7,097 research outputs found
Coupling radio propagation and weather forecast models to maximize Ka-band channel transmission rate for interplanetary missions
Deep space (DS) missions for interplanetary explorations are aimed at acquiring information about the solar system and its composition. To achieve this result a radio link is established between the space satellite and receiving stations on the Earth. Significant channel capacity must be guaranteed to such spacecraft-to-Earth link considering their large separation distance as well. Terrestrial atmospheric impairments on the space-to-Earth propagating signals are the major responsible for the signal degradation thus reducing the link’s channel temporal availability. Considering the saturation and the limited bandwidth of the conventional systems used working at X-band (around 8.4 GHz), frequencies above Ku-band (12-18 GHz) are being used and currently explored for next future DS missions. For example, the ESA mission EUCLID, planned to be launched in 2020 to reach Sun-Earth Lagrange point L2, will use the K-band (at 25.5-27 GHz). The BepiColombo (BC) ESA mission to Mercury, planned to be launched in 2016, will use Ka-band (at 32-34 GHz) with some modules operating at X-band too. The W-band is also being investigated for space communications (Lucente et al., IEEE Systems J., 2008) as well as near-infrared band for DS links (Luini at al., 3rd IWOW, 2014; Cesarone et al., ICSOS, 2011).
If compared with X-band channels, K-band and Ka-band can provide an appealing data rate and signal-to-noise ratio in free space due to the squared-frequency law increase of antenna directivity within the downlink budget (for the same physical antenna size). However, atmospheric path attenuation can be significant for higher frequencies since the major source of transmission outage is not only caused by convective rainfall, as it happens for lower frequencies too, but even non-precipitating clouds and moderate precipitation produced by stratiform rain events are detrimental. This means that accurate channel models are necessary for DS mission data link design at K and Ka band. A physical approach can offer advanced radiopropagation models to take into account the effects due to atmospheric gases, clouds and precipitation.
The objective of this work is to couple a weather forecast numerical model with a microphysically- oriented radiopropagation model, providing a description of the atmospheric state and of its effects on a DS downlink. This work is developed in the framework of the RadioMeteorological Operations Planner (RMOP) program, aimed at performing a feasibility study for the BC mission (Biscarini et al., EuCAP 2014). The RMOP chain for the link budget computation is composed by three modules: weather forecast (WFM), radio propagation (RPM) and downlink budget (DBM). WFM is aimed at providing an atmospheric state vector. Among the available weather forecast models, for RMOP purposes we have used the Mesoscale Model 5. The output of the WFM is the input of the RPM for the computation of the atmospheric attenuation and sky-noise temperature at the receiving ground station antenna. RPM makes use of radiative transfer solver based on the Eddington approximations well as accurate scattering models. Time series of attenuation and sky-noise temperature coming from the RPM are converted into probability density functions and then ingested by the DBM to compute the received data volume (DV).
Using the BC mission as a reference test case for the Ka-band ground station at Cebreros (Spain), this work will show the advantages of using a coupled WFM-RPM approach with respect to climatological statistics in a link budget optimization procedure. The signal degradation due to atmospheric effects in DS links in terms of received DV will be also investigated not only at Ka band, but also at X, K and W for intercomparison. The quality of the DS downlink will be given in terms of received DV and the results at different frequencies compared showing the respective advantages and drawbacks
Detection of buried objects using reflected GNSS signals
The use of reflected Global Navigation Satellite System (GNSS) signals for sensing the Earth has been growing rapidly in recent years. This technique is founded on the basic principle of detecting GNSS signals after they have been reflected off the Earth's surface and using them to determine the properties of the reflecting surface remotely. This is the so-called GNSS reflectometry (GNSS-R) technique. In this paper, a new application regarding the detection of metallic buried objects is analyzed and it is validated through several experimental campaigns. Although the penetration depth of GNSS signals into the ground is not optimal and depends on the soil moisture, GNSS signals can likely interact approximately with the first 10 cm of the ground and therefore can be reflected back by any metallic object buried on the first terrain layer. A very light and low-cost GNSS receiver prototype based on a software-defined radio approach was developed. This receiver can be used as a payload on board small drones or unmanned aerial systems to detect metallic objects (mines or other explosive devices). A signal processing tool based on an open-loop GNSS signal acquisition strategy was developed. The results of two experiments which show the possibility of using GNSS-R signals to detect buried metallic objects and to provide an estimate of their dimensions are discussed
Предварительная оценка энергоэффективности зданий в условиях резко континентального климата
