Pengaruh Perendaman Larutan KOH Dan NaOH Terhadap Kualitas Alginat Rumput Laut Sargassum Polycycstum C.A. Agardh

Sargassum polycystum seaweed is a type of brown algae that contains alginate. Alginate from S. polycystum did not optimally and alginate has an importnat role from a variety of industries. Alginate ekstraction obtained by submersion wes using NaOH and KOH solvent, then continued using Na2CO3 solvent. The purpose of this research was to determine the effect of immersion with KOH and NaOH with concentration 0,3%, 0,5% and 0,7% solution to the quality alginate from brown seaweed S. polycystum. Experimental design used was Rancangan Acak Lengkap (RAL). The results showed that aging of the KOH solution has a lower water content and higher viscosity than NaOH solution. The concentration of the solution used also affects the yield, moisture content, ash content and viscosity alginate S. polycystum. The higher concentration of the solution then the yield, moisture content and lower ash content, while viscosity alginate increased. The best results obtained in the treatment with a solution of KOH concentration of 0.7%

Effects of Electrical Current, pH, and Electrolyte Addition on Hydrogen Production by Water Electrolysis

Hydrogen is viewed as one of the most potential energy source in the future. One of methods to produce hydrogen is by electrolysis of water. Variables that was applied in this work were electrical current (0.5 A and 0.9 A), pH (13.47 and 13.69), and electrolyte additions (namely NaOH and KOH) with processing times for 30 minutes. The result of this work were variations of electrical current at 0.9 A, pH at 13.69 and electrolyte NaOH is at 278.394 L with volume rate 154.663 mL/s produced most amount of hydrogen, whereas condition of 0.5 A, pH 13.47 and electrolyte KOH was 75.122 L with volume rate of 41.734 mL/s yielded the lowest amount

Effect of electrolytes on the electrochemical performance of nickel cobaltite–titania nanotubes composites as supercapacitive materials

The effects of electrolytes on the electrochemical performance of nickel cobaltite–titania nanotubes composites as electrochemical capacitors were evaluated. Four types of electrolytes were selected to assess their effects on the prepared composites, namely aqueous electrolytes of 1.0 M KCl, 1.0 M HCl, 1.0 M KOH; and an organic electrolyte, 0.27 M tetra-n-butylammonium tetrafluoroborate (TBATFB) ionic liquid salt in acetonitrile. The composites performed better in 1.0 M HCl and 1.0 M KOH, than in 1.0 M KCl and 0.27 M TBATFB, which suggested that aqueous electrolytes with non-neutral pH would improve the specific areal capacitance values of the composites. Results have shown optimal performance in 1.0 KOH, which endowed the composite with excellent rate capability up to 200 mV s−1. Cyclic voltammogram of the composite analysed in 1.0 M KOH produced a leaf-shaped like profile, with higher current densities towards more positive potentials. Charge–discharge analyses in 1.0 M KOH has shown that the composite possessed specific areal capacitance of up to 214.76 µF cm−2 when it was evaluated at the current density of 350 µA cm−2. The composite also retained up to 97.79% of its specific areal capacitance when current density was increased to 400 µA cm−2. This material has demonstrated potential application for electrochemical capacitors through its facile fabrication technique

Pemanfaatan Limbah Abu Terbang (Fly Ash) Batu Bara sebagai Bahan Campuran Beton Geopolimer

