Laboratory evidence of a pre‐existing instability that can enhance the ionospheric heating efficiency

3-D optimal design of laminated yoke of billet heater for rolling wire rod using ON/OFF method The optimization method using the ON/OFF sensitivity analysis has an advantage that an epoch-making construction of magnetic circuit may be obtained. Therefore, it is attractive for designers of magnetic devices. We have already developed the ON/OFF method for the optimization of a static magnetic field problem, and the effectiveness is verified by applying it to the optimization of magnetic recording heads. In this paper, the ON/OFF sensitivity method is extended to the optimization of the eddy current problem using the adjoint variable. The newly developed ON/OFF method is applied to the determination of the optimal topology of the yoke of the billet heater for rolling wire rod. As a result, the optimal shape of yoke, which we could not imagine beforehand can be obtained. It is shown that the local heating of the yoke was reduced without decreasing the heating efficiency.

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Aggregation affects optical properties and photothermal heating of gold nanospheres

Scientific Reports ◽

10.1038/s41598-020-79393-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yiru Wang ◽

Zhe Gao ◽

Zonghu Han ◽

Yilin Liu ◽

Huan Yang ◽

...

Keyword(s):

Optical Properties ◽

Cross Section ◽

Laser Heating ◽

Dipole Approximation ◽

Gold Nanospheres ◽

Extinction Cross Section ◽

Heating Efficiency ◽

Photothermal Heating ◽

New Framework ◽

Laser Calorimetry

AbstractLaser heating of gold nanospheres (GNS) is increasingly prevalent in biomedical applications due to tunable optical properties that determine heating efficiency. Although many geometric parameters (i.e. size, morphology) can affect optical properties of individual GNS and their heating, no specific studies of how GNS aggregation affects heating have been carried out. We posit here that aggregation, which can occur within some biological systems, will significantly impact the optical and therefore heating properties of GNS. To address this, we employed discrete dipole approximation (DDA) simulations, Ultraviolet–Visible spectroscopy (UV–Vis) and laser calorimetry on GNS primary particles with diameters (5, 16, 30 nm) and their aggregates that contain 2 to 30 GNS particles. DDA shows that aggregation can reduce the extinction cross-section on a per particle basis by 17–28%. Experimental measurement by UV–Vis and laser calorimetry on aggregates also show up to a 25% reduction in extinction coefficient and significantly lower heating (~ 10%) compared to dispersed GNS. In addition, comparison of select aggregates shows even larger extinction cross section drops in sparse vs. dense aggregates. This work shows that GNS aggregation can change optical properties and reduce heating and provides a new framework for exploring this effect during laser heating of nanomaterial solutions.

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Study on External Gas-Assisted Mold Temperature Control with the Assistance of a Flow Focusing Device in the Injection Molding Process

Materials ◽

10.3390/ma14040965 ◽

2021 ◽

Vol 14 (4) ◽

pp. 965 ◽

Cited By ~ 1

Author(s):

Nguyen Truong Giang ◽

Pham Son Minh ◽

Tran Anh Son ◽

Tran Minh The Uyen ◽

Thanh-Hai Nguyen ◽

...

Keyword(s):

Injection Molding ◽

Temperature Control ◽

Mold Temperature ◽

Injection Molding Process ◽

Melt Flow ◽

Flow Focusing ◽

Molding Process ◽

Heating Efficiency ◽

Flow Length ◽

Insert Plate

In the injection molding field, the flow of plastic material is one of the most important issues, especially regarding the ability of melted plastic to fill the thin walls of products. To improve the melt flow length, a high mold temperature was applied with pre-heating of the cavity surface. In this paper, we present our research on the injection molding process with pre-heating by external gas-assisted mold temperature control. After this, we observed an improvement in the melt flow length into thin-walled products due to the high mold temperature during the filling step. In addition, to develop the heating efficiency, a flow focusing device (FFD) was applied and verified. The simulations and experiments were carried out within an air temperature of 400 °C and heating time of 20 s to investigate a flow focusing device to assist with external gas-assisted mold temperature control (Ex-GMTC), with the application of various FFD types for the temperature distribution of the insert plate. The heating process was applied for a simple insert model with dimensions of 50 mm × 50 mm × 2 mm, in order to verify the influence of the FFD geometry on the heating result. After that, Ex-GMTC with the assistance of FFD was carried out for a mold-reading process, and the FFD influence was estimated by the mold heating result and the improvement of the melt flow length using acrylonitrile butadiene styrene (ABS). The results show that the air sprue gap (h) significantly affects the temperature of the insert and an air sprue gap of 3 mm gives the best heating rate, with the highest temperature being 321.2 °C. Likewise, the actual results show that the height of the flow focusing device (V) also influences the temperature of the insert plate and that a 5 mm high FFD gives the best results with a maximum temperature of 332.3 °C. Moreover, the heating efficiency when using FFD is always higher than without FFD. After examining the effect of FFD, its application was considered, in order to improve the melt flow length in injection molding, which increased from 38.6 to 170 mm, while the balance of the melt filling was also clearly improved.

