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Theses/Dissertations

1996

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Articles 1 - 30 of 311

Full-Text Articles in Life Sciences

Chemical Communication In House Mice (Mus Musculus): Can They Recognize Gender From The Anogenital, Harderian Gland Or Mouth/Nose Odor?, Dawn Michele Andrews Dec 1996

Chemical Communication In House Mice (Mus Musculus): Can They Recognize Gender From The Anogenital, Harderian Gland Or Mouth/Nose Odor?, Dawn Michele Andrews

Dissertations and Theses

Identifying the sensory systems animals employ to communicate chemically and the function of the chemical signals facilitates further understanding of chemical communication. Increased knowledge of how animals use the olfactory and vomeronasal systems in order to interpret the meaning of body odors will aid in developing a more detailed organization of chemosensory pathways. The message that each body odor contains can change from species to species. The purpose of this thesis was to study three previously untested body odors in house mice (M musculus) for their role in gender recognition of conspecifics. These odors are the anogenital (feces, urine, and ...


The Evaluation Of Two Types Of Multivariate Analyses Applied To Grassland Vegetation Data From A Reclaimed Coal Mine Area In Southeast Kansas, Usa, Karen Frances Yates Dec 1996

The Evaluation Of Two Types Of Multivariate Analyses Applied To Grassland Vegetation Data From A Reclaimed Coal Mine Area In Southeast Kansas, Usa, Karen Frances Yates

Electronic Thesis Collection

This study presents an analysis of the use of classification and ordination techniques for the detection of sub-communities at a reclaimed coal refuse dump and strip minded area in southeast Kansas. Cover values for 58 grass, forb, and woody species were estimated in 103 systematically positioned plots across the reclamation grassland using the modified Daubenmeyer cover scale. The data were submitted to an array of default and variant classification and ordination analysis programs in order to assess their ability to detect sub-communities. The classifications obtained from the analyses were mapped and analyzed for differences in species composition, diversity, and spatial ...


Comparison Of Forest Stand Edges In Riparian And Mesic Habitats Along Watts Bar Reservoir Shoreline, Ruth Anne Hanahan Dec 1996

Comparison Of Forest Stand Edges In Riparian And Mesic Habitats Along Watts Bar Reservoir Shoreline, Ruth Anne Hanahan

Masters Theses

Approximately fifty years ago, the landscape upslope from the natural, riverine position banks of the Tennessee River was inundated by the closing of Watts Bar Dam. On the currently forested shoreline, habitats within the direct influence of the reservoir pool are riparian. Those above that influence are mesic. The purpose of this research was to determine compositional and structural differences between edges of mature forest stands established in a riparian habitat and those established in a mesic habitat along Watts Bar Reservoir shoreline.

Thirty quadrats were placed on shoreline sites with mature, minimally-disturbed forest stands: 15 in a riparian habitat ...


Strength Properties Of Steam Exploded Laser Printed Papers, Dhamodharan Srinivasan Dec 1996

Strength Properties Of Steam Exploded Laser Printed Papers, Dhamodharan Srinivasan

Master's Theses

The mam objective of this study was to investigate the effect of steam explosion pulping on the strength properties of recycled fibers. The properties considered were zerospan tensile strength, tensile breaking length, tensile stretch, tensile energy absorption, scott bond and pentosan content. This study also examined the important operating parameters that affect the properties. Laser printed waste paper was pulped by the steam explosion process. The experiments were statistically modeled to cover the various process variables. Chemical addition, residence time, pressure, and dispersant level were varied during the steam explosion experiments. Chemical addition was kept at four levels and other ...


The Factors Affecting The Transfer Of Training Based On The Opportunity To Perform Trained Tasks, David Arnold Blair Dec 1996

The Factors Affecting The Transfer Of Training Based On The Opportunity To Perform Trained Tasks, David Arnold Blair

Doctoral Dissertations

The purpose of this study was to identify and define the factors that affect the transfer of newly learned skills to the job. One factor that has been shown to affect the transfer of training to the job is the extent to which the training participants are given the opportunity to perform trained tasks once they return to their jobs. The opportunity to perform was to consist of two dimensions: breadth and activity level.

Training participants from a government facility and their immediate supervisors (N = 74) responded to two different questionnaires which measured the three dimensions of the opportunity to ...


