Vitreomacular Interface Abnormalities in Myopic Foveoschisis: Correlation With Morphological Features and Outcome of Vitrectomy

Purpose: To compare the morphologic characteristics and response to surgery of myopic foveoschisis (MF) with different patterns of vitreomacular interface abnormalities (VMIAs).Methods: In this observational case series, 158 eyes of 121 MF patients with epiretinal membrane (ERM) or vitreomacular traction (VMT) based on optical coherence tomography (OCT) were enrolled. All the eyes were divided into two groups by the pattern of VMIAs: ERM and VMT group. Sixty-one eyes underwent pars plana vitrectomy (PPV) and were followed up for at least 6 months. The morphologic characteristics based on OCT and the surgical outcome were evaluated.Outcome: ERM and VMT were found in 47.47 and 52.53% of the cases, respectively. A higher rate of foveal detachment (61.4 vs. 26.7%; p < 0.001) and a higher rate of outer lamellar macular hole (45.8 vs. 21.3%; p = 0.001) were detected in the eyes with VMT compared with those with ERM. In contrast, a lower rate of inner lamellar macular hole (28.9 vs. 60.0%; p = 0.001) was detected in the eyes with VMT compared with those with ERM. The disruption of the external limiting membrane (ELM) was more common in the eyes with VMT than in those with ERM (45.8 vs. 21.3%; p = 0.001). PPV was performed in 61 eyes with a mean follow-up time of 23.55 ± 19.92 months. After surgery, anatomical resolution was achieved in 51 eyes (83.6%). At the final visit, the mean central foveal thickness (CFT) decreased significantly from 547.83 to 118.74 μm, and the mean LogMAR BCVA improved significantly from 0.92 to 0.57. The VMT group was associated with a higher proportion of eyes with visual acuity improvement postoperatively (p = 0.02) and had more a decrease of CFT (P = 0.007) compared with the ERM group.Conclusion: In the eyes with MF, outer retinal lesions occurred more frequently in the eyes with VMT, whereas inner retinal lesions occurred more frequently in the eyes with ERM. Tangential force generated by ERM may act as a causative factor for the inner retinal lesions in MF, and inward-directed force resulting from VMT may act as a causative factor for outer retinal lesions in MF.

Design and Development of a Numerical Model and Study on Kinematic Analysis of a Circular Diamond Saw Blade for Ceramics

Diamond tools are currently being used by an increasing number of architects, miners and construction engineers because they are faster and easier to use than older, more traditional instruments like sledge hammers and pneumatic and hydraulic jacks. Bridge and highway surfaces are cut with diamond asphalt and concrete cutting machines to provide for quick, clean, and easy section removal and replacement. The entire cost is reduced since diamond tools take less time and manpower The experiment is carried out to validate the performance of diamond saw blades by taking into consideration characteristics such as normal force, tangential force, cutting speed, cut depth, and peripheral velocity. In present exploration work we are introductory phase of plan conclusion of a jewel device cutting edge with various segmental like 8,12,16,20 corn meal by utilizing Solid works programming we are planning the apparatus cutting edge after that we are imported in Ansys Software for Analysis reason. Computing the necessary qualities for examination and estimations of earthenware tiles likewise are some other stone molecule. Another power model of cutting is presented and inferred numerical demonstrating for chip thickness. Identical chip thickness to coarseness space proportion is gotten from the new power model another outspread opening like profile is presented. Fragmented sort jewel saw sharp edge with the measurement of 400 mm and different portion, for example, 8, 12, 16 and 20 are planned in Solid works effectively. An examination study between existing roundabout outspread space and cone like opening is done to decide deformity, stress dispersion, vibration and temperature conveyance.

Measurement and optimization of multi-attribute characteristics in milling epoxy granite composites using rsm and combined ahp-topsis

Epoxy granite composites with its wide range of applications in machine tool industries are manufactured by molding process and require post cast machining operations to meet the desired dimensional accuracy for assembly of machine tool structures. In this research work, milling of epoxy granite composites are carried out based on the experimental design from Response Surface Methodology (RSM) techniques and further the optimal solutions are determined by a novel hybrid algorithm AHP-TOPSIS. Central Composite Design (CCD) model is applied with three factors-three levels and the measured output responses are thrust force, tangential force and surface roughness. Experimental combinations of 20 different trials are performed using high speed steel end mill cutter of diameter 10mm with three levels of input parameters: speed; fibre content and feed rate at a uniform depth of cut. The relative importance matrix formulated proved to be highly consistent with its consistency ratio to a maximum of 0.000641 which lies below the higher range of 0.1. Consistency ratio of 0.000641 reveals that the optimal solutions determined will be highly reliable and the decision making is much more judicious. Optimal solution determined from hybrid AHP-TOPSIS methods are: speed 1800 rpm; feed rate 0.03 m/min and 0% percent fibre content. Functional relationships among parameters and responses established by RSM are consistent upto 95% and its significance is tested by analysis of variance. Comparison among predicted and experimental values of three measured responses convey that the percentage variations are minimum with up to 2.03% for surface roughness, 2.50% for thrust force and 2.71% for tangential force components. This research work provides a systematic procedure and clear framework for determination of optimal machining conditions by hybrid methodology on the basis of technique for order preference by similarity to ideal solution (TOPSIS) combined with analytical hierarchy procedure (AHP) for attribute weights and further analyzes the influence of machining parameters over measured responses.

