Structural and optical properties of Eu3+-doped sodium-lead-zinc-lithium-borate glasses (65−x)B2O315Na2O10PbO5ZnO5Li2OxEu2O3 (where x = 0, 0.05, 0.1, 0.5, 1.0, 2.0 and 4.0) have been measured and ...analyzed by varying the Eu3+ ion concentrations. The physical parameters such as polaron radius, field strength and inter nuclear distance have been determined from measurements of densities and refractive indices. The structural properties of the prepared borate glasses were analyzed based on X-ray diffraction (XRD) and FTIR instruments. The diffraction spectra show no characteristic peaks in these glasses, which indicates the amorphous nature of the glasses. The infrared spectrum of the Eu3+-doped sodium-lead-zinc-lithium-borate glass systems show three disparate regions for active absorption band around 830–860 cm−1, 1020–1040 cm−1 and 1170–1180 cm−1. The electronic transitions in the UV–vis and NIR regions are assigned to the 7F0 → 5D4, 7F0 → 5G2, 7F0 → 5L6, 7F0 → 5D3, 7F0 → 5D2, 7F0 → 5D1, 7F0 → 5D07F1 → 5D07F0 → 7F6 and 7F1 → 7F6 levels centered at 362 nm, 380 nm, 395 nm, 414 nm, 465 nm, 533 nm, 583 nm, 590 nm 2092 nm and 2202 nm respectively. Five transition bands of luminescence spectra have been observed by using an excited wavelength of 395 nm. The luminescence intensity ratio (R) of 5D0 → 7F2 (electric dipole) transition to 5D0 → 7F1 (magnetic dipole) transition has been determined to obtain the strength of the covalent/ionic bond between the Eu3+ ions and the surrounding ligands. Radiative life time and emission color of the glasses were estimated and compared with other literature data by varying Eu3+ concentrations. The experimental lifetime of the 5D0 level was found to increase with increasing Eu3+ ion content, suggesting higher non-radiative energy transfer among Eu3+ ions in the glasses.
•Eu3+ ion from 0.05 to 4.0 mol.% concentration doped in borate glass system are prepared.•All of samples showing no sharp diffraction peak indicates amorphous behavior.•The strongest luminescence achieved at 613 nm.•The longest luminescence life time is achieved by the 4.0_Eu glass for around 6.1 ms.
Abstract Developing an automatic detection method based on computer vision applied to the moon crescent is an innovative concept that can be further developed. This program will be highly useful for ...observers during the Moon crescent observation because it can help them recognize objects quickly. This paper proposes an automatic crescent moon detection method based on visual mechanisms and training using the Cascade Classifier algorithm. The stages of this method consist of building Haar structural features, extracting feature samples using Haar structural features, and training 981 images consisting of 654 positive images and 327 negative images using the Cascade Classifier. The results show that the crescent moon detection performance is quite good at detecting the crescent Moon. The developed program can recognize crescent moon objects, although it is limited to relatively large lunar illumination in the range of greater than 10% to less than 50%. Furthermore, our program can be applied in real-time situations.
Abstract
Indonesia is one of the countries located at the ring of fire which should be monitored to predict the eruption earlier and set the risk zones around with no human involvement especially ...while eruption taking place. Therefore, in this research, it is used a 4 wheeled mobile robot called PRAWIRA for this purpose. The robot should have the ability to avoid the obstacles in front of it in this area. It has been designed a real-time object detection system for volcano monitoring application using deep learning from the YOLOv5s model for 4 objects (trees, persons, stones, and stairs). It was used 484 images for the dataset after the pre-train process was conducted with several steps: object identification; dataset downloading (Google Chrome Extension and Open Images v6); image labeling (LabeImg); augmentation process (flip, blur, and rotation); and data training for varies epochs and batches by Jupyter Notebook GPU. The preliminary result for this research was presented in the mean average precision (mAP) of YOLOv5s (the smallest version). The first variation (batch = 16, epochs = 100) resulted in mAP_0.5 = 17.9% and mAP_0.5:0.95 = 7.27% with 0.262 hours of training time. The second (batch = 16, epochs = 500) resulted in mAP_0.5 = 25.7% and mAP_0.5:0.95 = 12.3% with 1.296 hours of training time, while the third (batch = 80, epochs = 100) resulted in mAP_0.5 = 17.7% and mAP_0.5:0.95 = 5.63% with 0.232 hours of training time. Furthermore, the last variation (batch = 80, epochs = 500) resulted in mAP_0.5 = 19.5% and mAP_0.5:0.95 = 8.92% with 1.085 hours of training time. Therefore, the second variation is the best result for the model with 14.8 MB of size. Moreover, interfaces for the best model were displayed to show the result of the training.
Discovery of electromagnets has had a great influence on the development of science and technology, which due to the nature of the magnetism that can be arranged so that it can provide practical ...benefits including electric motors, relays, power generators, and automatic door switches. In this research, an electromagnet the form of copper plate with hole in the middle for iron core. Each plate has an insulator that separates between each plate which is arranged in threads to form a helical coil of copper plate. Value obatained from design electromagnets using copper is 0 to 8 mT, with measurement using Gaussmeter as a reference in the development of sensors using giant magnetoresistance. The implications and application from this research is portable and concise high field in the form of copper plate models. In the future it potential apllication on biomedical and engineering.
