Retrieval of spatio-temporal distributions of particle parameters from multiwavelength lidar measurements using the linear estimation technique and comparison with AERONET

The results of the application of the linear estimation technique to multiwavelength Raman lidar measurements performed during the summer of 2011 in Greenbelt, MD, USA, are presented. We demonstrate that multiwavelength lidars are capable not only of providing vertical profiles of particle properties but also of revealing the spatio-temporal evolution of aerosol features. The nighttime 3β + 1α lidar measurements on 21 and 22 July were inverted to spatio-temporal distributions of particle microphysical parameters, such as volume, number density, effective radius and the complex refractive index. The particle volume and number density show strong variation during the night, while the effective radius remains approximately constant. The real part of the refractive index demonstrates a slight decreasing tendency in a region of enhanced extinction coefficient. The linear estimation retrievals are stable and provide time series of particle parameters as a function of height at 4 min resolution. AERONET observations are compared with multiwavelength lidar retrievals showing good agreement

Parity violation in deuteron photo-disintegration

We analyze the energy dependence for two types of parity-non-conserving (PNC) asymmetries in the reaction $\gamma D\to np$ in the near-threshold region. The first one is the asymmetry in reaction with circularly polarized photon beam and unpolarized deuteron target. The second one corresponds to those with an unpolarized photon beam and polarized target. We find that the two asymmetries have quite different energy dependence, and their shapes are sensitive to the PNC-meson exchange coupling constants. The predictions for the future possible experiments to provide definite constraints for the PNC-coupling constants are discussed.Comment: 22 pages, 12 figures. Submitted to Phys.Rev.C 10Oct.0

The Toroid Moment of Majorana Neutrino

If neutrino is the Majorana particle it can possess only one electromagnetic characteristic, the toroid dipole moment (anapole) in the static limit and nothing else. We have calculated the diagonal toroid moment (form factor) of the Majorana neutrino by the dispersion method in the one-loop approximation of the Standard Model and found it to be different from zero in the case of massive as well as massless neutrinos. All external particles are on the mass shells and there are no problems with the physical interpretation of the final result. Some manifestations of the toroid interactions of Majorana neutrinos, induced by their toroid moments, are also remarked.Comment: 22 pages, 1 table and 3 EPS-figures included, uses prd.sty, preprint.sty, aps.sty and epsfig.sty (RevTeX is used), major conceptual changes of E2-96-53 are include

Anomalous asymmetry of magnetoresistance in NbSe3_3 single crystals

A pronounced asymmetry of magnetoresistance with respect to the magnetic field direction is observed for NbSe$_3$ crystals placed in a magnetic field perpendicular to their conducting planes. It is shown that the effect persists in a wide temperature range and manifests itself starting from a certain magnetic induction value $B_0$, which at $T=4.2$ K corresponds to the transition to the quantum limit, i.to the state where the Landay level splitting exceeds the temperature.Comment: 4 pages, 6 figures, to be appeared in JETP Let

Impact of Electromagnetic Radiation of 4G/5G Base Stations on Medical Short-Range Devices in Urban Area

The impact of electromagnetic radiation created by micro base stations of 4G/5G cellular networks on receivers of medical short-range devices of different systems (capsule endoscopy system, body area network system, and active implant system) located inside buildings is analyzed for urban area. The analysis is made by the use of computer simulation involving the multipath radiowave propagation model which takes into account outdoor-to-indoor propagation. To perform the simulation, a 3D model of a fragment of urban area containing buildings of a height from 6 m to 60 m is developed. The integrated interference margin is used as a criterion of electromagnetic compatibility. Results of the analysis show that 4G/5G base stations can create the interference to all considered types of medical short-range devices in cases when emitters are located outside buildings and receptors are located inside buildings. In order to achieve electromagnetic compatibility between these base stations and considered medical systems, recommendations on reducing of levels of electromagnetic interference are given. Results of this research can be used to ensure safe operation of 4G/5G base stations with respect to vital medical devices

The AMMA mulid network for aerosol characterization in West Africa

Three ground based portable low power consumption microlidars (MULID) have been built and deployed at three remote sites in Banizoumbou (Niger), Cinzana (Mali) and M'Bour (Senegal) in the framework of the African Monsoon Multidisciplinary Analyses (AMMA) project for the characterization of aerosols optical properties. A description of the instrument and a discussion of the data inversion method, including a careful analysis of measurement uncertainties (systematic and statistical errors) are presented. Some case studies of typical lidar profiles observed over the Banizoumbou site during 2006 are shown and discussed with respect to the AERONET 7-day back-trajectories and the biomass burning emissions from the Combustion Emission database for the AMMA campaign

