scholarly journals Deformation Characteristics in a Stretch-Based Dimensional Correction Method for Open, Thin-Walled Extrusions

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1786
Author(s):  
Xianyan Zhou ◽  
Torgeir Welo ◽  
Jun Ma ◽  
Sigmund A. Tronvoll
Keyword(s):  
Low Cost ◽  
Wedge Angle ◽  
Dimensional Accuracy ◽  
Underlying Mechanism ◽  
Correction Method ◽  
Accuracy Improvement ◽  
Gap Opening ◽  
Thin Walled ◽  
Industrial Standards ◽  
And Control

Dimensional accuracy of incoming components is crucial for automated welding and assembly in mass volume production. However, thin-walled extrusions made to industrial standards show severe dimensional variations, including gap opening, sidewall inclination, local convexity, and so on. Thus, one major challenge is to provide a low-cost correction method to improve the dimensional accuracy at a level demanded by automated assembly and/or product fit-up. A novel correction method called transverse stretch and local bending (TSLB) has recently been developed, enabling one to efficiently correct the dimensional deviations in thin-walled, U-channel profiles at a low cost. However, the lack of in-depth understanding of the underlying mechanism makes it challenging to efficiently optimise and control the process. In this study, the feasibility of this new technique was experimentally validated by four groups of TSLB tests with different profile dimensions, showing a dimensional accuracy improvement of about 92% compared with the as-received parts. The evolution of the critical dimensional characteristics, including gap opening and bottom convexity, is analysed numerically throughout four stages consisting of inserting, releasing, calibration, and springback. It is found that the inserting stage greatly reduces the dimensional deviations in a pure bending state, while the calibration stages further minimise the deviations in the bending and transverse stretching combined state. In addition, the wedge angle of the tool is found to be critical to the dimensional accuracy improvement. The low wedge angle facilitates the correction of sidewall inclination and gap opening, while the high wedge angle contributes to mitigating bottom convexity. The overall outcome of this study enhances the fundamental understanding of the effects of in-process stretching and local-bending on the dimensional capabilities of U-channel extrusions. This can ultimately generate guidelines that will lead to new application areas of aluminium extrusions in highly competitive marketplaces.

Identificación de polaridad de los devanados en un motor trifásico de 6 terminales

2019 ◽  
pp. 13-19
Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva
Keyword(s):  
Low Cost ◽  
Voltage Reference ◽  
Three Phase ◽  
Voltage Phase ◽  
The Law ◽  
And Control

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.

Restoring and Controlling the Water Pollution of Endangered River in Bangladesh: A Case Study in Pabna City

2020 ◽  
Vol 3 (2) ◽  
pp. 68-81
Author(s):  
Abu Sadath ◽  
Farhana Afroz ◽  
Hosne Ara ◽  
Abdulla-Al Kafy
Keyword(s):  
Water Pollution ◽  
Local Community ◽  
River Flow ◽  
Low Cost ◽  
Design Approach ◽  
Government Officials ◽  
Conservation Plan ◽  
Policy Measures ◽  
And Control ◽  
Riverfront Development

Rivers are the lifeline of Bangladesh economy and serve as the source of water supply, fisheries, irrigation for agriculture, low-cost transport, generate electricity and conserve biodiversity. The Ichamati River situated in Pabna, Bangladesh is also a blessing for the city. However, recently, due to the irregular and unplanned activities adjacent to the riverside, the life, flow and water quality of the river is in a vulnerable condition. This study aims to identify the present status of the Ichamati River and provide an effective design approach and policy measures in restoring the river flow and control water pollution. The data was collected from the questioner surveys, key informant interviews and focus group discussions. Results suggest that several factors such as the construction of an illegal settlement, unplanned waste dumping, disposal of fiscal sludge through sewerage connection, lack of awareness among people regarding the importance of river biodiversity and absence of riverfront development and conservation plan are responsible for water pollution, inconsistent water flow and damaging the life cycle of Ichamati river. The design approach and policy measures were developed based on the perceptions of local community people, experts and government officials. The suggested policy measures will help to restore the flow of the river and reduce the water pollution, and the design approach will ensure the economic benefit of the riverfront development in future.

scholarly journals Information and information resources in COVID-19: Awareness, control, and prevention

