Mixing Rate Research Articles

Peripheral markers of nitrosative stress in children with autism spectrum disorder and bipolar disorder comorbidity during euthymic phase

BackgroundBipolar Disorder (BD) is often comorbid with Autism Spectrum Disorder (ASD) (Skokauskas & Frodl, 2015). However, to our knowledge, the etiological pathways of BD comorbidity in individuals with ASD was not given a particular focus in the literature. The present study aims to investigate the link between BD comorbidity and nitrosative stress in children and adolescents with ASD. MethodThe case group consisted of 41 participants with comorbid ASD and BD, while the control group consisted of 39 participants with ASD who did not have any past or present mood disorders. As indicators of nitrosative stress, serum levels of NO (Nitric Oxide), NO2/NO3 (Nitrite/Nitrate), 3-NT (3-Nitrotyrosine) and NOS-I (Nitric Oxide Synthetase-I) were compared between groups. ResultsSerum levels of NO and 3-NT were significantly higher in the case group. As the phenomenological findings of BD, the age of onset was 10.5, mixed attack rate was 70%, seasonality rate was 63.8%, and sub-threshold symptoms were seen in 36.6% of the cases. ConclusionThe present study indicated a relationship between BD comorbidity and nitrosative stress cascade among children and adolescents with ASD. Further studies with larger samples are needed to better understand the etiology of BD comorbidity in patients with ASD.

Numerical Modeling of the Dispersion Characteristics of Pollutants in the Confluence Area of an Asymmetrical River

It is challenging to investigate the transport and dispersion of contaminants in river confluence areas due to the complex flow dynamics. In recent studies on the flow dynamics in river confluence areas, it has been revealed that changes in inflow conditions (discharge ratio, width-depth ratio and concentration difference) can greatly influence pollutant diffusion. In this study, an asymmetric confluence-type river is modeled by a three-dimensional hydrodynamic water quality model, and three hydrodynamic scenarios are numerically simulated. The results show that a higher discharge ratio and width-depth ratio led to an increase in the lateral diffusion area of pollutants, deviation in the trajectory line of the mixing interface towards the opposite bank of the interchange, and an increase in the mixing rate of pollutants. For R = 0.267 and b/h = 3.75, the pollutants at the bottom are completely mixed in the exit end section. However, the difference in the pollutant concentration slightly affects the area, length and shape of the pollutant dispersion zone and notably affects only the concentration in each section.

The prevalence of urinary incontinence and risk factors in menopausal women in Turkey: A systematic review and meta‐analysis

AbstractThis study was conducted to determine the prevalence and risk factors of urinary incontinence in menopausal women. This systematic review and meta‐analysis followed PRISMA and COSMOS‐E guidelines. The searches were conducted on 1–15 April, 2022 using PubMed, EBSCO, Embase, PsycINFO, DOAJ, Web of Science, DergiPark, Scopus, Turkish Medline, Turkish Citation Index, TR Index and National Thesis Center search engines. The keywords ‘menopause, climacteric, urinary incontinence, risk factors, prevalence’ were used in the searches. The risk of bias was assessed using the Critical Appraisal Checklist for cross‐sectional studies developed by the Joanna Briggs Institute. Data were synthesized by meta‐analysis, meta‐regression and narrative methods. Eleven studies published between 2012 and 2022 were included. The total sample size of the studies was 2531. In this meta‐analysis, the estimated rate of urinary incontinence in women aged 40–65 years was 46.9% (95% CI: 0.346–0.595), and this result was statistically significantly affected by the moderator variables risk of bias (Q = 8.76, p = 0.013) and urinary incontinence diagnostic tools (Q = 27.60, p < 0.001). The estimated stress urinary incontinence rate was 19.1% (95% CI: 0.130–0.271), urge urinary incontinence rate was 5.1% (95% CI: 0.020–0.124) and the mixed urinary incontinence rate was 13.4% (95% CI: 0.092–0.192). The risk factors affecting urinary incontinence were found to be advanced age, menopause, diabetes mellitus, constipation, obesity, history of urinary incontinence during pregnancy and the postpartum period, mode of delivery, four or more births, urinary tract infection, family history of urinary incontinence and genetic predisposition. This meta‐analysis revealed that urinary incontinence and its types are highly prevalent in women aged 40–65 years and that the prevalence is influenced by the quality of research and the type of diagnostic tool used in addition to many risk factors. Planning and offering appropriate health care services based on these results could contribute to the protection and improvement of women's health.

