Ejection Of Air Research Articles

Evaluation of Clinical Performance of TiNi-Based Implants Used in Chest Wall Repair after Resection for Malignant Tumors.

In this study, we assessed the outcomes after surgical treatment of thoracic post-excision defects in 15 patients, using TiNi knitted surgical meshes and customized artificial TiNi-based ribs. Methods: Eight patients were diagnosed with advanced non-small cell lung cancer (NSCLC) invading the chest wall, of which five patients were T3N0M0, two were T3N1M0, and one was T3N2M0. Squamous cell carcinoma was identified in three of these patients and adenocarcinoma in five. In two cases, chest wall resection and repair were performed for metastases of kidney cancer after radical nephrectomy. Three-dimensional CT reconstruction and X-ray scans were used to plan the surgery and customize the reinforcing TiNi-based implants. All patients received TiNi-based devices and were prospectively followed for a few years. Results: So far, there have been no lethal outcomes, and all implanted devices were consistent in follow-up examinations. Immediate complications were noted in three cases (ejection of air through the pleural drains, paroxysm of atrial fibrillation, and pleuritis), which were conservatively managed. In the long term, no complications, aftereffects, or instability of the thoracic cage were observed. Conclusion: TiNi-based devices used for extensive thoracic lesion repair in this context are promising and reliable biomaterials that demonstrate good functional, clinical, and cosmetic outcomes.

Device Substantiation for Generating Artificial Rain Drops by Pneumohydraulic Liquid Spraying

The authors studied the pneumohydraulic device indicators for spraying liquids for irrigation, nutrition and protection of agricultural plants, taking into account the principles of water and energy conservation, based on preliminary gas saturation of sprayed water and the use of a cavitation effect in the design of the aerator unit during ejection and supply of air under pressure. (Research purpose) To determine the technological parameters of a pneumohydraulic device for spraying liquids to obtain controlled dispersive artificial rain and substantiate the choice of its optimal technical parameters depending on the operating modes. (Materials and methods) The authors used an algorithm for calculating parameters in EXCEL or WPS spreadsheet processor and mathematical expressions. (Results and discussion) The authors theoretically determined the minimum and maximum calculated parameters of the constructive solution geometry for spraying the liquid phase: water nozzle, air nozzle channel, mixing cell, middle annular gap, outlet nozzle. They changed indicators of operating water pressure – 0.20; 0.25; 0.30 and 0.35 megapascals; air – 0.25 and 0.30 megapascals, provided the water flow rate from 0.002 to 0.010 liter per second and air – from 0.0005 to 0.0090 kilogram per second. With an increase in the water flow rate within the specified limits and the ejection coefficient from 0.5 to 0.9, a linear increase in the average annular gap diameter from 2 to 15 millimetres was revealed, as well as a nonlinear dependence of the increase in the sprayer mixing cell diameter from 5 to 20 millimetres. The authors showed the possibility of reducing the mixing cell diameter if the water pressure was increased from 0.25 to 0.35 megapascal's and the air pressure was from 0.20 to 0.30 megapascals. They obtained the parameters values for the designed and experimental samples development, which turned out to be significantly less than when operating in the air ejection mode: the outlet nozzle and the middle annular gap – by 16 percent, the air nozzle – by 23, the diameter of the mixing cell – by 50 percent or more. (Conclusions) The authors obtained calculated data to optimize technological parameters and design solutions, which would speed up the manufacture of designed and model samples of the device and its experimental testing for the generation of dispersive artificial rain drops.

IMPROVING THE DESIGN OF THERMAL TOOLS FOR ROCK FRACTURING

The article deals with the main parameters of the thermodynamic working device for rock destruction due to the implementation of a new method of fuel mixture combustion in shock waves initiated by a high-speed torch burner in gas-dynamic combustion intensifiers. A device for thermal destruction of rocks has been developed, which belongs to the mining industry and can be used for directed impact on rocks when they are destroyed by hot gas jets in mining, stone processing and construction industries. Also, installed coaxial to the nozzle, with increasing inside diameter, a cylindrical nozzle, with two cascades of ejection holes - the first cascade is made at a distance from the Laval nozzle, equal to the distance to complete expansion of the jet of the torch, then, the accelerating section of the nozzle and the new, formed by burning the unburned fuel, jet of the burner. It is found that the cross sectional area of the inner hole of the cylindrical nozzle, is made with an excess of the area of the critical cross section of the nozzle Laval burner 2.5-3 times, in which, because of the rapid expansion of the gas flow in the nozzle, there is turbulization, with the formation of a powerful zone of heating of the gas flow and the appearance of a standing detonation wave in it. The drilling angle of the ejection holes of the first stage is 45-50º to the axis of the nozzle, which serves for ejection of atmospheric air, the oxygen of which reacts with the surplus of combustible in the main jet of the burner and the formation of a more powerful jet.

