fredy kurniawan - Academia.edu (original) (raw)

Papers by fredy kurniawan

THE 4TH INTERNATIONAL CONFERENCE ON MATERIALS AND METALLURGICAL ENGINEERING AND TECHNOLOGY (ICOMMET) 2020, 2021

Gelatine is the result of collagen hydrolysis that can be applied to products from various fields... more Gelatine is the result of collagen hydrolysis that can be applied to products from various fields such as food, industry, and health. Gelatine derived from fish skin, such as Pangasius hypophthalmus (striped catfish) has been developing as an alternative raw material for substituting mammals gelatine based of the ethical and religious perspective. The collagen is the part of skin tissue which structurally affected by the age of animal which can be represented by the body size. Hypothetically, the body size and extraction method will influence the characteristics of gelatine. The aim of the study was to determine the effect of striped catfish body size and extraction on viscosity and gelatine microstructure and it's potential for pharmaceutical purposes. The skins from young and adult size striped catfishes were treated using different extraction based on combination of temperature-acid-base treatment times. Gelatine viscosity were measured with viscometer and it's microstructures were observed using scanning electron microscope (SEM). The results found that the different body size (age) and extraction treatment influences the gelatine viscosity and microstructures. Based on viscosity and SEM analysis, the striped catfish from both body size were potentially pharmaceutical uses as halal material of capsule and microencapsulation for tablet preparation.

Current Research in Nutrition and Food Science Journal, 2021

Fish skin is the potential gelatin source since the increase of the demand for the halal food due... more Fish skin is the potential gelatin source since the increase of the demand for the halal food due to the religious consideration. The yield of gelatin obtained from connective tissue of animal skin greatly affected by the extraction process and age of the animals that used as raw material. Research about the potential of the Pangasius hypophthalmus (striped catfish) skin as halal gelatin source have been developing. However, there was no information about the correlation between the length of striped catfish that representing age with the gelatin content. Here we optimize the gelatin extraction method from striped catfish skin with different length body size (sub adult and adult size) using statistical analysis of Placket Burman Design. We performed preliminary study to determine the variables used in the main study. We used 9 variables in the extraction process and analyzed the p-value of each variable. According to this analysis, three variables with the lowest p-values were selec...

E3S Web of Conferences, 2020

Gelatin of milkfish (Chanos chanos) from Tarakan, North Borneo, Indonesia has been extracted succ... more Gelatin of milkfish (Chanos chanos) from Tarakan, North Borneo, Indonesia has been extracted successfully. The gelatin was extracted from the milkfish bone. In prior to extracting, the bone was cleaned with demineralized water and then dried at room temperature. The extraction process was done in several procedures. The first procedure has immersed the bone in 0.1 M NaOH for 48 hours. After that, it was washed until it reached neutral conditions and continued with immersing it in 0.1 M HCl for 72 hours and then washed it to get the neutral condition. The next procedure is the extraction process. It was using water solvents with a ratio of milkfish bone and water is 1: 3. The extraction process was carried out at 55ºC for 4 hours. The obtained gelatin was characterized. The results showed that moisture content 6.39%; ash content 1.92%; pH 6.1; viscosity 5.39 cP; and color 75 PtCo. This result was proved that the gelatin extraction successful.

Journal of Environmental and Public Health

This research aimed to assess the effectiveness of nanocellulose biofilter (NCB) made from pineap... more This research aimed to assess the effectiveness of nanocellulose biofilter (NCB) made from pineapple peel waste to reduce the number of microbes in water. Further processing of cellulose from nata de pina into nano size was proposed, then transformed into a filter membrane. Three types of NCB were developed: bacterial cellulose acetate membrane, bacterial cellulose acetate membrane with TiO2 treatment, and bacterial cellulose acetate membrane with TiO2 and graphite nanoplatelet treatment. These NCBs were used to filter microbes in several water sources in Padang City, West Sumatra Province. The filtering process was carried out using a filter holder where the NCB had been installed. The number of microbes contained in the water, including E. Coli, was determined before and after filtering. As a result, all NCBs reduced the total microbes in water by about 50%. Furthermore, when applied to water pollutant bacteria, E. Coli, all prepared NCBs reduced them by more than 90%. The effecti...

