scholarly journals Development of Metal Powder Hot Embossing: A New Method for Micromanufacturing

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 388 ◽  
Author(s):  
Elsa W. Sequeiros ◽  
Omid Emadinia ◽  
Maria Teresa Vieira ◽  
Manuel Fernando Vieira
Keyword(s):  
Low Cost ◽  
Hot Embossing ◽  
Critical Conditions ◽  
Process Equipment ◽  
Small Scale ◽  
Polymeric Binder ◽  
Industrial Sectors ◽  
Feedstock Preparation ◽  
Short Time ◽  
Further Development

Hot embossing is a small-scale, low-cost processing technology that can deliver products to the market in a short time. This microreplication technology is well established to produce polymeric components and has applications in several industrial sectors. The use of micropowder hot embossing in the production of metal components is an emerging and challenging process that, when compared to other typical technologies, brings some economic advantages in a volatile market with an increasing tendency to manufacture customized products. The main objective of this review is to analyze the potential of powder hot embossing and its developments in the production of metallic microparts/components. This technology requires four distinct steps: (1) production feedstock (preparation of mixtures), (2) hot embossing (shape forming), (3) debinding and (4) sintering. These steps are interrelated and influence the characteristics of the final metallic microparts. This study summarizes the approaches implemented for the use of different metallic powders and polymeric binder systems for the preparation of the feedstock, the mold materials and the critical conditions tested in the embossing step to produce green parts, and the production of the final parts through the application of debinding and sintering. Powder hot embossing is a viable replication technology that allows the production of new metallic microcomponents, contributing to the global scientific effort of miniaturizing manufacturing process, equipment and products. The merit of powder hot embossing for industrialization needs further development to assert itself in the market and compete with other micromanufacturing techniques.

CITTASLOW HAREKETİNDEN İLHAM ALINARAK TEKSTİL VE MODA SEKTÖRÜNDE DE YAVAŞLAMA HAREKETİNİN YAYGINLAŞTIRILMASI

2021 ◽  
Vol 7 (27) ◽  
pp. 47-55
Author(s):  
Tuğba ÖZTÜRK
Keyword(s):  
Human Life ◽  
Low Cost ◽  
Small Scale ◽  
Negative Effects ◽  
Small Cities ◽  
Slow Food ◽  
Permanent Damage ◽  
Urban Settlements ◽  
Short Time

The Cittaslow Movement, which emerged as a response to the negative effects of globalization on small cities, was founded in 1999 with the initiative of the mayors of four small urban settlements in Italy and the founder of Slow Food. This movement, which aims to improve the quality of life by preserving and maintaining the local values of the settlements, has been adopted by 30 countries and more than 200 small-scale urban settlements in a short time. This movement is so important that it has to be implemented in all areas of human life. Because natural resources are consumed faster than they should be, and there is a slowdown in every field that is experienced as if it were unlimited. And of course the textile and fashion sector is one of them. Low-cost disposable products cause permanent damage to nature and create a consumption spree. In this study, the Cittaslow movement was inspired by the emergence of a deceleration movement in the fashion sector and we tried to draw attention to what we can do as consumers.

Low-Cost Hardware Implementation of Human Blood Identification Device Using Feed-Forward Artificial Neural Network on FPGA

2018 ◽  
Author(s):  
Rizki Eka Putri ◽  
Denny Darlis
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Low Cost ◽  
Image Resolution ◽  
Blood Type ◽  
Feed Forward ◽  
Testing Facility ◽  
System Input ◽  
Artificial Neural ◽  
Short Time

This article was under review for ICELTICS 2018 -- In the medical world there is still service dissatisfaction caused by lack of blood type testing facility. If the number of tested blood arise, a lot of problems will occur so that electronic devices are needed to determine the blood type accurately and in short time. In this research we implemented an Artificial Neural Network on Xilinx Spartan 3S1000 Field Programable Gate Array using XSA-3S Board to identify the blood type. This research uses blood sample image as system input. VHSIC Hardware Discription Language is the language to describe the algorithm. The algorithm used is feed-forward propagation of backpropagation neural network. There are 3 layers used in design, they are input, hidden1, and output. At hidden1layer has two neurons. In this study the accuracy of detection obtained are 92%, 92%, 92%, 90% and 86% for 32x32, 48x48, 64x64, 80x80, and 96x96 pixel blood image resolution, respectively.

