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CO2 emission reduction of sectors such as aviation, maritime shipping, road haulage, and chemical production is challenging but necessary. Although these sectors will most likely continue to rely on carbonaceous energy carriers, they are expected to gradually shift away from fossil fuels. In order to do so, the prominent option is to utilize alternative carbon sources--like biomass and CO2 originating from carbon capture--for the production of non-fossil carbonaceous vectors (biofuels and e-fuels). However, the limited availability of biomass and the varying nature of other carbon sources necessitate a comprehensive evaluation of trade-offs between potential carbon uses and existing sources. Then, it is primordial to understand the origin of carbon used in sustainable aviation fuel (SAF) to understand the implications of defossilizing aviation for the energy system. Moreover, the production of SAF implies deep changes to the energy system that are quantified in this work. This study utilizes the linear programming cost optimization tool EnergyScope TD to analyze the holistic French energy system, encompassing transport, industry, electricity, and heat sectors while ensuring net greenhouse gas neutrality. A novel method to model and quantify carbon flows within the system is introduced, enabling a comprehensive assessment of greenhouse gas neutrality. This study highlights the significance of fulfilling clean energy requirements and implementing carbon dioxide removal measures as crucial steps toward achieving climate neutrality. Indeed, to reach climate neutrality, a production of 1,046 TWh of electricity by non-fossil sources is needed. Furthermore, the findings underscore the critical role of efficient carbon and energy valorization from biomass, providing evidence that producing fuels by combining biomass and hydrogen is optimal. The study also offers valuable insights into the future cost and impact of SAF production for air travel originating from France. That is, the European law ReFuelEU would increase the price of plane tickets by +33% and would require 126 TWh of hydrogen and 50 TWh of biomass to produce the necessary 91 TWh of jet fuel. Finally, the implications of the assumption behind the production of SAF are discussed. [ABSTRACT FROM AUTHOR]

Aviation activities have jeopardized the limited energy sources and thereby environmental sustainability due to fossil fuel consumption. Therefore, aircraft engines being the significant emission source have attracted the attention of engineers toward improvement of the design process. In this study, turbojet engine (TE) and its components were examined with exergy, environmental, and sustainability metrics. Then, the effects of several design variables such as turbine inlet temperature (TIT) ranging between 850 K and 1100 K and compressor pressure ratio (CPR) ranging between 3 and 4 on exergetic and environmental parameters were investigated. As a novelty, a new index named specific irreversibility production (SIP) was improved. According to exergy assessment, the wasted exergy ratio (WExR) of the combustor was found as highest changing between 42.46% and 51.89%. Moreover, exergy efficiency of the turbojet engine was determined between 16.42% and 21.92%. According to environmental assessments, the ecological effect factor (EcoEF) of the TE was computed between 4.77 and 6.08 under ranges of different design variables. Finally, the SIP of turbojet was gauged between 0.488 MW/kN and 0.586 MW/kN. Considering these results, the TIT and CPR have high effect on the optimum engine performance and environmental parameters. [ABSTRACT FROM AUTHOR]

Aim: To investigate magnetic resonance image quality and the number of motion artifact-related repeated sequences based on anesthesia or sedation management during preoperative MR imaging for DBS surgery. Material and Methods: The medical records of patients who underwent DBS procedures at the hospital of Ondokuz Mayis University, between April 2011 and October 2021 were retrospectively analyzed. Age, gender, and diagnosis information were recorded for each case. Patients were grouped into general anesthesia, sedation, no sedation groups. The evaluation of magnetic resonance images was performed by a specialized in neuroradiology. The radiologist classified the image quality as good, moderate, or poor based on artifacts resulting from unwanted motion. Results: A total of 127 patients, out of 190 patients, were included in the study. There were no significant differences in image quality based on anesthesia/sedation method and airway management (p>0.05). No significant differences were observed in the number of repeated sequences when compared based on anesthesia/sedation method and airway management (p>0.05). Conclusion: General anesthesia, sedation, or no sedation during preoperative magnetic resonance imaging in patients with movement disorders did not result in significant differences in image quality and the number of sequences requiring repetition. [ABSTRACT FROM AUTHOR]

