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Process Parameter Optimization of 3D-Printer Machine Using Response Surface Method for Printing Hydroxyapatite/Collagen Composite Slurry
No full textNowadays, various 3D-Printer technologies are commercially available. However, those printers could only be used for a certain material provided by the printer manufacturers. For new material, the commercial printer could not be employed directly and needs to be modified and its printing parameter has to be optimized to fit the property of the new material. This paper aimed to find the optimum parameters (print speed and layer height) based on printability material. The new material that would be developed was a composite of bioceramic powder (hydroxyapatite) and polymer (collagen) in the form of slurry with ratios of 99.84% (w/v) and 0.16% (w/v). While the printer was a commercial 3D-Printer machine with modification on its cartridge container and bracket. The printing parameters were layer height (0.65, 1.0, 1.35 mm) and print speed (14.4, 25, 35.6 mm/min). Optimization of the printing parameter used Response Surface Method (RSM) with 13 sets of specimens. Test specimens for defining printable material were printed in the form of line shape and a rectangular shape for case study. Printability as a responding of the optimum parameter setting was defined on the basis of 5%-maximum dimension error of the printed specimen compared to the 3D-CAD data. Data obtained was analyzed using ANOVA. The results show that the optimum setup printing parameter were 10.009 mm/min for print speed and 0.505 mm for layer height, respectively with the error dimension obtained from the experiment was 0.013 mm2 (0.59%) lower than that of the permitted error of 5% (0.125 mm2)
The optimization of oil extraction by surfactant-assisted aqueous extraction process of rice bran (Oryza sativa L.) using Box-Behnken design
No full textSurfactant-assisted aqueous extraction process (SAAEP) is used as an environmentally friendly alternative method for oil extraction. Rice (Oryza sativa L.) is one of the most widely produced and consumed foods, and it produces bran as a by-product. Therefore, this study aims to determine the optimum conditions for SAAEP from rice bran. The response surface methodology (RSM) technique was used to determine the optimum conditions. Furthermore, the Box-Behnken design (BBD) was selected as the study design with three factors and three levels. The independent variables used were surfactant and oil ratio (SOR) (3, 3.5, and 4), ultrasonication amplitude (60, 70, and 80), and ultrasonication contact time (15, 20, and 25 mins. Meanwhile, the dependent variable used was oil content. The extraction was carried out based on SAEEP. Also, the rice bran used was the IR 32 SR variety which passed the stabilization stage with a moisture content of 4.25, extracted oil of 20.64, and 2.04 meqO2/kg FFA levels. The optimal point was predicted to produce an extracted oil of 19.326. Furthermore, the prediction results were evaluated by experimental extraction at the optimal level. The results showed an extracted oil of 18.52±0.04, which is a difference of about 0.81 from the predicted values. It was concluded that the rice bran oil content can be successfully optimized using the RSM technique. Therefore, the optimum conditions for extracting rice bran oil are within the specified range of factors. © 2023 The Authors
Effect of heat treatment on antioxidant and antibacterial activity of Kaempferia galanga L. extract
No full textKaempferia galanga L. is a rhizome plant that is rich in health benefits, it can be processed into a herbal drink by heating. Meanwhile, heating is carried out to kill certain pathogenic bacteria present in a product with a minimum loss of nutrients and to maintain the bioactive compounds. Therefore, this study aimed to evaluate the effect of heating using temperatures at 60°C and 80°C for 10, 20, and 30 mins on the antioxidant and antibacterial activity of K. galanga extract. The extraction process was carried out using the sonication method with a frequency of 35 kHz for 20 mins and a water-solvent ratio of 1:2 (b/v). The extract was heated at 60°C and 80°C for 10, 20, and 30 mins, and then antioxidant and antibacterial activity were analyzed. The results showed that heating at 60°C and 80°C for 10, 20, and 30 mins significantly decreased the antioxidant and antibacterial activity. Furthermore, the heating using a temperature of 60°C for 10 mins can reduce microbial contamination by 3 logs compared to the control sample and still maintain the total phenolic and flavonoid, antioxidant activity, ferric reducing antioxidant power, ferrous ion chelating, and antibacterial activity of K. galanga water extract. © 2023, Rynnye Lyan Resources. All rights reserved
Pengukuran Dosimetri Pasien Tuberculosis pada Instalasi Kedokteran Nuklir RSPAD Gatot Soebroto
No full textKanker merupakan salah satu penyakit yang cukup fatal jika tidak ditangani dengan
baik, terbukti dari data tumor/kanked di Indonesia terjadi peningkatan dari 1,4 orang per 1000
penduduk pada 2013 menjadi 1,79 orang per 1000 penduduk pada 2018. Rumah Sakit Pusat
Angkatan Darat Gatot Soebroto yang memiliki fasilitas Instalasi Kedokteran Nuklir berfungsi
untuk menunjang pengobatan kanker. Fasilitas penunjang yang berada di Instalasi Kedokteran
Nuklir RSPAD Gatot Soebroto mampu untuk mendiagnosa dan mengobati jaringan yang
terinfeksi kanker secara spesifik sekaligus memberikan efek samping yang minimal pada
jaringan sehat disekitarnya.
