Search Results (547)

This study investigates the bond strength of fifteen cement-based adhesive mortars used for expanded polystyrene (EPS) in External Thermal Insulation Composite Systems (ETICS). Field surveys and contractor interviews (170 questionnaires) found that adhesive layer thicknesses in real applications typically range from 15–20 mm and frequently exceed 20 mm, in contrast to the smaller values most often recommended by guidelines and technical instructions. Laboratory testing was conducted using two approaches: the standardized pull-off procedure according to EAD 040083-00-0404 (EAD and EAD′ variants) and an in-house pull-off procedure designed to reflect practical conditions of substrate type (concrete slab, silicate block), substrate orientation (horizontal, vertical), and adhesive layer thickness (10 and 20 mm). The results showed that adhesive bond strength is strongly influenced by adhesive layer thickness, substrate type, and substrate orientation. Increasing thickness from 10 mm to 20 mm on concrete substrates typically reduced bond strength by about 65–75%, while vertical orientation lowered adhesion to about half of that obtained in horizontal placement. Silicate substrates exhibited generally lower bond strength but higher variability, occasionally with ratios above unity due to their greater porosity. In some configurations, detachment occurred already during specimen preparation, underlining the variability of performance. The combined effect of increased thickness and vertical orientation on concrete substrates reduced adhesion by about 85% compared to the 10 mm horizontal baseline, highlighting the severity of unfavorable application conditions, whereas on silicate blocks, the effect was weaker but accompanied by large variability. The findings indicate that adhesive layer thickness has a stronger impact on bond strength than orientation and that substrate properties play an important role. The study provides a comparative perspective on current and alternative testing approaches, revealing significant differences in the results. The author’s testing method makes it possible to account for, in laboratory conditions, primarily the geometric shape and orientation of samples that are close to the actual form of adhesive mortar application in real insulation installations. This allows for the assessment of the properties of mortars and substrates that were not exposed under the conditions of current testing methods. The above provides a basis for further discussion on the inclusion of realistic application conditions in the evaluation of adhesive mortars used for bonding thermal insulation in ETICS, and for the validation assessment of an additional testing method, which is currently of an experimental nature. Full article

Despite the widespread use of surgical guides, there is no universal sterilization protocol. Surgical guides are often designed for single use, but can become contaminated, which increases the risks of infection and implant failure. Purpose: This study evaluates the effects of alcohol immersion, alcohol spray, low temperature, and steam sterilization on the dimensional stability of surgical guides to ensure accurate implant placement and reduce failure. Material and Methods: One standard dental model was scanned using a laboratory scanner. Ninety guides were printed and were then divided into six groups allocated as control, alcohol spray, alcohol immersion with ultrasonication, low-temperature dry sterilization, and two autoclave methods. Specimens were stored in dry–dark media and scanned at 0, 3, and 7 days, with dimensional changes assessed using CloudCompare. The Shapiro–Wilk, Levene’s, Repeated measures one-way ANOVA, and Tukey’s post hoc tests were used to determine statistical differences. Results: Time significantly affects stability, with RMS values improving over time. Autoclave 121 °C and low-temperature 54 °C sterilization showed the lowest RMS values, indicating better stability. Conclusions: Within the limitations of the present study, the most effective approach for maintaining the dimensional stability of surgical guides was autoclaving at 121 °C, +1 bar for 20 min, and the second-best technique was low-temperature dry sterilization at 54 °C for 1 h. Full article

The main pathological, epidemiological, and clinical findings of haemonchosis in goats and sheep in a semi-arid region of Northeast Brazil are described. Necropsy records conducted between January 2012 and December 2021 at the Animal Pathology Laboratory (APL) of the UFCG, were reviewed. In 2022, a prospective study monitored the necropsies performed on these species. In total, necropsies were conducted on 410 goats and 319 sheep, haemonchosis was observed in 50 (12%) goats and 49 (15%) sheep. For goats, females (45/50, 90%; p ≤ 0.05), the age range of 13–35 months (25/50, 50%; p ≤ 0.05), and crossbred animals (38/50, 76%; p ≤ 0.05) were most affected. Both goat and sheep, respectively, raised in a semi-intensive system were more infected (41/50, 82%; 36/49, 76.5%; p ≤ 0.05). The animals came from the States of Paraíba, Pernambuco, Ceará, and Rio Grande do Norte. The proportion of goats (32/50, 64%) and sheep (30/49, 61.2%) with a normal body condition score was significantly different (p ≤ 0.05). The main pathological alterations (p ≤ 0.05) were the mucosal and carcass paleness, and the presence of H. contortus specimens in the abomasum. Haemonchosis remains a significant parasitic disease affecting small ruminants in the semi-arid region of Northeast Brazil, leading to mortality and decreased production rates, posing substantial economic challenges that adversely impact goat and sheep farming. Full article