Mechanisms Of Carnitine-Mediated Modulation Of Aflatoxin B1-Dna Adduct Formation, Ayub Mohd Yatim Dec 1996

Mechanisms Of Carnitine-Mediated Modulation Of Aflatoxin B1-Dna Adduct Formation, Ayub Mohd Yatim

Doctoral Dissertations

The main purpose of this study was to investigate the possible mechanism(s) of L-carnitine-mediated modulation of AFB1-DNA adducts formation. The first part of the study investigated the effect of increased doses of carnitine on AFB1 binding to macromolecules, AFB1 uptake, activity of glutathione S-transferase (GST), and total glutathione concentrations in freshly isolated hepatocytes. Carnitine dose was significantly correlated with the formation of AFB1-DNA adduct ( r = -0.68;p = 0.0002 ), AFB1-protein adduct (r = 0.58;p = 0.017), but not AFB1-RNA adduct (r = 0.14;p = 0.604). There ...


Gross And Histological Features Of A Myofascial Trigger Point In The Upper Trapezius, Kathryn E. Levee Dec 1996

Gross And Histological Features Of A Myofascial Trigger Point In The Upper Trapezius, Kathryn E. Levee

Electronic Theses and Dissertations

The purpose of this study was to precisely locate, in living humans, a myofascial trigger point associated with the upper portion of the trapezius muscle (TrP1) that refers pain to the head and neck and to determine if this point is associated with anatomical structures. This study is descriptive and utilizes data from measurements of the location of TrP1 in relation to anatomical landmarks, of pressure sensitivity overlying the trigger point and electromyography recordings in localizing the trigger point. Information obtained from living humans was used to determine anatomical correlation to structures in cadavers. Results indicated there is little variability ...


The Effects Of Benzo(A)Pyrene And Dimethylbenzanthracene On Cultured Porcine Aortic Endothelial Function, Michelle Lynn Kagey Dec 1996

The Effects Of Benzo(A)Pyrene And Dimethylbenzanthracene On Cultured Porcine Aortic Endothelial Function, Michelle Lynn Kagey

Master's Theses

Polycyclic aromatic hydrocarbons are environmental contaminants which have been shown to initiate and promote atherosclerosis and carcinogenesis in various animal species. These findings have been based primarily on the increase in incidence and size of smooth muscle cell tumors in these animals were exposed to benzo(a)pyrene (BaP) or dimethylbenzanthracene (DMBA). The endothelium has also been identified as an important mediator in vascular disease and atherogenesis, although the endothelial response to these PAHs has not been investigated. Thus, the focus of this study was on characterization of the endothelial response to BaP and DMBA. Concentration/response relationships for these ...


Expression And Regulation Properties Of Pseudomonas L-Arabinose Utilization Plasmids, Mary E. Barecki Dec 1996

Expression And Regulation Properties Of Pseudomonas L-Arabinose Utilization Plasmids, Mary E. Barecki

Master's Theses

The L-arabinose utilization pathway in Pseudomonas fluorescens is a unique metabolic pathway. In Pseudomonas, L-arabinose is converted to the end product α-ketogluterate and does not involve phosphorylated intermediates. This differs from the well studied L-arabinose pathway found in Escherichia coli which contains phosphorylated intermediates.

The enzymes of the L-arabinose pathway have been shown to be induced in the presence of L-arabinose in P. saccharophila. The current study determined regulatory properties of previously cloned chromosomal fragments of P. fluorescens which confer an L-arabinose positive phenotype to the surrogate host, Pseudomonas putida. Cells of P. putida containing plasmids pPZ221, pPZ222, pPZ224, pPZ226 ...


Expression Of Α4Β1 Integrin On Tissue Eosinophils In The August Rat, John C. Phipps Dec 1996

Expression Of Α4Β1 Integrin On Tissue Eosinophils In The August Rat, John C. Phipps

Master's Theses

The integrin α4β1 is expressed on a wide variety of peripheral leukocytes, and functions in recruitment of these cells to sites of inflammaiton. We infected august (AUG) rats with the helminth parasite Nippostrongylus brasiliensis and later used leukocytes from the peritoneum of the sensitized animals and antibodies against α4β1 integrin to localize that adhesion molecule on the cell surfaces after antigen challenge. We found that after antigen challenge, eosinophils, monocytes, and small lymphocytes, but not mast cells, expressed α4β1 integrin if the animals had been previously infected, but cells from uninfected animals did not show expression of this molecule. Our ...


