Force Air Research Articles

Tracheoesophageal fistula associated with perforated Meckel's diverticulum

Neonates with esophageal atresia and tracheoesophageal fistula (TEF) may present with respiratory distress. Intubation and mechanical ventilation may force air from the tracheobronchial tree, through a distal fistula and into the gastrointestinal tract. We present a newborn with TEF who became morbund during mechanical ventilation. High ventilator pressures transmitted via the TEF caused over distention of the gastrointestinal tract and perforation of a Meckel's diverticulum.

The synchronization of ventilation and locomotion in horses (Equus caballus).

Ciné film and synchronized records of respiratory flow were obtained from Thoroughbred racehorses cantering on a treadmill at speeds of 9 and 11 m s-1. Horses and some other galloping and hopping mammals link their breathing and locomotion, taking exactly one breath per stride. Three theoretical mechanisms by which the movements of locomotion might drive ventilation are considered. (i) Flexion of the lumbosacral joint and the resulting forward sweep of the pelvis pushes the viscera against the diaphragm. However, back flexion lags behind ventilation at 11 m s-1 and could not exclusively drive ventilation at this speed. (ii) Loading of the thorax by the impact of the forelimbs with the ground might force air out of the lungs. If the respiratory system were damped sufficiently to perform as this mechanism requires, the work of driving ventilation would make up approximately 15% of the total work of running. In comparison with other estimates of the work of ventilation this seems improbably high. (iii) The observed phase relationship between displacements of the viscera, caused by the accelerations of the body during running, and respiratory airflow is not consistent with a tuned visceral piston mechanism driving breathing. Thus, it would seem likely that back flexion is likely to contribute towards driving ventilation but loading of the thorax and the visceral piston mechanism do not.

Symptomatology of adductor spasmodic dysphonia: A physiologic model

Summary Vocal symptomatology of adductor spasmodic dysphonia (SD) is reviewed critically from historical, epidemiologic, and clinical perspectives. A model of symptomatology of this disorder based on a large patient population, and clinical and physiologic observations is advanced. The model incorporates crucial symptomatic and asymptomatic phonatory and nonphonatory physiologic parameters of laryngeal behavior in these patients. These parameters include vocal fold contact area, vocal fold collision force, glottic compression, and subglottic air pressure. Inappropriate efferent discharges from brain-stem basal ganglia are hypothesized as causing overadduction of the vocal folds in phonation, generating the basic and fundamental vocal symptom of adductor SD—strained, strangled, overpressured voice quality. Cortical loops are implicated as accountable for compensatory vocal behavior, not as the primary site of the disorder. Symptom occurrence, variability, magnitude, effects, and failure of treatment approaches, as well as recurrence of symptoms after ablative or invasive procedures, are explained by this model. The model also predicts that symptomatology of adductor spasmodic dysphonia is unique to this disorder and that symptoms are phonotopically organized. The minimal diagnostic battery based on the model is presented, and it is shown how this battery aids in the differential diagnosis of adductor SD and other phonatory disorders that closely mimic the vocal symptoms of adductor spasmodic dysphonia, including tremor.

An intelligent facility planning adviser

The problem of facility planning and allocation of floor space to specific functional work groups in an industrial environment requires many different pieces of information to be considered. In order to reduce the complexity of the problem-solving task and to achieve a reasonable decision in a timely manner, facility planning is often based on extensive general and approximate knowledge of the data required and a lot of experience with the given facilities, workgroups, products, and processes. In order to make more accessible the data needed to make decisions concerning use of facilities, as well as to support execution of a formal and effective methodology for handling the wide variety of activities concerned with the problem of facility planning, an artificial intelligence (AI)-based system, called the Intelligent Facility Planning Advisor, has been under development for the Air Force Air Logistics Center at Hill Air Force Base in Ogden, Utah. This paper describes the first two components developed for this system, called the Intelligent Floor Allocation Advisor and the Intelligent Department Level Layout Planning Advisor.

Solar wind monitor satellite

The need to predict accurately the occurrence of geomagnetic disturbances, which have caused blackouts and damaged power system equipment, is discussed. It is difficult for the US National Oceanic and Atmospheric Administration (NOAA) and the US Air Force Air Weather Service to jointly operate the Space Environment Services Center (SESC), the civil agency responsible for monitoring solar disturbances. The SESC observes the Sun and several geophysical parameters, including the Earth's magnetic field using both ground-based and space-based sensors. This effort is hampered by incomplete information, particularly the lack of information on the fluctuations of the solar wind. The effects of solar storms on man-made systems including radio communication and radar, spacecraft electronics, satellites, pipelines, and geophysical surveys as well as power systems, are described. The solar activity that causes the disturbances is examined. A proposed satellite to monitor the solar wind and improve forecasts is discussed, and the importance of a broad base of user support is stressed. >

Value of middle ear inflation as a diagnostic indicator of eustachian tube patency

The value of tubal inflation as a diagnostic procedure for Eustachian tube patency and function is controversial. In an attempt to assess the diagnostic value of air douche in atelectatic ears, 49 such ears of 40 patients were politzerized. The procedure was successful in 45 ears. However, of the four unsuccessful cases, two of the patients were able to autoinflate their ears. These results show that air douches pass regularly through the Eustachian tube into the tympanic cavity even in atelectatic ears, which by definition suffer from aeration deficiency, which is often considered to be secondary to 'Eustachian tube obstruction', or alternatively 'Eustachian tube dysfunction'. Thus, the ability to force air through the Eustachian tube by politzerization is of no diagnostic value as an indicator of normal or abnormal tubal patency or functioning in atelectatic ears and most probably in allied conditions.