Three populations of the western tubenose goby were analysed during the reproductive season of 2024 in the area of Žitný Island, Slovakia. Specimens were processed in the laboratory, where meristic and reproductive parameters were detected. Populations were female-dominated and all in good condition. Males showed a decrease in condition, probably due to different roles during reproduction. Females were characterised by increased values of the absolute (114–3997; mean 1299 oocytes) and relative number of oocytes (114–3206; mean 1225 oocytes), gonadosomatic index (3.02–93.27%; mean 19.49), and oocyte size (0.10–1.93 mm) compared to other native and/or invasive areas of occurrence. Comparing populations from 2024 with 2015, we found that females from the present study have smaller body sizes, higher values of absolute and relative number of oocytes, but lower values of gonadosomatic index and larger sizes of oocytes. This would suggest a shift to a more generalistic strategy based on a hypothesis derived from the theory of alternative ontogenies and invasive potential. Although the western tubenose goby is regarded as a native species in Slovakia, its reproductive parameters suggest a shift to more opportunistic behaviour. This pattern is consistent with its invasiveness in other non-native regions, such as parts of Europe and the Laurentian Great Lakes. Full article

Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant challenge, costing annually approximately USD 1.2 billion to the U.S. swine industry due to production losses associated with, but not limited to, reproductive failure, abortion, and high pre-weaning mortality among piglets. PRRSV is endemic, with thirty percent of the U.S. breeding herd experiencing outbreaks annually. The shedding status of animals on a farm is typically assessed using serum or processing fluids from piglets, but tongue tips from deceased animals are emerging as a potential alternative specimen to support farm stability assessment. This study explored the impact of various processing and testing strategies on tongue tips to enhance the sensitivity and specificity of PRRSV detection in sow herds. We collected tongue tips from 20 dead piglets across seven sow farms, testing different pooling strategies (individual testing, and pools of n = 5 or n = 20) and laboratory processing methods (tongue tip fluid—TTF, versus tongue tissue homogenate—TTH). Additionally, we simulated storage and shipping conditions, comparing frozen samples to refrigerated ones tested at intervals of 1, 4, and 7 days post collection. RT-PCR testing revealed higher sensitivity and lower cycle threshold (Ct) values for TTF compared to TTH, suggesting that tongue tips are better tested as TTF rather than TTH for PRRSV detection. Pooling samples reduced diagnostic accuracy. Frozen samples had lower absolute Ct values, and Ct values increased by 0.2 Ct values each day post collection when the sample was kept refrigerated, emphasizing the importance of minimizing shipping delays. Tongue tips are a practical, easy-to-collect specimen that target potentially infected animals (dead piglets), offering valuable insights into swine herd health, but sample processing approaches significantly influence diagnostic outcomes. If tongue tips are used by veterinarians to assess viral presence on a farm, testing the TTF instead of TTH should be prioritized. Storage and shipment conditions should be considered to optimize laboratory results. Full article

This study investigates the behaviour of dense silty sands with kaolinite clay under static drained/undrained conditions at low confining stress. Conventional laboratory tests assessed the mixtures’ physical properties, but standard void ratio methods proved inadequate for silty sands with kaolinite. Despite targeting 80% relative density, specimens exhibited loose sand behaviour in both drained and undrained tests. With increasing kaolinite content, conventionally reconstituted mixtures exhibit reduced peak stress ratios up to 10% fines, with little change beyond, while critical ratios generally rise at 25 kPa but remain unchanged or decrease slightly at 50 kPa. Analytical redefinition of minimum/maximum void ratios (based on sand–clay volumetric fractions) improved specimen reconstitution, yielding dense behaviour matching that of the host sand. The alternatively reconstituted mixtures display increasing drained peaks and minor changes in undrained peaks with increasing kaolinite content, with critical ratios increasing markedly at 25 kPa and only slightly at 50 kPa. However, this analytical void ratio determination method is limited to non-expansive, low-plasticity clays. Void ratios in silty sands with clay mineras are influenced by confining stress, drainage, saturation, clay content, and the sand skeleton structure. Unlike pure sands, these mixtures exhibit variable void ratios due to changes in the clay phase under different saturation levels. A new evaluation method is needed that accounts for clay composition, saturation-dependent consistency, and initial sand skeleton configuration to characterise these soils accurately. The findings highlight the limitations of conventional approaches and stress the need for advanced frameworks to model complex soil behaviour in geotechnical applications. Full article

