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The study evaluated a new model of a Plair SA airflow cytometer, Rapid-E + , and assessed its suitability for airborne pollen monitoring within operational networks. Key features of the new model are compared with the previous one, Rapid-E. A machine learning algorithm is constructed and evaluated for (i) classification of reference pollen types in laboratory conditions and (ii) monitoring in real-life field campaigns. The second goal of the study was to evaluate the device usability in forthcoming monitoring networks, which would require similarity and reproducibility of the measurement signal across devices. We employed three devices and analysed (dis-)similarities of their measurements in laboratory conditions. The lab evaluation showed similar recognition performance to that of Rapid-E, but field measurements in conditions when several pollen types were present in the air simultaneously showed notably lower agreement of Rapid-E + with manual Hirst-type observations than those of the older model. An exception was the total-pollen measurements. Comparison across the Rapid-E + devices revealed noticeable differences in fluorescence measurements between the three devices tested. As a result, application of the recognition algorithm trained on the data from one device to another led to large errors. The study confirmed the potential of the fluorescence measurements for discrimination between different pollen classes, but each instrument needed to be trained individually to achieve acceptable skills. The large uncertainty of fluorescence measurements and their variability between different devices need to be addressed to improve the device usability. [ABSTRACT FROM AUTHOR]

The Atmospheric InfraRed Sounder (AIRS) aboard Aqua provides essential long‐term data on vertical cloud fraction, particularly valuable in the Arctic region. This study offers a comprehensive assessment of Arctic vertical cloud fraction derived from AIRS through a comparison with independent ground‐ and space‐based radar and lidar observations. In comparison to the measurements at the North Slope Alaska site, results reveal a significant underestimation of low‐level cloud cover by AIRS, especially for near‐surface clouds, while mid‐ and high‐level cloud fractions show better consistency. In comparison to the satellite‐based product from 3S‐GEOPROF‐COMB, the accuracy varies across different underlying surfaces (land vs. sea) and seasons. AIRS shows significant positive biases in mid‐level cloud fraction over sea surfaces with sea ice concentration below 15%, indicating potential limitations in the cloud retrieval algorithm in regions with large sea ice variations. The issue of low‐level clouds identification is primarily caused by the limited penetrating capability of infrared hyperspectral sensing and the accuracy of preceding surface and atmospheric state products, which diminish the accuracy of AIRS low‐level cloud fraction. Plain Language Summary: The Atmospheric InfraRed Sounder (AIRS) instrument on the Aqua satellite provides important information on vertical cloud fraction in the Arctic. This research compared the AIRS cloud cover data with observations from ground‐based and space‐based radar and lidar. Findings are that AIRS underestimates low‐level clouds, especially near the surface, but is more accurate for mid‐ and high‐level clouds. The accuracy also varies over land and sea surfaces, as well as throughout different seasons. In regions with significant sea ice variations, AIRS overestimates clouds at mid‐levels. The study suggests that the ability to accurately detect low‐level clouds from AIRS is limited by the capability of infrared hyperspectral sensing to penetrate the atmosphere. Key Points: Initial evaluation of AIRS vertical cloud fraction product over the Arctic is presented using ground‐ and space‐based radar‐lidar observationsAIRS underestimates low‐level clouds, especially near the surface, more accurately reflects mid‐ and high‐level cloud fractionsAIRS mid‐level cloud fraction demonstrates significant positive biases over regions with sea ice concentration below 15% [ABSTRACT FROM AUTHOR]

This study draws on London's long experience with air pollution in order to improve our understanding of the overall effects of pollution exposure and how and why these effects evolve as locations develop. I compare uniquely detailed new mortality data covering 1866 to 1965 to the timing of London's famous fog events, which trapped emissions in the city. I show that air pollution was a major contributor to mortality in London over this period and that it interacted strongly with specific infectious diseases. As a consequence of this interaction, reductions in the infectious disease burden substantially altered the health costs of pollution. [ABSTRACT FROM AUTHOR]

