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Articles 189181 - 189210 of 196618

Full-Text Articles in Engineering

The Relationship Of Textbooks To Development Of Course Content In The Teaching Of Small Gas Engines, Frank Demchuck Jan 1972

The Relationship Of Textbooks To Development Of Course Content In The Teaching Of Small Gas Engines, Frank Demchuck

All Master's Theses

This study compares and evaluates the ideas and opinions of practitioners with the ideas and opinions of educational theorists. Information from the practitioners was gathered by questionnaire. Information from the theorists was gathered by a search of the related literature. The findings, showing the relationship or textbooks to the development of course content in the teaching of small gas engines, are presented and evaluated. A small gas engines textbook outline based on information gained from this study is also presented.

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Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris Jan 1972

Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris

Doctoral Dissertations

"Poly-(p-phenylenepyromellitamic acid)s have been synthesized over the weight average molecular weight range from 8,000 to 22,000 by reaction of pyromellitic dianhydride and p-phenylenediamine in dimethylformamide. The polymers were recovered as amorphous yellow powders having planar dimensions of 3-4 x 1-2 µm with thicknesses of 0.1-0.2 µm and contained 20-30% associated dimethylformamide. Consumption of reactants and attainment of the ultimate molecular weight of the polymer was found to occur within one minute. Thermogravimetry of the solid poly(amic acid)s was used in a method developed to determine the amount of associated dimethylformamide, to study the cyclization of poly(amic acid) to polyimide, and …

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Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds Jan 1972

Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds

Masters Theses

"A state of the art regarding the thermal behavior of bridges and considerations to be given to the resultant thermal effects is presented. The results of studies related to the thermal effects on bridges are reviewed. Studies attempting to relate environmental factors to bridge temperatures, and subsequently to bridge movements and stresses, indicate that the task is extremely complex. Some correlation has been made between equations predicting bridge temperatures and movements based on weather bureau records. However, further research is needed to evaluate the effects of factors other than temperature, such as creep, shrinkage, and humidity on bridge movements and …

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An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja Jan 1972

An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja

Masters Theses

"Fluidics, the new control technique finds its use amongst the conventional electronics and pneumatics due to some of its impressive features. Selected literature about bistable and proportional amplifiers has been presented for better understanding of the element behavior. Sensors; typical applications of fluidics have been described separately. An air flow velocity sensor has been set-up. Basically it consists of a cylinder placed across the air flow that sheds vortices in the wake due to 'Von Karman Vortex Street' phenomenon. The frequency of vortices gives a measure of velocity. The velocities obtained from the sensor have been compared to the ones …

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Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang Jan 1972

Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang

Masters Theses

"Thermal expansion, thermal hysteresis, and the monoclinic tetragonal phase transformation of ZrO₂ have been studied with high temperature x-ray diffractometry. The initial transformation temperature in pure ZrO₂, on heating, is about 1150ºC. The transformation occurs over a 100ºC temperature range and thermal hysteresis occurs on heating and cooling. The mechanism of the transformation is related to preferred vibrational modes of atoms on the AO -CO plane of the monoclinic structure. Because the monoclinic BO axis is parallel with the tetragonal [110] axis, structural relationships can be seen to be a controlling factor in the transformation. Initiation of …

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A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah Jan 1972

A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah

Masters Theses

"Four Liapunov functions used in stability studies are compared for accuracy on an eight machine power system. This comparison is made to determine which function is best in multimachine stability applications. Morgan's Estimating Technique is used to estimate when the Liapunov function would exceed its maximum value and thus to predict the critical switching time for the system"--Abstract, page ii.

