scholarly journals A pan-African spatial assessment of human conflicts with lions and elephants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Enrico Di Minin ◽  
Rob Slotow ◽  
Christoph Fink ◽  
Hans Bauer ◽  
Craig Packer
Keyword(s):  
Cost Effective ◽  
Local Communities ◽  
Mitigation Strategies ◽  
Human Pressure ◽  
High Quality ◽  
Species Ranges ◽  
African Lion ◽  
Pan African ◽  
African Lions ◽  
Conflict Mitigation

AbstractAfrican lions (Panthera leo) and African savanna (Loxodonta africana) and forest (L. cyclotis) elephants pose threats to people, crops, and livestock, and are themselves threatened with extinction. Here, we map these human-wildlife conflicts across Africa. Eighty-two percent of sites containing lions and elephants are adjacent to areas with considerable human pressure. Areas at severe risk of conflict (defined as high densities of humans, crops, and cattle) comprise 9% of the perimeter of these species’ ranges and are found in 18 countries hosting, respectively, ~ 74% and 41% of African lion and elephant populations. Although a variety of alternative conflict-mitigation strategies could be deployed, we focus on assessing the potential of high-quality mitigation fences. Our spatial and economic assessments suggest that investments in the construction and maintenance of strategically located mitigation fences would be a cost-effective strategy to support local communities, protect people from dangerous wildlife, and prevent further declines in lion and elephant populations.

The Formability and Elongation of Aluminum Alloys AA5083 and AA3003 for Micro-Truss Sandwiches Manufacturing

2020 ◽  
Vol 38 (9A) ◽  
pp. 1396-1405
Author(s):  
Arwa F. Tawfeeq ◽  
Matthew R. Barnett
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Cost Effective ◽  
Tensile Tests ◽  
Truss Structures ◽  
High Quality ◽  
Trade Off ◽  
Clad Layer ◽  
Higher Temperature ◽  
Different Shapes

The development in the manufacturing of micro-truss structures has demonstrated the effectiveness of brazing for assembling these sandwiches, which opens new opportunities for cost-effective and high-quality truss manufacturing. An evolving idea in micro-truss manufacturing is the possibility of forming these structures in different shapes with the aid of elevated temperature. This work investigates the formability and elongation of aluminum alloy sheets typically used for micro-truss manufacturing, namely AA5083 and AA3003. Tensile tests were performed at a temperature in the range of 25-500 ○C and strain rate in the range of 2x10-4 -10-2 s-1. The results showed that the clad layer in AA3003 exhibited an insignificant effect on the formability and elongation of AA3003. The formability of the two alloys was improved significantly with values of m as high as 0.4 and 0.13 for AA5083 and AA3003 at 500 °C. While the elongation of both AA5083 and AA3003 was improved at a higher temperature, the elongation of AA5083 was inversely related to strain rate. It was concluded that the higher the temperature is the better the formability and elongation of the two alloys but at the expense of work hardening. This suggests a trade-off situation between formability and strength. 

scholarly journals Visual Search and Conflict Mitigation Strategies Used by Expert en Route Air Traffic Controllers

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 170
Author(s):  
Ricardo Palma Fraga ◽  
Ziho Kang ◽  
Jerry M. Crutchfield ◽  
Saptarshi Mandal
Keyword(s):  
Visual Search ◽  
Traffic Control ◽  
Air Traffic Control ◽  
Relevant Information ◽  
Air Traffic ◽  
Mitigation Strategies ◽  
Air Traffic Controllers ◽  
Search Patterns ◽  
Potential Applications ◽  
Conflict Mitigation

The role of the en route air traffic control specialist (ATCS) is vital to maintaining safety and efficiency within the National Airspace System (NAS). ATCSs must vigilantly scan the airspace under their control and adjacent airspaces using an En Route Automation Modernization (ERAM) radar display. The intent of this research is to provide an understanding of the expert controller visual search and aircraft conflict mitigation strategies that could be used as scaffolding methods during ATCS training. Interviews and experiments were conducted to elicit visual scanning and conflict mitigation strategies from the retired controllers who were employed as air traffic control instructors. The interview results were characterized and classified using various heuristics. In particular, representative visual scanpaths were identified, which accord with the interview results of the visual search strategies. The highlights of our findings include: (1) participants used systematic search patterns, such as circular, spiral, linear or quadrant-based, to extract operation-relevant information; (2) participants applied an information hierarchy when aircraft information was cognitively processed (altitude -> direction -> speed); (3) altitude or direction changes were generally preferred over speed changes when imminent potential conflicts were mitigated. Potential applications exist in the implementation of the findings into the training curriculum of candidates.

