SPAR VI Technical Report for Experiment 76-22: Directional Solidification of Magnetic Composites

Samples of eutectic Bi/MnBi were directionally solidified during a low-g interval aboard the SPAR 6 flight and in a l-g environment under identical furnace velocity and thermal conditions. The Bi/MnBi eutectic is characterized by a regular rod eutectic whose morphology may be sensitive to thermo-solutal convection and by its components, MnBi, which is ferromagnetic. Morphological analyses on samples show statistically smaller interrod spacings and rod diameters with respect to samples grown under identical solidification furnace conditions in l-g. An adjustment between the interrod spacing, growth velocity, and total undercooling at the solidification interface is proposed. Morphological analyses on samples grown in l-g indicate little difference between results for different growth orientations with respect to the gravity vector. The magnetic properties are significantly affected, however, by the presence of a nonequilibrium magnetic phase and the nonequilibrium phase transforms to the equilibrium ferromagnetic phase during isothermal heat treatment

The growth of metastable peritectic compounds

The influence of gravitationally driven thermosolutal convection on the directional solidification of peritectic alloys is considered as well as the relationships between the solidification processing conditions, and the microstructure, chemistry, and magnetic properties of such alloys. Analysis of directionally solidified Pb-Bi peritectic samples indicates that appreciable macrosegregation occurs due to thermosolutal convection and/or Soret diffusion. A peritectic solidification model which accounts for partial mixing in the liquid ahead of the planar solidification interface and describes macrosegregation has been developed. Two-phase dendritic and banded microstructures were grown in the Pb-Bi peritectic system, refined two-phase microstructures have were observed, and candidate formation mechanisms proposed. Material handling, containment, casting, microstructural and magnetic characterization techniques were developed for the Sm-Co system. Alloys produced with these procedures are homogeneous

22. Current status of systematic radiopharmaceuticals for the treatment of painful metastatic bonr disease

Intractable bone pain secondary to bone metastasis from prostate or breast cancer, or other malignancies is a major problem in the management of the oncological patient. Treatment often includes the use of analgesic drug therapy; however, radiation therapy, hormonal therapy, chemotherapy, and surgery may also be needed. Advances in systemic radionuclide therapy have increased the number of treatment options available for patients with painful osseous metastases. This treatment modality offers three major advantages i.) by addressing all sites of involvement; and ii) by limiting irradiation of normal tissues due to selective absorption into bone which results in an improved therapeutic ratio. Patients with a positive bone scan are eligible for treatment, and indications and contraindications for use are well defined. Large, prospectively randomized clinical trials have established the efficacy of samarium-153 EDTMP and strontium-89 Cl as a first-line therapy. When these agents are used, pain relief often occurs rapidly and lasts several weeks to months with responses seen in 60–80% of patients, depending on the extent and stage of the disease. With the introduction of modern bone-seeking radiopharmaceuticals as Sm-153 EDTMP toxicity is rare and restricted to reversible myelosuppression. In summary, evidenced based literature suggests that these radiopharmaceuticals can significantly reduce pain and analgesic requirements, improve quality of life, reduce lifetime radiotherapy requirements and management costs, and may even slow the progression of painful metastatic lesions. Retreatment is safe and effective

Razlike između britanske i američke inačice engleskog standardnog jezika

Dvije glavne inačice engleskog standardnog jezika su britanska i američka. One se razlikuju na jezičnim nivoima leksika, gramatike, pravopisa i intonacije. U ovom radu se osim jezičnih razlika opisuju i početci engleskog jezika, povijest engleskog jezika u Sjedinjenim Američkim Državama, ostale važne inačice engleskog jezika te razlozi koji su potakli njihov nastanak. Također, analizom udžbenika i radnih bilježnica Engleskog jezika za razrednu nastavu navodi se koja je inačica dominantnija u Republici Hrvatskoj i koji je tomu razlog.The two main variants of the English language are British English and American English. They differ in lexis, grammar, spelling and intonation. The purpose of this paper is to describe the differences between British English and American English and, in order to accomplish this goal, the beginnings of the English language, the history of the English language in The United States, other variants of the English language and the reason for their formation are explained. Also, through analysing the English language textbooks and workbooks from 1st to 4th grade it is cited which variant of English is preffered in the Republic of Croatia and why