On 24 June 1994 at Fairchild Air Force Base, during practice for an air show, a low-flying B-52H aircraft banked its wings vertically and crashed. Emphasizing the activity of modeling drag and gravity, these notes examine the possibility of recovery with several models. First, with algebra, historical data lead to a model where in a free fall near Earth's surface, the distance fallen is proportional to time squared. Calculus then gives an ordinary differential equation to model free fall near Earth's surface. Second, with calculus, historical data lead to various models of drag on objects moving through air. Third, combining models of drag and gravity with Newton's Laws of Motion leads to ordinary differential equations that model free fall in air. Fourth, predictions from such models with ordinary differential equations are consistent with the aircraft crash. Further models examine the possibility of increasing engine thrust to regain the vertical component of lift. All models fit in a first course in differential equations, without requiring any computational machinery. However, numerical experiments show how uninformed use of professional software can produce rounding errors to cause the modelled aircraft to plunge to the bottom of the deepest oceans and shoot up into space. [ABSTRACT FROM AUTHOR]

The Indian Environmental Radiation Monitoring Network continuously monitors the outdoor natural gamma absorbed dose rate in air at different locations throughout India by employing Geiger–Mueller (GM) detector-based field-installed environmental radiation monitors (ERMs). Hyderabad, Telangana, India is known to have high natural background radiation levels due to the presence of high concentrations of primordial radionuclides in its granitic rocks. There are a total of 59 ERMs installed at various locations across Hyderabad. Long-term monitoring data of these locations are presented in this paper. The mean values of outdoor natural gamma absorbed dose rate in air at the monitoring locations were found to vary in the range of 104–258 nGy.h−1 with a mean of 193 ± 40 nGy.h−1. The mean annual effective dose due to outdoor natural gamma radiation was estimated to be 0.24 ± 0.05 mSv.y−1. Analysis of the long-term seasonal variation of outdoor natural gamma absorbed dose rate in air showed that the same was lowest during monsoons. [ABSTRACT FROM AUTHOR]

The main elements that define the climate of a place are air temperature and atmospheric precipitation. Through this study, we aim to highlight the significance and extent of the trends of the two climatic elements for the interval 1961- 2020 at the Cotnari meteorological station compared to those at the territorially neighboring stations Botoşani, Iaşi and Roman. For this purpose, we identified the basic thermo-pluviometric peculiarities at the Cotnari meteorological station for the period 1961-2020 and analyzed the evolution of the thermo-pluviometric parameters on interdecadal and interannual periods. We then applied the Mann-Kendall test combined with Sen's slope to estimate the trend over the reference period. Following these analyses, in Cotnari, taking as a reference the average annual temperature of 9.6°C and the average annual amount of precipitation of 543.8 mm, we found that after the year 2000, the trend of these two elements was positive, which shows an increase in air temperature and quantitative atmospheric precipitation. In total, the annual thermal averages increased statistically significantly by 0.33°C/decade. Annual precipitation increased during 1961–2020 by 2.2 mm/decade and showed modest statistical significance. [ABSTRACT FROM AUTHOR]

Rock collapse with large volumes can attain high speeds during their freefall motion. The impact of such a falling mass on the ground surface can initiate a powerful air blast with far-field destructive impact. To investigate the formation, disaster-causing mechanism and dynamic characteristics of rock collapse-induced air blasts, an existing coupled discrete-element method (DEM)–computational fluid dynamics (CFD) approach is employed on a rock collapse-generated air blast in Zengziyan, China (ZRC). The generated air blast shows a maximum velocity of over 50 m/s and subsequently dissipated rapidly. The high consistency between the simulated air blast dynamics and the video verified the DEM–CFD coupled method in the air blast modeling. Combined with the ZRC-induced air blast analysis, a simplified generalized model was designed to observe the potential effect of geomorphology. Results highlight the great contribution of geomorphology, to both air blast initiation and propagation. Collapsed rock mass with a free fall motion is prone to generate significant air blasts when colliding with the slope surface. Tremendous energy was transferred to the surrounding air at the moment. Compared with falling straight down, air blasts resulting from an airborne trajectory case show a longer propagation because the collapsed materials impart air a higher initial momentum parallel to the slope surface. In addition, air blast propagation in wide distribution areas in comparison to narrow valleys shows greater attenuation. This study will aid in understanding the mechanism of a rock collapse-induced air blast as well as the forward simulation of similar events for risk assessment. Highlights: DEM-CFD coupled method provides good performance in simulating the air blast dynamics. Large rock collapse with a free fall motion is prone to generate powerful air blasts when colliding with the slope surface. Geomorphology is greatly influential in both air blast initiation and propagation. [ABSTRACT FROM AUTHOR]