Models of Locomotive Traction Drives for the Improvement of Sand Feeding System

In this research, we calculated the key characteristics and parameters of the pneumatic injector using the set input and output gas flow values. We simulated the ejection of excessive air from the ambient to increase the flow rate of the air-and-sand mixture from the outlet chute of the sand feeding system of a locomotive using the CFD package of the FlowSimulation extension of the SolidWorks solid object design environment. We achieved the reduction of the compressed air consumption as compared to the standard locomotive sand-feeding systems.

Experimental researches of a two-level air-jet protection of an open surface of industrial baths of the big sizes

The developed two-level air-jet screen of an industrial bath is experimentally investigated. The principle of its operation is the supply of air by a shielding jet at the upper level and the suction of polluted air at the lower level symmetrically from opposite sides. At this stage of experimental research, the velocity fields and the nature of the interaction of inflow jets and suction flares have been studied. When determining the geometric dimensions of the air-jet screen structure, the location of key components and system elements, it is important to know, ensure and not exceed the allowable values of air flow velocity above the surface of the liquid mirror. During the observations of the aerodynamic properties of two-level air-jet screens, questions arose about the need to use flat rotational flows and control the velocity field in their interaction. Minimization of the interaction of inflow jets and flares of suction is the basis of the concept of designing a sсreen of this type. The shielding conditions have been experimentally confirmed due to the stabilization of the velocity field above the bath surface. The corresponding dependencies of change of formation of the protective air screen from the basic parameters as that a ratio of velocity "inflow-removal" and geometrical characteristics of a design are defined. For the developed air-jet screen of galvanic baths experimentally determined conditions of effective shielding are as follows: the ratio of the width of the slot for ejection of air from the working area to the width of the gas-tight wall is 0.75, and the ratio of screening jet velocity to air removal rate is within 0.3-2.45. This achieves a capture efficiency of up to 90 %. The expediency of arranging an ejection slot under the air supply slot to increase the flow rate and range of the jet has been confirmed.

Performance Evaluation of Second-Throat Diffuser for High Altitude Test facility

Aimed at the improvement of ability of the high altitude test (HAT) facility for rocket engine, a new designed secondary-throat diffuser with ejection of low total pressure and supersonic cold air is proposed. The main structural characteristic of the new-designed diffuser is that: a groove is added to the start of the secondary throat of diffuser, and the supersonic cold air with low total pressure is ejected into diffuser to form the gas film, which leads to a reduction of the wall temperature and thermal load of the new-designed diffuser, and an improvement of the ability of diffuser holding shock train. The effects of cold air on flow characteristics and performance of diffuser are numerically investigated in detail under different conditions including total pressure and Mach number. The results show that the wall temperature along the diffuser increases with an increase of Mach number, and decreases with an increase of total pressure; with an increase of Mach number, the starting position of pressure rise moves upstream to the inlet of diffuser; and with an increase of total pressure, the starting position of pressure rise moves downstream to the end of diffuser.

Swirling Flows in Cyclone Chambers with Nozzles of Small Flow Section

Experimental studies have been made of the hydrodynamics of cyclone chambers of varying geometry with tangential nozzles of small flow section. The character of the velocity and pressure distribution in the volume of such a chamber has been revealed. Dependences have been obtained for calculation of the tangential velocity at the periphery of a cyclone chamber and its resistance coefficient in a wide range of the flow sections (0.00138 ≤ α ≤ 0.024). For the first time a relationship has been established between the phenomenon of the ejection of air into a cyclone chamber and the twist factor in its central region.

