Multiple Tunnels Research Articles

Multiple-beam and double-mode staggered double vane travelling wave tube with ultra-wide band

This paper presents design, fabrication and cold test of an ultra-wide band travelling wave tube (TWT) with planar alignment multiple pencil beams. The fundamental double-mode of staggered double vane slow wave structure (SDV-SWS) rather than the only one mode are put forward and adopted to match with the same electron beam to increase the bandwidth greatly. Simultaneous planar alignment multiple pencil beam tunnels are designed to improve interaction impedance and then to enhance output power, gain, efficiency, growth rate. The transmission performance of a two-stage 51-period SDV-TWT in G-band with structure attenuator between two sections shows that it indeed has an ultra-wideband performance from 81 to 110 GHz. By using computer numerical control machining, the SDV-SWS was manufactured and a detailed cold test was conducted. Good agreement is found at the wide band, where S21 is above − 5 dB and S11 is below − 10 dB. 3D PIC simulations with double-mode multiple-beam SDV-TWT within total length of 70 mm show that it can get a nearly 2120 W peak output power, a 42.5 dB corresponding gain and a 10.7% electron efficiency at 94 GHz with a 22.1 kV beam voltage and a 3 × 0.15A beam current. The 3 dB bandwidth of our double-mode SDV-TWT can achieve about 29 GHz.

A generalized complex variable method for multiple tunnels at great depth considering the interaction between linings and surrounding rock

The mechanical analysis of multiple tunnels at great depth is an extremely common problem in practical engineering. Previous studies usually used the Schwarz alternating method to solve the multiple-tunnel problem with an iterative scheme, which resulted in low efficiency and precision. To this end, this paper presents a non-iterative analytical method to calculate the mechanical field of multiple lined tunnels. In this method, the analytic function is expanded by Laurent series on each tunnel boundary so that the stress and displacement fields in the whole multiply-connected domain can be expressed accurately. The conformal mappings of different tunnels are independent of each other, which makes it convenient to deal with multiple arbitrary-shaped boundaries. The basic equations for solving the mechanical fields are obtained according to the contact conditions and stress boundary conditions. In the solving process, the Fourier transform method is used to transform the boundary conditions into the frequency equations. Compared with the Schwarz alternating method, our method can directly obtain the high-quality result without any iteration. Finally, several examples are given to verify the accuracy and effectiveness of the proposed method.

An improved grey wolf optimization algorithm with multiple tunnels for updating

The grey wolf optimization (GWO) algorithm was proposed in 2014 and after several years of applications, it was used worldwide and all over the subjects which involved computation. Various improvements have been raised to increase the capability of optimization. Based on the best performance of the slimd mould (SM) algorithm in optimization, a hybridization of the SM and GWO algorithms was proposed about the updating equations, and the GWO algorithm with multiple tunnels for individuals to update their positions during iterations was revised. Simulation experiments were carried out and comparisons were made between the GWO algorithm with variable weights and our proposed new one. Better performance were confirmed and reported as conclusions.

Spatial impact analysis of trans-Yangtze highway fixed links: A case study of the Yangtze River Delta, China

As an important infrastructure connecting straits or rivers, the construction of fixed links has become an effective measure for improving traffic conditions and promoting socio-economic development in many countries and regions around the world. Thus, it has become a significant topic in the field of transport geography. Taking the Yangtze River Delta as its case area, this study proposes a spatial impact model of trans-Yangtze highway fixed links, consisting of three components: an accessibility model, modified gravity model, and traffic utilisation model, which are used to analyse, respectively, cross-Yangtze accessibility and changes to transport structure, cross-Yangtze urban interaction and changes to economic structure, and the utilisation relationship of fixed links. Making use of existing fixed links while planning and building new ones has become the basis for achieving regional integration and sub-regional cooperation in this area, the aim of which is to create the barrier-free circulation of elements. The results prove that this spatial impact model coincides with reality. The increase in the number of fixed links has significantly shortened cross-river travel time and facilitated a unification of north-south highway networks. It has also promoted the formation of a high-connection urban network along the river. Northern urban nodes have joined the southern economic circle and finally achieved north-south integration. There are complex relationships between fixed links and their hinterlands, showing obvious utilisation gaps between the links. The complete system of trans-Yangtze fixed links is comprised of several river crossing facilities and connected highways. The function of each link is related to its role in the regional highway network. From a small number of fixed links to the realisation of multiple trans-Yangtze bridges and tunnels with easy access to multiple arterial highways, a ‘many-to-many’ spatial pattern is created that ultimately leads to the evolution of regional transport and economic structures.

