A new version of the Price's algorithm for global optimization

We present an algorithm for finding a global minimum of a multimodal, multivariate functionwhose evaluation is very expensive, affected by noise andwhose derivatives are not available. The proposed algorithm is a new version of the well known Price’s algorithm and its distinguishing feature is that it tries to employ as much as possible the information about the objective function obtained at previous iterates. The algorithm has been tested on a large set of standard test problems and it has shown a satisfactory computational behaviour. The proposed algorithm has been used to solve efficiently some difficult optimization problems deriving from the study of eclipsing binary star light curves

Anforderungsspezifische Untersuchungen zur Weiterentwicklung von Fernwaermeleitungen Kurzfassung. Schlussbericht

With 7 refs., 3 tabs., 36 figs.SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Electrospun PVA membranes reinforced with cellulose nanocrystals and thermally reduced graphene oxide: thermal, mechanical and UV-protection properties

Polyvinyl alcohol (PVA) has been widely proposed as biodegradable films, but it suffers rapid UV degradation affecting mechanical properties, low water resistance and poor antimicrobial properties. To overcome these difficulties, it has been blend with nanocrystalline cellulose (CNC) to produce nanocomposite membranes; however, adding a third element such as reduced graphene oxide (rGO) to the blend with potential packaging applications has not been reported. Herein, CNC was isolated from agroindustrial wastes (sugarcane bagasse; SCB) and used along with thermally reduced graphene oxide (TrGO) to be incorporated into PVA for the production of electrospun membranes for packaging applications. A wide variety of electrospinning parameters were analyzed to obtain PVA:CNC:TrGO composite membranes and their effects on thermal stability, mechanical properties, UV protection and moisture absorption, were evaluated. The results show that the isolation of CNC from SCB presented two phases: monoclinic and triclinic of type I cellulose. The highest crystallinity index (78.96%) and the diameter (10–20 nm)-length (150–200 nm) relation were found at 50 °C using a fiber:acid solution ratio of 1:50. In the case of ternary composite membranes, only free-defect morphologies with a composition of 84.5:15.0:0.5 wt% (PVA:CNC:TrGO) were observed. As a result of the adequate orientation and dispersion of the CNC:TrGO in the PVA matrix an improved was observed in the thermal stability, mechanical (137.48 MPa, HIT), UV barrier (up to 6% compared to pure PVA) and moisture absorption (reducing from 4.8% to 0.05%) properties. The eco-friendly structured ternary nanocomposites support the desired properties to produce food packaging materials.</p

Supplementary information files for: Electrospun PVA membranes reinforced with cellulose nanocrystals and thermally reduced graphene oxide: thermal, mechanical and UV-protection properties

Supplementary files for article Electrospun PVA membranes reinforced with cellulose nanocrystals and thermally reduced graphene oxide: thermal, mechanical and UV-protection properties. Polyvinyl alcohol (PVA) has been widely proposed as biodegradable films, but it suffers rapid UV degradation affecting mechanical properties, low water resistance and poor antimicrobial properties. To overcome these difficulties, it has been blend with nanocrystalline cellulose (CNC) to produce nanocomposite membranes; however, adding a third element such as reduced graphene oxide (rGO) to the blend with potential packaging applications has not been reported. Herein, CNC was isolated from agroindustrial wastes (sugarcane bagasse; SCB) and used along with thermally reduced graphene oxide (TrGO) to be incorporated into PVA for the production of electrospun membranes for packaging applications. A wide variety of electrospinning parameters were analyzed to obtain PVA:CNC:TrGO composite membranes and their effects on thermal stability, mechanical properties, UV protection and moisture absorption, were evaluated. The results show that the isolation of CNC from SCB presented two phases: monoclinic and triclinic of type I cellulose. The highest crystallinity index (78.96%) and the diameter (10–20 nm)-length (150–200 nm) relation were found at 50 °C using a fiber:acid solution ratio of 1:50. In the case of ternary composite membranes, only free-defect morphologies with a composition of 84.5:15.0:0.5 wt% (PVA:CNC:TrGO) were observed. As a result of the adequate orientation and dispersion of the CNC:TrGO in the PVA matrix an improved was observed in the thermal stability, mechanical (137.48 MPa, HIT), UV barrier (up to 6% compared to pure PVA) and moisture absorption (reducing from 4.8% to 0.05%) properties. The eco-friendly structured ternary nanocomposites support the desired properties to produce food packaging materials. </p

Chest CT for early detection and management of coronavirus disease (COVID-19): a report of 314 patients admitted to Emergency Department with suspected pneumonia

Purpose: The purpose of our study was to assess the potential role of chest CT in the early detection of COVID-19 pneumonia and to explore its role in patient management in an adult Italian population admitted to the Emergency Department. Methods: Three hundred and fourteen patients presented with clinically suspected COVID-19, from March 3 to 23, 2020, were evaluated with PaO2/FIO2 ratio from arterial blood gas, RT-PCR assay from nasopharyngeal swab sample and chest CT. Patients were classified as COVID-19 negative and COVID-19 positive according to RT-PCR results, considered as a reference. Images were independently evaluated by two radiologists blinded to the RT-PCR results and classified as “CT positive” or “CT negative” for COVID-19, according to CT findings. Results: According to RT-PCR results, 152 patients were COVID-19 negative (48%) and 162 were COVID-19 positive (52%). We found substantial agreement between RT-PCR results and CT findings (p &lt; 0.000001), as well as an almost perfect agreement between the two readers. Mixed GGO and consolidation pattern with peripheral and bilateral distribution, multifocal or diffuse abnormalities localized in both upper lung and lower lung, in association with interlobular septal thickening, bronchial wall thickening and air bronchogram, showed higher frequency in COVID-positive patients. We also found a significant correlation between CT findings and patient’s oxygenation status expressed by PaO2/FIO2 ratio. Conclusion: Chest CT has a useful role in the early detection and in patient management of COVID-19 pneumonia in a pandemic. It helps in identifying suspected patients, cutting off the route of transmission and avoiding further spread of infection