Addition Of Silicon Research Articles

Enhancing steel properties with surface mechanical treatments

This research presents the modification of the microstructure on the surface of a dual phase steel (DP) using three different treatments: surface mechanical attrition treatment (SMAT), surface mechanical carburizing treatment (SMCT), and surface mechanical composite coating treatment (SMCCT). We used SMAT to refine the grain size under high strain and strain rate conditions and successfully induced a phase transformation to martensite. The introduction of carbon during SMAT resulted in surface mechano-chemical carburizing, which enhanced the martensite transformation. Furthermore, the addition of silicon during the process led to the formation of SiC and Fe3C particles dispersed within the ferrite and martensite matrix, creating a surface nano-composite. Analysis using SEM and XRD revealed that the carbon and silicon-treated steel exhibited 41.4% martensite, 4.4% bainite, and 54.1% ferrite, indicating increased transformation by these elements. As a result, the alterations in the surface microstructure led to changes in the mechanical properties of the DP steel. Initially, the DP steel had Y.S. of 250 MPa and U.T.S. of 350 MPa. After SMAT treatment, its Y.S. and U.T.S. increased to 280 MPa and 380 MPa, respectively. The addition of carbon and silicon further enhanced the Y.S. and U.T.S. to 350 MPa and 450 MPa. A significant change in microhardness is achieved from 150HV0.05 to 255HV0.05 while after SMCT and SMCCT is 275HV0.05. Despite an increase in surface roughness contributing to heighten friction, there was a significant reduction in wear. This phenomenon could be attributed to grain refinement, dislocation structures, and martensite phase transformations associated with surface hardening.

Apical and lateral accuracy of intraradicular impressions made using the indirect and direct technique at three different locations: A comparative in vitro analysis

Background:There is limited literature available comparing the accuracy of intraradicular impressions made with a novel hybrid impression material using the indirect and direct technique at three different locations.Materials and Methods:For this comparativein vitroanalysis, postspace was prepared in 15 recently extracted teeth and impressions made with vinyl polysiloxane, polyether (PE), vinyl polyether silicone (VPES), and pattern resin. Postpatterns obtained were re-seated on the teeth and longitudinally sectioned. A binocular microscope was used to measure apical and lateral discrepancies at three locations (L1, L2, and L3). L1 at the postcore junction, L2 at the middle of the post space, and L3, 2 mm short of the apical end. The data obtained were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software. One-way analysis of variance (ANOVA) (intergroup) followed by Tukey’sposthoctest withP≤ 0.05 was used.Results:The one-way ANOVA noted a highly significant difference at the apical location. Pattern resin had the highest apical discrepancy (151.93 ± 8.59 µm), whereas the lowest was with vinyl PE silicone (140.31 ± 11.46 µm). At L1, the highest discrepancy was seen with pattern resin (32.09 ± 2.31 µm), whereas the lowest was with the addition silicone (31.94 ± 2.54 µm). At L2, addition silicone (32.88 ± 2.81 µm) showed the highest discrepancy, whereas the lowest was with vinyl PE silicone (30.5 ± 8.79 µm). The PE group had the highest mean at the L3 location (31.38 ± 3.46 µm) and the lowest was with vinyl PE silicone (30.93 ± 2.25 µm). At all lateral locations, no significant difference was noted. Tukey’sposthoccomparison showed a significant difference between pattern resin and VPES (11.62 µm) followed by pattern resin and addition silicone (11.47 µm) apically.Conclusion:The indirect technique using VPES or addition silicone is more accurate than the direct technique at the apical location.

The Beneficial Effects of Soluble Silicon Fertilizer in Dendrobium Orchids: Silicon-Augmented Resistance against Damage by Insect Pests and Fungal Pathogens.

