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Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Since standard distributions do not fundamentally have an acceptable fit to all types of data sets, it is necessary to construct extensions of standard distributions to increase their capability in data modeling. As a result of this shortage in old ones, we proposed a novel generator based on the trigonometric function (Arctan). We selected the Frechet distribution as the baseline for the generator's applicability. This generator produces the "new Arctan Frechet distribution" (NATFD). The fundamental properties of the proposed distribution have been taken into consideration. Estimating the given distribution's parameters is accomplished using the maximum-likelihood method. A simulation study is carried out to evaluate the superiority of the proposed distribution, and two actual data sets are used. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The current work investigates the effects of drilling parameters on hole quality, including delamination and circularity, produced in hybrid composite materials consisting of neat glass fibre (NG) and hybrid glass fibre/Al-wire mesh in two distinct sequences, the first one being with Al-mesh in the outermost layers (AG) and the other with Al-mesh in the central layer (GA). The operation's process parameters are feed rate (F = 20, 40, and 60 mm/min), spindle speed (N = 1000, 2000, and 3000 rpm), and drill point angle (Ɵ = 90°, 120°, and 135°). Taguchi's L9 orthogonal array is used for the study. The optimal levels and effects of the process parameters were determined. Gray relational analysis (GRA) was employed to examine the complicated interactions influencing the results and ANOVA was used to evaluate the influence of process parameters. The results indicated that for all specimens, push-out delamination was more severe than peel-up. Circularity is minimized by using N = 3000 rpm, F = 20 mm/min, and Ɵ = 90°. At speed (N) of 3000 rpm circularity reduces by 83.5% and 76.5% compared to 1000 or 2000 rpm, respectively. Compared to other specimens, AG-specimen produced minimal delamination and circularity by an average of 6% and17.38%. The results of the confirmation test and regression model provide good agreement between the experimental and predicted results. [ABSTRACT FROM AUTHOR]

The observation of fibers in salvadora persica roots inspired us to consider the idea of using them as reinforcement to create an innovative composite. The current work focuses on the volumetric mass density, extraction, molding, and mechanical testing of composites and hybrid composites made from salvadora persica roots and glass fibers reinforced with two types of polyester matrix, chosen due their characteristics suitable for use in different orientations. Various extraction and combination methods have been used to identify an optimal approach for obtaining fibers from salvadora persica roots, considering its chemical composition (hemicellulose, pectin, and lignin). In this investigation, the hand lay-up method was used to mold specimens with different geometries. The composite and hybrid composite were combined with a polyester matrix and subjected to various mechanical tests namely; tensile, impact resistance, and water absorption. The results indicate that reinforcing polyester resins with SP fibers, whether long or short, enhances the overall mechanical properties of the composite. Additionally, improved adhesion between salvadora persica roots fibers and resin was observed. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper focuses on the shear behavior of reinforced concrete (RC) beams strengthened with carbon–glass-fiber-reinforced polymer (C-GFRP) plates under different anchoring schemes. The study consisted of four reinforced specimens: specimen CS-1 with no reinforcement and three groups of reinforced specimens SR-1, SR-2 and SR-3. The studies used a four-point bending test to evaluate the reinforcement effect of mechanically anchoring C-GFRP plates. The results of the analysis of load–deflection, strain and bearing capacity indicated that a better reinforcement effect was observed with fiber-reinforced polymer. The test results suggested that the occurrence time of critical oblique cracks was delayed and the development speed of critical oblique cracks was limited by mechanically anchoring the C-GFRP plates. C-GFRP plates significantly increased the stiffness of the reinforced specimen and reflected the superiority of mechanical anchoring. The ultimate shear capacity of the mechanically anchored C-GFRP plates has been significantly improved. With a reasonable increase in the amount of C-GFRP plate, the shear resistance of the test beam became stronger. Compared with the CS-1 specimen without reinforcement, the yield load values of the reinforced specimens SR-1, SR-2 and SR-3 increased by 5.56%, 18.80% and 26.50%, respectively. The ultimate load of reinforced specimens SR-1, SR- 2 and SR-3 increased by 11.64%, 17.47% and 31.51%, respectively. The researchers deduced their theoretical calculation method from the bearing capacity of RC beams strengthened by anchoring with carbon–glass-fiber-reinforced polymer plates. The test findings were in good accord with the theoretical calculation model of bearing capacity suggested in this research. [ABSTRACT FROM AUTHOR]

Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aims to evaluate the resistance to fracture of endodontically treated anterior permanent teeth restored with dentin posts of 3 different lengths and compare it with fiber posts with two-thirds of the length of the root canal. Thirty-six extracted mandibular premolars were used for the preparation of the dentin posts, while forty-eight extracted maxillary central incisors were endodontically treated and radicular post preparations were performed, then the teeth were randomly divided into four groups (n=12); group A (comparative group): restored with fiber-reinforced posts two-third of the canal length, group B, C and D were restored with dentin posts of two-third, half-length, and one-third of the intra-canal length respectively. The resistance to fracture of the samples was tested using a Universal Testing Machine, and the location of the fracture was examined under a stereomicroscope (x10). One-way ANOVA showed that dentin posts of two-thirds length had a statistically significant higher fracture resistance than fiber posts of two-thirds length, with favorable fracture patterns. Dentin posts with two-thirds of the root canal length can be a promising substitute for conventional glass fiber posts by acting as a micro-mechanical homogenous unit along with the root dentin. [ABSTRACT FROM AUTHOR]

This research paper presents the effect of using recycled concrete aggregate (RCA), from the Egyptian construction waste, in different proportions on the bond performance between concrete and its internal reinforcement, where two types of reinforcement were used: a- steel reinforcing bars, and b- glass fiber reinforced polymer (GFRP) bars. 72 samples of concrete were prepared and tested with replacement ratios for natural aggregate (NA) with RCA: 0, 20, 40, 60, 80, and 100 %. The samples were divided into 150 mm cubes to conduct axial compression tests, and pull-out samples to investigate the effect of replacement ratios on the bond between concrete with steel and GFRP rebars. Results showed that concrete loses 26% of its compressive strength after replacing NA with 100% RCA. The results of the pull-out test for steel samples showed 30% higher bonding than GFRP samples. A slight decrease in bond was observed between the control and the tested samples, where the steel and GFRP samples showed a decrease of 5% and 9%, respectively, over the control samples for each, at a replacement percentage of 100%. It was also clear that the steel reinforcement bars had a stronger bond with the concrete, and this can be attributed to the stronger mechanical interlocking of the steel ribs than their counterparts in the GFRP. Failure patterns showed the crushing of concrete with steel bars, in contrast to the GFRP bars, which showed slipping from within the concrete with failure of the ribs in many samples. [ABSTRACT FROM AUTHOR]

One of the most common statistical systems used in structures especially for wide span slabs are ribbed slabs with shallow wide beams (SWB). This experimental study aimed to investigate and enhance the flexural behavior of high-strength concrete SWB using hybrid longitudinal reinforcement from steel and advanced composite materials as a tensile main reinforcement in SWB. Longitudinal advanced composite bars locally manufactured from ribbed glass fiber reinforced polymer (GFRP) and the second type was ribbed basalt fiber reinforced polymer (BFRP). A group of six half scale SWB were examined in structures laboratory of American University in Cairo with dimensions 2.1 x 0.6 x 0.25 m for length (L), width (B) and depth (d) respectively with constant size effect (d/B). The first three specimens were completely reinforced at tension side with Steel, GFRP or BFRP ribbed bars to be considered a control specimen. Use of GFRP and BFRP bars enhanced the flexural capacity of SWB with 41% and 43% respectively compared to specimen completely reinforced with steel. But on the other hand, the crack propagation of specimens completely reinforced with GFRP and BFRP developed more quickly and had larger crack width compared to specimen completely reinforced with steel. Hybrid reinforcement from Steel with GFRP, Steel with BFRP and Steel with GFRP and BFRP specimens are used to enhance the crack pattern and mode of failure without a significant loss in flexural capacity of SWB. The flexural capacity of these three specimens was enhanced with 26%, 30% and 41% with a significant enhancement in crack pattern and ductility. [ABSTRACT FROM AUTHOR]

This study evaluated the resistance to fracture of endodontically treated premolars (ETPs) with mesio-occluso-distal (MOD) cavities filled with nanohybrid composite (NHC), fiber-reinforced composite (FRC), horizontal glass fiber posts (HFP), and ceramic inlays (CI). Eighty-four intact maxillary premolars were taken, and endodontic treatment was performed followed by MOD cavity preparations (except in the control group). They were distributed into 7 groups based on type of restoration: intact teeth (control group), ETP + MOD (not restored), NHC, FRC + NHC, HFP + NHC, FRC + HFP + NHC, and CI groups. Samples were subjected to universal testing machine until the fracture occurred and failure mode was visually inspected. Mean and standard deviation of fracture resistance of the 7 groups ranged from 265.6 ± 68.0 N to 1023.7 ± 76.5 N. The highest reading was noted for intact teeth followed by FRC + HFP + NHC group and then the CI group, with no significant difference among the 3 groups. The lowest reading was noted for the ETP + MOD group. Maximum unrepairable fractures were seen in the ETP + MOD and CI groups. FRC + HFP + NHC combination and CIs increased the resistance to fracture of ETPs significantly. [ABSTRACT FROM AUTHOR]