983 TUNNEL ASSISTED "FUNNEL” RESECTION: ESD OF LARGE CIRCUMFERENTIAL EGJ/CARDIA SIEWERT 2 LESION

A 74year old woman with alopecia, CAD on Plavix and Non-Hodgkin’s lymphoma s/p chemotherapy and radiation of the upper abdomen underwent endoscopy to evaluate dysphagia. It revealed a stenotic esophagus with diameter of 12-15 mm. Bougie dilation was performed. Three gastric lesions were seen: A large Paris IIa circumferential lesion extending from 1 cm proximal to the Z line to 4-5 cm distal to the Z line, a 4cm Paris IIb lesion at the proximal greater curvature lesion and a 2 cm cardia Paris Is lesion. Biopsy of all 3 lesions revealed adenoma. The patient was referred to us for ESD of the 3 lesions. There is scant literature on ESD of Siewert II EGJ lesions of gastric origin and virtually no literature on ESD for completely circumferential such lesions (Kim et al Surg Endo 2018). Circumferential en bloc resection of such lesions is challenging due to: 1. the narrow esophageal lumen and high EGJ vascularity, particularly in this patient with stenotic esophagus, post radiation fibrosis, and antiplatelet therapy. 2. the difficulty in achieving favorable scope position for ESD in the fundus and anterior cardia. Double bending scopes are helpful in this setting but not available in the US (Hamada VideoGIE 2019). We present a video that highlights techniques that can be used to achieve en bloc resection in such challenging lesions. The large circumferential lesion was removed in 424 minutes, specimen measured 7cm x 7cm. As shown on the video the “funnel” shaped specimen was affixed on cork in a way that orientation is preserved with the esophageal portion protruding through a hole. The second lesion was removed in 55 minutes, specimen measured 5.5 cm x 3.5 cm. The third lesion was removed in 44 minutes, specimen measured 2.5 cm x 2 cm. In all 3 cases, pathology revealed R0 resection of adenoma. The patient had delayed bleeding on POD#1 requiring endoscopic hemostasis. She also developed EGJ stricture requiring 7 endoscopic dilations over 3.5 months until resolution. The presented video includes the video of her follow-up endoscopy at 1 year showing well healed scars with no residual adenoma. We present an en bloc, R0 “funnel” resection of a challenging EGJ/cardia circumferential lesion in a patient with stenotic esophagus and post radiation fibrosis. A variety of advanced techniques were used to achieve successful en bloc resection including multiple tunnels, a 360 degree endoscope loop (previously described by us for EFTR in the fundus, VideoGIE 2019), omental plug for microperforation closure, and per-os traction using an external grasper. Even with expert skills and techniques the operator should expect long operative times for such resections but they are of major benefit to patients particularly for pre-cancerous lesions as they spare them extensive esophago-gastrectomy operations.

