Increase In Rate Research Articles

Nebulization and In Vitro Upper Airway Deposition of Liposomal Carrier Systems.

Liposomal carrier systems have emerged as a promising technology for pulmonary drug delivery. This study focuses on two selected liposomal systems, namely, dipalmitoylphosphatidylcholine stabilized by phosphatidic acid and cholesterol (DPPC-PA-Chol) and dipalmitoylphosphatidylcholine stabilized by polyethylene glycol and cholesterol (DPPC-PEG-Chol). First, the research investigates the stability of these liposomal systems during the atomization process using different kinds of nebulizers (air-jet, vibrating mesh, and ultrasonic). The study further explores the aerodynamic particle size distribution of the aerosol generated by the nebulizers. The nebulizer that demonstrated optimal stability and particle size was selected for more detailed investigation, including Andersen cascade impactor measurements, an assessment of the influence of flow rate and breathing profiles on aerosol particle size, and an in vitro deposition study on a realistic replica of the upper airways. The most suitable combination of a nebulizer and liposomal system was DPPC-PA-Chol nebulized by a Pari LC Sprint Star in terms of stability and particle size. The influence of the inspiration flow rate on the particle size was not very strong but was not negligible either (decrease of Dv50 by 1.34 μm with the flow rate increase from 8 to 60 L/min). A similar effect was observed for realistic transient inhalation. According to the in vitro deposition measurement, approximately 90% and 70% of the aerosol penetrated downstream of the trachea using the stationary flow rate and the realistic breathing profile, respectively. These data provide an image of the potential applicability of liposomal carrier systems for nebulizer therapy. Regional lung drug deposition is patient-specific; therefore, deposition results might vary for different airway geometries. However, deposition measurement with realistic boundary conditions (airway geometry, breathing profile) brings a more realistic image of the drug delivery by the selected technology. Our results show how much data from cascade impactor testing or estimates from the fine fraction concept differ from those of a more realistic case.

Studying Plastic Deformation Mechanism in β-Ti-Nb Alloys by Molecular Dynamic Simulations

Using molecular dynamics (MD) simulations, the transition of the plastic deformation mechanism of Ti-Nb alloys during the tensile process was studied, and the effects of temperature, Nb composition, and strain rate on the deformation mechanism were also investigated. The results show that the deformation process of Ti-Nb alloys involves defect formation, followed by twinning and ω-phase transition, and ultimately, dislocation slip occurs. The <111>{112} slip makes the ω-phase easily overcome the transition energy barrier, inducing the phase transition in the twinning process. Increasing temperature will enhance the plasticity and reduce the strength of the material, while increasing Nb composition will have the opposite effect on the deformation. The simulations show a competition between twinning and dislocation slip mechanisms. With the increase in Nb content, the plastic deformation mechanism of the alloy will change from twinning to dislocation slip. In addition, the plastic strain range increases with the increase in the deformation rate in Ti-Nb alloys. At a higher strain rate, the alloy’s plastic strain range is affected by various deformation mechanisms, which significantly influence the plasticity of the material. The findings of this study provide further insights into the design of Ti-Nb-based alloys.

Incidence, mortality and survival rates of lip, oral cavity and salivary glands cancers in Singapore: A half-century time trend analysis (1968-2017).

