic oscillator characterized by the cubic potential for various eigenstates are determined within the framework of the hypervirial-Padé summation method. For this purpose the E[3, 3] and E[3, 4] Padé approximants are formed to the energy perturbation series and given the energy eigenvalues up to fourth order in terms of the anharmonicity parameter \lambda.
Determination Of The Rotational Constant A_0 And The Bending Angle Cnc For Ch_3 Nc And Ch_3 ^{15}Nc Molecules, Mohammad Al-Share
Determination Of The Rotational Constant A_0 And The Bending Angle Cnc For Ch_3 Nc And Ch_3 ^{15}Nc Molecules, Mohammad Al-Share
Turkish Journal of Physics
The rotational constant A_0 for the ground state of CH_3 NC and CH_3 ^{15}NC isotopomers is calculated using a technique which was used earlier for CH_3CCH [9], CH_3CN [10] and SiH_3CCH [11]. This technique is based on calculating the moment of inertia tensors in the bent configuration due to the \nu_8 vibrational state, which is associated with the CNC bending vibration. These values of the moments of inertia are fitted with the values calculated from the rotational constant B_V, found experimentally by measuring the rotational frequencies in the microwave and infrared regions. From the fitting, the rotational constant A_0, the …
A Novel Radiative Substrate Heater, Abdullah Ceylan, Erdal Kaynak, Şadan Özcan, Tezer Firat
A Novel Radiative Substrate Heater, Abdullah Ceylan, Erdal Kaynak, Şadan Özcan, Tezer Firat
Turkish Journal of Physics
In this work, we have developed a new low cost radiative substrate heater for deposition of high-T_c superconducting thin films. It has all the features required for the preparation of high quality superconducting thin films. It is possible to reach ~ 800 °C substrate temperature with it by using only one 250 W halogen projector bulb.
The Zero Position Of The Forward-Backward Asymmetry In The B \Rightarrow K\Ell^+\Ell^- Decay With New Physics Effects, Altuğ Arda
Turkish Journal of Physics
Using the most general model-independent effective Hamiltonian comprising local four-Fermi operators (scalar, vector, and tensor operators), we study the sensitivity of the zero position of the lepton asymmetry to the new operators beyond the Standard Model (SM) in the B \rightarrow K\ell^+\ell^- decay. It is found that among all operators, only the scalar and tensor operators contribute to the forward-backward asymmetry, in which case the forward-backward asymmetry has a non-vanishing value.
Physical Characteristics Of Polymer Magnetic Microspheres, Rasim A. Ali-Zade
Physical Characteristics Of Polymer Magnetic Microspheres, Rasim A. Ali-Zade
Turkish Journal of Physics
In this study the structure and the magnetic properties of polymer microspheres, filled with magnetite nanoparticles are investigated. Average particle size of magnetite nanoparticles before and after being introduced into polymer microspheres, and the distance between nanoparticles in the polymer microspheres, are measured. Magnetization curve of polymer magnetic microspheres (PMMS) is determined. The magnetic susceptibility of PMMS with various diameters, and the dependence of PMMS magnetic susceptibility on diameter are determined. Magnetization occurs due to the orientation of PMMS as a magnetic moment. The total magnetic moment of PMMS is the sum of magnetic moments of PMMS sections which consist …
Simulation Of Millimeter-Wave Gunn Oscillations In Gallium Nitride, Cem Sevi̇k, Ceyhun Bulutay
Simulation Of Millimeter-Wave Gunn Oscillations In Gallium Nitride, Cem Sevi̇k, Ceyhun Bulutay
Turkish Journal of Physics
High field transport in wide bandgap semiconductors like GaN is of great technological importance. The negative differential mobility regime at high fields, under suitable conditions, can lead to millimeter-wave Gunn oscillations. Using extensive simulation based an ensemble Monte Carlo technique, the prospects of GaN Gunn diodes are theoretically investigated. The possibility of operating these Gunn diodes at their higher harmonic modes are explored. The main finding of this research is that the carrier dynamics in GaN can be tailored by an optimum choice of doping profile, temperature and bias conditions so that the efficiency of higher harmonic Gunn oscillations can …
