Journal articles: 'Melting term'

1

Zhou, Jian, Jing Li, Guoqiang Liu, Tao Yang, and Yongli Zhao. "Long-Term Performance and Deicing Effect of Sustained-Release Snow Melting Asphalt Mixture." Advances in Civil Engineering 2019 (June 11, 2019): 1–12. http://dx.doi.org/10.1155/2019/1940692.

Full text

Abstract:

To accelerate snow and ice melting, traditional chloride-based salts are spreaded on asphalt pavement surface, causing serious environmental pollution and infrastructure corrosion. For sustained-release snow melting asphalt mixture, the snow melting agent of Mafilon is directly added to asphalt mixture by replacing partial mineral powder to develop a new type of functional asphalt mixture. In this paper, through the Marshall test, immersion Marshall test, rutting test, trabecular bending test, and Cantabro test, the effects of Mafilon addition on asphalt pavement performance is systematically analysed. Meanwhile, salt precipitation rate is measured by conductimetry to estimate effective deicing period of the pavement. Finally, a new experimental device is designed to quantitatively evaluate snow melting effect of sustained-release snow melting asphalt pavement. The experimental results show that replacing 70% of the mineral powder with Mafilon by volume can achieve satisfactory snow melting effect without affecting usability of asphalt pavement.

APA, Harvard, Vancouver, ISO, and other styles

2

Abdelaziz, Yasser A., F. M. Megahed, and M. M. Abdel-Aal. "LONG-TERM STABILITY OF Co-C AND Pd-C EUTECTIC FIXED POINTS FOR THERMOCOUPLES CALIBRATION." Measuring Equipment and Metrology 82, no. 1 (2021): 26–29. http://dx.doi.org/10.23939/istcmtm2021.01.026.

Full text

Abstract:

Eutectic fixed points are close to becoming a reference for high temperatures calibration, especially as the new International Temperature Scale (ITS) approach to issue after the re-definition of the Kelvin unit. In this work the long-term stability of Co-C and Pd-C eutectic fixed points were investigated using NIS-Egypt facilities. The eutectic points were measured using Pt/Pd thermocouple. The total exposure to the Co-C and Pd-C melting temperature was about 200 h for the fixed-point cell and 150 h for the Pt/Pd thermocouple. The emfs of the thermocouple at the melting point were observed to drift by about 0.25 °C. Realization uncertainties were estimated to be ~ 0.446 ◦C for Co-C and ~0.742 for Pd-C (k = 2). Results show that Co-C and Pd-C eutectic cells can exhibit long term stability.

APA, Harvard, Vancouver, ISO, and other styles

3

Mira, Nadarajan, Liu, González-Benito, and Pritchard. "Lipid Thermal Fingerprints of Long-term Stored Seeds of Brassicaceae." Plants 8, no. 10 (October 14, 2019): 414. http://dx.doi.org/10.3390/plants8100414.

Full text

Abstract:

Thermal fingerprints for seeds of 20 crop wild relatives of Brassicaceae stored for 8 to 44 years at the Plant Germplasm Bank—Universidad Politécnica de Madrid and the Royal Botanic Gardens, Kew’s Millennium Seed Bank—were generated using differential scanning calorimetry (DSC) and analyzed in relation to storage stability. Relatively poor storing oily seeds at −20 °C tended to have lipids with crystallization and melting transitions spread over a wide temperature range (c. 40 °C) that spanned the storage temperature, plus a melting end temperature of around 15 °C. We postulated that in dry storage, the variable longevity in Brassicaceae seeds could be associated with the presence of a metastable lipid phase at the temperature at which they are being stored. Consistent with that, when high-quality seed samples of various species were assessed after banking at −5 to −10 °C for c. 40 years, melting end temperatures were observed to be much lower (c. 0 to −30 °C) and multiple lipid phases did not occur at the storage temperature. We conclude that multiple features of the seed lipid thermal fingerprint could be used as biophysical markers to predict potential poor performance of oily seeds during long-term, decadal storage.

APA, Harvard, Vancouver, ISO, and other styles

4

Lysenko, N. O., O. O. Pedash, V. V. Klochykhin, and P. O. Kasai. "Influence of long-term soaking on the structure and properties of IN625 alloy samples made by selective laser melting." Paton Welding Journal 2022, no. 1 (January 28, 2022): 41–47. http://dx.doi.org/10.37434/tpwj2022.01.08.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Dolan, Brenda, Steven A. Rutledge, S. Lim, V. Chandrasekar, and M. Thurai. "A Robust C-Band Hydrometeor Identification Algorithm and Application to a Long-Term Polarimetric Radar Dataset." Journal of Applied Meteorology and Climatology 52, no. 9 (September 2013): 2162–86. http://dx.doi.org/10.1175/jamc-d-12-0275.1.

Full text

Abstract:

AbstractA new 10-category, polarimetric-based hydrometeor identification algorithm (HID) for C band is developed from theoretical scattering simulations including wet snow, hail, and big drops/melting hail. The HID is applied to data from seven wet seasons in Darwin, Australia, using the polarimetric C-band (C-POL) radar, to investigate microphysical differences between monsoon and break periods. Scattering simulations reveal significant Mie effects with large hail (diameter > 1.5 cm), with reduced reflectivity and enhanced differential reflectivity Zdr and specific differential phase Kdp relative to those associated with S band. Wet snow is found to be associated with greatly depreciated correlation coefficient ρhv and moderate values of Zdr. It is noted that large oblate liquid drops can produce the same electromagnetic signatures at C band as melting hail falling quasi stably, resulting in some ambiguity in the HID retrievals. Application of the new HID to seven seasons of C-POL data reveals that hail and big drops/melting hail occur much more frequently during break periods than during monsoon periods. Break periods have a high frequency of vertically aligned ice above 12 km, suggesting the presence of strong electric fields. Reflectivity and mean drop diameter D0 statistics demonstrate that convective areas in both monsoon and break periods may have robust coalescence or melting precipitation ice processes, leading to enhanced reflectivity and broader distributions of D0. Conversely, for stratiform regions in both regimes, mean reflectivity decreases below the melting level, indicative of evaporative processes. Break periods also have larger ice water path fractions, indicating substantial mixed-phase precipitation generation as compared with monsoonal periods. In monsoon periods, a larger percentage of precipitation is produced through warm-rain processes.

APA, Harvard, Vancouver, ISO, and other styles

6

Winther, Jan-Gunnar. "Short- and Long-Term Variability of Snow Albedo." Hydrology Research 24, no. 2-3 (April 1, 1993): 199–212. http://dx.doi.org/10.2166/nh.1993.0022.

Full text

Abstract:

The progress of snow albedo for the 1991 winter from Helligdagshaugen research site, Norway, is presented. The temporal reduction of albedo decreases as the snow undergoes a process of metamorphosis, as long as the snow depth is large enough to prevent absorption of solar radiation by the underlying terrain. Later, as the snow depth becomes less than about 10 cm and the area of bare patches grows, there is an increase in the temporal rate of reduction in albedo. An accumulated daily maximum temperature index is shown to be a good predictor of both the long-term development of the snow albedo and the daily mean albedo. The actual albedo deviates from the predicted long-term albedo due to variable meteorological conditions of which solar radiation is the most important one. Solar radiation and snow albedo are negatively correlated. Linear regression is performed for a winter period with no melting and for two distinct melting periods. Snow albedo was first determined as a function of temperature index alone. An improved accuracy of 2-6 per cent in estimated snow albedo was obtained when solar radiation was included. Very similar regression coefficients were found for two different periods.

