scholarly journals 1.5 °C degrowth scenarios suggest the need for new mitigation pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lorenz T. Keyßer ◽  
Manfred Lenzen
Keyword(s):  
Technological Change ◽  
High Speed ◽  
Large Scale ◽  
High Energy ◽  
Climate Mitigation ◽  
Intergovernmental Panel ◽  
Economic Output ◽  
Integrated Assessment Modelling ◽  
Negative Emissions ◽  
Energy Emissions

Abstract1.5  °C scenarios reported by the Intergovernmental Panel on Climate Change (IPCC) rely on combinations of controversial negative emissions and unprecedented technological change, while assuming continued growth in gross domestic product (GDP). Thus far, the integrated assessment modelling community and the IPCC have neglected to consider degrowth scenarios, where economic output declines due to stringent climate mitigation. Hence, their potential to avoid reliance on negative emissions and speculative rates of technological change remains unexplored. As a first step to address this gap, this paper compares 1.5  °C degrowth scenarios with IPCC archetype scenarios, using a simplified quantitative representation of the fuel-energy-emissions nexus. Here we find that the degrowth scenarios minimize many key risks for feasibility and sustainability compared to technology-driven pathways, such as the reliance on high energy-GDP decoupling, large-scale carbon dioxide removal and large-scale and high-speed renewable energy transformation. However, substantial challenges remain regarding political feasibility. Nevertheless, degrowth pathways should be thoroughly considered.

scholarly journals Technology and human purpose: the problem of solids transport on the earth's surface

2012 ◽  
Vol 3 (1) ◽  
pp. 417-431 ◽  
Author(s):  
P. K. Haff
Keyword(s):  
Land Surface ◽  
High Speed ◽  
Large Scale ◽  
Potential Gradient ◽  
High Energy ◽  
Transport Infrastructure ◽  
Advective Transport ◽  
Long Distance ◽  
Solids Transport ◽  
Human Purpose

Abstract. Displacement of mass of limited deformability ("solids") on the Earth's surface is opposed by friction and (the analog of) form resistance – impediments relaxed by rotational motion, self-powering of mass units, and transport infrastructure. These features of solids transport first evolved in the biosphere prior to the emergence of technology, allowing slope-independent, diffusion-like motion of discrete objects as massive as several tons, as illustrated by animal foraging and movement along game trails. However, high-energy-consumption technology powered by fossil fuels required a mechanism that could support advective transport of solids, i.e., long-distance, high-volume, high-speed, unidirectional, slope independent transport across the land surface of materials like coal, containerized fluids, and minerals. Pre-technology nature was able to sustain large-scale, long-distance solids advection only in the limited form of piggybacking on geophysical flows of water (river sediment) and air (dust). The appearance of a generalized mechanism for advection of solids independent of fluid flows and gravity appeared only upon the emergence of human purpose. Purpose enables solids advection by, in effect, enabling a simulated continuous potential gradient, otherwise lacking, between discrete and widely separated fossil-fuel energy sources and sinks. Invoking purpose as a mechanism in solids advection is an example of the need to import anthropic principles and concepts into the language and methodology of modern Earth system dynamics. As part of the emergence of a generalized solids advection mechanism, several additional transport requirements necessary to the function of modern large-scale technological systems were also satisfied. These include spatially accurate delivery of advected payload, targetability to essentially arbitrarily located destinations (such as cities), and independence of structure of advected payload from transport mechanism. The latter property enables the transport of an onboard power supply and delivery of persistent-memory, high-information-content payload, such as technological artifacts ("parts").

Holographic femtosecond laser manipulation for advanced material processing

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Satoshi Hasegawa ◽  
Yoshio Hayasaki
Keyword(s):  
Material Processing ◽  
Femtosecond Laser ◽  
Laser Processing ◽  
High Speed ◽  
Large Scale ◽  
High Energy ◽  
Material Surface ◽  
Two Photon ◽  
Computer Generated Hologram ◽  
Femtosecond Laser Processing

AbstractParallel femtosecond laser processing using a computer-generated hologram displayed on a spatial light modulator, known as holographic femtosecond laser processing, provides the advantages of high throughput and high-energy use efficiency. Therefore, it has been widely used in many applications, including laser material processing, two-photon polymerization, two-photon microscopy, and optical manipulation of biological cells. In this paper, we review the development of holographic femtosecond laser processing over the past few years from the perspective of wavefront and polarization modulation. In particular, line-shaped and vector-wave femtosecond laser processing are addressed. These beam-shaping techniques are useful for performing large-area machining in laser cutting, peeling, and grooving of materials and for high-speed fabrication of the complex nanostructures that are applied to material-surface texturing to control tribological properties, wettability, reflectance, and retardance. Furthermore, issues related to the nonuniformity of diffraction light intensity in optical reconstruction and wavelength dispersion from a computer-generated hologram are addressed. As a result, large-scale holographic femtosecond laser processing over 1000 diffraction spots was successfully demonstrated on a glass sample.

