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Natural B
Published by Universitas Brawijaya
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189
Articles
Testing the Efficiency of The Sawdust dan Wood Glue Particulate Filters to Reduce The PM2.5 Emissions from Motorcycles

Wardoyo, Arinto Yudi Ponco, Rumpoko, Arsyal Karismadika, Abdurrouf, Abdurrouf

Natural B Vol 4, No 4 (2018)
Publisher : Natural B

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Abstract

The increase of motor vehicle population in Indonesia causes the increase of pollution substances in ambient air, such as Particulate Matter with the diameter <2.5 µm or fine particle (PM2.5). There are many methods developed to reduce the PM2.5 concentrations emitted by motor vehicles, such as a biomass particulate filter. This study was aimed to develop biomass PM2.5 filters made of sawdust and wood glue with three different composition ratio: F1, F2, and F3. The PM2.5 concentrations before and after passing through the filters were measured using a Digital Dust Monitor (Kanomax, Model 3443) for 200 seconds of the sampling times. The filter efficiency was obtained from the reduction ratio of the PM2.5 concentrations before and after being filtered. Based on the surface morphology test using an electron microscope SEM, the diameters of the filter pores were 9.11 – 19.7 µm with the different densities. The efficiency was 33% to 52%, depending on the ratio of the sawdust and wood glue. A higher filter density (2.72 x 10-3 g/cm3) generated a higher filter efficiency (52%).

Tensile Strength and Elongation Characteristics of Bioplastics Made from Cilembu Sweet Potatoes Starch with Various Types of Plasticizers

Nuriyah, Lailatin, Saroja, Gancang, Ghufron, Muhammad, Razanata, Arvi, Rosid, Nova Fathur

Natural B Vol 4, No 4 (2018)
Publisher : Natural B

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Abstract

Nowadays, many researchers are doing research in the field of degradable plastics with replacing synthetic polymers with natural synthetics for resulting the bioplastics. A natural raw that often used by the researcher is starch. For producing the bioplastic, the starch is mixed with plasticizers. The aims of this research are for observing the influences of the plasticizer to the tensile strength and elongation of bioplastic that made from the starch of Cilembu sweet potato. The plasticizers that used in this research are glycerol, sorbitol, and egg white. The bioplastics are produced in four stages, such as starch producing, heating and adding of the plasticizers, casting, and measuring the tensile strength and elongation. In the producing process of starch, firstly, the potato was destroyed, then it was blended with fresh water, after that it was settled down, followed by filtering and drying. The next stage was heating and adding of the plasticizers. The process of glycerol and sorbitol adding did at 45 oC while the heating process performed until gelatinization temperature was reached. However, while using egg white as a plasticizer, the process was started at 50 oC. After that, the casting stage was done, followed by the last stage, the testing of bioplastic samples. The results of the experiment show that the variation of the plasticizer affects the tensile strength and elongation of the bioplastic. The addition of plasticizer as many as 2,8% reduces the tensile strength of the bioplastic by 90% for glycerol and 75% for sorbitol. Whereas with the addition of the egg white, the tensile strength of the bioplastic is increased to 49%. For elongation property of the bioplastic, both glycerol and sorbitol as many as 2,8% will decrease the elongation value 32,8% and 16,1% respectively. However, the elongation values of the bioplastic fluctuated for the white egg plasticizer.

The CWT Features Uniqueness Analysis of EEG Signal Against 5 BCI Wheelchair Control Indicators Using the Friedman Method

Firdaus, Ahmad Kanzu Syauqi, Nadhir, Ahmad, Naba, Agus

Natural B Vol 4, No 4 (2018)
Publisher : Natural B

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Abstract

The analysis of the feature’s uniqueness of the electroencephalograph (EEG) signal extracted by continuous wavelet transform (CWT) method against the five BCI wheelchair control indicators has been done. The usage of Friedman method as measuring the uniqueness level of EEG signal features as well as their significance is used in this research. The EEG signals from three subjects that sitting on a regular chair were recorded when they were performing mental commands as seem as controlling a wheelchair with five control indicators. The recorded signals are decomposed by CWT. The absolute mean (|µ|) and the deviation standard (σ) of the CWT decomposition results are used as feature. Then, the uniqueness of |µ| and σ features are analyzed using Friedman Method. Based on the experiment results, it is known that the proposed method is able to map features according to their uniqueness level. The experiment result shows that the highest uniqueness value of |µ| feature from three subjects are 400 (“forward – backward” indicators), 437 (“neutral – turn left” indicators), and 597 (“neutral – turn left” indicators) respectively. While the highest uniqueness value of σ feature from each subjects are 380, 419, and 568 respectively in the same indicator pairs as |µ| feature.