Optimization of the Drawing Process of Low–Middle-Thickness Top Coal Based on a Simulation

Based on a theoretical analysis and simulation, the automated drawing characteristics for low–middle-thickness top coal are investigated, and the drawing process of top coal is optimized. For top coal with a 3 m thickness, a comparison is made between traditional and automated drawing process of top coal, which is used to highlight the superiority of automated drawing process. Then, for the automated top coal drawing, the effects of the round number on the drawing results of the entire working face are investigated, and the advantages and disadvantages of the multi-round drawing process are compared. Finally, the coal drawing results combined with automated and traditional methods are discussed, and an ideal optimized coal drawing process is proposed. The research results indicate that, for top coal with a 3 m thickness, the recovery rate of top coal by automated one-round drawing is slightly higher than that of traditional drawing, the drawing amount and drawing time of various drawing openings are relatively uniform for automated drawing, while the traditional coal drawing process shows fluctuating characteristics. For automated multi-round drawing, the top coal recovery rate decreases with an increase in the round number; however, the rock mixed rate in the drawn top coal is lower, and the drawing results at various drawing openings become more uniform. The combined automated–traditional drawing can achieve layered drawing of the top coal, avoid gangue drawing, and maintain a relatively high recovery rate, which is the optimal drawing process for this research project.

Focused ultrasound as an alternative to dry needling for the treatment of tendinopathies: A murine model.

Tendinopathies account for 30% of 102 million annual musculoskeletal injuries occurring annually in the United States. Current treatments, like dry needling, induce microdamage to promote healing but produce mixed success rates. Previously, we showed focused ultrasound can noninvasively create microdamage while preserving mechanical properties in ex vivo murine tendons. This present study compared growth factor, histological, and mechanical effects after focused ultrasound or dry needling treatments in an in vivo murine tendon injury model. Partial Achilles tenotomy was performed in 26 rats. One-week postsurgery, tendons were treated with focused ultrasound (1.5 MHz, 1-ms pulses at 10 Hz for 106 s, p+ = 49 MPa, p- = 19 MPa) or dry needling (30 G needle, 5 fenestrations over 20 s) and survived for 1 additional week. Blood was collected immediately before and after treatment and before euthanasia; plasma was assayed for growth factors. Treated tendons and contralateral controls were harvested for histology or mechanical testing. No differences were found between treatments in release of insulin growth factor 1 and transforming growth factor beta; vascular endothelial growth factor A concentrations were too low for detection. Histologically, focused ultrasound and dry needling tendons displayed localized fibroblast infiltration without collagen proliferation with no detectable differences between treatments. Mechanically, stiffness and percent relaxation of dry needling tendons were lower than controls (p = 0.0041, p = 0.0441, respectively), whereas stiffness and percent relaxation of focused ultrasound tendons were not different from controls. These results suggest focused ultrasound should be studied further to determine how this modality can be leveraged as a therapy for tendinopathies.

Optimization for biohydrogen purification process by chemical absorption techniques

