332 research outputs found
The role of the Rashba coupling in spin current of monolayer gapped graphene
In the current work we have investigated the influence of the Rashba
spin-orbit coupling on spin-current of a single layer gapped graphene. It was
shown that the Rashba coupling has a considerable role in generation of the
spin-current of vertical spins in mono-layer graphene. The behavior of the
spin-current is determined by density of impurities. It was also shown that the
spin-current of the system could increase by increasing the Rashba coupling
strength and band-gap of the graphene and the sign of the spin-current could be
controlled by the direction of the current-driving electric field
Optimisation of the vehicle transmission and the gear-shifting strategy for the minimum fuel consumption and the minimum nitrogen oxide emissions
The paper outlines a computationally efficient analytical method for evaluating the fuel consumption and the nitrogen oxide emissions during manoeuvres pertaining to the New European Driving Cycle. An integrated optimisation procedure is also included in the analyses with minimisation of the brake specific fuel consumption and minimisation of the nitrogen oxide emissions as objective functions. A set of optimum gear ratios are determined for a four-speed transmission, a five-speed transmission and six-speed transmission as the governing parameters in the optimisation process. The analysis highlights the determination of gear-shifting objective-driven strategies based on the minimisation of either of the declared objective functions. A reduction of 7.5% in the brake specific fuel consumption and a reduction of 6.75% in nitrogen oxide emissions are attainable in the best-case scenario for a six-speed transmission and a gear-shifting strategy based on the lowest brake specific fuel consumption for the case of an engine. The novel integrated analytical simulations and multi-objective optimisation have not been hitherto reported in literature. It provides the opportunity for an objective intelligent-based approach to the use of gear shift indicator technology. The results of this study also show that transmission optimisation can act as an effective and inexpensive mean to enhance the fuel efficiency and to reduce the emissions
Co-supervised learning paradigm with conditional generative adversarial networks for sample-efficient classification
Classification using supervised learning requires annotating a large amount
of classes-balanced data for model training and testing. This has practically
limited the scope of applications with supervised learning, in particular deep
learning. To address the issues associated with limited and imbalanced data,
this paper introduces a sample-efficient co-supervised learning paradigm
(SEC-CGAN), in which a conditional generative adversarial network (CGAN) is
trained alongside the classifier and supplements semantics-conditioned,
confidence-aware synthesized examples to the annotated data during the training
process. In this setting, the CGAN not only serves as a co-supervisor but also
provides complementary quality examples to aid the classifier training in an
end-to-end fashion. Experiments demonstrate that the proposed SEC-CGAN
outperforms the external classifier GAN (EC-GAN) and a baseline ResNet-18
classifier. For the comparison, all classifiers in above methods adopt the
ResNet-18 architecture as the backbone. Particularly, for the Street View House
Numbers dataset, using the 5% of training data, a test accuracy of 90.26% is
achieved by SEC-CGAN as opposed to 88.59% by EC-GAN and 87.17% by the baseline
classifier; for the highway image dataset, using the 10% of training data, a
test accuracy of 98.27% is achieved by SEC-CGAN, compared to 97.84% by EC-GAN
and 95.52% by the baseline classifier.Comment: 14 pages, 5 figure
Comparative modeling of CCRL1, a key protein in masked immune diseases and virtual screening for finding inhibitor of this protein
Human CCRL1 belongs to the family of silent chemokine receptors. This transmembrane protein plays a role in blunting function
of chemokines through binding to them. This will attenuate immune responses. Interaction between CCRL1 and CCL21 determines
this immune extinction. Thus inhibiting the action of this atypical chemokine seems to stimulate immune responses especially in
the case of suppressed and immune deficient conditions. In this study we predicted 3D structure of CCRL1 using comparative
modeling and Hiddebn Markov Model algorithm. Final predicted model optimized by Modeller v9.8 and minimized regarding
energy level using UCSF chimera candidate version1.5.3. ClasPro webserver was used to find interacting residues between CCRL1
and CCL21. Interacting residues were used as target for chemical inhibitors by simulated docking study. For finding potential
inhibitors, library of KEGG compounds screened and 97 obtained chemicals docked against interacting residues between CCRL1-
CCL21 and MolDock was used as docking scoring function. Results indicated that Hexadecanal is a potential inhibitor of CCRL1-
CCL21 interaction. Inhibition of this interaction will increase intercellular level of CCl21 and interaction between CCL21 and CCR7
causes immune potentiaiton
Multiparasitism of stink bug eggs: competitive interactions between Ooencyrtus pityocampae and Trissolcus agriope
