171,560 research outputs found
Extension of the sun-synchronous Orbit
No full textThrough careful consideration of the orbit perturbation force due to the oblate nature of the primary body a secular variation of the ascending node angle of a near-polar orbit can be induced without expulsion of propellant. Resultantly, the orbit perturbations can be used to maintain the orbit plane in, for example, a near-perpendicular (or at any other angle) alignment to the Sun-line throughout the full year of the primary body; such orbits are normally termed Sun-synchronous orbits [1, 2]. Sun-synchronous orbits about the Earth are typically near-circular Low-Earth Orbits (LEOs), with an altitude of less than 1500 km. It is normal to design a LEO such that the orbit period is synchronised with the rotation of the Earth‟s surface over a given period, such that a repeating ground-track is established. A repeating ground-track, together with the near-constant illumination conditions of the ground-track when observed from a Sun-synchronous orbit, enables repeat observations of a target over an extended period under similar illumination conditions [1, 2]. For this reason, Sun-synchronous orbits are extensively used by Earth Observation (EO) platforms, including currently the Environmental Satellite (ENVISAT), the second European Remote Sensing satellite (ERS-2) and many more. By definition, a given Sun-synchronous orbit is a finite resource similar to a geostationary orbit. A typical characterising parameter of a Sun-synchronous orbit is the Mean Local Solar Time (MLST) at descending node, with a value of 1030 hours typical. Note that ERS-1 and ERS-2 used a MLST at descending node of 1030 hours ± 5 minutes, while ENVISAT uses a 1000 hours ± 5 minutes MLST at descending node [3]. Following selection of the MLST at descending node and for a given desired repeat ground-track, the orbit period and hence the semi-major axis are fixed, thereafter assuming a circular orbit is desired it is found that only a single orbit inclination will enable a Sun-synchronous orbit [2]. As such, only a few spacecraft can populate a given repeat ground-track Sun-synchronous orbit without compromise, for example on the MLST at descending node. Indeed a notable feature of on-going studies by the ENVISAT Post launch Support Office is the desire to ensure sufficient propellant remains at end-of-mission for re-orbiting to a graveyard orbit to ensure the orbital slot is available for future missions [4]. An extension to the Sun-synchronous orbit is considered using an undefined, non-orientation constrained, low-thrust propulsion system. Initially the low-thrust propulsion system will be considered for the free selection of orbit inclination and altitude while maintaining the Sun-synchronous condition. Subsequently the maintenance of a given Sun-synchronous repeat-ground track will be considered, using the low-thrust propulsion system to enable the free selection of orbit altitude. An analytical expression will be developed to describe these extensions prior to then validating the analytical expressions within a numerical simulation of a spacecraft orbit. Finally, an analysis will be presented on transfer and injection trajectories to these orbits
Analytical sun synchronous low-thrust manoeuvres
No full textArticle describes analytical sun synchronous low-thrust manoeuvres
A grounded theory of female adolescent behaviour in the sun: comfort matters.
No full textThe aim of the research was to generate a grounded theory to explain the behaviour of young women in the sun. The study sought to explore the sun-related experiences of
young women in order to gain new insights into the influences upon them. The study was qualitative by design and utilised grounded theory method as developed by Glaser.
Twenty female participants, aged 14 to 17 years old were included in the study. They formed six groups. Thirteen interviews were carried out with the groups and six one-to one interviews took place with individuals. All interviews were semi-structured and were based upon the participants' experiences of being in the sun. Data was analysed using the
constant comparative method of data analysis, concordant with Glaserian grounded theory method. Five explanatory categories emerged from the data; Fitting In, Being Myself,
Being Physically Comfortable, Slipping Up and a core category of Being Comfortable. One of the issues that emerged was that some young women believed their social
acceptance depended on their appearance and they conformed to this end. The theory, derived from the categories, proposes that when in the sun, young women direct their
activities toward meeting physical and psychosocial comfort needs. Comfort matters to them because it has implications for their wellbeing. This thesis contributes to the literature about the behaviours of young women in the sun.