A theoretical explanation of natural ventilation at roof openings in urban road tunnels

Natural ventilation through openings in the roof of a road tunnel is a green technique that saves energy and greatly improves the air quality inside the tunnel. However, even though multiple tunnels with natural ventilation have been built in China, the theoretical basis for designing and constructing such tunnels is incomplete and there is as yet no uniform and systematic understanding of the natural-ventilation mechanism at the roof openings. Aimed at these problems and based on nearly six years of research and experiments, this paper presents a theoretical explanation of the flow-field characteristics in a road tunnel and the natural ventilation at its roof openings, including (i) the distribution and governing equations for the flow in the tunnel, (ii) the energy governing equation and (iii) the equation governing the natural ventilation at the roof openings. The presented theoretical formulas are consistent with the measured data. The main conclusions are as follows. (1) The airflow in a road tunnel is drag flow resulting from vehicles driving in a restricted space. The flow develops in a bottom-up manner and tends to be stable. The flow velocity is distributed double-logarithmically with height in the tunnel. (2) Moving vehicles are energy sources for the airflow in a road tunnel. Some of the energy transferred from a moving vehicle to the air increases the airflow velocity, while the rest is consumed in turbulence. As the flow develops, the kinetic energy increment decreases gradually and tends to zero, while the energy dissipation decreases gradually and tends to be stable. (3) The air above a road tunnel with roof openings can be sucked into the tunnel by the airflow induced therein by the unidirectional continuous traffic flow. This creates airflow from exterior to interior, but there is no corresponding ‘breathing’ phenomenon. The air inlet velocity at the roof openings differs considerably along the tunnel. It is maximum near the tunnel entrance and decreases gradually along the tunnel, presenting a concave curve.

Seismic Behavior of Triple Tunnel Complex in Soft Soil Subjected to Transverse Shaking

Combining multiple tunnels into a single tunnel complex while keeping the surrounding area compact is a complicated procedure. The condition becomes more complex when soft soil is present and the area is prone to seismic activity. Seismic vibrations produce sudden ground shaking, which causes a sharp decrease in the shear strength and bearing capacity of the soil. This results in larger ground displacements and deformation of structures located at the surface and within the soil mass. The deformations are more pronounced at shallower depths and near the ground surface. Tunnels located in that area are also affected and can undergo excessive distortions and uplift. The condition becomes worse if the tunnel area is larger, and, thus, the respective tunnel complex needs to be properly evaluated. In this research, a novel triple tunnel complex formed by combining three closely spaced tunnels is numerically analyzed using Plaxis 2D software under variable dynamic loadings. The effect of variations in lining thickness, the inner supporting structure, embedment depth on the produced ground displacements, tunnel deformations, resisting bending moments, and the developed thrusts are studied in detail. The triple tunnel complex is also compared with the rectangular and equivalent horizontal twin tunnel complexes in terms of generated thrusts and resisted seismic-induced bending moments. From the results, it is concluded that increased thickness of the lining, inner structure, and greater embedment depth results in decreased ground displacements, tunnel deformations, and increased resistance to seismic-induced bending moments. The comparison of shapes revealed that the triple tunnel complex has better resistance against moments with the least amount of thrust and surface heave produced.

Development and Application of Portable Intelligent Warning System for Safe Tunnelling

With the emphasis on the construction of transportation infrastructure and the continuous advancement of county-level expressways’ “all-access and full-passage”, as well as the continuous improvement of water environmental protection during the construction process, especially in mountainous areas, the ratio of highway bridges to tunnels is getting higher and higher, tunnel engineering The construction is implemented as a control project in the construction of the highway. The combination of monitoring and measurement work has played an important role in all aspects of the tunnel construction, especially in terms of project quality, engineering cost, and progress. Monitoring and measurement should be implemented. Pay attention to the design of construction organization. As we all know, tunnel engineering is a kind of underground engineering, which itself has many characteristics such as complexity, concealment, and unmeasurability. There are many problems such as unpredictability in the development of the tunnel itself. During the construction process, the poor geological environment will not only cause problems to the technicians, but also cause the tunnel collapse, water inrush, etc., and even cause life to the construction personnel in severe cases. Hazards, thereby affecting the normal operation of the construction, causing delays in the construction period, and other issues, which will have a huge economic impact on the project. With the skillful application of monitoring and measurement, the problems existing in tunnel engineering can be predicted, so as to solve the problems and finally determine the design scheme. The application of monitoring and measurement in China’s highway tunnels is essential. Due to its concealment and the complexity of engineering geology, tunnel construction safety accidents occur frequently. Monitoring and measurement are important means of tunnel construction safety guarantee, and its informatization and intelligence are inevitable trends for future development. The article analyzes key technical issues. Proposed a reasonable solution, compiled a reasonable positioning early warning algorithm, developed an intelligent early warning system for tunnel construction safety and a portable wearable device, and successfully applied it in multiple tunnels, achieved good application results, and achieved intelligent monitoring of tunnel construction safety Visualization and visualization.

