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Artykuły w czasopismach na temat "DSB substrates"
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Smith, Jason A., Laura A. Bannister, Vikram Bhattacharjee, Yibin Wang, Barbara Criscuolo Waldman i Alan S. Waldman. "Accurate Homologous Recombination Is a Prominent Double-Strand Break Repair Pathway in Mammalian Chromosomes and Is Modulated by Mismatch Repair Protein Msh2". Molecular and Cellular Biology 27, nr 22 (10.09.2007): 7816–27. http://dx.doi.org/10.1128/mcb.00455-07.
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ABSTRACT We designed DNA substrates to study intrachromosomal recombination in mammalian chromosomes. Each substrate contains a thymidine kinase (tk) gene fused to a neomycin resistance (neo) gene. The fusion gene is disrupted by an oligonucleotide containing the 18-bp recognition site for endonuclease I-SceI. Substrates also contain a “donor” tk sequence that displays 1% or 19% sequence divergence relative to the tk portion of the fusion gene. Each donor serves as a potential recombination partner for the fusion gene. After stably transfecting substrates into mammalian cell lines, we investigated spontaneous recombination and double-strand break (DSB)-induced recombination following I-SceI expression. No recombination events between sequences with 19% divergence were recovered. Strikingly, even though no selection for accurate repair was imposed, accurate conservative homologous recombination was the predominant DSB repair event recovered from rodent and human cell lines transfected with the substrate containing sequences displaying 1% divergence. Our work is the first unequivocal demonstration that homologous recombination can serve as a major DSB repair pathway in mammalian chromosomes. We also found that Msh2 can modulate homologous recombination in that Msh2 deficiency promoted discontinuity and increased length of gene conversion tracts and brought about a severalfold increase in the overall frequency of DSB-induced recombination.
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Aoki, Tatsuhiko, Hiroaki Kariyazaki, Koji Sueoka i Kouji Izunome. "Gettering Efficiency of Si (110)/(100) Directly Bonded Hybrid Crystal Orientation Substrates". Solid State Phenomena 156-158 (październik 2009): 369–73. http://dx.doi.org/10.4028/www.scientific.net/ssp.156-158.369.
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We have investigated the gettering efficiency at the interface of Si (110) and Si (100) directly bonded (DSB) substrates. DSB substrates were prepared by conventional bonding and grinding back methods. DSB substrates were intentionally contaminated with 3d transition metals (Fe, Ni, Cu) and then annealed at 1000 oC. The dependence of metal concentrations on the depth was evaluated by a secondary ionization mass spectrometer (SIMS). Furthermore, we observed the interface of DSB by transmission electron microscope (TEM), and characterized the form of the gettered metals.
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Lin, Yunfu, Tamas Lukacsovich i Alan S. Waldman. "Multiple Pathways for Repair of DNA Double-Strand Breaks in Mammalian Chromosomes". Molecular and Cellular Biology 19, nr 12 (1.12.1999): 8353–60. http://dx.doi.org/10.1128/mcb.19.12.8353.
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ABSTRACT To study repair of DNA double-strand breaks (DSBs) in mammalian chromosomes, we designed DNA substrates containing a thymidine kinase (TK) gene disrupted by the 18-bp recognition site for yeast endonuclease I-SceI. Some substrates also contained a second defective TK gene sequence to serve as a genetic donor in recombinational repair. A genomic DSB was induced by introducing endonuclease I-SceI into cells containing a stably integrated DNA substrate. DSB repair was monitored by selection for TK-positive segregants. We observed that intrachromosomal DSB repair is accomplished with nearly equal efficiencies in either the presence or absence of a homologous donor sequence. DSB repair is achieved by nonhomologous end-joining or homologous recombination, but rarely by nonconservative single-strand annealing. Repair of a chromosomal DSB by homologous recombination occurs mainly by gene conversion and appears to require a donor sequence greater than a few hundred base pairs in length. Nonhomologous end-joining events typically involve loss of very few nucleotides, and some events are associated with gene amplification at the repaired locus. Additional studies revealed that precise religation of DNA ends with no other concomitant sequence alteration is a viable mode for repair of DSBs in a mammalian genome.
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Kato, Tetsuji, Yuji Ohara, Takaya Ueda, Jun Kikkawa, Yoshiaki Nakamura, Akira Sakai, Osamu Nakatsuka i in. "Microscopic Structure of Directly Bonded Silicon Substrates". Key Engineering Materials 470 (luty 2011): 164–70. http://dx.doi.org/10.4028/www.scientific.net/kem.470.164.
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Using X-ray microdiffraction (XRMD) and transmission electron microscopy (TEM) techniques, we have investigated the microscopic structure of Si(011)/Si(001) direct silicon bonding (DSB) substrates. XRMD was performed to measure the local lattice spacing and tilting in the samples before and after oxide out-diffusion annealing. Diffraction analyses for (022) lattice planes with two orthogonal in-plane directions of X-ray incidence revealed anisotropic domain textures in the Si(011) layer. Such anisotropy was also confirmed by TEM in the morphology at the Si(011)/Si(001) bonded interface. The anisotropic crystallinity is discussed on the basis of interfacial defect structures which are proper to the DSB substrate.
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Dronkert, Mies L. G., H. Berna Beverloo, Roger D. Johnson, Jan H. J. Hoeijmakers, Maria Jasin i Roland Kanaar. "Mouse RAD54 Affects DNA Double-Strand Break Repair and Sister Chromatid Exchange". Molecular and Cellular Biology 20, nr 9 (1.05.2000): 3147–56. http://dx.doi.org/10.1128/mcb.20.9.3147-3156.2000.
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ABSTRACT Cells can achieve error-free repair of DNA double-strand breaks (DSBs) by homologous recombination through gene conversion with or without crossover. In contrast, an alternative homology-dependent DSB repair pathway, single-strand annealing (SSA), results in deletions. In this study, we analyzed the effect of mRAD54, a gene involved in homologous recombination, on the repair of a site-specific I-SceI-induced DSB located in a repeated DNA sequence in the genome of mouse embryonic stem cells. We used six isogenic cell lines differing solely in the orientation of the repeats. The combination of the three recombination-test substrates used discriminated among SSA, intrachromatid gene conversion, and sister chromatid gene conversion. DSB repair was most efficient for the substrate that allowed recovery of SSA events. Gene conversion with crossover, indistinguishable from long tract gene conversion, preferentially involved the sister chromatid rather than the repeat on the same chromatid. Comparing DSB repair in mRAD54wild-type and knockout cells revealed direct evidence for a role ofmRAD54 in DSB repair. The substrate measuring SSA showed an increased efficiency of DSB repair in the absence ofmRAD54. The substrate measuring sister chromatid gene conversion showed a decrease in gene conversion with and without crossover. Consistent with this observation, DNA damage-induced sister chromatid exchange was reduced in mRAD54-deficient cells. Our results suggest that mRAD54 promotes gene conversion with predominant use of the sister chromatid as the repair template at the expense of error-prone SSA.
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Osman, Fekret, Elizabeth A. Fortunato i Suresh Subramani. "Double-Strand Break-Induced Mitotic Intrachromosomal Recombination in the Fission Yeast Schizosaccharomyces pombe". Genetics 142, nr 2 (1.02.1996): 341–57. http://dx.doi.org/10.1093/genetics/142.2.341.
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Abstract The Saccharomyces cerevisiae HO gene and MATa cutting site were used to introduce site-specific double-strand breaks (DSBs) within intrachromosomal recombination substrates in Schizosaccharomyces pombe. The recombination substrates consisted of nontandem direct repeats of ade6 heteroalleles. DSB induction stimulated the frequency of recombinants 2000-fold. The spectrum of DSB-induced recombinants depended on whether the DSB was introduced within one of the ade6 repeats or in intervening unique DNA. When the DSB was introduced within unique DNA, over 99.8% of the recombinants lacked the intervening DNA but retained one copy of ade6 that was wild type or either one of the heteroalleles. When the DSB was located in duplicated DNA, 77% of the recombinants were similar to the deletion types described above, but the single ade6 copy was either wild type or exclusively that of the uncut repeat. The remaining 23% of the induced recombinants were gene convertants with two copies of ade6 and the intervening sequences; the ade6 heteroallele in which the DSB was induced was the recipient of genetic information. Half-sectored colonies were isolated, analyzed and interpreted as evidence of heteroduplex DNA formation. The results are discussed in terms of current models for recombination.
