Hygro-Thermo-Electric Properties of Carbon Nanotube Epoxy Nanocomposites with Agglomeration Effects

In the present study, the effective electric, thermal, and moisture properties of carbon nanotube (CNT) epoxy composites are derived by considering the agglomeration effect of CNT concentrations in the epoxy matrix. In this direction, the Voigt and Reuss homogenization method is adopted in the derivations. It is well known from experiments that the CNT thermal and electrical conductivities and the epoxy hygro-thermal expansion coefficients have significant effects on the behavior of CNT nanocomposites. Moreover, it has been experimentally proved that the agglomeration of CNTs in the matrix with high and low concentrations of the CNTs certainly affects the resistivity and, hence, the thermal expansion properties. Therefore, the effective elastic, thermal, electrical, and moisture properties for the randomly distributed CNTs in the matrix has been derived in terms of the agglomeration volume fractions of CNTs. In the effective relations, a single agglomeration parameter is considered to be active for a given potential. The results of variation in the hygro-electro-thermal properties due to change in CNT volume fraction as well as agglomeration parameters have been presented. The results and observation show that CNT agglomeration has a strong influence on the effective hygro-thermo-electric properties of the nanocomposites.     

Novel Drying Technology of Microsphere and Its Evaluation for Targeted Drug Delivery for Lungs

Carbopol microspheres of methotrexate (MxtCM), a drug used in the treatment of lung cancer, were prepared using a Buchi B-90 nano spray dryer. The surface morphology was found to be shriveled to nearly spherical, with an average size of 6.8 µm. The drug loading and percentage yield were found to be 77% ± 0.3% and 89% ± 0.4%, respectively. The in-vitro release was suggestive of the Baker and Lonsdale model, as the release pattern involved swelling and diffusion; the total methotrexate release after 12 h was 98.2% from MxtCM while, for the pure drug, it was 94.2% at 0.5 h. Liquification was witnessed during the stability studies at 37°C and at a relative humidity of 75%. This study concludes that the microsphere could be one of the most appropriate drug delivery methods for the successful delivery of methotrexate to the lungs. The pharmacokinetic (drug concentration) results following intravenous administration were 1,021 µg/g after 15 min; in comparison, in the spleen and liver, the concentration of the conventional dosage of Mxt was <401 µg/g after 10 min. We concluded that the methotrexate concentration was increased in the lungs when compared to the blood, spleen, and liver. The ingredients used in the formulation were confirmed harmless from histopathological studies. Thus, microspheres can be adopted in formulating and targeting methotrexate to the lungs.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART I WITH AND WITHOUT POUR POINT DEPRESSANT ADDITIVES

ABSTRACT

The yield stress, plastic viscosity and apparent viscosity and the dependence of the latter on the shear rate have been studied at different temperatures below pour point of Lingala (Krishna-Godavari basin, Eastern coast), Duliajan (Eastern region of Assam), Rava (Godavari basin) and Bombay-High (off-shore western region) indigenous crude oils

Four different commercial pour point depressant additives have been used to study their effects on the pour point, yield stress and plastic viscosity

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point, and crude base composition has a small effect. However, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the liquid matrix. As the temperature is lowered both the yield stress and plastic viscosity increase in case of each crude oil. However, the magnitude is dependent on the nature of the crude oil. With pour point depressant additives, the yield stress and plastic viscosity are decreased and this decrease is a function of nature of the liquid matrix of the crude oil and concentration of the additive     

Optimum anamorphic image generation using image rotation and relative entropy

Multimedia Tools and Applications - Anamorphosis is related to the art that gives illusion (distortion) over the image or object when the viewer looks the original image or from the random...     