Razlike između britanske i američke inačice engleskog standardnog jezika

Dvije glavne inačice engleskog standardnog jezika su britanska i američka. One se razlikuju na jezičnim nivoima leksika, gramatike, pravopisa i intonacije. U ovom radu se osim jezičnih razlika opisuju i početci engleskog jezika, povijest engleskog jezika u Sjedinjenim Američkim Državama, ostale važne inačice engleskog jezika te razlozi koji su potakli njihov nastanak. Također, analizom udžbenika i radnih bilježnica Engleskog jezika za razrednu nastavu navodi se koja je inačica dominantnija u Republici Hrvatskoj i koji je tomu razlog.The two main variants of the English language are British English and American English. They differ in lexis, grammar, spelling and intonation. The purpose of this paper is to describe the differences between British English and American English and, in order to accomplish this goal, the beginnings of the English language, the history of the English language in The United States, other variants of the English language and the reason for their formation are explained. Also, through analysing the English language textbooks and workbooks from 1st to 4th grade it is cited which variant of English is preffered in the Republic of Croatia and why

Radiation-Resistant Hybrid Lotus Effect for Achieving Photoelectrocatalytic Self-Cleaning Anticontamination Coatings

An experiment involving radiation-resistant hydrophobic coatings is planned for space exposure and experimental testing on the International Space Station (ISS) in 2011. The Lotus biocide coatings are designed for supporting space exploration missions. This innovation is an antibacterial, anti-contamination, and self-cleaning coating that uses nano-sized semiconductor semimetal oxides to neutralize biological pathogens and toxic chemicals, as well as to mitigate dust accumulation (see figure). The Lotus biocide coating is thin (approximately microns thick), lightweight, and the biocide properties will not degrade with time or exposure to biological or chemical agents. The biocide is stimulated chemically (stoichiometric reaction) through exposure to light (photocatalysis), or by an applied electric field (electrocatalysis). The hydrophobic coating samples underwent preliminary high-energy proton and alpha-ray (helium ion) irradiations at the Lawrence Berkeley National Laboratory 88" cyclotron and demonstrated excellent radiation resistance for a portion of the Galactic Cosmic Ray (GRC) and Solar Proton spectrum. The samples will undergo additional post-flight studies when returned to Earth to affirm further the radiation resistance properties of the space exposed coatings

Razlike između britanske i američke inačice engleskog standardnog jezika

Dvije glavne inačice engleskog standardnog jezika su britanska i američka. One se razlikuju na jezičnim nivoima leksika, gramatike, pravopisa i intonacije. U ovom radu se osim jezičnih razlika opisuju i početci engleskog jezika, povijest engleskog jezika u Sjedinjenim Američkim Državama, ostale važne inačice engleskog jezika te razlozi koji su potakli njihov nastanak. Također, analizom udžbenika i radnih bilježnica Engleskog jezika za razrednu nastavu navodi se koja je inačica dominantnija u Republici Hrvatskoj i koji je tomu razlog.The two main variants of the English language are British English and American English. They differ in lexis, grammar, spelling and intonation. The purpose of this paper is to describe the differences between British English and American English and, in order to accomplish this goal, the beginnings of the English language, the history of the English language in The United States, other variants of the English language and the reason for their formation are explained. Also, through analysing the English language textbooks and workbooks from 1st to 4th grade it is cited which variant of English is preffered in the Republic of Croatia and why

Obtenção de nanocristais de celulose bacteriana e sua aplicação no desenvolvimento de nanopartículas revestidas com xiloglucana de Tamarindus indica L.

