scholarly journals Thermal analysis of Casson rheological fluid with gold nanoparticles under the impact of gravitational and magnetic forces

2021 ◽  
Vol 28 ◽  
pp. 101433
Author(s):  
Farooq Hussain ◽  
Mubbashar Nazeer ◽  
Mohamed Altanji ◽  
Adila Saleem ◽  
M.M. Ghafar
2009 ◽  
Vol 46 (3) ◽  
pp. 137-152 ◽  
Author(s):  
Mile Djurdjevic ◽  
Glenn Byczynski ◽  
Carola Schechowiak ◽  
Hagen Stieler ◽  
Jelena Pavlovic

2018 ◽  
Vol 235 ◽  
pp. 50-58 ◽  
Author(s):  
D. Middendorf ◽  
U. Bindrich ◽  
P. Mischnick ◽  
K. Franke ◽  
V. Heinz

2021 ◽  
Author(s):  
MD Shafiqul Islam ◽  
Tae-Soon Choi ◽  
Tae-Hyun An ◽  
Kang-Hyun Song

Abstract LNG carriers are vessels used to store and transport liquefied natural gas. LNG, in its liquid form has the temperature of minus 163 degrees Celsius. Therefore, the types of steel used to build the hull structure must withstand the impact of low temperatures. Cargo Containment System (CCS) is used to reduce the transfer of heat from the outside environment into the cargo tank and to keep the LNG in liquid state. Presently, the most popular types of CCS are designed by GTT (Gaztransport & Technigaz). However, Korean shipyards, KOGAS (Korea Gas Corporation) and many other companies around the world are developing their own CCS systems. The thermal analysis of LNG carrier hull is generally performed by the CCS developer and therefore, in order to assist the new CCS developers and LNG carrier designers, KR has developed a guideline for temperature calculation of Membrane type LNG carrier’s hull. This study is a part of the guidelines and focuses on numerical and analytical solution procedures for accurate hull temperature calculation. For verification and accuracy of these methods, temperature calculation of a Membrane type LNG carrier hull is carried out and the results are compared with each other. Both methods, thoroughly analyzed in this study, could be applied in the design of membrane type LNG carrier hulls.


2021 ◽  
Author(s):  
Paula Ballikaya ◽  
Ivano Brunner ◽  
Claudia Cocozza ◽  
Ralf Kaegi ◽  
Marcus Schaub ◽  
...  

<p>Industrial activities and human population growth have resulted in an unprecedented increase in the release of particulate matter (PM) into the environment. Incidental nanoparticles (NPs) as a byproduct of industrial processes and engineered NPs are being discharged into terrestrial and aquatic ecosystems. Several studies on the impact of PM and NPs on human health have been conducted this century, but their effects on plants are poorly understood. What happens to them in forest ecosystems and trees has yet to be explored. The use of dendrochemistry to monitor air pollution is essential to provide past levels of contamination. Several studies have shown the ability of trees to accumulate pollutants into their annual rings, but the effect of particles at nano-scale is still largely unknown and their presence in tree rings unexplored.</p><p>In July 2019, a greenhouse experiment was conducted in order a) to confirm the uptake and transport of NPs in trees, b) to determine the delivery efficiency of different NPs entry pathways (leaves and roots), and c) to investigate the influence of surface-charged NPs on their uptake and transport. The fate of gold nanoparticles (AuNPs) was investigated in two tree species, European beech (<em>Fagus sylvatica</em> L.) and Scots pine (<em>Pinus sylvestris </em>L.). In the experiment, 40nm surface-charged AuNPs (positive, negative, and neutral AuNPs, hereafter referred to as treatments) were supplied once, separately to leaves and to roots. Twenty days after the treatment, Au concentration (mg kg<sup>-1</sup>) in leaves, stem and roots was determined by ICP-MS. In the leaf supply, Au concentrations were higher in leaves (98.3% and 99.2% on average, in beech and Scots pine respectively) and stems (1.4% and 0.45% on average) than in roots (0.3% and 0.35% on average). In the root supply, higher Au concentration was found in the roots (99.9 % on average in both species) than in the stems (0.1% on average in both species), whereas gold was not detected in the leaves. In the majority of cases, the measured Au was greater in beech than in Scots pine, probably due to their higher stomatal activity. AuNP concentrations among the treatments were significantly different (p value < 0.05), but distribution pattern in Scots pine were not discernible. In conclusion, AuNPs can be taken up by roots and leaves and transported to different compartments of trees. Different entry pathways influence the NP delivery within the plant tissues through transport mechanisms that are still unclear. It seems that NPs are allowed to move faster from the leaves through the phloem to the xylem and are further distributed throughout the plant system, including to the roots. The influence of surface-charged nanoparticles on their uptake and transport is not completely clear, and further research is needed in order to understand their behavior in trees.</p><p>This study shows the potential of trees as proxies to monitor NPs in forest ecosystems. Using tree rings as spatiotemporal indicators of the impact of particles on the environment will help a quantitative risk assessment and management of atmospheric particulate matter and NPs concentrations in the environment.</p>


