1,028 research outputs found

    Characterization of a planar 8 mm wide radiofrequency atmospheric pressure plasma source by spectroscopy techniques

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    Atmospheric pressure planar radiofrequency (RF) 13.56 MHz discharge in Ar gas generated in a long gap is investigated. The discharge operation with and without a dielectric barrier on the electrodes is studied as a function of the applied power and gas flow. The source afterglow is characterized and is analyzed for possible large-scale biomedical applications where low gas temperature is required. The discharge is studied by relative and absolute emission spectroscopies. A gas temperature as low as 330 +/- 50 K is determined from the rotational-vibrational band of OH emission. The absolute value of the discharge continuum irradiation is used to determine the electron density and the electron temperature. The electron-atom and electron-ion contributions to the bremsstrahlung radiation are calculated and are compared with measured spectra. The electron density of 1.9 +/- 1 x 10(20) m(-3) and electron temperature of 1.75 +/- 0.25 eV are measured in the discharge without a dielectric barrier. It is found that presence of the dielectric has a negligible effect on electron temperature, whereas the electron number density is almost six times lower in the discharge with the dielectric barrier

    Elaboration and characterization of the electrodeposited phosphates masses doped with various ions on stainless steel

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    The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L, with fluoride, Zn2+ and Cu2+ as dopant ions, using an electrochemical procedure and also the attempt to select the best conditions for stainless steel. The surface was characterized using X-ray difraction, AFM and contact angle measurements. X-ray has evidenced crystaline phases, contact angle measurements has established the balance hydrophyl-hydrophob and AFM established roughness values. The inductively coupled spectrometry (ICP-MS) has quantified the amount of cooper and zinc ions released. In order to be used in biomedical applications hemolysis and antibacterial tests have been performed.Fil: Totea, G.. Faculty of Applied Chemistry and Materials Science; RumaniaFil: Ionita, D.. Faculty of Applied Chemistry and Materials Science; RumaniaFil: Katunar, Maria Rosa. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂ­a de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de IngenierĂ­a; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂ­a de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de IngenierĂ­a; ArgentinaFil: Demetrescu, I.. Faculty of Applied Chemistry and Materials Science; Rumani

    Antibacterial nanocomposites based on Ag NPs and HMDSO deposited by atmospheric pressure plasma

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    The development of new multifunctional coatings with antimicrobial properties has a special interest in several applications for pharmaceutical and medical products. This work reports on the deposition of antimicrobial coatings based on silver nanoparticles (Ag NPs) embedded in an organosilicon film onto woven and nonwoven textiles. The Ag nanoparticles admixed with hexamethyldisiloxane (HMDSO) vapours are introduced by means of an atomizer system in the remote discharge of an atmospheric pressure plasma source operating in argon. The chemical properties and the surface morphology of the coatings with antimicrobial potential are discussed.This work was performed within the M-ERA-NET project PlasmaTex, contract 31/2016/ UEFISCDI. The financial support from the Ministry of Research and Innovation under the Nucleus contract 4N/2016 is gratefully acknowledged.info:eu-repo/semantics/publishedVersio

    September Arctic sea ice minimum prediction – a skillful new statistical approach

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    Sea ice in both polar regions is an important indicator of the expression of global climate change and its polar amplification. Consequently, broad interest exists on sea ice coverage, variability and long-term change. However, its predictability is complex and it depends strongly on different atmospheric and oceanic parameters. In order to provide insights into the potential development of a monthly/seasonal signal of sea ice evolution, we applied a robust statistical model based on different oceanic and atmospheric parameters to calculate an estimate of the September sea ice extent (SSIE) on a monthly timescale. Although previous statistical attempts of monthly/seasonal SSIE forecasts show a relatively reduced skill, when the trend is removed, we show here that the September sea ice extent has a high predictive skill, up to 4 months ahead, based on previous months' oceanic and atmospheric conditions. Our statistical model skillfully captures the interannual variability of the SSIE and could provide a valuable tool for identifying relevant regions and oceanic and atmospheric parameters that are important for the sea ice development in the Arctic and for detecting sensitive/critical regions in global coupled climate models with a focus on sea ice formation.</p

    Human Bone-Marrow-Derived Stem-Cell-Seeded 3D Chitosan–Gelatin–Genipin Scaffolds Show Enhanced Extracellular Matrix Mineralization When Cultured under a Perfusion Flow in Osteogenic Medium

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    Tissue-engineered bone tissue grafts are a promising alternative to the more conventional use of natural donor bone grafts. However, choosing an appropriate biomaterial/scaffold to sustain cell survival, proliferation, and differentiation in a 3D environment remains one of the most critical issues in this domain. Recently, chitosan/gelatin/genipin (CGG) hybrid scaffolds have been proven as a more suitable environment to induce osteogenic commitment in undifferentiated cells when doped with graphene oxide (GO). Some concern is, however, raised towards the use of graphene and graphene-related material in medical applications. The purpose of this work was thus to check if the osteogenic potential of CGG scaffolds without added GO could be increased by improving the medium diffusion in a 3D culture of differentiating cells. To this aim, the level of extracellular matrix (ECM) mineralization was evaluated in human bone-marrow-derived stem cell (hBMSC)-seeded 3D CGG scaffolds upon culture under a perfusion flow in a dedicated custom-made bioreactor system. One week after initiating dynamic culture, histological/histochemical evaluations of CGG scaffolds were carried out to analyze the early osteogenic commitment of the culture. The analyses show the enhanced ECM mineralization of the 3D perfused culture compared to the static counterpart. The results of this investigation reveal a new perspective on more efficient clinical applications of CGG scaffolds without added GO

    An information fusion approach for filtering GNSS data sets collected during construction operations

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    Global Navigation Satellite Systems (GNSS) are widely used to document the on- and off-site trajectories of construction equipment. Before analyzing the collected data for better understanding and improving construction operations, the data need to be freed from outliers. Eliminating outliers is challenging. While manually identifying outliers is a time-consuming and error-prone process, automatic filtering is exposed to false positives errors, which can lead to eliminating accurate trajectory segments. This paper addresses this issue by proposing a hybrid filtering method, which integrates experts’ decisions. The decisions are operationalized as parameters to search for next outliers and are based on visualization of sensor readings and the human-generated notes that describe specifics of the construction project. A specialized open-source software prototype was developed and applied by the authors to illustrate the proposed approach. The software was utilized to filter outliers in sensor readings collected during earthmoving and asphalt paving projects that involved five different types of common construction equipmen

    Cerebral Small Vessel Disease: Cognition, Mood, Daily Functioning, and Imaging Findings from a Small Pilot Sample

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    Cerebral small vessel disease, a leading cause of cognitive decline, is considered a relatively homogeneous disease process, and it can co-occur with Alzheimer's disease. Clinical reports of magnetic resonance imaging (MRI)/computed tomography and single photon emission computed tomography (SPECT) imaging and neuropsychology testing for a small pilot sample of 14 patients are presented to illustrate disease characteristics through findings from structural and functional imaging and cognitive assessment. Participants showed some decreases in executive functioning, attention, processing speed, and memory retrieval, consistent with previous literature. An older subgroup showed lower age-corrected scores at a single time point compared to younger participants. Performance on a computer-administered cognitive measure showed a slight overall decline over a period of 8–28 months. For a case study with mild neuropsychology findings, the MRI report was normal while the SPECT report identified perfusion abnormalities. Future research can test whether advances in imaging analysis allow for identification of cerebral small vessel disease before changes are detected in cognition
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