Modeling of bend discontinuity in plasmonic and spoof plasmonic waveguides

The paper proposes a method to characterize the bend discontinuity for plasmonic and spoof plasmonic waveguides in terms of scattering parameters. By means of this method, the waveguide is modelled by a two-port network and its scattering parameters are extracted. The parameters for the L-shaped sharp curved bends at different frequencies and under different bending angles are determined

Phenological characteristics of the invasive weed Cucumis melo

Phenology is the study of periodic biological events. The time of weed appearance, growth and reproduction are very important for decisions on invasive weed management. Cucumis melo is an annual invasive weed of soybean fields in the north of Iran that reproduces and spreads predominately through seed production. In order to study the phenology of wild melon was conducted an experiment in CRD at Research Farm of Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2012. Seeds first germinated after 10 days of planting, as soon as optimal soil temperatures were achieved. The weed exhibited monoecious tendencies, with production of male flowers rapidly followed by production of both male and female flowers on the same vine. Cucumis melo exhibited prolific fruit production, until senescence occurred at 75 and 92 days after establishment. First fruit formation was observed between 40 and 49 days after emergence, depending on temperature. To complete growth cycle, of Cucumis melo required about 448 and 733 degree days, respectively for late of May and 8 of June. The weed produced a maximum of 100 fruits/plant, but an average plant typically produced 48 fruits/plant. The seed number and seed weight was on average about 190 seeds/fruit and 0.55 g per 100 seeds, respectively. The results indicated that wild melon could produce a lot of fruits and seeds within a growth period of about 75 and 92 days.Keywords: Growth, monoecious plants, reproduction, wild melonPhänologische Eigenschaften der invasiven Unkrautart Cucumis meloZusammenfassungDie Phänologie befasst sich mit wiederkehrenden biologischen Abläufen. Auflauf, Wachstum und Samenproduktion invasiver Arten sind wichtig für Bekämpfungsentscheidungen. Cucumis melo ist eine einjährige, invasive Unkrautart, die im Norden Irans im Sojabohnenanbau vorkommt und sich vorwiegend durch Samenproduktion vermehrt und ausbreitet. Untersuchungen zur Phänologie dieser Unkrautart wurden 2012 auf der Versuchsstation der Gorgan Universität im Iran durchgeführt. Das Auflaufen erfolgte von Anfang bis Mitte Mai nach Erreichen optimaler Bodentemperaturen. Die Unkrautart zeigte monözische Tendenzen indem sowohl männliche als auch weibliche Blüten an einer Pflanze ausgebildet wurden. Cucumis melo zeigt eine starke Fruchtentwicklung bis zum Beginn der Seneszens nach etwa 75 Tagen nach der Keimung. In Abhängigkeit von der Temperatur wurde die erste Fruchtbildung 40 bis 49 Tage nach der Keimung beobachtet. Wachstumszyklus für Ende Mai und 8. Juni abzuschließen, Cucumis melo der erforderlichen etwa 448 und 733 Grad-Tagen. Die Unkrautart produzierte maximal 100 Früchte pro Pflanze und im Mittel produzierte eine Pflanze 48 Früchte. Die Samenanzahl und das Samengewicht lagen bei 190 Samen pro Frucht und 0,55 g pro 100 Samen. Die Ergebnisse zeigen, dass wilde Melonenarten innerhalb von 75 Tagen eine hohe Anzahl von Früchten und Samen produzieren können.Stichwörter: Monoecious Pflanzen, Reproduktion, Wachstum, wilde Melon

Home energy monitoring system towards smart control of energy consumption

The need to manage, control and reduce energy consumption has led researchers to propose reliable solutions based on new technologies to achieve this goal. Our contribution in this subject is presented in this paper and consists of the design, implementation and testing of a home energy monitoring system. The presented system is dedicated for residential customers and allows the monitoring and control of the energy consumption, based on distributed and central processing. The system includes distributed monitoring devices, a gateway and a graphical user interface (GUI). To connect the all parts we use a hybrid wireless solution based on the Wi-Fi and Bluetooth Low Energy standards. We present the design and the implementation of the monitoring device hardware as well as the embedded software used to calculate the electrical quantities. We also present the calibration methodology used to eliminate gain and offset errors. In terms of performance test results, we have achieved voltage measurement accuracy below 0.2% and current measurement accuracy below 0.5%. A GUI was also developed for the user to visualize and control remotely the household appliances.This work is supported by FCT with the reference project UID/EEA/04436/2013, COMPETE 2020 with the code POCI-01-0145-FEDER-006941

