Understanding the Hydrodynamics in a 2-Dimensional Downer by CFD-DEM Simulation

The gas-solid flows in a 2-dimensional downer were simulated using a CFD-DEM method. The predicted macro-scale flow structure had good agreement with the experiments. The distinct clustering phenomena at meso-scale were revealed throughout the downer. Influences of the collision properties of the wall and the particles on the hydrodynamics in downer were investigated

Load Sharing Multiobjective Optimization Design of a Split Torque Helicopter Transmission

Split torque designs can offer significant advantages over the traditional planetary designs for helicopter transmissions. However, it has two unique properties, gap and phase differences, which result in the risk of unequal load sharing. Various methods have been proposed to eliminate the effect of gap and promote load sharing to a certain extent. In this paper, system design parameters will be optimized to change the phase difference, thereby further improving load sharing. A nonlinear dynamic model is established to measure the load sharing with dynamic mesh forces quantitatively. Afterwards, a multiobjective optimization of a reference split torque design is conducted with the promoting of load sharing property, lightweight, and safety considered as the objectives. The load sharing property, which is measured by load sharing coefficient, is evaluated under multiple operating conditions with dynamic analysis method. To solve the multiobjective model with NSGA-II, an improvement is done to overcome the problem of time consuming. Finally, a satisfied optimal solution is picked up as the final design from the Pareto optimal front, which achieves improvements in all the three objectives compared with the reference design

Nutrition Diet of Grazing Sheep and Forage Supply on Natural Grassland

Forages are a major asset of any livestock operation and the foundation of most rations in a forage-based livestock system. The available nutrients in a forage influence individual animal production (e.g. gain per animal), while the amount of forage produced affects production per hectare. The relationship between voluntary food intake and animal productivity is well recognized. Many studies related to the regulation of food consumption by sheep and cattle have been reported (Provenza 1996). Willoughby (1958) dis-cussed a number of factors which might influence the herbage intake of grazing animals. By contrast, less attention has been given to the nutritional supply which influences the intake of herbage by grazing animals. It is necessary to know about animal daily nutrient requirements for production and forage supply in order to evaluate grazing capacity

Apolipoprotein E ε4 accelerates the longitudinal cerebral atrophy in open access series of imaging studies-3 elders without dementia at enrollment

IntroductionEarly studies have reported that APOE is strongly associated with brain atrophy and cognitive decline among healthy elders and Alzheimer’s disease (AD). However, previous research has not directly outlined the modulation of APOE on the trajectory of cerebral atrophy with aging during the conversion from cognitive normal (CN) to dementia (CN2D).MethodsThis study tried to elucidate this issue from a voxel-wise whole-brain perspective based on 416 qualified participants from a longitudinal OASIS-3 neuroimaging cohort. A voxel-wise linear mixed-effects model was applied for detecting cerebrum regions whose nonlinear atrophic trajectories were driven by AD conversion and to elucidate the effect of APOE variants on the cerebral atrophic trajectories during the process.ResultsWe found that CN2D participants had faster quadratically accelerated atrophy in bilateral hippocampi than persistent CN. Moreover, APOE ε4 carriers had faster-accelerated atrophy in the left hippocampus than ε4 noncarriers in both CN2D and persistent CN, and CN2D ε4 carriers an noncarriers presented a faster atrophic speed than CN ε4 carriers. These findings could be replicated in a sub-sample with a tough match in demographic information.DiscussionOur findings filled the gap that APOE ε4 accelerates hippocampal atrophy and the conversion from normal cognition to dementia

Long wavelength single photon like driven photolysis via triplet triplet annihilation

Photolysis has enabled the occurrence of numerous discoveries in chemistry, drug discovery and biology. However, there is a dearth of efficient long wavelength light mediated photolysis. Here, we report general and efficient long wavelength single photon method for a wide array of photolytic molecules via triplet-triplet annihilation photolysis. This method is versatile and LEGO -like. The light partners (the photosensitizers and the photolytic molecules) can be energetically matched to adapt to an extensive range of electromagnetic spectrum wavelengths and the diversified chemical structures of photoremovable protecting groups, photolabile linkages, as well as a broad array of targeted molecules. Compared to the existing photolysis methods, our strategy of triplet-triplet annihilation photolysis not only exhibits superior reaction yields, but also resolves the photodamage problem, regardless of whether they are single photon or multiple photon associated. Furthermore, the biological promise of this LEGO system was illustrated via developing ambient air-stable nanoparticles capable of triplet-triplet annihilation photolysis