Drought events have multiple adverse impacts on environment, society, and economy. It is thus crucial to monitor and characterise such events. Here, we compare the ability of selected state-of-the-art long-term reanalysis and remote-sensing products to represent major seasonal and multi-year drought events in the 2000–2020 period globally. We focus on soil moisture (or agroecological) drought and place the results in the context of trends in dry-season soil moisture. We consider surface and root-zone soil moisture from ERA5, the related ERA5-Land, and MERRA-2 reanalysis products, the ESA CCI remote-sensing surface soil moisture products (encompassing an ACTIVE, a PASSIVE and a COMBINED product), as well as its near real-time counterpart produced within C3S. In addition, we use a new root-zone soil moisture dataset derived from the ESA CCI COMBINED product. Except for ESA CCI surface and root-zone soil moisture, the considered products offer opportunities for drought monitoring since they are available in near real-time. We analyse 18 documented drought events within predefined spatial and temporal bounds derived from scientific literature. Based on standardised daily anomalies of surface and root-zone soil moisture, the drought events are characterised by their severity (the time accumulated standardised anomalies), magnitude (the minimum of the standardised anomalies over time), duration, and spatial extent. Product deviations in drought severity and magnitude are then placed in the context of trends in dry-season soil moisture, and potential reasons for diverging global soil moisture trends in the products are further investigated. All investigated products capture the considered drought events. Overall, responses of surface soil moisture tend to be weakest for the ACTIVE remote-sensing products in all metrics, but most pronounced in the drought magnitudes. Also, MERRA‑2 shows lower magnitudes than the other products. Except for the COMBINED products, the remote-sensing products tend to underestimate the spatial extents of larger droughts. Product differences in drought severity and magnitude for single events are consistent with the differences in dry-season soil moisture trends. These trends are globally diverse and partly contradictory between products. ERA5, ERA5-Land and the COMBINED products show larger fractions of drying trends, MERRA-2 and the C3S ACTIVE and PASSIVE products more widespread wetting trends. MERRA-2 surface air temperature shows regionally negative biases in trends compared to a ground observational product, which suggests that this reanalysis product underestimates drought trends. Also, the comparison with trends in selected land-surface characteristics and bioclimatic indicators shows that dry-season soil moisture trends may be affected by retrieval or modelling artifacts in some cases. In the root zone (based on the reanalysis products and the ESA CCI root-zone soil moisture dataset), the droughts are dampened in magnitude and smaller in spatial extent but show a tendency to prolonged durations. Based on the overall observational evidence and the consideration of the respective limitations of the included products, the present analyses suggest a consistent tendency towards drying during the last two decades in some regions, namely in parts of central Europe, in a region north of the Black Sea/Caspian Sea, in southern Africa, and in parts of Australia, Siberia and South America. [ABSTRACT FROM AUTHOR]

The lattice dynamics of tetragonal Sr2VO4 with a Ruddlesden—Popper-layered crystal structure was studied via Raman spectroscopy. We observed three of the four expected Raman-active modes under ambient conditions. Mode Grüneisen parameters and the implicit fractions of two A1g Raman-active modes were determined from high-pressure and high-temperature Raman spectroscopy experiments. The low-energy A1g Raman-active mode involving Sr motions along the c direction has a large isothermal Grüneisen parameter about seven times larger than that of the high-energy A1g Raman-active mode involving apical O motions along the c direction and is, therefore, more anharmonic. The thermodynamic Grüneisen parameter is significantly smaller in Sr2VO4 than in Sr2TiO4 due to the smaller Grüneisen parameter of the high-energy A1g Raman-active mode and other vibrational modes that still need to be identified. The explicit contribution of the low-energy A1g Raman-active mode is negative, and the implicit contribution due to volume change is much larger. Both volume implicit and anharmonic explicit contributions of the high-energy A1g Raman-active mode have similar positive values. The Raman experiment in the air shows that Sr2VO4 begins to decompose above 200 °C. [ABSTRACT FROM AUTHOR]

Upgrading waste re-utilization has been regarded as an important concept to promote the sustainable development of social economy. Herein, waste catkins were used as carbon source and template to prepare graphitic carbon/Co 3 O 4 composites through cobalt salt immersion, in-situ carbonization and calcination. The obtained Co 3 O 4 /C composites inherit the microtubular structure of catkins with ultra-thin tube wall and large tube cavity. Particularly, the sample (Co 3 O 4 /C-280) calcined at 280 °C in air shows a morphology of the hollow Co 3 O 4 spheres (av. 50 nm) evenly embedded on the biocarbon tube. As an anode for lithium-ion battery, such unique structure is more conductive to alleviate volume expansion. As expected, Co 3 O 4 /C-280 electrode has excellent rate capability at 5 A g−1 and stable long-cycle performance (647.3 mA h g−1, 1800 cycles, 1 A g−1). The presence of pseudo-capacitance behavior plays an important role in improving the capacity of material. The good electrochemical properties of Co 3 O 4 /C-280 can be ascribed to the synergistic effect of hollow tubular structure and graphitic carbon. Therefore, the strategy of making waste profitable is in line with the theme of green and sustainable development, and provides a reference for improving lithium storage performance of Co 3 O 4 -based anode materials. [ABSTRACT FROM AUTHOR]

