Articles de revues : « Instrumentation and techniques of general interest »

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McLean, Ian S., Ding-Qiang Su, Thomas Armstrong, Noah Brosch, Martin Cullum, Michel Dennefeld, George Jacoby et al. « Commission 9 : Instrumentation and Techniques : (Instrumentation et Techniques) ». Transactions of the International Astronomical Union 24, n^o 1 (2000) : 316–27. http://dx.doi.org/10.1017/s0251107x00003266.

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The last triennium, and coincidentally the last few years of the 20th century, has been a most remarkable time for Commission 9, and for astronomy in general. Ground-based astronomy in particular has received an enormous boost due to the arrival of an astonishing array of new telescopes, novel instruments and innovative techniques. For those of us closely involved in developing new observatories, instrumentation or detectors, the last few years have been rather hectic! As an astronomer with a long-time interest in the development of new instruments, what amazes me is the breadth of technology and the visionary scope of all these incredible new achievements. Many of the very large 8-10 meter class telescopes are now coming into full operation – yet, just as this is happening, numerous smaller “survey” telescopes are providing a wealth of new sources. Adaptive optics is being practiced at many sites and diffraction-limited imaging from the ground is now a reality. Several optical-IR interferometers are now working and more are coming along very soon. Detectors continue to get bigger and better, especially for the infrared, and instrumentation is increasingly more sophisticated, complex and efficient. Remote observing, robotic telescopes and global networks of telescopes are common, and international collaborations are larger and stronger than ever before.

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Martín, Francisco Ferrero, Marta Valledor Llopis, Juan C. Campo Rodríguez, Alberto López Martínez, Ana Soldado Cabezuelo, María T. Fernández-Arguelles et José M. Costa-Fernández. « Optoelectronic Instrumentation and Measurement Strategies for Optical Chemical (Bio)Sensing ». Applied Sciences 11, n^o 17 (26 août 2021) : 7849. http://dx.doi.org/10.3390/app11177849.

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There is a growing interest in the development of sensitive, portable, and low-cost instrumentation for optical chemical (bio)sensing. Such instrumentation can allow real-time decision-making for industry, farmers, and researchers. The combination of optical fiber schemes, luminescence spectroscopy techniques, and new materials for sensor immobilization has allowed the growth of optical sensors. This article focuses on the development of low-cost optoelectronic instrumentation and measurement strategies for optical chemical (bio)sensing. Most of the articles in this field have focused on the chemical sensors themselves, although few have covered the design process for optoelectronic instrumentation. This article tries to fill this gap by presenting designs for real applications, as carried out by the authors. We also offer an introduction to the optical devices and optical measurement techniques used in this field to allow a full understanding of the applications.

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Mendenhall, Stephen, Dillon Mobasser, Katherine Relyea et Andrew Jea. « Spinal instrumentation in infants, children, and adolescents : a review ». Journal of Neurosurgery : Pediatrics 23, n^o 1 (janvier 2019) : 1–15. http://dx.doi.org/10.3171/2018.10.peds18327.

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OBJECTIVEThe evolution of pediatric spinal instrumentation has progressed in the last 70 years since the popularization of the Harrington rod showing the feasibility of placing spinal instrumentation into the pediatric spine. Although lacking in pediatric-specific spinal instrumentation, when possible, adult instrumentation techniques and tools have been adapted for the pediatric spine. A new generation of pediatric neurosurgeons with interest in complex spine disorder has pushed the field forward, while keeping the special nuances of the growing immature spine in mind. The authors sought to review their own experience with various types of spinal instrumentation in the pediatric spine and document the state of the art for pediatric spine surgery.METHODSThe authors retrospectively reviewed patients in their practice who underwent complex spine surgery. Patient demographics, operative data, and perioperative complications were recorded. At the same time, the authors surveyed the literature for spinal instrumentation techniques that have been utilized in the pediatric spine. The authors chronicle the past and present of pediatric spinal instrumentation, and speculate about its future.RESULTSThe medical records of the first 361 patients who underwent 384 procedures involving spinal instrumentation from July 1, 2007, to May 31, 2018, were analyzed. The mean age at surgery was 12 years and 6 months (range 3 months to 21 years and 4 months). The types of spinal instrumentation utilized included occipital screws (94 cases); C1 lateral mass screws (115 cases); C2 pars/translaminar screws (143 cases); subaxial cervical lateral mass screws (95 cases); thoracic and lumbar spine traditional-trajectory and cortical-trajectory pedicle screws (234 cases); thoracic and lumbar sublaminar, subtransverse, and subcostal polyester bands (65 cases); S1 pedicle screws (103 cases); and S2 alar-iliac/iliac screws (56 cases). Complications related to spinal instrumentation included hardware-related skin breakdown (1.8%), infection (1.8%), proximal junctional kyphosis (1.0%), pseudarthroses (1.0%), screw malpositioning (0.5%), CSF leak (0.5%), hardware failure (0.5%), graft migration (0.3%), nerve root injury (0.3%), and vertebral artery injury (0.3%).CONCLUSIONSPediatric neurosurgeons with an interest in complex spine disorders in children should develop a comprehensive armamentarium of safe techniques for placing rigid and nonrigid spinal instrumentation even in the smallest of children, with low complication rates. The authors’ review provides some benchmarks and outcomes for comparison, and furnishes a historical perspective of the past and future of pediatric spine surgery.

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Livas, Christos, Albert Cornelis Jongsma et Yijin Ren. « Enamel Reduction Techniques in Orthodontics : A Literature Review ». Open Dentistry Journal 7, n^o 1 (31 octobre 2013) : 146–51. http://dx.doi.org/10.2174/1874210601307010146.

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Artificial abrasion of interproximal surfaces has been described for almost seventy years as orthodontic intervention for achievement and maintenance of ideal treatment outcome. A variety of terms and approaches have been introduced throughout this period implying a growing clinicians’ interest. Nevertheless, the widespread recognition of enamel stripping technique was initiated by the advent of bonded orthodontic attachments and a 2-article series of Sheridan in the 80’s. Since then, experimental and clinical research has been focused on the investigation of instrumentation efficacy and potential iatrogenic sequelae related to interproximal stripping. This review discusses the evolution, technical aspects and trends of enamel reduction procedures as documented in the literature.

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Hofmann, D., et Y. V. Tarbeyev. « Theoretical, physical and metrological problems of further development of measurement techniques and instrumentation in science and technology ». ACTA IMEKO 3, n^o 1 (7 mai 2014) : 23. http://dx.doi.org/10.21014/acta_imeko.v3i1.193.

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This is a reissue of a paper which appeared in ACTA IMEKO 1979, Proceedings of the 8th IMEKO Congress of the International Measurement Confederation, "Measurement for progress in science and technology", 21.-27.5.1979, Moscow, vol. 3, pp. 607-626.Common interest of both metrologists and representatives of science and technology in constant improvement of measurements as well as general trends in the development of research in the field of metrology, measurement technology and instrumentation at the present-day stage are shown. Problems of general metrology, of improving systems of units and standards ("natural" standards in particular) are considered in detail.

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Lieu, David. « Ultrasound Physics and Instrumentation for Pathologists ». Archives of Pathology & ; Laboratory Medicine 134, n^o 10 (1 octobre 2010) : 1541–56. http://dx.doi.org/10.5858/2009-0730-ra.1.

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Abstract Context.—Interest in pathologist-performed ultrasound-guided fine-needle aspiration is increasing. Educational courses discuss clinical ultrasound and biopsy techniques but not ultrasound physics and instrumentation. Objective.—To review modern ultrasound physics and instrumentation to help pathologists understand the basis of modern ultrasound. Data Sources.—A review of recent literature and textbooks was performed. Conclusions.—Ultrasound physics and instrumentation are the foundations of clinical ultrasound. The key physical principle is the piezoelectric effect. When stimulated by an electric current, certain crystals vibrate and produce ultrasound. A hand-held transducer converts electricity into ultrasound, transmits it into tissue, and listens for reflected ultrasound to return. The returning echoes are converted into electrical signals and used to create a 2-dimensional gray-scale image. Scanning at a high frequency improves axial resolution but has low tissue penetration. Electronic focusing moves the long-axis focus to depth of the object of interest and improves lateral resolution. The short-axis focus in 1-dimensional transducers is fixed, which results in poor elevational resolution away from the focal zone. Using multiple foci improves lateral resolution but degrades temporal resolution. The sonographer can adjust the dynamic range to change contrast and bring out subtle masses. Contrast resolution is limited by processing speed, monitor resolution, and gray-scale perception of the human eye. Ultrasound is an evolving field. New technologies include miniaturization, spatial compound imaging, tissue harmonics, and multidimensional transducers. Clinical cytopathologists who understand ultrasound physics, instrumentation, and clinical ultrasound are ready for the challenges of cytopathologist-performed ultrasound-guided fine-needle aspiration and core-needle biopsy in the 21st century.

