Spektra: Jurnal Fisika dan Aplikasinya
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PEMBUATAN GRAFT TULANG DENGAN PROSES EKSTRAKSI SENYAWA HIDROKSIAPATIT DARI TULANG KORTEKS SAPI
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Pembuatan senyawa hidrosiapatit dari tulang kortek paha sapi dengan proses ekstraksi telah dilakukan. Penelitian ini bertujuan untuk menghilangkan senyawa organik pada tulang sehingga dapat digunakan sebagai bahan baku graft tulang. Metode yang digunakan adalah metode kimia dengan merendam tulang di dalam larutan Natrium Hidroksida (NaOH). Pengaruh variasi konsentrasi dan waktu perendaman NaOH terhadap proses ekstraksi tulang dikaji. Variasi konsentrasi larutan yang digunakan adalah 1M, 2M dan 3M dengan waktu perendaman 30 menit, 60 menit, dan 90 menit di dalam autoklaf bertekanan 1,5 atm dan temperatur 121°C. Hasil rendaman dianalisa dengan FTIR dan menunjukan adanya puncak gugus fungsi zat anorganik P-O, CO3 2- , dan O-H menyerupai kandungan tulang manusia. Sampel yang direndam pada larutan NaOH pada konsentrasi 1M dan 2M dengan waktu perendaman 30 menit masih ditemukan gugus fungsi C-H, yang mengindikasikan bahwa serbuk hidroksiapatit masih mengandung material organik sehingga beresiko pada reaksi penolakan oleh tubuh manusia saat diimplan. Namun demikian, serbuk hidroksiapatit yang dihasilkan dengan perendaman pada konsentrasi 3M dengan waktu 30 menit sudah tidak mengandung unsur organik, sehingga dapat digunakan sebagai bahan baku graft tulang.
Kata-kata kunci: hidroksiapatit, kortek tulang sapi, Natrium Hidroksida, ekstraksi, graft tulang.
Abstract
The extraction of hydroxyapatite compounds from thigh bones cortex has been done. This research was aimed to remove the organic substances in the bones, so that it can be maintained as the raw material of a bone graft. The research employed a chemical method, the bone was soaked in the Natrium Hydroxide (NaOH) solution. The effect of various concentration and duration of bone's immersion in NaOH were also studied. The solution's various concentrations were 1M, 2M and 3M, therefore the various of immersion duration were 30 minutes, 60 minutes and 90 minutes in a 1.5 atm autoclave at a temperature of 121o C. The immersion results were studied throughout FTIR. The results showed that there were some peaks of the inorganic P-O, CO3 2- and O-H substance function, correspond to a human bone characteristic. Samples which were immersed in the 1M and 2M of NaOH solution with duration of 30 minutes have yet a C-H functional group. It indicated that the hydroxyapatite powders have yet organic substances, so there is still a risk of rejection by the human body when it is implanted. However, the sample which was immersed in 3M of NaOH solution with duration of 30 minutes has no any organic substances, it can be used as the raw material of a bone graft.
Keywords: Hydroxyapatite, cow bone cortex, Natrium Hydroxide, extraction, bone graf
STRUKTUR MIKRO DAN SIFAT MAGNETIK DARI LAPISAN TIPIS NANOKOMPOSIT Fe3O4/PVDF
Get PDFArtikel ini berhubungan dengan laporan pembuatan lapisan tipis nanokomposit Fe3O4/PVDF (Poly Vinylidine Fluoride) dengan fraksi berat nanopartikel Fe3O4 yang berbeda. Nanokomposit Fe3O4/PVDF disiapkan menggunakan metode sol-gel dan kemudian ditumbuhkan menggunakan alat spin coating di atas substrat kaca. Lapisan tipis nanokomposit Fe3O4/PVDF dikarakterisasi menggunakan XRD, FTIR, SEM, dan VSM untuk menentukan struktur mikro dan sifat magnetiknya. Fraksi berat nanopartikel Fe3O4 dalam matriks PVDF berpengaruh pada struktur mikro dan sifat magnetik nanokomposit. Hasil karakterisasi XRD dan FTIR menunjukkan bahwa nanokomposit telah terbentuk dan telah terjadi interaksi antara pengisi (Fe3O4) dengan molekul polimer PVDF. Morfologi permukaan nanokomposit memperlihatkan bentuk sperulus (spherulites) dan lamela radial. Analisis kurva histeresis dari nanokomposit Fe3O4/PVDF menunjukkan magnetisasi saturasi dari lapisan nanokomposit Fe3O4/PVDF bertambah dengan bertambahnya konsentrasi Fe3O4 dalam sampel. Pengaruh fraksi Fe3O4 dalam sampel nanokomposit Fe3O4/PVDF terhadap sifat struktur mikro dan sifat magnetik sampel dilaporkan secara rinci dalam artikel ini
