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Search Results: 1 - 10 of 648969 matches for " M. G. R.; "
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Swelling Behavior of Polyacrylamide Hydrogels near Phase Transition  [PDF]
R. R. Janot Pacheco, M. E. S. R. Silva, R. G. Sousa, R. F. S. Freitas
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.58063
Abstract:
Hydrogels based on acrylamide (AA) and sodium methacrylate (NMA) as ionic monomer were prepared by solution polymerization using N,N’-methylenebis(acrylamide) (MBA) or ethylene glycol dimethacrylate (EGMA) as crosslinkers and Ammonium Persulfate (APS) and N,N,N’,N’-Te-tramethyl-ethylenediamine (TMEDA) as initiators. Swelling behavior was greatly affected by NMA content near phase transition. Increasing ionic monomer concentration compared to total monomer one led to high expansion in water, oscillating around 285 g/g for MBA and 325 g/g for EGMA crosslinker, above 20% of NMA. Dynamic Light Scattering experiments were performed and, for both crosslinkers, the dynamic correlation length (ξ) decreased with increasing NMA content, contributing to diminish hydrogels spatial inhomogeneities.
Continuous Dependence for the Pseudoparabolic Equation
Yaman M,Gür
Boundary Value Problems , 2010,
Abstract: We determine the continuous dependence of solution on the parameters in a Dirichlet-type initial-boundary value problem for the pseudoparabolic partial differential equation.
Using the Resistance Depending on the Magnetic and Electric Susceptibility to Derive the Equation of the Critical Temperature  [PDF]
H. G. I. Hamza, M. H. M. Hilo, R. Abd Elgani, R. Abd Elhai, Mubarak Dirar
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.617119
Abstract: In this study the electromagnetic theory and quantum mechanics are utilized to find the resistivity in terms of electric and magnetic susceptibility in which the electron is considered as a wave. Critical temperature of the wire at which the resistance vanishes is found. In this case the resistance being imaginary which leads the real part of the resistance to real zero at critical temperature and the material becomes super conductor in this case. If one considers the motion of electron in the presence of inner magnetic field and resistance force, a new formula for the conductivity is to be found; this formula states that the material under investigation becomes a superconductor at critical temperature and depends on the strength of the magnetic field and friction resistance, and the substance conductivity is found to be super at all temperatures beyond the critical temperature.
Effect of Weak Magnetic Intergranular Phase on the Coercivity in the HDDR Nd-Fe-B Magnet  [PDF]
M. LIU, G. B. HAN, R. W. GAO
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.14038
Abstract: Assuming that intergranular phase (IP) existing between adjacent grains is a weak magnetic phase, we study the effect of IP on the coercivity in the HDDR Nd-Fe-B magnet. The results indicate that the coercivity increases with the increasing IP’s thickness d, but decreases with increasing its anisotropy constant K1(0). When the structure defect thickness r0 =6nm, d=1nm and K1(0)=0.15K1 (K1 is the normal anisotropy constant in the inner part of a grain), our calculated coercivity is in agreement with available experimental data.
Design and Development of a 2 × 1 Array of Slotted Microstrip Line Fed Shorted Patch Antenna for DCS Mobile Communication System  [PDF]
G. A. Bidkar, R. M. Vani, P. V. Hungund
Wireless Engineering and Technology (WET) , 2013, DOI: 10.4236/wet.2013.41009
Abstract:

Compact microstrip antennas have recently received much attention due to the increasing demand of small antennas for personal communication equipment. The problem of achieving a wide impedance bandwidth for compact microstrip antennas is becoming an important topic in microstrip antenna design. In this paper the design and development of a 2 × 1 array of a low cost slotted microstrip line fed shorted patch antenna (MFSPA) has been presented. Both the shorted patch and microstrip line feed network have air substrate. The material cost is thus reduced to a minimum. The array consists of two adjacent patches fed, using a simple microstrip T network. The impedance bandwidth of nearly 40%, covering the bandwidth requirement of 1750 MHz band is obtained. Also the antenna exhibits dual band operation. The cross polarization radiation in H-Plane observed with a single element antenna has been reduced considerably with 2 × 1 array. A peak antenna gain of 9.2 dBi is obtained with a small variation of 0.8 dBi. From the results obtained it is clear that the antenna array studied has a low cost fabrication and is suitable for applications in DCS mobile communication base station.

 

New Formulation Strategies in Topical Antifungal Therapy  [PDF]
Sevgi Güng?r, M. Sedef Erdal, Buket Aksu
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2013, DOI: 10.4236/jcdsa.2013.31A009
Abstract:

Fungal infections of the skin are one of the often faced with dermatological diseases in worldwide. Topical therapy is an attractive choice for the treatment of the cutaneous infections due to its advantageous such as targeting of drugs to the site of infection and reduction of the risk of systemic side effects. Currently, antifungal drugs are generally used as conventional cream and gel preparations in topical treatment. The efficiency of that treatment depends on the penetration of drugs through the target layers of the skin at the effective concentrations. However, stratum corneum, the outermost layer of the skin, is an effective barrier for penetration of drugs into deeper layers of the skin. The physicochemical characteristics of drug molecules and the types of the formulations are effective factors in topical drug delivery. Therefore, a number of formulation strategies have been investigated for delivering antifungal compounds through targeted site of the skin. This review article focuses on the new alternative formulation approaches to improve skin penetration of antifungal drugs.

