Optimized Solar Photovoltaic Generation in a Real Local Distribution Network

Remarkable penetration of renewable energy in electric networks, despite its valuable opportunities, such as power loss reduction and loadability improvements, has raised concerns for system operators. Such huge penetration can lead to a violation of the grid requirements, such as voltage and current limits and reverse power flow. Optimal placement and sizing of Distributed Generation (DG) are one of the best ways to strengthen the efficiency of the power systems. This paper builds a simulation model for the local distribution network based on obtained load profiles, GIS information, solar insolation, feeder and voltage settings, and define the optimization problem of solar PVDG installation to determine the optimal siting and sizing for different penetration levels with different objective functions. The objective functions include voltage profile improvement and energy loss minimization and the considered constraints include the physical distribution network constraints (AC power flow), the PV capacity constraint, and the voltage and reverse power flow constraints.Comment: To be published (Accepted) in: Proceedings of the IEEE PES Innovative Smart Grid Technologies Conference (ISGT), Washington D.C., USA, 201

Time-Series Analysis of Photovoltaic Distributed Generation Impacts on a Local Distributed Network

Increasing penetration level of photovoltaic (PV) distributed generation (DG) into distribution networks will have many impacts on nominal circuit operating conditions including voltage quality and reverse power flow issues. In U.S. most studies on PVDG impacts on distribution networks are performed for west coast and central states. The objective of this paper is to study the impacts of PVDG integration on local distribution network based on real-world settings for network parameters and time-series analysis. PVDG penetration level is considered to find the hosting capacity of the network without having major issues in terms of voltage quality and reverse power flow. Time-series analyses show that distributed installation of PVDGs on commercial buses has the maximum network energy loss reduction and larger penetration ratios for them. Additionally, the penetration ratio thresholds for which there will be no power quality and reverse power flow issues and optimal allocation of PVDG and penetration levels are identified for different installation scenarios.Comment: To be published (Accepted) in: 12th IEEE PES PowerTech Conference, Manchester, UK, 201

Predictability of International Stock Returns with Sum of the Parts and Equity Premiums under Regime Shifts

This research consists of two essays. The first essay entitled” Stock Return Forecasting with Sum-of-the-Parts Methodology: Evidence from Around the World”, examines forecasting ability of stock returns by employing the sum-of-the-parts (SOP) modeling technique introduced by Ferreira and Santa-Clara (2011).This approach decomposes return into three components of growth in price-earnings ratio, earnings growth, and dividend-price ratio. Each component is forecasted separately and fitted values are used in forecast model to predict stock return. We conduct a series of one-step ahead recursive forecasts for a wide range of developed and emerging markets over the period February 1995 through November 2014. Decomposed return components are forecasted separately using a list of financial variables and the fitted values from the best estimators are used according to out-of-sample performance. Our findings show that the SOP method with financial variables outperforms the historical sample mean for the majority of countries. Second essay entitled,” Equity Premium Predictability under Regime Shifts: International Evidence”, utilizes the modified version of the dividend-price ratio that alleviates some econometric concerns in the literature regarding the non-stationary and persistent predictor when forecasting international equity premium across different regimes. We employ Markov switching technique to address the issue of non-linearity between the equity premium and the predictor. The results show different patterns of equity premium predictability over the regimes across countries by the modified ratio as predictor. In addition, transition probability analysis show the adverse effect of financial crisis on regime transition probabilities by increasing the probability of switching between regimes post-crisis 2007 implying higher risk perceived by investors as a result of uncertainty inherent in regime transitions

Investigation of Peripheral Blood Mononuclear Cells Phagocytosis in Allergic Asthma Mice Model

The respiratory system is exposed to the potentially harmful environment agents. More importantly, respiratory system infection is an important risk factor for inflammation and some pathogens can be main responsible of asthma. Phagocytosis is a main mechanism to eliminate of microbial infection. Phagocytic clearance may control asthma pathogenesis. In asthma, cytokines balance may be changed, therefore we investigated possible change in phagocytes in the present study.14 male Balb/c mice were divided into two control and asthmatic group. Asthma model in mice was produced by ovalbumin. Peripheral blood mononuclear cells were separated and reduction nitro blue tetrazolium and latex bead florescence phagocytosis tests were done.There was no significant difference in phagocytosis and NBT reduction test between asthmatic and control groups (P≤0.05).Airway inflammation and unbalancing of cytokines in asthma might modulate phagocytosis function. Therefore, asthmatic patient might be more susceptible to airway infection but there was not any notable changes in phagocytosis

Investigation of the effect of probiotic yogurt and fenugreek on allergic asthma

Background: Asthma as the variable degrees of airway obstruction is reversible and allergic asthma is a common form of asthma. Yogurt is coagulated milk and fenugreek as a plant is used in traditional medicine. Oral administration of yogurt (as food) can provide probiotic agents that have the main effects on immune responses. In this study, the effect of yogurt and fenugreek on asthma was studied.  Materials and Methods: After producing of asthma model in BALB/c mice in 4 groups, groups were treated with yogurt, yogurt-probiotics, and yogurt-fenugreek. At least, total IgE in serum, IL-4, 5, 13 in BAL (Broncho-Alveolar lavage) fluid was measured. Histopathological sections were prepared and eosinophilic infiltration and mucus-secreting were investigated. Results: Eosinophilic infiltration and mucus hyper-secretion were decreased in treated groups. Total IgE in serum was decreased in asthma-yogurt-probiotic and asthma-yogurt-fenugreek groups in comparison with asthmatic and asthma-yogurt groups. The amount of IL-4 in BAL of the asthma-yogurt-fenugreek group was decreased. The amount of IL-5 in BAL of the asthma-yogurt-probiotic and asthma-yogurt-fenugreek groups was decreased. The amount of IL-13 was decreased significantly in three treated groups. Conclusion: This study showed that yogurt with fenugreek and probiotic has a strong effect on suppression of progression of airway inflammation and asthma pathophysiology.   &nbsp