Decrease In Depth Research Articles

Orthodontic Management of Different Stages and Grades of Periodontitis According to the 2017 Classification of Periodontal Diseases

Background/Objectives: The 2017 Periodontal Classification offers a comprehensive framework for the diagnosis and management of periodontitis based on staging and grading criteria. Orthodontic therapy is increasingly incorporated into the management of periodontitis to rectify malocclusion, pathological tooth migration, and occlusal stability. Nonetheless, few data directly correspond with this revised classification scheme. The objective of this systematic review is to figure out the influence of orthodontic therapy on periodontal outcomes in patients with Stage III and IV periodontitis, as categorized by the 2017 framework. Methods: A systematic review was performed in accordance with the PRISMA 2020 principles. The databases examined were PubMed, Web of Science, Scopus, and Google Scholar. The evaluation focuses on research published from 2012 to 2024. Seventeen studies were assessed after the application of the inclusion criteria. Key outcomes included clinical attachment level (CAL) improvement, probing depth (PD) decrease, and radiographic bone fill. Results: The integration of orthodontic treatment with periodontal therapy markedly enhanced CAL (mean gain: 4.35–5.96 mm), decreased PD (mean reduction: 3.1–6.3 mm), and facilitated radiographic bone regeneration (mean vertical fill: 4.89 mm). Patients with Stage IV Grade C periodontitis had the most significant improvement, especially with early orthodontic intervention subsequent to regenerative treatment. Prolonged follow-ups (up to 10 years) validated consistent results. Conclusions: Orthodontic intervention, as a supplementary measure to periodontal therapy, improves results in severe periodontitis, especially in Stage III and IV patients. These results underscore the need for multidisciplinary teamwork and defined protocols for including orthodontics in periodontitis therapy.

Fabrication of Highly Ordered Macropore Arrays in p-Type Silicon by Electrochemical Etching: Effect of Wafer Resistivity and Other Etching Parameters

Macroporous silicon is a promising substrate in the field of optics, electronics, etc. In this paper, highly ordered macropore arrays were fabricated in p-type silicon wafers by electrochemical etching using a double-tank cell. The effect of the silicon resistivity, etching voltage and etching time on the pore morphology was investigated and the influence mechanism was analyzed. The pore diameter would decrease with the increase in the silicon resistivity and the decrease in the etching voltage, due to the increase in the space charge region width (SCRL). The pore depth would increase with the resistivity and the voltage. However, too high resistivity would cause insufficiency at the pore tips and too high voltage would cause pore splitting, which may cause a decrease in the pore depth. Then, the aspect ratio of 21 can be obtained on the silicon wafer with a resistivity of 50–80 Ω·cm at the etching voltage of 5 V with a maximum etching rate of about 0.92 μm/min.

Optimization Study of Drainage Network Systems Based on the SWMM for the Wujin District, Changzhou City, Jiangsu Province, China

This study addresses the persistent issue of urban waterlogging in Wujin District, Changzhou City, Jiangsu Province, using a comprehensive approach integrating an optimized drainage network and low-impact development (LID) measures. Utilizing the Storm Water Management Model (SWMM), calibrated with extensive hydrological and hydraulic data, the model was refined through genetic algorithm-based optimization to enhance drainage efficiency. Key results indicate a substantial reduction in the average duration of waterlogging from 7.43 h to 3.12 h and a decrease in average floodwater depth from 21.27 cm to 8.65 cm. Improvements in the drainage network layout, such as the construction of new stormwater mains, branch drains, and rainwater storage facilities, combined with LID interventions like permeable pavements and rain gardens, have led to a 56.82% increase in drainage efficiency and a 63.88% reduction in system failure rates. The implementation effectively minimized peak flood flow by 25.38%, reduced runoff, and improved groundwater recharge and rainwater utilization. The proposed solutions offer a replicable, sustainable framework for mitigating flooding in urban environments, enhancing ecological resilience, and ensuring the safety and quality of urban life in densely populated areas.