The stability of the mine pillar is a key issue related to the safe mining underground. Reinforcing the mine pillar is an important method to improve its stability. To reveal the reinforcement effect and mechanism of concrete-encased mine pillars, laboratory tests and field engineering application studies were conducted. Four groups of tests were carried out considering different sample sizes, rock strengths, encasing material strengths, and encasing layer thicknesses. The results demonstrated that mortar-encased rock specimens exhibited significant improvements in peak stress and axial peak strain. The reinforcement effectiveness was inversely proportional to the specimen’s height-to-diameter ratio and rock strength, while directly proportional to the wrapping material strength and layer thickness. Orthogonal range analysis revealed the sensitivity ranking of influencing factors as follows: encasing thickness > specimen height-to-diameter ratio > encasing material strength > rock strength. After encasing, the failure mode transitioned from integral failure to fragmented failure, with encased specimens demonstrating enhanced energy absorption capacity and bearing capacity. Increasing encasing strength and thickness induced a tendency towards plastic deformation failure. The encased rock-specimen system can be regarded as a parallel composite structure of rock and mortar layer. This configuration not only increases the bearing capacity of the mortar layer but also significantly enhances the rock’s intrinsic bearing capacity through confining pressure provided by the encasing material, which grows substantially with improvements in encasing material strength and thickness. Field applications in mines demonstrated that concrete-encased reinforcement of key area pillars can effectively control overall ground pressure in mining operations. The research results of this paper indicated that the reinforcement of mine pillars by concrete wrapping can enhance the stability of mine pillars and provide a new idea for improving the safety of mines. Full article

Laboratory triaxial tests are essential for studying sandy soil behavior but have limited ability to capture localized deformation and microstructural evolution. The discrete element method (DEM) overcomes these limitations by enabling particle-scale analysis, where boundary conditions can critically affect simulation results. This study employed DEM-based triaxial compression simulations to compare rigid wall and flexible membrane boundaries for sand specimens with initial porosities of 35.5%, 38.2%, 40.8%, and 41.5% under confining pressures of 50, 100, and 150 kPa. The analyses covered macroscopic stress–strain and volumetric responses, shear band morphology, local porosity evolution, and contact force fabric. The results indicate that rigid and flexible boundaries produce similar pre-peak responses, but differ markedly in post-peak behavior and volumetric strain. Rigid boundaries constrain lateral deformation, induce stress concentrations, and underestimate post-peak strength, while flexible membranes apply confining pressure more uniformly and reproduce realistic bulging and porosity evolution. Based on these findings, rigid boundaries are suitable for dense sands when post-peak strength is not a concern, and for loose sands at small strains, whereas flexible membranes are necessary to capture volumetric contraction and realistic post-peak responses. This work provides mechanistic insights into boundary effects and offers a basis for more efficient selection of boundary conditions in DEM triaxial simulations. Full article

Background: p16 immunohistochemistry (IHC) serves as a surrogate marker for high-risk human papillomavirus (hrHPV) and is widely used in gynecologic pathology. However, few studies have directly compared the staining performance and reproducibility of different p16 antibody clones in this context. Methods: We retrospectively evaluated 176 gynecologic tumor specimens including 42 whole slide sections and 134 tissue microarray cores from the cervix, endometrium, vulva, and ovary using three fully automated p16 IHC assays: E6H4 (Ventana/Roche), JC8 (Agilent/Dako), and 6H12 (Leica). Two pathologists independently reviewed each case, and concordance and interobserver agreement were analyzed. Sensitivity, specificity, and Cohen’s κ statistics were calculated, with E6H4 serving as the reference. Results: All three antibody clones demonstrated excellent staining performance with preserved tissue morphology and minimal background artifacts. Concordance for p16 positivity/negativity was 100% across all clone pairings (95% CI: 97.9–100%). Interobserver reproducibility was also perfect, with a κ coefficient of 1.00 (95% CI: 0.94–1.00). Minor non-block staining patterns did not impair interpretability. Conclusions: Our findings indicate that E6H4, JC8, and 6H12 clones yield comparable staining results when used in conjunction with standardized automated protocols. These results support the practical interchangeability of these clones in clinical and research settings, particularly when cost, availability, or risk management require substitution. Laboratories should continue to perform internal validation and utilize external quality assurance programs when implementing p16 IHC. Full article

