Daftar accepted manuscript:


EfektivitasPaparan Medan Magnet LemahTerhadap Tingkat Kesempurnaan Pembakaran Bahan Bakar Minyak Beroktan Rendah

Author(s): Shinta Monika Utami, Giner Maslebu, Nur Aji Wibowo

ABSTRAK:Increase levels of octane fuel in order to efficient its increasingly scarce use has been done. However, consumers still maintain the use of low-octane fuel because of its affordable price. The treatment in the form of magnetic field exposure on fuel is a means that is believed able to improve the completeness of combustion. Tests were conducted on low-octane fuel with exposure to weak magnetic fields aimed at streamlining the scarcity of low-octane fuel usage. Exposure to weak magnetic fields in the storage tank before going into the combustion process will stretch the hydrocarbon bonds so that the hydrocarbon molecules are easier to oxidise.Fuel exposed to a weak magnetic field is applied to a two-stroke engine with varying engine workloads.The level of combustion completeness is measured from reduction of fuel consumption and the percentage of O2 emissions. The results of this study indicate that exposure to weak magnetic fields on low-octane fuel significantly improves the completeness of combustion processes.


Sensor Ultrasonik HCSR04 Berbasis Arduino Due untuk Sistem Monitoring Ketinggian

Author(s):  Fitri Puspasari, Imam Fahrurrozi, Trias Prima Satya, Galih Setyawan,
Muhammad Rifqi Al Fauzan, dan Estu Muhammad Dwi Admoko

ABSTRAK:  At present the development of the digitalization world is growing. In length measurements generally can only be measured through manual measurement that measures the device that wants to know its length. However,
now the world of digitalization is able to make measurements without touching the device to be measured. One of them is by utilizing sound wave sources or commonly referred to as ultrasonic waves. The purpose of this study was to prototype Arduino Due microcontroller digital distance measuring devices using HCSR04 sensor. The research method used is a direct comparison test method and telemetry measurement. Measurement results are displayed in a computer device to facilitate reading. This design is controlled through Arduino Due. The
prototype testing results of the tool can run well and can be accessed in real time.

Penentuan Pengaruh Jenis Insektisida terhadap Porositas Kertas Saring menggunakan Analisis Image


Author(s): Sepdian Joyta Shadday, Made Rai Suci Shanti Nurani Ayub, Riyani Setiyaningsih, dan Adita Sutresno

ABSTRAK: Database of filter paper porosity in mosquito resistance test becomes significant in the quality parameter of mosquito resistance paper test. Insecticide has an important role in such paper. Some insecticide used in the resistance test was included in the porosity test. In order to find the porosity of WM filter paper with WHO standard, an imageJ application is needed to look for the volume of air-cavity. The paper used in this measurement wasWMfilter paper without insecticide as the control paper andWMfilter paper with insecticide, namely cypermetrin, lamdacy halotrin, and permetrin with the concentrate that has been decided in the resistance test. The results of this study showed that the porosity of filter paper with 0,05% cypermetrin as the active insecticide was 47,78%, the porosity of filter paper with 0,03% lamdacy halotrin as the active insecticide was 49,37% and the porosity of filter paper with 0,25% permetrin as the active insecticide was 49,60%. Therefore, it was found out that based on its porosity, the filter paper with cypermetrin as the active insecticide was better.


Pengaruh ElNino terhadap Gelombang Signifikan di Perairan Indonesia

Author(s):  Achmad Fahruddin Rais

ABSTRAK:In the previous studies, the influence of ElNino on significant waves was not able to be analyzed properly because the simulation model used did not cover the super ElNino period. Therefore, a new research needs to be done based on data in the period of super ElNino. Before analyzing, I assess the accuracy ofwavewatch III (WW3) model significant wave by calculating correlation and root mean square error (RMSE) on significant wave of the altimeter satellite. The influence of ElNino on significant waves is obtained from the correlation between the oceanicnino index (ONI) 3.4 and the significant waves of WW3. I also calculate the ratio between significant wave composites of ElNino / LaNina and ElNino super events towards normal significant waves. The results show that the WW3 significant wave has good accuracy in Indonesian waters. ElNino and LaNina have a strong influence on significant waves in the Java Sea and Sunda Strait at period of December-January-February (DJF). ElNino (LaNina) is able to reduce (increase) the significant wave height until 30% to the normal condition in Java Sea and Sundastrait. In extreme cases, super ElNino is able to reduce a significant wave height until 50% to the normal condition.

