Oxygen Flow Rate Research Articles

Control of ferroelectricity in Ta-doped HfO2 and its non-zero-crossing current–voltage hysteresis behavior

Hafnium oxide (HfO2)-based ferroelectrics are being explored as potential candidates for ferroelectric memory devices due to their highly compatibility with complementary metal-oxide-semiconductor (CMOS) technology. Enhancing the remanent polarization and investigating the underlying mechanism are crucial tasks. In the present study, tantalum (Ta) was introduced as a dopant to induce ferroelectric properties in HfO2, a large portion of orthorhombic phase was recognized in the as-grown Ta:HfO2 without further thermal treatment. The remanent polarization of Ta:HfO2 thin films can be optimized by adjusting the oxygen flow rates during the sputtering process. The influencing factors for enhanced ferroelectric performance include the control of Ta concentration, its valence state, and the presence of singly ionized oxygen vacancies, which are influenced by oxygen addition. Furthermore, the resistive switching behavior showing non-zero crossing current–voltage (I–V) hysteresis is associated with ferroelectricity and the presence of oxygen vacancies. A model has been proposed to explain the ferroelectric resistive switching with non-zero crossing I–V characteristics by considering the role of oxygen vacancies and polarization effects. This model suggests that the oxygen vacancies at the surface layer, along with ferroelectric polarization, play a crucial role in electron transport.

The Effect of Spray Distance on the Hot Corrosion Behavior of HVOF‐Sprayed NiCrAlY Coatings in a Simulated Gas Turbine Environment

ABSTRACTTo utilize the unique properties of coatings produced using the high‐velocity oxy‐fuel (HVOF) method, this study examined the effect of spray distance on the hot corrosion behavior of NiCrAlY coatings deposited on a steel substrate. The coating samples were obtained at spray distances of 20, 25, and 30 cm. The flow rates of oxygen and propane were maintained constant at 300 and 60 lit/min, respectively. Additionally, the powder feeding rate was 32 g/min. The samples were then subjected to the hot corrosion test in a salt mixture of Na2SO4−60% V2O5 at 900°C in an ambient atmosphere. The surface and the cross section of the samples were observed using a scanning electron microscope (SEM) and the chemical composition of different sections was determined by energy‐dispersive spectroscopy (EDS). The phases were also characterized using X‐ray diffraction analysis (XRD). The best corrosion resistance was found in the sample coating formed at a spraying distance of 20 cm, as the results showed that increasing the spraying distance led to a reduction in the thermal and kinetic energy of the flame, resulting in increased porosity in the coating. This behavior can be attributed to the low oxide content of the coating, the higher aluminum content, and the richer NiAl phase, which serves as a reservoir for aluminum.

Decoding oxygen prescriptions: electronic health record documentation versus patient-reported use

BackgroundLong term oxygen therapy (LTOT) is prescribed for hypoxemia in pulmonary disease. Like other medical therapies, LTOT requires a prescription documenting the dosage (flow rate) and directions (at rest, with activity) which goes to a supplier. Communication with patients regarding oxygen prescription (flow rate, frequency, directions), monitoring (pulse oximetry) and dosage adjustment (oxygen titration) differs in comparison with medication prescriptions. We examined the communication of oxygen management plans in the electronic health record (EHR), and their consistency with patient-reported LTOT use.Study design and methodsA cross-sectional study was conducted in 71 adults with chronic lung disease on LTOT. Physician communication regarding oxygen management was obtained from the EHR. Participants were interviewed on their LTOT management plan. The information from each source was compared.ResultsThe study population was, on average, 64 years, two-thirds women, and most used oxygen for over 3 years. Only 45% of both at-rest and with-activity oxygen prescriptions were documented in the Electronic Health Record (EHR). Less than 20% of prescriptions were relayed to the patient in the after-visit summary. Of those with EHR-documented oxygen prescriptions, 44% of patients adhered to prescribed oxygen flow rates. Nearly all patients used a pulse oximeter (96%).InterpretationWe identified significant gaps in communication of oxygen management plans from provider to patient. Even when the oxygen prescription was clearly documented, there were differences in patient-reported oxygen management. Critical gaps in oxygen therapy result from the lack of consistent documentation of oxygen prescriptions in the EHR and patient-facing documents. Addressing these issues systematically may improve home oxygen management.

