Assessing radiative transfer models trained by numerical weather forecasts using sun-tracking radiometric measurements for satellite link characterization up to W band

Radio communications, and in particular Earth-to-satellite links, are worldwide used for delivering digital services. The bandwidth demand of such services is increasing accordingly to the advent of more advanced applications (e.g., multimedia services, deep-space explorations, etc.) thus pushing the scientific community toward the investigation of channel carriers at higher frequencies. When using carrier frequencies above X band, the main drawback is how to tackle the impact of tropospheric processes (i.e., rain, cloud, water vapor). This work assesses the joint use of weather forecast models, radiative transfer models and Sun-tracking radiometric measurements to explore their potential benefits in predicting path attenuation and sky noise temperature for slant paths at frequencies between K and W band, thus paving the way to the optimization of satellite link-budgets

ELITE OUTSIDE HITTERS IN VOLLEYBALL DO NOT MEET THEIR INDIVIDUAL POSSIBLE MAXIMUM IMPACT HEIGHT IN HIGH SPIKE JUMPS

It is assumed that a high impact height is a relevant factor for success in volleyball spikes. The purpose of the study was to investigate whether outside hitters hit the ball at the highest possible impact height. Spikes from position IV were analysed at a tournament of the European League. The posture of the athletes was less extended in the trunk and upper limb with increasing jump height. Regarding the body posture at the moment of impact, there was no effect on the post impact ball speed. It is concluded that there could be enhancement with respect to the impact height as jump height increases even in elite athletes without reducing ball speed. This should be addressed within the training process

Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)

The theory of diffusion in many-dimensional Hamiltonian system is applied to asteroidal dynamics. The general formulations developed by Chirikov is applied to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit) mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we investigate the diffusion \emph{along} and \emph{across} the separatrices of the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their relationship to diffusion in semi-major axis and eccentricity. The estimations of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type sympletic map and numerical integrations for times up to $10^{8}$ years.Comment: 27 pages, 6 figure

An Assessment of Changes in the Magnesium Level During Gynecological Abdominal Surgeries

Background: Magnesium (Mg) is the fourth most common cation in the human body and the second most intracellular cation after potassium. It has a fundamental role in several vital functions. As this essential ion is not measured in routine chemistry panels, little is known about its alterations during intraoperative time.Aim: The present study was designed to determine the negative eff ects of postoperative hypomagnesemia during and after surgeries.Subject and Methods: This study was a descriptive interventional study involving 74 patients. All patients underwent gynecological abdominal surgeries, and anesthesia protocols were standardized to comprise general and spinal anesthesia. All the patients were aged between 25 and 45 years, with ASA class I and II. Their total serum Mg level was measured 1 h before and 2 h after the surgery. The total serum Mg, calcium, and albumin level were measured by photometric methods. Data were analyzed using SPSS version 16.0 (Chicago Illinois, (USA). Inferential statistic was done using Vilksonnon-parametric and Pearson’s correlation test. P<0.05 were considered as significant.Results: The mean serum Mg levels were 1.87 (0.32) mg/dl before and 1.55 (0.34) mg/dl after the surgeries (The normal range: = 1.7-2.5 mg/dl). Results illustrated a significant hypomagnesemia after operations. Conclusion: Clinical impact of hypomagnesemia during surgeries needs to be studied further. Moreover, surgeons should be warned about the severity of probable electrolyte imbalances induced by perioperative events to decrease associated morbidities. Keywords: ASA, cation, gynecologic surgeries, magnesium, magnesium level, photometric method, standardized anesthesia, surgerie

Investigation of the long effective conjugation length in defect-free insulated molecular wires

Due to the “insulation” of the π-conjugated backbones, insulated molecular wires (IMWs) are expected to be applied to various optoelectronic applications and nanotechnology.[1] Recently, Kazunori et al have succeeded in the synthesis of a self-threading polythiophene with a polyrotaxane-like 3D architecture (PSTB, see Figure 1), for which an intrawire hole mobility of 0.9 cm2 V−1 s−1 has been measured.[2] Here, we aim to evaluate the extent of π-conjugation along polythiophene backbones sheathed within defect-free “insulating” layers. A comparison between the experimental Raman spectra of the self-threading oligomers (i.e. 2STB-5STB) and the corresponding PSTB polymer indicates that: (i) the ratio of relative intensities of the two most intense Raman bands (I1375/1445) increases with the elongation of the size chain but does not saturate up to the pentamer, and (ii) π-conjugation spreads over 17–18 thiophene units in the polymer. Whether the effective conjugation length of the polymer is better described by using the long oligomer extrapolation approach[3] or periodic DFT calculations of the polymer is discussed in detailed by exploiting the very recent potentialities of state-of-the-art quantum chemical simulations of vibrational properties for crystalline solids.[Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Accuracy comparison of different approaches for vortex sheet discretization on the airfoil in vortex particles method

The hierarchy of numerical schemes is developed for the solution of the boundary integral equation which arises in the vortex particles method. Two different approaches are considered and numerical schemes are presented, which provide 1-st and 2-nd order of accuracy with respect to two different norms. The developed finite element-type schemes have nearly the same computational cost as the simplest scheme with piecewise-constant solution. The necessary formulae are presented for linear system coefficients for the considered schemes