Orientadora : Profª Drª Maria Rita SierakowskiCo-orientador: Prof. Dr. Rilton Alves de FreitasDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Bioquímica. Defesa: Curitiba, 06/03/2013Bibliografia: f. 66-74Resumo: O desenvolvimento de materiais ecologicamente sustentáveis é de grande interesse industrial e científico por utilizar fontes de origem renovável, com baixo custo e alta biocompatibilidade. Entre os candidatos de grande potencial estão os nanocristais de celulose (NC) e a xiloglucana (XG). Observando que na parede celular vegetal as microfibrilas de celulose com a XG se organizam em complexas redes polissacarídicas pode-se utilizá-las mimetizando, em laboratório, a síntese de biocompósitos como nanofilmes, ou revestimentos tridimensionais. Na literatura, as condições de obtenção desses biocompósitos, são pouco relatadas. Assim, o objetivo deste trabalho foi desenvolver e otimizar os processos para a obtenção de partículas estáveis de NC adsorvidas com XG, para o desenvolvimento de revestimentos tridimensionais. Para tal, utilizamos como matérias primas a celulose de fonte bacteriana (CB), para sintetizar e isolar nanocristais de celulose bacteriana (NCB) e, a XG de sementes de Tamarindus indica, para os ensaios de adsorção. Os NCB foram produzidos por diferentes hidrólises (radicalar, com CH2O2, H2SO4, HCl e com a mistura híbrida entre H2SO4 e HCl [Hbd]). Após o isolamento, os NCB foram caracterizados em função de seu tamanho, carga, cristalinidade e morfologia, por granulometria a laser, espalhamento de luz dinâmico (DLS), potencial zeta (p?); difratometria de raios-X (DRX), e microscopia de força atômica (MFA). O revestimento NCB-XG foi avaliado através da isoterma de Langmuir, determinando a proporção de massa por colorimetria (I2/KI), seguida dos ensaios por p?, DLS e MFA. Também, foi realizada a síntese de nanofilmes por multicamadas alternadas de NCB e XG aplicando a técnica de automontagem (do inglês Layer by Layer - LbL). A deposição das camadas foi avaliada por microbalança de cristal de quartzo (MCQ), pela perda e ganho de massa. A rugosidade (RMS) das camadas foi medida por MFA, e a espessura (dx) por elipsometria. Nos resultados observou-se que somente as hidrólises ácidas (HCl, H2SO4 Hbd) obtiveram êxito no isolamento dos NCB, onde as medidas por granulometria a laser sugeriram tamanhos inferiores aos obtidos por CH2O2 e radicalar. Os atributos dos NCB isolados a partir das hidrólises com HCl (NCB-HCl), H2SO4 (NCB-H2SO4) e da mistura híbrida destes ácidos (NCB-Hbd) diferiram significativamente somente no valor do potencial zeta (-4,8 a -45,6 mV) dependendo do grau de sulfatação. Na interação com a XG o grau de sulfatação apresentou efeitos tanto negativos, quando em maior grau [NCB-H2SO4 vs NCB-HCl :211 vs 235 ?g.mg-1 (XG.NCB-1)], quanto positivos, quando em menor grau [NCB-Hbd vs NCB-HCl: 235 vs 275 ?g.mg-1 (XG.NCB-1)]. Dessa forma, por apresentar a maior adsorção, o NCB-Hbd foi escolhido para a síntese das partículas de NCB-XG. As análises dos filmes multicamadas demonstraram a formação de um sistema composto por deposição de camadas espessas de NCB (9,86 nm) e finas de XG (3,84 nm), com superfícies relativamente homogêneas (RMS: NCB/XG: 3,71/3,41 nm). Nós demonstramos, pela primeira vez, em literatura, a influência de modificações na superfície de NCB na interação com XG, obtendo NCB com maior adsorção a XG. Otimizamos as condições para obtenção de nanopartículas estáveis em solução de NCB-XG e seu potencial na aplicação para revestimentos homogêneos de partículas tridimensionais pela técnica de LbLAbstract: The development of environmentally friendly and sustainable materials represents great interest for industrial and scientific applications due their renewability (renewable sources), combined with low cost and high biocompatibility. Among the great potential candidates, there are cellulose nanocrystals (NC) and xyloglucan (XG). In plant cell wall, NC and XG are organized in complex polysaccharide chains in structures that might be mimic in laboratory conditions, targeting the development of biocomposites, as nanofilms or tridimensional coating, the last one case practically unexplored in scientific databases. Therefore, this study aims the development and optimization of several processes to obtain stable particles of NC for tridimensional coating with XG. Bacterial cellulose (BC) was used as raw material to isolate its nanocrystals, NCB, and XG from Tamarindus indica seeds for the adsorption experiments. NCB were isolated by various hydrolysis process (radical, CH2O2, H2SO4, HCl and a mix of HCl and H2SO4 [Hbd]), and were characterized by average size distribution using laser granulometry, dynamic light scattering, (DLS), net charge through zeta potential (p?), crystallinity with x-ray diffraction (XRD) and morphology by AFM. Coating was evaluated in solution through Langmuir isotherm assays using the I2/KI colorimetric method, p?, DLS and by AFM. In a second process, the Layer by Layer technique was utilized to coat NCB particles, evaluating mass loss and uptake through quartz crystal microbalance (QCM); thickness and roughness by ellipsometry and AFM, respectively. Only HCl, H2SO4 and Hbd hydrolysis succeeded to isolate the NCB, exhibiting lower size distribution values than compared methods, showing greater process efficiency. NCB characteristics isolated by HCl (NCB-HCl), Hbd (NCB-Hbd) and H2SO4 (NCB-H2SO4) differ only in zeta potential values (-4,8 mV to -45,6 mV) depending of sulfate content. Sulfation reaction exhibited negative effects, when present in a greater content (NCB-H2SO4 vs NCB-HCl: 211 vs 235 ?gXG.mgNCB-1), as well as positive whenever in a minor content (NCB-Hbd vs NCB-HCl: 235 vs 275 ?gXG.mgNCB-1), on the interaction with XG. Therefore, NCB-Hbd was chosen to synthetize NCB-XG particles due to its higher adsorption rate. Analysis by QCM, AFM and ellipsometry showed a multilayer of NCB-XG composed by a thick layer of NCB (9.86 nm) and thin of XG (3.84 nm) with a relative homogenous surface (NCB/XG roughness: 3.71/3.41 nm). Thus, NCB synthesis was optimized, revealing higher adsorption to XG and demonstrating the coating of stable and homogenous NCB-XG multilayer for application of tridimensional nanoparticles in solution

