Abstract Concrete’s deflection and cracking are influenced by flexural capacity. High-strength concrete tends to have high hydration rate, making it susceptible microcracks, thus, early maintenance is required. The weak nature of against tensile forces allows microcracks occur can propagate into macrocracks if the cracks not detected. Therefore, an innovation emerged called self-healing enabling cover independently. This method be used heal cracks, involving bacteria in mixture that active...

Bismuth-doped Barium Titanate ferroelectric ceramics (Ba1-xBixTiO3 at x = 0, 0.05, 0.10, 0.15, and 0.20) were effectively synthesized via co-precipitation. The influences of Bi content on their microstructure dielectric properties studied using XRD, FTIR, SEM, LCR meter instruments. XRD FTIR analyses validated the Bi-doped BaTiO3 formation showing a crystal structure change from tetragonal to cubic due excess content. revealed dense enhancing as higher concentrations, supported by SEM data....

Among the metal hydrides, magnesium has theoretically highest weight capacity for hydrogen storage (7.6 wt.%), lightweight and a reasonably low cost. However, high working temperature (>300°C), slow reaction kinetics (need more than 1 hour to produce 5 wt% of hydrogen) difficult activation limit practical application Mg-based hydrides. In order improve their performance, MgH2 was catalyzed with Ni nanoparticles which reactively milled under atmosphere. Phase identification microstructure...

Investigation on the iron sand characteristic of Syiah Kuala beach in Banda Aceh coastal region has been performed. Samples were prepared by mechanical alloying method using a planetary type high energy ball milling. As shown XRF results, results indicate that is dominated magnetite up to 85.80 %. The XRD test showed Fe3O4 (magnetite) appears as majority phase. Furthermore, magnetic properties observation found magnetization saturation (Ms) and remanent (Br) are decreasing with increasing...

We have investigated the magnetic and microwave absorbing properties of barium hexaferrite BaFe12−2xCoxZnxO19 (x = 0.0; 0.2; 0.4; 0.6) nanocrystalline prepared using solid state reaction method. The powder these ferrites were resulted by high energy ball mill for 1 h mixed with epoxy resin to be converted into a composite. results show structures Ba(Fe,Co,Zn)12O19 been formed. coercive force (Hc) decreases rapidly substitution Co Zn in structure Ba(Fe,Co,Zn)12O19. It's indicate that Co-Zn...

Magnesium (Mg) is currently known as one of the potential candidates for hydrogen absorbent material because theoretically, it has ability to absorb in large quantities 7.6 wt%. However, kinetic reaction Mg very slow; takes 60 min with high operating temperature (>400 °C). Therefore, we have studied MgH2-Ni-SiC-based storage system. The objective this study improve desorption and capacity. preparation was done through mechanical alloying technique. In method, milling carried out within 5 h,...

In this work, the microwave absorption performance of barium hexaferrite multi-nanolayers synthesized by aceramic method was investigated. The performances BaFe 12 O 19 and BaCoZnFe 10 with thicknesses 25, 50, 75, 100, 200, 300, 500, 1000 nm were evaluated using a vector network analyser (VNA) at room temperature to characterize reflected signal ( S 11 ) transmitted 21 in frequency range 7–13 GHz. multilayer structure enhanced due combination nanolayers. optimal achieved reflection loss less...

We have synthesized ZnO nanostructure by using two-step methods i.e ultrasonic nebulizer and chemical bath deposition (CBD) at 95oC for two hours. The morphology, structural, reflectance, photoluminescence properties been characterized the scanning electron microscope (SEM), X-ray diffraction (XRD) measurement, ultraviolet-visible (UV-Vis) spectrophotometer, spectrometer, respectively. Structurally, all samples possess polycrystalline hexagonal wurtzite structure, addition of Al-Cu decreases...

One famous photocatalyst to degrade methylene blue (MB) dye wastewater is SrTiO3 (strontium titanate or STO), whose performance can be enhanced by doping Aluminum (Al). This study aimed fabricate Al-doped STO (SrTi1-xAlxO3; x = 3 % and 5 %) photocatalysts compare the effects of low Al concentrations on photocatalytic performance. The were fabricated using a coprecipitation route confirmed XRD FTIR instruments. against MB was tested under varied UV light exposure hours examined UV–Vis...