Analysis and Safety Assessment of Lining Thickness Defects in Highway Tunnels

Linings are the main structure of a tunnel to withstand pressure from surrounding rock and their thickness is representative of their load carrying capacity. Tunnel lining thickness defects will have a direct impact on the long-term stability of the tunnel project. Existing research on lining thickness defects focuses on analysis of crown thickness defects using failure load as criteria and is applicable to theoretical research with a lack of guiding significance to actual projects. Based on the test results of lining thickness defects in multiple tunnels of the Liangping-Zhongxian Expressway in Chongqing, this paper covers analyses of thickness defect location and extent and numerical analysis of the effects of different thickness defects on structural performance. The analysis results show: under the same surrounding rock conditions the probability of tunnel lining thickness defects occurring at the hance is similar to at the crown; the probability of thickness defects increases as surrounding rock conditions worsen; when thickness defects exceed 10%, the thickness defect percentage is inversely proportional to the safety factor. The research findings are of practical significance and can provide guidance to NDT, defect treatment and safety assessment.

Crash-Prone Section Identification for Mountainous Highways Considering Multi-Risk Factors Coupling Effect

In order to identify crash-prone sections of the highways in mountainous areas professionally and exclusively, the common phenomena of “sharp turns”, “continuous long downhill”, “multiple tunnels”, “dangerous roadside environment”, and complex and changeable meteorological environment, which all imply risk factors of the mountainous highways, are comprehensively considered. Utilizing the improved classical coupling model, the coupling mechanism of the risk factors is revealed, and the coupling model of the traffic risk factors is constructed, by which the coupling degrees of multi-risk factors couplings are calculated respectively. Based on the coupling degrees of the above factors, the concept of vehicle operation risk index (VORI) of the mountainous highway is introduced and its numerical value is quantified as the basis for identifying the crash-prone sections. The 21 km of Songming to Huize section of the Songdai Highway in the Yunnan Province of China is selected as an example, and the good applicability of the identification model is verified.

Analysis and Study on Crack Characteristics of Highway Tunnel Lining

Lining cracks are one of the most common diseases in highway tunnels, and the existence of lining cracks directly affects the overall stability and durability of tunnels, which has an important impact on the safe operation of tunnels, and it is necessary to analyze and study the characteristics of tunnel lining cracks. Combining with the detection data of multiple highway tunnels in the field, the different types of tunnel cracks are divided, and the classification numerical statistics method is used to obtain that the number and length of annular cracks in highway tunnel cracks are significantly higher than those of the other two kinds of cracks, and the longitudinal cracks in tunnel crack cracking degree are greater than the circumferential cracks and the inclinded cracks. The influence degree of cracks on the safety of tunnel structure longitudinal cracks are relatively the largest, the inclinded cracks are second only to longitudinal cracks, and the influence of cyclic cracks is relatively small. It provides reference for tunnel engineering design, construction, operation management and comprehensive improvement work.