A new method for protection of sewage collectors against corrosion

The article provides data on microbiological (gas) corrosion of sewage collectors and structures on them. The results of inspection of Saint Petersburg structures are presented. The findings of the experiment for determination of stability of protective coatings conducted in a pressure suppression chamber in Novosibirsk are given. The known methods of corrosion prevention are considered in the work and a new one is offered, which is aeration of discharge liquid in the pressure suppression chamber by means of natural ejection of air into a penstock. The diagram of the effective construction of the pressure suppression chamber, allowing to implement the offered method, is presented. The carried out experiments on construction modeling of the pressure suppression chamber are described and optimal values of its geometrical parameters are given. The article also presents an engineering solution to collocation of the chamber and a gas cleaning plant on a sewage collector. Economic comparison of the offered method for protection of collectors versus the two most often used ones – fiberglass pipe lining and wall coating with polymer-silicate composition “Konusit KK-10” – is carried out. Cost estimation of fulfillment of the said methods for various diameters of the collector and its length is performed, as well as for various periods of time. Efficiency of the alternative way of corrosion prevention, offered by the authors, is proved.

Visualization of the air ejected from the temporary cavity in brain and tissue simulants during gunshot wounding

One hypothesis for the physical mechanism responsible for backspatter during cranial gunshot wounding is that air is ejected by the collapse of the temporary cavity formed around the bullet path. Using bovine and ovine heads and simulant materials, evidence of this ejection was sought by measuring the velocity of the air that was drawn in and ejected from the cavity in front of the wound channel after bullet impact. A laminar flow of fog-laden air was arranged in front of the wound channel and two high speed cameras recording at 30,000 frames/second captured the air motion. All samples were shot with standard 9mm×19mm FMJ ammunition. Different concentrations of ballistic gelatine were used to characterize the effect of elasticity of the material on the velocity of the air. Fresh bovine and ovine heads were shot with the same experimental set up to investigate if there was induction of air into, and ejection of air from the entrance wounds. The results show, for the first time, that the temporary cavity does eject air in gelatine. The velocity of in-drawn air for 3, 5 and 10% concentration of gelatine was 81, 76 and 65m/s respectively and the velocity of ejected air for 5 and 10% concentration of gelatine were 43 and 72m/s respectively. The results show that when the concentration of gelatine is increased, the velocity of the air drawn into the cavity decreases and the velocity of the ejected air increases. However, no ejection was observed in 3% gelatine, ovine or bovine heads. Although ejection of air was not observed, ejection of brain from the wound channel was seen. Using the velocity of the ejected brain, the minimum intracranial pressure required to eject the brain tissue was estimated to be 712kPa and 468kPa for the sheep and bovine heads respectively.

What Did and Did Not Cause Collapse of World Trade Center Twin Towers in New York?

Previous analysis of progressive collapse showed that gravity alone suffices to explain the overall collapse of the World Trade Center Towers. However, it remains to be determined whether the recent allegations of controlled demolition have any scientific merit. The present analysis proves that they do not. The video record available for the first few seconds of collapse is shown to agree with the motion history calculated from the differential equation of progressive collapse but, despite uncertain values of some parameters, it is totally out of range of the free fall hypothesis, on which these allegations rest. It is shown that the observed size range (0.01 — 0.1 mm) of the dust particles of pulverized concrete is consistent with the theory of comminution caused by impact, and that less than 10% of the total gravitational energy, converted to kinetic energy, sufficed to produce this dust (whereas, more than 150 t of TNT per tower would have to be installed, into many small holes drilled into concrete, to produce the same pulverization). The air ejected from the building by gravitational collapse must have attained, near the ground, the speed of almost 500 miles per hour (or 223 m/s, or 803 km/h) on average, and fluctuations must have reached the speed of sound. This explains the loud booms and wide spreading of pulverized concrete and other fragments, and shows that the lower margin of the dust cloud could not have coincided with the crushing front. The resisting upward forces due to pulverization and to ejection of air, dust, and solid fragments, neglected in previous studies, are indeed found to be negligible during the first few seconds of collapse but not insignificant near the end of crush-down. The calculated crush-down duration is found to match a logical interpretation of seismic record, while the free fall duration grossly disagrees with this record.

