The Impact of Stealthy Attacks on Smart Grid Performance: Tradeoffs and Implications

The smart grid is envisioned to significantly enhance the efficiency of energy consumption, by utilizing two-way communication channels between consumers and operators. For example, operators can opportunistically leverage the delay tolerance of energy demands in order to balance the energy load over time, and hence, reduce the total operational cost. This opportunity, however, comes with security threats, as the grid becomes more vulnerable to cyber-attacks. In this paper, we study the impact of such malicious cyber-attacks on the energy efficiency of the grid in a simplified setup. More precisely, we consider a simple model where the energy demands of the smart grid consumers are intercepted and altered by an active attacker before they arrive at the operator, who is equipped with limited intrusion detection capabilities. We formulate the resulting optimization problems faced by the operator and the attacker and propose several scheduling and attack strategies for both parties. Interestingly, our results show that, as opposed to facilitating cost reduction in the smart grid, increasing the delay tolerance of the energy demands potentially allows the attacker to force increased costs on the system. This highlights the need for carefully constructed and robust intrusion detection mechanisms at the operator.Comment: Technical report - this work was accepted to IEEE Transactions on Control of Network Systems, 2016. arXiv admin note: substantial text overlap with arXiv:1209.176

EFFECT OF SOME FERTILIZATION TREATMENTS ON GROWTH AND CHEMICAL COMPOSITION OF OCHNA SERRULATA (HOCHST.) WALP. SHRUBS

A set of pot experiments were conducted under saran house conditions (65% shade) at the Experimental Farm of the Hort. Res. Inst., ARC, Giza Egypt during 2013 and 2014 seasons in order to study the influence of two commercial liquid products, Vege Grow (V.G.) and Phos Root-X (P. R-X.) at the rates of 1, 2 and 4 ml/l of irrigation water for each, as well as the 3 combinations between V.G. and P. R-X. at the rates of 0.5, 1 and 2 ml/l for each on growth and chemical composition of one-year-old seedlings of Mickey Mouse plant (Ochna serrulata (Hochst.) Walp.) cultivated in 16-cm-diameter plastic pots filled with about 1.5 kg of sand + clay + peatmoss mixture (1:1:1, v/v/v). The control seedlings received no treatment. The obtained results indicated that means of all vegetative and root growth parameters improved greatly as a result of applying the various treatments used in this study. However, the dominance was for fertilization with V.G. at 2 ml/l treatment which gave the highest means in most measurements of vegetative and root growth in the two seasons. Similarly were those results of leaf content of photosynthetic pigments, total soluble sugars, N, P, K, Fe, Zn, Cu, Mn and protein, as content of these constituents increased in the leaves with various significant differences compared to control. Also,V.G. at 2 ml/l treatment recorded the utmost high content of most constituents above mentioned. Combining between V. G. and P. R-X. products did not induce any additional improvement neither in vegetative and root growth nor in chemical constituent contents, except for few cases. From the above results, it is recommended to fertilize one-year-old seedlings of Mickey Mouse shrubby plants, planted in 16-cm-diameter plastic pots with Vege Grow liquid commercial product at 2 ml/l two times/month during the growing season to get better growth and quality

Spontaneous otoacoustic emissions

This paper reviews spontaneous otoacoustic emissions

EFFECT OF DIFFERENT LEVELS OF NPK AND MICRONUTRIENT ON YIELD AND DISTRIBUTION OF NUTRIENTS IN MAIZE UNDER IRRIGATED AGRICULTURE

A field experiment was carried out in Kafer El Kadera village at El–Monofia Governorate, during 5 consecutive years, 2010–2014, to test the effects of NPK and balanced fertilization on the yield and its components, and distribution of nutrients in different parts of maize (var.30K8).There was a significant increase of the number of leaves/plant, the length of cob, the number of rows in the cob and the number of grains in the row as a result of treated plants with NPK according to soil testing plus foliar application of micronutrients by 34.18, 27.94, 32.182, and 33.43%, respectively.There was also a significant increase in the chilling % rate, weight of 100 grains and yield of grain / plant, yield /ton/ha by 16.52, 35.39, 68.40, and 72.92%, respectively.There was an increase in the concentration of nitrogen in the grains, Envelope and leaves and increase in the concentration of phosphorus in the Envelope (husk leaves), Cob core and leaves, Also, increase in the concentration of potassium in the Envelope, stem and root, and increase in calcium concentration in grains and leaves also, increase in sodium in the envelope and roots.Values of iron and manganese concentrations were increased in grains, envelope and leaves, as well as increased concentration of zinc and copper in leaves.Significant positive correlation was found between concentrations of most leaf nutrients concentrations and nutrient concentrations of grain except significant negative correlation between P concentrations in leaves and K concentrations in grains and between Mg in leaves and Zn in grains and between Na in leaves and Fe concentrations in grains. As well as significant positive correlation were found between Ca, Zn and yield