Arthroscopic Coracoclavicular Fixation Technique Using Multiple All-Suture Anchors

Acromioclavicular (AC) joint dislocation is a common injury, particularly among active young individuals. Numerous surgical procedures for treating acute, high-grade AC joint dislocation have been reported. However, no standard surgical procedure that restores the normal kinematics of the AC joint is available. Among the available coracoclavicular (CC) fixation techniques, cortical button fixation was recently introduced, and it has had successful outcomes. Moreover, it is advantageous because it can be used in arthroscopic procedures. However, because of the limited number of fixation tools, a fundamental problem in terms of horizontal instability and gradual subsidence of cortical buttons has been observed, eventually leading to a threat to vertical stability. Therefore, we developed a unique CC fixation technique with multiple small tunnels using all-suture anchors, which may overcome potential complications caused by cortical buttons that require bone tunnels with relatively large diameters. This arthroscopic CC fixation technique was designed to achieve the ideal horizontal and vertical stability that may restore native AC kinematics.

The Case Study of a Deep Pit Excavation above Multiple Metro Tunnels and Influential Factors Analysis on Tunnel Upheaval Behaviors

The Case Study of a Deep Pit Excavation above Multiple Metro Tunnels and Influential Factors Analysis on Tunnel Upheaval Behaviors

Combining diverse driving forces for smoke control in complex urban traffic link tunnels (UTLTs) using one-dimensional flow modelling

Urban traffic link tunnels (UTLTs) could become increasingly more complex because they incorporate both looped main tunnels and multiple branch tunnels. In such a complex tunnel structure, smoke control in the event of fire becomes more difficult than that in conventional simple tunnels due to the enhanced flow interactions among various branches. Moreover, there are still no specific smoke control guidelines for such complex tunnels. Furthermore, the use of a single smoke control method could be inapplicable or even unaffordable in UTLTs because the complicity of the configuration and the interaction between the flow of different branches. In this paper, hybrid ventilation modes which combine diverse flow driving forces are proposed for smoke control in UTLTs. The hybrid modes could exploit the advantages of each of the constitutive modes. Three-dimensional numerical simulations are performed to show the benefits of combining diverse driving forces. Then, a one-dimensional flow modelling approach was employed to investigate the efficiency of three hybrid modes. The results demonstrate that proper matching of various driving forces is crucial for effective application of the hybrid modes. This paper provides a new route for UTLT smoke control and also demonstrates the advantages of one-dimensional flow modelling in such designs.

Multiligament Repair With Suture Augmentation in a Knee Dislocation With Medial-Sided Injury

Knee dislocations often result in a severe multiligament injured knee (MLIK) with complex instability. Multiligament reconstruction can successfully restore knee stability and is commonly recommended, although surgical morbidity is induced by graft harvesting and tunnel drilling, and convergence of multiple tunnels can complicate the surgery. Therefore, as an alternative, primary repair of knee ligaments is currently reconsidered. The main advantages of primary repair consist of tissue preservation and decrease of surgical morbidity, which might improve knee functionality. Techniques in which avulsed ligaments are reapproximated to their anatomic origin have resulted in good clinical outcomes in selected patients over the past decade. More recently, repaired ligaments have been augmented with suture tape, to protect them from excessive stretch, which can improve healing and allows early rehabilitation. The surgical technique of primary repair in the multiligament injured knee has not yet been described. The purpose of this Technical Note is to explain suture augmented primary repair in KDIII-M injury, including the anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament.

Performance improvement of a four-terminal thermal amplifier with multiple energy selective tunnels

A new model of the energy selective electron (ESE) device composed of four electron reservoirs and four energy filters is proposed. The device can work as a thermal amplifier, which may be equivalent to a coupling system consisting of two three-electron-reservoir heat pumps. Expressions for the heat-pumping rate (HPR) and coefficient of performance (COP) of the device are analytically derived through the heat flows of two-terminal ESE devices. The maximum HPR and COP are calculated. It is found that the maximum HPR of the coupling system can attain 2 times of that of a three-electron-reservoir heat pump while its COP is still equal to that of a three-electron-reservoir heat pump. Moreover, the effects of the chemical potentials of electron reservoirs, central levels of energy filters, half width at half maximum of energy filters on the HPR and COP of the device are discussed in detail. The optimal configuration of the device is determined. The cut-off value of the half width at half maximum of energy filters is calculated. The optimum selection criteria of main parameters are provided.