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Davis, John. « Introduction to the Joint Commission Meeting on High Resolution Imaging from the Ground ». Highlights of Astronomy 8 (1989) : 545–46. http://dx.doi.org/10.1017/s1539299600008261.

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As a result of advances in instrumentation and techniques, from radio through to optical wavelengths, we have before us the prospect of producing very high resolution images of a wide range of objects across this entire spectral range. This prospect, and the new knowledge and discoveries that may be anticipated from it, lie behind an upsurge in interest in high resolution imaging from the ground. Several new high angular resolution instruments for radio, infrared, and optical wavelengths are expected to come into operation before the 1991 IAU General Assembly.

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Kim, Junseok A., et Karen D. Davis. « Magnetoencephalography : physics, techniques, and applications in the basic and clinical neurosciences ». Journal of Neurophysiology 125, n^o 3 (1 mars 2021) : 938–56. http://dx.doi.org/10.1152/jn.00530.2020.

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Magnetoencephalography (MEG) is a technique used to measure the magnetic fields generated from neuronal activity in the brain. MEG has a high temporal resolution on the order of milliseconds and provides a more direct measure of brain activity when compared with hemodynamic-based neuroimaging methods such as magnetic resonance imaging and positron emission tomography. The current review focuses on basic features of MEG such as the instrumentation and the physics that are integral to the signals that can be measured, and the principles of source localization techniques, particularly the physics of beamforming and the techniques that are used to localize the signal of interest. In addition, we review several metrics that can be used to assess functional coupling in MEG and describe the advantages and disadvantages of each approach. Lastly, we discuss the current and future applications of MEG.

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Gilli, R., F. Mattea, G. Martin et M. Valente. « X-RAY MICROTOMOGRAPHY TO CHARACTERIZE THE ROOT CANAL VOLUME EXTRACTED IN ENDODONTIC INSTRUMENTATION ». Anales AFA 33, n^o 3 (15 octobre 2022) : 70–76. http://dx.doi.org/10.31527/analesafa.2022.33.3.70.

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During the last decades, the analytical techniques of X-ray absorption contrast imaging have systematically gained greater relevance, mainly due to the ability to attain non-destructive exploration of the sample interior. The significant improvement in spatial resolution offered by X-ray micro-tomography, as compared to conventional computed tomography, has motivated its insertion in many biomedical fields, among which dentistry stands out. Particularly, for endodontics, microCT appears as a method of remarkable potential interest to study procedures involved in root canal treatments, where one of the main needs is the anatomical characterization of the root canal in the teeth. The present work reports on the adaptation of the microCT equipment of the LIIFAMIRx⃝laboratory at the E. Gaviola Physics Institute, CONICET and UNC, thus allowing to acquire of radiographic images of dental samples of interest, to be later used in the implementation of algorithms, intended to tomographic reconstruction and volume segmentation. As a result, radiographic images of premolar teeth were obtained with good contrast between the different materials present, and three-dimensional representations, whose visualization is comparable with the real samples. Moreover, it was possible to characterize the root canal volume of the tooth both in its natural form and after having undergone the instrumentation process in which the pulp tissue is extracted.

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Woike, Mark, Ali Abdul-Aziz, Nikunj Oza et Bryan Matthews. « New Sensors and Techniques for the Structural Health Monitoring of Propulsion Systems ». Scientific World Journal 2013 (2013) : 1–10. http://dx.doi.org/10.1155/2013/596506.

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The ability to monitor the structural health of the rotating components, especially in the hot sections of turbine engines, is of major interest to aero community in improving engine safety and reliability. The use of instrumentation for these applications remains very challenging. It requires sensors and techniques that are highly accurate, are able to operate in a high temperature environment, and can detect minute changes and hidden flaws before catastrophic events occur. The National Aeronautics and Space Administration (NASA), through the Aviation Safety Program (AVSP), has taken a lead role in the development of new sensor technologies and techniques for the in situ structural health monitoring of gas turbine engines. This paper presents a summary of key results and findings obtained from three different structural health monitoring approaches that have been investigated. This includes evaluating the performance of a novel microwave blade tip clearance sensor; a vibration based crack detection technique using an externally mounted capacitive blade tip clearance sensor; and lastly the results of using data driven anomaly detection algorithms for detecting cracks in a rotating disk.

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Martin, William J. « New technologies for large-genome sequencing ». Genome 31, n^o 2 (15 janvier 1989) : 1073–80. http://dx.doi.org/10.1139/g89-184.

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Interest in DNA sequencing has increased in recent years and research into new instrument systems to optimize and automate the process has been intensified. A number of commercial devices, from Europe, Japan, and the United States, which instrument aspects of (mainly) the Sanger method, are now available and several new DNA sequencing techniques have been reported. This review briefly describes current methods of DNA sequencing and provides an account of systems presently available or under development for instrumenting the technology. The problems of automation for large-scale DNA sequencing are discussed.Key words: sequencing, automation, genome, DNA, instrumentation.

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Manthos, I., K. Kordas, I. Maniatis, M. Tsopoulou et S. E. Tzamarias. « Signal processing techniques for precise timing with novel gaseous detectors ». Journal of Physics : Conference Series 2105, n^o 1 (1 novembre 2021) : 012015. http://dx.doi.org/10.1088/1742-6596/2105/1/012015.

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Abstract The experimental requirements in current and near-future accelerators and experiments have stimulated intense interest in R&D of detectors with high precision timing capabilities, resulting in novel instrumentation. During the R&D phase, the timing information is usually extracted from the signal using the full waveform collected with fast oscilloscopes; this method produces a large amount of data and it becomes impractical when the detector has many channels. Towards practical applications, the data acquisition should be undertaken by dedicated front-end electronic units. The selected technology should retain the signal timing characteristics and consequently the timing resolution on the particle’s arrival time. We investigate the adequacy of the Leading-edge discrimination timing technique to achieve timing with a precision in the order of tens of picosecond with novel gaseous detectors. The method under investigation introduces a “time-walk” which impinges on the timing resolution. We mitigate the effect of time-walk using three different approaches; the first based on multiple Time-over-Threshold, the second based on multiple Charge-over-Threshold information and the third uses artificial Neural Network techniques. The results of this study prove the feasibility of the methods and their ability to achieve a timing resolution comparable to that obtained using the full waveforms.

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Gnauck, Peter, Claus Burkhardt, Erich Plies et Wilfried Nisch. « In-Situ Ion Milling in the Transmission Electron Microscope (TEM) Outlook to a New Preparation Technique ». Microscopy and Microanalysis 7, S2 (août 2001) : 932–33. http://dx.doi.org/10.1017/s1431927600030737.

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Recent developments in transmission electron microscopy put high demands on specimen preparation. in general the imaging quality is not limited by the performance of the microscope but by the quality of the specimen. in order to achieve a spatial resolution of 0.1 nm in HRTEM undamaged samples with a thickness below 10 nm are required. in energy filtering analytical electron microscopy (EFTEM), a constant specimen thickness over large areas and very low contamination is needed.Conventional ion-milling techniques for TEM specimen preparation are essentially blind. Thus, it is left to chance whether the specimen detail of interest is suitable for TEM-imaging (many specimen areas are too thick). Another problem is the reaction of the specimen with the atmosphere during the transfer from the preparation stage to the microscope, which makes it very difficult to obtain the clean specimen surfaces that are needed in analytical EFTEM. Especially in high-resolution electron microscopy and electron holography the formation of amorphous oxidation and contamination layers on otherwise crystalline materials may seriously reduce the quality of high resolution images of the crystal structure.

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Marcelo de Morais Vitoriano, Bernardo Almeida Aguiar, Iuri Lopes Mesquita, Cláudio Maniglia-Ferreira, Fábio Almeida Gomes, Roberto Alves dos Santos et Marco Antonio Hungaro Duarte. « Evaluation of apically extruded debris during endodontic retreatment ». RSBO 10, n^o 1 (28 mars 2014) : 56–62. http://dx.doi.org/10.21726/rsbo.v10i1.895.

