Internal Tunnel Research Articles

Multitask vibration transformer for abnormal vibration identification and structural damage assessment in subway tunnels

As urban infrastructure becomes denser, subway operations face numerous risks, including adjacent construction and structural damage deterioration. Integrated monitoring is crucial to ensure safety. This study presents a multitask vibration transformer (M-TVT) model, which utilizes an Expert-Gate network to manage task-related information sharing. The model achieves integrated identification for the type and spatial distribution of internal and external tunnel abnormal vibration responses, along with assessing structural damage degree. Meanwhile, a tunnel-train-soil coupling experiment is conducted to validate the efficacy of the M-TVT model. The results demonstrate that the M-TVT model with the Expert-Gate network maintains high accuracy and stability, efficiently shares parameter information among tasks and achieves improvement in accuracy compared to single-task models.

Regulatory Mechanisms and Synergistic Enhancement of the Diiron YtfE Protein in Nitric Oxide Reduction.

The diiron-containing YtfE protein in Escherichia coli is pivotal in counteracting nitrosative stress, a critical barrier to bacterial viability. This study delves into the biochemical complexity governing YtfE's conversion of nitric oxide (NO) to nitrous oxide, a key process for alleviating nitrosative stress. Through site-directed mutagenesis, we explored YtfE's molecular structure, with a particular focus on two internal transport tunnels important for its activity. Our findings illuminate Tunnel 1 as the primary conduit for substrate transport, regulated by conformational shifts within the N-terminal domain that enable substrate access to the diiron core in the C-terminal domain. Tunnel 2 emerges as a secondary, supportive route, activated when Tunnel 1 is compromised. This result challenges a previous model of distinct tunnels for substrate entry and product exit, suggesting both tunnels are capable of transporting substrates and products. Our engineering efforts enhanced the role of Tunnel 2, enabling a synergistic operation with Tunnel 1 and tripling YtfE's enzymatic activity compared to its wild-type form. This research not only deepens our understanding of YtfE's regulatory mechanism for NO reduction but also introduces a strategy to amplify its enzymatic efficiency. The outcomes offer new ravenues for modulating bacterial stress responses.

Hydro-mechanical modeling of cohesive crack propagation of concrete lining in high internal pressure tunnels

High pressure tunnels with concrete lining have been extensively utilized in project practice. However, due to the characteristic of concrete being susceptible to cracking under tension, the lining inevitably develops cracks under high internal water pressure, posing a serious threat to the operation of tunnels. This study aims at developing a hydro-mechanical numerical model of cohesive crack propagation of concrete lining in high internal pressure tunnels. In this regard, the determination of cohesive element parameters is elucidated, the contact simulation within the software ABAQUS is improved to accurately characterize the interface between lining and surrounding rock, and the numerical calculation process in ABAQUS is realized using indirect coupled method. The simulation results align well with the physical model test and engineering monitoring data, demonstrating that the proposed method can accurately simulate the hydraulic interactions of high pressure tunnel. Additionally, a comparison with calculation models employing tie constraints to simulate the lining-surrounding rock interface is conducted. Finally, comparison with traditional continuum method reveals that while both methods exhibit consistent overall trends. It is recommended to choose the proposed method when describing the discontinuous propagation process of cracks, which cannot be simulated by the continuum analysis method.

Analytical solution of overlying pressure for shallowly buried underwater box tunnel: A case study of box jacking in Suzhou, China

Accurately predicting the overlying pressure is crucial for determining an appropriate cover depth of underwater box tunnels to avoid the uplifting failure. Based on the project of box jacking crossing the Beijing-Hangzhou Grand Canal in Suzhou, the characteristics of overlying pressure variation during tunneling are investigated. The monitoring results reveal that the fluctuation of overlying pressure is weakened during the rapid tunneling process. A modified analytical model for vertical earth pressure is conceived, in which the active and passive limit states for multi-layered soils are both considered. The probable range of overlying pressure obtained by the proposed model is suitable to cover the actual values. The anti-floating behavior of underwater box tunnels for two different working conditions is discussed by calculating the minimum cover depth. Using the calibrated analytical models, a parametric study is conducted to explore the influence of injection pressure, hardened slurry unit weight, soil internal friction angle, soil cohesion, and tunnel geometry. It is found that the injection pressure during the construction process is crucial for determining the necessary cover depth, and the change of box tunnel height makes it easier to trigger the variation of minimum cover depth.