To examine trends in incidence and mortality and evaluate overall survival (OS) of oral cancer in Singapore between 1968 and 2017. All diagnosed oral cancers by anatomical sites and population size were extracted from the Singapore Cancer Registry and the Department of Statistics Singapore. The trend of age-standardized incidence rate (ASIR) and mortality rate (ASMR) (per 100 000 person-years) of the lip, oral cavity and salivary gland cancers were evaluated by Prais-Winsten regressions for each ethnicity and gender. Kaplan-Meier curves were performed to evaluate the OS by anatomical sites in each age group by ethnicity and sex. Overall, 49, 3494 and 1066 people were diagnosed, and 28, 2310 and 476 died from lip, oral cavity and salivary gland cancers, respectively. The oral cavity cancer ASIR and ASMR reduced from 3.07 (1968-1972) to 2.01(2008-2012) and from 2.06 (1978-1982) to 1.21 (2013-2017) per 100 000 person-years, respectively, with both highest in Indians throughout the whole period. Male:Female ratio ranged from 3.43 (1973-1977) to 1.75 (2013-2017) and from 3.41 (1978-1982) to 2.40 (2013-2017) for ASIR and ASMR, respectively. However, both salivary gland cancer ASIR and ASMR increased from 0.50 (1968-1972) to 0.80 (2008-2012) and from 0.18 (1968-1982) to 0.42 (1988-1992) per 100 000 person-years, respectively, with both higher in males since 1993. Oral cavity cancer ASIR decreased for males aged ≥60, and Indian females ≥25, but increased among Chinese females aged ≥60. Oral cavity cancer ASMR decreased among Chinese aged 25-59, and among Malay males and Indian females. Salivary gland cancer ASIR increased among Chinese males aged ≥60 and Malay males aged 25-59; while ASMR increased among Chinese males aged ≥60. The median OS for oral cavity, lip and salivary gland cancers were 3.0, 9.3 and 18.1 years, respectively, with females surviving longer than males. Singapore has experienced a decline in the incidence and mortality of lip, oral cancer, an increase in in the incidence and mortality of salivary gland cancer, with an increase in the median overall survival rate. Monitoring the magnitude of oral cancer burden and the demographic, and temporal variations is necessary for tailoring health planning and setting priorities for future clinical care and research.

Integration of RS and GIS in assessing flood risk: A Case Study on Istanbul - Esenyurt

Floods, exacerbated by escalating urbanization, pose significant threats to life and property globally. Over the past decade, the Esenyurt district in Istanbul has witnessed a series of floods, highlighting existing flood risks. Rapid population growth in this area and dense urbanization caused by intensive construction increase flood risks. Given these factors, the study focuses on examining the historical impact of urbanization on flood risks, considering spatial and temporal changes. Landsat-8 satellite data, specifically examining NDVI, NDBI, and BU, was employed to detect building imprints and reveal their historical backgrounds for temporal risk calculations. The analysis showed a sudden increase in urbanization rates in 2016, 2017, and 2021. In the flood risk calculations, 2014 data for a return period of 100 years were used and flood inundation depth, economic damages, affected population and depth-damage function were taken into consideration. The results indicate that from 2014 to 2022, increasing urbanization led to a 32.9% increase in the population affected by floods, a 22.3% rise in potential economic damage, and a 13.6% increase in total flood risk. The relationship between flood risks, contemporary urbanization, and its economic dimensions has been evaluated to reduce risks and achieve sustainable cities.

Analysis of changes in the action potential morphology of the mouse sinoatrial node true pacemaker cells during ontogenetic development in vitro and in silico.

Maturation of the mouse is accompanied by the increase in heart rate. However, the mechanisms underlying this process remain unclear. We performed an action potentials (APs) recordings in mouse sinoatrial node (SAN) true pacemaker cells and in silico analysis to clarify the mechanisms underlying pre-postnatal period heart rate changes. The APs of true pacemaker cells at different stages had similar configurations and dV/dtmax values. The cycle length, action potential duration (APD90 ), maximal diastolic potential (MDP), and AP amplitude decreased, meanwhile the velocity of diastolic depolarization (DDR) increased from E12.5 stage to adult. Using a pharmacological approach we found that in SAN true pacemaker cells ivabradine reduces the DDR and the cycle length significantly stronger in E12.5 than in newborn and adult mice, whereas the effects of Ni2+ and nifedipine were significantly stronger in adult mice. Computer simulations further suggested that the density of the hyperpolarization-activated pacemaker сurrent (If ) decreased during development, whereas transmembrane and intracellular Ca2+ flows increased. The ontogenetic decrease in IK1 density from E12.5 to adult leads to depolarization of MDP to the voltage range in which calcium currents are activated, thereby shifting the balance from the "membrane-clock" to the "calcium-clock."

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity.