The article discusses the mechanical properties of glass fiber epoxy composites with three types of textile structures. Braided, knitted and woven sleeves were placed on a 3D printed flat core and impregnated with resin using the vacuum bag method. The 3-point flexural and tensile tests were performed. The results were compared with those of 3D-printed flat bars and proved that woven textile structures increase the strength and modulus of elasticity, whereas braided and knitted structures only increase the moduli. The advantages, drawbacks and failure modes of each reinforcement structure are also discussed including the drapeability on the spatial core. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether erbium laser irradiation emitted by modified glass-fiber tips would improve the intraradicular bonding of fiber posts. Forty human canines were endodontically treated and prepared for fiber-post placement. Roots were divided into five groups (n=8); according to the laser-tip combinations (2,940 nm Er:YAG and 2,780 nm Er,Cr:YSGG). Nonirradiated root canals served as control. Posts were cemented with self-adhesive resin cement and subjected to push-out test. Failure modes were characterized, and intraradicular bonded interfaces were analyzed by SEM and submitted to nanoleakage evaluation. Data were analyzed by two-way ANOVA and Tukey test (a=0.05). No significant differences were observed in cervical and middle sections (p>0.05), while significantly higher bond strengths were observed in apical sections (p<0.05). Laser irradiation reduced adhesive failures, cement-dentin gap formation, and nanoleakage apically. Laser-irradiation protocols employing end- or radial-firing tips improved bonding to apical intraradicular dentin contributing to more uniform bonded interfaces. [ABSTRACT FROM AUTHOR]

The processing of abrasive fibres in the carding process, in particular high-performance fibres such as glass, carbon or aramid fibres, can cause increased wear of the card clothing. In the FutureTex project 'HPFGarnitur', the wear of card clothing was investigated and an online wear measurement system has been developed. The aim of the project was both, to optimize the clothings to enable gentler processing of the fibres, and to develop a digital monitoring system to observe the degree of wear of the clothings, which offers a new possibility for maintenance prediction and production planning in the sense of Industry 4.0. [ABSTRACT FROM AUTHOR]

A new approach was used in drilling woven glass fiber reinforced polymer (GFRP) composites to clamping the specimen by a controllable force at drill entry and exit sides. The influence of cutting and support conditions on thrust force, push-out and peel-up delaminations, and burr factor was investigated. A series of ASTM tests were implemented to determine tensile, in-plane shear, Mode I and Mode II fracture toughness properties, which were used to predict the critical thrust force (CTF) at delamination initiation. The delamination and burr areas were accurately measured via inexpensive, easy, and accurate image processing technique. Result from drilling processes revealed that the supported specimens are approximately free from burr accompanied with insignificant peeling within the drill (10 mm)/support hole (12 mm) tolerance. By using support plates, the thrust force was increased up to 8.3% compared to the unsupported conditions. On the other hand, the delaminations were decreased by about 65.5%. The delaminations were dominated by Mode I fracture toughness, which is lower than that of Mode II by 41%. The predicted CTF using concentrated load models are slightly lower than the measured values, which interpret the occurrence of delamination damage on the cutting zone. [ABSTRACT FROM AUTHOR]

This study investigates the impact of openings on the behavior of arched beams and the effectiveness of different strengthening materials in enhancing their performance. The study involves three stages. The first stage focuses on the effect of openings on the behavior of curved beams. The second stage examines the effect of different strengthening materials, including carbon fiber sheets, glass fiber sheets, and steel plates, on the deflection and failure load in the presence of openings. In the third stage, Finite Element models are used to simulate the tested beams with different strengthening materials, and the differences between beams with and without openings are analyzed. The results show that the presence of openings negatively affects the ultimate load, deflection, and ductility ratio of arched beams. Regarding strengthening, beams strengthened with steel plates demonstrate a higher ultimate load, approximately 5.6% and 21% higher than beams strengthened with carbon fiber and glass fiber sheets, respectively. Moreover, the deflection of beams strengthened with steel plates is 6.4% and 8.9% higher than beams strengthened with CFRP and GFRP. The presented work is introduced to offer a valuable solution to some developed systems for controlling, repairing, and supporting structures. [ABSTRACT FROM AUTHOR]

Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

to investigate and compare the reinforcing effects of glass fibers (GFs) and ZrO 2 nanoparticles at different ratios on the Flexural Strength (FS), Microhardness (MH), and Surface Roughness (SR) of autopolymerizing provisional PMMA. A total of one hundred and twenty specimens of autopolymerizing PMMA were prepared for FS, MH, and SR tests and grouped as follows: no additives (control group), for the tested groups, different ratios of GFs and ZrO 2 at 5% of autopolymerizing PMMA were incorporated. The ratios of GFs/ZrO 2 nanoparticles were 0%-5%, 1%-4%, 2%-3%, 2.5%-2.5%, 3%-2%, 4%-1% and 5%-0% (n = 5). The FS was evaluated using the three-point bending test, MH was evaluated using the Vickers microhardness tester and SR was evaluated using a contact-type profilometer. Data were analyzed using ANOVA, Tukey's test, and Person correlation at 0.05 level of significance. The unreinforced group had the lowest FS, MH, and SR mean values followed by (0%GFs + 5% ZrO 2), (1% GFs + 4% ZrO 2), (2% GFs + 3% ZrO 2), (2.5% GFs + 2.5% ZrO 2), (3% GFs + 2% ZrO 2), (4% GFs + 1% ZrO 2) and (5% GFs + 0% ZrO 2) which had the highest values. Hybrid reinforcement with GFs, ZrO 2 nanoparticles, or a combination of them effectively improved flexural strength and microhardness of autopolymerizing provisional PMMA that would create provisional restorations with extended clinical service. GFs demonstrated superior reinforcing effects compared to ZrO 2 nanoparticles. However, reinforcement with 2.5–5% GFs increased the surface roughness for provisional restoration. [ABSTRACT FROM AUTHOR]

Vinylester-glass fiber composites have a wide scale of applications, however the combination between multiple fillers can cause some disadvantages due to complicated processing, high cost and incompatibility. This paper presents a novel trial for filling commercial vinylester (VE) resin with glass fiber (GF), as one filler component, in dual directions to prepare water pipe composite using the continuous winding technique, for the first time. 10% to 25% VE-GF composites were prepared with distributing GF in axial and hoop directions. The composites were cured via in-situ polymerization; the crosslinked network is occurred between catalyst and unsaturation sites in prepolymer. All concentrations show stability in all stages of thermal degradation, compared with blank VE; the more stable composite is 25% VE-GF. GF filled in axial and hoop directions enhanced the mechanical strength of both axes. The improved concentration (20% VE-GF composite) increased axial tensile strength and hoop tensile strength respectively to 32 MPa and 51 MPa, compared with 22 MPa and 42 MPa for blank VE. Furthermore, this concentration enhanced the strengths of surface harness and pull off from 39 BHC and 2.2 MPa to 46 BHC and 5.3 MPa, respectively. The 25% VE-GF composite decreased these values, but still higher than blank. GF improved the resistance of vinylester toward water absorption in different immersion conditions, especially the 25% VE-GF composites. The filling direction doesn't affect the composite stability. As a key issue for sustainable applied polymer composites, the proposed technique presents stable and low cost composite with one filler type, as physically, thermally and mechanically stable water pipe system. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the improvement of selected mechanical properties of a resin-modified glass-ionomer cement (RMGIC) with a discontinuous short E glass fiber flowable resin composites (GFRRC) to be used in load-bearing areas of permanent teeth. Methods: Experimental materials were prepared using two different weight proportions, 7 wt% (1.75% E glass fibers) and 25 wt% (6.25% E glass fibers) of a GFRRC into an RMGIC matrix. Flexural strength was evaluated in 0- and 24-hour hydration periods, and fracture toughness was assessed after 24 hours. The internal microstructure of fractured samples was evaluated using a scanning electron microscope. Results: The addition of 25% of GFRRC was more effective in strengthening RMGIC than the introduction of only 7% GFRRC. Hydration periods did not show any significant statistical difference (P > 0.05). SEM micrographs of experimental materials' fractured surfaces revealed pull-out and fractured fibers; the presence of the matrix attached to fibers indicates great fiber-matrix adhesion. Within the limitations of the study, the results revealed that reinforcing RMGIC with discontinuous short E glass fiber flowable resin composites (GFRRC) improved significantly the flexural strength and modestly enhanced fracture toughness. [ABSTRACT FROM AUTHOR]

To evaluate the push-out bond strength of the adjustable fiberglass post system to dentin. Twenty maxillary canine roots were endodontically treated and divided into two groups (n=10): conventional fiberglass posts (CFPs) and with single adjustable post (SAP) system. Two slices of each third were subjected to the push-out and failure pattern test and the most apical slice was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). Data were analyzed by the three-way analysis of variance, Tukey, and Friedman tests, and linear regression (a=0.05). The results showed higher push-out bond strength in the initial time interval for SAP (10.3±5.3, p<0.01). After 6 months, there was reduction in push-out bond strength for both (p<0.001). A higher percentage of adhesive and cohesive failures to dentin. After 6 months areas of maladaptation were noted (p=0.000). The SAP is completed to the promissory root canal in relation to alternative CFP. [ABSTRACT FROM AUTHOR]