Calorimetric Studies Of The Crystallization Growth Process In Glassy Se_{70}Te_{30-X}Ag_X Alloys, N. Mehta, D. Kumar, A. Kumar
Calorimetric Studies Of The Crystallization Growth Process In Glassy Se_{70}Te_{30-X}Ag_X Alloys, N. Mehta, D. Kumar, A. Kumar
Turkish Journal of Physics
Differential Scanning Calorimetry (DSC) is performed at different heating rates under non-isothermal conditions to study the crystallization kinetics of Se_{.70}Te_{.26}Ag_{.04} and Se_{.70}Te_{.24}Ag_{.06} chalcogenide glasses in terms of the activation energy of nucleation and growth process. To understand the nucleation and growth process, the values of the growth morphology parameter n and the numerical factor m of crystallization mechanism have been evaluated using different non--isothermal methods. The values of n and m have been found to be nearly equal, indicating that the present glasses have sufficient nuclei before DSC experiment and the activation energy for nucleation process E_N is zero. Hence, …
Cyclotron Resonant Heating And Acceleration Of Protons, O Vi & Mg X Ions In The North Polar Coronal Hole, E. Rennan Pekünlü, Kadri̇ Yakut, Hi̇cran Şart
Cyclotron Resonant Heating And Acceleration Of Protons, O Vi & Mg X Ions In The North Polar Coronal Hole, E. Rennan Pekünlü, Kadri̇ Yakut, Hi̇cran Şart
Turkish Journal of Physics
Ultraviolet Coronograph Spectrometer aboard Solar and Heliospheric Observatory (SOHO) has revealed the existence of temperature anisotropy of many minor ion species that populate the north solar polar coronal hole. In this study, we examined the propagation characteristics of ion-cyclotron waves which resonate with protons, O VI and Mg X ions. In our empirical model, radial variation of the magnetic field, electron and ion number densities, perpendicular and parallel temperature of protons, O VI and Mg X ions are adopted from the measurements of various instruments aboard SOHO. Since most of the measurements of SOHO instruments begin at 1.5 R (=r/R_{\odot}) …
Scas Officers And Council Members 2004 - 2005
Scas Officers And Council Members 2004 - 2005
Journal of the South Carolina Academy of Science
No abstract provided.
Effect Of Radiation On The Persistent Length Of A Chain, B. L. Oksengendler, Ni̇gora Turaeva, I. N. Ruban, S. Sh. Rashidova
Effect Of Radiation On The Persistent Length Of A Chain, B. L. Oksengendler, Ni̇gora Turaeva, I. N. Ruban, S. Sh. Rashidova
Turkish Journal of Chemistry
The effect of radiation on the persistent length of a chain in a water solution of polymer is considered in the work. This effect is suggested to be related to the breaking of the hydrogen bonds in hydrate layers around the chain. The kinetic equation of the breakage of the hydrogen bonds is defined and the stationary solution is found with the help of the equation. The expression of average value of the persistent length of the chain at a fixed average number of broken bonds is determined by means of the Poisson distribution. We found that the persistent length …
^{1}H, ^{13}C, ^{119}Sn Nmr, Mass, Mössbauer And Biological Studies Of Tri-,Di- And Chlorodiorganotin(Iv) Carboxylates, Hajra Masood, Saqib Ali, Mohummad Mazhar, Saira Shahzadi, Khadija Shahid
^{1}H, ^{13}C, ^{119}Sn Nmr, Mass, Mössbauer And Biological Studies Of Tri-,Di- And Chlorodiorganotin(Iv) Carboxylates, Hajra Masood, Saqib Ali, Mohummad Mazhar, Saira Shahzadi, Khadija Shahid
Turkish Journal of Chemistry
The reaction of 2-[(2,3-dimethylphenyl)amino]benzoic acid (HL) with tri- and diorganotin(IV) chlorides yielded complexes of the type R_{3}SnL and R_{2}SnL_{2} (R = n-C_{4}H_{9}, C_{6}H_{5}, C_{6}H_{5}CH_{2}, n-C_{8}H_{17}). The compounds R_{2}SnClL were obtained by a redistribution reaction between R_{2}SnL_{2} and R_{2}SnCl_{2}. All the compounds were characterized by CHN analysis, infrared, multinuclear NMR, mass and Mössbauer spectroscopy. The possible mode of carboxylate group bonding in solid as well as in solution is proposed on the basis of infrared, Mössbauer and NMR (^{1}H, ^{13}C, ^{119}Sn) spectroscopy.