Methane (CH4) is an important greenhouse as well as a chemically active gas. Accurate monitoring and understanding of its spatiotemporal distribution are crucial for effective mitigation strategies. Nowadays, satellite measurements are widely used for CH4 studies. Here, we use the CH4 products from four commonly used satellites (GOSAT, TROPOMI, ARIS, and IASI) during the period from 2018 to 2020 to investigate the spatiotemporal variations of CH4 in China. In spite of the same target (CH4) for the four satellites, differences among them exist in terms of the instrument, spectrum, and retrieval algorithm. The GOSAT and TROPOMI CH4 retrievals use shortwave infrared spectra, with a better sensitivity near the surface, while the IASI and AIRS CH4 retrievals use thermal infrared spectra, showing a good sensitivity in the mid–upper troposphere but a weak sensitivity in the lower troposphere. The GOSAT and TROPOMI observe high CH4 concentrations in the east and south and low concentrations in the west and north, which is highly related to the CH4 emissions. The IASI and AIRS show a more uniform CH4 distribution over China, which reflects the variation of CH4 at a high altitude. However, a large discrepancy is observed between the IASI and AIRS despite using a similar retrieval band, e.g., significant differences in the seasonal variations of CH4 are observed between the IASI and AIRS across several regions in China. This study highlights the CH4 differences observed by the four satellites in China, and caution must be taken when using these satellite products. [ABSTRACT FROM AUTHOR]

The Romanian Association for Aviation Propaganda (ARPA) was established on March 30, 1927, at the initiative of Colonel Aviator Gheorghe Rujinschi and Lieutenant Colonel (ret.) and Senator Ștefan Tătărescu, with the aim of stimulating the interest of compatriots in the field of aviation and even contributing financially to its development. It was conceived as an organization meant to complement the state's efforts towards the manufacturing or purchase of aircraft, as well as the training of aviation personnel. According to its statute, ARPA included prominent figures in the country, such as the ministers of War, Interior, Industry, Communications, Public Instruction, Public Works, Chambers of Commerce, Industry, Agriculture, Labour, as well as air navigation companies. Soon, they were joined by several tens of thousands of active members among Romanian citizens who paid an annual fee. ARPA made a significant contribution to the development and promotion of national aeronautics. It purchased numerous aircraft, funded four aviation schools where almost six hundred pilots were licensed, organized national and international air shows, encouraged scientific research in the field of aviation, and supported the development of aeronautical infrastructure. On October 11, 1947, ARPA was dissolved by the new regime established in Romania. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the patterns and trends of drought occurrence in the northern part of Poland on the example of the Łeba river basin in the years 1956–2015. The study of meteorological drought was conducted on the basis of the Standardized Precipitation Index (SPI) on the scale of 1, 3, 6, 9, and 12 months. Annual precipitation totals did not show significant changes in the analyzed period, except for the station in Wejherowo, which is characterized by a significant increasing trend. The analysis of the long term of the variability average annual air temperature showed its statistically significant increase in the analyzed area at the rate of about 0.2 °C per decade. During the analyzed period, 14 to 84 meteorological droughts were identified, with durations ranging from 200 to 300 months. As the period of accumulating values of SPI, the number of droughts decreased, while their total duration increased. Most droughts were mild in nature, while extreme droughts accounted for between 5.2% and 10.7% of the duration. Drought intensification was shown only for SPI-1 in February and March in Wierzchucino station. On the other hand, a decreasing trend in SPI values was noted during longer periods of accumulation (SPI-6, 9, and 12). [ABSTRACT FROM AUTHOR]

