Methods Of Analyses Research Articles

Energy security in the assessment of international indices

Subject. This article discusses the problem of a comprehensive and objective assessment of energy security. Objectives. The article aims to compare the main energy security indices used at the international level. Methods. For the study, I used the methods of systems, comparative, and structural analyses. Results. The article finds that energy security indices do not always fully take into account the specifics of each particular country. Conclusions. In the context of sanctions, the development of an index of energy security of the Russian Federation, reflecting socio-political, technological and environmental aspects, becomes an important task.

Enantioselective control in chiral crystallization of ethylenediamine sulfate using optical trapping with circularly polarized laser beams.

In this study, we conducted successful experiments on ethylenediamine sulfate (EDS), an organic compound, to investigate its enantioselectivity in chiral crystallization. We employed optical trapping with circularly polarized laser beams, using a continuous wave laser at 1064nm. By focusing the laser at the air-solution interface of a heavy water-saturated EDS solution, the formation of sub-micrometer-sized chiral EDS crystals was verified. Two generated enantiomorphs (d-crystal and l-crystal) were identified by the rotating analyzer method. The enantioselectivity in the chiral crystallization of EDS was assessed through 30 to 60 times experiments conducted under various conditions of laser powers and polarization modes, utilizing the count of generated crystals for each enantiomorph in the evaluation. Circularly polarized lasers at a specific power created an imbalance in the generation probability of the enantiomorphs, resulting in crystal enantiomeric excess values of 23% and -30%. The enantioselectivity mechanism was explored from two perspectives: refractive index differences of two enantiomorphs and 3D helical optical forces. Study of the thermodynamic mechanism was insufficient to explain the outcomes. Conversely, the 3D helical optical force mechanism revealed that the forces acting on EDS clusters in solution induced helical fluid motion, driving EDS nucleation, with the helicity of fluid motion determining the crystal's chirality. This approach will present new insights into chirality in industrial and research fields, with potential applications in regard to improving optical resolution and addressing the origin of homochirality.

Leptospirosis Relative Risk Estimates based on Continuous-Time, Discrete-Space Stochastic SIR-L-SI Transmission Model

Leptospirosis is a re-emerging global disease that has become endemic in Malaysia. The transmissions usually occur between animals especially rats to rats and rats to humans. Since, it is an easily contractable disease that can be transmitted directly through contact with infected rat’s urine or indirectly from the environment such as via water and soil, it is very challenging to curb this disease from infecting humans. Poor understanding of the disease and lack of epidemiological data also made leptospirosis is difficult to control. To cope with this problem, a leptospirosis disease transmission model is developed to study the mechanism of leptospirosis disease spread over continuous-time that may help to predict future caused of an outbreak. This study aims to construct a continuous-time and discrete-space stochastic SIR-L-SI (Susceptible, Infected, Recovered Humans-Leptospires in the Environment-Susceptible, Infectious Rats) of leptospirosis disease transmission to estimate the risk involved. A simple method of asymptotic and numerical analyses is applied as an alternative approach for solving simultaneous differential equations in the leptospirosis SIR-L-SI transmission model. The application of the proposed model is demonstrated using leptospirosis data for Malaysia. The results of asymptotic behaviour and numerical analysis provide useful information about susceptible and infective rat and human populations as well as offer relative risk estimates that can be used as one of the control measures in identifying hot-spot areas for this disease.

Oil Issues of the Smallest Arabic Member of the OPEC

The past, current status and future of the oil sector of the UAE are considered and analyzed. The author uses methods of comparative and systematic analyses, which are implemented for assessing the emirates’ oil in the context of the world, the Middle East, and the Persian Gulf area. The article mainly concludes that the Covid-19 pandemia has seriously hit the UAE oil market (harder than the other sectors of the national economy), however, the pandemia has made inland oil demand (and petroleum imports) of the emirates lower but the domestic crude oil production will unlikely increase in the foreseeable future above 200 kb/d. Still, the federation fares quite well as the OPEC pledged crude oil production cuts are concerned.

An electropneumatic cleaning device for piezo-actuator-driven picolitre-droplet dispensers.

