MEMS-Based Terahertz Detectors

A MEMS based novel THz detector structure is designed and realized by micro fabrication. The detector is then characterized to extract its mechanical performance. Operating in 1-5 THz band, the detector has a pixel size of 200 μm × 200 μm. Bimaterial suspension legs consist of Parylene-C and titanium, the pair of which provides a high mismatch in coefficients of thermal expansion. The pixel is a suspended Parylene-C structure having a 200 nm-thick titanium metallization. Operation principle relies on conversion of absorbed THz radiation into heat energy on the pixel. This increases the temperature of the free-standing microstructure that is thermally isolated from the substrate. The increase in temperature induces mechanical deflection due to bimaterial springs. The detector is designed to deliver a noise equivalent temperature difference (NETD) less than 500 mK and a refresh rate of 30 Hz

A Suspended Array of Square Patch Metamaterial Absorbers for Terahertz Applications

A suspended array of square metallic patches on a thin dielectric layer is introduced as a terahertz absorber. The absorber is fabricated on a metalized substrate and the device exhibits metamaterial behavior at specific frequencies determined by the size of the patches. It is feasible to place patches with different sizes in an array formation for a broadband absorber. Design of the absorber is described using electromagnetic simulations. The absorber structure was fabricated on a silicon wafer and its characteristics were measured using a terahertz time domain spectroscope. The measured data match well the simulations indicating strong absorption peaks in a band of 0.5-2 THz

A Linear General Type-2 Fuzzy Logic Based Computing With Words Approach for Realising an Ambient Intelligent Platform for Cooking Recipes Recommendation

This paper addresses the need to enhance transparency in ambient intelligent environments by developing more natural ways of interaction, which allow the users to communicate easily with the hidden networked devices rather than embedding obtrusive tablets and computing equipment throughout their surroundings. Ambient intelligence vision aims to realize digital environments that adapt to users in a responsive, transparent, and context-aware manner in order to enhance users' comfort. It is, therefore, appropriate to employ the paradigm of “computing with words” (CWWs), which aims to mimic the ability of humans to communicate transparently and manipulate perceptions via words. One of the daily activities that would increase the comfort levels of the users (especially people with disabilities) is cooking and performing tasks in the kitchen. Existing approaches on food preparation, cooking, and recipe recommendation stress on healthy eating and balanced meal choices while providing limited personalization features through the use of intrusive user interfaces. Herein, we present an application, which transparently interacts with users based on a novel CWWs approach in order to predict the recipe's difficulty level and to recommend an appropriate recipe depending on the user's mood, appetite, and spare time. The proposed CWWs framework is based on linear general type-2 (LGT2) fuzzy sets, which linearly quantify the linguistic modifiers in the third dimension in order to better represent the user perceptions while avoiding the drawbacks of type-1 and interval type-2 fuzzy sets. The LGT2-based CWWs framework can learn from user experiences and adapt to them in order to establish more natural human-machine interaction. We have carried numerous real-world experiments with various users in the University of Essex intelligent flat. The comparison analysis between interval type-2 fuzzy sets and LGT2 fuzzy sets demonstrates up to 55.43% improvement when general type-2 fuzzy sets are used than when interval type-2 fuzzy sets are used instead. The quantitative and qualitative analysis both show the success of the system in providing a natural interaction with the users for recommending food recipes where the quantitative analysis shows the high statistical correlation between the system output and the users' feedback; the qualitative analysis presents social scienc

Belief propagation algorithm for computing correlation functions in finite-temperature quantum many-body systems on loopy graphs

Belief propagation -- a powerful heuristic method to solve inference problems involving a large number of random variables -- was recently generalized to quantum theory. Like its classical counterpart, this algorithm is exact on trees when the appropriate independence conditions are met and is expected to provide reliable approximations when operated on loopy graphs. In this paper, we benchmark the performances of loopy quantum belief propagation (QBP) in the context of finite-tempereture quantum many-body physics. Our results indicate that QBP provides reliable estimates of the high-temperature correlation function when the typical loop size in the graph is large. As such, it is suitable e.g. for the study of quantum spin glasses on Bethe lattices and the decoding of sparse quantum error correction codes.Comment: 5 pages, 4 figure

P58IPK, a Plant Ortholog of Double-Stranded RNA-Dependent Protein Kinase PKR Inhibitor, Functions in Viral Pathogenesis

AbstractP58IPK is a cellular inhibitor of the mammalian double-stranded RNA-activated protein kinase (PKR). Here we provide evidence for the existence of its homolog in plants and its role in viral infection at the organism level. Viral infection of P58IPK-silenced Nicotiana benthamiana and Arabidopsis knockouts leads to host death. This host cell death is associated with phosphorylation of the α subunit of eukaryotic translation initiation factor (eIF-2α). Loss of P58IPK leads to reduced virus titer, suggesting that wild-type P58IPK protein plays an important role in viral pathogenesis. Although our complementation results using mammalian P58IPK suggest conservation of the P58IPK pathway in plants and animals, its biological significance seems to be different in these two systems. In animals, P58IPK is recruited by the influenza virus to limit PKR-mediated innate antiviral response. In plants, P58IPK is required by viruses for virulence and therefore functions as a susceptibility factor

