Rate Of Return Research Articles

Incentive Determination for Demand Response Considering Internal Rate of Return

The rapid expansion of renewable energy sources has led to increased instability in the power grid of Jeju Island, leading to the implementation of the plus demand response (DR) system, which aims to boost electricity consumption during curtailment periods. However, the frequency of curtailment owing to the increased utilization of renewable energy is outpacing the implementation of plus DR, highlighting the need for additional resources, such as energy storage systems (ESS). High initial investment costs have been the primary hindrance to the adoption of ESS by DR-participating companies but have not been fully considered in earlier studies on DR incentive determination. Therefore, this study proposes an algorithm for calculating appropriate incentives for plus DR participation considering the investment costs required for ESS. Based on actual load data, incentives are determined using an iterative mixed-integer programming (MIP) optimization method that progressively adjusts the incentive level to address the overall nonlinearity arising from both the multiplication of variables and the nonlinear characteristics of the internal rate of return (IRR), ensuring that the target IRR is achieved. A case study on the impact of factors such as IRR, ESS costs, and fluctuations in electricity rates on incentive calculations demonstrated that plus DR incentives required to achieve IRR targets of 5%, 10%, and 15% have increased linearly from 142.2 KRW/kWh to 363.0 KRW/kWh, confirming that the appropriate incentive level can be effectively determined based on ESS investment costs and target IRR. This result could help promote ESS adoption among DR companies and plus DR participation, thereby enhancing power grid stability.

OGC SO23 - Audit on Enhanced Recovery After Surgery (ERAS) in Oesophago-gastric Resections for Cancers

Abstract Background Enhanced Recovery After Surgery (ERAS) protocols, have been designed to guide clinicians in managing patients post-operatively, reducing hospital stay, complications and readmissions. Our trust’s ERAS protocol includes guidance on oral intake initiation, drain, catheter and epidural removal, investigation frequency, medications required on discharge and early mobilization. However, implementation of ERAS protocols in complex oncological surgery can be challenging, due to the multiple factors included and increasing complexity. We aimed to assess the compliance of ERAS implementation in a high volume resectional oesophago-gastric unit, and subsequent impact on morbidity. Method A retrospective review of all patients who underwent oesophago-gastric resections during March-April 2024 was performed. Patients were included if they completed an oesophagectomy, or subtotal/total gastrectomy resection for cancer. Electronic records and medical notes were reviewed and compared to all aspects of the trust’s ERAS protocol. The adherence percentage to the protocol was calculated. Results 20 patients underwent surgery. 85% started their oral diet on time per ERAS protocol. Adherence to ERAS was lowest for epidural (52.6%, 95% within 24-hours of target), catheter (55%, 90% within 24-hours of target), apical (55.6%, 100% within 24-hours of target), basal (53.8%, 85.7% within 24-hours of target), and abdominal drain removals (81.8%, 90.9% within 24-hours of target). All patients mobilized within four days post-op, with 65% achieving daily mobilization. VTE prophylaxis was prescribed for all, and discharge medication adherence ranged from 86.7% to 100%. The mean hospital stay was 9 days post-oesophagectomy, with a 3.2% emergency department return rate. Conclusion Implementation of an ERAS protocol is feasible in complex oesophago-gastric cancer surgery. Effective involvement and training of allied health, specialist pain services and the whole surgical team can decrease morbidity and length of stay in oesophagectomy, while avoiding excess emergency department presentations. Ongoing training and feedback of allied health, pain services, and surgical team at all levels is important to ensure adequate compliance.

