Preparación y caracterización de oleogeles con sebo y sebo parcialmente hidrolizado como organogeladores

The aim of this study was to evaluate the organogelation potential of tallow fat (TF) and partially hydrolyzed tallow fat (HTF) against saturated monoglyceride (MG) and a saturated monoglyceride + diglyceride mixture (MDG) as the organogelators. TF itself created oleogel at a 30% addition level, while HTF, MG and MDG oleogels were prepared at 10% addition levels. Fatty acid composition data showed that the oleogel of HTF (HTFO) was quite similar to those of MG and MDG oleogels. Solid fat content, free fatty acidity and peroxide values were found to be in acceptable ranges for HTFO. Thermal properties, crystal morphology and X-ray diffraction patterns were also evaluated. Rheological analyses indicated that all oleogels had higher storage modulus (G´) than loss modulus (G´´). The time-sweep test showed that after applying higher shear rates, the gels re-formed at rest. Further, all oleogels maintained their gelled consistency until around 54 °C. The results suggest that HTF could be a cheap, efficient, fast melting, safe and readily available organogelator.El objetivo de este estudio fue evaluar el potencial de la organogelación de grasa de sebo (GS) y grasa de sebo parcialmente hidrolizada (GSH) contra monoglicéridos saturados (MG) y mezcla de monoglicéridos + diglicéridos saturados (MDG) como organogelantes. Con la propia GS se creó un oleogel con un nivel de adición del 30%, mientras que los oleogeles de GSH, MG y MDG se prepararon con niveles de adición del 10%. Los datos de composiciones de ácidos grasos mostraron que el oleogel de GSH (OGSH) era bastante similar a los oleogeles de MG y MDG. El contenido de grasa sólida, la acidez grasa libre y los valores de peróxido se encuentran en rangos aceptables para OGSH. También se evaluaron las propiedades térmicas, la morfología del cristal y los patrones de difracción de rayos X. Los análisis reológicos indicaron que todos los oleogeles tenían un módulo de almacenamiento (G´) mayor que el módulo de pérdida (G´´). La prueba de barrido de tiempo mostró que después de aplicar velocidades de cizallamiento más altas, los geles se reformaron en reposo. Además, todos los oleogeles protegieron su consistencia gelificada hasta alrededor de 54 °C de temperatura. Los resultados han sugerido que GSH podría ser un organogelador barato, eficiente, de fusión aguda, seguro y fácilmente disponible

On The Dynamics Of The Difference Equation

In this paper, we studied the global behavior of the difference equation nbspwith non-negative parameters and the initial conditions nbspare non-negative real numbers

Frequency and temperature dependence of the dielectric and AC electrical conductivity in (Ni/Au)/AlGaN/AIN/GaN heterostructures

Cataloged from PDF version of article.The dielectric properties and AC electrical conductivity (sigma(ac))of the (Ni/Au)/Al(0.22)Ga(0.78)N/AlN/GaN heterostructures, with and without the SiN(x) passivation, have been investigated by capacitance-voltage and conductance-voltage measurements in the wide frequency (5kHz-5 MHz) and temperature (80-400 K) range. The experimental values of the dielectric constant (epsilon'), dielectric loss (epsilon ''), loss tangent (tan delta), sigma(ac) and the real and imaginary part of the electric modulus (M' and M '') were found to be a strong function of frequency and temperature. A decrease in the values of epsilon' and epsilon '' was observed, in which they both showed an increase in frequency and temperature. The values of M' and M '' increase with increasing frequency and temperature. The sigma(ac) increases with increasing frequency, while it decreases with increasing temperature. It can be concluded, therefore, that the interfacial polarization can occur more easily at low frequencies and temperatures with the number of interface states density located at the metal/semiconductor interface. It contributes to the epsilon' and sigma(ac). (C) 2009 Elsevier B.V. All rights reserved

