11,838 research outputs found
Photocatalytic production of organic compounds from CO and H2O in a simulated Martian atmosphere
[14C]CO2 and [14C]organic compounds are formed when a mixture of [14C]CO and water vapor diluted in [12C]CO2 or N2 is irradiated with ultraviolet light in the presence of soil or pulverized vycor substratum. The [14C]CO2 is recoverable from the gas phase, the [14C]organic products from the substratum. Three organic products have been tentatively identified as formaldehyde, acetaldehyde, and glycolic acid. The relative yields of [14C]CO2 and [14C]organics are wavelength- and surface-dependent. Conversion of CO to CO2 occurs primarily at wavelengths shorter than 2000 angstrom, apparently involves the photolysis of water, and is inhibited by increasing amounts of vycor substratum. Organic formation occurs over a broad spectral range below 3000 angstrom and increases with increasing amounts of substratum. It is suggested that organic synthesis results from adsorption of CO and H2O on surfaces, with excitation of one or both molecules occurring at wavelengths longer than those absorbed by the free gases. This process may occur on Mars and may have been important on the primitive earth
An overview of the demonstration advanced avionics system guest pilot evaluation conducted at Ames Research Center
The guest pilot flight evaluation of the Demonstration Advanced Avionics System (DAAS) is discussed. The results are based on the fifty-nine questionnaires that were completed by the participants. The primary purpose of the pilot evaluation was to expose the Demonstration Advanced Avionics System to the various segments of the general aviation community and solicit comments in order to determine the effectiveness of integrated avionics for general aviation. Segments of the community that were represented in the evaluation are listed. A total of sixty-four (64) flights were conducted in which one hundred and seventeen (117) pilots and observers participated. It was felt that the exposure each subject had with the DAAS was too short to adequately assess the training requirements, pilot workload, and the reconfiguration concept of the DAAS. It is recommended that an operational evaluation of the DAAS be made to assess: the training requirements or varying experience levels, the pilot workload in the ATC environment with unplanned route changes, and the viability of the reconfiguration concept for failures
Prime numbers, quantum field theory and the Goldbach conjecture
Motivated by the Goldbach conjecture in Number Theory and the abelian
bosonization mechanism on a cylindrical two-dimensional spacetime we study the
reconstruction of a real scalar field as a product of two real fermion
(so-called \textit{prime}) fields whose Fourier expansion exclusively contains
prime modes. We undertake the canonical quantization of such prime fields and
construct the corresponding Fock space by introducing creation operators
--labeled by prime numbers -- acting on the vacuum. The
analysis of our model, based on the standard rules of quantum field theory and
the assumption of the Riemann hypothesis, allow us to prove that the theory is
not renormalizable. We also comment on the potential consequences of this
result concerning the validity or breakdown of the Goldbach conjecture for
large integer numbers.Comment: 20 pages in A4 format, 2 figure
Rotating Leaks in the Stadium Billiard
The open stadium billiard has a survival probability, , that depends on
the rate of escape of particles through the leak. It is known that the decay of
is exponential early in time while for long times the decay follows a
power law. In this work we investigate an open stadium billiard in which the
leak is free to rotate around the boundary of the stadium at a constant
velocity, . It is found that is very sensitive to . For
certain values is purely exponential while for other values the
power law behaviour at long times persists. We identify three ranges of
values corresponding to three different responses of . It is
shown that these variations in are due to the interaction of the moving
leak with Marginally Unstable Periodic Orbits (MUPOs)
Rancang Bangun Pembelajaran Online Sistem Operasi Windows 7 dengan HTML 5
Website yang ada saat ini umumnya dibangun menggunakan tag – tag dalam HTML 4.1, dimana HTML 4.1 belum mendukung tampilan audio dan video, tetapi audio dan video dapat dilihat dan didengar dengan adanya aplikasi tambahan sesuai dengan keperluan. HTML 5 dikembangkan W3C yang telah mendukung audio dan video pada website tanpa harus tergantung pada aplikasi tambahan. Pada penulisan ini, penulis mengimplementasikan pembelajaran sistem operasi windows 7 di dalam website yang akan dibangun, dan penulis menggunakan metodologi waterfall, yang dimulai dengan tahap pendefinisian kebutuhan, analisis kebutuhan, perancangan sistem, pengkodean website, dan pengujian. Pada pengkodean website, penulis menggunakan actionscript untuk merancang konten dari website yang akan dibangun. Dari hasil rancang bangun website pembelajaran ini, diharapkan dapat membantu masyarakat untuk mengenal dan mengoperasikan sistem operasi windows 7 secara mendasar dengan mudah
The twisted fourth moment of the Riemann zeta function
We compute the asymptotics of the fourth moment of the Riemann zeta function
times an arbitrary Dirichlet polynomial of length Comment: 28 pages. v2: added reference
Quantum Mechanical Interaction-Free Measurements
A novel manifestation of nonlocality of quantum mechanics is presented. It is
shown that it is possible to ascertain the existence of an object in a given
region of space without interacting with it. The method might have practical
applications for delicate quantum experiments.Comment: (revised file with no need for macro), 12, TAUP 1865-91
Design, development, and flight test of a demonstration advanced avionics system
Ames Research Center initiated a program in 1975 to provide the critical information required for the design of integrated avionics suitable for general aviation. The program emphasized the use of data busing, distributed microprocessors, shared electronic displays and data entry devices, and improved functional capability. Design considerations included cost, reliability, maintainability, and modularity. As a final step, a demonstration advanced avionics system (DAAS) was designed, built, and flight tested in a Cessna 402, twin engine, general aviation aircraft. A functional description of the DAAS, including a description of the system architecture, is presented and the program and flight test results are briefly reviewed
Pomeron loops in zero transverse dimensions
We analyze a toy model which has a structure similar to that of the recently
found QCD evolution equations, but without transverse dimensions. We develop
two different but equivalent methods in order to compute the leading-order and
next-to-leading order Pomeron loop diagrams. In addition to the leading-order
result which has been derived from Mueller's toy model~\cite% {Mueller:1994gb},
we can also calculate the next-to-leading order contribution which provides the
correction. We interpret this result and discuss its
possible implications for the four-dimensional QCD evolution.Comment: 11 pages, 4 figure
Bosonic behavior of entangled fermions
Two bound, entangled fermions form a composite boson, which can be treated as
an elementary boson as long as the Pauli principle does not affect the behavior
of many such composite bosons. The departure of ideal bosonic behavior is
quantified by the normalization ratio of multi-composite-boson states. We
derive the two-fermion-states that extremize the normalization ratio for a
fixed single-fermion purity P, and establish general tight bounds for this
indicator. For very small purities, P<1/N^2, the upper and lower bounds
converge, which allows to quantify accurately the departure from perfectly
bosonic behavior, for any state of many composite bosons.Comment: 9 pages, 5 figures, accepted by PR
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