The Relationship Between Honeys Floral Origins and The Electrical Impedance of Honey Variants

Indriyani, Vivien Dwi, Santoso, Didik Rahadi, Widodo, Chomsin Sulistya

Natural B Vol 4, No 4 (2018)
Publisher : Natural B

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Abstract

One of the factors that influence the composition of honey is the plant that became the source of nectar. Honey derived from one plant species has a different composition with honey from other plant species. This study aims to analyze the effect of the origin of honey flower on the value of electrical impedance by using impedance spectroscopy and to analyze the relationship between ash content and electrical impedance in honey. This study used four gold needle electrodes and a set of PicoScope 5244B tools to measure the value of honey impedance. Measurements are made by injecting a current of 10 μA and using frequencies 1 Hz to 2 MHz. This study also measured ash content in honey. The sample used is kelengkeng, kaliandra, randu, coffee, and rubber honey. The results showed that the origin of honey flower affects the value of electrical impedance. The relationship between impedance and ash content is the smaller the ash content in honey the impedance value is greater.

The design of Plasma Reactor and Study of Oxgyen Gas Flow Effect against to the Carbon Ashing Rate in Steel K110

Permana, Antonius Prisma Jalu, Mbulu, Bernardus Crisanto Putra

Natural B Vol 4, No 4 (2018)
Publisher : Natural B

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Abstract

Thin film technology is a green technology in order to decrease industrial waste. The need of thin film cleaner in recoating process is a must. Build up of a plasma reactor using oxygen gas and generate with 2.45GHz microwave was studied. The main objective of this research was to determine alternative plasma generation using high frequency microwave 2.45GHz as a thin film cleaning media on thin film technology. The results show that plasma could generate with maximum pressure at 3cmHg or 30 Torr and it could decrease carbon on surface of steel K110.

The Efffect of Wave Sound at Frequency 3 kHz - 4 kHz on Logawa Rice Resistance to Rice Lices

Nadliroh, Kuni

Natural B Vol 4, No 3 (2018)
Publisher : Natural B

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Abstract

Rice lice is one type of pest that attacks rice, the presence of rice lice can damage the content of rice, rice form and color of rice. Rice that is exposed to rice lice pests will easily fragile and turn into powder and the color of the rice turns yellowish. Innovation is needed to reduce the population of rice lice in the storage phase, so this study aims to determine the effect of sound waves of 3 KHz to 4 KHz frequency on the resistance of logawa varieties to rice lice, in this study the rice plants given the treatment of sound waves of 3 KHz frequency until 4 KHz and without sound waves as controls. Giving of sound waves is done every day from 06.00 to 09.00.

Effect of Stirring Speed on Characteristics of Fe3O4 Nanoparticles Coated with Polyvinyl Alcohol and Glutaldehyde as a Crosslinker

Rahayu, Lale Budi Hutami, Wulandari, Ika Oktavia, Santjojo, Djoko Harry, Sabarudin, Akhmad

Natural B Vol 4, No 3 (2018)
Publisher : Natural B

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Abstract

Research on Fe3O4 nanoparticles is mostly done because of the unique nature of Fe3O4 which has magnetic properties, non-toxic, biocompatible and easily degraded so it is interesting to investigate as a drug delivery system. This nanoparticles were successfully synthesized by coprecipitation method with variations of stirring rate were 180 rpm (sample A), 250 rpm (sample B) and 320 rpm (sample C). FTIR analysis of Fe3O4 nanoparticles, was absorption at ~585 cm-1 for samples A and B showing the presence of Fe-O magnetite bond and absorption at ~623 cm-1 which were not very sharp for maghemite. However the sample B, only absorption at ~623 cm-1 which is sharp for maghemite (γ-Fe2O3) because of Fe2O3 cubic is not formed. SEM analysis did not show significant morphological differences in velocity variation. From XRD analysis known that the crystal size for samples A and B respectively of 6.4192 nm and 9.5513 nm for sample C could not be calculated because of many iron oxide phases present in it, so it is difficult to find FWHM. ESR analysis of nanoparticle samples shown Fe3O4 properties were ferromagnetic.

