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2022 ◽  
Vol 14 (2) ◽  
pp. 793
Author(s):  
Gregorio Sgrigna ◽  
Hélder Relvas ◽  
Ana Isabel Miranda ◽  
Carlo Calfapietra

Particulate matter represents a serious hazard to human health, and air quality models contribute to the understanding of its dispersion. This study describes particulate matter with a ≤10 μm diameter (PM10) dynamics in an urban–industrial area, through the comparison of three datasets: modeled (TAPM—The Air Pollution Model), measured concentration (environmental control stations—ECS), and leaf deposition values. Results showed a good agreement between ECS and TAPM data. A steel plant area was used as a PM10 emissions reference source, in relation to the four sampling areas, and a distance/wind-based factor was introduced (Steel Factor, SF). Through SF, the three datasets were compared. The SF was able to describe the PM10 dispersion values for ECS and leaf deposition (r2 = 0.61–0.94 for ECS; r2 = 0.45–0.70 for leaf); no relationship was found for TAPM results. Differences between measured and modeled data can be due to discrepancies in one district and explained by a lack of PM10 inventory for the steel plant emissions. The study suggests the use of TAPM as a suitable tool for PM10 modeling at the urban scale. Moreover, tree leaves are a low-cost tool to evaluate the urban environmental quality, by providing information on whether and when data from leaf deposition can be used as a proxy for air pollution concentration. Further studies to include the re-suspension of particles as a PM10 source within emission inventories are suggested.


2022 ◽  
Vol 354 ◽  
pp. 00006
Author(s):  
Marius Kovacs ◽  
Lorand Toth ◽  
Sorin Simion

Most of combustible dusts present both fire and explosion hazard. Explosion may occur at certain concentrations of dust mixed with air and in the presence of an ignition source. The threat posed by this real danger was confirmed by the events that took place in economic units such as: feed factories, wood products, textile industry, steel, etc. Among the parameters of explosiveness of combustible dust, which can cause an explosion, we mention: maximum explosion pressure, lower explosion limit, explosive index, minimum ignition energy, electrical resistivity of dust, minimum ignition temperature of dust layer and cloud, particle size and concentration of dust in suspension. The current paper presents the results of determinations of combustible wood dust concentrations, performed at an important economic unit, manufacturing veneer and wood panels, at a dusting ventilation installation composed of fan, cyclone and textile filter. These determinations were made in the pipe connecting the fan and the bag filter, to assess possible danger of explosion in the pipe, by relating the measured concentration to the lower explosion limit (concentration of wood dust).


2021 ◽  
Author(s):  
Teresa Vogl ◽  
Amy Hrdina ◽  
Christoph K. Thomas

<p>Understanding the source and transport behavior of atmospheric trace gases is important to better quantify, predict, and mitigate anthropogenic effects on the environment and climate. The relaxed eddy accumulation (REA) method enables measuring the fluxes of atmospheric compounds for which fast-response sensors are not available. In REA applications, air is sampled depending on the direction of the vertical wind w, into a reservoir for updrafts, and a reservoir for downdrafts, respectively. Deadbands are used to select only certain turbulent motions during sampling to obtain the concentration difference. The <em>β</em> factor is used to scale the measured concentration difference between both reservoirs to the flux.</p> <p>In this study, we evaluated a variety of different REA approaches with the goal of formulating recommendations applicable over a wide range of surfaces and meteorological conditions for an optimal choice of the <em>β</em> factor in combination with a suitable deadband. Observations with fast-response sensors were collected in three contrasting ecosystems offering stark differences in scalar transport and dynamics: a mid-latitude grassland ecosystem in Europe (Lindenberg, Germany), a loose gravel surface of the Dry Valleys of Antarctica, and a spruce forest site in the European mid-range mountains (Waldstein, Germany). REA applications were simulated using the high-frequency observations.</p>


Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 227
Author(s):  
Katarzyna Madej ◽  
Aleksandra Chmiołek ◽  
Kamila Szlachta ◽  
Wojciech Piekoszewski

Growing consumer interest in hemp oilseed supplements requires quality control. Therefore, appropriate, effective and verified analytical methods are needed for the determination of some bioactive cannabinoids in them. The aim of the study is to present an extended (compared to our previous research) validated high performance liquid chromatography with diode array detection (HPLC-DAD) method for the determination of four cannabinoids (cannabidiol, cannabidiolic acid, cannabinol and delta-9-tetrahydrocannabinol) in an oil matrix, which was used to determine these cannabinoids in seven commercial hemp oil supplements. In our method, the isolation of the target compounds was based on liquid extraction with acetonitrile combined with the freezing (at −41 °C) of the oil phase. The results show that in some cases, the determined concentrations of cannabinoids in the tested supplements differ significantly from those declared by the manufacturers. As for the main medicinal cannabinoid (CBD) in hemp oil supplements, in two cases, the measured concentration was significantly lower (1.45 and 1.81%) than the declared (5 and 5%), and in the other supplements, the obtained results confirm the declared amount of CBD within the error range from 3.29 to 9.2%. Therefore, to ensure the safe and beneficial use of these supplements by consumers, it is necessary to monitor their cannabinoid composition.