Tetrapod burrows from the Middle–Upper Triassic Chañares Formation (La Rioja, Argentina) and its palaeoecological implications

We describe tetrapod burrows from the uppermost Middle–lower Upper Triassic (latest Ladinian–early Carnian) Chañares Formation (Ischigualasto-Villa Unión Basin), La Rioja Province, northwestern Argentina. The burrows were found in different localities of the unit, but restricted to the lowermost 17 m of the formation. They occur at the same interval as a tetrapod assemblage composed of erpetosuchid and basal paracrocodylomorph pseudosuchians, basal traversodontid and chiniquodontid eucynodontians, and stenaulorhynchine rhynchosaurids. This assemblage differs from the typical Chañares fauna that occurs in stratigraphically higher levels. The burrows were found within the deposits of moderately developed palaeosols formed in volcanically-influenced braided fluvial facies under semi-arid climate conditions. The burrow systems are cylindrical to sub-cylindrical in cross-section, up to 25 cm in diameter, and characterized by long, multiple branching tunnels, several metres long, that meander horizontally or are slightly inclined (<30°), forming a complex network that is a result of passive fill of a previously open burrow. In general, these structures have a similar architecture and three-dimensional organization to those previously described from the upper parts of the Ischigualasto Formation in the same basin. It is hypothesised that some of these burrows were formed by small eucynodonts (e.g., basal traversodontids, chiniquodontids), and their co-occurrence with diverse, medium to large pseudosuchian predators (e.g., Luperosuchus, Tarjadia), suggests these non-mammaliaform eucynodonts would excavate burrows to live and avoid climate-stress conditions and/or predation. The new discovery of burrows in the Chañares Formation sheds light on the evolution of the palaeoecology of mammaliaform precursors during the dawn of the archosaur domain.

Structural Fat Grafting to Improve Outcomes of Vocal Folds' Fat Augmentation: Long-term Results.

Objective Evaluating the long-term outcomes of vocal fold structural fat grafting. Study Design Case series with chart review. Setting University hospital. Subjects and Methods Seventy-nine dysphonic patients (16-82 years; 55 with unilateral laryngeal paralysis and 24 with vocal fold scarring) underwent vocal fold fat injection. Fat was harvested by low-pressure liposuction and then processed by centrifugation. Refined fat aliquots were placed in the vocal fold and paraglottic space in multiple tunnels to enhance graft neovascularization. All patients were followed for 12 months, 15 for 3 years, and 5 for 10 years with videolaryngostroboscopy, maximal phonation time (MPT) measurement, Voice Handicap Index (VHI) questionnaire, and GRBAS (grade, roughness, breathiness, asthenia, strain) perceptual evaluation. Laryngeal computed tomography (CT) and/or magnetic resonance imaging (MRI) studies were performed in 16 patients 3 to 28 months postoperatively; MRI was repeated in 5 cases 12 to 18 months after the first radiological study. Results The voice quality of all patients improved after surgery, and long-term stability was confirmed by MPT, GRBAS, and VHI ( P ranging between .004 and <.001). The results achieved 1 year postoperatively remained stable at 3 and 10 years. Videolaryn-gostroboscopy showed improved glottic closure in all patients despite a limited amount of fat resorption. CT and MRI demonstrated survival of the fat grafts in all of the 16 examined cases. Serial MRI scans showed no change in graft size over time. Conclusions The reported clinical and radiological data demonstrate that fat is an effective filler for permanent vocal fold augmentation if the refined micro-aliquots are placed in multiple tunnels.