Computational studies on the catalytic potential of the double active site for enzyme engineering

Proteins possessing double active sites have the potential to revolutionise enzyme design strategies. This study extensively explored an enzyme that contains both a natural active site (NAS) and an engineered active site (EAS), focusing on understanding its structural and functional properties. Metadynamics simulations were employed to investigate how substrates interacted with their respective active sites. The results revealed that both the NAS and EAS exhibited similar minimum energy states, indicating comparable binding affinities. However, it became apparent that the EAS had a weaker binding site for the substrate due to its smaller pocket and constrained conformation. Interestingly, the EAS also displayed dynamic behaviour, with the substrate observed to move outside the pocket, suggesting the possibility of substrate translocation. To gain further insights, steered molecular dynamics (SMD) simulations were conducted to study the conformational changes of the substrate and its interactions with catalytic residues. Notably, the substrate adopted distinct conformations, including near-attack conformations, in both the EAS and NAS. Nevertheless, the NAS demonstrated superior binding minima for the substrate compared to the EAS, reinforcing the observation that the engineered active site was less favourable for substrate binding due to its limitations. The QM/MM (Quantum mechanics and molecular mechanics) analyses highlight the energy disparity between NAS and EAS. Specifically, EAS exhibited elevated energy levels due to its engineered active site being located on the surface. This positioning exposes the substrate to solvents and water molecules, adding to the energy challenge. Consequently, the engineered enzyme did not provide a significant advantage in substrate binding over the single active site protein. Further, the investigation of internal channels and tunnels within the protein shed light on the pathways facilitating transport between the two active sites. By unravelling the complex dynamics and functional characteristics of this double-active site protein, this study offers valuable insights into novel strategies of enzyme engineering. These findings establish a solid foundation for future research endeavours aimed at harnessing the potential of double-active site proteins in diverse biotechnological applications.

Flow Through a Passage With Scaled Additive Manufacturing Roughness Representing Different Printing Orientations

Abstract Components with internal passages created using some laser-sintering based, additive manufacturing (AM) systems can exhibit anisotropic surface features with an appearance of three-dimensional roughness superimposed on two-dimensional, rib-like features. This paper presents an investigation of flow over roughness representing internal cooling passages printed at different angles to the AM printing plane. A roughness geometry was acquired using an X-ray tomography scan of a direct-metal-laser-sintering (DMLS) created coupon with internal cooling passages. The base surface scan was then used to create four surfaces with notional rib-like features positioned at different angles relative to the spanwise flow direction. The flow resistance of each surface was measured using the roughness internal flow tunnel. The mean flow velocity profiles for the cases with ReDh ≤ 30,000 were characterized using a four-camera, tomographic, and particle tracking system. The results demonstrate roughness orientation effects include (1) reduced bulk flow resistance as the alignment angle from the spanwise direction increases, (2) generated flow in the spanwise direction and increased tunnel flow swirl as the alignment angle increases, and (3) velocity profile changes as the flow migrates away from the rough side of the tunnel to the opposing smooth wall. The particle tracking system also demonstrates that the mean streamwise flow profiles change significantly between the 30 deg and 45 deg roughness orientations. Finally, the equivalent sandgrain roughness measurements for the four surfaces were found to follow the trends predicted using the correlations of Bons (2002, “St and cf Augmentation for Real Turbine Roughness With Elevated Freestream Turbulence,” ASME J. Turbomach., 124(4), pp. 632–644.) and Sigal and Danberg (1990, “New Correlation of Roughness Density Effect on the Turbulent Boundary Layer,” AIAA J., 28(3), pp. 554–556.).

