Using the red-near infrared spectral to estimate ground cover based on vegetative indices

Rapid and accurate estimation of Ground Cover (GC) at regional and global scales for agricultural management application is only possible by using remote sensing (RS). In this study, two Vegetation Indices (VIs) including the Perpendicular Vegetation Index (PVI) and Normalized Difference Vegetation Index (NDVI) were used for estimating GC. Since the parameters of the bare soil line have an important role in calculating GC based on PVI, this line was extracted based on the red-NIRmin (minimum near infrared) method with different intervals (0.0001, 0.0005, and 0.0010). In addition to traditional statistics such as Root Mean Square Error (RMSE), the sensitivity analysis (S) was also used to sharpen the accuracy of the models' estimations. The results indicated that the PVI-based method, in contrast to the NDVI-based approach, had a better performance in estimating GC of wheat. The highest correlation between the observed GC and the estimated GC based on PVI method was achieved in interval length of 0.0005 (R2 = 0.91) with RMSE equal to 8.82. This regression line (GCEST = -3.47 + 0.96 GCOBS) was not significantly different from the 1:1 line. As expected, the best estimation was achieved when the sensitivity of estimated GC based on PVI (length of the interval: 0.0005) was almost constant and low compared to the other models.     

Thermally stable cellular poly(vinylidene) ferroelectrets: Optimization of CO2 driven inflation process

Electrically charged cellular ferroelectrets can show excellent thermally stable piezoelectric activity and are therefore progressively used in electrochemical transducers. Given that an optimized cellular structure is a key for improving charge density and the associated piezoelectric properties in this material, we investigated the influence of CO₂ inflation treatment using various gas diffusion expansion or inflation procedures on the piezoelectric d₃₃ coefficient and thermal stability of cellular poly(vinylidene) ferroelectrets and compare with the results (partially) obtained by N₂ inflation as reported in our previous study (Jahan, Mighri, Rodrigue, Ajji, J. Appl. Polym. Sci. 2019, 136, 47540). Samples were prepared using the conventional extrusion–stretching–inflation–corona charging method. Maximum d₃₃ coefficient for CO₂-inflated samples is found to be around 30% higher than that of N₂-inflated samples (327 pC/N compared to 251 pC/N) by stepwise pressure application method. The key parameters addressed in the inflation procedures are the changes in sample thickness, morphology, and the void-height distribution in both gas treatments. The ferroelectrets show excellent thermal stability for up to 4 days at 90, 110, and 120 °C in both treatments with a slightly improved performance in CO₂ gas. The higher activation energy of CO₂-inflated samples (0.52 eV) than the N₂-inflated ones (0.43 eV) further confirms the stability data. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47929.     

Multipolar Graviton in the Hydrogen Atoms

We derive multipolar gravitational radiation in the framework of quantum field theory in which the atomic states are treated nonrelativistically, and the gravitational waves are quantized. By relaxing the constraint e^ik·x ≈ 1, the multipolar transition rate is calculated when one graviton is emitted. As a consistency check, we recover the semiclassical result in the dipole approximation regime. Besides, we show that the dynamical mechanism that gives rise to spontaneous graviton emission by an atom, has a profound consequence on the lifetime of the atomic electron.     

Swallow: Resource and Tag Recommender System Based on Heat Diffusion Algorithm in Social Annotation Systems

Social annotation systems (SAS) allow users to annotate different online resources with keywords (tags). These systems help users in finding, organizing, and retrieving online resources to significantly provide collaborative semantic data to be potentially applied by recommender systems. Previous studies on SAS had been worked on tag recommendation. Recently, SAS‐based resource recommendation has received more attention by scholars. In the most of such systems, with respect to annotated tags, searched resources are recommended to user, and their recent behavior and click‐through is not taken into account. In the current study, to be able to design and implement a more precise recommender system, because of previous users' tagging data and users' current click‐through, it was attempted to work on the both resource (such as web pages, research papers, etc.) and tag recommendation problem. Moreover, by applying heat diffusion algorithm during the recommendation process, more diverse options would present to the user. After extracting data, such as users, tags, resources, and relations between them, the recommender system so called “Swallow” creates a graph‐based pattern from system log files. Eventually, following the active user path and observing heat conduction on the created pattern, user further goals are anticipated and recommended to him. Test results on SAS data set demonstrate that the proposed algorithm has improved the accuracy of former recommendation algorithms.     

On the measurement of friction coefficient utilizing the ring compression test

The main objective of this research was to investigate whether generalized friction calibration curves, as recommended in the literature for use with ring compression tests, are applicable to all types of materials and test conditions. Specifically, the effects of material properties, strain-rate sensitivity, and “barreling” on the behavior of friction calibration curves were investigated. To this end, a series of ring compression tests were conducted in order to determine the magnitude of the friction coefficient, μ, as well as the corresponding calibration curves for two types of modeling materials, white and black Plasticine. The experiments were first conducted using the Physical Modeling Technique (PMT) and then simulated via an elastic–plastic finite element code (ABAQUS). In contrast to the results available in the literature, where the same friction calibration curves are recommended for all types of materials and test conditions, the results of this investigation showed that friction calibration curves are indeed affected by the material properties and test conditions and every material possesses its own distinctive friction calibration curve.     