Recently, we introduced the liquid application method for time-resolved analyses (LAMA). The time-consuming cleaning cycles required for the substrate solution exchange and storage of the sensitive droplet-dispenser nozzles present practical challenges. In this work, a dispenser cleaning system for the semi-automated cleaning of the piezo-actuator-driven picolitre-droplet dispensers required for LAMA is introduced to streamline typical workflows.

Fabrication of Cellulose Powder Dielectric Composite Material using Pineapple Leaves Fiber

Pineapple, known for its delicious taste and nutritional value, generates substantial waste in the form of cores, leaves, and skin, resulting in significant yearly accumulations. Efficient disposal of pineapple waste has become a critical challenge due to its increasing production and potential environmental pollution. The objective of this paper is to volarize natural fibre derived from pineapple waste by fabricating it into a new dielectric composite material. The fabrication process of dielectric composite material was achieved by using the optimization technique through Design Expert software, resulting in noteworthy findings. Then, the properties of the fabricated materials were analysed in terms of their permittivity value and elemental composition. The permittivity value of the newly fabricated dielectric materials was measured using the vector network analyser (VNA) method, while their elemental composition was characterized using energy-dispersive X-ray (EDX) spectroscopy. The correlation between elemental composition and the permittivity value of newly fabricated composite materials is analysed in this paper. As a result, the dielectric composite material attained its highest permittivity (4.08) when composed of 76.02% carbon and 22.61% oxygen. Conversely, the material exhibited a lower permittivity value (2.87) when its carbon content decreased to 69.32% and its oxygen content increased to 29.81%. This outcome highlights the crucial role of carbon in absorbing and storing electromagnetic signals, influencing the dielectric properties of the material. In conclusion, this paper unveils a ground-breaking use for waste pineapple leaves, showcasing how their carbon content significantly affects the resulting dielectric composite material's permittivity. This innovative eco-friendly material presents a sustainable alternative for non-recyclable dielectric materials in electronic devices such as PCBs, antennas, and sensors, for example.

Propensity Score Weighting with Missing Data on Covariates and Clustered Data Structure

Propensity score (PS) analyses are increasingly popular in behavioral sciences. Two issues often add complexities to PS analyses, including missing data in observed covariates and clustered data structure. In previous research, methods for conducting PS analyses with considering either issue alone were examined. In practice, the two issues often co-occur; but the performance of methods for PS analyses in the presence of both issues has not been evaluated previously. In this study, we consider PS weighting analysis when data are clustered and observed covariates have missing values. A simulation study is conducted to evaluate the performance of different missing data handling methods (complete-case, single-level imputation, or multilevel imputation) combined with different multilevel PS weighting methods (fixed- or random-effects PS models, inverse-propensity-weighting or the clustered weighting, weighted single-level or multilevel outcome models). The results suggest that the bias in average treatment effect estimation can be reduced, by better accounting for clustering in both the missing data handling stage (such as with the multilevel imputation) and the PS analysis stage (such as with the fixed-effects PS model, clustered weighting, and weighted multilevel outcome model). A real-data example is provided for illustration.

Rigid alignment method for secondary analyses of optical coherence tomography volumes.

Optical coherence tomography (OCT) provides micron level resolution of retinal tissue and is widely used in ophthalmology. Millions of pre-existing OCT images are available from research and clinical databases. Analysis of this data often requires or can benefit significantly from image registration and reduction of speckle noise. One method of reducing noise is to align and average multiple OCT scans together. We propose to use surface feature information and whole volume information to create a novel and simple pipeline that can rigidly align, and average multiple previously acquired 3D OCT volumes from a commercially available OCT device. This pipeline significantly improves both image quality and visualization of clinically relevant image features over single, unaligned volumes from the commercial scanner.

Can a general factor be derived from employees’ responses to items on the Individual Work Performance Review?