Risk assessment models for development of carpal tunnel syndrome: clinical, anthropometric, and neuromuscular ultrasound predictors

BackgroundCarpal tunnel syndrome (CTS) is the most common entrapment neuropathy with multifactorial etiologies. We intended in this case–control study to identify, out of a comprehensive set of risk factors, the relatively important ones and develop a quantitative risk assessment model for this disorder. It was also legitimate to define the hazard of those factors in a dose-related manner and the acceptable safe limit especially for work-related stresses.ResultsAge and female predominance were comparable between the 60 patients (89 hands with electrophysiologically confirmed CTS) and 50 controls (100 hands). Occupation of the studied sample varied between housewives only, employed housewives, and manual workers with a distribution that differed significantly between patients and controls. Significantly higher body mass index (BMI) and mean wrist depth were found in patients than controls. Wrist ratio (clinically or sonographically) was significantly squarer in patients than controls. Overall workload and number of hours spent daily performing work with repeated hand movements or awkward hand position were significantly higher among patients than controls.ROC curves were constructed for wrist measurements and occupational stresses. Cut-off points of wrist ratio and internal carpal tunnel ratio (by ultrasound) to discriminate subjects with CTS were > 0.68 and ≤ 1.854, respectively. The best cut-off value for number of hours spent daily performing work with repeated hand movements was 3 h/ day. As for working with awkward hand position or cold exposure, cut-off value was 0.6 h/day for both.Two logistic regression models were conducted to investigate nonoccupational and occupational predictors of CTS. The independent predictors concluded from the first model were BMI, positive family history of CTS, wrist ratio, and decrease grip strength. As for the occupational model, predictors were tasks requiring awkward hand position and cold exposure.ConclusionOccupational risk assessment by clinical, anthropometric, and ultrasonographic measurement should be used in professions requiring repetitive or awkward hand movements, so that in overweight persons with square wrists appropriate workplace setup measures or assistive technology at work or home could be taken to prevent or decrease the impact of work hazards or help choose individuals with low risk for appropriate jobs.

Lining Structure of Water Conveyance Tunnel under Earthquake Action Research on Damage Law

Based on the concrete damage plasticity constitutive model (CDP model) of ABAQUS software, the dynamic response of high pressure internal water conveyance tunnel during earthquake is simulated, and the dynamic response and dynamic damage law of high internal water pressure water conveyance tunnel structure under surrounding rock grade, buried depth and seismic wave intensity are analyzed. The research shows that the surrounding rock grade is closely related to the dynamic response and damage characteristics of the lining structure of the water conveyance tunnel. The dynamic damage of the tunnel under grade Ⅲ surrounding rock is only 0.08, which is far less than 0.83 under grade Ⅳ surrounding rock. It can be considered that it will not cause great damage to grade Ⅲ surrounding rock under earthquake. The surrounding rock grade is better, which can provide more stable support and reduce the stress and vibration of the structure. If the tunnel is in the seismic zone, the buried depth can be used as one of the design control indexes in the tunnel design. The lining damage is mainly distributed at the top and upper arch waist of the tunnel. With the increase of the buried depth of the tunnel, the dynamic damage amount increases from 0.021 to 0.081, then to 0.085. the damage of the lining structure also increases. This may be because the deep buried tunnel is more constrained by the underground rock and soil layer, thereby reducing the transmission of seismic load. The change of seismic wave intensity can directly affect the damage characteristics of tunnel lining structure. The dynamic damage mainly occurs at the vault and arch waist, and the damage area expands from the vault and arch waist to the side wall and corner. The increase of seismic wave intensity will lead to dramatic changes in the stress of the structure, which will lead to more complex and serious damage.

Management of rarely seen internal tunnelling root resorption associated with a maxillary permanent incisor

This case presents clinical techniques and materials that may be applied in the management of internal tunnelling root resorption, a rare condition which has little published literature.A 25-year-old woman was referred to a specialist centre by her general dental practitioner following an incidental finding of a radiographic radiolucency, suggestive of root resorption associated with tooth 21. A provisional diagnosis of external cervical resorption was made, and following cone beam computed tomography (CBCT), a definitive diagnosis of internal tunnelling root resorption given. Non-surgical endodontic treatment was completed using continuous wave compaction with a calcium-silicate based sealer. No further intervention has been required.A summary of the histology, aetiology, prevalence, diagnosis, management and prognosis of internal tunnelling root resorption is provided. The benefits of CBCT for diagnosing and managing internal tunnelling resorption defects and using continuous wave compaction with a calcium-silicate based sealer, compared to cold obturation techniques, are discussed.