Environmental sustainability is one of the prime objectives of the manufacturing industries. To accomplish this focus, industries are developing low-energy consumption manufacturing process, which reduces production cost and the environmental impact. The GFRP composites find applications in various structural applications, such as aircraft, wind turbine blades etc. owing to their lightweight, high strength, and stiffness. In this study we explored manufacturing of glass fiber-reinforced polymer (GFRP) composite using vacuum-assisted resin infusion microwave curing (VARIMC) and thermal curing. This study investigated the role of curing parameters (microwave power and cure time) on mechanical performance of the GFRP composites. Analysis of energy consumption during VARIMC and thermal curing were also carried out in this work. The mechanical properties of GFRP composites are observed to be better at 540 W microwave power with cure time of 720 s compared to 8100 s for thermal curing (2000 W). The VARIMCed GFRP samples exhibited better or comparable properties than thermally cured samples. The VARIMC process utilized about 1.186 MJ/kg of energy, which was almost 36 times less than the energy consumed by thermal curing (43.2 MJ/kg). [Display omitted] [ABSTRACT FROM AUTHOR]

Due to their inexpensive cost and superior qualities compared to conventional metals, Glass Fibre Reinforced Plastic (GFRP) composites are frequently used in engineering applications. Despite the development of numerous non-traditional drilling methods, traditional mechanical drilling methods based on CNC machines are still utilized as the primary applications for composites due to their financial advantages. Damage in the composite materials during the drilling process due to delamination often happens. The delamination has directly related to the drilling force. A dynamic model of the drilling force is a function of the feed rate. Due to the unpredictable nature of the composite material's physical and chemical properties, it may be challenging to realize the dynamics of the drilling process in this material. In this paper, the mathematical model of the drilling process is obtained experimentally based on system identification. Then, to address the problem of controlling the drilling force of composite materials, this paper proposes a Model Reference Adaptive Control (MRAC) based on the Enhanced Flower Pollination Algorithm (EFPA) to handle the uncertainties and time-varying dynamics of the drilling process. The performance of the proposed controller is evaluated based on the Integral Time of Absolute Error (ITAE) index. The simulation results show that the proposed controller is effective in avoiding drilling-induced delamination in composite under different operation conditions. [ABSTRACT FROM AUTHOR]

In this work, we presented a new model called the alpha power inverse power Burr-Hatke distribution (APIPBHD). It provides several greater advantages in fitting a variety of different types of data. Estimates of the model parameters are provided and based on traditional research methods. We established the superiority of the proposed distribution by utilizing the importance and adaptability of the APIPBHD compared to other well-known distributions. The real data set includes 63 observations, all of which were manufactured to approximate the strengths of glass fibers to highlight the relevance and flexibility of the provided technique. We proved our superiority using one set of real data. Finally, major findings and conclusions are recorded at the end of the paper. Also, we added future work on the upcoming research depending on the proposed model. [ABSTRACT FROM AUTHOR]

This research studies the flexural behavior of concrete beams reinforced with biaxial geogrids, distributed short glass and steel fibers. No longitudinal steel reinforcement bars were used. Therefore, an amount of short glass and steel fibers was used to improve the concrete beam behavior against flexural failure. Eleven specimens of single reinforced (flexural reinforcement) concrete beams and double reinforced (compression and flexural reinforced) concrete beams using two biaxial geogrids sheet layers, with randomly distributed short glass and steel fibers were cast. The samples were tested using two points of load along the beam specimen span with an increment of loading by 5 KN to evaluate several parameters. The studied parameters are using geogrids as a main flexural reinforcement, using geogrid sheet layers as a flexural and compression reinforcement, using short glass and steel fibers as an additional reinforcement of concrete with various ratios 0.25 %, and 0.75 %. The test results indicated that the use of geogrid layers as the main flexural reinforcement improved the behavior of the concrete beam specimens at failure. As well as; more enhancement of beam specimens at failure was observed when using short glass and steel fibers with geogrid reinforcement in concrete beams. The tested beam specimens which were reinforced by geogrids in the flexural and compression zone using 0.75 % of steel fibers gave better results due to modes of failure, toughness, failure load capacity, crack width, and post cracking stiffness. [ABSTRACT FROM AUTHOR]