Photonic Sensors, 2022

A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tap... more A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tapered plastic optical fiber (POF) coated with graphene and multi-walled carbon nanotubes. The coating material was deposited onto a tapered POF with a taper waist diameter and a taper length of 0.45 mm and 1 cm, respectively. The addition of the coating material was used to increase the sensitivity and selectivity coefficient of the tapered POF toward the lard substance. The sensing mechanism is based on a simultaneous interaction of lard substance and an evanescent wave of tapered POF with the coating layers. The results showed that graphene coating on the tapered POF increased the selectivity coefficient of the tapered POF towards lard substance from 33.54 to 324.19, and it gave a sensitivity of 0.427 dBm/%. In comparison, multi-walled carbon nanotubes coating increased the selectivity coefficient to 71.65 and increased its sensitivity to 1.189dBm/%. Thus, the proposed configuration of ...

International Journal of Engineering & Technology, 2019

Milkfish (Chanos chanos) gelatin was successfully developed as biosensor material. The milkfish b... more Milkfish (Chanos chanos) gelatin was successfully developed as biosensor material. The milkfish bone was obtained from local restaurants in Tarakan, North Borneo, Indonesia. Gelatin was extracted from milkfish bone using acid method at 55°C. Characterization by FTIR showed that milkfish gelatin had similar functional group with commercial gelatin. The gelatin was used as biosensor material for detecting chromium. The gelatin was mixed with carbon in 1:1 ratio to form gelatin/carbon paste modified silver electrode. Electrochemical impedance spectroscopy (EIS) analysis of the gelatin/carbon paste modified silver electrode showed a better conductivity than paraffin/carbon paste modified silver electrode. Performance of the gelatin/carbon paste modified silver electrode in chromium (III) solution was conducted using cyclic voltammetry technique. Measurement was carried out at -1 V to +1 V with scan rate of 100 mV/s in acid and base condition. The best result was shown by gelatin/carbon ...

Nata de coco telah digunakan sebagai pengganti media gel elektroforesis pada sampel pewarna remaz... more Nata de coco telah digunakan sebagai pengganti media gel elektroforesis pada sampel pewarna remazol. Pada penelitian ini, diamati pengaruh pH larutan buffer, waktu elektroforesis dan aplikasi pemisahan gelatin menggunakan elektroforesis dengan media nata de coco. Nata de coco yang berumur 4 hari memiliki ketebalan yang sesuai yaitu 0,454 cm dan waktu inkubasi yang tidak terlalu lama sehingga umur tersebut digunakan dalam penelitian ini. Hasil resolusi elektroforesis terbaik didapatkan pada pengggunaan buffer fosfat yang terbuat dari garam–garamnya. Pada pengaruh pH dinyatakan dengan kekuatan ion, dimana semakin besar kekuatan ion larutan, maka semakin jauh jarak migrasi remazol. Lama waktu elektroforesis mempengaruhi jarak migrasi remazol Kondisi optimum elektroforesis gel menggunakan nata yang didapat, digunakan untuk uji pemisahan gelatin menggunakan pewarna remazol turquoise dan didapatkan dua pita pemisahan dengan jarak pita masing-masing 2 cm dan 3,6 cm.

Sensor emas terlapis NiO nanopartikel pada probe Quartz Crystal Microbalance (QCM) telah berhasil... more Sensor emas terlapis NiO nanopartikel pada probe Quartz Crystal Microbalance (QCM) telah berhasil dibuat. NiO nanopartikel dilapiskan pada permukaan sensor emas QCM berfungsi sebagai partikel aktif. Sensor emas QCM yang telah termoifikasi NiO nanopartikel dipasang pada crystal holder dan dicelupkan pada larutan gelatin sapi dan larutan gelatin babi dengan konsentrasi 100, 200, 300, 400, dan 500 ppm untuk menguji perbedaan frekuensi yang teramati pada larutan gelatin sapi dan larutan gelatin babi.

