Average Distribution Research Articles

Ultrafiltration membrane based on chitosan/adipic acid: Synthesis, characterization and performance on separation of methylene blue and reactive yellow-145 from aqueous phase

Here, we report for the first time using of the nontoxic chitosan/adipic acid cross-linked membrane CS/AA in the separation of methylene blue and reactive yellow-145 from aqueous phase. The reason we chose adipic acid as a cross-linking agent is because it gives the cross-linked membrane moderate flexibility due to the presence of four methylene groups in its structure. The structure of the cross-linked membrane CS/AA and their properties were confirmed through, FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and BET analysis. The thermal properties of membrane indicated an improvement in its flexibility and hydrophobicity, but this improvement was accompanied by a decrease in its thermal stability. pHpzc value and porosity of the CS/AA were 7.88, and 73.95 % respectively. The average pore radius distribution ranged from 2 to 27 nm. The prepared cross-linked membrane provides spontaneous and continuous purification of water with a high efficiency. This is due to the membrane CS/AA ability to separate methylene blue and reactive yellow-145 from the aqueous phase almost completely. The results revealed that the removal efficiency and permeation flux for MB were 100 % and 1 L/m2.h respectively at initial dye concentration of (4,8) mg/L, at 1 bar, and the removal efficiency and permeation flux for RY-145 were (94,96) % and (1.06, 2.09) L/m2.h respectively at 100 mg/L and at (1,1.5) bar. Such cross-linked nanopore polymer membranes provide a new approach for emerging novel purification systems, principally in the field of environmental field.

An examination of the usefulness of a quantitative appraisal method in nursing human resource management in primary hospital operating rooms: An example of integrated collaborative scheduling.

In recent years, China medical and health services have made great development. However, the management of nursing human resources in operating room of primary hospitals still faces a series of challenges. In the nursing work of operating room, high-quality nursing human resource management is important for improving the efficiency of operating room and ensuring the safety of patients. From January 2022 to December 2022, comprehensive collaborative scheduling and quantitative scoring evaluation methods were carried out in our hospital, and relevant data were collected. The flexible scheduling combined quantitative scoring performance appraisal system and the traditional scheduling plus average distribution performance appraisal system were statistically analyzed and compared in terms of annual surgical cases, annual overtime hours, annual back work hours, annual compensatory rest hours, and average daily working hours. This study was based on 30 medical staff (27 females and 3 males) in the operating room of a primary hospital. The annual operation volume increased by 387 cases compared with before, and the attitudes of patients to the service attitude and preoperative waiting time were significantly improved, reaching more than 95%. In addition, in the survey of surgeons, it was found that their satisfaction with preoperative preparation and operation time was significantly higher than that of the traditional scheduling method, and reached more than 95%. In the survey of nursing staff, it was found that the satisfaction with the traditional scheduling method was about 80%, and the satisfaction directly reached 100% after the comprehensive collaborative scheduling system. Based on the above survey, the satisfaction of nurses, doctors and patients with the new comprehensive collaborative scheduling system has improved compared with before. After the implementation of the comprehensive collaborative scheduling system, the annual surgical volume has increased significantly, and the average daily working hours of nursing staff have decreased. Comprehensive collaborative scheduling is an effective method of nursing human resource management in operating room, which can effectively improve the work efficiency of nurses and the satisfaction of patients, doctors and nurses. In practice, this method needs to be continuously explored and refined to adapt to different application scenarios and requirements.

Sonochemical-assisted method for efficient synthesis of Cu-MOF and evaluating its antibacterial properties

Sonochemical-assisted method was used to synthesize copper metal-organic frameworks (Cu-MOF) nanostructures. The final products were examined by related techniques such as XRD patterns, SEM image, BET N2 adsorption/desorption technique and FTIR spectrum. Microtiter plates microbiological assay were used to investigate antibacterial properties and the results were analyzed using ANOVA and Tukey HSD tests. The results showed that Cu-MOF nanostructures have a mesoporous nature with an average particle size distribution around 60 nm. The final product had the property of preventing the growth of all tested bacteria in certain concentrations. Minimum Inhibitory Concentration (MIC) values were observed in the range of 30–100 ppm. It was also discovered that this nanostructure can not kill bacteria completely. In addition, the minimal inhibitory concentration for biofilm growth (MIC-B) of the nanostructure was investigated. The MIC-B analyzes demonstrated that the growth of bacterial biofilm decreased with increasing Cu-MOF concentration.