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk. Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Chemical reaction effect across the moving flat plate with heat generation and MHD flow of Maxwell fluid with viscous dissipation

In this paper, the investigation centered on examining a Maxwell fluid’s convective double diffusive flow carefully considers factors such as chemical reactions, radiation, and the presence of a permeable moving flat plate. Additionally, the study encompassed the effects of heat generation and magnetohydrodynamics (MHD). The governing equations, initially expressed as partial differential equations, were converted into ordinary differential equations using a similarity transformation technique to facilitate the analysis. The computational power of MATLAB’s BVP4C software was harnessed to solve this resultant system of ODEs efficiently. The outcomes of this investigation were presented in the form of graphical representations that vividly depicted the behavior of the flow field, energy conservation, and concentration profiles under various parameter combinations. The research findings were thoughtfully summarized in a table, offering a comprehensive overview of temperature, velocity, and mass profiles across various parameters. These parameters included the Deborah number, chemical reaction rate, Eckert number, Lewis number, Prandtl number, porosity parameter, and MHD parameter. A notable discovery emerging from this study was the inverse relationship observed between nondimensional concentration contours and the magnitude of the chemical reaction rate. Simultaneously, it was observed that higher values of the Maxwell fluid led to a rise in the thickness of the temperature boundary layer. These findings offer valuable insights into the intricate interplay of physical and chemical phenomena in convective flows involving complex fluid properties and boundary conditions. The temperature outline diminishes as the heat generation rate increases, while the concentration profile declines with an elevation in the chemical reaction rate.

An investigation of vibrational analysis, thermodynamics properties and electronic properties of Formaldehyde and its stretch by substituent acetone, acetyl chloride and methyl acetate using first principles analysis

This study finds the equilibrium configuration, vibrational analysis, thermodynamic properties, and electronic properties of formaldehyde and its derivatives, namely acetone, acetyl chloride, and methyl acetate, using First Principles Analysis. It emphasizes the impact of substituents on the carbonyl group and the need for this comprehensive analysis. The computational methods employed in this work are Gaussian DFT), GaussSum and Moltran calculations. For formaldehyde, the optimization step starts from the energy of -114.51282 Hartree and gets optimized in the energy -114.5129634 Hartree. Similarly for Acetone, Acetyl chloride and Methyl acetate, optimization step start from -193.74375 Hartree, -613.26 Hartree, -266.805 Hartree and gets optimized in the energy -193.1744033 Hartree, -613.2941798 Hartree, -266.8358066 Hartree. Infrared (IR) spectroscopy is used to analyze vibrational frequencies. The C-H and C=O vibrations are highlighted, showing characteristic peaks for each compound. Heat capacity at constant volume (Cv), heat capacity at constant pressure (Cp), internal energy (U), enthalpy (H), entropy (S) and Gibb’s free energy (G) with change in temperature sharply increase from 10 K to 50 K and decreases the increase in rate from 50 K to 500 K. In the derivative of Formaldehyde, Methyl Acetate has the highest energy gap (i.e. -7.4222 eV) and Acetyl Chloride has the small energy gap (i.e. 5.6137 eV). The Chemical parameters like ionization potential, electron affinity, chemical hardness, chemical potential, electronegativity, electrophilicity index, and chemical softness have been also calculated. Electrostatic Potential (ESP) Surfaces, Molecular Electrostatic Potential (MEP), and Electron Density (ED) are visualized to understand charge distribution and reactivity regions. DOS spectra illustrate the density of electron states per unit energy.

Effect of the Physiological Parameters of Different Age Group Workers on Hoe Weeder

Research was done on the influence of physiological characteristics of different age groups on the hoe weeder at an agriculture working field (10 x 10 m2). Physiological indicators such as heart rate, oxygen consumption rate, and energy expenditure rate of workers of various ages (21–24, 25-28, 29–32, and 33–36 years) were measured while working on a hoe weeder in an agricultural field. Age-related increases in heart rate, oxygen consumption, and energy expenditure were seen among agricultural laborers in a 10 × 10 m2 field. The heart rate, oxygen consumption rate, and energy expenditure rate of those aged 21 to 24 were found to be the lowest while working on a hoe or weeder in an agricultural field. The physiological characteristics of the age group operator of 33–36 years were determined to be the same.