Structure and Magnetic Properties of the MnBi Low Temperature Phase

High purity MnBi low temperature phase has been prepared and analyzed using magnetic measurements and neutron diffraction. The low-temperature phase of the MnBi alloy has a coercivity μ0iHc of 2.0 T at 400 K, and exhibits a positive temperature coefficient from 0 to at least 400 K. The neutron data refinement indicated that the Mn atom changes its spin direction from c axis above room temperature to nearly perpendicular to the c axis at 50 K. A canted magnetic structure has been observed below 200 K. The anisotropy field increases with increasing temperature which gives rise to a high coercivity at the higher temperatures. The anisotropic bonded magnets have maximum energy products (BH)max of 7.7 and 4.6 MGOe at room temperature and 400 K, respectively

Nanocristais de celulose bacteriana carboxilados para imobilização de anticorpos e desenvolvimento de biossensores piezoelétricos

Orientador : Profª. Drª. Maria Rita SierakowskiCoorientador : Prof. Dr. Rilton Alves de FreitasTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ciências : Bioquímica. Defesa: Curitiba, 28/04/2017Inclui referências: 122-134Resumo: Novos materiais desenvolvidos a partir de fontes naturais de origem renovável, biocompatíveis e de baixo custo vêm recebendo atenção da academia e da indústria, e duas fontes promissoras são os cristais de celulose (NC) e as xiloglucanas (XG) de sementes de Tamarindus indica. O objetivo desta tese se baseou no desenvolvimento de materiais suportes a base desses polissacarídeos e, de acordo com as publicações geradas, a tese foi dividida em três partes. Na primeira (1), foi realizada a adsorção de XG em camadas de NC com quatro diferentes graus de sulfatação e de potencial zeta [0% SO3 -, isolado com HCl (? -4,8 mV); 0.42% SO3 -, usando uma mistura de HCl e H2SO4 (? -39,6 mV); e 0,65% SO3 -, usando somente H2SO4 (? -45,6 mV)]. A interação foi investigada através de várias técnicas [isotermas de Langmuir, microscopia de força atômica (AFM), ângulo de contato, espalhamento de luz dinâmico, elipsometria e medidas por microbalança de cristal de quartzo (QCM)]. Os experimentos de adsorção em água e por layer by layer (LbL) sugerem que o maior grau de esterificação na superfície de NC (0,65% SO3 -) prejudica a capacidade máxima de adsorção da XG e cria camadas adsorvidas instáveis. Entretanto, para o grupo 0,42% SO3 - não foi verificada alterações significativas na adsorção da XG além de ter uma maior estabilidade coloidal do que o grupo 0% SO3 - e de formar filmes mais estáveis, com menor rugosidade e espessura. Mas, testes iniciais de formação de filmes de XG com NC submetidos a oxidação com o reagente TEMPO apresentaram delaminação e foram descartados para a etapa de produção de biossensores bidimensionais. Na segunda parte (2), sensores piezoelétricos foram revestidos com filmes de NC e em seguida foi imobilizado anticorpos monoclonais IgG específicos para o antígeno NS1 do vírus da dengue. O revestimento do sensor foi acompanhado por AFM, QCM e QCM-D. O sensor desenvolvido foi capaz de detectar o antígeno NS1 em amostras de soros sanguíneos simulados no intervalo de concentração de 0,01 à 10 ?g.mL-1. O revestimento ainda proporcionou a capacidade de reconhecimento de NS1 através de ambos os equipamentos, QCM-D e QCM, com limites de detecção de 0,1 ?g.mL-1 e 0,32 ?g.mL-1, respectivamente. Na terceira parte (3), na tentativa de baratear o sensor desenvolvido na metodologia do artigo anterior, foi proposta a otimização do procedimento de obtenção de NC. Para isso, foi verificada a influência de prétratamentos mecânicos antes do procedimento de hidrólise da celulose. As amostras foram segregadas em relação ao grau de intensidade do tratamento mecânico, sendo: (a) agitação mecânica, (b) trituração, (c) cisalhamento por 