The present investigation presents the findings of an experiential examination of the effectiveness of a Mono-Pass Solar Air Heating System (MPSAH) using a paraffin-based phase changing material ...(P-PCM) as an energy storing medium for off-sunshine hours. A mono-pass solar air heating system was fabricated with the absorbers having parallelly placed plate fins for attaining the effective heat transfer during solar time. The trials had been carried out in two configurations on the days with similar irradiative pattern in March 2020 at 12.8750° N, 80.2257° E. In the first configuration, the unaltered solar air heating system was used and named as MPSAH. In the second configuration, the MPSAH was packed with the technical grade paraffin beneath the absorber and named as MPSAH-PPCM. The experiments had been accompanied at a fixed air flow rate of 0.167 kg/s. The results demonstrated that the incorporation of P-PCM into the plate finned SAH significantly improved its energy efficacy. The P-PCM increased the MPSAH's energy efficacy by 12.15 percent.
This study unveils a transformative approach to enhance solar air heater (SAH) performance, integrating rigorous numerical simulations, advanced Artificial Neural Networks (ANNs), and thorough ...experimental validation. Beginning with RNG k-ε turbulence model validation, the introduction of aerofoil-Coanda ribs strategically disrupts the thermal boundary layer, resulting in a remarkable 245.64% increase in Nusselt number. By optimizing critical geometrical parameters (p = 28 mm, e = 1.25 mm, g = 12 mm, w = 16 mm), a peak Thermal Hydraulic Performance Parameter (THPP) of 2.87 is achieved at Re 14,000. ANNs optimize a configuration (p = 29.68 mm, e = 1.22 mm, g = 13.68 mm, w = 16 mm), surpassing ANSYS data by 8.648% in THPP at Re 14,000. The theoretical THPPs (obtained after CFD and ANN based optimisation) of 3.12 was slightly exceeded by the experimental results of 3.07, attributed to enhanced friction. This research pioneers a comprehensive framework for achieving peak SAH performance, blending aerodynamics, computational intelligence, and practical experimentation for efficient and sustainable solar energy utilization.
The prevalence of spontaneous subarachnoid hemorrhage (SAH) in Indonesia is 4.2%, with a high mortality rate (up to 80%). Studies show that risk factors that can cause an increase in mortality rate ...are blood pressure, Glasgow Coma Scale (GCS), clinical presentation, characteristics of the brain CT-scan, pneumonia, electrolyte imbalance, and hyperglycemia. The author aims to find out the mortality rate of spontaneous SAH among patients of Pasar Minggu Hospital and associated risk factors.
This is a cross-sectional, descriptive analytic study of the medical records belonging to spontaneous SAH patients admitted to Pasar Minggu Hospital from January 2016 – November 2018. Data is analyzed with the Chi-square test (CI=95%, α=0.05).
Twenty-four subjects were obtained. Mortality rate is 20.8%. Most subjects are female (70.8%) aged <60 years old (75%), with a median age of 49 (34–78) years old, suffering from hypertension (62.5%), with eunatremia (91.7%) and normoglycemia (91.7%). GCS at onset is 9-14 in 50% of subjects. Hunt and Hess score is mostly 3 (54.2%). Modified Fisher score is mostly 3 and 4 (29.2% each). Pneumonia is found in 54.2% of subjects. There is significant correlation between GCS score and SAH mortality (p = 0.014). There is no significant correlation between age, blood pressure, Hunt and Hess score, modified Fisher score, hypernatremia, hyperglycemia, or pneumonia with mortality.
Mortality rate of spontaneous SAH in Pasar Minggu Regional General Hospital is still high. The significantly correlated risk factor is GCS score at onset.
•Energy performance of new designed infinity-shaped SAH are experimentally investigated.•Maximum exit air temperature rise is 48.4 °C for ∞TSAH and 36.2 °C oC for OTSAH.•∞TSAH performance is greater ...than that of OTSAH and the latter is greater than that of FPSAH.•Maximum average daily energy of ∞TSAH and OTSAH are 84.5% and 77.3%, respectively.•Maximum daily energy gain for ∞TSAH is greater than that of OTSAH by 42.6%. at SPF and 0.017 kg/s.
