A Novel Energy-Aware Clustering Method via Lion Pride Optimizer Algorithm (LPO) and Fuzzy Logic in Wireless Sensor Networks (WSNs)

Wireless Personal Communications - Recent technological advances and developments in the field of communication information systems, especially in microelectro mechanical systems have provided the...     

Synthesis of porous Mg-doped CeO2 powders via self-propagating high-temperature synthesis route

The aim of this study was synthesis of Mg-doped porous cerium oxide powder by self-propagating high-temperature synthesis reaction of Mg-xCeO₂-O₂ system. Results indicated that doping Mg in the CeO₂ crystal structure increased its lattice parameter slightly, and shifted the Ce-O band in the FTIR spectra from 490 to 574 cm⁻¹. Moreover, the EDS results revealed the distribution of Mg in the CeO₂ microstructure. There were a high volume fraction of interconnected macro-pores in the microstructure of cerium oxide after the synthesis process. Increase in the x-value from 0.05 to 0.25 mol decreased the mean size and volume fraction of pores from 2.4 to 1 µm and 50 to 30 vol%, respectively. In addition, the BET surface area of porous CeO₂ varied between 0.3 and 1.57 m²/g. Finally, it was inferred that the SHS technique can be introduced as a rapid and novel method for synthesis of Mg-doped porous CeO₂ powders.     

Theoretical Based Design of Ultra-Wideband Filter with Dual Band-Notch

Wireless Personal Communications - In this paper, a compact ultra-wideband microstrip band-pass filter with single/dual-notched bands is proposed. The filter is theoretically designed based on a...     

A dual-band multiple-input multiple-output microstrip antenna with metamaterial structure for LTE and WLAN applications

A method to enhance the gain of microstrip dual-band multiple-input multiple-output (MIMO) antenna using partially reflective surface (PRS) layer is introduced and investigated in this paper. The proposed antenna consists of two FR4 substrates. The lower substrate has two radiating patches with parasitic elements that are supplied independently and create the MIMO property of the antenna. The upper substrate which is known as superstrate is arrays of PRS unit cells. The PRS layer printed on either side of a dielectric substrate and causes the antenna gain to increase in both frequency bands. The proposed antenna is appropriate for LTE (2.4–3.1 GHz) and WLAN (5.1–5.8 GHz) applications. The measured values of S₁₁ and S₂₂ parameters of the antenna are less than −10 dB and its FBR and gain are 12.5 dB and 5dBi, respectively. The average half power beam-width (HPBW) is roughly 108^○.     

Estimation and Assessment of Temporal Stability of Periodicities of Droughts in Iran

The main objective of the present study was to identify the periodic behavior of monthly droughts in Iran. For this purpose, monthly precipitation data obtained from 41 synoptic stations for a period of 22 years (1992–2013) were used. To identify the frequency of different severities of drought, effective drought index (EDI) was calculated at monthly scale and then spectral analysis of time series of EDI was conducted for each station. Temporal stability of these periods was also estimated using the wavelet transform. The results of spectral analysis of monthly droughts in Iran showed that periodicities in time series of Iran’s droughts are very diverse and involve periods of 2 to 22 years. Assessment of temporal stability of periodicities using the wavelet transform also indicated that there is a dominant periodic interval (significant at a level of α = 0.1) only in 8 stations of Ardebil, Iranshahr, Zahedan, Bandar Lengeh, Shahroud, Khorramabad, Oroomieh, and Shahre Kord. Studying the variability of time series of EDI in 41 stations showed that the severity of wet years is declining and the severity of droughts is increasing. It was also observed that periodic intervals were shorter at the beginning but longer at the end of time series. This suggests that the probability of incidence of drought in Iran is increasing. Additionally, a reduction can be observed in interval between incidences of droughts in Iran. This means that the interval between occurrence of droughts were longer at the beginning and then shorter at the end of times series.     