The development of sustainable and energy-efficient asphalt pavements is essential to address the growing demand for climate-neutral transportation infrastructure. This study investigates the structural design and functional performance of low rolling resistance asphalt mixtures utilizing reclaimed asphalt pavement (RAP) and warm mix asphalt (WMA) technologies. Ten mixtures with WMA additive—including asphalt concrete (AC) and stone mastic asphalt (SMA) with and without RAP—were evaluated for volumetric and mechanical performance. Laboratory results show that RAP addition did not compromise compaction nor indirect tensile strength ratio (ITSR), and in some cases improved these properties. SMA and SMA RAP-modified mixtures achieved the highest resistance to rutting (as low as 5.0% rut depth), while AC and SMA mixtures both demonstrated low rolling resistance (coefficients of energy loss 0.00604–0.00636). Resistance to low-temperature cracking was strong for all mixtures, with thermal stress restrained specimen test (TSRST) fracture temperatures ranging from −32.8 °C to −36.0 °C. SMA mixtures generally exhibited superior resistance to fatigue (up to 63 με at 1 million cycles). Overall, three asphalt mixtures with different particle size distribution containing 14% RAP and a WMA additive (SMA 8 S_1 R, SMA 8 S_3 R, and AC 11 VS_2 R) demonstrated the best balance of rolling resistance, durability, and circularity, and are recommended for field trials to support climate-neutral and sustainable road infrastructure. These results encourage broader adoption of circular practices in road infrastructure projects, contributing to lower emissions and life-cycle costs. Full article

Vertical low-permeability barriers are widely used to improve the stability and seepage resistance of flood embankments. The present study evaluates three barrier technologies—vibrating beam slurry walls (VBSWs), deep soil mixing (DSM), and low-pressure grout injection (LPG)—through a series of consolidated drained triaxial tests and permeability coefficient tests on soil samples collected from the sites where different barrier installation technologies were used. All three barrier installation methods produced substantial improvements in both mechanical and hydraulic performance: the effective angle of internal friction (φ′) increased by 3–6° in samples with a plasticity index near 3.5%, and coefficients of permeability dropped from 10⁻⁸–10⁻⁷ m/s in untreated soils to below 10⁻⁹ m/s in treated specimens. The key finding of the study is that the barrier performance varies by the technology and the soil type. According to the result, DSM is the most effective technology used in clay-rich soils (φ′ increased up to 4°); LPG achieved the lowest permeability (7 × 10⁻¹¹ m/s) in granular soils; and VBSWs balanced strength and impermeability, most effective in silty sands. Flow-pump tests further demonstrated that treated soils required much longer to stabilize under a constant flow rate and could sustain higher hydraulic gradients before reaching equilibrium. These findings show the importance of matching barrier technology to soil plasticity and liquidity characteristics and highlight saturation as essential for reliable laboratory evaluation. The results provide a scientific basis for selecting and designing vertical barriers in flood-preventing infrastructure, offering performance benchmarks for improving hydraulic and geotechnical structures. Full article

The sea urchin Paracentrotus lividus is a good model in ecotoxicology, but adults living along the Italian coasts have a limited reproductive period. In this species, natural or human-driven pressures may lead to limited gamete availability for ecotoxicological surveys. This study investigates the quality of early developmental stages of wild and cultured sea urchins to be used in ecotoxicology, avoiding field collection of mature specimens. Adult sea urchins were cultured in the laboratory for 2 years. Every 45 days, fertilization and larval quality were checked and compared to those from adults sampled in the wild. Fertilization was never affected, differently from development, which was impaired in the larvae obtained from sea urchins reared for more than one year. Fertilization and embryotoxicity were performed using copper nitrate in wild and cultured sea urchins. Fertilization did not differ up to ten months, while similar embryotoxicity was only found up to 5 months. This study promotes rearing sea urchins in ‘ready-to-spawn’ conditions for ecotoxicology surveys by recommending 10- and 5-month rearing times to assess fertilization and embryo toxicity, respectively. Here, we provided a baseline in marine ecotoxicology to obtain gametes on demand, irrespective of reproductive period and other pressures that may impact gamete availability. Full article