High-Temperature Tensile Behavior of an As-Cast Ni-W-Co-Ta Medium–Heavy Alloy

High-temperature tensile experiments with tensile rates ranging from 0.01 s−1 to 10 s−1 were carried out at various temperatures ranging from 1000 °C to 1250 °C with a Gleeble-3800 thermal simulation tester to evaluate the physical properties of an as-cast Ni–W–Co–Ta medium–heavy alloy. The microstructure evolution of the alloy during high-temperature stretching was characterized by metallographic microscopy, scanning electron microscopy, and transmission electron microscopy. The results indicated the emergence of multiple slip lines and the parallel arrangement of dislocations in the grain of the alloy after high-temperature stretching, and typical characteristics of plane slipping were observed. The plasticity of the Ni–W–Co–Ta medium–heavy alloy increased, but its strength decreased with an increase in the deformation temperature. In contrast, an increase in the strain rate resulted in a noticeable increase in the strength and plasticity of the medium–heavy alloy. The experiments revealed that the maximum tensile strength of the as-cast Ni–W–Co–Ta medium–heavy alloy was 735 MPa (T = 1000 °C, ε˙ = 10 s−1). Additionally, the maximum reduction in area and elongation was 38.1% and 11.8% (T = 1250 °C, ε˙ = 10 s−1), respectively. The mode of fracture after high-temperature tensile deformation was brittle fracturing.

Adaptive Data Transmission Protocols for Energy Harvesting WSNs Used in Agriculture

Energy consumption is a major concern in wireless sensor networks (WSNs) as it affects the lifespan of sensor nodes. Battery-based WSNs have a short operating period, which makes them impractical for real-time applications, for instance in agriculture. Energy harvesting and suitable medium access control (MAC) protocols have been used to extend the lifetime of nodes. Receiver-initiated protocols have been proved to be the best solution for energy harvesting WSNs. However, they suffer from a key disadvantage, i.e. an increase in collision rate. These collisions need to be reduced using a multi-layer protocol structure. In such a context, a new solar-based hybrid MAC (SHMAC) protocol relying on receiver-initiation and characterized by a multi-layer structure is proposed. It is an adaptive protocol capable of adapting to changing weather conditions. The nodes with a high energy harvesting rate have a higher level of residual energy and are active for longer time periods compared with those with low energy harvesting characteristics. The proposed work has shown improvements in two major MAC layer parameters, i.e. collision rate and energy neutrality operation ratio (ENO).

Is respiratory sinus arrhythmia a modifiable index of symptom change in cognitive behavioral therapy for youth? A pooled-data analysis of a randomized trial

Objective We evaluated whether respiratory sinus arrhythmia (RSA) reactivity and resting RSA—physiological markers reflecting the increase in heart rate with inspiration and decrease during expiration related to parasympathetic influence on the heart—are modifiable and predict symptom change during youth psychotherapy. Methods: Diverse youth (N = 158; ages 7–15; 48.1% female) received the Modular Approach to Therapy for Children and completed pre-treatment (pre), post-treatment (post), and 18-months postbaseline (18Mo) assessments. We measured resting RSA, RSA reactivity during stress induction, and psychopathology symptoms. Results: Pre-to-post and pre-to-18Mo, reactivity decreased, and resting RSA increased. Changes in reactivity and resting RSA, separately, did not predict reduced psychopathology. Yet, decreased reactivity combined with increased resting RSA predicted reduced psychopathology over time, suggesting that observed RSA changes were beneficial for some. Higher dosage of a module utilizing slow-breathing, muscle-relaxation, and imagery predicted greater pre-to-18Mo changes in reactivity and resting RSA, whereas a similar module with less emphasis on slow-breathing did not. Conclusions: Findings raise the possibility that youth reactivity and resting RSA could be modifiable during cognitive behavioral therapy and contribute to the amelioration of psychopathology. More studies are needed to determine whether resting RSA and RSA reactivity are modifiable indices of symptom change in slow-breathing practices and psychotherapy. ClinicalTrials.gov Identifier NCT03153904, registered May 15, 2017.

Experimental investigation of a novel-designed inclined solar still with bio-wick under dynamic water flow

ABSTRACT This study experimentally investigates the inclined solar still (ISS) with the incorporation of fins and natural bio-jute cloth under dynamic flow. Experiments are conducted on bright sunny summer days in Coimbatore, Tamil Nadu, India. The newly developed ISS features greatly support passive solar desalination. An increase in mass flow rate (Mf) increases heat transfer meticulously pointing out 0.65, 0.8, and 1 kg/min case absorber, and the water temperature difference is within 3°C. An Mf of 0.285 kg/min is secure for the maximum water temperature reach and clean water yield of 70°C and 4.1 kg/m2, respectively, along with jute cloth, it was 1.6 kg/m2 more against without jute cloth. The presence of a jute cloth cumulative water yield of 2.5 kg/m2 at 0.635 kg/min is very close to the absence of a wick cumulative yield of 2.3 kg/m2 during 0.285 kg/min. From these results, the authors conclude higher Mf is feasible to increase the still performance and clean water yield. The implementation of a fully renewable passive solar still is strongly recommended to attain renewable and sustainable desalination.