Study On The Influence of Fiber Cutting Angle On Cutting Force In Ultrasonic Assisted Cutting CFRP Disc

Carbon fiber reinforced plastics (CFRP) is a new type of composite material that is widely used in the aviation field, the influence mechanism of fiber cutting angle on cutting force is analyzed, a theoretical model of ultrasonic assisted cutting force for CFRP is established, ultrasonic assisted longitudinal-torsional cutting experiments of CFRP disc are carried out, and compared with normal cutting process. According to the experimental results, the radar map of the cutting force along the circumference of CFRP unidirectional laminates is established, which show that the cutting force can be reduced by ultrasonic assisted cutting compared with ordinary cutting. Under the three cutting modes, the fiber cutting angle has a great influence on the tangential force, and the radial force of the same fiber cutting angle is less than the tangential force, the maximum radial force appeared near the fiber cutting angle of 120°, while the minimum tangential force and the minimum radial force both appear near the parallel direction cutting at 0°. The research results can be used for reference in the processing of CFRP and other composite materials.

Micromechanics of Drilling: A Laboratory Investigation of Formation Evaluation at the Bit

Challenging drilling applications and low oil prices have created a new emphasis on innovation in the industry. This research investigates the value of drill bit based force sensing at the rock-cutter interface. For this purpose, a laboratory-based mini-rig has been built in order to recreate a scaled drilling process. The work aims to build a better understanding of the collected force and torque data despite the semi-continuous drilling process. This data is then used to estimate the formation strength. A scaled drill bit with two cutters was designed with sensors integrated into the drill bit cutter, drill string and the mini-rig structure. The mini-rig design allowed the accurate control of depth of cut by utilizing a comprehensive data acquisition and control system during the experiments. Initially, fifty-five samples were prepared with various water/gypsum ratios for a uniaxial compression test, scratch test, and for testing in the mini-rig. Prior to the mini-rig experiments, the results of the uniaxial compression and scratch tests were used as a benchmark to extract rock properties and the state of stress behavior. The experiments under atmospheric conditions revealed that the mini-rig could accurately estimate formation strength from a few rotations. The force data at the bit-rock interface was correlated with the torque measurements, and the results indicate that the tangential force has similar trends and relatively similar values. The groove created by the drill bit's rotating trajectory has a 14.45 cm circumference. This allows for a significant amount of data to be captured from a single rotation. The circular cutter geometry's influence is crucial for a continuous process since the active cutting area is continuously changing due to the pre-cut groove. The performed depth of cuts ranged from 0.1 to 1 mm in the same groove, and thus the active cutting area can be accurately calculated in real-time while conducting the experiments. Tangential and normal force data from the scratch test was analyzed in order to provide insights for correlation with the mini-rig data. The analysis shows that both tests give similar trends to the force measurements from the mini-rig. Moreover, the benchmark value of formation strength that was obtained from the uniaxial compression test was also in the same range. This illustrates the potential viability of drill bit based formation strength measurement due to the similarity between mini-rig test results and those using more classical testing practices. The experimental setup can provide a continuous cutting process that allows an accurate estimation of formation strength during a semi-continuous drilling operation with analogous application in the field. This can lead to an in-depth understanding of drilled formation properties while drilling and possibly assist in evaluating cutter wear state in-situ.

New Modification of Vertical Muscle Transposition to Enhance Abducting Force in Sixth Nerve Palsy

Purpose:Since 1907, multiple transposition procedures have been established for the treatment of abducens paralysis. In this study, we try to determine where the transposed muscle should be reattached in order to increase the tangential force necessary to improve abduction.Methods:Retrospective case review of 12 consecutive patients with abducens paralysis. All patients underwent the transposition procedure between 2016 and 2019.Vertical rectus muscles are transposed to the insertion of lateral rectus muscle: The temporal parts are joined and sutured to the sclera on top of the lateral rectus muscle in the middle of the insertion. The nasal parts are sutured to the sclera following the spiral of Tillaux. The muscle junction suture is placed 8 mm from the insertion: The temporal parts of the vertical muscles bellies are joined and sutured to the lateral rectus muscle. A full tendon transposition was performed on 11 patients, a half tendon transposition procedure on one patient. The minimum follow-up was 3 months.Results:The mean preoperative deviation was ET of 37° (range: ET 24° to ET 51°). The mean preoperative abduction limitation was 5 mm from midline (range: -7 to -1mm). The postoperative mean deviation was ET of 2° PD (range: 0 to ET 5°). The postoperative mean abduction improvement was 5mm past midline (range: +2 to +6mm). There were no complications, or signs of anterior segment ischemia. Conclusions:To achieve the maximal abductive force from the transposed muscles, we suggest that the vertical muscles be reattached as close as possible to the middle of the lateral rectus insertion.

