95 research outputs found
Pengaruh Variasi Siklus Freezing-Thawing Pada Performansi Elektroda Karbon Dalam Sistem Capacitive Deionization
Full text linkElektroda karbon dari bahan karbon aktif dengan metode freezing thawing telah berhasil disintesa dan dikarakterisasi. Penelitian ini bertujuan untuk mengetahui nilai kapasitansi dan peformansi dari sistem capacitive deionization (CDI) dengan variasi siklus freezing thawing. Dalam penelitian ini menggunakan variasi siklus yakni 3, 4 dan 5 siklus. Selain variasi siklus, diteliti juga perbandingan performasi elektroda karbon menggunakan karbon aktif dimodifikasi dengan HNO3 dan tidak dimodikasi. Karakterisasi dilakukan melalui uji Cyclic Voltammetry (CV) dan uji Electrical Impedance Spectroscopy (EIS). Dalam uji CV elektroda karbon modifikasi memiliki nilai spesifik kapasitasi (26,78 F/g)lebih besar jika dibandingkan elektroda karbon tanpa modifikasi (22,77 F/g), keduanya dalam 5 siklus freezing-thawing. Hasil desalinasi, didapatkan pengurangan kadar garam 596 μs/cm NaCl untuk sistem CDI dengan tegangan sumber 1,9 V yaitu sebesar 55,70 % untuk karbon modifikasi dan 24,80 % untuk elektroda karbon tanpa modifikasi.
Rancang Bangun Sensor Polimer Serat Optik Untuk Pendeteksi Konsentrasi Ion Ca2+ Dalam Air
Full text linkTelah dirancang sebuah sistem sensor serat optik untuk mendeteksi konsentrasi ion Ca2+ dalam air. Penulis menggunakan serat optik jenis plastik (POF) Autonics FTP–320–10 dengan garis tengah jaket 2,2 mm dan inti 0,98 mm dan cladding 0,02 mm. Perancangan sensor POF dilakukan dengan metode pengupasan cladding yang nantinya akan diganti dengan larutan uji yaitu larutan ion Ca2+. Pengupasan dilanjutkan dengan etsa dengan larutan aseton 70%. Bagian POF yang terkupas disebut sebagai sensor head. Sistem disusun terdiri dari LED merah 650 nm sebagai sumber cahaya dan fototransistor BP1331 sebagai penerima. Data luaran sensor dihubungkan dengan sistem instrumentasi yang terdiri dari pengolah, penguat dan konversi digital (A/D). Larutan sampel logam yang dipakai adalah Ca(NO3)2 dengan konsentrasi 0,1 M, 0,2 M, 0,3 M, 0,4 M, dan 0,5 M. Larutan sampel akan kontak langsung dengan inti serat, dan bertindak sebagai “cladding baru”. Pengolahan hasil penelitian dilakukan dengan membuat grafik hubungan konsentrasi dan luaran sensor. Untuk melihat korelasi antara nilai absorbsi larutan terhadap tingkat konsentrasi dilakukan pengujian UV-vis Thermo Scientific GENESYS 10S. Puncak absorbsi maksimum pada beberapa variasi konsentrasi didapatkan pada panjang gelombang 300nm. Hasil pendeteksian konsentrasi ion logam Ca2+ dalam larutan Ca(NO3)2 untuk konsentrasi 0,25M dan 0,45M masing-masing didapat selisih sebesar 0,017M dan 0,031M.