Females of Trissolcus agriope (Platygastridae) avoid host (Brachynema signatum) eggs parasitized by conspecifics or Ooencyrtus pityocampae (Encyrtidae), but females of the latter species will superparasitize and multiparasitize, although they mostly attack unparasitized eggs. Females of T. agriope were more efficient in the laboratory and parasitized more hosts in 24 and 48 h. In multiparasitized hosts, O. pityocampae was a superior larval competitor and could complete also development as a facultative hyperparasitoid. When females of both species foraged together, T. agriope parasitized significantly more than O. pityocampae, about 50%in both cases, although O. pityocampae almost doubled its parasitism rate as the exposure period was lengthened from 24 h to 48 h. When O. pityocampae followed T. agriope in sequential foraging bouts, the former species successfully parasitized more hosts than the latter. The advisability of co-releases of both species to improve biological control of first generation B. signatum in Iranian pistachio orchards is discussed.Citation: Mohammadpour, M., Jalali, M. A., Michaud, J. P., Ziaaddini, M., & Hashemirad, H. (2014). Multiparasitism of stink bug eggs: Competitive interactions between Ooencyrtus pityocampae and Trissolcus agriope. Retrieved from http://krex.ksu.ed
Effect of tapered roller bearing supports on the dynamic behaviour of hypoid gear pair differentials
Noise and vibration refinement and energy efficiency are the key drivers in powertrain development. The final drive (the differential) is a source of vibration concern and also contributes to the powertrain inefficiency. To optimise differential characteristics for the key objectives of refinement and efficiency, detailed models of the gear interactions as well as the support bearing dynamics are required. This study reports the integrated lubricated bearing and gear contacts with an eight-degree-of-freedom dynamic analysis (a tribo-dynamic model). Non-Newtonian shear behaviour of thin lubricant-film conjunctions is taken into account in the integrated tribo-dynamic analysis, which has not hitherto been reported in the literature. The results show that the transmitted vibration spectra from the system onto the differential casing are dominated by the bearing frequencies rather than by those due to the meshing of gears. It is also shown that a sufficiently high bearing preload improves the vibration refinement but can lead to a marginally reduced transmission efficiency
Common Water Resources Conflict Analysis due to Agriculture Land Development Using Game Theory and GMCR+ (Case Study: Nazlouchay Basin in Urmia Lake Watershed)
IntroductionLand-use changes and development of irrigated agricultural lands are very important factors that affect natural resources such as the quantity and quality of water resources and the environment. Land use change is attributed to two major processes. The first process is the change in land cover, which is related to the expansion or limitation of the area of land used (such as pasture, agricultural or urban land). The second process is a change in land cover management type (for example, changes in irrigation, fertilizer use, crop type, harvesting methods or surface impermeability). Recently the Urmia lake has been accompanied by a reduction in water resources and the continuation of this process can completely cause to dry Urmia Lake. One of the approvals of the Iranian government after the formation of the National Working Group for the Lake Urmia restoration program was to prevent the development of agricultural lands in this watershed since 2014. Unfortunately, no serious and effective action has been taken in this case yet, and this process has progressed to cause conflicts in this region. Game theory is one of the most important methods used in modeling and analyzing water and environmental resources conflicts.Materials and MethodsIn the present study, using GMCR + software, the water resources conflicts arising from agricultural land development has been analyzed. In this conflict, by accurately identifying the set of decision-makers and their strategies in the conflict process (Regional Water Company, Agriculture Organization, Justice, and Profiteering Farmers), the model was executed with 4 players, 6 options, and 64 states. Players' performance was assessed once as ideal behavior (importance to the environment, sustainable development, and preference of long-term over short-term interests) and then as the use of completing a questionnaire. Then 4 states in the ideal behavior as equilibrium states and 7 states in the condition of using the questionnaire results were extracted as equilibrium states. The conflict was also examined in the coalition state of 3 government organizations (Regional Water Company, Agriculture Organization, and Justice Organization). Finally, the most probable states of equilibrium in the game results were identified.Results and DiscussionIn the discussion concerning equilibrium points, it is crucial to consider that for resolving the dispute and the proposed solution, we need to examine not only the stability of these points but also the state's priority from the perspective of stakeholders. Based on the discussions and the output results of the conflict model using the GMCR+ model, the optimal response and conflict resolution can be found in scenario 12. This scenario holds a high priority for three key players: the Agricultural Organization, the Regional Water Company, and the Justice Department. However, it doesn't share the same level of priority with the Profiteering Farmers. The reason for this divergence lies in the preference for personal gain and profit pursuit over the broader