Study of shallow-water effects on ship maneuverability using free-running model tests

Abstract In this study, we conducted turning tests with rudder angles $$\pm 35^\circ$$ ± 35 ∘ and $$\pm 20^\circ /20^\circ$$ ± 20 ∘ / 20 ∘ zig-zag maneuver tests in deep and shallow water using a model of a 3,600 TEU container ship called KCS. Through the comparison of these test results with the free-running test results of three other ships, the shallow-water effect on the maneuverability was investigated. The shallow-water effects obtained during the turning and zig-zag maneuvers are as follows: Turning: The advance ( $$A_D$$ A D ) decreases slightly when the water depth-to-ship draft ratio (h/d) is approximately 2.0 and increases significantly as the water depth decreases. The tactical diameter ( $$D_T$$ D T ) (up to $$h/d = 2.0$$ h / d = 2.0 ) is approximately the same as that in deep water and becomes significantly larger when h/d becomes smaller than 2.0. Thus, there is a slight difference in the appearance of the shallow-water effects in $$A_D$$ A D and $$D_T$$ D T . Zig-zag maneuvers: The overshoot angle increases slightly near $$h/d = 2.0$$ h / d = 2.0 compared with that in deep water and becomes significantly smaller as the water depth becomes shallower. The forward distance ( $$l_{20}$$ l 20 ), until reaching the heading $$+20^\circ /-20^\circ$$ + 20 ∘ / - 20 ∘ after steering, was approximately the same as that in deep water or decreased slightly, until approximately $$h/d = 2.0$$ h / d = 2.0 . Furthermore, it increased as the water depth decreased. This is because the course stability of the ship deteriorated at approximately $$h/d = 2.0$$ h / d = 2.0 .

Impact of light-induced atomic desorption on electric field sensing via electromagnetically induced transparency and its correction

In Rydberg quantum electric field sensing, the amplitude and linewidth of electromagnetically induced transparency (EIT) spectra significantly impact the accuracy of electric field measurements. This paper discusses the influence of atomic density on the amplitude and linewidth of EIT spectra in a vapor cell within a three-level ladder system driven by two-photon excitation. Due to the adsorption of alkali metal atoms on the inner surface of the vapor cell, the study utilizes light-induced atomic desorption effects to regulate the atomic density using LED light. This approach, combined with probe and coupling lasers, results in the formation of high-amplitude, low-linewidth EIT spectra. Based on the Rydberg atom sensing measurement system constructed in this study, when the number of atoms per cubic meter is less than 1.5×1024, a decrease in the optical depth at the bottom of the EIT leads to a reduction in amplitude and an increase in linewidth. When the number of atoms per cubic meter exceeds 4×1024, a decrease in the peak value at the top of the EIT results in a reduction in amplitude, with a slight decrease in linewidth. By adjusting the atomic density within the vapor cell through the power of desorption light and optimizing the laser Rabi frequency parameters, the atomic number density is maintained between 1.5×1024 and 4×1024 per cubic meter, yielding high-amplitude, low-linewidth EIT spectra. Additionally, the influence of introducing 365 nm desorption light on the accuracy of the constructed electric field measurement system is analyzed and corrected.

Probiotic Therapy as an Adjuvant in the Treatment of Periodontal Disease: An Innovative Approach.

Background and Objectives: Periodontal inflammation, often linked to oral microbiota dysbiosis dominated by pathogenic bacteria, remains a significant challenge in periodontitis management. Traditional periodontal therapies primarily reduce the bacterial load but fail to restore the microbiota balance. Probiotics offer a promising therapeutic adjunct with their ability to enhance beneficial bacteria. This study investigates the effects of probiotics on the oral microbiota, inflammatory markers (IL-1β, TNF-α), and clinical parameters (gingival index, bleeding index, and periodontal pocket depth). Materials and Methods: In this pilot study, 80 patients with moderate-to-severe periodontitis were assigned to two groups. Group A received standard periodontal therapy (non-surgical periodontal therapy (NSPT)) with probiotic supplementation (Lactobacillus reuteri, 2 × 10⁹ CFU daily for 8 weeks), and Group B received standard treatment with a placebo. Microbiological changes were assessed via quantitative PCR, while inflammatory markers (IL-1β, TNF-α) were analyzed using ELISA. Clinical parameters, including the gingival index (GI), bleeding index (BI), and periodontal pocket depth (PPD), were measured at baseline (T0), 4 weeks (T1), and 8 weeks (T2) using standardized methods. Results: Probiotic therapy (Group A) significantly reduced the pathogenic bacteria and increased the beneficial bacteria levels compared to the placebo (p < 0.01). Inflammatory markers decreased by 37% (IL-1β) and 42% (TNF-α), while clinical parameters improved, with reductions in the gingival and bleeding indices (-1.5, -1.3) and a 2 mm decrease in the periodontal pocket depth (p < 0.01). Conclusions: Probiotics, as an adjunct to periodontal therapy, effectively restore the microbiota balance, reduce inflammation, and improve clinical outcomes in periodontitis.

