4,209 research outputs found
The Italian Remote Sensing Data Archive: from DBRMS to Web Distribution
During the Antarctic campaign 1989-1990, a NOAA-HRPT receiving station was installed at the Italian Base, Mario Zucchelli Station, at Terra Nova Bay. The receiving station is operational when the base is open, usually from mid-October to mid-February. Three NOAA polar orbiting satellites are normally in operation at the same time, at the present they are NOAA-15, NOAA-17, NOAA-18. During the campaign 1998-1990 was installed a new dual-receiving HRPT station to get also DMSP (Defence Meteorological Satellites Program of USA) satellites and currently we receive three DMSP satellites f-13, f-14 and f-15. At the present about fifty passes per day are acquired and processed each day reaching a total of around 4500 passes per expedition.
All data acquired during campaigns are stored on DDS tape, which format is changed during years. Up to now more than 7 TB of data are stored on different media (from 8mm tapes to DDS4 tapes), regarding a period of time from V to XXII expedition.
In order to achieve a more flexible and reliable system to access all the above data, in 2005, a process to copy to Hard-Disk storage in RAID mode, has been started. The activity is a work in progress, in the meantime the opportunity to realize a web application to process and distribute data to scientific community has been planned. We created a working prototype system based on a LAMP open source architecture (Linux, Apache, MySQL, PHP) and the TERASCAN software (from SeaSpace Corp.) to process and archive remote sensing data. The demo provides a web form to query the relational database containing all data related to each raw acquired satellite pass and as final result a quicklook of the requested pass is showed.
This demo is just a first step of an application that in the future will be able to supply to the user a valid tool to navigate in entire data archive and eventually getting products such AVHRR images, TOVS profile, ARGOS data or extracting the complete satellite pass
The influence of self‐weight of elastic 2D structures in topology optimization via numerical technique Smooth Evolutionary Structural Optimization (SESO)
O presente artigo aborda a otimização topológica em problemas de elasticidade plana linear considerando a influência do peso próprio nos esforços em elementos estruturais. Utiliza‐se para este fim uma técnica numérica denominada Smooth ESO (SESO) que se baseia no procedimento de diminuição progressiva da contribuição de rigidez de elementos ineficientes com menores tensões até que ele não tenha mais influência. As aplicações do SESO são feitas com o método dos elementos finitos e considera‐se um elemento finito triangular e de alta ordem. Neste trabalho estende‐se a técnica SESO para a aplicação do peso próprio onde o programa, no cômputo de seu volume e peso específico, gera automaticamente uma força concentrada equivalente para cada nó do elemento. A avaliação é finalizada com a definição de um modelo de bielas e tirantes resultante das regiões de concentração de tensões. Nos exemplos de aplicação são apresentadas topologias ótimas de uma estrutura suspensa, de viga baixa e de viga parede considerando o peso próprio e obtendo‐se ótimas configurações e demonstrando que a consideração do peso próprio leva a maior robustez ao processo de otimização.This paper deals with topology optimization in plane elastic‐linear problems considering the influence of the self weight in efforts in structural elements. For this purpose it is used a numerical technique called SESO (Smooth ESO), which is based on the procedure for progressive decrease of the inefficient stiffness element contribution at lower stresses until he has no more influence. The SESO is applied with the finite element method and is utilized a triangular finite element and high order. This paper extends the technique SESO for application its self weight where the program, in computing the volume and specific weight, automatically generates a concentrated equivalent force to each node of the element. The evaluation is finalized with the definition of a model of strut‐and‐tie resulting in regions of stress concentration. Examples are presented with optimum topology structures obtaining optimal settings.Peer Reviewe
Oxidative potential associated with urban aerosol deposited into the respiratory system and relevant elemental and ionic fraction contributions
Size-segregated aerosol measurements were carried out at an urban and at an industrial site. Soluble and insoluble fractions of elements and inorganic ions were determined. Oxidative potential (OP) was assessed on the soluble fraction of Particulate Matter (PM) by ascorbic acid (AA), dichlorofluorescein (DCFH) and dithiothreitol (DTT) assays. Size resolved elemental, ion and OP doses in the head (H), tracheobronchial (TB) and alveolar (Al) regions were estimated using the Multiple-Path Particle Dosimetry (MPPD) model. The total aerosol respiratory doses due to brake and soil resuspension emissions were higher at the urban than at the industrial site. On the contrary, the doses of anthropic combustion tracers were generally higher at the industrial site. In general, the insoluble fraction was more abundantly distributed in the coarse than in the fine mode and vice versa for the soluble fraction. Consequently, for the latter, the percent of the total respiratory dose deposited in TB and Al regions increased. Oxidative potential assay (OPAA) doses were distributed in the coarse region; therefore, their major contribution was in the H region. The contribution in the TB and Al regions increased for OPDTT and OPDCFH