Optimum Functions for Radial Wires of Monopole Antennas with Arbitrary Elevation Angles

Monopole antennas on the earth usually use ground screen with simple radial wires to improve their radiation performance. The number of radials,N, is usually considered a constant in the screen. This paper studies the effect of changing N and considering it as a function of distance, ρ, from the monopole using a simple and yet a fast method. The function N(ρ) is optimized for different beam angles of an HF monopoleantenna. The theoretical functions are converted to practical functions to be formed using meandered lines. Practicable calculated results are validated bymethod of moments. Furthermore it is shown that for low angle radiation aconstant N(ρ) with optimized radius of the ground screen is the best choice. The results can be used for higher frequencies, i.e. VHF and UHF frequency bands as well

Surfactant and rainfall influenced clodinafop-propargyl efficacy to control wild oat (Avena ludoviciana Durieu.)

Abstract A nonionic (Citogate) and cationic (Frigate) surfactant were evaluated for their efficacy to enhance clodinafop-propargyl performance and minimize rainfall effect in controlling wild oat (Avena ludoviciana Durieu.). Moreover, by using the capillary rise technique the surface tension of these surfactants or surfactants plus clodinafop-propargyl aqueous solution was determined. Lower and higher surface tension values were recorded with aqueous solution of Citogate and Frigate alone and along with clodinafoppropargyl, respectively. The critical micelle concentration of Citogate (0.15% v/v) was higher than of Frigate (0.1% v/v). Both the tested surfactants minimized the rainfall effect and improved the performance of clodinafop-propargyl on wild oat. When Citogate was added to clodinafop-propargyl, herbicidal activity was higher than when Frigate was added, indicating that the surfactants potency to reduce surface tension of spray solution is a momentous factor in order to enhance clodinafop-propargyl performance. The data from rainfall treatment have confirmed this hypothesis, as it seems when Citogate was added to clodinafop-propargyl; rainfall adverse effect was lower which is presumably due to quick absorption of clodinafop-propargyl by wild oat leaves. In other words, clodinafop-propargyl infiltrated in short-term before it was washed off the wild oat leaf surface as a hypothesis

The Effect of Sugar Beet Broadleaf Herbicides on Fluorescence Induction Curves in Amaranthus retroflexus L. and Portulaca oleracea L.

Chlorophyll fluorescence analysis is a simple and rapid method for detecting herbicide effects after a short time following their application in photosynthetic apparatus in plants. Chlorophyll fluorescence measurements were carried out against two broad of weeds to describe how the Kautsky curve and its parameters were affected by herbicides. Desmedipham + phenmedipham + ethofumesate changed the chlorophyll fluorescence induction curve at all time intervals except four hours after spring (HAS) in Amaranthus retroflexus L. and at all doses of Portulaca oleracea L. 4 HAS. In contrast, chlorophyll fluorescence inhibition was evident by chloridazon at doses of 650 and 325 g a.i. ha-1 in P. oleracea and A. retroflexus respectively, for all time intervals. Furthermore, chlorophyll fluorescence decays only occurred by clopyralid in A. retroflexus at the highest dose. A biomass effective dose (ED50 and/or ED90) based on log-logistic dose-response curves for A. retroflexus were considerably higher than that of P. oleracea. The maximum quantum efficiency (FV/Fm) was stable, whereas the relative changes at the J step (Fvj) and area (the area between the Kautsky curve and the maximum fluorescence (Fm)) was more sensitive to all three herbicides. There was a relatively good correlation between fluorescence parameters taken 24 hours after the spraying and the dry matter taken three weeks later, for both species under study

Investigating the effects of external fields polarization on the coupling of pure magnetic waves in the human body in very low frequencies

In this paper we studied the effects of external fields' polarization on the coupling of pure magnetic fields into human body. Finite Difference Time Domain (FDTD) method is used to calculate the current densities induced in a 1 cm resolution anatomically based model with proper tissue conductivities. Twenty different tissues have been considered in this investigation and scaled FDTD technique is used to convert the results of computer code run in 15 MHz to low frequencies which are encountered in the vicinity of industrial induction heating and melting devices. It has been found that external magnetic field's orientation due to human body has a pronounced impact on the level of induced currents in different body tissues. This may potentially help developing protecting strategies to mitigate the situations in which workers are exposed to high levels of external magnetic radiation