Asymmetric Two-Step Thermosiphon for Containment Cooling of Small Modular Reactors

A thermosiphon is a heat transfer device that utilizes the phase change of a liquid and has a single closed-loop shape in a gravity-dominant field. This can be expressed as a single-step thermosiphon because boiling and condensation occur once per cycle. In contrast, the multistep thermosiphon, introduced for the first time in the field of thermal engineering in this study, is a new heat transfer mechanism in which boiling and condensation occur several times per cycle in a single loop with multiple channels. The new mechanism has a superior heat transfer rate compared to the existing single-step thermosiphon, and the operating pressure of the loop can be lowered. However, as the heat transfer rate increases, the circulation flow in the channel tends to pulsate. This thermohydraulic characteristic was confirmed through theoretical and computational analyses of a two-step thermosiphon. In this study, an improved concept of an asymmetric two-step thermosiphon was developed that can be applied to heat exchanger design by eliminating pulsating flow while maintaining the advantages of a two-step thermosiphon. The newly proposed heat transfer mechanism, termed the multistep thermosiphon, can be effectively used in the design of heat exchangers in industrial fields. In particular, if the asymmetric two-step thermosiphon is applied to the design of small nuclear reactor containments currently being developed in several countries, there are several advantages associated with the reduction of the containment volume and design pressure.

Epidemiology of oral cancer in South and South-East Asia: Incidence and mortality.

This study provides an epidemiological description of cancer in the lip, oral cavity, and oropharynx in the South and South-East Asia region. The number of new cases and deaths was extracted from the GLOBOCAN 2020 and the CI5 series. We present age-standardized incidence and mortality rates per 100,000 inhabitants. To assess temporal trends, we estimated the annual percent change. The incidence rates (ASR) for lip and oral cavity cancer in South and South-East Asia were highest in Taiwan (30.2), Sri Lanka (16.5), India (14.8), and Pakistan (13.2) among males. For oropharyngeal cancer, the highest rates were found in Taiwan (4.7), Bangladesh, Sri Lanka, and India (4.3, 2.9, and 2.6, respectively). Incidence rates were consistently higher in males compared to females. Overall, trends in lip and oral cavity cancer incidence were either stable or decreasing in most of the populations evaluated. In India, an increase in rates among males contrasted with a decline among females over the study period. Incidence and mortality rates of oral cavity cancer in South and South-East Asia are among the highest globally. Our results suggest an optimistic trend of reduction in oral cavity rates in the region, despite an increase in rates among Indian males.

Research on a Vibrationally Tuned Directional Seed Supply Method Based on ADAMS-EDEM Coupling and the Optimization of System Parameters

We have combined the theory of bulk dynamics and the agronomic requirements of precision sowing with the aim of resolving the technical problems of poor seed mobility and the difficulty in controlling suction posture, which leads to an increase in the leakage rate and a reduction in seed qualification index scores. In this study, a vibrationally tuned directional seed supply method and system are proposed. We carried out a force analysis of seeds, constructed kinematic equations for seeds and seed boxes to specify the state of the seed motion, and determined the structural parameters and the range of structural parameters that affect the seed suction posture. In addition, we coupled the ADAMS-EDEM simulation of the motion process of the seed and seed boxes and analyzed the vibrational tuning process of the seeds and the angle of inclination of the bottom surface of the seed box. The speed of the eccentric wheel and the eccentric distance were used as test factors. Three-factor and three-level Box–Behnken central combination testing with a single-grain rate, multiple-grain rate, and cavity rate were used as response indicators. Mathematical models were obtained between the experimental factors and the response indicators. Multi-objective optimization of mathematical regression models was carried out with Design-Expert 10.0.4 software. The optimal parameter combination obtained was a tilt angle of 14.27°, an eccentric wheel speed of 4.48 rad/s, and an eccentricity of 1.94 mm. The rate of single grains was 90.75%, the rate of multiple grains was 3.63%, and the rate of cavities was 5.62%. In bench performance tests, using an angle of inclination of 14°, the speed of the eccentric wheel was 4.50 rad/s and the eccentricity was 2 mm. The mean value of the single-grain rate was 89.28%, the mean value of the multiple-grain rate was 3.89%, and the mean value of the cavity rate was 6.83%. The test error was within permissible limits, and reliable results were achieved for parameter optimization. The results met the technical requirements for precision sowing. The results of the study can provide academic references for theoretical research on the methodology of posturing and directional seed supply. They can also provide ideas for the design and development of seed supply systems for precision sowing machinery.

