363 research outputs found
Sensitivity of Space Station alpha joint robust controller to structural modal parameter variations
The photovoltaic array sun tracking control system of Space Station Freedom is described. A synthesis procedure for determining optimized values of the design variables of the control system is developed using a constrained optimization technique. The synthesis is performed to provide a given level of stability margin, to achieve the most responsive tracking performance, and to meet other design requirements. Performance of the baseline design, which is synthesized using predicted structural characteristics, is discussed and the sensitivity of the stability margin is examined for variations of the frequencies, mode shapes and damping ratios of dominant structural modes. The design provides enough robustness to tolerate a sizeable error in the predicted modal parameters. A study was made of the sensitivity of performance indicators as the modal parameters of the dominant modes vary. The design variables are resynthesized for varying modal parameters in order to achieve the most responsive tracking performance while satisfying the design requirements. This procedure of reoptimization design parameters would be useful in improving the control system performance if accurate model data are provided
Rubrics in Nursing Education
Evaluating assignments or course work is a challenging job for faculty of
nursing. In order to avoid the dilemmas of evaluation, nurse educators use
rubrics as an evaluation tool. In educational technology, rubric refers to
„performance standard‟ for a student population. A rubric is defined as an
assessment tool that lays out the set standards and criteria to assess a
performance, assignment or behavior. The four essential components of a
rubric are task description, scale of achievement, dimensions & description
of dimensions. Various types of scoring rubrics are available. The type of
rubric chosen for assessment depends on the task being evaluated and the
needs of the assessor. Holistic rubrics, analytic rubrics, generic rubrics,
specific rubrics are the different types of rubrics. In nursing education,
rubrics has got wide range of applications such as to; assess clinical skills,
grade assignments, evaluate clinical competency and analyze presentations.
Rubrics helps to define "quality performance” and promote awareness on
critical components in a performance. Rubrics not only act as an evaluation
tool for instructors, but also act as a feedback proforma for students. Rubrics
are vital tools that can be utilized to solve the problem of subjectivity in
evaluation. Rubrics provide consistency in evaluation, reduces subjectivity
and enhances objectivity
Integration of Evidence-Based Practice in Nursing Education
Evidence based practice (EBP) has gained momentum globally, to provide effective and efficient health care.
Although EBP has evolved to a great extent over the last two decades and is accepted as an important concept by all
health care professionals, its integration in practice is still challenging. Integration of EBP in nursing profession both
in nursing practice and nursing education is an important issue. This article describes the experience of the authors
in integrating evidence based practice in nursing education in Manipal University. It focuses on the training of nurse
educators in EBP, alignment of EBP in curriculum and EBP practicum in curriculum so as to enable a nurse to identify
evidences, make appropriate clinical decisions and utilize EBP in rendering scientific and quality patient care
Resources for Evidence-Based Health Care: Accessibility and Availability
Evidence – Based Practice (EBP) is a problem solving approach to clinical care that incorporates the conscientious use of current best evidence from well-designed studies, clinician’s expertise, and patient values and preferences (Melnyk & Fineout-Overholt, 2005; Sackett, Straus, Richardson, Rosenberg, &Haynes, 2000). It is important to see clinical expertise as the ability to integrate research evidence and patients' circumstances and preferences to help patients arrive at optimal decisions (Guyatt, Cook,& Haynes, 2004). Research has shown that patient outcomes are 28% better when clinical care is based upon evidence, versus clinical practice steeped in tradition (Heater, Becker, & Olsen, 1998). The process of EBP minimizes the translation time needed for incorporating research findings into practice and clarifies the differences between ritualistic practice, habitual approaches, personal preferences, anecdotal experiences, empirical data, and statistical significance to support nursing practice (Alspach, 2006). The availability of evidence based practice tools and methods helps in faster identification of the best available evidence to provide care at the point it matters most.
