For a variety of reasons, the need for increased utilization of the world's pulpwood resource has become an important subject of discussion in the 1970's. Whole tree chipping, or the use of all above-ground portions of trees, is a feasible method of achieving this goal. Many reports have been published in the field of pulping whole tree chips, and articles pertinent to softwood pulping are discussed in the literature review of the present study. Because a noticeable lack of information on mixed component pulping of southern pines was observed in the literature, the present study was designed to investigate the following topics: 1) The chemical and biological differences between conventional chips and whole tree chips, and the nature of the variation in the composition of whole tree chips. 2) The results of pulping mixed whole tree components in a laboratory digester. 3) The nature of changes that could be expected to develop in a pulping system as the amount of whole tree chips was varied from 0 to 100% of chip input. Kraft pulping of loblolly pine (Pinus taeda, L) was chosen because it is the major pulping system and species in the southeastern U. S. Unscreened whole tree chips are highly variable in their composition, and age and species have a large effect on the chip composition. Mixed component cooks do not appear to have the poor qualities predicted by individual component cooks. When yield and pulping conditions are held constant and the percent of WTC material is increased, fibrous yield decreases, kappa number rises and pulp color darkens. This may be a result of liquor chemical exhaustion and precipitation of lignin onto pulp fibers. These results indicate that in a mill operation, WTC material should be pulped with increased chemical and liquor volume. / Master of Science

The U. S. Navy needs a medium-caliber (5-inch) ship-mounted gun that can deliver a payload to a range five times farther than the present capability. Such an increase in performance requires major design changes to both the gun and its ammunition. A gun which can shoot beyond the visible horizon needs additional support from subsystems which provide targeting information and assessment of battle damage to the intended target. <p>A system engineering approach to the fulfillment of this need is presented. The gun weapon system is characterized through a functional analysis of its component subsystems. From this analysis, an allocation of design requirements is made to the various subsystems. Of particular interest to this project were the gun itself, and the sophisticated ammunition which it fires. Trade studies involving the design alternatives for the gun and its ammunition were carried out within the context of the total system involving also the fire control and targeting subsystems. These design capabilities are compared to the top-level system requirements, then iteratively improved where necessary. The objective of this project was the establishment of the top-level design requirements for the gun and its ammunition. Additionally, a life-cycle cost appraisal was developed for the proposed design. / Master of Science

Recent task based performance feedback research has concentrated on investigation of the effects of feedback message characteristics to explain variance in individual's post feedback predicted performances. Results of this research have not been well integrated within existing performance feedback models. The present study was conducted to assess the differential effects of feedback message content and feedback message characteristics on real subsequent task performance. Results of the present study indicate that feedback message content, not characteristics, is the critical factor in improving subsequent performance. However, the subject's perception of certain feedback message characteristics is important in influencing subsequent performance via the subject's overall perception/acceptance of the feedback message (Ilgen, et al., 1979). Results also indicate that an additional 5% of the variance in subsequent performance can be explained by incorporating a measure of Locke, et al.'s (1981)goa1 setting into the desire/intention to respond to feedback components of the Ilgen, et a1. feedback model, when subjects are asked to articulate their behavioral plans for future task performance. Results are discussed within the framework of current feedback models and future research needs. / Ph. D.

Materiality is a pervasive accounting concept that has defied a precise quantitative definition. The Capital Asset Pricing Model (CAPM) approach to materiality provides a means for determining the limits that bound materiality. Also, the approach makes it possible to locate the point estimate within these limits based on certain assumptions. / Master of Science

This dissertation is a study of vertical penetration of right-cylindrical projectiles into dry granular soil (Ottawa sand). Rigid projectiles were impacted into the soil at velocities less than 1000 ft/sec. Past theories for predicting penetration in soils have almost exclusively been based upon the impact velocity and the corresponding maximum penetration. In this research, the motion of the projectile during the penetration process was obtained by utilizing microwaves. The motion characteristics were obtained by "bouncing" microwave signals from the bottom of the projectile as it moved downward, and recording the information on an Ampex CP 100 magnetic tape recorder. It was found that penetration of the projectiles into the granular media could successfully be predicted by expressing the resisting forces on the projectile by -M dv/dt = Av² + Cz + D v > v_c and by -M dv/dt = Bv + Cz + D 0 < v < v_c where M = mass of projectile V = velocity of projectile at time t z = depth of penetration at time t A,B,C,D = constant coefficients. v_c is a critical velocity at which the "flow'' of the soil changes from one regime to the other, and is believed to be related to the energy necessary for comminution of the sand particles. The static coefficients, C and D can be found from the strength properties of the soil (c, φ and y) or from a static penetration test. A linear relationship was found between the static resistance, C , and the dynamic resistance coefficient, B. The value of A is believed to be related to the comminution energy, and is not greatly affected by density changes in the sand. The stability of the projectile was found to be an important factor in the values of the penetration forces. / Ph. D.