The brain's "dark energy" puzzle upgraded: [18F]FDG uptake, delivery and phosphorylation, and their coupling with resting-state brain activity.

The brain's resting-state energy consumption is expected to be mainly driven by spontaneous activity. In our previous work, we extracted a wide range of features from resting-state fMRI (rs-fMRI), and used them to predict [18F]FDG PET SUVR as a proxy of glucose metabolism. Here, we expanded upon our previous effort by estimating [18F]FDG kinetic parameters according to Sokoloff's model, i.e., (irreversible uptake rate), (delivery), (phosphorylation), in a large healthy control group. The parameters' spatial distribution was described at a high spatial resolution. We showed that while is the least redundant, there are relevant differences between and (occipital cortices, cerebellum and thalamus). Using multilevel modeling, we investigated how much of the regional variability of [18F]FDG parameters could be explained by a combination of rs-fMRI variables only, or with the addition of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2), estimated from 15O PET data. We found that combining rs-fMRI and CMRO2 led to satisfactory prediction of individual variance (45%). Although more difficult to describe, and were both most sensitive to local rs-fMRI variables, while was sensitive to CMRO2. This work represents the most comprehensive assessment to date of the complex functional and metabolic underpinnings of brain glucose consumption.

Investigation of the Influence of the Oxygen Flow Rate on the Mechanical, Structural and Operational Properties of 86WC-10Co-4Cr Coatings, as Determined Using the High-Velocity Oxyfuel Spraying Method

The structural-phase composition and tribological and performance properties of coatings based on an 86WC-10Co-4Cr composition obtained by the HVOF method at varying (150 L/min, 170 L/min, 190 L/min) oxygen flow rates were studied. The results showed that the coefficient of friction of coatings in gear oil remained almost unchanged with the variation in oxygen flow rate. However, microhardness increased significantly with an increasing oxygen flow rate, reaching a maximum at 190 L/min. An increasing oxygen flow rate was also accompanied by an increase in roughness and coating thickness, with a decrease in porosity, particularly notable at 190 L/min. Adhesion strength reached the maximum values for the A2 and A3 coatings under high loads. The phase composition of the coatings included WC, W2C and CoO phases irrespective of the oxygen flow rate, and their microstructure was characterized by a more homogeneous and dense structure. Thus, this study confirmed that the optimal oxygen flow rate for achieving an improved performance and tribological characteristics of 86WC-10Co-4Cr coatings is 190 L/min.

Performance evaluation of p-type Cr2O3 thin films grown by reactive DC magnetron sputtering for Schottky diode applications

Abstract In this study, we present a comprehensive investigation into the impact of combined oxygen and argon flow rates on the physical properties of Cr2O3 thin films produced via reactive DC magnetron sputtering. Additionally, we explore the influence of oxygen flow rate on various aspects, including structural, morphological, optical, chemical, and electrical characteristics of the sputtered Cr2O3 thin films. Our analysis, based on XRD results, reveals the polycrystalline nature of the films. Surface morphology was examined through scanning electron microscopy. Optical analysis indicates a band gap ranging from 2.70 eV to 2.99 eV for the films. X-ray photoelectron spectroscopy analysis shows the splitting of Cr 2p core spectra into Cr 2p3/2 and Cr 2p1/2 domains within the range of 573 eV to 585 eV, alongside the presence of satellite peaks. Moreover, extracted electrical properties reveal the p-type conductivity of the deposited Cr2O3 thin film under various oxygen flow rates. Furthermore, we fabricate and characterize an ITO/p-Cr2O3/Al Schottky diode to provide additional insights into p-Cr2O3/Al Schottky diodes. Overall, this study contributes valuable insights and enhances our understanding of Cr2O3 thin film properties, particularly in the context of semiconductor devices like Schottky diodes.