This study aimed to investigate whether permissible inferences can be derived from employees’ standing on a general performance factor from their responses to the Individual Work Performance Review (IWPR) items. The performance of 448 employees was rated (by their managers) using the IWPR. Latent variable modelling was performed through a bifactor exploratory structural equation model with the robust version of the maximum likelihood estimator. The general factor’s score was also used to inspect correlations with two work performance correlates: tenure and job level. In line with international findings, the results suggested that a general factor could explain 65% of the common variance in the 80 items of the IWPR. Job level, but not tenure, correlated with general job performance. The results support calculating an overall score for performance, which might be a suitable criterion to differentiate top performers, conduct criterion validity studies, and calculate the return on investment of selection procedures or training programmes.Contribution: The present study provides initial evidence for a general factor influencing employees’ responses to items on a generic performance measure in South Africa. In addition, the study showcases the application of advanced statistical methods in factor analyses, demonstrating their efficacy in evaluating the psychometric properties of hierarchical factor models derived from data provided on performance measures.

Mediation Analyses of Intensive Longitudinal Data with Dynamic Structural Equation Modeling

Currently, dynamic structural equation modeling (DSEM) and residual DSEM (RDSEM) are commonly used in testing intensive longitudinal data (ILD). Researchers are interested in ILD mediation models, but their analyses are challenging. The present paper mathematically derived, empirically compared, and step-by-step demonstrated three types (i.e., 1-1-1, 2-1-1, and 2-2-1) of intensive longitudinal mediation (ILM) analyses based on DSEM and RDSEM models. Specifically, each ILM model was demonstrated with a simulated example and illustrated with the corresponding annotated Mplus codes. We compared two types of detrending methods in mediation analyses and showed that RDSEM was superior to DSEM because the latter included the time tj variable as a Level 1 predictor. Lastly, we extended ILM analyses based on DSEM and RDSEM to multilevel autoregressive mediation models, cross-classified DSEM, and intensive longitudinal moderated mediation models.

A rapid method to quantify sub-micrometer polystyrene particles in aqueous model systems by TOC analysis

For several laboratory experiments with microplastics, a simple and fast quantification method is advantageous. At the same time, the requirements are often lower compared to microplastic detection from environmental samples. We determined the concentration of non-purgable organic carbon of polystyrene (PS) particles (diameter 0.5, 1, 2, 6 μm) in suspension with known concentrations. Commercially available PS particles were used to test the Total Organic Carbon (TOC) analyzer method for quantifying microplastics in the lower micrometer range under absence of other organic compounds. Addition of iron or aluminum hydroxide to the samples prior to the measurement increased the recovery from 52.9 to 89.7% relative to measurements in the absence of metal hydroxides. With increasing particle size, the recovery in the presence of iron hydroxides decreased from 95.1% at 0.5 μm to 67.1% at 6 μm PS particles and in the presence of aluminum hydroxides from 92.6% at 0.5 μm to 88.9% at 6 μm PS particles. We conclude that metal hydroxides have a catalytic effect on the thermocatalytic oxidation of PS particles and allow a complete conversion to CO2 for a successful quantification of PS particles using a TOC analyzer. Especially for particles larger than 0.5 μm, in the absence of metal hydroxides, the TOC device is not able to fully oxidize the PS particle to CO2 and subsequently detect its concentration. Thus, TOC analysis of PS particles in the presence of metal hydroxides provides a cheap and simple alternative for quantifying microplastic particles in the lower micrometer range for laboratory experiments (e.g. sedimentation studies) where no other organic substances are present.

Magnetic Alignment of Collagen: Principles, Methods, Applications, and Fiber Alignment Analyses.

Anisotropically aligned collagen scaffolds mimic the microarchitectural properties of native tissue, possess superior mechanical properties, and provide the essential physicochemical cues to guide cell response. Biofabrication methodologies to align collagen fibers include mechanical, electrical, magnetic, and microfluidic approaches. Magnetic alignment of collagen was first published in 1983 but widespread use of this technique was hindered mainly due to the low diamagnetism of collagen molecules and the need for very strong tesla-order magnetic fields. Over the last decade, there is a renewed interest in the use of magnetic approaches that employ magnetic particles and low-level magnetic fields to align collagen fibers. In this review, the working principle, advantages, and limitations of different collagen alignment techniques with special emphasis on the magnetic alignment approach are detailed. Key findings from studies that employ high-strength magnetic fields and the magnetic particle-based approach to align collagen fibers are highlighted. In addition, the most common qualitative and quantitative image analyses methods to assess collagen alignment are discussed. Finally, current challenges and future directions are presented for further development and clinical translation of magnetically aligned collagen scaffolds.