Equivalence study of the resin-dentine interface of internal tunnel restorations when using an enamel infiltrant resin with ethanol-wet dentine bonding

This preregistered ex vivo investigation examined the dentinal hybrid layer formation of a resinous infiltrant (Icon), with reference to both thickness (HLT) and homogeneity when combined with modified tunnel preparation (occlusal cavity only) and internal/external caries infiltration. The adhesives Syntac and Scotchbond MP were used as controls (Groups 1 and 3) or in combination with Icon (Groups 2 and 4). A split-tooth design using healthy third molars from 20 donors resulted in 20 prepared dentine cavities per experimental group. The cavity surfaces (n = 80) were etched (37% H3PO4), rinsed, and air-dried. Rewetting with ethanol was followed by application of the respective primers. After labeling with fluorescent dyes, either Syntac Adhesive/Heliobond or Scotchbond MP Adhesive was used alone or supplemented with Icon. HLT, as evaluated by scanning electron microscopy, did not significantly differ (P > 0.05), and confocal laser scanning microscopy revealed homogeneously mixed/polymerized resin-dentine interdiffusion zones in all groups. Icon can be successfully integrated into an ethanol-wet dentine bonding strategy, and will result in compact and homogeneous hybrid layers of comparable thickness considered equivalent to the non-Icon controls, thus allowing for preservation of the tooth’s marginal ridge and interdental space in the case of internal/external infiltration of proximal caries.

Retrospective analysis and comparison of total internal disability preservation technique and standardized reconstruction technique

To investigate the efficacy and clinical results of total internal protection technique in anterior cruciate ligament reconstruction. A total of 56 patients undergoing anterior cruciate ligament reconstruction treated from January 2018 to December 2019 were selected. According to the different surgical methods, they were divided into total internal reconstruction group and standard bone tunnel group. There were 21 patients in the total internal reconstruction group, including 15 males and 6 females, aged from 20 to 48 with an average of (35.6±6.7) years old, and 35 patients in the standard tibial tunnel group, including 26 males and 9 females, aged 22 to 51 years old with an average of (33.7±9.6) years old. Preoperative examination of Lachman test was positive, magnetic resonance indicated anterior cruciate ligament rupture. There were no significant differences between the two groups in age, sex, body mass index, time from injury to ACL reconstruction, combined meniscus injury and operation method, operation time, ligament diameter, ligament length and other general information. Postoperative evaluation included operation duration, length and diameter of transplanted tendon after braid. International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score and perioperative complications 2 years after surgery. Both groups were followed up, ranging from 24 to 30 months with an average of (26.9±3.4) months. Postoperative incision healing was good, and no failure or joint infection occurred at the last follow-up. There was no statistically significant difference between the two groups in IKDC score, Lysholm score and Tegner score before, 1 year and 2 years after surgery. However, IKDC score, Lysholm score and Tegner score at 1 year and 2 years after surgery. The same postoperative function and stability of knee joint can be obtained by both the residual whole technique and the standardized reconstruction technique. In the residual whole group, only the semitendinosus muscle is taken, and the femoral thin muscle is retained, with greater tibial bone mass preserved, which is safe and effective in clinical practice.

External wrist ratio is not a proxy for internal carpal tunnel shape: Implications for evaluating carpal tunnel syndrome risk.

Carpal tunnel syndrome (CTS) is highly prevalent, resulting in decreased function and increased need for costly healthcare services. External wrist ratio (depth/width >0.70) is a strong predictor of the development of CTS and has been suggested to be a proxy for internal carpal tunnel (CT) shape. Conversely, sonography can more directly evaluate CT shape. The purpose of our study was to explore the relationship between wrist ratio and sonographic CT measurements to (1) evaluate the reliability of sonographic CT measurements and (2) explore how external wrist measures relate to anthropometric features of the CT. We used sonographic imaging on a sample of healthy participants (n = 226) to measure CT cross-sectional area, depth, width, and depth/width ratio. We conducted exploratory correlation and regression analyses to identify relationships of these measures with external wrist ratio. Reliability for dominant and nondominant sonographic CT measures ranged from good to excellent (0.79-0.95). Despite a moderate correlation between CT width and depth and their external wrist counterparts (0.33-0.41, p < 0.001), wrist ratio and CT ratio demonstrated weak to no correlation (dominant: r = 0.12, p = 0.053; nondominant: r = 0.20, p = 0.002) and the mean CT ratio was far lower than the mean wrist ratio (0.45 vs. 0.71 bilaterally). Supporting this, we observed several key differences in the relationship between external wrist measures compared to corresponding CT measures. Additionally, regression analyses combining participant factors and CT measurements produced models accounting for less than 15% of the variability in external wrist ratio (linear models) or correctly predicting less than 68% of wrist ratio-based risk categorization (logistic models). Overall, among healthy young adults, wrist shape is not an adequate proxy for CT shape.

