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Rekayasa ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 416-420
Author(s):  
Fandi Angga Prasetya ◽  
Niswatun Faria ◽  
Tri Eddy Susanto ◽  
Rizqi Ni’amul Firdaus ◽  
Yaski Achmad Zamzami

Sand casting waste has the potential to replace quartz sand in mortar manufacture because it contains high silica. This study uses sand casting waste from the steel industry in Gresik, Indonesia to observe how it affects the quality of the mortar. Initial characterization were carried out to determine the properties of the material, including; magnetic test which results are not attracted by magnets, moisture content test with a value of 0.328%, XRD test to determine the crystallinity content which results contain 99.52% Silica Quartz, and XRF test to determine the content of the compound in which results are 81.25% Silica dominant. Then observations were made by making mortar with the replacement of quartz sand by sand casting with variations of 0% wt, 25% wt, 50% wt, and 100% wt and then tested its compressive strength at 3 days, 7 days, and 28 days. Based on the research that has been done, the optimum result using sand casting is at 25% wt with a compressive strength of 251.15 kgf/cm2 at 28 days of age which is higher than the standard.


2021 ◽  
Author(s):  
Salima Chakroun ◽  
Haitham Elleuch ◽  
Dalel Sghaier ◽  
Mohamed Gaied

Abstract The present work is concerned the Acid Black 194 dye adsorption by Two smectitic clays (BJ and AJ) aged upper Eocene were sampled from Atlas Central of Tunisia in Kairouan region. Technical characterization was carried out using calcimetry and X-ray diffraction. The activation studies of clays by HCl/ Na2CO3 have been conducted to improve their physicochemical properties. The optimum result of the surface area after acid activation (aa) was 398 m2/g for BJ aa and AJ aa, after basic activation (ab) the surface area was 460 m2 /g for BJ ab and 440 m2/g for AJ ab. The characterization by XRD, chemical analysis and SEM observations, were performed before and after optimum activation.Moreover, the raw and activated samples (aa/ab) under the optimum activation conditions were used in the effluent treatment. Adsorption tests were made by batch system at 25 °C in different pH (2-12) and by varying the adsorbent amount (0.025-0.1 g). The best adsorption results were recorded with pH = 11 and amount adsorbent 0.025 g. The raw clay adsorption capacity was slightly better than activated samples. The best yield was given by BJ (94%). Therefore, clay can be used in various applications without any characteristic modification.


2021 ◽  
Vol 7 (4) ◽  
pp. 180
Author(s):  
Aylin Ece Kayabekir

Optimization is a widely used phenomenon in various problems and fields. Because time and resources are very limited in today's world, it can be said that the usage area of the optimization process will be expanded and spread in all areas of life. Although different methods are used in the realization of the optimization process, the performance of metaheuristic algorithms in solving problems has led to an increase in research on these methods. As in other fields, the application examples of these algorithms are diversifying and increasing in the field of structural engineering. In this study, the performance comparison of five different algorithms for the optimum design of an axisymmetric cylindrical wall with a dome is investigated. These algorithms are Jaya (JA), Flower pollination (FPA), teaching-learning-based optimization (TLBO) algorithms and two hybrid versions of these algorithms. ACI 318 regulation was used in reinforced concrete design with a flexibility method-based approach in the analyses. In the analyzes with five different situations of the wall height, some statistical values , and data of analysis numbers were obtained by running the algorithms a large number of times. According to the analysis results, Jaya algorithm is slightly better in terms of the speed of reaching the optimum result, but also all algorithms are quite effective and reliable in solving the problem.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Eman Alzahrani ◽  
Ashwaq T. Alkhudidy

This study examines the importance of utilizing green synthesis using lemon peel for gold nanoparticles over other chemicals since it is environmentally friendly, available, and cheap. Several parameters were optimized to ensure the extraction of the GNPs concentration of lemon peels using HAuCl4 and lemon peel extract having a ratio of 2 : 1. For the optimum result, the ratio used was 2 : 1. The gold nanoparticles fabrication happened in 10 minutes. The initial observation was the color change of the solution. The UV-visibility spectroscopic studies are performed to confirm the result. The experiments are done concurrently to ensure the solution is mixed on the proper ratio. The GNP is also characterized by the different techniques in their sizes and electronic transmission microscopy, essential in extracting gold nanoparticles. Other elements of the composition are removed by the EDAX methods, the FTIR method, and the TEM methods, all of which reveal the real reason behind the required extraction capacity. Most gold nanoparticles show a maximum absorption rate at the peak of 535 to 579 nm. The result obtained from the TEM and the SEM analysis revealed that the grain size is analogized to the average size of 6.67 nm. With a simple synthesis of the price, some processes show that the medically available nanoparticles are necessary. The used method in this paper to fabricate GNPs is cheap, easy, fast, and sustainable and it can be done with ease in any laboratory.