Research on a Novel High-Speed Pulsating Turning Technology

2015 ◽  
Author(s):  
Yuanfeng He ◽  
Wenwu Zhang
Keyword(s):  
Energy Consumption ◽  
High Speed ◽  
Large Scale ◽  
Cutting Speed ◽  
High Energy ◽  
Work Piece ◽  
Cutting Efficiency ◽  
Cutting Heat ◽  
Lathe Machine ◽  
Machine Speed

As one of the most important machining methods, common turning has been applied on vast machining fields. Parts in revolving shape can be easily machined using lathe machine. But severe cutting heat is often generated by the contact of tool and work-piece in the procedure of turning. High cutting heat not only affects tool life and processing quality but also leads to low cutting efficiency and high energy consumption. As to the demands of processing work-piece in large scale like marine shaft, heavy lathe is utilized. Considering the inertia load and the stability of the whole machine, speed of spindle is limited and the cutting efficiency is limited thusly because cutting speed is determined by rotate speed of spindle with fixed tool. A novel high-speed pulsating turning technology (HSPT) was proposed in this paper. The contact relation between tool and work-piece was modified to be pulsating instead of continuous in common methods. The advantages of HSPT include lower energy consumption, less cutting heat, higher cutting speed compared with common method. Features of energy consumption, contact duration of tools and work-piece, surface roughness, etc. was investigated through theoretical analysis and experiment study, which have verified the advanced performance of HSPT.

scholarly journals Meso/macroscopically multifunctional surface interfaces, ridges, and vortex-modified anode/cathode cuticles as force-driven modulation of high-energy density of LIB electric vehicles

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. Khalifa ◽  
S. A. El-Safty ◽  
A. Reda ◽  
M. A. Shenashen ◽  
M. M. Selim ◽  
...  
Keyword(s):  
Energy Density ◽  
High Speed ◽  
Large Scale ◽  
Coulombic Efficiency ◽  
Scale Up ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Diverse Range

Abstract Modulation of lithium-ion battery (LIB) anodes/cathodes with three-dimensional (3D) topographical hierarchy ridges, surface interfaces, and vortices promotes the power tendency of LIBs in terms of high-energy density and power density. Large-scale meso-geodesics offer a diverse range of spatial LIB models along the geodetically shaped downward/upward curvature, leading to open-ended movement gate options, and diffusible space orientations. Along with the primary 3D super-scalable hierarchy, the formation of structural features of building block egress/ingress, curvature cargo-like sphere vehicles, irregularly located serrated cuticles with abundant V-undulated rigidness, feathery tube pipe conifers, and a band of dagger-shaped needle sticks on anode/cathode electrode surfaces provides high performance LIB modules. The geodetically-shaped anode/cathode design enables the uniqueness of all LIB module configurations in terms of powerful lithium ion (Li+) movement revolving in out-/in- and up-/downward diffusion regimes and in hovering electron density for high-speed discharge rates. The stability of built-in anode//cathode full-scale LIB-model meso-geodesics affords an outstanding long-term cycling performance. The full-cell LIB meso-geodesics offered 91.5% retention of the first discharge capacity of 165.8 mAhg−1 after 2000 cycles, Coulombic efficiency of ~99.6% at the rate of 1 C and room temperature, and high specific energy density of ≈119 Wh kg−1. This LIB meso-geodesic module configuration may align perfectly with the requirements of the energy density limit mandatory for long-term EV driving range and the scale-up commercial manufactures.

scholarly journals Technology and human purpose: the problem of solids transport on the Earth's surface

2012 ◽  
Vol 3 (2) ◽  
pp. 149-156 ◽  
Author(s):  
P. K. Haff
Keyword(s):  
Land Surface ◽  
High Speed ◽  
Large Scale ◽  
Potential Gradient ◽  
High Energy ◽  
Transport Infrastructure ◽  
Advective Transport ◽  
Long Distance ◽  
Solids Transport ◽  
Human Purpose

