The present research attempts to analyze the surface topography of WEDMed Inconel 825 concerning surface crack density (SCDi) and recast layer thickness (RCLt). Formation of cracks, recast layer, and heat-affected zone are the major issues in determining the final performance of the WEDM machined sample. In this study, WEDM characteristics viz. pulse on time (Ton), pulse off time (Toff), gap voltage (SV), peak current (IP), wire tension (WT), and wire feed (WF) are optimized for the response SCDi and RCLt by response surface methodology. The outcome manifests that the topography of the machined surface becomes more rougher at the increased value of Ton, IP, and SV. RSM emerges as a great tool in the development of a predicted model based on the desirability approach and finding optimal parametric combinationm which results in reduced SCDi and RCLt. At the optimum combination of process parameters, i. e., 109 machine unit Ton, 36 machine unit Toff, 54 V SV, 120A IP, 9 machine unit WT and 7 m/min WF, the values obtained for SCDi and RCLt are 0. 00160 μ m/μ m2 and 20. 991μ m, respectively with an error of less than 5%.

The surface layer machined after electrical discharge machining (EDM) is different from it after traditional methods, and studying the surface layer structure machined by this method will contribute significantly to the selection of finishing methods. In this study, the surface layer of SKD61 steel after EDM using copper (Cu) electrode was analyzed. Technological parameters including discharge current (Ie), pulse on time (Ton), pulse off time (Tof), and voltage (Ue) were used in the study. The minimum recast layer thickness (RLT) was determined using the Taguchi method. The results showed that Ie, Ton, and Tof were significant influences on RLT, and Ue was insignificant. Minimum, value of RLT = 3.72 µm at process parameters Ie = 1 A, Ton = 50 µs, Tof = 12 µs, and Ue = 30 V. The machined surface layer after EDM is inconsistent with the workability of the product, and it should be removed from the machined surface.

The Micro wire electrical discharge machining (Micro wire-EDM) process is a modern machining process with various applications in manufacturing micro-parts. The recast layer remaining on the machined surfaces is an inevitable complication of this process. This layer can subsequently affect the machined parts performance. To optimize the recast layer in the micro wire-EDM of the molybdenum microparts, effect of the process parameters on the distribution amplitude of the recast layer was investigated using the Taguchi method. The obtained results showed that the optimal levels of the micro wire-EDM process parameters for achieving the optimal distribution amplitude of the recast layer are as follows: spark pulse-on time of 0.2 ms, cutting speed of 7 mm/min, process voltage of 17 V, and wire tension of 0.45 kg. Also the importance order of the effect of the process parameters on the distribution amplitude of recast layer is as follows: spark pulse-on time, process voltage, cutting speed, and wire tension.

Purpose: To examine the relationship between retinal nerve fiber layer (RNFL) measurements obtained using scanning laser polarimetry with variable corneal compensation (VCC) and central corneal thickness (CCT) measurements using pentacam in myopic patients.Methods: The study included 45 eyes from 45 myopic patients with intraocular pressure (IOP) measurements£21 mmHg. All participants had normal optic discs and normal standard automated perimetry visual fields. All patients underwent imaging with the GDx VCC and pentacam. We examined the relationship between GDx VCC RNFL measurements and CCT.Results: Mean spherical equivalent (SE) was -3.65±1.1 D (range: -1.00 to -6.5 D). Mean CCT was 530.9±24.32 mm with a range of 488 to 596 mm. TSNIT (temporal, superior, nasal, inferior, temporal) average, inferior average, superior average, TSNIT standard deviation (SD) and nerve fiber indicator (NFI) were not correlated with CCT. There were no correlations between RNFL thickness and refraction, age, corneal volume and mean keratometry. However, RNFL in patients with CCT£530 mm was significantly thinner than in those with thick corneas.Conclusion: RNFL measurements obtained using GDx VCC may not correlate with corneal thickness (CCT) and refraction in myopic patients. Myopic patients with CCT£530 have thinner RNFL than in those with thick corneas.

Purpose: To evaluate medium and large choroidal vessel layer thickness (MCVT and LCVT, respectively) in eyes with acute and chronic central serous chorioretinopathy (CSC) in comparison with age‑ matched controls. Methods: The study included 96 eyes of 96 patients with CSC, including 53 eyes with acute CSC, 43 eyes with chronic CSC, and 30 eyes of 30 age‑ matched normal subjects. Manual measurements of subfoveal choroidal thickness (SFCT), MCVT, and LCVT at subfoveal and 750 µ m nasal and temporal to the fovea locations were made on enhanced depth imaging optical coherence tomography (EDI‑ OCT) of the macula in all subjects using ImageJ software (National Institutes of Health, Bethesda, MD, USA). Results: SFCT in acute CSC was significantly larger than that in healthy eyes (P = 0. 0001). SFCT in acute CSC did not differ significantly from that in chronic CSC eyes. Subfoveal LCVT and MCVT in acute CSC eyes were greater than those in healthy eyes (P = 0. 02 and P = 0. 03, respectively). Mean SFCT and MCVT in chronic CSC eyes were significantly larger than those in control eyes (P = 0. 01 and P = 0. 04, respectively). No significant difference in LCVT was observed between chronic and control eyes. Conclusion: Choroidal vasculature is altered in both acute and chronic CSC. SFCT, MCVT, and LCVT are higher in eyes with acute CSC. The thickening of medium choroidal vessels is still detectable in chronic CSC compared to control eyes.