APA, Harvard, Vancouver, ISO, and other styles

7

Karelin, V. A., and Vl V. Salomatov. "A review of modern numerical and analytical models of heat transfer in a dielectric layer during melting due to microwave radiation." Journal of Physics: Conference Series 2119, no. 1 (December 1, 2021): 012074. http://dx.doi.org/10.1088/1742-6596/2119/1/012074.

Full text

Abstract:

Abstract In this work, numerical and analytical solutions of heat transfer in a dielectric layer during melting in the microwave field were considered. We considered solutions, where the source term was obtained based on the solution of Maxwell equation, as well as using the Lambert law. The conditions applicable for analytical solutions, allowing the parametric analysis, are determined. The areas of application of the technology of microwave melting of dielectrics, in particular with melting ice on water, defrosting products, etc., were also considered.

APA, Harvard, Vancouver, ISO, and other styles

8

Ospennikova, O. G., P. G. Min, A. M. Rogalev, and V. E. Vadeev. "On the chemical composition, structure and mechanical properties of alloy EP648 fabricated by deformation, project die casting and selective laser melting." Voprosy Materialovedeniya, no. 1(101) (May 3, 2020): 44–54. http://dx.doi.org/10.22349/1994-6716-2020-101-1-44-54.

Full text

Abstract:

The paper studies chemical composition, structure and mechanical properties of the heat-resistant nickel EP648 alloy obtained by deformation, die project casting and selective laser melting. It is shown that the deformed material is characterized by low porosity, high impact strength and ductility, the cast material has large grains, high long-term strength and low-cycle fatigue. The material obtained by selective laser melting is characterized by an increased content of oxygen and nitrogen, fine-grain structure with large variation in grain size strongly expressed and heredity, and also high short-term strength.

APA, Harvard, Vancouver, ISO, and other styles

9

Warner, Roland C., and W. Κ. Budd. "Modelling the long-term response of the Antarctic ice sheet to global warming." Annals of Glaciology 27 (1998): 161–68. http://dx.doi.org/10.3189/1998aog27-1-161-168.

Full text

Abstract:

The primary effects of global warming on the Antarctic ice sheet can involve increases in surface melt for limited areas at lower elevations, increases in net accumulation, and increased basal melting under floating ice. For moderate global wanning, resulting in ocean temperature increases of a few °C, the large- increase in basal melting can become the dominant factor in the long-term response of the ice sheet. The results from ice-sheet modelling show that the increased basal melt rates lead to a reduction of the ice shelves, increased strain rates and flow at the grounding lines, then thinning and floating of the marine ice sheets, with consequential further basal melting. The mass loss from basal melting is counteracted to some extent by the increased accumulation, but in the long term the area of ice cover decreases, particularly in West Antarctica, and the mass loss can dominate. The ice-sheet ice-shelf model of Budd and others (1994) with 20 km resolution has been modified and used to carry out a number of sensitivity studies of the long-term response of the ice sheet to prescribed amounts of global warming. The changes in the ice sheet are computed out to near-equilibrium, but most of the changes take place with in the first lew thousand years. For a global mean temperature increase of 3°C with an ice-shelf basal melt rate of 5 m a−1 the ice shelves disappear with in the first few hundred years, and the marine-based parts of the ice sheet thin and retreat. By 2000 years the West Antarctic region is reduced to a number of small, isolated ice caps based on the bedrock regions which are near or above sea level. This allows the warmer surface ocean water to circulate through the archipelago in summer, causing a large change to the local climate of the region.

APA, Harvard, Vancouver, ISO, and other styles

10

Elgafy, Ahmed, Osama Mesalhy, and Khalid Lafdi. "Numerical and Experimental Investigations of Melting and Solidification Processes of High Melting Point PCM in a Cylindrical Enclosure." Journal of Heat Transfer 126, no. 5 (October 1, 2004): 869–75. http://dx.doi.org/10.1115/1.1800492.

Full text

Abstract:

In the present work, a computational model is developed to investigate and predict the thermal performance of high melting point phase change material during its melting and solidification processes within a cylindrical enclosure. In this model the phases are assumed to be homogeneous and a source term, S, arises from melting or solidification process is considered as a function of the latent heat of fusion and the liquid phase fraction. The numerical model is verified with a test problem and an experiment is performed to assess the validity of the assumptions of it and an agreement between experimental and computational results is achieved. The findings show that utilizing of PCMs of high melting points is a promising technique especially in space applications.

APA, Harvard, Vancouver, ISO, and other styles

11

Born, A., and K. H. Nisancioglu. "Melting of Northern Greenland during the last interglacial." Cryosphere Discussions 5, no. 6 (December 21, 2011): 3517–39. http://dx.doi.org/10.5194/tcd-5-3517-2011.

Full text

Abstract:

Abstract. The Greenland ice sheet (GrIS) is losing mass at an increasing rate, making it the primary contributor to global eustatic sea level rise. Large melting areas and rapid thinning at its margins has raised concerns about its stability. However, it is conceivable that these observations represent the transient adjustment of the fastest reacting parts of the ice sheet, masking slower processes that dominate the long term fate of the GrIS and its contribution to sea level rise. Studies of the geological past provide valuable information on the long term response of the GrIS to warm periods. We simulate the GrIS during the Eemian interglacial, a period 126 000 yr before present (126 ka) with Arctic temperatures comparable to projections for the end of this century. The northeastern part of the GrIS is unstable and retreats significantly, despite moderate melt rates. Unlike the south and west, strong melting in the northeast is not compensated by high accumulation, or fast ice flow. The analogy with the present warming suggests that in coming decades, positive feedbacks could increase the rate of mass loss of the northeastern GrIS, exceeding the currently observed melting in the south.

APA, Harvard, Vancouver, ISO, and other styles

12

Kovar, Ladislav, Pavel Novak, and Tomas Hapla. "Lance Design for Scrap Melting Aggregates." Tehnički glasnik 15, no. 1 (March 4, 2021): 162–67. http://dx.doi.org/10.31803/tg-20200224122509.

Full text

Abstract:

Metallurgical aggregates, which are used for metal waste melting, are equipped with lances for blowing gaseous media. These gaseous media allow especially scrap melting and intense homogenization of the resulting melt. In connection with this, the blowing systems are developed both for blowing of gaseous media itself on the bath surface or into the melt and for blowing of the gas mixture with powdered substances. When designing the blowing systems and the individual lance tips and nozzles, it is necessary to respect certain criteria, the derivation of which is based on long-term experience and acquired knowledge in this field. The submitted paper summarizes the design recommendations, including the determination of the selected design characteristics of the nozzles for blowing gaseous media on the bath surface in the metallurgical aggregate. These design characteristics help designers and engineers to design systems that meet the high demands on quality, efficiency and operational reliability.

APA, Harvard, Vancouver, ISO, and other styles

13

Ebert, M., L. Hecht, C. Hamann, and R. Luther. "Laser-induced melting experiments: Simulation of short-term high-temperature impact processes." Meteoritics & Planetary Science 52, no. 7 (January 30, 2017): 1475–94. http://dx.doi.org/10.1111/maps.12809.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Komura, Motonori, Ken Nakajima, Toshio Nishi, Takayuki Ikehara, and Qiu Zhaobin. "Pulsed NMR Studies on Long-Term Crystallization Behavior and Melting Process of Natural Rubber under Elongation." Rubber Chemistry and Technology 81, no. 1 (March 1, 2008): 110–20. http://dx.doi.org/10.5254/1.3548191.

