Theoretical face pressure and drag characteristics of forward-facing steps in supersonic turbulent boundary layers

A theoretical investigation of the pressure distributions and drag characteristics was made for forward facing steps in turbulent flow at supersonic speeds. An approximate solution technique proposed by Uebelhack has been modified and extended to obtain a more consistent numerical procedure. A comparison of theoretical calculations with experimental data generally indicated good agreement over the experimentally available range of ratios of step height to boundary layer thickness from 7 to 0.05

Analysis of pressure distributions for a series of tip and trailing-edge controls on a 60 deg wing at Mach numbers of 1.61 and 2.01

Supersonic pressure distributions for tip and trailing edge controls on 60 deg delta win

In Situ Study of the Photodegradation of Carbofuran Deposited on TiO\u3csub\u3e2\u3c/sub\u3e Film under UV Light, Using ATR-FTIR Coupled to HS-MCR-ALS

The in situ study of the photodegradation of carbofuran deposited on a TiO2 catalyst film under UV light was carried out using the ATR-FTIR technique. The data were analyzed using a Hard–Soft Multivariate Curve Resolution-Alternating Least Squares (HS-MCR-ALS) methodology. Using S-MCR-ALS, four factors were deduced from the evolving factor analysis of the data, and their concentrations and spectra were determined. These results were used to draw qualitative and quantitative analyses of the major products of carbofuran photodegradation. The results of this analysis were in good agreement with GC-MS results and with reported mechanisms. Hard-MCR-ALS was then used to refine the spectra and concentrations, using a multistep kinetic model. The rate constant for the first step in the photodegradation of carbofuran was found to be 2.9 × 10–3 min–1. The higher magnitude of the correlation (96.87%), the explained variance (99.87%) and LOF (3.01), are good indicators of the reliability of the outcome of this approach. This method has been shown to be an efficient approach to study in situ photodegradation of pesticides on a solid surface

Three-loop QCD corrections and b-quark decays

We present three-loop (NNNLO) corrections to the heavy-to-heavy quark transitions in the limit of equal initial and final quark masses. In analogy with the previously found NNLO corrections, the bulk of the result is due to the beta_0^2 alpha_s^3 corrections. The remaining genuine three-loop effects for the semileptonic b --> c decays are estimated to increase the decay amplitude by 0.2(2)%. The perturbative series for the heavy-heavy axial current converges very well.Comment: 5 page

Calculation of the One- and Two-Loop Lamb Shift for Arbitrary Excited Hydrogenic States

General expressions for quantum electrodynamic corrections to the one-loop self-energy [of order alpha(Zalpha)^6] and for the two-loop Lamb shift [of order alpha^2(Z\alpha)^] are derived. The latter includes all diagrams with closed fermion loops. The general results are valid for arbitrary excited non-S hydrogenic states and for the normalized Lamb shift difference of S states, defined as Delta_n = n^3 DeltaE(nS) - DeltaE(1S). We present numerical results for one-loop and two-loop corrections for excited S, P and D states. In particular, the normalized Lamb shift difference of S states is calculated with an uncertainty of order 0.1 kHz.Comment: 4 pages, RevTe

Heavy-to-light decays with a two-loop accuracy

We present a determination of a new class of three-loop Feynman diagrams describing heavy-to-light transitions. We apply it to find the O(alpha_s^2) corrections to the top quark decay t -> bW and to the distribution of lepton invariant mass in the semileptonic b quark decay b -> ul\nu. We also confirm the previously determined total rate of that process as well as the O(alpha^2) corrections to the muon lifetime.Comment: 5 page

Free time of elderly people in terms of physical activity

Gerontological issues will gain more and more recognition, both in the social and medical aspect. The reason for this is the sharp increase in the percentage of the elderly population, which is related to a decline in birth rates on the one hand and an increase in life expectancy on the other. The aging of the population of Europe and Poland is probably the most important health and socio-political challenge in the coming years. In 2050, people aged 60-79 are expected to make up a quarter of the entire population of the European Union. Maintaining the appropriate level of health, independence and independence of the elderly becomes a great challenge. This is not only a public health challenge, but also a huge socio-economic problem. A typical situation in old age is the occurrence of several diseases at the same time. In addition, the situation is complicated by the procedure of a number of degenerative changes affecting almost all systems and functions of the system, deteriorating the possibility of functioning and rehabilitation. Taking up issues related to seniors becomes important for at least several reasons. The most important ones include: the increasing number of elderly people, the widespread cult of a financially efficient and independent person (completely different from the geriatric reality), the need to educate professionals to help or support those in need, and the need for mental changes in society regarding the aging process and old age itself. The aim of this article is to present the problem of leisure time of elderly people from the perspective of physical activity. The starting point for the considerations was the explanation of the concepts of "old age" and "aging". Next, the most important issues concerning human activity in late adulthood are presented and the main assumptions of the theory of activity are presented. Then the concept of free time was defined, the features of free time activity were discussed, and the functions of free time were also indicated. Attention was also paid to the structure of seniors' time budget and the types of free-time activity that dominate among them. Next, the problem of free time of old people is presented in the context of the theory of activity, paying particular attention to the issues related to the activation of seniors

How to Complete an Interactive Configuration Process?

When configuring customizable software, it is useful to provide interactive tool-support that ensures that the configuration does not breach given constraints. But, when is a configuration complete and how can the tool help the user to complete it? We formalize this problem and relate it to concepts from non-monotonic reasoning well researched in Artificial Intelligence. The results are interesting for both practitioners and theoreticians. Practitioners will find a technique facilitating an interactive configuration process and experiments supporting feasibility of the approach. Theoreticians will find links between well-known formal concepts and a concrete practical application.Comment: to appear in SOFSEM 201

Electroweak Radiative Corrections to Muon Capture

Electroweak radiative corrections to muon capture on nuclei are computed and found to be sizable. They enhance the capture rates for hydrogen and helium by 2.8% and 3.0% respectively. As a result, the value of the induced pseudoscalar coupling, g_P^exp, extracted from a recent hydrogen 1S singlet capture experiment is increased by about 21% to g_P^exp = 7.3 +/- 1.2 and brought into good agreement with the prediction of chiral perturbation theory, g_P^theory=8.2 +/- 0.2. Implications for helium capture rate predictions are also discussed.Comment: 6 page

Nonrelativistic QED Approach to the Lamb Shift

We calculate the one- and two-loop corrections of order α(Zα)6 and α2(Zα)6, respectively, to the Lamb shift in hydrogenlike systems using the formalism of nonrelativistic quantum electrodynamics. We obtain general results valid for all hydrogenic states with nonvanishing orbital angular momentum and for the normalized difference of S states. These results involve the expectation value of local effective operators and relativistic corrections to Bethe logarithms. The one-loop correction is in agreement with previous calculations for the particular cases of S, P, and D states. The two-loop correction in the order α2(Zα)6 includes the pure two-loop self-energy and all diagrams with closed fermion loops. The obtained results allow one to obtain improved theoretical predictions for all excited hydrogenic states