1 |
Impact of Municipal Water Characteristics on Corrosion of Steel and Copper PipingPrasad, Harsha 28 April 2016 (has links)
This research evaluated corrosion and scale deposition in steel and copper pipe sections from apartment complexes located in Rhode Island (RI), Massachusetts (MA), and Maryland (MD). Piping samples from these locations had corroded at an accelerated rate and consisted of HVAC piping, and domestic copper pipes. Pipes were analyzed by scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) to quantify the elemental composition of the samples. The water chemistry of each system was compared to the elemental data to determine correlations. Particular elements from the EDS analysis in comparison to the water quality parameters, Langelier Saturation Index, and Larson Skold indices exhibited inverse and direct correlations. The deposition of corrosion product and scales occurred in all systems that had implemented corrosion control in the form of pH adjustment and inhibitors to prevent infrastructure degradation. Although measures were taken to prevent corrosion, the current practices were not effective at the current dosing rate showing that the municipalities could consider other options such phosphate blend inhibitors and lime as effective corrosion control mechanisms.
|
2 |
Análise de Resíduo de Disparo de Armas de Fogo Utilizando ICP-MS: Caracterização de Munições Limpas.COSTA, R. A. 29 September 2016 (has links)
Made available in DSpace on 2018-08-01T21:58:45Z (GMT). No. of bitstreams: 1
tese_10255_Rayana Alvarenga Costa.pdf: 3195656 bytes, checksum: 244f9112e799add76c1a8840cbe40dce (MD5)
Previous issue date: 2016-09-29 / Tendo em vista a forte relação entre os crimes de homicídio e o uso de armas de fogo no Brasil, a Balística Forense tem como importante ferramenta a detecção de resíduos originados por disparo de armas de fogo (GSR - GunShot Residues) nas mãos de um suspeito, contribuindo para determinação da autoria de um disparo. Dentre os tipos de munições existentes, a munição limpa foi desenvolvida na última década para minimizar a exposição dos atiradores ao chumbo (Pb), visto que em munições convencionais este elemento, bem como o Ba e Sb se apresentam em concentrações significativas. Estudos mostram dificuldades na detecção de GSR de munição limpa por espectroscopia de energia dispersiva acoplado a microscopia eletrônica de varredura (MEV/EDS) e teste residuográfico. Técnicas analíticas modernas como a espectrometria de massas com plasma indutivamente acoplado (ICP-MS) vem sendo utilizada como uma análise rápida para a detecção de elementos químicos presentes nos GSR, por apresentar alta sensibilidade, seletividade e caráter multielementar. Desta forma, o objetivo deste trabalho foi avaliar a aplicabilidade da técnica da ICP-MS para quantificar os GSR advindos de munições limpas ou clean range ammunition ou non toxic ammunition utilizando pistola calibre .40 e revólver calibre .38 em função do número de disparos (n = 1-7 e n = 1-5, respectivamente). Os GSR foram coletados nas regiões da pinça-palmar e pinça-dorsal, sendo avaliadas sobre ambas as mãos (direita e esquerda). Os resultados obtidos foram comparados com técnicas clássicas dentro da balística forense: ensaio colorimétrico usando rodizonato de sódio e MEV/EDS. Resultados negativos foram observados para Pb e Ba usando o teste residuográfico para análise de GSR de munições limpas, até 7 disparos. Já a análise por MEV/EDS foi realizada no GSR produzido a partir de n = 7 (pistola calibre .40) e n = 5 (revólver .38) de munição limpa. As fotomicrográficas mostraram que o GSR produzido a partir da munição limpa não apresenta morfologia definida como os do GSR de munição convencional. Além disso, os resultados de EDS identificaram principalmente elementos como C, O, K, Al, S, Si, Cu, Zn, Ti, Cr, Cl, Mo, Sr e Fe. Diferente dos métodos convencionais, a técnica de ICP-MS mostrou resultado positivo para Pb, Ba e Sb com concentração máxima de 2,64 (±0,60) μg∙L-1, 10,9 (±5,44) μg∙L-1 e 0,12 (±0,02) μg∙L-1 para pistola .40 e 4,59 (±1,8) μg∙L-1, 1,95 (±1,1) μg∙L-1, 0,10 (±0,07) μg∙L-1 para revólver .38. Além deles, elementos como Al, Ti, Cr, Mo, Cu, Zn e Sr foram também detectados nos GSR de munições limpas. Observou-se que com o aumento do número de disparos houve o aumento da concentração de todos os elementos investigados e sugere-se que Al, Sr, Zn e Cu possam vir a ser utilizados como novos marcadores de GSR para munições limpas. Portanto, a técnica ICP-MS apresentou resultados promissores e mostrou-se adequada para a análise de GSR de munições limpas
|
3 |
Sp2 Bonded Carbon for Soft X-Ray Detector WindowsRowley, Joseph T. 07 January 2021 (has links)
Energy Dispersive X-Ray Spectroscopy (EDS) is a technique used to analyze materials to determine their elemental makeup. This technique is used extensively in the semiconductor industry, metallurgical industry, biology, chemistry, materials science, and other fields. EDS detectors are often attached to scanning electron microscopes (SEM) or transmission electron microscopes (TEM) and are actively cooled by liquid nitrogen or Peltier devices. A thin membrane, or window, is fitted to the front of the detector which allows for an airtight seal as well as transmission of x-rays. The challenge for these windows is maximizing the transmission of x-rays while maintaining mechanical integrity. Carbon is an element with a low atomic number and has several allotropes that have attributes desirable for an x-ray window. Amorphous carbon has good chemical resistance as well as being able to be sputtered, a low temperature process. Sputtered amorphous carbon is characterized in this work, including sputtered amorphous carbon that is used as part of x-ray windows. Part of this characterization involved using bulge testing. A bulge testing device was created at BYU and this is presented here. Additionally, this device was used to characterize thin films as part of this work. Graphene is a single layer of sp2 bonded carbon atoms in a plane. It is one of the stiffest materials known, as well as having an extremely high tensile strength (> 200 times steel). Single layer graphene has not been able to span the dimensions needed for use in a detector window, but many-layer graphene (MLG, a film with > 10 stacked layers of graphene) has been shown to span mm size openings. Many-layer graphene films were grown using chemical vapor deposition (CVD) on nickel substrates and suspended over different sized openings as well as on a silicon support structure. A description of synthesis and characterization of these films are presented here. Also presented is additional work to improve the fabrication of these MLG films by developing improved nickel substrate surfaces.
|
4 |
ELECTROSPUN ALUMINA FIBERS:SYNTHESIS AND CHARACTERIZATIONTuttle, Richard W. January 2006 (has links)
No description available.
|
5 |
Non-vascular Ehlers-Danlos Syndrome and Pregnancy: What are the Risks?Sondergaard, Krista A. 27 August 2012 (has links)
No description available.