By increasing understanding of the factors that influence them, it also adds to the body of knowledge related to the primary prevention of skin cancer with teenage girls in the United Kingdom. The outcome of the research and its contribution to knowledge is a grounded theory, which explains the basis of the behaviours of young women in the sun. It appears that no other study has explored the experiences of UK adolescent females specifically, in
a qualitative way and with the intention of producing a theory to explain them
POLAR investigation of the Sun—POLARIS
Full text linkThe POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75° with respect to solar equator. This challenging orbit is made possible by the challenging development of solar sail propulsion. This first extended view of the high-latitude regions of the Sun will enable crucial observations not possible from the ecliptic viewpoint or from Solar Orbiter. While Solar Orbiter would give the first glimpse of the high latitude magnetic field and flows to probe the solar dynamo, it does not have sufficient viewing of the polar regions to achieve POLARIS’s primary objective: determining the relation between the magnetism and dynamics of the Sun’s polar regions and the solar cycle
SunSmart? Skin cancer knowledge and preventive behaviour in a British population representative sample
No full textThe incidence of skin cancer has risen rapidly in the UK over the last 20 years, prompting public health organizations to try and raise awareness of the dangers of sun exposure and the need to practice sun-safe behaviour. This study aimed to assess baseline levels of sun-safe knowledge and behaviour in a British population-representative sample, prior to the launch of Cancer Research UK's 'SunSmart' campaign. A face-to-face survey was conducted through the Office for National Statistics as part of their Omnibus survey. In total, 1848 men and women aged 18 and over were interviewed. Knowledge of what to do to reduce skin cancer risk was modest. Two-thirds mentioned avoiding the sun by seeking shade, 50% mentioned covering up and only 43% said to use high factor sunscreen. Practice of sun-safe behaviours was also poor, with only one-third saying they sought shade, covered up or used high factor sunscreen to protect themselves from the sun. Men and those from lower socioeconomic groups were least informed and least likely to report using sun-protective behaviours. Increases in both knowledge and use of appropriate sun-protective behaviours are needed if skin cancer incidence rates are to decrease
Young Sun Kim
No full text학위논문(박사)--아주대학교 일반대학원 :의학과,2010. 2TABLE OF CONTENTS
ABSTRACT i
TABLE OF CONTENTS iii
LIST OF FIGURES v
ABBREVIATION vi
Ⅰ. INTRODUCTION 1
Ⅱ. MATERIALS AND METHODS 6
A. Materials 6
B. Subjects 6
C. Cell culture and viability 7
D. Transfection and depletion of siRNA 7
E. Immunocytochemistry 8
F. Co-immunoprecipitation and immunoblot analysis 8
G. Two-dimensional electrophoresis 9
H. Subcellular fractionation 10
I. Immunohistochemistry 10
J. Statistical analysis 11
Ⅲ. RESULTS 12
A. Localization of Prx III and Srx in A549 cells 12
B. Oxidation of Prx III in mink lung epithelial cells 12
C. Srx dependent regulation of Prx III oxidation in A549 cells 15
D. Srx is translocated into the mitochondria under oxidative stress 15
E. Overexpression of Prx I and III isoforms in human lung cancer 19
F. Nrf2 dependent expression of ARE-proteins in human lung cancer 19
G. Overexpression of Srx in human lung cancer 19
H. Survival of patients with lung cancer based on Srx expression 26
I. Expression of Srx in human lung cancer tissue 26
Ⅳ. DISCUSSION 28
Ⅴ. CONCLUSION 30
REFFERENCE 32
국문요약 40Maste
Perspectives on Identity, Migration, and Displacement
Full text linkPerspectives on Identity, Migration, and Displacement -- edited by Steven Tötösy de Zepetnek, I-Chun Wang, and Hsiao-Yu Sun (Kaohsiung: National Sun Yat-sen University Press, 2010. ISBN 9789860235418 209 pages, bibliography, index) is a collection of articles about sociological and literary aspects of identity formation as a consequence of (im)migration. (Im)migration results in the problematics of assimilation and hybridity and in postcolonial scholarship, in particular, attention is paid to the concept of migration termed Creolization on the ground that cultural contact, cultural transmission, and cultural transformation result in the creation of new cultures. Copyright release by National Sun Yat-sen University to the authors 2013
Phasia cana Sun 2003
No full textPhasia cana Spilostethus pandurus (Scopoly) (Hemiptera, Lygaeidae): New record. South Africa. Dysdercus superstitiosus (F.) (Hemiptera, Pyrrhocoridae): New record. Zimbabwe.Published as part of Sun, Xuekui & Marshall, Stephen A., 2003, Systematics of Phasia Latreille (Diptera: Tachinidae), pp. 1-320 in Zootaxa 276 (1) on page 310, DOI: 10.11646/zootaxa.276.1.1, http://zenodo.org/record/501951
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Integer-Magic Spectra of Sun Graphs
No full text國科會研究計畫：NSC 98-2115-M-032-005-MY3Let N be the set of all positive integers, and Zn={0, 1, 2, …, n-1}. For any h ∈ N, a graph G=(V,E) is said to be Zh-magic if there exists a labeling f : E → Zh\{0} such that induced vertex labeling f+ : V → Zh, defined by f+(v)= ∑uv∈Ef(uv), is a constant map. The integer-magic spectrum of G is the set IM(G)={ h ∈ N|G is Zh-magic}. A sun graph is obtained from attaching a path to each pair of adjacent vertices in an n-cycle. In this paper we showed that the integer-magic spectra of sun graphs are completely determined.國科會補正完畢國外SCIY紙本CA
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