Exoplanet transits as the foundation of an interstellar communications network

AbstractTwo fundamental problems for extraterrestrial intelligences (ETIs) attempting to establish interstellar communication are timing and energy consumption. Humanity's study of exoplanets via their transit across the host star highlights a means of solving both problems. An ETI ‘A’ can communicate with ETI ‘B’ if B is observing transiting planets in A's star system, either by building structures to produce artificial transits observable by B, or by emitting signals at B during transit, at significantly lower energy consumption than typical electromagnetic transmission schemes. This can produce a network of interconnected civilizations, establishing contact via observing each other's transits. Assuming that civilizations reside in a Galactic Habitable Zone (GHZ), I conduct Monte Carlo Realization simulations of the establishment and growth of this network, and analyse its properties in the context of graph theory. I find that at any instant, only a few civilizations are correctly aligned to communicate via transits. However, we should expect the true network to be cumulative, where a ‘handshake’ connection at any time guarantees connection in the future via e.g. electromagnetic signals. In all our simulations, the cumulative network connects all civilizations together in a complete network. If civilizations share knowledge of their network connections, the network can be fully complete on timescales of order a hundred thousand years. Once established, this network can connect any two civilizations either directly, or via intermediate civilizations, with a path much less than the dimensions of the GHZ.

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Mitigating the Energy Consumption and the Carbon Emission in the Building Structures by Optimization of the Construction Processes

Energies ◽

10.3390/en14113287 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3287

Author(s):

Alireza Tabrizikahou ◽

Piotr Nowotarski

Keyword(s):

Life Cycle ◽

Energy Consumption ◽

Structural Optimization ◽

Carbon Emissions ◽

Carbon Emission ◽

Construction Materials ◽

High Energy ◽

Building Structures ◽

Life Cycle Stages ◽

Reduction Of Energy Consumption

For decades, among other industries, the construction sector has accounted for high energy consumption and emissions. As the energy crisis and climate change have become a growing concern, mitigating energy usage is a significant issue. The operational and end of life phases are all included in the building life cycle stages. Although the operation stage accounts for more energy consumption with higher carbon emissions, the embodied stage occurs in a time-intensive manner. In this paper, an attempt has been made to review the existing methods, aiming to lower the consumption of energy and carbon emission in the construction buildings through optimizing the construction processes, especially with the lean construction approach. First, the energy consumption and emissions for primary construction materials and processes are introduced. It is followed by a review of the structural optimization and lean techniques that seek to improve the construction processes. Then, the influence of these methods on the reduction of energy consumption is discussed. Based on these methods, a general algorithm is proposed with the purpose of improving the construction processes’ performance. It includes structural optimization and lean and life cycle assessments, which are expected to influence the possible reduction of energy consumption and carbon emissions during the execution of construction works.

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Effects of the Geometric Parameters of Mixer on the Mixing Process of Foam Concrete Mixture and Its Energy Efficiency

Applied Sciences ◽

10.3390/app10228055 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8055

Author(s):

Sergey A. Stel’makh ◽

Evgenii M. Shcherban’ ◽

Anatolii I. Shuiskii ◽

Al’bert Yu. Prokopov ◽

Sergey M. Madatyan ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Lower Energy ◽

Geometric Parameters ◽

Concrete Mixture ◽

Mixing Process ◽

Conical Part ◽

Foam Concrete ◽

Optimal Range ◽

Optimal Values

The paper studies the influence of the geometric parameters of the mixer on the mixing process, the construction of the mixing body, its location in the mixer bulk, and the mixer shape and geometry. The technique of calculating the power spent on mixing the foam concrete mixture is described. The effects of the ratio of the mixture height to the mixer diameter, the number and width of reflective partitions, and the shape of the conical part of the mixer on the homogeneity of the foam concrete mixture and the power consumption are considered. The optimal ratios of the foam concrete mixture height to the mixer diameter have been determined. Moreover, the optimal range of the ratios of the partition width to the mixer diameter has been established, in order to obtain a homogeneous foam concrete mixture throughout the volume with lower energy consumption. The optimal values of the angle of the mixer conical part for the preparation of a foam concrete mixture have been determined.

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On the abundance of extraterrestrial life after the Kepler mission

International Journal of Astrobiology ◽

10.1017/s1473550414000767 ◽

2015 ◽

Vol 14 (3) ◽

pp. 511-516 ◽

Cited By ~ 12

Author(s):

Amri Wandel

Keyword(s):

Significant Fraction ◽

Habitable Zone ◽

Radio Telescopes ◽

Extraterrestrial Life ◽

Space Density ◽

Astronomical Data ◽

Unknown Probability ◽

Kepler Mission ◽

Average Longevity ◽

Electromagnetic Signals

AbstractThe data recently accumulated by the Kepler mission have demonstrated that small planets are quite common and that a significant fraction of all stars may have an Earth-like planet within their habitable zone. These results are combined with a Drake-equation formalism to derive the space density of biotic planets as a function of the relatively modest uncertainty in the astronomical data and of the (yet unknown) probability for the evolution of biotic life, Fb. I suggest that Fb may be estimated by future spectral observations of exoplanet biomarkers. If Fb is in the range 0.001–1, then a biotic planet may be expected within 10–100 light years from Earth. Extending the biotic results to advanced life I derive expressions for the distance to putative civilizations in terms of two additional Drake parameters – the probability for evolution of a civilization, Fc, and its average longevity. For instance, assuming optimistic probability values (Fb~Fc~1) and a broadcasting longevity of a few thousand years, the likely distance to the nearest civilizations detectable by searching for intelligent electromagnetic signals is of the order of a few thousand light years. The probability of detecting intelligent signals with present and future radio telescopes is calculated as a function of the Drake parameters. Finally, I describe how the detection of intelligent signals would constrain the Drake parameters.

