Influence of Flap Parameters on the Aerodynamic Performance of a Wind-Turbine Airfoil

A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient,lift coefficient,and drag coefficient.The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil;however,at small attack angles,its influence is significantly reduced.When the angle of attack exceeds the critical stall angle and the flap height is 1.5%of the chord length,the influence of the flap becomes very evident.As the flap height increases,the starting point of the separation vortex gradually moves forward and generates a larger wake vortex.Optimal aerodynamic characteristics are obtained for 1.5%(of the chord length)flap height and a 45°flap angle;in this case,the separation vortex is effectively reduced.

Nasal flap preservation in endoscopic dacryocystorhinostomy for nasolacrimal duct obstruction

AIM:To compare surgical outcomes between the conventional endoscopic dacryocystorhinostomy(DCR)and a modified endoscopic DCR for the treatment of nasolacrimal duct obstruction(NLDO),and evaluate factors associated with the surgical success rate.METHODS:Medical records of patients who underwent primary DCR surgery between January 2016 and July 2020 at the Otorhinolaryngology Department of Eye and Ear International Hospital,Lebanon were reviewed.RESULTS:The study group consisted of 50 consecutive modified endoscopic DCR and the control group consisted of 138 consecutive conventional endoscopic DCR.The success rates at 1y were 98.0%(49 out of 50)for modified DCR,significantly higher compared to 84.8%(117/138)for the conventional DCR;there was no significant difference in the success rate throughout the years in terms of both surgical techniques.The modified surgery vs traditional[adjusted odds ratio(aOR)=14.96]and having an adjunctive septoplasty surgery vs not(aOR=3.99)were significantly associated with higher odds of success.CONCLUSION:Mucosal flap preservation and apposition shows significant improvement in the surgical success rate.Moreover,there is no statistically significant difference found in terms of complication rate and mean operative time between the conventional and the modified techniques.

When the Combination of a Chinese Flap and Dufourmentel Makes It Possible to Treat a Hopeless Case of Squamous Cell Carcinoma of the Upper Lip

Cancers of the lip are the leading cause of labial defects, and treatment is essentially surgical. The success of a repair is assessed by two essential criteria: The functional character of the lip (restoration of continence allowing feeding) and the aesthetic quality of the repair. However, for many patients from countries whose medical infrastructure does not allow them to undertake complex reconstructions locally, medical transfers represent their only chance of treatment. The aim of this article is to share with you an extreme clinical case of labial reconstruction, the management of which was a real challenge, using two major flaps: the free ante-brachial flap and the DUFOURMENTEL-type bi-pediculated scalp flap.

Impact of Blade-Flapping Vibration on Aerodynamic Characteristics of Wind Turbines under Yaw Conditions

Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied,the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly understood.This study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics(CFD).In the CFD model,the blades are segmented radially to comprehensively analyze the distribution patterns of torque,axial load,and tangential load.The following results are obtained.(i)After applying flapwise vibration,the torque and axial thrust of wind turbines decrease in relation to those of the rigid model,with significantly increased fluctuations.(ii)Flapwise vibration causes the blades to reciprocate along the axial direction,altering the local angle of attack and velocity of the blades relative to the incoming wind flow.This results in the contraction of the torque region from a circular shape to a complex“gear”shape,which is accompanied by evident oscillations.(iii)Compared to the tangential load,the axial load on the blades is more sensitive to flapwise vibration although both exhibit significantly enhanced fluctuations.This study not only reveals the impact of flapwise vibration on wind turbine blade performance,including the reduction of torque and axial thrust and increased operational fluctuations,but also clarifies the radial distribution patterns of blade aerodynamic characteristics,which is of great significance for optimizing wind turbine blade design and reducing fatigue risks.

