Penetration Values Research Articles

Evaluating Physical Properties of Biochar-Modified Bitumen: An MCDM Approach Using TOPSIS and VIKOR

Bitumen is essential in road construction due to its binding properties, water resistance, and durability, ensuring stable and long-lasting pavements. This study explores the potential of using agricultural waste, specifically biochar, to enhance bituminous materials. Biochar was added to bitumen in increments of 0%, 2.5%, 5%, 7.5%, 10%, 12.5%, and 15% by weight to make biochar modified bitumen (BMB). The results showed that biochar increased the softening point, viscosity, and flash and fire points, indicating improved thermal stability and deformation resistance. Conversely, ductility and penetration values decreased, resulting in a harder, less flexible bitumen with better wear and indentation resistance. The modified bitumen was prepared at 160-180°C using a high shear mixer at 4000 rpm for 30 minutes and tested per IS code standards. To identify the optimal biochar-bitumen mix, Multicriteria Decision Making (MCDM) tools such as TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) and VIKOR were used. These tools provided a comprehensive ranking system to determine the best-performing composition. The study demonstrates that biochar significantly enhances bitumen's properties, making it a viable option for more sustainable and efficient road construction applications.

Performance of Road Pavement Using AC-WC Mixture with Glycerin Oleochemical Waste Substitution Material Based on Marshall Testing and IRI Value.

Abstract By the end of 2021, PT Pertamina was the sole oil asphalt producer in Indonesia, with a production capacity of 350,000 tons per year. However, domestic asphalt demand exceeds this supply, leading to 75% of asphalt still being imported. To reduce imports, Glycerin Pitch (GP), a waste product from the oleochemical industry and classified as a Toxic and Hazardous Substance (B3), can be used as a substitute for asphalt. Indonesia produces 650,000 tons of glycerol annually, with 3% resulting in GP. Tests on GP with inorganic content <10% and >10% were conducted. Rheology tests showed penetration values of 62.83 and 60.4 (0.1 mm), softening points of 60.5°C and 56.5°C, kinematic viscosities of 1197 cSt and 903 cSt, ductility >100 cm for both, and specific gravities of 1.074 g/cc and 1.054 g/cc. Aggregate tests revealed an abrasion value of 16.71%, flat and elongated particles at 7.52% (split) and 8.49% (screen), and material passing sieve No. 200 at 0.87% (coarse) and 9.49% (fine). The asphalt mixture design showed an aggregate gradation of 12% split, 44% screen, 41% stone dust, and 3% filler. The optimum GP content was 27% for GP1 and 14.2% for GP2, with an optimum asphalt content of 6%. Mixing and compaction temperatures were 130°C and 150°C for ACWC+GP1 and 150°C for ACWC+GP2. The Marshall Quotient was 211 Kg/mm for ACWC+GP1 and 316 Kg/mm for ACWC+GP2. Field tests on two segments (Pen 60/70 + GP1 and GP2) showed an International Roughness Index (IRI) of 3.21 and 2.89, respectively, classified as good. These findings suggest that GP is a viable substitute in asphalt mixtures, reducing import dependence while efficiently utilizing oleochemical waste.

Evaluating the dynamic response and phase angle behavior of SBS-modified asphalt mixtures for enhanced pavement performance

