Strength Tests Research Articles

Delivery of Vitamins through the Intraoral Cavity with Toothpaste Using Penetration Enhancers

Dental health is rarely deemed a significant factor for a healthy life despite its considerable impact on the human body. Many presume that regular dental check-ups and daily toothbrushing are sufficient to prevent oral health diseases. However, consuming certain nutrients is also required to attain a healthy oral cavity. Nutrients necessary for preserving dental health, namely calcium, phosphorus, fluorine, and various vitamins, contribute to the development, maintenance, and repair of oral tissues. Nevertheless, it can be challenging to be conscious of taking such nutrients on a daily basis. In this study, aiming to abolish such inconveniences, vitamins essential for dental health were combined in a toothpaste formulation with penetration enhancers (PEs) to achieve intraoral delivery of the vitamins while toothbrushing. Multiple tests were performed to evaluate the characteristics of the intraoral vitamin-delivery toothpaste (IOVT), such as abrasiveness and antibacterial strength tests. The same tests were also conducted on three different commercial toothpaste to draw comparisons with the IOVT. Additionally, to verify the IOVT’s penetration capability, a mass transport study, and a transepithelial electric resistance (TEER) value test were conducted using nightcrawlers’ skin. The data collected demonstrated congruency between multiple characteristics of the IOVT and those of the commercial toothpaste. Our key finding was that the greater TEER values demonstrated the high plausibility of effective intraoral delivery of vitamins, assisted by PEs, as components of the IOVT.

Relative Contribution of Metabolic Syndrome Components in Relation to Obesity and Insulin Resistance in Postmenopausal Osteoporosis.

Introduction. Osteoporosis (OP) affects 30% of postmenopausal women, often complicated by metabolic syndrome (MetS) with a still controversial role. We aimed to characterize MetS and its components in relation to bone mineral density (BMD), body mass index (BMI), and insulin resistance. Methods. Patients (n = 188) underwent DEXA scans, spine X-rays, and metabolic and hormonal investigations, including bone biomarkers, muscular strength, and physical performance tests, while insulin resistance was evaluated by the Homeostasis Model Assessment (HOMA-IR). Results. Patients with a normal BMD or osteopenia (n = 68) and with OP (n = 120) displayed 51.5% and 30.8% of MetS, but without differences in insulin resistance. When BMD was studied as a function of the cumulative MetS criteria and centiles of BMI, lower levels of BMD were observed beyond an inflection point of 27.2 kg/m2 for BMI, allowing for further stratification as lean and overweight/obese (OW/OB) subjects. In contrast with lean individuals (n = 74), in OW/OB patients (n = 46), MetS was associated with HbA1c (p < 0.0037, OR 9.6, 95% CI [1.64-55.6]) and insulin resistance (p < 0.0076, OR 6.7, 95% CI [1.49-30.8]) in the context where BMD values were lower than those predicted from BMI in non-OP subjects. In OP patients with fragility fractures (31% of MetS), glycemia also appeared to be the dominant factor for MetS (p < 0.0005, OR 4.1, 95% CI [1.63-10.39]). Conclusions. These data indicate a detrimental effect of insulin resistance in MetS on OP patients, while the prevalence of the syndrome depends on the proportion of obesity. These findings provide new insights into the pathogenic role of MetS and reveal the need to consider different strata of BMI and insulin resistance when studying postmenopausal OP.

Effects of different primers and colouring solutions on orthodontic bonding: shear bond strength and colour change

ObjectivesThis in vitro study evaluated the effect of different colouring solutions and primer systems used in the bonding of brackets on enamel colour change and bond strength.Materials and methods120 premolar teeth were divided into four main groups; brackets were bonded with 37% orthophosphoric acid + Transbond XT Primer in Group 1, 3 M Single Bond Universal in Group 2, Transbond Plus SEP in Group 3, and G-Premio Bond in Group 4. Each group was divided into three subgroups, and the teeth were placed in a cup containing coffee and tea mixture, in a cup containing cola and in distilled water. A bond strength test was applied to all teeth. Colour measurements of all teeth were performed at 2 different times: before bonding and after the bond strength test.ResultsThe average bond strength of the 37% orthophosphoric acid group was higher than that of the other groups. The effect of primer and solution groups on colour change was statistically significant (p = 0.001 and p = 0.023, respectively).ConclusionsIn this study, the bond strength was clinically sufficient in all primer groups. The highest colour change was observed when the tea–coffee solution and Transbond Plus SEP primer were used.Clinical relevanceThis study has identified enamel discoloration and bond strength from different colouring solutions and primer systems used for bonding braces, which can be used to inform clinicians and patients to achieve better treatment results.