MATHEMATICAL MODELING OF THE DESTABILIZATION OF ACID IN CRUDE OIL EMULSIONS USING POPULATION BALANCE EQUATION

In this current work, a phenomenological mathematical model that utilizes the population balance equation was developed to understand the destabilization process of acid in crude oil emulsions in laboratory conditions. The model considers changes due to advection, diffusion and binary coalescence of the dispersed acid phase. The model studies specifically the evolution of the droplet size distribution as a function of time for the top, next to bottom and bottom layers of a vertical cylinder. The resulting model was a nonlinear hyperbolic intergo-partial differential equation. As with many complex mathematical models, this model required a numerical solution. The source term modeling birth and death of droplets was numerically solved using Kumar’s fixed-pivot technique and converted to a system of partial differential equations. As for the advection-diffusion transport properties, five numerical solutions were examined each suitable under certain model properties. Four of the techniques were standard upwind schemes that are second, third and fourth order accurate, and the fifth was a non-standard method. All these schemes were also optimized to reduce the numerical errors to almost negligible. The non-standard method proved to be superior to the traditionally used upwind schemes for fine and course grids and low and high Reynolds numbers. Based on this algorithm, the numerical model was solved using initial literature experimental data for acid/oil emulsions and was able to provide a suitable prediction of droplet size distribution profiles for each of the three layers of interest in addition to both dispersed and continuous phase volumes. The model was also found to be a good predictive tool for the initial mean droplet size for early acid/oil emulsion days using an exponential regression model for each time step. The volume fraction of acid was found to be highly sensitive to changes in mean droplet size but was inconclusive in accessing the effect of standard deviation on the model evolution. The proposed algorithm has also presented evidence of the presence of a cohesive process dominating the system alongside the destabilization process of advection, diffusion and binary coalescence

Wind Farms Production: Control and Prediction

Wind energy resources, unlike dispatchable central station generation, produce power dependable on external irregular source and that is the incident wind speed which does not always blow when electricity is needed. This results in the variability, unpredictability, and uncertainty of wind resources. Therefore, the integration of wind facilities to utility electrical grid presents a major challenge to power system operator. Such integration has significant impact on the optimum power flow, transmission congestion, power quality issues, system stability, load dispatch, and economic analysis. Due to the irregular nature of wind power production, accurate prediction represents the major challenge to power system operators. Therefore, in this thesis two novel models are proposed for wind speed and wind power prediction. One proposed model is dedicated to short-term prediction (one-hour ahead) and the other involves medium term prediction (one-day ahead). The accuracy of the proposed models is revealed by comparing their results with the corresponding values of a reference prediction model referred to as the persistent model. Utility grid operation is not only impacted by the uncertainty of the future production of wind farms, but also by the variability of their current production and how the active and reactive power exchange with the grid is controlled. To address this particular task, a control technique for wind turbines, driven by doubly-fed induction generators (DFIGs), is developed to regulate the terminal voltage by equally sharing the generated/absorbed reactive power between the rotor-side and the grid-side converters. To highlight the impact of the new developed technique in reducing the power loss in the generator set, an economic analysis is carried out. Moreover, a new aggregated model for wind farms is proposed that accounts for the irregularity of the incident wind distribution throughout the farm layout. Specifically, this model includes the wake effect and the time delay of the incident wind speed of the different turbines on the farm, and to simulate the fluctuation in the generated power more accurately and more closer to real-time operation. Recently, wind farms with considerable output power ratings have been installed. Their integrating into the utility grid will substantially affect the electricity markets. This thesis investigates the possible impact of wind power variability, wind farm control strategy, wind energy penetration level, wind farm location, and wind power prediction accuracy on the total generation costs and close to real time electricity market prices. These issues are addressed by developing a single auction market model for determining the real-time electricity market prices