The extrusion-based fused deposition modeling (FDM) has become the most frequently used additive manufacturing method because of its shorten production time and cost. However, low surface quality remains a limitation to meet the regulatory standards set by traditional manufacturing, which requires post-processing to improve it. In this work, annealing and acetone vapor treatments are applied to short glass fiber reinforced PLA/TPU composites parts obtained by FDM, respectively. Their effects on the surface finishing, dimensional accuracy and mechanical properties of FDM parts using different post-processing methods are compared. The result shows that the annealing treatment dramatically improves the surface finish, but can reduce the dimensional accuracy and ductility of the FDM parts. Better ductility and dimensional accuracy but lower tensile strength are obtained by using acetone vapor treatment. [ABSTRACT FROM AUTHOR]

The article provides a review of the efficacy of Fiber-reinforced composite and glass fiber posttreatments, as well as clinical advice and a resource for treatment decisions. To evaluate the outcomes of direct restoration of endodontically treated premolars by glass fiber post and fiber-reinforced composite. A cross-sectional descriptive analysis of 56 endodontically treated premolars with one or two proximal and/or distal wall losses. Using a description of statistical analysis to describe clinical characteristics and treatment outcomes. Compare the association between restoration result factors, clinical characteristics, and variables relating to restoration colour using Chi-squared or Fisher's Exact, with a significance level (p<0.05). After 3 months of the direct restoration of endodontic premolars, the success rate of the fiber post was 100%, the success rate of the overall restoration was 92.9%, and the success rate (no need to repeat) of restoration was 100%. After 6 months of the direct restoration of endodontic premolars, the success rate of the fiber post was 100%, the success rate of the overall restoration was 82.1%, and the success rate of recovery (no need to repeat) was 94.6%. Using a glass fiber post and fiber-reinforced composite for direct restoration of an endodontically treated premolar provided significant benefits: high clinical effectiveness, little dental tissue loss, good aesthetics, and patient cost savings compared to indirect restoration. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicle helicopters are developing in recent years because they have better capabilities compared to unmanned aerial vehicle aircraft in terms of take-off and landing phase and controllability in areas with more difficult access. In this paper a helicopter blade was designed, aerodynamically and also by the finite element method analyzed, manufactured using 3D printing process. From the finite element analysis, it was observed that the blade will withstand the applied loadings, but also in flight of the unmanned aerial vehicle. The 3D printing of the blade was carried out in sections and after gluing, a blade made of polypropylene with 30% short glass fibres resulted. The microhardness of the blade is influenced by the proximity to the print bed and the 3D printing supports. Thus, both Shore D microhardness and Vickers microhardness showed higher values in proximity to the print bed. Microscopic analysis showed that the short glass fibre filament did not exhibit manufacturing defects, while conventional 3D printing defects such as voids and inter-track voids were found when 3D printing the blade sections. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glassfiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, toothspecimens were equally divided in half according to type of GFP to be used. In the half to receive milled-CAD-CAM posts, tooth specimens were molded with acrylic resin to obtain replicas. These were scanned to enable the laboratory to produce the milled-CAD-CAM GFPs (Fiber CAD Lab, Angelus) by the subtractive technique. The other half of samples received prefabricated GFPs (Exacto, Angelus) (n=15). The GFPs were cemented with dual-cure resin cement (Panavia F2.0, Kuraray). Each root was sectioned into two slices per root region (cervical, middle, apical) that were subjected to the push-out BS test, in a universal testing machine. Failure mode (FM) was classified by scores. The BS data were submitted to generalized linear model analyses, while FM was analyzed using the chi-square test (a=0.05). BS showed no significant difference among the three ES (p > 0.05). BS was significantly higher for prefabricated (mean 10.84 MPa) versus milled-CAD-CAM GFPs (mean 6.94 MPa) (p <0.0001), irrespective of ES. The majority showed mixed failures. It could be concluded that type of ES did not affect BS of GFPs to dentin, and prefabricated-GFPs had higher bond-strength than customized-milled-CAD-CAM GFPs. [ABSTRACT FROM AUTHOR]

To evaluate the feasibility of using a milled polyetheretherketone (PEEK) post and core in endodontically treated teeth with or without a ferrule. Sixty bovine tooth roots were endodontically treated followed by cementation of intraradicular retainers (IR), according to each experimental group: a) non-ferrule glass fiber post (f0FP); b) 2-mm-ferrule glass fiber post (f2FP); c) nonferrule resized glass fiber post (f0PR); d) 2-mm-ferrule resized glass fiber post (f2PR); e) non-ferrule PEEK post and core (f0PPC); and f) 2-mm-ferrule PEEK post and core (f2PPC). Metal crowns were made and cemented. A periodontal ligament was simulated using polyether. A force was applied to the palatine portion of each sample at 45°, until fracture. Fracture resistance data were submitted to two-way ANOVA and Tukey's test (a = 0.05). Three-dimensional digital models were developed to calculate the tensions formed in the root using finite element analysis. Models of glass fiber posts and PEEK posts and cores were evaluated with or without a ferrule. The results were analyzed by the Mohr-Coulomb criterion. The type of IR was not influenced by fracture strength (p = 0.243). There were significant statistical differences among the remaining factors. Ferrule groups had greater fracture resistance, and the failure mode of teeth with a ferrule was more catastrophic than the non-ferrule group. A ferrule increases fracture resistance and influences failure mode; the PEEK post and core did not modify the biomechanics of endodontically treated teeth, and resembled the glass fiber post results. The crack initiation point differed between the ferrule and non-ferrule groups. [ABSTRACT FROM AUTHOR]

