10,878 research outputs found

    Methodology of Construction of an Algorithm for the Systemic Learning of First Semester Students of the TICs Subject

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    Algorithms have become the primary source to start programming. Particularly, making an algorithm from a given problem and converting it into a program is of great importance for analysts, technologists, and computer engineers, that is why this article aims to give a clear idea of how to develop an algorithm for any given problem. The objective of this work was to develop a methodology that is not so complex and that allows our students to perform the algorithm, pseudo-code, flow diagram and finally be able to carry out the program. The tests carried out show that the methodology used gives good results, achieving a significant improvement in the learning of students in the first semester of industrial engineering.   Keywords: algorithms, flow diagrams, program, programming, software engineerin

    Dry anaerobic digestion of organic waste: A review of operational parameters and their impact on process performance.

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    open access articleDry digestion is a suitable technology for treating organic wastes with varying composition such as the organic fraction of municipal solids waste. Yet, there is a need for further research to overcome some of the disadvantages associated with the high total solids content of the process. Optimisation of inoculum to substrate ratio, feedstock composition and size, liquid recirculation, bed compaction and use of bulking agents are some of the parameters that need further investigation in batch dry anaerobic digestion, to limit localised inhibition effects and avoid process instability. In addition, further attention on the relation between feedstock composition, organic loading rate and mixing regimes is required for continuous dry anaerobic digestion systems. This paper highlights all the areas where knowledge is scarce and value can be added to increase dry anaerobic digestion performance and expansion

    Implementation of a 10.24 GS/s 12-bit Optoelectronics Analog-to-Digital Converter Based on a Polyphase Demultiplexing Architecture

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    AbstractIn this paper we present the practical implementation of a high-speed polyphase sampling and demultiplexing architecture for optoelectronics analog-to-digital converters (OADCs). The architecture consists of a one-stage divide-by-eight decimator circuit where optically-triggered samplers are cascaded to sample an analog input signal, and demultiplex different phases of the sampled signal to yield low data rate for electronic quantization. Electrical-in to electrical-out data format is maintained through the sampling, demultiplexing and quantization processes of the architecture thereby avoiding the need for electrical-to-optical and optical-to-electrical signal conversions. We experimentally demonstrate a 10.24 giga samples per second (GS/s), 12-bit resolution OADC system comprising the optically-triggered sampling circuits integrated with commercial electronic quantizers. Measurements performed on the OADC yielded an effective bit resolution (ENOB) of 10.3 bits, spurious free dynamic range (SFDR) of -32 dB and signal-to-noise and distortion ratio (SNDR) of 63.7 dB

    Vulvovaginal atrophy (VVA) in breast cancer survivors (BCS) is still an unmet medical need: results of an Italian Delphi Panel

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    Abstract: Purpose: VVA is a common disease, with approximately 50% of all postmenopausal women having related symptoms. VVA has a significant impact on the personal and sexual lives and on many aspects of women\u2019s self-esteem and emotional well-being. It is particularly frequent and severe in patients treated for BC, where it originates significant economic and social costs. Given the lack of published evidence on this subject, a Delphi Panel was carried out to evaluate:The epidemiology of VVA and of its risk-factors/comorbidities in ItalyThe present standard of care and unmet medical needsThe comparison between recent US epidemiological data and the Italian situationThe health resources used in VVA BC The burden of illnessDespite the considerable negative impact on quality of life, a disparity between the high prevalence of this condition and the infrequent clinical diagnosis is documented in medical practice and in surveys. This inaccuracy is thought to be primarily a consequence of patients\u2019 unwillingness and/or reluctance to report symptoms in the clinical setting and of health-care professional\u2019s difficulty in approaching this sensitive topic during routine consultations. Methods: A Delphi Panel methodology was used: a first round of written questionnaires, followed by a plenary meeting with a facilitator and by two additional rounds of telephone interviews. Results: The prevalence of the condition in Italy can be estimated in 115,000 cases out of 380,000 BC survivors. The Panel confirmed that the epidemiological findings of a recent pharmacoeconomic analysis of a US claims database can be applied to Italian patient population. The Panel confirmed also an estimate of 4.25 additional cases/100/yr of UTI (urinary tract infection) in VVA BC patients (vs. a non-VVA-matched population), of 3.68 additional cases of vulvovaginitis, of 6.97 cases of climacteric symptoms, and of 3.64 cases of bone and joint disorders. As far as the resource use is concerned, in the VVA BC populations, 33.4 additional gynecological visits/100/year can be expected, along with 22.8 additional cancer screenings, 7.07 additional outpatient visits and 5.04 screenings for HPV. Conclusions: Even in Italy, a diagnosis of VVA, especially in a BC population, is associated with a relevant increase in the burden of illness and social costs, compared to a control population matched for age without VVA. This is due essentially to an increase in comorbidities and resource utilization with the consequence that an adequate treatment could reduce the impact of the condition