Construction of energy-efficient buildings becomes a top priority for many countries. Yet certain obstacles in achieving internal environment comfort standards remain in regions with extreme continental climate. In addition to engineering and economic challenges, there exist design process issues since design data should closely correspond with resulting performance of the building. This paper focuses on accurate energy demand estimation during design stage. Two types of buildings designed for Ural-Siberian region of Russia and for Kazakhstan are examined: detached and medium-rise apartment buildings. Most influential factors are taken into consideration and general recommendations on improving energy efficiency using effective combination of structural and engineering solutions are given. Adaptation of design procedure in terms of extreme continental climate made by means of simplified but precise Passive House planning tool is demonstrated.Строительство энергоэффективных зданий является приоритетным направлением для многих стран. Однако в регионах с суровым климатом часто возникают проблемы достижения нормативных показателей комфорта внутренней среды. В идеале проектные значения потребностей в электроэнергии на отопление и кондиционирование здания должны точно соответствовать итоговым показателям. В этой статье рассматриваются методики точного прогнозирования энергопотребления на стадии проектирования. Исследовано два типа зданий, проектируемых для Урало-Сибирского региона России и Казахстана: индивидуальный дом и многоквартирный дом средней этажности. Даны рекомендации по снижению энергопотребления зданий путем эффективного сочетания конструктивных и инженерных решений. Показан учет основных факторов, влияющих на энергетический баланс зданий. На примере Пакета проектирования пассивного дома 2007 приведен пример адаптации упрощенной, но достаточно точной методики расчета к резко континентальным климатическим условиям
Geological, seismological and geodetic evidence of active thrustingand folding south of Mt. Etna (eastern Sicily): Revaluation of “seismicefficiency” of the Sicilian Basal Thrust
tGeological studies and morphological analysis, compared with seismological and geodetic data, suggestthat a compressive regime currently occurs at crustal depth in the western sector of Mt. Etna, accommo-dated by shallow thrusting and folding at the front of the chain, south of the volcanic edifice. In particular,a large WSW-ENE trending anticline, interpreted as detachment fold, is growing west and north of Cata-nia city (the Catania anticline). Geological data suggest that during the last 6000 years the frontal foldhas been characterized by uplift rates of ∼6 mm/yr along the hinge, consistent with the interferometricdata (10 mm/yr) recorded in the last 20 years. Moreover, a NNW-SSE oriented axis of compression hasbeen obtained by seismological data, consistent with GPS measurements over the last 20 years whichhave revealed a shortening rate of ∼5 mm/yr along the same direction. Besides the activity related to thevolcanic feeding system, the seismic pattern under the Mt. Etna edifice can be certainly related to theregional tectonics. The compressive stress is converted into elastic accumulation and then in earthquakesalong the ramps beneath the chain, whereas on the frontal area it is accommodated by aseismic defor-mation along an incipient detachment within the clayish foredeep deposits. The high rate of shorteningat the aseismic front of the chain, suggests a greater “seismic efficiency” in correspondence of ramps atthe rear.Published32-412T. Tettonica attivaJCR Journalrestricte
New Geological, seismological and geodetic evidence of active thrusting and folding south of Mt. Etna (eastern Sicily): revaluation of “seismic efficiency” of the Sicilian Basal Thrust
New geological, seismological and geodetic data indicate that a NNW-SSE compressive regime occurs in the
southern and western sector of Mt. Etna, accommodated by aseismic folding at the front of the chain. In particular, a
large WSW-ENE trending anticline (the Catania anticline) is growing west and north of Catania within a middle-late
Pleistocene fold system. For its location, geometry and growth rate, it is consistent with detachment fold models. We
exclude that this structure have developed in response to volcanic spreading, as proposed by previous authors. Looking
at the earthquakes distribution , an interesting finding is a clear trend of the seismic events deepening from very shallow
hypocenters, in the area south of Etna, down to a depth of about 35 km, towards the NNW. Moreover, most of the
events are clustered. We computed the focal mechanisms for the major and best recorded earthquakes occurring in the
area. One cluster located at few kilometers north-west of the summit craters shows fault mechanisms of the deeper
events with nearly horizontal P-axes striking NNW-SSE. A segment of the Sicilian Basal Thrust, located at crustal
depth under the northwestern sector of the volcano, could be the seismic source. We propose the occurrence of
detachment folding at the chain front, as response of a surface frontal propagation of this regional structure, migrating
within the clayish middle-late Pleistocene foredeep deposits or at the top of the buried Hyblean foreland sequence.
Geological and morphometric analyses suggest a maximum up warp deformation along the anticline axis of 40 m in the
last 6000-7000 yrs, with a vertical slip-rate of 5 - 7 mm/yr. These values are consistent with the growth rate of 9 - 10
mm/yr estimated by interferometric data and the horizontal shortening of 5 mm/yr obtained by GPS measurements.
Our analysis confirms that, besides the activity related to the volcanic feeding system, the seismic pattern under Mt.