ESG trends in Russia: Assessment, prospects and relations with stakeholders

Subject. The article addresses corporate governance, compliance with social and environmental standards. Objectives. The focus is on assessing the impact of sustainable development policy on economic performance. Methods. We apply methods of systems, comparative, structural, and logical analyses. Results. The paper established that compliance with the principles of sustainable development increases the company value, its competitiveness and investment appeal. Conclusions. In today's economic environment, the transition from "capitalism of business owners" to "stakeholder capitalism" is relevant for companies.

Implementation of diversification of dual-use goods production through public-private partnership of aviation holding companies

Subject. This article deals with the issues of realization of the production and scientific potential of the Russian aviation industry. Objectives. The article aims to assess the capabilities of defense enterprises in the development, production and output of civil aviation products, and analyze measures aimed to support the production of dual-use goods and improving the competitiveness of the Russian aircraft industry. Methods. For the study, I used the methods of logical, theoretical, and comparative analyses. Results. The article finds that the Russian helicopter industry is characterized by the completeness of the cycle of development, production and final sale of products. Russian Helicopters holding company has the technological resources and production facilities to successfully diversify production and produce goods that are competitive in the domestic and global markets. Conclusions. The development and production of new products involves an increase in the utilization of production capacities of Russian aviation industry enterprises and the development of the relevant infrastructure. The State can act as a guarantor in order to attract funds from private investors for the development of projects.

A fresh perspective on infrared spectroscopy as a prescreening method for molecular and stable isotopes analyses on ancient human bones

Following the development of modern genome sequencing technologies, the investigation of museum osteological finds is increasingly informative and popular. Viable protocols to help preserve these collections from exceedingly invasive analyses, would allow greater access to the specimens for scientific research. The main aim of this work is to survey skeletal tissues, specifically petrous bones and roots of teeth, using infrared spectroscopy as a prescreening method to assess the bone quality for molecular analyses. This approach could overcome the major problem of identifying useful genetic material in archaeological bone collections without resorting to demanding, time consuming and expensive laboratory studies. A minimally invasive sampling of archaeological bones was developed and bone structural and compositional changes were examined, linking isotopic and genetic data to infrared spectra. The predictive model based on Infrared parameters is effective in determining the occurrence of ancient DNA (aDNA); however, the quality/quantity of aDNA cannot be determined because of the influence of environmental and local factors experienced by the examined bones during the burial period.

Simple methods for measuring milk exosomes using fluorescent compound GIF-2250/2276

Exosomes are small extracellular vesicles (EVs) found in culture supernatants, blood, and breast milk. The size of these nanocomplexes limits the methods of EV analyses. In this study, nitrobenzoxadiazole (NBD), a fluorophore, conjugated endosome-lysosome imager, GIF-2250 and its derivative, GIF-2276, were evaluated for exosome analyses. A correlation was established between GIF-2250 intensity and protein maker levels in bovine milk exosomes. We found that high-temperature sterilization milk may not contain intact exosomes. For precise analysis, we synthesized GIF-2276, which allows for the covalent attachment of NBD to the Lys residue of exosome proteins, and labeled milk exosomes were separated using a gel filtration system. GIF-2276 showed chromatographic peaks of milk exosomes containing >3 ng protein. The area (quantity) and retention time (size) of the exosome peaks were correlated to biological activity (NO synthesis suppression in RAW264.7 murine macrophages). Heat denaturation of purified milk-derived exosomes disrupted these indicators. Proteome analyses revealed GIF-2276-labeled immunomodulators, such as butyrophilin subfamily 1 member A1 and polymeric immunoglobulin receptor. The immunogenicity and quantity of these factors decreased by heat denaturation. When milk exosomes were purified from market-sourced milk we found that raw and low-temperature sterilization milk samples, contained exosomes (none in high-temperature sterilization milk). These results were also supported by transmission electron microscopy analyses. We also found that GIF-2276 could monitor exosome transportation into HEK293 cells. These results suggested that GIF-2250/2276 may be helpful to evaluate milk exosomes.