Mathematical modelling and validation of the mechanical properties of HVOF-sprayed WC-12Co coatings considering the phase composition and defects generated at different process parameters

The thermal spraying process involves many machine-based parameters or independent variables (fuel flow rate, oxygen flow rate, powder feed rate, stand-off distance and many others in the HVOF process). Any combination of these parameters produces only two measurable responses, namely, particle temperature and particle velocity. In this current work, first, the machine-based spray parameters are varied in specific ways to produce different particle temperatures at near-constant velocities and vice-versa. This approach has reduced the number of independent variables to only two. These two factors further influence the in-flight particle reactions, thereby affecting the phase composition and the microstructural defects in the as-sprayed coatings. The X-ray diffraction patterns of the as-sprayed coatings revealed the presence of W2C, W, Co3W9C4, and amorphous Co-W-C phases apart from the WC phase. The W2C and W originated owing to the decarburization of the WC phase. On the other hand, the dissolution of the carbide in molten binder led to the formation of Co3W9C4 and the amorphous Co-W-C phase. The nano-hardness of both the carbide and binder phases increased with an increase in particle temperature owing to a higher degree of decarburization and carbide dissolution respectively. The porosity was the most significant micro-structural defect present in the as-sprayed coatings. An increase in either particle temperature or velocity reduced the porosity present in the as-sprayed coatings. The mechanical properties (microhardness, elastic modulus and indentation fracture toughness) tend to improve as porosity decreases. A comprehensive mathematical model was proposed to predict the mechanical properties of as-sprayed coatings as a function of composition and defects. Finally, the process maps of mechanical properties were plotted in temperature-velocity space.

Mechanism and kinetics of efficient removal of as from a high arsenic-bearing ZnSO4 solution using ultrasound enhanced oxygen

The traditional lime method for arsenic (As) removal from high arsenic-bearing ZnSO4 solution has disadvantages such as high cost, large amount of wet residue, significant secondary hazards, and long process flow. This study developed a new technology for efficient As removal using ultrasound enhanced oxygen. The effects of zinc roasting dust (ZRD) addition, reaction temperature, oxygen flow rate, and ultrasound power on As removal efficiency were investigated. Under the optimal conditions, the removal rate of As reached 97.90 %. The1O2, O2∙- and •OH radicals generated during the ultrasound-enhanced oxygen process significantly enhance the oxidation efficiency of As(III) and Fe2+. Ultrasound can also refine particle size and improve the removal efficiency of As. Compared with traditional lime method, the reaction time and wet residue amount have been reduced by 40 % and 70.37 %, respectively. Field emission scanning electron microscopy (FE-SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses indicate that As in ZnSO4 solution was primarily removed through by Fe(OH)3 colloidal adsorption and amorphous FeAsO4. Kinetic analysis revealed that the neutralization and As removal process using ZRD under ultrasound and oxygen action conforms to the internal diffusion control model. Ultrasound-enhanced oxygen As removal can reduce the reaction activation energy from 26.94 to 21.02 kJ/mol, effectively lowering the reaction barrier for As removal and demonstrating faster reaction rates under ultrasound conditions. Ultrasound-enhanced oxygen removal of As from high arsenic-bearing ZnSO4 solution provides an efficient and low-cost potential solution for enterprises.

Production of GeOx Films at Different Oxygen Flow Rates and Different Annealing Temperatures and Examination of Energy Band Gaps using Kubelka Munk Method

In this study, GeOx films were grown on silicon substrates using the Radio Frequency (RF) Magnetron Sputtering method at different oxygen flow rates and annealing temperatures. The films were produced at a substrate temperature of 250°C and a working pressure of 13 mTorr. Subsequently, the films were annealed at temperatures of 300°C, 500°C, 600°C, 700°C, 900°C, and 1000°C. Total and diffuse reflection measurements were performed to investigate the optical properties of the films. Energy band gaps were determined using diffuse reflection measurements and they were calculated using the Kubelka-Munk method. It was observed that the energy band gap increased with increasing oxygen ratio. Additionally, annealing temperatures were found to cause changes in the energy band gaps.

