Sintesis Nanopartikel Nikel Hidroksida Dari Logam Nikel Secara Elektrokimia Menggunakan Tegangan Tinggi

Nickel hydroxide nanoparticles have been synthesized by electrochemical method at high voltage. The metal of nickel was electrolyzed in demineralized water with addition natrium sitrat. The presence sodium citrate, was studied at various concentration, i.e. 0.1; 0.2; 0.3; 0.4 and 0.5 M. The electrolysis process carried out at 10; 15; 20; 25; 35; 45; 50 and 55 V. The best result obtained with the addition of sodium citrate 0.3 M at 55 V because product nickel hydroxide nanoparticles not easy agglomeration. Identification of the product show characteristic of β-Ni(OH)2. It was proven by the presence of O-H groups at λmax UV-Vis = 387 nm and the absorbance peak of FTIR at 3458-3048 cm-1. Futhermore, the XRD result indicates that the nanoparticles obtained is Ni(OH)2. Nanoparticles size obtained at range 20-70 nm with spherical morphology using TEM. The effect of surfactant, CTAB (Cetyl Trimethyl Amonium Bromide), was also studied in this research. It was investigated at concentration of sodium citrate 0.3 M and various voltage from 15; 25; 35; 45 to 55 V. The best product can be achieved at 55 V. The peak of O-H groups appeared at 2750-3750 cm-1. Difractogram of the product with and without surfactant gives the same pattern. The size of nanoparticles was 200 nm with spherical morphology. The nanoparticles was produced without surfactant is more stable and there is no agglomerasion. ========================================================================================= Nanopartikel nikel hidroksida (Ni(OH)2) telah disintesis secara elektrokimia menggunakan tegangan tinggi. Proses sintesis dilakukan melalui elektrolisis logam nikel dalam larutan aquademin dengan penambahan natrium sitrat pada tegangan tinggi. Pengaruh penambahan natrium sitrat dipelajari pada variasi konsentrasi 0,1; 0,2; 0,3; 0,4; 0,5 M. Proses elektrolisis dilakukan pada variasi tegangan 10; 15; 20; 25; 35; 45; 50 dan 55 V. Hasil terbaik diperoleh pada penambahan natrium sitrat 0,3 M dengan tegangan 55 V, hal ini karena nanopartikel nikel hidroksida yang dihasilkan tidak mudah mengalami penggumpalan. Identifikasi hasil yang diperoleh menunjukkan karakteristik dari β-Ni(OH)2. Analisa tersebut dibuktikan dengan adanya gugus O-H, yaitu pada max UV-Vis = 387 nm dan puncak serapan FTIR pada daerah 3458-3048 cm-1 . Analisa XRD menunjukkan bahwa hasil yang diperoleh adalah Ni(OH)2. Ukuran nanopartikel dianalisa menggunakan TEM dan diperoleh berkisar antara 20-70 nm dengan morfologi berbentuk bulat. Pengaruh surfaktan CTAB (Cetyl Trimethyl Ammonium Bromide) dan sonikasi pada sintesis Ni(OH)2 juga telah dipelajari pada penelitian ini. Studi tersebut dilakukan pada konsentrasi natrium sitrat 0,3 M dengan variasi tegangan dari 15; 25; 35; 45 hingga 55 V. Produk sintesis dengan adanya surfaktan diperoleh paling baik pada tegangan 55 V. Puncak serapan gugus O-H dari produk sintesis terjadi pada daerah 2750-3750 cm-1 . Difraktogram produk sintesis tanpa dan dengan penambahan surfaktan menunjukkan hasil yang sama. Ukuran nanopartikel diperoleh sekitar 200 nm dengan morfologi bulat. Nanopartikel Ni(OH)2 yang dihasilkan tanpa adanya surfaktan lebih stabil dan tidak mudah mengalami agglomerasi (penggumpalan)

Design of Table Chair Flexibility Products Using Antopometry Methods to Minimize Land Use