Robust Test Method of TSOP PEMs for Space Application

2019 ◽  
Author(s):  
Yasunobu Iwai ◽  
Koichi Shinozaki ◽  
Daiki Tanaka
Keyword(s):  
Evaluation Method ◽  
Low Cost ◽  
Reliability Evaluation ◽  
Test Method ◽  
Thermal Shock Test ◽  
Space Application ◽  
Space Applications ◽  
Limit Test ◽  
Long Time ◽  
Short Time

Abstract Compared with space parts, consumer parts are highly functional, low cost, compact and lightweight. Therefore, their increased usage in space applications is expected. Prior testing and evaluation on space applicability are necessary because consumer parts do not have quality guarantees for space application [1]. However, in the conventional reliability evaluation method, the test takes a long time, and the problem is that the robustness of the target sample can’t be evaluated in a short time. In this report, we apply to the latest TSOP PEM (Thin Small Outline Package Plastic Encapsulated Microcircuit) an evaluation method that combines preconditioning and HALT (Highly Accelerated Limit Test), which is a test method that causes failures in a short time under very severe environmental conditions. We show that this method can evaluate the robustness of TSOP PEMs including solder connections in a short time. In addition, the validity of this evaluation method for TSOP PEM is shown by comparing with the evaluation results of thermal shock test and life test, which are conventional reliability evaluation methods.

Tools of Transformation: Appropriate Technology in U.S. Countercultural Literature

2012 ◽  
Vol 44 (2) ◽  
pp. 75-93
Author(s):  
Peter Mortensen
Keyword(s):  
Low Cost ◽  
Appropriate Technology ◽  
Small Scale ◽  
Environmental Transformation ◽  
Buckminster Fuller ◽  
1960S And 1970S ◽  
The 1960S ◽  
Environmentally Sound ◽  
User Friendly ◽  
Second Wave

This essay takes its cue from second-wave ecocriticism and from recent scholarly interest in the “appropriate technology” movement that evolved during the 1960s and 1970s in California and elsewhere. “Appropriate technology” (or AT) refers to a loosely-knit group of writers, engineers and designers active in the years around 1970, and more generally to the counterculture’s promotion, development and application of technologies that were small-scale, low-cost, user-friendly, human-empowering and environmentally sound. Focusing on two roughly contemporary but now largely forgotten American texts Sidney Goldfarb’s lyric poem “Solar-Heated-Rhombic-Dodecahedron” (1969) and Gurney Norman’s novel Divine Right’s Trip (1971)—I consider how “hip” literary writers contributed to eco-technological discourse and argue for the 1960s counterculture’s relevance to present-day ecological concerns. Goldfarb’s and Norman’s texts interest me because they conceptualize iconic 1960s technologies—especially the Buckminster Fuller-inspired geodesic dome and the Volkswagen van—not as inherently alienating machines but as tools of profound individual, social and environmental transformation. Synthesizing antimodernist back-to-nature desires with modernist enthusiasm for (certain kinds of) machinery, these texts adumbrate a humanity- and modernity-centered post-wilderness model of environmentalism that resonates with the dilemmas that we face in our increasingly resource-impoverished, rapidly warming and densely populated world.

scholarly journals Development of a simplified gas ultracleaning process: experiments in biomass residue-based fixed-bed gasification syngas

2021 ◽  
Author(s):  
Christian Frilund ◽  
Esa Kurkela ◽  
Ilkka Hiltunen
Keyword(s):  
Activated Carbons ◽  
Low Cost ◽  
Fixed Bed ◽  
Carbonyl Sulfide ◽  
Gas Analysis ◽  
Small Scale ◽  
Cleaning Process ◽  
Medium Temperature ◽  
Gas Cleaning ◽  
Adsorption Affinity