Mechanism of Water Stress-Induced Xylem Embolism

We investigated the hypothesis that water stress-induced xylem embolism is caused by air aspirated into functional vessels from neighboring embolized ones (e.g. embolized by physical damage) via pores in intervessel pit membranes. The following experiments with sugar maple (Acer saccharum Marsh.) support the hypothesis. (a) Most vessels in dehydrating stem segments embolized at xylem pressures < -3 megapascals; at this point the pressure difference across intervessel pits between air-filled vessels at the segment's ends and internal water-filled vessels was >3 megapascals. This same pressure difference was found to be sufficient to force air across intervessel pits from air injection experiments of hydrated stem segments. This suggests air entry at pits is causing embolism in dehydrating stems. (b) Treatments that increased the permeability of intervessel pits to air injection also caused xylem to embolize at less negative xylem pressures. Permeability was increased either by perfusing stems with solutions of surface tension below that of water or by perfusion with a solution of oxalic acid and calcium. The mechanism of oxalic-calcium action on permeability is unknown, but may relate to the ability of oxalate to chelate calcium from the pectate fraction of the pit membrane. (c) Diameter of pores in pit membranes measured with the scanning electron microscope were within the range predicted by hypothesis (</=0.4 micrometer).

Performance Measurement during Simulated Air-to-Air Combat

Measurement and assessment of operator performance of complex tasks with decisional and psychomotor components of which only ultimate outcome measures are well defined provide difficult methodological challenges. One such task is the practice of air-to-air combat skills in simulated combat environments such as the Air Force Air Combat Maneuvering Instrumentation (ACMI) or ground-based visual flight simulators. Measurement and assessment of pilot performance in these environments are especially challenging because of the special cognitive and psychomotor skills involved in the freeplay and gamesmanship of two or more competing pilots. A review of the existing approaches to automated aircrew performance measurement was performed. Although the most common measurement models, using positional advantage or disadvantage, provide an adequate performance metric, other measures, such as control manipulation and the management of kinetic and potential energy, must be added to provide a refined performance measurement algorithm.

The Birth of Ordered Polymer Technology for Air Force Applications

ABSTRACTSince the late seventies, the Air Force Materials Laboratory and Air Force Office of Scientific Research has had a very energetic program in lyotropic liquid crystalline rigid-rod polymers. The objective of the multifaceted program was the attainment of mechanical properties for a structural material comparable with those currently obtained from fiber reinforced composites. This paper will describe the orgins of this program as derived from the unique aggregation properties of aromatic heterocyclic ladder polymers.

Appropriate suction device in rescue medicine

In rescue medicine, a suction apparatus must function in a variety of environmental conditions. To find an appropriate device for the Swedish Air Force air rescue service the Laerdal suction device 790,000 was selected for further testing according to international standards for aviation safety. Tests showed that vibrations had deleterious effects on the internal construction of the suction device. In addition, an electromagnetic field was generated affecting the navigation, autopilot, and communication systems. We conclude that the suction apparatus and probably other devices as well must be tested for their functioning in adverse environments and their ability to meet international aviation safety regulations.

Using Parametric Integer Programming To Plan The Mix Of An Air Transport Fleet

AbstractThe paper describes computatioaal procedures for parametric analysis on the objective function, the right hand side and the A-matrix of a pure integer program (IP). The procedures are simple to apply and not limited in the range of parameter variation that they can examine. They use any software capable of solving an IP at point values of the parameters.Planning the optimal mix of an air transport fleet is formulated as an IP in which the objective function includes for each type of airplane a fixed operating cost for having that type of plane in the fieet and an operating cost that varies with the number of planes. Planes have to be available to satisfy a number of different mission requirements and there is a limited capital budget for acquiring planes. A number of analyses on realistic data from the Canadian Forces Air Transport Fleet illustrate the usefulness of the parametric procedures in identifying robust solutions – solutions that are optimal or near optimal over a wide range of parameter...

The effect of n-alcohols on the force air bubble detachment from the surface of sulphur and graphite

The force of air bubble detachment from sulphur and graphite surfaces was measured in aqueous solutions of methanol, ethanol and propanol in the concentration range 0 – 300 mg/dm 3. At the same time the angle was measured at the moment of rupture of the systems sulphur—air bubble—solution and graphite—air bubble—solution. From the results obtained it was found that the detachement force decreased as a function of alcohol concentration in water due to the occurrence of polar interactions at the sulphur—solution and graphite—solution interfaces. It was also found that the changes in the contact angle at the moment of rupture were similar to changes in the equilibrium contact angle in these systems. Thence, changes of F 0 values as a function of alcohol concentrations in water were calculated from the equation connecting the detachment force with the surface tension of the solution, the size of the contact plane area, the diameter of the bubble and the equilibrium contact angle. Calculated changes agreed with those found experimentally.

