Thioethyl‐Porphyrazine/Nanocarbon Hybrids for Photoinduced Electron Transfer

A novel pyrene‐substituted thioethyl‐porphyrazine ( PzPy ) and the formation of supramolecular assembly with nanocarbons demonstrating photoinduced electron transfer ability are designed. As revealed by spectroscopic and electrochemical studies, PzPy displays wide spectral absorption in the visible range, charge separation upon photoexcitation, as well as bandgap and highest occupied/lowest unoccupied molecular orbital (HOMO/LUMO) energy values, matching the key requirements of organic optoelectronic. Moreover, the presence of a pyrene moiety promotes attractive interactions with π‐conjugated systems. In particular, theoretical calculations show that in the PzPy the HOMO and LUMO are localized on different positions of the molecule, i.e., the HOMO on the pyrene moiety and the LUMO on the macrocycle. Therefore, HOMO–LUMO excitation gives rise to a charge separation, preventing excitons recombination. Two kinds of noncovalent hybrid composites are prepared by mixing the PzPy with single‐wall carbon nanotubes (SWNTs) and graphene nanoflakes (GNFs), respectively, and used for photocurrent generation through charge transfer processes between PzPy and nanocarbons. Photoconduction experiments show photocurrent generation upon visible light irradiation of both PzPy /SWNT and PzPy /GNF composites (0.78 and 0.71 mA W^?1 at 500 nm, respectively), demonstrating their suitability for optoelectronic applications and light harvesting systems.     

Change detection using distance-based algorithms between synthetic aperture radar polarimetric decompositions

The present study introduces distance based change detection (CD) algorithms in polarimetric synthetic aperture radar (PolSAR) data. PolSAR images, due to interactions between electromagnetic waves and target and because of the high spatial resolution, can be used to study changes in the Earth’s surface. The purpose of this paper is to use features extracted from the fully-polarimetry imaging radar that involved Yamaguchi four-component and H/A/α decomposition based on the distance between the vectors of features for CD. We first extract features from polarimetric decompositions of multi-looked covariance (or coherency) matrix data. We then use two well-known distance measures namely Canberra and Euclidean distances for measuring the similarity between the vectors of polarimetric decompositions at different times. Assessment of incorporated methods is performed using different criteria, such as overall accuracy, area under the receiver operating characteristic curve, and false alarms rate. The results of the experiments show that Canberra distance has better performance with high overall accuracy and low false alarm rate than Euclidean distance and other compared algorithms to detect changes.     

Shape optimization using a NURBS‐based interface‐enriched generalized FEM

This study presents a gradient‐based shape optimization over a fixed mesh using a non‐uniform rational B‐splines‐based interface‐enriched generalized finite element method, applicable to multi‐material structures. In the proposed method, non‐uniform rational B‐splines are used to parameterize the design geometry precisely and compactly by a small number of design variables. An analytical shape sensitivity analysis is developed to compute derivatives of the objective and constraint functions with respect to the design variables. Subtle but important new terms involve the sensitivity of shape functions and their spatial derivatives. Verification and illustrative problems are solved to demonstrate the precision and capability of the method. Copyright © 2016 John Wiley & Sons, Ltd.     

Wheat Self-Sufficiency,Water Restriction and Virtual Water Trade in Iran

Sustainable food security is one of the policy-making targets in Iran, but water scarcity has always been a challenge to its actualization. Regarding this point, offering policies to address this challenge is essential. On the other hand, wheat is the most important commodity in the food baskets of Iranians, and due to the lack of equality in the supply and demand among the regions, a large amount of wheat is displaced every year. The displacement of wheat has resulted in virtual water trade among the regions and could be a possible solution to manage the water crisis in Iran. With respect to the necessity of research, the present study investigated the effects of economic policies on virtual water trade for wheat using a spatial equilibrium model. Therefore, the aim of this study was to investigate the pattern of virtual water trade flow and welfare changes which resulted from making different economic policies in the wheat market. The results showed that the wheat self-sufficiency policy reduces the total amount of virtual water trade, and will increase pressure on the water resources of Iran. The policy of paying tax and receiving subsidies also significantly affect the flow of virtual water trade. But that happens best when tax revenues are equal to the payment of subsidies.

     

A low power reconfigurable multi-mode continuous time Delta Sigma modulator for seven different mobile standards with VCO-based quantizer

In this research a novel low power multi-mode continuous time Delta Sigma modulator was designed to be compatible with many mobile wireless standards. This modulator has a reconfigurable structure to adapt to various standards from 0.2 to 20 MHz. The designed modulator uses a VCO-based quantizer not only for lowering power consumption, but also for reducing the required chip area. The presented modulator can function with up to third order of noise shaping, or in a low power mode in which the loop filter is disabled and only the VCO-based quantizer is used. The proposed modulator was implemented and simulated in transistor level in 180 nm technology. This modulator can digitize at least seven standards (LTE (20 MHz)/WLAN/LTE (9 MHz)/WCDMA/UMTS/Bluetooth/GSM) with a favorable dynamic range (65–89 dB) and power consumption (9.1 mW–670 μW).     

