Is cheating a human function? The roles of presence,state hostility,and enjoyment in an unfair video game

In sports and board games, when an opponent cheats, the other players typically greet it with disdain, anger, and disengagement. However, work has yet to fully address the role of the computer cheating in video games. In this study, participants played either a cheating or a non-cheating version of a modified open-source tower-defense game. Results indicate that when a computer competitor cheats, players perceive the opponent as being more human. Cheating also increases player aggravation and presence, but does not affect enjoyment of the experience. Additionally, players that firmly believed that their opponent was controlled by the computer exhibited significantly less state hostility compared to players that were less certain of the nature of their competitor. Game designers can integrate subtle levels of cheating into computer opponents without any real negative responses from the players. The results indicate that minor levels of cheating might also increase player engagement with video games.     

PET纤维纺丝中采用纳米微粒添加剂的相关问题

在许多市场和用途中采用尺寸更小的微粒材料的趋势正明显增长。在纤维纺丝中加入整个范围的添加剂（包含纳米微粒）开发具有特殊性能纺织品时存在着一些争论。纤维纺丝中的主要问题是开发低含量的添加剂。     

Synthesis and properties of chitosan-modified poly(vinyl butyrate)

Modification of chitosan by grafting of vinyl butyrate was carried out in homogeneous phase using potassium persulfate as redox initator and 1.5% acetic acid as solvent. The percent grafting and grafting efficiency were analysed and the high grafting efficiency up to 94% was observed. The effects of reaction variables such as monomer concentration, initiator concentration, temperature and reaction time were investigated. It was observed that the solubility of chitosan was markedly reduced after grafting with vinyl butyrate. The grafted product is insoluble in common organic solvents as well in dilute organic and inorganic acids. Characterization of the graft copolymers were carried out by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) technics. Characteristic signal of carbonyl group was observed at 1,731 cm⁻¹ which belongs to the poly vinyl butyrate segments in the graft copolymer. The melting transition of the chitosan main chain in the copolymer shifted to 124°C from its original value 101°C. In addition to these, we have also studied topology of the graft copolymer and the SEM micrograph showed continuous homogenous matrix which means there is no phase separation.     

Effects of different particle deposition parameters on adhesion of resin cement to zirconium dioxide and phase transformation

This study evaluated the effect of air-abrasion parameters such as particle size, distance, and time on adhesion of resin cement to zirconium dioxide (Y-TZP) and t→m phase transformation. Y-TZP blocks (N = 80) (In-Ceram YZ, Vita) (4 mm^3?×?4 mm^3?×?3 mm³) were assigned into eight groups (n = 10): air-abrasion with 30 μm (CoJet Sand, S30) and 110 μm (Rocatec-Plus, S110) silica-coated alumina particles, applied for either for 10–20 s (T = time), from a distance of 10–20 mm (D = distance), composing the following groups: S₃₀T₁₀D₁₀, S₃₀T₁₀D₂₀, S₃₀T₂₀D₁₀, S₃₀T₂₀D₂₀, S₁₁₀T₁₀D₁₀, S₁₁₀T₁₀D₂₀, S₁₁₀T₂₀D₁₀, and S₁₁₀T₂₀D₂₀. Resin composite (RelyX ARC) was bonded to Y-TZP blocks in polyethylene molds. The specimens were aged (10,000 thermal cycles and water storage for 90 days) prior to shear bond test. Failure types were analyzed under stereomicroscope and SEM, and phase transformation was calculated. Data (MPa) were analyzed using 3-way ANOVA and Tukey’s tests. Air-abrasion with 110 μm silica particles (10.96) presented significantly higher bond strength (p = 0.0149) compared to 30 μm (8.96). Time (p = 0.403) and distance (p = 0.179) parameters did not affect the results significantly. Air-abrasion with 110 μm particles (12.3) promoted higher bond strength than that of 30 μm (6.4) when applied for 10 s from a distance of 10 mm (Tukey’s). Failure types were predominantly adhesive. Phase transformation ranged between 30.3 and 35.9% for 30 μm particles and 23.8–43.7% for 110 μm particles. While the size of silica-coated alumina particles were more relevant parameter for resin cement adhesion to Y-TZP, time (up to 20 s) and distance (up to 20 mm) appear to be less pertinent.     

