Project Omnivore: A Variable Compression Ratio ATAC 2-Stroke Engine for Ultra-Wide-Range HCCI Operation on a Variety of Fuels

The paper describes the principal features of Omnivore, a spark-ignition-based research engine designed to investigate the possibility of true wide-range HCCI operation on a variety of fossil and renewable liquid fuels. The engine project is part-funded jointly by the United Kingdom's Department for the Environment, Food and Rural Affairs (DEFRA) and the Department of the Environment of Northern Ireland (DoENI). The engineering team includes Lotus Engineering, Jaguar Cars, Orbital Corporation and Queen's University Belfast.

Wide-band printed dipole antenna

The design and development of an L-band printed dipole antenna. optimized for wide-band applications near first resonance, is reported. This design has achieved more than 48% impedance bandwidth (VSWR 2:1), without degrading its overall radiation efficiency

Wide Band Rectangular Microstrip Antenna using Symmetric T-shaped Feed

Bandwidth enhancement of a rectangular microstrip antenna using a T-shaped microstrip feed is explored in this paper. A 2:1 VSWR impedance bandwidth of 23% is achieved by employing this technique. The far-field patterns are stable across the pass band. The proposed antenna can be used conveniently in broadband communications

Novel Wide Band Printed Dipole Antenna

Design, development and experimental observations of a L: band printed dipole antenna is presented.Bandwidth enhancement is achieved by end-loading or the dipole arms. Using the present technique Impedance bandwidth van be enhanced up to 50% without degrading the efficiency of the antenna.

Growth and characterization of nanostructured wide band gap semiconductors for optoelectronic applications

Department of Physics, Cochin University of Science and Technology

Slot Line Fed Dipole Antenna For Wide Band Applications

A slot line fed planar dipole antenna with a parasitic strip for wide band applications is presented. The presented antenna offers a 2:1 VSWR bandwidth from 1.66 to 2.71 GHz covering the DCS/ PCS/UMTS and IEEE 802.11b/g bands with a gain better than 6.5 dBi. The uniplanar design, simple feeding, and high gain make it a versatile antenna for wireless applications

An ultra-wide passband (5-30µm) filter for FTIR studies of Photosystem II

This paper reports on the design and manufacture of an ultra-wide (5-30µm) infrared edge filter for use in FTIR studies of the low frequency vibrational modes of metallo-proteins. We present details of the spectral design and manufacture of such a filter which meets the demanding bandwidth and transparency requirements of the application, and spectra that present the new data possible with such a filter. A design model of the filter and the materials used in its construction has been developed capable of accurately predicting spectral performance at both 300K and at the reduced operating temperature at 200K. This design model is based on the optical and semiconductor properties of a multilayer filter containing PbTe (IV-VI) layer material in combination with the dielectric dispersion of ZnSe (II-VI) deposited on a CdTe (II-VI) substrate together with the use of BaF2 (II-VII) as an antireflection layer. Comparisons between the computed spectral performance of the model and spectral measurements from manufactured coatings over a wavelength range of 4-30µm and temperature range 300-200K are presented. Finally we present the results of the FTIR measurements of Photosystem II showing the improvement in signal to noise ratio of the measurement due to using the filter, together with a light induced FTIR difference spectrum of Photosystem II.

Occurrence of wide-band tracheids in Cactaceae: wood variation during Pilosocereus auriasetus development

Studies of wide-band tracheids (WBTs) have aroused the interest of researchers who have searched to understand their origin, function, and phylogenetic implications. The present research has the objective of studying the distribution of WBTs, together with anatomic aspects of vegetative organs in different stages of Pilosocereus aurisetus, in order to understand the occurrence of WBTs in columnar cacti. Transverse and longitudinal sections of the stem (apex, middle, and base) and the root were made. The epidermis was present in the photosynthetic stem, but was substituted by periderm which was already well established in the root. The differentiation of the cortex is visible in the middle of the stem, becoming homogeneous in the base. WBTs were observed in the base and middle of young stems (WBT monomorphic wood); common in stems of globular cacti. However, WBTs/ fibrous dimorphic wood was observed in the base of adult stems, a result of the cambial activity producing vessel elements and fibers. This wood polymorphism of the Cactaceae can be interpreted as cambial variation, a common character of Caryophyllales. Due to the small size of the plant, the presence of WBTs in the young stem may be related to water retention necessary for its development, rather than to physical support of the plant.

Wide-band tracheids (WBTs) of photosynthetic and non-photosynthetic stems in species of Cactaceae

ARRUDA, E. AND G. F. A. MELO-DE-PINNA (Departamento de Botanica, Instituto de Biociencias. Universidade de Sao Paulo, Rua do Matao, travessa 14, Cidade Universitaria, Butanta, Caixa Postal 11461, 05422-970. Sao Paulo, SP, Brasil). Wide-band tracheids (WBTs) of the photosynthetic and non-photosynthetic stems in species of Cactaceae. J. Torrey Bat. Soc. 137: 16-29. 2010.-The absence of WBTs and wood polymorphisms in some species of the Caryophyllales may be related to the particular area of plant analyzed. The present research has the objective of studying the photosynthetic and non-photosynthetic stems of different species and stages of differentiation to register wood polymorphisms and to understand the distribution and occurrence of WBTs. Wood polymorphism was observed in the non-photosynthetic stern of young and adult plants of Opuntioideae and Cactoideae and is also found in the photosynthetic stem of young plants of some species of Cactoideae. Cactoideae present WBT/fibrous dimorphic wood that can be related to cambial variation associated with growth habits and plant development. As expected, in the photosynthetic stem of the adult columnar cacti the wood is monomorphic fibrous in which WBTs were not found. This wood contains a great amount of fibers due to necessity of the mechanical support. In contrast, the globular species do not possess fibers in this area of the stem in either adult or young plants. Opuntia monacantha Haw. had non-fibrous wood in which WBTs were observed in the axial system and in the inner parts of the rays. Fiber clusters were present in the axial system. This wood represents a variation in the wood types described for Opuntioideae. Also, in O. monacantha, cells similar to the WBTs were observed in the pith, which can be interpreted as variation in the morphogenic processes during the ontogeny of the plant, probably a case of homeosis. Monomorphic fibrous wood without WBTs was found along the entire stem of Pereskia bahiensis Gurke. This feature has been observed in other pereskias, and in addition to the others, indicates its proximity to the ancestral cacti.

