Thesis (Ed.D)--Boston University Thesis (M.Sc.Eng.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

Digitized by Kansas Correctional Industries

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2002. / "September 2002. / Includes bibliographical references (p. 175-189). / Between 1941 and 1945, movie theaters in the United States enjoyed a period of intense activity marked by record levels of attendance. Film scholars have explained this phenomenon by referring to the fascination exerted by "escapist" Hollywood films, which either idealized or completely negated the harsh economic and social conditions brought about by the outbreak of World War II. However, American photographer Arthur Fellig "Weegee" produced between 1943 and 1950 a series of photographs that reveal a more complex reality of movie going. Using infrared film and an invisible flash to cut through the almost complete darkness of the theater, his pictures reveal a peculiar function of the movie house at a specific moment in the history of the United States. By analyzing these photographs in the context of other sources of information such as posters, newspapers and magazine articles of the time, the dark and permissive interior of the movie theater emerges as an effective refuge from the violent forms of visual interaction that were established in public space as a consequence of wartime threats over American territory. Thus, at the time they serve as a starting point to recover a forgotten moment in the urban history of the United States, the images prompt a reevaluation of the spatial conditions of the movie theater itself-a site for public interaction that, interestingly, fosters unique forms of privacy and intimate exchange. / by Diana Ramirez Jasso. / S.M.

An analysis of John Steinbeck's humour leads to a better understanding of the author and his career. Steinbeck uses humour most often to characterize, to control his distance from his material, to intensify his serious passages, and to satirize. The study of his humour helps to solve the problems presented in his writing. His variety of forms, a result of his versatility and experimentation, is to some extent determined by his oscillation between humorous and serious treatments of subject matter. The fluctuation between serious and humorous works depends to a great extent on his degree of concern for his subject, while the inconsistency in the quality of his writing, as well as the inconsistency in the quality and quantity of his humour, is directly related to his degree of familiarity with his materials. Chapter One is a statement of the critical opinions of Steinbeck's humour. In Chapter Two the tradition of American humour is considered. The shaping of the national character is seen as a manifestation of national humour. The three main national characters are traced through from the American Revolution to the time of Mark Twain, when they emerged as elements of society. These elements are traced through to the present day with emphasis on Steinbeck's manipulation of them in his creation of humour. Chapter Three defines the qualities found in humour, then isolates humour from related modes. A definition of general areas of humour is followed by a definition of literary forms dependent on humour and by a discussion of techniques for the creation of humour. Chapter Four, a descriptive analysis of the humour in Steinbeck's works, attempts to determine the quality of the humour and to discover what types of humour predominate. Steinbeck's combination of the general areas of humour, his use of a variety of literary forms, and his utilization of different techniques are discussed. It is concluded that satire is the most persistent and the most successful element in his humour. Chapter Five deals with Steinbeck's uses of humour: to characterize, to control the distance from his material, to intensify the force of serious passages, and to satirize. In Chapter Six the chronology of the works, both fiction and non-fiction, is traced in order to determine the pattern of his humour. Issues which are serious but not crucial he tends to treat humorously, while those which are urgent he treats seriously. The relationship between the success of the writing, the success of the humour, and the author's familiarity with his materials is examined. In Chapter Seven a number of conclusions are reached. The fluctuations in the quality of Steinbeck's writing are directly related to his degree of familiarity with his materials. When he is remote from his subject matter there is a decline both in his artistry and in the quality of his humour. It is natural for him to view his material humorously, but crucial issues demand serious treatment. Although his tendency to experiment caused him to treat a wide range of topics, Steinbeck writes basically about America. He expresses himself through a natural sense of humour yet his writing pertains to the American scene in a way indicative of his concern as a humanist. / Arts, Faculty of / English, Department of / Graduate

