A New Study on Tri-Lindelöf Spaces Qoqazeh, Hamza; Atoom, Ali A.; Jaradat, Ali ...
WSEAS Transactions Mathematics,
11/2023, Letnik:
22
Journal Article
Odprti dostop
This paper defines new covering properties in tri-topological spaces called tri-Lindelöf space and the properties of this topological property and its relationship with some other types of ...tri-topological spaces will be studied. The effect of some types of functions on tri-Lindelöf spaces will be studied. This paper also investigates the necessary conditions through which the tri-topological space is reduced into a single topological space. Many and varied illustrative examples will be discussed and many well-known facts and theorems are generalized concerning Lindelöf spaces.
A Hausdorff topological space X is called superconnected (resp. coregular) if for any nonempty open sets U1,…Un⊆X, the intersection of their closures U‾1∩…∩U‾n is not empty (resp. the complement ...X∖(U‾1∩…∩U‾n) is a regular topological space). A canonical example of a coregular superconnected space is the projective space QP∞ of the topological vector space Q<ω={(xn)n∈ω∈Qω:|{n∈ω:xn≠0}|<ω} over the field of rationals Q. The space QP∞ is the quotient space of Q<ω∖{0}ω by the equivalence relation x∼y iff Q⋅x=Q⋅y.
We prove that every countable second-countable coregular space is homeomorphic to a subspace of QP∞, and a topological space X is homeomorphic to QP∞ if and only if X is countable, second-countable, and admits a decreasing sequence of closed sets (Xn)n∈ω such that (i) X0=X, ⋂n∈ωXn=∅, (ii) for every n∈ω and a nonempty relatively open set U⊆Xn the closure U‾ contains some set Xm, and (iii) for every n∈ω the complement X∖Xn is a regular topological space. Using this topological characterization of QP∞ we find topological copies of the space QP∞ among quotient spaces, orbit spaces of group actions, and projective spaces of topological vector spaces over countable topological fields.
The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together ...with the Modular Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al.
this issue
) MXGS constitutes the instruments of the Atmosphere-Space Interactions Monitor (ASIM) (Neubert et al.
this issue
). The main objectives of MXGS are to image and measure the spectrum of X- and
γ
-rays from lightning discharges, known as Terrestrial Gamma-ray Flashes (TGFs), and for MMIA to image and perform high speed photometry of Transient Luminous Events (TLEs) and lightning discharges. With these two instruments specifically designed to explore the relation between electrical discharges, TLEs and TGFs, ASIM is the first mission of its kind. With an imaging system and a large detector area MXGS will, for the first time, allow estimation of the location of the source region and characterization of the energy spectrum of individual events. The sensors have fast readout electronics to minimize pileup effects, giving high time resolution of photon detection for comparison with measurements on μs-time scales of lightning processes measured by the MMIA and other sensors in space or on the ground. The detectors cover the large energy range of the relevant photon energies. In this paper we describe the scientific objectives, design, performance, imaging capabilities and operational modes of the MXGS instrument.
The International Space Station (ISS) is the largest man-made structure to orbit Earth and has been conducting research for close to a decade and a half. Yet it is only the latest in a long line of ...space stations and laboratories that have flown in orbit since the early 1970s. The histories of these earlier programs have been all but forgotten as the public focused on other, higher-profile adventures such as the Apollo moon landings.A vast trove of stories filled with excitement, danger, humor, sadness, failure, and success,Outposts on the Frontierreveals how the Soviets and the Americans combined strengths to build space stations over the past fifty years. At the heart of these scientific advances are people of both greatness and modesty. Jay Chladek documents the historical tapestry of the people, the early attempts at space station programs, and how astronauts and engineers have contributed to and shaped the ISS in surprising ways.Outposts on the Frontierdelves into the intriguing stories behind the USAF Manned Orbiting Laboratory, the Almaz and Salyut programs,Skylab, the Apollo-Soyuz Test Project, Spacelab,Mirstation, Spacehab, and the ISS and gives past-due attention to Vladimir Chelomei, the Russian designer whose influence in space station development is as significant as Sergei Korolev's in rocketry.Outposts on the Frontieris an informative and dynamic history of humankind's first outposts on the frontier of space.
British Design brings together leading international scholars, designers and journalists to provide new perspectives on British design in the last sixty years, and how it at once looked back to the ...past with the continuation of traditions that spoke to Britain's design heritage, and looked forwards with the embrace of modernist and postmodernist style. The book responds to and develops new ways of understanding the recent history of design in Britain, with case studies on designed spaces and objects, including domestic interiors, retail spaces, schools and university buildings and transport. The contributors address significant moments and phenomena in the historical and social history of British design, from the rise and fall of the English Country House style and the Brutalist architectural boom of the 1960s to the modern shopping space, and consider the work of key contemporary designers ranging from Tommy Roberts to Thomas Heatherwick. British Design provides new criticism and analysis on how design, from the immediate post-war period to the present day, has developed and changed how we live and how we interact with the spaces in which we live. British Design is split into 13 chapters and is richly illustrated with 65 images, 16 of which are in full colour.