Graphene promotes the growth of Vigna angularis by regulating the nitrogen metabolism and photosynthesis.

Graphene has promising applications in agriculture and forestry. In the current study, six different concentrations of graphene (0mg/L, 0.01mg/L, 0.10mg/L, 1.00mg/L, 10.00mg/L, and 100.00mg/L) were used to investigate its effect on the growth and development of V. angularis plants in soil culture. The results showed that the group treated with 1.00mg/L graphene (G-1) had significantly increased plant height (19.86%), stem diameter (24.33%), and leaf area (13.69%), compared to the control group (CK). Moreover, all concentrations of graphene had positive effects on the total root length, total root surface area, and the number of root tips of V. angularis. Compared to the CK group, the G-1 group had significantly increased leaf water potential (37.89%), leaf conductivity (2.25%), and SOD, POD, and CAT activities (47.67%, 35.22%, and 199.3%, respectively). The G-1 group also showed improved leaf net photosynthetic rate, chlorophyll content, and soluble sugar content (51.28%, 24.25%, and 38.35%, respectively), compared to the CK group. Additionally, 1.00mg/L graphene led to a 23.88% increase in the podding rate and a 17.04% increase in the yield of V. angularis plants. The rhizosphere soil of V. angularis treated with 1.00mg/L graphene had a 25.14% increase in hydrolyzable nitrogen content and a 66.67% increase in available phosphorus content. RNA-seq data indicated that 1.00mg/L graphene induced the expression of photosynthesis and nitrogen transmembrane transport genes, including ATP synthase subunit b, photosystem I reaction center subunit XI, photosystem I reaction center subunit IV A, ferredoxin, and psbP-like protein 1, as well as genes for photosynthesis antenna proteins, glutamine synthetase, glutamate dehydrogenase 1, cyanate hydratase, protein fluG-like, and NRT1/PTR family, suggesting that graphene promoted the growth and development of V. angularis by enhancing the photosynthesis and nitrogen metabolism processes in V. angularis plants. Our results indicated that a suitable concentration of graphene could significantly promote the growth of V. angularis plants in soil.

Intramolecular Catalytic Hydrogen Atom Transfer (CHAT).