Management of Square Carcinoma of the Lower Lip Using Camille-Bernard Flap under Local Anesthesia: When Constraints Dictate Our Attitude

Introduction: Squamous cell carcinomas of the lip essentially pose a therapeutic management problem. In the West, their treatment is done under general anesthesia and follows the classic rules of oncology. In our context of exercise, we sometimes have a different attitude dictated by various constraints. Observation: 55-year-old patient with no notable history, seen in consultation for a very large ulcerative-budding lesion on the right 2/3 of the lower lip with mucocutaneous involvement without lymph node findings found on examination. Faced with this suspicious lesion and the patient’s financial difficulties, we decided to operate under local anesthesia to remove this tumor. The oncological excision was followed by immediate plasty using a Camille-Bernard flap with a good immediate aesthetic and functional result and postoperative day 7. The patient was unable to take his surgical specimen to anatomy-pathology and was lost to follow-up due to lack of financial resources. On anatomo-pathological analysis of the surgical specimen, the margins were healthy with confirmation of squamous cell carcinoma (anapathological reading made for scientific interest). Discussion: The particular mentality of certain patients and their difficult financial conditions push us to have an unconventional therapeutic attitude in oncology, but which nevertheless makes it possible to resolve certain problems that we often face. Local anesthesia is possible and realistic in cases like ours and the results can be acceptable and life-saving.

Evaluation of the versatility of perforators-enhanced rhomboid flap technique for ischial sores reconstruction

Background: Prolonged pressure on the skin known as pressure sores, can cause frequent injuries to the skin and underlying tissues. However, several prevention approaches, including non-surgical and surgical management,are available. In flap surgery for pressure sores, a variety of flap types may be used;each offers certain benefits and some incidences of complications and recurrence. This study evaluated the versatility of the perforatorenhanced rhomboid flap technique for ischial sore construction.Methods: This prospective study was conducted in the Plastic Surgery Department of Fayoum University Hospital.The perforator-enhanced rhomboid flap technique was employed in 20 patients with ischial pressure sores who failed to respond to conservative treatment. A proper history was obtained and a preoperative arterial duplex was performed to determine the site of the prominent perforators for their preservation at the base of the flap.Postoperative follow-ups and evaluations were performed.Results: The mean age of the study group was 43.7 ± 13.1, ranging from 19 to 65 years. Moreover, 80% of the participants were males while 20% were female. The main etiology of the sores was paraplegia in 45% of cases.The mean surface area of sores was 24.8 ± 6.3 cm2. In 75% of cases, the color match of the flap was rated as excellent. Similarly, 70% of the patients rated flap thickness as excellent. In 55% of the cases, the scar appearance was deemed excellent. Overall satisfaction was reported as excellent by 40% of the patients, while only 5% reported poor satisfaction. Approximately, 10% of the cases were identified with seroma, and 30% had wound dehiscence of a mean size of 1.33 ± 0.98 cm and required around 6.8 ± 1.9 weeks to heal.Conclusion: The perforator-enhanced rhomboid flap technique is a versatile method for reconstructing ischial pressure sores owing to its technical ease, short operative time, reliable vascularity, aesthetic outcome, matching skin color, and short recovery time. The main limitations include large defects with large surface areas, lack of a nearby donor site for a rhomboid flap, and scarring from prior procedures around the sore.

Adaptability of bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection

Background:Several reconstructive techniques have been used to reconstruct scalp defects.Numerous researchers have studied the utilization of bipedicled scalp advancement flaps for scalp defect coverage.In this study,we will assess the adaptability of a bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection.Methods:This study was performed at the Plastic Surgery Department,Fayoum University Hospital,on 20 patients with huge scalp tumors treated by adequate excision and reconstructed using a bipedicled scalp advancement flap from December 2021 to July 2023.Results:The study was conducted on 20 patients:16(80%)were men and 4(20%)were women presenting with large scalp tumors.The mean age was 57.4 years(33-68 years).The sites of the tumors were 10(50%)occipital,6(30%)parietal,and 4(20%)parieto-occipital.No major complications occurred postoperatively,and the bipedicled flaps survived well in all cases,with no necrosis.Conclusion:Huge scalp defects after tumor resection can be safely reconstructed with a large versatile bipedicled advancement scalp flap,either transversely or longitudinally oriented,with favorable functional results and accepted aesthetic results,apart from the alopecic area over the grafted donor site,which can be treated by tissue expansion if desired later.

Pedicled abdominal flap using deep inferior epigastric artery perforators for forearm reconstruction: A case report

BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.