Background: Thrombocytopenia (platelet count below 150 x 103/μL) is a common finding after open-heart surgery and can lead to various complications, including patient death. This study aimed to determine the extent of non–heparin-induced thrombocytopenia in open-heart surgery and to highlight the associated factors. Materials and Methods: In this cohort study, 842 patients who underwent valve and/or coronary bypass surgery over a 5-year period were retrospectively analyzed. After open-heart surgery, patients whose platelet count was less than 150 x 103/μL on a complete blood count 12 and 24 h after surgery were classified as thrombocytopenic. Three hundred twenty patients without thrombocytopenia and 21 patients with a high probability of heparin-induced thrombocytopenia were excluded from the study. Logistic regression analysis was used to assess the association of independent variables in moderate-severe thrombocytopenia: Age groups, sex, underlying disease, symptoms, type of surgery, pump time, pulsatile or non-pulsatile duration, degree of hypothermia, hemodilution, oxygenator type, use of an intra-aortic balloon, and erythrocyte transfusion counts were included in the analysis. Results: A total of 501 patients were diagnosed as having non–heparin-induced thrombocytopenia, and 64.3% were male. Three hundred seventy-seven (75.2%) patients had mild thrombocytopenia and 124 (24.7%) had moderate-severe thrombocytopenia. The postoperative platelet count was significantly lower than the preoperative platelet count (213 x 103 vs.117 x 103/μL; p < 0.001). Moderate-severe thrombocytopenia was associated with age ≥80 years odds (OR = 9.026, 95% CI: [1.757–46.363]; p = 0.008), isolated valve surgery (OR = 3.090, 95% CI: [1.867–5.114]; p < 0.001), and valve surgery with coronary bypass (OR = 4.938, 95% CI: [1.638–14.889]; p = 0.005) compared to isolated coronary bypass, type of oxygenator (Nipro vital compared with Affinity OR = 11.097, 95% CI: [1.923–64.023]; p = 0.007), erythrocyte transfusion count (OR = 1.219, 95%CI: [1.046–1.420]; p = 0.011). Conclusion: Age 80 years or older, surgical procedures including heart-valve surgery, and the number of red blood cell transfusions are associated with the risk of moderate-to-severe thrombocytopenia. This study provides a guide in terms of risk factors that may lead to moderate-to-severe thrombocytopenia after open-heart surgery. However, future multicentre prospective randomized studies may provide more detailed information on this subject. [ABSTRACT FROM AUTHOR]

The limited energy source indicates the necessity of efficient energy consumption in every field of life. Especially, the prompt growth in aviation sector makes this issue more important. In this study, effects of power settings on several thermodynamic indicators regarding low by-pass turbofan engine (LBP-TFE) are investigated. For this aim, the energy and exergy analyses are implemented to the system of turbofan engine for eighteen operating points. According to performance analysis, thrust value of the LBP-TFE changes from 10.77 kN to 71.8 kN throughout RPM values. According to exergetic findings, relative exergy losses from Fan outlet decreases from 52.34 % to 30.58 % whereas exergy efficiency of the LBP-TFE increases from 10.9 % to 30.1 %. Considering improved exergy efficiency, it changes 25.03 % and 41.03 % at the same RPM intervals. As for environmental assessments, environmental effect factor (EEF) of LBP-TFE diminishes from 5.8 to 1.32 while ecological effect factor decreases from 9.16 to 3.31. Finally, specific irreversibility production of LBP-TFE decreases from 0.4811 MW/kN and 0.2716 MW/kN. Considering these outcomes, behaviour of the investigated metrics regarding main components is different from each other. Therefore, the results of these parameters calculated for the whole engine could help understanding optimum running point in terms of exergetic and environmental sustainability. [ABSTRACT FROM AUTHOR]

Being one of the most common gas turbine systems, turbojet engines have been highly preferred in aviation sector owing to their higher thrust to weight ratio and reliability compared with reciprocating engines. To improve turbojet efficiency, a number of analyses have been applied on these systems in both theoretical and practical ways so far. In this study, it is analyzed that how bleed air ratio (BAR) ranging 1% and 8% taken from air compressor affects performance of small turbojet engine (STE) at cruise altitude of 10 km since the BAR is tried to decrease on new technology gas turbine engines. Moreover, influence of Mach number ranging from 0.5 to 0.75 on the STE performance is addressed. According to performance outcomes, as BAR increases up to the highest, net thrust of the turbojet engine decreases from 1.471 kN to 1.303 kN whereas SFC ascends from 35.99 g/kNs to 37.74 g/kNs, which corresponds to 11.42% decrement of thrust and 4.86% increment of SFC. However, the higher Mach leads net thrust and SFC to increase by 13.1% and 2.55%, respectively. Finally, the higher BAR causes environmental effect factor (EEF) of the engine higher from 6.397 to 6.650. However, increasing Mach affects its EEF in a way of enhancement of sustainability, namely the EEF decreases from 7.637 to 5.26. It could be inferred that the higher bleed air ratio compromises the engine performance whereas the higher Mach favorably affects efficiency of energy and exergy, which makes specific fuel consumption higher. [ABSTRACT FROM AUTHOR]