Tectonics of Cauvery basin (India) in onshore and offshore portions

Morphometric studies coupled with geophysical investigations from petroliferous basins provide valuable information about tectonics of the regions. We deduce six morphologic parameters from the River Cauvery's designated (sub)watersheds and perform dendrogram clustering analysis. The main channels of the (sub)watersheds showcase steeper gradient and meandering nature with less concavity. On the other hand, the distributaries portray lesser gradient and straight nature with greater concavity. From the offshore region of the Cauvery basin, we perform gravity modeling. The results show variations in gravity values from low to high, -150 to 50 mGal probably because of the basement ridge-depression features. This anomaly orientation indicates the extension of the sub-basin in the region. A strong NE-SW gravity trend possibly suggests a high-density plug at mid-crust. The low gravity values near the Vedaranyam region indicate low-density rocks within the basement. Places of high gravity anomaly show a decrease in bathymetry depth and vice versa. This indicates isostatic compensation of the Moho geometry, possibly due to crustal thinning in the offshore areas. Isostatic regional gravity fields are manifested by Moho relief and can have implications on the lithospheric mechanical strengths. Bathymetric studies indicate multi-directional slopes. Relatively flat areas can indicate depocenters. E-W trending lineaments mapped on the Precambrian basement from a portion of the study area is presumably a manifestation of Cauvery Shear zone, which also persists in the offshore region.

Forest‐Water Ecotones: Flooding Impacts on Ant Species Distribution

ABSTRACTNatural ecotones between forest and lake‐swamp succession impose severe environmental filters for ant fauna, compared to adjacent forest habitats. This filter effect may be more severe for soil than canopy fauna. We tested this hypothesis by investigating the patterns of species occurrence, richness and composition of soil and canopy ants in forest and lake‐swamp ecotones in a tropical river basin. We established two transects (250 m) at each site, one placed in the ecotone (i.e., flood zone) and the other inside the adjacent forest. Although upper and lower river basin had totally different ant species composition, the species occurrence, richness and composition distribution between habitats followed a similar pattern for both altitudes. Occurrence of soil ants and species richness was similar between interior and ecotone. The occurrence and species richness of canopy ants were both higher in the ecotones than in the forest interior. Ant species composition was similar between the ecotone and adjacent forest, for both soil and canopy fauna, and the ant species composition was different between seasons (dry and rainy) and between canopy and soil fauna. Most importantly, the environmental filter imposed by the ecotone and its unpredictable habitat conditions favoured fewer but opportunistic species, which drove the higher occurrence in these habitats. The years we studied were particularly dry and had a substantial decrease in lake depth. Hence, the abilities of species to best use unpredictable resources from the natural succession on the new dry grounds might have been defined by omnivorous, opportunistic and numerically dominant ants. The abiotic particularities of forest‐water ecotones are important in the temporal dynamics of ant species assemblages. Fluctuations in water dynamics can restrict soil assemblages, but subtle changes in soil flooding also affect canopy fauna and can have unpredictable effects due to intensified variations in seasonal dynamics.

The effectiveness of vitamin C in dental alveolus healing after dental extraction: A scoping review.

