Academic literature on the topic 'LD5655.V855 1984.W534'

This study examined shrinkage and related characteristics of two North American varieties of lodgepole pine: Pinus contorta var. latifolia and Pinus contorta var. murrayana, sampled at 10% of tree height. For var. murrayana, size was the only factor that had a significant effect on specific gravity; specific gravity decreased with increasing tree diameter. For var. Iatifolia, latitude was the only factor that had a significant effect on specific gravity; in general, specific gravity increased with increasing latitude. Conversely, specific gravity had a significant effect on radial shrinkage, the radial shrinkage tangential shrinkage ratio, and volumetric shrinkage for both varieties. The analysis of variance procedure indicated that the factors size, latitude, and elevation had no effect on the shrinkage of var. Iatifolia. However, for var. murrayana, radial shrinkage was affected by both tree size and latitude. Tangential shrinkage was also affected by latitude (increasing with increasing latitude). Linear correlations between radial shrinkage and growth rate, longitudinal shrinkage and distance I from the pith (a negative relationship), and specific gravity and growth rate were highly significant for both varieties. For var. Iatifolia, the linear association between specific gravity and heartwood percent was also significant. For var. murrayana, no difference in shrinkage or specific gravity was detected between the heartwood and sapwood. For var. Iatifolia, heartwood shrank less radially and had a lower specific gravity than sapwood. A comparison of the two varieties at their common latitudes indicated that murrayana trees have both higher specific gravity and shrinkage than do Iatifolia trees of the same size.
Master of Science

The major portion of this work details our investigation of trifluoroethoxy (TFE) substituted compounds with particular emphasis given to their preparation and possible applications. The three types of compounds studied were trifluoroethoxy substituted ketals, enol ethers, and dienol ethers. The ketal and enol ether work involved developing methodology for the large scale preparation of these structures as well as studies detailing their behavior. For the TFE ketals, preparation involved an acid-catalyzed alcohol exchange reaction. Applications included their use as non-complexing/acid-stable carbonyl protecting groups. The TFE enol ether work also involved preparation and applications studies. These structures were synthesized from propargyl ketones via a conjugate addition reaction. The applications were synthetic in nature mainly involving utilization of these compounds in cycloaddition and conjugate addition reactions. The last portion of this work involved our investigation into behavior of trifluoroethoxy substituted dienol ethers (substituted 1-trifIuoroethoxy-3-trialkylsiloxy-1,3- butadienes). Their preparation was accomplished by a method similar to that used by Danishefsky in his synthesis of the 1-methoxy analogs. The applications portion of this study focused on the use of these compounds as 4 carbon synthons in [4+2] cyclcoaddition reactions. Information gained from these studies provided insight into the effect the electron-withdrawing trifluoroethoxy group has on the reactivities of structures into which in has been incorporated.
Ph. D.

The commercial peanut dryers used today were first conceived when energy was relatively inexpensive. Since then, energy costs have increased significantly, and more efficient peanuts dryers are desirable. To evaluate dryer efficiency, a mobile fan test facility was designed, built and calibrated for on-site fan airflow and energy measurements. Four-, six-, and eight-trailer peanut dryers were tested for performance. The characteristics observed were delivery of fan airflow as compared to manufacturers' ratings, air distribution to each of the trailer supply ports, plenum leaks, and energy savings achieved by the use of flow controls. For testing, air to the dryer fan was provided by a centrifugal supply fan, where the flowrate was determined by measuring the pressure drop across calibrated perforated plate positioned between the two fans. Airflow through each of the trailer supply ports was determined in a similar manner by measuring the pressure drop across calibrated resistance plates. Measured airflow to the trailers from dryer fans was found to be 75 to 100% of the airflow given by the manufacturers' ratings. Air distribution was poor in dryers with no baffle. However, the installation of a baffle resulted in significant improvement in air distribution. The baffle a pressure rise which reduced total airflow up to 5%. Based on a recommended airflow of 0.167 m³/s per m³ of peanuts, fan inlets were restricted to reduce airflow, and energy savings as high as 35% were achieved. Repairs on poorly maintained dryers increased flowrate from 3 to 7%.