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A growing interest to preserve teeth into the mouth by patients resulted in the increasing number of endodontic retreatments, and when these happen, many different types of irritants are extruded through the foramen. Objective: This study analyzed in vitro the amount of debris extruded through the foramen using four instrumentation techniques during endodontic retreatment. Material and methods: Forty mesial-buccal roots of first molars were selected, instrumented with anatomical diameter up to size #30 ISO file and then obturated with gutta-percha and grossman sealer by lateral condensation. After, they were separated and randomly allocated into four groups with 10 teeth each for the endodontic retreatment procedure: G1 – conventional technique + solvent, G2 – conventional technique without solvent, G3 – ProTaper retreatment + solvent, G4 – ProTaper retreatment without solvent. In all groups, gutta-percha in the coronal portion was removed by using size 1-3 Gates Glidden drills. All teeth were irrigated with distilled water. The debris extruded through the foramen were collected and weighed by an analytical balance. Results: Group 4 had the lowest average for material extrusion through the foramen followed by groups 2, 3 and 1. When Tukey test for statistical analysis was applied, no significant difference among groups were found (p = 0.5664). Conclusion: We conclude that all instrumentation techniques used in this study produced debris which goes beyond the foramen.

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Bianchi, Federica, Nicolò Riboni, Veronica Termopoli, Lucia Mendez, Isabel Medina, Leopold Ilag, Achille Cappiello et Maria Careri. « MS-Based Analytical Techniques : Advances in Spray-Based Methods and EI-LC-MS Applications ». Journal of Analytical Methods in Chemistry 2018 (2018) : 1–24. http://dx.doi.org/10.1155/2018/1308167.

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Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. This review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.

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Li, Du, Rose Zhou et Rob Zanoya. « Cross-Sectional Transmission Electron Microscopy Sample Preparation Using Focus Ion Beam Machine and Wedge Technique ». Microscopy and Microanalysis 5, S2 (août 1999) : 894–95. http://dx.doi.org/10.1017/s1431927600017797.

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As features on an IC chip become smaller than the resolution power of an optical microscope and of the size of the grinding particles, the trend for preparing cross-sectional transmission electron microscopy (TEM) samples at specific locations (bits) is moving towards using a focused ion beam (FIB) machine. Details on how to use a FIB machine to prepare cross-sectional TEM samples have been outlined in many references.The general procedure is to first mark the specific location (bit) in the FIB machine and then grind the sample down to about 20 microns, 10 microns on each side of the feature of interest. After grinding, the sample is mounted on a pre-cut TEM grid and thinned with the FIB to about 0.1 micron in the region containing the feature of interest. There are several disadvantages to this method. First, the sample goes into the FIB machine at least twice—once for FIB marks on the location and once again for the final thinning.

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Ramohlola, Kabelo E., Emmanuel I. Iwuoha, Mpitloane J. Hato et Kwena D. Modibane. « Instrumental Techniques for Characterization of Molybdenum Disulphide Nanostructures ». Journal of Analytical Methods in Chemistry 2020 (16 décembre 2020) : 1–29. http://dx.doi.org/10.1155/2020/8896698.

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The excellent chemical and physical properties of materials (nanomaterials) with dimensions of less than 100 nm (nanometers) resulted in researchers and industrialists to have great interest in their discovery and applications in various systems/applications. As their sizes are reduced to nanoscale, these nanomaterials tend to possess exceptional properties differing from those of their bulk counterparts; hence, they have found applications in electronics and medicines. In order to apply them in those applications, there is a need to synthesise these nanomaterials and study their structural, optical, and electrochemical properties. Among several nanomaterials, molybdenum disulphide (MoS2) has received a great interest in energy applications due to its exceptional properties such as stability, conductivity, and catalytic activities. Hence, the great challenge lies in finding the state-of-the-art characterization techniques to reveal the different properties of MoS2 nanostructures with great accuracy. In this regard, there is a need to study and employ several techniques to accurately study the surface chemistry and physics of the MoS2 nanostructures. Hence, this review will comprehensively discuss a detailed literature survey on analytical techniques that can be used to study the chemical, physical, and surface properties of MoS2 nanostructures, namely, ultraviolet-visible spectroscopy (UV-vis), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, time-of-flight secondary ion mass spectroscopy (TOF-SIMS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopies (SEM and TEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS/X), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and electroanalytical methods which include linear sweep (LSV) and cyclic (CV) voltammetry and electrochemical impedance spectroscopy (EIS).

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Di Ruberto, Cecilia, Andrea Loddo et Lorenzo Putzu. « Special Issue on Image Processing Techniques for Biomedical Applications ». Applied Sciences 12, n^o 20 (14 octobre 2022) : 10338. http://dx.doi.org/10.3390/app122010338.

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Bernard, Sylvain, Olivier Beyssac et Karim Benzerara. « Raman Mapping Using Advanced Line-Scanning Systems : Geological Applications ». Applied Spectroscopy 62, n^o 11 (novembre 2008) : 1180–88. http://dx.doi.org/10.1366/000370208786401581.

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By allowing nondestructive chemical and structural imaging of heterogeneous samples with a micrometer spatial resolution, Raman mapping offers unique capabilities for assessing the spatial distribution of both mineral and organic phases within geological samples. Recently developed line-scanning Raman mapping techniques have made it possible to acquire Raman maps over large, millimeter-sized, zones of interest owing to a drastic decrease of the data acquisition time without losing spatial or spectral resolution. The synchronization of charge-coupled device (CCD) measurements with x,y motorized stage displacement has allowed dynamic line-scanning Raman mapping to be even more efficient: total acquisition time may be reduced by a factor higher than 100 compared to point-by-point mapping. Using two chemically and texturally complex geological samples, a fossil megaspore in a metamorphic rock and aragonite-garnet intergrowths in an Eclogitic marble, we compare here two recent versions of line-scanning Raman mapping systems and discuss their respective advantages and disadvantages in terms of acquisition time, image quality, spatial and imaging resolutions, and signal-to-noise ratio. We show that line-scanning Raman mapping techniques are particularly suitable for the characterization of such samples, which are representative of the general complexity of geological samples.

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Spyratou, Ellas, Kyriakos Kokkinogoulis, Georgios Tsigaridas, Georgios Kareliotis, Kalliopi Platoni, Mersini Makropoulou et Efstathios P. Efstathopoulos. « Novel Biophotonic Techniques for Phototherapy Enhancement : Cerenkov Radiation as a Bridge between Ionizing and Non-Ionizing Radiation Treatment ». Journal of Nanotheranostics 4, n^o 1 (27 février 2023) : 86–105. http://dx.doi.org/10.3390/jnt4010005.

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In oncology, tremendous research has been conducted on the use of alternative minimally invasive techniques for cancer treatment and diagnosis. The use of biophotonic techniques as a standalone treatment or together with conventional imaging techniques has gained interest among researchers in recent years, while biophotonic therapies such as photothermal and photodynamic therapies tend to bring the use of non-ionizing radiation in therapy back into the spotlight due to the progressive development of optical instrumentation, enhancement agents, molecular probes, light sources and nanocarriers. Thus, the coupling of non-ionizing with ionizing radiation (IR) and the combination of nanomedicine with nuclear medicine procedures are considered to be revolutionary strategies to optimize the therapeutic efficacy of biophotonic modalities and to develop theranostic applications for the better diagnosis and treatment of cancer. Recently, the low-intensity Cerenkov light emitted by tissues as a byproduct of the IR–biostructure interaction has been suggested as an effective internal light source that can trigger phototherapy and guide radiotherapy dosimetry using Cerenkov imaging. This review also provides an overview of in vitro and in vivo studies regarding the use of Cerenkov radiation produced by X-rays or radionucleotides and combined with nanoparticles as a hybrid method to induce enhanced photothermal and photodynamic therapies.

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Thatcher, P. J., et G. P. Briner. « The Application of X-Ray Powder Diffraction to Forensic Science ». Powder Diffraction 1, n^o 4 (décembre 1986) : 320–24. http://dx.doi.org/10.1017/s0885715600011994.