Lateral circumflex femoral artery perforator flap for the reconstruction of head soft tissue defects:Cross-region venous anastomosis

Background:Owing to its unique characteristics,the lateral circumflex femoral artery perforator(LCFAP)flap is often preferred for repairing head wounds with exposed skulls.However,given the vascular distribution in the head,particularly the veins,can lead to postoperative complications such as venous congestion of the flap.The rates of vascular exploration and necrosis in these flaps are significantly higher than in other body regions.Therefore,it is crucial to identify a safe and effective method for venous anastomosis of free flaps in the head region.Methods:This retrospective case series study included 10 patients with large head soft tissue defects treated at the Burn and Plastic Surgery Department of the Affiliated Hospital of Zunyi Medical University from January 2020 to December 2022.The head defects were reconstructed using LCFAP flaps,with flap veins anastomosed to the external jugular vein in the neck,either directly or via a bridging technique.Results:Among the 10 adult patients with massive head wound defects,7(70%)were men.The patients’mean age was 53.0 years(48–59 years).The wound defects were caused by trauma in 6(60%)patients and by tumors in 4(40%)patients.Postoperatively,no significant complications occurred,and all LCFAP flap survived without necrosis.Conclusion:The descending branch of the LCFAP flap effectively repairs massive head wound defects.The venous anastomosis method for this flap is associated with a low incidence of venous complications and a high patency rate,making it a clinically valuable reference.

Thrust Optimization of Flapping Wing via Gradient Descent Technologies

The current work aims at employing a gradient descent algorithm for optimizing the thrust of a flapping wing. An in-house solver has been employed, along with mesh movement methodologies to capture the dynamics of flow around the airfoil. An efficient framework for implementing the coupled solver and optimization in a multicore environment has been implemented for the generation of optimized solutionsmaximizing thrust performance & computational speed.

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Objectives: The anterolateral thigh (ALT) flap is often considered the workhorse in soft tissue reconstruction of head and neck defects secondary to trauma, infection, or tumor resection. Despite its many advantages, ALT flaps have been criticized due to variability in vasculature, which may result in inadequate or non-existent perforators. This retrospective study aims to investigate the utility and validity of positron emission tomography (PET) scan to identify the location and characteristics of perforators to the ALT flap. Methods: We performed a 10-year retrospective review of ALT flaps at our institution to identify patients with preoperative PET scans available for analysis. Three reviewers (attending physician, fellow, and resident) were asked to identify the number, location, and characteristics (myocutaneous versus septocutaneous) of ALT perforators on imaging, and reviewer agreement was assessed. Results were then compared to available operative data. Results: One hundred twenty-one patients were identified who underwent ALT free flap surgery. Thirty-eight preoperative PET scans were identified for review. At least one perforator was identified in 92.1% of scans. Agreement percentages regarding the number of perforators ranged from 53% - 61% whereas agreement regarding the location of a single perforator ranged from 79% - 90%. However, reviewers did not agree regarding the type of perforator, with agreement ranging from 34% - 53%. Poor agreement was observed when compared to intraoperative data, with the number of perforators ranging from 26% - 34% and the type of perforator 11% - 24%. These findings are likely due to insufficient data available in operative reports. Conclusion: Although initial studies suggest that PET scan shows promising evidence to support the capacity to preoperatively identify ALT perforators, future prospective studies are warranted to fully validate these findings.

Sternocleidomastoid flap for reconstruction of tongue small cell carcinoma: A case report

BACKGROUND The management of tongue carcinoma is excision and radical neck dissection followed with reconstruction.This is a case report of a patient with tongue squamous cell carcinoma(SCC)who underwent the procedure with sternocleidomastoid(SCM)flap reconstruction.CASE SUMMARY A 52-year-old woman without smoking history complained tongue ulcer since 3 years ago.Based on the histopathological examination,the patient was diagnosed with T2N2M0 right tongue SCC and underwent wide excision of tumor;right mandibular;neck dissection and were reconstructed with SCM flap.CONCLUSION SCC of the tongue requires wide excision and dissection of the neck and mandible if infiltration into the surrounding lymph nodes has been found.The SCM flap reconstruction could be used post-surgery.

