Multi-user Scheduling Schemes for Simultaneous Wireless Information and Power Transfer

In this paper, we study the downlink multi-user scheduling problem for a time-slotted system with simultaneous wireless information and power transfer. In particular, in each time slot, a single user is scheduled to receive information, while the remaining users opportunistically harvest the ambient radio frequency (RF) energy. We devise novel scheduling schemes in which the tradeoff between the users' ergodic capacities and their average amount of harvested energy can be controlled. To this end, we modify two fair scheduling schemes used in information-only transfer systems. First, proportionally fair maximum normalized signal-to-noise ratio (N-SNR) scheduling is modified by scheduling the user having the jth ascendingly ordered (rather than the maximum) N-SNR. We refer to this scheme as order-based N-SNR scheduling. Second, conventional equal-throughput (ET) fair scheduling is modified by scheduling the user having the minimum moving average throughput among the set of users whose N-SNR orders fall into a certain set of allowed orders Sa (rather than the set of all users). We refer to this scheme as order-based ET scheduling. The feasibility conditions required for the users to achieve ET with this scheme are also derived. We show that the smaller the selection order j for the order-based N-SNR scheme, and the lower the orders in Sa for the order-based ET scheme, the higher the average amount of energy harvested by the users at the expense of a reduction in their ergodic capacities. We analyze the performance of the considered scheduling schemes for independent and non-identically distributed (i.n.d.) Ricean fading channels, and provide closed-form results for the special case of i.n.d. Rayleigh fading.Comment: 6 pages, 3 figures. Submitted for possible conference publicatio

Characteristic Study of Solar Photovoltaic Array under Different Partial Shading Conditions

© The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Photovoltaic (PV) systems are frequently exposed to partial or complete shading phenomena. Partial shading has a profound impact on the performance of solar power generation. The operational performance of PV arrays under partial shading shows multiple maximum power point peaks, therefore it is challenging to identify the actual maximum power point. This paper investigates the impact of partial shading location on the output power of solar photovoltaic arrays with various configurations. Multiple photovoltaic strings, in both parallel and series configurations, are considered. Different random shading patterns are considered and analyzed to determine which configuration has higher maximum power point. The sensitivity of the partial shading can change according to the partial shading types, shading pattern, and the configuration used to connect all PV modules. Moreover, the study also investigates the output of the PV array with shading two random models, two consecutive models, and three random and consecutive modules. Experimental results validate the analysis and demonstrate the effect of various partial shading on the eficiency and performance of the PV system.Peer reviewe

Propositional calculus for adjointness lattices

Recently, Morsi has developed a complete syntax for the class of all adjointness algebras $\left( L,\leq ,A,K,H\right)$. There, $\left( L,\leq \right)$ is a partially ordered set with top element $1$, $K$ is a conjunction on $\left( L,\leq \right)$ for which $1$ is a left identity element, and the two implication-like binary operations $A$ and $H$ on $L$ are adjoints of $K$. In this paper, we extend that formal system to one for the class $ADJL$ of all 9-tuples $\left( L,\leq ,1,0,A,K,H,\wedge ,\vee \right)$, called \emph{% adjointness lattices}; in each of which $\left( L,\leq ,1,0,\wedge ,\vee \right)$ is a bounded lattice, and $\left( L,\leq ,A,K,H\right)$ is an adjointness algebra. We call it \emph{Propositional Calculus for Adjointness Lattices}, abbreviated $AdjLPC$. Our axiom scheme for $AdjLPC$ features four inference rules and thirteen axioms. We deduce enough theorems and inferences in $AdjLPC$ to establish its completeness for $ADJL$; by means of a quotient-algebra structure (a Lindenbaum type of algebra). We study two negation-like unary operations in an adjointness lattice, defined by means of $0$ together with $A$ and $H$. We end by developing complete syntax for all adjointness lattices whose implications are $S$-type implications