2021 ◽  
pp. 096100062110165
Author(s):  
Mohammadhiwa Abdekhoda ◽  
Fatemeh Ranjbaran ◽  
Asghar Sattari
Keyword(s):  
Low Cost ◽  
Information Resources ◽  
Age And Gender ◽  
Use Of Resources ◽  
Strategic Approach ◽  
Wide Range ◽  
Data Collection Instrument ◽  
Control And Prevention ◽  
And Gender ◽  
And Control

This study was conducted with the aim of evaluating the role of information and information resources in the awareness, control, and prevention of COVID-19. This study was a descriptive-analytical survey in which 450 participants were selected for the study. The data collection instrument was a researcher-made questionnaire. Descriptive and inferential statistics were used to analyze the data through SPSS. The findings show that a wide range of mass media has become well known as information resources for COVID-19. Other findings indicate a significant statistical difference in the rate of using information resources during COVID-19 based on age and gender; however, this difference is not significant regarding the reliability of information resources with regard to age and gender. Health information has an undisputable role in the prevention and control of pandemic diseases such as COVID-19. Providing accurate, reliable, and evidence-based information in a timely manner for the use of resources and information channels related to COVID-19 can be a fast and low-cost strategic approach in confronting this disease.

scholarly journals Investigation on Thermal Resistance and Capacitance Characteristics of a Highly Integrated Power Control Unit Module

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 958
Author(s):  
Maosheng Zhang ◽  
Yu Bai ◽  
Shu Yang ◽  
Kuang Sheng
Keyword(s):  
Thermal Resistance ◽  
Power Control ◽  
Electric Vehicles ◽  
Low Cost ◽  
Control Unit ◽  
Underlying Mechanism ◽  
Power Converter ◽  
Liquid Cooling ◽  
Integration Density ◽  
Unit Module

With the increasing integration density of power control unit (PCU) modules, more functional power converter units are integrated into a single module for applications in electric vehicles or hybrid electric vehicles (EVs/HEVs). Different types of power dies with different footprints are usually placed closely together. Due to the constraints from the placement of power dies and liquid cooling schemes, heat-flow paths from the junction to coolant are possibly inconsistent for power dies, resulting in different thermal resistance and capacitance (RC) characteristics of power dies. This presents a critical challenge for optimal liquid cooling at a low cost. In this paper, a highly integrated PCU module is developed for application in EVs/HEVs. The underlying mechanism of the inconsistent RC characteristics of power dies for the developed PCU module is revealed by experiments and simulations. It is found that the matching placement design of power dies with a heat sink structure and liquid cooler, as well as a liquid cooling scheme, can alleviate the inconsistent RC characteristics of power dies in highly integrated PCU modules. The findings in this paper provide valuable guidance for the design of highly integrated PCU modules.

scholarly journals Designing of an Advanced Compression Bioreactor with an Implementation of a Low-Cost Controlling System Connected to a Mobile Application

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 915
Author(s):  
Gözde Dursun ◽  
Muhammad Umer ◽  
Bernd Markert ◽  
Marcus Stoffel
Keyword(s):  
Mobile Application ◽  
Low Cost ◽  
Experimental Information ◽  
Raspberry Pi ◽  
Tissue Constructs ◽  
Cost Controlling ◽  
Controlling System ◽  
And Control ◽  
Tissue Models

(1) Background: Bioreactors mimic the natural environment of cells and tissues by providing a controlled micro-environment. However, their design is often expensive and complex. Herein, we have introduced the development of a low-cost compression bioreactor which enables the application of different mechanical stimulation regimes to in vitro tissue models and provides the information of applied stress and strain in real-time. (2) Methods: The compression bioreactor is designed using a mini-computer called Raspberry Pi, which is programmed to apply compressive deformation at various strains and frequencies, as well as to measure the force applied to the tissue constructs. Besides this, we have developed a mobile application connected to the bioreactor software to monitor, command, and control experiments via mobile devices. (3) Results: Cell viability results indicate that the newly designed compression bioreactor supports cell cultivation in a sterile environment without any contamination. The developed bioreactor software plots the experimental data of dynamic mechanical loading in a long-term manner, as well as stores them for further data processing. Following in vitro uniaxial compression conditioning of 3D in vitro cartilage models, chondrocyte cell migration was altered positively compared to static cultures. (4) Conclusion: The developed compression bioreactor can support the in vitro tissue model cultivation and monitor the experimental information with a low-cost controlling system and via mobile application. The highly customizable mold inside the cultivation chamber is a significant approach to solve the limited customization capability of the traditional bioreactors. Most importantly, the compression bioreactor prevents operator- and system-dependent variability between experiments by enabling a dynamic culture in a large volume for multiple numbers of in vitro tissue constructs.

