Thermal assessment of nano-particulate graphene-water/ethylene glycol (WEG 60:40) nano-suspension in a compact heat exchanger

In the present study, we report the results of the experiments conducted on the convective heat transfer of graphene nano-platelets dispersed in water-ethylene glycol. The graphene nano-suspension was employed as a coolant inside a micro-channel and heat-transfer coefficient (HTC) and pressure drop (PD) values of the system were reported at different operating conditions. The results demonstrated that the use of graphene nano-platelets can potentially augment the thermal conductivity of the working fluid by 32.1% (at wt. % = 0.3 at 60 °C). Likewise, GNP nano-suspension promoted the Brownian motion and thermophoresis effect, such that for the tests conducted within the mass fractions of 0.1%–0.3%, the HTC of the system was improved. However, a trade-off was identified between the PD value and the HTC. By assessing the thermal performance evaluation criteria (TPEC) of the system, it was identified that the thermal performance of the system increased by 21% despite a 12.1% augmentation in the PD value. Furthermore, with an increment in the fluid flow and heat-flux applied to the micro-channel, the HTC was augmented, showing the potential of the nano-suspension to be utilized in high heat-flux thermal applications.M. M. Sarafraz, Mohammad Reza Safaei, Zhe Tian, Marjan Goodarzi, Enio Pedone Bandarra Filho, and M. Arjomand

Basic effects of pulp refining on fiber properties- a review

The requirement for high quality pulps which are widely used in paper industries has increased the demand for pulp refining (beating) process. Pulp refining is a promising approach to improve the pulp quality by changing the fiber characteristics. The diversity of research on the effect of refining on fiber properties which is due to the different pulp sources, pulp consistency and refining equipment has interested us to provide a review on the studies over the last decade. In this article, the influence of pulp refining on structural properties i.e., fibrillations, fine formation, fiber length, fiber curl, crystallinity and distribution of surface chemical compositions is reviewed. The effect of pulp refining on electrokinetic properties of fiber e. g., surface and total charges of pulps is discussed. In addition, an overview of different refining theories, refiners as well as some tests for assessing the pulp refining is presented. (C) 2014 Elsevier Ltd. All rights reserved

Estimation of biomass and optimum of shrimp fishing season in Hormuzgan Province

This project was designed with for objective on estimation of Biomass and optimum time for catch season of P.merguinsis and M.affinis shrimps. This investigation was carried out monthly by swept area method in coastal waters of Hormozgan province. The optimum time for fishing season in Bandar Abbas to Sirik waters in 2004,2005 and 2006 respectively was about 25/9/2004, 24/9/2005 and 25/9/2006. Total allowable catch (T.A.C.) for P.merguiensis and M.affinis estimated in 2004 to 2006 were 600, 170 tonnes, 850, 550 tonnes and 650, 400 tonnes respectively. The densest catch was obtained for P.merguiensis (from 58/5 to 65/5 %) and the least catch for P.indicus (from 0/04 to 1/1 % ), respectievly

The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden

Experimental investigation and performance optimisation of a catalytic reforming micro-reactor using response surface methodology

In the present work, the chemical performance of a new catalyst mediated inside a micro-reactor for hydrogen production was experimentally assessed. The coated catalyst was prepared via particulate fouling technique by uniformly dispersing copper nano-flakes on silica as a conductive substrate. The catalyst was calcinated at 973 K to further strengthen the structure against creep and flow friction forces. The proposed method is a cost-effective technique for the production of catalyst, which in turn improves the economic viability of the hydrogen production with micro-reactors. The effect of different operating parameters such as temperature, velocity of the reactants, the amount of the catalyst coated on the walls of the reactor and the geometrical specifications of the micro-reactor on methanol conversion extent was experimentally studied. The stability of the catalyst was also examined and it was demonstrated that the mechanism of hydrogen and synthetic gas production with the proposed catalyst is diffusion-controlled such that with an increase in the flow rate of the reactants, the residence time decreased resulting in the reduction of methanol conversion extent. For an average velocity of 24000 ml/(g hr) at T = 773 K, the methanol conversion exceeded 97%. Likewise, using response surface methodology, the operation of the micro-reactor was optimised such that the methanol conversion was promoted to 100% at 773 K at catalyst loading of 1.0 g and velocity of 24000 ml/(g hr).M.M. Sarafraz, Mohammad Reza Safaei, Marjan Goodarzi, M. Arjomand

Fluid Flow & Heat and Mass Transfer through Passages with Complex Geometries for Advanced Technology Applications

International audienc

Fluid Flow & Heat and Mass Transfer through Passages with Complex Geometries for Advanced Technology Applications

International audienc