Quartz Crystal Resonator Parameter Calculation Based on Impedance Analyser Measurement Using GRG Nonlinear Solver

Quartz crystal resonator which is used as a basis for quartz crystal microbalance (QCM) sensor was modelled using many different approach. The well-known model was a four parameter model by modelling the resonator as a circuit composed from two capacitors, inductor and resistor. Those four parameters control the impedance and phase again frequency applied to the resonator. Electronically, one can measure the resonator complex impedance again frequency by using an impedance analyser. The resulting data were a set of frequency, real part, imaginary part, impedance value and phase of the resonator at a given frequency. Determination of the four parameters which represent the resonator model is trivial for QCM sensor analysis and application. Based on the model, the parameter value can be approximately calculated by knowing the series and parallel resonance. The values can be calculated by using a least mean square error of the impedance value between model and measured impedance. This work presents an approach to calculate the four parameters basic models. The results show that the parameter value can be calculated using an iterative procedure using a nonlinear optimization method. The iteration was done by keeping two independence parameters R0 and C0 as a constant value complementary. The nonlinear optimization was targeted to get a minimum difference between the calculated impedance and measured impedance.Keywords— QCM Sensor, four parameter model, impedance measurement

Desain High Frequency Pwm Menggunakan Cpld Dan Pemanfaatan Sistem Sebagai Kontrol Pada Dc-dc Flyback Up Converter

Pulse Width Modulation (PWM) menjadi bagian yang tak terpisahkan dari kebanyakan sistem kontrol. Salah satu kegunaan dari PWM adalah sebagai pengontrol daya pada rangkaian konverter DC-DC/DC-AC. Penggunaan PWM dengan frekuensi tinggi selalu menjadi alternatif untuk mengurangi besarnya ukuran trafo pada konverter Flyback. Frekuensi tinggi PWM dapat dihasilkan jika mengunakan model pencacah dengan kemampuan menghitung cepat. Teknik pencacahan rising dan falling untuk model pencacah dirancang mampu menghasilkan PWM dengan frekuensi lebih tinggi daripada teknik PWM yang dibangun pada mikrokontroller PIC16F87X. Besarnya frekuensi PWM yang dibangun pada komponen CPLD bergantung pada resolusi dan osilator kristal yang digunakan, nilai frekuensi yang mampu dihasilkan untuk resolusi PWM 10 bit dan frekuensi osilator kristal 48 MHz pada arsitektur PWM yang telah dirancang adalah 93.5 kHz. Serta desain high frequency PWM pada komponen CPLD dapat digunakan sebagai kontrol pada konverter Flyback untuk menaikkan tegangan DC dari 12V ke 400V

Analisis Keragaan Petani Kelapa Sawit Pola Plasma di Desa Mekar Jaya Kecamatan Kampar Kiri Tengah Kabupaten Kampar dan Pola Swadya di Desa Bukit Lembah Subur Kecamatan Ukui Kabupaten Pelalawan

Rapid growth of palm oil demand has provoked land expansion to grow oil palm. However, deforestation caused by land expansion has negative impacts to the environment. Some internaltional non-governmental organizations have established certification program to mitigate these impacts. The objective of Roundtable on Sustainable Palm Oil is to promote sustainable production in Palm Oil supply chain. The standard of RSPO certification consists of Principles and Criteria that must be complied by oil palm growers to be included in Palm Oil supply chain. The objective of this study is to analyse the performance of scheme and independent smallholders, to compare the performance of the two model of smallholders, and to assess the gap between the existing performance and the RSPO standard. Using a survey method the data were collected from selected farmers from the two farmers' group. The result shows that the performance of scheme smallholders is better than the independent smallholders. The assessment on productivity and farm income also shows that scheme smallholders are higher than the independent smallholders. Finally, the scheme smallholders applied good agricultural practices more than the independent smallholders

Pengaruh Ketebalan Lapisan Zinc Phthalocynine (Znpc) Di Atas Permukaan Polistiren/qcm Terhadap Sifat Viskoelastis Berdasarkan Nilai Impedansi

Pelapisan Zinc Phthalocynine (ZnPc) dilakukan untuk meningkatkan performa Quarzt Crystal Microbalance (QCM) sebagai biosensor. Deposisi lapisan ZnPc dilakukan menggunakan evaporator dengan variasi waktu deposisi 1 menit, 3 menit, 5 menit, 7 menit, dan 9 menit. Ketebalan lapisan ZnPc dihitung menggunakan modifikasi persamaan Saurbrey dan didapatkan hasil antara 0,103 - 0,502 . Uji sifat viskoelastis dilakukan menggunkan impedance analyzer hasil nilai impedansinya sebesar 15,7 Ω - 66,7 Ω. Ketebalan berpengaruh terhadap nilai impedansi. Semakin tebal lapisan, maka nilai impedansi semakin besar. Pelapisan ZnPc di atas permukaan QCM menyebabkan energi disipasi osilasi QCM semakin besar sehingga nilai impedansi yang terukur semakin besar seiring semakin tebalnya lapisan. Nilai impedansi yang kecil bersesuaian dengan sifat lapisan yang kaku dan nilai impedansi yang besar bersesuaian dengan sifat elastis. Semakin tebal lapisan ZnPc yang terdeposisi akan memberikan efek redaman yang besar pada QCM

Metode Pervaporator-Flow Injection (PV-FI) Untuk Penentuan Nitrogen Dalam Sampel Pupuk Secara In-Line