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Nussbaum, A., M. Shalit i A. Cohen. "Restriction-stimulated homologous recombination of plasmids by the RecE pathway of Escherichia coli." Genetics 130, nr 1 (1.01.1992): 37–49. http://dx.doi.org/10.1093/genetics/130.1.37.
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Abstract To test the double-strand break (DSB) repair model in recombination by the RecE pathway of Escherichia coli, we constructed chimeric phages that allow restriction-mediated release of linear plasmid substrates of the bioluminescence recombination assay in infected EcoRI+ cells. Kinetics of DSB repair and expression of recombination products were followed by Southern hybridization and by the bioluminescence recombination assay, respectively. Plasmid recombinants were analyzed with restriction endonucleases. Our results indicate that a DSB can induce more than one type of RecE-mediated recombination. A DSB within the homology induced intermolecular recombination that followed the rules of the DSB repair model: (1) Recombination was enhanced by in vivo restriction. (2) Repair of the break depended on homologous sequences on the resident plasmid. (3) Break-repair was frequently associated with conversion of alleles that were cis to the break. (4) Conversion frequency decreased as the distance from the break increased. (5) Some clones contained a mixture of plasmid recombinants as expected by replication of a heteroduplex in the primary recombinant. The rules of the DSB repair model were not followed when recombination was induced by a DSB outside the homology. Both the cut and the uncut substrates were recipients in conversion events. Recombination events were associated with deletions that spanned the break site, but these deletions did not reach the homology. We propose that a break outside the homology may stimulate a RecE-mediated recombination pathway that does not involve direct participation of DNA ends in the homologous pairing reaction.
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Rattray, Alison J., Brenda K. Shafer, Carolyn B. McGill i Jeffrey N. Strathern. "The Roles of REV3 and RAD57 in Double-Strand-Break-Repair-Induced Mutagenesis of Saccharomyces cerevisiae". Genetics 162, nr 3 (1.11.2002): 1063–77. http://dx.doi.org/10.1093/genetics/162.3.1063.
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Abstract The DNA synthesis associated with recombinational repair of chromosomal double-strand breaks (DSBs) has a lower fidelity than normal replicative DNA synthesis. Here, we use an inverted-repeat substrate to monitor the fidelity of repair of a site-specific DSB. DSB induction made by the HO endonuclease stimulates recombination >5000-fold and is associated with a >1000-fold increase in mutagenesis of an adjacent gene. We demonstrate that most break-repair-induced mutations (BRIMs) are point mutations and have a higher proportion of frameshifts than do spontaneous mutations of the same substrate. Although the REV3 translesion DNA polymerase is not required for recombination, it introduces ∼75% of the BRIMs and ∼90% of the base substitution mutations. Recombinational repair of the DSB is strongly dependent upon genes of the RAD52 epistasis group; however, the residual recombinants present in rad57 mutants are associated with a 5- to 20-fold increase in BRIMs. The spectrum of mutations in rad57 mutants is similar to that seen in the wild-type strain and is similarly affected by REV3. We also find that REV3 is required for the repair of MMS-induced lesions when recombinational repair is compromised. Our data suggest that Rad55p/Rad57p help limit the generation of substrates that require pol ζ during recombination.
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González-Barrera, Sergio, María García-Rubio i Andrés Aguilera. "Transcription and Double-Strand Breaks Induce Similar Mitotic Recombination Events inSaccharomyces cerevisiae". Genetics 162, nr 2 (1.10.2002): 603–14. http://dx.doi.org/10.1093/genetics/162.2.603.
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AbstractWe have made a comparative analysis of double-strand-break (DSB)-induced recombination and spontaneous recombination under low- and high-transcription conditions in yeast. We constructed two different recombination substrates, one for the analysis of intermolecular gene conversions and the other for intramolecular gene conversions and inversions. Such substrates were based on the same leu2-HOr allele fused to the tet promoter and containing a 21-bp HO site. Gene conversions and inversions were differently affected by rad1, rad51, rad52, and rad59 single and double mutations, consistent with the actual view that such events occur by different recombination mechanisms. However, the effect of each mutation on each type of recombination event was the same, whether associated with transcription or induced by the HO-mediated DSB. Both the highly transcribed DNA and the HO-cut sequence acted as recipients of the gene conversion events. These results are consistent with the hypothesis that transcription promotes initiation of recombination along the DNA sequence being transcribed. The similarity between transcription-associated and DSB-induced recombination suggests that transcription promotes DNA breaks.
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Willers, Henning, Fen Xia i Simon N. Powell. "Recombinational DNA Repair in Cancer and Normal Cells: The Challenge of Functional Analysis". Journal of Biomedicine and Biotechnology 2, nr 2 (2002): 86–93. http://dx.doi.org/10.1155/s1110724302204027.
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A major goal of current cancer research is to understand the functional consequences of mutations in recombinational DNA repair genes. The introduction of artificial recombination substrates into living cells has evolved into a powerful tool to perform functional analysis of DNA double strand break (DSB) repair. Here, we review the principles and practice of current plasmid assays with regard to the two major DSB repair pathways, homologous recombination and nonhomologous end-joining. A spectrum of assay types is available to assess repair in a wide variety of cell lines. However, several technical challenges still need to be overcome. Understanding the alterations of DSB repair in cancers will ultimately provide a rational basis for drug design that may selectively sensitize tumor cells to ionizing radiation and chemotherapy, thereby achieving therapeutic gain.
Rozprawy doktorskie na temat "DSB substrates"
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Casale, Marco. "Réalisation d'un laser DFB hybride sur substrat de verre". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT011/document.
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Les besoins actuels des systèmes de télécommunications et des capteurs optiques poussent à réaliser des circuits intégrés optiques présentant toujours plus de fonctions sur un même substrat. Atteindre un tel niveau d'intégration est difficile, car les matériaux et les procédés technologiques employés pour implémenter les différentes fonctions optiques ne sont pas toujours compatibles entre eux. Cette thèse s'inscrit dans la problématique de l'intégration des fonctions optiques actives (émission, amplification) et passives (multiplexage, filtrage, etc.) sur substrat passif et reporte la réalisation d'un laser DFB hybride tridimensionnel par échange d'ions sur verre passif et report de plaque d'un verre actif codopé Er3+:Yb3+. Ce laser est constitué d'un guide canal de Bragg, sélectivement enterré dans le substrat passif, et chargé par un guide plan, réalisé dans le verre actif (dopé avec une concentration massique de 2,3% en Er2O3 et 3,6% en Yb2O3). Il est caractérisé par une émission monomode de (420±15) µW à 1534 nm, pour (390±20) mW de puissance de pompe injectée. Ce dispositif ouvre ainsi la voie vers l'intégration de fonctions actives, localisées à la surface du substrat passif, avec des fonctions passives, réalisées en exploitant le volume et la surface du même substratThe current needs of optical telecommunications and sensors require developing integrated optical circuits providing different and heterogeneous functions on the same substrate. The main issue is the incompatibility between the manufacturing processes of these optical functions. This work deals with the integration of active (emission, amplification) and passive (multiplexing, filtering, etc.) functions on a passive glass substrate. Its aim is to develop a DFB three-dimensional hybrid laser by ion-exchange in passive glass. This laser is made of a Bragg channel waveguide, selectively buried in the passive glass substrate, loaded by a plane waveguide, defined at the surface of an Er3+:Yb3+ codoped active glass wafer. It emits a (420±15) µW laser signal at 1534 nm for (390±20) mW injected pump power. Hence this device opens the way towards the integration of active functions, located at the surface of the passive glass substrate, with passive ones, spreading at its surface and in its volume
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Almeida, Fernando Luis de. "Desenvolvimento de um sensor eletroquímico planar modificado com 1-2 Diaminobenzeno (DAB) para monitoração de nitrito por FIA-automatizada". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-30092010-105650/.