AbstractFor the realization of small-scale biomass-to-liquid (BTL) processes, low-cost syngas cleaning remains a major obstacle, and for this reason a simplified gas ultracleaning process is being developed. In this study, a low- to medium-temperature final gas cleaning process based on adsorption and organic solvent-free scrubbing methods was coupled to a pilot-scale staged fixed-bed gasification facility including hot filtration and catalytic reforming steps for extended duration gas cleaning tests for the generation of ultraclean syngas. The final gas cleaning process purified syngas from woody and agricultural biomass origin to a degree suitable for catalytic synthesis. The gas contained up to 3000 ppm of ammonia, 1300 ppm of benzene, 200 ppm of hydrogen sulfide, 10 ppm of carbonyl sulfide, and 5 ppm of hydrogen cyanide. Post-run characterization displayed that the accumulation of impurities on the Cu-based deoxygenation catalyst (TOS 105 h) did not occur, demonstrating that effective main impurity removal was achieved in the first two steps: acidic water scrubbing (AWC) and adsorption by activated carbons (AR). In the final test campaign, a comprehensive multipoint gas analysis confirmed that ammonia was fully removed by the scrubbing step, and benzene and H2S were fully removed by the subsequent activated carbon beds. The activated carbons achieved > 90% removal of up to 100 ppm of COS and 5 ppm of HCN in the syngas. These results provide insights into the adsorption affinity of activated carbons in a complex impurity matrix, which would be arduous to replicate in laboratory conditions.

scholarly journals Simultaneously Regulating Uniform Zn2+ Flux and Electron Conduction by MOF/rGO Interlayers for High-Performance Zn Anodes

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ziqi Wang ◽  
Liubing Dong ◽  
Weiyuan Huang ◽  
Hao Jia ◽  
Qinghe Zhao ◽  
...  
Keyword(s):  
High Performance ◽  
Surface Passivation ◽  
Coulombic Efficiency ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Growth Surface ◽  
Electron Conduction ◽  
Reduced Graphene ◽  
Metal Organic ◽  
Further Development

AbstractOwing to the merits of low cost, high safety and environmental benignity, rechargeable aqueous Zn-based batteries (ZBs) have gained tremendous attention in recent years. Nevertheless, the poor reversibility of Zn anodes that originates from dendrite growth, surface passivation and corrosion, severely hinders the further development of ZBs. To tackle these issues, here we report a Janus separator based on a Zn-ion conductive metal–organic framework (MOF) and reduced graphene oxide (rGO), which is able to regulate uniform Zn2+ flux and electron conduction simultaneously during battery operation. Facilitated by the MOF/rGO bifunctional interlayers, the Zn anodes demonstrate stable plating/stripping behavior (over 500 h at 1 mA cm−2), high Coulombic efficiency (99.2% at 2 mA cm−2 after 100 cycles) and reduced redox barrier. Moreover, it is also found that the Zn corrosion can be effectively retarded through diminishing the potential discrepancy on Zn surface. Such a separator engineering also saliently promotes the overall performance of Zn|MnO2 full cells, which deliver nearly 100% capacity retention after 2000 cycles at 4 A g−1 and high power density over 10 kW kg−1. This work provides a feasible route to the high-performance Zn anodes for ZBs.

scholarly journals A Proposal of a Motion Measurement System to Support Visually Impaired People in Rehabilitation Using Low-Cost Inertial Sensors

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 848
Author(s):  
Karla Miriam Reyes Leiva ◽  
Milagros Jaén-Vargas ◽  
Miguel Ángel Cuba ◽  
Sergio Sánchez Lara ◽  
José Javier Serrano Olmedo
Keyword(s):  
Visually Impaired ◽  
Inertial Sensors ◽  
Personal Autonomy ◽  
Low Cost ◽  
Step Length ◽  
Hand Position ◽  
Visually Impaired People ◽  
Gait Parameters ◽  
Impaired Person ◽  
Further Development

The rehabilitation of a visually impaired person (VIP) is a systematic process where the person is provided with tools that allow them to deal with the impairment to achieve personal autonomy and independence, such as training for the use of the long cane as a tool for orientation and mobility (O&M). This process must be trained personally by specialists, leading to a limitation of human, technological and structural resources in some regions, especially those with economical narrow circumstances. A system to obtain information about the motion of the long cane and the leg using low-cost inertial sensors was developed to provide an overview of quantitative parameters such as sweeping coverage and gait analysis, that are currently visually analyzed during rehabilitation. The system was tested with 10 blindfolded volunteers in laboratory conditions following constant contact, two points touch, and three points touch travel techniques. The results indicate that the quantification system is reliable for measuring grip rotation, safety zone, sweeping amplitude and hand position using orientation angles with an accuracy of around 97.62%. However, a new method or an improvement of hardware must be developed to improve gait parameters’ measurements, since the step length measurement presented a mean accuracy of 94.62%. The system requires further development to be used as an aid in the rehabilitation process of the VIP. Now, it is a simple and low-cost technological aid that has the potential to improve the current practice of O&M.