A Telegraph Best Science Book of the
Year "A witty yet in-depth exploration of the prospects
for human habitation beyond Earth… Spacefarers is
accessible, authoritative, and in the end, inspiring." ...-Richard
Panek, author of The Trouble with Gravity It's been over
fifty years since Apollo 11 landed on the moon. So why is there so
little human presence in space? Will we ever reach Mars? And what
will it take to become a multiplanet species? While many books have
speculated on the possibility of living beyond the Earth, few have
delved into the practical challenges. A wry and compelling take on
the who, how, and why of near-future colonies in space,
Spacefarers introduces us to the engineers, scientists,
planners, dreamers, and entrepreneurs who are striving right now to
make life in space a reality. While private companies such as
SpaceX are taking the lead and earning profits from human space
activity, Christopher Wanjek is convinced this is only the
beginning. From bone-whittling microgravity to eye-popping profits,
the risks and rewards of space settlement have never been so close
at hand. He predicts we will have hotels in low-earth orbit, mining
and tourism on the Moon, and science bases on Mars-possibly
followed (gravity permitting) by full blown settlements. "Nerdily
engaging (and often funny)…Technology and science fiction
enthusiasts will find much here to delight them, as Wanjek goes
into rich detail on rocketry and propulsion methods, including
skyhooks and railguns to fling things into orbit…He is a sensible
skeptic, yet also convinced that, in the long run, our destiny is
among the stars." - The Guardian "If the events of this
year have had you daydreaming about abandoning the planet entirely,
Spacefarers is a geekily pleasurable survey of the
practicalities and challenges." - The Telegraph "The best
book I've read on space exploration since Isaac Asimov." -Michael
Shermer, publisher of Skeptic
The past five decades have witnessed often fierce international rivalry in space, but also surprising military restraint. Now, with an increasing number of countries capable of harming U.S. space ...assets, experts and officials have renewed a long-standing debate over the best route to space security. Some argue that space defenses will be needed to protect critical military and civilian satellites. Others argue that space should be a "sanctuary" from deployed weapons and military conflict, particularly given the worsening threat posed by orbital space debris. Moltz puts this debate into historical context by explaining the main trends in military space developments since Sputnik, their underlying causes, and the factors that are likely to influence their future course. This new edition provides analysis of the Obama administration's space policy and the rise of new actors, including China, India, and Iran.
His conclusion offers a unique perspective on the mutual risks militaries face in space and the need for all countries to commit to interdependent, environmentally focused space security.
As biomaterial advances make headway into lightweight radiation protection, wound healing dressings, and microbe resistant surfaces, a relevance to human space exploration manifests itself. To ...address the needs of the human in space, a knowledge of the space environment becomes necessary. Both an understanding of the environment itself and an understanding of the physiological adaptations to that environment must inform design parameters. The space environment permits the fabrication of novel biomaterials that cannot be produced on Earth, but benefit Earth. Similarly, designing a biomaterial to address a space-based challenge may lead to novel biomaterials that will ultimately benefit Earth. This review describes several persistent challenges to human space exploration, a variety of biomaterials that might mitigate those challenges, and considers a special category of space biomaterial.
This work is a review of the major human and environmental challenges facing human spaceflight, and where biomaterials may mitigate some of those challenges. The work is significant because a broad range of biomaterials are applicable to the human space program, but the overlap is not widely known amongst biomaterials researchers who are unfamiliar with the challenges to human spaceflight. Additionaly, there are adaptations to microgravity that mimic the pathology of certain disease states (“terrestrial analogs”) where treatments that help the overwhelmingly healthy astronauts can be applied to help those with the desease. Advances in space technology have furthered the technology in that field on Earth. By outlining ways that biomaterials can promote human space exploration, space-driven advances in biomaterials will further biomaterials technology.
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Sand-grain-sized computers, self-healing materials and constellations of craft would reboot our reach, explain Igor Levchenko, Michael Keidar and colleagues.
We cannot properly understand history without a full appreciation of the spaces through which its actors moved, whether in the home or in the public sphere, and the ways in which they thought about ...and represented the spaces of their worlds. In this book Michael Scott employs the full range of literary, epigraphic and archaeological evidence in order to demonstrate the many different ways in which spatial analysis can illuminate our understanding of Greek and Roman society and the ways in which these societies thought of, and interacted with, the spaces they occupied and created. Through a series of innovative case studies of texts, physical spaces and cultural constructs, ranging geographically across North Africa, Greece and Roman Italy, as well as an up-to-date introduction on spatial scholarship, this book provides an ideal starting point for students and non-specialists.
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