Determination of interparticle radiative heat transfer and radiation absorption for ellipsoidal particle beds using Monte Carlo ray tracing

The calculation of radiative heat transfer between particles in particle-based solar systems presents significant challenges in terms of computational cost and accuracy. This study addresses these challenges by employing the discrete element method to generate random particle packings and the Monte Carlo ray tracing method to investigate the influence of particle shape and volume fraction (ϕ) on interparticle radiation transfer and the absorption of incident radiation. The results reveal that, at low volume fractions, the shape and orientation of ellipsoidal particles have a pronounced impact on direct radiative transfer. Oblate particles exhibit the highest average radiation distribution factor (RDF), and the dispersion of RDF data is more prominent for oblate and elongated prolate particles compared to spheres. As ϕ increases to 0.35, the contribution of indirect transfer from neighboring particles becomes significant for oblate particles, resulting in a reduction in the dispersion of RDF data. Furthermore, when ϕ reaches 0.55, the decisive factor in determining RDF becomes the shielding effect of particles positioned between the emitting and receiving particles. The average RDF tends to converge among particles of different shapes, although oblate and elongated prolate particles still exhibit considerably larger RDF dispersion compared to spherical and near-spherical particles. Additionally, the effective absorptivity of the particle bed for incident radiation decreases as the aspect ratio of particles increases at all volume fractions. Moreover, the transmitted fraction demonstrates an exponential relationship with the depth, and beds composed of spherical particles exhibit better radiation transmittance compared to beds containing non-spherical particles.

Photovolitaics Concept Integrated on the Grid With the STT-PLN Building

As we enter the 21st century, concerns over dwindling oil and gas reserves have become more pronounced. With energy demand on the rise, particularly in developed nations, projections indicate a 70% increase between 2000 and 2030. By the year 2017, global electricity demand is expected to reach 25.4 trillion kWh. Solar energy emerges as a promising solution, especially in regions like Indonesia, where the entire mainland covers roughly 2 million km2 and receives an average daily radiation distribution of 4.8 kWh/m2. This translates to a solar energy potential of 5.10 mW, equivalent to 112,000 GWp. Technically speaking, solar panels have shown an efficiency improvement of 17.4%. When considering components and the quality absorbed by solar power plants (PLTS) synchronized by KWH EXIM, calculations reveal a performance ratio of 81%, confirming the technical feasibility of implementing such systems

Modeling the deterioration of the stiffness and of the collagen fibril distribution in a discrete model of the cornea microstructure

We present a stochastic approach to model the mechanical deterioration of the reinforcing microstructure of the human cornea. The fundamental structural micro-components of the stroma, collagen and crosslinks, are assembled deterministically into an elementary trusswork cell, multiply repeated and distorted to form a three-dimensional shell with the shape of a cornea. The spatial orientation of the collagen-like elements of each cell is thus characterized stochastically with a non correlated random angle field, obeying an assigned probability density function, leading to a non-deterministic structural stiffness. It follows that the mechanical response of the model to the action of deterministic forces equivalent to the intraocular pressure is stochastic due to the random spatial orientation of collagen fibers. The deterioration of the mechanical stiffness of the collagen components is described through a scalar variable field, evolving in space and in time, representative of a progressive damage which causes heterogeneity and asymmetric behavior. The damage variable acts in two ways on the global stiffness: (i) by reducing the stiffness of the collagen components; (ii) by modifying the dispersion coefficient of the probability density function. The equilibrium equations of the damaging model are solved at discrete time steps, with a fully explicit solution scheme, by means of the stochastic finite element improved perturbation method. The results show that when the collagen fibril stiffness reduces to 10% of the healthy value, as expected in the case of the vision-impairing condition known as keratoconus, the displacement field due to intraocular pressure is significantly affected in terms of both average and variance distributions. This effect confers a typical conical shape to the cornea. In particular, the analysis shows that high values of the response variances are confined in the keratoconus area, which agrees with a high level of uncertainties due to loss of fibril organization and thickness reduction under pathologic conditions.

