549 research outputs found

    In-vivo stratum corneum hydration inspection using a non-invasive terahertz hand-held scanner

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    In this work, we successfully measured the hydration dynamics and thickness of the most external layer of skin; the stratum corneum (SC) of 95 healthy volunteers accurately using our own home-built hand-held THz scanner in reflection configuration. The water accumulation in this layer of skin has been monitored within one minute in a non-invasive fashion

    A robust protocol for in vivo THz skin measurements

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    This work presents an experimental setup to control the way in which pressure interferes with the repeatability of in vivo THz skin measurements. By integrating a pressure sensor circuit into our THz system, it is possible to identify which measurements were taken within a previously specified pressure range. The live response of the pressure sensor helps to acquire data within the desired pressure leading to greater consistency of data between measurements. Additionally, a protocol is proposed to help achieve repeatable results and to remove the effects of the natural variation of the skin through the course of the day. This technique has been shown to be able to quantify the changes induced in the skin following the application of a moisturising skin product and shows the measured result to be significantly different from natural skin variation. This research therefore prepares the way for further studies on the effectiveness of different skin products using in vivo THz measurements

    Optimized multilayer structure for sensitive THz characterization of thin-film glucose solutions

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    Terahertz time-domain spectroscopy (THz-TDS) has shown promise in biomedical sample characterization and high characterization sensitivity is in demand due to the thin-film (TF) feature of the sample. This paper proposes an optimized multilayer structure for sensitive characterization of TF aqueous solutions in reflection THz-TDS. Theoretical simulations are conducted for structural optimization and the 75 ”m window-sample-mirror structure displays the best sensitivity compared to other sandwich structures and traditional THz measurement geometries. 0-20% TF glucose solutions are then measured; and a spectral peak introduced by the proposed structure is observed to result in the high sensitivity. Our work provides a new way of customizing multilayer structure for THz thin-film characterization

    Quality control of leather by terahertz time domain spectroscopy

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    We use terahertz time-domain spectroscopy combined with effective-medium theory to measure moisture content and thickness of leather simultaneously. These results demonstrate that this method could become a standard quality control test for the industrial tanning process

    Terahertz time-domain spectroscopy for the analysis of latex film formation

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    The subject of latex film formation has been studied for many years and it is known to be affected by many environmental conditions such as evaporation rate, polymer glass transition temperature, T g, and particle size. Understanding latex film formation is particularly relevant to the paint industry, to ensure even coated films. In this study, THz-TDS was used to analyze various latex solutions with different polymer glass transition temperatures and particle sizes. 2D water distribution maps were produced, as a function of drying time, to monitor latex drying processes such as the ‘coffee-ring effect’

    Prototyping of petalets for the Phase-II Upgrade of the silicon strip tracking detector of the ATLAS Experiment

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    In the high luminosity era of the Large Hadron Collider, the HL-LHC, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front and back side surfaces of the carbon structure. Details are given on the assembly, testing and evaluation of several petalets. Measurement results of both mechanical and electrical quantities are shown. Moreover, an outlook is given for improved prototyping plans for large structures.Comment: 22 pages for submission for Journal of Instrumentatio

    Grade V small bowel injury after blunt abdominal trauma: a case report

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    Injury of the small intestine or mesentery that requires surgical intervention is relatively uncommon, presenting less than 1% of all trauma. Unstable hemodynamically patients with peritoneal irritation signs and stable hemodynamically patients with radiological signs of intestine or mesentery lesions need an exploratory laparotomy. A 33-year-old male patient, suffered a car accident in which he had a frontal impact collision and was between two structures for 30 minutes, and rescued by the fire department. Physical examination of the abdomen presents generalized pain on palpation of moderate intensity and rebound sign. An exploratory laparotomy was performed, the findings were: hemoperitoneum of 1500 ml was found, lesion in the bucket loop of 1.2 meters, 1.8 meters from the Treitz angle and 70 cm from the ileocecal valve. We managed with drainage, vascular control, resection of the devascularized intestinal loop and small bowel shotgun stoma were. The patient was transferred to the intensive care unit for hemodynamic management and a second look was performed 5 days after surgery where cavity lavage, stoma dismantling and end-to-end anastomosis of the small intestine in two planes were performed. On post-operative day 7 drains were removed, and the patient was discharged from the surgical service due to improvement, without complications. We recommend a multidisciplinary approach to patients with polytrauma, since they lead to a better and faster recovery, in the same way it allows us to detect and treat any abnormality that impacts the quality of life of patients early
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