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The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel Jan 1972

The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel

Masters Theses

"In this report the steady-state near-resonant vibration of a hollow fluid-filled beam is considered. The energy dissipation caused by the beam-fluid interaction is approximated by introducing a viscous damping force into the Bernoulli-Euler beam equation. A theoretical expression is developed for the displacement of the hollow beam by solving this modified Bernoulli-Euler beam equation. Tests are made using a cantilevered fluid-filled box to simulate a unit of beam-fluid length. The band-width technique is used to determine the incremental viscous damping coefficient from test data. A variety of fluids are used in the box to determine the effect of the fluid …

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A Comparison Of Analytical And Experimental Approaches In Determining The Thermoelastic Stresses Around A Cylindrical Inclusion Of Elliptical Cross-Section, Kenneth Byron Oster Jan 1972

A Comparison Of Analytical And Experimental Approaches In Determining The Thermoelastic Stresses Around A Cylindrical Inclusion Of Elliptical Cross-Section, Kenneth Byron Oster

Masters Theses

"Three approaches are used to determine the principal stress differences in an infinite elastic medium containing a cylindrical inclusion of elliptic cross-section due to a uniform temperature change. First, the two-dimensional equations of thermoelasticity are solved resulting in equations for the stress components anywhere in the medium material. Second, boundary displacements based on stress-strain relations are used as input displacements in a finite element program of the medium. Third, these same boundary displacements are used as input displacements on a photoelastic model simulating the medium. The problem is treated as one of plane strain in the first approach and one …

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Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd Jan 1972

Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd

Masters Theses

"The required synchronization of a dynamic crossed-field photomultiplier tube (DCFP) is accomplished by means of a phase-locked loop for which the salient feature is the use of the DCFP as the phase detector. This action is necessitated due to the unique sampling and phase focusing type of operation of the DCFP. The phase-locked loop is implemented by dithering the phase of the synchronizing RF drive signal, bandpass filtering the output pulses of the DCFP and using a synchronous detector at the dither frequency to determine the phase relationship between the incoming mode-locked laser pulses and the RF drive signal. The …

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A Study Of The System Lithia - Silica, Roy Richard Ramey Jan 1972

A Study Of The System Lithia - Silica, Roy Richard Ramey

Masters Theses

"X-ray intensity and d-spacing measurements were performed upon samples in the system Li₂O-SiO₂. Samples ranged from 0.0 to 28.0 mole percent lithia and were fired for 72 hours at temperatures from 920ºC to 1400ºC. Atomic absorption analyses were made upon the fired samples. Non-equilibrium conditions were prevalent and results are inclusive. Quartz is the stable phase in the high silica field at temperatures below 1050ºC with cristobalite stable above that. The quartz - cristobalite transformation occurs at 950ºC with the cristobalite transforming into tridymite at 1010ºC. There was wide scattering of data at 1000ºC and below. There was no correlation …

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A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney Jan 1972

A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney

Masters Theses

"Three methods for optimizing a proportional and a proportional-integral controller parameter problem were investigated on an iterative analog computer. The three methods were the parameter-perturbation correlation method, the absolute biasing method, and the variable step size method. The process controlled was third order linear. The performance function used to judge the quality of the controller was the time integral of the absolute value of error. All three methods required a trial and error adjustment of the parameters used in these methods. The optimum solution was obtained by all methods. The absolute biasing method, for both the proportional and the proportional-integral …

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The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer Jan 1972

The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer

Masters Theses

"The general theory of large elastic deformations is applied to the problem of a liquid-filled, axisymmetric membrane which is supported on a rigid horizontal plane and subjected to a variable external pressure. The variable external pressure is caused by submerging the membrane to various depths. The variation of the hydrostatic pressure in the inflating medium as well as in the surrounding environment is considered. By assuming large meridional deformations the stress field and the deformed shapes of a submerged membrane made of a neo-Hookean material are obtained. The effect of the initial shape on the deformed configuration of the membrane …

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Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang Jan 1972

Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang

Masters Theses

"By precise X-ray measurements, the lattice parameter of pure nickel (Fisher Co., reagent grade) was found to be 3.52389 Å at 25ºC. At the same temperature, the lattice parameters of iron samples were found to be: 2.86621 Å, 2.86624 Å and 2.86614 Å for purities of 99.999%, 99.985% and 99.9%, respectively. By measuring high angle back reflection lines, the linear coefficients of thermal expansion of both nickel and iron were precisely determined. Both, high purity nickel and iron, exhibited anomalies in their expansion coefficients near their Curie points. This is in agreement with some of the previously reported data. Some …

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Investigation Of A New Type Of Cloud Condensation Nuclei Counter: The Thermal Quench Chamber, Donald Arthur Hess Jan 1972

Investigation Of A New Type Of Cloud Condensation Nuclei Counter: The Thermal Quench Chamber, Donald Arthur Hess