Incredible Host Diversity and Regional Potential Distribution of an Oriental Parasitic Plant (Taxillus yadoriki)

This study investigates the host diversity and characteristics of the rare parasitic plant Silverberry-like taxillus (Taxillus yadoriki). Seogwipo, Jeju Island, where T. yadoriki grows naturally, was examined to clarify the diversity of host species, their location, and the part of the tree where T. yadoriki is attached. A total of 687 host trees were found. Taxillus yadoriki was intensively distributed in the lowlands below 200 m a.s.l. The host trees belonged to 40 species, four varieties, three cultivars, and two hybrids from 32 genera and 21 families, of which 23 taxa were identified as host plants for the first time in this study. Incredibly, this plant was found to be able to parasitize a variety of plants from 12 orders. Taxillus yadoriki was found to be parasitic in three orders of Gymnosperms, Ginkgoales, Cupressales, and Pinales, as well as nine orders of Angiosperms, including Magnoliales, Rosales, and Ericales. Rosaceae was the most diverse at 18.0%, and most species were broad-leaved and arboreal. Among them, Cryptomeria japonica and Litsea japonica had the highest frequency of parasitization and T. yadoriki was mainly attached to the upper part of the main tree and the main branch; as a result, T. yadoriki was distributed and showed specificity in the position of disturbance on the host. T. yadoriki’s specific distribution model was built as a Maxent program. The area under the curve of the receiver operation characteristic was 0.948 ± 0.026 (mean ± standard deviation), and the performance of the constructed model was excellent. Of the total eight environmental factors, density of artistic forest and meant temperature of coldest quarter accounted for 75.3% of the total importance, which was the main distribution determinant of species. In the average distribution probability map of T. yadoriki, the critical probability for determining distribution was calculated to be 0.2898 ± 0.1018. Accordingly, the distribution of species is predicted to expand from Jeju Island to the entire southern and southeastern coasts.

Investigating the Origins of Hot Neptunes from Radial Velocity Data

Abstract Hot Neptunes are extrasolar planets that are similar in size to Neptune in our solar system but are much closer to their host stars, completing an orbit in 10 days or less. The origin of hot Neptunes is not fully understood. A potential large third body at a distance can lead to the migration of long-period planets to become much closer to the host star, and such a dynamical process helps explain the origin of hot Jupiters. We investigate whether hot Neptunes could share a similar origin by analyzing radial velocity data from multiple sources for a sample of 34 hot Neptune systems. Hot Neptune systems appear to have similar values of linear trend to hot Jupiter systems. We perform a maximum likelihood analysis to constrain the mass and distance distribution of the putative third body. The overall fraction of hot Neptune systems with third bodies is consistent with unity, higher than 71% at the 2σ level. On average, the mass and distance distribution of the third bodies for hot Neptune systems is consistent with that for hot Jupiter systems. Our results suggest that hot-Neptune systems share the same origin mechanism as hot Jupiters, e.g., through the gravitational effect of third bodies.

Growth And Food Habits Of Red Snapper (Lutjanus Malabaricus) Catched In The Waters Of Central Mamuju, Makassar Strait

Red snapper is a basic fish that has economic value with intensive use and high market demand, so it is thought to have undergone biological changes. In this regard, the research aims to analyze the size distribution, growth and food habits of red snapper caught in Mamuju waters. This research is classified as a survey type with data sources from fishermen's catches. The results showed that the average size distribution of red snapper from Kambunong was ± 36.93 cm for males and ± 44.65 cm for females, Babana ± 29.81 cm for males and ± 41.14 cm for females, Pangale ± 31.45 cm for males and ± 33.75 cm female. The growth pattern of samples from Pangale and Kambunong was negative allometric, while Babana had a positive allometric pattern. The main types of food are white shrimp, tiger prawns, lencam fish, crab and lobster while cuttlefish is a complementary food. To catch red snapper, both males and females should use red snapper as their main food

