Background: Tension pneumothorax is a condition with frequent fatal complications. This condition is caused by a disruption in the lung - that creates a one-way valve allowing air to accumulate in the pleural space. The fatal complication is the prevention of blood returning to the right side of the heart - due intrathoracic pressure compressing the right atrium. The patient can exhibit symptoms of dyspnea, tachypnea, tracheal deviation, jugular venous distention, subcutaneous emphysema, and shock that can lead to rapid deterioration and death. Case Report: We report a case of massive subcutaneous emphysema complicating tension pneumothorax management. The patient is a 20-year-old male who presented to the emergency department with chest trauma and was in extremis with diffuse severe subcutaneous emphysema. Due to the distorted anatomy, airway management and chest decompression were performed with nonstandard techniques/equipment resulting in rapid patient stabilization. After 4 days in the hospital, he was discharged home with no deficits. Discussion: Many providers do not have the proper equipment or training to treat patients in this extreme condition. CT images demonstrate the anatomical distortions in this case and the increase in size required for invasive life-saving devices. Images demonstrate where many commercial 14 gauge angiocaths and cricothyrotomy kits will not suffice (due to distortion in the anatomy), and these should not be relied on solely. Conclusions: While trauma carts frequently maintain (1.75 - 2 inch) 14 gauge angiocaths, they should also have military grade angiocaths that are 3.25” in length, which will work in most cases. Some, but not all, military-grade cricothyrotomy kits, or individually assembled kits, have 6.0 endotracheal tubes and come with a bougie and cricothyrotomy hook which would have been sufficient in this patient. Prehospital and hospital healthcare personnel should be prepared for similar patient encounters.

This paper examine a passive cooling system for a humid climate. This system will be divided into two parts, a radiative system and an evaporative system combined into a roof pond system. Performance of the radiative system will be enhanced through the use of a selective cover which will make use of an atmospheric window between 8 and 13um. An attempt will also be made to thermally isolate the radiative system from convective gains with the evaporative system. The evaporative system will consist of a water, solvent and dye layer over the selective cover of the radiative system. The performance of the evaporative system will be enhanced by virtue of the increased vapor pressure made available through the use of solvents. The main solvent to be examined shall be methanol. The increased vapor pressure shall sufficiently increase the rate of evaporative cooling to a point where useful cooling is obtained even under high humidity conditions. It was found that a solution with a 0.8 mole fraction of methanol in the evaporative system could cool a sufficiently large water storage to 45°F using a 300 m2 roof pond. This is a heat sink which if used to provide cooling and dehumidification, will provide 576000BTU of cooling. This is the equivalent of a 3 ton unit operating 16 hours a day. It was found that a water layer thicker than 0.1 mm would radiatively isolate the selective cover, making the concept of a liquid thermal protection useless as a means of providing only convective protection. However, as a selective cover, teflon was found to make the best use of the 1-13um window. As a result, this would provide 33 BTU/ft2-might as compared to 11 BTU/ft2-night for a black cover. It was also found that a green of blue and yellow or red dye mixture, when dissolved in water, would provide a black surface throughout the visual and infrared range.

This report explains the development of a telephone line multiplexer to be used with a computer based personal paging system. The large geographical area coverage made possible by computer processing results in many calls having to cross telephone tariff boundaries. Since system users cannot be expected to pay long distance charges, dedicated lines which cross tariff boundaries must be leased. Multiplexing applied to those leased lines reduces the cost of data transmission, and is, therefore, justified. The design of the multiplexer proceeds from a specification set which is derived from user response requirements. Fundamentally, the response consists in advising the user, within a reasonable time, that a "page" has been accepted by the system. The specification set is then partitioned into functional blocks which are modeled using flow charts and state diagrams. Logic design follows directly from the models. Production of the multiplexer is followed by field installation. The savings resulting from the multiplexing are considerable.