Analysis of Kinang Jingkion Material as Road Subbase Layer Using Soil Cement Method

This research aims to analyze the California Bearing Ratio (CBR) and Unconfined Compressive Strength Test (UCS) values as road foundation layers using local materials, namely Kinang Jingkion. The soil and Kinang Jingkion materials for the study were taken from the Apalapsili quarry in Yalimo Regency. Additionally, the additive or soil stabilizer used was matos obtained from the testing of soil characteristics, including sieve analysis or gradation, Standard Proctor Test for light density, and liquid limit test. After testing, it was found that the soil from the Apalapsili quarry is granular soil and can be categorized as A-1-a according to SNI 03-6797-2002. Subsequent testing involved CBR and UCS testing on Mix Designs made of soil and cement with concentrations of 4%, 6%, and 8%. Next, additional Mix Designs were created with compositions of Kinang Jingkion, soil, cement at 4%, 6%, and 8%. Further Mix Designs included compositions of Kinang Jingkion, soil, matos at 2%, and cement at 4%, 6%, and 8%. From the UCS testing results, Mix Designs with soil and cement concentrations of 4% and 6% did not meet the compressive strength criteria, with compressive strength values of 9.26 Kg/Cm² and 17.4 Kg/Cm² respectively. According to SNI 6887-2012, the compressive strength value after 7 days of immersion should be within 25-35 Kg/Cm², while other Mix Designs met the criteria of SNI 6887-2012. CBR testing also utilized the same Mix Designs, and the highest CBR result was obtained from the Mix Design with compositions of Kinang Jingkion, soil, cement at 8%, and matos at 2%, with a CBR value of 112%. According to the 2018 Revised General Specifications, a CBR value of 112% indicates a Class A Foundation Layer.

Comparison of push-out bond strength and apical microleakage of different calcium silicate-based cements after using EDTA, chitosan and phytic acid irrigations.

This research was aimed to evaluate push-out bond strength and apical-microleakage after application of three different calcium silicate-based cements with irrigation solutions on simulated immature teeth. 40 maxillary permanent canine teeth were used for push-out bond strength test, and 120 maxillary permanent incisors were used for microleakage evaluation. 120 root slices were divided into four main groups (EDTA, Chitosan, Phytic acid, and Saline) and immersed these solutiouns according to irrigation procedures. Each irrigation group was divided into 3 subgroups (Biodentine, MTA Repair HP, and NeoPUTTY). The prepared teeth were divided into four groups according to irrigation procedure for microleakage test. EDTA irrigation with Biodentine group showed highest push-out bond strength value and saline group with Neoputty showed the lowest push-out bond strength value. The highest microleakage value was seen in saline group with MTA Repair HP, while the lowest microleakage value was observed chitosan with Biodentine group. Chitosan and phytic acid solutions can be recommended as an alternative irrigation solution to 17% EDTA in single-session apexification treatment, since they are non-toxic, naturally occurring materials, effectively remove the smear layer, and have a positive effect on bond strength and apical leakage. RESEARCH HIGHLIGHTS: One of the factors affecting the long-term success of root canal treatment is a hermetic seal. Non-hermetic or inadequate filling triggers a chronic inflammatory reaction in periapical tissues, causing fluids to enter the spaces and negatively affecting the success of the treatment. Therefore, this study will help clinicians choose the right biomaterial and irrigation solution that will affect the success of root canal treatment.