Chemistry education especially in senior high school has not been integrated to other disciplines... more Chemistry education especially in senior high school has not been integrated to other disciplines. Teachers deliver his knowledge to students by explaining a concept without showing what the relation of the concept which being to deliver with the other disciplines. Problem Based Learning (PBL) is one of the learning models which have positive impact to student’s achievement and the permanence of knowledge. Using PBL model we can do STEM (Science Technology, Engineering and Mathematics) approach. By integrating chemistry concept to other disciplines using STEM approach, it will make easier for the students to understand about science holistically. In this research, we have designed carbon monoxide gas detector as learning media and STEM interactive worksheet. This learning media was expected to visualize integration of a chemistry concept to other disciplines, so in such a way can improve the student achievement. The validation of carbon monoxide gas detector and worksheet as a learn...

Sel bahan bakar adalah peralatan elektrokimia yang mengubah energi kimia dalam bahan bakar secara... more Sel bahan bakar adalah peralatan elektrokimia yang mengubah energi kimia dalam bahan bakar secara langsung menjadi energi listrik. Direct Methanol Fuel Cell (DMFC) merupakan jenis sel bahan bakar yang menarik perhatian karena menghasilkan densitas energi yang tinggi dan menggunakan jenis bahan bakar cair yaitu metanol. Saat ini katalis berbasis Palladium (Pd) yang didepositkan pada elektroda berbasis karbon memainkan peranan penting untuk menggantikan Platina (Pt)/C karena cadangan terbatas, harga mahal, dan ketidakstabilan dalam operasi sebagai material elektrokatalis DMFC. Graphene sebagai material baru untuk elektroda DMFC telah terbukti dapat meningkatkan performa DMFC. Faktor keberhasilan reduksi graphene oxide menjadi graphene dipengaruhi oleh reduktor zink (Zn). Dalam penelitian ini diberikan variasi massa reduktor Zn senilai 0.8, 1.6, dan 2.4 gram. Metode sputtering diaplikasikan untuk mendepositkan nanopartikel PdAu pada graphene. Dari hasil pengujian scanning electron micr...

Pada penelitian ini pengaruh waktu infusi pada kadar asam klorogenat dalam sampel teh hijau dan t... more Pada penelitian ini pengaruh waktu infusi pada kadar asam klorogenat dalam sampel teh hijau dan teh hitam hasil pengolahan kebun teh Lawang telah berhasil dianalisis menggunakan spektrofometer UV VIS. Pengukuran asam klorogenat dilakukan berdasarkan waktu infusi yaitu dari menit ke 0 sampai dengan menit ke 30 dengan interval waktu 5 menit. Kadar asam klorogenat dalam sampel teh hitam pada tiap waktu infusi adalah 117,4569 mg/g (0 menit), 157,1031 mg/g (5 menit), 165,6275 mg/g(10 menit), 170,1532 mg/g (15 menit), 1787,9327 mg/g (20 menit), 168,1327 mg/g (25 menit), 140.7965 mg/g (30 menit) dan pada sampel teh hijau terukur 130.3195 mg/g (0 menit), 144.065 mg/g (5 menit), 154.7676 mg/g (10 menit), 168.468 mg/g (15 menit), 162.5686 mg/g (20 menit), 165.0445 mg/g (25 menit), 157.8896 mg/g (30 menit). Untuk waktu yang lebih lama maka kadar asam klorogenat akan semakin menurun. Waktu infusi maksimum untuk teh hitam adalah 20 menit dan 15 menit untuk teh hijau.

