Wetting Pattern Models for Drip Irrigation: New Empirical Model

Reliable information about the wetted dimensions of soil under drip irrigation helps designers to determine optimal emitter flow rates and spacings to reduce system equipment costs and provide better soil water conditions for the most efficient and effective use of water. This study presents a new empirical formula that predicts soil wetted dimensions around a drip emitter. The coefficients were obtained by using regression analysis on the results of field experiments done on the Pardis Agricultural Farm of Tehran University in Karaj, Iran. These data were also used to evaluate the semiempirical model of Zur and Schwartzman, the empirical model of Amin and Ekhmaj, and the analytical model WetUp. Statistical comparisons (mean error, root mean square error, and model efficiency) are made of the simulated data with the observed data. To evaluate the models, published experimental data by Risse et?al. and Li et?al. were also used. The results demonstrate that the suggested equations can be used for a wide range of discharge rates and soil types. The best result was obtained from the new empirical model proposed in this investigation. The lowest mean error for the wetted radius and wetted depth was 8.21 and 8.62?cm, respectively.     

Effects of nanoclay on hot mix asphalt performance

The purpose of this study was to evaluate of nanoclay effects as an additive on performance of asphalt mixtures. Two types of montmorillonite nanoclay, namely CA and CB, were used at concentrations of 2%, 4%, and 6%. Marshall, indirect tensile strength, resilient modulus, and dynamic creep tests were performed to investigate the effect of additives on moisture susceptibility, structural response, and rutting resistance. The results showed improvement of the asphalt mixture performance by adding nanoclay with respect to all tests. According to the results, samples containing nanoclay CA have better performance in comparison with the samples containing CB.     

Determining the internal quantum efficiency of organic Bulk Heterojunctions based on mono and bis–adduct fullerenes as acceptor

With the aid of optical modeling, the internal quantum efficiencies of organic Bulk Heterojunction (oBHJ) photovoltaic devices based on low band gap polymer of poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-(4,7-bis(2-thienyl)-2,1,3-benzothiadiazole)-5,5′-diyl] (Si-PCPDTBT) blended with the acceptors of 1-(3-Methoxycarbonyl) propyl-1-phenyl [6,6] C61 (PCBM) and bis–adduct (bis–PCBM) are determined. The Si-PCPDTBT:bis–PCBM devices show considerably lower short circuit current density (J_sc) as compared to the Si-PCPDTBT:PCBM devices. The results show that 30% of this smaller J_sc is due to the lower optical absorption of bis–PCBM, while the major losses originate from the electrical losses. It is found that for the best Si-PCPDTBT:bis–PCBM devices with an active layer thickness in the range of 70–100 nm, the inefficient charge generation within the bis–PCBM domains is the major contribution to the whole losses. Increasing the active layer thickness of Si-PCPDTBT:bis–PCBM device significantly enhances recombination losses in polymer/bis–fullerene matrix.     

Anthocyanins from Eugenia brasiliensis edible fruits as potential therapeutics for COPD treatment

Nine anthocyanins (1–9) from the edible fruits of Eugenia brasiliensis were identified by HPLC-PDA and LC–MS, and seven of these are described for the first time in this Brazilian fruit. Two of the major anthocyanins, delphinidin (8) and cyanidin (9), were studied for their inhibitory activity against chemokine interleukin-8 (IL-8) production before and after cigarette smoke extract (CSE) treatment of cells. In non-treated cells the amount of IL-8 was unchanged following treatment with cyanidin and delphinidin in concentrations 0.1–10 μM. Both delphinidin (8) and cyanidin (9) decreased the production of IL-8 in treated cells, at 1 and 10 μM, respectively. Delphinidin (8) demonstrated IL-8 inhibition in the CSE treated cells in a dose-dependent manner.     

RFID-based localization with Non-Blocking tag scanning

The simple and cheap passive RFID tag systems have recently been used for efficient localization of indoor mobile robots, where each RFID tag stores its own absolute position and the mobile robot carrying an RFID reader scans the RFID tags to localize itself. The available localization schemes using passive RFID systems do not consider the scanning delay which may cause location estimation error, especially when the robot moves at a high speed. In this paper, a new Non-Blocking scanning (reading) scheme is proposed to avoid collisions so that the scanning delay, and consequently the localization error, can be reduced. This scheme avoids collisions among tag replies by assigning tag IDs based on the FCA coloring scheme. Theoretical and simulation studies indicate that the new Non-Blocking scheme combined with the new tag arrangement pattern can achieve a good RFID localization performance in terms of both estimation error and scanning delay with reduction of tag/reader required complexities.     