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A presente dissertação de mestrado tem o propósito de relatar o desenvolvimento de um sensor planar eletroquímico com três eletrodos para o monitoramento de nitrito e seus interferentes (ácido úrico, ácido ascórbico e paracetamol). Para tal, no procedimento experimental é descrito o desenvolvimento do aparato extracorpóreo (mini-bomba compressora, válvulas solenóides e cela de análise). Esse é acoplado a um sistema de Análise por Injeção em Fluxo Automatizada (do inglês, Flow-injection Analysis) FIA-automatizada. Este trabalho também descreve a fabricação dos sensores em substrato de alumina, o processo de limpeza padrão dos eletrodos, o processo de obtenção dos eletrodos de referência em HCl (0,1 mol L-1) e ativação eletroquímica da superfície do eletrodo de trabalho com H2SO4 (0,1 mol L-1). Em seguida, é mostrada a estabilização dos eletrodos de referência Ag/AgCl em solução salina contendo cloretos, o estudo da secagem dos eletrodos em temperatura ambiente com exposição à luz e a caracterização dos mesmos por três métodos distintos, a saber: i) teste de reversibilidade (corrente redox vs. potencial); ii) variação do potencial com o tempo (coeficiente de degradação termodinâmica) e iii) variação do potencial com a concentração de cloretos. Também, apresenta-se a caracterização da área efetiva exposta do eletrodo de medição (trabalho) e os resultados da deposição de 1-2 Diaminobenzeno (DAB) como polímero seletivo. Além disso, são apresentados os resultados e discussões dos pseudo-eletrodos (recoberto ou não com Náfion® 117). Um ponto relacionado, a histerese associada à irreversibilidade dos eletrodos de referência resultou da ordem de 40 mVAg/AgCl Náfion® 117. Os potencias termodinâmicos observados foram da ordem de 100 ± 6 mVAg/AgCl Náfion® 117 para pseudo-eletrodo de referência sem e com Náfion® 117. Depois, foi realizado um estudo criterioso dos potenciais de resposta ao nitrito e aos interferentes por meio da técnica de DPV (do inglês, Differencial Pulse Voltammetry). Para evitar degradação acelerada (corrosão) do polímero sobre o eletrodo de trabalho, optou-se por realizar as medições com potencial igual a 0,50 VAg/AgCl Náfion® 117. Nessa condição, apresenta-se a monitoração de nitrito por FIA-automatizada na faixa de concentração de 50 a 250 mol L-1. Os resultados para a medição de nitrito mostraram que o sensor planar eletroquímico amperométrico desenvolvido é promissor, pois esse apresentou ótimo desempenho de reprodutividade (99,66%), sensibilidade (90 microA mol-1 L mm-2), seletividade (0,32%), repetitividade (91,28%) e estabilidade (15 ± 0,3 pA).In this Master of Science, it has been developed an electrochemical planar sensor defined with three electrodes for nitrite measuring and its interferents (uric acid, ascorbic acid and paracetamol). In the experimental procedure, it is shown the development of an extracorporis set up (mini-pump, solenoid valves and analysis cell) which is coupled to a system of Flow-injection Analysis (FIA). This work also describes the sensor fabrication using alumina substrates, the standard cleaning of the electrodes, the process to obtain Ag/AgCl reference electrodes in HCl (0.1 mol L-1) and electrochemical activation of the working-electrode surface with H2SO4 (0.1 mol L-1). Following, it is shown the study of drying for electrodes at room temperature with exposition to room light and their characterization using three different methods: i) reversibility test (redox current vs. potential); ii) variation of the potential with the time (thermodynamics degradation coefficient) and iii) variation of the potential with the chloride concentration. Also, it is presented the characterization of the effective exposed area of the working electrode and the results of the deposited 1-2 Diaminobenzene (DAB) is presented as a selective polymer. In addition, the results and discussions of the pseudo-reference (recovered or not with Nafion® 117) are presented. Related to irreversibility is the hysteresis associated to the reference electrodes which resulted in the order of 40 mVAg/AgCl Nafion® 117. The observed thermodynamic potentials were of (100 ± 6) mVAg/AgCl Nafion® 117 for pseudo-electrodes recovered with Nafion® 117. Later on, a careful study of the response to nitrite and to its interferents was performed by means of the DPV technique (Differential Pulse Voltammetry). In order to avoid accelerated degradation (corrosion) of the polymer, measurements were performed at a potential of 0,5 VAg/AgCl Nafion® 117. In this condition, nitrite was monitored using the automatized-FIA (Flow Injection Analysis) for concentration in the range of 50 to 250 mol L-1. The results have shown that the planar amperometric sensor for nitrite measuring is usefull since it was observed excellent performance related to reproducibility (99.66%), sensitivity (90 microA mol-1 L mm-2), selectivity (0.32%), repetibility (91.28%) and stability (15.0 ± 0.3 pA).
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Li, Hongbo. "FEM analysis with DSC modeling for materials in chip-substrate systems". Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280363.
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In electronic packaging, solder joints in surface mount technology are used for not only electrical connections, but mechanical connections as well. Due to the mismatch of the coefficients of thermal expansion of different components in chip-substrate systems, solder joints under thermal cycles could develop thermal stress inside and therefore experience fatigue failure after a certain number of load cycles. In this work, the disturbed state concept (DSC) model, a unified and hierarchical approach to model a variety of materials such as soils, rocks, ceramics, metals, and alloys, was appropriately modified to characterize a 63Sn-37Pb solder. This includes a modified hardening function that eliminates some inconsistency in the HISS-delta0 model when the bonding stress is nonzero, and a different fully adjusted state that is properly assumed from test data on the 63Sn-37Pb solder. A generalized computer procedure was then developed for 3-D constitutive level back prediction with the DSC model. In addition, a modified computer procedure for parameter determination was proposed and implemented to calculate the relative intact stress-strain curve for simple shear test data automatically. The above procedures for parameter determination and back prediction were used to model simple shear tests of the 63Sn-37Pb solder at different temperatures and strain rates. Based on material properties determined from test data at different combinations of temperature and strain rate, constitutive level back predictions were performed for each test data set using (1) specific material properties and (2) temperature and rate dependent material properties. Further, a 3-D DSC FEA (finite element analysis) program was used to simulate the same stress-strain behaviors of solder joints at different temperatures and strain rates. The results from back prediction and 3-D FEA simulation show that the test data have been better characterized by the modified DSC model. Moreover, 2-D and 3-D DSC FEA programs were employed to study the fatigue failure of a 144-Pin PBGA solder ball under cyclic thermomechanical loading. An accelerated-approximate procedure was incorporated into the 3-D FEA program to reduce the computational effort for fatigue analysis. Results of 3-D FEAs show that the 3-D geometry of a solder joint has significant influences on its fatigue life. The comparison of 2-D and 3-D results with the test results for the 144-pin PBGA solder ball indicates the FEA results are consistent with the initiation of failure observed in laboratory test. In addition, failure criteria based on fractional volume were also proposed for 2-D and 3-D FEAs by calibration of the available test results.
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Gao, Zhaoli. "CNT-TIM fabrication on aluminium alloy substrates /". View abstract or full-text, 2010. http://library.ust.hk/cgi/db/thesis.pl?MECH%202010%20GAO.
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Au, Ping Tong. "Mechanically stabilized bistable FLCD on flexible substrates /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20AU.
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Poller, Tilo. "Thermal and thermal-mechanical simulation for the prediction of fatigue processes in packages for power semiconductor devices". Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-154320.
