• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • No language data
  • Tagged with
  • 367
  • 367
  • 367
  • 367
  • 367
  • 43
  • 21
  • 21
  • 18
  • 18
  • 17
  • 13
  • 13
  • 13
  • 13
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Investigation of the acid-catalyzed reactions of arylhydroxylamines

Hartzell, Stephen L. 03 June 2011 (has links)
AbstractEugen Bomberger's original work was concerned with the rearrangement of the substituted N-phenylhydroxylamines, but the mechanism responsible for the wide variety of products has remained unsettled.First, this investigation was concerned with a suitable synthesis for the substituted N-alkyl-N-phenylhydroxylamines. Secondly, a better understanding of the mechanism could be accomplished by the identification of the decomposition products and through a kinetic study of the rearrangement utilizing ultraviolet spectroscopy. The study was successful with the product identification of five decomposed substituted N-.phenylhydroxylamines, but numerous products, which interfered with the kinetic study, were isolated from the rearrangement and only uninterpretable kinetic data could be collected.Ball State UniversityMuncie, IN 47306
32

An investigation of hole mobility and recombination in n-type germanium between the temperatures of 299.5�K and 343�K

Littlepage, Samuel C. 03 June 2011 (has links)
AbstractThis thesis investigates the mobility and recombination of light injected electron holes as a function of temperature. In this study the n-type germanium samples were placed in potentials which varied from two to twenty-five volts and the temperature varied from just above room temperature to the point where the sample exhibited thermal runaway.In addition, this thesis contains a number of techniques which were developed to complete the general topic. The techniques were in the preparation of the germanium samples, the hole collection circuit, high intensity light sources of short duration, light pulse detectors, and temperature monitoring of a small sample.Ball State UniversityMuncie, IN 47306
33

A finite geometry of twenty-five points

Boven, Evelyn W. 03 June 2011 (has links)
AbstractThis thesis has taken an axiomatic system for a finite geometry with a five-point line, introduced definitions of various familiar figures and relationships, and determined properties of the figures in this system. Many of the theorems found herein are true in ordinary Euclidean geometry, but several interesting properties also arise in contrast to the usual.Given consideration in this development are properties of parallelism, perpendicularity, and congruence, in a study of lines, segments, triangles, and quadrilaterals. Also included in the presentation is an introduction to circles and parabolas.Ball State UniversityMuncie, IN 47306
34

A herpetological survey of the Indiana dry prairies

Morris, Larry J. 03 June 2011 (has links)
In 1934 the region now known as the Jasper-Pulaski State Fish and Game Area was the subject of a herpetological survey by Major Chapman Grant. This has been the only study directed toward the sand prairie herpetofauna. A reinvestigation of the area seemed worthwhile, and a survey was conducted from April 1, 1971, to October 30, 1971.There seems to have been less change in the amphibian population then in that of the reptiles. One notable exception is Fowler’s Toad, which Grant did not believe to occur at Jasper-Pulaski but which is now very common, while the American Toad is much rarer.The turtle population has changed noticeably. The Mud Turtle and the Spotted Turtle seem to have disappeared.There also have been several changes in the snake population. Grant did not find the Bullsnake at Jasper-Pulaski but did report the Fox Snake as being very common. Now the reverse seems true. The Smooth Green Snake has now become very rare. The Northern Water Snake is apparently now much more abundant.In 1971, a total of thirty species of amphibians and reptiles was recorded in the area: three salamanders, eight frogs and toads, eight turtles, two lizards and nine snakes.Ball State UniversityMuncie, IN 47306
35

Relationship between an antepartum increase in knowledge of breastfeeding and attemps to breatfeed after parturition

Roepke, Judith Lomer 03 June 2011 (has links)
This thesis attempted to determine whether there was a relationship between an antepartum increase in knowledge of breastfeeding and women's choice to breastfeed after parturition. A group of women of low social class was given instruction about breastfeeding in three forty-five minute sessions during the last four months of pregnancy. Data, concerning the number of women who chose to breastfeed, were collected from the group that was given the information and from the group that was not given information. The data were analyzed statistically. The Chi Square test was applied to the data to determine whether there was any relationship between the giving of instruction about breastfeeding and the mothers' choices to breastfeed. Though more mothers in the experimental group did choose to breastfeed than in the control group, the relationship between the giving of instruction and the choice to breastfeed was not significant, according to statistical analysis.Ball State UniversityMuncie, IN 47306
36

Histochemical and ultrastructural characterization of silk glands in larval caddisflies Insecta, Trichoptera