In this study, parametric cycle analysis of a conceptual turbojet engine with an afterburner (TJEAB) was conducted at sea level conditions-zero Mach. Based on this analysis, exergetic sustainability parameters of TJEAB were scrutinized for military mode (MM) and afterburner mode (ABM). Constitutively, several design parameters of TJEAB were chosen so as to optimize performance and exergetic parameters which consist of specific fuel consumption (SFC), overall efficiency, exergy efficiency, environmental effect factor (EEF) and exergetic sustainability index (ESI). In this context, compressor pressure ratio (CPR), turbine inlet temperature (TIT) were preferred due to high effect of these variables on engine performance. CPR ranges from 4 to 11 whereas TIT varies from 1150 K to 1550 K. According to optimization of performance parameters, minimum SFC was achieved as 28.59 g/kN.s at MM and 43.95 g/kN.s at ABM. On the other hand, maximum overall efficiency is determined as to be 13.07 % at MM and to be 8.5 % at ABM. As for exergetic parameters, exergy efficiency was calculated as maximum with 30.85 % at MM and 23.2 % at ABM. Finally, maximum exergetic sustainability index of TJEAB was computed as 0.446 at MM and 0.269 at ABM. It is thought that energetic and exergetic parameters analyzed in this analysis could guide in designing turbojet engines in terms of lower fuel consumption thereby environmental-benign. [ABSTRACT FROM AUTHOR]

Achieving more eco‐friendly aircraft propulsion systems is of paramount importance in the aerospace industry since their exhaust emissions possess an important influence on the depletion of ozone layer. In this work, 24 turbofan engines having the close thrust ranging from 117 to 133 kN are examined using energetic, exergetic, and exergo‐environmental tools throughout the LTO cycle involving take‐off, climb‐out, approach, and taxi‐out phases. According to emission findings, the highest CO emission indexes (CO EIs) of the engines vary from 13.77 to 40.1 g/kg fuel in the idle phase; whereas the highest NOx EIs change from 18.4 to 64.36 g/kg fuel at take‐off phase. Moreover, the highest exergy efficiency (ExEFF) of the turbofan engines vary between 15.88% and 24.31% at the climb‐out phase whilst the lowest ExEFF change between 4.59% and 7.46% at the idle phase. Moreover, the idle phase is observed to have the highest wasted exergy ratio (WExR) varying from 18.5% to 19%; whereas the climb‐out phase enjoys the lowest WExR changing from 15.11% to 16.8%. As a new index, specific irreversibility production (SIP) of the engines is observed to range from 0.297 to 0.497 MW/kN at the taxi‐out phase; while SIP becomes the minimum at the climb‐out phase, changing from 0.138 to 0.269 MW/kN. It could be deduced that since by‐pass ratio and compressor pressure ratio of the engines have significant influences on exergetic and emission values, increasing the thrust of the engine does not mean raising its emission value or wasted exergy ratio. It is thought that this study helps find optimum design variables leading to the lowest environmental effect. [ABSTRACT FROM AUTHOR]

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Background: Patients are hospitalized for extended periods, particularly in intensive care units (ICUs). As a result, the saturation probe (pulse oximeter) remains attached for an extended period and microorganisms can grow in the wet environment. If the pulse oximeters are not reprocessed, cross-infection may occur. The literature contaiudies in which gloves were used for the measurement while various SpO (peripheral arterial oxygen saturation) measurements were compared with each other. However, such comparisons have yet to be made with the results of arterial blood gas SpO measurements by pulse oximeter, considered as the gold standard. The present study aimed to compare arterial blood gas values with the fingertip saturation measurement performed by having adult patients wear gloves of different colors, one after the other, on their fingers and determining the effect of the differently colored gloves (transparent, white, black, light blue) on saturation values.Methods: The study was conducted on 54 patients in an ICU. Intra-arerial blood gas SpO results were measured. Oxygen saturatieasured while the patient 1. did not wear gloves and 2. sequentially wore a series of gloves of different colors. Paired t-test, correlation analysis, and Bland Altman charts were used to evaluate the results.Results: The mean SpO% value of the participants’ intra-arterial blood gas measurements was 97.76±2.04. The mean SpO% value obtained from the measurements of the fingers with a transparent glove was 0.43 points lower than the mean SpO% value of the intra-arterial blood gas measurements (t=0.986, p=0.61). The mean SpO% value obtained from the measurements of the fingers with a white glove was 0.9oints lower than the mean SpO% value of the intra-arterial blood gas measurements (t=1.157, p=0.093).Conclusion: Of the measurements performed with a glove, the mean SpO% value obtained from the measurements of the fingers with a transparent glove was more consistent with the mean SpO% the intra-arterial blood gas measurements than measurement of the fingers without a glove.