XIII. Observations on the best methods of producing artificial cold

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96?0.5%, bending strength - 47.01?2 MPa, compressive strength - 170 ?5 MPa) was produced at 1100?C using the heating rate of 10?C/min.

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Life Cycle Assessment on the Effects of Parameter Setting in Direct Recycling Hot Press Forging of Aluminum

Materials Science Forum ◽

10.4028/www.scientific.net/msf.923.143 ◽

2018 ◽

Vol 923 ◽

pp. 143-148 ◽

Cited By ~ 2

Author(s):

Mohd Amri Lajis ◽

Nur Kamilah Yusuf ◽

Azlan Ahmad

Keyword(s):

Solid State ◽

Environmental Concern ◽

Parameter Setting ◽

Hot Press ◽

Metallic Material ◽

Forging Process ◽

Global Environmental ◽

The Subject ◽

Metal Shaping ◽

Recycling Techniques

Metallic material processing plays a significant role in terms of global environmental impact which contributes to the climate change phenomena that is a serious international environmental concern and the subject of much research and debate. Thus, energy-and resource-efficient strategies in the metal shaping technology domain need to be identified urgently. A frequent theme in the debates that surround waste and resources management is the extent to which the recycling of metallic materials offers genuine benefits to the environment. Solid state recycling techniques allow the manufacture of high density aluminum alloy parts directly from production scrap. In this paper the environmental impacts associated with ‘meltless’ scrap processing routes through hot press forging process with varying parameter has been studied. A comparative analysis has been performed, with different operating temperature and holding time of direct recycling hot press forging process AA6061 aluminum chip. The importance of an environmental performance analysis that included both parameter setting was discussed and highlighted throughout the paper. Finally, the application of the proposed parameter setup has resulted in the setting up of an eco-process. Indeed, LCA study on recycling (solid-state) are recommended as well it gives a noteworthy benefit to the environment and to fill the knowledge gap.

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Sub-surface melting in blue-ice fields in Dronning Maud Land, Antarctica: observations and modelling

Annals of Glaciology ◽

10.1017/s0260305500015767 ◽

1995 ◽

Vol 21 ◽

pp. 162-168 ◽

Cited By ~ 11

Author(s):

Carl Egede Bøggild ◽

Jan-Gunnar Winther ◽

Knut Sand ◽

Hallgeir Elvehøy

Keyword(s):

Solid State ◽

Extinction Coefficient ◽

Freezing Point ◽

Field Studies ◽

Climate Fluctuations ◽

Air Temperatures ◽

Dronning Maud Land ◽

Ice Field ◽

Antarctic Research ◽

Surface Melt

During the Norwegian Antarctic Research Expedition 1993/94, field studies were conducted on a blue-ice field in Jutulgryta, Dronning Maud Land. Measurements of sub-surface temperatures revealed that temperatures in blue ice were about 6°C higher than in the adjacent snow. Despite the predominantly negative air temperatures, a sub-surface melt layer was discovered within the uppermost metre of the blue ice. Here the temperature maximum was consistent throughout the entire month of observations, and resulted in both internal melt and water transport. The melting is a consequence of solar radiative penetration and absorption within the ice, i.e. the “solid-state greenhouse”. Sensitivity experiments using a non-stationary combined radiative and thermodynamic model reveal that the physical properties (here extinction coefficient, radiation transmittance and albedo) strongly control the formation and vertical extent of the melt layer. The persistence of the sub-surface melt layer increases the runoff volume from blue-ice fields, which otherwise might be restricted to a few yearly events when air temperatures reach or exceed the freezing point. The conditions required for melting activity are marginal in Jutulgryta. Hence, this phenomenon may serve as an indicator of climate fluctuations in the area.