Enhancing data rate of molecular communication system using Brownian motion

Inter‐symbol and co‐channel interferences restrict the capacity of molecular communication (MC) systems. In this study, the effect of these interferences on the data rate of MC systems is investigated to design an efficient MC system. To this end, the authors propose an analytical model for a diffusion‐based MC system comprised of two nanomachines when they exploit On/Off keying modulation. They model the Brownian motion of molecules in a one‐dimensional environment as a wiener process and the life expectancy of diffused molecules as an exponential process. First, they consider the inter‐symbol interference to derive the data rate of the MC system as a function of the receiver decision threshold and the symbol time duration. Hence, they propose an algorithm to obtain the optimal values of MC system parameters. Then, the effect of co‐channel interference is considered by assuming parallel MC systems. They propose a minimum distance between adjacent MC systems that their co‐channel interferences effect to be negligible. Moreover, they verify the accuracy of the analytical results by Monte–Carlo simulations. Results show a remarkable improvement in the data rate of MC systems. The derived results may find application in nanonetworks where nanomachines connect together to perform complex tasks.Inspec keywords: channel capacity, Monte Carlo methods, intersymbol interference, stochastic processes, Brownian motion, cochannel interferenceOther keywords: enhancing data rate, molecular communication system, Brownian motion, co‐channel interference, efficient MC system, diffusion‐based MC system, inter‐symbol interference, MC system parameters, parallel MC systems, adjacent MC systems, co‐channel interferences effect     

Chemical composition and in vitro antioxidant evaluation of a water-soluble Moldavian balm (Dracocephalum moldavica L.) extract

The chemical composition and antioxidant properties of a water-soluble extract of Moldavian balm (Dracocephalum moldavica L., syn. Moldavian dragonhead) prepared by hydrodistillation are presented in this study. The total phenol content was estimated as gallic acid equivalents by the Folin-Ciocalteu reagent method, while the qualitative-quantitative composition of the extract was determined by high performance liquid chromatography coupled with photodiode array detection. The antioxidant properties assessed included iron(III) reduction and iron(II) chelation and 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) and superoxide anion free radical scavenging. In addition, the ability of the extract to protect 2-deoxy-d-ribose and bovine brain-derived phospholipids against hydroxyl radical-mediated degradation was assessed. The extract principally contained polar compounds including hydroxycinnamic acids and flavonoids, with caffeic and ferulic acids, luteolin-7-O-glucoside, rosmarinic acid, luteolin and apigenin being identified from their chromatographic behavior and spectral characteristics. The Moldavian balm extract demonstrated activity in all the antioxidant assays; however, it was not as potent as the positive control except in the phospholipid-based assay where its hydroxyl radical scavenging activity was statistically indistinguishable from that demonstrated by Pycnogenol.     

Electrospun polycaprolactone/gelatin/bioactive glass nanoscaffold for bone tissue engineering

Polycaprolactone scaffolds, polycaprolactone/gelatin, and polycaprolactone/gelatin/bioactive glass scaffolds were prepared with ratios of 50/50, 25/75, and 75/25 for polymers and 5?wt% for the bioactive glass via electrospinning and then were characterized using. The results indicated that by adding gelatin and bioactive glass to polycaprolactone scaffold, the diameter of fiber decreased from 557 to 167?nm. The results showed growth of apatite layer on the scaffolds after immersion in simulated body fluid for 28?days. The results of mechanical test revealed that by adding bioactive glass to scaffolds, the ultimate tensile strength and Young's modulus increase about two folds.     

Tensor Properties of Added-mass and Damping Coefficients

It has been shown that in the context of a linear theory for a floating body with six degrees of freedom each of the 6× 6 added-mass and damping matrices contains three distinct Cartesian second-order tensors in regard to translational, rotational and interaction between translational and rotational oscillations. As a result of this, a new technique based on the transformation law of second-order tensors is introduced for motion analysis of offshore platforms which can be used as an alternative to the common methods in offshore engineering.     

Kinetic analysis of chlorpropamide dissolution from solid dispersions

Solid dispersions (SDs) of chlorpropamide were prepared by the solvent deposition technique using two grades of microcrystalline cellulose as carrier materials with different ratios of drug to carrier. The dissolution rate of chlorpropmide from the SDs was carried out at two physiological pH values of 1.1 and 7.25 simulating gastric and intestinal environments. The dissolution was dependent on the grade, the ratio of drug to carrier and pH. The higher dissolution was observed for more hydrophilic grade of the carrier as well as the higher ratio of carrier to drug. At the higher pH the drug dissolved much faster than the lower pH. X-ray diffraction showed some reduced drug crystallinity in SDs whereas infrared spectroscopy revealed no drug interactions with solvent and the carriers. The enhanced dissolution was attributed to the reduced drug crystallinity, decreased particle size, increased wettability and reduced aggregation of the hydrophobic drug particles. A novel model denoted as reciprocal powered time model with its theoretical justification was employed to analyze the dissolution data and proved to be superior to commonly used models for the analysis of the data. There was a quantitative relation between the model parameter and the ratio of carrier to drug which could be of value in dissolution rate prediction.