Dental extraction is a common procedure in dentistry. It is accompanied by postoperative pain and inflammation. In addition, it decreases bone volume and density. Vitamin C is an antioxidant and cofactor that promotes the synthesis and maturation of collagen, the proliferation and migration of fibroblasts and osteoblasts, accelerating the final phase of inflammation, promoting healing. The objective of this scoping review is to evaluate the effectiveness of vitamin c in dental alveolus healing after extraction and synthesize the available evidence and tits clinical implications. This review is registered on the Open Science Framework platform (https://osf.io/bstwk/). It was carried out under the PRISMA-ScR protocol, using the question: Is vitamin C effective in alveolar healing in patients undergoing dental extraction? The Pubmed/MEDLINE, Scopus, Web of Science and OPENGREY databases were used. Limiting itself to primary studies. A total of 287 articles were identified, applying selection criteria, 3 were included. Of a total of 135 patients, 59.8% were administered vitamin C; 46.6% 600 mg, 34.2% 500 mg and 19.2% 1500 mg. A decrease in pain, inflammation, probing depth and mesiodistal length of the socket was observed. The role of vitamin C is essential for healing, and therefore, bone regeneration after tooth extraction, reducing adverse effects such as pain and inflammation. Its administration is recommended to promote postoperative recovery. More studies are suggested to observe its effects in oral and maxillofacial surgery.

The Impact of Bridging Additives on Wellbore Strengthening in Shallow Unconsolidated Formations.

Drilling wells in unconsolidated formations is commonly undertaken to extract drinking water and other applications, such as aquifer thermal energy storage (ATES). To increase the efficiency of an ATES system, the drilling campaigns are targeting greater depths and enlarging the wellbore diameter in the production section to enhance the flow rates. In these cases, wells are more susceptible to collapse. Drilling fluids for shallow formations often have little strengthening properties and, due to single-string well design, come into contact with both the aquifer and the overburden. Drilling fluids and additives are experimentally investigated to be used to improve wellbore stability in conditions simulating field conditions in unconsolidated aquifers with a hydraulic conductivity of around 10 m/d. The impact on wellbore stability is evaluated using a new experimental setup in which the filtration rate is measured, followed by the use of a fall cone penetrometer augmented with an accelerometer to directly test the wellbore strengthening, and imaging with a scanning electron microscope (SEM) to investigate the (micro)structure of the filter cakes produced. Twelve drilling fluids are investigated with different concentrations of bentonite, polyanionic cellulose (PAC), Xanthan Gum, calcium carbonate (CaCO3), and aluminum chloride hexahydrate ([Al(H2O)6]Cl3). The filtration results indicate that calcium carbonate, average dp <20 μm, provides pore throat bridging and filter cake formation after approximately 2 min, compared to almost instantaneous discharge when using conventional drilling fluids. The drilling fluid containing 2% [Al(H2O)6]Cl3 forms a thick (4 mm) yet permeable filter cake, resulting in high filtration losses. The fall cone results show a decrease of cone penetration depth up to 20.78%, and a 40.27% increase in deceleration time while penetrating the sample with CaCO3 compared with conventional drilling fluid containing bentonite and PAC, indicating a significant strengthening effect. The drilling fluids that contain CaCO3, therefore, show high promise for field implementation.

The Unusual Seismic Activity from 2021 to 2024 in Eastern Austria: Insights from Seismic Sequences Relocation and Moment Tensor Inversion

ABSTRACT From 2021 to 2024, unusually strong seismic activity, including multiple sequences with five 3.8≤ML≤4.6 shocks, struck the Vienna basin and Mur-Mürz fault systems in Eastern Austria. Three earthquakes (ML 4.6, 4.5, and 3.8) occurred between March and May 2021. These earthquakes were followed by an increase in seismic activity in March 2023, with an ML 4.3 earthquake to the southwest of the 2021 events. In February 2024, an ML 4.5 earthquake occurred 10 km southwest of the ML 4.3 in 2023. We investigate activated faults relying on nonlinear relocations of the seismic sequences and probabilistic moment tensor inversion. The seismic sequences’ temporal evolution indicates a migration of seismic activity and a decrease of focal depths from northeast to southwest, suggesting a potential reactivation of the major fault systems in the region. The joint interpretation of the results shows distinct clusters along fault segments and focal mechanisms that match the region’s complex tectonic activity.