Ledipasvir and Sofosbuvir for untreated HCV genotype 1 infection in end stage renal disease patients: A prospective observational study

Introduction: Hepatitis C virus (HCV) infection in end stage renal disease (ESRD) is associated with increased mortality. Recently, numerous directly acting antiviral agents have been approved for the management of HCV. Ledipasvir along with Sofosbuvir has been approved for management of genotype 1 infection in patients with eGFR ≥30 mL/min. However, there is paucity of data regarding its role in the management of patients on dialysis. Material and Methods: This is a single center prospective open label observational study to assess the safety and efficacy of Ledipasvir and Sofosbuvir in hemodialysis (HD) patients who were diagnosed with HCV genotype 1 infection. Eligibility criteria were treatment naive HD patients with normal liver histology. We administered Ledipasvir and Sofosbuvir combination tablet on alternate days for a period of 12 weeks. Primary efficacy end point was the assessment of sustained virological response (SVR12), and the safety end point was the discontinuation of therapy secondary to adverse drug effects. Results: A total of 21 patients were treated with this regimen. Two patients expired during the study period and are not related to the therapy. SVR12 was achieved in all the 19 patients. None of the patients in our study discontinued the therapy or had severe adverse drug effects. One patient had head ache and another patient had giddiness which were managed symptomatically. Conclusion: Ledipasvir and Sofosbuvir combination therapy on alternate days, is effective even in ESRD patients, with excellent SVR12 rates, and it is as safe as in other population groups, without any major adverse reactions.     

Squeeze Infiltration Processing of Functionally Graded Aluminum–SiC Metal Ceramic Composites

The objective of the present work is on fabrication of functionally graded SiC/Al composite by direct squeeze infiltration of 6061 aluminum alloy using graded SiC porous preform prepared by inorganic porogen technique. Graded SiC preform is synthesized by varying the concentration of inorganic salt mixture and using Al as the binder. The microstructure analysis indicates the graded distribution of SiC particle and the melt has infiltrated completely throughout the preform to form functionally graded materials. The influence of preform and mold temperature, liquid metal superheat, squeeze pressure, and its rate of application plays major role on solidification microstructures and properties of the composites. The macro porous graded SiC preforms and the composites were characterized using SEM, optical microscopy, and XRD. The major interfacial reaction product is MgAl₂O₄ spinel which helps in formation of good interface bonding.     

Microstructural and Mechanical Characterization of Two Aluminium Based In Situ Composite Foams

In situ composites are multiphase materials where the reinforcing phase is synthesized within the matrix during composite fabrication. The present paper deals with the processing, microstructural and mechanical characterization of Al?C7Si?C0.3Mg?C10TiB₂ and Al?C4Cu?C10TiB₂ foams. Composite foams with very low relative density (??_r?=?0.17?C0.37) and foams containing uniform cell sizes were successfully processed. Since the TiB₂ particle sizes are less than 2???m and have a good wetting behaviour, TiB₂ can be very good foam stabilizers. Microstructural characterization of the cell walls showed significant grain refinement since TiB₂ is a grain refiner. Elemental mapping clearly showed TiB₂ particles at inter dendritic boundaries. Compression testing of the processed foams showed some interesting features. Stress?Cstrain curve showed a lot of serrations which indicated brittle fracture of the cell walls and edges. Hence, it is observed that a balance should be attained between the grain refinement of ??-Al grains and the amount of TiB₂ particles to obtain desirable mechanical properties. Energy absorbed by the processed foams was calculated and they were observed to be close to that of the commercially available ALPORAS foams.     

LOW TEMPERATURE FLOW CHARACTERISTICS OF SOME WAXY CRUDE OILS IN RELATION TO THEIR COMPOSITION : PART I WITH AND WITHOUT POUR POINT DEPRESSANT ADDITIVES

The yield stress, plastic viscosity and apparent viscosity and the dependence of the latter on the shear rate have been studied at different temperatures below pour point of Lingala (Krishna-Godavari basin, Eastern coast), Duliajan (Eastern region of Assam), Rava (Godavari basin) and Bombay-High (off-shore western region) indigenous crude oils

Four different commercial pour point depressant additives have been used to study their effects on the pour point, yield stress and plastic viscosity

From this study it has been found that wax concentration and its composition are primarily responsible for the variation in the pour point, and crude base composition has a small effect. However, the response of the pour point depressant additive in effecting the change in the pour point is primarily governed by the liquid matrix. As the temperature is lowered both the yield stress and plastic viscosity increase in case of each crude oil. However, the magnitude is dependent on the nature of the crude oil. With pour point depressant additives, the yield stress and plastic viscosity are decreased and this decrease is a function of nature of the liquid matrix of the crude oil and concentration of the additive