A new design of tubular solar air heater (SAH) is examined experimentally in this work. The SAH absorber consists of one row of adjacent equal tubes forming flat pack. Each tube contains two adjacent inner tubes, the diameter of each of which equals the radius of the outer tube. The two inner tubes form the shape of infinity (∞), therefore, the new design is expressed as infinity shaped tubular SAH (∞TSAH). The performance of the ∞TSAH is examined against ordinary tubular SAH (OTSAH)) having tubular absorber consists of one row of only adjacent equal tubes. The comparison is performed at different mass flow rates of the air (MFRs) and under single pass flow (SPF) and double pass flow (DPF) of the air. The findings show clearly that the output air temperature, energy efficiency and thermohydraulic efficiency, of ∞TSAH are better than that of OTSAH. The maximum output air temperature rise is about 47.1 °C and 37.1 °C for ∞TSAH and OTSAH, respectively at MFR of 0.017 kg/s and DPF condition. In addition, the ∞TSAH achieves maximum energy efficiency of 84.5% at MFR of 0.079 kg/s and DPF condition with percentage increment of 8.4% relative to OTSAH which achieves energy efficiency of 77.3% at the same condition. Moreover, the ∞TSAH achieves maximum thermohydraulic efficiency of 79% at MFR of 0.052 kg/s and DPF condition, while OTSAH achieves a value of 72.6% at MFR of 0.079 kg/s and DPF condition.
Objective: It is well known that spontaneous non-aneurysmal subarachnoid hemorrhage (SAH), also known as sine materia SAH (smSAH), has usually a better course and prognosis than its aneurysmal ...counterpart (aSAH). This might depend on different inflammatory mechanisms initiated by bleeding events of different origins. The aim of the present study was to explore the systemic inflammatory response in spontaneous SAH, comparing aSAH and smSAH. Methods: We performed a prospective observational study over a consecutive series of patients with SAH. For these patients, we collected all clinical data and, furthermore, performed venous blood sampling over six time points to analyze blood cells. We further performed the analysis of lymphocytes and monocytes by means of flow cytometry to quantify common subtypes. Statistical analysis included a t-student test, Chi-square test, multivariate logistic regression, and ROC analysis. Results: 48 patients were included: six (12.5%) with a diagnosis of spontaneous smSAH, and forty-two patients (87.5%) with aSAH. Significant differences on Day 0 were found for neutrophils and a systemic neuro-inflammatory index, namely, systemic inflammatory response index (SIRI). At the ROC analysis, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and SIRI exhibited satisfactory predictive power on day 0. At the multivariable logistic regression analysis, the combined index (NLR, LMR, SIRI at day 0) yielded an OR of 0.59 (95% CI 0.29– 1.21). LMR at day 0 yielded an OR of 1.25 (95% CI 0.94– 1.68), NLR at day 0 exhibited an OR of 0.68 (95% CI 0.42– 1.09), and SIRI at day 0 displayed an OR of 0.31 (95% CI 0.06– 1.49). Conclusion: This preliminary study indicated a possible role of some inflammatory indices that point out the importance of innate and adaptive immunity in the etiopathogenetic mechanisms. Drugs modulating these responses could eventually counteract or, at least, reduce secondary damage associated with SAH.