Bitumen exhibits viscoelastic properties, showcasing both viscous and elastic behaviors, which are characterized by the phase angle and dynamic modulus. Issues like early fatigue fractures, rutting, and permanent deformations in bituminous asphalt pavements arise due to moisture susceptibility, high-temperature deformation, low-temperature cracking, and overloading. These distresses result in potholes, alligator cracks, and specific deformations that lead to early pavement failure, increasing rehabilitation and maintenance costs. To address these issues, this study examines the dynamic modulus and phase angle behavior of Styrene Butadiene Styrene (SBS) modified and unmodified asphalt mixtures. SBS was incorporated in various proportions, ranging from 2 to 7% by the weight of bitumen. The asphalt mixture performance tester (AMPT) was utilized to measure the dynamic modulus at temperatures of 4.4, 21.1, 37.8, and 54.4 °C, and frequencies of 0.1, 0.5, 1, 5, 10, and 25 Hz. The study found significant correlations between dynamic modulus, temperature, loading frequency, and SBS content. Additionally, Multi Expression Programming (MEPX) and regression modeling were employed to estimate the dynamic modulus of SBS-modified HMA. Results indicated that increasing SBS content up to 7% decreased penetration and ductility values by up to 46% and 56%, respectively, while raising the softening point by 63% due to increased stiffness. The blend with 6% SBS by weight of bitumen exhibited superior performance compared to other mixtures. Phase angle initially increased with rising temperature, peaking at 37.8 °C at lower frequencies, and continued to increase at higher frequencies. Isothermal and isochronal plots showed that the 0% SBS mix had a higher phase angle due to increased bitumen content. Overall, the HMA mix with 6% SBS provided the best outcomes.

Enhancing performance and fuel resistance of modified epoxy asphalt using amine and carboxyl terminated PET co-hardener

In this study, a fuel-resistant modified epoxy asphalt was formulated using a co-hardener containing a commercial amine and carboxyl terminated PET (CTPET). Rheological, physical, mechanical, and fuel-resistance properties were evaluated across various epoxy polymer-to-asphalt ratios. The CTPET co-hardener enables blending with up to 85% epoxy polymer, preserving viscoelastic behaviour comparable to base asphalt. Notably, higher epoxy-to-asphalt ratios enhanced the complex shear modulus, phase angle, rutting resistance, and cohesion bonding. Furthermore, weight loss measurements after immersing the specimens in kerosene at 80°C for 24 h revealed losses of 1.08%, 0.24%, 0.18%, and 0.01% for blends containing 70, 75, 80, and 85 wt% epoxy, respectively, all well below the standard limit of 2%. The material also retained an elongation at break exceeding 1000%. Additionally, the penetration values, softening points, and tensile strengths remained stable before and after immersion, confirming the material’s durability and suitability for fuel-resistant applications.

Automated estimation of cementitious sorptivity via computer vision

Monitoring water uptake in cementitious systems is crucial to assess their durability against corrosion, salt attack, and freeze-thaw damage. However, gauging absorption currently relies on labor-intensive and infrequent weight measurements, as outlined in ASTM C1585. To address this issue, we introduce a custom computer vision model trained on 6234 images, consisting of 4000 real and 2234 synthetic, that automatically detects the water level in prismatic samples absorbing water. This model provides accurate and frequent estimations of water penetration values every minute. After training the model on 1440 unique data points, including 15 paste mixtures with varying water-to-cement ratios from 0.4 to 0.8 and curing periods of 1 to 7 days, we can now predict initial and secondary sorptivities in real time with high confidence, achieving R² > 0.9. Finally, we demonstrate its application on mortar and concrete systems, opening a pathway toward low-cost and automated durability assessment of construction materials.

Study on viscoelastic properties and rheological properties of SBS modified asphalt for road use with service life

SBS modified asphalt is an important material in the construction of high-grade highway, and its performance changes directly affect the pavement performance. In this study, SBS modified asphalt was extracted from the actual pavement with different service years, and the rheological properties of SBS modified asphalt with different service years were studied by macroscopic test and microscopic molecular dynamics simulation. The macroscopic test results show that the needle penetration value of SBS modified asphalt increases by 50.6 % after two years of service, and the viscosity of SBS modified asphalt increases by 54.8 % after 12 years of service. With the increase of service life, G∗ and G″ of SBS modified asphalt showed an increasing trend, and δ and G’’/G’ showed a decreasing trend. The molecular dynamics simulation results of SBS modified asphalt were consistent with the macroscopic experimental results. The rheological properties of SBS modified asphalt showed a decreasing trend with the service life, and the interfacial energies between SBS modified asphalt and aggregate also showed a decreasing trend. The research in this paper will provide a theoretical basis for the future study of the deterioration law of SBS modified asphalt and the formulation of road maintenance plan.