Palm oil decanter cake and crude glycerol, which are characterized by their highly biodegradable organic content and nutrient-rich composition, are attractive ingredients for biohydrogen production. In this experiment, we investigated (1) how to produce hydrogen more effectively by co-fermenting palm oil decanter cake and crude glycerol and (2) how to improve the quality of the hydrogen gas produced via chemical absorption technology. This study was divided into two parts. In the first part, the co-fermentation was conducted with a fixed decanter cake concentration of 1% total solids (TS) w/v and variable crude glycerol concentrations (0.25–2.0% w/v). The results showed that maximum biohydrogen production was achieved with 2.0% w/v crude glycerol, which had a hydrogen yield of 131 L kg−1 TSadded and a hydrogen productivity of 1310 mL L−1 d−1. In the second part of the experiment, biohydrogen purification was conducted using the chemical absorption technique by varying four different alkaline solutions: mono ethanolamine (MEA), ammonia (NH3), sodium hydroxide (NaOH), and potassium hydroxide (KOH). The highest hydrogen purity of 98.9% v/v was reached with the MEA solution at a 5 M concentration and a 280 mL min−1 feed mixed gas flow rate for an absorption time of 5 min. However, to achieve sustainable waste management in palm oil mill plants, the feasibility of integrating the biohydrogen production process with palm oil mill effluent from the biogas plants and applying a hydrogen gas quality improvement system need to be investigated further.

Study on the effect of turbulent jet combustion chamber on combustion characteristics at different ammonia energy ratio and optimization of an ammonia-diesel dual-fuel engine

In order to investigate the impact of turbulent jet combustion chamber (TJCC) on the combustion and emission characteristics of an ammonia-diesel dual-fuel (ADDF) engine and optimize the injection strategy of TJCC to achieve efficient and clean combustion at high ammonia energy ratio (AER), this paper established a three-dimensional simulation model. The findings demonstrated that raising the AER from 50% to 90% under heavy load conditions resulted in an increase in ITEg from 47.3% to 50.6% due to more uniform fuel distribution in the cylinder. Additionally, there was a significant reduction of over 70% in greenhouse gas (GHG) emissions, along with a decrease in the amount of diesel. The turbulent jet from TJCC caused the turbulence kinetic energy to rise in both intensity and range, which improved the mixing rate of diesel-ammonia-air and the flame propagation. The ITEg increased by 3.3%, 2%, and 0.7%, respectively, under the impact of the turbulent jet when AER was 50%, 70%, and 90%, respectively, compared to not injecting diesel in the TJCC. Finally, the ITEg reached 51.9% and unburned NH3, NO, and NO2 emissions were significantly reduced when AER was 90% and 10 mg of diesel was injected at 4°CA ATDC in the TJCC.

Analysis of parainfluenza virus infection in acute respiratory tract infection adult cases in Shanghai, 2015-2021

Objective: To study the infection status and epidemiological characteristics of parainfluenza virus (PIV) in acute respiratory tract infection adult cases in Shanghai from 2015 to 2021, and to provide a scientific basis for preventing and controlling PIV. Methods: Acute respiratory tract infections were collected from 13 hospitals in Shanghai from 2015 to 2021. Relevant information was registered, and respiratory specimens were sampled to detect respiratory pathogens by multiplex PCR. Results: A total of 5 104 adult acute respiratory tract infection cases were included; the overall positive rate of the respiratory pathogens was 29.37% (1 499/5 104). The positive rate of PIV was 2.61% (133/5 104), compared with 2.32% (55/2 369) and 2.85% (78/2 735) in influenza-like cases (ILI) and severe acute respiratory infection (SARI) cases, respectively. Among them, PIV3 accounted for the highest proportion (62.41%, 83/133), followed by PIV1 (18.80%, 25/133), PIV2 (9.77%, 13/133), and PIV4 (9.02%, 12/133). The incidence of PIV-positive cases was mainly distributed in the first and second quarters, accounting for 62.41% (83/133). The difference in the incidence in each quarter was significant (χ2=24.78, P<0.001). Mixed infection accounted for 18.80% (25/133) of 133 PIV-positive cases, the mixed infection rates of ILI and SARI were 18.18% (10/55) and 19.23% (15/78), respectively, and the main mixed pathogen of PIV was coronavirus 229E. Conclusions: There are a certain proportion of PIV-positive acute respiratory tract infection cases in Shanghai. It is necessary to strengthen the etiological surveillance in acute respiratory tract infection cases, especially the mixed infection of PIV and other pathogens.

