scholarly journals Sutures modified by incorporation of chlorhexidine and cinnamaldehyde: anti-Candida effect, bioavailability and mechanical properties

2019 ◽  
Vol 48 ◽  
Author(s):  
Raphael Cavalcante COSTA ◽  
Yuri Wanderley CAVALCANTI ◽  
Ana Maria Gondim VALENÇA ◽  
Leopoldina de Fátima Dantas de ALMEIDA
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Candida Albicans ◽  
Polyglactin 910 ◽  
Oral Infections ◽  
Therapeutic Alternative ◽  
Fungal Adhesion ◽  
Saline Solutions ◽  
Positive Effect

Abstract Introduction Antimicrobial sutures are a therapeutic alternative for the control of oral infections. Objective Incorporate Chlorhexidine (CHX) and Cinnamaldehyde (CN) in sutures and evaluate the anti-Candida effect, release of antimicrobials and mechanical properties. Material and method Silk (S) and Polyglactin 910 (P) sutures were aseptically sectioned (20 mm) and immersed for incorporation in 0.12% CHX, 0.4% CN and 0.9% saline solutions under stirring for 60 minutes (n = 10 / group). Suspensions of 500 μL of Candida albicans (ATCC 90028/ 1 × 106 CFU/mL) were used to evaluate fungal adhesion after the 48 h period at 37°C. The release of CLX and CN were evaluated at 0, 24 and 48 hours (n=3/group) by UV-VIS spectrophotometer (275 nm). The tensile strength and displacement (n=5/group) were evaluated after incorporation (30 mm/min, 50N). Data were analyzed by Anova and Tukey (α = 5%). Result No anti-Candida effect was observed on S and P sutures incorporated with CLX and CN (p>0.05). However, progressive release was verified up to 48 after treatment with CLX (S = 0.075 / P = 0.073 μg/mL) and CN (S = 35.33 /P= 5.72 μg/mL). There was a decrease in tensile strength in S (CLX = 9.9 / CN = 9.9 N) and P (CLX = 14.4 / CN = 15.5 N) (p<0.05). No differences were observed for the displacement for S (CLX = 19.3 / CN=20.7 mm) and P (CLX = 16.2 / CN=15.8 mm) (p>0.05). Conclusion The incorporation of CLX and CN did not have a positive effect on the biological and mechanical properties of the sutures evaluated.

scholarly journals Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Haoliang Huang ◽  
Guang Ye
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Cementitious Materials ◽  
Self Healing ◽  
Negative Effects ◽  
Numerical Studies ◽  
Healing Efficiency ◽  
The Impact ◽  
Positive Effect

In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.

scholarly journals Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 1

2016 ◽  
Vol 16 (1) ◽  
pp. 73-78
Author(s):  
M. Stachowicz ◽  
K. Granat ◽  
Ł. Pałyga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Glass ◽  
Mechanical Parameters ◽  
Significant Positive Effect ◽  
Technological Parameters ◽  
Physical Methods ◽  
High Silica ◽  
Positive Effect

Abstract In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating.

Basic Research on Lattice Structures Focused on the Tensile Strength

2015 ◽  
Vol 808 ◽  
pp. 193-198 ◽  
Author(s):  
Julia Kessler ◽  
Nicolae Bâlc ◽  
Andreas Gebhardt ◽  
Karim Abbas
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Basic Research ◽  
Mechanical Tests ◽  
Lattice Structures ◽  
Set Up ◽  
Definition Of ◽  
Manufacturing Technologies ◽  
Positive Properties ◽  
Positive Effect

This scientific survey is about the mechanical properties of lattice structures which are made by Selective Laser Melting. It’s a process based on Additive Manufacturing technologies. This technology allows the manufacturing of complex lattice structures, and further the integration of lattice structures into different applications. Focusing on the integration of these structures, it is necessary to know what kind of effect they have on applications and what positive properties they might support. More and more the industry searches for new supporting technologies and the trend is towards lightweight and material saving possibilities. [1, 2] A survey on this topic is indispensable. The main aim is to analyze different parameters that affect the mechanical properties. First of all the definition of the experimental set-up and the definition of the, to be tested, parameters are necessary. Furthermore the aim is to find several different parameters that have a positive effect on the mechanical properties. Above all the focus is on experimental set-ups that use mechanical tests, beginning with the test on tensile strength in accordance with DIN 50125. Depending on the results an application area could be chosen and assigned.