Air Force Air Weather Service’s requirements for global meteorological data

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Douglas A. Moore and Robert E. Peterson, "Air Force Air Weather Service’s requirements for global meteorological data," Appl. Opt. 23, 2474-2476 (1984) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Space Environment Laboratory

The National Oceanic and Atmospheric Administration's (NOAA) Space Environment Laboratory (SEL), along with several other NOAA programs, is slated for a major budget reduction in FY 1985, a reduction which would have a serious impact upon the space environment services now provided by the laboratory.SEL, jointly with the U.S. Air Force's Air Weather Service, operates the Space Environment Services Center (SESC) in Boulder, Colorado. SESC acquires, in near real‐time, world‐wide data on solar activity, on the terrestrial magnetic field, and on energetic particles at geostationary and polar orbiting satellite altitudes. Data are available to SESC from solar observatories operated by both the Air Force and a number of nongovernment organizations, the NOAA geostationary and polar orbiting satellites, and a U.S.‐Canadian magnetometer network.

Aircraft noise propagation and reception anomalies at a major airbase

When a U.S. Air Force Air Installation Compatible Use Zoning (AICUZ) study was presented to the local government authorities in the area surrounding one major U.S. airbase, there was some disbelief and much concern about the high noise exposures predicted. So the local government authorities commissioned their own land‐use compatibility study to be based on measured noise levels over an 18‐month period. The results of the study only exacerbated the worries—noise levels and exposures well in excess of those predicted and large numbers of people exposed to noise more than 20 dB in excess of that generally considered “intolerable.” Yet, complaints are so few as to be almost negligible, and the people seem remarkably healthy. Some of the reasons for the higher noise exposures relate to peculiar temperature effects in the high desert valley in which the base is situated. The low level of complaints is attributed to the scheduling and nature of the flights on the one hand and to the way of life of the local peo...

Mechanical Features of Ultrasound Emission in the Monogolian Gerbil,Meriones Unguiculatus

Ultrasonic emissions in gerbils are produced by body movements which force air through the larynx and out the nose. Social stimuli are necessary for their production, yet they do not seem to be oriented directly toward conspecifics. Much information could be contained in the physical parameters of the ultrasounds and their variation associated with body movements.

Ice Breaking with an Air Cushion Vehicle

The ice breaking mechanism under a slow moving air cushion vehicle is explored. The bending moments which cause the circumferential cracks in the ice are determined for the case where the pressure of the air cushion is sufficient to depress the water and force air below the ice field. References are given to the more difficult case where the pressure is insufficient to form an air cavity.

Traumatic Pneumocephalus

A patient with traumatic pneumocephalus following use of an oxygen-powered resuscitator with a face mask is presented. Pressures of 50 cm H2O delivered by the device apparently were sufficient to force air into the cranium through a fracture communicating with the nasal cavity. The authors feel that manual-powered resuscitators should be used on patients suspected of skull fracture.

Systemic Air Embolism Following Penetrating Trauma to the Lung

Systemic air embolism following penetrating injuries of the lung has not been widely recognized clinically. Experimental studies designed to reproduce the phenomenon in dogs have been at variance, although none has taken into consideration the often high intrabronchial pressures created during resuscitative efforts in such patients. Twelve patients with systemic air embolism following penetrating traumatic injuries to the lung have been seen at our hospital. Ventilatory pressures created during resuscitative thoracotomy in traumatized patients were monitored and found to be as high as 100 mm Hg. Penetrating injuries of the lung were created in mongrel dogs, and the animals were ventilated with pressures reaching 90 mm Hg. All dogs unequivocally developed systemic air embolism, with air visualized in the coronary arteries. It would appear that systemic air embolism following penetrating injury to the lung may result when increased intrabronchial pressure, such as found during manual ventilatory assistance, forces air through traumatic bronchovenous fistulae into the systemic circulation.

Kinetics of evaporation/oxidation of iridium

Iridium wires self-resistance-heated to temperatures in the range of 1675 to 2260°C (1948 to 2533 K) were oxidized in naturally convected oxygen and air at pressures in the range of 9.9×10−8 to 1.32 atm (10−2 to 1.34×105 Pa) and in force convected oxygen and air at pressures in the range of 4.6×10−3 to 0.84 atm (470 to 8.5×104 Pa). The experimental results were closely correlated by a theoretical rate equation based on control of the oxidation rates by the rates of evaporation of Ir(g), IrO2(g) and IrO3(g) and by the rates of their subsequent diffusion through the gaseous boundary layer. Apparent values were obtained for the standard state free energies of formation of IrO2(g) and IrO3(g) and were correlated linearly with temperature.