Parameter Analysis Method Research Articles

Gross morphological and ultrasonographic dimensions of normal feline kidney with reference to resistive index

Ultrasonography with color Doppler is the most quantitative analysis method for intra-renal parameters. There is a wide variation between authors in the measurement site and referencing the inter-lobar resistivity index (RI) in felines. Our objective is to morphometrically and ultrasonographically investigate the normal renal dimensions and vasculatures and draw up a normal reference value for the renal inter-lobar artery resistivity index (RI) using a Pulsed wave-Doppler ultrasonography. A total of twelve adult domestic cats were sedated and treated according to IACUC regulation guidelines to be examined using Doppler ultrasound. The same cats were used for morphometric investigation and divided into three groups regarding the used technique. The size difference between the right and left kidneys is slight, measuring 17 g (weight), 3.65 ± 0.06 cm (length), 2.54 ± 0.08 cm (width), and 2.21 ± 0.03 cm (thickness) for the right kidney, and about 15 g, 3.42 ± 0.06 cm, 2.32 ± 0.05 cm, and 2.13 ± 0.03 cm for the left one, respectively. There are three patterns of renal arteries’ point of origin. The mean RI values of both kidneys were 0.57 ± 0.08 (0.50–0.67) in the right kidney and 0.60 ± 0.08 (0.51–0.69) in the left kidney. The gross examination and ultrasonography measurements did not have a statistically different effect on the actual renal dimensions. Moreover, 0.69 is considered the standard resistivity index (RI) threshold of the feline inter-lobar artery with no correlation to the animal’s body weight.

Multiple sub-impacts phenomenon and influences on responses of elastic-plastic beam

The multiple sub-impact phenomenon, consisting of more than one short contact event, has frequently been observed in experiments and simulations. The multiple sub-impact phenomenon and its influences on impact responses lack systematic study. Hence, this paper presents a parametric analysis method, an extended hybrid, numerical-analytical model (EHNA model). The nature of multiple sub-impact responses of elastic-plastic beams struck by elastic-plastic spherical impactors is investigated parametrically. The occurrence and disappearance of multiple sub-impacts are observed. Their threshold curves are obtained and expressed analytically for low-velocity impacts. A characterization diagram is proposed to characterize the region of multiple sub-impacts in the relative stiffness ratio-effective mass ratio plane. The characterization diagram can be used to quickly predict the state of multiple sub-impacts or the state of a single impact without solving the impact responses in detail. It is validated experimentally and numerically for impacts with wide ranges of initial velocity, beam size, constraint, material property and contact type. The influences of multiple sub-impacts on impact force response, impact impulse, and energy loss are parametrically investigated. The high influence zones and several influence features are observed. The wide multiple sub-impact region proves that the multiple sub-impact phenomenon is ubiquitous. The strong influences on flexible beam impacts indicate that multiple sub-impacts cannot be neglected for structural damage and structural dynamics.

Addressing musculoskeletal curricular inadequacies within undergraduate medical education

BackgroundMusculoskeletal (MSK) injuries and diseases place a significant burden on the health care system. Despite this, research indicates that physician training in the area of MSK medicine has historically been inadequate, with a majority of medical students feeling that their training in MSK medicine is lacking. The goal of this investigation was to evaluate the efficacy of a new preclinical MSK curriculum that was implemented within a nationally accredited allopathic medical program.MethodsRetrospective analysis was completed on five consecutive years (2017–2021) of preclinical MSK curricular data for 549 medical students, including mid and end-of-course examinations and end-of-course student satisfaction surveys. Both parametric and non-parametric methods of analysis were used to examine within and between class differences (P < 0.05).ResultsThe new MSK curriculum covered 15 of 16 “core or must know” topics in MSK medicine, and academic performance was consistently high over the 5-year period of analysis (final course marks ranged from 76.6 ± 7.1 to 81.4 ± 8.1; failures/year: range from 0 to 4), being equal or above levels of student performance observed for other courses delivered during preclinical studies. Likert data from end-of-course surveys demonstrated that feedback was overwhelmingly positive (overall course satisfaction ranged from a low of 3.07/4.00 to a high of 3.56/4.00) and indicated that students felt that the new preclinical MSK curriculum did effectively support medical student learning and knowledge retention.ConclusionResults are expected to help advance the current body of knowledge that is dedicated to improving physician learning and knowledge retention in the area of MSK medicine and provides a curricular model that could be used by other nationally accredited medical programs to help enhance MSK learning at the preclinical levels of physician training.