Kerja praktik di Instalasi Kedokteran Nuklir RSPAD Gatot Soebroto telah
dilaksanakan, dan diharapkan dapat menambah ilmu, pengalaman, serta dapat menerapkan apa
yang sudah dipelajari di kelas selama perkuliahan sebagai dasar untuk yang ingin fokus bekerja
di bidang fisika medis
Exploring Covid-19 Survivor Perception Toward Government’s Policies in Responding to Covid-19
No full textEffective strategies could be generated by understand the problem through system thinking. Besides curing Covid-19, the government needs to formulate good risk communication to their society thus the society could accept the right message and act the right response. Before formulating the good risk communication, it is important to understand the society and their perception toward the pandemic. The understanding of perception is necessary to the balance response between risk and response. The exploration through Causal Loop Diagram (CLD) can show the structure of given system and help to capture a mental model. This study aims to develop CLD model of risk perception toward government attempts in handling Covid-19, so the government can formulate the strategies by proposing suggestion based in risk perception of society
Kalibrasi “Xr Fuse-2” dengan Bruker S8-Lion Sinar X untuk Menunjang Quality Control di PT Solusi Bangun Indonesia
No full textKerja Praktik di PT Solusi Bangun Indonesia Tbk dilakukan dengan tujuan agar
mahasiswa mendapatkan pengalaman bekerja di lapangan, menerapkan ilmu yang
telah dipelajari saat perkuliahan, mengetahui pola kerja dan perilaku kerja
profesional, cekatan menyelesaikan masalah keteknikan sesuai bidangnya, dan
berani menyampaikan gagasan serta inovasi baru di dunia kerja. Kerja Praktik ini
dilakukan selama dua bulan yaitu pada 23 Desember 2022 hingga 23 Februari 2023.
Kerja Praktik dilakukan di Laboratorium Quality Control PT Solusi Bangun
Indonesia, Narogong Plant. Quality Control semen pada laboratorium tersebut
ditangani oleh beberapa laboratorium seperti laboratorium Process Quality Control
(PQC), laboratorium fisika, dan laboratorium kimia. Tugas harian yang
dilaksanakan saat Kerja Praktik berada di bagian laboratorium kimia. Tugas
tersebut berupa pengujian untuk semen dan batubara. Selain tugas harian, diberikan
pula tugas khusus dan tugas tambahan. Tugas tambahan tersebut adalah Tugas
Khusus kalibrasi yang berjudul “Kalibrasi “xrFuse-2” dengan Bruker S8-Lion sinar
X untuk Menunjang Quality Control di PT Solusi Bangun Indonesia”. Proyek
tersebut membuahkan hasil xrFuse 2 yang telah terkalibrasi dan siap digunakan
untuk preparasi sampel semen. Adapun tugas tambahannya berupa membuat
Standard Operating Procedure (SOP) software SPECTRA. Kerja Praktik dapat
diselesaikan dengan baik juga mencapai harapan dan tujuan terlaksananya Kerja
Praktik ini
Association between leptin gene polymorphism and growth traits in Bali cattle
No full textLeptin (LEP) gene produces hormone leptin which is secreted by adipose tissue, and plays an important role in energy balance, regulating feed intake, regulating endocrine function, and immune functions. This study aims to identify molecular markers of LEP gene and its association with growth traits based on SNP in Bali cattle. The blood samples were collected from 16 male and 30 female Bali cattle. The growth data were recorded from 2018 to 2020, consist of body weight and body size. Amplification of leptin gene with polymerase chain reaction (PCR) using pair of primers, Leptin3Forward: 5'- AGCTTGGAAACATGGTGGTC-3' and Leptin3Reverse: 5'-CATGATGCTCCCTGGATTCT-3' with DNA target 898 bp. The SNPs were identified by the direct sequencing technique. Genotypes of the SNPs were identified using sequencing method. Association of LEP genotypes with growth traits was performed using oneway ANOVA. Three DNA polymorphisms of the LEP gene were found, namely g.2913C/T, g.3260T/C, and g.3549G/A. SNP g.2913C/T was significantly associated (P<0,05) with weaning shoulder height (WSH), weaning body length (WBL), weaning chest circumference (WCC), yearling shoulder height (YSH), yearling body length (YBL), and yearling chest circumference (YCC). Meanwhile, SNPs g.3260T/C and g.3549G/A were not associated with the body weight and body size in Bali cattle. In conclusion, the SNP g.2913C/T can be used as molecular marker for body size in weaning and yearling of Bali Cattle. © 2023 Diponegoro University. All rights reserved
Application of Steam Jet Agglomerator to Improve the Properties of Instanised Cocoa Drink Powder Mixed with Maltodextrin, Coconut Sugar and Sucrose