Full text

Abstract:

Abstract Long-term crystallization and melting process of natural rubber under elongation was investigated by measuring spin-spin relaxation time T2 by pulsed nuclear magnetic resonance (NMR). We examined the dependence of the both processes on extension ratio, crystallization temperature and crosslink density. It was found that the crystallization of natural rubber continued over three months even at 10 °C. According to the two-step melting process found for the first time under elongation, we proposed a model that crystalline part of natural rubber under large elongation is composed of two kinds of crystallites from highly extended and loose chains. The situation is caused by the microscopic distribution of extension ratio of the chains between crosslink points.

APA, Harvard, Vancouver, ISO, and other styles

15

Roy, Arunabha Mohan. "Multiphase Phase-Field Approach for Virtual Melting: A Brief Review." Material Science Research India 18, no. 2 (August 30, 2021): 102–7. http://dx.doi.org/10.13005/msri/180201.

Full text

Abstract:

A short review on a thermodynamically consistent multiphase phase-field approach for virtual melting has been presented. The important outcomes of solid-solid phase transformations via intermediate melt have been discussed for HMX crystal. It is found out that two nanoscale material parameters and solid-melt barrier term in the phase-field model significantly affect the mechanism of PTs, induces nontrivial scale effects, and changes PTs behaviors at the nanoscale during virtual melting.

APA, Harvard, Vancouver, ISO, and other styles

16

Perşoiu, A., and A. Pazdur. "Ice genesis and its long-term dynamics in Scărişoara Ice Cave, Romania." Cryosphere Discussions 4, no. 4 (October 6, 2010): 1909–29. http://dx.doi.org/10.5194/tcd-4-1909-2010.

Full text

Abstract:

Abstract. The paleoclimatic significance of the perennial ice deposit in Scărişoara Ice Cave has been remarked since the early 20th century, but a clear understanding of the processes involved in the genesis, age and long-term dynamics of ice hampered all attempts to extract valuable data on past climate and vegetation changes. In this paper, we present a model of ice genesis and dynamics, based on stable isotopes, ice level monitoring (modern and archived) and radiocarbon dating of organic matter found in the ice. Ice in Scărişoara Ice Cave mostly consists of layers of lake ice, produced as liquid water freezes from top to bottom in mid-autumn, a mechanism that was also acting in the past, during the Medieval Warm Period and the Little Ice Age. The ice block is not stable in shape and volume, being continuously modified by ablation on top, basal melting and lateral flow. Radiocarbon dating shows that the ice block is older than 1200 years, the rate of ice flow and basal melting suggesting that the ice could be much older.

APA, Harvard, Vancouver, ISO, and other styles

17

Zhang, Xiao-Lin, Chao-Ping Jiang, Feng-Ying Zhang, and Ya-Zhe Xing. "The evaluation of microstructure characteristic and corrosion performance of laser-re-melted Fe-based amorphous coating deposited via plasma spraying." Materials Express 9, no. 9 (December 1, 2019): 1100–1105. http://dx.doi.org/10.1166/mex.2019.1598.

Full text

Abstract:

The laser re-melting treatment was performed on the plasma-sprayed Fe-based amorphous coating to ameliorate the corrosion performance of the coating. The re-melting depth was about 200 μm which was mainly controlled by laser energy input, beam speed and facular dimension. The microstructure was characterized by scanning electron microscope (SEM), and X-ray diffraction (XRD). The corrosion property of the coatings was addressed via electrochemistry methods in a 3.5 wt.% NaCl solution. The results indicate that the plasma-sprayed coating becomes much denser after laser re-melting treatment. The connected porosity ratio in as-sprayed coating dramatically reduces from 16.3% to 2.4% after laser re-melting. The as-sprayed coating mainly contains amorphous and much limited crystal phase, and some amorphous phase in the as-sprayed coating crystalizes during laser re-melting. Polarization test demonstrated that the as-sprayed coating has a significantly dramatical effect for improving corrosion performance of carbon steel, while the laser re-melting process is a more efficient method. The influence level of the coating compactness in this study is roughly two times as big as that of amorphous in coating, in the term of improving corrosion resistance of carbon steel.

APA, Harvard, Vancouver, ISO, and other styles

18

Sikora, Antonín, Bedřich Porsch, and Julius Pouchlý. "Effect of Temperature History upon Stability and Melting of Poly(ethylene oxide)." Collection of Czechoslovak Chemical Communications 58, no. 11 (1993): 2595–604. http://dx.doi.org/10.1135/cccc19932595.

Full text

Abstract:

The effect of temperature history upon the distribution of molecular weights and melting points has been investigated with high-molecular poly(ethylene oxides). The results obtained by the size exclusion chromatography (SEC) and differential scanning calorimetry (DSC) have shown that a long-term annealing of high-molecular poly(ethylene oxides) results in a distinct degradation of polymeric chains. The change in distribution of molecular weights and the presence of oligomers formed by degradation markedly affect the melting points of poly(ethylene oxide). The diffusion of oligomers from crystalline into amorphous regions is manifested by a time change of melting point and crystallinity degree of poly(ethylene oxide). The degradation is also observed during X-ray measurements.

APA, Harvard, Vancouver, ISO, and other styles

19

Ray, U., A. Sarkar, S. Sen, B. Roychowdhury, and N. Barman. "Induction Heating of an Aluminum Billet: A Numerical Study of the Thermal Behavior." Applied Mechanics and Materials 110-116 (October 2011): 4697–704. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.4697.

Full text

Abstract:

In the present work, the heat transfer behavior during induction heating of a cylindrical aluminum billet is performed numerically. The heating process is represented by the energy conservation equation where the heat generation during heating is added as a volumetric source term. The evolution of latent heat during melting is also added as a volumetric source term. The continuity and the momentum conservation equations are considered to represent the flow field after melting starts. These governing equations are solved based on the control volume method. The enthalpy update scheme is used for evolution of melt-fraction during heating. The work predicts the evolution of temperature during heating, the distributions of temperature and melt-fraction in the domain. Subsequently, a parametric study is also performed.

APA, Harvard, Vancouver, ISO, and other styles

20

Fabry, Frederic, and Isztar Zawadzki. "Long-Term Radar Observations of the Melting Layer of Precipitation and Their Interpretation." Journal of the Atmospheric Sciences 52, no. 7 (April 1995): 838–51. http://dx.doi.org/10.1175/1520-0469(1995)052<0838:ltroot>2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Muts, Ihor R., Viktor Hlukhyy, Yaroslav V. Galadzhun, Pavlo Solokha, Stefan Seidel, Rolf-Dieter Hoffmann, Rainer Pöttgen, and Vasyl’ I. Zaremba. "SrPt3In2– an orthorhombically distorted coloring variant of SrIn5." Dalton Transactions 48, no. 30 (2019): 11411–20. http://dx.doi.org/10.1039/c9dt01808e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Ren, Qingxi, Ling Fu, Olayemi E. Dudu, Rui Zhang, Haiyan Liu, Zhiqiang Zheng, and Ying Ma. "New insights into the digestion and bioavailability of a high-melting-temperature solid triacylglycerol fraction in bovine milk fat." Food & Function 12, no. 12 (2021): 5274–86. http://dx.doi.org/10.1039/d1fo00259g.