Characterization Of P39, A Borrelia Burgdorferi Specific Protein, Jill M. Troyer Oct 1996

Characterization Of P39, A Borrelia Burgdorferi Specific Protein, Jill M. Troyer

Theses and Dissertations in Biomedical Sciences

Borrelia burgdorferi, the causative agent of Lyme disease, expresses a species specific, 39 kiloDalton protein of unknown function called P39. This protein is highly immunogenic and the presence of anti-P39 antibodies in patient sera is used as an indicator of B. burgdorferi infection. P39 is also a candidate for vaccine developement due to conserved expression of P39 among B. burgdorferi isolates. Since little is presently known about this important molecule, the present study was designed to characterize P39 and was carried out in six separate investigations. First, infectious and noninfectious isolates of B. burgdorferi were established in vitro, and the ...


Spirit Resting Places: A Nature Reader, Martin T. Thompson Sep 1996

Spirit Resting Places: A Nature Reader, Martin T. Thompson

Master of Arts in Liberal Studies (MALS) Student Scholarship

When not involved in the matters of earning a living by teaching, I tramp the woods and fields to hunt or fish, or just to saunter through nature's mysterious beauty, and I read and write. That my writings embody reflections on my observations of the natural world is an extension of the self-discovery quest I have taken up. The pieces in this collection are mottled leafy pattern pieces that attempt to help me make sense of a life that began in rural Upstate New York. I was born and raised in the snow-belt region of Tug Hill, 15 miles ...


The Influence Of Fluorescent Light On The Development Of In Vitro Fertilized Bovine Oocytes, Jared Bunch Aug 1996

The Influence Of Fluorescent Light On The Development Of In Vitro Fertilized Bovine Oocytes, Jared Bunch

Undergraduate Honors Capstone Projects

Advances in in vitro fertilization and in vitro culture techniques have allowed considerable progress in identifying physiological requirements of mammalian embryos. Parrish et al. (11) reported a major breakthrough on in vitro fertilization when his group identified heparin as an important factor for the capacitation of spermatozoa. Capacitation is necessary for fertilization of matured oocytes. During the precoculture era of embryos (prior to 1980), the development of early preirnplantation embryos was vary limited regardless of medium, medium supplement, gas atmosphere, osmolarity or pH used (7). Coculture techniques of fertilized oocytes using somatic cells during in vitro production, particularly of bovine ...


Evaluation Of A Rapid-Screening Toxicity Test Using The Ciliate, Colpoda Inflata (Stokes): Sensitivity And Bioavailability To Model Compounds, Daria Galina Mochan Aug 1996

Evaluation Of A Rapid-Screening Toxicity Test Using The Ciliate, Colpoda Inflata (Stokes): Sensitivity And Bioavailability To Model Compounds, Daria Galina Mochan

Dissertations and Theses

Standard toxicity tests often require high costs for maintaining healthy cultures, so few test species are employed in routine ecotoxicological analysis. An alternative is the "battery of tests" approach involving using rapid toxicity tests for screening. Rapid-screening toxicity tests must display organism sensitivity, similarity in responses to other test organisms, relevancy to many circumstances, and repeatability. Protozoa are ideal candidates for rapid-screening bioassays. They are cosmopolitan, play important roles in ecosystems, and have high reproductive rates. Many protozoa can form a resting stage (cyst) that remains viable during adverse conditions, eliminating the need for maintaining continuous cultures for testing. The ...


Thermal Preference Of Spring And Fall Chinook Salmon (Oncorhynchus Tshawytscha) During Smoltification, Sally T. Sauter Aug 1996

Thermal Preference Of Spring And Fall Chinook Salmon (Oncorhynchus Tshawytscha) During Smoltification, Sally T. Sauter

Dissertations and Theses

Innate species-specific temperature preferences of fish are subjected to fluctuations under a variety of environmental, physiological, and developmental conditions. The temperature preference patterns of two ecologically distinct races of chinook salmon (Oncorhynchus tshawytscha) were investigated as laboratory held animals underwent smoltification. Smoltification is a distinct developmental stage in the life history of anadromous salmonids when juvenile fish undergo profound behavioral, morphological, and physiological differentiation prepatory to seawater entry. A group of spring and fall chinook salmon were held under identical conditions of increasing water temperature over the course of smoltification. Another group of spring and fall chinook salmon were held ...


