34,155 research outputs found
Rotational CARS application to simultaneous and multiple-point temperature and concentration determination in a turbulent flow
Coherent anti-Stokes Raman scattering (CARS) from the pure rotational Raman lines of N2 is employed to measure the instantaneous (approximately 10 ns) rotational temperature of N2 gas at room temperature and below with good spatial resolution (0.2 x 0.2 x 3.0 cu mm). A broad bandwidth dye laser is used to obtain the entire rotational spectrum from a single laser pulse; the CARS signal is then dispersed by a spectrograph and recorded on an optical multichannel analyzer. A best fit temperature is found in several seconds with the aid of a computer for each experimental spectrum by a least squares comparison with calculated spectra. The model used to calculate the theoretical spectra incorporates the temperature and pressure dependence of the pressure-broadened rotational Raman lines, includes the nonresonant background susceptibility, and assumes that the pump laser has a finite linewidth. Temperatures are fit to experimental spectra recorded over the temperature range of 135 to 296 K, and over the pressure range of .13 to 15.3 atm
Application of plasmonic nanomaterials in nanomedicine
Plasmonic nanoparticles are being researched as a noninvasive tool for ultrasensitive
diagnostic, spectroscopic and, recently, therapeutic technologies. With particular
antibody coatings on nanoparticles, they attach to the abnormal cells of interest (cancer
or otherwise). Once attached, nanoparticles can be activated/heated with UV/visible/IR,
RF or X-ray pulses, damaging the surrounding area of the abnormal cell to the point of
death. Here, we describe an integrated approach to improved plasmonic therapy composed
of nanomaterial optimization and the development of a theory for selective radiation
nanophotothermolysis of abnormal biological cells with gold nanoparticles and selfassembled
nanoclusters. The theory takes into account radiation-induced linear and
nonlinear synergistic effects in biological cells containing nanostructures, with focus on
optical, thermal, bubble formation and nanoparticle explosion phenomena. On the basis
of the developed models, we discuss new ideas and new dynamic modes for cancer
treatment by radiation activated nanoheaters, which involve nanocluster aggregation in
living cells, microbubbles overlapping around laser-heated intracellular nanoparticles/
clusters, and laser thermal explosion mode of single nanoparticles (‘nanobombs’)
delivered to the cells.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2058
Selected reliability studies for the NERVA program
An investigation was made into certain methods of reliability analysis that are particularly suitable for complex mechanisms or systems in which there are many interactions. The methods developed were intended to assist in the design of such mechanisms, especially for analysis of failure sensitivity to parameter variations and for estimating reliability where extensive and meaningful life testing is not feasible. The system is modeled by a network of interconnected nodes. Each node is a state or mode of operation, or is an input or output node, and the branches are interactions. The network, with its probabilistic and time-dependent paths is also analyzed for reliability and failure modes by a Monte Carlo, computerized simulation of system performance
PassGAN: A Deep Learning Approach for Password Guessing
State-of-the-art password guessing tools, such as HashCat and John the
Ripper, enable users to check billions of passwords per second against password
hashes. In addition to performing straightforward dictionary attacks, these
tools can expand password dictionaries using password generation rules, such as
concatenation of words (e.g., "password123456") and leet speak (e.g.,
"password" becomes "p4s5w0rd"). Although these rules work well in practice,
expanding them to model further passwords is a laborious task that requires
specialized expertise. To address this issue, in this paper we introduce
PassGAN, a novel approach that replaces human-generated password rules with
theory-grounded machine learning algorithms. Instead of relying on manual
password analysis, PassGAN uses a Generative Adversarial Network (GAN) to
autonomously learn the distribution of real passwords from actual password
leaks, and to generate high-quality password guesses. Our experiments show that
this approach is very promising. When we evaluated PassGAN on two large
password datasets, we were able to surpass rule-based and state-of-the-art
machine learning password guessing tools. However, in contrast with the other
tools, PassGAN achieved this result without any a-priori knowledge on passwords
or common password structures. Additionally, when we combined the output of
PassGAN with the output of HashCat, we were able to match 51%-73% more
passwords than with HashCat alone. This is remarkable, because it shows that
PassGAN can autonomously extract a considerable number of password properties
that current state-of-the art rules do not encode.Comment: This is an extended version of the paper which appeared in NeurIPS
2018 Workshop on Security in Machine Learning (SecML'18), see
https://github.com/secml2018/secml2018.github.io/raw/master/PASSGAN_SECML2018.pd
The biochemical, physiological, and metabolic effects of Apollo nominal mission and contingency diets on human subjects while on a simulated Apollo mission Final report, Feb. - Jun. 1966
Biochemical, physiological, and metabolic effects of simulated Apollo mission with space diet on human
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