Chain conformation-dependent thermal conductivity of amorphous polymer blends: the impact of inter- and intra-chain interactions

2016 ◽  
Vol 18 (47) ◽  
pp. 32146-32154 ◽  
Author(s):  
Xingfei Wei ◽  
Teng Zhang ◽  
Tengfei Luo
Keyword(s):  
Thermal Conductivity ◽  
Polymer Blends ◽  
Amorphous Polymer ◽  
Scientific Research ◽  
Industrial Applications ◽  
Chain Conformation ◽  
The Impact ◽  
Thermal Conductivities

Polymers with high thermal conductivities are of great interest for both scientific research and industrial applications.

scholarly journals On parameterization of heat conduction in coupled soil water and heat flow modelling

2012 ◽  
Vol 7 (No. 4) ◽  
pp. 125-137 ◽  
Author(s):  
J. Votrubová ◽  
M. Dohnal ◽  
T. Vogel ◽  
M. Tesař
Keyword(s):  
Thermal Conductivity ◽  
Soil Water ◽  
Heat Transport ◽  
Preferential Flow ◽  
Thermal Conditions ◽  
Industrial Applications ◽  
Soil Thermal Conductivity ◽  
Vegetation Season ◽  
Simulation Results ◽  
The Impact

Soil water and heat transport plays an important role in various hydrologic, agricultural, and industrial applications. Accordingly, an increasing attention is paid to relevant simulation models. In the present study, soil thermal conditions at a mountain meadow during the vegetation season were simulated. A dual-continuum model of coupled water and heat transport was employed to account for preferential flow effects. Data collected at an experimental site in the Šumava Mountains, southern Bohemia, during the vegetation season 2009 were employed. Soil hydraulic properties (retention curve and hydraulic conductivity) determined by independent soil tests were used. Unavailable hydraulic parameters were adjusted to obtain satisfactory hydraulic model performance. Soil thermal properties were estimated based on values found in literature without further optimization. Three different approaches were used to approximate the soil thermal conductivity function, λ(θ): (i) relationships provided by Chung and Horton (ii) linear estimates as described by Loukili, Woodbury and Snelgrove, (iii) methodology proposed by Côté and Konrad. The simulated thermal conditions were compared to those observed. The impact of different soil thermal conductivity approximations on the heat transport simulation results was analysed. The differences between the simulation results in terms of the soil temperature were small. Regarding the surface soil heat flux, these differences became substantial. More realistic simulations were obtained using λ(θ) estimates based on the soil texture and composition. The differences between these two, related to neglecting vs. considering λ(θ) non-linearity, were found negligible.

High thermal conductivity in amorphous polymer blends by engineered interchain interactions

2014 ◽  
Vol 14 (3) ◽  
pp. 295-300 ◽  
Author(s):  
Gun-Ho Kim ◽  
Dongwook Lee ◽  
Apoorv Shanker ◽  
Lei Shao ◽  
Min Sang Kwon ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Polymer Blends ◽  
Amorphous Polymer ◽  
High Thermal Conductivity ◽  
Interchain Interactions

The Effects of Van Der Waals Bonding Strength on the In-Plane Lattice Thermal Conductivities of Multilayer Thin Films

2012 ◽  
Author(s):  
Weiyu Chen ◽  
Zhonghua Ni ◽  
Juekuan Yang ◽  
Yan Zhang ◽  
Deyu Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Bonding Strength ◽  
Van Der Waals ◽  
Interface Roughness ◽  
Multilayer Thin Films ◽  
Continuous Increase ◽  
Non Equilibrium Molecular Dynamics ◽  
The Impact ◽  
Thermal Conductivities

A non-equilibrium molecular dynamics (NEMD) simulation model is established to investigate the impact of vdW strength on thermal transport along the in-plane direction in argon bi-layer films (BLFs) and silicon BLFs. Simulation results indicate that higher strength leads to a higher in-plane thermal conductivity. However, interface roughness also increases with the continuous increase of the van der Waals (vdW) strength and leads to the reduction of thermal conductivities. The bonding strength does play an important role in manipulating thermal conductivity of multilayer thin films.

Objectivity of Scientific Research as an Ethical and Political Position (Book Review: P.P. Tolochko. Ukraine between Russia and the West: Historical and Nonfiction Essays. Saint Petersburg: Saint Petersburg University of Humanities and Social Sciences, 2018)

2019 ◽  
Vol 62 (11) ◽  
pp. 144-153
Author(s):  
Alexander S. Zapesotsky
Keyword(s):  
Social Sciences ◽  
Scientific Research ◽  
The West ◽  
Full Member ◽  
Saint Petersburg ◽  
Political Position ◽  
Humanities And Social Sciences ◽  
Nonfiction Essays ◽  
The Impact