The effects of soluble silicon fertilization on monocots and dicots have been widely studied. However, little is known regarding its effects on protecting epiphytes against insect and fungal pests. The efficacy of silicon fertilizer to reduce damage by thrips pest complexes, namely: Thrips palmi Karny, Frankliniella occidentalis Pergande, Chaetanaphothrips orchidii Moulton, and Chaetanaphothrips signipennis Bagnall (Thysanoptera: Thripidae), and the fungal pathogens: Botrytis cinerea Persoon (Helotiales: Sclerotiniaceae) and Fusarium spp. Link (Hypocreales: Nectriaceae) was examined during a nine-month greenhouse trial in Hawaii. The trial assessed yield, quality, and pest damage across three common varieties of dendrobiums. All replicates received additional soluble silicon fertilizer applications alternating weekly between soil drench and foliar (50 mg Si/plant) applications. Yield, quality, and spray length, pest damage, plant vigor, SPAD, and leaf temperature were measured. Data were analyzed using a generalized linear model (glm) with repeated measures followed by post-hoc pair-wise comparisons in R, version 4.3.1. Treatment effects were significant at p < 0.001 for the majority of the explanatory variables including: marketable yield, spray length, thrips damage, and fungal damage. Overall, the lavender variety ('Uniwai Supreme') benefited the most from silicon applications with a 73.0% increase in marketable yield, compared to the white variety ('Uniwai Mist'), which had an increase of 50.6% marketable sprays in contrast to its untreated control. Si benefits conferred to the purple variety ('Uniwai Royale') were intermediate to the lavender and white varieties. Although the magnitude of Si benefits varied among the varieties, all dendrobium varieties significantly benefited from silicon fertilization.

Is silicon worth it? Modelling degradation in composite silicon–graphite lithium-ion battery electrodes

The addition of silicon into graphite lithium-ion battery anodes has the potential to increase cell energy density. However, understanding the complex degradation behaviour in these composite systems remains a research challenge. Here, we developed a coupled electrochemical–mechanical model of a composite silicon/graphite electrode, including stress-driven crack formation and solid electrolyte interphase layer growth for each material, validated with experimental degradation data from an LG M50T cell. The model reveals self-limiting loss of silicon due to decreasing stress in the silicon as the silicon activity shifts to a lower state-of-charge. Higher C-rates can lead to lower degradation due to lower phase utilisation as voltage cut-offs are reached earlier. Increasing silicon content can reduce the stress in the silicon by distributing reaction current density over more material. Using this model, we explored whether the extra capacity from silicon is generally ‘worth’ the faster degradation compared to graphite-only electrodes. The model shows if you use the silicon, you lose it, as the higher initial capacity is rapidly lost with regular high depth-of-discharge events. However, silicon does have value if it enables full graphite utilisation without range anxiety; if high depth-of-discharge events are minimised then graphite’s superior longevity can be utilised while exploiting silicon’s high specific capacity. The model is integrated into PyBaMM (an open-source physics-based modelling platform); providing the research community and industry with the capability to reproduce our results and further explore the dynamic lifetime behaviour of composite electrodes.

Correction to: The Impact of Shelf-Life and Storage Conditions on the Accuracy and Performance of Additional Silicone Impression Materials: a Systematic Review and Meta-analysis

Correction to: The Impact of Shelf-Life and Storage Conditions on the Accuracy and Performance of Additional Silicone Impression Materials: a Systematic Review and Meta-analysis

Influence of silicon content on high temperature tribology performance of TiAlCrSiN coatings

A series of TiAlCrSiXN coatings with various silicon contents were fabricated on Si(100) and 304 stainless steel substrates using a radiofrequency magnetron sputtering system, aiming to examine the effects of various Si content on wear behaviors at room temperature and 700 °C. The addition of silicon notably increased the coatings' hardness from 21 GPa to 29 GPa, attributed to significant compressive residual stress (−3.4 GPa) that inhibited dislocation movement. Room temperature wear tests revealed that wear rates varied between 0.6 and 3.7 (10−6mm3N−1 m−1) with increasing silicon content. The lowest wear rate is observed at a silicon content of 3.1 at.%, which is associated with an ideal residual stress of −1.2 GPa. This stress level played a crucial role in preventing crack propagation and delamination, thus enhancing wear protection. At 700 °C, the coatings' wear resistance was mainly governed by their oxidation resistance, with the most resistant coatings exhibiting wear rates from 1.6 to 4.4 (10−6mm3N−1 m−1). The silicon addition promoted the formation of an amorphous Si3N4 phase, serving as an oxygen diffusion barrier, thus enhancing resistance to oxidation at elevated temperatures. The findings suggest that TiAlCrSiN coatings offer a promising solution for advanced tribological applications, demonstrating improved performance at temperatures up to 700 °C.