The fitness cost to females of exposure to males does not depend on water availability in seed beetles

Access to multiple males can benefit a female in terms of increased fecundity and/or offspring performance. However, the presence of more males can also impose costs on females that arise from an elevated mating rate (e.g. due to increased genital damage, loss of feeding opportunities) and/or increased harassment. Different environments might influence the relative magnitude of these costs and benefits, because they can influence how often males and females encounter each other as well as the nature of these encounters. In the seed beetle, Callosobruchus maculatus, water is a limiting resource for females that can be obtained from male ejaculates. Here we explored whether the net fitness of female seed beetles is affected by breeding in either a dry or a wet environment when housed with differing numbers of males (none, one or four). Consistent with costly male harassment, females housed with four males laid significantly fewer eggs than those housed alone or with a single male, but there was no effect of the number of males on female egg-laying rate, life span, larval development rate or egg–adult survival of offspring. Although females in the wet environment lived significantly longer, there was only tentative evidence that water availability affected the net fitness cost to females of being exposed to more males. We conclude that to understand the evolution of mating systems it is important to explore how the environment affects female fitness by balancing the costs and benefits of being exposed to males.This work was supported by Australian Research Council (M.J., DP160100285; M.H., Future Fellowship FT160100149)

Interface Friction Parameters for the Mathematical Modeling of Shell Structures with Infill

Thin metal or reinforced concrete shells with granular infill structures are considered in this article. These structures are massive and they are used as support for the construction of berthing quays, piers, artificial islands, shore protection, and other structures of coastal infrastructure. It is more convenient to use the thin shell structures during the development of the Arctic shelf, because it is possible to install them from the ice side. In addition, it is possible to enhance the technology and install thin shells with infill on deeper solid foundation layers. A mathematical model for the stresses on a compressible foundation soil in front of a thin cylindrical shell with infill due to the eccentric loading is developed. A modeling and experimental determination of the interface strength of the contact surface between the infill and the inner surface of the shell is proposed. The details of the construction stages and testing of the physical model used for the experiments are discussed. The effects of the interface friction on the shell behavior and on the foundation stresses in front of the wall are investigated. The influence of parameters affecting the interaction between the soil infill and the inner surface of the shell material is determined. It is based on a comparison of experimental results with calculations performed using the proposed mathematical model. The obtained parameters and proposed methods can be used in numerical simulations using the finite element method to analyze and design the thin shell structures with soil infill. The findings of the study and proposed methods can also be applied to the thin shell structures used in other facilities such as hydraulic, industrial, civil, and transportation

Singlet oxygen generation by photodynamic agents

Abstract The singlet oxygen quantum yield of photodynamic agents was measured at 546 nm, 630 nm, and on the far-red absorption peak. The technique employed is available in most laboratories, in which the photosensitization of lysozyme is used as an internal actinometer. Measurements in a pH 7.4 phosphate buffer plus 1% Triton X-! 00 (PB/X 100) are scaled to 0.52 for methylene blue in the phosphate buffer. The average quantum yields are: hematoporphyrin IX (0.73), protoporphyrin IX (0.56) zinc protoporphyrin IX (0.91), mesotetra-(4-sulfonato-phenyl) porphine (0.61), Photofrin s (0.89), benzoporphyrin derivative monoacid ring-A (0.84), chlorin e6 in PB (0.64), pheophorbide a (0.69), and aluminum phthalocyanine tetrasulfonate (0.38). Protection factors were measured for added azide ion, 1,4-diazabicyclo [ 2.2.2]-octane, and superoxide dismutase. Spectral evidence is presented for chlorin e6 interactions with PB/TX 100 and for binding to lysozyme

Constructing TI-Friendly Substitution Boxes Using Shift-Invariant Permutations

The threat posed by side channels requires ciphers that can be efficiently protected in both software and hardware against such attacks. In this paper, we proposed a novel Sbox construction based on iterations of shift-invariant quadratic permutations and linear diffusions. Owing to the selected quadratic permutations, all of our Sboxes enable uniform 3-share threshold implementations, which provide first order SCA protections without any fresh randomness. More importantly, because of the shift-invariant property, there are ample implementation trade-offs available, in software as well as hardware. We provide implementation results (software and hardware) for a four-bit and an eight-bit Sbox, which confirm that our constructions are competitive and can be easily adapted to various platforms as claimed. We have successfully verified their resistance to first order attacks based on real acquisitions. Because there are very few studies focusing on software-based threshold implementations, our software implementations might be of independent interest in this regard