91 research outputs found
DESIGN, FABRICATION AND EVALUATION OF SS 316 PUNCH DIE SET FOR ACCURATE SIZING OF SODIUM CROMOGLYCATE OCULAR INSERTS
Objective: Objective of the study was to design, fabricate & evaluate punch die set for accurate sizing of sodium cromoglycate ocular inserts prepared using few polymers and to compare with physico-chemical results of manually sized inserts.
Methods: The formulated ocular inserts were sized manually and by using punch die set. Ocular inserts sized by manual cutting & stainless steel 316 (SS 316) punch die set was compared and evaluated for various important physico-chemical parameters.
Results: Phenomenal differences were observed in all evaluated parameters like appearance, thickness, drug content and drug release studies. Ocular inserts sized using punch die set had improved appearance, uniform thickness both near the edges & in the center of insert and accurate drug content when compared to ocular inserts that were sized manually. Drug release studies were better for punch die sized inserts as against manually sized inserts.
Conclusion: Ocular inserts sized by punch die set was superior when compared to inserts sized manually. The results for evaluated parameters like appearance, thickness, drug content and drug release studies were accurate, uniform and consistent
Influence of Quenching Agents on Mechanical, Wear, and Fracture Characteristics of Al2O3 / MoS2 Reinforced Al-6061 Hybrid Metal Matrix Composite (MMCs)
Aluminium (Al) based composites enhance the mechanical and wear behavior by heat treatment. The quenching factors like cooling agent, cooling rate and temperature of cooling are expected to influence the hardness, tensile, and wear behavior of the Al MMCs. This research shows the outcomes of a sequence of experiments to find the wear and mechanical behavior of the Al6061-Al2O3-MoS2 hybrid composites are quenched with different quenching agents. Hardening of the developed hybrid composites was carried out at 510ºC for the time period of 2 hours. Later, the same composite samples were quenched in ice cubes and water separately. Finally, age-hardening was done at 180ºC temperature for 4 hours and then the samples were cooled under room temperature. Heat treated hybrid composites were subjected to evaluate the hardness, tensile, and wear behavior. The outcomes reveal that the heat treatment significantly enhances the wear and mechanical behavior of hybrid composites. High mechanical strength and improved wear characteristics were observed in the hybrid composites which were quenched using ice cubes. The fractured surface of the tensile test samples and the wornout surface of wear test specimens were studied using a SEM analysis
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Impact of obesity with impaired glucose tolerance on retinal degeneration in a rat model of metabolic syndrome.
PurposeMetabolic syndrome (MetS) is associated with several degenerative diseases, including retinal degeneration. Previously, we reported on progressive retinal degeneration in a spontaneous obese rat (WNIN/Ob) model. In this study, we investigated the additional effect of impaired glucose tolerance (IGT), an essential component of MetS, on retinal degeneration using the WNIN/GR-Ob rat model.MethodsThe retinal morphology and ultrastructure of WNIN/GR-Ob and age-matched littermate lean rats were studied by microscopy and immunohistochemistry. The retinal transcriptome of WNIN/GR-Ob was compared with the respective lean controls and with the WNIN/Ob model using microarray analysis. Expression of selected retinal marker genes was studied via real-time PCR.ResultsProgressive loss of photoreceptor cells was observed in WNIN/GR-Ob rats with an onset as early as 3 months. Similarly, thinning of the inner nuclear layer was observed from 6 months in these rats. Immunohistochemical analysis showed decreased levels of rhodopsin and postsynaptic density protein-95 (PSD-95) proteins and increased levels of glial fibrillary acidic protein (GFAP), vascular endothelial growth factor (VEGF), and calretinin in WNIN/GR-Ob rats compared with the age-matched lean controls, further supporting cellular stress/damage and retinal degeneration. The retinal transcriptome analysis indicated altered expression profiles in both the WNIN/GR-Ob and WNIN/Ob rat models compared to their respective lean controls; these pathways are associated with activation of pathways like cellular oxidative stress response, inflammation, apoptosis, and phototransduction, although the changes were more prominent in WNIN/GR-Ob than in WNIN/Ob animals.ConclusionsWNIN/GR-Ob rats with added glucose intolerance developed retinal degeneration similar to the parent line WNIN/Ob. The severity of retinal degeneration was greater in WNIN/GR-Ob rats compared to WNIN/Ob, suggesting a possible role for IGT in this model. Hence, the WNIN/GR-Ob model could be a valuable tool for investigating the impact of MetS on retinal degeneration pathology
On the interesting course of dichloroketene addition to 1,5-dimethyl-1,5-cyclooctadiene
Reaction of dichloroketene with 1,5-dimethyl-1,5 COD 6 charters an eventful course to furnish novel tricyclic ketone 10, through the intermediacy of tricyclic hydroxy olefin 9, in which the two carbon atoms of dichloroketene form a bridge across the eight mem-bered ring
Experimental studies of different quenching media on mechanical and wear behavior of Al7075/SiC/Al2O3 hybrid composites
The effects of SiC-Al2O3 particle in the Al alloy on the mechanical and wear characteristics of stir-casted Composites have been reported. The Al7075 is reinforced with 2, 4, 6 and 8 wt. % of (SiC + Al2O3) to manufacture the hybrid composite. Ceramic particulates were added into Al alloy to achieve the low wear rate and improving mechanical properties. Hardening of casted specimens at 480ºC for the duration of 2 hrs and the specimens were quenched into two different quenching media (water and ice cubes). Finally, age-hardening were carried out at the temperature of 160ºC for the duration of 4 hrs and cooled at room temperature. The tensile strength, hardness and wear behaviour of MMCs are evaluated on the un-treated and heat treated composite. The tensile strength and hardness of MMCs increases by incorporating SiC-Al2O3 particulates. The wear behaviour of the MMCs containing SiC-Al2O3 particulates revealed the high wear-resistance. The heat-treatment had considerably improved the properties when compared to the un-heat treated composites. The composites with the highest tensile strength, hardness and enhanced wear resistance were found in the composites quenched in ice cubes. Worned surfaces of the composite specimens were studied by using SEM and XRD analysi
Radar Signal Recovery using Compressive Sampling Matching Pursuit Algorithm
In this study, we propose compressive sampling matching pursuit (CoSaMP) algorithm for sub-Nyquist based electronic warfare (EW) receiver system. In compressed sensing (CS) theory time-frequency plane localisation and discretisation into a N×N grid in union of subspaces is established. The train of radar signals are sparse in time and frequency can be under sampled with almost no information loss. The CS theory may be applied to EW digital receivers to reduce sampling rate of analog to digital converter; to improve radar parameter resolution and increase input bandwidth. Simulated an efficient approach for radar signal recovery by CoSaMP algorithm by using a set of various sample and different sparsity level with various radar signals. This approach allows a scalable and flexible recovery process. The method has been satisfied with data in a wide frequency range up to 40 GHz. The simulation shows the feasibility of our method
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