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The knowledge about the reliability of power electronics is necessary for the design of converters. Especially for offshore applications it is essential to know, which fatigue processes happen and how the lifetime can be estimated. Numerical simulation is an important tool for the development of power electronic systems. This thesis analyse the thermal and thermal-mechanical behaviour of packages for power semiconductor devices with the help of simulations. One topic is the evaluation of different thermal models. The main focus is on the description of the thermal cross-coupling between the devices and the influence to the lifetime estimation. The power module is a well established package for power semiconductor devices. It will be explained how the heating period of power cycles influences the failure mode of this package type. Additionally, it will evaluated how SiC devices and DAB substrates influence the power cycling capability. The press-pack is in focus for high power applications as the package short-circuits during an electrical failure without external auxiliary systems. However, the knowledge about the power cycling behaviour is currently limited. With the help of simulations this behaviour will be analysed and possible weak points will be also derived. In the end of the work it will be discussed, how the lifetime can be estimated with help of FEM simulationsFür die Entwicklung von Umrichtern ist die Kenntnis über die Zuverlässigkeit der Leistungselektronik ein wichtiges Kernthema. Insbesondere für Offshore-Anwendungen ist das Wissen über die stattfindenden Ermüdungsprozesse und die Abschätzung der zu erwartenden Lebensdauer der Bauteile essentiell. Hierfür hat sich die Simulation als ein wichtiges Werkzeug für die Entwicklung und Lebensdauerbewertung von leistungselektronischen Anlagen etabliert. In der folgenden Arbeit wird das thermische und das thermisch-mechanische Verhalten der Leistungselektronik mittels Simulationen untersucht. Hierzu wird ein Vergleich zwischen verschiedenen thermischen Modellen für Leistungsbauelemente durchgeführt. Schwerpunkt ist die Beschreibung der thermischen Kopplung zwischen den Chips und deren Einfluss auf die Lebensdauerabschätzung. Ein weiterer Schwerpunkt ist das Leistungsmodul, welches sich als ein Standardgehäuse etabliert hat. Dazu wird erklärt, wie die Variation der Einschaltzeit im aktiven Lastwechseltest den Fehlermodus dieses Gehäusetyps beeinflusst. Weiterhin wird untersucht, wie SiC als Leistungshalbleiter und DAB als Substrat die Zuverlässigkeit beein- flusst. Der Press-Pack ist für Hochleistungsapplikationen von hohem Interesse, da dieses Gehäuse im elektrischen Fehlerfall ohne äußere Unterstützung kurzschliesst. Jedoch ist das Wissen über diese Gehäusetechnologie unter aktiven Lastwechselbedingungen sehr limitiert. Mit Hilfe von Simulationen wird dieses Verhalten untersucht und mögliche Schwachpunkte abgeleitet. Am Ende der Arbeit werden Möglichkeiten untersucht, wie Mithilfe von FEM Simulationen die Lebensdauer von Leistungsmodulen evaluiert werden kann
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Ge, Xiang. "Electrochemical deposition of fluoridated calcium phosphate on titanium substrates /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?MECH%202008%20GE.
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Liu, Chun Kit. "Process development and characterization of inductors for organic substrates /". View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MECH%202003%20LIU.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 70-72). Also available in electronic version. Access restricted to campus users.
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Zhang, Baoshe. "A study of substrate--liquid crystal interaction /". View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202003%20ZHANG.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 176-186). Also available in electronic version. Access restricted to campus users.
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Poller, Tilo. "Thermal and thermal-mechanical simulation for the prediction of fatigue processes in packages for power semiconductor devices". Doctoral thesis, Universitätsverlag der Technischen Universität Chemnitz, 2014. https://monarch.qucosa.de/id/qucosa%3A20135.
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The knowledge about the reliability of power electronics is necessary for the design of converters. Especially for offshore applications it is essential
to know, which fatigue processes happen and how the lifetime can be estimated. Numerical simulation is an important tool for the development
of power electronic systems. This thesis analyse the thermal and thermal-mechanical behaviour of packages for power semiconductor devices with the help of simulations. One topic is the evaluation of different thermal models.
The main focus is on the description of the thermal cross-coupling between the devices and the influence to the lifetime estimation. The power module is a well established package for power semiconductor devices. It will be explained how the heating period of power cycles influences the failure mode of this package type. Additionally, it will evaluated how SiC devices and DAB substrates influence the power cycling capability. The press-pack is in focus for high power applications as the package short-circuits during an electrical failure without external auxiliary systems. However, the knowledge about
the power cycling behaviour is currently limited. With the help of simulations this behaviour will be analysed and possible weak points will be also
derived.
In the end of the work it will be discussed, how the lifetime can be estimated with help of FEM simulations.Für die Entwicklung von Umrichtern ist die Kenntnis über die Zuverlässigkeit der Leistungselektronik ein wichtiges Kernthema. Insbesondere für Offshore-Anwendungen ist das Wissen über die stattfindenden Ermüdungsprozesse und die Abschätzung der zu erwartenden Lebensdauer der Bauteile essentiell. Hierfür hat sich die Simulation als ein wichtiges Werkzeug für die Entwicklung und Lebensdauerbewertung von leistungselektronischen Anlagen etabliert. In der folgenden Arbeit wird das thermische und das thermisch-mechanische Verhalten der Leistungselektronik mittels Simulationen untersucht. Hierzu wird ein Vergleich zwischen verschiedenen thermischen Modellen für Leistungsbauelemente durchgeführt. Schwerpunkt ist die Beschreibung der thermischen Kopplung zwischen den Chips und deren Einfluss auf die Lebensdauerabschätzung. Ein weiterer Schwerpunkt ist das Leistungsmodul, welches sich als ein Standardgehäuse etabliert hat. Dazu wird erklärt, wie die Variation der Einschaltzeit im aktiven Lastwechseltest den Fehlermodus dieses Gehäusetyps beeinflusst. Weiterhin wird untersucht, wie SiC als Leistungshalbleiter und DAB als Substrat die Zuverlässigkeit beein- flusst. Der Press-Pack ist für Hochleistungsapplikationen von hohem Interesse, da dieses Gehäuse im elektrischen Fehlerfall ohne äußere Unterstützung kurzschliesst. Jedoch ist das Wissen über diese Gehäusetechnologie unter aktiven Lastwechselbedingungen sehr limitiert. Mit Hilfe von Simulationen wird dieses Verhalten untersucht und mögliche Schwachpunkte abgeleitet. Am Ende der Arbeit werden Möglichkeiten untersucht, wie Mithilfe von FEM Simulationen die Lebensdauer von Leistungsmodulen evaluiert werden kann.
Książki na temat "DSB substrates"
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Bay, Mihee J., i Bruce K. Shapiro. Attention Deficit-Hyperactivity Disorder. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0060.
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Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder in children and is characterized by developmentally inappropriate levels of attention and/or activity level. The current diagnostic criteria are summarized in the recently updated DSM-5. Although the neurobiology of ADHD is not completely understood, dysfunction in the fronto-striatal network and catecholaminergic system is likely implicated in pathophysiology of ADHD although recent studies suggest involvement of other neural substrates as well. Stimulants have been the mainstay of pharmacotherapy for ADHD due to its role in increasing available catecholamines in the synapse. However, treatment approach should be multimodal.
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Pallanti, Stefano, Jennifer Barnes, Christopher Pittenger i Jane Eisen. Incompleteness and Harm Avoidance in OCD. Redaktor Christopher Pittenger. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228163.003.0009.
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Obsessive-compulsive disorder (OCD) has been traditionally linked with the motivational dimension of harm avoidance (HA). However, there is increasing evidence for the involvement of a second core dimension, referred to as Incompleteness (INC) or “not just right experiences” (NJREs), in a substantial fraction of patients. INC-driven compulsions are typically driven by feelings of discomfort or tension, rather than by anxiety. Appreciation of the importance of INC in OCD is one of the factors that motivated the movement of OCD out of the Anxiety Disorders chapter and into its own grouping in the latest edition of the Diagnostic and Statistical Manual (DSM-5). Both dimensions seem to contribute to OCD symptomatology, thus representing core features underlying the disorder. In this chapter, the differential roles and neural substrates of HA and INC are discussed, together with the consequent theoretical and clinical implications.