Purpose: The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated. Methods: Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (μCT) to evaluate the integrity and presence/volume of voids at the resin cement layer. Finite element analysis (FEA) of two three-dimensional (3D) models of each group were conducted, one considered ideal (without interface defects) and another containing the conditions identified in the μCT analysis. Push-out bond strength tests were conducted for all specimens. Results: The CFL group had the greatest mean values of void (Thirds cervical: 73.67; middle: 95.67; apical: 47.33) and gap concentration (Thirds cervical: 14.67; middle: 15.83; apical: 8.33) compared with CFP and RFP. A significant difference in bond strength was observed between the cervical (1.33 MPa) and middle thirds (1.85 MPa) compared with the apical third (4.85 MPa) of the CFL. A significant difference was observed in the bond strength in the CFL (1.33 MPa) and RFP (3.29 MPa) in the cervical third, which were statistically similar to the bond strength of the CFP. The tensile stress distributions were similar in most structures, localized in the cervical region on the lingual surface. Conclusions: Structural defects in the interface layer might influence the bond strength and biomechanical behavior under the different fiberglass post cementations. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the resistance of the union between a glass fiber post and radicular dentine after cleaning the root with 17% EDTA and filling with different endodontic cements. Methods: Forty uniradicular bovine incisors were removed to obtain root lengths of 18 mm. Endodontic treatment was performed on all roots using different filling cements (zinc oxide and eugenol-based, OZE; cement based on epoxy resin, AH) and cleaning solutions (saline, SA or EDTA), which made it possible to obtain four groups: OZESA, OZEEDTA, AHSA and AHEDTA. Subsequently, 12 mm of filling material was removed from the roots, and they were prepared to receive fiber posts luted with resin cement. To execute the mechanical cycles (2x106 cycles, 90 N, 4 Hz), coronal reconstruction was performed with a silicon matrix. The roots were then sliced (2-mm thick) to perform the push-out test. The results were analyzed using analysis of variance (one factor and two factors) and Tukey's test (α=0,05). Results: Bond strength (Mpa) was significantly higher for OZEEDTA (9,18) and AHEDTA (8,70) than for OZESA (6,06) AHSA (8,7). OZEEDTA also presented the highest values in the cervical region (15,18) but was significantly lower in the apical region (2,99). However, AHEDTA had a homogeneous bond strength in all thirds. Conclusion: Regardless of the endodontic cement used, EDTA was used as an irrigating solution, culminating in a higher bond strength between the glass fiber post and dentin. [ABSTRACT FROM AUTHOR]

This in vitro study compared the fracture resistance of weakened roots restored with milled or relined glass fiber post (GFP). Seventy bovine incisors were divided into seven groups, according to the weakening protocol (none: control; medium-weakened: MW; highlyweakened: HW) and post anatomization technique (non-relined, relined with Bulk Fill or Z350 resin; milled GFP: M). Roots were thermomechanical cycled and submitted to compression. Frequencies and groups were compared by the chi-square test and twofactor ANOVA, Tukey's, and t-test (a=5%). The HW-M obtained the lowest values, showing significant differences compared to all groups (p<0.001). The highest value was HW-Bulk fill, with significant difference compared to MW-M (p=0.037) and HW-M (p<0.001). The frequency of repairable fractures was 100% in the control, 87%, and 63% in the MW and HW, respectively. Relined or milled GFPs can be considered to rehabilitate weakened teeth since failure patterns were predominantly repairable in all groups. [ABSTRACT FROM AUTHOR]

The use of multidirectional composite-metal stacks employing glass fibre reinforced plastics (GFRP), is gaining traction in many industrial applications. However, finishing operations in these materials (e.g. drilling), often present problems such as delamination and burrs, which are mainly due to mechanical loads. This paper presents a hybrid approach to predicting drilling cutting forces based on mechanistic drilling models coupled with a 2D Finite Element Analysis (FEA). A comprehensive mechanical characterization of the GFRP that was used, to validate the new material constitutive model of the composite was carried out, and an accurate prediction of cutting forces was obtained. [ABSTRACT FROM AUTHOR]