Perry, Michael Gleason 03 June 2011 (has links)
Larvae of Cheumatopsyche analis and Hydropsyche betteni produce a water soluable silk fiber in an aquatic environment. Study of the morpholocial characteristics of the silk gland cells would provide valuable information of where the components of the fiber and associated adhesive secretions are produced and preliminary data on their chemical composition. The silk glands of Cheumatopsyche analis and Hydropsyche betteni were examined with specific histochemical stains for lipids, proteins, nucleic acids, mucopolysaccharides and carbohydrates. Whole mounts indicate a high degree of polymorphism of the nuclei throughout the gland. In both Cheumatopsyche analis and Hydropsyche betteni typical cellular organelles, invaginating plasma membranes and microvilli are present. Serial sections indicate immediate deposit of both fiber and adhesive secretions beginning at the blind end of the gland and continues proximally through the "manufacturing" portion to the "excretory" portion.The highly proteinaceous fiber demonstrates a lack of acid mucopolysaccharides and a prevalance of carbohydrates and some polymers containing glucose, galactose and/or glucosamine. The adhesive secretion in the "manufacturing" portion is a homogenous layer surrounding the fiber. It is comprized of large amounts of carbohydrates, mucopolysaccharides and a small amount of glycoprotein which increases slightly as it followed proximally. Light staining vacuoles of similar characteristics to the fiber punctuate the coating adhesive layer and to be continuous with the fiber. In the "excretory" portion the coating adhesive layer is not found. Fiber staining intensifies greatly and similar characteristics of the adhesive section are assumed by the fiber. Cells of this portion have long microvilli and demonstrate bands of carbohydrate and mucopolysaccharides within the cytoplasm. Possible material absorbtion is indicated.Ball State UniversityMuncie, IN 47306
37

Variation in the territorial song of the field sparrow

Carnes, Ann Julayne 03 June 2011 (has links)
The territorial song of the Field Sparrow, Spizella pusilla, was studied to determine if variations occur. Tape recordings were graphed by the use of a frequency to voltage converter and a pen recorder. Graphs were analyzed according to length of song, number of notes, length of second and last notes, frequency change, type of slurring, frequency range of song, and number of song patterns.The Field Sparrow was found to have a simple song, characterized by introductory notes followed by a trill. The song is of short duration, mean length was 2.7671 seconds, and the frequency range was between 3,000-5,500 Hz.Little variation was found to occur. Successive songs given by an individual indicated some variation. However, the nature of this variation was principally in number of notes and length of successive songs. All except two individuals were found to possess only one song pattern. Comparison of song patterns from one individual to another revealed considerable similarity. A cline in voice variation in the Field Sparrow is not indicated by the limited data available to this present study.Ball State UniversityMuncie, IN 47306
38

The use of an automatic controlled gain amphifier in nuclear lifetime measurements

Parvizi, Behram 03 June 2011 (has links)
In this study a unique pulse amplifier, with automatic controlled gain, was used to measure nuclear lifetimes. The significance of this circuit is that it reduces the spread in pulse amplitudes of those pulses selected by Ge(Li) and NaI(Tl) detectors from a single channel analyzer. In the first part of this study a coincidence circuit composed of an Ortec module with Ge(Li) and NaI(Tl) detectors was utilized. The coincidence curves of two different sources, 22Na (0.511 MeV from positron annihilation) and 133Ba (0.081-MeV excited state), were recorded by a multichannel analyzer. In the second part of this research the unique pulse amplifier was added to the original coincidence circuit. The coincidence curve of the two sources was again recorded, and comparison of the two methods was made. A twenty five percent improvement in time resolution for 22Na and a twenty percent improvement for 133Na was achieved.Ball State UniversityMuncie, IN 47306
39

Methods of educating the nursing mother

Peterson, John C. 03 June 2011 (has links)
AbstractThis study compared breast-feeding success rates for nursing mothers from three different population groups: (1) those with no medically supervised education, (2) those with exposure to supportive medical staff and to a patient education handout on breast-feeding, and (3) those with exposure to the handout and to a videotape on breast-feeding shown in the hospital during the first few days postpartum. Success was defined as using breast milk as the primary means of infant nutrition at five to six weeks postpartum. It was found that educating mothers in an organized fashion significantly improves success rates over that seen when organized patient education was not offered (p<.001). The group educated by postpartum videotapes tended to do better than the group educated by only patient education handouts and interested medical staff. This relationship was not significant at the .05 level (.05<p<.10), but was strong enough to warrant further investigation. Lack of correct information was related to all of the reasons for not breast-feeding and for prematurely stopping breast-feeding.Honors CollegeBall State UniversityMuncie, IN 47306
40

Investigation of bacterial mouth flora of Ball State University students

Langona, Michael R. 03 June 2011 (has links)
The occurrence of pathogenic and non-pathogenic bacteria isolated from the throats of Ball State University students was investigated in a surveillance study utilizing weekly throat swabbings. The reference population was divided into three groups: the control; semi-control; and experimental groups respectively. The experimental group was exposed to numerous bacterial pathogens and non-pathogens biweekly during one academic quarter. The objective of the study was to determine if the throat flora of an individual within the experimental group underwent colonial changes in relation to the bacterial organisms the individual was exposed to. The results of the study indicate that bacterial colonial changes did not occur within the throat region following bacterial exposure.Ball State UniversityMuncie, IN 47306

Page generated in 0.1104 seconds