Correlation of semi-quantitative findings of endolymphatic hydrops in MRI with the audiometric findings in patients with Meniere's disease

Purpose:To investigate the correlation between vestibular hydrops(VH),cochlearhydrops(CH),vestibular aqueduct non-visibility(VANV),and visually increased perilymphatic enhancement(VIPE)with the findings of pure-tone audiometry(PTA)in Meniere’s disease(MD)patients.Methods:In this cross-sectional study,53 ears belonging to 48 patients were divided into two groups and evaluated.In group“MD patients,”there were 24 ears of 19 patients diagnosed with the definite MD(14 patients with unilateral and 5 patients withbilateral involvements).The“control group”consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma.All the patients underwent 2 sessions of temporal bone MRI using the same 3T system:an unenhanced axial T1,T2,and 3D-FLAIR MRI,an intravenous gadoliniumenhanced axial T1 fat-sat,and 4 h after the injection,an axial 3D-T2 cube and 3D-FLAIR session.VH,CH,VANV,and VIPE were assessed.Subsequently,the correlation between EH indices and PTA findings(in three frequency domains of low,middle,and high)were evaluated,and the predictive value of MRI was calculated.Results:VH was significantly correlated with the hearing threshold in the low,middle,and highfrequency domains.CH was also correlated with the hearing threshold in the low and middle domains.Contrarily,VIPE was not associated with hearing thresholds,and VANV was only correlated with the hearing threshold in low frequencies.Conclusion:The grade of VH,CH,and VANV were significantly correlated with the hearing thresholds in PTA.

Effect of Pyrrole and N-Methylpyrrole Coatings on Corrosion Resistance of Mild Steel

Electrochemical polymerizations of various ratios of pyrrole and methylpyrrole monomers were performed in aqueous toluene-4-sulfinic acid sodium salt (T4SNa) electrolyte, using galvanostatic method. pH of electrolyte was adjusted by p-toluene sulfonic acid (PTSA). In order to prevent corrosion of mild steel substrates during coating deposition, specimens were pretreated in 0.5M oxalic acid solution, employing galvanostatic method. This would passivate the steel substrate and facilitate the coating process as well. Corrosion resistance of coated substrates was investigated in 1M NaCl solution using Tafel polarization technique. In addition, using scanning electron microscopy (SEM), morphological characterization of coatings produced, was investigated. Regarding the corrosion characteristics, results obtained revealed that the ratio of 1 to 1 (Pyrrole/Methylpyrrole) could play an important role.

Effect of Catalyst on the Formation of Silica Coating on Nickel Substrate by Sol-Gel Processing

In this research work silica coating was produced on nickel substrates by a sol-gel process. In order to increase the rate of hydrolysis and to reduce the rate of polymerization several acid catalysts including nitric acid-hydrochloric acid, acetic acid, hydrochloric acid and nitric acid were add to silica sol. Conversely, in order to control the rate of hydrolysis and to increase the rate of polymerization, basic catalyst of ammonia and ammonia hydroxyl were introduced in to the solution. Nickel specimens of known surface roughness were chemically cleaned and prepared by dipping in the sols. In order to produce a suitable silica coating the drying and firing cycles were optimized on these substrates. The structure and uniformity of the coatings produced were examined by scanning electron microscopy. Coatings composition was determined using glow discharge optical spectroscopy and EDAX microanalysis. Experimental result showed that hydrochloric acid, acetic acid, ammonia and acetic acid - ammonia are suitable catalytic agents for silica coating formation on nickel type substrate.

Application of Linear Model Predictive Control and Input-Output Linearization to Constrained Control of 3D Cable Robots

Cable robots are structurally the same as parallel robots but with the basic difference that cables can only pull the platform and cannot push it. This feature makes control of cable robots a lot more challenging compared to parallel robots. This paper introduces a controller for cable robots under force constraint. The controller is based on input-output linearization and linear model predictive control. Performance of input-output linearizing (IOL) controllers suffers due to constraints on input and output variables. This problem is successfully tackled by augmenting IOL controllers with linear model predictive controller (LMPC). The effecttiveness of the proposed method is illustrated by numerical simulation.