Influence of Thermal and Chemical Stresses on Thermal Properties, Crystal Morphology, and Mechanical Strength Development of a Sulfur Polymer Composite

The unique properties and sustainability advantages of sulfur polymer cement have led to efforts to use them as alternatives to traditional Portland cement. The current study explores the impact of environmental stresses on the strength development of polymer composite SunBG90, a material composed of animal and plant fats/oils vulcanized with 90 wt. % sulfur. The environmental stresses investigated include low temperature (−25 °C), high temperature (40 °C), and submersion in water, hexanes, or aqueous solutions containing strong electrolyte, strong acid, or strong base. Samples were analyzed for the extent to which exposure to these stresses influenced the thermo-morphological properties and the compressional strength of the materials compared to identical materials allowed to develop strength at room temperature. Differential scanning calorimetry (DSC) analysis revealed distinct thermos-morphological transitions in stressed samples and the notable formation of metastable γ-sulfur in hexane-exposed specimens. Powder X-ray diffraction confirmed that the crystalline domains identified by DSC were primarily γ-sulfur, with ~5% contribution of γ-sulfur in hexane-exposed samples. Compressive strength testing revealed high strength retention other than aging at elevated temperatures, which led to ~50% loss of strength. These findings reveal influences on the strength development of SunBG90, lending important insight into possible use as an alternative to OPC.

The influence of nanosunflower ash and nanowalnut shell ash on sustainable lightweight self-compacting concrete characteristics

The absence of biodegradability exhibited by plastics is a matter of significant concern among environmentalists and scientists on a global scale. Therefore, it is essential to figure out potential pathways for the use of recycled plastics. The prospective applications of its utilisation in concrete are noteworthy. The use of recycled plastic into concrete, either as a partial or complete substitution for natural aggregates, addresses the issue of its proper disposal besides contributing to the preservation of natural aggregate resources. Furthermore, the use of agricultural wastes has been regarded as a very promising waste-based substance in the industry of concrete manufacturing, with the aim of fostering the creation of an environmentally sustainable construction material. This paper illustrates the impact of nano sunflower ash (NSFA) and nano walnut shells ash (NWSA) on durability (compressive strength and density after exposure to 800 °C and sulphate attack), mechanical properties (flexural, splitting tensile and compressive strength) and fresh characteristics (slump flow diameter, T50, V-funnel flow time, L-box height ratio, segregation resistance and density) of lightweight self-compacting concrete (LWSCC). The waste walnut shells and local Iraqi sunflower were calcinated at 700 ± 50 °C for 2 h and milled for 3 h using ball milling for producing NSFA and NWSA. The ball milling succeeded in reducing the particle size lower than 75 nm for NSFA and NWSA. The preparation of seven LWSCC concrete mixes was carried out to obtain a control mix, three mixtures were created using 10%, 20% and 30% NWSA, and the other three mixtures included 10%, 20% and 30% NSFA. The normal weight coarse aggregates were substituted by the plastic waste lightweight coarse aggregate with a ratio of 75%. The fresh LWSCC passing capacity, segregation resistance, and filling capability were evaluated. The hardened characteristics of LWSCC were evaluated by determining the flexural and splitting tensile strength at 7, 14 and 28 days and the compressive strength was measured at 7, 14, 28 and 60 days. Dry density and compressive strength were measured after exposing mixes to a temperature of 800 °C for 3 h and immersed in 10% magnesium sulphate attack. The results demonstrated that the LWSCC mechanical characteristics were reduced when the percentages of NWSA and NSFA increased, except for 10% NWSA substitution ratio which had an increase in splitting tensile strength test and similar flexural strength test to the control mixture. A minor change in mechanical characteristics was observed within the results of LWSCC dry density and compressive strength incorporating various NSFA and NWSA` contents after exposing to temperature 800 °C and immersed in 10% magnesium sulphate attack. Furthermore, according to the findings, it is possible to use a combination of materials consisting of 10–20% NSFA and 10–20% NWSA to produce LWSCC.

The Impact of ChatGPT on the Development of Vocabulary Knowledge of Saudi EFL Students

This research was piloted to systematically compare the impact of ChatGPT-generated exercises versus traditional exercises on Saudi EFL students’ vocabulary size and the strength of word families. It aimed to answer the following questions: 1) To what extent does the integration of ChatGPT-generated exercises impact Saudi EFL students’ vocabulary size of word families? 2) To what extent does the integration of ChatGPT-generated exercises impact Saudi EFL students’ vocabulary size and strength of word families? This research holds significance because it provides educators with empirical results of the impact of ChatGPT’s role and function on the second language vocabulary development process. Sixty male Saudi students at Jouf University were selected by stratified random sampling. The design of this research is experimental. Consequently, samples were randomly assigned to different experimental conditions and groups (i.e., control and treatment groups). Computer-Adaptive Test of Size and Strength, as developed by Laufer and Goldstein (2004), was administered to both groups at the beginning and end of their studies in the IELP course with an interval of four months. The collected results from all participants (N=60) from both groups and in both intervals (i.e., pre-test and post-test) were clearly and concisely imported to Statistical Package for the Social Sciences SPSS. Multivariate Analysis of Variance was conducted. Results revealed that Saudi EFL students’ vocabulary development improved significantly in both groups. However, participants in the experimental group who experienced ChatGPT-generated exercises notably surpassed that of the control group in terms of vocabulary size and strength of word families.

