Utilization of the Antiferromagnetic IrMn Electrode in Spin Thermoelectric Devices and Their Beneficial Hybrid for Thermopiles

The thermoelectric effect in various magnetic systems, in which electric voltage is generated by a spin current, has attracted much interest owing to its potential applications in energy harvesting, but its power generation capability has to be improved further for actual applications. In this study, the first instance of the formation of a spin thermopile via a simplified and straightforward method which utilizes two distinct characteristics of antiferromagnetic IrMn is reported: the inverse spin Hall effect and the exchange bias. The former allows the IrMn efficiently to convert the thermally induced spin current into a measurable voltage, and the latter can be used to control the spin direction of adjacent ferromagnetic materials. It is observed that a thermoelectric signal is successfully amplified in spin thermopiles with exchange‐biased IrMn/CoFeB structures, where an alternating magnetic alignment is formed using the IrMn thickness dependence of the exchange bias. The scalable signal on a number of thermopiles allowing a large‐area application paves the way toward the development of practical spin thermoelectric devices. A detailed model analysis is also provided for a quantitative understanding of the thermoelectric voltages, which consist of the spin Seebeck and anomalous Nernst contributions.     

The Effects of Management Traffic on the Local Call Processing Performance of ATM Switches Using Queue Network Models and Jackson's Theorem

This paper considers a TMN‐based management system for the management of public ATM switching networks using a four‐level hierarchical structure consisting of one network management system, several element management systems, and several agent‐ATM switch pairs. Using Jackson's queuing model, we analyze the effects of one TMN command on the performance of the component ATM switch in processing local calls. The TMN command considered is the permanent virtual call connection. We analyze four performance measures of ATM switches—utilization, mean queue length and mean waiting time for the processor directly interfacing with the subscriber lines and trunks, and the call setup delay of the ATM switch—and compare the results with those from Jackson's queuing model.     

PbS/CdS/ZnS Quantum Dots: A Multifunctional Platform for In Vivo Near‐Infrared Low‐Dose Fluorescence Imaging

Over the past decade, near‐infrared (NIR)‐emitting nanoparticles have increasingly been investigated in biomedical research for use as fluorescent imaging probes. Here, high‐quality water‐dispersible core/shell/shell PbS/CdS/ZnS quantum dots (hereafter QDs) as NIR imaging probes fabricated through a rapid, cost‐effective microwave‐assisted cation exchange procedure are reported. These QDs have proven to be water dispersible, stable, and are expected to be nontoxic, resulting from the growth of an outer ZnS shell and the simultaneous surface functionalization with mercaptopropionic acid ligands. Care is taken to design the emission wavelength of the QDs probe lying within the second biological window (1000–1350 nm), which leads to higher penetration depths because of the low extinction coefficient of biological tissues in this spectral range. Furthermore, their intense fluorescence emission enables to follow the real‐time evolution of QD biodistribution among different organs of living mice, after low‐dose intravenous administration. In this paper, QD platform has proven to be capable (ex vivo and in vitro) of high‐resolution thermal sensing in the physiological temperature range. The investigation, together with the lack of noticeable toxicity from these PbS/CdS/ZnS QDs after preliminary studies, paves the way for their use as outstanding multifunctional probes both for in vitro and in vivo applications in biomedicine.     

Optical transfer function of slit-coupled systems: double-pass monochromators

The influence that the width of an intermediate slit has on the incoherent modulation optical transfer function of two identical systems coupled by a slit placed in the image plane of the first system is studied. The special case of a double-pass parabolized Ebert monochromator is considered in detail.     

Slurry sampling in serum blood for mercury determination by CV-AFS

The heavy metal mercury (Hg) is a neurotoxin known to have a serious health impact even at relatively low concentrations. A slurry method was developed for the sensitive and precise determination of mercury in human serum blood samples by cold vapor generation coupled to atomic fluorescence spectrometry (CV-AFS). All variables related to the slurry formation were studied. The optimal hydrochloric concentration and tin(II) chloride concentration for CV generation were evaluated. Calibration within the range 0.1-10 microg L(-1) Hg was performed with the standard addition method, and compared with an external calibration. Additionally, the reliability of the results obtained was evaluated by analyzing mercury in the same samples, but submitted to microwave-assisted digestion method. The limit of detection was calculated as 25 ng L(-1) and the relative standard deviation was 3.9% at levels around of 0.4 microg L(-1)Hg.     

