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Vivencias de fe ante la eucaristía en los confirmandos de la I.E. “Luis Alberto Sánchez”, La Zaranda, Pítipo, 2016Arrasco Gelacio, Maritza Cecilia, Gonzales Vasquez, Bertha January 2018 (has links)
La presente investigación realizada en la I.E. "Luis Alberto Sánchez”, la Zaranda, Pítipo-2016, responde a diversas problemáticas existentes en el área de educación religiosa, la más resaltante, se sitúa en torno a las vivencias de fe ante la Eucaristía que tienen los estudiantes, pues muchas veces no se le da la debida importancia. Ante esto, la investigación tuvo como objetivo general: Determinar las vivencias de fe ante la eucaristía en los confirmados de la I.E estudiada, por lo cual nos planteamos: ¿De qué manera los jóvenes confirmandos vivencian su fe ante la eucaristía en la I.E Luis Alberto Sánchez- La Zaranda- Pítipo 2016? El enfoque de la investigación es cuantitativo, de tipo descriptivo, con muestra no aleatoria. Como instrumento de recolección de datos se utilizó una encuesta. Se concluyó que los estudiantes presentan diversas deficiencias en torno a los actos de piedad y de fe, y que sólo el 50% se encuentran en un nivel idóneo de la escala. A su vez, los estudiantes muestran más fortalezas en los actos de fe que en los de piedad, manifestando paulatinamente un desarrollo constante. / Trabajo académico
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Frataxin (FXN) Based Regulation of the Iron-Sulfur Cluster Assembly ComplexRabb, Jennifer 2012 May 1900 (has links)
Iron-sulfur clusters are protein cofactors that are critical for all life forms. Elaborate multi-component systems have evolved for the biosynthesis of these cofactors to protect organisms from the toxic effects of free iron and sulfide ions. In eukaryotes, the Fe-S cluster assembly machinery operates in the matrix space of the mitochondria and contains a myriad of proteins that mediate sulfur, iron, and electron transfer to assemble Fe-S clusters on the scaffold protein ISCU2 and then distribute these clusters to target proteins. Our lab has recently described stable 3, and 4-protein complexes composed of the cysteine desulfurase NFS1, the co-chaperone ISD11, and ISCU2 (SDU), and NFS1, ISD11, ISCU2, and FXN (SDUF) subunits. In the latter, SDUF, FXN functions as an allosteric activator switching this assembly complex on for Fe-S cluster biosynthesis. Insufficient expression of the mitochondrial protein FXN leads to a progressive neurodegenerative disease, Friedreich's Ataxia (FRDA). In ~2% of patients, FRDA is caused by one of 15 known missense mutations on one allele accompanied by the GAA repeat on the other leading to a complicated phenotype that includes loss of Fe-S clusters. Here we present in vitro evidence that FRDA FXN variants are deficient in their ability to bind the SDU complex, their ability to stimulate the sulfur transfer reaction from NFS1 to ISCU2, and in their ability to stimulate the rate of cluster assembly on ISCU2. Here, in vitro evidence is presented that FXN accelerates the sulfur transfer reaction from NFS1 to ISCU2. Additionally, we present kinetic evidence that identifies the most buried cysteine residue, C104 on ISCU2 as the sulfur acceptor residue suggesting, FXN stabilizes a conformational change to facilitate sulfur delivery. Subsequent mutational studies suggest FXN binding to SDU results in a helix to coil transition in ISCU2 exposing C104 to accept the persulfide sulfur and thereby accelerating the rate of sulfur transfer. We further provide the first biochemical evidence that the persulfide transferred to ISCU2 from NFS1 is viable in Fe-S cluster formation. In contrast to human FXN, the Escherichia coli FXN homolog CyaY has been reported to inhibit Fe-S cluster biosynthesis. To resolve this discrepancy, a series of inter-species enzyme kinetic experiments were performed. Surprisingly, our results reveal that activation or inhibition by the frataxin homolog is determined by which cysteine desulfurase is present and not by the identity of the frataxin homolog. These data are consistent with a model in which the frataxin-less Fe-S assembly complex exists as a mixture of functional and nonfunctional states, which are stabilized by binding of frataxin homologs. Intriguingly, this appears to be an unusual example in which modifications to an enzyme during evolution inverts or reverses the mode of control imparted by a regulatory molecule.
