Pengaruh Waktu Hidrotermal terhadap Karakteristik Zeolite Socony Mobile-5 (ZSM-5) Tanpa Template Menggunakan Reaktor Autoclave

ZSM-5 is a synthetic zeolite which has a complex production process and is affected by operating conditions, such as temperature and time. In this study, synthesized ZSM-5 without template by hydrothermal method. An autoclave reactor was used for the hydrothermal process. The aim of this study was to investigate the effect of varied hydrothermal times of 24 and 48 hours with a hydrothermal temperature of 180oC on the characteristic of ZSM-5. The raw materials used were silica oxide and aluminum hydroxide as a source of silica and alumina. The synthesis results were characterized using X-Ray Diffraction (XRD). Based on XRD results, the best result was obtained in performed at 48 hours hydrothermal time indicating the formation of ZSM-5 material at the 22.2o position. The percentage crystallinity of the sample at the hydrothermal time of 48 hours was 51.3%.

On evaluating the potential of nanocomposites for heavy oil recovery

The present work investigates potential of nanocomposite (NCP) for enhancing the production in heavy oil formation. NCP was extracted from bauxite ore and the spectral characterization revealed that NCP was a crystalline material whose matrix consists of 64.5 wt.% alumina oxide (Al2O3), 15.7 wt.% iron oxide (Fe2O3), and 19.8 wt.% silica oxide (SiO2). The nanocomposite fluid, obtained by dispersing NCP into the targeted formation brine, showed a good dispersion over the two first days beyond which a hetero-aggregation, visible to the naked eye, was observed. Coreflooding assays, performed on Berea sandstone saturated with a heavy mineral oil (ρ = 0.854 g/cm3), revealed that 0.25wt.% of NCP dispersed in the formation brine yields a poor recovery. However, increasing the load in NCP from 0.25 to 0.75 wt.% and subsequently 1 wt.% using the same formation brine, showed an increase in the oil recovery up to 14.1% after the waterflooding stage. It was further found that the RF could be as high as 18.3% if 0.25 wt.% NCP was dispersed in a surface-active material (Polyvinyl alcohol, PVA in this study). The result was 4% higher than a scenario in which PVA was used alone. Moreover, it was shown that altering the composition of the preflush could increase the production to up to 11.3%. A comparative analysis with single nanoparticle revealed that the EOR using NCP was six-fold higher compared to that of SiO2 taken alone and 1.5-fold lower than those of Al2O3 or Fe2O3 taken alone.

Biomedical Radioactive Glasses for Brachytherapy

The fight against cancer is an old challenge for mankind. Apart from surgery and chemotherapy, which are the most common treatments, use of radiation represents a promising, less invasive strategy that can be performed both from the outside or inside the body. The latter approach, also known as brachytherapy, relies on the use of implantable beta-emitting seeds or microspheres for killing cancer cells. A set of radioactive glasses have been developed for this purpose but their clinical use is still mainly limited to liver cancer. This review paper provides a picture of the biomedical glasses developed and experimented for brachytherapy so far, focusing the discussion on the production methods and current limitations of the available options to their diffusion in clinical practice. Highly-durable neutron-activatable glasses in the yttria-alumina-silica oxide system are typically preferred in order to avoid the potentially-dangerous release of radioisotopes, while the compositional design of degradable glass systems suitable for use in radiotherapy still remains a challenge and would deserve further investigation in the near future.

Stabilisasi Tanah Gambut Menggunakan Abu Boiler Kelapa Sawit Ditinjau Dari Nilai Cbr Laboratorium

Palm ash is the waste from the palm ash combustion which contains a lot of silicate. In addition, palm ash also contains inorganic cations such as potassium and sodium. Palm ash is pozzolanic material, which is a non-binding material such as cement, but contains active Silica Oxide (SiO2) compounds which when reacted with free lime or calcium hydroxide (Ca (OH2)) and water will form materials such as cement, namely calcium Silica Hydrate. In this study we will use palm ash waste which has been stated to have good soil improvement results as a mixture of peat soil improvement in the hope of getting better improvement results from previous studies in terms of California Bearing Ratio values. The boiler ash to be used is a variation of the mixture of 0%, 5%, 10% and 15% to the weight of the soil sample and using 28 days treatment. The California Bearing Ratio value of the original peat soil is 0.247%, the percentage of 5% increases to 0.433%, at the percentage of 10% is 0.629% and at the percentage of 15% is 0,729%.