3D printed, subtractive, and conventional acrylic resins: Evaluation of monotonic versus fatigue behavior and surface characteristics

This study assessed the mechanical properties and surface characteristics of dental prosthetic acrylic resin fabricated by 3D printing, comparing it with subtractive, pressing, and molding techniques. Bar-shaped specimens (N= 90; 65 × 10 × 3.3 mm; ISO:207951) were prepared and assigned into six groups: PRINT (3D printing vis stereolithography with PriZma 3D Bio Denture, Makertech Labs); SUB (subtractive manufacturing with Vipiblock Trilux, Vipi); PRESS Base (pressing using muffle with Thermo Vipi Wave, Vipi for base); PRESS Tooth (pressing with Onda-cryl, Clássico for tooth); MOLD Base (molding using addition silicone with Vipi Flash, Vipi for base); and MOLD Tooth (molding with Dencor, Clássico for tooth). Monotonic flexural strength (FS) and elastic modulus (E) were measured using a three-point bending approach (n= 5) on a universal testing machine at a crosshead speed of 5 mm/min. Fatigue testing (n= 10) followed similar geometry and settings, with a frequency of 2 Hz, initial stress level at 20 MPa, and stress increments of 5 MPa every 2,500 cycles. Surface roughness (n= 10) was assessed through profilometry, and fractographic and topographic analyses were conducted. Statistical analyses included One-Way ANOVA for monotonic FS, roughness, and E, along with Kaplan-Meier with Mantel-Cox post-hoc and Weibull analysis for fatigue strength. PRINT showed lower monotonic FS than the SUB and PRESS Tooth but comparable fatigue strength to these groups and superior to PRESS Base and MOLD (Base and Tooth) groups. All groups had similar Weibull moduli. Surface roughness of the PRINT group was comparable to most techniques but higher than the PRESS Tooth group. Fractographic analysis revealed fractures originating from surface defects under tensile stress, with SEM showing scratch patterns in all groups except PRINT, which had a more uniform surface. Despite its lower monotonic strength, 3D printed resin demonstrated comparable fatigue strength to subtractive and pressing methods and similar surface roughness to most methods, indicating its potential as a viable option for dental prosthesis.

Pt(II) complexes bearing P,N-donor ligands as catalysts in chemoselective hydrosilylation, hydrogermylation, and hydroboration of terminal alkenes

In this report, we present the synthesis of six novel neutral platinum complexes employing readily available P,N-donor ligands through a straightforward two-step procedure. Subsequently, we investigated their catalytic activity in the hydroelementation of terminal olefins, highlighting their versatile utility in material and natural product chemistry. The efficient addition of silicon, germanium, and boron hydrides to the CC bond at low catalyst loading occurred exclusively in an anti-Markovnikov manner. Furthermore, our substrate scope encompasses a wide range of aliphatic and aromatic alkenes, featuring substituents with varying electronic properties. In contrast to many previous Pt-complexes, our catalytic system displayed exceptional chemoselectivity towards other unsaturated functional groups, such as carbonyl and internal CC bonds. Notably, it also exhibited remarkable tolerance to hydroxyl, alkoxyl, silyl, and thioether moieties. Additionally, we accentuated the prowess of our catalyst, showcasing its capability to sustain consistent activity and selectivity throughout numerous catalytic cycles.