scholarly journals Model-Based Slippage Estimation to Enhance Planetary Rover Localization with Wheel Odometry

2021 ◽  
Vol 11 (12) ◽  
pp. 5490
Author(s):  
Anna Maria Gargiulo ◽  
Ivan di Stefano ◽  
Antonio Genova
Keyword(s):  
Inertial Measurement Unit ◽  
Correction Method ◽  
Harsh Environments ◽  
Measurement Unit ◽  
Planetary Rovers ◽  
Model Based ◽  
Accurate Knowledge ◽  
And Control ◽  
Wheeled Vehicles ◽  
Rover Localization

The exploration of planetary surfaces with unmanned wheeled vehicles will require sophisticated software for guidance, navigation and control. Future missions will be designed to study harsh environments that are characterized by rough terrains and extreme conditions. An accurate knowledge of the trajectory of planetary rovers is fundamental to accomplish the scientific goals of these missions. This paper presents a method to improve rover localization through the processing of wheel odometry (WO) and inertial measurement unit (IMU) data only. By accurately defining the dynamic model of both a rover’s wheels and the terrain, we provide a model-based estimate of the wheel slippage to correct the WO measurements. Numerical simulations are carried out to better understand the evolution of the rover’s trajectory across different terrain types and to determine the benefits of the proposed WO correction method.

scholarly journals Collagen metabolism as a regulator of proline dehydrogenase/proline oxidase-dependent apoptosis/autophagy

Amino Acids ◽  
2021 ◽  
Author(s):  
Jerzy Palka ◽  
Ilona Oscilowska ◽  
Lukasz Szoka
Keyword(s):  
Cell Metabolism ◽  
Underlying Mechanism ◽  
Collagen Biosynthesis ◽  
Proline Metabolism ◽  
Proline Dehydrogenase ◽  
Histone Demethylases ◽  
Proline Oxidase ◽  
Prolyl Hydroxylases ◽  
Transport Chain ◽  
And Control

AbstractRecent studies on the regulatory role of amino acids in cell metabolism have focused on the functional significance of proline degradation. The process is catalysed by proline dehydrogenase/proline oxidase (PRODH/POX), a mitochondrial flavin-dependent enzyme converting proline into ∆1-pyrroline-5-carboxylate (P5C). During this process, electrons are transferred to electron transport chain producing ATP for survival or they directly reduce oxygen, producing reactive oxygen species (ROS) inducing apoptosis/autophagy. However, the mechanism for switching survival/apoptosis mode is unknown. Although PRODH/POX activity and energetic metabolism were suggested as an underlying mechanism for the survival/apoptosis switch, proline availability for this enzyme is also important. Proline availability is regulated by prolidase (proline supporting enzyme), collagen biosynthesis (proline utilizing process) and proline synthesis from glutamine, glutamate, α-ketoglutarate (α-KG) and ornithine. Proline availability is dependent on the rate of glycolysis, TCA and urea cycles, proline metabolism, collagen biosynthesis and its degradation. It is well established that proline synthesis enzymes, P5C synthetase and P5C reductase as well as collagen prolyl hydroxylases are up-regulated in most of cancer types and control rates of collagen biosynthesis. Up-regulation of collagen prolyl hydroxylase and its exhaustion of ascorbate and α-KG may compete with DNA and histone demethylases (that require the same cofactors) to influence metabolic epigenetics. This knowledge led us to hypothesize that up-regulation of prolidase and PRODH/POX with inhibition of collagen biosynthesis may represent potential pharmacotherapeutic approach to induce apoptosis or autophagic death in cancer cells. These aspects of proline metabolism are discussed in the review as an approach to understand complex regulatory mechanisms driving PRODH/POX-dependent apoptosis/survival.

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