|
6 |
Avaliação da composição elementar de filmes finos de ligas metálicas depositados por Arco Catódico Filtrado em Vácuo utilizando RBS e EDS quantitativo / Evaluation of the elemental composition of alloy thin films deposited by Filtered Cathodic Vacuum Arc using RBS and quantitative EDS analysisOblitas, Raissa Lima de 26 September 2016 (has links)
Devido à relevância de filmes finos, as técnicas que são utilizadas para produzi-los e também para caracteriza-los tem se tornado importante. Neste contexto, foram analisados filmes finos de até 100 nm, de duas ligas metálicas (cromel e alumel), obtidos a partir da deposição por plasma de Arco Catódico Filtrado em Vácuo (Filtered Cathodic Vacuum Arc - FCVA). O objetivo deste projeto foi avaliar a similaridade em composição elementar entre os materiais utilizados para deposição, que operam como cátodos, e os filmes finos depositados, a partir de medições obtidas pela técnica de microanálise quantitativa Energy Dispersive Spectroscopy (EDS). Para comparação entre resultados e apreciação de compatibilidade, foi realizada avaliação estatística considerando o Teste t, no qual a estatística do teste é dada pela Distribuição t de Student, adotando nível de significância de 5%. Os valores obtidos por EDS Quantitativo para os cátodos foram de (em wt%) (90,3 ± 0,5)% de Ni e (9,72 ± 0,19)% de Cr para o cromel e (95,1 ± 0,8)% de Ni, (2,02 ± 0,14)% de Mn, (1,65 ± 0,04)% de Si e (1,15 ± 0,05)% de Al para o alumel. Já para os filmes finos, foram de (90,2 ± 0,5)% de Ni e (9,8 ± 0,5)% de Cr para o cromel e (95,2 ± 0,4)% de Ni, (2,8 ± 0,4)% de Mn, (0,77 ± 0,17)% de Si e (1,08 ± 0,09)% de Al para o Alumel, ambos apresentando compatibilidade com as medidas por Rutherford Backscattering Spectrometry (RBS) - técnica comumente utilizada para este tipo de espécime. Verificou-se que a composição elementar do filme fino de cromel não apresentou diferença significativa com o cátodo da mesma liga. Entretanto, para o filme fino de alumel, houve evidências de diferença significativa com relação ao cátodo, apontada pelo elemento silício. / Due the relevance of thin films, the techniques used to produce and also to characterize them has become important. In this context, it was analyzed thin films up to 100 nm of two alloys (Chromel and Alumel) obtained by plasma deposition using Filtered Cathodic Vacuum Arc (FCVA). The objective of this project was to evaluate the similarity in elemental concentration of the materials used for deposition, which act as cathodes, and the deposited thin films, through measurements obtained by quantitative microanalysis technique Energy Dispersive Spectroscopy (EDS). In order to compare results and compatibility assessment was performed statistical analysis considering the t-test in which the test statistic is given by the Student\'s t - distribution, adopting a significance level of 5%. The values obtained by Quantitative EDS for the cathodes were (in wt%) (90.3 ± 0.5)% of Ni and (9.72 ± 0.19)% of Cr for the Chromel and (95.1 ± 0.8)% of Ni, (2.02 ± 0.14)% of Mn, (1.65 ± 0.04)% of Si and (1.15 ± 0.05)% of Al for the Alumel. As for the thin films, they were (90.2 ± 0.5)% of Ni and (9.8 ± 0.5)% of Cr for the Chromel and (95.2 ± 0.4)% of Ni, (2.8 ± 0.4)% of Mn, (0.77 ± 0.17)% of Si and (1.08 ± 0.09)% for Al Alumel, both featuring compatibility with the measures by Rutherford Backscattering Spectrometry (RBS) - technique commonly used for this type of specimen. It was verified that the elemental concentration of the thin film of Chromel presented no significant difference with the cathode of the same alloy. However, for the Alumel thin film, there was evidence of a significant difference with respect to the cathode, appointed by element Silicon.