Background: To evaluate the effect of room air and sulfur hexafluoride (SF6) gas in idiopathic macular hole(MH)surgery. Methods: Retrospective, interventional, and comparative study. 238 eyes with the idiopathic macular hole that underwent pars plana vitrectomy, internal limiting membrane peeling, fluid-air exchange, and 20% SF6 (SF6 group:125 eyes) or room air tamponade (air group: 113 eyes) were reviewed. The primary outcome measure was the closure rate of primary surgery. Results: The baseline characteristics of the SF6 group and air group were comparable except for the hole size (479.90 ± 204.48 vs. 429.38 ± 174.63 μm, P = 0.043). The anatomical closure rate was 92.8% (116 / 125) with the SF6 group and 76.1% (86 / 113) with the air group (P < 0.001). A cut-off value of MH size to predict primary anatomical closure was 520 μm, which is based on the lower limit of 95% confidential interval of the MH size among the unclosed patients in the air group. There was no significant difference in anatomical closure rates between SF6 and air group (98.7% vs. 91.9%, P = 0.051) for MH ≤ 520 μm, whereas a significantly lower anatomical closure rate was shown in the air group than SF6 group (46.2% vs. 84.0%, P < 0.001) for MH > 520 μm. Conclusion: SF6 exhibited more effectiveness than air to achieve a good anatomical outcome for its longer tamponade when MH > 520 μm. [ABSTRACT FROM AUTHOR]

The minimum energy required after bridge-burst to function a commercially available RP-1 exploding bridgewire detonator with a gold bridgewire was investigated using two capacitor discharge units (CDUs) making use of state-of-the-art on/off high-voltage high-current switches. Both switches are capable of shutting off the current flow in ≈ 100 ns and the conduction time was varied systematically to limit the duration of electrical energy delivered from the CDU until a detonation go/no-go threshold was reached. It was found that the minimal extra electrical energy required for a soft-fire (a statistically marginal go) was approximately half that required for a hard-fire (a definite go). The measured energy required to function the RP-1 detonator from the 11.5 kV CDU was approximately 20 mJ greater than for the 600 V CDU, and it is postulated that this was due to arcing across the detonator terminals and an associated current shunt that was not efficient at depositing energy conducive to detonator functioning. Measurements of the bridgewire temperatures bursting in air showed that the maximum temperature reached was consistent (≈ 18 kK) when sufficient energy was delivered that the detonator functioned (either soft- or hard-fire), but that the temperature for a sub-threshold bridgewire burst was significantly cooler at approximately 8 kK. Furthermore, it was demonstrated that the intensity of the light emitted at burst scaled with deposited energy. A related finding is that the light emission from the bridgewire peaks some tens of nanoseconds after both peak voltage and peak electrical power. [ABSTRACT FROM AUTHOR]

The article focuses on airshows, airmail, and airfields for West Grows Wings. It mentions stagecoach, train, and automobile were the primary sources of transportation for Westerners and railroad workers laid thousands of miles of track, and construction workers built thousands of miles of roads. It also mentions boosters and businessmen attributed the popularity of airplanes to the lack of public exposure to them.

Combining Power‐to‐X (PtX) processes with high temperature heat pumps (HTHP) can significantly increase their energy efficiency. Evaluating the example of oxymethylene ethers (OME) production from H2 via H2O electrolysis and captured CO2 from air shows that by upgrading waste heat streams using HTHP, a process overall energy efficiency of higher than 61 % can be achieved compared to 30 % in conventional integrated processes. Thereby, the waste heat stream from H2O electrolysis already covers the low temperature heat demand for CO2 capture via direct air capture, not only for OME but also for various PtX products. Importantly, a significant lever for the energy efficiency enhancement is the consideration of other low temperature heat‐demanding sectors. High overall process energy efficiencies and the electrification of the industry are key aspects towards a sustainable mobility sector. [ABSTRACT FROM AUTHOR]

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Entrapped air pockets reduce flood conveying capacity of a surcharged drainage tunnel, and could be released explosively as geysers from vertical dropshafts. Nevertheless, the impact of dropshaft inflow on air pocket expulsion has hitherto not been fully understood. In this work, experiments was performed on a simplified drainage system consisting of a dropshaft with inflow. An air pocket was introduced into the tunnel; its dynamics in the dropshaft was measured with a high speed camera and pressure transducers. A heuristic analysis on the kinematics of the air pocket showed that when the dropshaft inflow is greater than a critical flow dependent on the dropshaft diameter, the increased compression leads to stronger air pocket expulsion, as spewing and/or ejection of air-water mixture. Observed occurrence of the phenomena generally agrees with the prediction. [ABSTRACT FROM AUTHOR]

