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Significance Women in science face barriers to professional advancement. One of the most important forums for international climate science is the Intergovernmental Panel on Climate Change, where there has been a slow increase in the proportion of women authors since the first assessment in 1990. Our survey of more than 100 female Intergovernmental Panel on Climate Change authors explores their experience and perceptions, the barriers to their full participation that they identify, and recommendations for improvements. While we find that some women reported a positive experience, others felt women were poorly represented and heard and encountered barriers beyond their gender including race, nationality, command of English, and discipline. The study contributes to the larger literature on gender and science and provides recommendations for greater inclusion.

A parametric numerical investigation is performed of the natural convection and heat transfer in an enclosure with opposing wavy walls, layered by a porous medium, saturated by a hybrid nanofluid, at different inclination angles. The Galerkin finite element method is used to obtain steady-state solutions of the heat and mass convection laws by application of the semi-implicit method for pressure linked equations algorithm. The Darcy-Brinkman model is used for representing the state variables change in the porous layer. The influence of six parameters on the flow and heat transfer rate is described. These are the inclination angle, varied from 0o to 90o, the Rayleigh number (104 ≤ 𝑅𝑎 ≤ 107), the Darcy number (10-5 ≤ 𝐷𝑎 ≤ 10-2), the porous layer width (0.2 ≤ 𝑊p ≤ 0.8), the number of undulation (1≤ 𝑁 ≤ 4), and the nanoparticle volume fraction (0 ≤ 𝜙 ≤ 0.2). It is found that the inclination angle is a very influential control parameter for the hybrid nanofluid in the enclosure. Its effect is modulated by the other parameters. The model predicts that adding the nanoparticles enhances the heat transfer between the opposing walls of the cell compared to the pure fluid over the whole range of inclination angles. Finally, a comparison of the heat transfer enhancement based on the suspension of Al2O3 nanoparticles in water as a single nanofluid versus using Cu-Al2O3 nanoparticles in water as a hybrid nanofluid indicates better heat transfer performance by the hybrid nanofluid.

Abstract Liquid fuels are likely to remain the main energy source in long-range transportation and aviation for several decades. To reduce our dependence on fossil fuels, liquid biofuels can be blended to fossil fuels – or used purely. In this paper, coconut methyl ester, standard diesel fuel (EN590:2017), and their blends were investigated in 25 V/V% steps. A novel turbulent combustion chamber was developed to facilitate combustion in a large volume that leads to ultra-low emissions. The combustion power of the swirl burner was 13.3 kW, and the air-to-fuel equivalence ratio was 1.25. Two parameters, combustion air preheating temperature and atomizing air pressure were adjusted in the range of 150–350 °C and 0.3–0.9 bar, respectively. Both straight and lifted flames were observed. The closed, atmospheric combustion chamber resulted in CO emission below 10 ppm in the majority of the cases. NO emission varied between 60 and 183 ppm at straight flame cases and decreased below 20 ppm when the flame was lifted since the combustion occurred in a large volume. This operation mode fulfills the 2015/2193/EU directive for gas combustion by 25%, which is twice as strict as liquid fuel combustion regulations. The 90% NO emission reduction was also concluded when compared to a lean premixed prevaporized burner under similar conditions. This favorable operation mode was named as Mixture Temperature-Controlled (MTC) Combustion. The chemiluminescent emission of lifted flames was also low, however, the OH* emission of straight flames was clearly observable and followed the trends of NO emission. The MTC mode may lead to significantly decreased pollutant emission of steady-operating devices like boilers, furnaces, and both aviation and industrial gas turbines, meaning an outstanding contribution to more environmentally friendly technologies.

AbstractThe bioenergy crops such as energycane, miscanthus, and sorghum are being genetically modified using state of the art synthetic biotechnology techniques to accumulate energy‐rich molecules such as triacylglycerides (TAGs) in their vegetative cells to enhance their utility for biofuel production. During the initial genetic developmental phase, many hundreds of transgenic phenotypes are produced. The efficiency of the production pipeline requires early and minimally destructive determination of oil content in individuals. Current screening methods require time‐intensive sample preparation and extraction with chemical solvents for each plant tissue. A rapid screen will also be needed for developing industrial extraction as these crops become available. In the present study, we have devised a proton relaxation nuclear magnetic resonance (1H‐NMR) method for single‐step, non‐invasive, and chemical‐free characterization of in‐situ lipids in untreated and pretreated lignocellulosic biomass. The systematic evaluation of NMR relaxation time distribution provided insight into the proton environment associated with the lipids in the biomass. It resolved two distinct lipid‐associated subpopulations of proton nuclei that characterize total in‐situ lipids into bound and free oil based on their “molecular tumbling” rate. The T1T2 correlation spectra also facilitated the resolution of the influence of various pretreatment procedures on the chemical composition of molecular and local 1H population in each sample. Furthermore, we show that hydrothermally pretreated biomass is suitable for direct NMR analysis unlike dilute acid and alkaline pretreated biomass which needs an additional step for neutralization.