Optical Properties of Aerosols from Long Term Ground-Based Aeronet Measurements

AERONET is an optical ground-based aerosol monitoring network and data archive supported by NASA's Earth Observing System and expanded by federation with many non-NASA institutions including AEROCAN (AERONET CANada) and PHOTON (PHOtometrie pour le Traiteinent Operatonnel de Normalisation Satellitaire). The network hardware consists of identical automatic sun-sky scanning spectral radiometers owned by national agencies and universities purchased for their own monitoring and research objectives. Data are transmitted hourly through the data collection system (DCS) on board the geostationary meteorological satellites GMS, GOES and METEOSAT and received in a common archive for daily processing utilizing a peer reviewed series of algorithms thus imposing a standardization and quality control of the product data base. Data from this collaboration provides globally distributed near real time observations of aerosol spectral optical depths, aerosol size distributions, and precipitable water in diverse aerosol regimes. Access to the AERONET data base has shifted from the interactive program 'demonstrat' (reserved for PI's) to the AERONET homepage allowing faster access and greater development for GIS object oriented retrievals and analysis with companion geocoded data sets from satellites, LIDAR and solar flux measurements for example. We feel that a significant yet under utilized component of the AERONET data base are inversion products made from hourly principal plane and almucanter measurements. The current inversions have been shown to retrieve aerosol volume size distributions. A significant enhancement to the inversion code has been developed and is presented in these proceedings

Radioactive contamination of ZnWO4 crystal scintillators

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopurity level of the ZnWO4 crystal scintillators is briefly addressed.Comment: 15 pages, 8 figures, 6 tables, submitted for publicatio

Методика синтеза согласующих устройств для широкополосных радиотехнических устройств с нестабильным импедансом нагрузки на основе метода вещественных частот

The aim of this work is to develop a method for the synthesis of matching devices for broadband radio engineering systems with varying impedance in different operating conditions. To achieve this goal, a criterion (complex criterion) is proposed for minimizing the value of the modulus of the sensitivity invariant of the reflection coefficient function to a change in the load impedance with restrictions on the square of the deviation of the power transmission ratio from a given level. It is proposed to use a combination of methods of real frequencies together with the shown complex criterion, which made it possible to implement an effective approach to the synthesis of matching devices for broadband radio engineering systems with an unstable load impedance. To verify the approach, a matching device was synthesized, which made it possible to reduce the loss of the power transmission factor level transmitted to the UHF/VHF antenna of the AD-44 / CW-TA-30-512 range when it is located in various operating conditions by at least 50 % in relation to losses obtained with a standard matching device.Целью работы является разработка метода синтеза согласующих устройств для широкополосных радиотехнических систем с изменяющимся импедансом в различных условиях их эксплуатации. Для достижения поставленной цели предложен критерий (комплексный критерий) минимизации значения модуля инварианта чувствительности функции коэффициента отражения к изменению импеданса нагрузки с ограничениями на квадрат отклонения коэфициента передачи мощности от заданного уровня. Предложено использовать сочетание методов вещественных частот совместно с показанным комплексным критерием, что позволило реализовать эффективный подход к синтезу согласующих устройств для широкополосных радиотехнических систем с нестабильным импедансом нагрузки. Для верификации подхода было синтезировано согласующее устройство, которое позволило уменьшить потери уровня коэффициента передачи мощности передаваемого в антенну UHF/VHF диапазона AD-44 / CW-TA-30-512 при расположении ее в различных условиях эксплуатации не менее чем на 50 % по отношению к потерям, полученным со штатным согласующим устройством

Reduction of Aerosol Absorption in Beijing Since 2007 from MODIS and AERONET

An analysis of the time series of MODIS-based and AERONET aerosol records over Beijing reveals two distinct periods, before and after 2007. The MODIS data from both the Terra and Aqua satellites were processed with the new Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm. A comparison of MAIAC and AERONET AOT shows that whereas MAIAC consistently underestimated peak AOT values by 10-20% in the prior period, the bias mostly disappears after mid-2007. Independent analysis of the AERONET dataset reveals little or no change in the effective radii of the fine and coarse fractions and of the Angstrom exponent. At the same time, it shows an increasing trend in the single scattering albedo, by approx.0.02 in 9 years. As MAIAC was using the same aerosol model for the entire 2000-2010 period, the decrease in AOT bias after 2007 can be explained only by a corresponding decrease of aerosol absorption caused by a reduction in local black carbon emissions. The observed changes correlate in time with the Chinese government's broad measures to improve air quality in Beijing during preparations for the Summer Olympics of 2008