Kata kunci : konsentrasi molar, serat optik plastik (POF), fototransistor
Pengaruh Besar Medan Magnet terhadap Pengurangan Kadar CaCO3 dalam Air
Full text linkThe research on the influence of magnetic field over the CaCO3 precipitation in water has been carried out. The hard water is water contaminated with Ca2+, Mg2+, CO32-. Those ions are surrounded by water molecules which is also known as hydration shell. The hydration shell is a layer that holds ions to form a molecule such as a CaCO3. The given magnetic field will affect the hydration shell. The study was conducted by varying the magnitudes of the magnetic field which equal to 0.05 and 0.1 Tesla. The sample solution for this research is 520 mg/L CaCO3. The experiment has been accomplished within 120 minutes experiment resulted a maximum reduction percentage of 28.57% for the magnetic field value of 0.05 Tesla. While the magnetic field value of 0.1 Tesla obtained 57 ,69 % of the maximum reduction
Wire-Mesh 16 × 16 Capacitance Sensor for Analysis of Capacitance Distribution on Cylindrical Pipe
No full textAplikasi Pengolahan Citra Elektrokardiograf dan Jaringan Syaraf Tiruan untuk Identifikasi Penyakit Jantung Koroner
No full textBAND-PASS FILTER CIRCUIT DESIGN FOR MULTI-FREQUENCY ELECTRICAL IMPEDANCE TOMOGRAPHY SYSTEM
Full text linkBAND-PASS FILTER CIRCUIT DESIGN FOR MULTI-FREQUENCY ELECTRICAL IMPEDACE TOMOGRAPHY SYSTEM. Electrical Impedance Tomography (EIT) is one of the emerging imaging technologies recently. The principle of EIT system is inject electric current into impedance object and measure the voltage based on the electrodes array. The current source that precise, stable, and wide-bandwidth is required to obtain voltage measurements accurately. The current source used for this EIT system is Voltage-Controlled Current Source (VCCS). The VCCS block circuit consists of several circuits, one of them is a filter circuit. The suitable filter for multi-frequency EIT system is band-pass filter. This research has been designed and fabricated a band-pass filter with cut-off frequency 1 and 250 kHz, which is using Butterworth coefficient, unity gain, and Sallen-Key topology
Optimisation of ultra-violet and visible light based technologies for disinfection applications in clinical and other environments
Full text linkThis thesis was previously held under moratorium from 27th February 2012 until 27th February 2014.Despite enormous worldwide research efforts and resource commitments, infectious disease problems associated with medical care and with food and water supplies remain as serious public health problems in both developed and developing countries. New infection control technologies are required and this study investigated ultraviolet and visible light-based technologies for microbial inactivation. A major aspect of the work was the modelling optimisation of the High-Intensity Narrow-Spectrum light Environmental Decontamination System (HINS-light EDS), a ceiling-mounted light source developed at the Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), which provides continuous decontamination of air and surfaces within illuminated environments. This study involved the design and development of a fully integrated and controllable HINS-light EDS. Initial investigations in the study involved the use of pulsed ultraviolet (PUV)-light for microbial inactivation, and results demonstrated the effectiveness of PUV-light for inactivation of the bacterial species Staphylococcus epidermidis and Staphylococcus aureus and the yeast species Saccharomyces cerevisiae in liquid suspension using both a broadband spectrum and 260 (± 10) nm light pulses. To determine the visible-light wavelength sensitivity of a number of significant bacterial species, this study utilized a continuous xenon white-light source in combination with a range of narrow-band optical filters (10 nm FWHM) to expose L. monocytogenes, S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) in liquid suspension. Results demonstrated that the bacteria showed sensitivity to wavelengths of light within the visible region, with the peak wavelength for inactivation being 405 (± 5) nm. The study also investigated the use of 405 nm High Intensity Narrow Spectrum (HINS) light, generated from light-emitting diodes (LEDs). When comparing the inactivation kinetics of MRSA, S. aureus, S. epidermidis and L. monocytogenes using the 405 nm HINS-light with those from the 405 nm filtered light, at an irradiance of 8.6 mWcm-2, similar results are found, indicating that the applied