 Pengaruh Polyurethan terhadap Kemampuan Meredam Suara Home Made Foam

Author(s):  Riki Perdana, Tri Utami, Erlin Eveline, Devi Afriani, dan Suparno

ABSTRAK: Effective foam composition has been produced as sound absorbing material based on sound absorption coefficient value. The method used is experimentation, by mixing the main ingredients (polyurethan) with the developer liquid (isocyanate). There are five variations of research, with the isocyanate as a control variable. The results obtained from the first to fifth variations in a row are 0.152; 0.072; 0.042; 0.028 and 0.056. From thefindings it can be concluded that theless polyurethan is added the greater the absorption coefficient value so it is better toabsorbs the sound.

 Analisis Nilai Ketidakpastian dan Faktor Kalibrasi pada Alat Ukur Radiasi di Balai Pengamanan Fasilitas KesehatanSurabaya

Author(s):  Kardianto, Kurnia Hastu Kristanti, Kandi Ayu Tiswatidan Yanurita Dwihapsari

ABSTRAK: Radiation measurement calibration for ionizing radiation instrument is a compulsory procedure in hospitals and health facilities according to Minister of Health Regulation No. 54/2015. This study observed radiation measurement calibration in health facilities across East Java and was conducted at Surabaya Health Facilities Security Center (BalaiPengamananFasilitasKesehatan Surabaya). The uncertainty and calibration factor were measured and calculated on 20 analog pocket dosimeters, 20 digital pocket dosimeters and 10gammasurveymeters with reference sources of Cs-137. From 40 pocket dosimeters and 10gammasurveymeters, only 1 analog pocket dosimeter was not feasible to use because its calibration factor was outside the allowed standard value.


 Studi Proses Difusi yang Melewati Membran dengan Pendekatan Kompartemen

Author(s): Fransiska Retno Kuntari, Susatyo Pranoto, dan Adita Sutresno


ABSTRAK: Diffusion is an important process in daily life, especially in the system of the human body. In this study, the diffusion process in human body system was studied using the compartments approach. The purpose of this study is to examine the effect of channel area, concentration, and diffusion coefficient on the rate of diffusion. Two compartments each sized were separated by a perforated barrier that represents areas of high and low concentrations, which were connected by a channel. Two Conductivity Probe sensors were placed in each compartment with the same distance to the barrierand were connected with a Vernier interface and a computer that hadLogger Lite 1.9.4 installed. The conductivity data is converted into concentration, then analyzed. The compartment model can be used to studydiffusion process in the human body system. Diffusion rate is directly proportional to channel area, concentration and diffusion coefficient.

Determinasi Kandungan pada Campuran Lemak Babi dengan Sapi menggunakan Spektroskopi Inframerah Dekat dan Partial Least Square Regression

Author(s):  Rizki E. Agustin, Nur A. Wibowo, dan Ferdy S. Rondonuwu

ABSTRAK: Fat is one of important elements for human’s body. Therefore, fat is often added as one of main ingredients both in food industry activity and in cosmetic products. In this study, another technique was done to make an assumption about the content of fat by using Near Infrared Spectroscopy, NIRS and it was followed by Partial Least Square Regression, PLSR. This assumption was done by making 21 samples with the pork fat percentage toward the cow fat (w/w), which was0,00, 0,05 until 1,00with the interval of 0,05. This calibration model was developed using 11 samples of even concentrate and it was validated by using 10 samples of odd concentrate. The infra-red spectrum used in this study was around 4.000-10.000 cm-1. Prior data treatment covered smoothing, normalizing, the first, and the second derivative which were used to optimized the developed PLSR-NIRS prediction models. The second descending spectrum was used to increase the spectrum resolution before PLS analysis was done. Overall, the NIRS and PLSR techniques were sucessful in showing the percentage of the content in the mixted samples of pork and cow fat.

Uji Aktivitas Antibakteri dan Permeabilitas Membran Hibrid Nilon-TiO2

Author(s):  Binti Istikomatul Isrofiyah, Wenny Maulina*) dan Supriyadi

ABSTRAK: Hybrid membranes from nylon and titanium dioxide (TiO2) were prepared using hydrogen chloride (HCl) as precursor and acetyl aceton as chelating agent in the casting solution by phase inversion methods. The aim of this study was investigated antibacterial effect and permeation flux due to the impact of TiO2 contents on the hybrid membranes. Among all the prepared membranes, nylon-TiO2 hybrid membranes with mass fraction 70%:30% exhibited the best antibacterial effect. Meanwhile, the additions of TiO2were raised water and sodium chloride (NaCl) permeability from 0 to 40%.

Pencitraan Inframerah Dekat dari Lemak Sapi pada Model Lemak Tissue

Author(s):  Chrisli Elfri Sahuleka, Jodelin Muninggar, dan Ferdy S. Rondonuwu

ABSTRAK: All women concern for their beauty. Some ways are done to obtain beauty with the use of creams, routine care in beauty clinics, up to plastic surgery by having liposuction on the desired part of the face. In the early procedures of plastic surgery, a 2-4cm incision is made on the skin before sucking the fat out. This cutting can cause various risks. Therefore, a non-destructive method is needed to identify the position of fat as a pre-plastic surgery procedure. Near Infrared Spectroscopy is a method for quickly and precisely identifying and measuring a sample without damaging it. This study aims to determine the area spectral and or wavelength sensitivity for fat and several other important components and todeterminethe position offatfrom a one-dimensional image.The results show that the location of fat is in position 11-28. From this, it can be concluded that NIRS can inform the position of fat from a one-dimensional image.