Masters Theses

"The design and development of a new type of cloud condensation nuclei counter was undertaken to provide a new laboratory and field instrument that operates on a different theoretical basis than the thermal diffusion chamber now being used by meteorologists and other scientists. In the new instrument the test aerosol is pumped through a tube where it is first humidified and then cooled at constant pressure to create a supersaturation, causing water vapor to condense upon the nuclei in the aerosol sample. The concentration of cloud condensation nuclei is then determined by counting the water drops. The control of temperature …

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Transient Cooling Of A Sphere Due To Boiling, Salil K. Banerjee Jan 1972

Transient Cooling Of A Sphere Due To Boiling, Salil K. Banerjee

Masters Theses

"The time - dependent surface temperature is determined for a sphere subjected to cooling by boiling. One dimensional heat transfer is considered and the solid is assumed to be homogeneous, isotropic and opaque to thermal radiation and to have temperature independent physical properties. The initial temperature of the sphere and the coolant are assumed to be uniform and arbitrary. The boiling heat transfer coefficient at the surface of a sphere is a strong function of the surface temperature thus resulting in an extremely nonlinear transient heat conduction problem. As a practical application of the problem, the process of quenching has …

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A Practical Approach To The Exhaust Silencing Of A Pneumatic Rock Drill, Morton Gary Barth Jan 1972

A Practical Approach To The Exhaust Silencing Of A Pneumatic Rock Drill, Morton Gary Barth

Masters Theses

"One-third octave spectrum analyses of the exhaust noise produced by a medium sized pneumatic rock drill were obtained during free recriprocation to determine the most troublesome bands of noise. Noise reduction techniques were then used to design exhaust mufflers which would reduce the level of the exhaust noise to an acceptable level with a minimum increase in back pressure. The prototype mufflers evaluated included an expansion chamber, a resonator, and various modified expansion chambers. One of the modified expansion chambers tested provided very good attenuation reducing the exhaust noise from 113 dBA to 87 dBA at the operator's ear position. …

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Use Of Isotopes To Reduce Neutron-Induced Radioactivity And Augment Thermal Quality Of The Environment Of An Underground Nuclear Explosion, Nathaniel Fred Colby Jan 1972

Use Of Isotopes To Reduce Neutron-Induced Radioactivity And Augment Thermal Quality Of The Environment Of An Underground Nuclear Explosion, Nathaniel Fred Colby

Masters Theses

"The use of isotopes to include radioactive waste products to reduce the neutron-induced activity of an underground nuclear explosion and its application in the field of geothermal power stimulation is discussed. A shield composed of selected isotopes surrounding a fusion device will capture excess neutrons producing isotopes with short half-lives. Subsequent rapid decay will prolong the high temperature in the vicinity of the explosion and decrease the activity. Long-lived isotopes created by neutron capture in the host rock would be minimized. The investigation is conducted for strontium-90, cesium-137, cerium-144, technetium-99, rhodium-103 and -105. Of these, the first three appear to …

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Use Of Glass Separated From Municipal Refuse In Asphaltic Concrete, Thomas Eugene Keith Jan 1972

Use Of Glass Separated From Municipal Refuse In Asphaltic Concrete, Thomas Eugene Keith

Masters Theses

"The recent interest in municipal refuse recycling has brought about the development of several systems for separation of the refuse into components. One of the components reclaimed is a glass-rich fraction which, although primarily glass, contains various non-glass materials which the system is not able to remove. Clean waste glass can be used as an asphaltic concrete aggregate, and it would be desirable to use this glass-rich fraction in a similar manner. However, the effect, if any, of the non-glass components on the properties of an asphaltic mixture must be determined in order to utilize the glass-rich fraction with a …

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Drift Velocity Measurements Of Various Materials Floating On Water Waves, Paul Keith Scherrer Jan 1972

Drift Velocity Measurements Of Various Materials Floating On Water Waves, Paul Keith Scherrer

Masters Theses

"A study was conducted to determine the affects of deep water gravity waves on oil lenses and surface floats. The experiment was conducted in a wave tank equipped with a mechanical wave generator. The data obtained consisted of the measured velocities of oil lenses and thin plastic floats under the action of a variety of wave conditions. It was found that waves do cause a movement of the oil lenses and surface floats, and their velocity was found to be greater than the surface drift predicted by Stokes' theory of mass transport by waves in a single component fluid. For …