Book Review: P.P. Tolochko. Ukraine between Russia and the West: Historical and Nonfiction Essays. Saint Petersburg: Saint Petersburg University of Humanities and Social Sciences, 2018. - 592 pp. ISBN 978-5-7621-0973-4This author discusses the problem of scientific objectivity and reviews a book written by the medievalist-historian P.P. Tolochko, full member of the National Academy of Sciences of Ukraine (NASU), honorable director of the NASU Institute of Archaeology. The book was published by the Saint Petersburg University of Humanities and Social Sciences in the autumn of 2018. The book presents a collection of articles and reports devoted to processes in Ukraine and, first of all, in Ukrainian historical science, which, at the moment, is experiencing an era of serious reformation of its interpretative models. The author of the book shows that these models are being reformed to suit the requirements of the new ideology, with an obvious disregard for the conduct of objective scientific research. In this regard, the problem of objectivity of scientific research becomes the subject of this review because the requirement of objectivity can be viewed not only as a methodological requirement but also as a moral and political position, opposing the rigor of scientific research to the impact of ideological, political and moral systems and judgments. It is concluded that in this sense the position of P.P. Tolochko can be considered as the act of profound ethical choice.

scholarly journals Lightweight Cement Conglomerates Based on End-of-Life Tire Rubber: Effect of the Grain Size, Dosage and Addition of Perlite on the Physical and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 225
Author(s):  
Andrea Petrella ◽  
Michele Notarnicola
Keyword(s):  
Grain Size ◽  
End Of Life ◽  
Compression Tests ◽  
Tire Rubber ◽  
Impact Compression ◽  
Weight Percentage ◽  
Deep Groove ◽  
Mechanical Strengths ◽  
The Impact ◽  
Thermal Conductivities

Lightweight cement mortars containing end-of-life tire rubber (TR) as aggregate were prepared and characterized by rheological, thermal, mechanical, microstructural, and wetting tests. The mixtures were obtained after total replacement of the conventional sand aggregate with untreated TR with different grain sizes (0–2 mm and 2–4 mm) and distributions (25%, 32%, and 40% by weight). The mortars showed lower thermal conductivities (≈90%) with respect to the sand reference due to the differences in the conductivities of the two phases associated with the low density of the aggregates and, to a minor extent, to the lack of adhesion of tire to the cement paste (evidenced by microstructural detection). In this respect, a decrease of the thermal conductivities was observed with the increase of the TR weight percentage together with a decrease of fluidity of the fresh mixture and a decrease of the mechanical strengths. The addition of expanded perlite (P, 0–1 mm grain size) to the mixture allowed us to obtain mortars with an improvement of the mechanical strengths and negligible modification of the thermal properties. Moreover, in this case, a decrease of the thermal conductivities was observed with the increase of the P/TR dosage together with a decrease of fluidity and of the mechanical strengths. TR mortars showed discrete cracks after failure without separation of the two parts of the specimens, and similar results were observed in the case of the perlite/TR samples thanks to the rubber particles bridging the crack faces. The super-elastic properties of the specimens were also observed in the impact compression tests in which the best performances of the tire and P/TR composites were evidenced by a deep groove before complete failure. Moreover, these mortars showed very low water penetration through the surface and also through the bulk of the samples thanks to the hydrophobic nature of the end-of-life aggregate, which makes these environmentally sustainable materials suitable for indoor and outdoor elements.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

scholarly journals Oil and Flower Production in Rosa damascena trigintipetala Dieck under Salinity Stress in Taif Region, Saudi Arabia

2021 ◽  
Vol 13 (8) ◽  
pp. 4547
Author(s):  
Mohamed E. El-Sharnouby ◽  
Metwally M. Montaser ◽  
Sliai M. Abdallah
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Salinity Stress ◽  
Growth Parameters ◽  
Industrial Applications ◽  
Rosa Damascena ◽  
Flower Production ◽  
Survival Percentage ◽  
The Impact ◽  
Tolerance To Salinity

The flower industry depends on oil and fragrance, which is addressed in the current work. Different concentrations of NaCl (0, 250, 500, 1000, and 1500 ppm) were applied to Taif rose plants (Rosa damascena var. trigintipetala Dieck) to evaluate their effects on growth and essential oil content. Results clearly indicated the highest survival percentage (98.3%) was seen in untreated plants compared to plants under salinity stress. Moreover, increasing the NaCl levels induced an adverse effect on the growth parameters of Taif rose plants, while some essential oil contents were increased to the maximum degree of their tolerance to salinity stress. The extracted essential oils were analyzed using GC/MS. The essential oils of Taif rose plants treated with 500 ppm NaCl recorded the highest values of citronellol, geraniol and phenylethyl alcohol contents (16.56, 8.67 and 9.87%), respectively. NaCl at 250 ppm produced the highest values of heneicosane (13.12%), and then decreased to the lowest value (7.79%) with the increase of NaCl to 1500 NaCl, compared to the control and other NaCl levels. The current results could highlight the impact of salinity stress on Rosa damascena Miller var. trigintipetala Dieck for better economic and industrial applications.

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