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Pyrolysis is a thermochemical process commonly used for bio-oil, bio-char, and syngas production. It is particularly attractive due to its cost-effectiveness and low environmental impact. Therefore, this study utilizes coffee waste to produce activated carbon in a slow pyrolysis reactor at different reaction temperatures and residence times. The results obtained in this study show that bio-oil yields tend to increase when moderate reaction temperatures and short residence times are used. In contrast, the bio-char yields are higher at low reaction temperatures and long residence times. The Scanning Electron Microscopic (SEM) images of the coffee waste, bio-char, and activated carbon indicate that the pore size of the bio-char tends to decrease due to heating and tends to increase in the area after using ZnCl2 as activating agent. Coffee waste is a suitable feedstock for activating carbon production.

Introduction: Adult patients who have suffered acute cardiac or pulmonary failure are increasingly being treated using extracorporeal membrane oxygenation (ECMO), a cardiopulmonary bypass technique. While ECMO has improved the long-term outcomes of these patients, neurological injuries can occur from underlying illness or ECMO itself. Cerebral autoregulation (CA) allows the brain to maintain steady perfusion during changes in systemic blood pressure. Dysfunctional CA is a marker of acute brain injury and can worsen neurologic damage. Monitoring CA using invasive modalities can be risky in ECMO patients due to the necessity of anticoagulation therapy. Diffuse correlation spectroscopy (DCS) measures cerebral blood flow continuously, noninvasively, at the bedside, and can monitor CA. In this study, we compare DCS-based markers of CA in veno-arterial ECMO patients with and without acute brain injury. Methods: Adults undergoing ECMO were prospectively enrolled at a single tertiary hospital and underwent DCS and arterial blood pressure monitoring during ECMO. Neurologic injuries were identified using brain computerized tomography (CT) scans obtained in all patients. CA was calculated over a twenty-minute window via wavelet coherence analysis (WCA) over 0.05 Hz to 0.1 Hz and a Pearson correlation (DCSx) between cerebral blood flow measured by DCS and mean arterial pressure. Results: Eleven ECMO patients who received CT neuroimaging were recruited. 5 (45%) patients were found to have neurologic injury. CA indices WCOH, the area under the curve of the WCA, were significantly higher for patients with neurological injuries compared to those without neurological injuries (right hemisphere p = 0.041, left hemisphere p = 0.041). %DCSx, percentage of time DCSx was above a threshold 0.4, were not significantly higher (right hemisphere p = 0.268, left hemisphere p = 0.073). Conclusion: DCS can be used to detect differences in CA for ECMO patients with neurological injuries compared to uninjured patients using WCA. [ABSTRACT FROM AUTHOR]