In an increasingly advanced era, allproperty or home furniture is required to have arenewable innovation and efficiency. This is becauseproperty or home furniture currently has a very largemass or size. Large furniture sizes such as chairs andtables have an average area of 500cm2. Almost 90% ofIndonesian people have tables and chairs as the contentsof their household furniture. Not only functioned athome, in restaurants, cafes, malls, offices, in parks andall places where if there is interaction between humans,there must be chairs and tables as places for interaction.But sometimes the owners of chairs and tables oftencomplain about the size of the tables and chairs, so they need a large enough area to place these two items. Theproblem that exists in society today is the narrowing ofempty land in one place. Sometimes there is homefurniture that is not ergonomic, such as a chair that istoo high, a table that is too low and so on. By using thisanthopometric method, the measurements obtainedinclude a chair along the 95th percentile 25 cm, chairlength 33 cm 95th percentile, table length 68 cm 5thpercentile, chair height 39 cm 5th percentile, table height69 cm 5th percentile, and finally lower surface height. atable of 54 cm on the 95th percentile, and it is hoped thatthe manufacture of a chair flexibility table productdesign can overcome all the problems of land limitationsthat exist in today's society

Improving The Heat Value of Biobriquettes Made From Rice Husk and Cabbage with The Addition of Palm Oil

Biobriquette can be used as an alternative fuel because it is made from inexpensive materials and uses simple technology, and it is expected to help overcome the energy (fossil) crisis. The problem is determining how to boost the calorific value of briquettes made from waste biomass materials. Cabbage contains approximately 18.80% fiber, so there is cellulose content that can be processed into high-value products such as briquettes, and using rice husks as fuel can increase the calorific value. The goal of this study is to determine the best calorific value of biobriquettes by varying the method of adding coconut oil and the composition of rice husks and cabbage. The stages of making cabbage and rice husk biobriquettes are raw material preparation, carbonization, adhesive manufacture, briquetting, and quality testing. The variables used are variations in the composition of rice husks: cabbage in ratios of 40:60, 50:50, 60:40, 70:30, and 80:20, as well as the variable method of giving palm oil by mixing with ingredients and dyeing after it becomes briquettes. According to the findings of this study, the best biobriquette mixing ratio resulted in the highest calorific value found in a mixture of 40% rice husk and 60% cabbage with the method of adding palm oil by dipping, with a calorific value of 6.283 kcal/g, a combustion rate of 0.0616 g/minute, and the duration of the flame is 60.26 minutes

Potential dyes from edible mushrooms for human health

Colors (dyes or pigments) have been applied in many sectors of human life, such as textile industries, food, and medicine, thus becoming a crucial factor that cannot be neglected. The origin of color can be obtained from nature or synthetic sources. Nowadays, synthetic colors are used more often than natural ones. However, the use of synthetic colors needs to be considered as they have the potential to cause health problems and contribute to waste issues. On the other hand, natural color sources are dominated by the plant kingdom, such as mushrooms, which are advantageous for health, more economical, and environmentally friendly. The method used in this review was to explore the literatures that discus dyes or pigments from macro fungi or mushrooms. Furthermore, the dyes or pigments were classified from edible or medicinal mushroom, then dyes or pigments were categorized based on their chemical structure. Mushrooms of various genera and species produce different colors that belong to constituent melanin, terpenoids, carotenoids, quinone, styrylpyrone, azulene, and pteridine. Therefore, natural colors are very promising for application in human health, due to their active compounds potency as anticancer, anti-HIV, antioxidant, and antimicrobial. In addition, pigments containing azulene structures from mushrooms are developed as solar cells and UV protection

Implementation of Material Requirement Planning (MRP) in Controlling Raw Materials for Shoes Products at PT.XYZ

PT. XYZ is an industry in East Java that produces products made from animal skins as raw materials. The product produced by this industry is loafers. So far, this industry has had problems with leather raw materials which often experience excess supply requiring high investment, although at certain times they also experience shortages which result in not fulfilling consumer demand. MRP is a system specifically designed to ensure the availability of materials, items or components when needed to meet production schedules and ensure the availability of finished products for consumers in situations of surging demand. MRP can answer exactly what material, how much, and when (what, how much and when) is needed so that the production process can run according to schedule. The results of this study indicate that the Material Requirement Planning (MRP) method has a total raw material inventory control cost of Rp. 189,646,600 and by using the company's method, the raw material control value is Rp. 323,325,500 Savings in raw material control costs that can be obtained by applying the MRP method are Rp. 17,416,700 or about 0.94%

BIODIESEL FROM NYAMPLUNG (CALOPHYLLUM INOPHYLLUM) SEED OIL WITH A TRANSESTERIFICATION PROCESS USING A CONTINOUS FLOW SYSTEM IN THE REACTOR