scholarly journals 2D-3D integration of hexagonal boron nitride and a high-κ dielectric for ultrafast graphene-based electro-absorption modulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hitesh Agarwal ◽  
Bernat Terrés ◽  
Lorenzo Orsini ◽  
Alberto Montanaro ◽  
Vito Sorianello ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hafnium Oxide ◽  
High Speed ◽  
Hexagonal Boron Nitride ◽  
Temperature Stability ◽  
Cost Effective ◽  
Fold Increase ◽  
Building Blocks ◽  
High Quality ◽  
New Device

AbstractElectro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs.

scholarly journals Fast and Cost-Effective Synthesis of High-Quality Graphene on Copper Foils Using High-Current Arc Evaporation

Materials ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 804 ◽  
Author(s):  
Helge Lux ◽  
Matthias Edling ◽  
Peter Siemroth ◽  
Sigurd Schrader
Keyword(s):  
Cost Effective ◽  
High Current ◽  
High Quality ◽  
Copper Foils ◽  
Effective Synthesis ◽  
Arc Evaporation

A cost-effective acid degumming process produces high-quality Jatropha oil in tropical monsoon climates

2015 ◽  
Vol 117 (7) ◽  
pp. 1079-1087 ◽  
Author(s):  
Shih-Yuan Chen ◽  
Nattawee Teerananont ◽  
Thanita Sonthisawate ◽  
Piyanan Sreesiri ◽  
Chanakan Puemchalad ◽  
...  
Keyword(s):  
Cost Effective ◽  
Jatropha Oil ◽  
High Quality ◽  
Tropical Monsoon ◽  
Degumming Process

Understanding the complementary nature of paid and volunteer crowds for content creation

2020 ◽  
pp. 37
Author(s):  
Claudia Flores-Saviaga ◽  
Ricardo Granados ◽  
Liliana Savage ◽  
Lizbeth Escobedo ◽  
Saiph Savage
Keyword(s):  
Real World ◽  
Limited Resource ◽  
Cost Effective ◽  
High Quality ◽  
Power Cost ◽  
Non Profit ◽  
Content Creation ◽  
Online Study ◽  
Complementary Nature ◽  
Different Populations

Crowdsourced content creation like articles or slogans can be powered by crowds of volunteers or workers from paid task markets. Volunteers often have expertise and are intrinsically motivated, but are a limited resource, and are not always reliably available. On the other hand, paid crowd workers are reliably available, can be guided to produce high-quality content, but cost money. How can these different populations of crowd workers be leveraged together to power cost-effective yet high-quality crowd-powered content-creation systems? To answer this question, we need to understand the strengths and weaknesses of each. We conducted an online study where we hired paid crowd workers and recruited volunteers from social media to complete three content creation tasks for three real-world non-profit organizations that focus on empowering women. These tasks ranged in complexity from simply generating keywords or slogans to creating a draft biographical article. Our results show that paid crowds completed work and structured content following editorial guidelines more effectively. However, volunteer crowds provide content that is more original. Based on the findings, we suggest that crowd-powered content-creation systems could gain the best of both worlds by leveraging volunteers to scaffold the direction that original content should take; while having paid crowd workers structure content and prepare it for real world use.

scholarly journals Toward Cost-Effective Manufacturing of Silicon Solar Cells: Electrodeposition of High-Quality Si Films in a CaCl2-based Molten Salt

2017 ◽  
Vol 56 (47) ◽  
pp. 15078-15082 ◽  
Author(s):  
Xiao Yang ◽  
Li Ji ◽  
Xingli Zou ◽  
Taeho Lim ◽  
Ji Zhao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molten Salt ◽  
Cost Effective ◽  
Silicon Solar Cells ◽  
High Quality ◽  
Si Films
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