Synthesis And Characterization Of Cu(Ii) Complexes Of Two Ligands Derived From Malonyl Dichloride, Nevi̇n Karaböcek, Serdar Karaböcek, Hasan Mazlum, İsmai̇l Deği̇rmenci̇oğlu, Keri̇m Serbest
Synthesis And Characterization Of Cu(Ii) Complexes Of Two Ligands Derived From Malonyl Dichloride, Nevi̇n Karaböcek, Serdar Karaböcek, Hasan Mazlum, İsmai̇l Deği̇rmenci̇oğlu, Keri̇m Serbest
Turkish Journal of Chemistry
Two different mononucleating ligands incorporating N_{4} and N_{2}S_{2} donor units, 2-(1,3-benzothiazole-2-yl-methyl)-1,3-benzothiazole (L^{1}) and N,N'-bis-(2-amino-phenyl)-malonamide (H_{2}L^{2}) were synthesized by a new method from malonyl dichloride as starting material, and their mononuclear copper(II) complexes were prepared and characterized by elemental analyses, ^{1}H- and ^{13}C-NMR, IR, magnetic moments and mass spectral studies. Elemental analyses, and stochiometric and spectroscopic data of the metal complexes indicate that the metal ions are coordinated to the nitrogen and sulfur atoms and the data support the proposed structure of L^{1}, H_{2}L^{2} and their mononuclear copper(II) complexes. Moreover, the copper(II) complexes of L^{1} and H_{2}L^{2} have a 1:1 metal …
Synthesis And Antimicrobial Activity Of Some Pyridyl And Naphthyl Substituted 1,2,4-Triazole And 1,3,4-Thiadiazole Derivatives, Khosrow Zamani, Khalil Faghihi, Taraneh Tofighi, Mohammad Reza Shariatzadeh
Synthesis And Antimicrobial Activity Of Some Pyridyl And Naphthyl Substituted 1,2,4-Triazole And 1,3,4-Thiadiazole Derivatives, Khosrow Zamani, Khalil Faghihi, Taraneh Tofighi, Mohammad Reza Shariatzadeh
Turkish Journal of Chemistry
Synthesis of new 1,2,4-tri and 1,3,4-thiadiazoles, bearing isomeric pyridyl and 1-naphthyl is reported using 1,4-disubstituted thiosemicarbazides in alkaline and acidic media, respectively. The methylthio and benzylthio derivatives of the synthesized triazoles are also reported. All of the synthesized compounds were characterized by their FT-IR, ^{1}H-NMR and mass spectral data. The antibacterial studies of some of the synthesized compounds against S. aureus} and E. coli} as MIC values are reported. None of them have important antibacterial activities.