Dairy ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 658-670
Author(s):  
Melissa Di Rocco ◽  
Johann Scollard ◽  
Riona Sayers ◽  
Ambrose Furey ◽  
Martin Danaher ◽  
...  

The aim of this study was to investigate the distribution of cefquinome in different dairy products during the processing of naturally contaminated milk or spiked milk. The analysis of cefquinome residues in milk, skimmed milk, buttermilk, whey, cream, butter, curd, and cheese samples was performed using a water:acetonitrile solvent extraction and C18 dispersive solid-phase extraction (d-SPE) clean-up, followed by ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS) determination. The target concentration of cefquinome was achieved in the spiked milk (100 µg kg−1). During its processing, the antibiotic migrated primarily with the skimmed milk as opposed to cream (ratios of 3.6:1 and 2.8:1 for experiments A and B, respectively), and with the buttermilk during butter manufacture (ratios of 6.9:1 and 4.6:1), but was equal in the curd and whey during the manufacture of cheese. In the milk collected from treated animals, the measured concentration of cefquinome was considerably high (approx. 5000 µg kg−1). The results obtained from the dairy products were similar to those obtained in the spiked study (ratios of 8.2:1 and 3.1:1 for experiments A and B, respectively, during the separation of skimmed milk and cream; 6.0:1 and 5.0:1 for A and B, respectively, during the separation of buttermilk and butter). However, during cheesemaking, cefquinome migrated with the whey after cutting the curd, with ratios of 0.54:1 and 0.44:1 for experiments A and B, respectively. The difference in the migration of cefquinome between curd and whey in spiked and animal studies is probably due to the different concentration levels in the two different experiments. The results of this study showed that, in dairy products manufactured from milk containing cefquinome residues, the drug migrated primarily with the high-water-containing fractions.


2021 ◽  
Vol 8 (4) ◽  
pp. 249-272
Author(s):  
Marinko Oluić ◽  
Sreten Romandić ◽  
Ratko Vasiljević

The main goal of the presented exploration was to estimate potential for mineralization in the Mawat ophiolitic massif in Kurdistan, Iraq. The aim of the study was to explore existing copper mineralization and assessor elements gold, platinoids and chromium. Geological exploration detected two types of Cu occurrence a) secondary Cu carbonates (malachite) and b) Cu sulfides (chalcopyrite-pyrite). The Mawat region is mostly built of ultrabasic and basic rocks: peridotites, gabbros, serpentinites and basalts which are heavily deformed, with faults mostly oriented NNW-SSE, and NE-SW. The first phase of exploration comprised digital processing of ASTER and QuickBird satellite images, with appropriate geometrical and radiometric corrections and transformation into coordinate system. Color composite images were produced in different scales. They served to define lithological composition, tectonic settings, location of the points of interest etc. The field work was designed to check satellite data in situ, with focus on perspective rock formations, which might host copper mineralization, and other elements. The host rocks of the ore occurrences are primarily gabbros and metagabbros intersected by diabase dykes, epidote and quartz veins. Secondary mineralization is the product of surficial weathering and it is represented by malachite and limonite. The geophysical survey was very useful in the detection of area with elevated induced polarization and low resistivity. Three perspective areas have been selected for detailed explorations: Waraz, Mirava-Chenara and Konjirin-Kuradawi. The concentration of copper varies highly in very wide ranges; the maximum measured concentration of Cu was determined in Waraz area 6.7%. Some rock samples also show concentration of gold from 0.36 to 2.59 ppm Au. Keywords: Mawat ophiolitic massif, geologic-geophysical explorations, copper mineralization, Kurdistan-Iraq


Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1772
Author(s):  
Toni Schiller ◽  
Elke Sondermann ◽  
Andreas Meyer

Interdiffusion coefficients are key parameters for the solidification process of liquid alloys. However, the determination of interdiffusion coefficients in liquid metals at high temperatures is a challenging and extensive task, due to a variety of potential systematic errors. In recent years we have developed an X-ray in situ shear cell method for the measurement of interdiffusion coefficients in binary metallic melts. This technique enables the monitoring of the experiment in order to exclude fatal errors. Utilizing X-ray contrast, the method also provides a time-resolved concentration distribution. Such an in situ data set contains significantly more information than ex situ evaluated experiments. Available analyzing strategies do not fully exploit this potential yet. We present three new analyzing approaches that are able to retrieve a concentration-dependent interdiffusion coefficient from only one in situ data set. In that way, larger concentration differences become accessible for an experiment, which considerably decreases efforts. Using simulations, the approaches are checked for robustness. Furthermore, the approaches are run on real in situ data from a binary (0 to 9 at% Au-content) Al–Au alloy at 1000 °C which results in a concentration-dependent interdiffusion coefficient within the measured concentration range.