Cellulose Nanofiber Films with Gold Nanoparticles Electrostatically Adsorbed for Facile Surface-Enhanced Raman Scattering Detection.

Cellulose nanofiber (CNF) holds great promise in applications such as surface-enhanced Raman scattering (SERS), catalysis, esthesia, and detection. This study aimed to build novel CNF-based SERS substrates through a facile synthetic method. Citrate-reduced gold nanoparticles (AuNPs) were adsorbed on the cationized CNF surface due to electrostatic interactions, and uniform AuNPs@(2,3-epoxypropyl trimethylammonium chloride)EPTMAC@CNF flexible SERS substrates were prepared by a simple vacuum-assisted filtration method. The probe molecule methylene blue was chosen to assess the performance of the CNF-based SERS substrate with a sensitivity up to 10-9 M, superior signal reproducibility (relative standard deviation (RSD) = 4.67%), and storage stability (more than 30 days). Tensile strength tests indicated that the CNF-based films had good mechanical properties. In addition, CNF-based substrates can easily capture and visually identify microplastics in water. These results demonstrate the potential application of the flexible, self-assembled AuNPs@EPTMAC@CNF flexible SERS substrate for prompt and sensitive detection of trace substances.

Preparation of a bio-based PU/EP IPN concrete adhesive with optimized performance and decent adhesion

An adhesive serves as a vital tool in construction, repair, and rehabilitation projects. Typically crafted from polymer materials such as epoxies or polyurethane latex, it facilitates the creation of resilient bonds between a variety of surfaces, ranging from concrete-concrete and metal-concrete to concrete-composites. However, employing epoxy or polyurethane individually as adhesives often demonstrate insufficient performance and weak interfacial adhesion during service. In this study, an adhesive combining polyurethane and epoxy was synthesized, featuring an interpenetrating polymer network (IPN) structure. This innovative agent was created using polyols sourced from soybean oil and a commercial epoxy resin. By tuning the infusion of polyurethane content, the resultant resin exhibited favorable flowability in civil applications, simultaneously improved strength and toughness due to the IPN structure, and outstanding thermal stability. Notably, the incorporation of 20 wt% polyurethane yielded a polymer with a remarkable tensile strength of 35.9 MPa. Additionally, the bonding adhesion of the prepared resins on concrete specimens was investigated through splitting tensile test and shear strength test. The study explored the influences of polyurethane content, concrete strength, and adhesive layer thickness on interfacial bonding strength. The introduction of an IPN structure within the PU-20 agent proved advantageous for enhancing the bonding adhesion of the concrete, resulting in remarkable interfacial tensile and shear strengths of 4.56 MPa and 21.73 MPa, respectively.

Influence of titanium dioxide nanotubes with alkyl ammonium alkyl bromide on the physicochemical properties and adhesion of experimental adhesive resins to dentin

ObjectiveThis study evaluated the effect of the incorporation of titanium dioxide nanotubes with alkyl trimethyl ammonium bromide (ntTiO2/ATAB) into experimental adhesive resins on their physicochemical properties and adhesion to dentin. Materials & methodsThe experimental adhesive resins were formulated with 66.66 wt% Bis-GMA and 33.33 wt% HEMA, photoinitiator with addition of ntTiO2/ATAB (1:1) in different concentrations: G1%, G2.5%, and G5%. One groups with no ntTiO2/ATAB addition was used as control (G0%). An optical tensiometer was used to analyze the contact angle (COA) by the sessile drop method (distilled water and α-bromonaphthalene) (n = 5), while the surface free energy (SFE) was calculated using Owens-Wendt-Rabel-Kaelble method. Flexural strength (FS) test (three-point bending) of polymerized adhesive samples was performed according to ISO 4049:2019 (n = 10) after 24 h or one year of water storage at 37 °C, as well as for the microtensile bond strength (μTBS) test, in which a commercial adhesive (GSBMP) was also used as control (n = 10). The adhesive-dentin interfaces were evaluated by scanning electron microscopy and X-ray spectrometry (n = 5). Data were analyzed by one-way (COA and SFE), two-way (FLE and μTBS) ANOVA and Tukey's test (α = 0.05). ResultsG5% showed the highest COA with nonpolar liquid and higher SFE than G0%. The G5% showed decreased FS compared to G0%. The μTBS of both controls (G0% and GSBMP) decreased after one year. TiO2/ATAB-containing adhesives to dentin showed no significant decrease after one year. All adhesives formed hybrid layer and the resin tags inside the dentinal tubules. ConclusionsThe incorporation of 1 and 2.5% of ntTiO2/ATAB into experimental adhesive resins did not impar the SFE. After one year, any concentration of ntTiO2/ATAB reduced the FS compared with control, but did not impair the μTBS.

