1,350 research outputs found
Harmful Gases Profiling in Meru Menora Tunnel using SICK Sensor
This paper discusses the study on the measured harmful gases due to traffic emission in the Meru Menora Tunnel, a Malaysia highway tunnel. The hazardous gasses data would help in promoting essential ventilation system inside the tunnel for the health and safety of the users. The emission gasses concentration reading is divided into two main components comprise of Nitrogen Dioxide (NO2), and Carbon Monoxide (CO). Other than that, the visibility also been measured by using SICK sensor. The measurement has been done during normal, festive and school holiday seasons. Festive season shows the highest number of traffic and thus giving the worst air quality. Ventilation fan system can be activated based on the concentration level of gases and visibility in the tunnel
Uji Performansi Rice Transplanter Tipe Walking Model Pf48 (2 Zs-4a) di Desa Tanjung Kecamatan Tanjung Kabupaten Lombok Utara-NTB
Dalam meningkatkan kinerja pekerja dan hasil panen khususnya padi, pemerintah memberikan teknologi pertanian berupa mesin rice transplanter kepada kelompok tani di Desa Tanjung, Kecamatan Tanjung, Kabupaten Lombok Utara. Mesin rice transplanter merupakan mesin yang digunakan untuk menanam padi secara merata. Pada penelitian ini dilakukan uji performansi mesin rice transplanter tipe walking model PF48 (2 ZS-4A) pada lahan persawahan di Desa Tanjung Kecamatan Tanjung Kabupaten Lombok Utara dengan tujuan untuk melakukan uji performansi mesin rice transplanter serta mengetahui efektivitas dan efisiensi mesin rice transplanter terhadap berbagai luas petakan sawah dan sistem tanam. Metode yang digunakan adalah eksperimental dengan penelitian dilakukan dilapangan. Parameter penelitian dari kondisi lahan saat penanaman, keadaan hasil tanam, jarak baris tanam, jumlah rumpun per lubang, kedalaman tanam, total waktu tanam, kecepatan maju alat, kapasitas lapang efektif, kapasitas lapang teoritis dan efisiensi lapang. Analisis data pada penelitian ini adalah pengukuran dari awal pengoperasian mesin rice transplanter pada luasan yang berbeda, yaitu terkecil (400 m2), sedang (700 m2) dan terbesar (1.000 m2) serta penggunaan sistem tanam yang berbeda (memanjang dan memendek) pada setiap petakan. Pada penelitian ini, dari segi luasan, efisiensi lapang pada petakan terbesar (1.000 m2) lebih efisien (83%) dibandingkan dengan petakan lainnya. Sedangkan, efisiensi lapang berdasarkan sistem tanam lebih efisien dengan menggunakan sistem memanjang dibandingkan dengan sistem memendek. Di mana efisiensi lapang yang didapatkan pada sistem memanjang di atas 50%, yaitu 68% untuk luasan terkecil, 75% untuk luasan sedang, dan 83% untuk luasan terbesar. Sedangkan pada sistem memendek, didapatkan efisiensi 24% untuk luasan terkecil, 35% untuk luasan sedang dan 45% untuk luasan terbesar.
Kata kunci: efektivitas, efisiensi, rice transplanter, sistem tanam, tanaman pad
Gaseous optical contamination of the spacecraft environment: A review
Interactions between the ambient atmosphere and orbiting spacecraft, sounding rockets, and suborbital vehicles, and with their effluents, give rise to optical (extreme UV to LWIR) foreground radiation which constitutes noise that raises the detection threshold for terrestrial and celestial radiations, as well as military targets. Researchers review the current information on the on-orbit optical contamination. Its source species are created in interaction processes that can be grouped into three categories: (1) Reactions in the gas phase between the ambient atmosphere and desorbates and exhaust; (2) Reactions catalyzed by exposed ram surfaces, which occur spontaneously even in the absence of active material releases from the vehicles; and (3) Erosive excitative reactions with exposed bulk (organic) materials, which have recently been identified in the laboratory though not as yet observed on spacecraft. Researchers also assess the effect of optical pumping by earthshine and sunlight of both reaction products and effluents
Bandwidth enhancement of rectangular dielectric resonator antenna using circular slot coupled technique
This article presents a technique to enhance the bandwidth of a rectangular dielectric resonator antenna using a circular slot. The structures are designed and simulated using CST Microwave Studio software, and it is found that the circular slot exhibits a bandwidth of 36.44% (0.92-1.33 GHz). The circular slot is compared with the rectangular slot. It is shown that the rectangular slot produces a bandwidth of 6.39% (1.06-1.13 GHz). Both structures exhibit similar radiation patterns with slightly different gains at 3.10 and 3.25 dBi. The bandwidth is enhanced more than five times using the circular slot, compared to the rectangular slot
Wideband Branch Line Coupler with Open Circuit Coupled Lines