Spatial and Temporal Dynamics of Ecological Parameters in Various Land Use Types in China during the First 20 Years of the 21st Century

Ecological quality in China has experienced significant improvements due to the interplay of climate change and human activities. Nevertheless, previous studies exploring the trend of ecological parameters have always overlooked the effects of land use types. Therefore, in this study, we explored the spatiotemporal variation in ecological parameters in various land use types and discussed the relationship between ecological parameters and climatic factors in China during the first 20 years of the 21st century. The results show that: (1) The area of grassland and unutilized land decreased, and the area of other land use types increased. (2) Distinct variations in the average, slope, and interval distribution of ecological parameters across various land use types were evident. Particularly significant increases in ecological parameters were observed in cultivated land and forest. (3) The influence of land use and land cover change on ecological parameters was evident. The conversion of cultivated land, forest, and grassland into water bodies, constructive land, and unutilized land resulted in a significant decrease in ecological parameters. (4) The distinct climatic conditions resulted in heightened monthly variations in the ecological parameters. Significant monthly fluctuations in ecological parameters were observed for cultivated land, forest, grassland, and constructed land, while water bodies and unutilized land did not exhibit such variations. (5) The correlation between ecological parameters and climatic factors varied considerably in various land use types in different regions.

Correlation between electrical conductivity and antibacterial activity of chitosan-stabilized copper and silver nanoparticles

In this study chemical reduction method is used to synthesize the copper and silver nanoparticles. Chitosan was utilized as a stabilizing agent, a suitable medium for nanoparticle growth, and to stop the oxidation and aggregation of the particles. Various characterization such as FTIR Spectra, UV spectra, PL spectra, XRD, EDAX, TEM and Zeta potential approaches were used to examine the copper and silver nanoparticles. The antibacterial activity was assessed through the disc diffusion method. The antibacterial activity to the selected human pathogens, which included two bacterial pathogens such as S. pyogenes and K. pneumoniae as well as one fungal pathogen, Candida albicans . The size and shape of the synthesized CuNPs and AgNPs were evaluated using TEM. The average size distribution is 23.65 nm for CuNPs and 21.76 nm for AgNPs. Copper and AgNPs show antibacterial efficacy against two bacterial strains and a fungi strain. The AgNPs show significant antibacterial activity in comparison with the Chitosan and CuNPs.

High Accuracy Localization Scheme Using 1-Bit Side Information: Achievability from a GDoP Perspective

In this paper, we provide a novel methodology for high-precision positioning that utilizes 1-bit additional information, which applies to various positioning techniques. The proposed approach leverages binary information to indicate if a user is within a specified space of interest and refines the estimated location information outside this area. By matching the estimated locations outside the area of interest with the valid location information within, this methodology corrects the positional data obtained through any arbitrary positioning technique, aligning the estimated positions with the intended spatial boundaries. Performance analysis metrics, such as Average Positioning Error (APE) and Cumulative Distribution Function for positioning coverage, were employed to assess the effectiveness of the proposed methods. Numerical simulations demonstrate how the proposed method enhances the averaged positioning accuracy, significantly outperforming the conventional time of arrival method. Furthermore, the proposed positioning correction methodology demonstrates validated feasibility applicable to an arbitrary existing positioning method.