Abstract The expansion of Sargassum muticum in the Danish estuary Limfjorden between 1984 and 1997 was followed by a decrease in abundance of native perennial macroalgae such as Halidrys siliquosa. Although commonly associated with the expansion of exotic species, it is unknown whether such structural changes affect ecosystem properties such as the production and turnover of organic matter and associated nutrients. We hypothesized that S. muticum possesses ‘ephemeral’ traits relative to the species it has replaced, potentially leading to faster and more variable turnover of organic matter. The biomass dynamics of S. muticum and H. siliquosa was therefore compared in order to assess the potential effects of the expansion of Sargassum. The biomass of Sargassum was highly variable among seasons while that of Halidrys remained almost constant over the year. Sargassum grew faster than Halidrys and other perennial algae and the annual productivity was therefore high (P/B = 12 year−1) and exceeded that of Halidrys (P/B = 5 year−1) and most probably also that of other perennial algae in the system. The major grazer on macroalgae in Limfjorden, the sea urchin Psammechinus miliaris, preferred Sargassum to Halidrys, but estimated losses due to grazing were negligible for both species and most of the production may therefore enter the detritus pool. Detritus from Sargassum decomposed faster and more completely than detritus from Halidrys and other slow-growing perennial macrophytes. High productivity and fast decomposition suggest that the increasing dominance of S. muticum have increased turnover of organic matter and associated nutrients in Limfjorden and we suggest that the ecological effects of the invasion to some extent resemble those imposed by increasing dominance of ephemeral algae following eutrophication.

Climate change is a notorious and serious problem that needs to be attended with no delays. Mitigation of fossil fuel emissions are mandatory to reduce the production of green-house gases, however, as population increases, the global energy demand increases as well, with fossil fuels acting as the main energy source, globally. Worldwide, different strategies towards the development of sustainable societies applying circular economy principles and decarbonization of the industrial infrastructures are among the most important goals to achieve for the coming years. The use of biomass to accomplish such goals by producing bio-derived commodities and biofuels have gained track on the last two decades. One important source of biomass that has been highly studied in the recent years is the one coming from the aquatic feedstock called macro algae, which is normally used for food and cosmetic applications. However, the application of the macro algae to produce the so-called third generation biofuels or other chemical commodities, although having some drawbacks, seem to lead to promising results for the coming years with more and more mature technologies for such tasks. Belonging to the genus Ulva, the sea lettuce, a group of green algae have been identified as a potential candidate to be used to produce bio-derived products. In this work, through a literature review, the effects of the use of carbon and oil worldwide were appraised, as well as some of the most studied alternatives to mitigate the negative effects caused to the environment using fossil fuels. The possible use of macro algae as a promising candidate to produce bio-derived products was also highlighted. Using an Ulva sp. collected from the coast at county Durham, qualitative analysis of the cellulose and ulvan biochemical fractions were obtained. Through Fourier-Transformed Infrared Spectroscopy, the possible existence of acetylated cellulose in algae was explored. Mass-spectrometry analysis was performed to clarify the obtained results from the ...

(2002). Electrolytic Deposition (Electroplating) of Metals. Transactions of the IMF: Vol. 80, No. 2, pp. 67-72.

Visible‐light‐activated yellow amorphous TiO2 (yam‐TiO2) was synthesised by a simple and organic‐free precipitation method. TiN, an alternative precursor for TiO2 preparation, was dissolved in hydrogen peroxide under acidic condition (pH ~ 1) adjusted by nitric acid. The yellow precipitate was obtained after adjusting pH of the resultant red brown solution to 2 with NH4OH. The BET surface area of this sample was 261 m2/g. The visible light photoactivity was evaluated on the basis of the photobleaching of methylene blue (MB) in an aqueous solution by using a 250 W metal halide bulb equipped with UV cutoff filter (λ > 420 nm) under aerobic conditions. Yam‐TiO2 exhibits an interesting property of being both surface adsorbent and photoactive under visible light. It was assigned to the η2‐peroxide, an active intermediate form of the addition of H2O2 into crystallined TiO2 photocatalyst. It can be concluded that an active intermediate form of titanium peroxo species in photocatalytic process can be synthesised and used as a visible‐light‐driven photocatalyst.