Three-dimensional surface area analyses of developing maxillary second premolar root apices for age estimation using CBCT images

Three-dimensional surface area analyses of developing root apices for age estimation in children and young adults have shown promising results. The current study aimed to apply this three-dimensional method to develop a regression model for estimating age in Malaysian children aged 7 to 14 using developing maxillary second premolars. A training sample of 155 cone-beam computed tomography scans (83 Malays and 72 Chinese) was analysed, and the formula was subsequently validated on an independent sample of 92 cone-beam computed tomography scans (45 Malays and 47 Chinese). The results showed a strong correlation (r = 94 %) between the chronological age as a dependent variable and the predictor variables, including root surface area of the apex, sex, ethnicity, and root development status (open/closed apices). For this model, the predictor variables accounted for 88.4 % of the variation in age except sex and ethnicity. A mean absolute error value of 0.42 indicated that this model can be reliably used for Malaysian children. In conclusion, this study recognises the method of three-dimensional surface area analyses as a valuable tool for age estimation in forensic and clinical practice. Further studies are highly recommended to assess its effectiveness across different demographic groups.

IN VIVO POSTERIOR-STABILIZED TOTAL KNEE KINEMATICS: IT IS NOT ALL ABOUT THE IMPLANT DESIGN

Numerous papers present in-vivo knee kinematics data following total knee arthroplasty (TKA) from fluoroscopic testing. Comparing data is challenging given the large number of factors that potentially affect the reported kinematics. This paper aims at understanding the effect of following three different factors: implant geometry, performed activity and analysis method.A total of 30 patients who underwent TKA were included in this study. This group was subdivided in three equal groups: each group receiving a different type of posterior stabilized total knee prosthesis. During single-plane fluoroscopic analysis, each patient performed three activities: open chain flexion extension, closed chain squatting and chair-rising. The 2D fluoroscopic data were subsequently converted to 3D implant positions and used to evaluate the tibiofemoral contact points and landmark-based kinematic parameters.Significantly different anteroposterior translations and internal-external rotations were observed between the considered implants. In the lateral compartment, these differences only appeared after post-cam engagement. Comparing the activities, a significant more posterior position was observed for both the medial and lateral compartment in the closed chain activities during mid-flexion. A strong and significant correlation was found between the contact-points and landmarks-based analyses method. However, large individual variations were also observed, yielding a difference of up to 25% in anteroposterior position between both methods.In conclusion, all three evaluated factors significantly affect the obtained tibiofemoral kinematics. The individual implant design significantly affects the anteroposterior tibiofemoral position, internal-external rotation and timing of post-cam engagement. Both kinematics and post-cam engagement additionally depend on the activity investigated, with a more posterior position and associated higher patella lever arm for the closed chain activities. Attention should also be paid to the considered analysis method and associated kinematics definition: analyzing the tibiofemoral contact points potentially yields significantly different results compared to a landmark-based approach.

Novel Surface Impedance Formulation via FILT and Prony Method for FDTD Analyses of Lossy Media

Novel Surface Impedance Formulation via FILT and Prony Method for FDTD Analyses of Lossy Media

The Strategic Positioning and Implementation Path of Red Cultural Resources in the Civic and Political Education Curriculum of Colleges and Universities

Abstract Red culture is an excellent cultural achievement formed by the Chinese leading people in long-term revolutionary practice, and it has become an indispensable content of ideological and political education in colleges and universities with its high value and rich connotation. Based on the strategic positioning of red cultural resources in the curriculum system of ideological and political education in colleges and universities, this paper designs the teaching path of red cultural, ideological, and political courses and implements it. It also constructs an assessment system to evaluate the quality of teaching in red culture and civic politics and proposes the use of the particle swarm algorithm to optimize the index assignment method in hierarchical analyses. Then, the fuzzy comprehensive assessment method is used to assess the teaching approach’s implementation effect. The implementation of the teaching path resulted in medium-high assessment scores for the teaching content, teaching method, and teaching effect, indicating the effectiveness of the red culture and civics teaching path. Students’ learning attitudes were significantly improved (3.5 points) compared with those before teaching (2.26 points), and it was found that the scores on the ideological and political quality test of the students who were taught with the integration of red resources were significantly higher than those of the traditional classes (P<0.05). This paper is critical for integrating cultural resources from the red minority into ideological and political education in colleges and universities.