Optimum Profiles of Endwall Contouring for Enhanced Net Heat Flux Reduction and Aerodynamic Performance

Successfully utilized non-axisymmetric endwalls to enhance turbine efficiencies(aerodynamic and turbine inlet temperatures)by controlling the characteristics of the secondary flow in a blade passage.This is accomplished by steady-state numerical hydrodynamics and deep knowledge of the field of flow.Because of the interaction between mainstream and purge flow contributing supplementary losses in the stage,non-axisymmetric endwalls are highly susceptible to the inception of purge flow exit compared to the flat and any advantage rapidly vanishes.The conclusions reveal that the supreme endwall pattern could yield a lowering of the gross pressure loss at the design stage and is related to the size of the top-loss location being productively lowered.This has led to diminished global thermal exchange lowered in the passage of the vane alone.The reverse flow adjacent to the suction side corner of the endwall is migrated farther from the vane surface,as the deviated pressure spread on the endwall accelerates the flow and progresses the reverse flow core still downstream.The depleted association between the tornado-like vortex and the corner vortex adjacent to the suction side corner of the endwall is the dominant mechanism of control in the contoured end wall.In this publication,we show that the non-axisymmetric endwall contouring by selective numerical shape change method at most prominent locations is advantageous in lowering the thermal load in turbines to augment the net heat flux reduction as well as the aerodynamic performance using multi-objective optimization.

Clinical Efficacy of GBR Technique Combined with Temporary Bridgework-Guided Gingival Contouring in Treating Upper Anterior Tooth Loss with Labial Bone Defects

Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions.

An Open CAM System for Dentistry on the Basis of China-made 5-axis Simultaneous Contouring CNC Machine Tool and Industrial CAM Software

China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture （CAM） technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design （CAD）/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for den-tistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system.

Dosimetric Effects Due to Inter-Observer Variability of Organ Contouring When Utilizing a Knowledge-Based Planning System for Prostate Cancer

Purpose: Radiotherapy is a widely accepted standard of care for early-stage prostate cancer, and it is believed that the plan quality and treatment outcome are associated with contour accuracy of both the target and organs-at-risk (OAR). The purposes of this study are to 1) assess geometric and dosimetric uncertainties due to inter-observer contour variabilities and 2) evaluate the effectiveness of geometric indicators to predict target dosimetry in prostate radiotherapy. Methods: Twenty prostate patients were selected for this retrospective study. Five experienced clinicians created unique structure sets containing prostate, seminal vesicles, bladder, and rectum for each patient. A fully automated script and knowledge-based planning routine were utilized to create standardized and unbiased plans that could be used to evaluate changes in isodose distributions due to inter-observer variability in structure segmentation. Plans were created on a “gold-standard” structure set, as well as on each of the user-defined structure sets. Results: Inter-observer variability of contours during structure segmentation was very low for clearly defined organs such as the bladder but increased for organs without well-defined borders (prostate, seminal vesicles, and rectum). For plans generated with the user-defined structure sets, strong/moderate correlations were observed between the geometric indicators for target structure agreement and target coverage for both low-risk and intermediate-risk patient groups, while OAR indicators showed no correlation to final dosimetry. Conclusions: Target delineation is crucial in order to maintain adequate dosimetric coverage regardless of the associated inter-observer uncertainties in OAR contours that had a limited impact upon final dosimetry.

General Theory of Body Contouring: 1. Processes of Quick and Slow Modulation of Subcutaneous Fat Tissue

It is shown that modulation of subcutaneous white adipose tissue (sWAT) volume after application of different physical factors in body contouring procedures cannot be characterized by a single physiological reaction with dispersed reaction times, supposing that several different dynamic processes with different characteristic reaction times must be involved. Quick modulation of sWAT with characteristic times of 103 - 105 s must be connected with such processes as hyaluronan production and consequent water retention in the tissue, as well as with reversible modulation of its mechanical properties. It is supposed that slow processes with characteristic times of up to 3 × 106 s can be caused by modulation of lipolytic activity of adipocytes through changesin their micro-environment or through their transdifferentiation, as well as through death and removal of adipocytes from sWAT.