Fabrication of bimetallic Cu/Pt nanoparticles modified glassy carbon electrode and its catalytic activity toward hydrogen evolution reaction

The film of poly(8-hydroxyquinoline) was formed by cyclic voltammetery method on the surface of glassy carbon electrode and poly(8-hydroxyquinoline) modified glassy carbon electrode, p(8-HQ)MGCE, was prepared. Cu²⁺ ion was adsorbed on the polymer matrix due to complexation with 8-hydroxyquinoline units Copper nanoparticles were deposited onto p(8-HQ)MGCE by applying potential and prepared copper nanoparticles galvanic replaced with platinum to fabricate poly(8-hydroxyquinoline)–Pt/Cu composite on the surface of GCE. Stripping voltammetery of Cu in aqueous 0.1 M KSCN + Britton–Robinson buffer, pH = 2.0, solution was used to quantify the copper present on the electrode surface. The amount of platinum was estimated from the electrooxidation peak of Pt in aqueous 0.1 M H₂SO₄ solution. The nature of Cu/Pt–p(8-HQ) on the surface of GCE was characterized by scanning electron microscopy. Cu/Pt–p(8-HQ) modified GCE can be used as a convenient conducting substrate for electrocatalytic hydrogen evolution reaction (HER). The effects of different parameters such as number of cycles, replacement time, scan rate of potential, and etc were investigated to obtaining optimum condition for HER.     

The Influence of Growing Region on Fatty Acids and Sterol Composition of Iranian Olive Oils by Unsupervised Clustering Methods

Twenty seven Iranian olive oil samples were collected from different provinces to evaluate fatty acids and sterol compositions. The samples were collected from different geographical locations that varied in altitude, temperature, humidity and rain fall. The sample collected from the northern part of Iran by the Caspian Sea had higher oleic acid [G₂ sample (75.98%)] and lower linoleic acid [Go₅ sample (6.5%)] and palmitic acid [G₂ sample (10.78%)] concentrations than samples from the southern part of the country such as F₁ whose contents of C16:0, C18:1 and C18:2 were 15.27, 62.73 and 16.09%, respectively, in the southern part, the climate is dry and the temperature variation is wider and the elevation is 1,488 m. The results indicated that oleic acid was the predominant fatty acid with 62.7% for F₁ sample in the warmer climate at the south of Iran to 76.0% for G₂ sample in the cooler climate in the north of Iran. According to the results, the highest content of β-sitosterol was 87% related to samples G₉ and Z₃ from the north of Iran and the lowest content was 69.95% related to sample F_1–24 from the south of Iran. Clustering techniques such as principal component analysis and hierarchical cluster analysis were carried out on olive composition data to show similarities and discrimination between samples as a function of the cultivation zone. The two methods applied clearly showed the effect of growing regions on the distribution of the olive oil samples in the high dimensional space created by fatty acid and sterol compositions.     

Improvement of Furfural Production from Concentrated PreHydrolysis Liquor (PHL) of a Kraft-Based Hardwood Dissolving Pulp Production Process

Hemicelluloses present in the prehydrolysis liquor (PHL) of the hardwood kraft-based dissolving pulp production process can be utilized in the production of furfural, which is an important renewable, non-petroleum-based platform chemical. A lower furfural yield was observed from the concentrated sugars in PHL in acetic-acid-catalyzed systems. The reaction rate of sugar consumption and furfural destruction in PHL was higher than those of model xylan and xylose systems, which may be due to the side-reactions of lignin with sugars and carbonization of oligomeric sugars. In order to minimize these side-reactions, a steam-stripping method of generated furfural was adopted. The results showed that the method was effective in increasing the furfural yield (41.5%) from the concentrated PHL.     

Characterization of Wood and Wood-Plastic Composite

Wood-plastic composites (WE) were prepared with low-grade wood (kadom, simul, and mango) of Bangladesh and MMA (methyl methacry-late) under Co-60 gamma irradiation with a 3-Mrad dose (800 krad/h). Polymer loading and tensile properties of the composites were determined and the effect of urea and N-vinyl pyrrolidone (NVP) on these properties was studied. The polymer loading (PL) increases slightly (2-3%) with the addition of urea to the MMA + MeOH solution: however, this increment is 616% with NVP addition and 12-54% with urea + NVP, depending on the type of wood. Similarly, the tensile strength (TS) increased by 11-25%, the bending strength (BS) by 31-48%, and the compressed strength (CS) by 40-67%. To further characterize the composite, the samples were investigated with infrared (IR), electron-spin resonance (ESR), and thermally simulated luminescence (TSL) techniques. IR studies reveal that MMA was grafted with the wood substrate; ESR and TSL investigations detected the residual free radicals (not the primary free radicals) in the composites.     

Retracted and replaced: Enabling technologies for the ‘always best connected’ concept

The following article from Wireless Communications and Mobile Computing ‘Enabling technologies for the “always best connected” concept’ by N. Passas, S. Paskalis, A. Kaloxylos, F. Bader, R. Narcisi, E. Tsontsis, A. S. Jahan and H. Aghvami published online on 23 August 2004 in Wiley InterScience ( www.interscience.wiley.com ) and in print on 2 March 2005 in Wireless Communications and Mobile Computing Volume 5 Issue 2 pp 175–191 has been retracted and replaced by agreement between the authors, the journal editors and John Wiley & Sons, Ltd. The article has been retracted due to the omission of the following contributing authors: M. O'Droma and I. Ganchev who are included as contributing authors in the replacement article. (DOI: 10.1002/wcm.392 )