Interpretasi Batuan BawahPermukaan Prospek Bijih Besi di Kawasan Desa Pagubugan dan Desa Pagubugan Kulon Kecamatan Binangun Kabupaten CilacapBerdasarkan Survei Magnetik

Author(s): Adib Meiditha Wibowo,Sehah, dan Sukmaji Anom Raharjo

ABSTRAK: Geophysical exploration to determine the potential of iron sand in the Pagubugan Village and Pagubugan Kulon Village areas, District of Binangun, Regency of Cilacap has been carried out from May to August 2018 using the magnetic method. The acquisition of magnetic data has been done in the research area at the geographical position stretching from 109.2988° E to 109.31892° E and 7.68430° S to 7.70402° S. Morphologically, the research location is the part of the easterncoastal in the district of Binangun. The results of the modeling and interpretation of magnetic anomaly data that obtained indicate the presence of rockdeposite which thought to contain iron ore which intersects with clay, silt, sand, gravel, and crust from the Alluvium formation with a magnetic susceptibility value of 0.0094 cgs units. This rockdeposite is estimated to lie at a depth of 0 to 53 meters and stretches at the geographical position from 109.30981° E and 7.69264° S to 109.31787 °E and 7.69575° S.

Blood Pressure Monitor Design Using MPX5050GP Pressure Sensor and Visual C# 2010 Express

Author(s):  Ayu Jati Puspitasari, Endarko, Iim Fatimah

ABSTRAK: Blood pressure monitor (BPM) usingoscillometric method with MPX5050GP pressure sensor has been successfully fabricated and calibrated. Oscillometric method ismeasurement method to observe cuff pressure oscillations. In this study, the oscillometric waveform measured by fabricated BPM used Arduino Uno which processes pulse rate, systolic and diastolic pressures. Measurement results of pulse rate, systolic and diastolic pressures will be displayed and recorded inapplication designed using Visual C# 2010 Express. Fabricated BPM capable of measuring pulse rate and blood pressure in the range of 40-260 mmHg withratio of systolic and diastolic pressures were achieved 0.48 and 0.78, respectively. The system has an average error of systolic pressure, diastolic pressure, and pulse ratewere -4.38 mmHg (2.72%), 0.10 mmHg (5,55%), and 4.48 bpm (6.07%).

Kinetika Reaksi Proses Pirolisis Pada Sekam Padi

Author(s): Casnan, Erliza Noor, Hartrisari Hardjomidjojo, Irzaman, Eti Rohaeti

ABSTRAK: This study aims to determine the reaction kinetics of the rice husk pyrolysis process by analyzing the characteristics of the Thermogravimetry Analysis (TGA) curve. Characteristics of the TGA Curve describes the process of losing mass to the temperature in the pyrolysis process with various stages of material phase changes due to the heating process. The pyrolysis process is influenced by temperature, time, and heating rate, so by analyzing the temperature, time and heating rates, the reaction kinetics will be obtained. The kinetic reaction of the pyrolysis process based on the Arrhenius equation, the speed of the decomposition reaction is influenced by changes in mass or mass fraction per unit time. Exponential factor value (A) will affect the speed of reaction of the pyrolysis process, the greater the value of A, the greater the reaction speed and vice versa. Value (A) in the pyrolysis process of HCl washed and heated rice husk, the value is smaller when compared with the value of A process of rice husk pyrolysis without washing and heating.

Sintesis Ca2P2O7 dari Limbah Kerang dengan Metode Solvothermal

Author(s): Faisal Akbar, Retno Kusumaningrum, Mi’rajShabrin Jamil, Alfian Noviyanto

ABSTRAK: Synthesize of calcium pyrophosphate (CPP) was made using solvothermal method followed by heat treatment. Source of calcium carbonate using green shells waste and blood clams waste. CaO was obtained by decompose calcium carbonate at 1000°C for 2 hours in air atmosphere. CaO powder was mixed with H3PO4 to synthesize CaHPO4 using solvothermal method at 130°C for 16 hours. Calcium pyrophosphate was obtained after heat treatment of CaHPO4at 800°C for 2 hours.However, impurity phases were observed for calcium pyrophosphate from green shells waste. Moreover, the average particle size of calcium pyrophosphate from green shells waste was 1.5 ± 0.8 µm compared to 258 ± 294 nm of blood clams waste.


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