Experimental study of the discharge process of a thermal energy storage system based on granular material operated as a fluidized or confined bed

The stable generation of green electricity by Concentrated Solar Power (CSP) plants is subjected to the proper performance of Thermal Energy Storage (TES) systems, which constitute a critical subsystem of the plant. TES systems based on granular material have already been tested for industrial scale, allowing the operation at high temperature. Depending on the particle size of the granular material and the velocity of the working fluid, the bed conforming the TES system may be operated in a bubbling fluidized or a fixed bed regime. Further, beyond minimum fluidization conditions the bed can operate as fixed if the particles are mechanically confined. The performance of the discharge process of a lab-scale TES system (20.5 cm of diameter, 1 m bed height and 55 kg of silica sand as bed material) of granular material operated as a fluidized bed and as a confined bed was experimentally analyzed for various air volumetric flow rates. For the fluidized bed configuration, the bed temperature was found to be uniform along the bed height due to the high axial mixing rate caused by gas bubbles. During the discharge process of the fluidized bed TES system, the bed temperature decreased exponentially from the initial bed temperature to the temperature of the cooling fluid, with a faster temperature reduction for higher flow rates of fluid. The confined bed operation resulted in a stable temperature of the fluid at the outlet, close to the maximum temperature of the system, for around 45 min when discharging the bed with 700 Nlpm of cold air, whereas after 45 min of the discharge process, the outlet temperature of gas for the fluidized bed was roughly half the temperature obtained from the confined bed. However, the average air pressure drop during the discharge of the TES system of granular material operated as a fluidized bed is stable at around 0.16 bar, while the pressure drop of the confined bed is significantly higher, decreasing from 0.65 to 0.30 bar as the discharge process of the bed progressed.

Developing a focused ultrasound treatment for tendinopathies in a large animal model

Current treatments for tendinopathies produce mixed success rates, with 0-84% of patients showing improvement. Our prior work in rats suggests mild microdamage induced by focused ultrasound (fUS) may perform better than traditional treatments for tendinopathies, like dry needling. Here, we work to scale our work in rats to larger animal models and develop treatment monitoring. Ex vivo bovine digital flexor tendons were obtained and injected with collagenase to induce chronic tendinopathy. One day later, tendons were treated with focused ultrasound at 1.1–3.68 MHz, with 1–10ms pulses at pressures up to p + = 127 MPa/p− = 35 MPa repeated at 0.2–1 Hz for up to 20 min. Treatments were monitored with passive cavitation detection (PCD; Sonic Concepts Y-107) and Philips/ATL L7-4 controlled by the Verasonics research ultrasound system in passive cavitation imaging (PCI) mode. Samples were collected for histological analysis. Preliminary results suggest that lower pulse repetition frequencies produce mild mechanical microdamage with no evidence of thermal necrosis. PCI and PCD results show no consistent trends to indicate the intended mechanical microdamage bioeffect has been achieved. Work is continuing to determine the treatment parameters that produce the intended bioeffects in the smallest time and to develop a means to monitor treatment progress. [Work supported by NIHR01EB032860.]

Influence of initial plume shape on miscible porous media flows under density and viscosity contrasts

The effect of the initial condition upon the transport dynamics of miscible flowing fluids in a porous medium is investigated under viscosity and density contrasts. Such flows have attracted significant attention due to their importance in many fields of science and engineering, such as $\mathrm {CO}_2$ sequestration and aquifer remediation. Using high-resolution two-dimensional numerical simulations, we illustrate the impact of viscosity and density contrasts on the temporal evolution of the spreading and mixing quantities. We show that such impact depends on the initial shape of the source distribution where the solute is injected and on the intensity of the horizontal background flux. We find that rates of mixing are dependent on whether the solute is more or less viscous than the ambient fluid, a result usually not taken into consideration in studies on gravity fingering. At higher background flux, the effects due to horizontal viscous fingering dominate over gravitational fingering. Our computational analysis also suggests a non-trivial relationship between mixing and the length of the plume's interface under fingering instabilities. Finally, we show how a stratified permeability field can interact with these sources of instabilities and affect the transport behaviour of the plume.

