RPRDC: Reliable Proliferation Routing with low Duty-Cycle in Wireless Sensor Networks

Ensuring reliable energy efficient data communication in resource constrained Wireless Sensor Networks (WSNs) is of primary concern. Traditionally, two types of re-transmission have been proposed for the data-loss, namely, End-to-End loss recovery (E2E) and per hop. In these mechanisms, lost packets are re-transmitted from a source node or an intermediate node with a low success rate. The proliferation routing(1) for QoS provisioning in WSNs low End-to-End reliability, not energy efficient and works only for transmissions from sensors to sink. This paper proposes a Reliable Proliferation Routing with low Duty Cycle RPRDC] in WSNs that integrates three core concepts namely, (i) reliable path finder, (ii) a randomized dispersity, and (iii) forwarding. Simulation results demonstrates that packet successful delivery rate can be maintained upto 93% in RPRDC and outperform Proliferation Routing(1). (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Coatings and surface treatments for protection against low-velocity erosion-corrosion in fluidized beds

Surface coatings and treatments have been used to reduce material loss of components in bubbling fluidized bed combustors (FBCs). The performance of protective coatings in FBC boilers and laboratory simulations is reviewed. Important coating properties to minimize wastage appear to be high hardness, low oxidation rate, low porosity, high adhesion and sufficient thickness to maintain protection for a long period. Economic considerations and criteria for choosing a suitable coating or treatment are discussed for the different types of bubbling FBC. © 1995.

Mechanical Properties And Constitutive Relationships Of 30Crmnsia Steel Heated At High Rate

In this paper, the mechanical behavior of 30CrMnSiA steel after heating at a high rate are investigated experimentally and theoretically, including a detailed discussion of the effects of strain rate and temperature. Two constitutive models are presented to describe the mechanical response of this material after heating at a high rate, and verified by experimental results. (C) 2007 Elsevier B.V. All rights reserved.

Mechanical properties and constitutive relationships of 30CrMnSiA steel heated at high rate

In this paper, the mechanical behavior of 30CrMnSiA steel after heating at a high rate are investigated experimentally and theoretically, including a detailed discussion of the effects of strain rate and temperature. Two constitutive models are presented to describe the mechanical response of this material after heating at a high rate, and verified by experimental results. (C) 2007 Elsevier B.V. All rights reserved.

Influence of composition on the structure and properties of Fe-Pd-P and Ni-Pd-P amorphous alloys

Ternary alloys of nickel-palladium-phosphorus and iron-palladium- phosphorus containing 20 atomic % phosphorus were rapidly quenched from the liquid state. The structure of the quenched alloys was investigated by X-ray diffraction. Broad maxima in the diffraction patterns, indicative of a glass-like structure, were obtained for 13 to 73 atomic % nickel and 13 to 44 atomic % iron, with palladium adding up to 80%.

Radial distribution functions were computed from the diffraction data and yielded average interatomic distances and coordination numbers. The structure of the amorphous alloys could be explained in terms of structural units analogous to those existing in the crystalline Pd₃P, Ni₃P and Fe₃P phases, with iron or nickel substituting for palladium. A linear relationship between interatomic distances and composition, similar to Vegard's law, was shown for these metallic glasses.

Electrical resistivity measurements showed that the quenched alloys were metallic. Measurements were performed from liquid helium temperatures (4.2°K) up to the vicinity of the melting points (900°K- 1000°K). The temperature coefficient in the glassy state was very low, of the order of 10^-4/°K. A resistivity minimum was found at low temperature, varying between 9°K and 14°K for Ni_x-Pd_80-x -P₂₀ and between 17°K and 96°K for Fe_x-Pd_80-x -P₂₀, indicating the presence of a Kondo effect. Resistivity measurements, with a constant heating rate of about 1.5°C/min,showed progressive crystallization above approximately 600°K.

The magnetic moments of the amorphous Fe-Pd-P alloys were measured as a function of magnetic field and temperature. True ferromagnetism was found for the alloys Fe₃₂-Pd₄₈-P₂₀ and Fe₄₄-Pd₃₆-P₂₀ with Curie points at 165° K and 380° K respectively. Extrapolated values of the saturation magnetic moments to 0° K were 1.70 µ_B and 2.10 µ_B respectively. The amorphous alloy Fe₂₃-Pd₅₇-P₂₀ was assumed to be superparamagnetic. The experimental data indicate that phosphorus contributes to the decrease of moments by electron transfer, whereas palladium atoms probably have a small magnetic moment. A preliminary investigation of the Ni-Pd-P amorphous alloys showed that these alloys are weakly paramagnetic.