Back analysis of the shear strength parameters of 3D landslides with Bayesian approach and reliability theory

To establish an accurate model for determining the shear strength parameters of sliding surfaces while considering the variability and uncertainty of geotechnical parameters, a reliability back analysis method for parameters based on Bayesian theory and a three-dimensional slope stability analysis method are proposed in this paper. First, the prior information of shear strength parameters is updated according to the field test information based on Bayesian theory. Then, combined with the reliability theory, the influences of different two-dimensional and three-dimensional sliding surface shapes on the parameters back analysis are studied. The results show that the uncertainty of parameters decreases with the increase in the amount of test data after introducing the test data to update the mastered parameter information based on Bayesian theory, and it is of great significance to consider the shape and three-dimensional effect of the sliding surface accurately to improve the accuracy of parameter determination and slope stability analysis.

Do higher education institutions contribute to countries’ SDG progress: Evidence from university rankings

The UN Sustainable Development Goals (SDGs) have become a universal call to action over the past few years and a basis for assessing the progress of sustainable development of countries and organizations. This paper aims to identify the relationship between the sustainable development activities of universities in different regions of the world, as reflected in the Times Higher Education Impact Rankings (THE IR), and the progress towards achieving SDGs of the countries in which these universities operate. The research methods were correlation analysis and robust regression tools, and parametric and non-parametric methods of variance analysis. The information base was the results of annual reports based on the THE IR and Sustainable Development Reports for 2017–2021. The results confirm the existence of directly proportional close correlations between the variables, while the regression analysis confirmed that a one-unit increase in the overall THE IR ranking score leads to a corresponding increase in the overall progress of countries in achieving SDGs (on average by 0.2-0.3 units) and SDGs 3, 8, 11, 16 in particular. It was also found that universities play a key role in achieving different SDGs in various regions. In Latin America, the Caribbean, the Middle East, and North Africa, universities are critical for SDG 17 achieving. In OECD countries, universities contribute most to SDG 3. Examples of the best practices that can be used as a guide for university administrations that are at the beginning of developing sustainable development policies are also given. Funding Inna Makarenko gratefully acknowledges support from the Jean Monet module project “Transparency. Accountability. Responsibility. Governance. Europe. Trust. Sustainability” financed by the Erasmus+ program (101085395 – TARGETS – ERASMUS-JMO-2022-HEI-TCH-RSCH).

Comparative Characteristics of Eating Behavior, Habits, and Patterns of Normal and Overweight Children, Including Obese Children

Introduction: One of the reasons for the high prevalence of overweight and obesity among adults, and especially children and adolescents, is eating habits and eating behavior, which are formed by the rules of nutrition established in the family. Purpose of the Study: Conduct a comparative assessment of the nature of nutrition and eating habits of overweight schoolchildren, including obesity, and those with normal body weight to justify the development of measures aimed at preventing the formation of overweight and alimentary-related diseases. Materials and Methods: The materials for the study were the data of a survey of 2029 schoolchildren aged 7-17. The survey program included questions reflecting knowledge of the principles of healthy eating and adherence to its principles in family and school meals, the structure and mode of eating were studied. Statistical analysis was carried out using STATISTICA 10 and Microsoft Excel application packages. Parametric methods of analysis were used. Differences were considered statistically significant at p&lt;0.05. Results: A high frequency of adherence to the consumption of high-calorie foods was established, which is typical both for respondents with overweight and obesity, and with normal body weight. In the group of children with overweight and obesity, a higher frequency of food intake was revealed both on weekends and on school days 75.4% versus 65.6% and in the group with normal body weight, respectively, 73.4% versus 60.8% (p≤0.05), which is largely due to the greater proportion of children in this group who eat according to the main diet at school (73.2% versus 59.3%, p≤0.05), as well as attending the canteen in addition to the main nutrition (78.6% vs. 14.3%, (p≤0.05), more often buying main meat and fish dishes (6.7% vs. 4.8%), cereals (1.8% vs. 7%), sausages or wieners (4.0% vs. 1.1%), less often - fruits (2.7% vs. 3.4%), which increases the energy value of the diet compared to children with normal body weight. Conclusion: The study made it possible to identify violations of eating behavior and eating habits in schoolchildren with different BMI indicators, which pose additional risks of overweight and obesity in schoolchildren. Habits in the group of children with overweight, which are the source of the formation of risk factors for diseases associated with overweight and obesity, as well as the peculiarities of eating habits in the group of children with normal body weight. The data obtained require the need to develop preventive measures aimed at creating positive motivation in children to reduce the consumption of critically important nutrients, develop healthy eating habits, and consume food that is balanced with regard to actual energy consumption and physiological need for food and biologically valuable substances.