Contact angle measurement is a technique which can be used to determine the surface properties of... more Contact angle measurement is a technique which can be used to determine the surface properties of a substance and observe the interaction of surfaces. When polar liquid dropped on a non-polar solid, it will make an interaction that can observed from the contact angle. In simple way, the different polarity of the solid and the liquid sample will affect to the contact angle obtained. In this work the value of contact angle will be correlated to the polarity of the sample. The results showed that the plot between polarity parameter with contact angle on polytetrafluoroethylene substrat has a correlation which formed a sigmoidal curve with R2=0,954. It means the polarity of liquids can be determined by the contact angle values.

Telah dibuat elektroda pembanding Ag/AgCl dengan menggunakan berbagai jenis membran. Membran yang... more Telah dibuat elektroda pembanding Ag/AgCl dengan menggunakan berbagai jenis membran. Membran yang digunakan berasal dari bahan yang mudah diperoleh, yaitu poliisoprena dan LDPE. Kinerja dari elektroda pembanding Ag/AgCl yang dibuat, diamati dengan membandingkan voltammogram larutan K 4 [Fe(CN) 6 ] 0,1 M yang diperoleh dengan voltammogram yang dihasilkan oleh elektroda Ag/AgCl komersial. Semua pengukuran dilakukan menggunakan sistem tiga elektroda dengan teknik voltammetri siklik dimana elektroda emas sebagai elektroda kerja, elektroda platina sebagai elektroda pembantu, dan elektroda Ag/AgCl (hasil buatan sendiri/komersial) sebagai elektroda pembanding. Pengukuran dilakukan setiap 2 jam selama 24 jam, kemudian dilanjutkan setiap 24 jam selama 6 hari, dan dilajutkan lagi setiap 3 hari selama 6 hari. Voltammogram yang diperoleh dari hasil pengukuran elektroda pembanding Ag/AgCl dengan berbagai jenis membran dibandingkan dengan hasil pengukuran elektroda pembanding Ag/AgCl komersil...

Sensor Quartz emas dari QCM ( Quartz Crystal Microbalance ) yang terlapis senyawa Nanopartikel Ni... more Sensor Quartz emas dari QCM ( Quartz Crystal Microbalance ) yang terlapis senyawa Nanopartikel Ni(OH) 2 telah berhasil dibuat. Senyawa Nanopartikel Ni(OH) 2 disintesis dengan menggunakan metode pengendapan. Pada pelapisan senyawa Nanopartikel Ni(OH) 2 pada Quartz emas dari QCM dilakukan bantuan Polimer Konduktif Polianilin dengan metode voltametri siklik. Pelapisan senyawa Nanopartikel Ni(OH) 2 pada Quartz emas dari QCM dengan metode layer by layer. Pengujian dilakukan dengan variasi konsentrasi (100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm) dan variasi pH (pH 7, pH 4, dan pH 9) dari larutan gelatin. Gelatin Sapi dan Gelatin Babi dapat dibedakan dengan menggunakan sensor QCM yang telah termodifikasi ini pada pH larutan Basa (pH 9). Kata Kunci : Quartz Crystal Microbalance (QCM), Senyawa Nanopartikel Polianilin, Polimer Konduktif Ni(OH) 2 , Voltametri Siklik, Elektrolisis, Gelatin, Sapi, dan Babi

Jurnal Sains dan Seni ITS, Feb 13, 2019

Abstrak-Senyawaan Seng telah disintesis secara elektrolisis. Logam seng (Zn) digunakan sebagai an... more Abstrak-Senyawaan Seng telah disintesis secara elektrolisis. Logam seng (Zn) digunakan sebagai anoda dan katoda. Pengaruh potensial pada pembentukan senyawaan Seng diamati. Produk senyawaan seng dikarakterisasi dengan spektrofotometer UV-Vis. Nilai Absorbansi tertinggi sebesar 0,613 diperoleh pada λ = 224 nm dengan potensial 6 V dalam natrium sitrat. Nilai absorbansi tertinggi mengindikasikan bahwa senyawaan seng terbentuk paling banyak pada kondisi tersebut.