With the rapid growth of the wind energy industry, wind turbine blades installed in the early stages are reaching their retirement service life one after another. Efficient and proper recycling and utilization of discarded blades are crucial for the sustainable development of the industry. This paper analyzes and compares existing recycling technologies, including heat recovery, chemical recovery, and mechanical recovery. The primary component of wind turbine blades is GFRP, an inexpensive material ideally recycled through mechanical means. Therefore, this paper proposes an innovative hierarchical mechanical recycling method. By considering the structural characteristics and residual value of the blades, the scheme simplifies the processing process, reduces costs, maximizes material value, and promotes comprehensive recycling of wind turbine blades. Additionally, exploring the feasibility of using thermoplastic composites to manufacture wind turbine blades aims to address challenges in the recycling process and support the green development, transformation, and upgrade of the wind power industry. We aim to contribute to the sustainable development of the wind power industry and collectively welcome a bright future of clean energy. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study is to investigate the mechanical properties, such as the dynamic hardness and indentation elastic modulus, of commercially available aesthetic orthodontic brackets, such as ceramic and plastic brackets, by the dynamic micro-indentation method. Five ceramic brackets, which were made of alumina (both monocrystalline and polycrystalline forms) or zirconia, and two plastic brackets, which were made of glass fiber-reinforced polycarbonate or polyamide, were tested. There were significant differences in the mechanical properties of the monocrystalline and polycrystalline alumina brackets. The mechanical properties of the glass fiber-reinforced plastic bracket were significantly superior to these of the non-glass-fiber-reinforced plastic bracket. The differences in the crystal structures of the ceramic brackets surface affected the dynamic hardness and indentation elastic modulus. Furthermore, the short glass fibers contained in the plastic bracket might contribute to the improvement of the mechanical properties. [ABSTRACT FROM AUTHOR]

This study investigated the effect of aviation turbine fuel exposure on interlaminar and in-plane shear properties of E-glass/epoxy composite. The two types of test specimens, namely bare and resin-coated specimens with varying thicknesses as per the ASTM standard, were made out of E-glass/epoxy composite to evaluate their interlaminar and in-plane shear properties. These all types of specimens were immersed inside the aviation turbine fuel for two months and then afterward their effect on the reduction of mechanical properties like interlaminar and in-plane shear tests properties were experimentally investigated. Test results show that ATF fuel exposure has reduced the interlaminar shear strength by 10.04 %, 7.83 %, and 6.01 % for bare, with 0.1 mm and 0.2 mm resin coating, respectively. Similarly, in-plane shear strength was reduced by 14.75 %, 11.22 %, and 7.52 % for bare, with 0.1 mm and 0.2 mm resin coating, respectively, and in-plane shear modulus was reduced by 10.87 %, 8.94 %, and 6.52 % for bare, with 0.1 mm and 0.2 mm resin coating conditions as compared to as-received (without ATF exposure) specimens. SEM micrographs and results too showed that properties were reduced and indicated that the glass/epoxy composite was resistive to fuel ingression. It was observed that bare specimens exhibited a reduction in shear properties due to ATF ingression to the polymeric network and induced internal stresses, which not only degraded the matrix and fiber-matrix adherence but created micro-cracks too in the resin at interfaces. Resin-coated specimens limit fuel ingression, which has led to a reduction in properties. [ABSTRACT FROM AUTHOR]

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Microfeatures fabrication on FRPs is very essential nowadays because of its growing demand in various industries like aerospace, automobile, space, marine, etc. Glass fiber reinforced plastic (GFRP) composite is one among the FRPs that has many potential applications with extraordinary physical, chemical and mechanical properties. Generation of microholes on GFRP composite has gained its pace in recent years because of its applications in circuit boards and filters in biomedical applications. This study focuses on the generation of microholes in GFRP composite using an in-house developed electrolyte-sonicated micro-electrochemical discharge machining (ES-µ-ECDM) system. The process parameters voltage (V), concentration (wt%), and feed rate (µm/s) are selected at three levels for performing experiments using FCC-RSM modeling. The machining responses material removal rate (MRR) and overcut (OC) are analyzed. A RSM-based regression model is developed, and a multi-objective optimization using the MOJAYA algorithm is employed to obtain a set of non-dominated Pareto optimal solutions. The Pareto optimal solution set showed a feed rate of 5 µm/s should be employed for better MRR and OC. The SEM micrographs have shown a feed rate of 5 µm/s produced smooth surfaces at voltages and concentrations less than 55 V and 17.5 wt%, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)