Effectiveness of the ZeroFly® storage bag fabric against stored-product insects

The ZeroFly^® Storage Bag is a woven polypropylene bag (PP) that has deltamethrin incorporated in its fibers, and represents a novel approach to reducing stored-product insect pest-related postharvest losses. Fabric samples from ZeroFly bags, polypropylene (PP) bags, jute bags, malathion-treated PP bags, malathion-treated jute bags and GrainPro bags were affixed to the bottom of 9-cm Petri dishes and 20 adults of either Sitophilus oryzae (L.) or Tribolium castaneum (Herbst) were introduced to determine contact sensitivity of insects exposed to ZeroFly bag fabric. Knockdown, mortality and number of progeny were recorded for different exposure periods (24, 48 or 72 h) and oviposition periods (7, 14 or 21 d). Additionally, mini bags were made from ZeroFly bags, PP bags, laminated PP bags and jute bags, and used to determine ability of adult S. oryzae, T. castaneum and Rhyzopertha dominica (F.) to chew through the bags and efficacy of ZeroFly bags at preventing insect infestations from outside and to contain infestations within bags. Knockdown assessment for ZeroFly bag fabric showed that time required to knockdown 99% of S. oryzae and T. castaneum was <3 h. For 72-h exposure to ZeroFly bag fabric, mortalities for S. oryzae and T. castaneum were 76.7 and 62.2%, respectively; mortality was ≤6% in other fabrics. ZeroFly bag fabric also significantly suppressed progeny production by S. oryzae and T. castaneum for all exposure periods. No insects from the three species tested were able to chew through miniature ZeroFly bags, indicating the bag fabric will prevent entry or exit of insects.     

Optimal Steffensen-type methods with eighth order of convergence

This paper proposes two classes of three-step without memory iterations based on the well known second-order method of Steffensen. Per computing step, the methods from the developed classes reach the order of convergence eight using only four evaluations, while they are totally free from derivative evaluation. Hence, they agree with the optimality conjecture of Kung-Traub for providing multi-point iterations without memory. As things develop, numerical examples are employed to support the underlying theory developed for the contributed classes of optimal Steffensen-type eighth-order methods.     

Reactive power planning using a new hybrid technique

Voltage deviation and stability constrained VAr planning or reactive power planning (RPP) is an important challenging issue in power systems. This paper presents a new hybrid technique for modeling and solving RPP problem taking into account the static voltage stability constraint. First, the uncertain fuzzy clustering theory is employed to select new candidate VAr source locations. Then, modified gray code is applied and used to represent a series of non-uniform VAr capacity intervals at different candidate buses. Based on the new ordering of the VAr capacity intervals, a simplified piecewise linear function between the total transfer capability and new VAr capacity is derived and applied as static voltage stability constraint in RPP problem. Last, the RPP optimization problem is solved by a self adaptive fuzzy chaotic interactive honey bee mating optimization (FCIHBMO) technique taking advantage of the modified gray code. In the FCIHBMO algorithm, a modified definition of the updating factors on generation solution is proposed. In the case study, uncertain fuzzy clustering mechanism, the modified gray code, and the modified HBMO are applied to the IEEE 118-bus and IEEE 300-bus systems. Test results conclude that the proposed hybrid technique is a simplified and effective approach for voltage stability constrained VAr planning with contingency considered.     

Synthesis,crystal structure and urease inhibitory activities of Schiff base metal complexes

Six new transition metal complexes (1–6) with Schiff base were synthesized and crystallographically characterized. Their urease inhibitory activities were evaluated. Three of them showed potent inhibitions against jack bean urease. Mn(II) complex (2) possessed the best jbU inhibitory activity with IC₅₀ of 8.30 ± 0.93 μM, which was much better than those of the corresponding ligand and control ion. The investigation on the stability constants and the structure-activity relationships of the complexes indicated that the complexes interacted with the enzyme in the whole complex forms rather than the free ions.     

Predicting turbulent flow friction coefficient using ANFIS technique

The friction coefficient is widely used for technical and economical design of pipes in irrigation, land drainage, urban sewage systems and intake structures. In the present study, the friction factor in pipes is estimated by using adaptive neuro-fuzzy inference system (ANFIS) and grid partition method. The data derived from the Colebrook’s equation were considered for ascertaining the neuro-fuzzy model. Present approach developed an ANFIS technique to predict the friction coefficient as output variable based on pipe relative roughness and Reynold’s number as input variables. The performance of the ANFIS model was evaluated against conventional procedures. Correlation coefficient (R2), root mean squared error and mean absolute error were used as comparing statistical indicators for the assessment of the proposed approach’s performance. It was found that the adaptive neuro-fuzzy inference system model is more accurate than other empirical equations in modeling friction factor.