scholarly journals Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca
Keyword(s):  
Data Fusion ◽  
Spatial Variability ◽  
Urban Areas ◽  
Road Traffic ◽  
Dispersion Model ◽  
Low Cost ◽  
Spatial Modelling ◽  
City Centre ◽  
Small Scale ◽  
The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

scholarly journals Recent Developments of Antimony-Based Anodes for Sodium- and Potassium-Ion Batteries

2021 ◽  
Author(s):  
Bochao Chen ◽  
Ming Liang ◽  
Qingzhao Wu ◽  
Shan Zhu ◽  
Naiqin Zhao ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Low Cost ◽  
Potassium Ion ◽  
Research Progress ◽  
Research Directions ◽  
Weak Charge ◽  
Recent Developments ◽  
High Theoretical Capacity ◽  
Further Development ◽  
Sodium And Potassium

AbstractThe development of sodium-ion (SIBs) and potassium-ion batteries (PIBs) has increased rapidly because of the abundant resources and cost-effectiveness of Na and K. Antimony (Sb) plays an important role in SIBs and PIBs because of its high theoretical capacity, proper working voltage, and low cost. However, Sb-based anodes have the drawbacks of large volume changes and weak charge transfer during the charge and discharge processes, thus leading to poor cycling and rapid capacity decay. To address such drawbacks, many strategies and a variety of Sb-based materials have been developed in recent years. This review systematically introduces the recent research progress of a variety of Sb-based anodes for SIBs and PIBs from the perspective of composition selection, preparation technologies, structural characteristics, and energy storage behaviors. Moreover, corresponding examples are presented to illustrate the advantages or disadvantages of these anodes. Finally, we summarize the challenges of the development of Sb-based materials for Na/K-ion batteries and propose potential research directions for their further development.

scholarly journals A low-cost technique to measure bank erosion proces ses along middle-size river reaches

2018 ◽  
Author(s):  
Gonzalo Duró ◽  
Alessandra Crosato ◽  
Maarten G. Kleinhans ◽  
Wim S. J. Uijttewaal
Keyword(s):  
Laser Scanning ◽  
Spatial Scales ◽  
Low Cost ◽  
Bank Erosion ◽  
Water Levels ◽  
Small Scale ◽  
Observation Distance ◽  
River Bank ◽  
Erosion Processes ◽  
Rtk Gps

Abstract. Diverse methods are currently available to measure river bank erosion at broad-ranging temporal and spatial scales. Yet, no technique provides low-cost and high-resolution to survey small-scale bank processes along a river reach. We investigate the capabilities of Structure-from-Motion photogrammetry applied with imagery from an Unmanned Aerial Vehicle (UAV) to describe the evolution of riverbank profiles in middle-size rivers. The bank erosion cycle is used as a reference to assess the applicability of different techniques. We surveyed 1.2 km of a restored bank of the Meuse River eight times within a year, combining different photograph perspectives and overlaps to identify an efficient UAV flight to monitor banks. The accuracy of the Digital Surface Models (DSMs) was evaluated compared with RTK GPS points and an Airborne Laser Scanning (ALS) of the whole reach. An oblique perspective with eight photo overlaps was sufficient to achieve the highest relative precision to observation distance of ~1:1400, with 10 cm error range. A complementary nadiral view increased coverage behind bank toe vegetation. The DSM and ALS had comparable accuracies except on banks, where the latter overestimates elevations. Sequential DSMs captured signatures of the erosion cycle such as mass failures, slump-block deposition, and bank undermining. Although this technique requires low water levels and banks without dense vegetation, it is a low-cost method to survey reach-scale riverbanks in sufficient resolution to quantify bank retreat and identify morphological features of the bank failure and erosion processes.

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