Both TPN- and DPN-linked isocitrate dehydrogenases have been identified in the thoracic muscle mitochondria from the face fly and the American cockroach. The DPN-linked enzyme from these two insects is closely related on the basis of chromatographic pattern. DPN-linked IDH has been isolated from face fly thoracic muscle mitochondria and purified 50-fold from the initial mitochondria acetone powder extract in good yield (22%). The enzyme may be stored without loss of activity as a suspension in 0.3 sat. (NH₄)₂SO₄ containing 20 mM potassium phosphate, pH 7.0, for three weeks at room temperature. It was found that the enzyme requires mg⁺⁺or Mn⁺⁺ for activity, but the optimal metal ion concentration depends upon the Mg⁺⁺ or Mn⁺⁺ to substrate ratio. The optimal stimulation effect of ADP on the enzyme activity was found to be 2 mM in correlation with the concentration of DPN⁺ (4mM), isocitrate (6mM), and Mg⁺⁺(6mM) . The pH optimum varied depending on the concentrations of the reaction cofactors involved. As a result, the activity of DPN-linked IDH is pH dependent. Kinetic studies on the forward reaction revealed several interesting properties of the DPN-linked IDH. At lower pH values, the stimulatory effect of ADP on the enzyme was observed to be less than at higher pH. It has been clarified in the text that in the presence of ADP, the maximal pH shifts slightly higher". The results indicate that the stimulation provided by ADP is not solely due to the amount of ADP which participates in the reaction but is rather controlled by H+ concentration in a specific fashion. The effect of pH on the activity of DPN-linked IDH is dependent on the concentrations of isocitrate and DPN+. The enzyme is inhibited by low concentration (0.16 mM) of p-chloromercuribenzoate. Comparative kinetic studies at pH 7.0 and 6.0 reveal that the enzyme is inhibited by the reaction products. With DPNH as the variable substrate, Lineweaver-Burk plots reveal a pattern of competitive inhibition for isocitrate. Furthermore, with a-ketoglutarate as the variable substrate, Lineweaver-Burk plots reveal a pattern of noncompetitive inhibition for both DPN and isocitrate. The reaction catalyzed by purified enzymes is inhibited by ATP and EDTA. DPN-linked IDH was activated by citrate. / Ph. D.

This dissertation deals with an analysis of impulsively loaded plastic plates that includes effects of large deformations and midplane forces. Specifically, it deals with a circular plate of uniform thickness simply supported at its edges. The impulsive loading is characterized by an initial velocity distribution. The analysis assumes that the plate is an isotropic, rigid, ideally plastic material. Shear deformations and longitudinal inertia are neglected. Both bending and midplane forces are considered. The midplane forces can be either applied prior to the impulse or generated by deformations of the midplane. Deformations of the cross section are based on the assumption that a line initially normal to the midplane remains straight and normal after deformation. Strains are nonlinear with respect to transverse displacements but contain only linear radial displacement terms. Finally, the Tresca yield criteria are used. An interaction equation is derived between the plastic moment and normal force. The relationship indicates that the greater the midplane force the smaller the required bending moment for plastic flow. When the midplane force reaches a maximum value, the plate no longer carries a moment. Equilibrium equations are derived for the motion of the plate which are consistent with the von Karman plate theory. Governing equations are then developed for the three possible phases of motion. The initial Phase 1 includes a bending hinge that travels from the support to the center of the plate. Phase 2, which is initiated when the hinge reaches the center, continues until either the motion ceases or a portion of the plate becomes a membrane. Phase 3 described the motion of the membrane hinge from its initial point of origin to its final stopping point. These governing equations are solved for two types of bending moment-midplane-force interaction relationships. One relationship is based on displacement of the neutral surface from the midplane surface. The second is based on the magnitude of the midplane forces. Both types of plastic plate behavior are examined. Plots of final central deformation for various applied midplane forces and impulses are presented that clearly illustrate that even small amounts of midplane forces have a significant effect on the final deformation of plastic plates. Numerical results of the large deformational analyses are also presented. Plots are given showing the influence of the magnitude of the impulse on bending hinge velocity, initiation of membrane behavior, location of the membrane hinge, and the final deformation of the plate. A comparison is made between results of the large deformational analysis and experimental data. It shows excellent agreement. For the small and intermediate range of impulses the agreement is within experimental scatter. For the large impulses the calculated deformations are slightly conservative. Reasons for this deviation are discussed. Finally a critical examination is made of the various other suggested approaches that have possible application to the behavior of plastic plates. / Ph. D.