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Molecular Weight and Chain-Length of Natural and Synthetic Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3547986 ◽

1934 ◽

Vol 7 (1) ◽

pp. 34-39 ◽

Cited By ~ 1

Author(s):

A. J. Wildschut

Keyword(s):

Chain Length ◽

Freezing Point ◽

Specific Viscosity ◽

Molecular Weights ◽

Gutta Percha ◽

Synthetic Rubber ◽

The Subject ◽

Molecular Substances ◽

Very High

Abstract The determination of the chain-length of high molecular substances, as, e.g., rubber and gutta-percha, has lately been the subject of many investigations, though as yet the problem has not been definitely solved. The ordinary methods—measurements of the raising of the boiling point and of the depression of the freezing point—can be used only for molecular weights of some thousands, and there always remains a large gap between these compounds and the far greater natural ones. To bridge over this gap Staudinger has developed a supposition according to which it is possible to determine very high molecular weights by means of a viscosimetric method. This method depends on the known fact that for dilute solutions, in which the molecules do not hinder each other (so-called sol-solutions), the specific viscosity is proportional to the length of the molecule. For homologs we have:

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Photochemical Chain Reactions in Amorphous Solids

Laser Chemistry ◽

10.1155/lc.9.155 ◽

1988 ◽

Vol 9 (1-3) ◽

pp. 155-170 ◽

Cited By ~ 3

Author(s):

Arthur J. Sedlacek ◽

Charles A. Wight

Keyword(s):

Solid State ◽

Spray Deposition ◽

Product Yield ◽

Amorphous Solids ◽

Quantum Yields ◽

Intermediate Step ◽

Radical Chain ◽

Chain Reactions ◽

Recombination Processes ◽

The Subject

In this article, we review recent work in the authors' laboratory on the subject of free radical chain reactions of chlorine with small hydrocarbons in amorphous solids. The solids are formed as thin films by spray deposition of the gaseous reagents onto a cryogenic window. Reactions are initiated by excimer laser photolysis at 308 nm, which dissociates a small fraction of the chlorine molecules to atoms. Product yields and branching ratios are determined by infrared absorption spectroscopy. Reactions of chlorine with cyclopropane or cyclobutane proceed by true chain reactions, as evidenced by high product quantum yields (number of product molecules formed per laser photon absorbed by the sample). Measurements of the dependence of the product yield on the relative concentrations of chlorine and hydrocarbon provide clues to the reaction mechanism in the solid state. The cyclobutane reaction appears to involve H atom transfer from cyclobutane to cyclobutyl radical as an intermediate step in the overall reaction. Reaction of chlorine with propane, n-butane, or isobutane does not appear to involve chain propagation and is dominated by radical recombination processes which result in low quantum yields. All of these results are discussed in terms of reactions which occur in a solid state environment where molecular motion is severely restricted.

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Solid-State Nanopores for Nanoparticle Sensing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.618.8 ◽

2014 ◽

Vol 618 ◽

pp. 8-13

Author(s):

Lei Wang ◽

Wen Yuan Zhao ◽

Dan Mo ◽

Quan Jun Liu

Keyword(s):

Solid State ◽

Electric Field ◽

Comsol Multiphysics ◽

Particle Detection ◽

Fundamental Study ◽

Detection Techniques ◽

Sensing Technology ◽

The Subject ◽

Single Particle Detection ◽

Low Charge

In recent years, single particle detection techniques based on driving nanoparticles through nanoscopic pores with a voltage or pressure had been the subject of numerous studies. Since particles with high charge, such as DNA and proteins, have been widely used for research, there was little information about the translocation behavior of nanosized particles which with low charge. However, nanoparticles include virus and colloids are important samples for nanopore sensing technology. In this study, we employed the solid-state nanopore to sense nanoparticles as fundamental study. Nanopore with diameter of 185 nm has been used to detect the nanoparticles with compared low zeta potential of-16 mv in different voltages. And simulations of electric field strength was made by using COMSOL Multiphysics to assist analyze the translocation behavior. The result suggests that the nanoparticles could transport the nanopore under the large electric field. By rising up the bias voltage could favor the detection of the nanoparticles.