Tehnika smanjenja opterećenja na unutrašnjim aerovagama tokom supersoničnih prelaznih pojava

Design of slender supersonic missiles requires a comprehensive experimental support in the form of wind tunnel data for a wide range of flight parameters (angle of attack and Mach number). However, in supersonic wind tunnel testing, the problem exists of transient loads at the times of the starting and stopping of the supersonic flow. In the environments of pronounced transient loads, characteristic of blowdowin wind tunnels like the T-38 of the Military technical Institute in Belgrade, it is necessary to provide control of the use of internal wind tunnel balances in the permitted design load ranges. The presented technique is related to the definition and implementation of a methodology for reducing the transient loads on wind tunnel balances in supersonic wind tunnel tests. By limiting the clearance between the model and its tail support (sting) to a magnitude which permits normal tests, but results in model-support contact during the excessive loads, part of the loads is transferred to the support sting, relieving the balance. The technique improves control over the wind tunnel test process, improves measurement accuracy and prevents damage to sensitive instrumentation (wind tunnel balances).

Full-scale model test for the performance of DDS prestressed composite lining with SCC-NC of high internal pressure shield tunnel

To meet the requirements of structure design for high internal pressure with large diameter tunnel and long-distance concrete pouring, a Double-layered and Double-looped Steel-strand(DDS) prestressed composite lining with Self-Compacting Concrete (SCC) and Normal Concrete (NC) was presented. A series of SCC and NC properties tests were conducted to prepare optimal DDS prestressed concrete, followed by a standing full-scale loading test to demonstrate the features of deformation and bearing capacity for the composite lining. The results showed that the DDS combined bearing structure has good bearing capacity to internal pressure, where the bearing process was divided into three stages. In the elastic stage, there was no cracks appeared and the structure began to show a tensile trend with the increase of internal pressure. The structure entered the inelastic stage when the internal pressure reached 1.1 MPa, the cracks were found to initiate. As the internal pressure was increased to 1.3 MPa, the structure entered the crack propagation stage, where the expansion of cracks in the inner lining would lead to a stress redistribution. For the internal pressure from 0 to 1.45 MPa, the average proportion of internal pressure borne by the inner lining decreases from 80 % to 70 %, while the one by the outer lining increases from 20 % to 30 %. Our findings demonstrate the mechanical behavior of the optimized bearing structures and provide guidance for the design and construction in related tunnel engineering.

Wetting vs Droplet Aggregation: A Broadband Rotational Spectroscopic Study of 3-Methylcatechol ⋯ Water Clusters.

Two competing solvation pathways of 3-methylcatechol (MC), an atmospherically relevant aromatic molecule, with up to five water molecules were explored in detail by using a combination of broadband rotational spectroscopy and computational chemistry. Theoretically, two different pathways of solvation emerge: the commonly observed droplet pathway which involves preferential binding among the water molecules while the solute serves as an anchor point for the formation of a water cluster, and an unexpected wetting pathway which involves interactions between the water molecules and the aromatic face of MC, i.e., a wetting of the π-surface. Conclusive identification of the MC hydrate structures, and therefore the wetting pathway, was facilitated by rotational spectra of the parent MC hydrates and several H218O and 13C isotopologues which exhibit splittings associated with methyl internal rotation and/or water tunneling motions. Theoretical modelling and analyses offer insights into the tunneling and conversion barriers associated with the observed hydrate conformers and the nature of the non-covalent interactions involved in choosing the unusual wetting pathway.

Wetting vs Droplet Aggregation: A Broadband Rotational Spectroscopic Study of 3‐Methylcatechol⋅⋅⋅Water Clusters

AbstractTwo competing solvation pathways of 3‐methylcatechol (MC), an atmospherically relevant aromatic molecule, with up to five water molecules were explored in detail by using a combination of broadband rotational spectroscopy and computational chemistry. Theoretically, two different pathways of solvation emerge: the commonly observed droplet pathway which involves preferential binding among the water molecules while the solute serves as an anchor point for the formation of a water cluster, and an unexpected wetting pathway which involves interactions between the water molecules and the aromatic face of MC, i.e., a wetting of the π‐surface. Conclusive identification of the MC hydrate structures, and therefore the wetting pathway, was facilitated by rotational spectra of the parent MC hydrates and several H218O and 13C isotopologues which exhibit splittings associated with methyl internal rotation and/or water tunneling motions. Theoretical modelling and analyses offer insights into the tunneling and conversion barriers associated with the observed hydrate conformers and the nature of the non‐covalent interactions involved in choosing the unusual wetting pathway.

