scholarly journals Terahertz wireless communications in space

2021 ◽  
Vol 2 (7) ◽  
pp. 31-38
Author(s):  
Meltem Civas ◽  
Ozgur B. Akan

The New Space Era has increased communication traffic in space by new space missions led by public space agencies and private companies. Mars colonization is also targeted by crewed missions in the near future. Due to increasing space traffic near Earth and Mars, the bandwidth is getting congested. Moreover, the downlink performance of the current missions is not satisfactory in terms of delay and data rate. Therefore, to meet the increasing demand in space links, Terahertz band (0.1-10 THz) wireless communications are proposed in this study. In line with this, we discuss the major challenges that the realization of THz band space links pose and possible solutions. Moreover, we simulate Mars-space THz links for the case of a clear Mars atmosphere, and a heavy dust storm to show that even in the worst conditions, a large bandwidth is available for Mars communication traffic.

2018 ◽  
pp. 86-105
Author(s):  
Carlos Hugo Soria Caceres

RESUMENLas infraestructuras de transporte presentes sobre el territorio condicionan las relaciones sociales y de comunicación de muchos espacios. Grandes estaciones, puertos o aeropuertos se presentan como ejes de centralidad sobre los que se distribuyen flujos de mercancías y personas, configurando a su vez el diseño y la funcionalidad de las ciudades. Hoy en día, con el avance producido en sectores como el ferrocarril de alta velocidad, las estaciones han transformado su función principal de nudo de intercambio, proyectándose como nuevos espacios comerciales y de negocio. En este artículo se analiza este nuevo fenómeno de transformación espacial y social vinculado a la alta velocidad ferroviaria, focalizando su ámbito en España. Se desgrana a su vez el papel de las comunidades sociales, políticas y empresariales para la ciudad y el espacio público presentes en las nuevas estaciones de ferroviarias. Palabras clave: ferrocarril; espacio público; urbanismo. ABSTRACTThis work aims to discuss the transport infrastructures presents on the territory and the conditions to the social and communication relations of many spaces. Large stations, ports or airports are presented as axes of centrality on which flows of goods and people are distributed, configuring in turn the design and functionality of cities. Nowadays, with the advance produced in sectors such as high-speed rail, the stations have transformed their main function as an exchange hub, projecting themselves as new commercial and business spaces. This article analyzes this new phenomenon of spatial and social transformation linked to high-speed rail, focusing its scope in Spain. At the same time, the role of the social, political and business communities for the city and the public space present in the new railway stations.Keywords: railroad; public space; urbanism.


Geoforum ◽  
2021 ◽  
Vol 124 ◽  
pp. 99-109
Author(s):  
Shanti Sumartojo ◽  
Robert Lundberg ◽  
Leimin Tian ◽  
Pamela Carreno-Medrano ◽  
Dana Kulić ◽  
...  

Author(s):  
Věra Kameníková

For optimal use and function in the public interior evaluation of seating furniture is important in terms of typology, ergonomics, safety, quality of design, used materials, ecology and other properties. The aim is to adjust the dimensional requirements of the seating furniture for public interior to meet the needs of the current population and reflect the proportional changes in the human body over the last decades.Due to the ageing of population and growing number of people with movement and physiological limitations (which also include the elderly), it will become, in near future, more topical need to modify the rules related to seating furniture that is used in public space. Particularly, in the term of simple and non-discriminatory sitting down and standing up.Proposal to change standards is based on the analysis of used values, the results of the current anthropometrical survey and addition of parameters that were processed by using ergonomic software.In most of the activities related to the seating there is an interaction with the surrounding furniture. Based on this assumption arise the importance of connection between seating furniture and reaching distance of the person sitting on it. Ranges are in the computer simulation divided according to intensity - static, dynamic and comfortable (with the preservation of the natural physiological limitations of joints). The resulting values of simulations can be defined distances suitable for placing objects near seating furniture to ensure the possibility of full utilization.If the principles are kept and they come from the needs of people with limitations, it is certain that the environment will suit all healthy individuals and at the same time it will be non-discriminatory for a greater proportion of people with physical limitations.


2022 ◽  
Vol 8 (2) ◽  
pp. 85-98
Author(s):  
Walter Timo De Vries

Changes in spatial planning and land management practices, regulations and operations have frequently relied on the uptake of innovations in geospatial technologies. This article reviews which ones the spatial planning and land management domains has effectively adopted and which new ones might potentially disrupt the domain in the near future of 2021 and beyond. Based on an extensive concept-centric trends synthesis and meta-review, the analysis demonstrates that whilst geospatial technologies are clearly gaining wider societal recognition and while private companies are indeed developing promising applications, its adoption in office work of public officials and public decision makers remains almost as limited as before. The potentially most disruptive technologies for the domain are however BIM, Block chain and Machine learning.