|
7 |
Avaliação da composição elementar de filmes finos de ligas metálicas depositados por Arco Catódico Filtrado em Vácuo utilizando RBS e EDS quantitativo / Evaluation of the elemental composition of alloy thin films deposited by Filtered Cathodic Vacuum Arc using RBS and quantitative EDS analysisRaissa Lima de Oblitas 26 September 2016 (has links)
Devido à relevância de filmes finos, as técnicas que são utilizadas para produzi-los e também para caracteriza-los tem se tornado importante. Neste contexto, foram analisados filmes finos de até 100 nm, de duas ligas metálicas (cromel e alumel), obtidos a partir da deposição por plasma de Arco Catódico Filtrado em Vácuo (Filtered Cathodic Vacuum Arc - FCVA). O objetivo deste projeto foi avaliar a similaridade em composição elementar entre os materiais utilizados para deposição, que operam como cátodos, e os filmes finos depositados, a partir de medições obtidas pela técnica de microanálise quantitativa Energy Dispersive Spectroscopy (EDS). Para comparação entre resultados e apreciação de compatibilidade, foi realizada avaliação estatística considerando o Teste t, no qual a estatística do teste é dada pela Distribuição t de Student, adotando nível de significância de 5%. Os valores obtidos por EDS Quantitativo para os cátodos foram de (em wt%) (90,3 ± 0,5)% de Ni e (9,72 ± 0,19)% de Cr para o cromel e (95,1 ± 0,8)% de Ni, (2,02 ± 0,14)% de Mn, (1,65 ± 0,04)% de Si e (1,15 ± 0,05)% de Al para o alumel. Já para os filmes finos, foram de (90,2 ± 0,5)% de Ni e (9,8 ± 0,5)% de Cr para o cromel e (95,2 ± 0,4)% de Ni, (2,8 ± 0,4)% de Mn, (0,77 ± 0,17)% de Si e (1,08 ± 0,09)% de Al para o Alumel, ambos apresentando compatibilidade com as medidas por Rutherford Backscattering Spectrometry (RBS) - técnica comumente utilizada para este tipo de espécime. Verificou-se que a composição elementar do filme fino de cromel não apresentou diferença significativa com o cátodo da mesma liga. Entretanto, para o filme fino de alumel, houve evidências de diferença significativa com relação ao cátodo, apontada pelo elemento silício. / Due the relevance of thin films, the techniques used to produce and also to characterize them has become important. In this context, it was analyzed thin films up to 100 nm of two alloys (Chromel and Alumel) obtained by plasma deposition using Filtered Cathodic Vacuum Arc (FCVA). The objective of this project was to evaluate the similarity in elemental concentration of the materials used for deposition, which act as cathodes, and the deposited thin films, through measurements obtained by quantitative microanalysis technique Energy Dispersive Spectroscopy (EDS). In order to compare results and compatibility assessment was performed statistical analysis considering the t-test in which the test statistic is given by the Student\'s t - distribution, adopting a significance level of 5%. The values obtained by Quantitative EDS for the cathodes were (in wt%) (90.3 ± 0.5)% of Ni and (9.72 ± 0.19)% of Cr for the Chromel and (95.1 ± 0.8)% of Ni, (2.02 ± 0.14)% of Mn, (1.65 ± 0.04)% of Si and (1.15 ± 0.05)% of Al for the Alumel. As for the thin films, they were (90.2 ± 0.5)% of Ni and (9.8 ± 0.5)% of Cr for the Chromel and (95.2 ± 0.4)% of Ni, (2.8 ± 0.4)% of Mn, (0.77 ± 0.17)% of Si and (1.08 ± 0.09)% for Al Alumel, both featuring compatibility with the measures by Rutherford Backscattering Spectrometry (RBS) - technique commonly used for this type of specimen. It was verified that the elemental concentration of the thin film of Chromel presented no significant difference with the cathode of the same alloy. However, for the Alumel thin film, there was evidence of a significant difference with respect to the cathode, appointed by element Silicon.
|
8 |
Analýza plicních vzorků infikovaných Aspergillus fumigatus a Pseudomonas aeruginosa metodami rastrovací elektronové mikroskopie / Analysis of pulmonary samples infected with Aspergillus fumigatus and Pseudomonas aeruginosa by scanning electron microscopyJuříková, Tereza January 2018 (has links)
Despite the significant progress in medicine, infectious diseases are life-threatening thanks to an increasing number of multiresistant strains of microorganisms and late detection of pathological agents. An opportunistic fungus Aspergillus fumigatus cause respiratory system diseases called aspergillosis. The invasive pulmonary aspergillosis affects immunocompromised patients after inhalation of ubiquitous conidia of A. fumigatus and results in 450,000 deaths per year. The biofilm formation in the infected tissue protects A. fumigatus against antimicrobial drugs. Late therapy may not be effective. Infection of immunocompromised patients and biofilm formation is characteristic also for gram negative bacteria Pseudomonas aeruginosa, which is due to the production of many factors of virulence and multiresistance a dreaded opportunistic pathogen. Scanning electron microscopy (SEM) provides detail information about morphology of microorganisms with the resolution in range of tens of nanometers that allows to observe microorganisms in the infected tissue and its pathological changes. Mass spectrometry allows to detect infection and its course based on identification of characteristic microbial molecules. The aim of this study was to optimize sample preparation of tissues infected with A. fumigatus or P....