Experimental investigations to assess surface fatigue failure in rolling contact bearing

Rolling element bearings are the most important components in almost all rotating machines. These bearings are often subjected to repetitive load cycles at different operating conditions. Excessive loads, speeds, and improper operating conditions lead to the propagation of defects on their load-bearing surfaces, thereby causing a negative impact on the performance of rotating machines. This paper presents the results of experimental investigations to assess wear propagation in roller bearings using lubricant degradation, vibration, and statistical parameter analysis methods. A roller bearing setup was developed in the laboratory, and the test bearing (NJ 307E) was subjected to fatigue tests over a period of 900 h. The bearing was operated at a speed and radial load of 800 rpm and 1 kN, respectively. The film thickness analysis revealed a transition in lubrication regimes during 600–900 h of operation. Grease structure degradation and oxidation analyses were carried out using scanning electron microscope images and the Fourier transform infrared radiation technique. Further, the vibration signals are extracted from the bearing housing at regular intervals. Using the fast Fourier transform technique, these vibration signals were used to analyze bearing fault frequencies to highlight the faults developed on bearing contact surfaces. The statistical features of vibration signals such as root mean square, kurtosis, and crest factor were used to assess the severity of wear propagated on the bearing contact surfaces. Integrating tribological and vibration parameter analysis techniques provided a reliable assessment of surface fatigue wear propagated on the roller-bearing contact surfaces.

The impact of maternal smoking during pregnancy and the age of smoking initiation on incident dementia: A prospective cohort study.

The impact of early-life tobacco exposure on dementia has remained unknown. Using the UK Biobank, the associations of maternal smoking during pregnancy (MSDP) and age of smoking initiation (ASI) with the onset time of all-cause dementia were estimated with accelerated failure time models. The effects of MSDP and ASI on brain structure and their genetic correlation to Alzheimer's disease (AD) were analyzed. A Mendelian randomization (MR) analysis was conducted. The time ratios for smokers starting in childhood, adolescence, and adulthood (vs never smokers) were 0.87 (0.76 to 0.99), 0.92 (0.88 to 0.96), and 0.95 (0.89 to 1.01). MSDP and smoking in adolescence altered many brain regions, including the hippocampus. In genetic analysis, MSDP was genetically and causally linked to AD, and a younger ASI was genetically correlated to a higher AD risk. Early-life smoking accelerated dementia onset and was genetically correlated to AD. MSDP demonstrated genetic and causal linkage to AD risks. Unlike the commonly used Cox proportional hazards model, this article uses a parametric survival analysis method - the accelerated failure model - to explore the relationship between exposure to onset time. It can be used as an alternative method when the proportional hazards assumption is not met. Genetic analyses including genetic correlation study and MR analysis and brain structure analyses were conducted to support our findings and explore the potential mechanisms. The study reveals the relationship between different smoking initiation periods and the onset time of dementia and shows that earlier smoking exposure has a more significant impact on dementia. It emphasizes the importance of preventing early smoking. In the future, more research focusing on the relationship between early exposure and dementia is called for to provide more detailed prevention measures for dementia that cover all age groups.