2021 ◽  
Vol 8 (2) ◽  
pp. 41
Author(s):  
Sudjarwo Sudjarwo ◽  
Poedjiarti S ◽  
Angerina N

Borax, in illictic additive substance, is added on certain food product as a e preservative and rubbery. Therefore, the determination of borax in the food product such as meatball is very impotant in view of meatball is a food product often consumed by community. Vis- Spectrophotometric method with curcumine 0.125% as a reagent and glacial acetic acid-sulphuric acid has been used for determination of borax in this research. Curcumin reagent was selected because sensitivity of the method and the reproducibility of the results are affected by quality of the reagent other than rigorous observance of the reaction conditions (temperature, time, reagent quantities). Glacial acetic acid- sulphuric acid was used to create acid condition, so that curcumin and boron form a violetred 2:1 complex called rosocyanin. The optimum result was obtained when 1/. ml solution of 0.125% curcuumin and 1.0 ml concentrated sulphuric acid were added and the absorbance was measured after 70 minutes at 547 nm. The results showed linear regression y = 1.3127x – 0.0994, r = 0.9690 > r table (n = 5) is 0.878 and p = 0.007 (p< 0.01) and Vxo is was 15,53%. The detection limit and quantitation limit were 9.7.10-4 ppm and 2.94. 10-3 ppm respectively. The recovery and coefficient variation were 47.56%±3,92%. Determination of borax in three meatball samples which were taken from a location in Surabaya showed that the sample contained borax with concentration of 0.0205; 0.0151; 0.0210 (% w/w) respectively.


2021 ◽  
Author(s):  
A. White ◽  
R. Miller ◽  
E. Bellu ◽  
J. J. Wylde

Abstract Objectives/Scope Selection of "first fill" demulsifiers for new, undeveloped, oil fields has significant limitations, typically relying on data from test work with synthetic emulsion created in a laboratory using highly contaminated drilling samples of crude oil. Additional separation challenges related to offshore production of high viscosity, low API crude oil, from a low temperature reservoir results in a low probability of success in selecting a suitable first fill demulsifier using the traditional bottle test alone. Methods, Procedures, Process To give improved speed of oil/water separation, water quality, interface quality and top oil dehydration, samples of chemical free oil and produced water were used to screen alternative existing products against the base case demulsifier via bottle testing. The emulsions were created using a high shear stirrer to mimic the system conditions of the wells coming online and water droplet size within the emulsion was determined via cross polarizing thermal microscopy. For the purposes of these tests, demulsifier performance was ranked on speed and completeness of separation, interface quality, water quality and grind out (BS&W) characteristics. Results, Observations, Conclusions Several differences were observed between the initial and subsequent test work. The low shear emulsion created in the early work was found to be very unstable, separating easily with no residual emulsion in the crude oil. The emulsion created under high shear conditions gave a much closer correlation in terms of water droplet distribution to that measured during the field test and resulted in a much more stable emulsion that was more difficult to separate and typically left unresolved emulsion in the oil after the bulk of the water had separated. Whilst the original demulsifier recommendation was still able to facilitate separation it was found that it was no longer the optimum product, with other previously disregarded products able to provide a higher level of performance on the high shear emulsion. Novel/Additive Information This paper demonstrates that a higher level of performance was achieved with an enhanced screening process, namely through high shear stirring and confirmation of water droplet size within the emulsion. When added to the standard bottle testing conditions, the development of demulsifiers can better ensure an optimum result, fit for purpose for the application.