FLOWS THROUGH FOREST CANOPIES IN COMPLEX TERRAIN

Recent progress on boundary layer flow within and above tall forest canopies in complex terrain is reviewed from the perspective of developing methods to interpret carbon dioxide fluxes from tower measurements in real terrain. Two examples of complex terrain are considered in detail: a forest edge, which exemplifies nonuniform forests, and hilly terrain, which can lead to drainage currents at night. Dynamical arguments show that, when boundary layer winds approach a forest edge, the mean wind adjusts on a length scale of approximately 3L(c), where L(c) is the canopy drag length scale, which depends inversely on the leaf area density of the forest. Over a further distance that also scales on L(c), turbulence in the flow adjusts, and the mixing and transport in the canopy approaches the homogeneous limit. Even low hills change the neutral flow within and above the forest canopy substantially. When the canopy is tall, pressure gradients drive flow up both the upwind and downwind slopes of the hill, leading to an ejection of air out of the top of the canopy just downwind of the crest. This flow at the crest can then advect scalar out of the top of the forest, leading to large variations in the flux of scalar across the hill. At night, when the air near the ground cools and becomes stably stratified, turbulence within the canopy can collapse, even when the flow above the canopy remains turbulent. This leads to a decoupling of the air motions within the canopy from those above. The air above the canopy can then continue to pass up and over the hill, as it does in the neutral case, but at the same time, air within the canopy drains down the hill slopes as drainage currents. These analyses will help us understand when flux towers are reliably measuring the net ecosystem exchange and suggest ways of correcting the flux tower data in more complex situations.

Double-Jet Ejection of Cooling Air for Improved Film Cooling

Film cooling in gas turbines leads to aerodynamic mixing losses and reduced temperatures of the gas flow. Improvements of the gas turbine thermal efficiency can be achieved by reducing the cooling fluid amount and by establishing a more equal distribution of the cooling fluid along the surface. It is well known that vortex systems in the cooling jets are the origin of reduced film-cooling effectiveness. For the streamwise ejection case, kidney vortices result in a liftoff of the cooling jets; for the lateral ejection case, usually only one dominating vortex remains, leading to hot gas flow underneath the jet from one side. Based on the results of numerical analyses, a new cooling technology has been introduced by the authors, which reaches high film-cooling effectiveness as a result of a well-designed cooling hole arrangement for interaction of two neighboring cooling jets (double-jet film cooling (DJFC)). The results show that configurations exist, where an improved film-cooling effectiveness can be reached because an anti-kidney vortex pair is established in the double-jet. The paper aims at the following major contributions: (1) to introduce the DJFC as an alternative film-cooling technology to conventional film-cooling design; (2) to explain the major phenomena, which leads to the improvement of the film-cooling effectiveness by application of the DJFC; and (3) to prove basic applicability of the DJFC to a realistic blade cooling configuration and present the first test results under machine operating conditions.

Local Convective Heat Transfer From a Constant Heat Flux Flat Plate Cooled by Synthetic Air Jets

The effects of a small-scale, rectangular synthetic air jet on the local convective heat transfer from a flat, heated surface were measured experimentally. The synthetic jet impinges normal to the surface and induces small-scale motions by zero-net mass flux, time-periodic entrainment, and ejection of ambient air at frequencies whose periods are far higher than the characteristic thermal time scale. The velocity field between the jet orifice and the target plate is measured in planar cross sections using particle image velocimetry and is related to the local heat transfer from the plate. The present work suggests that synthetic jets can lead to substantial enhancement of the local heat transfer from heated surfaces by strong mixing that disrupts the surface thermal boundary layer. The dependence of the local heat transfer coefficient on the primary parameters of jet motion is characterized over a range of operating conditions.

Turbulence Structure of the Unstable Atmospheric Surface Layer and Transition to the Outer Layer