PROPERTI MEKANIK TARIK BAJA WIRE O 3.2 MM DAN PC BAR O 7.1 MM SEBAGAI TULANGAN PADA TIANG PANCANG BETON PRATEKAN SPUN PILE
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Paper ini menyajikan properti mekanik tarik baja tulangan wire berdiameter 3.2 mm dan PC bar berdiameter 7.1 mm yang digunakan sebagai tulangan transversal dan longitudinal untuk tiang pancang beton pratekan spun pile. Pembebanan aksial tarik dilakukan menggunakan mesin Universal Testing Machine (UTM). Regangan tarik yang terjadi pada baja tulangan dibaca oleh sensor strain gauge yang ditempel pada bagian sisi luar baja tulangan. Beban tarik dan regangan baja tulangan direkam menggunakan alat data logger. Hasil pengujian tarik ini berupa kurva hubungan antara tegangan dan regangan. Analisis kurva tersebut menghasilkan modulus elastisitas PC bar adalah 230 GPa dan wire dan 220 GPa. PC bar memiliki tegangan leleh 1404 MPa dan tegangan ultimit 1469 MPa. Regangan saat leleh PC bar 0.007 dan regangan ultimitnya 0.023. Sedangkan wire memiliki tegangan ultimit 712 MPa. Nilai elongasi wire dan PC bar adalah 2.0% dan 8.7%.
Kata-kata kunci: properti mekanik tarik, PC bar, wire, spun pile.
Abstract
This paper presents the tensile mechanical properties of the 3.2 mm in diameter of the wire and 7.1 mm in diameter of PC bars used as transverse and longitudinal reinforcement for prestressed spun piles. The axial tensile loading is carried out on using Universal Testing Machine (UTM) machine. The tensile strain was occurring in the reinforcing steel read by the strain gauge sensor attached to the outer side of the reinforcing steel. The tensile load and reinforcement steel strain are recorded using the data logger. The result of this tensile test is a curve of the stress and strain relationship. The elastic modulus of PC bar and the wire is 229577 MPa and 219774 MPa. The yield and ultimate stress of the PC bar are 1404 MPa and 1469 MPa. The yield and ultimate strain are 0.007 and 0.023, respectively. Wire 3.2 mm has a 712 MPa ultimate stress. The value of wire and PC bar elongation is 2.0% and 8.7%, respectively.
Keywords: tensile mechanical property, PC bar, wire, spun pile
OPTICAL PROPERTIES ANALYSES OF CHLOROPHYLL OF LEAF EXTRACT BY UV-VIS SPECTROMETER AS PRE-STUDY OF DYE SENSITIZER
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Telah dilakukan studi ekstraksi awal klorofil dari 3 jenis daun yaitu daun bayam (Amarantus), daun pepaya (Carica papaya), dan daun jarak (Ricinus communis). Ekstraksi dilakukan dengan teknik penghancuran menggunakan blender. Pelarut yang digunakan adalah isopropanol, asam asetat, dan DI water. Hasil penyaringan ekstrak daun diperoleh larutan sebayak 75 ml untuk setiap larutan ekstrak klorofil. Uji Ultrasonic Visible memberikan konfirmasi adanya penyerapan di rentang cahaya ultraviolet dan cahaya tampak. Sementara itu, serapan klorofil teramati di rentang cahaya tampak. Apabila dibandingkan serapan UV dan cahaya tampak, pada larutan ekstrak masih mengandung banyak gugus asam dibandingkan klorofil yang di ekstrak.
Kata-kata kunci: daun bayam, daun pepaya, daun jarak, absorbansi, klorofil
ABSTRACT
We studied for chlorophyll extract from 3 leaf types that are spinach leaf (Amarantus), papaya leaf (Carica papaya), and castor leaf (Ricinus communis). The extraction is done by using a blender. The solvents used are isopropanol, acetic acid, and DI water. The result of leaf extract was obtained 75 ml solution for each solution of chlorophyll extract. The Visible Ultrasonic Test confirms absorption in the range of ultraviolet light and visible light. Meanwhile, chlorophyll uptake is observed in the visible light spectrum. When compared to UV absorption and visible light, in the extract solution still contains a lot of acid groups than the chlorophyll extracted.