Full text

Abstract:

Short-term consumption of a high-melting-temperature solid TAG fraction (30S) in milk fat did not bring obvious health risks. Conversely, it led to positive physiological and biochemical activities by suppressing appetite and increasing fecal loss.

APA, Harvard, Vancouver, ISO, and other styles

23

Aurich, J. C., and M. Burkhart. "Qualität steigern mit Selective Laser Melting/Quality improvement with selective laser melting – An approach to manage requirements with additive manufacturing." wt Werkstattstechnik online 105, no. 11-12 (2015): 793–97. http://dx.doi.org/10.37544/1436-4980-2015-11-12-33.

Full text

Abstract:

Additive Manufacturing (AM) ist der Überbegriff für unterschiedliche Fertigungsverfahren, welche durch das schichtweise Aufbringen von Werkstoff die Herstellung von Bauteilen ermöglichen. Selective Laser Melting (SLM) ist ein additives Fertigungsverfahren zur Herstellung von Produkten mit hoher Detailgenauigkeit und Designfreiheit. Der Fachbeitrag stellt ein Konzept vor, bei dem durch systematisches Vorgehen untersucht wird, ob Produktanforderungen mit SLM besser erfüllt werden können als mit konventionellen Fertigungsverfahren.   Additive Manufacturing (AM) is the term for various manufacturing technologies that enable manufacturing of components by adding layer after layer of material. Selective Laser Melting (SLM) is an additive manufacturing technology that allows to manufacture products with high accuracy and design freedom. In this article an approach is presented to systematically examine, if product requirements can be fulfilled better with SLM than with conventional manufacturing technologies.

APA, Harvard, Vancouver, ISO, and other styles

24

Loveless, Stephan, Dina Prialnik, and Morris Podolak. "On the Structure and Long-term Evolution of Ice-rich Bodies." Astrophysical Journal 927, no. 2 (March 1, 2022): 178. http://dx.doi.org/10.3847/1538-4357/ac4962.

Full text

Abstract:

Abstract The interest in the structure of ice-rich planetary bodies, in particular the differentiation between ice and rock, has grown due to the discovery of Kuiper Belt objects and exoplanets. We thus carry out a parameter study for a range of planetary masses M, yielding radii 50 ≲ R ≲ 3000 km, and for rock to ice mass ratios between 0.25 and 4, evolving them for 4.5 Gyr in a cold environment, to obtain the present structure. We use a thermal evolution model that allows for liquid and vapor flow in a porous medium, solving mass and energy conservation equations under hydrostatic equilibrium for a spherical body in orbit around a central star. The model includes the effect of pressure on porosity and on the melting temperature, heating by long-lived radioactive isotopes, and temperature-dependent serpentinization and dehydration. We obtain the boundary in parameter space (size, rock content) between bodies that differentiate, forming a rocky core, and those which remain undifferentiated: small bodies, bodies with a low rock content, and the largest bodies considered, which develop high internal pressures and barely attain the melting temperature. The final differentiated structure comprises a rocky core, an ice-rich mantle, and a thin dense crust below the surface. We obtain and discuss the bulk density–radius relationship. The effect of a very cold environment is investigated, and we find that at an ambient temperature of ∼20 K, small bodies preserve the ice in amorphous form to the present.

APA, Harvard, Vancouver, ISO, and other styles

25

Ab Ghani, Noor Asikin, Iziana Yahya, Mohd Arif Anuar Mohd Salleh, Shamsuddin Saidatulakmar, Zainal Arifin Ahmad, and Ramani Mayappan. "Microstructure Evolution of Sn-3.5Ag-1.0Cu-0.5Ni/Cu System Lead Free Solder under Long Term Thermal Aging." Advanced Materials Research 620 (December 2012): 263–67. http://dx.doi.org/10.4028/www.scientific.net/amr.620.263.

Full text

Abstract:

Due to environmental concerns, lead-free solders were introduced in replacing the lead-based solders in microelectronics devices technology. Although there are many lead-free solder available, the Sn-Ag-Cu solder was considered the best choice. But the solder has its draw backs in terms of melting temperature and intermetallic formations. In this study, the effect of 0.5wt% Ni addition on the microstructure of the Sn-3.5Ag-1.0Cu solder was investigated. The solder was synthesized via powder metallurgy route which includes blending, compacting and sintering. The solders were characterized for its densities and melting temperatures. SEM was used to observe the microstructure of intermetallic phases. The solders were melted on copper substrate at 250°C for one minute and aged at 150°C from 0 to 400 hours. The phases formed were studied under SEM. The SEM results showed the presence of Cu6Sn5, Cu3Sn, Ag3Sn and (Cu,Ni)6Sn5 intermetallics.

APA, Harvard, Vancouver, ISO, and other styles

26

Frick, Claudia, and Heini Wernli. "A Case Study of High-Impact Wet Snowfall in Northwest Germany (25–27 November 2005): Observations, Dynamics, and Forecast Performance." Weather and Forecasting 27, no. 5 (May 16, 2012): 1217–34. http://dx.doi.org/10.1175/waf-d-11-00084.1.

Full text

Abstract:

Abstract Accurate numerical weather prediction of intense snowfall events requires the correct representation of dynamical and physical processes on various scales. In this study, a specific event of high-impact wet snowfall is examined that occurred in the northwestern part of Germany in November 2005. First, the synoptic evolution is presented, together with observations of precipitation type and vertical temperature profiles, which reveal the existence of a so-called potential melting layer during the early period of wet snowfall. During the main part, the performance of the operational forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) is investigated. It is shown that only the short-term predictions captured the snowfall event, whereas earlier forecasts were in error concerning the phase and/or amount of precipitation. However, even the short-term forecasts produced the onset of surface snowfall too late (i.e., during the dry snowfall period). Reasons for the misforecasts are errors on various scales. For the early forecasts, they include an inaccurate representation of the upper-level trough and a misplacement of the surface cyclone. For the later forecasts, a slight overestimation of the depth of the potential melting layer and a potentially too fast snow melting process in the model lead to the erroneous prediction of surface rainfall during the wet snowfall period. Hindcast experiments with the high-resolution Consortium for Small-Scale Modeling (COSMO) model also point to the necessity of improving its snow melting parameterization in order to provide useful predictions of potentially high-impact wet snowfall events.

APA, Harvard, Vancouver, ISO, and other styles

27

Perşoiu, A., and A. Pazdur. "Ice genesis and its long-term mass balance and dynamics in Scărişoara Ice Cave, Romania." Cryosphere 5, no. 1 (January 31, 2011): 45–53. http://dx.doi.org/10.5194/tc-5-45-2011.