Risk of fracture of the acromion depends on size and orientation of acromial bone tunnels when performing acromioclavicular reconstruction

Current techniques for anatomic repair of the dislocated acromioclavicular (AC) joint aim on reconstruction of the AC ligaments and utilize tunnels drilled through the acromion . This improves the stability of the reconstruction but might also increase the risk of fractures at the acromion. The purpose of this study was to evaluate the fracture risk for the acromion after transacromial tunnel placement for anatomic AC joint stabilization procedure. It was hypothesized that the risk of fracture of the acromion is correlated to size and orientation of bone tunnels commonly used for anatomic AC joint reconstruction. A finite element analysis was used to simulate multiple bone tunnels and incoming force vectors (lateral vs. superior). Different tunnels were analysed, horizontal meaning an anterior-posterior orientation versus a vertical inferior-superior orientation through the acromion. Two tunnel diameters were simulated (2.4 vs. 4.5mm). Furthermore, the tunnel length and distance between tunnels were altered. Forty-five cadaveric specimens (median age: 64years, range 33-71years) were utilized for data acquisition. Out of these, 30 specimens were used to evaluate basic tunnel orientations and drill diameters using a MTS 858 servohydraulic test system. With regard to the tunnel orientation and drill hole size, the loads to failure were limited. The acromion is at higher fracture risk, with a superior to inferior directed incoming force. Position, size and direction of bone tunnels influenced the loads to failure. Horizontal tunnels with a higher diameter (4.5mm) had the most impact on load to failure reduction. A long horizontal tunnel with a diameter of 4.5mm reduced the load to failure with medial direction of force to 25% of the native acromion. The identical tunnel with a diameter of 2.4mm reduced the load to failure to 61%. Both 2.4-mm horizontal tunnels with a medium and short length did not reduce the load to failure. Tunnels placed at the acromion did not result in an increased risk of fracture. However, descriptive data showed a tendency for an increased fracture risk if tunnels are placed at the acromion, especially in horizontal direction with diameters of 4.5mm. In addition, the pattern of fracture was dependent on the orientation of the bone tunnels and the size. However, the results indicate a "safe zone" for the placement of bone tunnels within the anterior half of the acromion, which does not affect the loads to failure at the acromion. Therefore, current techniques for anatomic AC joint reconstruction which utilize fixation of grafts or sutures at the acromion are safe within current ranges of tunnel placement and sizes.

Clinical application of homogenizing fat transplatation

Objective To discuss the clinical application of different particle size of grain fat sieved by the homogenizing fat extractor. Methods A lot of 68 patients in this group were women, and the average age was 28 years. With the aid of tumescent technique, anterior and lateral thigh fat granules were extracted using liposuction needle; after the homogenizing fat extractor and sieve purification, fat particles were obtained with uniform particle size and no fibrous tissue for different sizes of 2.00 mm, 0.90 mm, 0.50 mm and 0.28 mm, respectively. After choosing corresponding diameter of fat transplantation needle and appropriate injection level according to fat particle size, the multiple spot and multiple track tunnels, multi-level injection for the facial soft tissue deficiency or cavity were then carried out. With long-term postoperative follow-up, evaluation of different grades were given for the complication, fat survival rate and satisfaction. Results The results were followed up for 3-12 months postoperatively; as responding, the facial appearance of graft field deformity or deficiency was significantly improved and the skin of the recipient area was soft; wrinkles was relieved, and so that they appeared young plump well-pleasing appearance. And there were no complications, such as infection, hematoma, fat liquefaction, pigmentation, induration and so on. Satisfactory results were obtained. Conclusions The treatment of facial soft tissue deficiency or deficiency, by choosing corresponding diameter of fat transplantation needle and appropriate injection level according to the differences of fat particle size sieved by the homogenizing fat extractor, can acheive a high fat survival rate, and stable long-term effect. Thus, this safe and ideal method for rejuvenation of facial treatment is worth promoting. Key words: Fat transplantation; Homogenization; Small fat granule; Micro fat granule; Superfine fat granule