Dalam melakukan analisis bahan padat hampir selalu diperlukan penanganan sampel awal yangseringkali melibatkan proses destruksi, destilasi atau ekstraksi yang banyak menyita waktu, tenaga,dan bahan kimia. Oleh karena itu terwujudnya metode analisis yang memungkinkan analisis bahanpadat secara inline sangatlah dinantikan untuk efisiensi ketiga hal tersebut. Pada penelitian ini,metode Pervaporator-Flow Injection (PV-FI) dioptimasi untuk penentuan nitrogen dalam sampelpadat pupuk. Parameter yang diamati meliputi variabel kimiawi dan operasional, yaitu lamaperendaman sampel dalam NaOH, konsentrasi NaOH, dan lama pemanasan. Hasil penelitianmenunjukkan bahwa pemanasan sangat berpengaruh terhadap perolehan kembali nitrogen dari60,54 % hingga 87,31 %. Kondisi optimum yang telah dicapai adalah lama perendaman 5 menitdan konsentrasi NaOH 10 % dengan ketepatan 87,31±0,98 % dan ketelitian 98,88 % serta limitdeteksi sebesar 0,228 μg

SPATIAL MODELING OF MULTI-SCENARIO OPTIMAL SOLAR PV POWER PLANT DISTRIBUTION TO SUPPORT INDONESIA'S CLEAN ENERGY ACHIEVEMENT TARGETS

The increasing population brings the increasing energy demand. The increasing production of fossil energy makes many gas emissions. This causes some effect like global warming. The production of clean energy concerns the world government. Solar energy has great attention from many countries worldwide, seeing the potential of the energy produced, the ease of installation process, and the small risk of damage. The potential of solar energy in Indonesia itself reaches 4.8 KWh/m2 or equivalent to 112,000 GWp. Currently, the Indonesian government has a target for constructing solar power plants in 2025 of 0.87 GW or around 50 MWp/year. The absence of research on determining the appropriate location based on multiple aspects is one of the obstacles in planning the construction of a solar PV power plant. Good planning is needed to determine the management and installation of an optimum and sustainable solar PV power plant. This research aims to develop an effective and efficient multi-scenario spatial model for the distribution of Solar PV (Photovoltaic) power plant development in Indonesia. The novelty in the study of the distribution of solar energy potential integrates meteorological and Geographic aspects and socio-economic aspects. The integration of dynamic multi-spatial data is used to determine the location of the development of solar power plants. Meteorological data is used to calculate potential energy, socio-economic data is used to determine the location for energy demand, and geographic aspect is used to know the suitable environment to install solar PV. The output of this research is the location of the priorities for the development of communal solar power plants in Indonesia. The distribution of effective Solar PV power plant development in Indonesia using a multi-scenario spatial model is divided into five suitability classes. The percentage of suitability class is 0.2% very low class, 3.5% low, 32.4% medium 56.9% high class, and very high 7%. The result is published in WebGIS that can access in link http://bit.ly/ModelPLTSIndonesia. It is hoped the results of this research can be used as material for consideration and one of the solutions for policymakers in making decisions regarding the development of communal solar power plants in Indonesia

MULTI-SCENARIO SPATIAL MODELING OF HEALTH FACILITIES DEVELOPMENT TO SUPPORT THE ACHIEVEMENT OF UNIVERSAL HEALTH COVERAGE

The availability of health facilities that the community can easily reach is one way to improve the degree of health of residents in a region. The ratio of the number of health facilities and residents in Indonesia is currently only about 1:11000. In addition, the equalization of health facilities in Indonesia is also reasonably uneven because the number of health facilities is more centralized in Java, Indonesia. The transfer of the New Capital of Indonesia launched in 2024 to the island of Kalimantan makes Kalimantan Island a magnet for new people's lives, so it needs to be considered infrastructure development, especially in the health sector. This research attempts to model the conformity of health facilities development on the island of Kalimantan spatially by considering the aspect of accessibility as support and comfort and disaster aspects as a barrier. The accessibility aspect will consider geographical and social criteria, the comfort aspect will consider the criteria for air pollution and noise pollution, and the disaster aspect will consider the criteria for floods, landslides, and forest fires. The integration of Geographic Information Systems and Remote Sensing Technology will be carried out using Multi-Criteria Decision Analysis (MCDA). This study will produce recommendations for the appropriate area for the construction of health facilities on the island of Kalimantan. This study is expected to be a consideration for authorized parties in planning health facilities on the island of Kalimantan in preparation for becoming the Capital of the New Country in Indonesia

Investigation of Ground Motion and Local Site Characteristics of the 2018 Lombok Earthquake Sequence

In 2018, Lombok Island was hit by a major earthquake sequence. The Indonesia Meteorological, Climatological, and Geophysics Agency (BMKG) reported that the Lombok Island earthquake sequence started with an Mw 6.4 foreshock, followed by an Mw 6.8 main shock, aftershocks of Mw 5.8 and Mw 6.2, and a second mainshock of Mw 6.9 in the eastern part of Lombok. This study presents an investigation of strong motion characteristics using the Indonesia National Strong Motion Network (INSMN) data from two accelerometer stations, the MASE station (at Praya Lombok International Airport, Lombok Island, Vs30 = 770 m/s, SB site class) and TWSI station (in Sumbawa Island, Vs30 = 1152 m/s, SB site class). Signal analysis techniques using a power spectrum via fast Fourier transform, wavelet transform and horizontal-to-vertical spectral ratio (HVSR) have been applied in this study. There are significant differences in the results (e.g., predominant frequencies, wavelets, H/V ratios, and frequencies at peak H/V ratio) for the MASE and TWSI stations, highlighting the importance of actual Vs30 profiles and the limitation of the site class system in providing necessary predictive information. The variation of the peak ground acceleration (PGA) values and the spectral amplitudes could only be explained by hypothesizing the effect of the volcanic structure of Mount Rinjani on the strong motion waveforms