Full text

Abstract:

Abstract. The paleoclimatic significance of the perennial ice deposit in Scărişoara Ice Cave has been remarked on since the early 20th century, but a lack of understanding of the processes involved in the genesis, age and long-term dynamics and volume fluctuations of ice hampered all attempts to extract valuable data on past climate and vegetation changes. In this paper, we present a model of ice genesis and dynamics, based on stable isotopes, ice level monitoring (modern and archived) and radiocarbon dating of organic matter found in the ice. Ice in this cave mostly consists of layers of lake ice, produced as liquid water freezes from top to bottom in mid-autumn, and floor ice, produced as inflow water in winter freezes on top of the lake ice. This mechanism was also acting in the past, during the Medieval Warm Period and the Little Ice Age. The ice block is not stable in shape and volume, being continuously modified by ablation on top and sides, basal melting and lateral flow. Radiocarbon dating shows that the ice block is older than 1000 years, but ice flow and differential basal melting suggesting that the ice could be much older.

APA, Harvard, Vancouver, ISO, and other styles

28

Meijer, H. A. "Long-Term Sludge Disposal Policy in The Netherlands." Water Science and Technology 26, no. 5-6 (September 1, 1992): 1157–64. http://dx.doi.org/10.2166/wst.1992.0557.

Full text

Abstract:

The disposal of sewage sludge in The Netherlands will change in the coining ten years from predominantly beneficial use to landfill after optimum volume and solids reduction by technical means. A new regulation prohibits the beneficial use of sludge, even when pollutants are present in very small quantities. Compared with limit values that are regarded as acceptable in regulations elsewhere in the world, the new Dutch standards are very stringent. Unfortunately the flue gas standards for sludge incineration are also more severe than in other countries, necessarily requiring high tech facilities to achieve these limits. As a result sludge treatment costs will rise immensely in the future. A secondary effect is that studies on the development of alternative technologies for sludge treatment, besides drying, composting and incineration, once again become meaningful. Such alternatives include melting and wet oxidation.

APA, Harvard, Vancouver, ISO, and other styles

29

Vasilyev, G. P., N. V. Peskov, A. A. Burmistrov, N. A. Timofeev, P. E. Zakharov, and I. A. Yurchenko. "Ground Source Heat Pump Modeling: Accounting of Ground Moisture Freezing-Melting in a Model of Heat Transfer outside Deep Borehole." Applied Mechanics and Materials 704 (December 2014): 102–12. http://dx.doi.org/10.4028/www.scientific.net/amm.704.102.

Full text

Abstract:

This paper contains the results of research, carried out with financial support from the Ministry of Education and Science of the Russian Federation (contract ID RFMEFI57914X0026). For the ground source heat pump (GSHP) used as a heating system in regions with cold climate the thermal effects of ground moisture freezing-melting processes can make an essential long-term impact on GSHP performance. However, widely known models of heat transfer inside and outside GSHP borehole do not take into account such effects. In this paper we propose a method of engineering estimation of freezing-melting latent heat in the frame of modified cylindrical source model. The key feature of the method is the definition of effective thermal conductivity of ground to "convert" the latent heat of phase transition into equivalent heat flux from outer ground. The method is validated by laboratory measurements of ground thermal conductivity during the freezing-melting process.

APA, Harvard, Vancouver, ISO, and other styles

30

Vasilyev, G. P., V. F. Gornov, N. V. Peskov, M. V. Kolesova, A. A. Burmistrov, N. A. Timofeev, V. A. Leskov, and I. A. Yurchenko. "Accounting for “Zero Curtain” Effect in GSHP Simulation." Applied Mechanics and Materials 664 (October 2014): 243–49. http://dx.doi.org/10.4028/www.scientific.net/amm.664.243.

Full text

Abstract:

This paper contains the results of research, carried out with financial support from the Ministry of Education and Science of the Russian Federation (contract ID RFMEFI57914X0026). For the ground source heat pump (GSHP) used as a heating system in regions with cold climate the thermal effects of ground moisture freezing-melting processes can make an essential long-term impact on GSHP performance. However, widely known models of heat transfer inside and outside GSHP borehole do not take into account such effects. In this paper, we propose a method of engineering estimation of freezing-melting latent heat in the frame of modified cylindrical source model. The key feature of the method is the definition of effective thermal conductivity of ground to "convert" the latent heat of phase transition into equivalent heat flux from outer ground. The method is validated by laboratory measurements of ground thermal conductivity during the freezing-melting process.

APA, Harvard, Vancouver, ISO, and other styles

31

Copland, Luke, Martin J. Sharp, and Peter W. Nienow. "Links between short-term velocity variations and the subglacial hydrology of a predominantly cold polythermal glacier." Journal of Glaciology 49, no. 166 (2003): 337–48. http://dx.doi.org/10.3189/172756503781830656.

Full text

Abstract:

AbstractThe surface velocity of a predominantly cold polythermal glacier (John Evans Glacier, Ellesmere Island, Canada) varies significantly on both seasonal and shorter time-scales. Seasonal variations reflect the penetration of supraglacial water to the glacier bed through significant thicknesses of cold ice. Shorter-term events are associated with periods of rapidly increasing water inputs to the subglacial drainage system. Early-season short-term events immediately follow the establishment of a drainage connection between glacier surface and glacier bed, and coincide with the onset of subglacial outflow at the terminus. A mid-season short-term event occurred as surface melting resumed following cold weather, and may have been facilitated by partial closure of subglacial channels during this cold period. There is a close association between the timing and spatial distribution of horizontal and vertical velocity anomalies, the temporal pattern of surface water input to the glacier, and the formation, seasonal evolution and distribution of subglacial drainage pathways. These factors presumably control the occurrence of highwater-pressure events and water storage at the glacier bed. The observed coupling between surface water inputs and glacier velocity may allow predominantly cold polythermal glaciers to respond rapidly to climate-induced changes in surface melting.

APA, Harvard, Vancouver, ISO, and other styles

32

Nakayama, Yoshihiro, Ralph Timmermann, and Hartmut H. Hellmer. "Impact of West Antarctic ice shelf melting on Southern Ocean hydrography." Cryosphere 14, no. 7 (July 13, 2020): 2205–16. http://dx.doi.org/10.5194/tc-14-2205-2020.

Full text

Abstract:

Abstract. Previous studies show accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were previously small and increased in the middle of the 20th century. This enhanced melting is a likely source of the observed Ross Sea (RS) freshening, but its long-term impact on the Southern Ocean hydrography has not been well investigated. Here, we conduct coupled sea ice–ice shelf–ocean simulations with different levels of ice shelf melting from West Antarctic glaciers. Freshening of RS shelf and bottom water is simulated with enhanced West Antarctic ice shelf melting, while no significant changes in shelf water properties are simulated when West Antarctic ice shelf melting is small. We further show that the freshening caused by glacial meltwater from ice shelves in the Amundsen and Bellingshausen seas can propagate further downstream along the East Antarctic coast into the Weddell Sea. The freshening signal propagates onto the RS continental shelf within a year of model simulation, while it takes roughly 5–10 and 10–15 years to propagate into the region off Cape Darnley and into the Weddell Sea, respectively. This advection of freshening modulates the shelf water properties and possibly impacts the production of Antarctic Bottom Water if the enhanced melting of West Antarctic ice shelves continues for a longer period.

APA, Harvard, Vancouver, ISO, and other styles

33

Liston, Glen E., Jan-Gunnar Winther, Oddbjørn Bruland, Hallgeir Elvehøy, and Knut Sand. "Below-surface ice melt on the coastal Antarctic ice sheet." Journal of Glaciology 45, no. 150 (1999): 273–85. http://dx.doi.org/10.3189/s0022143000001775.