Environmental Method for Synthesizing Amorphous Silica Oxide Nanoparticles from a Natural Material

Numerous studies have been performed on the generation of several silicon-based engineering materials that often have used chemical materials that have high risks for health and the safety of the environment. Generally, in the synthesis of Nano-silica, tetramethoxysilane, tetraethoxysilane, and tetraethyl orthosilicate (TEOS) are used as precursor materials; however, these materials are toxic and expensive for the production of Nano-silica. This paper presents an environmentally friendly short method (EFSM) with high efficiency for the synthesis of amorphous silica oxide Nanoparticles by using agricultural waste called rice husks (RHs). Use of the EFSM method as an alternative to the chemical methods would have the advantages of fast and simple operation, controllability, great pureness of the Nanoparticles, and low manufacturing cost. A Nanoparticles (NPs) evaluation was conducted with energy-dispersive spectroscopy (EDS), field emission scanning electron microscope (FESEM) and X-ray fluorescence (XRF). By applying the EFSM method, non-toxic amorphous silica nanoparticles with a purity of 94.5% and particle size less than 100 nm was synthesized without using any chemical material.

Bond Strength Between Resin Cement to High-Translucency Zirconia Following Sandblasting And Non-Thermal Plasma Treatment

Objective: The aim of this study was to compare the bond strength of High-Translucency zirconia (HT) and lithium disilicate dental ceramics, under different surface treatments. Material And Methods: For this, ceramics were divided into groups: Control Group (C) (n = 5), lithium disilicate sheets, conditioned with 10% hydrofluoric acid, followed by application of 37% phosphoric acid, silane and universal adhesive application; Group HTAI (n = 5), HT zirconia sheets were blasted with silica oxide, followed by the application of universal adhesive; Group HTPAI (n = 5), HT zirconia sheets were blasted with silica oxide, followed by the application of non-thermal plasma and universal adhesive and the HTP Group (n = 5), HT zirconia received only the application of non-thermal argon plasma. Subsequently, the specimens of each group were subjected to a cementation process with resin cement, obtaining cylinders. After 24 h of storage, in distilled water, at 37°C, the specimens were subjected to a mechanical micro-shear test. The data obtained were submitted to ANOVA One-way followed by the Tukey test (5%). Results: The HTP Group was excluded from the statistical analysis, as adhesions failed within the storage period. In addition, it was not possible to verify a statistical difference between the control group C and the experimental groups HTAI and HTPAI. Conclusion: The results showed that the applicability of high translucency zirconia can potentially be compared to the lithium disilicate bond strength, when submitted to the same surface treatments, except for the plasma application, which alone was not effective. KEYWORDS Lithium disilicate; Nonthermal plasma; Zirconia ceramic.

Preparation of magnetite-silica–cetyltrimethylammonium for phenol removal based on adsolubilization

In this study, we successfully coated cetyltrimethylammonium–silica on magnetite. The material produced is used to degrade phenol waste in the waters. The effect of the addition of cetyltrimethylammonium bromide (CTAB) on the ability of phenol adsorption was assessed through changes in CTAB concentration of 1, 5, and 10 mM. The results of Fourier-transform infrared spectroscopy explain that CTAB has electrostatic interactions with the silica surface, which is induced by opposite-loaded patches on the opposite surface of silica oxide. The results of the vibrating sample magnetometer show that the magnetite that has been coated by silica–CTA has magnetic properties that are weaker than the initial magnetite, which indicates that the silica–CTA layer has blocked the magnetite. Based on the measurement of the gas sorption analyzer, the largest pore size is in the micro-mesh region, which is between 2 and 6 nm. All magnetite-silica–cetyltrimethylammonium (MS–CTA) showed good adsorption ability of phenol and correlated with the amount of loaded CTAB and admicelle density of the adsorbent. The amount of phenol adsorbed increases proportionately with the increasing density of CTAB admicelles. The maximum phenol adsorption capacity (0.93 mg g−1 adsorbent) is achieved by MS–CTA prepared at a CTAB concentration of 10 mM.

The Effect of Eggshell Powder as an Accelerator for Blended Cement Concrete

Blended concrete has later strength development with long maturity strength development. An accelerator is thus needed to enhance the early strength development of concrete. This paper shows the combination of ground palm oil fuel ash and eggshell powder that was designed for later and early strength development, respectively. Two types of eggshell powder were utilised in concrete: uncarbonised eggshell powder and decarbonised eggshell powder. The study was initiated with compression test for concrete curing at age 1, 3, 7, and 28 days followed by rapid evaluation test of setting time to investigate the preliminary performance between materials. The results revealed decarbonised eggshell powder as a high accelerator that can improve the early age of concrete strength development. Meanwhile, despite showing the best performance, uncarbonised eggshell powder is a very low accelerator thus not fit the purpose. In conclusion, the combination of ground palm oil fuel ash (rich with silica oxide) and decarbonised eggshell powder (rich with calcium oxide) provided dual function, where ground palm oil fuel ash and decarbonised eggshell powder took later and early strength development, respectively. The combination between silica oxide and calcium oxide in cementitious materials has potential to be utilised to enhance the early age of a blended concrete strength development.