Graphene-based current mode logic circuits: a simulation study for an emerging technology

In this paper, the usage of graphene transistors is introduced to be a suitable solution for extending low power designs. Static and current mode logic (CML) styles on both nanoscale graphene and silicon FINFET technologies are compared. Results show that power in CML styles approximately are independent of frequency and the graphene-based CML (G-CML) designs are more power-efficient as the frequency and complexity increase. Compared to silicon-based CML (Si-CML) standard cells, there is 94% reduction in power consumption for G-CML counterparts. Furthermore, a G-CML 4-bit adder respectively offers 8.9 and 1.7 times less power and delay than the Si-CML adder

Graphene-based current mode logic circuits: a simulation study for an emerging technology

In this paper, the usage of graphene transistors is introduced to be a suitable solution for extending low power designs. Static and current mode logic (CML) styles on both nanoscale graphene and silicon FINFET technologies are compared. Results show that power in CML styles approximately are independent of frequency and the graphene-based CML (G-CML) designs are more power-efficient as the frequency and complexity increase. Compared to silicon-based CML (Si-CML) standard cells, there is 94% reduction in power consumption for G-CML counterparts. Furthermore, a G-CML 4-bit adder respectively offers 8.9 and 1.7 times less power and delay than the Si-CML adder

Personality Type A or Personality Type D, Which is a Strong Predictor of Coronary Heart Disease?

Considering the increasing incidence and prevalence of coronary heart disease and the increasing emphasis of health researchers on the association and relationship of psychosocial factors with the occurrence and persistence of cardiovascular disease, the need to identify the desired factors and determine each of the personality and psychological factors. The effect is felt more than ever in patients who are also the target of the present study. The main purpose of this study was to determine the predictors of coronary heart disease based on personality types. Among cardiovascular patients, men and women aged 25-60 years in Shahid Madani and 29 Bahman hospitals in Tabriz, who were admitted to surgical wards for coronary angiography in 2015, 50 people were selected who met the inclusion criteria. Also, 50 patients were selected from the patients' companions and answered the questionnaires of Denollet type D personality and Ratus personality pattern questionnaire. Findings showed that the variables of negative emotions, social inhibition of the personality type D subscale were predictors of coronary heart disease. But the role of personality type A in predicting coronary heart disease is not significant. Social inhibition was also the strongest predictor of coronary heart disease. The present study showed that personality factors are predictors of coronary heart disease

Conventional diverting techniques and novel fibr-assisted self-diverting system in carbonate reservoir acidizing with successful case studies

Conventional diverting techniques may not be useful, and the use of the advanced and well-documented diverting technique is needed to overcome the complexity and heterogeneity of carbonate reservoirs. Nowadays, there have been a lot of materials and techniques utilized for acid diversion. This paper aimed to consider various utilization of fiber-assisted self as the diverting system in acidifying carbonate reservoirs. One of the main reasons for its ability to overcome uncertainty is that the fiber itself is an inherent property, allowing for an automatic diversion adjustment downhole. When a media with infinite permeability, such as a perforation tunnel or natural fracture, is filled and bridged with a material of finite permeability such as degradable fiber, this creates a temporary skin to injectivity in that zone. This is a powerful concept, as it is a way, despite uncertainty from a lack of logging data or uncertainty in the data itself, of dampening the reservoir’s natural permeability contrast. It does not rely on petrophysical certainty to design a successful treatment

Review of underground hydrogen storage: Concepts and challenges

The energy transition is the pathway to transform the global economy away from its current dependence on fossil fuels towards net zero carbon emissions. This requires the rapid and large-scale deployment of renewable energy. However, most renewables, such as wind and solar, are intermittent and hence generation and demand do not necessarily match. One way to overcome this problem is to use excess renewable power to generate hydrogen by electrolysis, which is used as an energy store, and then consumed in fuel cells, or burnt in generators and boilers on demand, much as is presently done with natural gas, but with zero emissions. Using hydrogen in this way necessitates large-scale storage: the most practical manner to do this is deep underground in salt caverns, or porous rock, as currently implemented for natural gas and carbon dioxide. This paper reviews the concepts, and challenges of underground hydrogen storage. As well as summarizing the state-of-the-art, with reference to current and proposed storage projects, suggestions are made for future work and gaps in our current understanding are highlighted. The role of hydrogen in the energy transition and storage methods are described in detail. Hydrogen flow and its fate in the subsurface are reviewed, emphasizing the unique challenges compared to other types of gas storage. In addition, site selection criteria are considered in the light of current field experience.Cited as: Hematpur, H., Abdollahi, R., Rostami, S., Haghighi, M., Blunt, M. J. Review of underground hydrogen storage: Concepts and challenges. Advances in Geo-Energy Research, 2023, 7(2): 111-131. https://doi.org/10.46690/ager.2023.02.0

Enhancement of dynamic wireless power transfer system by model predictive control

Wireless power transfer (WPT) system based on a dynamic wireless charging (DWC) scheme, eliminates waiting time for charging electric vehicles (EVs), increases the range of motion, reduces the size of Li-ion battery, and automates the charging process. In the DWC method, an EV frequently passes the charger transmitter pads at maximum speed to charge the onboard battery. The charger must have a quick and smooth transient response that employs the proper charging strategy for the battery. Here, a model predictive controller (MPC) is proposed to deploy a suitable DWC based on constant current/voltage (CC/CV) charging protocol. The designed MPC functionality is demonstrated by simulation and experimental results for both CC/CV strategies while battery state of charge (SOC) is estimated by a simple and stable technique in the primary side. The applied CC/CV MPC scheme performs properly in all conditions with a fast critically damped start-up, which makes it a potential choice to charge EV in dynamic and static modes. The simulation results of the proposed controller are verified by implementing a 90 W WPT testbed at 85.5 kHz switching frequency and 100 mm coils’ air gap