No full textCold cocoa (chocolate) drink is highly in demand in tropical countries, especially in the cocoa-producing regions. Due to a relatively high fat content and a strong structure of cocoa powder particle, the solubility of cocoa powder in a relatively low temperature of water is low. A method that can create easily dissolved powder in relatively low temperature of water is highly desired by cocoa beverage producers. The objective of this study was to investigate the performance of a laboratory-scale steam jet agglomerator that was used to produce instanised cocoa drink powder with a higher solubility. In this study, two experimental variables, namely drying duration and stabiliser/sweetener addition, were used. Three drying durations, namely 4, 6 and 8 h, were applied. Cocoa powder (60) was mixed with maltodextrin (40). For other samples, cocoa powder (55) was mixed with a sweetener (45). Sucrose, coconut sugar and mixture of sucrose and coconut sugar was used as sweeteners. The results showed that the solubility of the cocoa powder mixed with coconut sugar was the highest. All samples exhibited good flowability and cohesiveness. The fineness modulus of the agglomerated samples was higher than that of the raw ingredients. The colour of the cocoa drink powders formulated with maltodextrin had propensity to be the brightest. In addition, samples with maltodextrin exhibited significantly low moisture content. The results presented that steam jet agglomerator has potential to improve the most important quality parameters of the cocoa drink powder. © 2022, The Author(s), under exclusive licence to Society for Sugar Research & Promotion
Alteration of Phenolic and Volatile Compounds of Tea Leaf Extract by Tyrosinase and β -Glucosidase during Preparation of Ready-to-Drink Tea on Farm
No full textBlack tea has a lower antioxidant capacity than other teas, such as green tea, white tea, and oolong tea. Tannase and tyrosinase can be used as a treatment to improve the quality of black tea infusion. Tannase has been reported to be an effective way to enhance antioxidant activity in black tea infusion. Meanwhile, tyrosinase could produce higher theaflavin content than thearubigin. Research about Ready-to-Drink (RTD) black tea preparation with the addition of tannase and tyrosinase to fresh tea leaves before pasteurization has not been reported. This study aimed to find a good combination of tannase (1 mg/ml) and tyrosinase (111; 446; 1785 U/ml) to produce high antioxidant activity of RTD black tea. The results showed that higher tyrosinase concentration decreased the antioxidant activity (DPPH and reducing power), epicatechin (EC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG) content yet increased the theaflavin content and theaflavin (TF)/thearubigin (TR) ratio in the tannase-tyrosinase treated black tea. Still, the highest concentration of tyrosinase (1785 U/ml) in tannase-tyrosinase black tea produces higher antioxidant activities, gallic acid, EC, and EGC content than commercial black tea and tyrosinase without tannase-treated black tea. Thus, the combination of tannase (1 mg/ml) and tyrosinase (1785 U/ml) could be the best treatment to produce high-antioxidant black tea
The optimization of oil extraction by surfactant-assisted aqueous extraction process of rice bran (Oryza sativa L.) using Box-Behnken design
No full textSurfactant-assisted aqueous extraction process (SAAEP) is used as an environmentally friendly alternative method for oil extraction. Rice (Oryza sativa L.) is one of the most widely produced and consumed foods, and it produces bran as a by-product. Therefore, this study aims to determine the optimum conditions for SAAEP from rice bran. The response surface methodology (RSM) technique was used to determine the optimum conditions. Furthermore, the Box-Behnken design (BBD) was selected as the study design with three factors and three levels. The independent variables used were surfactant and oil ratio (SOR) (3, 3.5, and 4), ultrasonication amplitude (60, 70, and 80), and ultrasonication contact time (15, 20, and 25 mins. Meanwhile, the dependent variable used was oil content. The extraction was carried out based on SAEEP. Also, the rice bran used was the IR 32 SR variety which passed the stabilization stage with a moisture content of 4.25, extracted oil of 20.64, and 2.04 meqO2/kg FFA levels. The optimal point was predicted to produce an extracted oil of 19.326. Furthermore, the prediction results were evaluated by experimental extraction at the optimal level. The results showed an extracted oil of 18.52±0.04, which is a difference of about 0.81% from the predicted values. It was concluded that the rice bran oil content can be successfully optimized using the RSM technique. Therefore, the optimum conditions for extracting rice bran oil are within the specified range of factors