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Momentum Distribution and Charge Density in Solid-State Theory

Zeitschrift für Naturforschung A ◽

10.1515/zna-1993-1-234 ◽

1993 ◽

Vol 48 (1-2) ◽

pp. 151-158 ◽

Cited By ~ 1

Author(s):

Jean-Louis Calais

Keyword(s):

Solid State ◽

Charge Density ◽

Momentum Distribution ◽

State Theory ◽

Charge Densities ◽

Momentum Distributions ◽

Solid State Theory ◽

The Subject ◽

Theoretical Characterization ◽

Methodological Aspects

Abstract We present a discussion of a number of conceptual and methodological aspects associated with the theoretical characterization and computation of charge densities and momentum distributions in solids. The main ambition has been to stress properties that both exact and approximate quantities must possess. We have also attempted to point out conceptual and computational trends which would seem to be of importance for the future of the subject.

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Sub-surface melting in blue-ice fields in Dronning Maud Land, Antarctica: observations and modelling

Annals of Glaciology ◽

10.3189/s0260305500015767 ◽

1995 ◽

Vol 21 ◽

pp. 162-168 ◽

Cited By ~ 5

Author(s):

Carl Egede Bøggild ◽

Jan-Gunnar Winther ◽

Knut Sand ◽

Hallgeir Elvehøy

Keyword(s):

Solid State ◽

Extinction Coefficient ◽

Freezing Point ◽

Field Studies ◽

Climate Fluctuations ◽

Air Temperatures ◽

Dronning Maud Land ◽

Ice Field ◽

Antarctic Research ◽

Surface Melt

During the Norwegian Antarctic Research Expedition 1993/94, field studies were conducted on a blue-ice field in Jutulgryta, Dronning Maud Land. Measurements of sub-surface temperatures revealed that temperatures in blue ice were about 6°C higher than in the adjacent snow. Despite the predominantly negative air temperatures, a sub-surface melt layer was discovered within the uppermost metre of the blue ice. Here the temperature maximum was consistent throughout the entire month of observations, and resulted in both internal melt and water transport. The melting is a consequence of solar radiative penetration and absorption within the ice, i.e. the “solid-state greenhouse”. Sensitivity experiments using a non-stationary combined radiative and thermodynamic model reveal that the physical properties (here extinction coefficient, radiation transmittance and albedo) strongly control the formation and vertical extent of the melt layer. The persistence of the sub-surface melt layer increases the runoff volume from blue-ice fields, which otherwise might be restricted to a few yearly events when air temperatures reach or exceed the freezing point. The conditions required for melting activity are marginal in Jutulgryta. Hence, this phenomenon may serve as an indicator of climate fluctuations in the area.

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Colour centre generation in diamond for quantum technologies

Nanophotonics ◽

10.1515/nanoph-2019-0196 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1889-1906 ◽

Cited By ~ 14

Author(s):

Jason M. Smith ◽

Simon A. Meynell ◽

Ania C. Bleszynski Jayich ◽

Jan Meijer

Keyword(s):

Solid State ◽

Ion Implantation ◽

Electron Irradiation ◽

Research Effort ◽

Wide Band ◽

Colour Centre ◽

Wide Band Gap ◽

Colour Centres ◽

Delta Doping ◽

The Subject

AbstractEffective methods to generate colour centres in diamond and other wide band-gap materials are essential to the realisation of solid state quantum technologies based on such systems. Such methods have been the subject of intensive research effort in recent years. In this review, we bring together the various techniques used in the generation and positioning of colour centres in diamond: ion implantation, delta-doping, electron irradiation, laser writing and thermal annealing. We assess the roles and merits of each of these techniques in the formation of colour centres for different quantum technologies and consider future combinations of the techniques to meet the requirements of the most demanding applications.

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