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Leite, Maria José de Holanda. Gesso e rejeitos de mineração na correção de um solo salino-sódico e no crescimento inicial do maracujazeiro amarelo. Amplla Editora, 2022. http://dx.doi.org/10.51859/amplla.grm747.1122-0.
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O maracujazeiro-amarelo é considerado uma espécie sensível aos sais (Ayers & Westcot, 1999). Assim o declínio produtivo da cultura deve ocorrer quando a condutividade elétrica do ambiente radicular das plantas atingisse valores superiores a 1,3 dS m-1. Entretanto, algumas pesquisas têm demonstrado que, apesar da salinidade provocar reflexos negativos no crescimento, na capacidade produtiva da cultura e na qualidade dos frutos (Soares et al., 2008; Cavalcante et al., 2009), a utilização de corretivos pode amenizar os efeitos da salinidade, resultando em maior desenvolvimento das mudas e produção de frutos pelas plantas (Souza et al., 2008). Alguns trabalhos mostraram que a utilização de rejeitos de mineração como constituinte de substratos para emergência e produção de mudas de várias espécies vegetais, como Carica papaya L. (Alencar, 2004); Moringa oleifera Lam. (Alves, 2005); Jatropha curcas L. (Trajano et al., 2010); Cnidoscolus quercifolius Pohl. (Farias Júnior, 2011) e Mimosa caesalpiniifolia Benth. (Rodrigues, 2011), pode ser uma alternativa promissora para diminuição dos impactos ambientais destes rejeitos. Contudo, estudos avaliando o efeito destes rejeitos em solos salinizados são quase inexistentes. O presente trabalho teve o objetivo de avaliar o efeito do gesso agrícola e doses de rejeitos de vermiculita e de caulim, sobre os atributos químicos de um solo salino-sódico e o crescimento do maracujazeiro amarelo.
Części książek na temat "DSB substrates"
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Yoo, W. S., i H. Matsunami. "Growth Simulation of SiC Polytypes and Application to DPB-Free 3C-SiC on Alpha-SiC Substrates". W Springer Proceedings in Physics, 66–77. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-84804-9_8.
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Kavitha S, K. V. S. S. S. S. Sairam i Ashish Singh. "Substrate Effects on the Plasmonic Resonance of Graphene Nano-Antenna". W Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde221098.
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In this manuscript, a pentagon shaped plasmonic graphene nano patch antenna is designed and investigated on silicon dioxide, silicon nitride and zinc oxide substrates. The optical characteristics of the graphene such as conductivity and permittivity are analyzed at various values of chemical potential using Kubo conductivity model. The plasmonic resonance of the proposed nano-antenna is analyzed through the graphene chemical potential varied in the span from 0.0 eV to 2.0 eV. It is observed that the proposed pentagon shaped graphene nano patch antenna shows good plasmonic resonance characteristics at 29.8750 THz with the reflection coefficient of -27.4153 dB, 91.5650 THz with -27.5179 dB and 853.7350 THz with -40.3267 dB on silicon dioxide, zinc oxide and silicon nitride substrates respectively. These optimum characteristics are observed at the chemical potential values 2.00 eV and 0.50 eV for the proposed graphene nano patch antenna.
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"Substrate Integrated Waveguide Diplexer Design". W Practical Approach to Substrate Integrated Waveguide (SIW) Diplexer, 135–48. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-2084-0.ch006.
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This chapter implements the microwave diplexer circuit model established in Chapter 4, using the twenty-first substrate integrated waveguide transmission line technology. No separate junction (resonant or non-resonant) was utilised in achieving the diplexer, as the use of an external junction for energy distribution in a diplexer normally increases design complexity and lead to a bulky device. The design also featured a novel input/output coupling technique at the transmit and the receive sides of the diplexer. The proposed SIW diplexer has been simulated using the full-wave finite element method (FEM), Keysight electromagnetic professional (EMPro) 3D simulator. The design has also been validated experimentally and results presented. Simulated and measured results show good agreement. The measured minimum insertion loss achieved on the transmit and the receive channels of the diplexer are 2.86 dB and 2.91 dB, respectively. The measured band isolation between the two channels is better than 50 dB.
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Matthews, Keith, i David Christmas. "Neurosurgery for psychiatric disorders". W New Oxford Textbook of Psychiatry, 1266–71. Oxford University Press, 2012. http://dx.doi.org/10.1093/med/9780199696758.003.0163.
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Despite its chequered past, modern NMD bears little similarity to historical freehand procedures. Advances in neuroimaging mean that anatomical substrates for depression and OCD are being elucidated. Ablative procedures such as ACAPS and ACING are unlikely to undergo randomized controlled trials but prospective clinical audit suggests that such procedures may offer improvement to selected patients with treatment-refractory depression and OCD. Interventions such as VNS and DBS offer the possibility of double-blind testing but as yet there is insufficient evidence to suggest that such procedures offer greater effectiveness.
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"Microstrip Diplexer Design". W Practical Approach to Substrate Integrated Waveguide (SIW) Diplexer, 122–34. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-2084-0.ch005.
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In this chapter, the microstrip square open-loop resonator (SOLR) has been utilised in the implementation of the microwave diplexer circuit model established in Chapter 4. The SOLR is very popular and well known resonator type commonly used in the implementation of microwave passive devices including filters and diplexers, due to its compact size. The simulation and measurement results show good agreement, with a band isolation of about 50 dB achieved between the transmit (Tx) and the receive (Rx) bands of the diplexer.
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Saxena, Anurag, i Bharat Bhushan Khare. "A Hammer Type Textile Antenna With Partial Circle Ground for Wide-Band Application". W Design and Optimization of Sensors and Antennas for Wearable Devices, 15–24. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9683-7.ch002.
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In this chapter, a partial circle ground textile patch antenna for wideband applications with better bandwidth is presented. The simulated antenna is proposed on textile jeans substrate having dielectric constant of 1.7. The radius of textile jeans substrate antenna is 15 mm. The overall simulation of partial circle grounded shaped antenna has been done using CST simulation tool. The simulated antenna resonates at frequency 9.285 GHz with the reflection coefficient of -28 dB. It covers a bandwidth from 7.008 GHz to 9.64 GHz. It has maximum directivity of 4.540 dBi.
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Mishra, Bal Mukund, Supriyo Roy i Goutam Kumar Bose. "Tribological and Micro-Structural Characterization of Ni-Cu-P-W Coatings". W Advanced Surface Coating Techniques for Modern Industrial Applications, 209–25. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4870-7.ch009.
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Ni-Cu-P-W coating was deposited by electroless method on mild steel substrate to study the crystallization and tribological behavior at different annealing temperatures. Energy dispersive x-ray (EDX) analysis, scanning electron microscopy (SEM), x-ray diffraction (XRD), and differential scanning calorimeter (DSC) were used to study the composition, surface morphology, phase behavior, and thermal behavior of the coating, respectively. Tribological study was conducted using Pin-on-Disc tribotester. EDX analysis confirms the presence of Ni, Cu, P, and W in the deposit. SEM image shows the surface is dense, smooth, and without any observable nodule. Some of the samples were heat treated to 300°C, 500°C, and 700°C for 1 hour to observe the crystallographic change by XRD. One sharp crystalline peak of Ni (111) is present in all condition, but the intensity increases rapidly with the heat treatment temperature. The phase transition temperature of this quaternary coating analyzed by DSC was 431.8°C.
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Ravivarma, P., T. Sudha, E. Sathish i G. S. Annie Grace Vimala. "A Novel Dual Polarized Dual Band Antenna for Wireless Backscattering Applications". W Antenna Design for Narrowband IoT, 149–61. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-9315-8.ch011.
