• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 172
  • 113
  • 18
  • 15
  • 13
  • 11
  • 8
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 5
  • 5
  • Tagged with
  • 461
  • 461
  • 76
  • 66
  • 60
  • 58
  • 50
  • 47
  • 43
  • 41
  • 38
  • 35
  • 34
  • 34
  • 34
  • 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.
151

A Metal-Analysis and Risk Assessment of Heavy Metal Uptake in Common Garden Vegetables

LeCoultre, T. D., Scheuerman, Phillip R. 01 January 2001 (has links)
No description available.
152

Survey of Double Bass Drumming: History, Technique, and Performance Practice

January 2019 (has links)
abstract: Double bass drumming is a genre of drum set performance that utilizes a bass drum pedal for both the right and left feet. This allows the feet to function much like the hands, and provides the ability to play faster rhythmic passages on the bass drum that would otherwise be impossible in the classic single-pedal arrangement. The feet are then elevated to new levels of importance, which creates new challenges in four-limb coordination. This double bass drumming tradition has been in use since the mid-20th century, and it has become extremely popular since that time. Today, virtually every drum set retailer offers the double bass pedal as part of their inventory. Many large drum solo competitions, such as the Guitar Center Drum-Off, also include a double bass pedal as part of the provided drum set. However, even with this recent growth in popularity of double bass drumming, there remains a significant lack of scholarly research on the topic. This could be due to the popularity of double bass drumming remaining fairly new, and that the primary implementation of this drumming style remains outside of the art music tradition. This document will help further bring this complex drumming tradition to light by providing an in-depth analysis of the double-bass drumming style through historical overview, explanation of various technical approaches and considerations, and an analysis of common double bass drumming performance practice. / Dissertation/Thesis / Doctoral Dissertation Music 2019
153

Heavy metal ion resistance and bioremediation capacities of bacterial strains isolated from an antimony mine

Sekhula, Koena Sinah January 2005 (has links)
Thesis (M.Sc. (Biochemistry)) --University of Limpopo, 2005 / Refer to document
154

Känsla för metal : Att gestalta känslor med hjälp av symphonic metal

Lindgren, Mats January 2015 (has links)
Syftet med det här arbetet var att gestalta fem olika känslor inom genren symphonic metal. Därigenom ville jag avgöra vilka verktyg jag kunde ha nytta av i framtiden för att gestalta känslor musikaliskt och vilka skillnader som finns mellan att gestalta olika känslor. För att göra detta använde jag mig av referenslyssning av tio låtar plus några orkestrala stycken per känsla. Resultatet av lyssningen, tillsammans med olika låtskrivningstekniker, litteratur, Kirnbergers intervallkaraktäristik och Matthesons tonartskaraktäristik, användes till att skriva och arrangera mina fem låtar.   Resultatet blev att jag hade lyckats skildra känslorna bra med den metod jag hade använt, men att intervallkaraktäristiken och tonartskaraktäristiken var onödiga; det skulle räcka med mina kunskaper som jag hade förvärvat under utbildningen, referenslyssning och min känsla som låtskrivare. Jag kunde inte heller urskilja några skillnader mellan att gestalta de olika känslorna; metoden var universellt tillämplig.
155

