A Study on a New Independent Metering Valve for Hydraulic Boom Excavator

Nowadays, hydraulic excavators are an indispensable part of the construction industry; however, conventional hydraulic excavators consume a great deal of fossil fuel and release a large amount of pollution emissions into the environment. This causes many unwanted costs, therefore, effective solutions are required to solve the above-mentioned problems. In this paper, a new independent metering system is proposed to improve energy-saving and reduce costs of a conventional system. In detail, a directional valve is used to control movement and three electro-hydraulic poppet valves are integrated to adjust the flow rate at the inlet and outlet ports of the boom cylinder. In addition, a control strategy based on the coordination between the speed of the pump and the opening area of the spool valve is designed to improve the performance of the system. Specifically, the valves are controlled based on the strategy that the meter-in valve is opened fully to reduce throttling losses and that the meter-out valve is controlled to reduce leakage. The speed of the pump is adjusted according to the feedback position signal. To demonstrate the effectiveness of the new configuration, a real test bench of the boom system was built under laboratory conditions. From the experimental results, the new independent metering valve system not only works with a high tracking precision, but it also reduces energy consumption. Compared with a conventional independent metering system, the fuel economy of the proposed structure can achieve a reduction of approximately 6.5%.

Observational aspects including weather radar for tropical cyclone monitoring

Hkkjr ekSle foKku foHkkx ¼vkbZ- ,e- Mh-½ ds iwokZuqeku izn’kZu ifj;pkstuk ¼,Q- Mh- ih-½ ds lanHkZ esa dh xbZ fofHkUu izs{k.kkRed lqfo/kkvksa vkSj rduhdksa dh leh{kk dh xbZ gSA ftudk iz;ksx pØokr ds iFk dk irk yxkus vkSj m".kdfVca/kh; pØokrksa dks le>us ds fy, fd;k tk ldrk gSA izkS|ksfxdh ds laca/k esa fd, x, iz;klksa ds okLrfod ijh{k.k ls izpkyukRed lanHkZ esa gekjs iwokZuqekuksa ds fu"iknu dk irk pyrk gSA bl laca/k esa vko’;d mik;ksa ij bl 'kks/k&i= esa fopkj&foe’kZ fd;k x;k gSA In the context of the Forecast Demonstration Project (FDP) of the India Meteorological Department (IMD), a review is made of the various observational facilities and techniques which can be deployed, for the detection tracking and understanding of tropical cyclones. The real test of the efforts in terms of technology is the performance of our forecasts in an operational context. The paper discusses the steps needed in this regard.

Performance Analysis of ZigBeePRO Network Using the Shortest Path Algorithm for Distributed Renewable Generation

The communication requirement for integrating Distributed Renewable Generation (DRG) into Smart Grid (SG) is not strict, where the reliability and critical demand of data delivery are compromised due to the low-data rate and power of ZigBee. However, the presence of various dielectric constant materials in the DRG can cause transmission impairments of the electromagnetic wave. In this paper, we have analysed the performance of the ZigBeePRO network by applying the shortest path algorithm while delivering energy data from the solar DRG to the SG. The DRG architecture is created by considering a real test-bed of 35 kW solar DRG at Universiti Putra Malaysia (UPM). The numbers of nodes are calculated from specifications of the ZigBeePRO enabled Waspmote embedded board, inverters, and electrical parameters of a Photovoltaic (PV) module. The results of the obtained propagation path loss model indicate that the Transverse Electric (TE) and Transverse Magnetic (TM) polarizations are proportional to the loss of the propagation path at different incident angles (α); however, an exception is observed for the TM polarization at α = 55 o. Due to this polarization effect, the brick-built type cabin at the DRG site is a consequence of a higher propagation path loss than the Iron (III)-made cabin. The other performance parameters, including network throughput, data loss, and ZigBeePRO collision, are also evaluated.

The Numerical Simulation of Thermal Abuse and Runaway in Lithium Ion Battery Pack

Computer simulations today play an important role in the field of science and technology. The same is true in the field of electrochemistry, where they are used mainly to model the charging and discharging processes in various types of batteries, at the various loads and temperature processes associated with it. This article deals with the possibility of modeling thermal abuse, which subsequently leads to the thermal runaway effect in a lithium ion battery pack. The simulation is accompanied by experimental measurements and comparison of the original results from the real test and simulation.

Electric Machines Virtual Laboratory: Testing of DC Motor

This article describes the realization of testing the characteristics of a DC motor on Simulink as a virtual laboratory. Testing of DC motors based on real conditions in a physical laboratory by combining two DC machines coupled to shafts including DC motors and DC generators. The types of DC motors tested include separately excited DC motors, shunt DC motors, and series DC motors. The implementation of the Simulink model adopts the wiring diagram in the real test. The test procedure is also adopted on the real test procedure. The data from the test results are made in DC motor characteristics graph. Virtual laboratory using Simulink can be used to realize DC motor testing, including test procedures, running no-load DC motors, increasing the load of DC motors with infinitely simulation features on Simulink. The results of the study show the characteristics of the experimental data for all types of DC motors tested according to the theory.