Mix optimization and mechanical properties evaluation of lime-fly ash-stabilized loess in various engineering applications

Determining a rational mix ratio for lime-fly ash-stabilized loess (LFSL) can achieve multiple benefits of economy, environmental protection, and engineering quality improvement. This research was designed to optimize the mix ratios of LFSL applied in the pavement structure, subgrade, slopes, and foundations by conducting the unconfined compressive strength (UCS) test, California bearing ratio (CBR) test, resilient moduli (MR) test, triaxial test and uniaxial consolidation test on LFSL and lime-stabilized loess (LSL). Combined with the initial consumption of lime (ICL) test result and relevant specifications, the optimized mix ratios are as follows: 2% lime + 11.82% fly ash and 2% lime + 3.95% fly ash can reach the strength requirement of road base and subbase, respectively; 2% lime + 3.84% fly ash in building foundations and subgrade and 2% lime + 3.55% fly ash in slopes can reach the equal improvement effect of the LSL with 8% lime content. Three-factor comprehensive models were established and fitted in well with the experimental results of the LFSL with 2% lime content. Moreover, the development of correlations between UCS and other mechanical indices offers a shortcut for engineering property estimation. Finally, based on the abundant literature on LSL, another approach to estimating engineering quality was proposed for the LFSL with 2% lime content, which enhances the universality and practicability of the estimation models further.

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Experimental Investigation of the Impact of Blended Fibers on the Mechanical Properties and Microstructure of Aeolian Sand Concrete.

To investigate the effect of hybrid fibers on the compressive strength of aeolian sand concrete, compressive strength tests were conducted on aeolian sand concrete with single polypropylene fibers and aeolian sand concrete with mixed polypropylene fibers and calcium carbonate whisker, and their variation rules were studied. Using scanning electron microscopy and nuclear magnetic resonance, the microstructure and pore structure of specimens were analyzed, and a mathematical model of the relationship between compressive strength and pore structure was established with gray entropy analysis. The results show that the compressive strength of hybrid fiber aeolian sand concrete first increases and then decreases with an increase in whisker content. When the replacement rate of wind-accumulated sand is 80% and the fiber content is 0.1%, the optimal volume content of whisker is 0.4%, and the 28 d compressive strength of whisker is 24.8% higher than that of aeolian sand concrete. The average relative errors of compressive strength at 7 d and 28 d are 8.16% and 7.48%, respectively, using the GM (1,3) model. This study can provide effective theoretical support for the application of calcium carbonate whisker and polypropylene fibers in aeolian sand concrete.

Variations in Composition and Size of Red Sand in Pinang City, North Sumatra to Improve Concrete Quality

This study further explores the problems in the concrete material studied in terms of variations in the structure of the constituent materials and the grain size of red sand on the compressive strength test of quality concrete material with code K-350. The primary raw material uses red sand with compositions ranging from 0%, 2%, 4%, and 6% with sizes ranging from 120, 100, and 80 mesh. After all the ingredients are mixed, printing is carried out according to the predetermined sample size; after the sample is deposited for one day and one night, the sample is opened from the mold mall. To see the quality of the sample, testing was carried out by testing the concrete structure through the SEM test, and the sample elements were looked at by testing XRD, compressive strength, and water absorption. The results obtained were a successive decrease in water absorption in red sand samples with a composition of 4%. In addition, the maximum compressive strength value was obtained at the proportion of 120 mesh material, and 6 percent of the material composition obtained a compressive strength value of 35.27 MPa. When viewed from the size of the concrete structure using the scanning Electron Microscope test, it was found that the size of the red sand mixture concrete structure has a much smaller pore structure when compared to other mixtures. and in the X-Ray Diffraction test, it was found to contain elements in the form of SiO2, CaO3, Ca (OH)2 with the highest intensity of silicon.