Spatio-Temporal Dynamics of Soil Penetration Resistance Depending on Different Conservation Tillage Systems

As conservation tillage becomes one of the foundations of sustainable crop production, important questions arise about its value, which needs to be defined and evaluated. One of the most important indicators of soil compaction is penetration resistance (PR), which comes as a short-term response to the state of soil physics. The objective of this work is to compare different tillage treatments (TT) on soil compaction on silty clay loam Stagnosol and silt Gleysol in the continental part of Croatia. The research included three tillage treatments: ST—conventional tillage, CTD—deep conservation tillage, and CTS—shallow conservation tillage. PR was determined on each soil depth of 5 cm up to 80 cm, and measuring was provided on two measuring dates. The obtained results showed a higher influence of the year factor than TT. In the upper layers (up to 35 cm), PR values between TT were with significant differences, but in most cases below root-limiting critical values, while in deeper soil layers (35–80 cm), we found that penetration values on each tillage treatment begin to stabilize and smooth out in most cases, with similar dynamics on both soil types and measurement dates. In most of the cases, the highest PR was measured for conservation treatments in wetter soil conditions.

Correlation between cone resistance with standard penetration value for predicting consistency of cohesive soil in Eastern India

Correlation between cone resistance with standard penetration value for predicting consistency of cohesive soil in Eastern India

Performance enhancement of asphalt mixture through the addition of recycled polymer materials

Enhancing the performance of asphalt binders is essential for ensuring the long-term durability and serviceability of asphalt mixtures, as it can help reduce the frequency of maintenance and repair work, ultimately leading to the development of more sustainable transportation infrastructure. To achieve this goal, this study investigates the effects of incorporating recycled polymer materials, including reclaimed polyvinyl chloride (PVC) and polystyrene (PS) derived from household waste, into hot mix asphalt. The experimental work involved subjecting the polymer-modified asphalt binders to a range of physical tests, such as softening point, penetration, ductility, indirect tensile strength, Marshall stability, and moisture susceptibility, and the results showed that the addition of recycled polymers, with an optimal content of 4%, led to lower penetration values and higher softening point temperatures, indicating improved resistance to temperature changes. Further analysis of the asphalt mixture performance revealed several beneficial outcomes, including a decrease in flow, a boost in the asphalt mixture's resistance to moisture-induced damage, and an improvement in Marshall stability and indirect tensile strength, with the inclusion of 4% recycled polymers yielding increases in Marshall stability of 43.7% and 37.4% for PVC and PS-modified mixes, respectively, and increments in indirect tensile strength of 32.2% and 29.7% for the same mixes. The study concludes that the use of recycled polymers can effectively enhance the performance and durability of asphalt mixtures, contributing to the development of more sustainable asphalt pavement construction practices by utilizing locally available or reused materials, which could lead to the increased knowledge and application of stronger and more weather-resistant asphalt mixes, ultimately promoting the advancement of sustainable transportation infrastructure.

Segregation GWAS to linearize a non-additive locus with incomplete penetrance: an example of horn status in sheep