Abstract Su704: Body Mass Index and Outcomes of In-Hospital Cardiac Arrest

Background: Although previous studies have reported an association between a patient’s body mass index (BMI) and outcomes for various cardiovascular conditions, the relationship between BMI and survival for in-hospital cardiac arrest (IHCA), a condition for which emergent response is required, has not been fully described. Aims: Examine the association between BMI and survival outcomes for IHCA. Methods: Within the Get With The Guidelines®-Resuscitation, we identified 56,411 patients with IHCA and available BMI data during 2005-2012 when weight and height data were collected in the registry. BMI was classified as underweight [<18.5 kg/m 2 ], normal [18.5 to 24.9 kg/m 2 ], overweight [25.0 to 29.9 kg/m 2 ], obese [30.0 to 34.9 kg/m 2 ], and very obese [≥35.0 kg/m 2 ]). Using multivariable hierarchical models with hospital as a random effect, we examined the association between BMI and survival to discharge, stratified by cardiac arrest rhythm type (shockable and non-shockable). As secondary outcomes, we examined rates of sustained return of spontaneous circulation for > 20 minutes (ROSC) and favorable neurological survival (i.e., survival to discharge without severe neurological disability). Results: Among 10,219 patients with a shockable arrest rhythm, 3,964 (38.7%) survived to discharge. After multivariable adjustment, compared with overweight patients, those who were underweight, of normal weight, and very obese had lower survival rates, whereas obese patients had similar survival rates ( Table ). Underweight patients also had a lower rate of ROSC and favorable neurologic survival ( Table ). Among 46,192 patients with a non-shockable arrest rhythm, 7,331 (15.8%) survived to discharge. After multivariable adjustment, all BMI groups had similar rates of survival, ROSC, and favorable neurologic survival, except for underweight patients ( Table ). Conclusions: Although the association between BMI and survival outcomes for IHCA varied by initial rhythm, underweight patients consistently had lower survival rates of survival. Very obese patients generally had similar outcomes to other weight groups, underscoring that morbid obesity was not a negative predictor of survival outcomes for IHCA.

The economic, social, and environmental impact of ecologically centered integrated pest management practices in East Africa

Agricultural pest management faces mounting challenges with increasing pressure to reduce chemical pesticide use while ensuring food security, and environmental sustainability. Ecologically centered approaches, such as integrated pest management (IPM), offer promising sustainable agroecological crop protection alternative solutions to pesticides. This study assesses the investment viability and environmental sustainability of two IPM interventions—mango fruit fly IPM (FF-IPM) and push-pull technology (PPT) in Kenya and Uganda, using project investment and adoption data from 2007 to 2021. The study also evaluates these technologies contribution to food security and poverty reduction. FF-IPM integrates biological control, cultural practices, and targeted bait traps to manage fruit flies in mango production, while PPT employs Desmodium and Brachiaria grass to control stemborers and striga weed. The findings highlight that these IPM interventions achieved a combined net present value of $500 million, with a benefit-cost ratio of about 8:1, and an internal rate of return of 21%, comparable to returns from improved crop varieties. These technologies also improved food security for 641,000 people, lifted 445,349 people above the poverty line, representing 2% of the poor population in both countries, and generated an average income increase of $5 per capita in Kenya and Uganda annually. Environmentally, they sequestered 2.7 million tons of CO2 equivalent, valued at $12.2 million, and are reducing pesticide use by 86,000 to 204,000 L per year. These results demonstrate the potential of IPM approaches to simultaneously enhance livelihoods, local economies, and generate global environmental public goods, suggesting that addressing adoption barriers could further amplify these positive outcomes.

Techno-Economic Analysis of BAU-STR Dryer for Rice Drying: An Approach to Accelerate Adoption