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Although forensic science is regarded with a certain amount of fascination and admiration by the general public, to the practising forensic scientist it is often associated with painstaking and frustrating examinations.This is particularly so in the most traditional area of forensic science, namely that of contact evidence where the identification and comparison of minute samples may provide an important clue for the investigator and assist in the conviction or exoneration of an accused person.Contact evidence may include hairs and other fibres, paint samples, glass fragments, stains, soils and other deposits. Modern instrumentation such as infra-red spectrophotometry, gas chromatography, atomic absorption spectroscopy and energy dispersive X-ray analysis now allows a relatively simple identification of the composition of these materials. However, these techniques are not necessarily directed towards the absolute determination of structure of materials and this is particularly so in the case of crystalline materials of forensic interest such as soil, mortar, brick dust and paint fillers. Although the techniques previously mentioned provide the basis of an elemental analysis this may not be of much assistance in a forensic approach where chemical structure is the basis of a scentific comparison.

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Schwartz, Christofer, Ingo Sander, Fredrik Bruhn, Mathias Persson, Joakim Ekblad et Christer Fuglesang. « Satellite Image Compression Guided by Regions of Interest ». Sensors 23, n^o 2 (9 janvier 2023) : 730. http://dx.doi.org/10.3390/s23020730.

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Small satellites empower different applications for an affordable price. By dealing with a limited capacity for using instruments with high power consumption or high data-rate requirements, small satellite missions usually focus on specific monitoring and observation tasks. Considering that multispectral and hyperspectral sensors generate a significant amount of data subjected to communication channel impairments, bandwidth constraint is an important challenge in data transmission. That issue is addressed mainly by source and channel coding techniques aiming at an effective transmission. This paper targets a significant further bandwidth reduction by proposing an on-the-fly analysis on the satellite to decide which information is effectively useful before coding and transmitting. The images are tiled and classified using a set of detection algorithms after defining the least relevant content for general remote sensing applications. The methodology makes use of the red-band, green-band, blue-band, and near-infrared-band measurements to perform the classification of the content by managing a cloud detection algorithm, a change detection algorithm, and a vessel detection algorithm. Experiments for a set of typical scenarios of summer and winter days in Stockholm, Sweden, were conducted, and the results show that non-important content can be identified and discarded without compromising the predefined useful information for water and dry-land regions. For the evaluated images, only 22.3% of the information would need to be transmitted to the ground station to ensure the acquisition of all the important content, which illustrates the merits of the proposed method. Furthermore, the embedded platform’s constraints regarding processing time were analyzed by running the detection algorithms on Unibap’s iX10-100 space cloud platform.

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Beckhoff, Burkhard. « Traceable Characterization of Nanomaterials by X-ray Spectrometry Using Calibrated Instrumentation ». Nanomaterials 12, n^o 13 (30 juin 2022) : 2255. http://dx.doi.org/10.3390/nano12132255.

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Traceable characterization methods allow for the accurate correlation of the functionality or toxicity of nanomaterials with their underlaying chemical, structural or physical material properties. These correlations are required for the directed development of nanomaterials to reach target functionalities such as conversion efficiencies or selective sensitivities. The reliable characterization of nanomaterials requires techniques that often need to be adapted to the nano-scaled dimensions of the samples with respect to both the spatial dimensions of the probe and the instrumental or experimental discrimination capability. The traceability of analytical methods revealing information on chemical material properties relies on reference materials or qualified calibration samples, the spatial elemental distributions of which must be very similar to the nanomaterial of interest. At the nanoscale, however, only few well-known reference materials exist. An alternate route to establish the required traceability lays in the physical calibration of the analytical instrument’s response behavior and efficiency in conjunction with a good knowledge of the various interaction probabilities. For the elemental analysis, speciation, and coordination of nanomaterials, such a physical traceability can be achieved with X-ray spectrometry. This requires the radiometric calibration of energy- and wavelength-dispersive X-ray spectrometers, as well as the reliable determination of atomic X-ray fundamental parameters using such instrumentation. In different operational configurations, the information depths, discrimination capability, and sensitivity of X-ray spectrometry can be considerably modified while preserving its traceability, allowing for the characterization of surface contamination as well as interfacial thin layer and nanoparticle chemical compositions. Furthermore, time-resolved and hybrid approaches provide access to analytical information under operando conditions or reveal dimensional information, such as elemental or species depth profiles of nanomaterials. The aim of this review is to demonstrate the absolute quantification capabilities of SI-traceable X-ray spectrometry based upon calibrated instrumentation and knowledge about X-ray interaction probabilities.

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Muto, Shunsuke, et Motoki Shiga. « Application of machine learning techniques to electron microscopic/spectroscopic image data analysis ». Microscopy 69, n^o 2 (12 novembre 2019) : 110–22. http://dx.doi.org/10.1093/jmicro/dfz036.

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Abstract The combination of scanning transmission electron microscopy (STEM) with analytical instruments has become one of the most indispensable analytical tools in materials science. A set of microscopic image/spectral intensities collected from many sampling points in a region of interest, in which multiple physical/chemical components may be spatially and spectrally entangled, could be expected to be a rich source of information about a material. To unfold such an entangled image comprising information and spectral features into its individual pure components would necessitate the use of statistical treatment based on informatics and statistics. These computer-aided schemes or techniques are referred to as multivariate curve resolution, blind source separation or hyperspectral image analysis, depending on their application fields, and are classified as a subset of machine learning. In this review, we introduce non-negative matrix factorization, one of these unfolding techniques, to solve a wide variety of problems associated with the analysis of materials, particularly those related to STEM, electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy. This review, which commences with the description of the basic concept, the advantages and drawbacks of the technique, presents several additional strategies to overcome existing problems and their extensions to more general tensor decomposition schemes for further flexible applications are described.

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Pande, Charuta, Hans Friedrich Witschel et Andreas Martin. « New Hybrid Techniques for Business Recommender Systems ». Applied Sciences 12, n^o 10 (10 mai 2022) : 4804. http://dx.doi.org/10.3390/app12104804.

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Besides the typical applications of recommender systems in B2C scenarios such as movie or shopping platforms, there is a rising interest in transforming the human-driven advice provided, e.g., in consultancy via the use of recommender systems. We explore the special characteristics of such knowledge-based B2B services and propose a process that allows incorporating recommender systems into them. We suggest and compare several recommender techniques that allow incorporating the necessary contextual knowledge (e.g., company demographics). These techniques are evaluated in isolation on a test set of business intelligence consultancy cases. We then identify the respective strengths of the different techniques and propose a new hybridisation strategy to combine these strengths. Our results show that the hybridisation leads to substantial performance improvement over the individual methods.

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Bruner, Harlan J., Yabo Guan, Narayan Yoganandan, Frank A. Pintar, Dennis J. Maiman et Michael A. Slivka. « Biomechanics of polyaryletherketone rod composites and titanium rods for posterior lumbosacral instrumentation ». Journal of Neurosurgery : Spine 13, n^o 6 (décembre 2010) : 766–72. http://dx.doi.org/10.3171/2010.5.spine09948.

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Object Interest is increasing in the development of polyaryletherketone (PAEK) implants for posterior lumbar fusion. Due to their inherent physical properties, including radiolucency and the ability to customize stiffness with carbon fiber reinforcement, they may be more advantageous than traditional instrumentation materials. Customization of these materials may allow for the development of a system that is stiff enough to promote fusion, yet flexible enough to avoid instrumentation failure. To understand the feasibility of using such materials in posterior lumbosacral instrumentation, biomechanical performances were compared in pure moment and combined loadings between two different PAEK composite rods and titanium rods. Methods Four human cadaver L3–S1 segments were subjected to pure moment and combined (compressionflexion and compression-extension) loadings as intact specimens, and after L-4 laminectomy with complete L4–5 facetectomy. Pedicle screw/rod fixation constructs were placed from L-4 to S-1, and retested with titanium, pure poly(aryl-ether-ether-ketone) (PEEK), and carbon fiber reinforced PEEK (CFRP) rods. Reflective markers were fixed to each spinal segment. The range of motion data for the L3–S1 column and L4–5 surgical level were obtained using a digital 6-camera system. Four prewired strain gauges were glued to each rod at the level of the L-4 screw and were placed 90° apart along the axial plane of the rod to record local strain data in the combined loading mode. Biomechanical data were analyzed using the ANOVA techniques. Results In pure moment, when compared with intact specimens, each rod material similarly restricted motion in each mode of bending, except axial rotation (p < 0.05). When compared with postfacetectomy specimens, each rod material similarly restricted motion (p < 0.05) in all bending modes. In combined loading, rod stiffness was similar for each material. Rod strain was the least in the titanium construct, intermediate in the CFRP construct, and maximal in the pure PEEK construct. Conclusions Pure PEEK and CFRP rods confer equal stiffness and resistance to motion in lumbosacral instrumentation when compared with titanium constructs in single-cycle loading. The carbon fiber reinforcement reduces strain when compared with pure PEEK in single-cycle loading. These biomechanical responses, combined with its radiolucency, suggest that the CFRP may have an advantage over both titanium and pure PEEK rods as a material for use in posterior lumbosacral instrumentation. Benchtop fatigue testing of the CFRP constructs is needed for further examination of their responses under multicycle loading.