We present a new model of the structure of turbulence in the unstable atmospheric surface layer, and of the structural transition between this and the outer layer. The archetypal element of wall-bounded shear turbulence is the Theodorsen ejection amplifier (TEA) structure, in which an initial ejection of air from near the ground into an ideal laminar and logarithmic flow induces vortical motion about a hairpin-shaped core, which then creates a second ejection that is similar to, but larger than, the first. A series of TEA structures form a TEA cascade. In real turbulent flows TEA structures occur in distorted forms as TEA-like (TEAL) structures. Distortion terminates many TEAL cascades and only the best-formed TEAL structures initiate new cycles. In an extended log layer the resulting shear turbulence is a complex, self-organizing, dissipative system exhibiting self-similar behaviour under inner scaling. Spectral results show that this structure is insensitive to instability. This is contrary to the fundamental hypothesis of Monin--Obukhov similarity theory. All TEAL cascades terminate at the top of the surface layer where they encounter, and are severely distorted by, powerful eddies of similar size from the outer layer. These eddies are products of the breakdown of the large eddies produced by buoyancy in the outer layer. When the outer layer is much deeper than the surface layer the interacting eddies are from the inertial subrange of the outer Richardson cascade. The scale height of the surface layer, z s, is then found by matching the powers delivered to the creation of emerging TEAL structures to the power passing down the Richardson cascade in the outer layer. It is z s = u * 3 /kes, where u * is friction velocity, k is the von Karman constant and es is the rate of dissipation of turbulence kinetic energy in the outer layer immediately above the surface layer. This height is comparable to the Obukhov length in the fully convective boundary layer. Aircraft and tower observations confirm a strong qualitative change in the structure of the turbulence at about that height. The tallest eddies within the surface layer have height z s, so z s is a new basis parameter for similarity models of the surface layer.

Some Basic Properties of the Surrogate Subgrid-Scale Heat Flux in the Atmospheric Boundary Layer

The development of improved subgrid-scale (SGS) models for large-eddy simulation of scalar transport in the atmospheric boundary layer requires an improved understanding of basic properties of the SGS fluxes. High frequency atmospheric wind speed and temperature data sampled at a height of 1.7 m are used to measure SGS heat fluxes and dissipation of temperature variance, by means of one-dimensional filtering and invoking Taylor's hypothesis. Conditional averaging is used to isolate interesting features of the SGS signals, and to relate them to the large-scale characteristics of the flow, such as the presence of coherent structures. Both mean and conditionally averaged SGS quantities are compared with those obtained using a standard eddy-diffusivity model. Within the limitations imposed by the one-dimensional data analysis, we observe that the model appears unable to reproduce important features of the real signals, such as the negative dissipation of temperature variance associated with strong negative resolved temperature gradients due to the ejection of warm air under unstable atmospheric stability conditions.

Development of the system for tritium removal from the air of working premises

Abstract The paper presents the expediency of developing the system for tritium removal from large air volumes in working rooms. The system is intended both to prevent ejection of air contaminated by tritium in the atmosphere in emergency tritium release from processing equipment of the experimental closed loop modelling the ITER vacuum-fuel system, and to purify air to sanitary standards. Schematic layout and a design of the system elements are presented. Operation principle consists in timely detection of tritium leakage by control pickups, in locking and switching off the ventilation, as well as in air purification using gas purifying facility (AGPF). In the AGPF gaseous tritium oxidizes on alumopalladium catalyst to oxide, and produced ultraheavy water is absorbed by zeolites. The facility is composed of air heater, converter (column with catalyst), water cooler, two parallel adsorbers (columns with zeolite) and gas blower.

Elastic response of catamaran wetdeck to liquid impact

The impact of an elastic plate onto the compressible fluid without free surface deformation is considered. The ability of the liquid volume to be deformed is geometrically limited which leads to severe impact conditions. The present analysis is focused on the stresses in the plate and the hydrodynamic loads under the impact. The motivation for this research comes from ship hydrodynamics, where the hulls of a catamaran restrict the liquid outflow and the water impacts onto the wetdeck. The influence of the air on the impact process is investigated. The analysis did not reveal any great advantage of utilizing the air-cushion effect or ejection of air into the water near the impact region to prevent high stresses in the elastic plate. It was found that in the problem considered, the stress peaks far from the plate centre and the one-mode approximation does not provide correct information about the stress level.

Isentropic mixing in the Arctic stratosphere during the 1992–1993 and 1993–1994 winters

Dynamic isolation of the winter Arctic circumpolar vortex during 1992–1993 and 1993–1994 (the second and third northern hemisphere winters of the UARS mission) is studied using quasi‐horizontal isentropic trajectories. Ejection of vortex air and entrainment of mid‐latitude air into the vortex are quantified and compared with climatological values obtained from the analysis of 16 Arctic winters. A number of unusual features of both winters are discussed. The most notable features are the anomalous isolation experienced by the vortex during December 1992 and the unusual degree of isolation and persistence of the vortex during February and March of both years. The 1992–1993 winter season is the most consistently isolated vortex on record. Only during January 1993, when entrainment is large, is this pattern of extreme isolation broken.