Postharvest food loss and waste offset worldwide agricultural productivity and food security. Insufficient drying and storage are the prominent drivers of food loss and waste in underdeveloped countries. Mechanical grain drying systems have distinct benefits over sun drying but are inaccessible to underserved communities due to high capital costs and energy demand. This study evaluated the techno-economic and financial performance of a half-ton-capacity BAU-STR dryer. The moisture extraction rate, drying rate, drying efficiency, and energy consumption were used as technical performance indicators. In contrast, the net present value (NPV), internal rate of return (IRR), benefit–cost ratio (BCR), and payback period were considered economic performance indicators. The technical performance analysis results revealed that the moisture content of rice was reduced from 19.5% to 13.5 ± 0.15% in 4.0 h with an average drying rate of 1.5%/h and a drying efficiency of 75.1%. The financial performance analysis resulted in a drying cost, NPV, IRR, BCR, and PBP of USD 0.96 per 100 kg of grain, USD 3018, 135%, 3.0, and 0.73 yr., respectively, when the annual use was 240 h. If the yearly use of the dryer increased from 240 to 720 h, a higher NPV, IRR, and BCR, as well as a lower payback period and drying cost, could be achieved. Adopting a BAU-STR dryer for drying grain (rice and corn) among underserved communities could play a key role in postharvest food loss and waste.

Developmental studies of the sublingual and mandibular salivary glands in Japanese quails (Coturinx coturinx japonica)

Abstract Background The Japanese quail (Coturinx coturnix japonica) has a crucial role in the lives of humanity since the 12th century and continues to play main roles in our industry and scientific research. The advantages that the Japanese quail has, such as heavy egg production and high-quality meat with low cholesterol and fat contents, Moreover, the Japanese quail is easily managed, with high feeding conversion, low cost of investment, and high rate of returns. Salivary glands are a part of the lingual apparatus that secretes serios and mucous saliva. Whereas, the saliva secretions have different roles in the food variation, apprehension, and moisture of food bolus. The morphological and cytochemical analysis are done on 20 healthy Japanese quail embryos of 6th, 10th, 11th, and 13th days of incubation and 25 healthy quail chicks at hatching day old, 7th, 14th, 30th, and 60th days old. These samples are investigated histologically, histochemically, and scanned by electron microscopy serially. Our purpose of the study is to highlight the area of the oropharyngeal salivary glands and their role in food variation, as few studies spoke about that in Japanese quail. Results The primordia of the sublingual and mandibular salivary glands were noticed at the 6th and 10th days of the prehatching respectively as an epithelial bud. After hatching, both primordia were elongated and differentiated into secretory units. These glands were mucous polystomatic tubulo-alveolar paired glands, which were situated in the submucosa of the oropharyngeal floor (sublingual floor and paralingual grooves). The sublingual glands consisted of 3–5 lobes extended from the two Os ceratobranchial by their wide ends caudally, to beyond the median sulcus of the prefrenular part of the sublingual space rostrally. The taste buds were variable in size and position. The mandibular glands lay on the paralingual groove, which arose at the 10-day old embryo. The mandibular glands were located dorsomedial to the sublingual glands and extended longitudinally from the rostral border of the frenulum linguae to the caudal tips of the sublingual glands. The taste buds decreased in volume and number with advancing age. Conclusion Overall, salivary glands increase in their alcianophilic activity of the secretions with advancing age, which indicates low PH within the secretory end pieces.

Economic impact of innovative entrepreneurship education: Dynamic modelling methods

AbstractThis paper aims to explore the economic impact of innovative entrepreneurship education and proposes a dynamic modelling method to quantify this impact. The paper establishes a theoretical analysis framework, starting from the effects of innovative entrepreneurship education on the regional economy, and establishes a corresponding dynamic economic model. This model comprises processes such as variable definition, relationship establishment, parameter setting and architecture construction. Different levels of education and forms of innovative entrepreneurship education were experimentally analysed from multiple perspectives. In the comparative experiment between innovative entrepreneurship education and traditional education, the entrepreneurial intention score of the innovative entrepreneurship education group was scattered in the range of 90–100, higher than the 60–80 score of the traditional education group. In the experimental survey on investment return rates of different forms of innovative entrepreneurship education, it was found that the investment return rate of education was the lowest, only 6.82%, and the return rate of entrepreneurship competition was the highest, reaching 9.19%. The experimental results have proven a positive correlation between innovative entrepreneurship education and economic growth. It is suggested that the government and enterprises should increase their investment in innovative entrepreneurship education to promote sustainable economic development.