STUDY THE ORDER OF MORPHOLOGY SELF-ASSEMBLED TRIBLOCK COPOLYMER THIN FILMS BY FFT OF THE AFM IMAGES

ABSTRACT A variety of block copolymer thin films with well-ordered nanostructures, which can be employed as templates for nanotechnologies including nanostructure membranes, nanoparticle synthesis, photonic crystal, and high-density information storage media, can be realized simply and at low cost by self-assembly. Long range ordering of morphology is paramount to realize applications of self-assembled block copolymer thin films in nanotechnologies. A better understanding of what parameters affect the ordering process can lead to the production of highly ordered arrays of nanostructures. In this paper, in order to effectively analyze the improvement in ordering, the Fast Fourier transform (FFT) analysis of the AFM images is used. Fast Fourier transform provide a mathematical analysis of the image that is similar to producing a diffraction pattern. From this "diffraction pattern" information on the order in the system can be obtained. Moreover, calculating an ordering parameter from the FFT provides a quantitative measure of the order present in the polymer template. The order parameter is calculated using equations which were tested against a manufactured perfect system and imperfect system to ensure that a perfect system would provide an order parameter of 1 and an imperfect system would create an order parameter of 0. The results show that the method is reasonable and effective to analyze the improvement in ordering that is achieved by using solvent annealing. Furthermore, the method can be used to understand the parameters in triblock copolymer thin film self-assembly process that create the most well ordered system

Complete genome sequencing of Pseudomonas syringae pv. actinidiae Biovar 3, P155, kiwifruit pathogen originating from China

Pseudomonas syringae pv. actinidiae is a bacterial pathogen of kiwifruit. Based on the results of the pathogenicity assay, we sequenced the strain Pseudomonas syringae (Psa3) P155 which possesses a series of virulence and resistance genes, CRISPR candidate elements, prophage related sequences, methylation modifications, genomic islands as well as one plasmid. Most importantly, the copper resistance genes copA, copB, copC, copD, and copZ as well as aminoglycoside resistance gene ksgA were identified in strain P155, which would pose a threat to kiwifruit production. The complete sequence we reported here will provide valuable information for a better understanding of the genetic structure and pathogenic characteristics of the genome of P155

Draft genome of the Marco Polo Sheep (<i>Ovis ammon polii</i>)

Background: The Marco Polo Sheep (Ovis ammon polii), a subspecies of argali (Ovis ammon) that is distributed mainly in the Pamir Mountains, provides a mammalian model to study high altitude adaptation mechanisms. Due to over-hunting and subsistence poaching, as well as competition with livestock and habitat loss, O. ammon has been categorized as an endangered species on several lists. It can have fertile offspring with sheep. Hence, a high-quality reference genome of the Marco Polo Sheep will be very helpful in conservation genetics and even in exploiting useful genes in sheep breeding. Findings: A total of 1022.43 Gb of raw reads resulting from whole-genome sequencing of a Marco Polo Sheep were generated using an Illumina HiSeq2000 platform. The final genome assembly (2.71 Gb) has an N50 contig size of 30.7 Kb and a scaffold N50 of 5.49 Mb. The repeat sequences identified account for 46.72% of the genome, and 20 336 protein-coding genes were predicted from the masked genome. Phylogenetic analysis indicated a close relationship between Marco Polo Sheep and the domesticated sheep, and the time of their divergence was approximately 2.36 million years ago. We identified 271 expanded gene families and 168 putative positively selected genes in the Marco Polo Sheep lineage. Conclusions: We provide the first genome sequence and gene annotation for the Marco Polo Sheep. The availability of these resources will be of value in the future conservation of this endangered large mammal, for research into high altitude adaptation mechanisms, for reconstructing the evolutionary history of the Caprinae, and for the future conservation of the Marco Polo Sheep

Evaluation of soil fertility of the shelter-forest land along the Tarim Desert Highway

To study the changes of soil fertility of the shelter-forest land along the Tarim Desert Highway, soils from the forest land were collected at the layers of 0-10 cm, 10-20 cm, 20-30 cm. Different soil fertility parameters were measured, and quantitative evaluation of soil fertility was performed by the soil integrated fertility index (IFI). The main results show that the construction of the shelter forest along the Tarim Desert Highway improved the soil physical structure, increased soil porosity and enhanced water-holding capacity. With the increase of plantation time of the shelter forest, soil microbial biomass C, N, P and the activities of six types of enzyme were enhanced, which promoted the accumulation and transformation of soil nutrients of the forest land. Consequently, the soil nutrients in 12-year-old forest land were much higher than in the newer ones and drifting sand. However, soil salt content of the older forest land was higher owing to the drip-irrigation with salt water. Through the comprehensive evaluation, we found that soil fertility index in the forest land was enhanced with the forest age, and it had close correlations with the growth indices of the forest trees. In summary, construction of the shelter-forest along the Tarim Desert Highway accelerated the improvement of aeolian soil in the forest land, and the soil fertility improved year by year. We conclude that the forest trees grow normally under the stress of the present drip-irrigation with salt water