Numerical Analysis and Parameter Optimization of Wear Characteristics of Titanium Alloy Cross Wedge Rolling Die

Cross wedge rolling has the advantages of high production efficiency, good product quality, high material utilization, environmental protection, and low cost. It is one of the best processing methods for producing shaft blanks. In this paper, a cross wedge rolling die of TC4 titanium alloy is studied. Based on the Archard wear model, a modified model suitable for cross wedge rolling die wear analysis is derived through finite element simulation. Then, the modified Archard wear model is imported into Deform-3D software for finite element analysis. Orthogonal experimental design is used to combine and analyze different process parameters. Finally, the beetle antennae search (BAS)-genetic algorithm (GA)-back propagation neural network (BPNN) algorithm is used to predict the degree of die wear and to optimize the simulation parameters, which can acquire the process parameters that have the least impact on die wear. The results show that the wear distributions of cross wedge rolling tools is uneven. In general, the most serious areas are basically concentrated in the wedge-shaped inclined plane and rectangular edge lines. The reason is that the tangential force and radial force received by the die are relatively large, which leads to increased wear. Moreover, the temperature change is most severe on the wedge-shaped ridge line. When in contact with the workpiece, the temperature rises sharply, which makes the local temperature rise, the mold hardness decrease, and the wear accelerate. Through response surface method (RSM) analysis, it is concluded that the deformation temperature is the main factor affecting wear depth, followed by the forming angle, and that there is an interaction between the two factors. Finally, the feasibility of the BAS-GA-BP algorithm for optimizing the wear behavior of dies is verified, which provides a new process parameter optimization method for the problem of die wear in the cross wedge rolling process.

Experimental Study on the Influence of Water and Cavitation on Propeller Load during Ice-Propeller Milling

When the ice-class propeller sails in an icy sea, it is affected by external factors such as water, ice, and cavitation, and the process of mutual interference is extremely complicated. In order to study the influence of water and cavitation on propeller load during the ice-propeller milling process, a test platform for ice–water propeller milling action was constructed. The load and cavitation of the propeller and single blade were measured during ice-propeller milling in air and water (atmospheric pressure and decompression conditions). Simultaneously, the changes in the load and bearing force of the propeller and blade were studied at different working conditions. The results show that, in the process of ice–water propeller milling, the direction of the propeller thrust generated by the water is opposite to that of the axial force generated by ice; the combined action of the two causes propeller thrust loss, whereas the combined action of water and ice increases propeller torque. The presence of water increases the thrust, torque, and bearing force of the fluctuating amplitude of the blade. The occurrence of cavitation reduces the thrust and torque of the propeller and blade and increases thrust fluctuating amplitudes while decreasing the tangential force fluctuating amplitude of the blade.

Evaluation of: MOSSA, MOALO, MOVO and MOGWO Algorithms in Green Machining for High Production Performance in Turning of X210Cr12 Steel

The current study investigates the Wet and MQL machining, when turning of X210Cr12 steel, using a multilayer-coated carbide insert (GC-4215) with various nose radius, the consideration of the tool geometry with different cooling modes allow as to assess the comportment of the machined steel against the cutting combinations. The response surface methodology (RSM) has been used for regression analysis and to evaluate the contribution of the cutting parameters on surface roughness, tangential force and cutting power using ANOVA analysis. The developed models have been used to predict the studied output factors according to the selected cutting parameters for wet and MQL machining. A comparative between the cooling techniques have been established to determine the most effective technique in terms of part quality, lubricant consumption and power consumption. Finally, four new optimization technics have been used for the process optimization using the MQL models for an environment-friendly machining.

Wheel drive with integrated differential

The performance indicators of wheeled arable machine-tractor units, which are accelerated on the working gear, depend on the operating modes of the wheels during this period. When the wheel is skidding, soil lumps break down in the contact spot, the soil structure is destroyed. Based on the system analysis of the wheels operation, the method of their improvement is justified by continuous control of the eccentric point of application of the driving torque and external load. As a result of the analysis for the first time, a soil-sparing wheel mover with the properties of a differential, a tangential force regulator and clearance regulator was developed. In the case of an eccentric application of a vertical load and a longitudinal pushing force, one of the satellites of the wheeled planetary gearbox is the leading and bearing one. The purpose of the article is to analyze the factors influencing the automatic adaptation of the wheel drive to changing operating conditions. It is established the relationship between the driving moment and the rolling resistance moment, the moments of inertia of the wheel and the drive gear of the integrated differential.