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Immobilized metallodithiolate ligand supports for construction of bioinorganic model complexesGreen, Kayla Nalynn 15 May 2009 (has links)
The A-cluster active site in acetyl coA synthase exploits a Ni(CGC)2-
metallopeptide as a bidentate ligand to chelate the catalytically active square-planar
nickel center used to produce acetyl coA. As Nature utilizes polypeptides to isolate and
stabilize the active sites, we have set out to immobilize biomimetic complexes to
polyethylene-glycol (PEG) rich polystyrene polymer beads (TentaGel). The PEG rich
resin-beads serve to imitate the peptidic superstructure of enzyme active sites as well as
to protect the resin-bound models from O2 decomposition. As a model of the NiN2S2
ligand observed in the A-cluster of acetyl coA synthase, the CGC tripeptide was
constructed on resins using Merrifield solid phase peptide synthesis and then metallated
with NiII to produce bright orange beads. Derivatization with M(CO)x (M = Rh, W)
provided qualitative identification of Ο-Ni(CGC)M(CO)x
n- via ATR-FTIR.
Additionally, Neutron Activation Analysis (NAA) and UV-vis studies have determined
the concentration of Ni and CGC, and qualitatively identify Ο-Ni(CGC)2-. Furthermore,
infrared studies and NAA experiments have been used to identify and quantify Ο-
Ni(CGC)Rh(CO)2
1-. The S-based reactivity of Ni(ema)2-, a good model of Ni(CGC)2-, toward
oxygenation and alkylation has been pursued and compared to neutral NiN2S2
complexes. The spectroscopic, electrochemical and structural effects of these
modifications will be discussed and supported using DFT computations and electrostatic
potential maps of the resulting Ni(ema)*O2
2- and Ni(ema)*(CH2)3 complexes.
Having firmly established the synthesis, characterization and reactivity of
NiN2S2
2- systems in solution and resin-bound, CuIIN2S2 analogues were explored. The
synthesis and identification of solution complexes, Cu(ema)2-, Cu(emi)2-, and Cu(CGC)2-
via UV-Vis, EPR, and –ESI-MS will be discussed in addition to their S-based reactivity
with Rh(CO)2
+
. Furthermore, the resin-bound Cu(CGC)2- complex has been produced
and characterized by EPR and its Rh(CO)2 adduct identified by ATR-FTIR and
compared to the analogous NiN2S2
2- systems.
As the active site of [FeFe] Hydrogenase utilizes a unique peptide-bound propane
dithiolate bridge to support the FeFe organometallic unit, [FeFe]Hydrogenase models
have been covalently anchored to the resin-beads via similar carboxylic acid
functionalities. The characterization (ATR-FTIR, EPR, Neutron Activation Analysis),
stability and reactivity of the immobilized models complexes are discussed as well as
work toward establishing the microenvironment of resin-bound complexes.
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The production-assembly-distribution system design problem: modeling and solution approachesLiang, Dong 15 May 2009 (has links)
This dissertation, which consists of four parts, is to (i) present a mixed integer
programming model for the strategic design of an assembly system in the international
business environment established by the North American Free Trade Agreement
(NAFTA) with the focus on modeling the material flow network with assembly
operations, (ii) compare different decomposition schemes and acceleration techniques to
devise an effective branch-and-price solution approach, (iii) introduce a generalization of
Dantzig-Wolf Decomposition (DWD), and (iv) propose a combination of dual-ascent
and primal drop heuristics.
The model deals with a broad set of design issues (bill-of-materials restrictions,
international financial considerations, and material flows through the entire supply chain)
using effective modeling devices. The first part especially focuses on modeling material
flows in such an assembly system.
The second part is to study several schemes for applying DWD to the productionassembly-
distribution system design problem (PADSDP). Each scheme exploits
selected embedded structures. The research objective is to enhance the rate of DWD convergence in application to PADSDP through formulating a rationale for
decomposition by analyzing potential schemes, adopting acceleration techniques, and
assessing the impacts of schemes and techniques computationally. Test results provide
insights that may be relevant to other applications of DWD.
The third part proposes a generalization of column generation, reformulating the
master problem with fewer variables at the expense of adding more constraints; the subproblem
structure does not change. It shows both analytically and computationally that
the reformulation promotes faster convergence to an optimal solution in application to a
linear program and to the relaxation of an integer program at each node in the branchand-
bound tree. Further, it shows that this reformulation subsumes and generalizes prior
approaches that have been shown to improve the rate of convergence in special cases.
The last part proposes two dual-ascent algorithms and uses each in combination
with a primal drop heuristic to solve the uncapacitated PADSDP, which is formulated as
a mixed integer program. Computational results indicate that one combined heuristic
finds solutions within 0.15% of optimality in most cases and within reasonable time, an
efficacy suiting it well for actual large-scale applications.