This paper reports a method for measuring the complex permittivity and permeability of hexagonal ferrite composite as lossy material. The measurement using waveguide in microwave band. In order to measure S-parameter ferrite, sample should completely fill end holder. material are measured vector network analyzer (VNA) frequency range from 7 14 GHz. Their permittivity, magnetic dielectric loss tangent values were calculated at given thickness according NRW formula transmit line frequency....

The curriculum 2013 emphasizes learning physics using process skills approach to develop the scientific of students. Based on need analysis obtained that assessment instruments used by teachers is not in accordance with learning. aims this research produce a science for high school instrument was developed restricted direct current circuit subject. method development research. thirty- five test items written form multiple choice. Science indicatorsinclude observing, formulating hypothesis,...

Abstract The study of the MgH 2 double-catalyzed Ni and SiC based storage system has been done. objective this is to improve hydrogen desorption temperature capacity. material preparation was done through mechanical alloying technique. In method, milling carried out within 5 hours, 10 hours 15 with ratio ball powder speed 350 rpm catalyst insertion by wt% SiC. Results from XRD measurements revealed that sample successfully reduced a nanocrystal scale. phase emerging observation as main...

Magnesium (Mg) is regarded as one of the candidate material for absorbing hydrogen, because theoretically, has ability to absorb hydrogen in large quantities (7.6 wt%). However, Mg shortage, namely its kinetic reaction very slow, it takes time at least 60 minutes with high operating temperatures (300-400°C). The aim this study improve desorption temperature Mg-based storage material. In work, we used nano-nickel (Ni) catalyst MgH2 and obtained by reactive mechanical milling method. duration...

Hydrogen storage in metal hydrides, compared to conventional methods, is regarded as one of the best solutions due higher volumetric capacity and safety. Magnesium magnesium-based alloys are promising candidates for hydrogen storage. The magnesium form MgH2 amounts 7.6 wt%. Unfortunately, Mg has a high thermodynamic stability therefore, relatively slow desorption kinetics, which major drawbacks application material. Various techniques developed improve sorption characteristics by...

Among the metal hydrides, magnesium has theoretically highest weight capacity for hydrogen storage (7.6wt.%), lightweight and a reasonably low cost. However, high working temperature (<300°C), slow reaction kinetics (need more than 1 hour to produce 5 wt% of hydrogen) difficult activation limit practical application Mg-based hydrides. In order improve their performance, MgH 2 was catalyzed with Ni nanoparticles which reactively milled under atmosphere. Phase identification microstructure...

La-doped ZnO (with 0, 1, 5 and 7 wt.% La) thin films were deposited on Si substrates by ultrasonic spray pyrolysis, using frequency of 1.7MHz, heated at 450?C for 15min. The effect La addition the structural optical properties was analysed. X-ray diffraction patterns confirmed that all prepared had a polycrystalline hexagonal wurtzite structure with highly preferred texture in (002) plane case containing La. Atomic force microscopy analyses surface morphology is affected root mean square...

Magnesium (Mg) as one of the potential candidate material for absorbing hydrogen, because theoretically has ability to absorb large quantities hydrogen 7,6 wt%. However, kinetic reaction Mg is very slow. Its takes 60 minutes adsorp with operating temperature (adsorb/desorb) high 350°C. Therefore, in this study discusses storage materials based on MgH2-SiO2. The purpose improve desorption system MgH2. main MgH2 combined inserting SiO2 catalyst was successfully extracted from quartz sand...

We have investigated the effect of thickness on microwave absorbing properties barium ferrite (BaFe12O19) powder prepared by a solid-state reaction method with sintering temperature 1100°C for 5 hours. The sample was analyzed using XRD, SEM, PERMAGRAPH, and vector network analyzer (VNA). were measured at frequency in range 8.2 – 12.4 GHz. Permeability, permittivity reflection loss (RL) calculated given based transmit line theory. results show optimal RL −23.07 dB can be obtained 10.72 GHz...

Abstract Anticipating the global trends of biodegradable plastic and its application to packaging industries, this study was conducted prepare a seaweed (Eucheuma cottonii) based blended with polysaccharides derived from various tropical fruit seeds which are abundantly available in Indonesia such as avocado, jack fruits durian. The objective is an environmentally friendly edible bioplastic. were obtained through extraction bioplastic blends heated at 80°C for 30 minutes. characterization...