Optimization and scale-up of Clostridium perfringens type D culture and epsilon-toxin production: Effects of stirring, glucose and pH adjustment

The effects of some main bacteria culture parameters including mixing rate, glucose (GC) concentration, steps of GC addition, and steps of pH adjustment on both C. perfringens bacteria growth and its epsilon toxin production in a bench-scale 20-L glass carboy were investigated. The optimized mixing rate of 300 rpm, GC concentration of 4 g L−1, and 3-step addition of GC resulted in the bacteria and toxin concentrations of 0.16 g L−1 and 330 ng mL−1, respectively. Also, the induction of a pH shock at the reaction time of 180 min led to the remarkable enhancement of toxin production (367 ng mL−1). Upon applying both optimized conditions for GC addition and pH adjustment, the high toxin concentration of 433 ng mL−1 was obtained. Using the constant mixing rate technique, the process was scaled up to a 1500-L industrial bioreactor, where its performance was close to the bench-scale bioreactor (i.e., toxin concentration of 419 ng mL−1). The results revealed the reliability of this method to economically improve and scale up the bacteria culture process, which can be further used for other microbial fermentations.

Experimental investigation of the acid-oil emulsion stability influenced by operational conditions and oil properties

Improper design of acidizing may cause new induced formation damages in the form of stable acid-oil emulsion, which would hinder fluid flow inside the pore passages of reservoirs. Furthermore, unwanted reduction of injected acid capability to resolve precipitations and rock should also be expected because the acid droplets are trapped in crude oils. There are not enough experimental studies and data on the effect of operating conditions and crude oil properties on the stability of acid-oil emulsions. This study focused on the formation of emulsion and its stability as well as acid-induced sludge formation for various crudes affected by mixing intensity (as a representation of acid injection rate to the reservoir), acid volume percent or AMR (as a representation of acid volume in the porous medium), temperature and crude oil viscosity. The experimental results showed that there exists a direct relation between emulsion stability and the mixing speed, which depends on crude oil properties such as viscosity and asphaltic compounds. Three crude samples of A, B and C from an oil reservoir were tested. Samples A and B showed 20 and 4 % higher emulsion stability at a mixing speed of 1500 rpm compared to that at 500 rpm. Higher shear rates produce larger interfacial areas and maybe easier and faster adsorption of various protonated asphaltenes and precipitates. Furthermore, changes in temperature from 30 to 85 °C caused 37 and 63 % increase in emulsion stability, probably because of higher droplets and molecules kinetic energy. AMR had a reverse impact in such a way that changing from 0.2 to 0.8 resulted in 87 % reduction in emulsion stability for both samples of A and B. However, the emulsion stability of sample C had not been changed by AMR, temperature and mixing shear rate. It seems that little sensitivity existed in the case of less viscous sample (C). It can therefore be inferred that crude oil properties are imperative during emulsion formation. More experiments were performed for diluted crude B by a mixture of toluene and heptane, keeping colloidal instability index intact, for reducing its viscosity from 56 to 2.5 cP at ambient temperature. Finally, a reduction of 17 % was observed in emulsion stability at 85 °C, AMR of 0.5 and mixing speed of 1500 rpm. The findings of this study facilitated a better understanding of operating conditions which influence the stability of HCl-oil emulsions during acidizing jobs.

Numerical modeling of plunging jets of brine: Mass transport and implications for desalination plant outfalls

Plunging jets are used in many environmental and industrial applications to enhance mixing and mass transfer rates. One of the current challenges in applying plunging jet reactors for brine dispersal from desalination plants is that the density of brine causes the jet to drop straight to the seafloor. This hypoxic fluid disperses slowly and elicits a toxic effect on the local marine ecosystem. To provide new insights and improvements, we have developed a numerical model that considers the co-transport of brine in a two-phase air–fluid system. In our model, Navier–Stokes describes the transport of fluid, and Nernst–Planck describes the transport of dissolved brine. One of the key observations we made is that brine convection is characterized by competition between the positive buoyancy of air–fluid mixtures and the negative buoyancy of brine–fluid mixtures. Depending on the jet flow rate, the brine would either (1) ascend radially from the plume or (2) drop straight downwards. In our experiments, we demonstrate the same behaviors. Ultimately, it may be possible to reduce the destructive effects of high-density brine impinging on the seafloor by optimizing the jet to promote air entrainment, thus maintaining the system in its radial mixing regime.