Exploring and analyzing omics using bioinformatics tools and techniques

Parida, Mrutyunjaya 01 May 2018 (has links)
During the Human Genome Project the first hundred billion bases were sequenced in four years, however, the second hundred billion bases were sequenced in four months (NHGRI, 2013). As efforts were made to improve every aspect of sequencing in this project, cost became inversely proportional to the speed (NHGRI, 2013). Human Genome Project ended in April 2003 but research in faster and cheaper ways to sequence the DNA is active to date (NHGRI, 2013). On the one hand, these advancements have allowed the convenient and unbiased generation and interrogation of a variety of omics datasets; on the other hand, they have substantially contributed towards the ever-increasing size of biological data. Therefore, informatics techniques are indispensable tools in the field of biology and medicine due to their ability to efficiently store and probe large datasets. Bioinformatics is a specialized domain under informatics that focusses on biological data storage, organization and analysis (NHGRI, 2013). Here, I have applied informatics approaches such as database designing and web development in the context of biological datasets or bioinformatics, to create a novel web-based resource that allows users to explore the comprehensive transcriptome of common aquatic tunicate named Oikopleura dioica (O .dioica), and access their associated annotations across key developmental time points, conveniently. This unique resource will substantially contribute towards studies on development, evolution and genetics of chordates using O. dioica as a model. Mendelian or single-gene disorders such as cystic fibrosis, sickle-cell anemia, Huntington’s disease, and Rett’s syndrome run across generations in families (Chial, 2008). Allelic variations associated with Mendelian disorders primarily reside in the protein-coding regions of the genome, collectively called an exome (Stenson et al., 2009). Therefore, sequencing of exome rather than whole genome is an efficient and practical approach to discover etiologic variants in our genome (Bamshad et al., 2011). Renal agenesis (RA) is a severe form of congenital anomalies of the kidney and urinary tract (CAKUT) where children are born with one (unilateral renal agenesis) or no kidneys (bilateral renal agenesis) (Brophy et al., 2017; Yalavarthy & Parikh, 2003). In this study, we have applied exome-sequencing technique to selective human patients in a renal agenesis (RA) pedigree that followed a Mendelian mode of disease transmission. Exome sequencing and molecular techniques combined with my bioinformatics analysis has led to the discovery of a novel RA gene called GREB1L (Brophy et al., 2017). In this study, we have successfully demonstrated the validation of exome sequencing and bioinformatics techniques to narrow down disease-associated mutations in human genome. Additionally, the results from this study has substantially contributed towards understanding the molecular basis of CAKUT. Discovery of novel etiologic variants will enhance our understanding of human diseases and development. High-throughput sequencing technique called RNA-Seq has revolutionized the field of transcriptome analysis (Z. Wang, Gerstein, & Snyder, 2009). Concisely, a library of cDNA is prepared from a RNA sample using an enzyme called reverse transcriptase (Nottingham et al., 2016). Next, the cDNA is fragmented, sequenced using a sequencing platform of choice and mapped to a reference genome, assembled transcriptome, or assembled de novo to generate a transcriptome (Grabherr et al., 2011; Nottingham et al., 2016). Mapping allows detection of high-resolution transcript boundaries, quantification of transcript expression and identification of novel transcripts in the genome. We have applied RNA-Seq to analyze the gene expression patterns in water flea otherwise known as D. pulex to work out the genetic details underlying heavy metal induced stress (unpublished) and predator induced phenotypic plasticity (PIPP) (Rozenberg et al., 2015), independently. My bioinformatics analysis of the RNA-Seq data has facilitated the discovery of key biological processes participating in metal induced stress response and predator induced defense mechanisms in D. pulex. These studies are great additions to the field of ecotoxicogenomics, phenotypic plasticity and have aided us in gaining mechanistic insight into the impact of toxicant and predator exposure on D. pulex at a bimolecular level.
156

Evaluation of Total Fume and Heavy Metal Emission Factors Applicable to Gas Metal Arc Welding

Jilla, Abhinay 23 May 2019 (has links)
Welding is a metal joining process widely used in many manufacturing facilities around the world. It involves the process of heating the base and filler metals to a high temperature that leads to the formation of fumes. Welding emissions consist of gaseous pollutants and micron and sub-micron particles consisting of different heavy metals. Health risks associated with exposures to weld fume is well recognized in the literature. This research evaluates emissions and emission factors applicable to gas metal arc welding (GMAW) on AH 36 (mild steel) and 316 L (stainless steel). Emission factors evaluated consisted, total fume, chromium, cobalt, lead, manganese, and nickel. A weld fume chamber is used to capture the welding fumes onto a filter and then further analyzed to quantify the total fume and heavy metal emissions. Critical operating parameters such as current, voltage, shielding gas, welding speed, and contact tube to work distance (CTWD) were considered while evaluating emissions and emission factors. The parameters with greater influence on emissions are selected, and then the heavy metal emissions are quantified by varying those parameters using inductively coupled plasma atomic emission spectrometry (ICP-AES) and portable XRF (X-Ray Fluorescence) analyzer. The heavy metal results from the ICP-AES and XRF are compared to explore the feasibility of using XRF analyzer in quantifying the heavy metals in welding fumes. Using the heavy metal emissions, the lifetime carcinogenic and non-carcinogenic risks are evaluated for the GMAW process. The mild steel (MS) and stainless steel (SS) statistical analysis results indicate current and voltage are most influencing parameters in generating the fumes in GMAW. This research found a significant linear relationship between ICP-AES and XRF heavy metal results. The lifetime carcinogenic and non-carcinogenic risks results indicate high potential health risks if not properly managed.
157