HISTOCHEMICAL AND IMMUNOHISTOCHEMICAL FEATURES OF DIFFERENTIATED TROPHOBLAST IN CHORIONIC VILLI OF THE PLACENTA IN PRETERM LABOR

The importance of studying the histochemical and immunohistochemical features of the diff erentiated trophoblast in chorionic villi of the placenta in preterm labor is determined by the threatening nature of this condition for both mother and fetus, as well as its high prevalence and serious consequences for the health of both. The understanding of the damage to the trophoblast of chorionic villi in the placenta can be expanded by histochemical and immunohistochemical methods, which allow the assessment of the concentration of specifi c marker molecules in one way or another.Objective. To determine certain histochemical and immunohistochemical characteristics of proteins in the trophoblast of theintermediate and terminal chorionic villi of the placenta in preterm labor.Material and Methods. The obtained material (30 placentas from preterm deliveries and 30 placentas from normalpregnancies) was fi xed for 20-24 hours in 10 % neutral formalin solution buff ered in Lilly’s phosphate buff er. After tissue removal, the placental tissue was dehydrated in an ascending ethanol series and embedded in paraffi n at a temperature of approximately 58 °C. Serial histologic sections were cut at 5.0 μm thickness using an MS-2 sliding microtome. After deparaffi nization, histological sections were stained with hematoxylin and eosin, histochemical methods for total protein with bromophenol blue according to Bonhéme, and immunohistochemical techniques according to the manufacturer’s protocols (Dako, Denmark). In particular, immunohistochemical reactions were performed with monoclonal antibodies against trophoblast hormone- placental lactogen and placental alkaline phosphatase. Visualization of primary antibodies was performed using the Dako polymer visualization system with diaminobenzidine as chromogen (resulting in brown staining of the sites of studied antigens). In addition to the descriptive method of histopathologic research, computer morphometry of digital microphotographs of histologic sections was performed using a Delta Optical Evolution 100 microscope and an Olympus SP550UZ digital camera. Digital copies of the images were processed using a legitimate copy of the ImageJ v1.52f computer program developed for histometric studies (National Institutes of Health, USA). Specifi cally, the evaluation of staining intensity (optical density) was performed on digital microphotographs using the method of computer microdensitometry. For this purpose, a microprobe method was used to obtain a computer brightness value in an 8-bit analysis system with 256 gray levels – from black (0) to white (255).The obtained values were then transformed into relative optical density values (r.OD) by logarithmic transformation (naturallogarithm method). The relative optical density value ranges from 0 (absolute transparency of the object) to 1 (absolute opacity of the object). The obtained digital data were processed using statistical analysis methods. A legitimate copy of the statistical analysis computer program PAST v4.14 was used, with a preliminary check for normal distribution using the Shapiro- Wilk test. Since, according to this test, the hypothesis of normal distribution was not rejected for the statistical samples studied (at p=0.05), parametric methods of statistical analysis were applied: calculation of the mean and its standard error, Student’s t-test (two-tailed, unpaired). In addition, the non-parametric Mann- Whitney test was used for the reliability of the conclusions. The research was conducted as part of the scientifi c research project «Preservation and Restoration of Reproductive Health in Women and Girls with Obstetric and Gynecological Pathology» at the Department of Obstetrics and Gynecology of Bukovinian State Medical University (state registration number 0121U110020, duration 2021-2025).Results. Microscopic examination of histological sections stained with hematoxylin and eosin did not reveal any diff erencesin the structure of chorionic villus trophoblast in the placenta of preterm labor compared to normal pregnancy. However,histochemical and immunohistochemical methods of investigation revealed a number of features in the trophoblast of chorionic villi, where fundamental events related to substance exchange occur – intermediate immature, intermediate mature, terminal villi, including terminal «specialized villi».Conclusions. According to the obtained histochemical and immunohistochemical data, in preterm labor, compared to normalpregnancy, no changes are observed in the trophoblast of intermediate immature villi, while in intermediate mature and terminal villi, there is a decrease in histochemical staining for total protein and immunohistochemical staining for specifi c trophoblast proteins – placental lactogen hormone and placental alkaline phosphatase enzyme.