Full text

Abstract:

AbstractIn the Jutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has been observed. The melting takes place during the summer months in blue-ice areas under conditions of below-freezing air and surface temperatures. Adjacent snow-covered regions, having the same meteorological and climatic conditions, experience little or no subsurface melting. To help explain and understand the observed melt-rate differences in the blue-ice and snow-covered areas, a physically based numerical model of the coupled atmosphere, radiation, snow and blue-ice system has been developed. The model comprises a heat-transfer equation which includes a spectrally dependent solar-radiation source term. The penetration of radiation into the snow and blue ice depends on the solar-radiation spectrum, the surface albedo and the snow and blue-ice grain-sizes and densities. In addition, the model uses a complete surface energy balance to define the surface boundary conditions. It is run over the full annual cycle, simulating temperature profiles and melting and freezing quantities throughout the summer and winter seasons. The model is driven and validated using field observations collected during the Norwegian Antarctic Research Expedition (NARE) 1996–97. The simulations suggest that the observed differences between subsurface snow and blue-ice melting can be explained largely by radiative and heat-transfer interactions resulting from differences in albedo, grain-size and density between the two mediums.

APA, Harvard, Vancouver, ISO, and other styles

34

Liston, Glen E., Jan-Gunnar Winther, Oddbjørn Bruland, Hallgeir Elvehøy, and Knut Sand. "Below-surface ice melt on the coastal Antarctic ice sheet." Journal of Glaciology 45, no. 150 (1999): 273–85. http://dx.doi.org/10.1017/s0022143000001775.

Full text

Abstract:

AbstractIn the Jutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has been observed. The melting takes place during the summer months in blue-ice areas under conditions of below-freezing air and surface temperatures. Adjacent snow-covered regions, having the same meteorological and climatic conditions, experience little or no subsurface melting. To help explain and understand the observed melt-rate differences in the blue-ice and snow-covered areas, a physically based numerical model of the coupled atmosphere, radiation, snow and blue-ice system has been developed. The model comprises a heat-transfer equation which includes a spectrally dependent solar-radiation source term. The penetration of radiation into the snow and blue ice depends on the solar-radiation spectrum, the surface albedo and the snow and blue-ice grain-sizes and densities. In addition, the model uses a complete surface energy balance to define the surface boundary conditions. It is run over the full annual cycle, simulating temperature profiles and melting and freezing quantities throughout the summer and winter seasons. The model is driven and validated using field observations collected during the Norwegian Antarctic Research Expedition (NARE) 1996–97. The simulations suggest that the observed differences between subsurface snow and blue-ice melting can be explained largely by radiative and heat-transfer interactions resulting from differences in albedo, grain-size and density between the two mediums.

APA, Harvard, Vancouver, ISO, and other styles

35

Rufli, Henry, and Jakob Schwander. "A floating-station structure." Annals of Glaciology 47 (2007): 79–81. http://dx.doi.org/10.3189/172756407786857839.

Full text

Abstract:

AbstractLong-term maintenance of camp constructions on snow and ice surfaces involves repeated adjustments of the vertical position of buildings due to snow accumulation or ice ablation. The principle of a low-effort vertical-adjustment station structure is presented. The basic idea is to construct a floatable spherical-shaped building that can be lifted by adding water underneath, which will then refreeze, or can be lowered by melting ice away from the base. Under cold polar conditions, the power requirement for melting the base free is approximately 100 Wm–2 and is usually available as waste heat from the electric power generator of the station.

APA, Harvard, Vancouver, ISO, and other styles

36

Tapasa, Kanit, Ekarat Meechoowas, Usuma Naknikham, and Tepiwan Jitwatcharakomol. "Evaluation of Furnaces Performance of Glass Factories in Thailand." Key Engineering Materials 702 (July 2016): 135–38. http://dx.doi.org/10.4028/www.scientific.net/kem.702.135.

Full text

Abstract:

The objective of this project is to evaluate the energy consumption and the efficiency of glass melting furnaces using a thermodynamic principle and heat (energy) balance analysis. The approach can carry out more accurate result of wall losses than the direct temperature measurement at the furnace walls. Six furnaces from different factories in Thailand were studied. To construct the heat balance of glass furnace, the amount of heat for melting raw materials batch to glass melt (Hex), input energy (Hin) and the heat of content of offgas had to be known. The heat (energy) balance indicated the performance of glass furnaces in term of energy consumption.Glass furnace, Efficiency, Heat balance

APA, Harvard, Vancouver, ISO, and other styles

37

Slater, Donald A., Fiamma Straneo, Denis Felikson, Christopher M. Little, Heiko Goelzer, Xavier Fettweis, and James Holte. "Estimating Greenland tidewater glacier retreat driven by submarine melting." Cryosphere 13, no. 9 (September 26, 2019): 2489–509. http://dx.doi.org/10.5194/tc-13-2489-2019.

Full text

Abstract:

Abstract. The effect of the North Atlantic Ocean on the Greenland Ice Sheet through submarine melting of Greenland's tidewater glacier calving fronts is thought to be a key driver of widespread glacier retreat, dynamic mass loss and sea level contribution from the ice sheet. Despite its critical importance, problems of process complexity and scale hinder efforts to represent the influence of submarine melting in ice-sheet-scale models. Here we propose parameterizing tidewater glacier terminus position as a simple linear function of submarine melting, with submarine melting in turn estimated as a function of subglacial discharge and ocean temperature. The relationship is tested, calibrated and validated using datasets of terminus position, subglacial discharge and ocean temperature covering the full ice sheet and surrounding ocean from the period 1960–2018. We demonstrate a statistically significant link between multi-decadal tidewater glacier terminus position change and submarine melting and show that the proposed parameterization has predictive power when considering a population of glaciers. An illustrative 21st century projection is considered, suggesting that tidewater glaciers in Greenland will undergo little further retreat in a low-emission RCP2.6 scenario. In contrast, a high-emission RCP8.5 scenario results in a median retreat of 4.2 km, with a quarter of tidewater glaciers experiencing retreat exceeding 10 km. Our study provides a long-term and ice-sheet-wide assessment of the sensitivity of tidewater glaciers to submarine melting and proposes a practical and empirically validated means of incorporating ocean forcing into models of the Greenland ice sheet.

APA, Harvard, Vancouver, ISO, and other styles

38

Pokladníková, Hana, František Toman, and Tomáš Středa. "Negative impacts of snow melting on the soil." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 56, no. 1 (2008): 143–48. http://dx.doi.org/10.11118/actaun200856010143.

Full text

Abstract:

Intensity of snowmelt erosion was computed for cadastral areas of Pohořelice, Strážnice, Kuchařovice, Holešov, Dukovany, Vizovice, Velké Meziříčí and Bystřice nad Pernštejnem on the base of 1980–2006 data for the period November to March. Mean long-term soil loss was estimated according to ZACHAR (1981) equation on the base of average rate of snowmelting, amount of melting water, outflow and infiltration characteristics, topographical factor, soil factor and vegetation factor. For the studied localities the average rate of snowmelting varied from 2.29 mm.day−1 to 7.90 mm.day−1. Also amount of melting water reached the maximum in Bystřice nad Pernštejnem in dependence on climatic region (6.11 cm of water column). Outflow and infiltration characteristics varied from 0.94 to 1.14. High value of topographical factor (10.5) was assessed in Vizovice. Soil factor was estimated according to main soil unit from Estimated Pedologic-Ecological Unit EPEU. Its values varied from 0.31 in Velké Meziříčí to 0.47 in Holešov. Vegetation factor varied from 0.2938 in Vizovice to 0.4881 in Kuchařovice. Average soil loss as a consequence of snow melting varied in interval from 0.61 t.ha−1.year−1 in Pohořelice to 30.08 t. ha−1.year−1 in Vizovice.