General Theory of Body Contouring: 2. Modulation of Mechanical Properties of Subcutaneous Fat Tissue

Subcutaneous white adipose tissue (sWAT) can be described micromechanically as a foam structure. It is shown that according to this model, mechanical stiffness of this tissue is primarily dependent on the average cell size and is almost independent of the dispersion of cell sizes in a local adipocytes’ population. Whereas the influence of natural fat renewal process with a rate of 10% per year must be of minor importance for mechanical properties of sWAT, induced adipocytes’ death can substantially reduce local sWAT stiffness. The sWAT which contains two or more different subpopulations of adipocytes of varying sizes with a spatially clustered structure can demonstrate significant inhomogeneity of their mechanical properties when compared with those of sWAT consisting of a single population of adipocytes. It is proposed that this effect may be an important pathophysiological feature of cellulite. Transformation of the cell shape from quasispherical to wrinkled or elliptical forms makes adipocytes more susceptible to thermo-mechanical stress reducing the strain needed to achieve the local plastic deformation. These mechanical features of sWAT are essential for understanding the mechanisms of different non-invasive and minimal invasive body contouring procedures.

Combination of facial skeletal contouring surgery and aesthetic surgeries for Asians-personal experience

Facial skeletal contouring surgery such as reduction malarplasty and reduction angleplasty is popular in Asian countries. With rapid economic development, an increasing number of patients receive facial skeletal contouring surgery combined with other facial aesthetic sur geries. From January 2014 to December 2016, a total of 37 patients underwent Facial skeletal contouring surgery combined with facial esthetic surgeries in our department. The modified L-shape reduction malarplasty and reduction mandibular angleplasty were performed using reciprocating saws. The combined facial esthetic surgeries are 4 cases of double eyelid blepharoplasty, 6 cases of augmentation rhinoplasty, 2 cases of autologous fat transplantation and 1 case of augmentation genioplasty. 36 patients were satisfied with the final facial contour and appearance. No severe complications were seen in our series. Facial skeletal contouring surgeries can drastically and permanently change the patient's facial contour. Plastic surgeons should be acquainted with the metabolic aesthetic trends and be familiar with all the surgical techniques. The selection of an appropriate procedure or combined procedures for individual patients should be made according to the cultural background, patient's chief complain, anatomic variations and possible operative sequ elae.

Facial liposuction combined with botulinum toxin type A:A technique for lower facial contouring

Background:Botulinum toxin type A injection,a noninvasive alternative method for treating masseteric hypertrophy,is inadequate for treating patients with a round lower face.This study aimed to investigate the operative technique and clinical results of liposuction followed by botulinum toxin type A injections in patients with masseteric hypertrophy and excessive subcutaneous fat.Methods:Sixty-five patients(50 women and 15 men)were treated using this technique between May 2014 and January 2019.Their mean age was 26.3 years(range,18–35 years)and the mean follow-up period was 13 months(range,8–18 months).Results:All patients achieved slimmer lower cheeks with improved jaw definitions after the procedure.Among the 65 patients,61(94%)expressed satisfaction with the results and believed that the procedure produced their desired face shape.No major complications were observed.The effect of this combination treatment remained stable for 12 months after the procedure.Conclusion:The authors believe that liposuction followed by botulinum toxin type A injections is an effective technique for the treatment of masseteric hypertrophy and excessive subcutaneous fat.It is also a relatively simple and safe treatment approach.

A Proposed Mesh Placement for Repair of Ventral Hernia and Contouring of the Abdomen

Introduction: Abdominal wall defects and muscle redundancy in the form of protruded abdomen still represent a challenging problem. The aim of this article is to reconstruct the abdominal wall and regain the abdominal contour through the application of biosynthetic meshes in certain fashion. Patients and Methods: this is a prospective study done 25 patients with long standing ventral hernia and lax abdominal muscle wall. All patients were performed at Zagazig university hospitals in the period between September 2011 and November 2013. Polypropylene mesh is used for every patient after anatomical hernia repair for hernioplasty and then shaping like outstretched hand (fingers processes). The aim is to reinforce the abdominal wall and reshape the abdomen. Results: regarding to the aesthetic aspect and success rate of the abdominal wall reconstruction, we have a good satisfactory results without recurrence in a period of 2 years follow up. Three patients are suffered from wound infection and partial edge ischemia in two patients. Bleeding and delayed wound healing in ten patients and persistent seroma are occurred in fife patients. Conclusion: It is safe with a good patient satisfaction to combine ventral hernia repair and abdominoplasty in cases with excess skin and musculofascial laxity of the abdominal wall (pendulous abdomen) with application of this finger processes mesh, after following the proper technique and precautions.

Optimization of endwall contouring in axial compressor S-shaped ducts

This paper presents a numerical investigation of the potential aerodynamic benefits of using endwall contouring in a fairly aggressive duct with six struts based on the platform for endwall design optimization.The platform is constructed by integrating adaptive genetic algorithm（AGA）, design of experiments（DOE）, response surface methodology（RSM） based on the artificial neural network（ANN）, and a 3D Navier–Stokes solver.The visual analysis method based on DOE is used to define the design space and analyze the impact of the design parameters on the target function（response）.Optimization of the axisymmetric and the non-axisymmetric endwall contouring in an S-shaped duct is performed and evaluated to minimize the total pressure loss.The optimal ducts are found to reduce the hub corner separation and suppress the migration of the low momentum fluid.The non-axisymmetric endwall contouring is shown to remove the separation completely and reduce the net duct loss by 32.7%.

Interpolation-based contour error estimation and componentbased contouring control for five-axis CNC machine tools

High accuracy contour error estimation and direct contour error control are two major approaches to reduce the contour error.However, two key factors make them complex for five-axis machine tools: the nonlinear kinematics and the coupling between the tool position and orientation. In this study, by finding the reference point nearest to the current actual position, and interpolating the point with two neighboring reference points and using the distance ratio, a new contour error estimation method for five-axis machine tools is proposed, which guarantees high accuracy while depending on only the reference points. By adding a weighted contour error on the tracking error in the workpiece coordinate system, and specifying a desired second-order error dynamics based on the error variable, an effective contouring control method is proposed, which can alleviate the problem: when the contour error components are introduced into the controller, the contour errors increase instead in some regions of the tracking trajectory. A series of experiments are performed on a tilting-rotary-table(TRT) type five-axis machine tool. The results reveal that the proposed estimation method has high accuracy, and compared with the case without contour error control, the proposed control approach can reduce the contour error along the whole trajectory.

Investigation of Non-Axisymmetric Endwall Contouring in a Compressor Cascade

The current paper presents experimental and computational results to assess the effectiveness of non-axisymmetric endwall contouring in a compressor linear cascade. The endwaU was designed by an endwall design optimi- zation platform at 0° incidence （design condition）. The optimization method is based on a genetic algorithm. The design objective was to minimize the total pressure losses. The experiments were carried out in a compressor cascade at a low-speed test facility with a Mach number of 0.15. Four nominal inlet flow angles were chosen to test the performance of non-axisymmetric Contoured Endwall （CEW）. A five-hole pressure probe with a head diameter of 2 mm was used to traverse the downstream flow fields of the flat-endwall （FEW） and CEW cascades. Both the measured and predicted results indicated that the implementation of CEW results in smaller comer stall, and reduction of total pressure losses. The CEW gets 15.6% total pressure loss coefficient reduction at design condition, and 22.6% at off-design condition （＋7° incidence）. And the mechanism of the improvement of CEW based on both measured and calculated results is that the adverse pressure gradient （APG） has been reduced through the groove configuration near the leading edge （LE） of the suction surface （SS）.

Adaptive estimation and nonlinear variable gain compensation of the contouring error for precise parametric curve following

Contour following is one of the most important issues faced by many computer-numerical-control(CNC) machine tools to achieve high machining precision. This paper presents a new real-time error compensation method aiming at reducing the contouring error caused by facts such as servo lag and dynamics mismatch in parametric curved contour-following tasks. Due to the lack of high-precision contouring-error estimation method for free-form parametric curved toolpath, the error can hardly be compensated effectively. Therefore, an adaptive accurate contouring-error estimation algorithm is proposed first, where a tangential-error backstepping method based on Taylor's expansion is developed to rapidly find the closest point on the parametric curve to the actual motion position. On this foundation, the contouring error is compensated using a proposed nonlinear variable-gain compensation method, where the compensation gain is obtained according to not only the contouring-error magnitude but also its direction variation. The stability of the system after compensation is analyzed afterwards according to the Jury stability criterion.By design of the compensator in accordance with the presented contouring-error compensation method as well as the stability analyzation result, the balance between the response speed and the contour control stability can be effectively made. Experimental tests demonstrate the feasibility of the presented methods in both contouring-error estimation and contour-accuracy improvement.Contributions of this research are significant for enhancing the contour-following performance of the CNC machine tools.

Tip-leakage flow loss reduction in a two-stage turbine using axisymmetric-casing contouring

In order to reduce the losses caused by tip-leakage flow, axisymmetric contouring is applied to the casing of a two-stage unshrouded high pressure turbine（HPT） of aero-engine in this paper. This investigation focuses on the effects of contoured axisymmetric-casing on the blade tipleakage flow. While the size of tip clearance remains the same as the original design, the rotor casing and the blade tip are obtained with the same contoured arc shape. Numerical calculation results show that a promotion of 0.14% to the overall efficiency is achieved. Detailed analysis indicates that it reduces the entropy generation rate caused by the complex vortex structure in the rotor tip region, especially in the tip-leakage vortex. The low velocity region in the leading edge（LE） part of the tip gap is enlarged and the pressure side/tip junction separation bubble extends much further away from the leading edge in the clearance. So the blocking effect of pressure side/tip junction separation bubble on clearance flow prevents more flow on the tip pressure side from leaking to the suction side, which results in weaker leakage vortex and less associated losses.