A high-speed image sensing technique with adjustable frame rate based on an ordinary CCD

In the sinusoidal phase modulating interferometer technique, the high-speed CCD is necessary to detect the interference signals. The reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing technique with adjustable frame rate based on ail ordinary CCD was proposed. And the principle of the image sensor was analyzed. When the maximum frequency and channel bandwidth were constant, a custom high-speed sensor was designed by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been enhanced by controlling the number of pixels of every frame; therefore, the ordinary of CCD can be used as the high frame rate image sensor with small amount of pixels. The multi-output high-speed image sensor has the deficiencies of low accuracy, and high cost, while the high-speed image senor with small number of pixels by using this technique can overcome theses faults. The light intensity varying with time was measured by using the image sensor. The frame rate was LIP to 1600 frame per second (f/s), and the size of every frame and the frame rate were adjustable. The correlation coefficient between the measurement result and the standard values were higher than 0.98026, and the relative error was lower than 0.53%. The experimental results show that this sensor is fit to the measurements of sinusoidal phase modulating interferometer technique. (c) 2007 Elsevier GmbH. All rights reserved.

Influence of a building's integrated-photovoltaics on heating and cooling loads

Building integrated photovoltaics (BIPV) has the potential to become a major source of renewable energy in the urban environment. BIPV has significant influence on the heat transfer through the building envelope because of the change of the thermal resistance by adding or replacing the building elements. Four different roofs are used to assess the impacts of BIPV on the building's heating-and-cooling loads; namely ventilated air-gap BIPV, non-ventilated (closed) air-gap BIPV, closeroof mounted BIPV, and the conventional roof with no PV and no air gap. One-dimensional transient models of four cases are derived to evaluate the PV performances and building cooling-and-heating loads across the different roofs in order to select the appropriate PV building integration method in Tianjin, China. The simulation results show that the PV roof with ventilated air-gap is suitable for the application in summer because this integration leads to the low cooling load and high PV conversion efficiency. The PV roof with ventilation air-gap has a high time lag and small decrement factor in comparison with other three roofs and has the same heat gain as the cool roof of absorptance 0.4. In winter, BIPV of non-ventilated air gap is more appropriate due to the combination of the low heating-load through the PV roof and high PV electrical output. © 2005 Elsevier Ltd. All rights reserved.

Innovative fabrication of PZT pillar arrays by a colloidal approach

An innovative approach for fabricating pillar arrays for ultrasonic transducer applications is disclosed. It involves the preparation of concentrated piezoelectric lead zirconate titanate (PZT) suspensions in aqueous solutions of epoxy resin and its polymerization upon adding a polyamine based hardener. Zeta potential and rheological measurements revealed that 1wt.% dispersant, 20wt.% of epoxy resin and a hardener/epoxy resin ratio of 0.275mLg -1, were the optimized contents to obtain strong PZT samples with high green strength (35.21±0.39MPa). Excellent ellipsoidal and semi-circle shaped pillar arrays presenting lateral dimensions lower than 10μm and 100μm height were successfully achieved. The organics burning off was conducted at 500°C for 2h at a heating rate of 1°Cmin -1. Sintering was then carried out in the same heating cycle at 1200°C for 1h. The microstructures of the green and sintered ceramics were homogeneous and no large defects could be detected. © 2011 Elsevier Ltd.

A neuro-inspired method for data rate limited feedback control

The nervous system implements a networked control system in which the plants take the form of limbs, the controller is the brain, and neurons form the communication channels. Unlike standard networked control architectures, there is no periodic sampling, and the fundamental units of communication contain little numerical information. This paper describes a novel communication channel, modeled after spiking neurons, in which the transmitter integrates an input signal and sends out a spike when the integral reaches a threshold value. The reciever then filters the sequence of spikes to approximately reconstruct the input signal. It is shown that for appropriate choices of channel parameters, stable feedback control over these spiking channels is possible. Furthermore, good tracking performance can be achieved. The data rate of the channel increases linearly with the size of the inputs. Thus, when placed in a feedback loop, small loop gains imply a low data rate. ©2010 IEEE.

Desorption and Ripening of Low Density InAs Quantum Dots

In this paper, combining low deposition rate with proper growth temperature, we have developed a way to prepare very low-density quantum dots (QDs) suited for the study of single OD properties without resorting to submicron lithography. Experiment results demonstrate that InAs desorption is significant during growing the low density QDs. Ripening of InAs QDs is clearly observed during the post-growth annealing. Photoluminescence spectroscopy reveals that the emission wavelength of low density InAs QDs arrives at 1332.4 nm with a GaAs capping layer.