Statistical Properties of Habitable Zones in Stellar Binary Systems
Observations of exoplanets and protoplanetary disks show that binary stellar systems can host planets in stable orbits. Given the high binary fraction among stars, the contribution of binary systems to Galactic habitability should be quantified. Therefore, we have designed a suite of Monte Carlo experiments aimed at generating large (up to 106) samples of binary systems. For each system randomly extracted we calculate the intersection between the radiative habitable zones (HZs) and the regions of dynamical stability using published empirical formulations that account for the dynamical and radiative parameters of both stars of the system. We also consider constraints on planetary formation in binary systems. We find that the habitability properties of circumstellar and circumbinary regions are quite different and complementary with respect to the binary system parameters. Circumbinary HZs are, generally, rare ( 434%) in the global population of binary systems, even if they are common for stellar separations 720.2 au. Conversely, circumstellar HZs are frequent ( 6580%) in the global population but are rare for stellar separations 721 au. These results are robust against variations of poorly constrained binary system parameters. We derive ranges of stellar separations and stellar masses for which HZs in binary systems can be wider than the HZs around single stars; the widening can be particularly strong (up to one order of magnitude) for circumstellar regions around M-type secondary stars. The comparison of our statistical predictions with observational surveys shows the impact of selection effects on the habitability properties of detected exoplanets in binary systems
On the Sensitivity of a Hollow Sphere as a Multi-modal Resonant Gravitational Wave Detector
We present a numerical analysis to simulate the response of a spherical
resonant gravitational wave detector and to compute its sensitivity. Under the
assump- tion of optimal filtering, we work out the sensitivity curve for a
sphere first taking into account only a single transducer, and then using a
coherent analysis of the whole set of transducers.Comment: 24 pages, 11 figures, published versio
Rare lymphoid malignancies of the breast: report of two cases illustrating potential diagnostic techniques.
Two cases of lymphoid malignancy involving the breast are herein presented. Both patients were admitted with a palpable breast mass. Ultrasound demonstrated hypoechoic, ill-defined lesions of the breast in both patients; mammogram also showed spiculated breast densities. Both patients underwent core biopsy, which revealed lymphomatous cells. Total-body evaluation was also performed by computed tomography and positron emission tomography/computed tomography revealing no other fluorodeoxyglucose-avid foci in the first case and supra and subdiaphragmatic disease in the second one
Usefulness of hybrid SPECT/CT for the 99mTc-HMPAO-labeled leukocyte scintigraphy in a case of cranial osteomyelitis
Cranial osteomyelitis is a potentially fatal lesion. White blood cell scanning (WBC) with 99mTc-hexamethylpropylene amine oxime (HMPAO) has proven highly sensitive and specific in the diagnosis and follow-up of patients with suspected osteomyelitis. In this report we show the usefulness of SPECT and transmission CT performed simultaneously using a hybrid imaging device for the functional anatomic mapping of soft tissue and cranial bone infections. 99mTc-HMPAO-labeled leukocytes scintigraphy was performed on an elderly diabetic man with an intracranial mass lesion and with suspected temporal bone infection. Planar scans were acquired 30 min, 4 h, and 24 h after injection. SPECT/CT was obtained 6 h after tracer injection, using a dual-head camera coupled with a low-power X-ray tube. The scintigraphic results were matched with the results of surgery and of clinical follow-up. The planar images alone were true-positives for abscess in this patient. SPECT/CT improves the accuracy of 99mTc-HMPAO scintigraphy especially in discriminating between soft-tissue and bone involvement. In fact, SPECT/CT also showed temporal bone osteomyelitis. This result indicates that SPECT/CT performed using a hybrid device can improve imaging with 99mTc-HMPAO-labeled leukocytes in patients with suspected osteomyelitis by providing accurate anatomic localization and precise definition of the extent of infection
Renal sympathetic nerve ablation for the treatment of difficult-to-control or refractory hypertension in a haemodialysis patient.
Haemodialysis patients show sympathetic hyperactivity. Hyperactivation of the sympathetic nervous system aggravates hypertension and it is related to left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. We report the first use of renal sympathetic nerve ablation for correction of uncontrolled hypertension in an end-stage renal disease patient on maintenance dialysis. We observed a progressive and sustained reduction of systemic blood pressure. Our case demonstrates the safety, the feasibility and the efficacy of this procedure. These findings suggest, however, that further clinical trials are needed into renal nerve radiofrequency ablation therapy for the treatment of hypertension and for the improvement of cardiovascular prognosis in this high-risk patient group
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