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One-pot three-step mechanically assisted synthesis and catalytic performance of tripodal metallic complexes

Reaction Chemistry & Engineering ◽

10.1039/d1re00194a ◽

2021 ◽

Author(s):

Rima Tedjini ◽

Raquel Viveiros ◽

Teresa Casimiro ◽

Vasco D.B. Bonifácio

Keyword(s):

Energy Consumption ◽

Lower Energy ◽

Catalytic Performance ◽

Green Technology ◽

Waste Reduction ◽

One Pot ◽

Reaction Conversion

Mechanosynthesis is an emergent green technology that proceeds under solventless or vestigial solvent conditions. Major advantages relay in waste reduction and lower energy consumption, without compromising or enhancing reaction conversion....

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Effect of the Window Position in the Building Envelope on Energy Consumption

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.11174 ◽

2018 ◽

Vol 7 (3) ◽

pp. 1861

Author(s):

Neveen Y. Azmy ◽

Rania E. Ashmawy

Keyword(s):

Energy Consumption ◽

Light Intensity ◽

Environmental Performance ◽

Lower Energy ◽

Climatic Conditions ◽

Building Envelope ◽

Natural Lighting ◽

Energy Plus ◽

Window Position

Windows play a significant role as they largely influence the energy load. Although there are many studies on the energy-efficient windows design, there is still a lack in information about the mutual impact of windows’ size, position and orientation on the energy loads. In this paper, the effect of different window positions and orientations on the energy consumption in a typical room in an administrative building that is located in the hot climatic conditions of Cairo city, Egypt is considered. This case study has been modeled and analyzed to achieve good environmental performance for architectural space, as well as assessing its impact on the amount of natural lighting required by using the Energy Plus program. The study concludes that the WWR (Window Wall Ratio) 20% square north-oriented upper opening consumes 25% lower energy than the rectangular 3:1 opening in the lower west-oriented façade. The upper openings are the highest in terms of light intensity, as they cover about 50% of the room area. The WWR 30% rectangular north-oriented upper 3:1 opening consumes 29% lower energy than the rectangular lower 3:1opening in the façade. Regarding light intensity, the upper openings are the best for natural lighting as the light covers more than 60% of the room area.

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An Overview of Technologies for Lower Energy Consumption in Smart Buildings

IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society ◽

10.1109/iecon.2018.8592895 ◽

2018 ◽

Cited By ~ 2

Author(s):

Sam Moayedi ◽

Fares AlJuheshi ◽

Ahmad Almaghrebi ◽

Jan Haase ◽

Hiroaki Nishi ◽

...

Keyword(s):

Energy Consumption ◽

Lower Energy ◽

Smart Buildings

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Pilot Pipe and Damping Orifice Arrangements Analysis of a Pilot-Control Globe Valve

Journal of Fluids Engineering ◽

10.1115/1.4047533 ◽

2020 ◽

Vol 142 (10) ◽

Author(s):

Jin-yuan Qian ◽

Jia-yi Wu ◽

Zhi-xin Gao ◽

Zhi-jiang Jin

Keyword(s):

Energy Consumption ◽

Pressure Distribution ◽

Lower Energy ◽

Flow Resistance ◽

Flow Characteristics ◽

Incoming Flow ◽

Local Flow ◽

Flow Capacity ◽

Bottom Face ◽

Globe Valve

Abstract Compared to conventional globe valves, the pilot-control globe valve (PCGV) possesses advantages of lower energy consumption and higher space utilization. In order to analyze the effects of pilot pipe and damping orifice arrangements, this work proposes four PCGVs and conducts simulations to compare their overall performances, overall flow characteristics, and local flow characteristics around the valve core. In general, the arrangement of the pilot pipe has larger effects on the hydroperformances of PCGVs than the arrangement of the damping orifice. The pipe-parallel-mounted type PCGV performs better in hydroperformance than the pipe-perpendicular-mounted type PCGV, and thus is recommended in practice. As the specified valve core travel increases, the flow resistance of PCGVs decreases and the flow capacity of PCGVs increases. However, overlarge specified valve core travel has little effects on the flow resistance and flow capacity of PCGVs. Besides, the increased specified valve core travel could effectively reduce the wear induced by the uneven pressure distribution on the external lateral face of valve core, but it has little effect on the wear induced by the uneven pressure distribution on the bottom face. For all pipe-perpendicular-mounted type PCGVs, the variation of axial force imposed on the valve core relative to the specific valve core travel presents similar tendencies under different incoming flow velocity within the scope of the investigation, which could be concluded into a fitting equation. This work could be referred for the optimization of PCGVs and other similar valves.

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