Approaching Multifractal Complexity in Decentralized Cryptocurrency Trading

Multifractality is a concept that helps compactly grasp the most essential features of financial dynamics. In its fully developed form, this concept applies to essentially all mature financial markets and even to more liquid cryptocurrencies traded on centralized exchanges. A new element that adds complexity to cryptocurrency markets is the possibility of decentralized trading. Based on the extracted tick-by-tick transaction data from the Universal Router contract of the Uniswap decentralized exchange, from 6 June 2023 to 30 June 2024, the present study using multifractal detrended fluctuation analysis (MFDFA) shows that even though liquidity on these new exchanges is still much lower compared to centralized exchanges, convincing traces of multifractality are already emerging in this new trading as well. The resulting multifractal spectra are, however, strongly left-side asymmetric, which indicates that this multifractality comes primarily from large fluctuations, and small ones are more of the uncorrelated noise type. What is particularly interesting here is the fact that multifractality is more developed for time series representing transaction volumes than rates of return. On the level of these larger events, a trace of multifractal cross-correlations between the two characteristics is also observed.

Transition from pediatric to adult care system in patients with complex epilepsies: Necker model for transition evaluated on 70 consecutive patients

AbstractObjectiveComplex epilepsies such as epileptic and developmental encephalopathies require multidisciplinary care throughout life. A coordinated transition program is therefore essential to provide optimal support for patients leaving pediatric for adult care. The aim of this study is to describe and evaluate our transition program for complex epilepsies, focusing on the last step in this program, that is, the multidisciplinary transition day hospital (MTDH).MethodsWe performed a retrospective observational study including patients with complex epilepsies who underwent the full steps of the transition program at Necker–Enfants Malades Hospital between May 2021 and June 2023, with a follow‐up until February 2024. We described the cohort and detailed the interventions performed during the MTDH including medical, medicosocial, educational, daily life abilities, and laboratory and imaging assessments with the participation of one member of the adult team.We evaluated two indicators of our program: (1) the “adult first clinic attendance rate,” defined by the percentage of patients attending their first adult clinic; and (2) the “return rate,” defined by the percentage of patients who requested a pediatric encounter after their transfer.ResultsOur cohort included 70 patients with a mean age of 19.1 years (interquartile range = 16.3–19.5). Eighty percent had an epilepsy syndrome diagnosis; 72.8% were treated with three or more antiseizure medications. All patients had their appointment at the adult clinic within 6 months of the day hospital, and only two families requested a pediatric encounter after the transfer.SignificanceThe transition program is key for an optimal transfer of patients with complex epilepsies to adult care. It requires a comprehensive multidisciplinary approach and provides a complete summary of the medical record. Our program secures a smooth landing in adult care and is a promising model to better manage the challenging transition process, especially in patients with complex epilepsy.

Feasibility of snakehead fish hatchery (Channa striata) using a round pond in Labuan Amas Selatan district, Hulu Sungai Tengah regency, Kalimantan Selatan province, Indonesia

<p>This study aims to determine the technicalities and analyze the feasibility of <em>snakehead fish</em> (<em>Chana striata</em>) hatchery using round ponds in Labuan Amas Selatan District. The data collection methods used are observation, interviews, and documentation. The data analysis used is a qualitative descriptive analysis to determine the technical aspects of the fish hatchery, financial analysis to determine the feasibility of the business with profit analysis, Payback Period (PP), Break Event Point (BEP), Net Present Value (NPV), Net Benefit Cost (Net B/C), and Internal Rate of Return (IRR). The study results show that <em>snakehead fish</em> hatchery using round ponds produces <em>snakehead fish</em> seed in 7 cycles in one year; in each cycle, 6–10 pairs of <em>snakehead fish</em> are used, which can be spawned with an average nursery time of 1.5 months. <em>Snakehead fish</em> cultivation techniques include broodstock maintenance, broodstock selection, spawning, larval transfer and maintenance, nursery, harvesting, and marketing. The results of the business feasibility analysis obtained a profit value of IDR 63,465,000/year with a speedy return on investment for 1.64 years, the BEP value of production = 20,742 seed < the production value = 56,000 seed, and the BEP price of IDR 667/seed < the current price = IDR 1,800/seed. The NPV value at the hatchery reached IDR 366,007,925, meaning NPV > 0, Net B/C > 1 value of 4.62, and IRR value of 62.81%, which means it is greater than the current interest rate of 6%. Based on various financial analyses, the <em>snakehead fish</em> hatchery business using round ponds is profitable and feasible.<strong></strong></p>

