Measuring the Asborption Coefficient of Aquatic Particles Retained on Filter Using a Photo-Oxidation Bleaching Technique

This report describes a method for the determination of the particulate absorption coefficient that aims to improve the T-R method of Ferrari and Tassan, (1995, 2002) giving an alternative to the visual deternination of the bleached state of the sample on the filter and introducing a photoxidation bleaching technique to optimize the depigmentation process.JRC.H.3-Global environement monitorin

Implementazione di un sistema di controllo atto a ottimizzare l’efficienza di convertitori DC-DC impiegati in ambito Automotive e realizzati con tecnologia GaN

Lo scopo del presente progetto di ricerca è quello di dimostrare quelli che potrebbero essere i miglioramenti nell’adottare tecnologie GaN nei convertitori di potenza, soffermandosi sull’ambito Automotive. Si è dunque progettato, simulato ed infine analizzato un sistema di conversione bidirezionale DC-DC. Le prestazioni ottime sono state poi raggiunte attraverso l’introduzione di un sistema di controllo in grado di garantire, in ogni condizione, il miglior funzionamento possibile che garantisca il soddisfacimento delle richieste da parte del veicolo. Questo consentirà quindi di gestire il funzionamento del convertitore sia nelle fasi di scarica che in quelle di rigenerazione (regenerative braking). Al convertitore, è stato introdotto anche un controllo adattivo per la ricerca del dead-time ottimo dei segnali di pilotaggio dei transistor

Emotion comprehension and regulation in children with different sensitivity in relation to parenting stress

openConsiderato il ruolo della sensibilità e dell'importanza della qualità dell'ambiente nel delineare lo sviluppo individuale, la ricerca indaga la relazione tra la sensibilità, come considerata dal quadro teorico dell'environmental sensitivity, e comprensione e regolazione emotiva nei bambini dai 2 ai 6 anni, in relazione allo stress genitoriale

International Intercomparison of In Situ Chlorophyll-a Measurements for Data Quality Assurance of the Swedish Monitoring Program

Chlorophyll-a is an essential climate variable. Chlorophyll-a in situ measurements are usually used for the validation of satellite images. Previous intercomparisons have shown that there can be substantial differences between in situ laboratories. In order to shed light on these differences, we arranged international chlorophyll-a intercomparisons with eight participating laboratories during 1–2 July 2021. We performed two dedicated transects through Bråviken bay (NW Baltic proper) and sampled four stations in each transect along a chlorophyll-a gradient. We took three surface replicates per laboratory and per station, i.e., 24 samples per laboratory. The samples were filtered through Whatman GF/F filters, and filters were frozen in liquid nitrogen and distributed in dry ice to all laboratories together with chlorophyll-a standards. The results between labs compared quite well. The mean normalized bias (MNB) of the standard measurements ranged between −23% and +19% for all laboratories and −7% to +19% for the Baltic Sea laboratories compared to high-performance liquid chromatography. The MNB of the two Bråviken transects ranged between −23 and +17% for all laboratories (compared to the median of all spectrophotometric and fluorometric measurements) and between −2 and +17% for the Baltic Sea laboratories. On average, the chlorophyll-a concentrations measured by the fluorometric method were about 13% higher than those measured by spectrophotometry, and fluorometry samples tended to have more scatter. The largest uncertainties seem to be caused by variable storage and extraction methods and are not fully captured in this intercomparison. This is demonstrated by analyzing historical comparisons revealing very large uncertainties (root mean square difference (RMSD) up to 109% and bias up to 68%), possibly due to too low filtration volumes and due to different extraction and storage methods. Our recommendation is to flash-freeze samples in liquid nitrogen and store them at −80°C. After storage, they should be extracted and measured at room temperature within 6–24 h. Our results also indicate that ethanol is much more efficient in extracting Chl-a than acetone. Last but not least, we would like to point out that the uncertainties in measuring chlorophyll-a by satellite are now within the range of in situ data, as shown here by comparing the in situ results from this study with published remote sensing results from the literature.publishedVersio

christian faith in bing xin s early life tradition and western values in the early 20th century china