Etna edifice can be certainly related to the regional dynamics. The compressive stress is converted into elastic
accumulation and then in earthquakes along the ramps to the rear of the chain, whereas along the frontal detachment it
is accommodated by aseismic ductile deformation. In fact, despite the high rates of convergence, the seismicity is
moderate at the front of the chain and the “seismic efficiency" of the Sicilian Basal Thrust is greater in correspondence
of ramps at the rear, where strong earthquakes can occur.Publishedhttp://www.geoscienze2014.it/1T. Geodinamica e interno della Terraope
The Estimation of Cortical Activity for Brain-Computer Interface: Applications in a Domotic Context
In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm technique. Results showed that the use of the cortical-estimated activity instead of the unprocessed EEG improves the recognition of the mental states associated to the limb movement imagination in the group of normal subjects. The BCI methodology presented here has been used in a group of disabled patients in order to give
them a suitable control of several electronic devices disposed in a three-room environment devoted to the neurorehabilitation. Four of six patients were able to control several electronic devices in this domotic context with the BCI system
CDK4/6 Inhibitors in Breast Cancer Treatment: Potential Interactions with Drug, Gene, and Pathophysiological Conditions
Palbociclib, ribociclib, and abemaciclib belong to the third generation of cyclin-dependent kinases inhibitors (CDKis), an established therapeutic class for advanced and metastatic breast cancer. Interindividual variability in the therapeutic response of CDKis has been reported and some individuals may experience increased and unexpected toxicity. This narrative review aims at identifying the factors potentially concurring at this variability for driving the most appropriate and tailored use of CDKis in the clinic. Specifically, concomitant medications, pharmacogenetic profile, and pathophysiological conditions could influence absorption, distribution, metabolism, and elimination pharmacokinetics. A personalized therapeutic approach taking into consideration all factors potentially contributing to an altered pharmacokinetic/pharmacodynamic profile could better drive safe and effective clinical use
DIAGNÓSTICOS DE ENFERMAGEM NAS COMPLICAÇÕES EM SALA DE RECUPERAÇÃO ANESTÉSICA
<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:PT-BR; mso-fareast-language:PT-BR;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> This is a descriptive, exploratory study with a qualitative method and non-experimental design, with analysis of absolute and relative frequency of data. It shows how to identify nursing diagnoses according to NANDA Taxonomy II in Post Anesthesia Care Unit (PACU). The sample consisted of 30 adult patients undergoing elective surgery with general anesthesia, and evaluation of physical conditions according to American Society of Anesthesiologists (ASA 1). The field of study was the PACU, which has 8 beds in a mixed network hospital in the city of Santos. Data were collected through a structured method, with data on gender, age, medical diagnoses, intervention-surgical anesthetic, surgical time, anesthetic time, vital signs including blood pressure at admission, assessment of the index of Aldrete KrouliK; and complications such as nausea, vomiting and pain. After the analysis of the nursing problems, nursing diagnoses were identified, with the greatest frequency being hypothermia, nausea, and acute pain. Este es un estudio descriptivo, exploratorio, con método cualitativo y rasgo no empírico, con análisis de frecuencia absoluta y relativa de los datos. Presenta como objetivo identificar los diagnósticos de enfermería según la Taxonomía II de la NANDA, en la Sala de Recuperación Post-Anestésica (SRPA). La muestra estaba constituida por 30 enfermos adultos, sometidos a cirugía selectiva, con anestesia general y evaluación de las condiciones físicas Americam Society of Anesthesiologists (ASA1). El campo de estudio fue la SPRA, la cual cuenta con 8 camas de un hospital de la red mixta de la ciudad de Santos. Los datos fueron colectados a través de un instrumento estructurado, con datos referentes al sexo, edad, diagnóstico médico, intervención anestésico quirúrgica, tiempo quirúrgico, tiempo anestésico, signos vitales, incluyendo verificación de la tensión arterial en la internación, índices de Aldrete Kroulik y complicaciones como náusea, vómito y dolor. Tras el análisis de los problemas de enfermería, fueron identificados los diagnósticos de enfermería, siendo los de mayor frecuencia la hipotermia, náusea y dolor agudo.Este é um estudo descritivo, exploratório, com método quantitativo e delineamento não experimental, com análise de freqüência absoluta e relativa dos dados. Apresenta como objetivo identificar os diagnósticos de enfermagem, segundo a Taxonomia II da NANDA, na Sala de Recuperação Pós-Anestésica (SRPA). A amostra foi constituída de 30 pacientes adultos, submetidos à cirurgia eletiva, com anestesia geral, e avaliação das condições físicas Americam Society of Anesthesiologists (ASA 1). O campo de estudo foi a SRPA, a qual conta com 8 leitos, de um Hospital da rede mista da cidade de Santos. Os dados foram coletados por meio de um instrumento estruturado, com dados referentes ao sexo, idade, diagnóstico médico, intervenção anestésico-cirúrgica, tempo cirúrgico, tempo anestésico, sinais vitais incluindo verificação de pressão arterial na internação, avaliação do índice de Aldrete KrouliK; e complicações como náusea, vômito e dor. Após o levantamento dos problemas de enfermagem, foram identificados os diagnósticos de enfermagem, sendo os maior freqüência a hipotermia, náusea e dor aguda.  
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