Hand grip strength test is not an indicator of flexibility performance among teenagers

There are some opinions that say the hand grip strength test can be a good predictor of the overall fitness of an individual. How correct is that? Thus, the main aim of this study is to investigate the relationship between hand grip strength test results with flexibility level as measured by the sit-and-reach test. For the purpose of this study 69 teenagers aged 18 to 23 years old mean ± SD = (19 ± 2.7), with body weight mean ± SD = (64.49 ± 13.47 Kg) and height mean ± SD (163.82 ± 8) have been recruited voluntarily. All participants performed two times hand grip test on their dominant hand, and the best performance was selected for further analysis. Participants then performed three trials of the sit-and-reach test with only the best performance recorded for analysis. The Pearson-correlation was used to analyse the data. Results indicated weak or no correlation between hand grip strength performance with sit-and-reach performance (r = 0.08, p &gt; .01). It can be said that muscular strength performance measured by hand grip strength test may not be used to also indicate flexibility performance. Further studies are suggested to be performed on other age groups and other fitness components.

Denture base materials: An in vitro evaluation of the mechanical and color properties

ObjectivesThis study aimed to compare the physical and mechanical properties of four denture base materials: Polyan IC (PA), milled polymethylmethacrylate (PMMA), three-dimensional (3D)-printed resin (3DP), and SR Ivocap (SR). MethodsNinety-six samples were prepared and divided into four groups as follows. Group A consisted of 3DP (Asiga DentaBASE, Asiga) fabricated using a manufacturer-recommended 3D printer (Asiga Pro 4k, Asiga). Group B comprised milled PMMA (MP) (Ivotion Base, Ivoclar Vivadent). Group C included PA (BredentSenden), meanwhile, group D involved SR (Ivoclar VivadentSchaan). Cuboid samples (65 mm x 10 mm x 2.5 mm) were used for biaxial flexure strength testing in a universal testing machine (UTM). Cylindrical samples of 20 mm x 40 mm were used for compressive strength testing in a UTM. Additionally, cuboid samples (65 mm x 10 mm x 2.5 mm) were used for Vickers surface hardness testing in a microhardness tester. disk samples (10 mm x 2.5 mm) were employed for color stability testing both in a coffee solution and Coca-Cola, using a digital spectrophotometer. Statistical analyses were performed using one-way analysis of variance and Tukey's post hoc analysis (α=0.05). ResultsMP demonstrated superior compressive strength (p = 0.002) and color stability compared to that exhibited by 3DP (p < 0.001) while displaying similar flexure strength (p = 0.336) and hardness (p = 0.708). MP and PA displayed similar compressive strength (p = 0.081), flexure strength (p = 0.159), and color stability in coke (p = 0.071). However, MP had reduced hardness (p < 0.001) and color stability in coffee (p < 0.001). Moreover, MP demonstrated a higher compressive strength (p < 0.001) than that displayed by SR. However, the flexure strength, hardness, and color stability were similar (p > 0.05). Furthermore, 3DP exhibited comparable compressive strength (p = 0.334) to that of PA but demonstrated significantly lower flexure strength (p = 0.005), hardness (p < 0.001), and color stability (p < 0.001) compared to PA. In comparison to SR, PA had a higher compressive strength (p < 0.001), hardness (p = 0.001), and color stability in coffee (p < 0.001), although they demonstrated similar (p > 0.05) flexure strength and color stability in coke. ConclusionsThe MP and PA demonstrated superior compressive strength than that exhibited by the other materials tested. The tested materials had similar flexure strengths, except for PA which demonstrated superiority over the 3DP. Among all tested materials, PA exhibited the highest hardness, while the 3DP was the least color-stable. Clinical SignificanceConsidering the mechanical properties and color stability, Polyan and milled polymethylmethacrylate are preferred for complete denture fabrication. However, the limited repairability and complex handling of Polyan should be considered.