Energy recovery from landfill gas in Egypt

AbstractIn developing countries, the transition from dumpsites to landfills is particularly important for addressing the challenges of waste management and promoting sustainable development. The goal of this study is to determine the quantity of gas emissions from landfills in Egypt using LandGEM, Afvalzorg, and Mexico models, as well as analyze the financial benefits and greenhouse gas reductions of producing electricity from municipal solid waste, considering seven different landfills across Egypt. A financial assessment was conducted using the entire lifecycle cost, levelized cost of energy, net present value, internal rate of return, and payback period. While the environmental assessment adopted a methodology to determine greenhouse gas production and reductions due to landfill gas valorization, in a span of 30 years, greenhouse gas emissions are expected to be reduced by 81% following landfill gas utilization based on a 75% gas collection efficiency. Furthermore, the potential electricity generation reaches 358 gigawatt-hours, with plant capacities ranging between 3 and 40 megawatts. The positive net present values obtained demonstrate that landfill gas for electricity generation in Egypt is financially feasible for big landfills. This aims to provide first-hand technical knowledge to waste management stakeholders, including policymakers, planners, decision-makers, and investors, to guide waste management planning and promote financially feasible investment in landfill gas to energy in Egypt. Graphical Abstract

Brand Loyalty through Consumer Protection of Selected E-Commerce Firms

Ensuring consumer rights and addressing their various concerns has been identified as a crucial step in securing customer loyalty. However, the e-commerce sector in Nigeria has struggled to retain its customers due to its failure to adequately protect consumer rights. This lack of consumer rights protection has resulted in poor customer loyalty, with users frequently abandoning e-commerce platforms. This study examines the effect of consumer protection on brand loyalty within selected e-commerce firms. The research surveyed 497 active users of these e-commerce platforms with a 90.3% return rate and employed multiple regression analysis to assess the results. The findings revealed that consumer protection has a significant effect on purchase decisions (Adj.R² = 0.660, F(3, 445) = 290.639, p < 0.05), customer trust (Adj.R² = 0.580, F(3, 445) = 207.126, p < 0.05) and customer satisfaction (Adj.R² = 0.590, F(3, 445) = 215.819, p < 0.05) of listed e-commerce firms in Lagos State, Nigeria. Consequently, the study concludes that consumer brand protection significantly influences the brand loyalty of selected e-commerce firms, recommending that e-commerce management prioritize the recognition and protection of consumer rights to enhance brand loyalty

Advancing sustainable EV charging infrastructure: A hybrid solar-wind fast charging station with demand response