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noneWu, Ming-Tung 03 July 2002 (has links)
none
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Adsorption, desorption, and stabilization of arsenic on aluminum substituted ferrihydriteMasue, Yoko 12 April 2006 (has links)
Because of As toxicity, the complexity of its chemistry, and the recent lowering of the maximum contaminant level of As in municipal drinking water, there has been considerable interest for improved methods to remove As from water. Although Al and Fe hydroxides have been extensively studied as adsorbents for As removal during water treatment, coprecipitated Al:Fe hydroxides have received only minimal attention. The theoretical and experimental feasibility of coprecipitated Al:Fe hydroxide systems were evaluated by studying their mineralogy, stability, and As adsorption and desorption behavior.
The broad XRD peaks revealed that Al was substituted into the ferrihydrite structure and that this was the only major product up to about a 2:8 Al:Fe molar ratio. Gibbsite and bayerite were identified when Al content was higher. The rate of recrystallization of ferrihydrite into goethite and hematite was significantly reduced as Al substitution was increased.
In general, adsorption capacity of both AsV and AsIII decreased with increase in Al:Fe molar ratio; however, similar AsV adsorption capacities were observed with Fe and Al:Fe hydroxides with Al:(Al+Fe) molar ratios < 0.20. Both AsIII and AsV adsorption isotherms were effectively described by Langmuir and Freundlich equations. Adsorption maxima of AsV on Fe and Al:Fe hydroxides were observed at pH 3 to 7, and that of AsV on Al hydroxide was observed at pH 5.2, with significant decreases in adsorption with increase and decrease in pH. Adsorption maxima of AsIII decreased by approximately 4 % for each 10 % increase in Al substitution up to 5:5 Al:Fe molar ratio. Adsorption maxima of AsIII on Fe and Al:Fe hydroxides were observed at pH 8 to 9. AsIII adsorption on Al hydroxide was negligible. Counterion Ca2+, compared to Na+, enhanced the retention of AsV, especially at pH > 7. Counterion concentration did not significantly affect AsV adsorption. Though phosphate desorbed both AsV and AsIII from all Al:Fe hydroxides, quantitative desorption was never observed.
The results of this study indicate the possible utility of coprecipitated Al:Fe hydroxide in wastewater treatment. Based on adsorption/desorption behavior and stability of the Al:Fe hydroxide product, the preferred Al:Fe molar ratio was 2:8.
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Behavior of carbon fiber reinforced polymer (CFRP) anchors strengthening reinforced concrete structuresSun, Wei, 1982- 09 February 2015 (has links)
Carbon Fiber Reinforcement Polymer (CFRP) materials are widely used to strengthen reinforced concrete structures because they are light weight, have high strength, and are relatively easy to install. In strengthening applications, CFRP strips are typically attached to the concrete surface using epoxy resin with fibers oriented in the direction needing additional tensile strength. However, if CFRP strips rely exclusively on bond strength with concrete, only 40% to 50% of the CFRP tensile strength can be developed before debonding occurs. In order to fully develop the tensile strength of CFRP strips, some form of anchorage is needed. CFRP anchors can be applied with relative ease and have recently been shown to provide effective anchorage of CFRP strips to concrete members. In many cases, however, current anchorage details may resulting in fracture or failure of CFRP anchors prior to developing the full strength of CFRP strips. Many design parameters, the effects of which are not well understood, can affect the behavior and strength of CFRP anchors. Moreover, previous studies have demonstrated that the quality of installation can influence anchor strength substantially. The objectives of the study presented are to: 1) provide engineers with design guidelines for CFRP anchors, and 2) deliver a reliable test for controlling the quality of installation and materials of CFRP anchorage systems. In all, 39 tests on 6”×6”×24” rectangular concrete beams were conducted to study the influence of five parameters on CFRP anchor strength and effectiveness: 1) the width of the CFRP strip being developed, 2) the material ratio of CFRP anchor to CFRP strip, 3) the concrete strength, 4) the length/angle of anchor fan, and 5) the bond between CFRP strip and concrete (bonded/unbonded). The same tests also served to develop the test methodology for quality control of the CFRP anchorage system. Based on experimental results, guidelines for designing CFRP anchors are proposed. A test specimen and methodology are also proposed for qualifying CFRP materials and anchorage-system installations. A Finite Element (FE) formulation was selected to provide a computational tool that is suited for simulating the behavior of CFRP strips and CFRP anchors. The ability of the selected FE formulation to reproduce the effects on behavior of varying the anchor-material ratio, concrete strength, length of anchor fan, and bond conditions was investigated. Six FE simulations were built by adjusting simulation parameters and comparing results with six experimental tests. Comparisons between experimental and numerical results indicate that the proposed FE formulation and parameter selections reproduced load-deflection and local strain behaviors with high fidelity. / text
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INVESTIGATION OF DIAMOND COATINGS ON IRON BASED MATERIALS BY MICROWAVE PLASMA CHEMICAL VAPOR DEPOSITION2015 September 1900 (has links)
Diamond thin films on Fe based materials (ferrous alloys) for the purpose of improving their surface properties such as wear and corrosion resistance have been investigated. There are main barriers restricting the quality and adhesion of diamond coatings on Fe based materials. Firstly, the incubation time of diamond nucleation is long due to the high solubility of carbon in Fe. Secondly, graphite soot forms before diamond nucleation due to the catalytic effect of Fe for formation of graphitic carbon. Thirdly, high internal stress remains at the interface which is induced by the large difference in the thermal expansion coefficients of diamond and most of the Fe based materials. Surface modification and interlayers are two important approaches to overcome these problems. In this work, the effect of Cr content in Fe-Cr alloys on diamond nucleation and growth is being studied in order to clarify the mechanisms of Cr in diamond deposition. Furthermore, in order to enhance the adhesion and quality of diamond coatings, Al based interlayers are being investigated on ferrous alloys.