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 379 ◽  
Author(s):  
Sumanth Ranganathan ◽  
Volker Sieber

Hydrogen peroxide is an important chemical of increasing demand in today’s world. Currently, the anthraquinone autoxidation process dominates the industrial production of hydrogen peroxide. Herein, hydrogen and oxygen are reacted indirectly in the presence of quinones to yield hydrogen peroxide. Owing to the complexity and multi-step nature of the process, it is advantageous to replace the process with an easier and straightforward one. The direct synthesis of hydrogen peroxide from its constituent reagents is an effective and clean route to achieve this goal. Factors such as water formation due to thermodynamics, explosion risk, and the stability of the hydrogen peroxide produced hinder the applicability of this process at an industrial level. Currently, the catalysis for the direct synthesis reaction is palladium based and the research into finding an effective and active catalyst has been ongoing for more than a century now. Palladium in its pure form, or alloyed with certain metals, are some of the new generation of catalysts that are extensively researched. Additionally, to prevent the decomposition of hydrogen peroxide to water, the process is stabilized by adding certain promoters such as mineral acids and halides. A major part of today’s research in this field focusses on the reactor and the mode of operation required for synthesizing hydrogen peroxide. The emergence of microreactor technology has helped in setting up this synthesis in a continuous mode, which could possibly replace the anthraquinone process in the near future. This review will focus on the recent findings of the scientific community in terms of reaction engineering, catalyst and reactor design in the direct synthesis of hydrogen peroxide.


Author(s):  
Raghuraj Sharan Saxena ◽  
Rishik Shrivastava ◽  
Ritu Muchhal ◽  
Rahul Tiwari

As the wireless technology is advancing rapidly, there is also an increasing demand for high data rates and large bandwidth. So, the new generation technology (5G) is proposed. For this purpose, there is a need of advanced antenna design, and here the authors are using a microstrip patch antenna, which is highly preferred due to low profile, simple manufacturing, and ease of feeding. This research presents the design of 28.132 GHz microstrip patch antenna. We have used FR-4 substrate here is which has a dielectric constant Er= 4.3 and a thickness of 0.5 mm. The dimensions of patch are 4.8×6.8×0.5mm including the ground plane. It has a bandwidth of 1.613 GHz, return loss of -19.175 dB, VSWR 1.24 dB, VSWR as 1.24 dB, gain as 3.82 dB and total efficiency of -3.116 dB.. The designing and simulation of this antenna is performed by CST studio suite software and various specifications such as S-parameter, VSWR, and radiation pattern is discussed. Furthermore, comparative analysis is done, which is indicating the variation of antenna parameters on varying the design dimensions.


STUDIUM ◽  
2018 ◽  
pp. 43-79
Author(s):  
Manuel Acón Pérez

Resumen Durante la segunda mitad del siglo xvii las coffee houses proliferaron en Inglaterra y, lejos de ser un fenómeno excepcional, estaban totalmente integradas en la vida cotidiana del país. Eran establecimientos públicos a los que podía acceder cualquier hombre, siempre que tuviera dinero para permitirse una taza de café. Se convirtieron en lugares de interacción social alejados de la esfera privada —el hogar— y de la esfera de autoridad —la corte—, que  alcanzaron  reconocimiento gracias a sus ideales de sociabilidad, debate e igualitarismo. Las coffee houses se convirtieron en el reflejo de la vida cotidiana de una nueva clase media emergente, en la que el empirismo y el refinamiento comenzaban a aflorar. Quedaron vinculadas al incipiente mercantilismo de la época, pero igualmente tuvieron especial incidencia en la política y la cultura inglesas. También recibieron críticas, especialmente desde el ámbito femenino, aunque debemos considerarlas como una oposición frente a la exclusión que las mujeres sufrían para poder acceder a determinados ámbitos públicos. En definitiva, la aparición de las coffee houses supuso la creación de un nuevo espacio de sociabilidad donde no se trata de excluir a ningún sector social y donde las opiniones comenzaron a convertirse en opinión pública. Palabras clave: coffee house, sociabilidad, espacio público, siglo xvii, Inglaterra   Abstract During the second half of the 17th Century, coffee houses proliferated in England and, far from being an exceptional phenomenon, they were fully integrated into the daily life of the country. They were public establishments that could be accessed by any man, provided he had the money to afford a cup of coffee. They became places of social interaction far from the private sphere (the home) and the sphere of authority (the court), which achieved recognition thanks to their ideals of sociability, debate and egalitarianism. The coffee houses became the reflection of the daily life of a new emerging middle class, in which empiricism and refinement began to surface. They were linked to the incipient mercantilism of the time, but also had a special impact on English politics and culture. They also received criticism, especially from the female environment, although we must consider them as an opposition to the exclusion that women suffered in order to gain access to certain public spheres. In short, the emergence of coffee houses was the creation of a new space of sociability where it is not a question of excluding any social sector and where opinions began to become public opinion. Key words: coffee house, sociability, public space, 17th Century, England


Author(s):  
Rachmani Aprilia Sari ◽  

The purpose of this study was to analyze the implementation of cooperation between PT. PLN and private companies. The scope of his research is the provision of electricity infrastructure, which is one of the supporting sectors f or economic growth. The government is currently promoting this policy to meet the increasing demand for electricity. PT. PLN as a State Owned Enterprise (BUMN) is the implementer of government policies in terms of electricity that is still unable to meet the availability of electricity. Based on this, the government provides opportunities for the private sector to participate in the business of providing electricity for the public interest by utilizing Renewable Energy (EBT). The findings of this study are that electricity is generated through power plants owned by private companies and the result is that electricity is sold to PT. The research was carried out in a normative juridical manner with data obtained from electricity and tariff regulations, literature books and journals, public-private cooperation contracts. The results of this study are the application of the principle of economic equilibrium in the Power Purchase Agreement contract between the Government, namely PT PLN (Persero) and the private partnership.


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