The Impact of Shelf-Life and Storage Conditions on the Accuracy and Performance of Additional Silicone Impression Materials: a Systematic Review and Meta-analysis

The Impact of Shelf-Life and Storage Conditions on the Accuracy and Performance of Additional Silicone Impression Materials: a Systematic Review and Meta-analysis

Conventional Dental Impressions vs. Impressions Reinforced with Rigid Mouthguards.

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones-from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann-Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique.

Effect of Silicon Addition on Microstructure, Hardness and Young’s Modulus of Injection Molded AZ91D Alloy

Effect of Silicon Addition on Microstructure, Hardness and Young’s Modulus of Injection Molded AZ91D Alloy

Study on Impression Techniques and Materials for Implant among Dentists in Erbil city: A Survey study.

Background and Objectives: The Success and longevity of implant prosthesis is affected by an accurate fit which can be achieved through a proper impression technique and material, the techniques of impression taking can be made by either a closed or open tray impression procedures or by implant level impression technique. The main objective of the presented research was to investigate the most preferable impression material and technique for dental implant placement. Materials and methods: This research’s focus is on impression materials and the various impression techniques that can be used in implant restoration with a note on the recent advancements, with the help of a questionnaire given to dental professionals and postgraduate students who perform implants in Erbil City. Around 72 dentists were chosen, 24 of them were inside our teaching hospital, and 48 of them were chosen by random sampling. Results: The information gathered in this study sample group shows that the highest rate was for open tray technique about 54.2%, 37.5% responded closed tray and 8.3% responded abutment level. Regarding the most preferable material 75% responded for addition silicone, 23.6% responded for condensation silicone and 1.4% responded for alginate. According to most preferable type of tray 93.1% answered perforated stock tray and 6.9% answered special tray. 56.9% of the practitioners chose One step (heavy-light), 22.2% chose two step spaced putty wash, 13.9 % chose one step (monophase single viscosity) and 6.9% answered two-step unspaced putty wash. Conclusions: In conclusion open tray technique, stock tray, addition type of silicon and one-step (heavy-light) impression technique is the most preferable in this study. Keywords: Implant, Impression, open tray, closed tray, abutment, materials.

Recycling of Spent FCC Catalysts: Conversion of Leached Residues to Zeolite ZSM-5.

The commercial recycling of spent FCC catalyst typically focuses on recovering only 1-3 % of rare-earth elements, with the remaining residues often disposed of in landfills. Here, we present a novel method to close a recycling loop for spent FCC catalyst. The method involves a series of leaching steps: Firstly, the spent catalyst material is leached with HNO3 to remove rare-earth elements such as La; second, solvothermal leaching with HCl removes most of Al and impurities like Fe, Ni and V; finally, a third leaching with H2SO4 removes Ti. The solid residues are then used to synthesize ZSM-5 without the addition of any extra silicon or aluminum sources after mild activation. The impurities in the synthesis gel strongly modify the properties of the zeolite, with ZSM-5 crystals containing higher levels of impurities exhibiting lower crystallinities, surface areas, acidities, cracking activities, as well as larger particle sizes.

Effect of propolis on the mechanophysical properties of addition silicon dental impression material

Background Dental impressions should be disinfected to stop the transmission of germs among dental workers since they provide a risk of diseases. The aim of this study was to examine the effects of two disinfectants (16 mg/ml propolis and 5.25% sodium hypochlorite) on the detail reproduction, linear dimensional change, compatibility with gypsum products, wettability, and surface roughness of addition silicon material. Methods Ninety specimens were created using Addition silicon impression material, and they were then divided into three groups at random. Ten specimens from each test group were used in each test. Utilizing apparatus made in accordance with ISO 4823:2015, detail reproduction, linear dimensional change, and compatibility with gypsum products are assessed. A digital Profilometer was uutilized to evaluate surface roughness, and a Goniometer was utilized to evaluate wettability by taking the contact angle. Before testing, the specimens were immersed for 10 minutes each in two disinfection solutions: 16 mg/ml propolis and 5.25% NaOCL. The control group received no disinfection. One-way ANOVA tests and the Kruskal-Wallis test, which was statistically significant at a level of p 0.05, were used to examine the data. Results Comparing the linear dimensional change, surface roughness, and wettability of Addition silicon specimens immersed in 16 mg/ml propolis, 5.25% NaOCL, or the control group demonstrated statistically significant differences (p&lt; 0.05), while details reproduction and compatibility with gypsum revealed statistically no significant differences (p &gt; 0.05). Conclusion Within the parameters of this study, the addition silicon can be immersed in 16 mg/ml propolis for 10 min. to disinfect it without compromising its dimensional accuracy, detail reproduction, compatibility with gypsum products, surface roughness, or wettability.