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This chapter presents a compact patch antenna for backscattering application. The model utilizes a crossed slot etched on single layer low loss substrate. The dimensions of the radiating patch are tuned through parametric analysis of the model in order to improve cross-polarization (dB) isolation and the axial ratio beamwidth of the antenna, and the results are compared with other conventional antennas. The antenna attains an impedance characteristic of -17.65dB at 2.15GHz and -22.28 dB at 2.4GHz operating frequency and provides an impedance bandwidth (|S11|≤-10dB) of 60MHz ant both bands. The antenna achieves a maximum gain of 6.8dB at 2.15GHz and 7.3dB at 2.4GHz in the direction of propagation. The antenna also gives a cross-polarization (dB) of -12 dB for a wide beam angle. Finally, a good agreement has been obtained for using the proposed design for modern dual-band wireless backscattering applications.
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Ankolekar, Sandeep, i Michela Simoni. "Post-stroke cognitive impairment". W Stroke in the Older Person, 381–98. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198747499.003.0025.
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‘Post-stroke cognitive impairment’ explores in great depth the burden of post-stroke cognitive impairment, its pathological substrates and clinical characteristics, the causes of these impairments, post-stroke dementia, and the risk factors implicated. The chapter examines common definitions (vascular cognitive impairment, vascular dementia, post-stroke cognitive impairment), the DSM-5 criteria (Diagnostic and Statistical Manual of Mental Disorders-5), ICD-10 criteria (International Classification of Diseases), NINDS-AIREN criteria (National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l’Enseignement en Neurosciences) for vascular dementia, and vascular mild cognitive impairment. The VASCOG (vascular cognitive disorder) criteria are also described. A pragmatic approach to investigations and various assessment scales, a description of important clinical trials, and the management of these disorders are also included.
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Nwajana, Augustine O., Emenike Raymond Obi, Gerald Kelechi Ijemaru, Emmanuel U. Oleka i Destiny Chidi Anthony. "Fundamentals of RF/Microwave Bandpass Filter Design". W Handbook of Research on 5G Networks and Advancements in Computing, Electronics, and Electrical Engineering, 149–64. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-6992-4.ch005.
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This chapter presents the basic approach of microwave bandpass filter design for 5G network applications. The chapter serves as a reference source to microwave stakeholders with little or no filter design experience. It should help them to design and implement their first filter device using microstrip technology. A three-pole Chebyshev bandpass filter with centre frequency of 2.6 GHz, fractional bandwidth of 3%, passband ripple of 0.04321 dB, and return loss of 20 dB has been designed. The designed filter implementation is based on the Rogers RT/Duroid 6010LM substrate with a 10.7 dielectric constant and 1.27 mm thickness. The circuit model and microstrip layout results of the BPF are presented and show good agreement. The microstrip layout simulation results show that a less than 1.8 dB minimum insertion loss and a greater than 25 dB in-band return loss were achieved. The overall device size of the BPF is 18.0 mm by 10.7 mm, which is equivalent to 0.16λg x 0.09λg, where λg is the guided wavelength of the 50 Ohm microstrip line at the filter centre frequency.
Streszczenia konferencji na temat "DSB substrates"
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Sullivan, Jim, Harry Kirk, Sien Kang, Philip Ong i Francois Henley. "High Temperature Oxygen Out-Diffusion from the Interfacial SiOx Bond Layer in Direct Silicon Bonded (DSB) Substrates". W 2006 IEEE international SOI. IEEE, 2006. http://dx.doi.org/10.1109/soi.2006.284422.
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Huang, Yao-Tsung, Angelo Pinto, Chien-Ting Lin, Che-Hua Hsu, Manfred Ramin, Mike Seacrist, Mike Ries i in. "Amorphization and Templated Recrystallization (ATR) Study for Hybrid Orientation Technology (HOT) using Direct Silicon Bond (DSB) Substrates". W 2007 International Symposium VLSI Technology, Systems and Applications (VLSI-TSA). IEEE, 2007. http://dx.doi.org/10.1109/vtsa.2007.378957.
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Ivosevic, M., R. Knight, S. R. Kalidindi, G. R. Palmese, A. Tsurikov i J. K. Sutter. "Optimal Substrate Preheating Model for Thermal Spray Deposition of Thermosets onto Polymer Matrix Composites". W ITSC2003, redaktorzy Basil R. Marple i Christian Moreau. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.itsc2003p1683.
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Abstract High velocity oxy-fuel (HVOF) sprayed, functionally graded polyimide/WC-Co composite coatings on polymer matrix composites (PMC's) are being investigated for applications in turbine engine technologies. This requires that the polyimide, used as the matrix material, be fully crosslinked during deposition in order to maximize its engineering properties. The rapid heating and cooling nature of the HVOF spray process and the high heat flux through the coating into the substrate typically do not allow sufficient time at temperature for curing of the thermoset. It was hypothesized that external substrate preheating might enhance the deposition behavior and curing reaction during the thermal spraying of polyimide thermosets. An additional difficulty arises from the low thermal conductivity and low specific heat capacity of the PMC substrate, which prevent effective substrate preheating by the HVOF jet as in the case of metallic substrates. A simple analytical process model for the deposition of thermosetting polyimide onto polymer matrix composites by HVOF thermal spray technology has been developed. The model incorporates various heat transfer mechanisms and enables surface temperature profiles of the coating to be simulated, primarily as a function of substrate preheating temperature. Four cases were modeled: (i) no substrate preheating; (ii) substrates electrically preheated from the rear; (iii) substrates preheated by hot air from the front face; and (iv) substrates electrically preheated from the rear and by hot air from the front. Thermal properties of the polyimide needed for the simulations were determined by Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA). Microstructural characterization of the coatings and the morphology of polyimide splats sprayed both with and without substrate preheating were analyzed using standard metallographic techniques. Coating temperature in cases (iii) and (iv) never dropped below the crosslinking temperature of the polyimide feedstock. This was the critical condition required for the curing reaction and successful deposition of thermosets by HVOF thermal spraying.
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Curtis, Sabrina M., Duygu Dengiz, Prasanth Velvaluri, Lars Bumke, Eckhard Quandt, Marian Sielenkämper, Stephan Wulfinghoff, Gowtham Arivanandhan, Zixiong Li i Manfred Kohl. "Bistable Actuators Based on Shape Memory Alloy/ Polymer Composites". W SMST2022. ASM International, 2022. http://dx.doi.org/10.31399/asm.cp.smst2022p0001.
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Abstract The thermal induced martensitic phase transition in TiNiHf was exploited for bi-directional actuation with TiNiHf/SiO2/Si composites. When compared to free-standing films of similar thickness, films on a substrate exhibit a reduced fatigue effect upon thermal cycling and a smaller hysteresis width. Differential scanning calorimetry (DSC) and cantilever deflection measurements (CDM) results showed that the transition temperatures of fabricated TiNiHf films and TiNiHf/SiO2/Si bimorph composites decrease with thermal cycling. The change in transition temperatures after 40 thermal cycles is significantly reduced for TiNiHf films bound to a SiO2/Si substrate compared to the functional fatigue DSC results reported for freestanding films. The thermal hysteresis width is also reduced for TiNiHf films constrained by SiO2/Si and Si substrates compared to freestanding films of similar thicknesses. With proper composition selection and microstructural control, TiNiHf films can be promising SMA films for bistable actuators with PMMA/TiNiHf/Si composites.
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Schurz, Daniel, i Warren W. Flack. "Performance of a Dual Side Substrate Metrology System for Micromachining Lithography". W ASME 2004 3rd Integrated Nanosystems Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/nano2004-46040.
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Advances in micromachining (MEMS) applications such as optical components, inertial and pressure sensors, fluidic pumps and radio frequency (RF) devices are driving lithographic requirements for tighter registration, improved pattern resolution and improved process control on both sides of the substrate. Consequently, there is a similar increase in demand for advanced metrology tools capable of measuring the Dual Side Alignment (DSA) performance of the lithography systems. There are a number of requirements for an advanced DSA metrology tool. First, the system should be capable of measuring points over the entire area of the wafer rather than a narrow area near the lithography alignment targets. Secondly, the system should be capable of measuring a variety of different substrate types and thicknesses. Finally, it should be able to measure substrates containing opaque deposited films such as metals. In this paper, the operation and performance of a new DSA metrology tool is discussed. The UltraMet 100 offers DSA registration measurement at greater than 90% of a wafer’s surface area, providing a true picture of a lithography tool’s alignment performance and registration yield across the wafer. The system architecture is discussed including the use of top and bottom cameras and the pattern recognition system. Experimental data is shown for tool performance in terms of repeatability and reproducibility over time. The requirements for tool accuracy and methods to establish accuracy to a NIST traceable standard are also discussed.