Intramolecular catalysis (IntraCat) is the acceleration of a process at one site of a molecule catalyzed by a functional group in the same molecule; an external agent such as a solvent typically facilitates it. Here, we report a general first-principles-based IntraCat mechanism, which strictly occurs within a single molecule with no coreagent being involved─we call it intramolecular catalytic transfer of hydrogen atoms (CHAT). A reactive part of a molecule (chat catalyst moiety or chat agent, represented by -OOH, -COOH, -SH, -CH2OH, -HPO4, or another bifunctional H-donor/acceptor group) catalyzes an interconversion process, such as keto-enol or amino-imino tautomerization, and cyclization in the same molecule, while being regenerated in the process. It can thus be regarded as an intramolecular version of the intermolecular H atom transfer processes mediated by an external molecular catalyst, e.g., dihydrogen, water, or a carboxylic acid. Earlier, we proposed a general mechanistic systematization of intermolecular processes, illustrated in the simplest case of the H2-mediated reactions classified as dihydrogen catalysis [Asatryan, R.; et al. Catal. Rev.: Sci. Eng., 2014, 56, 403-475]. Following this systematization, the CHAT catalysis belongs to the category of relay transfer of H atoms, albeit in an intramolecular manner. A broader class of intramolecular processes includes all types of H-transfer reactions stimulated by an H-migration, which we call self-catalyzed H atom transfer (SC-HAT). The CHAT mechanism comprises a subset of SC-HAT in which the catalytic moiety is regenerated (i.e., acts as a true catalyst and not a reagent). We provide several characteristic examples of CHAT mechanism based on detailed analysis of the corresponding potential energy surfaces. All such cases showed a dramatically reduced activation barrier relative to the corresponding uncatalyzed H-transfer reactions. For example, we show that CHAT can facilitate long-range H-migration in larger molecules and can occur multiple times in one molecule with multiple interconverting groups. It also facilitates amino-imino tautomerization of unsaturated GABA-analogues and peptides, as well as intramolecular cyclization processes to form heterocycles, e.g., oxygenated rings. CHAT pathways may also explain the pH-dependent increase of mutarotation rate of glucose-6-phosphate demonstrated in pioneering experiments that introduced the classical IntraCat concept. In addition, we identify a ground electronic state CHAT pathway as an alternative to the UV-promoted long-range molecular crane keto-enol conversion with a remarkably low activation energy. To initially assess the possible impact of the new keto-enol conversion pathway on combustion of n-alkanes, we present a detailed kinetic analysis of isomerization and decomposition of pentane-2,4-ketohydroperoxide (2,4-KHP). The results are compared with key alternative reactions, including direct dissociation and Korcek channels (for which a new alkyl group migration channel is also identified), revealing the competitiveness of the CHAT pathway across a range of conditions. Taken together, this work provides insight into a general class of reaction pathways that has not previously being systematically considered and that may occur in a broad range of contexts from combustion to atmospheric chemistry to biochemistry.

Numerical simulation for radiative hybrid nanofluid (TiO2+Fe3O4∕H2O) flow due to a non-uniform stretching sheet with variable permeability

Variable permeability plays a crucial role in various manufacturing and technical applications such as fixed-bed catalytic reactors, heat exchangers, and dying, among others. The primary focus of this paper is to investigate the impacts of variable permeability on hybrid nanofluid (HNF) flow due to nonlinear sheet stretching with thermal heat flux. The HNF is made up of a mixer of [Formula: see text] and [Formula: see text] nanoparticles and water serving as the base fluid. Using efficient similarity transformations, the flow-governing equations are converted into a set of ordinary differential equations, and the resulting system is computationally solved by using the MATLAB program (bvp4c). The impact of various physical variables on the fluid velocity and heat transfer characteristics is analyzed via graphs. It is found that as the permeability parameter rises, the velocity of the HNF diminishes while the temperature amplifies. The drag force coefficient declines with an intensification of the volume fraction of the [Formula: see text] nanoparticles. The HNF [Formula: see text] exhibits 0.45–0.75% increase in heat transfer rate when compared to a nanofluid [Formula: see text] for different values of heat source parameter. The current investigation is compared to the existing literature, revealing a good level of agreement.

Exploring the Nexus between Women's Literacy Rates and Family Size: A Case Study of Nepal

The literacy rate of a nation serves as a pivotal indicator of its developmental trajectory across the globe . However, in many developing countries, including those in South Asia, a notable gender disparity persists in literacy rates, with women lagging behind men. This study focuses on Nepal, a representative country in this region, utilizing data spanning thr ee decades from the National Population Census (1991 to 2021). The findings reveal a considerable rise in women's literacy rates over the thr ee decade period, marking a noteworthy shift from the substantially low rates observed in 1991. The trend consisten tly ascended in subsequent years 2001, 2011, and 2021 indicating a positive trajectory in female literacy. Crucially, an intriguing relationship emerged between women's literacy rates and family size. Historically, when female literacy rates were considera bly lower, the national average family size tended to be higher. However, with the progressive increase in female literacy rates in recent y ears, a marked shift toward smaller, nuclear family sizes, averaging around four members, was observed. This shift i mplies that literate women exhibit heightened self awareness regarding family planning, influencing the move toward maintaining smaller nuclear families. Notably, while male literacy rates exceeded 50% even three decades prior, solely bolstering male liter acy did not correlate with maintaining nuclear family sizes. The study emphasizes the unique effectiveness of female literacy in shaping and mainta ining the transition toward smaller nuclear family structures. These findings underscore the critical role of women's education in influencing family planning and size, marking a pivotal factor in shaping societal structures and developmental paradigms.