Analysis of Sedimentation Rate at Royoq Port (Kutai Barat, Kalimatan Timur) with Hydrodynamic Modeling

Abstract Sedimentation in port areas can have a significant impact on port operations and shipping safety. The accumulation of sediment material in the harbor area can cause a decrease in depth, limiting the size of ships that can enter the harbor. Our research aims to analyze the flow patterns and sedimentation rates in Royoq Harbor, a crucial step toward maintaining the safety and smooth operation of the harbor. The model simulation was conducted on a 75-kilometer stretch of the Mahakam River that was separated into three monitoring locations at Royoq Port for 2023. The research method used is hydrodynamic modeling with Delft3D. The results showed that the existence of the harbor decreased current velocity to 0.5 m/s on the west side and 0.2 m/s on the east side, as well as a change in current direction around the harbor as it headed from upstream to downstream. This phenomenon triggers the formation of stagnation zones that increase the risk of sedimentation. The sedimentation rate in the study area is 96.29 m3/year or 34 tons/year. The sedimentation rate in the west of the harbor has a value of 5.49 m3/year, while in the east of the harbor it is 97.9 m3/year. In addition, the Delft3D modeling results for six months showed a change in the morphology of the water bottom in the port, with sedimentation ranging from 0.03 m to 0.4 m on the west and east sides and erosion between −0.002 m to −0.01 m on the north side. To maintain the safety and smooth operation of the harbor, it is recommended that regular monitoring of the water depth and dredge sediments be conducted if necessary, supporting SDG 9 on building resilient infrastructure.

Mechanism of selective texturing of CFRP by femtosecond laser

Carbon fiber-reinforced polymer (CFRP) has become an indispensable key material in the aerospace field due to its advantages of lightweight and high strength. In this study, a new process of selective texturing by femtosecond laser is proposed to improve the surface performance of CFRP without destroying fiber continuity. To explore the process mechanism of selective texturing of CFRP, the concept of the removal threshold is proposed, the influence of laser scanning direction and laser energy on the groove and the HAZ is studied. Furthermore, the optimization strategy of processing parameters during selective texturing is given. It is found that the scanning direction influences the transfer path of the heat significantly and therefore affects the groove geometry. As the scanning angle increases, the ablation threshold of resin rises gradually, while the ablation threshold of carbon fiber experiences a rapid increase before 30° and a gentle increase thereafter. Additionally, the groove shows a steady growth in width and undergoes a stepped decrease in depth, and the width of the HAZ increases. As laser energy increases, the width of the groove and HAZ increases, and the depth of the groove increases in a step pattern. The selective texturing mechanism of surface resin involves the coupling superposition of multiple effects, including photolysis resulting from multi-photon absorption, pyrolysis caused by direct laser energy absorption, thermal effects due to heat transfer of fiber, thermal effects of pyrolysis gas, and mechanical denudation. The laser energy density of 12–13 J/cm2 is the optimal parameter range for achieving selective texturing.

A Multi-Enzyme Complex That Mitigates Hepatotoxicity, Improves Egg Production and Quality, and Enhances Gut and Liver Health in Laying Hens Exposed to Trace Aflatoxin B1.

Aflatoxin B1 is a prevalent secondary hazardous metabolite generated by fungus present in feed ingredients and the surrounding environment: enzymes are currently being recognized as an efficient and promising approach to reducing the associated risks. The objective of this study was to assess the effects of varying doses of enzyme complexes on several parameters in laying hens that were exposed to aflatoxin. During an 8-week experiment, a total of 288 Yukou Jingfen No.6 laying hens were placed into four groups. These groups included a group treated with toxins (CON group) and groups supplemented with compound enzyme complexes at doses of 250 g/t (E1 group), 500 g/t (E2 group), and 1000 g/t (E3 group). The E2 and E3 groups exhibited a statistically significant 2.6% increase in egg production rate compared to the CON group (p < 0.05). In addition, the E2 group showed significant improvements in both the feed-to-egg ratio and egg weight (p < 0.05). In addition, the E2 and E3 groups showed improved hutch unit and egg white height compared to the control group (p < 0.05). The E2 and E3 groups showed a substantial rise in liver health indicators, namely serum alanine transaminase (ALT) and alkaline phosphatase (ALP) activity. On the other hand, malondialdehyde (MDA) was lowered, and total superoxide dismutase (T-SOD) and total antioxidant capacity (T-AOC) were raised. These findings were statistically significant (p < 0.05). The E2 and E3 groups showed notable enhancements in intestinal morphology, as evidenced by a rise in villus height and a decrease in crypt depth in all segments of the intestine (p < 0.05). Furthermore, analysis of 16S rRNA sequencing revealed that these participants had a higher prevalence and variety of microorganisms in their gut microbiota. More precisely, there was a significant rise in the abundance of Bacteroidota and a decline in Firmicutes at the level of the phylum. In general, the inclusion of the enzyme complex had advantageous impacts on performance, egg quality, intestinal morphology, intestinal barrier function, and intestinal flora in laying hens. Our results indicate that toxin-degrading enzymes, when used as feed additives, play a significant role in mitigating AFB1 contamination in diets and improving the production performance of laying hens.