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Subsidizing Charitable Giving with Rebates or Matching: Further Laboratory Evidence

Southern Economic Journal ◽

10.1002/j.2325-8012.2006.tb00738.x ◽

2006 ◽

Vol 72 (4) ◽

pp. 794-807

Author(s):

Catherine C. Eckel ◽

Philip J. Grossman

Keyword(s):

Charitable Giving ◽

Laboratory Evidence

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Use of a membrane module for semi-direct air evaporative cooling

Indoor and Built Environment ◽

10.1177/1420326x19877510 ◽

2019 ◽

Vol 29 (10) ◽

pp. 1346-1358 ◽

Cited By ~ 1

Author(s):

Sebastian Englart

Keyword(s):

Moisture Content ◽

Relative Error ◽

Air Temperature ◽

Evaporative Cooling ◽

Cross Flow ◽

Membrane Module ◽

Transfer Model ◽

Air Cooling ◽

Heating Efficiency ◽

Circulating Water

This study discusses the use of a membrane module for semi-direct evaporative air cooling. A cross-flow membrane module was used to carry out this air treatment process. For such a flow, it was proposed to describe and solve the heat and mass transfer model as a one-dimensional problem. The mathematical model was used to determine the moisture content and air temperature at the outlet from the module and the temperature of the circulating water. Results obtained using the proposed model are in good agreement with the experimental data. The relative error for the air temperature at the module outlet did not exceed 0.5%. For the moisture content, the relative error did not exceed 4%. For the circulating water temperature, the relative error did not exceed 0.6%. This paper also discusses the heating efficiency of the evaporative cooling process. Methods for determining the unit cooling indicator and the energy efficiency ratio are also proposed.

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Field and laboratory evidence that Bungowannah virus, a recently recognised pestivirus, is the causative agent of the porcine myocarditis syndrome (PMC)

Veterinary Microbiology ◽

10.1016/j.vetmic.2008.11.026 ◽

2009 ◽

Vol 136 (3-4) ◽

pp. 259-265 ◽

Cited By ~ 23

Author(s):

Deborah S. Finlaison ◽

Katherine R. King ◽

Melinda J. Frost ◽

Peter D. Kirkland

Keyword(s):

Causative Agent ◽

Laboratory Evidence

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An External Validation of Laboratory Evidence for Earned Dignity

Journal of Applied Social Psychology ◽

10.1111/j.1559-1816.1995.tb02614.x ◽

1995 ◽

Vol 25 (13) ◽

pp. 1204-1213 ◽

Cited By ~ 2

Author(s):

E. Rae Harcum ◽

Ellen F. Rosen ◽

Constance J. Pilkington ◽

Linda C. Petty

Keyword(s):

External Validation ◽

Laboratory Evidence

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A hybrid Zakharov particle simulation of ionospheric heating

Physics of Fluids B Plasma Physics ◽

10.1063/1.860269 ◽

1992 ◽

Vol 4 (3) ◽

pp. 708-718 ◽

Cited By ~ 10

Author(s):

K. L. Clark ◽

G. L. Payne ◽

D. R. Nicholson

Keyword(s):

Particle Simulation ◽

Ionospheric Heating

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Observations of HF-induced instability in the auroral E region

Annales Geophysicae ◽

10.5194/angeo-31-1103-2013 ◽

2013 ◽

Vol 31 (6) ◽

pp. 1103-1108 ◽

Cited By ~ 1

Author(s):

N. M. Schlatter ◽

N. Ivchenko ◽

B. Gustavsson ◽

T. Leyser ◽

M. Rietveld

Keyword(s):

Lower Layer ◽

Central Feature ◽

Ionospheric Heating ◽

E Region ◽

Uhf Radar

Abstract. Enhancements were observed in backscattered radar power during an ionospheric heating experiment from two distinct altitude regions in the auroral E region above Tromsø. For the experiment the EISCAT Tromsø heater was operated with O mode and X mode alternated at 4.04 MHz, close to the 3rd electron gyroharmonic. Ion-line data recorded with the EISCAT UHF radar reveal different temporal evolutions as well as different ion-line characteristics for the enhancements from the two altitude regions. The upper layer is dominated by a strong central feature, whereas the lower layer has three peaks corresponding to the central feature and the two ion lines. The altitude region of the two closely spaced (altitude separation ~ 5 km) but distinct enhancements is close to the critical altitude for the heater wave.

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