Fifteen abomasally cannulated, growing wether lambs were used in two metabolism studies to evaluate the utilization of RNA and DNA. Wethers were blocked by weight and breeding and randomly assigned within block to one of five treatments with the restriction that no animal receive the same treatment in both trials. All animals were fed 350 g, twice daily, of a basal ration supplying 7.1 g nitrogen. In addition, the lambs received twice daily infusions of either soy protein, RNA, DNA, or a 1:1 combination of RNA and DNA or a sham infusion. Tris buffer was used as the solvent for RNA and DNA, the carrier for soy protein and the sham infusion. Infusions, except for the sham, were calculated to be isonitrogenous supplying 2.5 g nitrogen per day. Following a 10-day preliminary period, all urine and feces were collected during a 10-day collection period. Jugular blood was obtained at 6 and 12 hr post feeding on the last day of each trial. Crude protein digestibility was significantly elevated for the nucleic acid infusions over that for the sham. The RNA value, though not different from DNA or the combination, was comparable to that for the soy. Calculated by difference, the absorption values of RNA, DNA, and the combination of RNA and DNA were 97, 77, and 72%, respectively. Nitrogen retention, expressed in g/day, tended to be higher for the nucleic acids than for the sham. The combination of RNA and DNA was not different from the soy treatment which had the highest (P< .05) nitrogen retention. Urinary urea, allantoin, and ammonia levels were elevated (P <.05) for the nucleic acid treatments over the sham. Urinary creatinine and “other” nitrogen (nitrogen unaccounted for) were not affected by treatment. Blood urea.nitrogen tended to be higher for the combination of RNA and DNA than the sham, while RNA, DNA, and the soy treatments were higher (P <.05) than the sham. Serum protein concentrations were unaffected by treatment. The amino acid concentrations either tended to be higher or were higher for the nucleic acids, especially the RNA and combination of RNA and DNA, than for the sham. Concentrations for the nucleic acid treatments compared well with those for the soy treatment and in some cases were higher than the soy. From these data, the following conclusions were made: 1) nucleic acids are well digested and absorbed; 2) retention and utilization of nitrogen from nucleic acids appears to be minimal; 3) the majority of the absorbed nucleic acids are excreted as urea and allantoin; and 4) essential and non-·essential plasma free amino acids are increased by exogenous nucleic acids. The effect may be influenced by urea recycling to the rumen as the result of nucleic acid degradation. Urea recycling would stimulate microbial growth with consequent increases in microbial amino acid synthesis. Amino acids associated with the urea cycle were noted to be affected. / Master of Science

In order to demonstrate the ability of microbubble flotation to superclean coal to ash levels of less than 2%, several Eastern U. S. coals have been tested. The results show that the process is capable of producing superclean coal with improved recovery as compared to the conventional flotation process.To further improve and understand the microbubble flotation process, electrokinetic studies of the hydrocarbon oils used in flotation as collectors have been conducted. Also, the effect of oil emulsifiers on the zeta potential of oil droplets has been studied. In general, oil droplets are negatively charged and negative zeta potential is reduced with the addition of nonionic and cationic surfactants. On the other hand, the negative charge is increased with the addition of an anionic reagent. It has also been shown that the negative zeta potential of oil droplets increases with increasing hydrocarbon chain length.The effects of different collectors on induction time and flotation have been determined by conducting microflotation and induction time experiments using an Elkhorn seam coal sample. The results show that industrial oils combined with the coal have the shortest induction times and, therefore, the highest flotation yields as compared to pure hydrocarbon oils. It has also been shown that oil emulsifiers tend to increase flotation yield and reduce particle/bubble induction time. / Master of Science

A control chart that simultaneously tracks the mean and variance of a normally distributed variable with no compensation effect is defined in this work. This joint control chart is compared to five other charts: an Χ chart, an s² chart, a Reynolds and Ghosh chart, a Repko process capability plot, and a t-statistic chart. The criterion for comparison is the probability of a Type II sampling error. Several out-of-control cases are examined. In the case of Repko, an equation is defined to compute the Type II error probability. The results indicate that the Reynolds and Ghosh statistic is powerful for cases when the variance shifts out of control. The Χ chart is powerful when the mean shifts with moderate changes in the variance. The joint chart is powerful for moderate changes in the mean and variance. / Master of Science

For all those sports enthusiasts within the Blacksburg area; for all members of the student body interested in intercollegiate, intramural, or individual sports competition; for all members of the administration interested in school prestige; and for all members of the athletic plant staff; a new building to house intercollegiate sports activities is a very vital and realistic problem - vital because of the present inadequacy and inflexibility of the War Memorial Hall, and realistic because of actual plans now in progress to expand the athletic facilities of Virginia Polytechnic Institute. This thesis deals with the design of a building that will meet the needs of adequacy and flexibility. / Master of Science

There has been increasing interest in the use of Very Small Aperture Terminals (VSATs) in satellite communication links operating in the Ku and Ka bands. Such systems offers the advantage of low signal margins and therefore, low cost. For the same reason, however, VSATs links can be strongly impaired by tropospheric scintillations. The VA Tech OLYMPUS propagation experiment which includes 12, 20, 30 GHz beacon receivers at an elevation angle of 14° provides us with valuable multi-frequency scintillation data. This dissertation focuses on the characterization of tropospheric scintillations on earth-space paths. Tropospheric scintillations are rapid fluctuations of signal caused by multiple scattering from the sma11 scale turbulent refractive index inhomogeneities in the troposphere. Analysis of the scintillation results from the VA Tech OLYMPUS experiment for both short term and long term studies is presented. The results include spectral characteristics, frequency scaling and statistics of the scintillation intensity, statistics of scintillation fading, diurnal and meteorological trends as well as a comparison with the current CCIR predictive model. Sma11 scale spatial diversity is a potential means to counteract tropospheric scintillation fading; it can be cost effective because of the low cost of VSATs. The VA Tech experiment includes 12, 20, 30 GHz beacon receivers and colocated 20 and 30 GHz diversity receivers that allows us to study this restoration technique. In this dissertation the effects of spatial diversity are studied through a cross-correlation analysis. Experimental results are compared to a theoretical model in which the atmosphere is characterized by an "anisotropic" Kolmogorov spectrum. A method to determine minimum vertical spacing between terminals to achieve good diversity performance is introduced. / Ph. D.