Research on Opening and Closing Synchronization of Flexible Hatch on Space Shuttle

2017 ◽  
Vol 10 (1) ◽  
pp. 189-198
Author(s):  
Yue Wang ◽  
Hong Liu ◽  
Bo Peng
Keyword(s):  
Space Shuttle ◽  
Opening And Closing

Research on Opening and Closing Synchronization of Flexible Hatch on Space Shuttle

2018 ◽  
Vol 12 (3) ◽  
pp. 55-68
Author(s):  
Yue Wang ◽  
Hong Liu ◽  
Bo Peng
Keyword(s):  
Space Shuttle ◽  
Basic Theory ◽  
Flexible Body ◽  
Position Accuracy ◽  
Space Industry ◽  
Key Points ◽  
Substitution Principle ◽  
Opening And Closing

The space industry is developing rapidly, specifically with the development of the space shuttle. The position accuracy of the shuttle hatch is always a key problem when the space shuttle is in orbit. When hatch position accuracy meets the requirement of the central lock acquisition domain, the central lock can capture and lock, otherwise it will cause the hatch to not close properly. Aiming at this problem, this article solves it by using the basic theory of flexible body ADAMS. First, composite hatches are converted into an equivalent shell by using the equal stiffness substitution principle, deriving the neutral file (MNF) of the hatch by a classical module in ANSYS, and testing synchronization and accuracy of it under the condition of ideal rigidity and flexibility. Eventually, we obtain the curve of motion displacement at key points, then we can estimate whether the synchronization and accuracy of the hatch meets the requirements.

The effect of back-melting on the continuity of crystallographic orientation and composition in HgZnTe

1992 ◽  
Vol 50 (2) ◽  
pp. 1696-1697
Author(s):  
H.J. Zuo ◽  
M.W. Price ◽  
R.D. Griffin ◽  
R.A. Andrews ◽  
G.M. Janowski
Keyword(s):  
Directional Solidification ◽  
Space Shuttle ◽  
Solidification Process ◽  
Space Experiment ◽  
Infrared Detection ◽  
Directionally Solidified ◽  
Crystallographic Defects ◽  
Semiconducting Alloys ◽  
Uniform Composition ◽  
Growth Experiments

The II-VI semiconducting alloys, such as mercury zinc telluride (MZT), have become the materials of choice for numerous infrared detection applications. However, compositional inhomogeneities and crystallographic imperfections adversly affect the performance of MZT infrared detectors. One source of imperfections in MZT is gravity-induced convection during directional solidification. Crystal growth experiments conducted in space should minimize gravity-induced convection and thereby the density of related crystallographic defects. The limited amount of time available during Space Shuttle experiments and the need for a sample of uniform composition requires the elimination of the initial composition transient which occurs in directionally solidified alloys. One method of eluding this initial transient involves directionally solidifying a portion of the sample and then quenching the remainder prior to the space experiment. During the space experiment, the MZT sample is back-melted to exactly the point at which directional solidification was stopped on earth. The directional solidification process then continues.

Upgrades to the caution and warning system of the space shuttle

2003 ◽  
Author(s):  
Jeffrey W. McCandless ◽  
Robert S. McCann ◽  
Bruce R. Hilty
Keyword(s):  
Space Shuttle ◽  
Warning System

UPAYA MENINGKATKAN KOMPETENSI PEDAGOGIK GURU SDN TURUSGEDE DI SEMESTER I TAHUN PELAJARAN 2018/2019 DALAM MEMBUKA DAN MENUTUP PEMBELAJARAN MELALUI SUPERVISI AKADEMIK TEKNIK PENILAIAN DIRI SENDIRI

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Siti Ulfah
Keyword(s):  
Elementary School ◽  
Action Observation ◽  
The Self ◽  
Self Assessment ◽  
Test Technique ◽  
Assessment Technique ◽  
First Semester ◽  
Opening And Closing ◽  
Academic Year ◽  
Learning By Using

The purposes of this reasearch are 1) describing the efforts of increasing the elementary school of Turusgede teachers pedagogic competence at the first semester of 2018/2019 academic year in opening and closing the learning by using the self assessment technique and 2) analysing the increase of the elementary school of Turusgede teachers pedagogic competence at the first semester of 2018/2019 academic year in opening and closing the learning by using the self assessment technique. This research is School Action Research (SAR). This research is taken palce in elementary school of Turusgede, Subdistrict of Rembang, Regency of Rembang. The time of this research is the early-middle first semester of 2018/2019 academic year. The subjects of this research are teachers in the elementary school of Turusgede, Subdistrict of Rembang, Regency of Rembang, consist of twelve teachers. The data of this research is teachers pedagogic competence in opening and closing the learning. The techniques of collecting data are using nontest technique and test technique. The tools of collecting data are using the sheets of observation, camera application on hand phone and the form of self assessment. The technique of analizing data in this research is decriptive comparation. The procedure of this research is using Cycle Model, consist of four steps: planning, action, observation and reflection. Each cycle is going on one week. The results of this research are 1) the academic supervision with self assessment technique is previously sharing the form of self assessment to the subjects of this research, 2) self assessment technique is self assessment according to the next theme and matter, 3) self assessment technique is self assessment after the learning finish and 4) teachers pedagogic competence with self assessment technique is increasing and including good category (B) that according with the result of observation and including very good category (A) that according with the result of self assessment. Key words: Pedagogic, Supervision, Self Assessment Technique.

Signs and symptoms of craniomandibular dysfunction in a population of Spanish children

2018 ◽  
Vol 16 (1) ◽  
pp. 24
Author(s):  
Maria Esperanza Sánchez-Sánchez
Keyword(s):  
Signs And Symptoms ◽  
Permanent Teeth ◽  
Tooth Sensitivity ◽  
Craniomandibular Dysfunction ◽  
Teeth Grinding ◽  
Specific Questionnaire ◽  
Other Hand ◽  
Opening And Closing

The craniomandibular dysfunction (CMD) is a pathology that can appear at early ages. In a sample of 36 childrenresiding in Madrid (Spain), of both sexes, with ages between 7 and 13 years, the prevalence of signs and symptomsof CMD was analyzed. For that purpose, we did a dental and muscular examination, together with temporomandibularjoints, functional and occlusal examination, and completed with a specific questionnaire. The results revealedthat 100% showed some sign or sympthom of CMD. 77,8% of the pacients presented 3 or more CMD signs.The most prevalent were painful muscle palpation (94,4%), together with sliding anteriorly (91,7%), painful jointpalpation (69,4%), wear facets in permanent teeth (41,7%) and altered opening and closing trayectory (38,9%). Onthe other hand, only 38,9% showed any CMD symptom. The most prevalent symptoms were night teeth grinding(27,8%), followed by tooth sensitivity (19,4%) and fullness in the ears (16,7%). We conclude that in our sample,25% presented mild CMD (less that 3 signs or symptoms), 58,3% presented moderate CMD (from 3 to 6 signs orsymptoms) and 16,7% showed severe CMD (more than 6 symptoms). Nevertheless, it’s important to remark thatnone of these pacients came seeking treatment for his CMD and these symptoms were refered only when beingasked. Hence the importance of a comprehensive clinic history to precociously diagnose this pathology and havethe ability to prevent its progression.

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