This study aims to design an efficient hybrid solar-wind fast charging station with an energy storage system (ESS) to maximize station efficiency and reduce grid dependence. The research employs Monte Carlo simulation to capture renewable energy source (RES) uncertainties, models stochastic electric vehicles (EVs) driver behavior and fleet diversity, and utilizes an Erlang B queuing model for EV load demand estimation. A hybrid optimization approach combining the Binary-Gravitational Search Optimization Algorithm (B-GOA) and the Non-dominated Crowding Sort Optimization Algorithm (NCSOA) is implemented for efficient optimization in a combined binary-continuous solution space. Results demonstrate superior performance of the proposed approach compared to existing methods, with high-RES penetration significantly reducing grid reliance. This study contributes to advancing sustainable EV charging infrastructure development and enhancing overall grid stability through improved load flexibility and demand response management. The analysis reveals Scenario IV as the most economically viable, with the highest Net Present Value of 1,025,895.32€. Most scenarios favor 5 chargers (44–46 kW) and 4 Type 3 wind generators. Battery capacity varies widely (108–372 kWh), as does grid connection (0–292 kW). Despite varying initial investments, Scenarios II-VII show a consistent 4-year Internal Rate of Return, indicating good economic potential across different configurations.

Comparison of Pediatric and Adult Mandibular Fractures: Identifying Differences in Presentation and Management Using a National Trauma Database.

Facial fractures in children are less common than in adults but can lead to significant long-term complications, including growth abnormalities and functional issues. Mandibular fractures are the most common facial fractures in both age groups, yet there is no consensus on optimal management strategies. This study investigates the epidemiology, presentation, treatment, and outcomes of mandibular fractures in pediatric versus adult populations. The authors conducted a retrospective, population-based study using 2016 to 2019 data from the National Trauma Data Bank. Patients with mandibular fractures were categorized into pediatric (below 18y) and adult (18y or above) groups. The authors analyzed demographics, fracture mechanism, treatment modality, hospital outcome, and complication data. Of the 42,866 patients with operative mandibular fractures, 3968 were pediatric (mean age: 13.3y), and 38,898 were adult (mean age: 36.2y). The primary fracture etiology for both groups was being struck, followed by motor vehicle incidents and falls. Pediatric patients were more frequently treated at level I trauma centers, had shorter times for surgical intervention, and were more frequently transferred to other facilities compared to adults. Antibiotic use was similar between groups, and hospital complications were infrequent, with low rates of infection and unplanned return to the operating room. Mandibular fractures in children, though less common than in adults, exhibit unique epidemiological and management characteristics. Children were more frequently transferred for care and received surgical intervention sooner than adults. Antibiotic use and complication rates were low and similar across both groups. Further research is needed to establish specific treatment guidelines for pediatric mandibular fractures.

Utilization of Enhanced Recovery After Surgery (ERAS) protocol in pediatric laparoscopic sleeve gastrectomy: a quality improvement project.

The obesity epidemic has led to an increased number of adolescents requiring metabolic and bariatric surgery (MBS), but there is paucity of data on the impact of implementing all aspects of Enhanced Recovery After Surgery (ERAS) protocols to improve outcomes in this population. We implemented a comprehensive ERAS pathway for adolescents undergoing laparoscopic sleeve gastrectomy (LSG). Key elements included pre-operative fasting with carbohydrate loading in the morning of surgery, comprehensive anti-emetic and analgesic regimens including intra-operative lidocaine infusion (initiated before formal ERAS launch), regional anesthesia, and early goal-directed ambulation. We tracked opioidutilization, rescue anti-emetic use, time to oral intake,and hospital length of stay (HLOS) as outcome measures, and post-operative pain and returns to the system as balancing measures. Eighty-six patients(52 patients pre-ERAS and 34 patients post-ERAS) underwent LSGwith no differences in demographics. The post-ERAS group had earlier time to oral intake (3.0 vs. 5.5 h, p = 0.003), used less rescue anti-emetics, (8.0vs.16.0 mg, p < 0.001), and had shorter HLOS (33 vs. 54 h, p < 0.001) but no difference in opioid use (0.370 vs. 0.435 MME/kg, p = 0.17), post-operative pain scores or return to the system. Our novel use of bariatric-specific ERAS protocol with intra-operative lidocaine infusion accelerates the time to goal-directed oral intake and decreases HLOS without increasing the rate of returns to the system. This study highlights the feasibility and effectiveness of adapting adult ERAS protocols to the pediatric MBS population. Level III.