Keywords: spinach leaf, papaya leaf, Castor leaf, absorbance, chlorophyll
PENGARUH GELOMBANG MIKRO (MICROWAVE ASSISTED) TERHADAP KURVA HISTERISIS DARI BAHAN FERROMAGNETIK CoPd BERBENTUK ELLIPSOID
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Until now the data storage device is still constrained unstable because of the super paramagnetic effect. This effect can occur when the value of bit density increases or when the magnetic energy decreases which causes the process of demagnetization due to the magnetization orientation changed in the presence of high temperature. CoPd as one of the ferromagnetic materials has magnetic anisotropy value and large coercivity of the field, so that this material can be patterned with very small size according to the requirement of data storage tool. However, data analysis of the CoPd hysteresis curve is required when the microwave assisted at the CoPd would give to rise of temperature. Therefore, we observe the value of the coercivity of the field on the ellipsoid CoPd material with the dimension of size the diameter varied. In addition external field, the microwave assisted with the value of amplitude is 10000 mT and the value of frequency is 80 GHz give to the sample. Retrieval of data using a micromagnetic simulation program from a public software called Object Oriented Micromagnetic Framework (OOMMF). From the data processing, it is found that coercivity of the field becomes smaller when dimension of sample are getting bigger, This means that the reversal of magnetization of CoPd is getting smaller. With these results it can be concluded that CoPd are suitable for use as data storage devices. The best dimensions are (150x150x450) nm3 and (165x165x495) nm3.
Keywords: CoPd, hysteresis curve, microvawe assisted, coercivity of the fiel
ANALYSIS OF PROCIMATE ON THE CHARCOAL BRICKET AGRICULTURAL WASTE
No full textAbstractResearch has been conducted to know the best and worst quality of charcoal briquettes from agricultural wastes based on their proximate content. These agrarian wastes are rice husk, sugarcane baggage, cassava peel, corncob, and coconut shell. The research method is pyrolysis carbonization at 700-800 oC for 45 min and proximate analysis with techniques that suitable Indonesian National Standard (SNI) for testing of moisture, ash, volatile matter, and fixed carbon content. The research result showed that the best charcoal briquettes quality is cassava peel because it has the lowest water content of 0.3833% and the lowest ash content of 0.8452%. While the worst charcoal briquettes quality is corncob because it has the highest water content of 2,412% and the lowest fixed carbon of 71,442%.Keywords: charcoal briquettes, agricultural wastes, proximate analysis
ANALYSIS OF THE INFLUENCE OF GOLD NANOPARTICLE ADDITION TO PHOTOLUMINESCENCE EMISSION INTENSITY AND DECAY TIME OF 618-CDSE QUANTUM DOTS
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Telah dilakukan pencampuran nanopartikel emas dengan kuantum dot CdSe 618. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penambahan nanopartikel emas terhadap intensitas emisi dan waktu peluruhan fotoluminesensi kuantum dot CdSe 618. Dalam 2 mL kuantum dot CdSe 618, ditambahkan nanopartikel emas sebanyak 40 µL, 80 µL, dan 120 µL. Pada setiap penambahan tersebut, dilakukan pengujian fotoluminesensi dan time-resolved photoluminescence, masing-masing untuk mengetahui intensitas emisi dan waktu peluruhan fotoluminesensi kuantum dot CdSe 618 setelah ditambahkan dengan nanopartikel emas. Dilakukan pula pengukuran terhadap rentang panjang gelombang absorpsi dari nanopartikel emas, beserta ukuran diameter partikel-partikelnya. Hasil pengujian menunjukkan bahwa secara keseluruhan, intensitas emisi kuantum dot CdSe 618 setelah ditambahkan dengan nanopartikel emas menjadi lebih rendah, dan nilai waktu peluruhan fotoluminesensi menjadi lebih besar. Penurunan intensitas emisi dan peningkatan waktu peluruhan fotoluminesensi diakibatkan oleh kemunculan plasmon pada nanopartikel emas.
Kata-kata kunci: nanopartikel emas, kuantum dot, fotoluminesensi.
Abstract
We have done the mixing of gold nanoparticles and CdSe 618 quantum dots. The purpose of this study is to see the influence of gold nanoparticles increment to emission intensity and photoluminescence decay time of CdSe 618 quantum dots. Into 2 mL of CdSe 618 quantum dots, we added gold nanoparticles as much as 40 µL, 80 µL, and 120 µL. At each adding, we did photoluminescence and time-resolved photoluminescence testings, to see emission intensity and photoluminescence time decay of CdSe 618 quantum dots after the adding of gold nanoparticles. We also did a measurement of absorption wavelength range of gold nanoparticles, along with diameter size of the particles. The results showed that, overall, the emission intensity of CdSe 618 quantum dots became lower after the adding of gold nanoparticles, and the value of photoluminescence decay time became bigger. The decrease of emission intensity and the increment of photoluminescence decay time were caused by the appearance of a plasmon at gold nanoparticles.
