Semiclassical theory for small displacements

Characteristic functions contain complete information about all the moments of a classical distribution and the same holds for the Fourier transform of the Wigner function: a quantum characteristic function, or the chord function. However, knowledge of a finite number of moments does not allow for accurate determination of the chord function. For pure states this provides the overlap of the state with all its possible rigid translations (or displacements). We here present a semiclassical approximation of the chord function for large Bohr-quantized states, which is accurate right up to a caustic, beyond which the chord function becomes evanescent. It is verified to pick out blind spots, which are displacements for zero overlaps. These occur even for translations within a Planck area of the origin. We derive a simple approximation for the closest blind spots, depending on the Schroedinger covariance matrix, which is verified for Bohr-quantized states.Comment: 16 pages, 4 figures

Serum creatine kinase isoenzymes in children with osteogenesis imperfecta

This study evaluates serum creatine kinase isoenzyme activity in children with osteogenesis imperfecta to determine its usefulness as a biochemical marker during treatment with bisphosphonate. The changes of creatine kinase (CK) isoenzyme activity during and after discontinuation therapy were observed. These results could be useful in addressing over-treatment risk prevention. Introduction The brain isoenzyme of creatine kinase (CKbb) is highly expressed in mature osteoclasts during osteoclastogenesis, thus plays an important role in bone resorption. We previously identified high serum CKbb levels in 18 children with osteogenesis imperfect (OI) type 1 treated for 1 year with bisphosphonate (neridronate). In the present study, serum CK isoenzymes were evaluated in the same children with continuous versus discontinued neridronate treatment over a further 2-year follow-up period. Methods This study included 18 children with OI type 1, 12 with continued (group A) and 6 with ceased (group B) neridronate treatment. Auxological data, serum biochemical markers of bone metabolism, bone mineral density z-score, and serum total CK and isoenzyme activities were determined in both groups. Results Serum CKbb was progressively and significantly increased in group A (p < 0.004) but rapidly decreased to undetectable levels in group B. In both groups, the cardiac muscle creatine kinase isoenzyme (CKmb) showed a marked decrease, while serum C-terminal telopeptide (CTx) levels were almost unchanged. Conclusions This study provides evidence of the cumulative effect of neridronate administration in increasing serum CKbb levels and the reversible effect after its discontinuation. This approach could be employed for verifying the usefulness of serum CKbb as a biochemical marker in patients receiving prolonged bisphosphonate treatment. Moreover, the decreased serum CKmb levels suggest a systemic effect of these drugs

Are stealth scalar fields stable?

Non-gravitating (stealth) scalar fields associated with Minkowski space in scalar-tensor gravity are examined. Analytical solutions for both non-minimally coupled scalar field theory and for Brans-Dicke gravity are studied and their stability with respect to tensor perturbations is assessed using a covariant and gauge-invariant formalism developed for alternative gravity. For Brans-Dicke solutions, the stability with respect to homogeneous perturbations is also studied. There are regions of parameter space corresponding to stability and other regions corresponding to instability.Comment: 10 pages, 1 table, no figures, to appear in Phys. Rev,

Preservice Teachers\u27 Perceptions of the Influence and Value of an Embedded, School-Based Field Experience

This study explored how preservice teachers perceive the influence and value of an embedded, school-based field experience. Information was gathered from preservice teachers using surveys and a focus group interview. The data collected showed that an embedded field experience tied to a language arts methods course was generally a positive influence leading to great self-efficacy. Further, the data compared similarly to research supporting the notion that embedded field experiences generally have the effect of strengthening preservice teachers’ self-efficacy. Looking at Bandura’s work in Self-efficacy: Toward a unifying theory of behavioral change, it shows that early interactions and successes will boost the self-efficacy of preservice teachers. This study found that successful experiences help preservice teachers value their embedded, school-based field experiences and help view it as something positive. Even if the experience had its difficulties, preservice teachers were able to learn from the situation and if they ever find themselves in a similar circumstance, they will feel more confident about handling things. Therefore, when these preservice teachers become in-service teachers, they will feel more confident about their abilities compared to in-service teachers who did not have similar experiences in their teacher preparation program

Use of an artificial miniaturized enzyme in hydrogen peroxide detection by chemiluminescence

Advanced oxidation processes represent a viable alternative in water reclamation for potable reuse. Sensing methods of hydrogen peroxide are, therefore, needed to test both process progress and final quality of the produced water. Several bio-based assays have been developed so far, mainly relying on peroxidase enzymes, which have the advantage of being fast, efficient, reusable, and environmentally safe. However, their production/purification and, most of all, batch-to-batch consistency may inherently prevent their standardization. Here, we provide evidence that a synthetic de novo miniaturized designed heme-enzyme, namely Mimochrome VI*a, can be proficiently used in hydrogen peroxide assays. Furthermore, a fast and automated assay has been developed by using a lab-bench microplate reader. Under the best working conditions, the assay showed a linear response in the 10.0–120 µM range, together with a second linearity range between 120 and 500 µM for higher hydrogen peroxide concentrations. The detection limit was 4.6 µM and quantitation limits for the two datasets were 15.5 and 186 µM, respectively. In perspective, Mimochrome VI*a could be used as an active biological sensing unit in different sensor configurations

High temperature tribological characterization of TiAl laser cladding coating on Ti6Al4V alloy