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1228
Author(s):  
Romain Garreau ◽  
Benoît Falquet ◽  
Lisa Mioux ◽  
Laurent Bourguignon ◽  
Tristan Ferry ◽  
...  

Background: Vancomycin is widely used for empirical antimicrobial therapy in critically ill patients with sepsis. Continuous infusion (CI) may provide more stable exposure than intermittent infusion, but optimal dosing remains challenging. The aims of this study were to perform population pharmacokinetic (PK) analysis of vancomycin administered by CI in intensive care unit (ICU) patients to identify optimal dosages. Methods: Patients who received vancomycin by CI with at least one measured concentration in our center over 16 months were included, including those under continuous renal replacement therapy (CRRT). Population PK was conducted and external validation of the final model was performed in a dataset from another center. Simulations were conducted with the final model to identify the optimal loading and maintenance doses for various stages of estimated creatinine clearance (CRCL) and in patients on CRRT. Target exposure was defined as daily AUC of 400–600 mg·h/L on the second day of therapy (AUC24–48 h). Results: A two-compartment model best described the data. Central volume of distribution was allometrically scaled to ideal body weight (IBW), whereas vancomycin clearance was influenced by CRRT and CRCL. Simulations performed with the final model suggested a loading dose of 27.5 mg/kg of IBW. The maintenance dose ranged from 17.5 to 30 mg/kg of IBW, depending on renal function. Overall, simulation showed that 55.8% (95% CI; 47–64%) of patients would achieve the target AUC with suggested dosages. Discussion: A PK model has been validated for vancomycin administered by CI in ICU patients, including patients under CRRT. Our model-informed precision dosing approach may help for early optimization of vancomycin exposure in such patients.


Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2807
Author(s):  
Alessio Cardini ◽  
Elisa Pellegrino ◽  
Laura Ercoli

This study investigated the occurrence of 12 pharmaceuticals (PhCs) in surface water in Central Italy, aiming to improve the estimation of the predicted environmental concentration (PEC) by normalizing the loads to the number of inhabitants of the drainage system in rural, periurban, and urban areas. We performed two sampling campaigns assessing the concentration of PhCs (measured environmental concentration (MEC)) in surface water and in effluent from a wastewater treatment plant. The reliability of PEC calculated by the refined formula was assessed and compared to the ratio obtained by the unrefined formula. MECs of diclofenac, estradiol, estrone, ibuprofen, metformin, naproxen, sulfamethoxazole, atenolol, carbamazepine, and dehydro-erythromycin were significantly higher in urban than in periurban and rural areas, and increases were 12-, 3600-, 256-, 33-, 18-, 120-, 10-, 5-, 2-, and 1-fold, respectively. Refinement of PEC improved estimation of PhC concentrations for all areas, especially for the urban one. The environmental risk was predicted as low for atenolol, carbamazepine, erythromycin, metformin, and naproxen; low/medium for diclofenac and ibuprofen; and high for clarithromycin, estradiol, estrone, and sulfamethoxazole. Overall, the highest risk was posed by PhCs in effluent, while a progressively decreasing risk was estimated for urban, periurban, and rural areas.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
C Meune ◽  
F.X Goudot ◽  
T Boukertouta ◽  
A Lazureanu ◽  
S Msadek ◽  
...  

Abstract Background Natriuretic peptides (NPs) are widely used in the diagnosis and risk stratification of heart failure (HF).NPs may have a reduced discriminative ability in the subgroup of elderly patients. Methods We examined all biological tests performed from February 2010 to August 2015 in two districts in the French Brittany. We report the “real-world” use of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in an elderly population and examine the measured concentration and potential impact of the cut-off value's selection. Results From a total of 3,606,432 tests ordered in 557,650 adult patients, 56,653 included at least one NT-proBNP measurement. NT-proBNP measurements gradually increased by 10-y age categories up to 80–90 y, and 39,828 (70.3%) of all measurements have been done in patients ≥75y. NT-proBNP concentrations increased with advanced age (Pearson's correlation coefficient: 0.2; p<10–5), with concentrations of 3,564±6,440 ng/L in patients ≥75y. NT-proBNP was inversely correlated with creatinine clearance (p<10–5). Respective proportions of NT-proBNP below the threshold value were 22.6% in patients aged 70 to 80y and less than 10% in those over 80 y when considering a single threshold value of 125 ng/L, and 31% and 33% in the same groups when considering a dual age-adjusted threshold value of 450 ng/L in patients >75y (p<0.001 for all comparisons). Conclusion Among a very large cohort, we observed that NT-proBNP is increasingly measured in elderly patients. NT-proBNP concentrations increase with age, and the selection of the threshold value markedly impacts the proportion of “low” versus “high” results. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Roche Diagnostics Proportion (in %) of low NT-proBNP


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