BackgroundThe objective of this study was to introduce a genome-wide association study (GWAS) in conjunction with segregation analysis on monogenic categorical traits. Genotype probabilities calculated from phenotypes, mode of inheritance and pedigree information, are expressed as the expected allele count (EAC) (range 0 to 2), and are inherited additively, by definition, unlike the original phenotypes, which are non-additive and could be of incomplete penetrance. The EAC are regressed on the single nucleotide polymorphism (SNP) genotypes, similar to an additive GWAS. In this study, horn phenotypes in Merino sheep are used to illustrate the advantages of using the segregation GWAS, a trait believed to be monogenic, affected by dominance, sex-dependent expression and likely affected by incomplete penetrance. We also used simulation to investigate whether incomplete penetrance can cause prediction errors in Merino sheep for horn status.ResultsEstimated penetrance values differed between the sexes, where males showed almost complete penetrance, especially for horned and polled phenotypes, while females had low penetrance values for the horned status. This suggests that females homozygous for the ‘horned allele’ have a horned phenotype in only 22% of the cases while 78% will be knobbed or have scurs. The GWAS using EAC on 4001 animals and 510,174 SNP genotypes from the Illumina Ovine high-density (600k) chip gave a stronger association compared to using actual phenotypes. The correlation between the EAC and the allele count of the SNP with the highest –log10(p-value) was 0.73 in males and 0.67 in females. Simulations using penetrance values found by the segregation analyses resulted in higher correlations between the EAC and the causative mutation (0.95 for males and 0.89 for females, respectively), suggesting that the most predictive SNP is not in full LD with the causative mutation.ConclusionsOur results show clear differences in penetrance values between males and female Merino sheep for horn status. Segregation analysis for a trait with mutually exclusive phenotypes, non-additive inheritance, and/or incomplete penetrance can lead to considerably more power in a GWAS because the linearized genotype probabilities are additive and can accommodate incomplete penetrance. This method can be extended to any monogenic controlled categorical trait of which the phenotypes are mutually exclusive.

Evaluasi Kapasitas Pondasi Tiang Pancang Menggunakan Data Kalendering Pada ABT1-ABT 2 Underpass STA 2+550 Binjai-Stabat

A pile foundation is needed to support the building, if the hard soil layer is very deep. The pile foundation functions to move or transfer the load above it (superstructure) to deeper soil layers. For this purpose, it is necessary to evaluate the capacity of a single pile and the capacity of a group of piles that are capable of carrying the load above them. Evaluation of pile capacity requires calendaring data in the form of field driving data which is carried out when the pile reaches hard ground with penetration and rebound values taken for 10 strokes. Based on calendaring data, single pole capacity analysis was carried out using several methods. The results of the bearing capacity analysis from one method are compared with other methods and their relationship with pile penetration. The capacity value of the pile group is calculated based on the pile efficiency. Most of the pile capacities show almost the same single pile capacity values, such as the Hiley method (666.16 kN), Navy-Mckay (752.14 kN), Janbu (440.91 kN), except that the Sanders method gives results that are much different from The value of other methods is 1138.28 kN, this could be because this method only considers the weight of the pile. The relationship between single pile capacity and pile penetration shows that the smaller the pile penetration value, the greater the pile capacity. This is obtained in all methods used, although with different calculation methods and method.

A study on the performance of super duplex stainless steel cladding over mild steel using a CMT welding

Low carbon steels can be cladded with super-duplex stainless steels to enhance the surface’s mechanical and wear properties. The current study examines the impact of process parameters on weld bead geometry and dilution % during cold metal transfer (CMT) cladding of super duplex stainless steel 2507 over low carbon steel. Response Surface Methodology (RSM) with a Central Composite Design matrix was used to optimize the process parameters (welding current, welding speed, and nozzle to workpiece distance (NTD)). The adequacy of the model was checked using an ANOVA analysis. The optimal bead width, height, penetration, and dilution values were 8.05 mm, 4.52 mm, 1.56 mm and 14.64%, respectively. The ideal input parameters were 200 A of welding current, 4.64 mm/s of welding speed, and 14 mm of NTD. The welding speed is the most dominant parameter, followed by the welding current and NTD. The cladding samples were prepared from the optimal parameters. The CMT-clad layer’s microstructure, microhardness, and wear properties were also evaluated. The results indicate a dense crack-free and non-porous clad surface was obtained under optimal conditions.