Galaxy emission line classification using 3D line ratio diagrams

Two-dimensional (2D) line ratio diagnostic diagrams have become a key tool in understanding the excitation mechanisms of galaxies. The curves used to separate the different regions - HII-like or else excited by an active galactic nucleus (AGN) - have been refined over time but the core technique has not evolved significantly. However, the classification of galaxies based on their emission line ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) line ratio diagnostic diagrams. We introduce a specific set of 3D diagrams, the ZQE diagrams, which separate the oxygen abundance and the ionisation parameter of HII region-like spectra, and which also enable us to probe the excitation mechanism of the gas. By examining these new 3D spaces interactively, we define a new set of 2D diagnostics, the ZE diagnostics, which can provide the metallicity of objects excited by hot young stars, and which cleanly separate HII region-like objects from the different classes of AGNs. We show that these ZE diagnostics are consistent with the key log[NII]/H$\alpha$ vs. log[OIII]/H$\beta$ diagnostic currently used by the community. They also have the advantage of attaching a probability that a given object belongs to one class or to the other. Finally, we discuss briefly why ZQE diagrams can provide a new way to differentiate and study the different classes of AGNs in anticipation of a dedicated follow-up study.Comment: 21 pages, 15 figures, accepted for publication in ApJ. Due to size limitations, the supplementary STL file for the 3D-printable diagram is available here: http://www.mso.anu.edu.au/~fvogt/online_material.htm

Management of root rot and wilt diseases of date palm offshoots using certain biological control agents and its effect on growth parameters in the New Valley Governorate, Egypt

Root Rot and wilt diseases were observed on different date palm offshoots in nurseries and new orchards in New Valley Governorate, Egypt. Pathogenicity tests showed that Fusarium oxysporum, F. solani and F. moniliforme were the causal agents of root rot and wilt diseases on date palm offshoots (cv. Saidy). In addition, the isolates of the three Fusarium spp. differed in their pathogenic capabilities. The effect of Bacillus subtilis (BSM1), B. megaterium (BMM5), B. cereus (BCM8), Trichoderma viride (TVM2), T. harzianum (THM4) as bioagents against root rot/wilt disease complex of date palm offshoots under natural infection in nursery cultivated in two location (Al-Kharga and El-Dakhla) and also, on growth of the tested pathogenic fungi under laboratory were evaluated. Under laboratory conditions, all the tested bioagents inhibited the growth of the pathogenic fungi with different percentages. Bacillus megaterium and B. subtilis showed the highest percentage of fungal growth inhibition, while T. harzianum gave the lowest ones. At the field level, the application of bioagents significantly reduced the disease severity compared with untreated offshoots (control) in both locations. Bacillus megaterium and T. viride showed the highest protection against fungal causal agents, while B. cereus and T. harzianum gave the lowest ones in this respect. Moreover, the bioagents significantly improved the growth parameters of offshoots viz. plant height, number of leaves plant-1, leaflet number leaf-1, and leaf thickness. Bacillus megaterium and T. viride recorded the highest values of all growth parameters in El-Kharga and El-Dakhla locations, while B. cereus and T. harzianum gave the lowest ones.

Role of N-terminal pro B-type natriuretic peptide in acute exacerbation of chronic obstructive pulmonary disease

AbstractObjectivesAcute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a major public health problem. Recognition of comorbid heart dysfunction in such patients is often difficult. The aim of this work is to evaluate the role of N-terminal pro B-type natriuretic peptide (Nt-pro BNP) in AECOPD with respiratory failure.Patients and methodsThis study was conducted on 20 patients with AECOPD and respiratory failure. All patients were subjected to history taking, clinical examination, routine laboratory investigations, arterial blood gases analysis, echocardiography and estimation of plasma level of NT-pro BNP.ResultsPatients were classified into 3 groups: Group I: those without heart dysfunction (40%), Group II: those with diastolic heart failure (40%), and Group III: those with systolic heart failure (20%). NT-pro BNP mean±SD in group I was 673.38±416.02, in group II 1962±847.88, and in group III 6776.75±1433.59pg/ml. There was a statistically significant difference between the three groups (p=0.001). NT-pro BNP showed a statistically significant inverse correlation with pH (p=0.005), ejection fraction (p=0.007) and a direct one with both left ventricular systolic (p=0.008) and diastolic (p=0.016) dimensions and E/A (p=0.016). The NT-pro BNP significantly decreased after recovery from AECOPD (p=0.030). The receiver operating characteristic curve demonstrated a ruling out of LV dysfunction in AECOPD of a sensitivity of 100% and a specificity of 60%; and a ruling in of a sensitivity of 48% and a specificity of 67%.ConclusionPlasma BNP is usually elevated in AECOPD and is related to right or left ventricular systolic or diastolic dysfunction