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Zhou, Qingqing, Zhigang Xu et Zhimin Liu. « Molecularly Imprinting–Aptamer Techniques and Their Applications in Molecular Recognition ». Biosensors 12, n^o 8 (29 juillet 2022) : 576. http://dx.doi.org/10.3390/bios12080576.

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Molecular imprinting–aptamer techniques exhibit the advantages of molecular imprinting and aptamer technology. Hybrids of molecularly imprinted polymer–aptamer (MIP–aptamer) prepared by this technique have higher stability, binding affinity and superior selectivity than conventional molecularly imprinted polymers or aptamers. In recent years, molecular imprinting–aptamer technologies have attracted considerable interest for the selective recognition of target molecules in complex sample matrices and have been used in molecular recognition such as antibiotics, proteins, viruses and pesticides. This review introduced the development of molecular imprinting–aptamer-combining technologies and summarized the mechanism of MIP–aptamer formation. Meanwhile, we discussed the challenges in preparing MIP–aptamer. Finally, we summarized the application of MIP–aptamer to the molecular recognition in disease diagnosis, environmental analysis, food safety and other fields.

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Płotka-Wasylka, Justyna, Małgorzata Rutkowska, Bartłomiej Cieślik, Alan Tyburcy et Jacek Namieśnik. « Determination of Selected Metals in Fruit Wines by Spectroscopic Techniques ». Journal of Analytical Methods in Chemistry 2017 (2017) : 1–9. http://dx.doi.org/10.1155/2017/5283917.

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Background.The determination of metals in different types of food and beverages samples has drawn significant attention due to several reasons with the most important one being the nutritional and toxic effects of these elements or their compounds. The knowledge of certain elements content in wines/fruit wines is of special interest due to their toxicity in case of excessive intake and also the effect they seem to have on the organoleptic properties of wine.Results.The study was focused on measuring the concentration levels of trace metals in fruit wines. Analysis of K, Ca, Fe, Zn, Cd, Mg, Pb, Sn, and Hg in so-calledhomemade fruit winewas carried out by AES, AAS, CV-AAS, and GF-AAS techniques. The calculated calibration curves showed good linearity range for all tested analytes (with coefficient of determination in the range from 0.989 to 0.999). The low values of the limit of detection (from 0.0031 μg/L to 0.47 mg/L) and the limit of quantification (from 0.009 μg/L to 1.41 mg/L) were obtained.Conclusions.The allowed levels of metal in fruit wines are prescribed by the International Office for Grapes and Wines (OIV). The data obtained from the study area for all metals did not exceed the international limits.

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Chiulan, Ioana. « Editorial on Special Issue “Biomaterials, Polymers and Tissue Engineering” ». Applied Sciences 12, n^o 12 (15 juin 2022) : 6078. http://dx.doi.org/10.3390/app12126078.

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Izzetti, Rossana, Marco Nisi, Stefano Gennai et Filippo Graziani. « Evaluating the Relationship between Mandibular Third Molar and Mandibular Canal with Semiautomatic Segmentation : A Pilot Study on CBCT Datasets ». Applied Sciences 12, n^o 1 (5 janvier 2022) : 502. http://dx.doi.org/10.3390/app12010502.

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Inferior alveolar nerve injury is the main complication in mandibular third molar surgery. In this context, cone-beam computed tomography (CBCT) has become of crucial importance in evaluating the relationship between mandibular third molar and inferior alveolar nerve. Due to the growing interest in preoperative planning in oral surgery, several post-processing techniques have been implemented to obtain three-dimensional reconstructions of a volume of interest. In the present study, segmentation techniques were retrospectively applied to CBCT images in order to evaluate whether post-processing could offer better visualization of the structures of interest. Forty CBCT examinations performed for inferior third molar impaction were analyzed. Segmentation and volumetric reconstructions were performed. A dataset composed of multiplanar reconstructions for each study case, including segmented images, was submitted for evaluation to two oral surgeons, two general practitioners and four residents in oral surgery. The visualization of root morphology, canal course, and the relationship with mandibular cortical bone on both native CBCT and segmented images were assessed. Inter-rater agreement showed values of intraclass correlation coefficient (ICC) above 0.8 for all the examined parameters. Oral surgeons presented higher ICC values (p < 0.05). Segmented images can improve preoperative evaluation of the third molar and its relationship with the surrounding anatomical structures compared to native CBCT images. Further evaluation is needed to validate these preliminary results.

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Dugheri, Stefano, Nicola Mucci, Giovanni Cappelli, Lucia Trevisani, Alessandro Bonari, Elisabetta Bucaletti, Donato Squillaci et Giulio Arcangeli. « Advanced Solid-Phase Microextraction Techniques and Related Automation : A Review of Commercially Available Technologies ». Journal of Analytical Methods in Chemistry 2022 (4 février 2022) : 1–15. http://dx.doi.org/10.1155/2022/8690569.

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The solid-phase microextraction (SPME), invented by Pawliszyn in 1989, today has a renewed and growing use and interest in the scientific community with fourteen techniques currently available on the market. The miniaturization of traditional sample preparation devices fulfills the new request of an environmental friendly analytical chemistry. The recent upswing of these solid-phase microextraction technologies has brought new availability and range of robotic automation. The microextraction solutions propose today on the market can cover a wide variety of analytical fields and applications. This review reports on the state-of-the-art innovative solid-phase microextraction techniques, especially those used for chromatographic separation and mass-spectrometric detection, given the recent improvements in availability and range of automation techniques. The progressively implemented solid-phase microextraction techniques and related automated commercially available devices are classified and described to offer a valuable tool to summarize their potential combinations to face all the laboratories requirements in terms of analytical applications, robustness, sensitivity, and throughput.

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Borio, Daniele, et Letizia Lo Presti. « Data and Pilot Combining for Composite GNSS Signal Acquisition ». International Journal of Navigation and Observation 2008 (12 mai 2008) : 1–12. http://dx.doi.org/10.1155/2008/738183.

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With the advent of new global navigation satellite systems (GNSS), such as the European Galileo, the Chinese Compass and the modernized GPS, the presence of new modulations allows the use of special techniques specifically tailored to acquire and track the new signals. Of particular interest are the new composite GNSS signals that will consist of two different components, the data and pilot channels. Two strategies for the joint acquisition of the data and pilot components are compared. The first technique, noncoherent combining, is from the literature and it is used as a comparison term, whereas the analysis of the second one, coherent combining with sign recovery, represents the innovative contribution of this paper. Although the analysis is developed with respect to the Galileo E1 Open Service (OS) modulation, the obtained results are general and can be applied to other GNSS signals.

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Mazur, Marcus D., Vijay M. Ravindra, Meic H. Schmidt, Darrel S. Brodke, Brandon D. Lawrence, Jay Riva-Cambrin et Andrew T. Dailey. « Unplanned reoperation after lumbopelvic fixation with S-2 alar-iliac screws or iliac bolts ». Journal of Neurosurgery : Spine 23, n^o 1 (juillet 2015) : 67–76. http://dx.doi.org/10.3171/2014.10.spine14541.

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OBJECT S-2 alar-iliac (S2AI) screws are an attractive alternative to conventional fixation with iliac bolts because they are lower profile, require less muscle dissection, and have greater pullout strength. Few studies, however, compare outcomes between these techniques. METHODS The authors conducted a retrospective cohort study of consecutive adult patients at a single institution from December 2009 to March 2012 who underwent lumbopelvic fixation using S2AI screws or iliac bolts. Medical records were reviewed for patients with clinical failure, defined as an unplanned reoperation because of instrumentation failure and/or wound-related complications. Univariate, multivariate, and survival analyses were used to compare patients who required reoperation with those who did not. Method of pelvic fixation was the main predictor variable of interest, and the authors adjusted for potential confounding risk factors. RESULTS Of the 60 patients included, 23 received S2AI screws. Seventeen patients (28%) underwent an osteotomy. The mean follow-up was 22 months. A Kaplan-Meier survival model was used to evaluate the time to reoperation from the initial placement of lumbopelvic instrumentation. The failure-free rate was 96.6% at 6 months, 87.0% at 1 year, and 73.5% at 2 years. Reoperation was more common in patients with iliac bolts than in those with S2AI screws (13 vs 2; p = 0.031). Univariate analysis identified potential risk factors for unplanned reoperation, including use of iliac bolts (p = 0.031), absence of L5–S1 interbody graft (p = 0.048), previous lumbar fusion (p = 0.034), and pathology other than degenerative disease or scoliosis (p = 0.034). After adjusting for other risk factors, multivariate analysis revealed that the use of S2AI screws (OR 8.1 [1.5–73.5]; p = 0.030) was the only independent predictor for preventing unplanned reoperation. CONCLUSIONS Both S2AI screws and iliac bolts were effective at improving fusion rates at the lumbosacral junction. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for wound-related complications and instrumentation failures than the use of iliac bolts.