Surface modification of cellulosic fibres for multi-purpose TiO2 based nanocomposites

Vegetable cellulose fibres have been surface modified using the hydrolysis of tetraethoxysilane (TEOS), octyltrimethoxysilane (OTMS) or phenyltrimethoxysilane (PTMS), followed by the layer-by-layer deposition of previously synthesized TiO₂ nanoparticles. Raman, FTIR and ²⁹Si Solid State NMR spectroscopies, and SEM were used to characterize the resulting nanocomposites. Water contact angle measurements were performed and the results indicate a quite distinct behaviour depending on the employed surface modification procedure. We anticipate that some of the cellulose-based composite materials have potential to be used in self-cleaning surfaces and reinforcing agents in polymer matrices, namely due to their hydrophobic surface and photostability when exposed to solar radiation.     

Detection of multiple disease indicators by an autonomous biomolecular computer

The promise of biomolecular computers is their ability to interact with naturally occurring biomolecules, enabling in the future the development of context-dependent programmable drugs. Here we show a context-sensing mechanism of a biomolecular automaton that can simultaneously sense different types of molecules, allowing future integration of biomedical knowledge on a broad range of molecular disease symptoms in the decision of a biomolecular computer to release a drug molecule.     

Metabolic profiling of liver from hypercholesterolemic pigs fed rye or wheat fiber and from normal pigs. High-resolution magic angle spinning 1H NMR spectroscopic study

This study presents the first application of a high-resolution magic angle spinning 1H NMR approach to elucidate the metabolic effects of a hypercholesterolemic condition and two high-fiber diets based on rye and wheat bread, respectively, in intact pig liver biopsy samples. Standard 1D and spin-echo 1H spectra were acquired on a total of 20 biopsy samples, and 2D total correlation spectroscopy experiments were carried out on selected samples for assignment of the observed resonances. Principal component analyses and partial least-squares regression discriminant analysis revealed differences in the hepatic lipid content and choline-containing compounds between normal and hypercholesterolemic pigs. In addition, the results demonstrated that the liver metabolite profile of hypercholesterolemic pigs fed a high-fiber rye bread differed from that of pigs fed high-fiber wheat bread with respect to both the lipoprotein fractions and the choline-containing compounds. These findings suggest that earlier reports on high-fiber rye diet-induced effects on plasma HDL/LDL content partially can be ascribed to effects on liver cholesterol metabolism and that the hepatic phospholipase pathways of phosphatidylcholine breakdown are affected by the high-fiber rye diet.     

Shorted Microstrip Patch Antenna Using Inductively Coupled Feed for UHF RFID Tag

A very small patch‐type RFID tag antenna (UHF band) using ceramic material mountable on metallic surfaces is presented. The size of the proposed tag is 25 mm×25 mm×3 mm. The impedance of the antenna can be easily matched to the tag chip impedance by adjusting the size of the shorting plate of the patch and the size of the feeding loop. The measured maximum reading distance of the tag at 910 MHz was 5 m when it was mounted on a 400 mm × 400 mm metallic surface. The proposed design is verified by simulation and measurements which show good agreement.     

Techno-economic analysis of MJ class high temperature Superconducting Magnetic Energy Storage(SMES) systems applied to renewable power grids

High temperature Superconducting Magnetic Energy Storage(SMES) systems can exchange energy with substantial renewable power grids in a small period of time with very high efficiency. Because of this distinctive feature, they store the abundant wind power when the power network is congested and release the energy back to the system when there is no congestion. However, considering the cost and lifespan of SMES systems, there is an urgent demand to conduct a cost-benefit analysis to justify its role in smart grid development. This study explores the application and performs economic analysis of a 5 MJ SMES in a practical renewable power system in China based on the PSCAD/EMTDC software. An optimal location of SMES in Zhangbei wind farm is presented using real power transmission parameters. The stabilities of the renewable power grid with and without SMES are discussed. In addition, a financial feasibility study is conducted by comparing the cost and the savings from wind power curtailment of deploying SMES and battery. The economic analysis tries to find the balance between SMES investment cost and wind farm operation cost by using real data over a calendar year. The technical analysis can help guide the optimal allocation of SMES for compensating power system instability with substantial wind power. Further, the economic analysis provides a useful indication of its practical application feasibility to fight the balance between cost and benefit.