2020 ◽  
Vol 22 (8) ◽  
Author(s):  
Barbara De Berardis ◽  
Magda Marchetti ◽  
Anna Risuglia ◽  
Federica Ietto ◽  
Carla Fanizza ◽  
...  

AbstractIn recent years, the introduction of innovative low-cost and large-scale processes for the synthesis of engineered nanoparticles with at least one dimension less than 100 nm has led to countless useful and extensive applications. In this context, gold nanoparticles stimulated a growing interest, due to their peculiar characteristics such as ease of synthesis, chemical stability and optical properties. This stirred the development of numerous applications especially in the biomedical field. Exposure of manufacturers and consumers to industrial products containing nanoparticles poses a potential risk to human health and the environment. Despite this, the precise mechanisms of nanomaterial toxicity have not yet been fully elucidated. It is well known that the three main routes of exposure to nanomaterials are by inhalation, ingestion and through the skin, with inhalation being the most common route of exposure to NPs in the workplace. To provide a complete picture of the impact of inhaled gold nanoparticles on human health, in this article, we review the current knowledge about the physico-chemical characteristics of this nanomaterial, in the size range of 1–100 nm, and its toxicity for pulmonary structures both in vitro and in vivo. Studies comparing the toxic effect of NPs larger than 100 nm (up to 250 nm) are also discussed.


Oncotarget ◽  
2017 ◽  
Vol 8 (24) ◽  
pp. 38618-38630 ◽  
Author(s):  
Yanan Cui ◽  
Xiaoning Song ◽  
Suxin Li ◽  
Bing He ◽  
Lan Yuan ◽  
...  

2013 ◽  
Vol 7 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Radovan Hudák ◽  
Martin Šarik ◽  
Róbert Dadej ◽  
Jozef Živčák ◽  
Daniela Harachová

Abstract Thermal analysis of laser processes can be used to predict thermal stresses and consequently deformation in a completed part. Analysis of temperature is also the basic for feedback of laser processing parameters in manufacturing. The quality of laser sintered parts greatly depends on proper selection of the input processing parameters, material properties and support creation. In order to relatively big heat stress in the built part during sintering process, the thermal simulation and thermal analysis, which could help better understand and solve the issue of parts deformations is very important. Main aim of presented work is to prepare input parameters for thermal simulations by the use of RadTherm software (Thermoanalytics Inc., USA), directly during the sintering process and after the process and find out the impact of the heat stress on a final shape and size of the prototype. Subsequently, an annealing process of constructed products after DMLS could be simulated and specified.


2020 ◽  
Vol 32 (4) ◽  
pp. 241-246
Author(s):  
Krzysztof Jakub Stojek ◽  
Jan Felba ◽  
Johann Nicolics ◽  
Dominik Wołczyński

Purpose This paper aims to develop thermal analysis method of thermal joints characterization. The impact on convection on thermal resistance analysis with use thermography for silver-based thermal joints were investigated for non-metallized and metalized semiconductor surfaces. Heat transfer efficiency depends on thermal conductivity; radiation was used to perform thermographic analysis; the convection is energy loss, so its removing might improve measurements accuracy. Design/methodology/approach Investigation of thermal joints analysis method was focused on determination of convection impact on thermal resistance thermographic analysis method. Measuring samples placed in vacuum chamber with lowered pressure requires transparent window for infrared radiation that is used for thermographic analysis. Impact of infrared window and convection on temperature measurements and thermal resistance were referred. Findings The results showed that the silicon window allowed to perform thermal analysis through, and the convection was heat transfer mode which create 15% energy loss. Originality/value It is possible to measure thermal resistance for silver-based thermal joints with convection eliminated to improve measurements accuracy.


Sign in / Sign up

Export Citation Format

Share Document