Evaluating edge joint preparation impact on penetration depth in laser-arc hybrid welding

Nowadays, conventional welding technologies such as submerged arc welding (SAW) are still used in most heavy-steel industries. This type of traditional technology means that welding takes up a large part of the productive time. As a solution to this problem, there are welding methods, such as Laser-Arc Hybrid Welding (LAHW), that have the potential to reduce the cost of manufacturing large steel structures. This is possible due to the reduced number of weld passes required to join thicker steel sections, as large thicknesses can be welded in one or a few passes.A problem with LAHW is achieving satisfactory quality. For this reason, it is essential to study the starting conditions, e.g. edge joint preparation. The target of this research work is to find out the relationship between the penetration value of the weld bead obtained and the edge joint preparation. The evolution of the molten pool and the behavior of the molten material in the joint is discussed for the different edge joint preparation configurations. The effect of the roughness is that it affects the wetting of the molten material in the joint, which would affect the penetration result, together with the gap and air volume gap used in the joint. Cut-wire is also used in the research, in samples that presented a larger air volume gap. The behavior of the molten metal inside the joint in this case is also discussed. In addition, the quality of the weld beads has also been determined by making macrographs, microstructural analysis, X-ray, microhardness profiles, tensile test and Charpy test. Some pores and cracks have been found, although destructive tests show adequate behavior of the weld bead. It is possible to elucidate from the findings that as the roughness, gap and/or air volume gap of the edge joint increases, the penetration value obtained increases. Cut-wire samples obtained full penetration.

Microbiological and Molecular Investigation of Antimicrobial Resistance in Staphylococcus aureus Isolates from Western Romanian Dairy Farms: An Epidemiological Approach.

Antimicrobial therapy is the most frequently used medical intervention for bovine mastitis in the dairy industry. This study aims to monitor the extent of the antimicrobial resistance (AMR) problem in Staphylococcus aureus in the dairy industry in Western Romania. Twenty farms were selected by random sampling in a transverse epidemiological study conducted across four counties in Western Romania and divided into livestock units. This study assessed the association between the resistance genes to phenotypic expression of resistance and susceptibility. Isolates of S. aureus were identified and q-PCR reactions were used to detect antibiotic resistance genes. One hundred and fifty bovine and 20 human samples were positive for S. aureus. Twenty five percent of bovine isolates (30/120) and none(0/30) of the human isolates were methicillin-resistant S. aureus (MRSA). All isolates were susceptible to fosfomycin, ciprofloxacin, netilmicin, and resistant to ampicillin and penicillin. S. aureus isolates regarded as phenotypically resistant (R) were influenced by the origin of the samples (human versus bovine, χ2 = 36.510, p = 0.013), whether they were methicillin-resistant S. aureus (χ2 = 108.891, p < 0.000), the county (χ2 = 103.282, p < 0.000) and farm of isolation (χ2 = 740.841, p < 0.000), but not by the size of the farm (χ2 = 65.036, p = 0.306). The multiple antibiotic resistance index was calculated for each sample as the number regarded as phenotypically resistant (R)/total antibiotics tested (MARI = 0.590 ± 0.023) was significantly higher (p < 0.000) inmethicillin-resistant S. aureus (0.898 ± 0.019) than non-methicillin-resistant S. aureus (0.524 ± 0.024) isolates. For the antibiotics tested, the total penetrance (P%) of the resistance genes was 59%, 83% for blaZ, 56% for cfr, 50% for erm(B), 53% for erm(C), 57% for mecA and 32% for tet(K). Penetrance can be used as a parameter for guidance towards a more accurate targeting of chemotherapy. P% in S. aureus was strongly positively correlated with the multiple antibiotic resistance index (r = +0.878, p < 0.000) with the potential to use the same limit value as an antibiotic management decision criterion. Considering cow mastitis, the penetrance value combined with the multiple antibiotic resistance index suggests that penetrance could serve as a useful parameter for more precise targeting of chemotherapy for S. aureus.