Biodiesel production from calophyllum inophyllum be obtained via esterification and transesterification,  using two continuous reactors with catalyst NaOH at a concentration (0.4 ;0.6,0.8; 1) wt%,  calophyllum inophyllum seed oil and reaction temperature (40, 50,60)oC. This research was to determine the effect of catalyst amount and reaction temperature on transesterification of calophyllum inophyllum seed toward yield Fatty Acid Methyl Ester . The last step is analysis  yield of  Fatty Acid Methyl Ester with Gas Chromatography (GC). The highest yield is obtained on the amount of 1% NaOH catalyst and at a temperature of 60oC with   yield of  87.036%

BIODIESEL FROM NYAMPLUNG (CALOPHYLLUM INOPHYLLUM) SEED OIL WITH A TRANSESTERIFICATION PROCESS USING A CONTINOUS FLOW SYSTEM IN THE REACTOR

Biodiesel production from calophyllum inophyllum be obtained via esterification and transesterification,  using two continuous reactors with catalyst NaOH at a concentration (0.4 ;0.6,0.8; 1) wt%,  calophyllum inophyllum seed oil and reaction temperature (40, 50,60)oC. This research was to determine the effect of catalyst amount and reaction temperature on transesterification of calophyllum inophyllum seed toward yield Fatty Acid Methyl Ester . The last step is analysis  yield of  Fatty Acid Methyl Ester with Gas Chromatography (GC). The highest yield is obtained on the amount of 1% NaOH catalyst and at a temperature of 60oC with   yield of  87.036%

THE USAGE OF EIGEN VALUE AND VECTOR TO DETERMINE THE PRIORITY OF FACTORS IN INDONESIAN BATIK PURCHASE

Modern batik is one of the fashion trends that are always in demand by the market. When choosing batik, many factors are considered including the type of batik (writing or stamp), fabric material, motif, quality, color, price, and design (model). Of all these factors, the most influencing people in buying batik are prices, motifs, colors, and designs (models). This study used Eigen Values and Vectors to determine the priority of factors that influence batik purchases. To find out the factors that are most in demand by the market among the four factors (price, motif, color, and design), the study was conducted by providing a questionnaire containing a comparison between one factor and another. Respondents write down which factors to choose and give weight to each choice. The next step is to calculate the eigen values and make a decision based on the normalized eigen vector

An Integrated In Silico and In Vitro Assays of Dipeptidyl Peptidase-4 and α-Glucosidase Inhibition by Stellasterol from Ganoderma australe

Background: Ganoderma fungus is rich in terpenoids. These compounds are known for their anti-hyperglycemic activities. However, the study of terpenoids as the secondary metabolite from Ganoderma as a dipeptidyl peptidase-4 (DPP-4) inhibitor remains unexplored. In addition, we examined the α-glucosidase inhibition activity. Objective: This study aimed to isolate the major terpenoid from non-laccate Ganoderma and examined its inhibitor activity on DPP-4 and α-glucosidase enzymes, and its interaction. Methods: The compound was isolated using column chromatography from Ganoderma australe. The structure of the isolated compound was confirmed by 1H and 13C nuclear magnetic resonance spectroscopy, while the inhibitory activity was evaluated using an enzymatic assay. The interaction of the isolated compound with DPP-4 and α-glucosidase enzymes was investigated using an in silico study. Results: The isolated compound was identified as stellasterol; IC50 values for DPP-4 and α-glucosidase inhibitor were 427.39 µM and 314.54 µM, respectively. This study revealed that the inhibitory effect of stellasterol on DPP-4 enzyme is through hydrophobic interaction, while the α-glucosidase enzyme is due to the interaction with six amino acids of the enzyme. Conclusion: Stellasterol is the major component of the steroid from G. australe. Enzyme inhibitory assay and in silico study suggest that stellasterol may contribute antidiabetic activity with a mechanism closer to acarbose rather than to sitagliptin

Manufacture of Solar Panel with 300W Inverter for Household Electricity Needs

Solar panels are semiconductor elements that can convert solar energy into electrical energy. This Research on Solar Power Plants (PLTS) assemble with materials such as solar panels, 3000 W inverters, batteries, relays and control chargers, after that the load calculations are carried out, then implementation and testing is carried out. This research also aims as a renewable electric power in the future. From the results of the PLTS load test carried out at the researcher's house, the highest load was 405.32 watts, while the highest load test results used PLN electricity, which was 267.06 watts. So it can be said that this research is successful in meeting the electricity needs of household scale