Design and simulation of a low voltage wide band RF MEMS switch

This paper presents design of an electrostatic wide band shunt capacitive coupling RF MEMS switch with low actuation voltage. The key factors of the RF MEMS switch design are the proper scattering parameters, low actuation voltage, and the cost of the fabrication process. An overview of the recent low actuation voltage RFMEMS switches has been presented. These designs still suffer from the complexity of process, lack of reliability, limitation of frequency band, and process cost. RF characteristics of a shunt RF MEMS switches are specified mostly by coupling capacitor in upstate position of the membrane Cu. This capacitor is in trade-off with actuation voltage. In this work, the capacitor is eliminated by using two short high impedance transmission lines, at the input and output of the switch. The simulation results demonstrate an improvement in the RF characteristic of the switch.

Low-Cost Ultra-Wide Genotyping Using Roche/454 Pyrosequencing for Surveillance of HIV Drug Resistance

Background: Great efforts have been made to increase accessibility of HIV antiretroviral therapy (ART) in low and middle-income countries. The threat of wide-scale emergence of drug resistance could severely hamper ART scale-up efforts. Population-based surveillance of transmitted HIV drug resistance ensures the use of appropriate first-line regimens to maximize efficacy of ART programs where drug options are limited. However, traditional HIV genotyping is extremely expensive, providing a cost barrier to wide-scale and frequent HIV drug resistance surveillance. Methods/Results: We have developed a low-cost laboratory-scale next-generation sequencing-based genotyping method to monitor drug resistance. We designed primers specifically to amplify protease and reverse transcriptase from Brazilian HIV subtypes and developed a multiplexing scheme using multiplex identifier tags to minimize cost while providing more robust data than traditional genotyping techniques. Using this approach, we characterized drug resistance from plasma in 81 HIV infected individuals collected in Sao Paulo, Brazil. We describe the complexities of analyzing next-generation sequencing data and present a simplified open-source workflow to analyze drug resistance data. From this data, we identified drug resistance mutations in 20% of treatment naive individuals in our cohort, which is similar to frequencies identified using traditional genotyping in Brazilian patient samples. Conclusion: The developed ultra-wide sequencing approach described here allows multiplexing of at least 48 patient samples per sequencing run, 4 times more than the current genotyping method. This method is also 4-fold more sensitive (5% minimal detection frequency vs. 20%) at a cost 3-5 x less than the traditional Sanger-based genotyping method. Lastly, by using a benchtop next-generation sequencer (Roche/454 GS Junior), this approach can be more easily implemented in low-resource settings. This data provides proof-of-concept that next-generation HIV drug resistance genotyping is a feasible and low-cost alternative to current genotyping methods and may be particularly beneficial for in-country surveillance of transmitted drug resistance.

Studio di geometrie di antenne su pcb per trasmissione wireless ultra-wideband

La presente tesi tratta la progettazione e la simulazione via software di geometrie di antenne da realizzare direttamente su Printed Circuit Board (PCB) per schede di trasmissione dati wireless Ultra Wide Band. L’obiettivo principale di questo studio è la realizzazione di un prototipo per impieghi biomedici umani (ad esempio trasmissione di dati provenienti da un ECG). Lo scopo del lavoro svolto è quello di trovare la miglior soluzione di integrazione per un’antenna il più possibile compatta da realizzare poi direttamente sul substrato dove verrà stampato il circuito del trasmettitore stesso. L’antenna verrà quindi realizzata esclusivamente attraverso microstrisce conduttrici (le medesime che formeranno i collegamenti tra i vari componenti del circuito) prendendo in considerazione le grandezze parassite di ogni conduttore, quali resistenza, induttanza, capacità ecc. In conclusione, il circuito di trasmissione wireless completo di antenna sopra descritto è attualmente in fase di realizzazione e nel prossimo futuro verrà testato in laboratorio.

Analog mitigation of out of band strong interferers in wide band acquisition for multiband HF transmissions

It is clear that in the near future much broader transmissions in the HF band will replace part of the current narrow band links. Our personal view is that a real wide band signal is infeasible in this environment because the usage is typically very intensive and may suffer interferences from all over the world. Therefore, we envision that dynamic multiband transmissions may provide better satisfactory performance. From the very beginning, we observed that real links with our broadband transceiver suffered interferences out of our multiband but within the acquisition bandwidth that degrade the expected performance. Therefore, we concluded that a mitigation structure is required that operates on severely saturated signals as the interference may be of much higher power. In this paper we address a procedure based on Higher Order Crossings (HOC) statistics that are able to extract most of the signal structure in the case where the amplitude is severely distorted and allows the estimation of the interference carrier frequency to command a variable notch filter that mitigates its effect in the analog domain.