APA, Harvard, Vancouver, ISO, and other styles

39

Hide, Raymond. "Forecasting short-term changes in the Earth's rotation." Symposium - International Astronomical Union 128 (1988): 287–88. http://dx.doi.org/10.1017/s007418090011962x.

Full text

Abstract:

Summary of PosterIt has long been appreciated that atmospheric motions must contribute to the excitation of fluctuations in the Earth's rotation (Munk and MacDonald 1960, Lambeck 1980, Rochester 1984) but the exploitation of modern meteorological data, collected largely to meet the demands of daily global weather forecasting, in the routine evaluation of angular momentum exchange between the atmosphere and the solid Earth was not initiated until comparatively recently (Hide et al. 1980). This procedure constitutes a necessary step towards the accurate separation of these features of the observed non-tidal changes in the length of day and polar motion and that are of meteorological origin from those that must be attributed to other geophysical processes, such as angular momentum transfer between the solid Earth and other fluid regions of the Earth (liquid metallic core, oceans, etc.), and to changes in the inertia tensor of the solid Earth associated with earthquakes, melting of ice, etc.

APA, Harvard, Vancouver, ISO, and other styles

40

Vikrant, Kumar, Eilhann E. Kwon, Ki-Hyun Kim, Christian Sonne, Minsung Kang, and Zang-Ho Shon. "Air Pollution and Its Association with the Greenland Ice Sheet Melt." Sustainability 13, no. 1 (December 23, 2020): 65. http://dx.doi.org/10.3390/su13010065.

Full text

Abstract:

The Greenland Ice Sheet (GrIS) has been a topic of extensive scientific research over the past several decades due to the exponential increase in its melting. The relationship between air pollution and GrIS melting was reviewed based on local emission of air pollutants, atmospheric circulation, natural and anthropogenic forcing, and ground/satellite-based measurements. Among multiple factors responsible for accelerated ice melting, greenhouse gases have long been thought to be the main reason. However, it is suggested that air pollution is another piece of the puzzle for this phenomenon. In particular, black carbon (BC) and other aerosols emitted anthropogenically interact with clouds and ice in the Arctic hemisphere to shorten the cloud lifespan and to change the surface albedo through alteration of the radiative balance. The presence of pollution plumes lowers the extent of super cooling required for cloud freezing by about 4 °C, while shortening the lifespan of clouds (e.g., by altering their free-energy barrier to prompt precipitation). Since the low-level clouds in the Arctic are 2–8 times more sensitive to air pollution (in terms of the radiative/microphysical properties) than other regions in the world, the melting of the GrIS can be stimulated by the reduction in cloud stability induced by air pollution. In this study, we reviewed the possible impact of air pollution on the melting of the GrIS in relation to meteorological processes and emission of light-absorbing impurities. Long-term variation of ground-based AERONET aerosol optical depth in Greenland supports the potential significance of local emission and long-range transport of air pollutants from Arctic circle and continents in the northern hemisphere in rapid GrIS melting trend.

APA, Harvard, Vancouver, ISO, and other styles

41

Götz, I. G., and M. Primicerio. "Spherically symmetric Stefan problem with the Gibbs–Thomson law at the moving boundary." European Journal of Applied Mathematics 7, no. 3 (June 1996): 249–75. http://dx.doi.org/10.1017/s0956792500002345.

Full text

Abstract:

This paper deals with the spherically symmetric Stefan problem in three space dimensions. The melting temperature satisfies the Gibbs–Thomson law. The solution is obtained as a limit of solutions of similar problems containing a small additional kinetic term in the melting temperature. Under some structural assumptions we show that the phase-change boundary has at most one discontinuity point t = T0 (see the corresponding result for the planar Stefan problem in Götz & Zaltzman (1995)). In the one-phase problem the discontinuity point always exists. At the time T0 the whole solid phase melts instantaneously. We study also the asymptotical stability (t → ∞) of stationary solutions satisfying boundary conditions of thermostat type.

APA, Harvard, Vancouver, ISO, and other styles

42

Grapes, R. H. "Pyrometamorphic breakdown of cordierite - muscovite intergrowths." Mineralogical Magazine 67, no. 4 (August 2003): 653–63. http://dx.doi.org/10.1180/0026461036740124.

Full text

Abstract:

AbstractBackscattered electron imaging of cordierite-muscovite intergrowths near the margin of a schist xenolith in trachytic tephra of the Wehr Volcano, East Eifel area, Germany, show that they have undergone disequilibrium melting to form spinel + biotite + sillimanite/?mullite + peraluminous melt. Textures indicate that in the initial stage of reaction, spinel, biotite and sillimanite/?mullite formed with melt produced in cordierite and spinel + ?mullite with melt after muscovite, providing evidence of two different reaction pathways. Fe-Mg distributions between biotite/spinel, cordierite/spinel, cordierite/ biotite suggest a melting temperature of ∼770°C, implying overstepping of various calculated and experimentally determined mineral breakdown curves of between 30 and 170°C during short-term heating before the xenolith was quenched on eruption.

APA, Harvard, Vancouver, ISO, and other styles

43

Huai, Baojuan, Michiel R. van den Broeke, and Carleen H. Reijmer. "Long-term surface energy balance of the western Greenland Ice Sheet and the role of large-scale circulation variability." Cryosphere 14, no. 11 (November 25, 2020): 4181–99. http://dx.doi.org/10.5194/tc-14-4181-2020.

Full text

Abstract:

Abstract. We present the surface energy balance (SEB) of the western Greenland Ice Sheet (GrIS) using an energy balance model forced with hourly observations from nine automatic weather stations (AWSs) along two transects: the Kangerlussuaq (K) transect with seven AWSs in the southwest and the Thule (T) transect with two AWSs in the northwest. Modeled and observed surface temperatures for non-melting conditions agree well with RMSEs of 1.1–1.6 K, while reasonable agreement is found between modeled and observed 10 d cumulative ice melt. Absorbed shortwave radiation (Snet) is the main energy source for melting (M), followed by the sensible heat flux (Qh). The multiyear average seasonal cycle of SEB components shows that Snet and M peak in July at all AWSs. The turbulent fluxes of sensible (Qh) and latent heat (Ql) decrease significantly with elevation, and the latter becomes negative at higher elevations, partly offsetting Qh. Average June, July and August (JJA) albedo values are <0.6 for stations below 1000 m a.s.l. and >0.7 for the higher stations. The near-surface climate variables and surface energy fluxes from reanalysis products ERA-Interim, ERA5 and the regional climate model RACMO2.3 were compared to the AWS values. The newer ERA5 product only significantly improves ERA-Interim for albedo. The regional model RACMO2.3, which has higher resolution (5.5 km) and a dedicated snow/ice module, unsurprisingly outperforms the reanalyses for (near-)surface climate variables, but the reanalyses are indispensable in detecting dependencies of west Greenland climate and melt on large-scale circulation variability. We correlate ERA5 with the AWS data to show a significant positive correlation of western GrIS summer surface temperature and melt with the Greenland Blocking Index (GBI) and weaker and opposite correlations with the North Atlantic Oscillation (NAO). This analysis may further help to explain melting patterns on the western GrIS from the perspective of circulation anomalies.