Distributed Model Predictive Contouring Control for Real-Time Multi-Robot Motion Planning

Existing motion planning algorithms for multi-robot systems must be improved to address poor coordination and increase low real-time performance.This paper proposes a new distributed real-time motion planning method for a multi-robot system using Model Predictive Contouring Control(MPCC).MPCC allows separating the tracking accuracy and productivity,to improve productivity better than the traditional Model Predictive Control(MPC)which follows a time-dependent reference.In the proposed distributed MPCC,each robot exchanges the predicted paths of the other robots and generates the collision-free motion in a parallel manner.The proposed distributed MPCC method is tested in industrial operation scenarios in the robot simulation platform Gazebo.The simulation results show that the proposed distributed MPCC method realizes real-time multi-robot motion planning and performs better than three commonly-used planning methods(dynamic window approach,MPC,and prioritized planning).

Influence of Hub Contouring on the Performance of a Transonic Axial Compressor Stage with Low Hub-Tip Ratio

The rotor blade height with low hub-tip ratio is relatively longer,and the aerodynamic parameters change drastically from hub to tip.Especially the organization of flow field at hub becomes more difficult.This paper takes a transonic 1.5-stage axial compressor with low hub-tip ratio as the research object.The influence of four types of rotor hub contouring on the performance of transonic rotor and stage is explored through numerical simulation.The three-dimensional numerical simulation results show that different hub contourings have obvious influence on the flow field of transonic compressor rotor and stage,thus affecting the compressor performance.The detailed comparison is conducted at the rotor peak efficiency point for each hub contouring.Compared with the linear hub contouring,the concave hub contouring can improve the flow capacity,improve the rotor working capacity,and increase the flow rate.The flow field near blade root and efficiency of transonic rotor is improved.The convex hub contouring will reduce the mass flow rate,pressure ratio and efficiency of the transonic rotor.Full consideration should be given to the influence of stator flow field by hub contouring.

A pre-compensation method of the systematic contouring error for repetitive command paths

For a repetitive command path, pre-compen- sating the contouring error by modifying the command path is practical. To obtain the pre-compensation value with better accuracy, this paper proposes the use of a back propagation neural network to extract the function of systematic contouring errors. Furthermore, by using the extracted function, the contouring error can be easily pre- compensated. The experiment results verify that the proposed compensation method can effectively reduce contouring errors.

Asian facial recontouring surgery

Most East Asian women prefer a smaller and smoother facial contour.To meet this aesthetic preference,the concept and surgical techniques of modern facial bone contouring surgery have evolved.Initially,facial bone contouring surgery was limited to procedures like mandibular angle and malar reductions.However,contemporary Asian facial bone contouring surgery now places a stronger emphasis on addressing the entire facial profile from a three-dimensional perspective,a concept referred to as Profiloplasty.In this article,we review the evolution of surgical techniques in Asian facial bone contouring surgery and present its current surgical concepts,particularly focusing on the three-dimensional aspects.

Surgical circumferential contouring:lower body,upper body,and in-between

Deformities in the body contouring population are rarely isolated to one area,and procedures can be combined to achieve more substantial results.While there is no formula for optimal surgical sequencing and timing,there are certain principles which-when applied appropriately-can yield results that are reliable,aesthetically pleasing,and aligned with the patient’s desires and preferences.In this article,we outline our latest thinking in circumferential body contouring and how to integrate the lower body lift with procedures of the abdomen,upper body,breasts,back,and arms to achieve the complete 360°look.

Wound healing in postbariatric body contouring surgery

Due to the continuous development in the field of bariatric surgery, there is an increasing need for postbariatric body contouring surgery. The morbidity of postbariatric patients predisposes them to develop wound healing complications. In this article we describe the preoperative, intraoperative and surgical factors influencing the wound healing and therefore the final outcome. The most common postbariatric body contouring procedures, including brachioplasty, breast contouring surgery, abdominoplasty/circumferential body lift and medial thigh lift are being discussed in terms of wound healing characteristics and subsequent complications. The preoperative preparing as well as special operative techniques are described in order to achieve a low rate of wound healing complications.