Abstract
Improved ground and aerial system technologies enable mapping and monitoring forests and land to mitigate forest fires. UAV plays a role in monitoring by collecting forest area images from ...the air, which could be processed into 2D and 3D images. They can be analyzed to identify land cover types and objects in forest areas. This image data collection uses the DJI Phantom 4 Pro UAV controlled automatically with a flight plan made with Pix4D Capture, which is then processed using Agisoft. The result of the mapping has an average GSD of 2,03 cm/px. The mapping result shows that the 3D image produced can show objects in various land cover types. Weather related parameters were measured using ground sensors both in forest and plain area. We had successfully gathered forest and plain area images in addition to weather related parameters in Tangkuban Perahu Mountain area.
In this work, multi wall carbon nanotube (MWCNT) doped borate glass has been successfully developed by melt quenching technique with the chemical composition 67.5B
2
O
3
-20ZnO-12Gd
2
O
3
-Er
2
O
3
...-0.5MWCNT. Several peaks observed from absorption spectra due to transition from
4
I
15/2
as a ground state into several states i.e.
4
G
11/2
,
2
G
9/2
,
4
F
7/2
,
4
F
5/2
,
2
H
11/2
,
4
S
3/2
,
4
F
9/2
,
4
I
11/2
, and
4
I
13/2
. The sample shows a strong emission in 1536 nm because of
4
I
13/2
→
4
I
15/2
transition under 520 nm wavelength excitation. Emission around 402 nm and 471 nm under 270 nm excitation could be the indication for presence of MWCNT. The sample exhibits NIR to NIR up-conversion under 1500 nm excitation. Absorption data have been used to calculate optical band gap energy through Tauc plot method. This study shows that MWCNT doped borate glass could be a promising material for solid state application in NIR region.
Indonesia is one of the countries that lies in the pacific ring of fire, the highlighted area that known to be active by seismic and volcano activities. Indonesia has a total of 129 active volcanoes ...that make the land fertile, but also vulnerable to disaster. When a volcanic eruption occurs, the current fixed monitoring system is not fully reliable. On the other hand, monitoring of further volcano activities is critically needed in this situation. Therefore, a volcano monitoring system that can move freely and controlled safely is needed. To solve this problem, a mobile robot that capable of moving in volcano area has been developed. The robot locomotion system is designed with 2 DC motor using 4-wheel drive configuration. Each motor implements a PID Controller to adjust the speed that has been set. In addition, the robot is also equipped with a camera (Logitech C920), vibration sensor (ADXL 345), temperature sensor (DHT 11), carbon dioxide gas sensor (MG-811), and sulphur dioxide gas sensor (TGS 2602) to retrieve volcanic condition data, as its function for volcano monitoring. The microcontroller used to adjust motor control and read sensors data is Nucleo STM32-F466RE, while the mini-PC that being used for integrated data communication and processing is Raspberry PI 3B+. PID Controller has been successfully applied with average deviation of 2.5% for the left motor, and 2.75% for the right motor.
In this study, we modeled the effects of flaws in a solid material as three different slit types (rectangular, rectilinear, and semicircular) and their orientations in a duralumin (aluminum alloy) ...plate in simulations based on 137Cs gamma backscattering. The simulations were performed using the Monte Carlo GEANT4 simulation toolkit. The simulation results showed that the shape of the slit had a small effect on the backscattering peak curve. Rotating the slit on the Y-axis and Z-axis of the duralumin plate influenced the 137Cs backscattering peak height in the energy range from 0.185 to 0.20 MeV, where the backscattering peak areas exhibited specific patterns due to the slit orientations.
•Geometry of duralumin plate affected 137Cs backscattering peak curve.•Slit type affected backscattering curve peak with 137Cs gamma-rays.•Flaw orientation influenced backscattering curve peak and area.•GEANT4 used to simulate radiation measurements.
We have developed a new volcano early warning system based on sensor node, internet of things (IoT) and UAV to overcome some problems in Indonesian volcano monitoring system. Data (monitored by ...sensor node) transmission and communication is managed by the IoT while UAV is used for remote sensing data to complete the system to predict the geological status of the volcano. An intelligent-battery UAV is needed for this purpose which manage the power utilization for field application. First stage of the remote sensing process is volcano region mapping for constructing an orthophoto before it is combined with field sensor data. Therefore, we have conducted a laboratory experiment to map some region in ITB, Bandung in different weather as real volcano condition. We have constructed day, night, sunny and cloudy maps of ITB after some data collected through flight and control plan as real volcano environment. Some grid flight plans were chosen for expected result as well as battery saving for each 5 meters data collection. A 3D software has been used for modelling of the orthophoto construction and resulted in 0 - 8 meters error of 20000 - 24000 m2 monitored area. Therefore, this method could be used in real volcano application.
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