Master of Science

A reconfiguration is developed for 2-dimensional mesh architectures and applied to a fault T tolerant cellular architecture. The reconfiguration is accomplished by adding communications paths to each cell which can be enabled by means of transistor switches controlled by decoding the contents of a register containing the relative position of faulty cells. This enables faulty cells to be bypassed and operations of cells in the same row east of the faulty cell to be shifted one cell to the east and a spare cell included in the active pattern.

A modified s-value algorithm is also developed which enables a cell to determine the size of a square pattern that may be centered on that cell.

Master of Science

Nurses teach to maintain health and prevent disease. Rapport and good communication skills are especially required when teaching such sensitive subjects as prevention of sexually transmitted diseases, including acquired immune deficiency syndrome (AIDS). Neurolinguistic programming (NLP) is a communication technique that proposes to enhance rapport. Rapport is enhanced by the use of a combination of verbal and nonverbal techniques where the individual is matched and mirrored by the interviewer and verbal communication follows the sensory system most preferred by the speaker. The study investigated the effect of NLP as a rapport builder and teaching technique in one-on-one nurse-client teaching transactions including client satisfaction with the relationship and retention of knowledge of AIDS prevention information. A quasi-experimental design was used. Volunteer nurses were trained to teach AIDS prevention. Their adult volunteer clients were the treatment group. The control group of clients were taught by the nurses using the basic AIDS prevention curriculum. The two groups were compared according to the results of pre-test/post-test knowledge scores and satisfaction ratings for the nurse teacher. Data was analyzed using analysis of covariance and analysis of variance. There were no statistically significant differences between the two groups. Qualitative A data was collected after the completion of the teaching that supported usefulness of the techniques for teaching. Further studies were recommended.
Ed. D.

Robotic mechanisms are defined in this dissertation to be closed-loop, in-parallel actuated mechanical devices possessing several degrees-of-freedom. Parallel robotic mechanisms have recently received attention in the robotics literature as a potential alternative to the existing serial industrial robot. Serial robots are in a cantilever configuration which makes them relatively compliant and Ieads to poor accuracy. Many serial manipulators have motors that are carried on moving links which limits dynamic performance. Robotic mechanisms are in a parallel configuration which provides excellent stiffness, load-bearing, and accuracy. Robotic mechanisms combine the advantages of serial robots and closed-loop single-degree-of-freedom mechanisms to form a versatile new robotic tool. This dissertation presents theoretical kinematic analysis and design of planar robotic mechanisms. The topics covered are type and number synthesis, kinematic position solution, velocity and acceleration analysis, kinetostatic analysis, workspace optimization, and link interference avoidance. Throughout this work, comparisons are made among three general manipulator configurations: serial, parallel-serial, and fully parallel. Strengths and limitations are discussed for each configuration type. This investigation provides the analytical foundation for implementation of planar robotic mechanisms. Closed-form solutions to the kinematic position, velocity, and acceleration problems are presented. Manipulator reachable hand areas are maximized. An underlying theme of this work is tradeoffs between competing factors relating to various configurations of parallel robotic mechanisms; these tradeoffs are important design considerations. The recommendation of this dissertation is to pursue practical development of robotic mechanisms for general industrial manipulation tasks.
Ph. D.

An electronically-controlled positive-displacement bellows-type air pump has been developed in the Bio-medical Engineering Laboratory for the treatment of adult Sleep Apnea Syndrome (SAS). An electronically-controlled positive-displacement pump has been employed in order to eliminate the pressure regulator and accompanying noise of present therapeutic devices. The positive-displacement pump is found to quietly and effectively provide the required airway pressures for the treatment of adult Sleep Apnea Syndrome. New developments in the reduction of the size and noise levels of current therapeutic devices, however, preclude mass production of the bellows-type pump because of its size disadvantage. The custom nasal mask and exhalation valve, control system, pressure-monitoring alarm system, and the controlled humidifier of the positive-displacement pump should be incorporated within the present fanâ type Nasal Continuous Positive Airway Pressure (NCPAP) system to provide quieter, more comfortable, and safer NCPAP therapy. Before the design and development of the positive displacement NCPAP pump is detailed in this thesis, however, the problem of adult Sleep Apnea Syndrome is introduced, available therapies are investigated, and the current NCPAP therapy system is examined.

Master of Science