Sustainable Production of Roofing Tiles Using Glycerine Pitch as An Alternative Binder

A large quantity of glycerine pitch (GP) generated from the oleo-chemical industry has led to significant environmental issues when it is disposed of without proper treatment. This study investigated the possibility of utilizing glycerine pitch as an alternative binder in the production of roofing tile, namely GP-RT. The percentage of GP incorporated by weight of tile ranges from 3 – 9 %. A transverse strength test was performed on the tiles in dry and wet conditions to investigate their durability in harsh conditions. A water absorption test was performed to determine the water uptake of the tiles produced. The specimen with the greatest flexural strength was achieved when 7% of GP was utilized. The mechanical properties of the tile can be enhanced when GP was mixed with a similar amount of used cooking oil (UCO), which achieved the greatest strength (4389 N and 9.48 MPa) when 5% of GP and 5% of UcO were used for the tile’s production. The water resistivity of the tiles can be enhanced by the coating process. The lowest percentage of water absorption (2.82%) and the greatest wet transverse strength (2746 N) were achieved when the tile was coated with a layer of UCO via the immersion method. Conclusively, the full replacement of cement with GP as an alternative binder is possible. The incorporation of multiple waste materials (GP, UCO, and fly ash) in tile production is a feasible attempt to reduce the disposal of these waste materials to landfills, thus preserves a greener environment for future generations.

THE INFLUENCE OF MICROALLOYING WITH BORON ON PROPERTIES OF AUSTENITE STAINLESS STEEL X8CRNIS18-9

More recently a modified stainless steels have been used to produce various structural elements that work in complex operating conditions. Stainless steel X8CrNiS18-9 (standard EN 10088-3: 2005) is the most commonly used austenitic stainless steel due to its good machinability. This steel has high mechanical and working properties thanks to a complex alloying, primarily with the elements such as chromium and nickel. The content of sulphur present in the steel from 0.15 to 0.35% improves machinability. However, while sulphur improves machinability at the same time decreases the mechanical properties particularly toughness. The addition of sulphur, which is the cheapest available additive for free machining, will impair not only the transverse strength and toughness, but also the corrosion resistance.The aim of this work is to determine the influence of microalloying with boron on the machinability, corrosion resistance and mechanical properties the mentioned steel, but alsoto determine the effect of microalloying with boron on above steel, which is already microalloyed with zirconium, tellurium, or both elements (zirconium and tellurium) due to modification of non-metallic inclusions and improvement of properties.

THE STRENGTH OF TRANSVERS ACRYLIC RESIN WITH GLASS FIBER SOAKED IN TEA

Background: In acrylic removable dentures, brokenness often occurs in the midline region of the maxilla. Resistance to fracture depends on the physical properties of the material namely the transverse strength. This can be prevented by the addition of glass fibers. Tea is consumed by many people, acrylic resin dipped in steeping tea will reduce the strength of acrylic resin. How the physical properties of acrylic resin are modified by the addition of glass fiber effect when immersed in a tea solution. Purpose: This study was to determine the strength of transverse acrylic resin with the addition of glass fibers soaked in tea. Method: Rectangular acrylic resin with a size of 10 x 65 x 2.5 mm. The number of samples is 24. divided into 4 groups. namely 2 groups without glass fiber and 2 groups with glass fiber. The sample is measured by transverse strength using an autograph (Shimadzu) tool, then data is analyzed using ANOVA. Result: Acrylic resin without glass fiber immersed in tea solution decreases its transverse strength. while the acrylic resin was given glass fiber the strength value of the transversion does not differ significantly either soaked or not. Conclusion: Acrylic resin which is given glass fiber and soaked in tea does not reduce the strength of the transversion. This is due to the glass fiber filling the cavity in the acrylic resin.