Keywords: gold nanoparticles, quantum dots, photoluminescence
ANALOG COMPUTER FOR STUDYING DIATOMIC MOLECULAR SPECTRA IN TERAHERTZ FREQUENCY
Get PDFThis paper introduces a harmonic oscillator model for rovibronic terahertz spectrum of a model of a rigid diatomic rotor with some control parameters. The model shows a study of rotationally-resolved terahertz band spectra of the vibrational transition in diatomic molecules. THz radiation absorption is used as a closed-form system known as the analog computer dynamics mode. The optical terahertz region spectrum of the diatomic molecule consists of a series of lines. Their separations are not exactly constant. A diatomic molecule is not truly a rigid rotator, because it simultaneously vibrates with a small amplitude. Due to quantized vibrational and rotational energy levels and the selection rules, allowed transitions result in a highly ordered spectrum consisting of a P branch separated by a central gap. Adjacent spectral lines are separated by a spacing of 2B, and since line intensities depend on Boltzmann factor for thermal population and quantum number J, each branch monotonically increases and decreases. As temperature increases, more lines are observed, and line intensities decrease due to the population being spread over more rotational levels. Interactivity research also involves on effects of the fundamental vibrational frequency, rotational constant B and temperature included line width on the observed spectrum
TWO-DIMENSIONAL DYNAMICS OF SPHERICAL GRAIN FLOATING ON THE PROPAGATING WAVE FLUID SURFACE
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Abstract
Simulation of a spherical grain floating in fluid surface propagating sinusoidal wave is performed using molecular dynamics method by assuming that superposition of buoyant, gravitational, and viscous forces will make the grain to move in two-dimension. It is different than previous result, where the grain can only move in one-dimension since size of the grain Db << λf. In this work Db < λf so that direction of buoyant force must be considered. It is predicted theoretically that the two-dimensional motion tends to be a one-dimensional motion when Db/λ less than a certain value, but it remains as a two-dimensional motion when more than that value. In 20 s of observation frequency of the sinusoidal wave can determine whether the grain will move in the same direction of the travelling wave or not.
Keywords: grains, simulation, buoyant force, gravitational force, viscous force
MOISTURE ABSORPTION AND FTIR CHARACTERISTIC OF TAPIOCA STARCH BIOCOMPOSITE REINFORCED DRAGON FRUIT ROOT FIBER (HYLOCEREUS POLYRHIZUS)
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Biokomposit dari pati tapioka dan serat akar buah naga telah berhasil dibuat. Sebanyak 0, 2, 4, dan 6% serat (dari berat kering pati) digunakan sebagai penguat biokomposit. Fabrikasi biokomposit menggunakan metode solution casting. Pengujian serapan uap air digunakan untuk mengetahui persentase penyerapan uap air. Gugus fungsi dari biokomposit ditentukan dengan karakterisasi FTIR (Fourier Transform Infra-Red). Persentase penyerapan uap air menunjukkan bahwa, film pati tapioka mempunyai serapan uap 21,7%. Hasil ini lebih tinggi dibandingkan dengan film tapioka ditambah serat. Fenomena ini didukung dengan analisis FTIR pada gugus serapan air sekitar wavenumber 1647 cm-1. Pada daerah tersebut terlihat bahwa, film pati tapioka memiliki absorban yang tinggi dibandingkan film pati tapioka ditambah serat.
Kata-kata kunci: biokomposit, pati tapioka, serat akar buah naga, FTIR, serapan uap air.
Abstract
Tapioca starch biocomposites reinforced dragon fruit root fiber was successfully produced. As much 0, 2, 4 and 6% fiber fractions (from dry starch weight basis) were used as reinforcement in biocomposites. The fabrication of biocomposites was solution casting method. Moisture absorption testing was used to know the percentage of moisture absorption. The functional group of biocomposites was determined by FTIR (Fourier Transform Infra-Red) characterization. The moisture absorption percentage of tapioca starch film was 21,7%. This result was higher than fiber-reinforced biocomposites film. This phenomenon was supported by FTIR analysis on functional group (water absorption band) at wavenumber 1647 cm-1. In this wavenumber, tapioca starch film has higher absorbance than fiber-reinforced biocomposites film.
Keywords: biocomposites, tapioca starch, dragon fruit root fiber, FTIR and moisture absorption