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Vallée, Marc A., Richard S. Smith et Pierre Keating. « Metalliferous mining geophysics — State of the art after a decade in the new millennium ». GEOPHYSICS 76, n^o 4 (juillet 2011) : W31—W50. http://dx.doi.org/10.1190/1.3587224.

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Mining exploration was very active during the first decade of the twenty-first century because there were numerous advances in the science and technology that geophysicists were using for mineral exploration. Development came from different sources: instrumentation improvements, new numerical algorithms, and cross-fertilization with the seismic industry. In gravity, gradiometry kept its promise and is on the cusp of becoming a key technology for mining exploration. In potential-field methods in general, numerous techniques have been developed for automatic interpretation, and 3D inversion schemes came into frequent use. These inversions will have even greater use when geologic constraints can be applied easily. In airborne electromagnetic (EM) methods, the development of time-domain helicopter EM systems changed the industry. In parallel, improvements in EM modeling and interpretation occurred; in particular, the strengths and weaknesses of the various algorithms became better understood. Simpler imaging schemes came into standard use, whereas layered inversion seldom is used in the mining industry today. Improvements in ground EM methods were associated with the development of SQUID technology and distributed-acquisition systems; the latter also impacted ground induced-polarization (IP) methods. Developments in borehole geophysics for mining and exploration were numerous. Borehole logging to measure physical properties received significant interest. Perhaps one reason for that interest was the desire to develop links between geophysical and geologic results, which also is a topic of great importance to mining geologists and geophysicists.

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Sujbert, László, et György Orosz. « Frequency Domain Identification of Data Loss Models ». ACTA IMEKO 6, n^o 4 (28 décembre 2017) : 61. http://dx.doi.org/10.21014/acta_imeko.v6i4.476.

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Recently measurement data loss has been of greater interest, due to the spread of sensor networks and the idea of Internet of things. A procedure is proposed that is able to identify the most frequently employed data loss models. It is assumed that the communication protocol provides information about data loss, i.e. the so-called data availability indicator function is known. The power spectral density (PSD) of the indicator function is representative for the model, and can be used for identification. Spectral estimation is carried out by Fast Fourier Transform (FFT) based techniques. The paper introduces the identification procedure for random independent, random block-based and general Markov model-based data loss patterns. The efficiencyof the proposed method is demonstrated by simulation and measurement results.

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Liu, James K., Jimmy Patel, Ira M. Goldstein et Jean Anderson Eloy. « Endoscopic endonasal transclival transodontoid approach for ventral decompression of the craniovertebral junction : operative technique and nuances ». Neurosurgical Focus 38, n^o 4 (avril 2015) : E17. http://dx.doi.org/10.3171/2015.1.focus14813.

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The transoral approach is considered the gold-standard surgical route for performing anterior odontoidectomy and ventral decompression of the craniovertebral junction for pathological conditions that result in symptomatic cervicomedullary compression, including basilar invagination, rheumatoid pannus, platybasia with retroflexed odontoid processes, and neoplasms. Extended modifications to increase the operative corridor and exposure include the transmaxillary, extended “open-door” maxillotomy, transpalatal, and transmandibular approaches. With the advent of extended endoscopic endonasal skull base techniques, there has been increased interest in the last decade in the endoscopic endonasal transclival transodontoid approach to the craniovertebral junction. The endonasal route represents an attractive minimally invasive surgical alternative, especially in cases of irreducible basilar invagination in which the pathology is situated well above the palatine line. Angled endoscopes and instrumentation can also be used for lower-lying pathology. By avoiding the oral cavity and subsequently using a transoral retractor, the endonasal route has the advantages of avoiding complications related to tongue swelling, tracheal swelling, prolonged intubation, velopharyngeal insufficiency, dysphagia, and dysphonia. Postoperative recovery is quicker, and hospital stays are shorter. In this report, the authors describe and illustrate their method of purely endoscopic endonasal transclival odonotoidectomy for anterior decompression of the craniovertebral junction and describe various operative pearls and nuances of the technique for avoiding complications.

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Kellner, Christopher Paul, Alexander G. Chartrain, Dominic A. Nistal, Jacopo Scaggiante, Danny Hom, Saadi Ghatan, Joshua B. Bederson et J. Mocco. « The Stereotactic Intracerebral Hemorrhage Underwater Blood Aspiration (SCUBA) technique for minimally invasive endoscopic intracerebral hemorrhage evacuation ». Journal of NeuroInterventional Surgery 10, n^o 8 (23 mars 2018) : 771–76. http://dx.doi.org/10.1136/neurintsurg-2017-013719.

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BackgroundEndoscopic intracerebral hemorrhage (ICH) evacuation techniques have gained interest as a potential therapeutic option. However, the instrumentation and techniques employed are still being refined to optimize hemostasis and evacuation efficiency.ObjectiveWe describe the application of a specific endoscopic technique in the treatment of ICH called the Stereotactic Intracerebral Hemorrhage Underwater Blood Aspiration (SCUBA) technique. It differs from previously described minimally invasive ICH interventions in that it combines two separate neuroendoscopic strategies in two phases, the first under dry-field conditions and the second using a wet-field strategy.MethodsAll patients who underwent endoscopic ICH evacuation with the SCUBA technique from December 2015 to September 2017 were included.ResultsThe SCUBA technique was performed in 47 patients. The average evacuation percentage was 88.2% (SD 20.8). Active bleeding identified to derive from a specific source was observed in 23 (48.9%) cases. Active bleeding was addressed with irrigation alone in five cases (10.6%) and required electrocautery in 18 cases (38.3%). Intraoperative bleeding occurred in 3 patients (6.4%) and postoperative bleeding occurred in a single case (2.1%).ConclusionsThe SCUBA technique provides surgeons with a defined strategy for true endoscopic hematoma evacuation. In particular, the fluid-filled cavity in SCUBA Phase 2 has the potential to provide several advantages over the traditional air-filled strategy, including clear identification and cauterization of bleeding vessels and visualization of residual clot burden. Further investigation is necessary to compare this technique to others that are currently used.

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García-Pérez, Miguel A. « The Decade 1989–1998 in Spanish Psychology : An Analysis of Research in Statistics, Methodology, and Psychometric Theory ». Spanish Journal of Psychology 4, n^o 2 (novembre 2001) : 111–22. http://dx.doi.org/10.1017/s1138741600005710.

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This paper presents an analysis of research published in the decade 1989–1998 by Spanish faculty members in the areas of statistical methods, research methodology, and psychometric theory. Database search and direct correspondence with faculty members in Departments of Methodology across Spain rendered a list of 193 papers published in these broad areas by 82 faculty members. These and other faculty members had actually published 931 papers over the decade of analysis, but 738 of them addressed topics not appropriate for description in this report. Classification and analysis of these 193 papers revealed topics that have attracted the most interest (psychophysics, item response theory, analysis of variance, sequential analysis, and meta-analysis) as well as other topics that have received less attention (scaling, factor analysis, time series, and structural models). A significant number of papers also dealt with various methodological issues (software, algorithms, instrumentation, and techniques). A substantial part of this report is devoted to describing the issues addressed across these 193 papers–most of which are written in the Spanish language and published in Spanish journals–and some representative references are given.

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Worley, Christopher G., Lav Tandon, Patrick T. Martinez et Diana L. Decker. « Application of micro-XRF for nuclear materials characterization and problem solving ». Powder Diffraction 28, n^o 2 (16 avril 2013) : 127–31. http://dx.doi.org/10.1017/s0885715613000201.