In people with neuromotor deficits of trunk and lower extremities, maintaining and regaining balance is a difficult task. Many undergo rehabilitation to improve their movement capabilities, health, and overall interactions with their environment. Rehabilitation consists of a set of interventions designed to improve the individual’s mobility and independence. These strategies can be passive, active or task-specific and are dependent on the type of injury, how the individual progresses, and the intensity of the activity. Some of the common rehabilitation interventions to strengthen muscles and improve coordination are accomplished either by the manual assistance of a physical therapist, bodyweight suspension systems or through robotic-assisted training. There are several types of rehabilitation robotic systems and robotic control strategies.However, there are few robotic studies that compare their robotic device’s control strategy to common rehabilitation interventions. This dissertation introduces robotic strategies centered around rehabilitation ones and characterizes human motion in response to the robotic forces. Two cable-driven robotic systems are utilized to implement the robotic controllers for different tasks. Further details of the two cable-driven systems are discussed in Chapter 1. The validation and evaluation of these robotic strategies for standing rehabilitation is discussed in Chapter 2. A case study of a robotic training paradigm for individuals with spinal cord injury is presented in Chapter 3. Chapter 4 introduces a method to redistribute individuals’ weight using pelvic lateral forces. Chapter 5 and 6 characterizes how young and older groups respond to external perturbations during their sit-to-stand motion. This dissertation presents robotic strategies that can be implemented as rehabilitation interventions. It also presents how individuals’ biomechanics and muscle responses may change depending on the force control paradigm.These robotic strategies can be utilized by training individuals to improve their reactive and active balance control and thus reduce their risk of falling.

No description available.

The activity and wettability of raw fused silica capillary tubing was found to be widely variable which places severe limitations on the reproducibility of column deactivation and inertness. Hydrothermal treatment of the raw fused silica with nitric acid was proven to be very effective for cleaning and maximizing the degree of silanol coverage of the surface. The capillary rise method was used to obtain contact angle data for untreated fused silica and fused silica treated with a variety of deactivating reagents. This contact angle data was used in the construction of Zisman plots which allowed quantitative comparison of the wettability and degree of surface coverage obtained with the different deactivants. The thermal stability of the final column was related to the success of the deactivation procedure. The choice of cross-linking initiator was also found to have an affect on column inertness. In the synthesis of intermediate polarity polysiloxane stationary phases, mixtures of commercially available cyclic siloxanes were shown to be a viable alternative to the use of dichlorosilanes as starting material. The main advantages were the simplification of the synthesis procedure, simpler and better molecular weight control of the polymer, and the elimination of HC1 as a by-product of both the polymerization and endcapping steps. A new stationary phase, 7% cyanoethyl, 7% phenyl, 1% vinyl, methyl polysiloxane was synthesized and found to be more polar than OV-1701 with higher temperature stability, easily cross-linked, and suitable for use in supercritical fluid chromatography. / Ph. D.

In this thesis an approximate method is developed which predicts the aerodynamic force on a cone-cylinder body in axially symmetric transonic now. The method places more emphasis on the physics of the now than on the mathematical rigors of solving the typical reduced non-linear transonic equation of motion. Under the assumption that the now is that of a steady, irrotational, inviscid, compressible gas, the body pressures are determined and the associated force defined. Recognizing that the transonic pressures are influenced by the character of the subsonic compressible pressures, which are obtained in this analysis through Gothert’s Rule, it is then mandatory that the incompressible case be defined with the best possible accuracy. Comparisons with experiments indicate that the classical method (axially distributed sources and sinks) does not provide this required accuracy. Thus the surface distributed vortex ring theory is used in the present analysis to obtain the incompressible body pressures. Gothert’s Rule, which represents a linear solution for the subsonic case, is known to be applicable up to a limit value of tree stream Mach number. An investigation is carried out herein to determine both the correct form of the rule and its limits of applicability. As a result of this investigation, it is concluded that the upper limit is the lower free stream critical Mach number. Also, at this Mach number, a solution is immediately available tor the lower limit of the transonic range of Mach number. In solving the transonic problem the law or stationarity of local Mach number is of fundamental importance. For an assumed isentropic flow over the body, and for sonic conditions being present at some point on the surface, the body pressures can be described in the ratio p_L/p*. Here p_L is the local surface pressure and p* is the sonic (body) pressure. Through the stationarity law, this ratio is recognized as an invariant for transonic speeds so long as the flow field remains essentially irrotational. Thus any change in local pressure is only a function of the free stream Mach number for any given body position. By this approach, the pressure distribution is defined for a range of Mach number from below to above the sonic stream value. The method is then capable of prediction for almost all of the transonic range of Mach number. It is only when the head shock baa significant curvature, causing the now adjacent to the body to be rotational, that the method fails. Though the procedure developed here is not capable of spanning the entire transonic range, it does provide a wider range of applicability than other known theories. Finally, for this problem, a correlation of transonic pressure drag data is formulated. This correlation is founded on physical interpretation and is not limited to the usual transonic similarity restrictions. In fact, to the author's knowledge, this is the first known such correlation tor axially symmetric flow covering the range of body sizes and Mach numbers considered in this investigation. In so far as is practicable the results obtained in this thesis have been compared to available experimental results. In particular, the drag data from this analysis compare closely with experimental transonic values. Experiment bears out the conclusion that the upper limit for linear theory is the lower critical tree stream Mach number. And, the pressures determined by the vortex ring theory agrees well with the low-speed experimental results obtained by the author. / Ph. D.