interests of the entire catchment area.ConclusionIn recent years, despite the imposed restrictions, the Urmia Lake Basin has witnessed a notable increase in the cultivation of water-intensive crops. This shift has transformed arid lands into irrigated ones and altered agricultural areas into residential zones. According to the principles of the tax evasion game, when land development carries no moral or financial consequences for profit-driven farmers, and they are aware that regulatory institutions will not commit excessive resources to prevent and effectively combat the expansion of illegal farmlands, Profiteering Farmers will consistently engage in unauthorized development under any conflict scenario. In light of the revenue potential of this situation and the opportunity to enhance one's social standing, Profiteering Farmers will persist in unauthorized development regardless of the prevailing conflict circumstances. The findings underscore the critical role of the Regional Water Company and the Agricultural Organization. These entities must proactively employ their legal capacities to impede and deter the expansion of agricultural lands. Additionally, the Justice Organization assumes primary responsibility as a crime prevention factor, while its secondary role as a judicial enforcer within this conflict situation appears fitting. Therefore, all situations are stable for Profiteering Farmers. It seems that creating a platform and conditions in which Profiteering Farmers do not develop agricultural land themselves or do not develop land due to the protection of government institutions, can be very thoughtful and effective
Seroprevalence of Toxoplasma gondii
Toxoplasma gondii is an obligate intracellular protozoan parasite causing toxoplasmosis in animals and humans. Primary maternal infection with toxoplasmosis during pregnancy is frequently associated with transplacental transmission to the fetus. However it is not certain whether Toxoplasma infection can cause recurrent abortion. The aim of this study was to determine the relationship between Toxoplasma infection and abortion via detection of anti-Toxoplasma gondii antibodies in sera of women with obstetrical problems and compare the results with control group consisting of women with history of normal delivery. Sera from 130 women with abortion and sera of 130 women with normal delivery were tested for IgG and IgM anti-Toxoplasma gondii antibodies by ELISA method. The present study revealed 24.6% of the samples with abortion and 21.5% of the samples with normal delivery were positive for IgG antibodies. However, statistical analysis indicated no significant differences (P>0.05). In addition, IgM antibody was detected in one woman who had aborted but not in women with normal childbirth. This study showed no significant difference between the case and control groups in IgG anti-Toxoplasma antibody but detected one sample with IgM antibodies in woman with abortion during the first trimester of pregnancy. In order to determine the relationship between Toxoplasma infection and abortion, anti-Toxoplasma IgG avidity and PCR to discriminate between recent and prior infections are recommended
An Investigation into the Oil Transport and Starvation of Piston-Ring Pack
In order to accurately predict the lubricant film thickness and generated friction in any tribological contact, it is important to determine appropriate boundary conditions, taking into account the oil availability and extent of starvation. This paper presents a two-dimensional hydrodynamic model of a piston ring pack for prediction of lubricant film thickness, friction and total power loss. The model takes into account starvation caused by reverse flow at the conjunctional inlet wedge, and applied to a ring pack, comprising a compression and scraper ring. Inlet boundaries are calculated for an engine cycle of a four-cylinder, four-stroke gasoline engine operating at 1500 r/min with conditions pertaining to the New European Drive Cycle. The analysis shows the two main sources of starvation: first, due to a physical lack of inlet meniscus and second, due to reverse flow at the inlet wedge significantly affecting the prevailing conditions from the generally assumed idealised boundary conditions. Such an approach has not hitherto been reported in literature
Flexible Power Electronic Transformer for Power Flow Control Applications
This paper proposes a Flexible Power Electronic Transformer (FPET) for the application in the micro-grids. The low frequency transformer is usually used at the Point of Common Coupling (PCC) to connect the low voltage grid and utility network to each other. The conventional 50Hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. In this paper, the whole system represented as two, three-phase AC systems with an intermediate high-frequency transformer for power flow controlling. The FPET consists of a high frequency transformer and three-phase to single-phase matrix converter. The matrix converters are modulated with a Pulse Width Modulation (PWM) strategy for a bi-directional power flow control. Phase shift modulation strategy in two sides of FPET is used for power flow controlling by PI controller from utility network to low voltage grid and vice versa. FPET model is established in Matlab/Simulink software with controller for power flow controlling. Presented simulation results have shown the validity of the proposed control system for FPET through the Matlab/Simulink simulation
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