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A number of spatially resolved elemental imaging techniques are commonly employed to examine plutonium and other nuclear materials (e.g., scanning electron microscopy). Up until the past 10–15 years, micro-X-ray fluorescence (MXRF) instrumentation had been relatively uncommon, and even currently, it is underutilized for spatially resolved nuclear materials analysis and imaging. In the current study, a number of plutonium materials problem solving applications are presented to demonstrate the power and utility of MXRF for providing unique, spatially resolved elemental composition information. Applications discussed include identification of multiple insoluble fractions in plutonium and neptunium mixed oxide, spatially resolved imaging of plutonium residue and other elements on surface swipes, and spatial mapping of impurities in plutonium metal. The mixed oxide particle analysis demonstrated the ability to non-destructively identify particles of interest for potential extraction and analysis by other methods. The surface swipes study demonstrated the unique ability of MXRF to non-destructively image large multiple cm2 sized, non-conducting, radiologically contaminated samples. The plutonium metal investigation showed the capability of MXRF to non-destructively map elemental heterogeneity directly in an actinide matrix. Such information is extremely valuable prior to using destructive analysis (DA) trace elemental analytical chemistry techniques. If a metal is found to contain significant elemental impurity heterogeneity by MXRF, time consuming destructive sample preparation and analysis do not need to be repeated to confirm that the sample is indeed heterogeneous.

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Campuzano, Susana, María Pedrero et José M. Pingarrón. « Electrochemical Nucleic Acid-Based Biosensing of Drugs of Abuse and Pharmaceuticals ». Current Medicinal Chemistry 25, n^o 33 (24 octobre 2018) : 4102–18. http://dx.doi.org/10.2174/0929867324666171121103156.

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Background: Studies on the interactions of DNA with small molecular drugs are currently performed both to explore their mechanism of action and to develop new drugs. Electrochemical biosensors offer a very promising alternative to more complex conventional techniques for drug determination due to rapidness, low cost, simplicity, high sensitivity and compatibility with use in different settings. In this review, selected electrochemical nucleic acid-based biosensing methods described so far for the determination of pharmaceuticals and illicit drugs are briefly overviewed, discussing their basics and main features. A section pointing out general conclusions and future directions in this field is also provided. Results: The 42 selected contributions described electrochemical platforms to determine drugs of interest by monitoring their specific interactions with nucleic acids (DNA and aptamers), DNA damage and specific DNA-protein interactions. The highlighted approaches reported the use of electrodes unmodified or modified with nanomaterials and/or polymers in which DNA-drug interaction was followed by electrochemical detection of DNA puric bases, active drug or diffusion-free markers, and monitoring changes in the surface layer morphology/permeability and charge transfer resistance using different electrochemical techniques. Conclusion: Although electrochemical nucleic acid biosensing approaches constitute an interesting option for drugs determination in terms of cost, simplicity and miniaturized instrumentation, validating exhaustively their performance in real samples against conventional methodologies and implementing them into portable and automatic high throughput devices, together with exploring novel electrode modifications with nanomaterials and polymers and studying in more detail their multiplexing ability for analysis of a large number of analytes, is still needed.

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Delgado, José, Juan José Galiana-Merino, Francisco J. García-Tortosa, Jesús Garrido, Luca Lenti, Salvatore Martino, José A. Peláez, Martín J. Rodríguez-Peces, Carlos Sanz de Galdeano et Juan L. Soler-Llorens. « Ambient Noise Measurements to Constrain the Geological Structure of the Güevéjar Landslide (S Spain) ». Applied Sciences 11, n^o 4 (5 février 2021) : 1454. http://dx.doi.org/10.3390/app11041454.

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The reactivation of very large landslides may cause severe damage to society. Its prevention and management requires detailed information on the geometry and structure of these landslides, but the use of standard techniques (boreholes) may be prohibitive from an economic point of view. To overcome these difficulties, geophysical techniques are of special interest because they allow for studying very large areas at a reasonable cost. In this paper, we present a case study wherein the analysis of ambient noise allowed us to produce a model of a large landslide near Granada (southern Spain). The geometry and location of the failure zone, as well as the assessment of the state of involved materials, were estimated by combining two available boreholes and different geophysical techniques (downhole tests and the spectral analysis of ambient noise, horizontal to vertical spectral ratios (HVSR) and the frequency-wavenumber (f-k) methods). The results have allowed us to differentiate between values within the landslide mass with respect to those of stable materials, and to perform for the first time a comprehensive geological model of this unstable mass. Differences were also observed within the landslide mass (earth flow vs. slide zones), which are attributed to differences in the degree of alteration and the disturbance of the internal structure of materials constituting the landslide mass. These results show that techniques based on the measurement of ambient noise are of special interest for studying very large, highly remolded landslide masses.

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Im, Yunjeong, Gyuwon Song et Minsang Cho. « Perceiving Conflict of Interest Experts Recommendation System Based on a Machine Learning Approach ». Applied Sciences 13, n^o 4 (9 février 2023) : 2214. http://dx.doi.org/10.3390/app13042214.

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Academic societies and funding bodies that conduct peer reviews need to select the best reviewers in each field to ensure publication quality. Conventional approaches for reviewer selection focus on evaluating expertise based on research relevance by subject or discipline. An improved perceiving conflict of interest (CoI) reviewer recommendation process that combines the five expertise indices and graph analysis techniques is proposed in this paper. This approach collects metadata from the academic database and extracts candidates based on research field similarities utilizing text mining; then, the candidate scores are calculated and ranked through a professionalism index-based analysis. The highly connected subgraphs (HCS) algorithm is used to cluster similar researchers based on their association or intimacy in the researcher network. The proposed method is evaluated using root mean square error (RMSE) indicators for matching the field of publication and research fields of the recommended experts using keywords of papers published in Korean journals over the past five years. The results show that the system configures a group of Top-K reviewers with an RMSE 0.76. The proposed method can be applied to the academic society and national research management system to realize fair and efficient screening and management.

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Ratre, Pooja, Nazim Nazeer, Roshani Kumari, Suresh Thareja, Bulbul Jain, Rajnarayan Tiwari, Arunika Kamthan, Rupesh K. Srivastava et Pradyumna Kumar Mishra. « Carbon-Based Fluorescent Nano-Biosensors for the Detection of Cell-Free Circulating MicroRNAs ». Biosensors 13, n^o 2 (4 février 2023) : 226. http://dx.doi.org/10.3390/bios13020226.

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Currently, non-communicable diseases (NCDs) have emerged as potential risks for humans due to adopting a sedentary lifestyle and inaccurate diagnoses. The early detection of NCDs using point-of-care technologies significantly decreases the burden and will be poised to transform clinical intervention and healthcare provision. An imbalance in the levels of circulating cell-free microRNAs (ccf-miRNA) has manifested in NCDs, which are passively released into the bloodstream or actively produced from cells, improving the efficacy of disease screening and providing enormous sensing potential. The effective sensing of ccf-miRNA continues to be a significant technical challenge, even though sophisticated equipment is needed to analyze readouts and expression patterns. Nanomaterials have come to light as a potential solution as they provide significant advantages over other widely used diagnostic techniques to measure miRNAs. Particularly, CNDs-based fluorescence nano-biosensors are of great interest. Owing to the excellent fluorescence characteristics of CNDs, developing such sensors for ccf-microRNAs has been much more accessible. Here, we have critically examined recent advancements in fluorescence-based CNDs biosensors, including tools and techniques used for manufacturing these biosensors. Green synthesis methods for scaling up high-quality, fluorescent CNDs from a natural source are discussed. The various surface modifications that help attach biomolecules to CNDs utilizing covalent conjugation techniques for multiple applications, including self-assembly, sensing, and imaging, are analyzed. The current review will be of particular interest to researchers interested in fluorescence-based biosensors, materials chemistry, nanomedicine, and related fields, as we focus on CNDs-based nano-biosensors for ccf-miRNAs detection applications in the medical field.

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Papaspyridakou, Panagiota, Panagiota Giannoutsou et Malvina G. Orkoula. « Non-Destructive and Non-Invasive Measurement of Ethanol and Toxic Alcohol Strengths in Beverages and Spirits Using Portable Raman Spectroscopy ». Biosensors 13, n^o 1 (13 janvier 2023) : 135. http://dx.doi.org/10.3390/bios13010135.