    Improving signal stability in a multi-electrode array (MEA) system for cardiac biopsies

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    This work evaluates the performance of a microelectrode array (MEA) to be used in a specific platform dedicated for measuring field potentials of small human cardiac samples. A test bench has been developed to characterize the electrodes by measuring their impedance as well as to modify their characteristic curve using a replatinization process, where black platinum is deposited on the indicated areas of the MEA flex-pcb. This set-up consists of the array of microelectrodes made of gold, together with its corresponding electronic adapter board, a potentiostat and an electrochemical interface. Phosphate buffered saline (PBS), which is commonly considered for this type of analysis, has been used for impedance characterization. Initially, the impedance presents a highly variable behavior at different frequencies as well as between the different channels of the array. Once the platinization process has been carried out, the impedance in all the recording channels is very similar and has decreased over a large part of the frequency range under study. A complete electrical model of the electrodes has been proposed and analyzed, achieving better results by including the mathematical constant phase element (CPE) associated with capacitive behavior (model fitting error < 2%). Finally, the characterization of the different noise contributions has been carried out. Based on the obtained results, it can be concluded that the evaluated system allows the recording of field potential signals from small human cardiac tissues

    High Performances Corrugated Feed Horns for Space Applications at Millimetre Wavelengths

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    We report on the design, fabrication and testing of a set of high performance corrugated feed horns at 30 GHz, 70 GHz and 100 GHz, built as advanced prototypes for the Low Frequency Instrument (LFI) of the ESA Planck mission. The electromagnetic designs include linear (100 GHz) and dual shaped (30 and 70 GHz) profiles. Fabrication has been achieved by direct machining at 30 GHz, and by electro-formation at higher frequencies. The measured performances on side lobes and return loss meet the stringent Planck requirements over the large (20%) instrument bandwidth. Moreover, the advantage in terms of main lobe shape and side lobes levels of the dual profiled designs has been demonstrated.Comment: 16 pages, 7 figures, accepted for publication in Experimental Astronom

    The Rest-Frame Optical Spectrum of MS 1512-cB58

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    Moderate resolution, near-IR spectroscopy of MS1512-cB58 is presented, obtained during commissioning of the the Near IR Spectrometer (NIRSPEC) on the Keck II telescope. The strong lensing of this z=2.72 galaxy by the foreground cluster MS1512+36 makes it the best candidate for detailed study of the rest-frame optical properties of Lyman Break Galaxies. A redshift of z=2.7290+/-0.0007 is inferred from the emission lines, in contrast to the z=2.7233 calculated from UV observations of interstellar absorption lines. Using the Balmer line ratios, we find an extinction of E(B-V)=0.27. Using the line strengths, we infer an SFR=620+/-18 Msun/yr (H_0=75, q_0=0.1, Lambda =0), a factor of 2 higher than that measured from narrow-band imaging observations of the galaxy, but a factor of almost 4 lower than the SFR inferred from the UV continuum luminosity. The width of the Balmer lines yields a mass of M_vir=1.2x10^10 Msun. We find that the oxygen abundance is 1/3 solar, in good agreement with other estimates of the metallicity. However, we infer a high nitrogen abundance, which may argue for the presence of an older stellar population.Comment: 14 pages, including 3 figures. Accepted for publication in ApJ Letter

    The SXI telescope on board EXIST: scientific performances

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    The SXI telescope is one of the three instruments on board EXIST, a multiwavelength observatory in charge of performing a global survey of the sky in hard X-rays searching for Supermassive Black Holes. One of the primary objectives of EXIST is also to study with unprecedented sensitivity the most unknown high energy sources in the Universe, like high redshift GRBs, which will be pointed promptly by the Spacecraft by autonomous trigger based on hard X-ray localization on board. The recent addition of a soft X-ray telescope to the EXIST payload complement, with an effective area of ~950 cm2 in the energy band 0.2-3 keV and extended response up to 10 keV will allow to make broadband studies from 0.1 to 600 keV. In particular, investigations of the spectra components and states of AGNs and monitoring of variability of sources, study of the prompt and afterglow emission of GRBs since the early phases, which will help to constrain the emission models and finally, help the identification of sources in the EXIST hard X-ray survey and the characterization of the transient events detected. SXI will also perform surveys: a scanning survey with sky coverage of about 2pi and limiting flux of 5x10^{-14}cgs plus other serendipitous. We give an overview of the SXI scientific performance and also describe the status of its design emphasizing how it has been derived by the scientific requirements.Comment: 9 pages, 6 figures, to be published in Proc. of SPIE, vol 7435-11, 200
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