Background: Primary lung neoplasms are, frequently represented by solid, solitary, or multiple formations. However, malignant cavitary lesions may be presented as lung adenocarcinomas. Those malignant lesions differ from benignant bullae by the thickness heterogeneity of its surrounding shape. Case Description: The present clinical case reports a 14-year-old female dog, of mixed breed, with an increase in the coughs frequency, fatigue, and exercise intolerance. A chest X-ray was taken, a large emphysematous cystic area was found, with thickened and irregular walls located in the left caudal pulmonary lobe, which measured 8 x 7.5 x 3 cm, and rejected the bronchial branch corresponding to the left caudal pulmonary lobe, in addition to thickening of the bronchial walls, compatible with bronchopathy. The tomographic examination of the cavity showed an air content structure, oval to round in shape, with irregular thick hyperattenuating walls measuring approximately 0.4 cm in thickness, occupying more than 30% of the left hemithorax, and pulmonary lobectomy was chosen. Histopathology confirmed the diagnosis of bronchoalveolar adenocarcinoma, with the presence of sparse areas of necrosis and dystrophic calcification. Conclusion: The present case successfully diagnosed a malignant bulae, after a surgical remove. The tomographic finds although not confirmatory, suggest a malignant component by the shape and thickness of its wall. The tomographic exam is of great importance, because only through it, it is possible to evaluate if there is lymph node or pleural involvement or the presence of small metastasis foci. There is indication for surgery and histopathological examination of the piece for a definitive diagnosis. [ABSTRACT FROM AUTHOR]

An array of air chambers embedded on the tunnel track is numerically investigated for different configurations. The air chambers act as an in-tunnel countermeasure to alleviate non-linear steepening of compression waves during propagation process thereby mitigating emission of high amplitude micro-pressure waves (MPWs) from the exit portal. The air chambers are designed to entrap the incoming flow and induce damping behavior so as to reduce wave steepening in tunnels. Initially, qualititative comparisons are made between Helmholtz resonator and damping type air chambers. Thereafter, the quantitative assessment of the compression wave properties are checked in detail. From results, over damped air chamber shows 60 % reduction in peak over pressure for weak compression wave whereas the Helmholtz resonator and critically damped shows 35 % and 22 %, respectively. Similarly, due to the presence of over damped air chamber, 17 % reduction in maximum pressure gradient is noticed while critically damped shows close to 10 % reduction. [ABSTRACT FROM AUTHOR]

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Indoor air cleaners can contribute to reducing infection risks by the filtration of virus-carrying droplets. There are various national standards to test indoor air cleaners that determine the clean air delivery rate (CADR), but typically only as a size-integrated value for particles > 0.3 μm. Thus, a test method using potassium chloride (KCl) and paraffin as surrogate particles in the size range of viruses and exhaled droplets was developed. We show that air cleaners with fibrous and electrostatic filters are generally capable of reducing the airborne particle concentrations. However, for electret filters, the performance can strongly degrade over time by being loaded with particles. By comparing filters with different efficiencies in the same air cleaner, we demonstrate that the use of high-efficiency filters can be even at the expense of the cleaning efficacy. We developed a mathematical model to estimate the inhaled dose of viruses and show that the combination of natural venting and an air cleaner can lead to a substantial reduction of the infection risk. [ABSTRACT FROM AUTHOR]

In this study, roasted spent Co-Mo/Al2O3 hydrodesulfurization (HDS) catalyst was dissolved in oxalic acid (H2C2O4) solution and optimum conditions were determined for obtaining cobalt oxalate dihydrate (CoC2O4∙2H2O). The thermal decomposition behavior of the obtained CoC2O4∙2H2O was investigated by TG/DTG-DTA analysis. The characterization of CoC2O4∙2H2O was carried out by XRD, FT-IR and SEM-EDS analytical techniques. Optimum conditions for the production of CoC2O4∙2H2O were determined as 25 oC temperature, 0.25 M H2C2O4 concentration, 1/20 g mL-1 solid/liquid ratio and 300 rpm stirring speed. CoC2O4∙2H2O was obtained with a reaction yield of 90.9 %. TG/DTG-DTA analysis carried out in dry air atmosphere showed that CoC2O4∙2H2O decomposed in two steps. In the first step that occurs between 118-196 oC temperatures, CoC2O4∙2H2O is dehydrated. In the second step, which occurs between 248-279 oC temperatures, it was determined that metallic cobalt was formed first, and then metallic cobalt was oxidized and converted into Co3O4 compound because it was performed in the air atmosphere [ABSTRACT FROM AUTHOR]