Ti6Al4V alloy has proven to be an important engineering material due to the excellent strength, weight ratio, high corrosion resistance and biocompatibility. However, the alloy is susceptible to mechanical degradation in applications involving sliding wear or abrasion. In order to improve wear resistance, coatings by laser cladding of intermetallic Ti48Al2Cr2Nb on Ti6Al4V have been developed. Different process parameters: laser power (W), scanning speed (mm/min), powder feeding rate (g/min) and preheating temperature of substrate (°C) were optimized, resulting in a microstructure of the coatings considered appropriate, with good metallurgical bond, though cracks and pores were observed [1]. The composition and microstructure of the coatings were evaluated using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, further the tribological properties were evaluated using a ball on disk tribometer, with Al2O3 ball, constant speed of 0.1 m/s, 10 N load at room temperature and 500 °C. We measure the 3D surface topography obtained from the wear scar and calculated the wear rate. The coatings microstructure consists of -TiAl phase and 2-Ti3Al. The wear test results at room temperature show a lower wear rate for the coating compared to the substrate. At high temperature the coating have a higher friction coefficient and a higher rate of wear is obtained when compared with the substrate, obtaining differences between the coatings depending on the wear mechanism observed in the worn surface.The authors acknowledge the economical support from the Ministry of Science and Innovation of the Government of Spain through research project MAT2011-28492-03 and the Generalitat Valenciana through support ACOMP/2014/151. Thanks also to Dr. José Luis Jorda by X-ray diffraction analysis performed

Resilience and Personal Improvement of Students with Motor Disabilities

The condition of disability causes multiple changes in the life of a person, putting into play different mechanisms that allow him to adapt to the new situation and learn to live with important restrictions that require an effort to realize a normalized life, in a society where there is no shortage discriminatory and differentiating attitudes, which make the process of adaptation to society more difficult, all this influences the efforts to achieve the personal improvement of the disabled and the strengthening of their resilient posture. The objective of the research is to establish the resilience and personal improvement of students with disabilities in the Universidad Técnica de Manabí. The research shows an analysis of the functional and conceptual background of the phenomenon related to motor disability and the rights of people who suffer from it to develop their social skills to obtain a profession. It addresses the concept of resilience and what is related to the ability of people with disabilities to overcome. The results obtained in the application of the SV-RES test prepared by the researchers (Saavedra &amp; Villalta, 2008a), to the students who suffer motor disability and who are enrolled in different careers of the technical university of Manabí, are offered. Offer in tables and an analysis related to the resilience and personal improvement of said students is presented

Useful thecniques to improve student's abilities to read in english : a study conduted with third grade students in the Oxforf School, Santiago.

Chapter 1 Statement of the Problem, Justification, Significance, Research Question, Definition of Key Terms, Chapter II Review of the Literature, Chapter III Methodology Procedure, Statistic Analysis, Sample, Chapter IV Observations, Firidings, Statistic Results, Conclusion, Recommendations, Bibliography

Development of laser cladding MCrAlY coatings: high temperature friction and wear behaviour

Temperature can have a significant effect on the extent of wear damage of metallic components. Thermal barrier coatings with MCrAlY (where M=Ni, Co, Fe or combinations) alloys can improve the high temperature tribological and friction wear behaviour. In this work the dry friction and wear behaviour at room temperature and high temperature of new developed NiCoCrAlY and CoNiCrAlY laser cladding coatings were evaluated. Dense coatings, with good metallurgical bonding to the AISI 304 substrate was obtained by coaxial laser cladding tracks (40% overlapping), with previously optimized laser parameters. Tribological tests were performed by sliding wear at room temperature and 500 ºC, with an Al2O3 counterpart in ball on disk configuration tribometer. The wear scar surface was evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D wear track topography was measured by inductive contact profilometer which enabled the wear rate calculation. The microstructure of the coatings consists of - Ni/-NiAl or -Co/-(Co,Ni)Al phases depending on the chemical composition of the alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY coating, the high temperature also reduces the friction coefficient, while it significantly increases the friction coefficient of CoNiCrAlY coating. The main damage mode is abrasion and adhesion, caused by oxides and partially-oxidized particles in the contact surface. The coatings and substrate results were compared, resulting in improved wear behaviour.The authors acknowledge the financial support of the Ministry of Science and Innovation of the Government of Spain through research project MAT2011-28492- C03 and the Generalitat Valenciana through ACOMP/2013/114 support. Professor Juan Carlos Pereira Falcón thanks the University of Carabobo for the financial support to pursue his doctoral studies at the UPV

Renewable Energy Sources on the Change of Energy Matrix in Manabí Province

The exploitation, distribution, and consumption of energy have caused the greatest environmental pollution on the planet and accelerated climate change; even though it has been the promoter of the social, economic development of many generations. Contemporary man can continue to increase his social development, but looking for alternatives to energy development. The work shows a model of energy development that will guarantee the sustainability of social development in the areas of the province of Manabí where energy arrives with low quality and in other places does not exist. The objective of the work is to propose the diversification of the energy matrix from the gradual and progressive introduction of technologies based on the use of renewable resources that it has was distributed in the territory of the province. This result will allow the use of indigenous renewable resources, reduce environmental pollution, and improve the quality of life of populations based on the principle of energy sustainability