The HYPEX^® process is a novel method for conditioning spent ion exchange resins from nuclear power plants, aiming to reduce final waste volume and carbon emissions by stabilizing the resins in metakaolin-based geopolymers. This study addresses the challenge posed by the natural variability of commercial metakaolin and defines a testing strategy to ensure consistent performance of the final matrix. The reactivity of two batches of metakaolin, characterized by comparable chemical composition and BET surface area, was evaluated by monitoring temperature evolution during geopolymerization at varying water-to-solid ratios. The resulting geopolymers were tested for compressive strength, water permeability, and strontium leachability to assess correlations between precursor properties and final matrix performance. Despite similar compositions, the two batches showed marked differences in compressive strength that could be linked to early thermal behavior. These findings demonstrate that conventional precursor characterization is insufficient to guarantee reproducibility and that thermal profiling is useful to predict mechanical performance. The results suggest the implementation of thermal response monitoring as a quality control tool to ensure the reliability of geopolymer wasteforms in nuclear applications. A simplified analytical model for the thermal evolution during geopolymerization was also developed, matching qualitatively the measured evolution, to suggest scale-up rules from laboratory specimens to full-scale drums, which should be achieved while preserving the thermal evolution. Full article

This study assessed and compared the shear bond strength of self-adhesive and self-etching resin cements for indirect aesthetic restorations to dentin. Four different materials, lithium disilicate ceramics, zirconia ceramics, polymethyl methacrylate (PMMA) composites, and hybrid materials, were used for indirect restorations cemented to dentin. The null hypothesis was that there would be no differences in shear bond strength between the investigated materials. Eighty extracted human molars were used. Eighty dentin specimens with a flat surface were prepared and randomly distributed in groups of 10 (n = 10). From each material (Cerasmart 270, Initial LiSi Blok, Katana ZR Noritake, and Crowntec Next Dent), 20 blocks were made and cemented to the dentin samples. Half of the blocks from each material were cemented to dentin using self-etching resin cement (Panavia V5), and the other half using self-adhesive resin cement (i-CEM). After the specimens were prepared, a laboratory test was conducted to evaluate the shear bond strength. The fracture type was determined using a light microscope, and SEM confirmed the results. The results were statistically analysed. All materials cemented with self-etching cements (Panavia V5) showed statistically higher shear strength values than those cemented with self-adhesive resin cement (i-CEM). In the specimen groups where self-adhesive cement (i-CEM) was used, Cerasmart 270 bonded statistically better. A statistical difference was found between all groups of materials cemented with self-etching cement. The Initial LiSi Block showed the strongest bond, followed by Katana Zr Noritake, Crowntec NextDent, and Cerasmart 270. Adhesion fracture to dentin was observed for all groups cemented with i-CEM. This study highlights the superior performance of self-etching cements in terms of shear bond strength. 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP), a functional monomer, was found to enhance adhesion strength significantly. However, using self-adhesive cements was associated with a weaker bond to dentin, highlighting the importance of the right cementing agent in restorative dentistry. Full article

This study investigates a non-destructive, compact pulse-echo ultrasonic method that combines an external transmitter with a single receiving sensor to identify different surface treatments applied to cementitious materials. The primary objective was to evaluate whether treatment-induced acoustic changes could be reliably quantified using time-domain signal parameters. Three types of surface conditions were examined: untreated reference specimens (R), specimens treated with a standard lithium silicate solution (A), and those treated with an enriched formulation containing hexylene glycol (B) intended to enhance pore sealing via gelation. A broadband piezoelectric receiver collected the backscattered echoes, from which the maximum amplitude, root mean square (RMS) voltage, signal energy, and effective duration were extracted. Receiver operating characteristic (ROC) analysis was conducted to quantify the discriminative power of each parameter. The results showed excellent classification performance between groups involving the B-treatment (AUC ≥ 0.96), whereas the R vs. A comparison yielded moderate separation (AUC ≈ 0.61). Optimal cut-off values were established using the Youden index, with sensitivity and specificity exceeding 96% in the best-performing scenarios. The results demonstrate that a single-receiver, one-sided pulse-echo arrangement coupled with straightforward amplitude metrics provides a rapid, cost-effective, and field-adaptable tool for the quality control of silicate-surface treatments. By translating laboratory ultrasonics into a practical on-site protocol, this study helps close the gap between the experimental characterisation and real-world implementation of surface-treatment verification. Full article