MORPHOMETRIC PARAMETERS OF MATURITY OF PLACENTAL CHORINAL VILLI IN PREMATURE LABOR

Aim – to establish some morphometric parameters of placental villi in premature birth in comparison with physiological pregnancy.Material and methods. The material (30 placentas in premature births and 30 placentas in physiological pregnancies) was fixed for 22-24 hours in a neutral buffered 10% formalin solution. Next, the material was dehydrated in an ascending battery of alcohols and embedded into paraffin at 580С. Serial histological sections 5 μm thick were made on a sled microtome. After deparaffinization, serial histological sections were stained with hematoxylin and eosin, and with a chromotrope - water blue according to N.Z.Slinchenko. In addition to the descriptive method of histopathological examination, computer morphometry was performed on previously obtained digital copies of optical microscopic images of the tissue (Delta Optical Evolution 100 microscope {planachromatic lenses according to the required optical magnification} and Olympus SP550UZ digital camera). Digital copies of the image were analyzed using a freeware copy of the ImageJ v1.52 computer program specialized for digital histometric studies. In particular, the percentage of different types of chorionic villi was calculated on digital copies of optical images using the unrepeatable score test method. The obtained digital data were processed statistically. In particular, with the help of a copy of the free (freeware) computer program for statistical calculations PAST v 4.14, a preliminary test for the normality of the distribution was applied according to the Wilkie-Hahn-Shapiro test. For all studied statistical samples, according to this criterion, the hypothesis about the normality of the distribution was not rejected (at p=0.05), therefore, parametric methods of statistical analysis were used: calculation of the arithmetic mean and its error, the odd two-sided Student's test. Along with the Student's test, the non-parametric Mann-Whitney U test was also used. Results. It was considered most important to start assessing the state of the placenta according to the percentage ratios between different types of villous formations. In particular, according to modern ideas about different types of chorionic villi in the II and III trimesters of pregnancy, the following types of villous formations of the placenta were distinguished: stem villi ("early" and late"), intermediate villi (immature and mature), terminal villi, terminal "specialized" villi, mesenchymal villi, embryonic villi, trophoblastic and villous processes. The total amount of the specified villi should be equal to 100%. The division of villi into primary, secondary, and tertiary villi is relevant only for the 1st trimester of pregnancy, therefore, it is not suitable for studying the morphological features of premature birth.Conclusions. According to the obtained morphometric data, the immaturity of the chorionic tree is noted in premature birth compared to physiological pregnancy. This can be seen from a noticeable increase in the percentage of stem "early" villi, intermediate immature and mature villi, mesenchymal and embryonic villi, trophoblastic and villous processes, but with a significant decrease in the percentage of terminal villi.

Back analysis of shear strength parameters of slope based on BP neural network and genetic algorithm

AbstractEfficient and accurate acquisition of slope shear strength parameters is the key to slope stability analysis and landslide prevention engineering design. This paper establishes a back analysis method based on uniform design, artificial neural network, and genetic algorithm. It can obtain the shear strength parameters of slopes based on information such as the radius and center coordinates of the slip surface obtained from on‐site investigations. This method has been applied to engineering practice. The research results indicate that the stability of the waste dump slope is most sensitive to the response of the internal friction angle of the loose body, followed by cohesion, and least sensitive to the response of the soil volume weight. This method can effectively reduce the number of network training samples and efficiently and quickly determine the initial weights of the BP (abbreviation for back‐propagation) neural network. This method can efficiently and quickly conduct back analysis to obtain the shear strength parameters of slopes. Using the obtained shear strength parameters for slope stability calculation, the most dangerous slip surface abscissa error, ordinate error, and slip surface radius error are only 3.59%, 0.95%, and 1.83%. It is recommended to promote the back analysis method of shear strength parameters in engineering practice in the future.