A major problem encountered in the designing and construction of any nuclear reactor system is the removal of heat from the core of the reactor. In the V.P.I. UTR-10, the heat is removed from the fuel plates by the light water moderator-coolant which is pumped between the plates. The maximum temperature which the fuel will attain is determined by the coolant temperature, the coolant flow rate, and the reactor operating power. The latter two of these are given by the reactor instrumentation. No provisions were made which allowed the temperature of the coolant in the region of the fuel elements to be measured. In order to ascertain this coolant temperature, an array of copper-constantan thermocouples was inserted between the individual plates of the fuel elements. The temperature of the coolant near the bottom and top of the 144 fuel plates was found using this thermocouple arrangement. These results were used to predict temperature of the coolant and fuel at a power level of 100 Kw. It is believed that with appropriate modifications of the present system no major difficulties should be encountered in increasing the reactor's licensed power from 10 Kw to 100 Kw. / Master of Science

A method for removing chemical contaminants, such as phenol, from a stream of waste water has been proposed. The method uses a device for contacting water with activated carbon, called a "panel bed". In this device, water flows across a bed of activated carbon retained within a set of parallel louvers. Construction permits contaminants in the entering stream of water to be adsorbed on carbon particles, starting from the entrances of the spaces between the louvers. A pulseback technique is used to remove the region containing "contaminated" activated carbon. Pulseback is applied periodically after appropriate intervals of operation. This research aims to determine operating characteristics of a panel bed and focuses on the study of pulseback. From a previous design of a panel bed filter for removing fly ash from stack gases, and from a basic study of characteristics of activated carbon adsorption isotherms, a panel bed was constructed which was believed to be suitable for contacting activated carbon with waste water. Pulseback consists of a reverse transient flow of water across the panel bed of activated carbon. Detailed descriptions of pulseback equipment, data on the spill of carbon that accompanies pulseback, and correlation of the carbon spill data are included. The carbon spill during pulseback appears to correlate with "active time", where this term refers to the time during which a reverse pressure difference, created by the reverse transient flow of water, exceeds a critical minimum value necessary for any spill at all to occur. For the specific design of equipment used in this study, the spill is relatively small if the active time is less than 60 milliseconds. Beyond 60 milliseconds, for the specific equipment used, the spill is linear with active time, and occurs at a rate that appears related to Zenz's modification of the Francis weir formula to describe efflux of solids from a static bed through an opening. / Master of Science

An experiment has been performed which establishes the capability of the reactor at V.P.I. to provide a satisfactory neutron supply for neutron radiography. Several different specimens including low Z materials and heavier materials such as iron have been used as test objects. The effects of alternate methods of obtaining the radiographs and of the different experimental parameters have been studied. Quantitative investigations were made of the effects of voids of different depths in varying thicknesses of three test specimens which consisted of graphite, bakelite, and plexiglass. The results of these studies showed that it would be practical to detect voids of as little as 1/32 of an inch at depths of up to one inch in the test specimens. It is felt that the research performed in this experiment adequately demonstrated the usefulness of neutron radiographic methods in non-destructive testing and the capability of the V.P.I. reactor facility for this technique. / Master of Science