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Ersin Sar&inodot;çam,1,2 Ali Do&gbreve;an Dursun,3,4 Gülçin Türkmen Sar&inodot;y&inodot;ld&inodot;z,5,6 Nalan Can,7 Engin Bozkurt,1 U&gbreve;ur Gönüllü,8 Nihal Basay,9 Meral Türkmen,10 Abdülaziz Denli,11 Mustafa Ünlü12 1Department of Cardiology, Medicana International Ankara Hospital, Ankara, Turkey; 2Department of Cardiology, At&inodot;l&inodot;m University Medical School, Ankara, Turkey; 3Department of Physiology, At&inodot;l&inodot;m University Medical School, Ankara, Turkey; 4Check-up Center, Home Care Services, Medicana International Ankara Hospital, Ankara, Turkey; 5Department of General Surgery, Medicana International Ankara Hospital, Ankara, Turkey; 6Operating Room Services, Vocational School of Health Services, At&inodot;l&inodot;m University, Ankara, Turkey; 7Department of Nuclear Medicine, Medicana International Ankara Hospital, Ankara, Turkey; 8Department of Pulmonary Medicine, At&inodot;l&inodot;m University Medical School, Ankara, Turkey; 9Department of Pulmonary Medicine, Medicana International Ankara Hospital, Ankara, Turkey; 10Department of Internal Medicine, Medicana International Ankara Hospital, Ankara, Turkey; 11Department of Physical Medicine and Rehabilitation, Medicana International Ankara Hospital, Ankara, Turkey; 12Department of Nuclear Medicine, Gazi University Medical School, Ankara, TurkeyCorrespondence: Ersin Sar&inodot;çamDepartment of Cardiology, Medicana International Ankara Hospital, Sö&gbreve;ütözü Cd. 2165. Sokak No: 6, Sö&gbreve;ütözü, Ankara, 06520, TurkeyTel +90 5324066440Fax +90 3122203170Email saricamersin@yahoo.comBackground: In the post-acute COVID-19 syndrome, many patients suffer from palpitations, effort-associated fatigue, and even sudden death. The mechanism of heart involvement in this syndrome is uncertain. The main purpose of the study was to identify possible cardiac involvement causes in patients with post-acute COVID-19 by using biomarkers such as NT-proBNP and nitric oxide (NO) and cardiac imaging modalities.Methods: In this cross-sectional study, a total of 105 participants were included according to the existence of symptoms, and 40 of these participants were asymptomatic patients. The ages of the participants ranged from 20 to 50 years. All patients were healthy before COVID-19. The symptoms were defined as palpitations and/or fatigue association with exercise in post-acute COVID-19 term. The comparison of the two groups was made by using biochemical parameters (NT-proBNP, Troponin I, NO) and imaging techniques (echocardiography, cardiovascular magnetic resonance (CMR) and cardiac positron emission tomography (PET)).Results: The symptomatic patients had higher NT-proBNP levels compared with asymptomatic patients (132.30± 35.15; 76.86± 16.79, respectively; p < 0.001). Interestingly, the symptomatic patients had lower NO levels than asymptomatic patients (9.20± 3.08; 16.15± 6.02, respectively; p < 0.001). Echocardiography and CMR were normal. However, we found regional increased 18F-FDG uptake on cardiac PET to be compatible with myocardial fatigue.Conclusion: We found elevated NT-proNBP levels, low serum NO levels, and increased 18F-FDG uptake on cardiac PET in post-acute COVID syndrome. Cardiac PET could replace or be added to CMR for detecting subtle subacute/chronic myocarditis. The follow-up of patients with post-acute COVID-19 could target the possibility of risk of heart failure.Keywords: post-acute COVID-19, cardiac involvement, laboratory tests, imaging

In this study, the settling performance of lateritic nickel ores in the Counter Current Decantation (CCD) thickeners following the High-Pressure Acid Leaching (HPAL) process was investigated in detail. The samples used within the scope of the study were obtained from the overflow of the 2nd CCD thickener under the condition that Manisa-Gördes and Eskişehir-Karaçam lateritic nickel ores were fed to the plant at different times. A series of settling tests were performed for both ores using anionic, cationic, and nonionic flocculants of various ionicity and molecular weight. Sedimentation performance was evaluated based on parameters such as settling time, clarity, and compression. To determine the optimum conditions for the tests, a preliminary test was performed, and the pulp solids content was determined as 7% and the flocculant dosage as 850 g/t. According to the test results, nonionic and very low anionic flocculants gave better results. It was found that flocculation was negatively affected with increasing anionicity, and results could be obtained only with very low anionicity flocculants. It was determined that the settling rate was very fast with cationic flocculants, but the amount of compression was not favorable, especially for Gördes ore. However, it is envisaged that the amount of consumption can be reduced if cationic flocculants are used especially for Karaçam ore. When a comparison was made between the ores, similar results were obtained in general and only for Karaçam ore, thickener underflow density gave a successful result for all flocculant performances. On the other hand, it was concluded that variable ore structures and unstable process parameters influence the flocculant adsorption mechanisms and thus on the settling behavior. [ABSTRACT FROM AUTHOR]

The verification of the desired capacity increase in the grinding circuits is performed by simulation studies as they suggest accurate and fast alternatives compared to expensive and laborintensive methods, particularly for the evaluation of situations that require investment. In this study, simulation was used to evaluate the alternatives that can be made to increase the capacity from 38.86 tph to 90 tph in a grinding circuit where copper slag is autogenously milled. The slag sample was characterized by drop weight and abrasion tests to describe the breakage in autogenous (AG) milling. The performances of the existing circuit and equipment were determined by a comprehensive sampling study, and modeling studies were carried out to form the basis of the simulations. Simulation scenarios were evaluated as investment free and investment requiring alternatives. In the investment free option changing fresh feed size distribution was examined however, capacity could be increased up to only 42 tph. In investment option, increasing the mill motor capacities was simulated and 90 tph target throughput was provided. This result was validated in the plant by replacement of mill motors of AG and pebble mill for 1000 kW and 750 kW, respectively. [ABSTRACT FROM AUTHOR]