Mathematical Modeling on the Multiphase Flow during Top–Bottom Combined Blowing Basic Oxygen Furnace Steelmaking Process

A 3D mathematical model on the multiphase flow and splashing phenomenon in a 210 t Basic oxygen furnace converter is established. The turbulent multiphase flow of the molten steel, slag, and oxygen is simulated by the combined realizable k−ε model and volume of fluid model. The trajectory of argon bubbles and the interaction between the molten steel and argon is simulated by the two‐way coupled Lagrangian discrete phase model. Effects of the lance height and bottom‐blowing gas flow rate on the multiphase flow and splashing phenomenon are investigated. The results indicated that the cavity depth is decreased from 0.45 to 0.36 m when the lance height increases from 1700 to 2300 mm. The cavity depth is not significantly affected by the bottom‐blowing argon flow rate with the 44 000 m3 h−1 top‐blowing oxygen flow rate and 1700 mm lance height. The increased lance height resulted in a decrease in splashing. When the oxygen lance height increases from 1700 to 2300 mm, the amount of the splashed molten steel decreases from 3774.3 to 1953.0 kg.

Influence of Oxygen and Nitrogen Flow Ratios on the Microstructure Evolution in AlCrTaTiZr High-Entropy Oxynitride Films

This study explores the influence of oxygen and nitrogen flow ratios on the microstructure and mechanical properties of AlCrTaTiZr high-entropy oxynitride films. Oxygen flow rates (0%–0.75%) were adjusted while maintaining a fixed nitrogen flow ratio (RN = 15%) to fabricate films with similar compositions. The results show that increasing oxygen flow enhanced hardness through solid solution strengthening and grain refinement, though excessive oxygen caused an amorphous structure and reduced hardness. After annealing at 900 °C, the hardness of all films was further increased. The film with a nitrogen flow ratio 40 times higher than oxygen exhibited the highest hardness of 21.8 GPa, along with superior mechanical performance. These findings highlight the potential of high-entropy oxynitride films for applications requiring high wear resistance and adhesion.

Continuous Diffused Oxygen Therapy for Wound Healing

What Is the Issue? Wounds are prevalent across health care settings, costing Canada an estimated $12 billion per year in wound care. Chronic wounds (wounds that do not heal in the typical amount of time, which can depend on the size and type of wound) can have a significant impact on a patient’s quality of life and health. Healing tissue has a high need for oxygen. Oxygen can be delivered in several ways, including topical oxygen therapy, which delivers oxygen directly to the wound. One type of topical oxygen therapy is continuously diffused oxygen (CDO) therapy, which uses a device that takes oxygen from the air and then delivers pure, humidified oxygen to the wound. We previously completed a Rapid Review on CDO therapy for wounds in 2020. This review aimed to determine if new evidence has since been published on this topic. What Did We Do? To inform decisions about CDO therapy for wound healing, we sought to identify and summarize literature comparing the clinical effectiveness and cost-effectiveness of CDO therapy versus conventional wound care. We also attempted to identify evidence-based recommendations for the use of CDO therapy. We searched key resources, including journal citation databases, and conducted a focused internet search for relevant evidence published since 2019. One reviewer screened articles for inclusion based on predefined criteria, critically appraised the included studies, and narratively summarized the findings. What Did We Find? CDO therapy appears to be clinically effective for treating patients with diabetic foot ulcers, particularly chronic or hard-to-heal ulcers that have not responded to standard care. Rates of adverse events were comparable between patients receiving CDO and patients receiving standard care. Two cost-effectiveness studies reported that CDO is likely to be cost-effective compared to standard care for patients with chronic, hard-to-heal diabetic foot ulcers. We identified fewer studies for other types of wounds. Preliminary evidence suggests that CDO therapy may be helpful for patients with other types of wounds that are chronic or have not responded to standard care. Reporting on adverse events was limited. Limited evidence suggests that patients receiving CDO therapy had better outcomes if their wound was debrided more frequently as well as if they received CDO therapy for a longer time. The evidence-based guidelines recommend the use of topical oxygen therapy (of which CDO is a subtype) for treating diabetic foot ulcers that have failed to heal with standard care. One guideline suggested that topical oxygen therapy may be considered for other types of non-neoplastic, hard-to-heal wounds. We did not find cost-effectiveness evidence for wounds other than diabetic foot ulcers that met the inclusion criteria for our report. We also did not identify any clinical effectiveness or cost-effectiveness evidence, or any guidelines regarding the use of CDO to treat First Nations, Inuit, and Métis patients, that met the inclusion criteria for our report. What Does This Mean? CDO therapy may be beneficial and more cost-effective than standard care for patients with hard-to-heal, chronic diabetic foot ulcers that have not responded to standard care. Evidence-based guidelines also recommend the use of CDO therapy for this patient population. The clinical effectiveness and cost-effectiveness of CDO therapy for other types of wounds is still unclear. It is also unclear if there is an optimal way to provide CDO (e.g., oxygen flow rate, debridement, length of treatment). We identified limited evidence that reported on patient ethnicity. Considering that some groups, including First Nations, Inuit, and Métis Peoples, have higher rates of diabetes than the overall population in Canada — which may lead to higher rates of diabetic foot ulcers — decision-makers involved in implementing CDO therapy should consider ways to ensure equitable access for all patients who may need this treatment.