Impression Disinfection and Its Effect on Dimensional Accuracy and Surface Detail in the Times of COVID-19: An In Vitro Study.

Introduction The disinfection of impressions is crucial to eliminate the viral and other microbial loads to prevent the cross contamination of diseases. The aim of this study was to compare the effect of different virucidal disinfecting methods on the dimensional accuracy and surface detail reproduction (SDR) of impression materials. Methods A total of 160 samples were fabricated with different impression materials using zinc oxide eugenol (Group 1), alginate (Group 2), polyether (Group 3), and addition silicone (Group 4) impression materials, each containing 40 samples (n=40). These groups were further divided into Subgroups A, B, C, and D (n=10) based on the disinfecting method used. Disinfection was carried outusing 0.2% peracetic acid (A), a natural polymer of glucosamine (B), ultraviolet (UV) radiation (C), and ozonated water (D). The disinfected impressions were poured in type IV gypsum, and the obtained casts were checked for dimensional accuracy and surface detail reproduction (SDR). For dimensional accuracy, a one-way analysis of variance (ANOVA) test and, for surface detail reproduction, the chi-square test were used to compare the different subgroups of each impression material separately. Results Zinc oxide eugenol samples showed the lowest mean dimensional change when disinfected with 0.2% peracetic acid (1A=154.1 µm), and alginate showed the lowest mean dimensional change when disinfected using ozonated water (2D=134.9 µm). On the other hand, the lowest mean dimensional change observed in polyether and addition silicone samples was those which were disinfected using UV radiation (3C=100.9 µm and 4C=113.5 µm). Surface detail was reproduced adequately in most of the samples. Conclusion A 0.2% peracetic acid could be used to disinfect zinc oxide eugenol impressions, ozonated water for alginate impressions, and UV radiation for polyether and addition silicone impressions.

Effect of Methyl Hydro-Silicone Oil Content and Aging Time on Compression Modulus and Breakdown Strength of Additional Liquid Silicone Rubber Gel.

The performance of silicone rubber gel elastomers is affected by the composition and structure of the crosslinker. In this work, a two-component addition liquid silicone rubber gel material was developed, and the effects of the contents of two methyl hydro-silicone oils on the compression modulus and breakdown strength of the silicone rubber gel insulating material, as well as the performance change after hot air aging at different times (24 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h), were studied. The results showed that the breakdown strength and compression modulus exhibited an upward trend with the increase in the hydrogen silicone oil content. The best performance was achieved in the silicone rubber gel with Si-H:Si-Vi = 1.4:1. Moreover, with the increase in aging time, the breakdown strength decreased and the compression modulus increased.

Influence of copper and silicon on phase transformations in the iron – carbon system

Influence of copper and silicon on phase transformations in the iron – carbon system

Preparation and characterization of porous reaction bonded silicon nitride by paraffin emulsified suspension

Porous Si3N4 ceramics with an interconnected pore structure were prepared by a paraffin emulsified suspension method. The effects of the volume ratio of paraffin to silicon and Y2O3 addition on the structure and properties of porous Si3N4 were studied. Uniform dispersed pores introduced by the emulsified paraffine droplets can be observed in the green samples. With the increase of the volume ratio of paraffin to silicon, the bulk density and the strength of the sample were decreased, and the apparent porosity and Darcy permeability were increased. The formation of α-Si3N4 whiskers could be promoted by the addition of the Y2O3 during the nitriding process, and numerous nano whiskers could be obtained in the pores left by the paraffine droplets with suitable addition of the Y2O3. The porous Si3N4 with interconnected whiskers prepared via the paraffin emulsion method exhibited potential application for hot gas particular matter filtration.

