The influence of blast furnace slag content on the mechanical and durability properties of raw perlite-based geopolymer mortars

In this work, 21 different raw perlite (RP) -based geopolymer mortars (RPGMs) were manufactured. Blast furnace slag (BFS) was replaced by RP in 7 different proportions with respect to the CaO/SiO2 oxide ratio of RP and BFS mixture in the RPGMs. Sodium hydroxide (NaOH= 5, 10, and 15 M) was used as alkaline medium for geopolymer synthesis in the RPGMs. The ultrasound pulse velocity (Upv), flexural strength (ffs) and compressive strength (fcs), water absorption, acid and sulfate durability of the RPGMs are investigated. The test results revealed that the BFS improved the mechanical properties of RPGMs for the low and medium alkaline medium of 5M and 10M, respectively. On the other hand, BFS had negative effect on the mechanical properties of RPGMs produced at a high alkaline medium of 15M. Moreover, the BFS improved the acid and sulfate durability of the RPGMs.

Carbon-Bonded Alumina Filters Coated by Graphene Oxide for Water Treatment

The aim of this paper is to prepare nano-functionalized ceramic foam filters from carbon-bonded alumina. The carbon-bonded filters were produced via the Schwartzwalder process using a two-step approach. The prepared ceramic foam filters were further coated using graphene oxide. Graphene oxide was prepared by the modified Tour method. The C/O of the graphene oxide ratio was evaluated by XPS, EDS and elemental analysis (EA). The amount and type of individual oxygen functionalities were characterized by XPS and Raman spectroscopy. The microstructure was studied by TEM, and XRD was used to evaluate the interlayer distance. In the next step, filters were coated by graphene oxide using dip-coating. After drying, the prepared composite filters were used for the purification of the water containing lead, zinc and cadmium ions. The efficiency of the sorption was very high, suggesting the potential use of these materials for the treatment of wastewater from heavy metals.

An Innovated 80V-100V High-Side Side-Isolated N-LDMOS Device

We used TCAD Synopsys 3D tools and device simulators to propose an innovative device structure of 80V-100V high-side NLDMOS by using the silicon to silicon-di-oxide ratio with side trench. The high-side can also be developed by placing an NBL structure which can deliver a high as over 200V isolation voltage. The 3D structure can clear see the optimized linear p-top and n-drift region have better charge balance with linear doping profile to get the benchmark breakdown voltage (BVdss) of 80V with on-resistance (Ron) as low as 130 mΩ-mm2 and 100V with on-resistance as low as 175 mΩ-mm2.The linear p-type buried layer using high dosage and lower energy to achieve the better SOA and higher isolation voltage. Optimized linear p-top and PBL can improve Ron by 32.5% compare to other 100V high side device which have done from reference.

Utilization of Fe-Oxide Composites for as Removal from Aqueous Solutions

This work was done to assess the arsenate (AsV ) removal from the model solution by sorbents based on Fe-oxide. Two samples were compared in sorption properties, synthetically prepared Fe-oxide and bentonite/iron oxide (ratio 2:1). The effect of pH and initial metal ion concentration was investigated. The optimum pH for arsenic adsorption by both samples was found to be about 3.0. The adsorption increased very significantly with decreasing pH for both samples. The Fe-oxide sample achieved the maximum adsorption capacity 24,1 mg.g-1 AsV at pH 3, composite sample 14,1 mg.g -1 AsV at pH 3. The adsorption of AsV on Fe-oxide sample increased with the increasing initial metal ion concentration up to 40 mg/l and then equilibrium was established, by contrast of bentonite/Fe-oxide sample shown no significant change at this concentration range.