The wave and vibratory power transmission in a finite L-shaped Mindlin plate with two simply supported opposite edges

In this paper,wave and vibratory power transmission in a finite L-shaped Mindlin plate with two simply supported opposite edges are investigated using the wave approach.The dynamic responses,active and reactive power flow in the finite plate are calculated by the Mindlin plate theory （MPT） and classic plate theory （CPT）.To satisfy the boundary conditions and continuous conditions at the coupled junction of the finite L-shaped plate,the near-field and far-field waves are entirely contained in the wave approach.The in-plane longitudinal and shear waves are also considered.The results indicate that the vibratory power flow based on the MPT is different from that based on the CPT not only at high frequencies but also at low and medium frequencies.The influence of the plate thickness on the vibrational power flow is investigated.From the results it is seen that the shear and rotary inertia correction of the MPT can influence the active and reactive power at the junction of the L-shaped plate not only at high frequencies but also at low and medium frequencies.Furthermore,the effects of structural damping on the active and reactive power flow at the junction are also analyzed.

Axial Compression Behavior and Analytical Method of L-Shaped Column Composed of Concrete-Filled Square Steel Tubes

Based on the characteristics of an L-shaped column composed of concrete-filled square steel tubes, the axial compression experiment and nonlinear finite element analysis were carried out to study the mechanical property of the L-shaped column. The load-displacement curve for the L-shaped column, the deflection and load-strain curves for the mono columns were obtained by the axial compression experiment. The results show that the L-shaped column exhibits a flexural-torsional buckling failure mode. The numerical simulation by the finite element analysis shows that the bearing capacity and failure mode are in accordance with those of the axial compression experiment and the feasi- bility of the finite element analysis is proved. For the calculation of the bearing capacity of the L-shaped column com- posed of concrete-filled square steel tubes, an analytical method is proposed based on the theory of the elastic stability and spatial truss model. The results of the analytical method are in good agreement with those of the axial compression experiment and the finite element analysis.

Research on vibration characteristics of L-shaped plate using a mobility power flow approach

L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided into two substructures to simplify analysis. The coupled bending moment was then deduced by applying a continuous vibration property on the common edge. Next, the response on any point of the plate and the input and transmitted power flow formulas were calculated. Numerical simulations showed the distribution of the coupled bending moment and the response of the whole structure. The validity of this method was verified by the SEA approach.

Joint 2D DOA and Doppler frequency estimation for L-shaped array using compressive sensing

A joint two-dimensional(2D)direction-of-arrival(DOA)and radial Doppler frequency estimation method for the L-shaped array is proposed in this paper based on the compressive sensing(CS)framework.Revised from the conventional CS-based methods where the joint spatial-temporal parameters are characterized in one large scale matrix,three smaller scale matrices with independent azimuth,elevation and Doppler frequency are introduced adopting a separable observation model.Afterwards,the estimation is achieved by L1-norm minimization and the Bayesian CS algorithm.In addition,under the L-shaped array topology,the azimuth and elevation are separated yet coupled to the same radial Doppler frequency.Hence,the pair matching problem is solved with the aid of the radial Doppler frequency.Finally,numerical simulations corroborate the feasibility and validity of the proposed algorithm.

Laboratory test on the combined cooling effect of L-shaped thermosyphons and thermal insulation on high-grade roadway construction in permafrost regions

With the completion of the Qinghai-Tibetan Railway,economic development of related areas has been greatly accelerated.This,in return,calls for building or upgrading more roadways,especially high-grade roadways.In cold regions,the thawing of permafrost can induce settlement damage of and even failure to railway (or roadway) embankments.Thermosyphons (self-powered refrigera-tion devices that are used to help keep the permafrost cool) have proved effective in mitigating thaw settlement by maintaining the thermal stability of the embankments.However,for high-grade roadway embankments of great width,stabilizing or cooling ef-fects of traditional geotechnological measures may be limited.To enhance the cooling effect of thermosyphons,an L-shaped thermosyphon was designed.A laboratory test was carried out to study the combined cooling effect of the L-shaped thermosyphon and thermal insulation applying to roadbed construction.The angle between the evaporator and condenser sections of the L-shaped thermosyphon is 134 degrees,and the L-shaped thermosyphon was inserted into the soil at an angle of 5 degrees with the road surface.The tested results show that the L-shaped thermosyphon is effective in removing heat from a roadway in winter.When the ambient air temperature is lower than the soil temperature,the thermosyphon is active and extracts the heat in the soil around it.When the ambient air temperature is higher than the soil temperature,the thermosyphon is inactive,and no heat is in-jected into the soil through the L-shaped thermosyphon.Compared to embankments with straight thermosyphons,the inner parts of the embankments with L-shaped thermosyphons were significantly cooled.It is hoped that the present study would be useful to the application of L-shaped thermosyphons in the construction of high-grade roadways in cold regions.

