•The mechanism by which waves affect the distribution of oil droplet sizes and entrainment rate was investigated.•The influence of mixing energy on the distribution of oil droplet sizes and ...entrainment rate was investigated.•Mathematical relationships were established to determine the correlation between the DSD and the energy dissipation rates, as well as between the oil entrainment rate and the energy dissipation rates.•Appropriate mathematical functions were employed to fit the cumulative distribution of oil droplet.
Oil dispersed on the water surface undergoes fragmentation into droplets, subsequently entering the water column under wave action. The oil entrainment rate and the droplet size distribution (DSD) significantly influence the subsequent migration and transformation of oil in the water column. A wave tank system was employed to investigate the impact of wave action on oil entrainment rate and DSD. The experimental results revealed that increased wave height and wave frequency facilitated the entry of oil into the water column and fragmented it into dispersed droplets. Relationships between oil entrainment rate and energy dissipation, as well as DSD, were established and supported by mathematical regression analyses. Non-linear regression analysis indicated that the cumulative frequency distribution of DSD adhered to the Log-Normal and Rosin-Rammler distributions. These findings contribute to a comprehensive understanding of natural oil dispersion and subsea transport, valuable for estimating the origin of oil spills.
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Cooling and temperature homogeneity are the key technical problems for the proton exchange membrane fuel cell (PEMFC) thermal management. In this paper, a one-dimensional model of a PEMFC with ...phase-change cooling (flow boiling cooling) is proposed for PEMFC thermal management, and the heat transfer of microchannel flow boiling is integrated with PEMFC cooling. Five organic coolants (Novec 649, HFC-365mfc, HFE-356mec, HFE-347pcf2, and HFE-7100) and single-phase water are compared by the PEMFC average temperature of the catalyst layer (ATCL) and temperature difference of the catalyst layer (TDCL). The PEMFC temperature characteristics with organic coolant are investigated in detail. The results indicate that HFE-7100 exhibited the lowest ATCL and minimum TDCL among the coolants. The maximum TDCL of HFE-7100 is 5.5 K at current density of 1.2 A/cm2, which can completely keep the PEMFC operating temperature at proper and uniform conditions. The minimum ATCL of Novec 649 is over 353 K, which dissatisfies the cooling demand. The TDCLs of PEMFCs with different organic coolants have a minimum value when the coolant outlet vapour mass fraction is 0.4. Temperature uniformity should be the most important factor for mass flow control in PEMFCs using organic coolants.
•A proton exchange membrane fuel cell phase-change cooling model is proposed.•Boiling cooling for fuel cell has lower flow rate sensitivities.•Minimum temperature difference along channel appears at 0.4 mass fraction.•HFE-7100 coolant maximum temperature difference is 5.5 K.
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat worldwide. To isolate defense-related genes against the pathogen, a suppression ...subtractive hybridization library was constructed for an incompatible interaction. From the library, 652 sequences were determined to be unigenes, of which 31 were determined as genes involved in signal transduction and 77 were predicted to encode defense-related proteins. Expression patterns of 12 selected signal transduction and defense-related genes were determined using quantitative real-time polymerase chain reaction. Signal transduction genes started increasing their expression at 12 h post inoculation (hpi), and expressions of the most of the transport and resistance-related genes were induced at 18 hpi. The gene expression results indicate specific molecular and cellular activities during the incompatible interaction between wheat and the stripe rust pathogen. In general, the expression increase of wheat signal transduction genes soon after inoculation with the pathogen inducing various defense-related genes, including reactive oxygen species, ATP-binding cassette (ABC) transporters, pathogenesis-related proteins, and genes involved in the phenylpropanoid pathway. The activities of these defense genes work in a sequential and concerted manner to result in a hypersensitive response.
The effects of different olefin contents in fuel (nominally 8.2 and 17.2% in volume) on the performance and exhaust emissions of a modern gasoline direct injection engine at speeds of 1500, 3500, and ...5000 rpm under 10, 25, 50, 75, and 100% engine loads were investigated. The experimental results showed that reducing the olefin content had little impact on brake power, while it obviously increased brake-specific fuel consumption and decreased brake thermal efficiency at low and medium speeds. In addition, lower exhaust gas temperatures were observed at low speeds. The comparative results indicated that reducing the olefin content decreased CO emissions by −5.8 to 22.8%, but slightly increased (less than 5%) CO2 emissions. Likewise, total hydrocarbon emissions decreased, while NO x emissions also decreased by 5–15% under most of the operating conditions. Most importantly, great reductions in particle mass concentrations and particle number emissions were observed when lower olefin content gasoline was used, with decreases of up to 87.4 and 95.8%, respectively. Moreover, particle mass and particle number changes suggest that a lower olefin content facilitates the formation of larger soot particles. Therefore, although reducing the olefin content is disadvantageous to engine performance, it markedly reduces CO, total hydrocarbon, NO x , particle mass, and particle number emissions, in line with the latest national emission regulations.
This paper presents the design of a waste heat recovery system for a China VI emission standards (China VI) natural gas engine to address cooling challenges. A heat balance bench experiment was ...conducted to characterize the waste heat properties of the engine's exhaust, exhaust gas recirculation exhaust (EGR), and coolant. A transcritical dual-loop Rankine cycle system was modeled and analyzed using MATLAB to recover this waste heat. The system utilizes two loops: high-temperature loop to recover exhaust waste heat and EGR waste heat and low-temperature loop to recover waste heat from the coolant and high-temperature loop, improving overall recovery. The low-temperature loop is based on a transcritical cycle, making the system more compact than a subcritical alternative and better suited for vehicle applications. Analysis identified water as the working fluid for high-temperature loop and R32 as the optimal working fluid for low-temperature loop. The Rankine cycle waste heat recovery system was found to increase the engine's power output by approximately 71.29 kW at rated operating conditions, representing a 21.03% gain over the original power.
