1,497 research outputs found
Kinematic synthesis of flight control systems for light aircrafts
In this paper, kinematic synthesis of a planar flight control system mechanism has been conducted for a light aircraft designed and built by TAL To achieve a simple construction, the four-bar linkages are used in the synthesis. Freudenstein's Method and Bloch's Method are utilized for analytical three and four bar position syntheses respectively. A case study of an elevator flight control system is presented
Vesicle adhesion and fusion studied by small-angle x-ray scattering.
We have studied the adhesion state (also denoted by docking state) of lipid vesicles as induced by the divalent ions Ca2+ or Mg2+ at well-controlled ion concentration, lipid composition, and charge density. The bilayer structure and the interbilayer distance in the docking state were analyzed by small-angle x-ray scattering. A strong adhesion state was observed for DOPC:DOPS vesicles, indicating like-charge attraction resulting from ion correlations. The observed interbilayer separations of ∼1.6 nm agree quantitatively with the predictions of electrostatics in the strong coupling regime. Although this phenomenon was observed when mixing anionic and zwitterionic (or neutral) lipids, pure anionic membranes (DOPS) with highest charge density σ resulted in a direct phase transition to a multilamellar state, which must be accompanied by rupture and fusion of vesicles. To extend the structural assay toward protein-controlled docking and fusion, we have characterized reconstituted N-ethylmaleimide-sensitive factor attachment protein receptors in controlled proteoliposome suspensions by small-angle x-ray scattering
Quantization with maximally degenerate Poisson brackets: The harmonic oscillator!
Nambu's construction of multi-linear brackets for super-integrable systems
can be thought of as degenerate Poisson brackets with a maximal set of Casimirs
in their kernel. By introducing privileged coordinates in phase space these
degenerate Poisson brackets are brought to the form of Heisenberg's equations.
We propose a definition for constructing quantum operators for classical
functions which enables us to turn the maximally degenerate Poisson brackets
into operators. They pose a set of eigenvalue problems for a new state vector.
The requirement of the single valuedness of this eigenfunction leads to
quantization. The example of the harmonic oscillator is used to illustrate this
general procedure for quantizing a class of maximally super-integrable systems
Perception of ‘English’ and Motivation in Learning English
This study aims to present high school students’ perception of “English” through the impressions and images and the effect of these perceptions on their motivation in learning English. This qualitative study is based on the data about students’ metaphors and the focus group interview to determine their effect on the students’ motivation. The research group for metaphors consists of 128 high school students from four different grades. 79 metaphors were collected and grouped under 12 categories. In addition, two different focus group interviews are held with 7 students having negative and positive perspectives to determine the effect of these perceptions on students’ motivation in learning English. According to the analysis of the data from focus group interviews, students mostly perceive “English” as a target language to learn rather than a foreign language, spoken by a definite society or belonging to a culture. The results of metaphor study also indicate that the students regarding “English” positively tend to have a higher participation and motivation in comparison to the students having negative perceptions
Teachers
The study examines the views of classroom teachers on the preparedness of primary school first year pupils with preschool education on learning mathematics subjects. The sample of the study consists of 15 classroom teachers teaching first year of primary school
Deconvolution of overlapping peaks from differential scanning calorimetry analysis for multi-phase NiTi alloys
The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.tca.2018.05.014 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/An adaptive function capable of fitting the curve of Differential Scanning Calorimetry (DSC) data for any NiTi phase transformation peak has been developed. A novel methodology was applied in conjunction with this new equation, allowing for the deconvolution of multiple overlapping NiTi phase transformation peaks. Characteristic transformation properties determine by this methodology closely matched those ascertainable by current analysis techniques. This novel analysis technique allows for better determination of characteristic properties of complex NiTi materials with overlapping phase transformations or multiple embedded memories.Natural Sciences and Engineering Research Council of CanadaCanadian Foundation for Innovatio
A meta-analysis of training effects on English phonological awareness and reading in native Chinese speakers
Enhancing English phonological awareness is critical in promoting native English speakers’ reading development. However, less attention has been paid to the role of phonological awareness development for English language learners in a logographic context. This meta-analysis aims to evaluate the effectiveness of training native Chinese speakers’ English phonological awareness and reading across age groups. Thirty-three articles, including 37 independent samples, were identified as training studies that reported English phonological awareness as an outcome measure, and 16 articles, including 17 independent samples, featured training studies that reported reading as an outcome measure. Results based on a random-effect model revealed the effect sizes for overall English phonological awareness (including English syllable awareness, phoneme awareness, and rhyme awareness) and overall reading (including word reading and pseudoword reading) were g = 0.651 (n = 3137) and g = 0.498 (n = 1506), respectively. Specifically, instructional training exerted a small impact on word reading (g = 0.297), moderate effects on syllable awareness (g = 0.468) and pseudoword reading (g = 0.586), a medium to large effect on phoneme awareness (g = 0.736), and a large impact on rhyme awareness (g = 0.948). The moderator analyses yielded several significant findings. Regarding the English phonological awareness outcome, programs integrating lexical semantic knowledge exhibited the largest trend in enhancing native Chinese speakers’ skills. Among all age groups, upper elementary students benefited most from instructional training. Furthermore, more intensive training had a greater impact than less intensive training. In terms of the reading outcome, similar to English phonological awareness findings, upper elementary students realized the greatest improvements. Additionally, unpublished articles indicated a larger training effect on reading than published ones. These findings provide practitioners with guidelines for delivering effective instruction to promote phonological awareness and reading ability for English language learners in a logographic language context
The comparision of glybenclamide and metformin-loaded bacterial cellulose/gelatin nanofibres produced by a portable electrohydrodynamic gun for diabetic wound healing
Wound dressings made from natural polymers are an important aspect of biomaterials. Protein-based materials are less likely to instigate an immunogenic response and have the capacity to degrade in vivo, also without triggering an inflammatory response. Therefore, gelatin (GEL) was chosen and combined with bacterial cellulose (BC) to produce nanofibres and the potential of an all-natural polymer construct was determined. GEL and BC were successfully electrospun with metformin (Met) and glybenclamide (Gb) using a portable, point of need electrospinning set up. The virgin fibre group exhibited a significant effect on the proliferation of L929 (mouse fibroblast) cells but all fibre samples can safely be applied on wound site without risk of cytotoxicity. According to the results obtained by animal tests, the GEL-BC-Gb group showed better recovery than the GEL-BC-Met group. Diabetic wounds treated with GEL-BC-Met were characterized by moderate re-epithelialization and partially organized granulation tissue. Moderate to complete re-epithelialization and well-formed granulation tissue were observed in diabetic wounds treated with GEL-BC-Gb. The histologic scores obtained on day 14 confirmed that the GEL-BC-Gb group played a stronger wound-healing role compared to the GEL-BC-Met group. The highest decrease of TNF-α level was observed in the GEL-BC-Gb group at the end of the experiment but there is no significant difference between drug-loaded fibre groups. Therefore, topical administration of Met and Gb in a sustained release form has a high potential for diabetic wound healing with high bioavailability and fewer systemic side effects but Gb showed better improvement according to the results of the animal tests
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