Long-term microleakage trends in access cavities conditioned with phosphoric acid and deproteinizing agent for root-canal-treated teeth: an investigation of fluid filtration and microscopy analysis

This study evaluated the long-term microleakage of access cavities conditioned with phosphoric acid and deproteinizing agents for root-canal-treated teeth using fluid filtration and microscopical analysis. Occlusal surfaces of extracted human mandibular premolars (N = 90) were removed leaving a 4 mm coronal length from the cemento-enamel junction. After root canal treatment, the specimens were randomly divided into four experimental groups (n = 21) and the remaining teeth were used for positive control group (n = 6): SB: 35% H₃PO₄ + Adper Single Bond 2; SSB: 35% H₃PO₄ + 5.25% NaOCl + 10% Sodium ascorbate (C₆H₇NaO₆) + Adper Single Bond 2; XP: 35% H₃PO₄₊XP Bond; SXP: 35% H₃PO₄₊5.25% NaOCl + 10% Sodium ascorbate + XP Bond. All cavities were restored with a resin composite (Filtek Z250). After removing the root filling from the apical side, teeth were subjected to fluid filtration test for 1 week, 6 and 12 months followed by ×2500 thermocycling after 1st week and 6th months each. Data were analyzed using one-way ANOVA and Dunnet T3 tests (α = 0.05). SEM analyses were carried out after each microleakage evaluation in two random teeth from all groups. Microleakage values in groups SB and XP presented no significant difference in any of the evaluated period (p > 0.05). Microleakage results of SXP (0.01665) group showed significant difference compared to XP (0.03377) and SB (0.03049) groups after 12 months. SSB group (0.00901) showed significantly less microleakage among all other groups (0.01665–0.03377) (p < 0.05). Prior to endodontic treatment, in access cavities, acid etching with 35% H₃PO₄ followed by the application of NaOCl and sodium ascorbate completely destroyed the collagen layer, reducing the microleakage and resin–dentin interface degradation up to 12 months.     

Analysis of structural,morphological alterations,wettability characteristics and adhesion to enamel after various surface conditioning methods

Minimal invasive dental reconstructions and orthodontic appliances are bonded to enamel without removing the enamel with rotating instruments but the top layer of enamel may be partially aprismatic and impair adhesion. The objectives of this study were to investigate the effect of mechanical surface conditioning methods for removing enamel on its structural, morphological alterations, wettability characteristics, and adhesion of resin-based cement to the conditioned surfaces. Maxillary human incisors (N = 40, n_quadrant = 160) were obtained and coronal sections were embedded in acrylic with their labial surfaces exposed. The teeth were randomly divided into four groups and the enamel surface of each tooth was divided into four quadrants. The surfaces were conditioned in a clockwise manner by one of the following methods: (1) Non-conditioned enamel acted as the control group (C); (2) Silicone-coated disk (Sof-Lex disc, Black, 3 M ESPE) (SD); (3) Diamond bur at slow speed (DB) and (4) Airborne particle abrasion (50 μm Al₂O₃, 2 bar, 5 s) (AA). Surface roughness was measured at each quadrant using a non-contact digital profilometer and contact angle measurements were performed using a goniometer. Enamel surfaces were then etched with 37% H₃PO₄ for 60 s and roughness and wettability measurements were repeated. The enamel surfaces in each quadrant received resin composite luting cement (Variolink II, Ivoclar Vivadent) incrementally in a polyethylene mold (diameter: 1 mm²; height: 4 mm) and photopolymerized. The specimens were stored in distilled water for 24 h at 37 °C until the testing procedures and then shear force was applied to the adhesive interface until failure occurred in a Universal Testing Machine (0.5 mm/min). Microshear bond (μSBS) was calculated by dividing the maximum load (N) by the bonding surface area of the resin cement. Representative enamel surfaces were analyzed under the scanning electron microscope (SEM) (x5000) to assess the surface morphology. Failure types were analyzed using optical microscope and SEM. Data (MPa) were analyzed using one-way ANOVA and Tukey`s test for each parameter and Linear model for group comparisons (α = 0.05). Surface conditioning method significantly affected the adhesion results (p < 0.001), surface roughness (p = 0.017), and contact angle (p < 0.001). Interaction terms were significant (p > 0.05). AA (338 ± 182) created significantly higher surface roughness compared to SD (308 ± 180) and DB (242 ± 197) (p < 0.05). After etching with 37% H₃PO₄, DB (307 ± 223) resulted in significantly lower roughness than those of SD (385 ± 173) and AA (414 ± 193) (p < 0.05). AA (40 ± 11) delivered significantly lower contact angle compared to those of SD (61 ± 9) and DB (59 ± 10). After etching with 37% H₃PO₄, AA (42 ± 10) and DB (50 ± 10) presented the lowest contact angle (p < 0.05). Mean μSBS results (MPa) showed significant difference between the experimental groups (p = 0.011) and were in descending order as follows: DB (20 ± 8)^a?a b < C (12 ± 5)^b. Failure types were predominantly mixed failure type between the enamel and the resin cement with more than half of the resin remained on the enamel surface (32 to 33 out of 40) in all groups. Cohesive failure in the enamel was not observed in any of the groups. SEM analysis showed that AA group leaves abundant particles on the enamel surface and after DB and AA, etching could not remove the particles completely and expose the enamel prisms.     