Incisional hernia treatment with polypropylene graft: results of 10 years

Purpose: To report herein our results of tension-free repair of large incisional hernia with polypropylene mesh using a modification of the method that was described by Usher. Method: Two hundred ninety-one patients who were operated on between January 1994 and December 2004 were studied. Two hundred thirty-two patients were female (79.7%), and 59 were male (20.3%). The average follow-up period was 55 months. The patients were evaluated for infection, recurrences, hematoma and seroma formation, sinuses and enterocutaneous fistula formation. Results: Infection was observed in eight patients (2.7%). Graft removal due to infection was encountered only in two patients (0.6%). Recurrence was observed in six patients (2.1%). Two patients (0.6%) developed hematoma while another two developed seroma. No patient developed enterocutaneous fistula. Conclusion: By using our modified technique wecan decrease the expected complications after tension-free repair of large incisional hernias. © Springer-Verlag 2006

Frequency and temperature dependence of the dielectric and AC electrical conductivity in (Ni/Au)/AlGaN/AlN/GaN heterostructures

The dielectric properties and AC electrical conductivity (σ ac)of the (Ni/Au)/Al 0.22Ga 0.78N/AlN/GaN heterostructures, with and without the SiNx passivation, have been investigated by capacitance-voltage and conductance-voltage measurements in the wide frequency (5kHz-5 MHz) and temperature (80-400 K) range. The experimental values of the dielectric constant (ε'), dielectric loss (ε' '), loss tangent (tand), σ ac and the real and imaginary part of the electric modulus (M' and M' ') were found to be a strong function of frequency and temperature. A decrease in the values of ε' and ε' ' was observed, in which they both showed an increase in frequency and temperature. The values of M' and M' ' increase with increasing frequency and temperature. The σ ac increases with increasing frequency, while it decreases with increasing temperature. It can be concluded, therefore, that the interfacial polarization can occur more easily at low frequencies and temperatures with the number of interface states density located at the metal/semiconductor interface. It contributes to the e' and σ ac. © 2009 Elsevier B.V. All rights reserved

Frequency dependent electrical characteristics of (Ni/Au)/AlGaN/AlN/GaN heterostructures

The main electrical parameters such as ideality factor (n), zero bias barrier height (Bo), series resistances (R s), depletion layer width (W D) and interface state densities (N SS) of (Ni/Au)/AlGaN/AlN/GaN heterostructures have been extracted from the current-voltage (I-V) at room temperature, and frequency dependent capacitance voltage (C-V) and conductance-voltage (G/w-V) measurements. The high value of n and R s were attributed to the existence of an interfacial layer (IL) and particular distribution of N ss. The density distrubition profile of N ss was obtained from both forward bias I-V data and low-high frequency (C LF-C HF) measurement methods. In addition, the voltage dependent R s profile obtained both I-V and admittance measurements are in good agreement. As a result, the existence of an IL, R s and N ss lead to deviation from the ideal case of these heterostructures

Prevalence of Subclinical Hypothyroidism among Patients with Acute Myocardial Infarction

Introduction. Subclinical hypothyroidism (SCH) is defined as a serum thyroid-stimulating hormone (TSH) level above the upper limit of normal despite normal levels of serum free thyroxine. There is growing evidence that SCH is associated with increased cardiovascular risk. We tried to investigate prevalence of SCH in acute myocardial infarction patients. Methods and Results. We evaluate free T3, free T4, and TSH levels of 604 patients (age 58.4) retrospectively, who have been admitted to the coronary intensive care unit between years 2004–2009 with the diagnosis of ST elevation (STEMI) or non-ST elevation acute myocardial infarction (NSTEMI). Mild subclinical hypothyroidism (TSH 4.5 to 9.9 mU/l) was present in 54 (8.94%) participants and severe subclinical hypothyroidism (TSH 10.0 to 19.9 mU/l) in 11 (1.82%). So 65 patients (10.76%) had TSH levels between 4.5 and 20. Conclusions. In conclusion, 65 patients (10.76%) had TSH levels between 4.5 and 20 in our study, and it is a considerable amount. Large-scale studies are needed to clarify the effects of SCH on myocardial infarction both on etiologic and prognostic grounds