Integrated outstanding precision and mechanical performance of transparent 3D photonic crystal devices employing cross-linked nanospheres via thermoforming in a rubbery state

2020 ◽  
Vol 8 (9) ◽  
pp. 2993-2999 ◽  
Author(s):  
Dan Chen ◽  
Ying Yao ◽  
Yunming Wang ◽  
Yue Fu ◽  
Jiaqi Zheng ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Mechanical Performance ◽  
Rubbery State ◽  
Mechanical Performances

Transparent photonic crystal devices with preferable optical and mechanical performances fabricated by employing cross-linked photonic crystal nanospheres in a rubbery state.

scholarly journals Mechanical Performance of Glass-Based Geopolymer Matrix Composites Reinforced with Cellulose Fibers

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2395 ◽  
Author(s):  
Gianmarco Taveri ◽  
Enrico Bernardo ◽  
Ivo Dlouhy
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Fiber Surface ◽  
Cellulose Fiber ◽  
Maximum Effect ◽  
Matrix Composites ◽  
Curing Conditions ◽  
Chevron Notch ◽  
Geopolymer Matrix ◽  
Mechanical Performances

Glass-based geopolymers, incorporating fly ash and borosilicate glass, were processed in conditions of high alkalinity (NaOH 10–13 M). Different formulations (fly ash and borosilicate in mixtures of 70–30 wt% and 30–70 wt%, respectively) and physical conditions (soaking time and relative humidity) were adopted. Flexural strength and fracture toughness were assessed for samples processed in optimized conditions by three-point bending and chevron notch testing, respectively. SEM was used to evaluate the fracture micromechanisms. Results showed that the geopolymerization efficiency is strongly influenced by the SiO2/Al2O3 ratio and the curing conditions, especially the air humidity. The mechanical performances of the geopolymer samples were compared with those of cellulose fiber–geopolymer matrix composites with different fiber contents (1 wt%, 2 wt%, and 3 wt%). The composites exhibited higher strength and fracture resilience, with the maximum effect observed for the fiber content of 2 wt%. A chemical modification of the cellulose fiber surface was also observed.

scholarly journals Assessments on the Performance of Asphalt Mixtures Prepared with Adhesion Promoters

2019 ◽  
Vol 8 (3S3) ◽  
pp. 332-339
Keyword(s):  
Mechanical Performance ◽  
Water Immersion ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Adhesion Promoters ◽  
Modified Asphalt ◽  
Service Characteristics ◽  
Bonding Properties ◽  
Mechanical Performances

Asphalt pavement is typically susceptible to moisture damage. However, it could be improved with the incorporation of additives or modifiers through binder modifications. The objective of the study is to assess the effect of adhesion promoters, namely PBL and M5000, onto the Hot Mix Asphalt (HMA). The performance of asphalt mixture has been assessed in terms of the service characteristics, the bonding properties, and mechanical performances. The service characteristics were assessed through the Workability Index (WI) and Compaction Energy Index (CEI) to evaluate the ease of asphalt mixture during the mixing and compaction stage. The bonding properties of the modified asphalt mixtures were determined using the boiling water test and static water immersion test to signify the degree of coating after undergoing specific conditioning period and temperature. The mechanical performances of the modified asphalt mixture were evaluated via Marshall stability, semi-circular bending, and modified Lottman tests. All specimens were prepared by incorporating adhesion promoters at the dosage rates of 0.5% and 1.0% by weight of asphalt binder. From the investigation, the bonding properties significantly improved for the modified asphalt mixture compared to the control mixture. The WI of the modified asphalt mixture increased while the CEI decreased in comparison to the control specimen. This implies the workability of modified asphalt mixture is better and requires less energy to be compacted. Modified asphalt mixture generally had better mechanical performance. Therefore, it can be deduced that the asphalt mixture with adhesion promoters have better overall performance than the control mixture.

scholarly journals On the Use of Biobased Waxes to Tune Thermal and Mechanical Properties of Polyhydroxyalkanoates–Bran Biocomposites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2615
Author(s):  
Vito Gigante ◽  
Patrizia Cinelli ◽  
Maria Cristina Righetti ◽  
Marco Sandroni ◽  
Giovanni Polacco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wheat Bran ◽  
Mechanical Performance ◽  
Low Cost ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Polymeric Matrix ◽  
Flour Milling ◽  
Mechanical Performances ◽  
Analytic Models

In this work, processability and mechanical performances of bio-composites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) containing 5, 10, and 15 wt % of bran fibers, untreated and treated with natural carnauba and bee waxes were evaluated. Wheat bran, the main byproduct of flour milling, was used as filler to reduce the final cost of the PHBV-based composites and, in the same time, to find a potential valorization to this agro-food by-product, widely available at low cost. The results showed that the wheat bran powder did not act as reinforcement, but as filler for PHBV, due to an unfavorable aspect ratio of the particles and poor adhesion with the polymeric matrix, with consequent moderate loss in mechanical properties (tensile strength and elongation at break). The surface treatment of the wheat bran particles with waxes, and in particular with beeswax, was found to improve the mechanical performance in terms of tensile properties and impact resistance of the composites, enhancing the adhesion between the PHBV-based polymeric matrix and the bran fibers, as confirmed by predictive analytic models and dynamic mechanical analysis results.