Comparison of methanol/hydrochloric,ferric chloride acid versus tribochemical silica coating for adhesion of resin cement to zirconium dioxide

This study compared air-abrasion and etching regimens on adhesion of resin luting agent to zirconium dioxide. Ceramic specimens (LAVA, 3 M ESPE) (N = 16) were embedded in acrylic resin and exposed surfaces were polished. The specimens were randomly assigned into four groups (n = 12, 3 specimens for each disc): SC: Air-borne particle abrasion (30 μm aluminum oxide particles coated with silica, CoJet, 3 M ESPE); MH: Heated chemical solution (Methanol-800 mL; 37% Hydrochloric Acid-200 mL; Ferric Chloride-2 g) at 100 °C for 30 min, MHP: Primer (Metal/Zirconia Primer, Ivoclar Vivadent) + MH, P: Primer only (Metal/Zirconia Primer). Cylindrical molds (internal diameter: 0.7 mm; height: 1.5 mm) were placed on each conditioned specimen, filled with resin cement (Multilink Automix) and photo-polymerized for 60 s. After 24 h, the molds were removed and the specimens were stored in distilled water at 37 °C for six months). Microshear test was performed in a Universal Testing Machine (1 mm/min). Failures types were classified as adhesive, mixed, or cohesive. In another set of specimens (n = 2 per group) contact angle measurements were recorded. Data were analyzed statistically using Kruskal–Wallis and Dunn’s tests (α = 0.05). The surface conditioning method significantly affected the mean bond strength (MPa) (p < 0.0001): SC(18.3 ± 0.3)^a < P(5.00 ± 0.07)^b < MHP(4.7 ± 0.08)^c < MH(0.84 ± 0.01)^c. While Group SC showed mainly adhesive (58%) and mixed (41.7%) failure types, groups MH, MHP, and P presented exclusively adhesive failures. SC, MHP, and P (29–32°) showed lower contact angle than MH (78.9°). Volume loss was the highest with MHP (9.92 μl) followed by SC (9.67 μl).     

Improvement of Interfacial Adhesion of Glass Fiber/Epoxy Composite by Using Plasma Polymerized Glass Fibers

This study intends to produce plasma polymer thin films of γ-glycidoxypropyltrimethoxysilane (γ-GPS) on glass fibers in order to improve interfacial adhesion of glass fiber-reinforced epoxy composites. A low frequency (LF) plasma generator was used for the plasma polymerization of γ-GPS on the surface of glass fibers at different plasma powers and exposure times. X-ray photoelectron spectroscopy (XPS) and SEM analyses of plasma polymerized glass fibers were conducted to obtain some information about surface properties of glass fibers. Interlaminar shear strength (ILSS) values and interfacial shear strength (IFSS) of composites reinforced with plasma polymerized glass fiber were evaluated. The ILSS and IFSS values of non-plasma polymerized glass fiber-reinforced epoxy composite were increased 110 and 53%, respectively, after plasma polymerization of γ-GPS at a plasma power of 60 W for 30 min. The improvement of interfacial adhesion was also confirmed by SEM observations of fractured surface of the composites.     

Characterization of Heat Treated Titanium-Based Implants by Nondestructive Eddy Current and Ultrasonic Tests

This study presents nondestructive characterization of microstructure and mechanical properties of heat treated Ti, Ti-Cu, and Ti-6Al-4V titanium-based alloys and 17-4 PH stainless steel alloy for biomedical implant applications. Ti, Ti-Cu, and 17-4 PH stainless steel based implants were produced by powder metallurgy. Ti-6Al-4V alloy was investigated as bulk wrought specimens. Effects of sintering temperature, aging, and grain size on mechanical properties were investigated by nondestructive and destructive tests comparatively. Ultrasonic velocity in specimens was measured by using pulse-echo and transmission methods. Electrical conductivity of specimens was determined by eddy current tests. Determination of Young’s modulus and strength is important in biomedical implants. Young’s modulus of specimens was calculated by using ultrasonic velocities. Calculated Young’s modulus values were compared and correlated with experimental values.     

Functionalized Hybrid Coatings on ABS Surfaces by PLD and Dip Coatings

It is important to give water-repellent and antibacterial properties to the acrylonitrile butadiene styrene (ABS) surfaces of the hearing aids. In this study, the sol–gel Si and sol–gel Ti solutions were prepared from the reactions of silicon ethoxide, titanium butoxide and methacrylic acid. The catalyst and Dynasylan F8815 were added to the sol–gel solutions to give hydrophobic properties onto the ABS surfaces. Additionally, silver nanoparticles were synthesized by nanosecond laser and added to the coating solutions to give extra antibacterial properties. The surfaces of the ABS targets were coated using the sol–gel dip coating and pulsed laser deposition techniques. The coatings with good adhesion between film and substrate and good water-repellent properties were achieved. The average contact angles for the coated ABS surfaces were measured in the range between 120 and 125 degrees. The obtained sol–gel materials and produced thin films onto the ABS surfaces were also analyzed in terms of the antibacterial properties. The highly antibacterial properties were observed in the sol–gel solutions and the thin films.