Effects of gelatin concentration, adding temperature and mixing rate on texture and quality characteristics of model gels.

In this study, the effects of gelatin concentrations (GC) (5.0-10.0 g/100 g), mixing rate (MR) (100-1100 rpm), and gelatin addition temperature (GAT) (55, 60, and 65°C) were investigated on the main textural and various physicochemical properties of model gels (n = 72) prepared using sucrose and glucose syrup (40-42 DE). Considering the p-value of the F-statistic calculated by analysis of variance and the 5% significance level, the production parameters and their interactions had a significant effect on the quality parameters. The influence of the production parameters GC, MR, and GAT, and the interaction of these parameters, GC * MR, GC * GAT, MR * GAT, and GC * MR * GAT of the model gels on the quality characteristic were expressed by converting the Type III SS values into percent values. When all quality characteristics were considered together, MR was the most influential with a score of 58%. PCAmix, a combination of factorial analysis with PCA, was used to visualize the correlations between the production parameters and the quality characteristics of the modeled gels. A great influence was observed between MR and moisture content, color properties, and texture parameters, except springiness. A moderate effect of GC and a minor effect of GAT could be characterized. With the 2D-map of observations, the model gels could be clearly divided into two groups according to the MRs. In accordance with the observations diagram of PCAmix, the similarity dendrogram of AHC also formed two clusters, one cluster for the samples with MR 100 and 200 rpm and one cluster for the samples with MR 500 and 1100 rpm.

Numerical Investigation of the Influence of a Splitter Plate on Mixing Transfer in the Ducts of a Rotary Energy Recovery Device

The rotary energy recovery device (RERD) is integral in reducing energy consumption in desalination processes. The absence of a physical piston in RERD ducts allows salinity transfer from the brine to the seawater stream, which reduces RERD efficiency. To address this challenge, this study investigates the potential of utilizing splitter plates as a flow control technique to decrease the mixing degree within RERDs. Numerical simulations were performed to examine five different splitter plate configurations in RERD ducts in order to identify optimal designs for reducing the mixing degree. The analysis of internal streamlines and vortex distributions revealed that horizontal splitter plates positioned at the duct inlet effectively suppressed swirling flows, while splitter plates positioned at the center of the duct suppressed the formation of flow-induced vortices. This resulted in a more uniform salinity distribution and a reduction in the mass transfer rate between brine and seawater streams. The most significant reduction in the volumetric mixing rate was observed when employing cross-spread splitter plates positioned at the center of the duct. This paper presents an innovative method to reduce the mixing degree in the RERD.

ASSESSING THE LONG-TERM EFFECTS OF GST ON CHOSEN SECTORS IN THE INDIAN ECONOMY

The Goods and Services Tax (GST) has been a transformative tax reform in India, ushering in a unified and integrated tax structure for goods and services across the nation. This paper delves into the profound and diverse impacts of GST on key sectors, including Automobile, Agriculture, Financial, Infrastructure, and Hospitality. Drawing upon a rich tapestry of literature and quantitative data analysis, the study unveils nuanced sector-specific dynamics. The agriculture sector, following GST implementation, experienced mixed growth rates but showcased remarkable increases in GDP contribution, suggesting significant growth potential. The automobile sector maintained consistent GDP contributions, while the financial sector exhibited steady growth, Although with fluctuations in growth rates. The infrastructure sector faced declining growth rates, reflecting complex interactions with GST and broader economic reforms. The hospitality sector displayed consistent growth rates and an expanding role in the economy. The studys findings underscore the importance of sector-specific responses to GST, highlighting the need for tailored adaptation strategies. Recommendations include enhanced GST awareness and training programs, specialized impact assessment tools, and simplified compliance platforms. This study contributes to a comprehensive understanding of how GST has shaped various sectors, ultimately contributing to Indias economic evolution. KEYWORDS: Goods and Services Tax (GST), Tax Reform, Indian Economy, Sector-Specific Impact, Agriculture Sector, Automobile Sector, Financial Sector, Infrastructure Sector, Hospitality Sector, GDP Contribution, Growth Rates, Capital Investment, Sectoral Resilience, Compliance, Economic Evolution.