The Effect Of Thyroid Hormone On The Expression Of A7 Myosin Heavy Chain Mrna In Xenopus Laevis, Bradley Thomas Butkovich Aug 1996

The Effect Of Thyroid Hormone On The Expression Of A7 Myosin Heavy Chain Mrna In Xenopus Laevis, Bradley Thomas Butkovich

Master's Theses

It has long been known that thyroid hormone (TH) is responsible for metamorphosis in tadpoles. It is also known that A7 MHC, an adult muscle isoform, is expressed in adult Xenopus laevis frogs, but not in larvae. Furthermore, the appearance of A7 corresponds with the onset of metamorphosis. The present study investigated the relationship between TH and the expression of A7 MHC mRNA in Xenopus laevis. Isolated tails in culture and 6-n-propyl 2-thiouracil (PTU) treated tails were treated with TH and the presence of A7 mRNA analyzed with in-situ hybridization, and RT-PCR. It was found that TH caused substantial regression ...


The Effects Of 2,4-Dichlorophenoxyacetic Acid On The Diazotrophic Soil Microbial Community, Denise M. Brown Aug 1996

The Effects Of 2,4-Dichlorophenoxyacetic Acid On The Diazotrophic Soil Microbial Community, Denise M. Brown

Master's Theses

This study measures the effects of 2,4- dichlorophenoxyacetic acid (2,4-D) on growth and nitrogen fixation capabilities of the native microbial soil community during eight field trials conducted over an eight month period. After application of 2,4-D, soil samples were analyzed for enumeration of diazotrophic and general microbial communities, and for nitrogenase activity as measured by the acetylene reduction assay (ARA). Statistical analyses were conducted using Minitab. Results show that 2,4-D significantly stimulated growth of diazotrophic microbes in 87.5% of the trials and was found to have a stimulatory growth effect on the general microbes in ...


Feasibility Of Stocking Grass Carp (Ctenopharyngodon Idella; Cyprinidae) To Control Hydrilla (Hydrilla Verticillata; Hydrocharitaceae) In Lake Anna, Virginia, Paul Matthew Overton Aug 1996

Feasibility Of Stocking Grass Carp (Ctenopharyngodon Idella; Cyprinidae) To Control Hydrilla (Hydrilla Verticillata; Hydrocharitaceae) In Lake Anna, Virginia, Paul Matthew Overton

Master's Theses

The goal of this study was to demonstrate the feasibility of using triploid ·Ctenopharvngodon idella (grass carp) to control Hydrilla verticillata in the Waste Heat Treatment Facility (WHTF) in Lake Anna, Virginia. The four objectives were to determine: the frequency of occurrences of grass carp over hydrilla; the proportions of hydrilla to other aquatic macrophytes in the guts of grass carp; effects of physical and chemical factors on movement of grass carp; and a theoretical stocking rate of grass carp for the WHTF. Frequency of occurrence of grass carp over hydrilla was calculated to be 84% and correlated with impoundment ...


Osteology, Morphology, And Female Choice In Species Of The Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro Barrella Aug 1996

Osteology, Morphology, And Female Choice In Species Of The Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro Barrella

Master's Theses

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the utility of different osteological and morphological characters for phylogenetic analyses was done using clear and double stained specimens and measurements of morphometric parameters respectively. Scanning electron microscopy was used to study the morphology of the egg chorion. Female choice tests were also conducted to test male traits that may be preferred by females. The osteological analysis showed that some characters previously unreported may be phylogenetically useful. Head scalation patterns were found to be intraspecifically variable, making them inappropriate to use in systematics. Each morphometric parameter ...


Effects Of Roads On Behavior And Survival Of Black Bears In Coastal North Carolina, David M. Brandenburg Aug 1996

Effects Of Roads On Behavior And Survival Of Black Bears In Coastal North Carolina, David M. Brandenburg

Masters Theses

I studied the effects of roads on the behavior and survival of black bears (Ursus americanus) at Marine Corps Base Camp Lejeune in Coastal North Carolina from May 1990 to December 1992. I used mark-recapture methods, radiotelemetry, and a Geographic Information System (GIS) for the study.

I estimated there were 16 bears on the study area in 1990. By 1992, the population likely was reduced to ≤6 bears (3.3 bears/100 km2), primarily from vehicle-kills. Since 1988, vehicle-kills accounted for 20 of 28 (71 %) of the total known mortality. The annual female survival rate was 71 % for female ...