Among Chinese writers of the 20th century, Xie Wanying 谢婉莹 (1900–1999), known with her pen name Bing Xin 冰心, has been considered by literary critics as "the writer of love" and "the philosopher of love". Nevertheless, this label seems to have ignored an element that could let us identify important conflicts within her works, that can be attributed to her contacts and relations with people and institutions linked to the Christian faith. Therefore, in the first period of Bing Xin's literary production (1920–1930), this peculiar aspect of Western culture, the Christian belief, seems to be for her the expression of a definitely alternative and unconventional way to achieve truth in the early 20th century China

Sensitivity Studies for the Exercise I-1 of the OECD/UAM Benchmark

OECD/NEA has initiated an international Uncertainty Analysis in Modeling (UAM) benchmark focused on uncertainties in modeling of Light Water Reactor (LWR). The first step of uncertainty propagation is to perform sensitivity to the input data affected by the numerical errors and physical models. The objective of the present paper is to study the effect of the numerical discretization error and the manufacturing tolerances on fuel pin lattice integral parameters (multiplication factor and macroscopic cross-sections) through sensitivity calculations. The two-dimensional deterministic codes NEWT and HELIOS were selected for this work. The NEWT code was used for analysis of the TMI-1, PB-2, and Kozloduy-6 test cases; the TMI-1 test case was investigated using the HELIOS code. The work has been performed within the framework of UAM Exercise I-1 "Cell Physics.

Effetti dei parametri geometrici e della presenza di reticolante in transistor elettrochimici organici

La bioelettronica studia come connettere ed interpretare i segnali di sistemi biologici con quelli elettronici. Fino a poco tempo fa i dispositivi utilizzati erano costituiti da materiali semiconduttori inorganici come il silicio, che risultano incompatibili con la crescita cellulare, e non permettono una trasduzione diretta di segnali biologici in elettrici. Sono stati perciò sostituiti da materiali organici, ovvero polimeri conduttori, più morbidi, biocompatibili e capaci di trasdurre i segnali ionici in quelli elettronici. È qui che nasce la bioelettronica organica. Questa tesi si è occupata della fabbricazione e caratterizzazione di Transistor Elettrochimici Organici (OECTs) basati sul polimero conduttivo poli(3,4-etilenediossitiofene):poli(stirenesulfonato) (PEDOT:PSS), disponibile in soluzione acquosa e attualmente largamente utilizzato. Questi transistor hanno molteplici applicazioni, in particolare i dispositivi qui descritti sono stati progettati per un’innovativa applicazione, ovvero per la misura dell’integrità di tessuti cellulari. Per fare ciò questi dispositivi devono resistere alle condizioni a cui sono esposti durante le analisi dei tessuti, nonché essere veloci, per poter avere risposte sensibili in ambito biologico. Lo scopo di questa tesi è l’ottimizzazione di questi dispostivi tramite la modifica di alcuni parametri. È difatti possibile aumentarne la velocità di risposta modificando la lunghezza del canale cambiando la metodologia di fabbricazione, o aumentarne la durabilità all’interno del medium in cui sono immersi, a discapito delle prestazioni elettriche, cambiando la percentuale di reticolante utilizzata nella soluzione di PEDOT:PSS. Si è potuto osservare che i transistor con un canale di 2mm e concentrazione di reticolante all’1% nella soluzione di PEDOT:PSS sono i più efficienti, in quanto combinano durabilità del film polimerico nel tempo a dei tempi di risposta nello spegnimento dei dispositivi brevi e stabili

Phytoplankton pigment in situ measurements uncertainty evaluation: an HPLC interlaboratory comparison with a European-scale dataset