Nose and Sinus Air Flow Model  [PDF]
R. De Luca, M. Gamerra, G. Sorrentino, E. Cantone
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.610068
Abstract: Air flow in nose and sinuses is studied by means of a simple model based on the steady-state ideal fluid flow assumption and repeated use of Bernoulli’s equation. In particular, by describing flow of air drawn in through the vestibulumnasi during inspiration, we investigate how ventilation of the maxillary sinus is affected by surgical removal of part of the lateral walls of the nasal cavity close to the ostiummeatal complex. We find that, according to the model proposed, removal of tissues from this inner part of the nasal cavity may cause a decrease of the flux rate from the maxillary sinus.


Deciphering of Space Images of the Inder Salt-Dome Upland in ENVI 4.7 Program  [PDF]
K. M. Akhmedenov, A. G. Koshym, R. Z. Zhumabekova
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.53029
Abstract:

Space images play an important role in the Earth study as they bring the main information received from the Space Flyer Units (SFU) to help researchers. Space images’ deciphering gives the opportunity to study the territory and to plot different maps. On the basis of the space image obtained from Landsat 5TM (30 m resolution, 01.09.2012 year), we managed to get a picture of the modern relief of the northern part of Inder lake. When comparing the space image with topographic maps of 1985, we succeeded to identify the dynamics of landforms change on the studied area, what has been shown on the drawn map of the relief of the Inder salt dome uplift. 14 classes, corresponding to a particular type of terrain or to a landscape complex, have been distinguished on the studied area. Inder salt dome uplift is a paradynamic conjugation, consisting of highly karsted Inder Mountains corresponding to large diapir uplift, and of the Inder Lake having a large ellipsoidal shape. Geomorphologically, the investigated territory is located on the left bank of Zhaiyk River, and presents a salt dome uplift in the form of a plateau-like hill raised above the surrounding surface from 12 to 40 m. The maximum height reaches 42.5 m (g. Suatbaytau). The crest of the Inder salt dome is composed of Low Permian sediments (rock salt with anhydrite, potassiummagnesium salts), and has an area of about 210 km2. Inder lake’s basin is represented by a tectonic depression, which is the local basis of erosion and is a drainage place of the Inder uplift karstic water. The lake area is 150 km2. Depending on the climatic conditions, the water level can vary.

Synthesis of 4-Phenylphthalonitrile by Vapor-Phase Catalytic Ammoxidation of Intermediate 4-Phenyl-o-Tolunitrile: Reaction Kinetics  [PDF]
G. A. Bagirzade, D. B. Tagiyev, M. R. Manafov
Modern Research in Catalysis (MRC) , 2014, DOI: 10.4236/mrc.2014.31002
Abstract:


Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl-o-tolu- nitrile into the aimed 4-phenylphthalonitrile and CO2 are described by half-order equation on concentration of substratum and to be independent of the oxygen and ammonia partial pressures. It has been revealed that formation of 4-phenylphthalimide from byproducts is due to hydrolysis of 4-phenylphthalonitrile; carbon dioxide is produced by oxidation of 4-phenyl-o-tolunitrile and decarboxylation of 4-phenylphthalimide, and 4-phenylben- zonitrile is produced from 4-phenyl-o-tolunitrile and 4-phenylphthalimide.


UPLCMS Method Development and Validation of Amlodipine, Hydrochlorthiazide and Losartan in Combined Tablet Dosage Form  [PDF]
Anandkumar R. Tengli, G. Shivakumar, B. M. Gurupadayya
American Journal of Analytical Chemistry (AJAC) , 2015, DOI: 10.4236/ajac.2015.63021
Abstract: A simple, rapid, sensitive and specific UPLCMS method was developed and validated following ICH guidelines for simultaneous estimation of tablet dosage form containing amlodipine (AMLO) hydrochlorothiazide (HCT) and losartan (LOSAT) using telmisartan (TELMI) as an internal standard (IS). The separation was achieved using Waters ACQUITY BEH C18 (1.7 μm, 2.1 × 50 mm) column with gradient mode, mobile phase containing acetonitrile (A) & 1% ammonium acetate (B) pH adjusted to 2.8 with trifluoro acetic acid with gradient mode. The flow rate was 0.4 mL·mL﹣1 and the injection volume 2 μl. The retention time for amlodipine, hydrochlorothiazide and losartan was found to be 3.7, 2.5 and 3.9 min, respectively. The developed method was found to be linear over the concentration range of 50 - 300 ng·mL﹣1, 125 - 750 ng·mL﹣1 and 500 - 3000 ng·mL﹣1 for AMLO, HCT and LOSAT respectively. The signal intensities obtained in ion mode for amlodipine, hydrochlorothiazide, losartan and telmisartan (IS) they were found to be much higher positive ion mode (M+)﹣ parent ion at m/z, 409.02, 297.97, 422.91 and 515.03, respectively, in QUATTROZQ full scan mass spectra.
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