The Study of Thermolplastic Elastomer Based on Polyamide 6: Preparation, Morphology and Mechanical Performance

2011 ◽  
Vol 332-334 ◽  
pp. 1490-1493
Author(s):  
Chun Wang Yi ◽  
Nan Fan Li ◽  
Chao Sheng Wang ◽  
Zhi Han Peng ◽  
Shi Yan Chen
Keyword(s):  
Adipic Acid ◽  
Acid Content ◽  
Ring Opening ◽  
Mechanical Performance ◽  
Thermoplastic Elastomer ◽  
Polyamide 6 ◽  
Ring Opening Polymerization ◽  
Polymerization Process ◽  
End Groups ◽  
Mechanical Performances

In this study,a new thermoplastic elastomer based on polyamid 6, and polytetrahydrofuran was prepared by continuous hydrolytic ring-opening polymerization process. The effective of adipic acid content on the number-average molecular and the content of amino end groups was investigated. The morphology deduce of TPMP, mechanical performances were also investigated.

Basalt Fiber Reinforced Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 1103-1108 ◽  
Author(s):  
Yong Xin Yang ◽  
Jie Lian
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Water Solubility ◽  
Mechanical Performance ◽  
Basalt Fiber ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Mechanical Performances ◽  
Better Than

In this paper, mechanical performances of 480 specimens are tested and influences of basalt fiber ratio, slenderness, soakage material are studied. Results indicate that mechanical properties of BFRC are better than plain concrete. It can be found that the best mechanical performance may be get when the basalt fiber soaked by water-solubility material and its ratio at 8.4 to 14 kg per square meter as well as slenderness at 600 to 800.

scholarly journals Mechanical Performances of Isolated Cuticles Along Tomato Fruit Growth and Ripening

2021 ◽  
Vol 12 ◽  
Author(s):  
José J. Benítez ◽  
Susana Guzmán-Puyol ◽  
Francisco Vilaplana ◽  
José A. Heredia-Guerrero ◽  
Eva Domínguez ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Tomato Fruit ◽  
Mechanical Analysis ◽  
Fruit Growth ◽  
Elastic Behavior ◽  
Loss And Damage ◽  
Well Differentiated ◽  
Mechanical Performances ◽  
A Minor ◽  
Cooperative Association

The cuticle is the most external layer that protects fruits from the environment and constitutes the first shield against physical impacts. The preservation of its mechanical integrity is essential to avoid the access to epidermal cell walls and to prevent mass loss and damage that affect the commercial quality of fruits. The rheology of the cuticle is also very important to respond to the size modification along fruit growth and to regulate the diffusion of molecules from and toward the atmosphere. The mechanical performance of cuticles is regulated by the amount and assembly of its components (mainly cutin, polysaccharides, and waxes). In tomato fruit cuticles, phenolics, a minor cuticle component, have been found to have a strong influence on their mechanical behavior. To fully characterize the biomechanics of tomato fruit cuticle, transient creep, uniaxial tests, and multi strain dynamic mechanical analysis (DMA) measurements have been carried out. Two well-differentiated stages have been identified. At early stages of growth, characterized by a low phenolic content, the cuticle displays a soft elastic behavior. Upon increased phenolic accumulation during ripening, a progressive stiffening is observed. The increment of viscoelasticity in ripe fruit cuticles has also been associated with the presence of these compounds. The transition from the soft elastic to the more rigid viscoelastic regime can be explained by the cooperative association of phenolics with both the cutin and the polysaccharide fractions.

Detection of Voids in Carbon/Epoxy Laminates and Their Influence on Mechanical Properties

2017 ◽  
Vol 25 (5) ◽  
pp. 371-380 ◽  
Author(s):  
Luca Di Landro ◽  
Aurelio Montalto ◽  
Paolo Bettini ◽  
Stefania Guerra ◽  
Fabrizio Montagnoli ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Mechanical Performance ◽  
Thermal Analyses ◽  
Void Content ◽  
Processing Conditions ◽  
Micro Computed Tomography ◽  
Sem Image ◽  
Beam Shear ◽  
Mechanical Performances ◽  
Curing Cycle