Effect of HVOF parameter on titanium oxide (TiO2) coating characteristics on AZ81 magnesium alloy

High-velocity oxy-fuel (HVOF) coating to enhance the erosion, wear, and corrosion-resistant properties crucial for orthopedic applications. HVOF is distinguished for its capability to provide surfaces with a dense and superior finish. Porosity and hardness serve as vital process variables in assessing performance. This current study aims to optimize HVOF process parameters to minimize porosity values in titanium oxide (TiO2) coatings applied on AZ81 magnesium substrate. Oxygen flow, liquefied petroleum gas (LPG) flow, coating material feed rate, and spray distance were selected due to their significant impact on the coating quality. Statistical techniques such as response surface methodology (RSM), analysis of variations, and design of experiments (DoE) were employed to obtain the necessary results. The findings indicate that LPG flow has the most significant influence on coating quality, followed by standoff distance, oxygen flow rate, and feed rate. The coating obtained using optimal spray parameters exhibits a lower surface porosity of 0.86 vol.% and achieves a greater hardness of 922 HV. This has been confirmed through validation via the response graph. Consequently, the optimized parameters for TiO2 deposit entail an oxygen flow rate of 266 lpm, an LPG flow rate of 68 lpm, a powder feed rate of 35 g/min, and a spray distance of 236 mm. KEY WORDS: High-velocity oxy-fuel, Response surface methodology, Porosity, Hardness, AZ81 Magnesium alloy, Titanium oxide Bull. Chem. Soc. Ethiop. 2024, 38(6), 1869-1886. DOI: https://dx.doi.org/10.4314/bcse.v38i6.28

Efficacy of a novel oxygen scavenger mask in reducing local oxygen concentrations below the surgical fire risk threshold: an experimental proof-of-concept study

BackgroundThis study aims to evaluate the efficacy of an oxygen scavenging mask device in reducing local oxygen concentrations from nasal cannula ventilation compared to a standard open facial surgical field.MethodsThis is a controlled experiment using a custom-fabricated silicone midfacial oxygen scavenging device, SimMan airway management trainer manikin (Laerdal Medical, Stavanger, Norway), handheld oxygen detector (Forensics Detectors, Los Angeles, United States) and oxygen from a Datex Ohmeda Aisys Carestation anesthesia unit (GE HealthCare, Chicago, United States). Oxygen concentrations were measured at 18 facial landmarks (Fig. 1) with nasal cannula flow of 2, 4, and 6 L/min of 100% FiO2 in both masked and unmasked conditions (Fig. 2).ResultsThe mean oxygen concentration in the facial surgical field was 20.95% with the scavenger mask and 24.8% without (P < 0.001; two-tailed paired t-test). The unmasked condition was associated with suprathreshold oxygen concentration levels at 13 of 18 facial landmarks (Table 1). The device significantly reduced local oxygen concentration at 16 of 18 facial landmarks (Table 1). The device provided safe oxygen concentration levels at all three flow rates, and measured oxygen concentrations directly correlated with oxygen flow rate in the unmasked condition (Table 2).ConclusionsAn oxygen scavenger mask device reduced local oxygen concentrations from nasal cannula ventilation to below the 23% fire threshold in the entire facial surgical field external to the mask in these experiments. The device may reduce intraoperative fire risk in patients that require supplementary oxygen during surgery.

Optimization of diformylfuran production from 5-hydroxymethylfurfural via catalytic oxidation in a packed-bed continuous flow reactor.