scholarly journals Effect of Potassium Phosphate Content in Aluminosilicate Matrix on Mechanical Properties of Carbon Prepreg Composites

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 61
Author(s):  
Eliška Kohoutová ◽  
Pavlína Hájková ◽  
Jan Kohout ◽  
Aleš Soukup
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Potassium Phosphate ◽  
Composite Plates ◽  
Phosphate Content ◽  
Layer Composite ◽  
Weave Fabric ◽  
The Matrix ◽  
Positive Effect ◽  
Alkali Activated

Six matrices based on alkali-activated aluminosilicate with different amounts of potassium phosphate were prepared for the production of six-layer composite plates. The addition of potassium phosphate in the matrix was 2 wt%, 4 wt%, 6 wt%, 8 wt% and 10 wt% of its total weight. The matrix without the potassium phosphate was also prepared. The aim of this study was to determine whether this addition has an effect on the tensile strength or Young’s modulus of composites at temperatures up to 800 °C. Changes in the thickness and weight of the samples after this temperature were also monitored. Carbon plain weave fabric was chosen for the preparation of the composites. The results show that under normal conditions, the addition of potassium phosphate has no significant effect on the mechanical properties; the highest measured tensile strengths were around 350 MPa. However, at temperatures of 600 °C and 800 °C the addition of potassium phosphate had a positive effect, with the tensile strength of the composites being up to 300% higher than the composites without the addition. The highest measured values of composites after one hour at 600 °C were higher than 100 MPa and after 1 h at 800 °C higher than 85 MPa.

Effect of Two-Step Surface Treatment on the Mechanical Properties of Hollow Integrated Core Sandwich Composites with GF/CF Hybrid Face Sheets

2013 ◽  
Vol 8 (2) ◽  
pp. 155892501300800
Author(s):  
Kejing Yu ◽  
Haijian Cao ◽  
Kun Qian ◽  
Hongshun Li ◽  
Juanjuan Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Surface Treatment ◽  
Carbon Fibers ◽  
Bending Strength ◽  
Fiber Strength ◽  
Sandwich Composites ◽  
Infrared Spectrometer ◽  
Positive Effect ◽  
Scanning Electron

In this study, the effect of a two-step surface treatment on the mechanical properties of hollow integrated core sandwich composites with glass fiber/carbon fiber (GF/CF) hybrid face sheets were investigated. The presence of functional groups on the surface during the two-step treatment was characterized by Fourier transform infrared spectrometer (FTIR). The results of tensile strength on single filaments indicated that no extra loss of fiber strength was observed after the two-step surface treatment for both the glass and carbon fibers. Scanning electron microscopy (SEM) data confirmed the positive effect of the two-step surface treatment on the hollow integrated core sandwich fabric with GF/CF hybrid face sheets. It was found that the hollow integrated core sandwich composites with GF/CF hybrid face sheets showed significant improvements in tensile strength, bending strength and compression strength after the two-step surface treatment, which indicated the two-step surface treatment was efficient.

Effect of Carboxymethylcellulose on Plasticized Polylactide

2013 ◽  
Vol 658 ◽  
pp. 19-24
Author(s):  
Chamaiporn Yamoum ◽  
Rathanawan Magaraphan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Melting Temperature ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Melting Temperatures ◽  
Negative Effect ◽  
Positive Effect

Polylactide (PLA) was plasticized by two types of plasticizers, glycerol and triacetin. These plasticized PLA were mixed with carboxymethylcellulose (CMC). It was found that with only small amount of CMC, 4.5 wt%, it is effectively to lower glass transition, cold crystallization and melting temperatures of glycerol-plasticized PLA (PLA-g) but not much affected on tensile properties. Moreover, increasing amount of CMC twice could not much affect thermal properties but largely reduced tensile strength, modulus and elongation. The melt flow index of the PLA-g increased largely with the amount of CMC. When 4.5 wt% CMC was added to the glycerol-triacetin plasticized PLA, only glass transition temperature became lower than that of 4.5 wt% CMC filled PLA-g but melting temperature and crystallinity were rather increased with poorer mechanical properties. Increasing amount of CMC tended to enhance melting temperature but still rather poor mechanical properties and high melt flow index. So, the CMC had strong positive effect on melt and negative effect on solid properties of plasticized PLA.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

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