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Völkel, R., H. P. Herzig, Ph Nussbaum, W. Singer i R. Dändliker. "Microlens Lithography". W Diffractive Optics and Micro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/domo.1996.dwb.4.
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The future demands for flat panel display (FPD) manufacturing is a resolution of 3-5 μm for large substrates of 550 × 650 mm2 size. Standard lithographic techniques, like wafer stepping or proximity printing can be used. Unfortunately, these methods have some severe drawbacks which significantly increase the fabrication costs. Using a wafer stepper, the small printing area will cause numerous exposure steps. The stepping has to be very accurate, because stitching errors can be easily seen in the display pattern. Using a proximity printer, the substrate is set some 20-50 μm behind the mask to achieve a resolution of 3-5 μm. This is not an easy task for large substrates. The costs for these highly planar substrates are immense. A direct contact may easily damage the expensive photomask.
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Ravi, Kesavan, Yuji Ichikawa, Kazuhiro Ogawa, Tiana Deplanke, Olivier Lame i Jean-Yves Cavaille. "Mechanistic Study and Characterization of Cold Sprayed Ultra-High Molecular Weight Polyethylene-Nano Ceramic Composite Coating". W ITSC2015, redaktorzy A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen i C. A. Widener. ASM International, 2015. http://dx.doi.org/10.31399/asm.cp.itsc2015p0585.
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Abstract The cold spray deposition of ultra high molecular weight polyethylene (UHMWPE) powder mixed with nano alumina, fumed nano alumina and fumed nano silica was attempted on two different substrates namely polypropylene (PP) and aluminum (Al). Approximately 4mm and 1mm thick coating were observed on Al and PP substrates respectively with UHMWPE and fumed nano alumina mixture. The nano ceramic particles played an important role as a bridge bond between the particles. The coatings with nano alumina, fumed nano alumina and fumed nano silica were very contrasting in terms of coating thickness. Gas temperature and pressure played an important role in the deposition. The differential scanning calorimetry (DSC) results of the coatings showed that UHMWPE was melt crystallized after the coating. The substrate properties also affected the deposition mechanism greatly.
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Nguyen, Mary-Anne, i Andy Sarles. "Microfabrication for Packaged Biomolecular Unit Cells". W ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3068.
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This paper focuses on developing a closed fluidic environment for packaging biomolecular unit cells, which consists of a synthetic lipid bilayer and other biomolecules contained in a near solid-state material with two regions that contain hydrophobic oil (i.e. nonpolar solvent) surrounding aqueous droplets. This research provides a stepping-stone towards an autonomic biomolecular material system, whereby a packaged system will allow for precise droplet interface bilayer (DIB) formation without the interference of outside contamination for long-term applications. Also, substrate materials need to maintain droplets and preserve the self-assembly and stimuli-responsive properties of biomolecules within the unit cell. A critical feature of an encapsulating material is that it does not absorb either of the liquid phases required to form DIBs. Oil depletion tests within sealed, polymeric substrates show that polydimethylsiloxane (PDMS) absorbs full volume of injected hexadecane in approximately 27 hours. However, polyurethane substrates maintain the original amount of oil injected even after several weeks. Bilayer lifetime is also monitored within an environment in which the oil is also depleting. The results of this test show the longevity of a DIB to be shorter than oil lifetime. The lipid-encased droplets disconnect after approximately 10 hours, when there is only approximately <60% amount of oil present. In addition, an initial microfluidic substrate is designed such that a single T-junction intersection can be used to form monodisperse droplets within a primary oil-filled channel and a downstream increase in channel width can be used to connect droplets to form DIBs.
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Gunther, Michael, Klaus-jurgen Wolter, Martin Rittner i Wolfgang Nuchter. "Failure Mechanisms of Direct Copper Bonding Substrates (DCB)". W 2006 1st Electronic Systemintegration Technology Conference. IEEE, 2006. http://dx.doi.org/10.1109/estc.2006.280090.
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Sung, C. Y., Haizhou Yin, H. Ng, K. L. Saenger, G. Pfeiffer, V. Chan, R. Zhang i in. "Direct Silicon Bonded (DSB) Mixed Orientation Substrate for High Performance Bulk CMOS Technology". W 2006 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 2006. http://dx.doi.org/10.7567/ssdm.2006.h-1-1.
Pełny tekst źródłaRaporty organizacyjne na temat "DSB substrates"
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Wilson, Thomas E., Avraham A. Levy i Tzvi Tzfira. Controlling Early Stages of DNA Repair for Gene-targeting Enhancement in Plants. United States Department of Agriculture, marzec 2012. http://dx.doi.org/10.32747/2012.7697124.bard.
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Gene targeting (GT) is a much needed technology as a tool for plant research and for the precise engineering of crop species. Recent advances in this field have shown that the presence of a DNA double-strand break (DSB) in a genomic locus is critical for the integration of an exogenous DNA molecule introduced into this locus. This integration can occur via either non-homologous end joining (NHEJ) into the break or homologous recombination (HR) between the broken genomic DNA and the introduced vector. A bottleneck for DNA integration via HR is the machinery responsible for homology search and strand invasion. Important proteins in this pathway are Rad51, Rad52 and Rad54. We proposed to combine our respective expertise: on the US side, in the design of zincfinger nucleases (ZFNs) for the induction of DNA DSBs at any desired genomic locus and in the integration of DNA molecules via NHEJ; and on the Israeli side in the HR events, downstream of the DSB, that lead to homology search and strand invasion. We sought to test three major pathways of targeted DNA integration: (i) integration by NHEJ into DSBs induced at desired sites by specially designed ZFNs; (ii) integration into DSBs induced at desired sites combined with the use of Rad51, Rad52 and Rad54 proteins to maximize the chances for efficient and precise HR-mediated vector insertion; (iii) stimulation of HR by Rad51, Rad52 and Rad54 in the absence of DSB induction. We also proposed to study the formation of dsT-DNA molecules during the transformation of plant cells. dsT-DNA molecules are an important substrate for HR and NHEJ-mediatedGT, yet the mode of their formation from single stranded T-DNA molecules is still obscure. In addition we sought to develop a system for assembly of multi-transgene binary vectors by using ZFNs. The latter may facilitate the production of binary vectors that may be ready for genome editing in transgenic plants. ZFNs were proposed for the induction of DSBs in genomic targets, namely, the FtsH2 gene whose loss of function can easily be identified in somatic tissues as white sectors, and the Cruciferin locus whose targeting by a GFP or RFP reporter vectors can give rise to fluorescent seeds. ZFNs were also proposed for the induction of DSBs in artificial targets and for assembly of multi-gene vectors. We finally sought to address two important cell types in terms of relevance to plant transformation, namely GT of germinal (egg) cells by floral dipping, and GT in somatic cells by root and leave transformation. To be successful, we made use of novel optimized expression cassettes that enable coexpression of all of the genes of interest (ZFNs and Rad genes) in the right tissues (egg or root cells) at the right time, namely when the GT vector is delivered into the cells. Methods were proposed for investigating the complementation of T-strands to dsDNA molecules in living plant cells. During the course of this research, we (i) designed, assembled and tested, in vitro, a pair of new ZFNs capable of targeting the Cruciferin gene, (ii) produced transgenic plants which expresses for ZFN monomers for targeting of the FtsH2 gene. Expression of these enzymes is controlled by constitutive or heat shock induced promoters, (iii) produced a large population of transgenic Arabidopsis lines in which mutated mGUS gene was incorporated into different genomic locations, (iv) designed a system for egg-cell-specific expression of ZFNs and RAD genes and initiate GT experiments, (v) demonstrated that we can achieve NHEJ-mediated gene replacement in plant cells (vi) developed a system for ZFN and homing endonuclease-mediated assembly of multigene plant transformation vectors and (vii) explored the mechanism of dsTDNA formation in plant cells. This work has substantially advanced our understanding of the mechanisms of DNA integration into plants and furthered the development of important new tools for GT in plants.