Climatology of large‐scale isentropic mixing in the Arctic winter stratosphere from analyzed winds

Dynamic isolation of the winter Arctic circumpolar vortex is studied using analyzed winds derived from geopotential height fields. Isentropic trajectories are calculated for assemblages of particles initialized on uniform latitude‐longitude grids. Transport across isolines of Ertel potential vorticity (PV) is used to characterize the mixing processes of ejection of vortex air and entrainment of midlatitude air into the vortex. During January and February a barrier to mixing, where exchange of air is inhibited, typically forms near the vortex boundary. At 450 K, transport across the barrier is predominantly in the form of thin filaments of particles ejected from the vortex. These filaments tend to wrap around the vortex, creating a layered structure of vortex and midlatitude air at the vortex edge. Near or total splits of the vortex into two or more distinct vortex fragments are quite common based on these trajectory calculations. Significant entrainment deep into the vortex is rare and results from only a limited number of the splitting events. During December and March the mixing barrier is less evident due to nonconservative factors during the spin‐up and breakdown of the vortex, respectively. In December both ejection and entrainment are only weakly inhibited by the mixing barrier. Exchange in March is dominated by ejection of air from the vortex.

Rehabilitation of the Laryngectomized Patients

The recent advancement in the management of the laryngeal cancer has raised the overall cure rate to over 75%, which is uniquely high as a cancer cure rate. The number of laryngectomees going back to the society with various handicaps increases each year. The rehabilition of these people is an urgent problem.There are four problems in rehabilitation. The first is the management of problems related to the use of a new air way. The others are the rehabilitation of voice, mental rehabilitation and the management of the senile diseases.The department of otolaryngology, the university of Osaka has a laryngectomees' association, which consists of about 700 patients. These laryngectomees were questioned about the physical complaints. Besides the loss of speech, their complaints included intolerance of hot foods, aerophagia, difficult sipping, anosmia, tracheal bleeding in winter, abdominal blowing, frequent breaking wind, difficult straining, stenosis of tracheal stoma and urticaria.I). The most important problem of all is a tracheal bleeding in winter. The typical finding of tracheo-bronchitis sicca hemorrhagica diffusa is the obstruction of the trachea and the bronchi due to an accumulation of blood crusts. Endoscopic removal of crusts is necessary. Patients should be instructed to maintain an adequate temperature and humidity to the air way.II). The speech rehabilitation is the most important for laryngectomees. In Japan, Tapia's artificial larynx is widely used as an excellent substitute. Some improvements need to be directed for the easier use by begginers. The conventional type has to be raised from the tracheal stoma during each inspiration. The new type revised by us has an inspiratory valve in such a way that patient can inspire without releasing the pipe from the tracheal stoma.Of course, the ideal substitute for normal voice is esophageal speech. To obtain the data for the more effective way of teaching esophageal speech, the mechanism of speech was studied using X-ray cinematography in 50 patients with esophageal voice. The relation of esophageal speech to respiration was studied using an indicator, which showed the direction of air current during respiration. The direction thus recorded is shown as a line in the films.The author could obtain some additional informations from the present study, by correlating the air intake to the phase of respiration. The modes of air intake are best classified into these five types; injection during inspiration, direct inhalation without injection independent of respiration, injection during expiratory phase and combined type of inhalation and injection.The shape of the pseudoglottis can be classified into these five types; simle form, simple form with subglottic space, larynx-like form, multiglottic form and incomplete form.From the proficiency of speech, which was evaluated phonetically, the author summarized that good esophageal voice is produced by1). air intake by injection during inspiration, 2). pseudoglottis formation by simple form or simple form with subglottic space, and3). ejection of air by uniform contraction of the lower esophagus and“squeezing up”contraction of the upper esophagus.III). The mental rehabilitation of laryngectomees is an urgent problem in the social and clinical aspects, too, They can not laugh and speak emotionally. Doctors must lead them to be going back to the society with the normal mental condition.IV). In the management of the diseases of old age of the laryngectomees, there are several important problems. The most cardinal of them is the early diagnosis of lung metastasis and double cancer in other organs. Laryngectomees should be instructed to maintain a comfortable circumstances with an adequate temperature and humidity in winter.