Evaluation of the Effectiveness of Disinfectants on Impression Materials.

Background The disinfection of dental impression materials is a cornerstone of infection control in dental practice. This study aimed to evaluate the effectiveness of two disinfectants, sodium hypochlorite and iodophor, on alginate and silicone impression materials, which are prone to microbial contamination. Methods The study was structured into two main groups based on the impression material: Group I (alginate) and Group II (addition silicone), each further subdivided into two subgroups for disinfection with sodium hypochlorite and iodophor. For each subgroup, initial microbial swabs were taken before any treatment, followed by a second swab after rinsing and a final swab after disinfection. The mean colony-forming unit (CFU) counts, standard deviations, and standard errors of the mean were calculated for each stage of treatment. Results Prior to disinfection, Group I had a mean CFU count of 2,529.40, while Group II had a lower mean CFU of 1,417.40. After rinsing, there was a significant decrease in CFUs in both groups, with Group I at 1,337.10 and Group II at 415.10. Post-disinfection, Group I showed a mean CFU count of 73.00 for sodium hypochlorite and 0.00 for iodophor. Similarly, Group II achieved a CFU reduction of 99.00 with sodium hypochlorite and 0.00 with iodophor, demonstrating a marked reduction in microbial presence. Conclusion Iodophor was exceptionally effective in disinfecting both alginate and silicone impression materials, eliminating all detectable CFUs. Sodium hypochlorite also significantly reduced microbial counts but was not as effective as iodophor. Rinsing prior to disinfection was instrumental in reducing the microbial load, underscoring its importance in the disinfection protocol.

Evaluating the Effects of Chronic Oral Exposure to the Food Additive Silicon Dioxide on Oral Tolerance Induction and Food Sensitivities in Mice.

The increasing prevalence of food sensitivities has been attributed to changes in gut microenvironment; however, ubiquitous environmental triggers such as inorganic nanoparticles (NPs) used as food additives have not been thoroughly investigated. We explored the impact of the NP-structured food-grade silicon dioxide () on intestinal immune response involved in oral tolerance (OT) induction and evaluated the consequences of oral chronic exposure to this food-additive using a mouse model of OT to ovalbumin (OVA) and on gluten immunopathology in mice expressing the celiac disease risk gene, HLA-DQ8. Viability, proliferation, and cytokine production of mesenteric lymph node (MLN) cells were evaluated after exposure to . C57BL/6J mice and a mouse model of OT to OVA were orally exposed to or vehicle for 60 d. Fecal lipocalin-2 (Lcn-2), anti-OVA IgG, cytokine production, and immune cell populations were analyzed. Nonobese diabetic (NOD) mice expressing HLA-DQ8 (NOD/DQ8), exposed to or vehicle, were immunized with gluten and immunopathology was investigated. MLN cells exposed to presented less proliferative T cells and lower secretion of interleukin 10 (IL-10) and transforming growth factor beta () by T regulatory and cells compared to control, two factors mediating OT. Mice given exhibited intestinal Lcn-2 level and interferon gamma () secretion, showing inflammation and less production of IL-10 and . These effects were also observed in OVA-tolerized mice exposed to , in addition to a breakdown of OT and a lower intestinal frequency of T cells. In NOD/DQ8 mice immunized with gluten, the villus-to-crypt ratio was decreased while the intraepithelial lymphocyte counts and the Th1 inflammatory response were aggravated after treatment. Our results suggest that chronic oral exposure to blocked oral tolerance induction to OVA, and worsened gluten-induced immunopathology in NOD/DQ8 mice. The results should prompt investigation on the link between exposure and food sensitivities in humans. https://doi.org/10.1289/EHP12758.