Techno-economic feasibility study of ammonia recovery from sewage sludge digestate in wastewater treatment plants

Wastewater treatment plants play a vital role in resource recovery, particularly through biogas production, a key renewable energy source. Beyond biogas, the digestate from anaerobic digestion is rich in nutrients like ammonia. This study explored the feasibility of recovering ammonia from sewage sludge digestate using air stripping. The process was modeled using Aspen Plus® software, utilizing real data from As-Samra WWTP in Jordan. Various operational parameters, such as digestate feed flow, air flow rate, temperature, and pressure, were analyzed to optimize ammonia recovery. The results showed that with a feed flow rate between 10,000 and 30,000 kg/hr, ammonia recovery reached 85%, with production exceeding 100 kg/hr, where the effect of the flow rate appears mostly at elevated feeding temperatures. Increased air flow rates significantly boosted recovery, achieving 90% efficiency at 60 °C with 50,000 kg/h as air flow. Flashing pressure peaked at 1.5 bar, with 85% efficiency at 95 °C, while higher pressures yielded diminishing returns, stabilizing production around 106 kg/hr. The NaOH feed rate also influenced output, rising from 100 kg/hr at a 50 kg/hr feed rate to 107 kg/hr at 750 kg/hr, with recovery efficiency exceeding 85%. The economic analysis showed that the project had a payback period of 6.07 years, reflecting a reasonable recovery of the initial investment. The net present value was 122,924 USD over 15 years, with 8% amortization rate, indicating that the project created value beyond the initial cost. The internal rate of return was 14.23%, surpassing the discount rate and highlighting the project's financial attractiveness.

Design and Technical-Economic-Environmental Evaluation of a Biorefinery Using Non-Marketable Edible Mushroom Waste

Edible mushrooms are gaining popularity as functional foods, not only for their distinctive taste and subtle flavor but also for their potential health benefits. They are rich in essential nutrients, including carbohydrates, proteins, fiber, minerals, and vitamins. However, it is estimated that up to 30% of total mushroom production generates non-marketable waste, which is currently used as animal feed, fertilizer, or compost. From a circular economy perspective, the objective of this work is to propose a conceptual design for a biorefinery to produce high-value-added products from non-marketable edible mushroom waste and to conduct a comprehensive assessment using modeling and simulation tools for process engineering. The general approach first involves identifying high-potential products, then determining the best processing routes, followed by developing a process flowsheet diagram for a case study (A. bisporus), and ultimately conducting a comprehensive assessment of the biorefinery to evaluate its sustainability. As a result, the proposed biorefinery may produce chitin, citric acid, and fertilizer, demonstrating the technical feasibility of waste valorization in terms of product yields, with positive profitability in terms of the rate of return on investment and payback period, and low environmental impact in terms of water and energy consumption as well as CO2 emissions.

Techno-Economic analysis of ceramic matrix composites integration in remaining useful Life Aircraft Engine Hot Section Components

AbstractCeramic Matrix Composites (CMCs), specifically SiC/SiC composites, represent a significant innovation in aerospace material technology, offering superior performance over traditional nickel-based superalloys in high-temperature turbine blade applications. This study presents a novel techno-economic assessment, filling a critical gap in the literature by directly comparing the economic and technical viability of CMCs versus superalloys. Unlike previous studies, which primarily focus on technical performance or cost analysis independently, this work integrates both aspects, providing a holistic comparison across key economic metrics, including acquisition, machining, maintenance, and recycling costs. The results demonstrate that SiC/SiC blades offer a 15–20% higher Net Present Value (NPV) and a 17% greater Internal Rate of Return (IRR) over a 20-year lifecycle than superalloys. Despite higher initial costs, CMCs achieve an estimated 2 to 3 years reduction in payback period, mainly due to their superior thermal and creep resistance, leading to fewer maintenance interventions and longer operational lifetimes. Although machining costs for CMCs are higher, these are more than offset by the long-term savings achieved through improved fuel efficiency and lower maintenance costs. A comprehensive sensitivity analysis, incorporating fluctuations in discount rates and material costs, further validates the economic robustness of CMCs in various operational scenarios. This study is the first to compare CMCs and superalloys, offering new insights into the financial implications of material selection in aerospace manufacturing. The findings present critical engineering recommendations that empower aerospace manufacturers and decision-makers to optimise material selection for improved efficiency and cost-effectiveness in high-performance turbine applications.