Impact of Ultrasound Guidance During Placement of Tunnel Dialysis Catheter

Objective: To determine incidence of neck hematoma between with and without ultrasound guided placement of internal jugular vein tunnel dialysis catheter Methodology: A retrospective study was conducted at Heart and Vascular Institution, Kulsum International Hospital, Islamabad. Period: Six months from October 2021 to March 2022. Patients, who presented with End Stage renal failure requiring tunnel dialysis catheter for hemodialysis, were included into this retrospective study. Patient’s statistic profile, indications, signs and symptoms were recorded. Tunnel dialysis catheters were placed through internal jugular vein with or without ultrasound guidance. The study's outcome was measured in terms of the incidence of neck hematoma compared between the two study groups. Results: Overall, out of twenty patients, 13 (65.0%) were male and 7 (35.0%) were female. Age ranged from 16 to 70 with average of 51.0 ± 16.2 years. The incidence of neck hematoma was 3 (30.0%) in internal jugular vein tunnel dialysis catheter placement without ultrasound guidance (group B) compared to none 0 (0.0%) in patients undergoing internal jugular vein tunnel dialysis catheterization with ultrasound guidance (group A). Conclusion: The incidence of neck hematoma was 30% which can be reduced to 0% if ultrasound is used as guidance in cannulation of internal jugular vein during the placement of tunnel dialysis catheter.

P-glycoprotein mechanical functional analysis using in silico molecular modeling: Pharmacokinetic variability according to ABCB1 c.2677G > T/A genetic polymorphisms

P-glycoprotein (P-gp) is a widely membrane-expressed multi-drug transporter. It is unclear whether the pharmacokinetic diversity of P-gp substrates is highly dependent on ABCB1 polymorphisms encoding P-gp. The purpose of this study is to analyze the mechanistic function of P-gp through in silico molecular modeling and to approach the resolution of controversy over pharmacokinetic differences according to ABCB1 polymorphisms. P-gp conformations of apo, ligand-docked, and outward-facing states can be modeled based on structural information of human P-gp. And polymorphic P-gp structures were constructed through homology modeling. ABCB1 c.2677G > T/A (Ala893Ser/Thr), did not correspond to P-gp's nucleotide-binding-domain (NBD) or drug-binding-pocket (DBP) or involve mechanical conformational changes. Although amino acid substitution by ABCB1 c.2677G > T/A caused a 30 % increased strain in an α-helix hinge between the NBD and DBP in P-gp's internal tunnel, there were no overall structural changes compared to wild-type. ABCB1 c.2677G > T/A may increase torsional energy, impacting conformational change rate, but this does not significantly affect P-gp's general functioning. Fexofenadine docking into P-gp's DBP explained the substrate interaction, but no effect by ABCB1 c.2677G > T/A was confirmed. Our findings provide additional insights useful in resolving the debate about the influence of ABCB1 polymorphisms on the interindividual pharmacokinetic variability of P-gp substrates.

Nesting Etiquacy of Stingless Bee &lt;i&gt;Tetragonula “Iridipennis”&lt;/i&gt; Species Group

In this study a total of 42 feral colonies of Tetragonula “iridipennis” were domesticated and observed for their nesting behaviour in feral nest and also in hive. Observation on the nesting behaviour revealed that, they generally inhabit old mud and stone walls, and the shape and colour of nest entrance were predominantly elliptical and black, respectively. The length and width of the entrance tube ranged between 9-13 and 3-9 mm, respectively on different substrata. The external and internal tunnel length ranged between 0-18 and 3-156 mm, respectively. The orientation of hive entrance was mainly towards northeast and east. Number of brood pots constructed/ batch and time required for a worker to construct the single brood pot were recorded.

Present Status on Internal Wind Tunnel Balance Technology

No abstract