Acylated Iridoid Glycosides From Verbascum Lasianthum, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Acylated Iridoid Glycosides From Verbascum Lasianthum, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Turkish Journal of Chemistry
From the roots of Verbascum lasianthum Boiss. ex Bentham 4 catalpol derivatives, 6-O-(\alpha-L-rhamnopyranosyl)-catalpol (1), verbascoside A [= 6-O-(4''-O-trans-p-methoxycinnamoyl)-\alpha -L-rhamnopy- ranosylcatalpol] (2), pulverulentoside I [= 6-O-(3''-O-acetyl-2''-O-trans-p-methoxycinnamoyl)-\alpha -L-rham-nopyranosylcatalpol] (3), and buddlejoside A_{5} [= 6-O-(2''-O-acetyl-3''-O-trans-p-methoxycinnamoyl)-\alpha -L-rhamnopyranosylcatalpol] (4), as well as aucubin (5) and an aucubin derivative, unduloside III [= 6-O-(3''-O-trans-p-methoxycinnamoyl)- \alpha-L-rhamnopyranosylaucubin] (6), were isolated and characterized. The structure elucidation of the compounds was established on the basis of spectroscopic evidence. Buddlejoside A_{5} (4) was found for the first time in the genus Verbascum.
Cationic Rearrangements Of An Endo}-Cyclopropyl Methanol System Incorporated In A Benzonorbornadiene System, Abdullah Menzek, Melek Karakaya
Cationic Rearrangements Of An Endo}-Cyclopropyl Methanol System Incorporated In A Benzonorbornadiene System, Abdullah Menzek, Melek Karakaya
Turkish Journal of Chemistry
Chloride 18 (47%) and alcohol 21 (44%) were isolated from the reaction of alcohol 20 with SOCl_2. Cyclopropylcarbinyl -- cyclopropylcarbinyl rearrangement leads to chloride 22, which hydrolyses on separation to give alcohol 21. Chloride 18 results from cyclopropyl -- allylcarbinyl rearrangement, followed by a 1,2 -- aryl shift (sequential rearrangement). Syntheses of compounds 23 and 24 support the structures. The behaviour of 20 differs from that of exo isomer 14, probably due to the nature of the intermediates in these reactions.
3-Hydroxy Fatty Acids From The Flowers Of Hypericum Lysimachioides Var. Lysimachioides, Hasan Çeti̇n Özen, Mehmet Başhan, Zuhal Toker, Cumali̇ Keski̇n
3-Hydroxy Fatty Acids From The Flowers Of Hypericum Lysimachioides Var. Lysimachioides, Hasan Çeti̇n Özen, Mehmet Başhan, Zuhal Toker, Cumali̇ Keski̇n
Turkish Journal of Chemistry
Fatty acid methyl esters in the leaves and flowers of Hypericum lysimachioides var. lysimachioides (Guttiferae) were analyzed by gas chromatography and gas chromatography-mass spectrometry. The flowers of H. lysimachioides var. lysimachioides produced unusual 3-hydroxy fatty acids [3-hydroxy- tetradecanoic acid (3-OH-C14:0) and 3-hydroxy-octadecanoic acid (3-OH-C18:0)], along with other normal fatty acids. Major components were linolenic and palmitic acids for both leaves and flowers.