Safety Assessment of Airtight Protective Doors of Nuclear Power Plants Subjected to Wind-Borne Missile Impact

This paper aims to study the dynamic response and damage of airtight protective doors of nuclear power plants subjected to tornado and wind-borne missile impact. Firstly, a safety performance evaluation method is proposed, considering the structural characteristics of the airtight protective door and relying on support rotation and airtightness. Then, the commercial finite element (FE) program LS-DYNA is utilized to perform the numerical simulations of airtight protective doors in nuclear power plants exposed to tornadoes and wind-borne missile impacts. Subsequently, the parameter analysis method is employed to investigate the impact of keel quantity, size and arrangement, door panel thickness, door core material, and boundary conditions on the dynamic response, airtightness, and failure mode of the airtight protective door. The results show that tornado wind pressure has little effect on the resistance of airtight protective doors and that the impact load of wind-borne missiles plays a leading role. The number and thickness of the keel have significant effects on the force transfer mode and failure mode of airtight protective doors. The thickness of the door panel has a great influence on the damage mode and airtightness of airtight protective doors. The door core improves the local resistance of the airtight protective door to a certain extent, and foam aluminum material has a better energy absorption effect. The change in boundary conditions has little influence on the resistance of airtight protective doors.

Experience in the treatment of lymphatic malformations in children

BACKGROUND: In the treatment of lymphatic malformations, the problem of radical removal and a high risk of recurrence remains.&#x0D; AIM: Improving the efficiency of treatment of children with lymphatic malformations by introducing new surgical methods and optimizing sclerotherapy.&#x0D; MATERIAL AND METHODS: The results of treatment of 150 patients with lymphangiomas and an experimental study of the effects of sclerosing drugs on the lining of lymphangioma are presented. The study included 67 (44.7%) girls and 83 (55.3%) boys. The patients were divided into three groups. The first group (72 children) consisted of patients with radical removal of lymphangioma. The second group included 70 patients with partial resection of lymphangioma and sclerosis of residual cavities. The third group (8 children) consisted of patients operated on by video endoscopic method. A histological study of micropreparations of lymphangioma after sclerosis with ethanol and sodium tetradecyl sulfate with an exposure of 5 minutes was carried out. Statistical analysis was carried out using the StatTech v. 2.2.0 using methods of parametric and non-parametric analysis. Results were considered statistically significant at p 0.05.&#x0D; RESULTS: In the first group of patients, 9 (11.1%) relapses occurred, in the second — 12 (12.3%), in the third group — 0 relapses. Treatment combined with sclerotherapy did not lead to a significant increase in the recurrence rate (p=0.541). Types of lymphatic malformations and their location did not significantly affect the risk of recurrence (p=0.232 and p=0.552, respectively). Sclerosis of the lymphangioma lining with 70% ethanol and a liquid form of sodium tetradecyl sulfate caused total desquamation of the endothelium. Sclerosing with the foam form of sodium tetradecyl sulfate led to total desquamation of the endothelium during a 3-minute exposure.&#x0D; CONCLUSION: The introduction of minimally invasive methods of treatment and the improvement of sclerosis will make the results of treatment of children with lymphangiomas better.

Characteristic study and design factor analysis of a novel non-pneumatic tyre with V-shaped spokes

Compared with conventional pneumatic tyres, non-pneumatic tyres (NPTs) have various advantages such as zero-blowout risk, maintenance-free, and environment-friendliness. Instead of compressed air, NPTs employ elastic spokes as the main load-carrying structure. Honeycomb and flexible radial spokes are the commonly used types, and various spoke geometries are also continuously emerging. In this study, an innovative NPT with V-shape spokes was developed. With the specially designed V-shape spokes, the NPT can achieve better supporting performance and aerodynamic characteristics. A finite element (FE) model was constructed for the proposed NPT, and mechanical properties were studied. Prototypes of the proposed NPT were fabricated, and experimental test confirmed the fidelity of the FE model. To reveal the impact mechanism of design parameters on the mechanical properties of the proposed NPT, we used the Taguchi method for parametric analysis. Based on the verified FE model, orthogonal experimental simulations were conducted to study the interactions among the design parameters and the multi-axis properties such as the radial, longitudinal, lateral, and torsional stiffnesses. Based on the result analysis, design principles are extracted for the proposed NPT to satisfy its multi-axis mechanical property demands.