Test on mechanical behavior of SRC L-shaped columns under combined torsion and bending moment

Investigations of the seismic behavior of steel reinforced concrete L-shaped columns under constant axial compression and cycled bending-shear-torsion load were performed.Six specimens,which considered two parameters,i.e.,the moment ratio of torsion to bending(γ)and the aspect ratio(column length-to-depth ratio,φ),were prepared for the experiment.In this study,the failure process,torsion-displacement hysteresis curves,and flexure-displacement hysteresis curves were obtained.The failure characteristics,mechanical behavior of specimens such as the failure patterns,hysteresis curves,rigidity degradation,ductility and energy dissipation,are analyzed.The experimental research indicated that the major failures of the specimens were bending failure,bending-shear failure and bending-torsion failure as the moment ratio of torsion to bending(γ)increased.The torsion-displacement hysteresis curves were pinched in the middle,formed a slip platform,and the phenomenon of“load drop”occurred after the peak load.The bending-displacement hysteresis curves were plump,which showed that bending capacity of the specimen was better than its torsion capacity.Additionally,the energy dissipation of the specimen was dominated by torsion in the early stage and ultimately governed by the bending moment in the later phase.Test results also indicated that the displacement ductility coefficient and interstory rotation angle of the failure point were less than 3.0 and 1/50,respectively,which means the test specimen performance does not meet the requirement of the Chinese Code for Seismic Design of Buildings(GB 50011-2014)in this respect.

Bandwidth Numerical Analysis of Triangular Patch Antenna Fed by L-Shaped Probe

A single layer triangular patch antenna fed by an L-shaped probe was investigated numerically by using FDTD (Finite Difference Time Domain) method. It achieves >40% impedance bandwidth (VSWR<2) and stable radiation pattern across the passband. The triangular patch antenna with two orientations of L-shaped probe has almost the same characteristics, such as impedance bandwidth and radiation pattern. The bandwidth vs feeding position was also investigated, the broadband characteristic can be observed when the feeding position is only in a small segment along the centerline.

“In situ bone flap” combined with vascular pedicled mucous flap to reconstruction of skull base defect

BACKGROUND At present,neuroendoscopy technology has made rapid development,and great progress has been made in the operation of lesions in the saddle area of the skull base.However,the complications of cerebrospinal fluid and intracranial infection after the operation are still important and life-threatening complications,which may lead to poor prognosis.AIM To investigate the method of in situ bone flap combined with nasal septum mucosal flap for reconstruction of enlarged skull base defect by endonasal sphenoidal approach and to discuss its application effect.METHODS Clinical data of 24 patients undergoing transnasal sphenoidal endoscopic approach in the Department of Neurosurgery,Affiliated 2 Hospital of Nantong University from January 2019 to December 2022 were retrospectively analyzed.All patients underwent multi-layer reconstruction of skull base using in situ bone flap combined with nasal septum mucosa flap.The incidence of intraoperative and postoperative cerebrospinal fluid leakage and intracranial infection were analyzed,and the application effect and technical key points of in situ bone flap combined with nasal septum mucosa flap for skull base bone reconstruction were analyzed.RESULTS There were 5 cases of high flow cerebrospinal fluid(CSF)leakage and 7 cases of low flow CSF leakage.Postoperative cerebrospinal fluid leakage occurred in 2 patients(8.3%)and intracranial infection in 2 patients(8.3%),which were cured after strict bed rest,continuous drainage of lumbar cistern combined with antibiotic treatment,and no secondary surgical repair was required.The patients were followed up for 8 to 36 months after the operation,and no delayed cerebrospinal fluid leakage or intracranial infection occurred during the follow-up.Computed tomography reconstruction of skull base showed satisfactory reconstruction after surgery.CONCLUSION The use of in situ bone flap combined with vascular pedicled mucous flap to reconstruction of skull base defect after endonasal sphenoidal approach under neuroendoscopy has a lower incidence of cerebrospinal fluid leakage and lower complications,which has certain advantages and is worthy of clinical promotion.