20 passagens por moinho e (d) cisalhamento por 40 passagens por moinho. E foram caracterizadas por reologia, AFM, difração de raios-x e rendimento de NC isolados. De acordo com os resultados obtidos, não foi verificada diferença significativa do pré-tratamento para produção de NC. Assim, sugere-se que não é necessário um pré-tratamento mecânico e, com isso, o custo final da obtenção de NC pode ser diminuído. Palavras-chave: Xiloglucana. Nanocristais de celulose. Biossensores. Dengue. Filmes finos. Proteína NS1Abstract: Novel materials developed from renewable and natural sources with biocompatibility and low cost have receiving great attention from academia and industry. Two promises sources are cellulose nanocrystals (NC) and xyloglucan (XG) from Tamarindus indica. seeds. At present thesis, the main goal was the development of support materials based on these two polysaccharides. In according to published papers, this thesis was organised in three sections. The first (1), the adsorption behavior of XG on layers of bacterial cellulose nanocrystals (BCN) with four different sulfate content and zeta potential (?) values [0% SO3 -, using only HCl (? -4.8 mV); 0.42% SO3 -, using a mix of HCl and H2SO4 (? -39.6 mV); and 0.65% SO3 -, using only H2SO4 (? -45.6 mV)] was investigated. The adsorption was evaluated by several techniques (Langmuir isotherms, atomic force microscopy, contact angle, dynamic light scattering, ellipsometry and quartz crystal microbalance measurements). The experiments in water suspension and layer by layer (LbL) suggest that high sulfate substitution on BCN surface (0.65% SO3 -) impairs the original interaction with XG, resulting in lower maximum adsorbed amount (Qmax) of XG on BCN and unstable deposited layers with desorption. Therefore, 0.42% SO3 - did not significantly impair XG adsorption, and the greater colloidal stability than 0% SO3 - resulted in higher XG mass adsorption in water suspension and thin films with lower roughness, thickness and without desorption. However, initial test of XG films with NC subjected to oxidation with the TEMPO reagent presented delamination and were discarded for the production stage of twodimensional biosensors. In the second section (2), piezoelectric sensors were previously coated with thin films of bacterial cellulose nanocrystals (CN) to provide a more sensitive and adapted interface for the attachment of monoclonal immunoglobulin G (IgGNS1) and to favor specific detection of non-structural protein 1 (NS1) of dengue fever. The assembly of the immunochip surface was analyzed by atomic force microscopy (AFM) and the NS1 detection was followed by quartz crystal microbalance with (QCM-D) and without energy dissipation monitoring (QCM). The CN surface was able to immobilize IgGNS1, as confirmed by AFM topography and phase images along with QCM-D. The system was able to detect the NS1 protein in serum simulated in the range of 0.01- 10 ?g.mL-1, by both QCM and QCM-D. The limits of detection of the two devices were 0.1 ?g.mL-1 for QCM-D and 0.32 ?g.mL-1 for QCM. At last (3), in order to optimize and reduce the cost of piezoeletric immunochip, was proposed a study to optimize the hydrolysis procedure. For this, the influence of mechanical pretreatment before the hydrolysis procedure was verified on the pristine cellulose submitted to four different mechanical process: (1) magnetic stirring, (2) blender, and milled by (3) 20 and (4) 40 passages in supermasscolloider mill. All the samples were evaluated according to yield, morphology and size (atomic force microscopy), crystallinity (x-ray diffraction). Not all CNC differed in evaluated characteristics suggesting that, intense mechanical pretreatment are not exclusively required, prior to hydrolysis. Key-words: Xyloglucan. Celulose nanocrystals. Biossensors. Dengue. Thin films. NS1 protein