Distribution of Heavy Metals and Trace Elements in Soils of Southwest Oregon

Khandoker, Rafiqul Alam 23 April 1997 (has links)
Soil samples from 118 sites on 71 geologic units in southwest Oregon were collected and analyzed to determine the background concentrations of metals in soils of the region. Sites were chosen in areas that were relatively undisturbed by human activities. The U.S. Environmental Protection Agency approved total-recoverable method was used to recover metals from samples for analysis. The twenty six metals analyzed were: Ag, AI, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Tl, V and Zn. The Klamath Mountains followed by the Coast Range contain the highest soil concentrations of AI, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, V and Zn. Soils of the Coastal Plain and High Lava Plains contain the lowest concentrations of these metals. Unusually high soil As concentrations are found at two sites in the Klamath Mountains. All Be and Cd values above laboratory's reporting limits are also from the Klamath Mountains and Coast Range. Concentrations of soil Ba and La are fairly uniform throughout the region. Soil Pb levels are generally low with a few exceptions in the Klamath Mountains, Coast and Cascade Ranges. The region west of the Cascade Range has higher soil Hg contents than in the east. Soil metal concentrations are generally much higher in the region west of the Cascade Range, excluding the Coastal Plain, than in the east with the exception ofNa, because of more ultramafic rocks and a wetter climate. Soil metal concentrations are directly related to soil development with the highest concentrations being found in well developed Alfisols and Ultisols and the lowest concentrations in poorly developed Entisols. Most metals have similar averages and ranges of concentration compared to the rest of the United States (U.S.). Metals with high values compared to the rest of the U.S. are Cr, Co, Cu, Mn and Ni. In general, AI, Co, Cr, Cu, Fe, La, Li, Mg, Na, Ni, and V are concentrated in the B horizon while Ba, Ca, Hg, K, Mn, Pb and Zn are concentrated in the A horizon.
158

Fe(II)-catalyzed transformation of ferrihydrite associated with natural organic matter

Zhou, Zhe 01 December 2018 (has links)
The association between natural organic matter (NOM) and iron (Fe) minerals was widely found in soil and sediments and has been shown to impact the fate of Fe minerals and NOM. Ferrihydrite, a ubiquitous Fe mineral, serves as important sink for NOM and rapidly transforms to secondary Fe minerals in the presence of Fe(II). The associated NOM has been found to influence the Fe(II)-catalyzed ferrihydrite transformation pathway, but it remains unclear how various NOM affects this transformation and the implication. This study specifically investigates how different species of NOM affect Fe(II)-catalyzed ferrihydrite transformation under different C/Fe ratios. A series of Fe isotope tracer experiments were conducted to measure Fe atom exchange and electron transfer between aqueous Fe(II) and ferrihydrite in the presence of diverse NOM species. The fate of Ni during Fe(II)-catalyzed transformation of NOM-Fh coprecipitate was also investigated. Ferrihydrite was found less susceptible to Fe(II)-catalyzed transformation with increasing C/Fe ratio and fulvic acids and Suwannee River NOM (SRNOM) in the coprecipitates need lower C/Fe ratio than humic acids to completely inhibit formation of secondary Fe minerals. At C/Fe ratios where ferrihydrite transformed to secondary minerals, goethite was dominant in ferrihydrite coprecipitated with humic acids, whereas lepidocrocite was favored in ferrihydrite coprecipitated with fulvic acids and SRNOM. Adsorbed SRNOM may be more inhibitive than coprecipitated SRNOM on Fe(II)-catalyzed ferrihydrite transformation under similar C/Fe ratios. Despite no secondary mineral transformation at high C/Fe ratios, Mössbauer spectra indicated electron transfer still occurred between Fe(II) and ferrihydrite coprecipitated with fulvic acid and SRNOM. In addition, isotope tracer experiments revealed that a significant fraction of structural Fe(III) in the ferrihydrite mixed with the aqueous phase Fe(II) (~85%). After reaction with Fe(II), Mössbauer spectroscopy indicated some subtle changes in the crystallinity, particle size or particle interactions in the coprecipitate. The effect of coprecipitated SRNOM on Ni(II) distribution during Fe(II)-catalyzed ferrihydrite transformation was investigated with adsorbed Ni(II) and coprecipitated Ni(II). Ni(II) adsorbed on ferrihydrite was more resistant to acid extraction after Fe(II)-catalyzed transformation and suggested that structural incorporation of Ni into secondary Fe minerals occurred. With coprecipitated SRNOM, ferrihydrite did not transform to secondary minerals in the presence of Fe(II) but extensive Fe atom exchange between aqueous Fe(II) and structural Fe(III) still occurred. Limited change in Ni stability was observed, suggesting there was only small portion of Ni redistributed in the presence of Fe(II). Pre-incorporated Ni(II) in Ni-SRNOM-Fh coprecipitate was partially released (6-8 %) in the presence of Fe(II), but the distribution of remaining Ni(II) in the solid did not change measurably. Our observation suggests that the presence of SRNOM limited the redistribution of Ni most likely because of limited transformation of ferrihydrite to secondary minerals.
159

Simultaneous mobilization of polychlorinated biphenyl compounds and heavy metals from a field contaminated soil

Ehsan, Sadia. January 2006 (has links)
No description available.
160

Modeling surface complexation relationships in forest and agricultural soil

Taillon, Kate January 2005 (has links)
No description available.

Page generated in 0.0409 seconds