DFF's diverse applications in pharmaceuticals, fungicides, and polymer synthesis motivate the development of efficient production methods. This study reports the continuous-flow synthesis of DFF from 5-HMF in a packed-bed reactor. The Box-Behnken design coupled with response surface methodology (RSM) was employed to optimize the reaction parameters (catalyst, solvent, temperature, oxygen flow rate, catalyst amount) for DFF yield. Ru/Al2O3 in toluene proved to be the most effective catalyst-solvent combination. The optimal conditions for DFF production were identified as: 140 °C reaction temperature, 10 ml min-1 oxygen flow rate, and 0.15 g catalyst loading. Under these conditions, a DFF yield of 84.2% was achieved.

The effect of oxidation on tribology behavior of nickel-graphite coated stainless steel SS420

The main solution to the challenge of maintaining maximum sealing in the compressor section of each gas turbine is the use of abradable coatings. These coatings have a double duty, including (a) maintaining the lagging and (b) protecting the tips of the rotor blades. Choosing the type of abradable coating primarily depends on the service temperature of the coating. Nickel-graphite (Ni-G) coating is a good choice for use up to 480 °C and, or steel/sub-alloy rotor blades. In this research, the Ni-G coating was applied by the flame spraying method of Ni-G powder with a thickness of about 250 μm on an SS420 stainless steel substrate. The effect of the composition of the bonding layer was also investigated using two compositions, Ni-5Al and NiCrAlY. Obtaining the knowledge of applying Ni-G coating by flame spraying, identifying the structural and compositional characteristics of the coating (through optical and electron metallography), and the effect that oxidation can have on the tribological behavior of the coating were among the goals of this project. The best conditions for spraying the Ni-G coating were achieved an oxygen gas pressure of 6 bar, oxygen flow rate of 18 L min−1, acetylene pressure of 1.5 bar, acetylene flow rate of 24 L min−1, and the distance between the gun head and the sample surface was 22 cm. The results showed that placing the coating in oxidizing conditions increases its coefficient of friction. The increase in the coefficient of friction was attributed to the formation of oxide shells on the surface of the coating after 500 h of exposure to oxidation conditions. Corresponding to the higher coefficient of friction, the oxidized coating showed a decrease in wear resistance as a result of oxidation. This result can show the decrease in abradable of this coating with increasing service time.

The n-MoO3/p-Si heterojunction photodiode: Influence of the MoO3 film thickness on the ultraviolet and infrared photodetector performance

Here, we studied the effect of the MoO3 thin film thickness on the ultraviolet (UV) and infrared (IR) photodiode properties of the n-MoO3/p-Si heterojunction structure. Initially, the metal molybdenum (Mo) thin films with different thicknesses (50,150, and 250 nm) were created via DC magnetron sputtering on a p-type Si substrate. Then, the MoO3 thin films were synthesized using a thermal oxidation method with an optimal oxygen flow rate of 60sccm. XRD and Raman analysis showed that the structure of prepared thin films has converted from an amorphous to an orthorhombic (α-MoO3) crystalline phase with increasing thickness. The optical transmittance of the layers was tuned by controlling the thickness, and the maximum transmittance for the 50 nm-thick film was achieved in the broad wavelength range of 300–1100 nm. The current density–voltage (J–V) characteristics indicate the prepared samples' rectifying behavior under dark conditions. The heterojunction photodiode with a 50 nm-thick MoO3 layer shows the best performance. This sample had a maximum amount of transmittance in the UV–visible and IR regions, compared to other samples, which leads to efficient electron-hole separation and transportation. This sample demonstrates a significant photoresponse ratio (ILight/IDark) of about 55 and 52.5 in the ultraviolet (UV) and infrared (IR) regions, respectively.

There is No Increased Pulmonary Risk Following Total Hip Arthroplasty in Patients Who Have Obstructive Sleep Apnea Without Underlying Lung Disease

