Effect of Nano-Cluster Compactness on Thermal Physical Properties of Nanofluids

2011 ◽  
Author(s):  
Zhaozan Feng ◽  
Wei Li ◽  
Tingting Wu
Keyword(s):  
Thermal Conductivity ◽  
Critical Analysis ◽  
Water Solution ◽  
Thermal Conductance ◽  
Empirical Method ◽  
Trade Off ◽  
Cluster Compactness ◽  
Nano Cluster ◽  
Semi Empirical ◽  
Thermal Physical Properties

This paper reports an experimental work on the viscosities of 30% (in volume) ethylene glycol water solution based nanofluids, and presents a critical analysis of the experimental reports on thermal conductivity and dynamic viscosity in terms of the mechanism of aggregation and show that, by manipulating the morphology of the aggregates, the first-best trade-off between the thermal conductance and rheological behavior of general nanofluids can be approximately achieved. Attempt to regulate the viscosity of nanosized SiO2 suspensions was made following a semi-empirical method named particle grading.

Influence of Contact Pressure on the Thermal Contact Conductance of Layered AA3003 Aluminium

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Contact Pressure ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Contact Conductance ◽  
Contact Conductance ◽  
Interface Thermal Resistance ◽  
Measurement Results ◽  
Semi Empirical ◽  
The Relationship

For the optimization of the annealing process of aluminium coils, simulation of the process is often performed. To simulate the process with higher accuracy, reliable input parameters are required and the thermal conductivity (thermal contact conductance) is one of them. In the present study, the thermal conductivity and thermal contact conductance of AA3003 alloy sheets were measured by a steady state comparative longitudinal heat flow method at different contact pressure. To evaluate the thermal conductance at the interface, thermal resistance network model' was applied. In addition, the surface roughness of the sheets was also investigated. Based on the measurement results, the semi-empirical equation for the relationship between thermal contact conductance and contact pressure was obtained

Modeling the Effects of O-sulfonation on the CID of Serine

2020 ◽  
Author(s):  
Kenneth Lucas ◽  
George Barnes
Keyword(s):  
Sulfo Group ◽  
High Energy ◽  
Empirical Method ◽  
Side Chain ◽  
Energy Structure ◽  
Direct Dynamics ◽  
Theoretical Mass ◽  
Intermolecular Proton Transfer ◽  
Dynamics Simulations ◽  
Semi Empirical

We present the results of direct dynamics simulations and DFT calculations aimed at elucidating the effect of \textit{O}-sulfonation on the collision induced dissociation for serine. Towards this end, direct dynamics simulations of both serine and sulfoserine were performed at multiple collision energies and theoretical mass spectra obtained. Comparisons to experimental results are favorable for both systems. Peaks related to the sulfo group are identified and the reaction dynamics explored. In particular, three significant peaks (m\z 106, 88, and 81) seen in the theoretical mass spectrum directly related to the sulfo group are analyzed as well as major peaks shared by both systems. Our analysis shows that the m\z 106 peaks result from intramolecular rearrangements, intermolecular proton transfer among complexes composed of initial fragmentation products, and at high energy side-chain fragmentation. The \mz 88 peak was found to contain multiple constitutional isomers, including a previously unconsidered, low energy structure. It was also seen that the RM1 semi empirical method was not able to obtain all of the major peaks seen in experiment for sulfoserine. In contrast, PM6 did obtain all major experimental peaks.

Theoretical investigation of Ramachandran plot of N-formyl-L-alanine-amide

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Genetic Algorithm ◽  
Theoretical Investigation ◽  
Energy Analysis ◽  
Empirical Method ◽  
Conformational Space ◽  
Ramachandran Plot ◽  
Global Minima ◽  
Reasonable Time ◽  
Semi Empirical

The full conformational space of N-formyl-L-alanine-amide was explored by the semi-empirical method AM1 coupled to the Multi Niche Crowding (MNC) genetic algorithm implemented in a package of programs developed in our laboratory. The structural and energy analysis of the resulting conformational space E(,ψ) exhibits 5 regions or minima ɣL, ɣD, ɛL, D and αD. The technique provides better detection of local and global minima within a reasonable time.

scholarly journals A Semi-Empirical Model for Predicting Frost Properties

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 412
Author(s):  
Shao-Ming Li ◽  
Kai-Shing Yang ◽  
Chi-Chuan Wang
Keyword(s):  
Thermal Conductivity ◽  
Linear Programming ◽  
Numerical Model ◽  
Empirical Model ◽  
Quantitative Method ◽  
Predictive Ability ◽  
Dimensionless Temperature ◽  
Crystal Shape ◽  
Proposed Model ◽  
Semi Empirical

In this study, a quantitative method for classifying the frost geometry is first proposed to substantiate a numerical model in predicting frost properties like density, thickness, and thermal conductivity. This method can recognize the crystal shape via linear programming of the existing map for frost morphology. By using this method, the frost conditions can be taken into account in a model to obtain the corresponding frost properties like thermal conductivity, frost thickness, and density for specific frost crystal. It is found that the developed model can predict the frost properties more accurately than the existing correlations. Specifically, the proposed model can identify the corresponding frost shape by a dimensionless temperature and the surface temperature. Moreover, by adopting the frost identification into the numerical model, the frost thickness can also be predicted satisfactorily. The proposed calculation method not only shows better predictive ability with thermal conductivities, but also gives good predictions for density and is especially accurate when the frost density is lower than 125 kg/m3. Yet, the predictive ability for frost density is improved by 24% when compared to the most accurate correlation available.

High‐Temperature Skin Softening Materials Overcoming the Trade‐Off between Thermal Conductivity and Thermal Contact Resistance

Small ◽  
2021 ◽  
pp. 2102128
Author(s):  
Taehun Kim ◽  
Seongkyun Kim ◽  
Eungchul Kim ◽  
Taesung Kim ◽  
Jungwan Cho ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Trade Off

scholarly journals How Good Is the STW Sensor? An Account from a Larger Shipping Company

2021 ◽  
Vol 9 (5) ◽  
pp. 465
Author(s):  
Angelos Ikonomakis ◽  
Ulrik Dam Nielsen ◽  
Klaus Kähler Holst ◽  
Jesper Dietz ◽  
Roberto Galeazzi
Keyword(s):  
High Frequency ◽  
Additional Data ◽  
Empirical Method ◽  
Influential Factor ◽  
Sensor Data ◽  
Sea State ◽  
Shipping Company ◽  
Frequency Sensor ◽  
Semi Empirical

This paper examines the statistical properties and the quality of the speed through water (STW) measurement based on data extracted from almost 200 container ships of Maersk Line’s fleet for 3 years of operation. The analysis uses high-frequency sensor data along with additional data sources derived from external providers. The interest of the study has its background in the accuracy of STW measurement as the most important parameter in the assessment of a ship’s performance analysis. The paper contains a thorough analysis of the measurements assumed to be related with the STW error, along with a descriptive decomposition of the main variables by sea region including sea state, vessel class, vessel IMO number and manufacturer of the speed-log installed in each ship. The paper suggests a semi-empirical method using a threshold to identify potential error in a ship’s STW measurement. The study revealed that the sea region is the most influential factor for the STW accuracy and that 26% of the ships of the dataset’s fleet warrant further investigation.

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