Fly ash can be used in the manufacture of concrete geopolimer. The replacement of the use of cement with fly ash can reduce the cost of manufacture of concrete and can reduce global warming posed from the production of cement. This research aims to know the influence of the use of fly ash, variations in concentrations of KOH and Na2SiO3/KOH ratio relationships against the concrete compressive strength of concrete geopolimer and test the level of immobilisasi of heavy metals contained in concrete geopolimer. Geopolimer synthesized from fly ash using a mixed solution of KOH and Na2SiO3. The solution is prepared the day before use. Initially prepared a solution of KOH with concentrations of 8 M, 10 M, 12 M, 15 M and Na2SiO3/KOH ratio 0.8; 1.2; 1.6; 2.0. These materials are mixed while stirring and inserted into the mold cylinder diameter 4 cm height 8 cm. Batter the already hardened issued and in the dry at a temperature of 80оC for 24 hours, then the samples were dried at room temperature for 21 days, then performed a test of strong press, porosity and heavy metal content. Test result showed a strong increase with added press Molarity KOH and Na2SiO3/KOH ratio, strongly press the highest 30.26 MPa produced on the molar ratio of 14 m and Na2SiO3 KOH/KOH 2.0. Instead, the porosity obtained decreased with increasing molar NaOH and KOH Na2SiO3/ratio. The lowest porosity 6.49% obtained in Molarity KOH 14 and Na2SiO3/KOH ratio is 2.0. Concrete geopolimer able to immobilize heavy metals found in the fly ash with either. Metal Pb reduced from 8,954 mg/L be 0.66 mg/L, the metal Cr reduced from 6,978 mg/L be 2.096 mg/L, Cu Metal reduced from 12.355 mg/L be 7.350 mg/l. so as to meet the Government Regulation Number 101 by 2014

Nash Equilibria, collusion in games and the coevolutionary particle swarm algorithm

In recent work, we presented a deterministic algorithm to investigate collusion between players in a game where the players’ payoff functions are subject to a variational inequality describing the equilibrium of a transportation system. In investigating the potential for collusion between players, the diagonalization algorithm returned a local optimum. In this paper, we apply a coevolutionary particle swarm optimization (PSO) algorithm developed in earlier research in an attempt to return the global maximum. A numerical experiment is used to verify the performance of the algorithm in overcoming local optimum

Shifting Core and Slipping Foundation: An Uncertain Future of Landscape Architecture in European Universities

Faced with the dual and often conflicting necessity to be scientific and design practices the discipline of landscape architecture today is challenged to re-examine its core and intellectual foundation. There is a growing trend toward design as reflective practice. The discipline is maturing and needs autonomous theories and methods. Global and social externalities favor attention to landscape and landscape-based design. Landscape is not only an integrative and evolving concept and practice but also a trans-disciplinary cultural concern. Under such circumstances the core of landscape architecture is shifting and its intellectual foundation is questione

Analisis Energi Dispersif dan Uji Kapasitansi Karbon Aktif Sabut Pinang (Areca Catechu L) Sebagai Elektroda Kapasitor

Tanaman pinang termasuk jenis palma yang belum banyak dikembangkan pemanfaatannya saat ini pemanfaatannya hanya untuk bahan makanan, pewarna kain dan obat-obatan. Pada tanaman pinang terdapat sabut pinang yang memiliki senyawa selulosa yang cukup besar mencapai 40% menjadikan sabut pinang sebagai karbon aktif dalam pembuatan elektroda kapasitor dengan bantuan aktivasi fisika dan kimia. Tujuan penelitian ini adalah untuk mengetahui pengaruh variasi konsentrasi aktivator terhadap karakterisasi karbon aktif dan untuk mengetahui nilai kapasitansi elektroda kapasitor. Penelitian ini menggunakan KOH dengan konsentrasi 1 M, 3 M, 5 M dengan tiga karekterisasi yaitu EDX, UV-Vis dan Kapasitansi Meter. Hasil penelitian menunjukkan karbon aktif yang paling banyak terdapat pada pada sampel aktivasi fisika sebesar 38,47 % : KOH 5 M 36,64 % : KOH 3 M 26,41 % : KOH 1 M 20,13 % . Luas permukaan karbon aktif aktivasi fisika 13,01 g : KOH 1 M 14,51 g, : KOH 3 M 14,52 g dan KOH 5 M 14,53 g. Luas permukaan karbon aktif mempengaruhi besar nilai kapasitansi, 0,93F, 1,19F, 1,81 F dan 2,00F