Synthesis and characterization of biodegradable block copolymers of poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol)

The synthesis of two low molecular weight linear unsaturated oligoester precursors, poly(propylene fumarate‐co‐sebacate) (PPFS) and poly(ethylene fumarate‐co‐sebacate) (PEFS), are described. PPFS, PEFS, and poly(ethylene glycol) are then used to prepare poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PPFS‐co‐PEG) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PEFS‐co‐PEG) block copolymers. The products thus obtained are investigated in terms of the molecular weight, composition, structure, thermal properties, and solubility behavior. A number of design parameters including the molecular weights of PPFS, PEFS, and PEG, the reaction time in the polymer synthesis, and the weight ratio of PEG to PPFS or to PEFS are varied to assess their effects on the product yield and properties. The hydrolytic degradation of PPFS‐co‐PEG and PEFS‐co‐PEG in an isotonic buffer (pH 7.4, 37°C) is investigated, and it is found that the fumarate ester bond cleaves faster than does the sebacate ester bond. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 295–300, 2004     

Evaluation of repeatability and reproducibility of continuous friction measuring equipment (CFME) using cross-correlation

Lack of sufficient friction between tyre and pavement is known to be one of the contributing factors in vehicle crashes. The application of new technologies can be used to determine the low friction areas or vulnerable accident sites at both the project and network levels. Continuous friction devices are one of the newest systems currently used in European countries that have recently been introduced to the United States. Continuous friction measuring devices are designed to measure the friction under conditions similar to those produced by an anti-lock braking system. Although continuous friction measuring equipment (CFME) provides valuable information about surface friction, processing of the relatively large amount of data produced is time-consuming. Traditional methods such as comparing the average friction provide a quick and simple data analysis method; however, they neglect other important characteristics such as friction spatial variation and low friction spots. This study proposes a methodology based on cross-correlation to compare CFME measurements. The data used in the study were collected during the annual rodeo that took place at the Virginia Smart Road. Two GripTester and one Dynatest 6875H Highway Friction Tester were used for data collection. Cross-correlation was used to synchronise the measurements. Repeatability and reproducibility of the measurements were evaluated based on the maximum cross-correlation value.     

Nigella sativa L. improves lipid profile and prevents atherosclerosis: Evidence from an experimental study on hypercholesterolemic rabbits

The effects of Nigella sativa (NS) on lipid profile, C-reactive protein, oxidized LDL, antioxidant capacity, Apo A and Apo B and fatty streak formation in hypercholesterolemic male rabbits were examined. Fifteen rabbits were distributed into three groups of five each [normal diet, hypercholesterolemic diet (1% cholesterol) and hypercholesterolemic diet (1% cholesterol) supplemented with 5% NS]. They received rabbit laboratory chow diet for a period of 8 weeks. At the start and end of the study, fasting blood was taken from all animals. NS significantly decreased fatty streak formation as well as total cholesterol (TC) and low-density lipoprotein (LDL) in hypercholesterolemic male rabbits. NS showed positive effects on other factors (triacylglycerol, high-density lipoprotein, C-reactive protein, oxidized LDL, antioxidant capacity, Apo A and Apo B), but these were insignificant. Based on favorable efficiency of NS on TC and LDL reduction and its anti-atherogenic cardioprotective properties, it is suggested using this plant with fat-rich diets simultaneously may reduce their adverse health effects.     

Oversampled multi-phase time-domain bit-error rate processing for transmitter testing

High speed serial interfaces (HSSI) are continually pushed toward operating at higher speed to meet the demand for higher bandwidth. As a result, the timing constraints for HSSI devices get tighter. Consequently, HSSI devices experience issues such as timing jitter and bit-errors. This paper investigates techniques to speed up HSSI bit-error rate and jitter testing. The proposed oversampling-based transmitter test scheme accelerates transmitter jitter and eye diagram testing by means of a multi-phase bit-error rate test circuit (BERT). The proposed scheme creates parallel BERT elements working in conjunction that are able to digitize the input signal jitter behavior in a multi-phase manner. The more phases we deploy the faster the test is completed. We accurately extract the transmitter jitter in time domain and finish the whole transmitter test within tens of milliseconds, exceeding the current norm of 100 ms.     

Contouring control of a 3-[P2(US)] parallel manipulator

A three-translational degree of freedom parallel mechanism is introduced in this research. Kinematic and dynamic modelling of the parallel mechanism is investigated and equations of motion are derived via Lagrange formulation. Reduced dynamic equations of the robot are represented as a matrix form for implementation in inverse dynamics control of the constrained system. Equivalent contouring errors are represented in moving tangent-normal coordinates system in joint space. Contouring control of the robot is applied to the system using inverse-dynamics-based feedback linearization technique and application of the control technique is represented through two proposed manoeuvres for robot motion. Trajectory planning of the end-effector path is performed by specification of some accuracy points and cubic spline interpolation through them. Response performance in contour following of the control system is improved by appropriate choice of control parameters and by decoupling of error dynamics via assigning suitable structures for control matrices. The results of practical implementation of the control technique show proper accuracy of the control system in following two desired trajectories and acceptable errors are created with respect to the desired contours.