Flame Atomic Absorption Spectrometric Determination Of Manganese In Alloys After Preconcentration Onto Amberlite Xad-4 Loaded With Saccharomyces Carlsbergensis, Sitki Baytak, A. Rehber Türker
Flame Atomic Absorption Spectrometric Determination Of Manganese In Alloys After Preconcentration Onto Amberlite Xad-4 Loaded With Saccharomyces Carlsbergensis, Sitki Baytak, A. Rehber Türker
Turkish Journal of Chemistry
A sensitive and simple enrichment method using microorganisms as an adsorbent is described for the determination of trace manganese in alloys. Manganese was determined by flame atomic absorption spectrometry after preconcentration onto Amberlite XAD-4 loaded with Saccharomyces carlsbergensis. The optimum values of pH, amount of adsorbent, amount of microorganism, eluent type and volume of sample solution were determined for the quantitative recovery (>95%) of manganese. Results have been compared with those obtained without using microorganisms. Under optimum conditions, recoveries were 98 \pm 3% with microorganisms and 68 \pm 2% without microorganisms for manganese at a 95% confidence level. The …
Synthesis And Some Reactions Of 4-Benzoyl-5-Phenyl-1-Pyridin-2-Yl-1h- Pyrazole-3-Carboxylic Acid, Ahmet Şener, Esvet Akbaş, M. Kasim Şener
Synthesis And Some Reactions Of 4-Benzoyl-5-Phenyl-1-Pyridin-2-Yl-1h- Pyrazole-3-Carboxylic Acid, Ahmet Şener, Esvet Akbaş, M. Kasim Şener
Turkish Journal of Chemistry
The 1H-pyrazole-3-carboxylic acid 2, obtained from the furandione 1 and 2-hydrazinopyridine, was decarboxylated to give 4-benzoyl-5-phenyl-1-pyridin-2-yl-pyrazole derivative 3. Some ester 4 derivatives of 2 were prepared by the Fischer esterification reactions of 2 with various alcohols. Cyclocondensation reactions of 2 with phenyl hydrazine or hydrazine hydrate led to the formation of derivatives of pyrazolo[3,4-d]pyridazine 5 derivatives.
Chemically Crosslinked N-Vinyl-2-Pyrrolidone/2-Hydroxyethyl Methacrylate (Vp/Hema) Copolymer For The Controlled Release Of Cyclic Oligopeptide, Bashir Ahmad, Shumaila Bashir, Shams-Un Nisa, M. B. Huglin
Chemically Crosslinked N-Vinyl-2-Pyrrolidone/2-Hydroxyethyl Methacrylate (Vp/Hema) Copolymer For The Controlled Release Of Cyclic Oligopeptide, Bashir Ahmad, Shumaila Bashir, Shams-Un Nisa, M. B. Huglin
Turkish Journal of Chemistry
Crosslinked copolymers of various compositions of N-vinyl-2-pyrrolidone (VP) and 2-hydroxyethyl methacrylate (HEMA) were prepared chemically in the presence of a crosslinking agent. The swelling mechanism was non-Fickian with about 86% conversion of feed composition to crosslinked copolymer. The reactivity ratios r_1 = 0.045 and r_2 = 3.07 for VP and HEMA indicate that HEMA is more reactive than VP in the reaction. Hydrophilicity, hydrophobicity and monomer composition in the copolymer controlled the drug release from the hydrogels.
A Convenient Synthesis Of 3,6-Disubstituted-1,4-Dihydro-[1,2,4,5]Tetrazines And Preparation Of New Acetic Acid Derivatives Containing 5-Oxo-4-Phenylamino- 4,5-Dihydro-[1,2,4]Triazole, Ahmet Demi̇rbaş
Turkish Journal of Chemistry
A series of compounds 8a-e, was synthesized by condensation of compounds 7a-e with ethyl bromoacetate. The treatment of compounds 8a-e with hydrazine hydrate afforded the corresponding hydrazide derivatives (9a-e). Subsequently, compounds 9a-e were converted to alkylidene hydrazides (10a-e). Moreover, upon heating in the presence of carboxylic acids, compounds 9a-e unexpectedly gave 1,4-dihydro-[1,2,4,5]tetrazine derivatives (11a-e).
The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid
The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid
Turkish Journal of Chemistry
The photochemical reduction of methylene green with methylamine and ethylamine in 50% aqueous isopropanol was studied. The photochemical reduction was carried out in a special type of optical processor associated with a deoxygenating system, a temperature controlling unit and a magnetic stirring system. A monochromatic light of 657 nm wavelength was used for irradiation of oxygen free reaction solutions in a double walled reaction cell. The transmitted light was measured and recorded in terms of electrical signals with the help of a calibrated galvanometer. Acidities of the solutions were measured with the help of a spectrophotometer based on the Hammet …