Fe-Cr alloys (with 20~80 wt.% Cr) were exposed to a CH4-H2 mixture in a microwave plasma enhanced chemical vapor deposition (MPCVD) reactor. Severe metal dusting and carburization were observed on the alloys with low Cr content and diamond did not nucleate on those alloys until a graphite intermediate layer had been formed, which takes a long incubation time. Increasing Cr concentration in the Fe-Cr alloys promotes the formation of a Cr carbide buffer layer, which inhibits metal dusting and the formation of graphite soot. Consequently, diamond nucleation and growth can be greatly enhanced, and continuous diamond films with enhanced adhesion have been deposited on the Fe-80Cr alloys.
Al based interlayers including Al and Al/AlN interlayers were deposited on ferrous alloys (SS316 and Kovar: FeNiCo) to enhance diamond deposition. The deposition was carried out in a microwave plasma chemical vapor deposition (MPCVD) reactor using a CH4-H2 mixture. The obtained samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based X-ray absorption spectroscopy (XAS) and indentation testing. The results show that a single Al layer can effectively suppress the formation of graphite at the interface and the inward diffusion of carbon into Fe based substrates, and thereby enhances diamond nucleation and growth. The dual layers of Al/AlN can further enhance the adhesion of diamond coatings comparing with the single Al interlayer.
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Career dynamics : tailoring individual and organisational needs; a study of the application of professional development approaches to post experience career development in further educationCorkindale, Julia January 1999 (has links)
occupied by the consequences of the major legislative and structural changes of the last decade, are failing to recognise and cultivate the full professional potential of their academic staff to the detriment of the college, those individual members of staff and the students. This work investigates the current application of Human Resource Management in the Further Education sector and the consequences for the professional development of academic staff. In doing so, it examines current theories relevant to the organisational perspective and to the perspective of the individual member of staff. These include theories of organisational change, as well as career theory, adult development and motivation. Studies one and two focussed primarily on the whole college perspective, while three and four canvassed the views and opinions of individual members of academic staff. Most of the analysis concentrates on study four as this emerged as the most significant data. The first two shorter studies provided a benchmark for the rest of the research. Studies one and two examined the current organisational perspective on professional development. Study one involved content analysis of staff development policies collated from colleges throughout the sector, while study two followed up this information with a series of in-depth interviews with staff development managers from a range of colleges. The second half of the research concentrated on an examination of the views of as many staff as possible at a small number of colleges. Study three, a questionnaire survey undertaken with academic staff at two large Further Education colleges, provided useful quantitative data. Based on the findings of the questionnaire, the fourth and final study involved detailed one-to-one interviews with individual members of staff, which were then examined using qualitative data analysis methods. Coupled with data drawn from the questionnaire survey, the key conclusions are presented in chapter seven and used as a basis for the recommendations in chapter eight. The thesis concludes that current Human Resource Management approaches have led to a neglect of the career and professional development interests of the individual and an alternative model of the employment relationship is proposed. It is also suggested that the current rhetoric of Human Resource Development is inappropriate to the field of Further Education and has underestimated and misinterpreted the unique and peculiar qualities of an academic culture. It concludes that by shifting the strategic focus to the professional development of its individual members, the organisational as well as the individual will benefit.
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A history of the Santa Fe Railroad in Arizona to 1917Wisbey, Herbert A. (Herbert Andrew), 1919- January 1946 (has links)
No description available.
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