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A Study On The Lateral Placement Of Automobiles Due To Restrictions On Two-Lane Rural Highways, Warren Chip Woods Jan 1972

A Study On The Lateral Placement Of Automobiles Due To Restrictions On Two-Lane Rural Highways, Warren Chip Woods

Masters Theses

"The driver of an isolated vehicle on a given section of highway, whether it is urban or rural, will choose a path on the pavement that offers the least resistance to driver effort and which to him seems safest. Lateral obstructions, such as retaining walls, trees, bridge abutments, ect., which may cause him to deviate from the desired path represent some degree of hazard to the driver and should be removed, if practicle. The purpose of this investigation was to determine any change in the lateral placement of automobiles due to side restrictions on rural two-way, two-lane highways. Phase one …

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An Analysis Of Single Wire Earth Return (Swer) System For Rural Electrification, Balwinder Singh Samra Jan 1972

An Analysis Of Single Wire Earth Return (Swer) System For Rural Electrification, Balwinder Singh Samra

Masters Theses

"The primary objective of this investigation was to determine the general applicability of Single Phase Earth Return(SWER) system for rural electrification where the load density is low, for example electrification of farms and small villages in emerging nations. The limitations of SWER system of distribution are many and it is necessary to make judicious use of such transmission. In this investigation the construction costs of transmission and distribution by SWER system is compared with single phase and three phase systems for loads of 25KVA and 50KVA. Phase converters are required to operate a three phase motor on a single phase …

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Feasibility Study Of Using A Steam Power System In A Small Garden Tractor, Niranjan Kumar Doshi Jan 1972

Feasibility Study Of Using A Steam Power System In A Small Garden Tractor, Niranjan Kumar Doshi

Masters Theses

"This thesis is a feasibility study of using a steam power system in a small garden tractor. The relative advantages of steam power are discussed and compared with the characteristics of internal combustion engines. A monotube boiler is designed where steam is generated in stacked tube spirals. The boiler generates 225 lbs/hr of dry saturated steam at 500 psia, which corresponds to an engine output of 20 IHpage A rotary positive displacement engine is employed to expand the steam to 16 psia. A rotor instead of a piston eliminates the conventional connecting rod and crank shaft. The engine developes 15 …

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Design And Test An Operational Amplifier Speed Transducer, Tung-Ming Huang Jan 1972

Design And Test An Operational Amplifier Speed Transducer, Tung-Ming Huang

Masters Theses

"This thesis describes the design of an angular speed transducer. The purpose of this device is to provide a D.C. voltage which is proportional to the angular speed of a rotating shaft at any instant. The speed of the shaft is defined from a magnetic pickup monitoring a gear or similar device attached to the end of the shaft of a piece of rotating equipment. The signal from the magnetic pickup is modified and compared to a frequency generated in the feedback loop of the speed transducer and the error is sent to an integral type controller. The output of …

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Development Of A Sampling System And Characterization Of Stormwater Runoff From A Small Urban Area, William Clark Ford Jan 1972

Development Of A Sampling System And Characterization Of Stormwater Runoff From A Small Urban Area, William Clark Ford

Masters Theses

"Increasing urbanization and the demand for high quality water have directed attention to the problem of combined sewer overflows, while recent research has demonstrated that stormwater alone, without the influence of sanitary sewage, carries a significant pollutional load. The purpose of this investigation was to determine the quality and pollutional contribution of stormwater runoff from a small urban area, with specific emphasis on the development of a suitable sampling and flow recording system, the characterization of runoff and the correlation of runoff quality with local environmental factors and storm characteristics. The system developed consisted of an automatic sampler capable of …

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Structural Test And Analysis Of A Vierendeel Steel And Concrete Composite Girder, Melvin Crews Oestreich Jan 1972

Structural Test And Analysis Of A Vierendeel Steel And Concrete Composite Girder, Melvin Crews Oestreich

Masters Theses

"The results of the structural load testing of a unique type of steel and concrete composite girder are described. The structural system, referred to as a composite Vierendeel girder, is a hybrid type which incorporates features of a castellated beam and a Vierendeel truss. The performance of the composite girder agreed reasonably well with calculated values based on section properties for a prismatic beam. Observations indicated web stiffeners were required on the stub beams to prevent premature failure of the system. Failure of the girder was due to concrete crushing over a stub web beam. Design considerations for a structural …

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Characterization And Staged Lagoon Treatment Of Swine Feedlot Waste, Abraham H. Loudermilk Jr. Jan 1972

Characterization And Staged Lagoon Treatment Of Swine Feedlot Waste, Abraham H. Loudermilk Jr.