This paper experimentally examines the performance of solar air heater (SAH) having a newly designed tubular absorber comprising adjacent parallel tubes called tubular SAH (T_SAH) via energy, exergy, ...and enviroeconomic standpoints. A comparative performance assessment between T_SAH and flat plate solar air heater (F_SAH) at diverse air mass flow rates (MFRs) of 0.075, 0.05, and 0.025 kg/s is performed. Experiments for both heaters are tested using two flow pass arrangements of single-pass (SP) and double-pass (DP). The results reveal that maximum enhancement in thermal and exergy efficiencies of 133 % and 330 %, respectively is obtained when using SP T_SAH against SP F_SAH at air MFR of 0.025 kg/s. It is found that when there is an increase in air MFR, there is a significant increment in thermal efficiency, whereas there is a reduction in exergy efficiency. Despite the performance in the case of T_SAH is more effective than F_SAH, the enhancement in the case of DP F_SAH due to using DP flow configuration is greater than that of DP T_SAH. Finally, the results indicate that the carbon credit earned regarding the amount CO2 mitigated for SP F_SAH and SP T_SAH at MFR of 0.075 kg/s is estimated at 391.6 $/year and 561.9 $/year, respectively.
OBJECTIVEModern surgical planning and prognostication requires the most accurate outcomes data to practice evidence-based medicine. For clinicians treating children following traumatic brain injury ...(TBI) these data are severely lacking. The first aim of this study was to assess published CT classification systems in the authors' pediatric cohort. A pediatric-specific machine-learning algorithm called an artificial neural network (ANN) was then created that robustly outperformed traditional CT classification systems in predicting TBI outcomes in children.METHODSThe clinical records of children under the age of 18 who suffered a TBI and underwent head CT within 24 hours after TBI (n = 565) were retrospectively reviewed.RESULTS"Favorable" outcome (alive with Glasgow Outcome Scale GOS score ≥ 4 at 6 months postinjury, n = 533) and "unfavorable" outcome (death at 6 months or GOS score ≤ 3 at 6 months postinjury, n = 32) were used as the primary outcomes. The area under the receiver operating characteristic (ROC) curve (AUC) was used to delineate the strength of each CT grading system in predicting survival (Helsinki, 0.814; Rotterdam, 0.838; and Marshall, 0.781). The AUC for CT score in predicting GOS score ≤ 3, a measure of overall functionality, was similarly predictive (Helsinki, 0.717; Rotterdam, 0.748; and Marshall, 0.663). An ANN was then constructed that was able to predict 6-month outcomes with profound accuracy (AUC = 0.9462 ± 0.0422).CONCLUSIONSThis study showed that machine-learning can be leveraged to more accurately predict TBI outcomes in children.
Objective: Our aim was to assess the short- and long-term prognosis in patients suffering from non-aneurysmal non-perimesencephalic SAH (Na-NPM-SAH).
Methods: Based on admission CT-scan, SAH was ...categorized as perimesencephalic (PM) or non-perimesencephalic (NPM). Based on digital subtraction angiography (DSA) results, patients were classified as normal DSA (Na-SAH) or aneurysmal SAH (aSAH). Between 1997 and 2010, 67 of 571 patients with non-traumatic SAH (11.7%) suffered from non-aneurysmal non-perimesencephalic SAH. Retrospective analyses of the 67 patients were undertaken, and compared with the aneurysmal SAH group. Long-term follow-up was assessed.
Results: The cohort consisted of 67 Na-NPM-SAH patients, mean age 54.8 years (range: 21-84), 56.7% male. Acute phase: 10.4% mortality and 3% rebleeding (two patients) during the acute phase. Long-term: extensive follow-up was possible in all except one of the survivors at discharge. Mortality was 6.6% during the 510 patient-years follow-up period (median follow-up time per patient, 8.95 years); rebleeding rate was 0-1.6%. An aneurysmal source was found in 13% of patients who underwent a second angiography. Aneurysmal SAH: 312 patients, with confirmed aneurysm by angiography. The mortality rate for Na-NPM-SAH during the acute phase was 10.4%, vs. 20% for aneurysmal SAH in the general database, p = 0.049.
Discussion: Na-NPM-SAH patients without an identifiable bleeding source on initial angiography might have a more benign short- and long-term prognosis than aneurysmal SAH patients. Our study confirms an important diagnostic advantage of a second arteriography. Still, despite the major concern of an undetected aneurysm, the long-term rebleeding rate was low in this subgroup of patients.
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