Various dental luting agents are available to dental clinicians, each of them has its own particularities and indications; thus, selecting which cement to use may be complicated. Resin cements are one type of composite consisting of resin matrix and filler inorganic particles. The bonding between resin matrix and fillers are created via inter phase agent. This inter-phase agent consists of silanes long chain molecule in which organic silica is a component. That means resin cements are composed of three phases that are structurally different; organic phase, inorganic phase and inter phase (48).
The grafting of SAN to a rubber component is the most essential part of the synthesis of ABS because it combines a styrene-acrylonitrile copolymer with a rubber substrate. The features of the ABS synthesized will depend on the composition of the reagents involved in the grafting process. This process starts with the abstraction of allylic hydrogens of the rubber substrate or by copolymerization of the double bonds in rubber. The grafting process always leaves a certain amount of ungrafted SAN. The proportion of ungrafted SAN in the final product depends on the conditions used of the manufacture of ABS.
In 1975, Yoshimura M, et al. isolation, and purification of Monascus pigments through column chromatography by using Sephadex G-50 (3 cm × 5 cm) column with 0.1 M potassium phosphate buffer of pH 7.0 was used as effluent for flow rate of 0.5 mL/min. A number of column and eluants were preferred to isolation and purification of different Monascus pigments by researchers. In 1983, Hin-Chung Wong and Philip E. Koehler used silica gel column, 2× 20 cm, 60- 200 mesh suspended in hexane
In a separate beaker, 10-3 M of synthesized SB was dissolved in 10 ml DMF. The two solutions were mixed together under stirring and resulting yellow precipitate solution was transferred to a sonochemical bath. After 60 minutes of sonochemical treatment, the resulting CdS precipitate was collected, filtered, washed with double distilled water and absolute ethanol several times to remove the unreacted chemicals, and finally dried in an oven at 80oC for 5hours. Similar procedure was adopted to synthesize uncapped CdS
Abstract This study measured the shear bond strength of conventional glass ionomer cements (GICs; Ketac Molar Easymix and Fuji IX) bonded Biodentin that had been allowed to set for 2 different time intervals. Forty-eight Biodentin specimens were prepared; half were stored for 12 minutes, and the remaining 24 specimens were stored for 48hours at 37 °C and 100% humidity. Each group was divided into 2 subgroups of 12 specimens, and each GIC was layered on each of the Biodentin preparations. The GIC-Biodentin shear bond strengths were measured and were compared by using one-way analysis of variance. The shear bond strengths with the 12-minute and 48-hour Biodentin were 5.25 Mpa and 6.62Mpa respectively, for Ketac Molar Easymix and 7.46 Mpa
Furthermore, this scaffold induced osteogenic differentiation of BMSC both in vitro and in vivo by activating integrin and BMP/Smad signaling pathway. Calvarial defect healing was also significantly enhanced in the nanocomposite group . Although chitosan-nHAp composite biomaterials have proven their worth as potential scaffold systems, ternary composite systems have also been widely prepared employing chitosan/nanoHAp with β-glycerophosphate [44,45,46], polyamide-6,6 , collagen , starch , gelatin [104,105,113], zinc oxide , poly(galacturonic acid) , poly(lactide-co-glycolide) , cellulose , collagen gels , hyaluronic acid , Cu-Zn alloy nanoparticles (nCu-Zn) , sodium carboxymethyl cellulose [51, 57, 58,
silica fume concreteis used to produce high strength concrete.The factors that have a beneficial effect onstrength( like dense concrete, strongaggregates) also have a beneficial effecton abrasion resistance. silica fumeconcrete caters to all this needs. Chemical resistance A major reason for the improvedresistance of concrete to acidic andsulphate waters is the reduction in theca(oh)2 content of the cement paste,which decreases linearly with the amountof silica fume added. with 20% silica fumeby weight of cement ,very little of ca(oh)2produced by the Portland cementhydration is left in well hydrated cementpaste. Alkali aggregate reaction The amount of pozzolona needed for reducing the alkali aggregate expansiondepends on the reactivity of pozzolona.studies have shown that less than 10% of silica fume is found adequate for thispurpose as compared to fly ash whichrequires 30%-40% replacement High Strength Concrete High Performance Concrete (HPC)enhanced with silica fume is so strong itbecomes an economical alternative tosteel.
As it is used in extreme environments with elevated temperature and pressure, it is prone to oxidation. To inhibit oxidation process, matrix modification with silicon, zirconium or by multilayer oxidation protection coatings consisting of silicon carbide is done. C/C composites comprise of non-homogeneous structures like fibres, matrix and pores, and all of them combine to give a diversity of microstructures and owing to its complexity; it is difficult to predict the thermal carrying capacity (Manocha Lalit M., 2003). Other drawbacks are inhomogeneity, insufficient stability of friction coefficient cause due to humidity and high-cost of
According to von Post classification system, the type of the peat used is classified under H7 which is pseudo-fibrous peat or hemic peat. This present study focusing on study to determine the strength development before and after fiber inclusion on the peat for stabilized purposes. The mechanical test such as compaction test, unconfined compressive strength (UCS) test and California bearing ratio (CBR) test were conducted on the peat with or without inclusion of fiber ( 0.25%, 0.5%, 0.75%) and 5% cement insertion. Based on compaction test results, the highest maximum dry density is 0.617 Mg/m3 for peat with fiber inclusion 0.5% with the optimum moisture content is 69.19%. The sample cured for 7 days and 28 days before the UCS test were conducted.
Bonded surfaces were ground by 1200 grit SiC paper and polished using diamond paste (2 µm) followed by cleaning in ethanol and acetone prior to diffusion bonding. Good bonding was achieved when the temperature used was between 700 to 8000c and holding time between 30 to 90minutes. The pressure was between 1 to 5MPa. Bonding separated when the temperature used was less than 7000c and above 8250c. Successful bonding happened when the holding time was between 30 to 90minutes and bonding was also successful at 120minutes.