Implementing EBP in health care is complex and challenging. One of the main components of EBP is retrieving evidence from different sources. Information explosion with thousands of health literature and research papers published every year has created a need to expand the knowledge base for providing evidence based health care worldwide. Retrieval of evidence from various sources may be difficult due to several reasons. It may be difficult for health professionals to find the best available evidence due to time constraints (Ervin, 2002) or lack of knowledge among health professionals to effectively search for evidence (Sitzia, 2002). It is even difficult to find authentic sources of evidence
Accurate Determination of Comet and Asteroid Orbits Leading to Collision With Earth
Movements of the celestial bodies in our solar system inspired Isaac Newton to work out his profound laws of gravitation and motion; with one or two notable exceptions, all of those objects move as Newton said they would. But normally harmonious orbital motion is accompanied by the risk of collision, which can be cataclysmic. The Earth s moon is thought to have been produced by such an event, and we recently witnessed magnificent bombardments of Jupiter by several pieces of what was once Comet Shoemaker-Levy 9. Other comets or asteroids may have met the Earth with such violence that dinosaurs and other forms of life became extinct; it is this possibility that causes us to ask how the human species might avoid a similar catastrophe, and the answer requires a thorough understanding of orbital motion. The two red square flags with black square centers displayed are internationally recognized as a warning of an impending hurricane. Mariners and coastal residents who know the meaning of this symbol and the signs evident in the sky and ocean can act in advance to try to protect lives and property; someone who is unfamiliar with the warning signs or chooses to ignore them is in much greater jeopardy. Although collisions between Earth and large comets or asteroids occur much less frequently than landfall of a hurricane, it is imperative that we learn to identify the harbingers of such collisions by careful examination of an object s path. An accurate determination of the orbit of a comet or asteroid is necessary in order to know if, when, and where on the Earth s surface a collision will occur. Generally speaking, the longer the warning time, the better the chance of being able to plan and execute action to prevent a collision. The more accurate the determination of an orbit, the less likely such action will be wasted effort or, what is worse, an effort that increases rather than decreases the probability of a collision. Conditions necessary for a collision to occur are discussed, and warning times for long-period comets and near-Earth asteroids are presented
IN VITRO CYTOTOXIC ACTIVITY OF ISOLATED COMPOUNDS FROM VIBURNUM PUNCTATUM BUCH-HAM EX D. DON
Objective: The main aim of the study was to screen the isolated compounds of Viburnum Punctatum for its in vitro anticancer activity and its percentage viability against HCT 15 (Human Colon Cancer Cells) Cell lines.Methods: Pet ether, Chloroform, Methanol and Aqueous extracts was prepared and assayed for the presence of phytochemicals. Two compounds were isolated from the methanol extract of Viburnum Punctatum by column chromatography such as ME1 (Quercetin) and ME2 (Kaemferol-3-glycoside) characterised by UV, IR, MS, 1H NMR and 13C NMR. The above isolated compounds were subjected to in vitro anticancer activity on HCT 15 cell lines was evaluated by Micro culture Tetrazolium (MTT) assay.Results: ME1 showed significant cytotoxic activity than the ME2 on HCT 15 cells with a percentage viability of 54.60 and 67.18 in the concentration of 10µg/ml and 50µg/ml respectively.Conclusion: On the basis of obtained results, ME1 and ME2 isolated from a methanolic extract of Viburnum Punctatum represent a new group of cytotoxic against HCT 15 Cell lines
Effect of monsoon on coastal fish diversity of Goa: an example from the gillnet fishery
The dynamics of fauna in coastal ecosystems are influenced by seasonal patterns in the oceanographic environment. It is well known that the monsoon along south-west coast of India influences the movement and spawning of fishes. Thus, they have direct effect on the richness, abundance and evenness of fish diversity in the ecosystem. This study investigates how the monsoon affects the commercial gillnet fishery along the coast of Goa. Fishing experiments were conducted in popular gillnet fishing grounds and the temporal pattern in diversity indices between October 2013 and September 2014 was assessed. A total of 124 fish species (40 families), 16 crustacean species (4 families) and 9 molluscan species (8 families) were recorded. The species diversity was found to be significantly different during the monsoon season and the species abundance distribution followed a geometric series during this period indicating signs of ecosystem perturbations. The economic and biological aspects of gillnet fishing in relation to the monsoon season in Goa are also discussed
MIL-91(Ti), a small pore metal-organic framework which fulfils several criteria : an upscaled green synthesis, excellent water stability, high CO2 selectivity and fast CO2 transport
The research leading to these results has received funding from the European Community Seventh Framework Program (FP7/2007-2013) [grant agreement number 608490] (project M4CO2) and from the ANR ‘CHESDENS’ (ANR-13-SEED-0001-01).A multidisciplinary approach combining advanced experimental and modelling tools was undertaken to characterize the promises of a small-pore type Ti-based metal-organic framework, MIL-91(Ti) for CO2 capture. This material was prepared using two synthesis strategies, i.e. under hydrothermal conditions and under reflux, and its single component adsorption behaviour with respect to CO2, CH4 and N2 was first revealed by gravimetry measurements. This hydrophilic and highly water stable MOF is characterized by a relatively high CO2 adsorption enthalpy. Molecular simulations combined with in situ powder X-ray diffraction evidenced that this is due to the combined interaction of this probe with N-H and P-O groups in the phosphonate linker. High CO2 selectivities in the presence of either N2 or CH4 were also predicted and confirmed by co-adsorption measurements. The possibility to prepare this sample under reflux represents an environmentally friendly route which can easily be upscaled. This green synthesis route, excellent water stability, high selectivities and relatively fast transport kinetics of CO2 are significant points rendering this sample of utmost interest for CO2 capture.PostprintPostprintPeer reviewe
Comet/Asteroid Protection System (CAPS): Preliminary Space-Based Concept and Study Results
There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) is a future space-based system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This Technical Memorandum provides a compilation of key related topics and analyses performed during the CAPS study, which was performed under the Revolutionary Aerospace Systems Concepts (RASC) program, and discusses technologies that could enable the implementation of this future system
Citations of the Top 100 Most-cited Papers of the Journal Scientometrics in Web of Science and its Association and Correlation with Scopus and Google Scholar Citations
This study is conducted to analyse the citations of the top 100 most-cited papers of the journal Scientometrics in Web of Science (WoS) and its association and correlation with corresponding citations in Scopus and Google Scholar (GS). Chi-square and Spearman’s rank rho are used to ascertain the association and correlation among these citations in different platforms. GS citations for the papers are comparatively higher than the citations in the other two databases. Scopus citations are slightly higher than WoS citations. The study found that there is significant association among level of citations of top 100 cited papers of the journal Scientometrics in WoS and its corresponding level of citations in Scopus and Google Scholar and also high positive correlation among citations in the three databases
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