Private Investor-based Transmission Expansion Planning in Deregulated Environments

Abstract—Deregulation in power systems creates new uncertainties and escalates the previous ones. The presence of these uncertainties causes the transmission network to remain a monopoly and the private investors not to be interested in investing in new transmission lines. This article presents a new merchant-based transmission network expansion planning algorithm from the viewpoint of private investors. The point estimation method is used to handle the uncertainties, and the genetic algorithm is used as the optimization tool. The proposed method provides insights for private investors to deal with the uncertainties and to find appropriate transmission projects in which to invest.     

A model for estimation of permeability and free flowing porosity

This work highlights the application of an adaptive neuro-fuzzy inference system (ANFIS) for predictions of NMR log parameters including free flowing porosity (FFP) and permeability by using field log data. The input parameters of model were neutron porosity, sonic transit time, bulk density, and electrical resistivity. The outputs of model were also permeability and FFP values. The ANFIS model was trained by using hybrid method. Results showed that the developed model is effective in prediction of field NMR log data. Outcomes of this study can be used in areas of petroleum engineering where accurate and immediate predictions of logging data are required.     

Study of inlet temperature effect on single and double inlets cyclone performance

In this paper, a comprehensive study is performed in order to demonstrate the effect of the flow and particle temperature on cyclone performance. Three main characteristics of the low-mass-loading gas-solid cyclone separators, including: pressure drop, particle separation efficiency and natural vortex length are investigated. Eulerian-Lagrangian approach is employed to solve the unsteady Navier-Stokes and energy equations to model the flow of particles. Because of the strong swirling flow in cyclone, Reynolds stress transport model (RSTM) is used to calculate the Reynolds stresses. Numerical simulation is accomplished at a temperature range of 293–700 K and four inlet velocities. Also, a comparison is conducted between two Stairmand high efficiency cyclones with the same dimensions, one with single inlet and the other with double inlets to declare the effect of the second inlet on cyclone performance. The analysis of results shows that the swirling flow becomes weaker for higher temperature cases and thus, flow pressure drop and particle separation efficiency is noticeably decreased. Increasing in temperature causes decrease in natural vortex length. Also, study of natural vortex length is performed for the studied range of temperature.     

Measurement of low-loss aqueous solutions permittivity with high detection accuracy by a contact and free-label resonance microwave sensor

In this paper, a microwave sensor is designed and built to measure the permittivity of aqueous solutions. The samples used in this experiment are different purities of ethanol mixed with water. Ethanol solution with different purities is a widely used material in industry. Structures of meander, ladder, and T-structure were used to design the sensor. Then the designed sensor is simulated in CST software in range of relative dielectric from 10 to 80. After obtaining the desired answer in the simulation, the proposed sensor is built on the Rogers 4003 substrate, the built-in sensor measured ethanol solution with a purity of 5% to 35% (equivalent to permittivity of 76 to 58), and is showed a sensitivity of 4% and a Q-factor of 3500. The results of simulation and measurement are consistent with each other, and they indicated that the proposed sensor beyond the fluids can be supported and determine their relative dielectrics.     

A Combined Experimental and Theoretical Approach to Study Temperature and Moisture Dynamic Characteristics of Intermittent Paddy Rice Drying

Intermittent drying of paddy rice is fully investigated both theoretically and experimentally. A model is developed to describe simultaneous heat and mass transfer for the drying stages and mass transfer for the tempering ones. The model is considered for both cylindrical and spherical geometries. The model excels in considering non-constant paddy rice and air physical properties as well as surface vaporization and convection. The consequent equations are numerically solved with finite-difference method of line using implicit Runge–Kutta. Furthermore, a set of experiments is conducted in a laboratory-scale fluidized bed dryer to estimate the moisture diffusivity of rice and evaluate the effects of different parameters. Two correlations for moisture diffusivity are derived for each geometry based on the experimental results. It is noteworthy that the geometry choice leads to significantly different moisture diffusivities. As a result, the diffusivity values obtained for spherical presentation is 2.64 times greater than that of cylinder. Moreover, the cylindrical model fits the experimental results more precisely, especially for tempering stage (AARD_cyl = 1.03%; AARD_sph = 1.53%). Model results reveal that thermal equilibrium is quickly reached within the first 2 min. Air velocity shows no influential effect on drying upon establishment of fluidized condition. In addition, drying rate is drastically improved after applying the tempering stage. A definition for tempering stage efficiency is also proposed which shows that 3 h tempering will be 80% efficient for the studied case. Rising temperature significantly improves the drying rate, while it does not contribute much in the tempering efficiency.     