Dietary Staus Index: Association With Food Groups And Body Mass Index In Rural East Tennessee Women Living In Public Housing, Linda Lou Knol Aug 1996

Dietary Staus Index: Association With Food Groups And Body Mass Index In Rural East Tennessee Women Living In Public Housing, Linda Lou Knol

Masters Theses

Dietary Status Index: Association with Food Groups and Body Mass

Index in Rural East Tennessee Women Living in Public Housing Objective: To determine if any differences existed in the number of servings per week consumed from designated food groups between women with low, medium or high Dietary Status Index (DSI) scores. Also, to determine if an association exists between Dietary Status Index (DSI) and Body Mass Index (BMI). DSI, a measure of both dietary adequacy and moderation, is the arithmetic mean of the Dietary Adequacy Score (DAS) and the Dietary Moderation Score (DMS).

Subjects: 121 non-pregnant females, 18 years or ...


The Flora And Ecology Of Seidman Park, Kent County, Michigan, Pamela J. Laureto Aug 1996

The Flora And Ecology Of Seidman Park, Kent County, Michigan, Pamela J. Laureto

Master's Theses

A floristic study of Seidman Park, Kent County, Michigan was performed. The study identified 521 vascular plants belonging to 96 families and 284 genera. The plant communities of Seidman Park were delimited by identification of dominant species and observation of the physical environment. It was believed that communities existed within the upland forest that could not be identified by observation alone. The use of Non-Metric Multidimensional Scaling (NMS) ordination techniques identified three communities within the upland forest. These were a xeric community, a dry-mesic community and a nutrient-rich community. Three sub-communities of the dry-mesic community were also identified.


Feeding Habits Of Juvenile Largemouth Bass Micropterus Salmoides (Lacepede), Thomas R. Goodwill Jul 1996

Feeding Habits Of Juvenile Largemouth Bass Micropterus Salmoides (Lacepede), Thomas R. Goodwill

Honors Theses

The stomachs of 110 juvenile largemouth bass, Micropterus salmoides (Lacepede) were examined to learn the early feeding habits of bass in a brackish environment. Bass were found to have five primary food sources: Taphromysis bowmani, Cloeon sp., Gammarus mucronatus, Micropterus salmoides, and Lepidophthalmus louisianum. Three feeding trends were observed during the course of the study. First, bass seemed to display prey selection. Second, bass length increased as prey size increased. Third, the types of prey eaten by the bass changed as the bass increased in size.


Characterization Of A Newly Cloned Dna Damage- Inducible Gene From Saccharomyces Cerevisiae Strain D43, June-Home Chen Jul 1996

Characterization Of A Newly Cloned Dna Damage- Inducible Gene From Saccharomyces Cerevisiae Strain D43, June-Home Chen

Master's Theses

The identification and characterization of DNA damage-inducible genes is an important topic in the study of the integrity of the cellular genome. Previously, a TnlO-lacZ derivative was inserted randomly into yeast cells and the resulting mutants were screened for insertions in DNA damage-inducible genes. S. cerevisiae strain D43 was identified as one such TnlO-lacZ insertion mutant. DNA sequencing results show the insertion in D43 is located within the TDH2 gene, which encodes glyceraldehyde-3-phosphate dehydrogenase. Treatment of strain D43 with DNA damaging agents and heat shock suggest TDH2 is responsive to DNA damage, but not to heat shock. Haploid mutants carrying ...


The Real Cost Of Beef: A Monetary Assessment Of The Environmental Degradation Caused By Beef Production, Carolyn Babcock Jul 1996

The Real Cost Of Beef: A Monetary Assessment Of The Environmental Degradation Caused By Beef Production, Carolyn Babcock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The environmental degradation caused by beef production is severe. The current literature assesses the ecological damage, but falls short of assigning a per pound dollar amount to reflect the real cost of beef. In the United States, most of the environmental focus has been centered around the use of public lands for grazing and the grazing fee the government considers appropriate. The fee covers the maintenance of the grazing program, which includes maintenance of the actual land. This paper will concentrate on beef-related environmental degradation and select specific damage for monetary valuation.