Numerical parameters study on seismic performance of short replaceable link with perforated web: Bearing capacity and overstrength

This study builds on experimental research of replaceable links with perforated web by using finite element software to develop a finite element model (FEM) of the link. The model’s reliability and accuracy were confirmed by comparing its results with experimental data. The simulation results closely match the experimental hysteresis curves, demonstrating the model's accuracy. Additionally, the simulations effectively replicated the observed failure modes, confirming the model's reliability and practical relevance. Building on this, 22 different finite element models were developed to investigate the impact of various parameters on link performance, including the shape and size of web openings, the number of openings, flange weakening depth, and link length ratio. The analysis revealed that links with circular or elliptical web openings have higher overstrength coefficients than other shapes. Additionally, as the link length ratio and flange weakening depth decrease, the overstrength coefficient tends to increase. These findings offer valuable theoretical insights and reference data for designing and optimizing replaceable link with perforated web.

Knowledge sourcing strategy and radical innovative performance: A temporal approach

Prior research on open innovation has so far taken a static view, by focusing on stable patterns of external knowledge sourcing that only depict a snapshot of a firm's external search at a given point in time. Such a static view, however, ignores the fact that a firm's portfolio of external knowledge sources evolves over time. Our study attempts to address this gap by clarifying how temporal variations in a firm's knowledge sourcing activities (i.e., changes in external search breadth and external search depth) affect its radical innovative performance. We conceptualize temporal variations as encompassing simple change events (i.e., single transformative events captured through increases or decreases in breadth and depth) and multiple change events (i.e., repeated changes captured through increases and/or decreases in breadth and depth); and then develop theoretical arguments that draw on the organization learning theory. We find that asymmetries emerge when comparing simple and multiple change events in external breadth and external depth. Our findings contribute to prior research on open innovation by providing insights into the temporal dynamics and evolution of knowledge sourcing activities.

Palaeoenvironmental interpretation and isotope stratigraphy of the Campanian–Danian successions in the Zagros Foreland Basin (Kabir Kuh, Lurestan, Iran)

The successions of the Gurpi Formation and the lower Pabdeh Formation were examined through analyses of lithology, sequence stratigraphy, stable isotope stratigraphy, and ichnofossils in the Jahangir Abad and Abhar sections of the Kabir Kuh anticline within the Lurestan Zone. Stratigraphic correlation with the well-dated Gandab section, located within the same anticline, indicates a late Campanian to early Danian age for these successions. This correlation further confirms the presence of notable carbon isotope excursions associated with the Campanian-Maastrichtian Boundary Event (CMBE) and Mid-Maastrichtian Event (MME). Field observations, along with sedimentological and paleontological analyses, suggest that the Kabir Kuh area was situated within the fore-bulge of the Zagros foreland basin during the Late Cretaceous. Changes in lithology, fossil content, and ichnofacies indicate a significant decrease in water depth at the end of the Campanian and the beginning of the Maastrichtian. This interval contains shallow marine macrofossils, including oysters (mainly Lopha), benthic foraminifers, and fossil debris traces, indicative of a high-energy environment. In contrast, shallow-water facies are not recorded within the middle and late Maastrichtian sequences. These sequences are composed of pelagic mud-dominated facies containing deep-sea ichnofossils, indicating a rapid increase in water-depth during the middle–late Maastrichtian. The observed late Campanian to early Maastrichtian shallowing is associated with the development of the Zagros fore-bulge, while the subsequent deepening and significant sediment deposition during the mid to late Maastrichtian are attributed to the subsidence of the basin. This research re-evaluates and refines the existing sequence stratigraphic and sedimentary models of the Zagros foreland basin, offering new perspectives on its geological evolution.