Design and experimental research of air-assisted nozzle for pesticide application in orchard.

This article reports the design and experiment of a novel air-assisted nozzle for pesticide application in orchard. A novel air-assisted nozzle was designed based on the transverse jet atomization pattern. This article conducted the performance and deposition experiments and established the mathematical model of volume median diameter (D50) and liquid flow rate with the nozzle design parameters. The D50 of this air-assisted nozzle ranged from 52.45 μm to 113.67 μm, and the liquid flow rate ranged from 142.6 ml/min to 1,607.8 ml/min within the designed conditions. These performances meet the low-volume and ultra-low-volume pesticide application in orchard. The droplet deposition experiment results demonstrated that the droplet coverage distribution in different layers and columns is relatively uniform, and the predicted value of spray penetration (SP) numbers SPiA , SPiB , and SPiC (i = 1, 2, and 3) are approximately 70%, 60%, and 70%, respectively. The droplet deposits on the foliage of the canopy (inside and outside) uniformly bring benefit for plant protection and pesticide saving. Compared with the traditional air-assisted nozzle that adopts a coaxial flow atomization pattern, the atomization efficiency of this air-assisted nozzle is higher. Moreover, the nozzle air pressure and liquid flow rate are considerably lower and greater than the traditional air-assisted nozzle, and these results proved that this air-assisted nozzle has great potential in orchard pesticide application. The relationship between the D50 and nozzle liquid pressure of this air-assisted nozzle differs from that of traditional air-assisted nozzles due to the atomization pattern and process. While this article provides an explanation for this relationship, further study about the atomization process and mechanism is needed so as to improve the performance.

Formulation and In-Vitro Penetration Test of Ketoprofen Patch with Addition Aloe vera Powder (Aloe vera L.) Bioenhancer

Ketoprofen is a non-steroidal anti-inflammatory drug (NSAID) which is generally used to reduce pain and inflammation. The main obstacle in administering drugs via transdermal is the low penetration of drugs through the skin. Aloe vera contains lignin compounds which are thought to be bioenhancer. This research aims to formulate ketoprofen and aloe vera powder in form patch and compare penetration patch with and without the addition of aloe vera powder. Preparation patch 3 formulas were made with different ratios of HPMC E5 and Eudragit E100 polymers F1 (6:2), F2 (8:2), F3 (10:2). Formula 3 is the best formula with a comparison of HPMC E5 and Eudragit E 100 of 10:2. Formula 3 has a thin, dry patch and is easy to remove from the mold. F3 then remade with additions bioenhancer by 5 % and patch without additions bioenhancer. The results of the physical quality test showed that the formula with and without the addition of aloe vera as an enhancer has uniform weight, thickness, pH and folding resistance which meets the requirements for patch preparation. Franz diffusion cell result for patch preparations with the addition of aloe vera showed a better penetration value than without the addition of aloe vera with a cumulative value of 92.5815 μg/cm2 and a total flux of 260.4355 μg/cm2 hour.

Study of Characteristics of Bitumen and Aggregate with Use of Plastic Waste

Plastic is everywhere, and its use in different forms is increasing day by day despite discouragement from the government. Plastic waste disposal is a global issue since they are non-biodegradable and toxic in burning. Plastic pollution threatens food quality, human health, sanitation, and the ecosystem and contributes to climate change. The usage of plastic waste in elements (bitumen and aggregate) used in road construction was the main objective of this study. With use of appropriate plastic waste in building of road would not only reduce material cost but also contributes in solving plastic waste management issue. Nepal being a developing country with low Gross Domestic Product (GDP) where most of the districts are still deprived of good flexible pavement networks, plastic modified roads could be a value engineering and economic solution. The paper highlights by which method plastic waste can be used effectively in road construction by performing different experimental tests reflecting the characteristics of bitumen and aggregate on addition of plastic. The study has determined the penetration, softening point, ductility values of bitumen and impact and abrasion values of aggregate in addition to different percentage of plastic waste. According to the study, bitumen's penetration and ductility value drop with increasing plastic content, making it better suited for usage in warmer climates, but its softening point rises, ensuring a stronger resistance to flow in services. Comparably, when in aggregate plastic content rises, both its AIV value and its LA abrasion value fall, enhancing the aggregate's toughness and ability to endure greater wear and tear.