Effect of Strength and Durability of Sand Cement Brick Containing Recycled Concrete Aggregate and Cold Bottom Ash

Introduction The market price of brick has risen sharply due to the insufficient brick supply. Therefore, implementing RCA as one of the alternative materials for sand replacement is significant. The consumption of natural aggregate (NA) can be reduced by using the RCA. It is a good step to utilize recycled concrete to minimize the problem of excess waste materials. The results of using RCA and CBA as sand replacements contribute to better performance in compressive strength as compared to the normal brick. The density of the brick was also reduced by 4.95% as the RCA and CBA took place in the brick. Besides that, the water absorption was decreased when incorporating RCA and CBA in the cement brick due to less free water in the mix and fewer voids. Aims This study aims to ascertain the performance, strength, and durability characteristics of sand cement bricks incorporated with RCA and CBA as partial replacements for sand. Methods Percentages of 1.5%, 3.0%, 4.5%, and 6.0% of CBA and 15%, 30%, 45%, and 60% of RCA were chosen for partial sand replacement. The brick had dimensions of 215 mm in length, 65 mm in depth and 105 mm in width. Density, compressive force, and water absorption tests were undertaken after each of the three varied ratios of water to cement (1:5, 1:6, and 1:7). Results The finding indicates that with the optimum RCA and CBA replacement and the correct water to cement ratio, the performance of the new brick is better than the normal brick. Conclusion The optimum sand-to-cement ratio is 1:6, according to the overall results of selecting the optimal sand-to-cement ratio by density, compressive strength, and water absorption test. However, the result for the density value shows that the average brick density is inferior to the control brick. For all of the sample bricks, the compressive strength was best at a sand cement ratio of 1:6. However, as each of the samples complies with the British Standard criterion of less or equal to 15% absorption, it was determined that the sand cement brick's capacity for water absorption was sufficient.

Strength Properties of Blended Cement Mortar with Metakaolin and Rice Husk Ash

This study investigates the feasibility of using rice husk ash (RHA) and metakaolin as substitutes for Ordinary Portland Cement (OPC) in mortar production to reduce greenhouse gas emissions associated with construction. The study employs MM3 grade mortar, with RHA replacing cement at varying percentages (0%, 5%, 10%, and 15%), while metakaolin consistently substitutes 10% of the cement. Compressive strength tests are conducted on specimens cured for 7, 14, and 28 days to assess performance. The study utilizes OPC 53-grade cement with a water-cement ratio of 0.4. In total, four mortar mixes are prepared, and each mix comprises nine specimens, totaling 45 specimens. Initially, conventional mortar is evaluated for its physical and mechanical properties. The study aims to contribute to ongoing efforts in the construction industry to explore sustainable alternatives to conventional materials, such as RHA and metakaolin, while ensuring the requisite strength properties of mortar are maintained. Key Words: Rice husk ash, metakaolin, cement, sand, mortar and compressive strength

The Effect of Physical Exercise on Functional Capacity and Perception of Well-Being in Older Adults

Study purpose. The study aimed to evaluate the effect of strength training exercises on functional capacity, quality of life and perception of well-being in elderly people. Materials and Methods. It was used a mixed study with sequential explanatory design, in which 25 elderly females between 62 and 85 years participated in a physical exercise program for eight weeks, with a frequency of 3 days and sessions of 58 minutes on average. The Senior Fitness Test battery of test item was conducted with a grip strength test, heart rate monitoring in a 6-minute test, SF-36 health questionnaire and post-intervention focus group oriented to well-being analysis. Results. Cardiorespiratory capacities, strength and flexibility improved significantly (p&lt; .05), but agility and heart rate did not change (p&gt; .05). Scores increased in the 8 quality of life dimensions analyzed, and in subjective well-being, health improvement was identified in both the self-perception and autonomy of daily activities related to vitality, motivation, social interaction and adherence to physical activity. The findings indicate that physical exercise based on strength training improves functional capacity, health-related quality of life and the well-being of seniors. Conclusions. The findings of this study show that eight weeks of physical exercise based on strength training with affordable means (own body weight, elastic bands and dumbbells) with a frequency of 3 days a week, contribute to improving the functional capacity of strength and flexibility in upper and lower limbs, and cardiorespiratory endurance in older females. This intervention was also found to have a positive impact on quality of life, as well as on the perception of well-being.