Control of the continuous rheocasting process

In the continuous rheocasting process, a semi-solid alloy is obtained from the exit port of the apparatus at a given rate and with a given fraction of solid. This solid fraction is dependent on the corresponding temperature within the solid-liquid range which should be controlled accurately by the process parameters for a given rheocaster stirring chamber. For this purpose a heat flow model has been established for the continuous rheocasting of Bi-17 wt% Sn alloy. The heat transfer calculations are based on the solution of the two-dimensional partial differential equations using a finite difference method. An excellent agreement between calculations and experimental results is found. Computations are carried out in order to find the influence of stirring chamber dimensions on the alloy exit temperature and therefore, the volume fraction of solid. The influence of input metal temperature and metal flow rate on the exit temperature and volume fraction of solid are also found.     

Modeling of Alkali Pretreatment of Rice Husk Using Response Surface Methodology and Artificial Neural Network

Rice husk as a widely available lignocellulosic material was subjected to an alkaline pretreatment process. The alkaline pretreatment was carried out under various conditions. The influence of process parameters, such as pretreatment time, solid loading, and NaOH concentration, on the glucose and xylose yields were investigated by means of appropriate models. The maximum glucose and xylose yields obtained under optimum pretreatment condition were 68.82% and 53.77%, respectively. Response surface methodology (RSM) and artificial neural network were used to model the pretreatment processes. Both modeling methodologies were statistically compared by means of the coefficient of determination and relative mean square error. It was concluded that the artificial neural network shows a somewhat better performance compared to RSM.     

Decarbonization of EU energy sector: techno-feasibility analysis of 100% renewables by 2050 in Cyprus

Clean Technologies and Environmental Policy - Cyprus continues to be one of the European Union’s most energy import-dependent countries. It is of worthy note that Cyprus is also the only...     

Fragility assessment of an outrigger structure system based on energy method

Fragility curves development in structures has always been a focus of research interest among structural and earthquake engineers for which the maximum story drift is usually considered as the engineering demand parameter (EDP) known as the conventional approach. This paper aims at calculating the fragility curves of a tall building with outrigger braced system by considering the plastic strain energy as the EDP and compare it with the conventional approach. In addition, the effect of optimizing the position of outriggers on the exceedance probability of the structure under near- and far-fault seismic loadings is investigated in this paper. Fragility curves of this structure in four performance levels including immediate occupancy (IO), life safety (LS), collapse prevention (CP), and instability is extracted based on the conventional method. The fragility curves for the aforementioned performance levels are also extracted based on the plastic strain energy and compared with the conventional approach. The results have demonstrated that optimizing the location of the bracing system would lower the exceedance probability of the structure. Moreover, the exceedance probability of the investigated building with outrigger braced system under far-fault records in various levels is more than that of near-fault records. It is also concluded that the conventional approach would lead to more conservative results compared with the energy approach.     

Durability and economics investigations on triple stack configuration and its power management strategy for fuel cell vehicles

The durability and cost are the most important bottlenecks in fuel cell vehicle (FCV) commercialization. To alleviate these two drawbacks, a new power management strategy (PMS) is proposed on a triple fuel cell stack configuration (TFSC) to enhance the fuel cell lifetime in a commercialized FCV such as Toyota-Mirai. The two main innovations of the present study are summarized to: (i) lifetime assessing study of the proposed TFSC under the vehicular condition and comparing them with those of single fuel cell stack configuration (SFSC), and (ii) performing an economics analysis to compute and compare the stack costs of triple and single configurations. The lifetime is calculated based on all the operating modes during the combined driving cycle including start/stop cycles, idling or constant potential operation, load cycling, and high current operation. The result reveals that TFSC improves the lifetime by 18.93% compared to the SFSC. It also indicates that during the FCV lifespan, the stack cost of the TFSC is around 14% less than that of the SFSC, which makes triple stack more feasible.