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The measurement of ethanol and toxic alcohol (methanol and isopropanol) strengths in beverages and spirits is crucial for health reasons but also for the identification of adulterated products. Many methodologies have been reported in the literature, based mainly on chromatographic and on spectroscopic techniques. Chromatographic techniques are laborious and time-consuming, while spectroscopic techniques are rapid and need no special sample pretreatment. All techniques were only applied to off-line or at-line manner. In the present work, Raman spectroscopy was used for fast and non-destructive measurements. A “through the container” method was developed for a non-invasive analysis, i.e., analysis without unsealing the bottles. This method, coupled with a miniature portable Raman, can serve for in-line measurements in a production line. The optimum laser focus for maximum spirit signal and minimum glass-wall signal was investigated. Calibration curves for the alcohols of interest were constructed and validated. The limits of detections were calculated and proved to be lower than the legitimate values. The influences of the liquor color and the bottle color, shape, and thickness were checked. Twenty-eight alcoholic products were studied. The concentrations found were compared against the nominal values (from the bottle labels).

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Verstockt, Jan, Simon Verspeek, Filip Thiessen, Wiebren A. Tjalma, Lieve Brochez et Gunther Steenackers. « Skin Cancer Detection Using Infrared Thermography : Measurement Setup, Procedure and Equipment ». Sensors 22, n^o 9 (26 avril 2022) : 3327. http://dx.doi.org/10.3390/s22093327.

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Infrared thermography technology has improved dramatically in recent years and is gaining renewed interest in the medical community for applications in skin tissue identification applications. However, there is still a need for an optimized measurement setup and protocol to obtain the most appropriate images for decision making and further processing. Nowadays, various cooling methods, measurement setups and cameras are used, but a general optimized cooling and measurement protocol has not been defined yet. In this literature review, an overview of different measurement setups, thermal excitation techniques and infrared camera equipment is given. It is possible to improve thermal images of skin lesions by choosing an appropriate cooling method, infrared camera and optimized measurement setup.

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Greco, Valentina, Alessandro Giuffrida, Marcello Locatelli, Fabio Savini, Ugo de de Grazia, Luigi Ciriolo, Miryam Perrucci et al. « Emerging Trends in Pharmacotoxicological and Forensic Sample Treatment Procedures ». Applied Sciences 13, n^o 5 (22 février 2023) : 2836. http://dx.doi.org/10.3390/app13052836.

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One of the most discussed topics concerns the sample preparation before the analysis and, therefore, all the operations necessary to eliminate the interferents, clean up the specimens, and extract the analytes of interest, reducing the matrix effect. This review highlights the fundamental steps in the treatment of postmortem samples used in forensic analysis. Through critical literature research, it was possible to choose among the countless works that could provide a general overview of the state-of-the-art in this field. Different biological matrices have been considered; blood and urine (the traditional biological fluids) are used to investigate the presence of substances that may have caused death, whilst other body fluids, such as bile and oral fluids, are still under discussion for their usability (and suitability). In the second part of the review, all the solid matrices obtained after autopsy were further divided into conventional and unconventional matrices to facilitate proper understanding. The choice of literature was also made according to the most widely used pretreatment techniques and the most representative innovative techniques.

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Kobylińska, Katarzyna, Tadeusz Orłowski, Mariusz Adamek et Przemysław Biecek. « Explainable Machine Learning for Lung Cancer Screening Models ». Applied Sciences 12, n^o 4 (12 février 2022) : 1926. http://dx.doi.org/10.3390/app12041926.

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Modern medicine is supported by increasingly sophisticated algorithms. In diagnostics or screening, statistical models are commonly used to assess the risk of disease development, the severity of its course, and expected treatment outcome. The growing availability of very detailed data and increased interest in personalized medicine are leading to the development of effective but complex machine learning models. For these models to be trusted, their predictions must be understandable to both the physician and the patient, hence the growing interest in the area of Explainable Artificial Intelligence (XAI). In this paper, we present selected methods from the XAI field in the example of models applied to assess lung cancer risk in lung cancer screening through low-dose computed tomography. The use of these techniques provides a better understanding of the similarities and differences between three commonly used models in lung cancer screening, i.e., BACH, PLCOm2012, and LCART. For the presentation of the results, we used data from the Domestic Lung Cancer Database. The XAI techniques help to better understand (1) which variables are most important in which model, (2) how they are transformed into model predictions, and facilitate (3) the explanation of model predictions for a particular screenee.

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Pagliari, Francesca, Elisa Sogne, Davide Panella, Gerardo Perozziello, Carlo Liberale, Gobind Das, Alice Turdo et al. « Correlative Raman–Electron–Light (CREL) Microscopy Analysis of Lipid Droplets in Melanoma Cancer Stem Cells ». Biosensors 12, n^o 12 (1 décembre 2022) : 1102. http://dx.doi.org/10.3390/bios12121102.

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Among all neoplasms, melanoma is characterized by a very high percentage of cancer stem cells (CSCs). Several markers have been proposed for their identification, and lipid droplets (LDs) are among them. Different techniques are used for their characterization such as mass spectrometry, imaging techniques, and vibrational spectroscopies. Some emerging experimental approaches for the study of LDs are represented by correlative light–electron microscopy and by correlative Raman imaging–scanning electron microscopy (SEM). Based on these scientific approaches, we developed a novel methodology (CREL) by combining Raman micro-spectroscopy, confocal fluorescence microscopy, and SEM coupled with an energy-dispersive X-ray spectroscopy module. This procedure correlated cellular morphology, chemical properties, and spatial distribution from the same region of interest, and in this work, we presented the application of CREL for the analysis of LDs within patient-derived melanoma CSCs (MCSCs).

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Pavón, Rubén Muñoz, Ángela Moreno Bazán, Jorge Jerez Cepa, Antonio A. Arcos Álvarez, Jesús María Alonso Trigueros, Marcos García Alberti et Jaime Reinoso Tellaeche. « New Use of BIM-Origami-Based Techniques for Energy Optimisation of Buildings ». Applied Sciences 12, n^o 3 (30 janvier 2022) : 1496. http://dx.doi.org/10.3390/app12031496.

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Outstanding properties and advanced functionalities of thermal–regulatory by origami-based architecture materials have been shown at various scales. However, in order to model and manage its programmable mechanical properties by Building Information Modelling (BIM) for use in a covering structure is not a simple task. The aim of this study was to model an element that forms a dynamic shell that prevents or allows the perpendicular incidence of the sun into the infrastructure. Parametric modelling of such complex structures was performed by Grasshopper and Rhinoceros 3D and were rendered by using the V-ray’s plugin. The elements followed the principles of origami to readjust its geometry considering the sun position, changing the shadow in real time depending on the momentary interest. The results of the project show that quadrangular was the most suitable Origami shape for façade elements. In addition, a BIM-based automated system capable of modifying façade elements considering the sun position was performed. The significance of this research relies on the first implementation and design of an Origami constructive element using BIM methodology, showing its viability and opening outstanding future research lines in terms of sustainability and energy efficiency.

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Pascacio, Pavel, Sven Casteleyn, Joaquín Torres-Sospedra, Elena Simona Lohan et Jari Nurmi. « Collaborative Indoor Positioning Systems : A Systematic Review ». Sensors 21, n^o 3 (2 février 2021) : 1002. http://dx.doi.org/10.3390/s21031002.

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Research and development in Collaborative Indoor Positioning Systems (CIPSs) is growing steadily due to their potential to improve on the performance of their non-collaborative counterparts. In contrast to the outdoors scenario, where Global Navigation Satellite System is widely adopted, in (collaborative) indoor positioning systems a large variety of technologies, techniques, and methods is being used. Moreover, the diversity of evaluation procedures and scenarios hinders a direct comparison. This paper presents a systematic review that gives a general view of the current CIPSs. A total of 84 works, published between 2006 and 2020, have been identified. These articles were analyzed and classified according to the described system’s architecture, infrastructure, technologies, techniques, methods, and evaluation. The results indicate a growing interest in collaborative positioning, and the trend tend to be towards the use of distributed architectures and infrastructure-less systems. Moreover, the most used technologies to determine the collaborative positioning between users are wireless communication technologies (Wi-Fi, Ultra-WideBand, and Bluetooth). The predominant collaborative positioning techniques are Received Signal Strength Indication, Fingerprinting, and Time of Arrival/Flight, and the collaborative methods are particle filters, Belief Propagation, Extended Kalman Filter, and Least Squares. Simulations are used as the main evaluation procedure. On the basis of the analysis and results, several promising future research avenues and gaps in research were identified.

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Articles de revues sur le sujet « Instrumentation and techniques of general interest »

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