ENHANCEMENT OF DENTURE-BASED MATERIAL PMMA BY INCORPORATION OF SILANIZED HALLOYSITE NANOTUBES

The aim: This study evaluates the effect of adding silanized halloysite nanotubes to the polymethylmethacrylate (PMMA) resin on its hardness, impact strength, transverse strength. Materials and methods: Three groups of acrylic resin were prepared, one group without HNTs, was used as a control group (A). The other two groups contained 0.3% (B), 0.6% wt of silanized halloysite nanotubes (C). For each one, hardness, impact strength and transverse strength were measured. One-way ANOVA and Tukey’s test were used for comparison. Results: Regarding to the impact test, there was no significant difference between 0.3% concentration and the pure (control) group while 0.6% concentration had significant decrease compared to the pure group and so between the 0.3% group 0.6% group. For the hardness test, the 0.3% group had no significant difference with the pure group and a significant difference between group 0.6% group and the pure group while there was a no significant decrease between the 0.3% and 0.6% group with the higher hardness mean in the 0.3% compared to 0.6% group. For the transverse strength, both 0.3% wt concentration and 0.6% concentration showed significant difference compared to the pure group and also between each other with the lowest impact strength in 0.6% group followed by 0.3% group with the highest transverse strength in the pure group. Conclusions: The silanation of halloysite nanotubes reduces the mechanical properties of the heat-cured acrylic denture base material. The more concentration of silanazed halloysite nanotubes is added, the more weakening occurs in the acrylic material relating to the hardness, transverse strength and impact strength.

A comparison between the effect of LASER and WATER BATH on heat-cured acrylic denture base material vitro study

Curing stage by utilizing Water Bath (W.B.) one of the stages of making a denture, in this investigation, we assess the influence of utilizing W.B. and diode laser light of frequency (1064nm) with force 50mW on samples of heat-curing acrylic (PMMA) on transverse strength of this material. We utilized a sample with dimension (8x 0.8x0.3) cm. 40 samples utilized in this investigation, 20 illuminated by laser with deferent span time of light, and the staying 20 samples prepared by regular W.B. procedure. We estimated the samples' dimension when prepared by the two procedures. From a correlation on the influence of these two procedures on the quality of the samples by utilizing t-test, we reason that the samples that illuminated with laser become more quality and when we increment the term time (p>1), while there are no concedes between the samples that rewarded with ordinary W.B. (p>0.05). We presumed that utilizing laser be more accomplishment in improving the quality of heat-curing acrylic material that utilized for denture base.

PENGARUH LARUTAN SODIUM HIPOKLORIT TERHADAP KEKUATAN TRANSVERSAL PADA BAHAN BASIS GIGI TIRUAN RESIN AKRILIK POLIMERISASI PANAS

Among various ways to clean the denture based material is by its immersion in disinfectant solution, such as sodium hypochlorite. Heat polymerized acrylic is denture based material that is easily broken because of its low transverse strength. This study was aimed to observe the transverse strength of denture based material heat polymerized acrylic resin after immersion in sodium hypochlorite. This research used 24 samples of heat cured acrylic resin plates measuring 65 mm long, 10 mm wide and 2.5 mm thick. The samples being divided into 4 groups were immersed in sodium hypochlorite 1% and water for 8 hours and 24 hours in 7 days. The transverse strength of acrylic plate were then tested using universal testing machine. The measurement results were statistically analyzed employing “one way ANOVA”. The result showed no significant changes on transverse strength of heat-cured acrylic plate. It was concluded that sodium hypochlorite solution did not provide any significant changes in the transverse strength of heat cured acrylic resin.

Evaluating the effect of variable fiber content on mechanical properties of additively manufactured continuous carbon fiber composites

Fiber volume fraction is a driving factor in mechanical properties of composites. Micromechanical models are typically used to predict the effective properties of composites with different fiber volume fractions. Since the microstructure of 3D-printed composites is intrinsically different than conventional composites, such predictions need to be evaluated for 3D-printed composites. This investigation evaluates the ability of the Voigt, Reuss, and Halpin–Tsai models to capture the dependence of modulus and strength of 3D-printed composites on varying fiber volume fraction. Tensile coupons were printed with continuous carbon fiber-reinforced Onyx matrix using a Markforged Mark Two printer. Specimens were printed at five different volume fractions with unidirectional fibers oriented at either [Formula: see text] to obtain longitudinal, shear, and transverse properties, respectively. It is shown that the Voigt model provides an excellent fit for the longitudinal tensile strength and a reasonable fit for the longitudinal modulus with varied fiber content. For the transverse direction, while the Reuss model fails to capture the transverse modulus trend, the Halpin–Tsai model provides a reasonable fit as it incorporates more experimental parameters. Like conventional composites, addition of fibers degrades the transverse strength, and the transverse strength decreases with increasing fiber volume fraction. The shear modulus variation with fiber content could not be fitted reasonably with either Halpin–Tsai model or Reuss model.