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Schwartz, Bertha, Vaclav Vetvicka, Ofer Danai i Yitzhak Hadar. Increasing the value of mushrooms as functional foods: induction of alpha and beta glucan content via novel cultivation methods. United States Department of Agriculture, styczeń 2015. http://dx.doi.org/10.32747/2015.7600033.bard.
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During the granting period, we performed the following projects: Firstly, we differentially measured glucan content in several pleurotus mushroom strains. Mushroom polysaccharides are edible polymers that have numerous reported biological functions; the most common effects are attributed to β-glucans. In recent years, it became apparent that the less abundant α-glucans also possess potent effects in various health conditions. In our first study, we explored several Pleurotus species for their total, β and α-glucan content. Pleurotuseryngii was found to have the highest total glucan concentrations and the highest α-glucans proportion. We also found that the stalks (stipe) of the fruit body contained higher glucan content then the caps (pileus). Since mushrooms respond markedly to changes in environmental and growth conditions, we developed cultivation methods aiming to increase the levels of α and β-glucans. Using olive mill solid waste (OMSW) from three-phase olive mills in the cultivation substrate. We were able to enrich the levels mainly of α-glucans. Maximal total glucan concentrations were enhanced up to twice when the growth substrate contained 80% of OMSW compared to no OMSW. Taking together this study demonstrate that Pleurotuseryngii can serve as a potential rich source of glucans for nutritional and medicinal applications and that glucan content in mushroom fruiting bodies can be further enriched by applying OMSW into the cultivation substrate. We then compared the immune-modulating activity of glucans extracted from P. ostreatus and P. eryngii on phagocytosis of peripheral blood neutrophils, and superoxide release from HL-60 cells. The results suggest that the anti-inflammatory properties of these glucans are partially mediated through modulation of neutrophileffector functions (P. eryngiiwas more effective). Additionally, both glucans dose-dependently competed for the anti-Dectin-1 and anti-CR3 antibody binding. We then tested the putative anti-inflammatory effects of the extracted glucans in inflammatory bowel disease (IBD) using the dextran sulfate sodium (DSS)–induced model in mice. The clinical symptoms of IBD were efficiently relieved by the treatment with two different doses of the glucan from both fungi. Glucan fractions, from either P. ostreatus or P. eryngii, markedly prevented TNF-α mediated inflammation in the DSS–induced inflamed intestine. These results suggest that there are variations in glucan preparations from different fungi in their anti-inflammatory ability. In our next study, we tested the effect of glucans on lipopolysaccharide (LPS)-induced production of TNF-α. We demonstrated that glucan extracts are more effective than mill mushroom preparations. Additionally, the effectiveness of stalk-derived glucans were slightly more pronounced than of caps. Cap and stalk glucans from mill or isolated glucan competed dose-dependently with anti-Dectin-and anti-CR-3 antibodies, indicating that they contain β-glucans recognized by these receptors. Using the dextran sulfate sodium (DSS)-inflammatory bowel disease mice model, intestinal inflammatory response to the mill preparations was measured and compared to extracted glucan fractions from caps and stalks. We found that mill and glucan extracts were very effective in downregulatingIFN-γ and MIP-2 levels and that stalk-derived preparations were more effective than from caps. The tested glucans were equally effective in regulating the number of CD14/CD16 monocytes and upregulating the levels of fecal-released IgA to almost normal levels. In conclusion, the most effective glucans in ameliorating some IBD-inflammatory associated symptoms induced by DSS treatment in mice were glucan extracts prepared from the stalk of P. eryngii. These spatial distinctions may be helpful in selecting more effective specific anti-inflammatory mushrooms-derived glucans. We additionally tested the effect of glucans on lipopolysaccharide-induced production of TNF-α, which demonstrated stalk-derived glucans were more effective than of caps-derived glucans. Isolated glucans competed with anti-Dectin-1 and anti-CR3 antibodies, indicating that they contain β-glucans recognized by these receptors. In conclusion, the most effective glucans in ameliorating IBD-associated symptoms induced by DSS treatment in mice were glucan extracts prepared from the stalk of P. eryngii grown at higher concentrations of OMSW. We conclude that these stress-induced growing conditions may be helpful in selecting more effective glucans derived from edible mushrooms. Based on the findings that we could enhance glucan content in Pleurotuseryngii following cultivation of the mushrooms on a substrate containing different concentrations of olive mill solid waste (OMSW) and that these changes are directly related to the content of OMSW in the growing substrate we tested the extracted glucans in several models. Using dextran sulfate sodium (DSS)–inflammatory bowel disease (IBD) mice model, we measured the colonic inflammatory response to the different glucan preparations. We found that the histology damaging score (HDS) resulting from DSS treatment reach a value of 11.8 ± 2.3 were efficiently downregulated by treatment with the fungal extracted glucans, glucans extracted from stalks cultivated at 20% OMSWdownregulated to a HDS value of 6.4 ± 0.5 and at 80% OMSW showed the strongest effects (5.5 ± 0.6). Similar downregulatory effects were obtained for expression of various intestinal cytokines. All tested glucans were equally effective in regulating the number of CD14/CD16 monocytes from 18.2 ± 2.7 % for DSS to 6.4 ± 2.0 for DSS +glucans extracted from stalks cultivated at 50% OMSW. We finally tested glucans extracted from Pleurotuseryngii grown on a substrate containing increasing concentrations of olive mill solid waste (OMSW) contain greater glucan concentrations as a function of OMSW content. Treatment of rat Intestinal epithelial cells (IEC-6) transiently transfected with Nf-κB fused to luciferase demonstrated that glucans extracted from P. eryngii stalks grown on 80% OMSWdownregulatedTNF-α activation. Glucans from mushrooms grown on 80% OMSW exerted the most significant reducing activity of nitric oxide production in lipopolysaccharide (LPS) treated J774A.1 murine macrophages. The isolated glucans were tested in vivo using the Dextran Sodium Sulfate (DSS) induced colitis in C57Bl/6 mice and found to reduce the histology damaging score resulting from DSS treatment. Expression of various intestinal cytokines were efficiently downregulated by treatment with the fungal extracted glucans. We conclude that the stress-induced growing conditions exerted by OMSW induces production of more effective anti-inflammatory glucans in P. eryngii stalks.
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Ruschau i Tossey. L52209 Application of Repair Coatings to Wet Surfaces. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), czerwiec 2004. http://dx.doi.org/10.55274/r0010377.
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The field application of pipeline repair and rehabilitation coatings can be greatly dependent upon the ambient conditions on the day of the scheduled repair. In some cases, such as the application of FBE at girth welds, temporary shelters can be built over the girth weld area to protect pipe from the elements. However, for the majority of pipeline applications, coatings must be applied to a pipe surface that is not optimized for coating application. Specifically, pipelines which are in service during the repair coating operation will be at the temperature of the product flowing through them regardless of the ambient temperature. This poses a very large problem when the temperature of the pipeline is below the dew point of the ambient air, because condensation will occur continuously on the pipe surface. The objective of this work was to determine the performance implications of applying pipeline repair coatings to wet or damp surfaces. Six liquid repair coatings were applied to steel substrates with varying degrees of surface wetness. Three coatings were standard epoxies; three were specially formulated for wet surface tolerance. The coatings were tested for cathodic disbondment resistance, mechanical strength, and how each coating interacts with water during curing. FTIR and DSC analysis of each coating when mixed and cured in wet conditions (water added to the mix) showed no evidence of water interacting with the coating and changing the chemical structure or the chemical properties. Thus it was concluded that the wet surface tolerant coatings, while manufacturers may claim that they were formulated to absorb and accommodate water, in reality just have a better ability to displace water than standard repair coatings.