Rotation-Invariant and Relation-Aware Cross-Domain Adaptation Object Detection Network for Optical Remote Sensing Images

In recent years, object detection has shown excellent results on a large number of annotated data, but when there is a discrepancy between the annotated data and the real test data, the performance of the trained object detection model is often degraded when it is directly transferred to the real test dataset. Compared with natural images, remote sensing images have great differences in appearance and quality. Traditional methods need to re-label all image data before interpretation, which will consume a lot of manpower and time. Therefore, it is of practical significance to study the Cross-Domain Adaptation Object Detection (CDAOD) of remote sensing images. To solve the above problems, our paper proposes a Rotation-Invariant and Relation-Aware (RIRA) CDAOD network. We trained the network at the image-level and the prototype-level based on a relation aware graph to align the feature distribution and added the rotation-invariant regularizer to deal with the rotation diversity. The Faster R-CNN network was adopted as the backbone framework of the network. We conducted experiments on two typical remote sensing building detection datasets, and set three domain adaptation scenarios: WHU 2012 → WHU 2016, Inria (Chicago) → Inria (Austin), and WHU 2012 → Inria (Austin). [d=Y.C.]The results show that our method can effectively improve the detection effect in the target domain, and outperform competing methods by obtaining optimal results in all three scenarios.The results show that our method can effectively improve the detection effect in the target domain, and in the comparison methods, we get the optimal results in all three scenarios.

Laser Hardening of Unimax Stainless Steel

Nowdays, laser hardening of materials brings a comparative advantage over the conventional hardening technique. Fast cooling rate due to the heat distribution through its own bulk material, self-quenching property (rapid cooling without external water or oil), environmentally friendly characteristics since the procedure does not exhaust smoke, the localized heat input due to adjustable laser spot size to avoid distortion and minimum time to finish the operation are some of the advantages to mention. NIKO is a company specialized in making electrical products like socket outlets and switches by using injection molding techniques. Unimax is a kind of stainless steel used by the company to prepare some parts of the injection molding components like a Nozzle. This time, the company is using more and more fiber-reinforced polymers throughout their product line. These composites are far stronger than the polymer, but on the downside, the fibers are quite abrasive. The objective of this research was to harden the Unimax stainless steel using Nd:YAG (neodymium-doped yttrium aluminum garnet) laser technique. First, the laser transverse speed and spot size were identified as the primary process parameters. Then, the traverse speed of 100, 150 and 400 mm/min and spot size of 2164, 2169, 2288 and 2412 um were assigned with 3 replications. Afterwards, thermal simulation was done using COMSOL Multiphysics© followed by the real test on the metal bar. Therefore, the highest hardness of 650 HV was obtained at a speed of 150 mm/min and a spot size of 2169 um diameters. Finally, the corresponding depth of hardness and roughness values of 200 um below the surface and unmelt samples respectively were obtained. HIGHLIGHTS Laser hardening of materials brings a comparative advantage over the conventional hardening technique The laser transverse speed and spot size were identified as the primary process parameters. Afterwards, thermal simulation was done using COMSOL Multiphysics© followed by the real test on the stainless steel bar The depth of hardening and Vickers hardness (HV) increased with the smaller spot size and slow traverse speed of the ND:YAG laser, but this resulted in a melt on the surface of the hardened metal One of the problems of making products using injection molding techniques using fiber-reinforced polymers is the abrasive nature of the fibers which widen the injection nozzle GRAPHICAL ABSTRACT

Natural disasters, population displacement and health emergencies: multiple public health threats in Mozambique

In early 2019, following the 2015–2016 severe drought, the provinces of Sofala and Cabo Delgado, Mozambique, were hit by Cyclones Idai and Kenneth, respectively. These were the deadliest and most destructive cyclones in the country’s history. Currently, these two provinces host tens of thousands of vulnerable households due to the climatic catastrophes and the massive influx of displaced people associated with violent terrorist attacks plaguing Cabo Delgado. The emergence of the COVID-19 pandemic added a new challenge to this already critical scenario, serving as a real test for Mozambique’s public health preparedness. On the planetary level, Mozambique can be viewed as a ‘canary in the coal mine’, harbingering to the world the synergistic effects of co-occurring anthropogenic and natural disasters. Herein, we discuss how the COVID-19 pandemic has accentuated the need for an effective and comprehensive public health response in a country already deeply impacted by health problems associated with natural disasters and population displacement.

Real test for Thai premier may come after MP vote

Headline THAILAND: Real test for premier may come after MP vote