Viral Hepatitis A to E in South Mediterranean Countries

Viral hepatitis represents an important health problem in the South Mediterranean countries, Egypt, Libya, Tunisia, Algeria and Morocco. Emerging natural history and epidemiological information reveal differences in the overall epidemiology, risk factors and modes of transmission of viral hepatitis A, B, C, D, E infections in the South Mediterranean region. The differences in the in incidence and prevalence of viral hepatitis across North African countries is attributed to variations in health care and sanitation standards, risk factors and immunization strategies. The active continuous population movement through travel, tourism and migration from and to the South Mediterranean countries contribute to the spread of infections due to hepatitis viruses across borders leading to outbreaks and emergence of new patterns of infection or introduction of uncommon genotypes in other countries, particularly in Europe

Assessment of left atrial function in dilated cardiomyopathy patients using speckle-tracking echocardiography

Background: The available methods to assess left atrial function (LAF) have some limitations as angle dependence and opposite distortion. The objective of the current study was to evaluate LAF in dilated cardiomyopathy (DCM) of ischemic (IDCM) and non-ischemic etiologies (NIDCM) using speckle tracking echocardiography (STE). Methods: 52 patients with systolic heart failure were included in our study; 27 with IDCM and 25 with NIDCM along with 15 healthy controls. All patients underwent conventional echocardiography, tissue doppler imaging, and speckle tracking echocardiography. The later modality was used to compare left atrial function in IDCM and NIDCM groups. Results: We found the left atrial maximum volume and the left atrial total emptying volume to be higher in patients with dilated cardiomyopathy compared to healthy patients (52.19 ± 6.01 vs.  21.87 ± 1.69 cm3/m2; p <0.001 and 28.67 ± 4.34 vs. 15.67 ± 2.02 cm3/m2, respectively). Conversely, left atrial emptying index and left atrial active ejection fraction were lower in patients with DCM compared to healthy controls (9.60 ± 2.29 vs. 8.27 ± 3.01 cm3/m2; p< 0.001 and 23 ± 2.56 vs. 37.47 ± 3.54 %; p<0.001, respectively). When comparing the IDCM group with NIDCM patients, we found no significant difference in left atrial maximum volume and left atrial active emptying volume. However, the NIDCM patients had significantly lower left atrial total emptying volume, and left atrial active ejection fraction (8.93 ± 1.86 vs. 9.60 ± 2.29 cm3/m2 and 23 ± 2.56 vs. 31.19 ± 1.66 %; p<0.001). on comparing strain function, DCM patients had lower systolic (28.22 ± 3.84 vs. 60.87 ± 3.07 %, p<0.001), and left atrial systolic strain rate (-2.66 ± 0.45 vs. -3.81 ± 0.35; p = 0.003) compared to healthy controls. All strains and strain rates were significantly lower in NIDCM patients compared to IDCM patients.   Conclusion: STE is a promising method for evaluating LAF in DCM patients. Patients with DCM had significantly lower left atrial systolic and late diastolic strains and strain rates compared to healthy patients. Moreover, NIDCM could be differentiated from IDCM by having more impairment in the LA dynamic reservoir and booster pump function

EFFECT OF SOME HORMONAL TREATMENTS ON GROWTH AND CHEMICAL COMPOSITION OF RHAPHIOLEPIS UMBELLATA SHRUB

A pot experiment was consummated on Rhaphiolepis umbellata seedlings grown under seran greenhouse at Al-Zohriya Garden, Hort. Res. Inst., ARC, Giza, Egypt during the two consecutive seasons 2017 and 2018, to study effects of five foliar spray treatments of a mixture containing three growth regulators (PGR), at the same concentration for each, on plant growth and chemical composition. The three-tested PGR were NAA, GA3 and BA, while the five concentrations for each were 0 (control treatment), 100, 200, 300 and 400 ppm. Obtained results indicated that, generally, all recorded vegetative and root growth traits; i.e., plant height, stem diameter, numbers of branches and number of leaves/plant, leaf area, root length and number of roots/plant increased significantly under the effect of all tested PGR treatments, compared to the control plants. The highest increases in this regard were recorded in plants sprayed with PGR at 200 ppm, while the least values were found in the untreated control plants, followed by plants sprayed with the highest PGR concentration of 400 ppm for the two seasons. The same trend was noticed in respect of leaf chemical constituents, as plants that recorded the highest vegetative and root growth (treated 200 ppm PGR) also contained the highest values of total chlorophyll and carotenoids (mg/g f.w.) as well as percentages oftotal carbohydrate, N, P and K in leaf tissues. Accordingly, it could be recommended to apply the mixture of these three growth regulators 200 ppm on seedlings of Rhaphiolepis umbellata, two times monthly during the growing season to get the best plant growth and quality