dose is the important factor regardless of the source. The most significant area of this study was the development, testing and modelling of a fully-integrated HINS-light Environmental Decontamination System (EDS). Previous work within ROLEST saw the development of an initial prototype model which has been successfully trialled within an NHS hospital, with results showing significant reductions of environmental contamination levels in isolation rooms. This initial prototype had a number of design and operational limitations which required improving. In this study, a new topology for the HINS-light EDS has been developed and its light distribution has been studied. Optimal parameters for the uniform light distribution have been established including: the Lambertian mode number (m), configuration of the Fresnel lens and diffuser, space distance between light source (LEDs), Fresnel lens and diffusers, and the optimum LED-to-LED array spacing. A mathematical model which allows analysis of the light distribution from different topologies has been successfully developed, with results proving that intensity distribution of the system is in good agreement with experimental data. In addition the system has improved thermal management with integrated power supplies providing a light-weight compact design suitable for ceiling mounting. Analytical study of safety calculations and risk assessment of the new HINS-light EDS prototype have been evaluated and calculated. The results confirm that the HINS-light EDS, at an irradiance level of 0.08 mWcm-2 for each individual 405 nm LED engine, and with a total irradiance level of 0.32 mWcm-2 at a distance of 200 cm below the system, is safe in relation to UV, UV-A and thermal interaction with unprotected skin and eyes and blue light retinal hazard. Bacterial inactivation data using this new prototype HINS-light EDS has been shown to achieve reductions in bacterial levels on agar surfaces of up to 73% for S. aureus, 57% for E. coli and 55% for L. monocytogenes, after 6 hours exposure at a distance of 200 cm below the system. The results demonstrate that the improved prototype system is effective for inactivation of pathogenic bacteria in exposed environments.Despite enormous worldwide research efforts and resource commitments, infectious disease problems associated with medical care and with food and water supplies remain as serious public health problems in both developed and developing countries. New infection control technologies are required and this study investigated ultraviolet and visible light-based technologies for microbial inactivation. A major aspect of the work was the modelling optimisation of the High-Intensity Narrow-Spectrum light Environmental Decontamination System (HINS-light EDS), a ceiling-mounted light source developed at the Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), which provides continuous decontamination of air and surfaces within illuminated environments. This study involved the design and development of a fully integrated and controllable HINS-light EDS. Initial investigations in the study involved the use of pulsed ultraviolet (PUV)-light for microbial inactivation, and results demonstrated the effectiveness of PUV-light for inactivation of the bacterial species Staphylococcus epidermidis and Staphylococcus aureus and the yeast species Saccharomyces cerevisiae in liquid suspension using both a broadband spectrum and 260 (± 10) nm light pulses. To determine the visible-light wavelength sensitivity of a number of significant bacterial species, this study utilized a continuous xenon white-light source in combination with a range of narrow-band optical filters (10 nm FWHM) to expose L. monocytogenes, S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) in liquid suspension. Results demonstrated that the bacteria showed sensitivity to wavelengths of light within the visible region, with the peak wavelength for inactivation being 405 (± 5) nm. The study also investigated the use of 405 nm High Intensity Narrow Spectrum (HINS) light, generated from light-emitting diodes (LEDs). When comparing the inactivation kinetics of MRSA, S. aureus, S. epidermidis and L. monocytogenes using the 405 nm HINS-light with those from the 405 nm filtered light, at an irradiance of 8.6 mWcm-2, similar results are found, indicating that the applied dose is the important factor regardless of the source. The most significant area of this study was the development, testing and modelling of a fully-integrated HINS-light Environmental