Lead Activation Of A Developmentally Regulated Calcium Channel In Rat Hippocampal Nerve Terminals, Troy E. Rhodes Jul 1996

Lead Activation Of A Developmentally Regulated Calcium Channel In Rat Hippocampal Nerve Terminals, Troy E. Rhodes

Theses and Dissertations in Biomedical Sciences

Low level lead (Pb2+) exposure may produce lasting deficits in learning and memory by altering calcium (Ca2+) dependent processes. Isolated presynaptic nerve terminals from rat hippocampus were loaded with the intracellular (Ca2+) indicator Fura-2. The changes in cytoplasmic free calcium ([Ca2+]i) were measured by stopped-flow fluorescence spectroscopy following depolarization with elevated potassium on a millisecond time scale (Lentzner et al., 1992). Depolarization promoted a rapid increase in Ca2+i which occured in two kinetically distinguishable phases: a fast component, representing the activity of rapidly inactivating Ca2+ channels (τ ~ 60 msec), and a slow ...


Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck Jul 1996

Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck

Community & Environmental Health Theses & Dissertations

The purpose of this study was to analyze the accuracy of FDA approved immunoassays for the detection of drug positive urine samples.

Federal civilian employees are tested under the strict protocol of the Department of Health and Human Services mandatory guidelines for federal workplace drug testing programs. The guidelines provide for a two instrument testing protocol for the analysis of urine samples. The first is an FDA approved immunoassay. Samples which test positive on this screening immunoassay are then submitted for confirmatory testing with the "gold standard" gas chromatography/mass spectrometry.

Agency monthly drug testing summaries, required under the DHHS ...


Neuronal Toxicity Of Humoral Factors From Patients With Diabetic Neuropathy And Mechanism Of Neuronal Death On Cultured Adrenergic Neurons: Studies Of Autoimmune Pathogenesis In Diabetic Neuropathy, Dong Liu Jul 1996

Neuronal Toxicity Of Humoral Factors From Patients With Diabetic Neuropathy And Mechanism Of Neuronal Death On Cultured Adrenergic Neurons: Studies Of Autoimmune Pathogenesis In Diabetic Neuropathy, Dong Liu

Theses and Dissertations in Biomedical Sciences

Diabetic neuropathy is an extremely common medical problem because of the high frequency of diabetes and its complications. Diabetic neuropathy consists of not one, but many patterns of nerve injury, each potentially with its own discrete pathogenic mechanisms. Evidence is accumulating that indicates autoimmunity plays a role in diabetic peripheral neuropathy. However, the significance of immunopathogenesis of diabetic neuropathy is as yet unclear.

Using the N1E-115 mouse neuroblastoma cell line (NB) as a model of the adrenergic autonomic neuron, we found that sera of IDDM patients with neuropathy inhibit growth and differentiation of adrenergic neurons in culture (Pittenger et al ...


An Account Of Expert Phylogenetic Tree Construction From The Problem-Solving Research Tradition In Science Education, Steven D. Brewer Jun 1996

An Account Of Expert Phylogenetic Tree Construction From The Problem-Solving Research Tradition In Science Education, Steven D. Brewer

Dissertations

Content knowledge, strategic knowledge, and forms of knowledge organization used in phylogenetic tree construction are described to account for expert performance. A literature review is used to situate this research with respect to studies of: (a) the teaching of evolution, (b) problem-solving expertise, (c) physics and biology problem solving, and (d) the practice of phylogenetic systematics. Rationales are provided for the development of a computer-based problem-solving environment, model problems, and research problems and methodology.

Each problem consisted of a matrix of coded and polarized phylogenetic data organized by taxa and characters. Four series of research problems were constructed that varied ...


The Factors Influencing Electrographic Toner Flotation, Udaykumar Ratilal Raval Jun 1996

The Factors Influencing Electrographic Toner Flotation, Udaykumar Ratilal Raval

Master's Theses

Conventional deinking is the process of removing the ink from usable paper fiber. Electrographic toners are hydrophobic in nature because they have negligible negative charge. A study of the effect of fundamental properties leading to electrographic toner flotation in presence of free fibers has not been reported.

Flotation deinking of fused "sharp" toner fraction below 300 micron in the presence of free fibers was performed in the Hallimond tube. Cationic (Dodecyltrimethyl ammonium bromide - DTAB) and anionic (Sodium dodecyl sulfate - SDS) surfactants having similar molecular weights were used at two concentration levels and two pH levels. The effect of surfactant concentration ...