Evaluation of Modified Frailty Index for Predicting Postoperative Outcomes After Upper-Extremity Replantation and Revascularisation Procedures.

Upper extremity (UE) replantation and revascularization are challenging surgical procedures, with survival rates being 50% to 90%. Preoperative risk stratification is challenging yet crucial as patients with comorbid conditions face increased complications. This study assesses the predictive value of the modified 5-item frailty index (5-mFI) for postoperative complications in these procedures. A retrospective study was done using the ACS NSQIP database (2011-2021) for UE replantation/revascularization. The 5-mFI score assigned points for comorbidities including pulmonary disease, heart failure, diabetes, hypertension, and functional status (0-5 scale; 1 point to each). 5-mFI scores stratified patients into <2 (low-risk) or ≥2 (high-risk) categories. Of 2,305 patients, the mean age and BMI were 53.13 years and 28.53 kg/m2 respectively. The 5-mFI≥2 cohort experienced higher rates of all-cause complications, systemic complications, unplanned readmissions, and return to the operating room on univariate analysis. There was no significant difference in wound complication rates. Multivariable logistic regression showed that a higher 5-mFI was significantly associated with increased risks of all-cause mild and severe systemic complications. Wound complications, length of stay over 30 days, unplanned readmission, and return to the operating room were higher in high-risk patients, however not statistically significant. 5-mFI is an effective tool for evaluating risk in UE replantation and revascularization, correlating high scores with significantly increased postoperative complications. High-risk patients with 5-mFI≥2 also had more reoperations and readmissions. The use of 5-mFI in preoperative assessments can help personalize management, enhancing patient selection and care quality in these complex reconstructions.

Impact of Insurance Status on Postoperative Recovery After Microsurgical Breast Reconstruction.

Persistent disparities in breast reconstruction access have been widely documented, yet a significant research gap remains in understanding the impact of social determinants of health (SDOH) on postoperative outcomes and complications. A retrospective chart review was performed on all patients who underwent abdominal-based free-flap breast reconstruction between August 2018 and December 2022 at a racially, ethnically, and socioeconomically diverse urban academic institute with a historically underserved patient population. Patients were stratified by the public (Medicare and Medicaid) versus private insurance as a proxy for SDOH. Patient demographics, length of stay (LOS), timing in progression through postoperative recovery milestones, and complications were compared. A total of 162 patients were included, and 57% of patients had public insurance, with this group more likely to be Hispanic (OR2.7; p=0.003) and Spanish-speaking (OR3.4; p=0.003). Privately insured patients were more likely to be non-Hispanic black (OR2.7; p=0.006). Patients with public insurance had a higher rate of unplanned return to the operating room within 90 days and a higher incidence of complications, though not statistically significant. They also experienced a significantly longer LOS than privately insured patients (3.6±1.0 days vs 3.0±0.7 days; p<0.0001). Logistic regression identified a LOS exceeding 3 days as independently associated with public insurance status (OR3.0; p=0.03), bilateral procedure (OR5.6; p=0.0007), preoperative functional-dependent status (OR7.0; p=0.04), and higher BMI (OR1.1; p=0.03). Patients with public insurance were more likely to encounter delays in achieving recovery milestones. Public insurance status, serving as a proxy for a disadvantage in SDOH, is predictive of extended LOS and postoperative recovery delays following microsurgical breast reconstruction. This underscores the need for future quality improvement efforts to address and mitigate these disparities.