Decontamination System (EDS). Previous work within ROLEST saw the development of an initial prototype model which has been successfully trialled within an NHS hospital, with results showing significant reductions of environmental contamination levels in isolation rooms. This initial prototype had a number of design and operational limitations which required improving. In this study, a new topology for the HINS-light EDS has been developed and its light distribution has been studied. Optimal parameters for the uniform light distribution have been established including: the Lambertian mode number (m), configuration of the Fresnel lens and diffuser, space distance between light source (LEDs), Fresnel lens and diffusers, and the optimum LED-to-LED array spacing. A mathematical model which allows analysis of the light distribution from different topologies has been successfully developed, with results proving that intensity distribution of the system is in good agreement with experimental data. In addition the system has improved thermal management with integrated power supplies providing a light-weight compact design suitable for ceiling mounting. Analytical study of safety calculations and risk assessment of the new HINS-light EDS prototype have been evaluated and calculated. The results confirm that the HINS-light EDS, at an irradiance level of 0.08 mWcm-2 for each individual 405 nm LED engine, and with a total irradiance level of 0.32 mWcm-2 at a distance of 200 cm below the system, is safe in relation to UV, UV-A and thermal interaction with unprotected skin and eyes and blue light retinal hazard. Bacterial inactivation data using this new prototype HINS-light EDS has been shown to achieve reductions in bacterial levels on agar surfaces of up to 73% for S. aureus, 57% for E. coli and 55% for L. monocytogenes, after 6 hours exposure at a distance of 200 cm below the system. The results demonstrate that the improved prototype system is effective for inactivation of pathogenic bacteria in exposed environments
CORRIGATUM TO : STRAIN GAUGE SENSOR OF MASS MEASUREMENT USING A BRASS CANTILEVER
No full text<p><strong>Corrigatum to :</strong> Ayu, H.D., Jufriadi,A., Pranata, K.B., Endarko, Muntini, M.S., Jurnal Nuetrino:Jurnal Fisika dan Aplikasinya. 2017 April: 9(2):52-59. (Doi: 10.18860/neu.v9i1.4138: Gambar 4,5,16 dan table 1 pada halaman 54 dan 59 kerang jelas desainya dan table tidak ada sitasi.</p><p><strong>Arratum: </strong>Ayu, H.D., Jufriadi,A., Pranata, K.B., Endarko, Muntini, M.S., Jurnal Nuetrino:Jurnal Fisika dan Aplikasinya. 2017 April: 9(2):52-59. (Doi: 10.18860/neu.v9i1.4138:<strong></strong></p><p>Gambar 4, 5 dan 16 diperjelas dengan gambar desain seperti gambar dibawah ini. Table 1 ditambahkan sitasi di daftar pustaka</p></jats:p
Analisis Keterbacaan Buku Teks Fisika SMK Kelas X
Full text linkTujuan penelitian ini adalah untuk mengetahui tingkat keterbacaan buku teks fisika SMA kelas X pada materi Suhu dan Kalor. Metode penelitian ini adalah penelitian deskriptif dengan bentuk penelitian menggunakan analisis isi dengan menelaah buku pelajaran fisika SMK kelas X. Objek yang dipilih yang dipilih dalam penelitian ini adalah buku teks fisika untuk SMK kelas X karangan Endarko dkk. penerbit Direktorat Pembinaan Sekolah Menengah Kejuruan. Teknik pengumpulan data dalam penelitian ini adalah teknik observasi langsung melalui studi kepustakaan. Teknik analisis data yang digunakan analisis data adalah deskriptif kualitatif. Berdasarkan analisis data disimpulkan bahwa hasil analisis tingkat keterbacaan buku ajar fisika untuk SMK kelas X pada materi suhu dan kalor karangan Endarko dkk dari beberapa indikator sudah memenuhi syara
Design of Temperature Measurement System on the Drying Process of Madura Tobacco Leaves
Full text linkThe quality of dried chopped leaves of tobacco is an important factor. The present work developed an oven for drying process to measure and evalute on drying shrinkage characteristic of choped leaves Madura tobacco. The oven has three racks for analyzing and monitoring the rate of drying shrinkage of Madura tobacco. Every rack has a different amount of chopped leaves as follows: 120 g on top rack, 100 g for middle rack and 80 g for bottom rack. Rate of drying shrinkage was analyzed for 20 minutes. The results showed that every rack has different rate of drying shrinkage for drying time. The rate of drying shrinkage was achieved at 26-35% for all racks with temperature distribution in oven at 25 – 30 C
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