ARTERIAL HYPERTENSION AS A COMPONENT OF METABOLIC SYNDROME IN MEN IN AN OPEN URBAN POPULATION

Purpose. To determine blood pressure (BP) levels and the prevalence of arterial hypertension (AH), as a component of metabolic syndrome, in men of an open urban population aged 25–64 years. Materials and methods. A one-time epidemiological study was conducted on a representative sample of men 25–64 years old, formed from the electoral lists of citizens of the city of Tyumen in the amount of 1000 people, the response was 85.0%. To analyze the prevalence of AH as a component of the metabolic syndrome, the NCEP ATP III (2004), IDF (2005), All-Russian Scientific Society of Cardiology (2009) assessment criteria were used. Results. The levels of systolic BP in men of the Tyumen population were high due to the average age groups of 35–44 and 45–54 years; in the same groups there was a significant increase in the average values and percentile distribution of the trait. According to the levels of diastolic BP in men of the Tyumen population, a directional age trend of the indicator was formed with a significant increase in its levels in each subsequent age group. In terms of the prevalence of AH, the standardized indicator in the male population of Tyumen 25–64 years old was 59.8%; a positive relationship was established with age in the younger and older age categories. Conclusion. Thus, the study results obtained in an open urban population, which identified the most vulnerable age categories of men with regard to the development of metabolic syndrome, represent a scientific basis for the formation of a preventive program in the region.

Transport parameters for PFOA and PFOS migration through GCL's and composite liners used in landfills

The effect of applied stress (20, 60, and 150 kPa) on the diffusion of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) through a geosynthetic clay liner (GCL) is examined. The diffusion coefficients deduced from GCL diffusion tests for PFOA and PFOS decrease linearly with decreasing final bulk GCL void ratio (increasing applied stresses). The different components of the same GCL are also tested for PFOA and PFOS sorption. No statistically significant sorption of PFOA is observed for any of the components of the GCL. However, some sorption of PFOS onto the cover and carrier geotextiles of the GCL is observed with in an average distribution coefficient, Kd ∼2.22 ml/g for the GCL. Permeants containing different PFAS compounds are tested to assess their impact on the Geomembrane (GMB) - GCL interface transmissivity in composite liners. Results show PFAS concentrations up to 20 ppm had negligible impact on the GMB-GCL interface transmissivity. Lastly, the GCL specimens extracted from the diffusion tests are tested for hydraulic conductivity. No impact of PFAS is seen on the hydraulic conductivity of GCLs subjected to high applied loads, but a small increase is seen on the GCLs subjected to relatively low applied stresses.

Quasi-one-dimensional approach to heat transfer: General formulation and its application to transformer windings

A quasi-one-dimensional approach to conduction heat transfer with convective boundary conditions is developed for bodies of variable geometry. The novelty of the method is demonstrated on the windings in oil-filled distribution transformers with partial cooling ducts. We obtain analytical solution for the windings average temperature rise and tangential temperature distribution and find them in an excellent agreement with the FEM simulation, numerically confirming the validity of the reduction from 2D to 1D. When the quasi-one-dimensional approach is applied to calculation of temperature rise for the low and high voltage windings in industrial setting we obtain 1% and 5% discrepancy with the industrial tests respectively. Hence, the method offers reliable estimates of the temperature rise, and temperature distribution in a chosen direction, in bodies of variable geometry.

Results of Reconstruction of U400M Cyclotron Magnetic Structure

U400M isochronous cyclotron was create on the base of U300 classic cyclotron and is under operation at FLNR, JINR since 1996. U400M cyclotron is intended for accelerating the ion beams with A/Z= 2.286 – 9 to energy W = 80 – 6 MeV/nucl. Cyclotron have H-type main magnet with 4-meter pole diameter and 4 pairs of spiral type sectors. In 2022 year, the reconstruction of cyclotron magnetic structure was held on. The reconstruction included the replacement of magnet main coil, mapping and correction of cyclotron magnetic field. In the frame of the mapping, the magnetic field was corrected to improve its average radial distribution and to compensate the first harmonic. For cyclotron magnetic field mapping the automatic measurement system, based on 14 Hall probes, was used.