|
9 |
Quantitative Analysis of TiWCN in Cemented Carbide : A Comparison of Spectroscopic TechniquesOlander, Petra January 2010 (has links)
The aim of this master thesis was to compare EELS in TEM with TEM-EDS and WDS-EPMA for quantitative analysis of γ-phase in cemented carbide. Especially, the quantification of the light elements nitrogen and carbon in compounds like TiCxN1-x is interesting, since this is problematic. The techniques were compared by acquiring spectra for quantification of two samples of cemented carbide containing γ-phase (Tix,W1-x)(CyN1-y) with different nitrogen and tungsten content. Also, a rigorous evaluation about how EELS spectra best is acquired and processed was performed in order to enable the comparison. Experimental results show that EELS gives satisfying results for TiC0.7N0.3 and that EELS is comparable with WDS-EPMA for quantification of nitrogen, carbon and titanium in (Tix,W1-x)(CyN1-y) when the atomic concentration of nitrogen is around 20%. However, EELS was not used for quantification of tungsten. Concluded is also that EELS and WDS should be considered as complementary rather than competing techniques.
|
10 |
Mineraliseringar utmed REE-linjen i sydvästra BergslagenLinnros, Henrik January 2014 (has links)
This paper briefly summarizes Bergslagen as a bedrock province in order to give background to the genesis and presence of REE-bearing minerals (short for Rare Earth Elements) in the region. These mineralizations mainly occur along the REE-line, a line aproximately a hundred kilometers in length between Norberg in the north and Nora in the south with a width of a few kilometers. Situated in the southwest of Bergslagen it is currently one of only a few places in Sweden where REE-bearing iron oxide mineralizations are potentially economically viable for mining. Ore microscopy has been conducted in order to characterize an ore sample from Myrbacksfältet, one of few sulphide rich iron oxide mineralizations within the REE-line. Additionally, an electron microscope analysis of a sample from Stålklockan, a suspected REE-bearing mineralization also within the REE-line was confirmed by EDS (short for Energy Dispersive Spectrum) analysis. An interactive map has been made of the REE- line to aid with visualization in an attempt to collect all known geospatial-, mineral- and bedrock information in one place. The map is available in PDF format in conjunction with this text. A static version of this map is presented under 4.1 (REE-linjen). / Berggrundsprovinsen Bergslagens regionala geologi beskrivs inledningsvis för att ge bakgrund till de fyndigheter av REE-förande mineral (eng. Rare Earth Elements; Sällsynta jordartsmetaller) som förekommer utmed en ungefär hundra kilometer lång och ett par kilometer bred zon. Detta geografiskt och mineralogiskt avgränsade område kallas REE-linjen och ligger i sydvästra Bergslagen. I detta område mellan Norberg i norr och Nora i söder finns idag några av de få potentiellt ekonomiskt brytbara fyndigheterna av REE-förande mineral i Sverige vilket har gjort en kartkonstruktion vari spatiell-, mineralogisk-, och berggrundsdata över området finns sammanställd meningsfull. En sådan karta har gjorts i ArcGIS och presenteras i interaktivt PDF format i anslutning till texten. Malmmikroskopisk karaktärisering av en sulfidrik järnmalm från Myrbacksfältet i REE-linjen, såväl som en elektronmikroskopisk EDS (Energy Dispersive Spectrum) analys av ett prov från Stålklockan i Riddarhyttans malmfält har genomförts.
|
Page generated in 0.03 seconds