BackgroundObstructive sleep apnea (OSA) is a frequent comorbidity. The current study evaluated whether there is a difference in the perioperative outcome after total hip arthroplasty (THA) in patients who had a low to moderate risk for OSA and high risk for OSA, respectively. MethodsAfter excluding patients who had concomitant lung disease (chronic obstructive pulmonary disease, asthma, or lung fibrosis) and those missing a STOP-Bang Score, 1,141 THA patients who had OSA were included in this retrospective study. Patients at low to moderate risk for OSA (STOP-Bang Score 0 to 4) and patients at high risk for OSA (STOP-Bang Score 5 to 8) were compared, and SpO2 (oxygen saturation) drops < 90% as well as readmission rates were compared between patients who did and did not use continuous positive airway pressure (CPAP). ResultsThere was no difference in the risk of SpO2 drop below 90% (1 versus 0%, P = 0.398) and readmission rate (2 versus 2%, P = 0.662) between patients who had low to moderate OSA risk (327 THA) and high OSA risk (814 THAs). There was no difference in SpO2 (P > 0.999) and a decrease in oxygen flow rate from the postanesthesia care unit to the morning of the first postoperative day. A CPAP device was used by 41% (467 of 1,141) of patients. There were no differences in SpO2 drop < 90% (0 versus 0%, P = 0.731) and readmission rate (2 versus 2%, P = 0.612) between patients who did and did not use a CPAP machine. ConclusionsThe current study showed no difference in perioperative outcomes between OSA patients undergoing THA who had a low STOP-Bang Score and patients who had a high STOP-Bang Score, regardless of the use of a CPAP machine. These data suggest that an elevated Stop-Bang Score does not indicate an increased perioperative risk for OSA patients when deciding on outpatient discharge.

A novel approach to wastewater treatment control: A self-organizing fuzzy sliding mode controller

&lt;p&gt;The treatment of wastewater plays a crucial role in protecting the environment and ensuring the sustainable use of resources. This research paper presents a new methodology for managing wastewater treatment operations, utilising Self-Organizing Fuzzy Sliding Mode Controller (SOFSMC) to enhance the efficiency of treatment procedures. MATLAB Simulink functions as a simulation tool that facilitates meticulous analysis. SOFSMC presents a control strategy that is both adaptive and robust. This strategy effectively regulates crucial parameters, including dissolved oxygen levels, pH levels, and flow rates. It achieves this within the challenging and complex framework of wastewater treatment, which is characterised by dynamic and nonlinear dynamics. Using a SOFSMC for wastewater treatment control is novel approach. This novel technique creates a self-learning, dynamic system using fuzzy logic (FL) and sliding mode control (SMC). This unique approach can autonomously adapt to wastewater treatment processes' complex and nonlinear dynamics, improving efficiency, resource optimisation, and system dependability. The results emphasise the potential of SOFSMC as a revolutionary approach for wastewater treatment. This approach can improve treatment effectiveness, conserve resources, and protect the environment. The proposed method SOFSMC, exhibits commendable outcomes, with an integrated absolute error of 0.082 mg/L, an integrated square differential error of 0.091 mg/L, and a response time of 1.85 seconds This study offers a substantial advancement in the field of wastewater treatment regulation, highlighting its significance in the context of sustainable water management and environmental conservation.&lt;/p&gt;

Preparation, microstructure and properties of Yb2O3-x optical hydrophobic films for infrared windows

In order to improve the adaptability of infrared windows in harsh wet environments, Yb2O3-x films were prepared by ion assisted reactive thermal evaporating deposition. The surface morphology, microstructure, composition, optical properties, hardness, residual stress and hydrophobicity of Yb2O3-x films were comprehensively characterized. The effects of the oxygen flow rate on the properties of the Yb2O3-x films had been explored. It is found that the root-mean-square roughness of the films increases as the flow rate increases from 10 sccm to 35 sccm. The crystallization characteristics are closely related to the oxygen flow rate, and the film prepared at 15 sccm exhibits the best crystallinity. X-ray photoelectron spectroscopy (XPS) testing shows that the ratio of Yb to lattice oxygen decreases, while the content of trivalent Yb ions in the film increases with increasing oxygen flow rate. Thin film prepared at lowest oxygen flow rate exhibits highest optical absorption, which is related to oxygen defects in the films. Moreover, films prepared at 15 sccm, 25 sccm and 35 sccm show good transparency in the long-wave infrared band. The hardness of the film prepared at 15 sccm is about 9 GPa. Due to change in density of the thin film, the compressive stress of the film decreases with increase of oxygen flow rate. The hydrophobicity of the film is affected by the surface chemical composition and surface roughness, and the maximum water contact angle is 100°. In a word, the Yb2O3-x films are found to be excellent hydrophobic protective coatings for infrared windows.