Cracking characteristics evaluation for reinforcement basalt fiber reactive powder concrete beam using acoustic emission

New types of fibers such as basalt fibers are gradually being used to reinforce cement-based concrete materials. To provide a basis for the further popularization of basalt fibers and basalt fiber reinforced reactive powder concrete (BFRPC) materials, the bending mechanical properties and fracture properties of BFRPC beams were investigated by innovatively applying four-point bending test and multiple acoustic parameter analysis methods. On the one hand, the load vs. displacement curve and crack pattern of reinforcement BFRPC beam were obtained from the four-point bending test. On the other hand, Acoustic emission (AE) technology was used to monitor the cracking process of reinforcement BFRPC beam under four-point bending load, and the AE signal was analyzed to illustrate the cracking characteristics of reinforcement BFRPC beam. The results revealed that AE hits, amplitude, counts, duration, and energy have a similar changing trend with bending load. Cumulative hits and cumulative energy are positively linearly related to the displacement and quadratically related to the sum of crack widths, and the correlation coefficients are all above 0.95. Besides, the cracking process of reinforcement BFRPC beam can be divided into four stages by the variation of AE basic parameters with bending load. The main rebars yielding is an important turning point of the crack characteristic of reinforcement BFRPC beam. AE signal data varies greatly in different locations, and it has an obvious advantage to detect the formation of invisible cracks. The results of predicting concrete damage and cracking by AE signal data are consistent with the experimental phenomenon. The low-stress brittle fracture caused by tensile fracture was reduced, and the tensile resistance and flexural bearing capacity of the reinforcement BFRPC beam were increased. The results obtained in this paper support the damage assessment and structural health monitoring for cement base concrete materials under bending load.

Quantitative Morphometric Analysis and Prioritization of Sub-Watersheds for Soil Erosion Susceptibility: A Comparison between Fuzzy Analytical Hierarchy Process and Compound Parameter Analysis Method

Quantitative Morphometric Analysis and Prioritization of Sub-Watersheds for Soil Erosion Susceptibility: A Comparison between Fuzzy Analytical Hierarchy Process and Compound Parameter Analysis Method

Investigation of pH-dependent extraction methods for PFAS in (fluoropolymer-based) consumer products: A comparative study between targeted and sum parameter analysis

Here, we report a comparative study of different sum parameter analysis methods for the extraction of per- and polyfluoroalkyl substances (PFAS) from manufactured consumer products, which can be measured by combustion ion chromatography (CIC). Therefore, a hydrolysis-based extraction method was further developed, which accounts for the addition of hydrolyzable covalently bound polyfluoroalkylated side-chain polymers (SFPs) to the extractable organic fluorine portion of the mass balance proposed as "hydrolyzable organically bound fluorine" (HOF). To test this hypothesis, the method was applied to 39 different consumer products containing fluoropolymers or monomeric PFAS taken from four different categories: outdoor textiles, paper packaging, carpeting, and permanent baking sheets. We also evaluated the method's efficiency by extracting four synthesized fluorotelomer polyacrylate reference compounds. The total fluorine (TF) and extractable organically bound fluorine (EOF) values were measured through CIC using established protocols. The TF values ranged from sub-ppb to %-levels, depending on the compound class. All samples showed results for hydrolyzed organofluorine (HOF) between 0.03 and 76.3 μg/g, while most EOF values were lower (<LOD to 58.1 μg/g). Moreover, the methods were contrasted with the "total hydrolyzable precursor" (THP) assay analyzed using gas-chromatography coupled mass spectrometry (GC-MS), which yielded concentrations of 6:2–10:2 fluorotelomer alcohols (<LOD-568 μg/g) for textile and paper samples. Furthermore, targeted analytical investigation of 25 compounds via liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) was conducted and accounted for significantly lower sum amounts (<LOD-0.98 μg PFAS/g). To estimate the fluorine mass balance of all methods, the fluorine levels of target analytical data were calculated and compared to the sum parameter values and evaluated. Finally, the efficiency of the extraction method was approximated by the recovery analysis of four selected SFP model compounds compared to their TF values, yielding 36.7–74.0% after extraction and 3.8–36.3% after processing the extract for the HOF sum parameter.