APA, Harvard, Vancouver, ISO, and other styles

44

Korobeinikov, Andrei, and Alex Mcnabb. "Long-term global climate dynamics: A Hopf bifurcation causing recurrent ice ages." Journal of Applied Mathematics and Decision Sciences 5, no. 4 (January 1, 2001): 201–14. http://dx.doi.org/10.1155/s1173912601000153.

Full text

Abstract:

Rapid and dramatic changes in climate and glacial conditions have taken place during the last 2.5 million years of the earth's history. Huge ice sheets expanded and contracted periodically, at times covering large areas of North America and Europe. Global sea levels dropped and rose 100 m to 150 m in response to the growth and melting of glaciers, causing continental coast lines to move far into present sea areas and then retreated again. We will use a simple conceptual model to demonstrate that these climate and glacier fluctuations can be a consequence of a supercritical Hopf bifurcation in models of the “ocean-land-atmosphere” system.

APA, Harvard, Vancouver, ISO, and other styles

45

Suprun, A. D., and M. A. Razumova. "Long-term existence of a solid surface under temperature above melting point. Is it possible?" Applied Physics A: Materials Science & Processing 67, no. 2 (August 1, 1998): 237–39. http://dx.doi.org/10.1007/s003390050764.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Chi, Zhang, Tan Yiqiu, Chen Fengchen, Ye Qing, and Xu Huining. "Long-term thermal analysis of an airfield-runway snow-melting system utilizing heat-pipe technology." Energy Conversion and Management 186 (April 2019): 473–86. http://dx.doi.org/10.1016/j.enconman.2019.03.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Lin, Jia Horng, Ying Hsuan Hsu, Chen Hung Huang, Yu Chun Chuang, Ting Ting Li, and Ching Wen Lou. "Sound-Absorbing Evaluation on Nylon 6/Low-Melting PET Nonwoven Fabric." Applied Mechanics and Materials 184-185 (June 2012): 1207–10. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.1207.

Full text

Abstract:

In recent years, as quality life improves, people begin to focus on quiet environment. Long-term noise pollution makes trouble of dysphoria and concentrating for people, thus noise-reduction has become an urgent project. This study uses Nylon 6 fibers, blended with different contents of low-melting PET fibers (10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%), to fabricate Nylon6/ LPET nonwoven fabrics after needle-punching process. Afterwards, their maximum tensile strength, air permeability, sound absorption coefficient were all evaluated. When low-melting PET fibers contain 30 wt%, the nonwoven fabric has the better sound-absorbing property. Herein, the maximum tensile strength reaches 70.79 N and 31.01 N, respectively in CD and MD; the air permeability is about 116.5 [cm3/(cm2/s)]

APA, Harvard, Vancouver, ISO, and other styles

48

McPhee, M. G. "Analysis and Prediction of Short-Term Ice Drift." Journal of Offshore Mechanics and Arctic Engineering 110, no. 1 (February 1, 1988): 94–100. http://dx.doi.org/10.1115/1.3257130.

Full text

Abstract:

Techniques for kinematic analysis and dynamic, “free-drift” ice modeling are described and applied to interpretation of ice-drift data from recent marginal ice zone (MIZ) experiments. Kinematic description is based on a complex demodulation algorithm that separates inertial and tidal components from lower frequency, “synoptic” drift. Complex demodulation produces the time series of phasors (complex numbers describing phase and amplitude of the oscillating components), useful for separating the physical processes active in the upper ocean/ice system. Free-drift ice motion modeling utilizes a similarity theory for planetary-boundary-layer dynamics that includes the effect of buoyancy, both from rapid melting at the ice/ocean interface, and/or from a pre-existing density gradient (pycnocline) within the boundary layer. Two examples are considered: one in which a band of ice in the Bering Sea drifted rapidly away from the rest of the pack when it encountered warm water at the ice edge; and a second in which drift in the Greenland Sea was apparently affected by both a shallow pycnocline and a period of rapid melt.

APA, Harvard, Vancouver, ISO, and other styles

49

Moiduddin, Khaja, Syed Hammad Mian, Mohammed Alkindi, Sundar Ramalingam, Hisham Alkhalefah, and Osama Alghamdi. "An In Vivo Evaluation of Biocompatibility and Implant Accuracy of the Electron Beam Melting and Commercial Reconstruction Plates." Metals 9, no. 10 (September 30, 2019): 1065. http://dx.doi.org/10.3390/met9101065.

Full text

Abstract:

The use of additive manufacturing in medical applications has become more prevalent over the last decade. Studies have proved that reconstruction plates with a mesh structure enhance the biocompatibility and bone-ingrowth formation. However, limited studies have been reported in the customization and in vivo clinical assessment of mesh implants. The purpose of this study was to investigate the surgical treatment and implant fitting accuracy using three different reconstruction plates. Fifteen goats were divided into one control and three experimental groups (Groups 1, 2, and 3) with five in each group. An experimental segmental defect was created on these animals and was adopted with customized electron beam melting reconstruction titanium plates with mesh in Group 1 and without mesh in Group 2 and commercial reconstruction plate in Group 3. All the animals were subjected to radiographic analysis before and after surgery. The subjected animals were sacrificed after 3 months and the electron beam melting reconstruction plates were compared with the commercial plate based on clinical and histology analysis and implant fitting accuracy. Both the electron beam melting reconstruction plates (with mesh and without mesh) and commercial plates survived the three months post-operation, revealing good wound-healing with new bone formation and without any foreign-body reaction. The electron beam melting reconstructed plate with mesh (Group 1) was found to have a better implant fitting when compared to the other two groups. The average discrepancy between Groups 2 and 3 was not significant. Certainly, the commercial plate (Group 3) was found to have the least accuracy as compared to other electron beam melting reconstruction plates (Group 1 and Group 2). Custom design electron beam melting fabricated reconstruction plates possessed better functionality, aesthetic outcome, and long-term biocompatibility when compared to commercial plates. Animal results indicated that the electron beam melting plates with mesh (Group 1) were superior in comparison to the other two groups due to its ability to provide better bone-in-growth and osseointegration on its porous microstructure.

APA, Harvard, Vancouver, ISO, and other styles

50

Beyeler, E. P., and S. I. Gu¨c¸eri. "Thermal Analysis of Laser-Assisted Thermoplastic-Matrix Composite Tape Consolidation." Journal of Heat Transfer 110, no. 2 (May 1, 1988): 424–30. http://dx.doi.org/10.1115/1.3250502.

Full text

Abstract:

A novel approach to producing composite parts using thermoplastic-matrix tapes is described. A thermal analysis is presented for the case of focused heat sources such as lasers for melting and consolidating the prepregs in a continuous manufacturing process. A numerical grid generation method is employed to account for the complex geometry of the solution domain. Heat transfer is modeled using an orthotropic domain made of two-dimensional, continuous fiber anisotropic laminates. Heat of crystallization melting/solidification are included in the form of a heat generation term. The temperature distributions and thermal histories in the laminated composites are presented for varying consolidation speeds. The effects of preheating the consolidated laminate are investigated and the overall feasibility of the proposed process is discussed.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Melting term'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles