Athena: Advanced air launched space booster

The infrastructure for routine, reliable, and inexpensive access of space is a goal that has been actively pursued over the past 50 years, but has yet not been realized. Current launch systems utilize ground launching facilities which require the booster vehicle to plow up through the dense lower atmosphere before reaching space. An air launched system on the other hand has the advantage of being launched from a carrier aircraft above this dense portion of the atmosphere and hence can be smaller and lighter compared to its ground based counterpart. The goal of last year's Aerospace Engineering Course 483 (AE 483) was to design a 227,272 kg (500,000 lb.) air launched space booster which would beat the customer's launch cost on existing launch vehicles by at least 50 percent. While the cost analysis conducted by the class showed that this goal could be met, the cost and size of the carrier aircraft make it appear dubious that any private company would be willing to invest in such a project. To avoid this potential pitfall, this year's AE 483 class was to design as large an air launched space booster as possible which can be launched from an existing or modification to an existing aircraft. An initial estimate of the weight of the booster is 136,363 kg (300,000 lb.) to 159,091 kg (350,000 lb.)

The neutron and its role in cosmology and particle physics

Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic

A concept "bank laws" in a wide and narrow value

Досліджено сутність поняття “банківське законодавство” в широкому і вузькому значенні.Essence of concept "bank laws" in a wide and narrow value is investigated

Synthesis, Structures and Photoluminescence Properties of a Series of Alkaline Earth Metal-Based Coordination Networks Synthesized Using Thiophene-Based Linkers

Three new 3-D coordination networks were synthesized using alkaline-earth metal centers, calcium, and strontium, with 2,5-thiophenedicarboxylate (TDC) as the organic linker. [Ca₂(TDC-2H)₂(DMF)₂]_<i>n</i> [<b>1</b>, space group <i>P</i>2₁/<i>n</i>, <i>a</i> = 10.0704(3) Å, <i>b</i> = 14.2521(3) Å, <i>c</i> = 17.5644(6) Å, β = 94.281(2)°] is composed of tetrameric calcium polyhedral clusters, which are connected by the organic linkers. Coordinated DMF molecules are present within the 1-D channel along the [010] direction. [Ca­(TDC-2H)]_<i>n</i> [<b>2</b>, space group <i>Pbcm</i>, <i>a</i> = 5.3331(5) Å, <i>b</i> = 6.8981(4) Å, <i>c</i> = 18.141(2) Å] consists of chains of edge-sharing calcium octahedra, connected by organic linkers, to form a dense network. [Sr­(TDC-2H)­(DMF)]_<i>n</i> [<b>3</b>, space group <i>P</i>2₁/<i>n</i>, <i>a</i> = 5.9795(3) Å, <i>b</i> = 17.058(1) Å, <i>c</i> = 11.3592(6) Å, β = 91.257(1)°] forms a structural topology almost identical to compound <b>1</b> except that the chains are built by combinations of edge- and face-sharing polyhedra. Compounds <b>1</b> and <b>3</b> were synthesized using DMF as solvent, whereas compound <b>2</b> crystallizes using ethanol. Photoluminescence studies reveal that the topologies of the networks and the presence of the coordinated solvent molecules control the luminescence properties of the compounds

Synthesis, Structures and Photoluminescence Properties of a Series of Alkaline Earth Metal-Based Coordination Networks Synthesized Using Thiophene-Based Linkers

Three new 3-D coordination networks were synthesized using alkaline-earth metal centers, calcium, and strontium, with 2,5-thiophenedicarboxylate (TDC) as the organic linker. [Ca₂(TDC-2H)₂(DMF)₂]_<i>n</i> [<b>1</b>, space group <i>P</i>2₁/<i>n</i>, <i>a</i> = 10.0704(3) Å, <i>b</i> = 14.2521(3) Å, <i>c</i> = 17.5644(6) Å, β = 94.281(2)°] is composed of tetrameric calcium polyhedral clusters, which are connected by the organic linkers. Coordinated DMF molecules are present within the 1-D channel along the [010] direction. [Ca­(TDC-2H)]_<i>n</i> [<b>2</b>, space group <i>Pbcm</i>, <i>a</i> = 5.3331(5) Å, <i>b</i> = 6.8981(4) Å, <i>c</i> = 18.141(2) Å] consists of chains of edge-sharing calcium octahedra, connected by organic linkers, to form a dense network. [Sr­(TDC-2H)­(DMF)]_<i>n</i> [<b>3</b>, space group <i>P</i>2₁/<i>n</i>, <i>a</i> = 5.9795(3) Å, <i>b</i> = 17.058(1) Å, <i>c</i> = 11.3592(6) Å, β = 91.257(1)°] forms a structural topology almost identical to compound <b>1</b> except that the chains are built by combinations of edge- and face-sharing polyhedra. Compounds <b>1</b> and <b>3</b> were synthesized using DMF as solvent, whereas compound <b>2</b> crystallizes using ethanol. Photoluminescence studies reveal that the topologies of the networks and the presence of the coordinated solvent molecules control the luminescence properties of the compounds

Structural Chemistry of Akdalaite, Al₁₀O₁₄(OH)₂, the Isostructural Aluminum Analogue of Ferrihydrite

As part of an effort to characterize clusters and intermediate phases likely to be encountered along solution reaction pathways that produce iron and aluminum oxide-hydroxides from Fe and Al precursors, the complete structure of Al10O14(OH)2 (akdalaite) was determined from a combination of single-crystal X-ray diffraction (SC-XRD) data collected at 100 K to define the Al and O positions, and solid-state nuclear magnetic resonance (NMR) and neutron powder diffraction (NPD) data collected at room temperature (~300 K) to precisely determine the nature of hydrogen in the structure. Two different synthesis routes produced different crystal morphologies. Using an aluminum oxyhydroxide floc made from mixing AlCl3 and 0.48 M NaOH, the product had uniform needle morphology, while using nanocrystalline boehmite (Vista Chemical Company Catapal D alumina) as the starting material produced hexagonal plates. Akdalaite crystallizes in the space group P63mc with lattice parameters of a = 5.6244(3) &#197; and c = 8.8417(3) &#197; (SC-XRD) and a = 5.57610(2) &#197; and c = 8.77247(6) &#197; (NPD). The crystal structure features Al13O40 Keggin clusters. The structural chemistry of akdalaite is nonideal but broadly conforms to that of ferrihydrite, the nanomineral with which it is isostructural

A Calcium Coordination Framework Having Permanent Porosity and High CO₂/N₂ Selectivity

A thermally stable, microporous calcium coordination network shows a reversible 5.75 wt % CO₂ uptake at 273 K and 1 atm pressure, with an enthalpy of interaction of ∼31 kJ/mol and a CO₂/N₂ selectivity over 45 under ideal flue gas conditions. The absence of open metal sites in the activated material suggests a different mechanism for selectivity and high interaction energy compared to those for frameworks with open metal sites

A Calcium Coordination Framework Having Permanent Porosity and High CO₂/N₂ Selectivity

A thermally stable, microporous calcium coordination network shows a reversible 5.75 wt % CO₂ uptake at 273 K and 1 atm pressure, with an enthalpy of interaction of ∼31 kJ/mol and a CO₂/N₂ selectivity over 45 under ideal flue gas conditions. The absence of open metal sites in the activated material suggests a different mechanism for selectivity and high interaction energy compared to those for frameworks with open metal sites

A Calcium Coordination Framework Having Permanent Porosity and High CO₂/N₂ Selectivity

A thermally stable, microporous calcium coordination network shows a reversible 5.75 wt % CO₂ uptake at 273 K and 1 atm pressure, with an enthalpy of interaction of ∼31 kJ/mol and a CO₂/N₂ selectivity over 45 under ideal flue gas conditions. The absence of open metal sites in the activated material suggests a different mechanism for selectivity and high interaction energy compared to those for frameworks with open metal sites