This paper focuses on the design of a Wideband Branch Line Coupler by using open circuits coupled lines technique. The design is implemented by adding four open circuits coupled lines to the structure of the Conventional Branch Line Coupler. The proposed design of Wideband Branch Line Coupler is simulated using CST microwave software. The simulation results show that the coupler is operated at 3.8 GHz with coupling factor of -3dB and 90̊ phase difference between the two output ports. The prototype is fabricated and measured to validate the simulated results. A similar Wide Bandwidth is observed on simulation and measurement. The structure achieved a fractional bandwidth of 42.63%, and return loss of 21 dB compared to the Conventional Branch Line Coupler (BLC)
Frequency Reconfigurable Epsilon Negative Metamaterial Antenna
This paper proposes metamaterial (MTM) inspired frequency reconfigurable antenna based on thecircular electric field coupled (ELC) resonator. It is composed of circular shape ELC resonator with the radius size of 7 mm. By inserting two switches between the gaps at both side of the circular ELC resonator, it is possible to switch ON or OFF the unit cell. The antenna has been simulated using CST Microwave Studio software tool. The simulation result shows that the proposed antenna is capable of reconfiguring between two different frequencies which are2.18 GHz and 2.64 GHz. The simulated bandwidth at -10 dB is 4.12 % at resonance frequency of 2.18 GHz and 8.7% at 2.64 GH
Evaluation of Double Loop IC Module for Inductive Coupled Fed RFID Tag Wire Embedded Antenna
This paper presents an evaluation on double loop integrated circuit module for inductive couple fed RFID Tag. The inductive couple feed gives advantage especially for flexible wire embedded antenna in controlling the manufacturing varians as the chip is not directly connected to the antenna. Thus electrostatic discharged effect and manufacturing errors can be minimized. An inductor loop is directly connected to the RFID chip before it is placed to indirectly coupled the energy from a meandered dipole antenna. The coupled energy should be enough to turn on the chip to communicate with the reader. The inductive coupled energy is achieved by manipulating the near field magnetic field between the antenna body and the inductor loop. To evaluate the performance, the antenna and the inductive feeding loop is designed to operate at RFID UHF band (860 MHz – 960 MHz) and simulated using CST software. The antenna body impedance is evaluated to match the impedance of the chip and the loop. It is confirmed that the double loop inductor has higher inductance values and thus should be counted in conjugate impedance between the antenna body and the chip module. The tag with overall dimension of 60 mm x 16 mm can be read at distance at least 9 meters through out the band
Low loss waveguide-based Butler matrix with iris coupling control method for millimeterwave applications
This paper proposes a low loss 4×4 Butler matrix based on rectangular
waveguide cavity resonators technology for millimeterwave
beamforming network using iris coupling method. This method has
the advantage of controlling the electrical fields and the coupling factor
inside a complex medium such as waveguide cavity resonators.
The coupling factor of 6 dB for 4×4 Butler matrix is achieved by
tuning the iris coupling k-value between the waveguide cavity resonators.
Thus, avoiding a higher phase difference losses and component
losses at upper millimeterwave bands. To validate the proposed
method, CST software simulations are performed under several
iris coupling k-values to achieve a 6 dB coupling factor. Then,
the proposed 4×4 Butler matrix is 3D metal printed using selective
laser melting (SLM) technique. The measured reflection and
isolation coefficients are observed below −10 dB, with coupling
coefficients ranging between −6 and −7 dB. The phase differences
of −42.02°, 42.02°, −130.95°, and 133.3° are achieved at the outputs.
It confirmed that using this proposed method has the superiority
over the conventional microstrip and waveguide coupling
methods by a 1 dB coupling factor loss and a 3° phase difference
error
Harmful gases profiling in Meru Menora Tunnel using SICK sensor
This paper discusses the study on the measured harmful gases due to traffic emission in the Meru Menora Tunnel, a Malaysia highway tunnel. The hazardous gasses data would help in promoting essential ventilation system inside the tunnel for the health and safety of the users. The emission gasses concentration reading is divided into two main components comprise of Nitrogen Dioxide (NO2), and Carbon Monoxide (CO). Other than that, the visibility also been measured by using SICK sensor. The measurement has been done during normal, festive and school holiday seasons. Festive season shows the highest number of traffic and thus giving the worst air quality. Ventilation fan system can be activated based on the concentration level of gases and visibility in the tunnel
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