Economic Dispatch of Multi Regional Power Systems Based on CMOPSO Algorithm

With the progress of society and the aggravation of environmental pollution, the economic dispatch of the power system is developing towards multiple environmental and economic goals. To improve energy utilization efficiency, this study innovatively proposes a multi-objective particle swarm optimization algorithm based on competitive learning, and uses this algorithm to solve multi regional environmental and economic scheduling problems. In addition, the study solves static and dynamic economic (S-DE) scheduling problems in multiple regions through improved competitive group optimization algorithms. The research results show that under different testing systems, the average distribution uniformity indicators of the research algorithm built on competitive learning are 0.8058 and 0.8457, and the average anti generation distance is 67.6316 and 1664.0978. The improved competitive group optimization algorithm solves the maximum, minimum, and average fuel costs for static economic scheduling in multiple regions, which are 656.2243 $/h, 655.8592 $/h, and 655.9866 $/h, respectively. Thus, the designed algorithm can effectively solve economic scheduling problems, which is of great significance for resource integration, saving power generation costs, and reducing pollution emissions.

Assessment of the grindability and component variation of torrefied agricultural wastes for industrial furnace application

The utilization of agricultural solid biowastes is essential for resource saving and bioenergy conversion. By this way, the demand of industrial furnace for biomass would be compensated, and the energy structure would also be greener. Among them, torrefaction is a hopeful technology for solid biofuel production. This study investigates the grinding performance of torrefied biochar to achieve the grindability and component variation analysis of torrefied agricultural wastes for fluidized bed boiler, and thus realize pulverized biochar injection for industrial application. Totally crystallinity index (CrI), average particle size distribution, energy input for grinding process, component analysis, and elemental carbon state are adopted and analyzed around Hardgrove grindability index (HGI). The values of HGI are in the range of 45–120, 45–105, 60–120, and 60–135, respectively. The results indicate that torrefaction is conducive for biochar properties upgrading, especially for a higher temperature, and thus contributes to a higher HGI, lower particle size and grinding energy input, as well as better elemental carbon state. The produced powder from torrefied biochar is highly correlated to torrefaction temperature and biochar component, and thus leads to an excellent industrial application potential. Overall, this study is conducive for the agricultural biowastes conversion and solid biofuel production.

Aerodynamic Analysis of Variable Camber-Morphing Airfoils with Substantial Camber Deflections

In recent years, morphing wings have become not only a concept, but an aerodynamic solution for the aviation industry to take a step forward toward future technologies. However, continuously morphing airfoils became an interesting answer to provide green energy solutions. In this paper, the authors conducted experimental research on a continuously camber-morphing airfoil using the Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD) methods. The main objective of this work was to research a variety of morphing airfoils with different camber deflections. An average velocity distribution and turbulence distribution were compared and are discussed. The two-dimensional PIV results were compared to the CFD simulations to validate the numerical method’s accuracy and obtain the aerodynamic coefficient’s trends. A further comparison revealed that morphing airfoils have better aerodynamic performance than conventional airfoils for very low camber deflections and create substantial amounts of drag for significant camber deflections.

Investigation of pin and perforated heatsink cooling efficiency and temperature distribution

The uneven temperature distribution resulting from thermal stresses in heat sinks is a significant issue in modern electronic devices. This numerical investigation utilizes fluid to analyze the cooling, flow, and heat transfer characteristics of eight different heat sink designs. These include pin–fin heat sinks with circular, triangular, square, and hexagonal cross-sections, as well as their perforated versions. The results show that the thermal resistance range for all geometries was between Rth = 0.29 and 0.51 K W−1. The circular cross-section pin structure was found to be the most efficient in terms of thermal resistance, while the triangular perforated structure was the least efficient. The narrow and low temperature distribution indicates a high cooling potential for the heat sink. It has been observed that the temperature range studied is between 308.732 and 315.273 K. The circular cross-section pin structure is most efficient in terms of homogeneous distribution between 308.73 and 311.306 K. The pin-type structure with a square cross-section attained the maximum Performance Evaluation Criteria (PEC) of 1.1872 at P = 689 Pa, while the pin-type structure with a triangular cross-section attained the lowest PEC of 0.67 at P = 2750 Pa. The investigation revealed that, in relation to PEC, perforated structures had superior performance compared to other pin designs, except for the square-section pin structure. This research found that measuring the efficiency of a heat sink based just on thermal resistance or average temperature distribution is not enough; the PEC criteria must also be taken into account.