The Estimate of Instantaneous Solar Radiation Intensity Using Energy Conversion Method

Saroja, Gancang, Nuriyah, Lailatin, Widodo, Chomsin S, Novanata, M. F.

Natural B Vol 4, No 3 (2018)
Publisher : Natural B

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Abstract

The intensity of solar radiation provides information of amount energi that is transferred by the sun in a unit time. The information is used in many sectors for designing and assembling systems with solar energi sources. The measurement of the intensity of solar radiation directly requires a complex set of tools and procedures. This study aims to provide an estimate of instantaneous solar radiation by using energi conversion methods. The working principle of the method used is to capture the flux of solar radiation with a piece of black copper plates and then extract the energi into the water medium through direct contact of the water-copper plates. The increase of fluid temperatur is measured as a function of the time duration of radiation exposure. The radiation intensity value is obtained from derivation of the gradient value of the increasing temperatur. The results show that the energi conversion method gives the radiation intensity value matching the radiation intensity value based on the calculation of astronomical formulation. In the location of the experiment, at noon, the energi conversion method gives an instantaneous solar radiation intensity of 1149, 63 W/m2 with a difference of 0.59% with the calculation result of the astronomical formula.

Fourier Integral Implementation to Obtain the Velocity Signal and Displacement Signal from Digital Data of MEMS Accelerometer Sensor

Wasis, Wasis

Natural B Vol 4, No 3 (2018)
Publisher : Natural B

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Abstract

This paper discusses and implements a simple technique to obtain the velocity and the displacement signals from the digital data of the MEMS accelerometer sensor, which is an acceleration signal. The method used is a numerical integral, i.e. discrete Fourier integral. Technically, the digital signal data from the MEMS accelerometer sensor is converted from time domain to frequency domain by using Discrete Fourier Transform (DFT). In the frequency domain, the acceleration signal component is integrated once to obtain its velocity components, and is integrated twice to obtain its displacement component. Furthermore, Invers Discrete Fourier Transform (IDFT) is performed to obtain the form of velocity and displacement signals in time domain. The application of these theories and methods gives quite good results, especially for low frequency signals recorded at high sampling rates.

Study of Thermal Neutron Flux and Generated Energy from Linac using CR-39 Detector in Liquid Medium

Widyanti, Kurnia Nur, Widodo, Chomsin S., Bunawas, Bunawas

Natural B Vol 4, No 3 (2018)
Publisher : Natural B

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Abstract

Linac surgery is required in radiotherapy activities. However, if Linac operated more than 8 MV can cause additional radiation of neutrons, as well as triggers forming secondary cancer. The study was conducted to determine the distribution of thermal neutron flux and energy responses on the trace. One method to detect neutrons is to use a nuclear trace detector. Measurements were made using a CR-39 detector coated with a Boron radiator. A number of detectors were placed on the surface of the sphere and entered into a 30×30×30 cm3 fantom. Irradiation is done by placing fantom under Linac gantry with 100cm SSD distance. After irradiation, then etching. The results of the measurements showed that the distribution of thermal neutron fluxes spread in all directions. Linac 10 MV neutron flux value varies, starting at 0° of 1,637×103 n/cm2.s and decrease at 135°of 1.285×103 n/cm2s. The highest Linac 15 MV at detector position 0° of 10.723x104 n/cm2.s and decreased at 135° of 5.142x104 n/cm2s. This proves that the farther from the source the less the thermal neutron flux value due to the collision process. While Linac 10 MV and 15 MV produce range of diameter ranging from 8.21-16.75 (μm) and 9.21-17.45 (μm), with energy response value 0.5-3.5 MeV. The larger the energy response, the smaller the diameter and vice versa, this is due to the effect of penetration on the depth of the distance resulting in smaller track.