Phytoplankton pigment data play a crucial role in ecological studies, enabling the identification of algal groups and estimation of primary production rates. Accurate measurements of chlorophyll a (TChl a) and other marine pigments are essential for the development of bio-optical algorithms and the validation of satellite data products. High-performance liquid chromatography (HPLC) is the gold standard method for quantifying multiple pigments in a single water sample. This study aims to investigate the uncertainties associated with phytoplankton pigment quantification by comparing duplicate sample analyses conducted by two laboratories, the Joint Research Centre of the European Commission (J) and the DHI Group, Denmark (D). The analyses were performed using the same HPLC method. The dataset comprised 957 natural samples collected between 2012 and 2017 from various European seas, representing different trophic conditions with TChl a concentrations ranging from 0.083 to 27.35 mg/m3. The study compared the results of the two independent analyses for TChl a and primary phytoplankton pigments, including chlorophyll b, chlorophyll c, carotens, fucoxanthin, 19′-butanoyloxyfucoxanthin, diadinoxanthin, diatoxanthin, 19′-hexanoyloxyfucoxanthin, peridin, and zeaxanthin. The percent difference between the two analyses was calculated to assess the uncertainties associated with pigment quantification. The mean percent difference observed between the two independent analyses of TChl a was 10.8%. For the primary phytoplankton pigments, the associated mean percent difference was 16.9%. These results meet the requirements of 15% and 25% uncertainties, respectively, which are applicable for the validation of satellite data products. The comparative analysis between the two laboratories demonstrates that the uncertainties associated with phytoplankton pigment quantification are within acceptable ranges for the validation of satellite data products. Moreover, the study investigates the propagation of uncertainties in diagnostic pigment values to phytoplankton indexes, which are derived using pigment-based algorithms to characterize phytoplankton populations according to functional types

Antiradical activity of phenolic metabolites extracted from grapes of white and red Vitis vinifera L. cultivars

A diet rich in plant foods is strongly recommended for its beneficial effect on human health. In fact, plant secondary metabolites may exert various biological activities on mammalian cells. Among them, phenolics are excellent natural antioxidants able to rescue cell redox unbalance responsible for the onset of different pathologies. For these reasons, the present work was focused on the study of grape extracts obtained from eight different Italian Vitis vinifera cultivars, quite rare in Italian viticulture and not yet completely chemically characterized. For each preparation, total simple phenolic, flavonoidic and anthocyaninic content was measured through spectrophotometrical assays, while detailed biochemical profile was revealed by LC-MS analyses. In order to valorize the products of these varieties and increase our knowledge about their potential healthy role, the antioxidant power of the samples was evaluated by two different in vitro antiradical tests: DPPH and FRAP. Moreover, free radical scavenging properties of eleven grape pure compounds were investigated, with the aim to: a) compare their real antiradical property with the theoretical one; b) identify which one of them possessed the best bioactivity; c) understand how they might singularly contribute to the nutraceutical effect of the whole grapevine phytocomplex

Bio-optical Algorithms for European Seas: Performance and Applicability of Neural-Net Inversion Schemes

The report presents and discusses the application of Multi Layer Perceptron (MLP) neural networks to derive Chlorophyll-a concentration (Chl-a), absorption of the yellow substance at 412 nm (ays(412)) and concentration of the total suspended matter (TSM) from remote sensing reflectance Rrs values. MLPs were developed on the basis of data collected within the framework of the Coastal Atmosphere and Sea Time Series (CoASTS) and Bio-Optical mapping of Marine Properties (BiOMaP) programs carried out by the Institute for Environment and Sustainability (IES), JRC of E.C., Italy. Investigated oceanographic regions include the Eastern Mediterranean Sea, the Ligurian Sea, the Northern Adriatic Sea, the Western Black Sea, the English Channel and the Baltic Sea. The study verifies the applicability of MLPs to retrieve ocean color data products in each basin. For instance, the highest accuracy in retrieving Chl-a has been found in the Easter Mediterranean Sea and the Ligurian Sea (14 and 25 %, respectively). In the case of ays(412), the MLP is the most performing in the waters of the English Channel and the Baltic Sea (14 and 13%). Instead, the TSM retrieval is the most accurate in the Black Sea and at the Acqua Alta Oceanographic Tower (14 and 19%). To enhance mission specific ocean color resuls, MLP coefficients are also computed applying band-shift corrections to produce Rrs spectra at wavelengths matching those of SeaWiFS, MODIS and MERIS. Resulting tables of MLP parameters are reported to permit independent applications of neural networks presented in this analysis.JRC.H.3-Global environement monitorin