Magnetic field properties inside the jet of Mrk 421

Aims. We aim to probe the magnetic field geometry and particle acceleration mechanism in the relativistic jets of supermassive black holes. Methods. We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measurements from 2022 December 6–8. During the IXPE observation, we also monitored Mrk 421 using Swift-XRT and obtained a single observation with XMM-Newton to improve the X-ray spectral analysis. The time-averaged X-ray polarization was determined consistently using the event-by-event Stokes parameter analysis, spectropolarimetric fit, and maximum likelihood methods. We examined the polarization variability over both time and energy, the former via analysis of IXPE data obtained over a time span of 7 months. Results. We detected X-ray polarization of Mrk 421 with a degree of ΠX = 14 ± 1% and an electric-vector position angle ψX = 107 ± 3° in the 2–8 keV band. From the time variability analysis, we find a significant episodic variation in ψX. During the 7 months from the first IXPE pointing of Mrk 421 in 2022 May, ψX varied in the range 0° to 180°, while ΠX remained relatively constant within ∼10–15%. Furthermore, a swing in ψX in 2022 June was accompanied by simultaneous spectral variations. The results of the multiwavelength polarimetry show that ΠX was generally ∼2–3 times greater than Π at longer wavelengths, while ψ fluctuated. Additionally, based on radio, infrared, and optical polarimetry, we find that the rotation of ψ occurred in the opposite direction with respect to the rotation of ψX and over longer timescales at similar epochs. Conclusions. The polarization behavior observed across multiple wavelengths is consistent with previous IXPE findings for HSP blazars. This result favors the energy-stratified shock model developed to explain variable emission in relativistic jets. We considered two versions of the model, one with linear and the other with radial stratification geometry, to explain the rotation of ψX. The accompanying spectral variation during the ψX rotation can be explained by a fluctuation in the physical conditions, for example in the energy distribution of relativistic electrons. The opposite rotation direction of ψ between the X-ray and longer wavelength polarization accentuates the conclusion that the X-ray emitting region is spatially separated from that at longer wavelengths. Moreover, we identify a highly polarized knot of radio emission moving down the parsec-scale jet during the episode of ψX rotation, although it is unclear whether there is any connection between the two events.

Evaluation of a green methanol production system using the integration of water electrolysis and biomass gasification

For a long time, the development of green shipping has been highly valued by countries and organizations. Biomass gasification-based green methanol is seen as a long-term alternative to conventional shipping fuel to reduce greenhouse gas emissions in the maritime sector. While the operational benefits of renewable methanol as a marine fuel are well-known, its cost and environmental performance depend largely on the production method. In this study, a green methanol production system based on the integration of biomass gasification and water electrolysis is proposed and evaluated via the parametric and thermodynamic analysis methods. The water electrolysis is used to increase the hydrogen content in syngas, thereby increasing the production of methanol. The results show that as the S/C ratio increases, the mass flow rate and the calorific value of product gas, the mole flow rate of methanol decreases. The enhancement of the H2/CO ratio can increase the mole fraction of H2, thereby increasing the methanol yield. The mole flow rate of methanol dramatically increases from 925.0 kmol/h to 3725.2 kmol/h. Additionally, the mole flow rate of methanol in the proposed system is 10776.0 kmol/h, larger than the traditional system of 3603.4 kmol/h. The carbon element conversion rate of the proposed system is 94.6%, higher than the 31.5% of the traditional system. This system can significantly provide an efficient green methanol production method for the shipping sector, while also helping to find a feasible solution for the consumption of renewable energy.

Parametric LCA integrating a product's State of Health: A decision-making tool based on environmental impact in the context of circular strategy.

Circular processes such as remanufacturing, reuse, recycling, make it possible to extend the life of products and thus reduce their environmental impact. However, they introduce uncertainties of quantities and qualities that bring significant challenges for manufacturers and others stakeholders. To reduce such uncertainties and give decision-makers more information for selecting a circular strategy driven by the environment, a parametric life cycle analysis method is essential. The aim of this article is to propose a method based on the performance parameters of each process of product closed-loop to calculate the environmental impact of a product in different closed loops, considering the product's state of health. To achieve this objective, the product life cycle process with closed circular processes were first specified. Then, its parameterization was completed to simulate different scenarios. Based on parameters defined, formulas to facilitate the simulation of several circular scenarios for a given product has been defined. This allows identifying the circular strategies with the lowest environmental footprint. Illustrated by a case study on an electric circuit breaker, our approach demonstrates its effectiveness in supporting eco-responsible decisions.