Masters Theses

"Feedlot pollution is developing into a serious problem because of the trend toward intensive farming techniques and the increasing number of animals in confinement feeding operations. The purpose of this study was to characterize swine waste collected under a slotted feeding floor using a water-carriage system, and to evaluate the treatment of this waste in a staged lagoon system consisting of an anaerobic, a dual anaerobic-aerobic, and an aerobic lagoon. A small feeding floor unit capable of maintaining 3 separate groups of animals, and a pilot 3-lagoon system were designed, constructed, and operated for a period of approximately 4 months. …

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Managerial Appraisals - A Systems View, James Thomas Hatlan Jan 1972

Managerial Appraisals - A Systems View, James Thomas Hatlan

Masters Theses

"In the past decade much has been written concerning the performance appraisal which can be defined as the systematic analysis of the individual with respect to his performance on the job. The appraisal's importance lies in the fact that its impact is felt in the areas of control, promotion, and managerial development all of which are essential for the progressive firm. This study is an attempt to offer something new and something different. The author offers a systematic study of industry in general with specific help from key corporations and utilities. His investigations encompass the three elements of appraising and …

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A Tensi-Volumetric Apparatus: Theory, Calibration, And Use In An Investigation Of The Oxygen Non-Stoichiometry Of Pure Batio₃, Glenn Jon Conger Jan 1972

A Tensi-Volumetric Apparatus: Theory, Calibration, And Use In An Investigation Of The Oxygen Non-Stoichiometry Of Pure Batio₃, Glenn Jon Conger

Masters Theses

"The development of the tensi-volumetric apparatus has been traced to its current position of significance in studies relating to oxide non-stoichiometry. Components of the tensi-volumetric apparatus, especially the capacitance membrane manometer, were examined in detail as were the parameters affecting the performance of such an apparatus. Based on a careful consideration of components and performance, a tensi-volumetric apparatus has been designed, built, and its operation theoretically justified for its particular physical configuration. Results of existing studies of the oxygen non-stoichiometry of barium titanate have been used to predict its behavior during a tensi-volumetric study. Specific analytical procedures developed for use …

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Design Of A Torsional Vibration Machine, Prafulchandra Pragjibhai Desai Jan 1972

Design Of A Torsional Vibration Machine, Prafulchandra Pragjibhai Desai

Masters Theses

"In this thesis the design of the major components of a torsional vibration machine is presented. The machine is a torsional vibration actuator which will deliver a mean output angular velocity with a superimposed harmonic component. This type of motion can be used to study the torsional vibration characteristics of models representing crankshafts, gear trains, torsional dampers, and other systems. The primary machine elements of the actuator are a power source, flywheel, and a Hooke's joint. The power source consists of a D.C. shunt motor and a drive transmission using 3 V-belts. Through the use of a Hooke's joint, approximate …

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Calculation Of Buildup Factors For Multilayer Slab Shields Using The Monte Carlo Method, John Paul Kuspa Jan 1972

Calculation Of Buildup Factors For Multilayer Slab Shields Using The Monte Carlo Method, John Paul Kuspa

Masters Theses

"Gamma-ray beams normally incident upon slab shields of varying compositions are studied using a computer program based upon the Monte Carlo technique. Initial gamma energies of 1, 4, 6, and 8 MeV are considered. The shielding materials used were aluminum, iron, and lead. Both single and double material shields were investigated, at a variety of thicknesses up to a maximum of five mean free paths. Two secondary gamma processes are included in this simulation: annihilation gammas from pair production and bremsstrahlung from the electrons. The primary effort is the calculation of the dose, energy, and number buildup factors for these …

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