137 research outputs found

    Monotone Proofs of the Pigeon Hole Principle

    Get PDF
    Lecture Notes in Computer Science. Geneva, Switzerland, July 9-15

    Challenges in Model Development for Meat Composition Using Multipoint NIR Spectroscopy from At‐Line to In‐Line Monitoring

    Get PDF
    This study evaluates the efficiency of multipoint near‐infrared spectroscopy (NIRS) to predict the fat and moisture content of minced beef samples both in at‐line and on‐line modes. Additionally, it aims at identifying the obstacles that can be encountered in the path of performing in‐line monitoring. Near‐infrared (NIR) reflectance spectra of minced beef samples were collected using an NIR spectrophotometer, employing a Fabry‐Perot interferometer. Partial least squares regression (PLSR) models based on reference values from proximate analysis yielded calibration coefficients of determination of 0.96 for both fat and moisture. For an independent batch of samples, fat was estimated with a prediction coefficient of determination of 0.87 and 0.82 for the samples in at‐line and on‐line modes, respectively. All the models were found to have good prediction accuracy; however, a higher bias was observed for predictions under on‐line mode. Overall results from this study illustrate that multipoint NIR systems combined with multivariate analysis has potential as a process analytical technology (PAT) tool for monitoring process parameters such as fat and moisture in the meat industry, providing real‐time spectral and spatial information. Citing Literatur

    Laser Induced Breakdown Spectroscopy for Quantification of Sodium and Potassium in Minced Beef: a Potential Technique for Detecting Beef Kidney Adulteration

    Get PDF
    Beef is a rich source of important minerals, with potassium (K) being the most abundant mineral quantitatively except in cured meats where sodium (Na) from the added salt predominates. This study evaluates the capability of LIBS for quantification of the Na and K contents of minced beef as a potential method of detecting beef kidney adulteration. Additionally, the study aims to demonstrate the ability of LIBS to provide spatial mineral information of minced beef. A LIBS system was employed to collect spectral information of adulterated minced beef samples. Atomic absorption spectroscopy (AAS) was used to obtain reference values for Na and K. The chemometric technique of partial least squares regression (PLSR) was used to build the prediction models. Spatial mineral maps of minced beef samples were generated based on the predicted percentages of Na and K. The models for Na and K yielded calibration coefficients of determination (Rc2) of 0.97 and 0.91 respectively. Similarly, a good calibration model was obtained for adulteration yielding a Rc2 of 0.97. Good prediction accuracy was observed for all models. Spatial mapping provided two major advantages: (a) representative measurements of samples and (b) spatial distribution of multi-elements. The results observed illustrate the ability of LIBS combined with chemometrics as a potential monitoring tool for mineral quantification as well as adulteration detection for the meat processing industry

    Real-time insight into the multistage mechanism of nanoparticle exsolution from a perovskite host surface

    Get PDF
    In exsolution, nanoparticles form by emerging from oxide hosts by application of redox driving forces, leading to transformative advances in stability, activity, and efficiency over deposition techniques, and resulting in a wide range of new opportunities for catalytic, energy and net-zero-related technologies. However, the mechanism of exsolved nanoparticle nucleation and perovskite structural evolution, has, to date, remained unclear. Herein, we shed light on this elusive process by following in real time Ir nanoparticle emergence from a SrTiO3 host oxide lattice, using in situ high-resolution electron microscopy in combination with computational simulations and machine learning analytics. We show that nucleation occurs via atom clustering, in tandem with host evolution, revealing the participation of surface defects and host lattice restructuring in trapping Ir atoms to initiate nanoparticle formation and growth. These insights provide a theoretical platform and practical recommendations to further the development of highly functional and broadly applicable exsolvable materials

    Ultraviolet and visible emissions of Er3+ in KY(WO4)2 single crystals co-doped with Yb 3+ ions

    Get PDF
    Abstract In this paper we studied the luminescence of Er 3+ in KY(WO 4 ) 2 co-doped with Yb 3+ at room temperature and at cryogenic temperature in the 360-860 nm range. We found 13 emissions of erbium in the ultraviolet and visible range, and studied the emissions after two pump wavelengths, one at 981 nm resonant to the maximum absorption of ytterbium and one at 798 nm resonant to the 4 I 9/2 energy level of erbium.

    Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius

    Get PDF
    We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as due to the presence of a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods. We use CoRoT color information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy and preliminary results from Radial Velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star are derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. We examine carefully all conceivable cases of false positives, and all tests performed support the planetary hypothesis. Blends with separation larger than 0.40 arcsec or triple systems are almost excluded with a 8 10-4 risk left. We conclude that, as far as we have been exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which we derive a period of 0.853 59 +/- 3 10-5 day and a radius of Rp = 1.68 +/- 0.09 REarth. Analysis of preliminary radial velocity data yields an upper limit of 21 MEarth for the companion mass, supporting the finding. CoRoT-7b is very likely the first Super-Earth with a measured radius.Comment: Accepted in Astronomy and Astrophysics; typos and language corrections; version sent to the printer w few upgrade

    Effects of adding Tiotropium or Aclidinium as triple therapy using impulse oscillometry in COPD

    Get PDF
    INTRODUCTION: Long-acting muscarinic antagonists confer improvements in spirometry when used in addition to inhaled corticosteroids and long-acting beta-agonists (ICS/LABA) in COPD. The dual objectives of this proof of concept study were to evaluate trough effects of tiotropium (TIO) or aclidinium (ACL) when used as triple therapy and to assess if impulse oscillometry (IOS) might be more sensitive than spirometry in detecting subtle differences in bronchodilator response. METHODS: Patients with moderate to severe COPD already taking ICS/LABA were randomized to receive add-on therapy in cross-over fashion with either TIO 18 ”g od or ACL 322 ”g bid for 2–3 weeks each. Measurements of IOS, spirometry, 6-min walk test, St George’s Respiratory Questionnaire (SGRQ) and Baseline/Transition Dyspnoea Index (TDI) were made at baseline and after chronic dosing at trough (12 h for ACL and 24 h for TIO), in addition to domiciliary diurnal spirometry. RESULTS: 13 patients were completed: mean age 69 years, FEV(1) 52 % predicted, FEV(1)/FVC 0.48, and R5 202 % predicted. There were no differences in any visit-based trough IOS or spirometry outcomes comparing TIO versus ACL. Resonant frequency but not total airway resistance at 5 Hz (R5) significantly improved from baseline with both treatments while peripheral airway resistance (R5–R20) significantly improved with ACL. Visit-based FEV(1), and forced and relaxed vital capacity were also significantly improved from baseline with both treatments. There were no significant differences in diurnal FEV(1) and FEV(6) profiles between treatments. 6-min walk distance and post-walk fatigue significantly improved from baseline with ACL, while post-walk dyspnea improved with TIO. SGRQ symptom score significantly improved to a similar degree with both treatments. TDI significantly improved with ACL versus TIO by 1.54 units. CONCLUSION: We observed comparable bronchodilator efficacy at trough with TIO and ACL when used as triple therapy in COPD, while IOS was no more sensitive than spirometry

    Efficacy and safety of once-daily aclidinium in chronic obstructive pulmonary disease

    Get PDF
    BACKGROUND: The long-term efficacy and safety of aclidinium bromide, a novel, long-acting muscarinic antagonist, were investigated in patients with moderate to severe chronic obstructive pulmonary disease (COPD). METHODS: In two double-blind, 52-week studies, ACCLAIM/COPD I (n=843) and II (n=804), patients were randomised to inhaled aclidinium 200 ÎŒg or placebo once-daily. Patients were required to have a post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity ratio of ≀70% and FEV1<80% of the predicted value. The primary endpoint was trough FEV1 at 12 and 28 weeks. Secondary endpoints were health status measured by St George's Respiratory Questionnaire (SGRQ) and time to first moderate or severe COPD exacerbation. RESULTS: At 12 and 28 weeks, aclidinium improved trough FEV1 versus placebo in ACCLAIM/COPD I (by 61 and 67 mL; both p<0.001) and ACCLAIM/COPD II (by 63 and 59 mL; both p<0.001). More patients had a SGRQ improvement≄4 units at 52 weeks with aclidinium versus placebo in ACCLAIM/COPD I (48.1% versus 39.5%; p=0.025) and ACCLAIM/COPD II (39.0% versus 32.8%; p=0.074). The time to first exacerbation was significantly delayed by aclidinium in ACCLAIM/COPD II (hazard ratio [HR] 0.7; 95% confidence interval [CI] 0.55 to 0.92; p=0.01), but not ACCLAIM/COPD I (HR 1.0; 95% CI 0.72 to 1.33; p=0.9). Adverse events were minor in both studies. CONCLUSION: Aclidinium is effective and well tolerated in patients with moderate to severe COPD

    Real-time insight into the multistage mechanism of nanoparticle exsolution from a perovskite host surface

    Get PDF
    In exsolution, nanoparticles form by emerging from oxide hosts by application of redox driving forces, leading to transformative advances in stability, activity, and efficiency over deposition techniques, and resulting in a wide range of new opportunities for catalytic, energy and net-zero-related technologies. However, the mechanism of exsolved nanoparticle nucleation and perovskite structural evolution, has, to date, remained unclear. Herein, we shed light on this elusive process by following in real time Ir nanoparticle emergence from a SrTiO3 host oxide lattice, using in situ high-resolution electron microscopy in combination with computational simulations and machine learning analytics. We show that nucleation occurs via atom clustering, in tandem with host evolution, revealing the participation of surface defects and host lattice restructuring in trapping Ir atoms to initiate nanoparticle formation and growth. These insights provide a theoretical platform and practical recommendations to further the development of highly functional and broadly applicable exsolvable materials
    • 

    corecore