Enhancing the flexural capacity of RC beams under various loading rates through strengthening with ultra-high-performance fiber-reinforced concrete

This study investigates the enhancement of impact resistance in reinforced concrete (RC) beams using ultra-high-performance fiber-reinforced concrete (UHPFRC). Three types of steel fibers and two fiber volume fractions (0.75% and 1.5%) were considered. UHPFRC-strengthened RC beams exhibited an increase in flexural strength by approximately 6% at a fiber volume fraction of 1.5% compared to plain RC beams, due to effective crack suppression. Steel fibers in the UHPFRC strengthening layer inhibited the deep propagation of cracks into the compressive zone, resulting in a more gradual decrease in the neutral axis depth of RC beams. Under impact loading, UHPFRC-strengthened beams showed up to 7% lower deflection, with straight steel fibers providing superior impact resistance. RC beams strengthened with UHPFRC including straight steel fibers demonstrated improved residual flexural strength at higher fiber volumes. This highlights UHPFRC's effectiveness in enhancing impact resistance of RC beams according to the fiber type and volume fraction.

Bone Density Correlates With Depth of Subsidence After Expandable Interbody Cage Placement: A Biomechanical Analysis.

Biomechanical analysis. To evaluate the depth of subsidence resulting from an expandable interbody cage at varying bone foam densities. Expandable interbody cages have been shown to be associated with increased rates of subsidence. It is critical to evaluate all variables which may influence a patient's risk of subsidence following the placement of an expandable interbody cage. In the first stage of the study, subsidence depth was measured with 1Nm of input expansion torque. In the second stage, the depth of subsidence was measured following 150 N output force exerted by an expandable interbody cage. Within each stage, different bone foam densities were analyzed, including 5, 10, 15, and 20 pounds per cubic foot (PCF). Five experimental trials were performed for each PCF material, and the mean subsidence depths were calculated. Trials which failed to reach 150 N output force were considered outliers and were excluded from the analysis. There was an overall decrease in subsidence depth with increasing bone foam density. The mean subsidence depths at 150 N output force were 2.0±0.3mm for 5 PCF, 1.8±0.2mm for 10 PCF, 1.1±0.2mm for 15 PCF, and 1.1±0.2mm for 20 PCF bone foam. The mean subsidence depths at 1Nm of input torque were 2.3±0.5mm for 5 PCF, 2.3±0.5mm for 10 PCF, 1.2±0.2mm for 15 PCF, and 1.1±0.1mm for 20 PCF bone foam. Depth of subsidence was negatively correlated with bone foam density at both constant input torque and constant endplate force. Because tactile feedback of cage expansion into the subsiding bone cannot be reliably distinguished from true expansion of disc space height, surgeons should take bone quality into account when deploying expandable cages.

Controls on glacial kettle morphology

AbstractGlacial kettles are surficial depressions that form in formerly glaciated terrain when buried stagnant ice melts within pro‐glacial sediments, often deposited by meltwater streams. Kettles, like other glacial landforms, provide insight into the impact of climate on landscape evolution, such as the extent and timing of glaciations. The geometry of kettle features is variable, but existing theory does not explain the range of observed morphologies. Our study aims to establish a quantitative relationship between the depth of ice burial and the resulting morphology of terrain collapse in kettle depressions. To do so, we simulated kettle formation in the laboratory by burying ice spheres of four sizes in well‐sorted coarse sand at four different depths. As the spheres melt at room temperature, a glacial kettle analog forms at the surface. We scanned the resulting kettle topography with a portable LiDAR scanner to produce 3D digital elevation models of each depression, from which we measured each depression's depth and width and, in one instance, the time series of kettle formation. Using this data, we quantified the relationship between the sphere diameter, burial depth and resulting dimensions of the kettle by developing a set of equations, which we then applied to full‐scale features. Our results indicate that ice burial deeper than one sphere diameter corresponds to a decrease in depression depth and an increase in depression width. This application offers insight into the interdependence of ice burial depth and kettle geometry.