•China VI natural gas engine holds substantial potential in waste heat utilization.•Transcritical dual-loop Rankine cycle is designed for waste heat recovery.•Water and R32 are the optimal working fluid combination.•Engine's power increases by 21.03% at the rated condition.
Experiments and simulations were performed to investigate the effect of ethanol direct injection plus gasoline port injection (EDI + GPI) on engine performance. Gasoline direct injection plus GPI ...(GDI + GPI) was also tested as a reference to EDI + GPI. The experimental results showed that volumetric efficiency increased with the raise of direct injection ratio in both EDI + GPI and GDI + GPI conditions. The volumetric efficiency and IMEP of EDI + GPI were greater than that of GDI + GPI, due to the stronger charge cooling effect of EDI. Combustion process was improved by EDI when ethanol energy ratio (EER) was less than 42%, however further increase of EER led to the deterioration of combustion process. Simulation results showed that ethanol's high laminar flame speed played a dominate role to the improvement of combustion process. Although EDI negatively affected the equivalence ratio around spark plug, this disadvantage was offset by the high laminar flame speed of ethanol, resulting in shorter initial and major combustion durations. Simulation results also found that combustion process was deteriorated when EER was greater than 42%, which was mainly due to over-cooling and poor mixing of EDI. Regarding emissions, NO decreased while CO and HC increased with the raise of both EDI and GDI ratios.
•EDI + GPI showed higher volumetric efficiency and IMEP than GDI + GPI did.•EDI + GPI led to lower in-cylinder temperature and shorter combustion duration.•Ethanol's high laminar flame speed was the main contributor to short combustion duration.•HC and CO of EDI + GPI first decreased and then increased with the raise of ethanol ratio.
The version of this article published in BMC Genomics 2013, 14: 274, contains 9 unpublished genomes (Botryobasidium botryosum, Gymnopus luxurians, Hypholoma sublateritium, Jaapia argillacea, Hebeloma ...cylindrosporum, Conidiobolus coronatus, Laccaria amethystina, Paxillus involutus, and P. rubicundulus) downloaded from JGI website. In this correction, we removed these genomes after discussion with editors and data producers whom we should have contacted before downloading these genomes. Removing these data did not alter the principle results and conclusions of our original work. The relevant Figures 1, 2, 3, 4 and 6; and Table 1 have been revised. Additional files 1, 3, 4, and 5 were also revised. We would like to apologize for any confusion or inconvenience this may have caused.
Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported.
In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 94 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed. Importantly, cellulases of some GH families are present in fungi that are not known to have cellulose-degrading ability. In addition, our results also showed that in general, plant pathogenic fungi have the highest number of CAZymes. Biotrophic fungi tend to have fewer CAZymes than necrotrophic and hemibiotrophic fungi. Pathogens of dicots often contain more pectinases than fungi infecting monocots. Interestingly, besides yeasts, many saprophytic fungi that are highly active in degrading plant biomass contain fewer CAZymes than plant pathogenic fungi. Furthermore, analysis of the gene expression profile of the wheat scab fungus Fusarium graminearum revealed that most of the CAZyme genes related to cell wall degradation were up-regulated during plant infection. Phylogenetic analysis also revealed a complex history of lineage-specific expansions and attritions for the PL1 family.
Our study provides insights into the variety and expansion of fungal CAZyme classes and revealed the relationship of CAZyme size and diversity with their nutritional strategy and host specificity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To improve the engine overall performance, an adaptive flow optimization procedure is proposed in this paper to synthesize turbocharger compressor optimum designs. Two objective functions are ...involved in the adaptive optimization. They are the traditional compressor design and the compressor design with consideration of improving engine overall performance. The two-step decomposition approach is chosen to generate optimum designs. The optimized designs not only satisfy turbomachinery and engine constraints but also have optimum objective function values in the two fields. Performance sensitivity analysis of compressor main design variables is performed for the flow optimization design process. A centrifugal compressor is redesigned for a turbocharged gasoline engine, as an example, based on the adaptive flow optimization process. The calculating results show a more than 5% increase of isentropic efficiency in comparison with the base line compressor, resulting in a more than 19% increase of engine torque at low speed conditions.
Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion ...in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism.
The majority of germ tubes of the pathotype CYR32 of Puccinia striiformis f.sp. tritici formed on the surface of spike organs of the susceptible wheat cv. Suwon 11 penetrated through the stomatal ...pore, only a few germ tubes formed small appressoria over the stomata. In the lemma, palea and glume, the stripe rust fungus spread between the parenchyma cells close to the inner epidermal layer, but the fungus did not develop between the thick‐walled cells near the outer epidermal layer of these organs. In the awn and stem, spread of the stripe rust was confined to the intercellular spaces of the chlorophyll parenchyma, beneath the invaded stomatal pore of the epidermis and the urediniospores to be released disrupted the epidermis. In the caryopsis, the spread of hyphae was restricted to the intercellular spaces of the pericarp cells.
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