High-risk human papillomavirus distribution in different cytological classification women

High-risk human papillomavirus (HR-HPV) infection is a major cause of infection-related cancer worldwide. 3101 HR-HPV-positive females were retrospectively analyzed and grouped using the cervical cytological screening (ThinPrep cytological test, TCT) evaluations combined with colposcopy. The HPV16 infection rate is the highest in all groups. HPV16 was the most frequent in each group, with significant differences between the four groups (χ2 = 23.41, P = 0.0001). The distribution of HPV16 and HPV33 correlated with the pathologic stage in each group. The mixed infection rate of mRNA testing differs significantly between groups (P < 0.01, χ2 = 17.44, P = 0.002). HR-HPV infection duration of less than six months accounted for 87.65%, 6 and 12 months of persistent infection (28.28%), and more than one year of continuous infection accounted for only 16.48%. The top three HPV types in a group with a duration of more than 12 months were HPV52 (3.03%), HPV16 (2.55%), and HPV39 (1.58%). The least clearance types were HPV39 (63.48%), 56 (69.54%), and 52 (71.44%) more than 12 months. This study revealed the region's primary pathogenic subtypes on different cervical lesions and provided the basis for diagnosing and treating HPV infection.

Experimental Study on Heat Transfer Enhancement of Modified CuO Nanofluid in Helical Grooved Tube

This study proposes a novel technology to enhance heat transfer by combining nanofluid and helical grooved tubes. The researchers used a two-step method to obtain a stable modified CuO nanofluid. They then constructed an experimental setup to investigate the single-phase heat transfer of the nanofluid in a helical grooved tube, and compared its performance to traditional methods under varying volume fractions and Reynolds numbers. The experimental results indicate that the use of nanofluid in the helical grooved tube significantly improves the convective heat transfer coefficient. Furthermore, the heat transfer coefficient increases gradually with the addition of nanoparticle volume fraction and Reynolds number. The helical grooved tube’s internal structure causes local turbulence at low Reynolds numbers, intensifying the nano-scale eddies and turbulence inside the nanofluid, enhancing fluid mixing and thermal diffusion rates, and thus improving the heat transfer efficiency.

CFD-Based Thermal Abuse Simulations including Gas Generation and Venting of an 18650 Li-Ion Battery Cell

A high-resolution, 3D, computational fluid dynamics (CFD) model was developed and implemented for simulating the heat and gas generation during thermal runaway failure of an 18650 Li-ion battery cell. The model accounts for volumetric gas generation within the active material of the cell and for gas flow through the jellyroll, into the headspace regions, through the safety vent, and out into the surrounding air space. The simulation captures the key features of the oven test, including: self-heating from decomposition reactions, initial venting (i.e. blowdown), temperature decrease due to evaporative cooling, thermal runaway, a second venting event associated with thermal runaway, and cooldown. The highly detailed geometric model of the safety vent allowed for new insight into the physics of venting during thermal runaway. Secondary flows, including ring vortices, counter-rotating vortex pairs, and corner vortices, were found to increase the rate of mixing of the vented gases with the surrounding air. The simulation was compared to previously reported experimental results and found to have good qualitative agreement of jet flow direction. The present thermal abuse model forms the basis for future studies to consider the role of gas impingement heat transfer and gas combustion in full battery pack propagating failures.