Desorption and Ripening of Low Density InAs Quantum Dots

In this paper, combining low deposition rate with proper growth temperature, we have developed a way to prepare very low-density quantum dots (QDs) suited for the study of single OD properties without resorting to submicron lithography. Experiment results demonstrate that InAs desorption is significant during growing the low density QDs. Ripening of InAs QDs is clearly observed during the post-growth annealing. Photoluminescence spectroscopy reveals that the emission wavelength of low density InAs QDs arrives at 1332.4 nm with a GaAs capping layer.

Dependence of wet etch rate on deposition, annealing conditions and etchants for PECVD silicon nitride film

The influence of deposition, annealing conditions, and etchants on the wet etch rate of plasma enhanced chemical vapor deposition (PECVD) silicon nitride thin film is studied. The deposition source gas flow rate and annealing temperature were varied to decrease the etch rate of SiN_x:H by HF solution. A low etch rate was achieved by increasing the SiH_4 gas flow rate or annealing temperature, or decreasing the NH_3 and N_2 gas flow rate. Concen-trated, buffered, and dilute hydrofluoric acid were utilized as etchants for SiO_2 and SiN_x:H. A high etching selectivity of SiO_2 over SiN_x:H was obtained using highly concentrated buffered HF.

Multiple melting behavior of isotactic polypropylene and poly(propylene-co-ethylene) after stepwise isothermal crystallization

The multiple melting behavior of several commercial resins of isotactic polypropylene (iPP) and random copolymer, poly(propylene-co-ethylene) (PPE), after stepwise isothermal crystallization (SIC) were studied by differential scanning calorimeter and wide-angle X-ray diffraction (WAXD). For iPP samples, three typical melting endotherms appeared after SIC process when heating rate was lower than 10 degreesC/min. The WAXD experiments proved that only alpha-form crystal was formed during SIC process and no transition from alpha1- to alpha2-form occurred during heating process. Heating rate dependence for each endotherm was discussed and it was concluded that there were only,two major crystals with different thermal stability. For the PPE sample, more melting endotherms appeared after stepwise isothermal crystallization. The introduction of ethylene comonomer in isotactic propylene backbone further decreased the regularity of molecular chain, and the short isotactic propylene sequences could crystallize into gamma-form crystal having a low melting temperature whereas the long sequences crystallized into alpha-form crystal having high melting temperature.

LOCALIZED ENHANCEMENTS OF Fe+10 DENSITY IN THE CORONA AS OBSERVED IN Fe xi 789.2 nm DURING THE 2006 MARCH 29 TOTAL SOLAR ECLIPSE

Habbal, Shadia Rifai; Morgan, Huw; Johnson, Judd; Arndt, Martina Belz; Daw, Adrian; Jaeggli, Sarah; Kuhn, Jeff; Mickey, Don, LOCALIZED ENHANCEMENTS OF Fe+10 DENSITY IN THE CORONA AS OBSERVED IN Fe xi 789.2 nm DURING THE 2006 MARCH 29 TOTAL SOLAR ECLIPSE, The Astrophysical Journal, Volume 663, Issue 1, pp. 598-609

Microwave curing for high density package

Summary form only given. Currently the vast majority of adhesive materials in electronic products are bonded using convection heating or infra-red as well as UV-curing. These thermal processing steps can take several hours to perform, slowing throughput and contributing a significant portion of the cost of manufacturing. With the demand for lighter, faster, and smaller electronic devices, there is a need for innovative material processing techniques and control methodologies. The increasing demand for smaller and cheaper devices pose engineering challenges in designing a curing systems that minimize the time required between the curing of devices in a production line, allowing access to the components during curing for alignment and testing. Microwave radiation exhibits several favorable characteristics and over the past few years has attracted increased academic and industrial attention as an alternative solution to curing of flip-chip underfills, bumps, glob top and potting cure, structural bonding, die attach, wafer processing, opto-electronics assembly as well as RF-ID tag bonding. Microwave energy fundamentally accelerates the cure kinetics of polymer adhesives. It provides a route to focus heat into the polymer materials penetrating the substrates that typically remain transparent. Therefore microwave energy can be used to minimise the temperature increase in the surrounding materials. The short path between the energy source and the cured material ensures a rapid heating rate and an overall low thermal budget. In this keynote talk, we will review the principles of microwave curing of materials for high density packing. Emphasis will be placed on recent advances within ongoing research in the UK on the realization of "open-oven" cavities, tailored to address existing challenges. Open-ovens do not require positioning of the device into the cavity through a movable door, hence being more suitable for fully automated processing. Further potential advantages of op- - en-oven curing include the possibility for simultaneous fine placement and curing of the device into a larger assembly. These capabilities promise productivity gains by combining assembly, placement and bonding into a single processing step. Moreover, the proposed design allows for selective heating within a large substrate, which can be useful particularly when the latter includes parts sensitive to increased temperatures.