The rates of penetration, metabolism, and excretion of DDT have been studied in vivo in resistant and susceptible strains of the German cockroach, Blattella germanica (L.). The cockroaches were exposed to various DDT treatments for intervals ranging from 3 to 72 hours. DDT and its metabolites were identified and quantitated in external, internal, and excreta fractions using gas-liquid chromatography. The identifications were verified by thin-layer chromatography. It has been shown that DDT penetration is nearly identical for the three cockroach strains used in this study (two resistant and one susceptible strain). For this reason penetration is not thought to be related to the DDT resistance mechanism in this insect. Susceptible and resistant cockroaches are both capable of converting DDT to dicofol which was the only metabolite observed. The conversion rate is somewhat faster in the resistant strains than in the susceptible strain but in no case exceeds 20% of the absorbed dose. Dicofol production reaches a maximum which is not exceeded in the presence of additional DDT. Female cockroaches of all three strains convert DDT to dicofol at a faster rate than their respective males. The inhibition of dicofol production by the synergist sesamex occurs at a high level in all strains, but results in mortality in the susceptible strain. Therefore, metabolism does not seem to be a major resistance mechanism. Excretion of unchanged DDT is apparently not related to the observed resistance levels. The excretion mechanism is, however, capable of removing much of the penetrated DDT provided the insect can survive the treatment. Excretion of DDT was consistently higher in male cockroaches than in females. The combined effects of the detoxication and excretion mechanisms are extremely efficient in removing penetrated DDT from this insect, particularly at higher treatment levels. Never-the-less, resistant cockroaches have and can apparently withstand much higher internal concentrations of DDT than susceptible cockroaches. The DDT-resistance mechanism of these cockroaches appears to be similar in nature to the unknown mechanism responsible for resistance to knockdown (Kdr) or paralysis by DDT in houseflies. This mechanism may alter the site of action of DDT and result in a reduced binding capacity of resistant insect nerve tissue for the DDT molecule as compared to susceptible insect nerve tissue. / Ph. D.

The minerals of the humite group have the formula nM₂SiO₄• M₁₋ₓTiₓ(OH₃F)₂₋₂ₓ0ₓ₂ where M is Mg, Fe, Mn, Ca, Zn in decreasing order of abundance, x < 1, and n=1 for norbergite, n=2 for chondrodite, n= 3 for humite, and n=4 for clinohumite. Description of the humites as alternating layers of forsterite (Mg₂SiO₄) and sellaite and/or brucite (MgF₂ and Mg(OH)₂) composition is incorrect because no layers with these compositions are present in the structure. The humites are structurally analogous to olivine in that both consist of a hexagonal close-packed array of anions (O, OH,F), zigzag chains of edge-sharing, M-filled octahedra and isolated Si04 tetrahedra. They differ from olivine in that none of the available tetrahedral sites coordinated by one or more OH or F anions is occupied by Si; this results in a stagger of the chains of octahedra. Substitution of Fe, Mn, and Ca for Mg has the same effect on the unit cell volume (normalized to half the mean anion-anion distance along the normal to (001)) in minerals with the humite structure as it does in minerals with the olivine structure. Fifty-five humite mineral samples have been analyzed by microprobe x-ray emission methods for F, Mg, Si, Ca, Ti, Mn, Fe, and Zn. Al, P, Cl, Cr, Co, Ni, Cu, and Pb were not detected by analysis or wavelength scanning at the less than 0.03 weight percent level. The OH⁻¹ concentrations were calculated using atomic proportions and assuming electro- static charge balance in the M₁₋ₓTiₓ(OH,F)₂₋₂ₓ0₂ₓ part of the formulae. Epitaxial intergrowths between members of the humite group have been predicted on the basis of their similar structures and wet chemical analyses. Most chemical analyses of humite minerals show substantial anion deficiencies which lead to non-stoichiometric Si:(OH + F + O_Ti) ratios; many also indicate non-stoichiometry in the olivine equivalent portion of the formula. In contrast, the microprobe analyses indicate that the humite minerals are stoichiometric. They also suggest that most bulk chemical analyses are deficient in H₂O and were made with material which contained minor amounts of other mineral impurities. Single crystal x-ray diffraction studies were made on nine microprobe analyzed humites to determine the effects of minor chemical substitution on the unit cell parameters. These studies show that the substitution of (Fe + Mn) for Mg increases the normalized cell volume; that Ti+ 2(O) for Mg + 2(OH,F) has little effect on the cell volume; and that (OH,F) + tetrahedral vacancies for 0 + Si results in a decrease in cell volume. / Ph. D.

The design, fabrication and operation of a split Hopkinson bar apparatus is described. The theoretical basis for the experimental determination of material properties for materials subjected to high compressive strain rates using the split Hopkinson bar is discussed along with the assumptions made and their meanings. Some preliminary results for a lucite material are used to illustrate the type of information obtained from using the method. Limitations of the method and conclusions are discussed and recommendations are made. / Master of Science

Theoretical analysis and comparison of three basic digital data communication systems, namely, amplitude-shift keying (ASK), frequency-shift keying (FSK), and phase-shift keying (PSK), for both binary coded and M-ary coded transmissions are presented in this paper. The analysis is limited to only nonfading received signal in additive Gaussian noise. Both coherent and noncoherent detection schemes are considered. A symbol error-rate or probability of error is used as the performance criterion for comparison purpose. / Master of Science