Abstract. Displacement of mass of limited deformability ("solids") on the Earth's surface is opposed by friction and (the analog of) form resistance – impediments relaxed by rotational motion, self-powering of mass units, and transport infrastructure. These features of solids transport first evolved in the biosphere prior to the emergence of technology, allowing slope-independent, diffusion-like motion of discrete objects as massive as several tons, as illustrated by animal foraging and movement along game trails. However, high-energy-consumption technology powered by fossil fuels required a mechanism that could support fast advective transport of solids, i.e., long-distance, high-volume, high-speed, unidirectional, slope-independent transport across the land surface of materials like coal, containerized fluids, minerals, and economic goods. Pre-technology nature was able to sustain regional- and global-scale advection only in the limited form of piggybacking on geophysical flows of water (river sediment) and air (dust). The appearance of a mechanism for sustained advection of solids independent of fluid flows and gravity appeared only upon the emergence of human purpose. Purpose enables solids advection by, in effect, simulating a continuous potential gradient, otherwise lacking, between discrete and widely separated fossil-fuel energy sources and sinks. Invoking purpose as a mechanism in solids advection is an example of the need to import anthropic principles and concepts into the language and methodology of modern Earth system dynamics. As part of the emergence of a generalized solids advection mechanism, several additional transport requirements necessary to the function of modern large-scale technological systems were also satisfied. These include spatially accurate delivery of advected payload, targetability to essentially arbitrarily located destinations (such as cities), and independence of structure of advected payload from transport mechanism. The latter property enables the transport of an onboard power supply and delivery of persistent-memory, high-information-content payload, such as technological artifacts ("parts").

The continuity of craft masculinities: from letterpress to offset-lithography

Hot Metal ◽  
2016 ◽  
Author(s):  
Jesse Adams Stein
Keyword(s):  
Technological Change ◽  
High Speed ◽  
Large Scale ◽  
Printing Press ◽  
Social Agency ◽  
Shop Floor ◽  
The Press ◽  
Letterpress Printing ◽  
Labour History ◽  
Technical Artefact

This chapter considers the effect that an autonomous technical artefact – the printing press – had on the workers in charge of them, the press-machinists. It establishes how the printing press possesses material and social agency in the continuity and transformation of craft masculinity. This issue is examined in the context of the technological shift from letterpress printing to high-speed offset-lithography, which took place chiefly in the 1970s. While the compositors’ experience of technological change has received some attention in labour history and sociology, the trade of press-machining has been almost entirely ignored. Charting the printing industry’s transition from letterpress to offset-lithography opens a new window of understanding into the relevance and influence of large-scale technical machinery on the shop floor. This is related back to the reinforcement of craft masculinities in declining industrial contexts. This allows us to see how particular practices and identities are sometimes maintained and reinvigorated when a conservative institution is threatened with change.

The Effect of Chevrons on the Primary and Secondary Swirlers on the Dynamic Behavior of the Flow Generated by a Counter-Rotating Radial-Radial Swirler

2016 ◽  
Author(s):  
Sheng-Chieh Lin ◽  
Wessam Estefanos ◽  
James Brennan ◽  
Samir Tambe ◽  
San-Mou Jeng
Keyword(s):  
Reynolds Number ◽  
Dynamic Behavior ◽  
High Speed ◽  
Large Scale ◽  
Swirling Flow ◽  
Vertical Plane ◽  
High Energy ◽  
Flow Dynamic ◽  
Trailing Edge ◽  
Combustion Dynamics

An experimental investigation was conducted to study the effect of chevrons on the dynamic behavior of the swirling flow generated by a counter-rotating radial-radial swirler. 3X models of a low swirl number swirler (SN ≈ 0.6) were used to achieve lower velocities for the same Reynolds number (Re) and enhanced visibility of the flow characteristics by enabling high spatial and temporal resolutions. Three swirler configurations were used, including the baseline with no chevrons. Configuration 2 features chevrons on the trailing edge of the primary swirler, and configuration 3 has chevrons on the trailing edge of both primary and secondary swirlers. The swirlers were tested in water flow at Reynolds number (Re) = 51,500 which corresponds to the typical operational pressure drop of 4% of atmospheric pressure for the corresponding 1X model of the swirler at ambient conditions. Water testing was used since it allows additional slowing down of the flow dynamic features so that they can be captured and analyzed. Measurements were conducted in a vertical plane passing through the swirler centerline, and two horizontal (cross-sectional) planes using a High-Speed, Two Dimensional, Particle Image Velocimetry (2D PIV) system to obtain the mean, turbulent and dynamic behavior of the flow. Results of this study introduce the concept of chevrons on swirlers as a promising approach to change the flow dynamic behavior and thus, affect combustion dynamics. The results show that the presence of chevrons break down the region of high modal energy into several smaller regions. However, configuration 2 has few regions of the highest modal energy among the configurations, whereas the modal energy values for configurations 3 has the lowest magnitudes. Thus, the secondary chevrons in configuration 3 play an important role to eliminate these high-energy local spots as well as meet the requirement to break down the large scale structures.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

The Potential of Photoelectrochemical Carbon Sinks

2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Greenhouse Gas ◽  
Large Scale ◽  
High Efficiency ◽  
Carbon Sink ◽  
Solar Fuels ◽  
Negative Emissions ◽  
Viable Approach ◽  
Low Sensitivity

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>

Sign in / Sign up

Export Citation Format

Share Document