Materials, 2019

The extract of honeycomb waste was studied as a corrosion inhibitor on 304 stainless steel in H2S... more The extract of honeycomb waste was studied as a corrosion inhibitor on 304 stainless steel in H2SO4 solutions. The honeycomb waste was obtained from beekeeping at Lawang-Malang, East Java, Indonesia. Electrochemical and scanning electron microscopy methods were used to investigate the performance of the corrosion inhibition process. The inhibition efficiency of the inhibitor (2000 mg/L) reached 97.29% in 0.5 M H2SO4 and decreased with the acid concentration. Kinetic parameters were calculated to explain the effect of acid concentration on the inhibition process. The study on the adsorption behavior of the extracts followed the Frumkin isotherm model. The adsorption of the inhibitor on the 304 stainless steel surface was confirmed by the negative and lower values of Gibbs free energy. The obtained scanning electron microscopy (SEM) images were confirmed by comparing the surface of the specimens with and without inhibitor after corroding for one week. The results indicated that the ex...

TELKOMNIKA (Telecommunication Computing Electronics and Control), 2019

Nowadays, an electronic nose becomes an important tool for detecting gas. The electronic nose con... more Nowadays, an electronic nose becomes an important tool for detecting gas. The electronic nose consists of gas sensor array combined with neural networks to recognize patterns of the sensor array. Currently, the implementation of the neural network on the electronic nose systems still use personal computer so that less flexible or not portable. This paper discusses the electronic nose system implemented in a Field Programmable Gate Array (FPGA). The sensor array consists of eight Quartz Crystal Microbalance (QCM) coated with chemical materials. The eight channel-frequency counter is used to measure the frequency change of the sensor due to the presence of gas adsorbed to the surfaces. The bipolar sigmoid activation function used in the neuron model is approximated by a second order equation. The experimental result showed that the electronic nose system could recognize all the types of gas with 92% success rate.

IOP Conference Series: Materials Science and Engineering, 2019

SGPN-NPs paste electrode as biosensor have been successfully fabricated. The electrode was made b... more SGPN-NPs paste electrode as biosensor have been successfully fabricated. The electrode was made by modification material such as silica gel, solid paraffin, liquid paraffin and nickel nanoparticles. All modification material would be mixed into paste and then modified on the silver electrode which covered by glass tube. Comparison result will be studied by silver electrode with and without modification. The performance of the biosensor was investigated in medical sample, i.e. insulin. The electrochemical response from the biosensor was performed by cyclic voltammetry (CV) in phosphate buffer solution (pH = 7.0) at room temperature. The best response of the biosensor was achieved by silver electrode with modification. This SGPN-NPs paste electrode can detect insulin at potential of-0.667 V. The obtained calibration curve followed a linear equation, Ipc =-5.1350c-330.2550, with R 2 = 0.97564. The limit of detection (LOD) and sensitivity of the biosensor for insulin detection were 4.92257 nM and 1.6353 μA.nM-1 .mm-2 , respectively. The result confirm that SGPN-NPs paste electrode is favorable for detecting medical sample, especially insulin.

Malaysian Journal of Fundamental and Applied Sciences, 2018

Polymer electrolytes film based on polyethylene oxide (PEO) complexes with NaClO4 salt with a rat... more Polymer electrolytes film based on polyethylene oxide (PEO) complexes with NaClO4 salt with a ratio of EO: Na = 20:1 and fly ash as filler has been prepared by solution casting technique. The crystallinity of the solid polymer electrolyte was characterized by X-Ray Diffraction (XRD). The interaction between PEO and Na-ions confirmed by Fourier Transform Infra Red (FTIR) analysis. The ionic conductivity of the solid polymer electrolyte was investigated by impedance analysis from 1 MHz to 1 Hz at a varied temperature of 50°C, 60°C, 70°C, 80°C, and 90°C. The maximum ionic conductivity of EO: Na = 20 was 5.31 x 10-5 S cm-1 and increases to 2.13 x 10-4 S cm-1 by the addition of fly ash 5% at the temperature of 60°C.