Evaluation of Bio-Rejuvenator and Compaction Conditions on Stiffness Modulus and Indirect Tensile Strength of Recycled Hot Mix Asphalt.

This study focuses on the investigation of the effect of a reclaimed asphalt material (RAP) and a bio-rejuvenator (mix of vegetable oils) on the stiffness modulus and indirect tensile strength (ITS) values of eight bituminous mixtures produced by using three types of compaction, with different RAP amounts (25% and 50%) and rejuvenator (0%, 0.20%, 0.40% and 0.60% by mass of RAP). A conventional hot mix asphalt was considered as the reference mix. All tests were performed on cylindrical samples produced using: Marshall compaction with 50 blows/side, cored cylindrical specimens from slabs compacted using a roller compactor (39 passes), and, respectively, gyratory compaction on 80 gyrations. Stiffness modulus and ITS values showed strong linear variation with the increase in rejuvenator content, independently of test temperature and type of compaction. The rejuvenating effect of the bio-rejuvenator was observed to counterbalance the impact of RAP. The results at 20 °C for gyratory specimens for the mix with 50% RAP and 0.40% bio-rejuvenator were comparable/closer (under 5% relative difference) to those obtained for the reference mix. A strong correlation between stiffness modulus values of mixes and penetration values of the corresponding binder blends was obtained (R2≥0.977).

Evaluation of the Sealing Ability of Various Root Canal Obturation Techniques in Permanent Molars: An In vitro Study.

Achieving a reliable seal in root canal obturation is essential for the success of endodontic treatment. Despite the availability of multiple techniques, the comparative sealing abilities of these methods remain a topic of investigation, particularly in permanent molars. This in vitro study involved 60 extracted permanent molars, divided randomly into three groups: Group A (lateral compaction), Group B (thermoplasticized gutta-percha), and Group C (single cone). After instrumentation and obturation, the sealing ability was assessed using a dye penetration method. Arbitrary values were assigned to quantify the extent of dye penetration. The mean dye penetration values were as follows: Group B (thermoplasticized gutta-percha) had the lowest penetration (2.1 ± 0.3 mm), followed by Group A (lateral compaction) (3.5 ± 0.4 mm), and Group C (single cone) exhibited the highest penetration (5.2 ± 0.6 mm). In this study, thermoplasticized gutta-percha demonstrated superior sealing ability compared to lateral compaction and single cone techniques in permanent molars. These findings underscore the importance of selecting an effective obturation technique to ensure optimal seal integrity in root canal therapy.

Assessment of reflex risks of inhalation exposure to harmful substances among the Murmansk oblast population

This study aimed to assess the individual risks of immediate (reflex) effects of inhalation exposure to nitrogen oxide and nitrogen and sulfur dioxides among the population of the Murmansk Oblast. The study was conducted in seven cities and covered the period of October, November, and December 2021. The considered chemical compounds belong to the third hazard class. Calculations were carried out using mathematical models, linking the penetration values with the actual concentrations of pollutants in the atmospheric air and their maximum permissible one-time concentrations. A table of normal probability distribution was used to convert probits into risks. The calculated risk values were compared with the acceptable values of the maximum risks of immediate action. The acceptable value of nitrogen oxide and dioxide (0.02–0.05) was found to be exceeded in the city of Kovdor in November and December. In the city of Monchegorsk, the acceptable value of sulfur dioxide was exceeded in November.