Defects, such as voids and delaminations, may significantly reduce the mechanical performance of components made of composite laminates. Distributed voids and porosity are generated during composite processing and are influenced by prepreg characteristics as well as by curing cycle parameters. On the basis of rheological and thermal analyses, as well as observations of laminates produced by different processing conditions, curing pressure appears the most influent factor affecting the void content. This work compares different methods for void analysis and quantitative evaluation (ultrasonic scan, micro-computed tomography, acid digestion, SEM image analysis) evidencing their applicative limitations. Carbon/epoxy laminates were produced in autoclave or oven by vacuum bag technique, using different processing conditions, so that void contents ranging from 0% to 7% volume were obtained. Effects of porosity over laminates mechanical performances are analysed. The results of tensile and compressive tests are discussed, considering the effect that different curing cycles have over void content as well as over fibre/resin fraction. Interlaminar strength, as measured by short beam shear tests, which is a matrix-dominated property, exhibits a reduction of failure strength up to 25% in laminates with the highest void content, compared to laminates with no porosity.

Investigation on selective laser sintering of PA12: dimensional accuracy and mechanical performance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Achille Gazzerro ◽  
Wilma Polini ◽  
Luca Sorrentino
Keyword(s):  
Mechanical Performance ◽  
Selective Laser Sintering ◽  
Central Zone ◽  
Dimensional Accuracy ◽  
Laser Sintering ◽  
Point Of View ◽  
Content Type ◽  
Mechanical Performances ◽  
The Many ◽  
Additional Support

Purpose Selective laser sintering (SLS) has passed other techniques, thanks to its high print resolution, its ability to print microscale geometries without any additional support, its surface quality and its long-term thermal stability. However, despite the many advantages of SLS compared to fusion deposition modelling, there are still today some limitations on the materials to be printed. A limit critical from an industrial point of view is the aging of PA12 powder, i.e. the degradation of its physical and chemical performances, due to the high temperatures and the long printing cycles, thus involving a decrease of the mechanical properties of the printed parts. The purpose of this study was to charaterize mechanically and dimensionally specimens printed in PA12 through SLS by means of virgin or aged powder, i.e. powder just used for five printing cycles. Design/methodology/approach To achieve this aim, a set of specimens were designed, built, measured and mechanically tested; the obtained results were put into relationship with the values of the process parameters used to print them. Statistical tools to design the experiments and to analyse the obtained results were used. Findings The results show that the SLS process carried out through a Sintratec machine on PA12 powder has a good repeatability. To obtain the best dimensional and mechanical performances, it is needed to use virgin powder and place the part in the central zone of the printing area. Originality/value There are no scientific articles dealing with the influence of both the aging of the powder and the manufacturing parameters on the dimensional and mechanical characterization of specimens printed with SLS technique in PA12.

Development of Heat-Resisting Aluminum Alloy Material for Pistons

2008 ◽  
Vol 51 ◽  
pp. 105-110 ◽  
Author(s):  
Jian Lei ◽  
Nan Li ◽  
Mu Cheng Rao
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Fatigue Failure ◽  
Thermal Fatigue ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Temperature Performance ◽  
Alloy Material ◽  
Mechanical Performances ◽  
Comparative Trials

That the main invalidation of high-powered engine pistons is thermal fatigue failure has been confirmed through analyzing auto piston invalidation. And a solution has been proposed to use heat-resisting aluminum alloy material in place of conventional piston material ZL109. Comparative trials for both materials have been conducted on their mechanical performances at normal and high temperatures as well as casting properties. The result indicates that they have close room temperature mechanical performance and casting properties. But at 350°C, high temperature performance is raised by 30~40 MPa.

Experimental Research on the Physi-Mechanical Performances of Geosynthetics

2013 ◽  
Vol 341-342 ◽  
pp. 33-37 ◽  
Author(s):  
Jun Hu ◽  
Hui Zeng ◽  
Xiao Bin Wang
Keyword(s):  
Experimental Research ◽  
Mechanical Performance ◽  
Term Effect ◽  
Influence Of Temperature ◽  
Long Term Effect ◽  
Influence Of Temperature On ◽  
Mechanical Performances ◽  
Better Than

The physi-mechanical performances of geosynthetics were studied by the test on the geosynthetics produced by one factory. Tests of stretching, top-breaking, pierce, tearing, etc. under different materials, temperatures and moistures were done by indoor study, thus studying the physi-mechanical performances of geosynthetics under different conditions. The research shows: the stretching performance of nonwoven textile is better than the woven textile's; The influence of temperature on the geosynthetics is remarkable, it should be emphasized during the construction; The moisture has a little impaction on the mechanical performance of geosynthetics; These achievements provide scientifical data and references for the physi-mechanical performances of geosynthetics, while no further study on the long-term effect, it should be studied in future.

Sign in / Sign up

Export Citation Format

Share Document