2021 ◽  
Vol 5 (1) ◽  
pp. 18
Author(s):  
Dimitra Kosmidi ◽  
Chrysa Panagiotopoulou ◽  
Panagiotis Angelopoulos ◽  
Maria Taxiarchou

Kaolin is an industrial mineral used in a wide variety of applications due to its crystalline structure, mineral and elemental composition. After kaolin undergoes heat treatment in a specific temperature range, metakaolin, which exhibits a strong pozzolanic reaction, is formed. This paper examines the effects of different kaolin qualities on the thermal activation process of metakaolin production. The qualities of kaolin depend on the impurities they contain, such as mica, feldspar and quartz. In this study, four different samples of kaolin are investigated. Each sample was heat treated in a lab-scale rotary kiln in order to study the chemical, structural and morphological changes that occurred and their influence on pozzolanic activity. The parameters being considered in the experimental process were the temperature and the duration of the treatment. Thus, the calcination process for each of the four kaolin types was carried out at 600, 650 and 700 °C for 3 h. The occurred changes were monitored using XRD, FTIR and DTA analysis. Additionally, the reactivity of all thermally treated samples was evaluated based on the Chapelle test. The results showed that the fewer the impurities, the easier the transformation of the material to metakaolin. The optimum result was the metakaolin, which originated from the purest quality of kaolin and was comparable to the commercial product. Finally, the pozzolanic activity of the thermally activated samples also depended on the purity of the kaolin.


2021 ◽  
Vol 1192 (1) ◽  
pp. 012016
Author(s):  
M I M Zin ◽  
N S Shamsudin ◽  
F Ali ◽  
W M F W Nawawi

Abstract This project aimed to study the reinforcement effect of fungal chitin at different loading on chitin/PLA composite. The chitin nanofibers were extracted from three mushroom species (oyster mushroom Pleurotus ostreatus, shiitake mushroom Lentinula edodes, enoki mushroom Flammulina velutipes) and used as a reinforcement element in PLA. The chitin/PLA composite was fabricated using a solvent-casting method followed by the hot-compress molding method. In the solvent-casting method, the chitin nanofibers were dispersed in PLA/chloroform mixture and the mixture was left for solvent evaporation. The solvent-free chitin/PLA thin film was then filled in dog bone mold before proceeded with hot-compress molding at 190°C and 70 bar. The samples with different chitin loading were tested with tensile test to study the mechanical performance of nanocomposite. The chitin/PLA composite from oyster mushroom shows the optimum result (σ= 43 MPa, E= 12 MPa) at 5% chitin loading. The increment of the chitin loading leads to a decrease in both strength and strain. However, for the samples from enoki and shitake mushrooms, the optimum chitin loading is 10% with 55 MPa and 56 MPa tensile strength, respectively. This study suggests the potential of fungal chitin as reinforcement in PLA.


2021 ◽  
Vol 896 (1) ◽  
pp. 012025
Author(s):  
B P Samadikun ◽  
W Oktiawan ◽  
Junaidi ◽  
A K Rais ◽  
T A Taqiyya ◽  
...  

Abstract Indonesia is one of the countries that still have to deal with waste problems. In reducing waste, the government has made a series of efforts to reduce waste, especially wastewater. There are many kinds of wastewater. One of them is laundry wastewater. This research aims to estimate the dangerous substance in laundry wastewater and how to treat it. The method using some variables like Al-Al, Al-Fe, Fe-Fe, and Fe-Al and the voltage is changing from 20 V, 30 V, 40 V, and 60 V. The research shows that the most optimum result of laundry wastewater treatment was using Al-Fe electrode plate 60 V. The result that the phosphate concentration decreased by 6.56 mg/l from 9.58 mg/l to 3.01 mg/l and obtained phosphate removal efficiency of 68.56%. The most optimum results for the removal of phosphate levels contained in the 60 V voltage.


2021 ◽  
Vol 926 (1) ◽  
pp. 012021
Author(s):  
F I P Sari ◽  
B S Wibowo ◽  
R Irwanto ◽  
S Sarfita

Abstract Bioethanol has been known as one of the alternative energy sources to replace petroleum. The use of bioethanol as a fuel has requirements that must meet fuel standards or refer to as Fuel Grade Ethanol (FGE). Further refining is required to achieve this qualification. The distillation method is the most commonly used method in bioethanol purification, but the results are less than optimal and sometimes the ethanol produced will be more volatile. Distillation-adsorption method using clay-based materials was developed to solve this problem. The purpose of this study is to purify bioethanol and determine the physical characteristics of the bioethanol produced and to assess the % purity of bioethanol from adsorption distillation. Characterization of activated natural kaolin as adsorbent, determination of the optimum contact time in the distillation-adsorption process, determination of the optimum mass of kaolin used and determination of the physical properties of bioethanol have been carried out. The results showed that 1 hour adsorption distillation could increase the ethanol content from 7.9% to 29.33%. In the study of the effect of the mass of kaolin, the optimum result was 25.25% ethanol using a mass of 5 grams. physical properties test of bioethanol obtained a density of 0.8211 gr/cm3 and a viscosity of 2.096 cps.


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