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The light polarization properties provide relevant information about linear–optical media quality and condition. The Stokes–Mueller formalism is commonly used to represent the polarization properties of the incident light over sample tests. Currently, different Stokes Polarimeters are mainly defined by resolution, acquisition rate, and light to carry out accurate and fast measurements. This work presents the implementation of an automatic Stokes dynamic polarimeter to characterize non-biological and biological material samples. The proposed system is configured to work in the He-Ne laser beam’s reflection or transmission mode to calculate the Mueller matrix. The instrumentation stage includes two asynchronous photoelastic modulators, two nano-stepper motors, and an acquisition data card at 2% of accuracy. The Mueller matrix is numerically calculated by software using the 36 measures method without requiring image processing. Experiments show the efficiency of the proposed optical array to calculate the Mueller matrix in reflection and transmission mode for different samples. The mean squared error is calculated for each element of the obtained matrix using referenced values of the air and a mirror. A comparison with similar works in the literature validates the proposed optical array.

Fucus spiralis L. is a broadly distributed monoecious intertidal seaweed. The specific status of F. spiralis however is debatable. Here, we contribute to the bioinformatics and systematics of F. spiralis by analysing the complete mitochondrial and plastid genomes of a specimen from California, U.S.A. The F. spiralis mitogenome is 36,396 base pairs (bp) in length and contains 67 genes, and the plastid genome is 125,066 bp in length and contains 171 genes. The F. spiralis genomes are 99.7% and 99.8% similar in nucleotide sequence to F. vesiculosus, and support the revised classification of F. spiralis to Fucus vesiculosus var. spiralis.

In this paper, we describe the sensitivity and impedance measurement method for UHF RF identification (RFID) chips. The measurements are performed using an RFID tester (RFID reader with variable output power and frequency) and a vector network analyzer. No special impedance matching is required: chips can be connected to standard 50-Omega connectors allowing the sensitivity and threshold impedance to be measured directly in a fast and efficient way. We present experimental data for two UHF Gen2 chips (NXP UCODE G2XM and Impinj Monza 2) in thin-shrink small outline packages. The results have been verified using two chip assemblies matched to 50 Omega . This method can also be applied to chips in other packages: flip-chip, strap, etc.

Crack detection is existing structures using measured dynamic response information is presented in this paper. The general area of health assessment of existing structures in the presence of uncertainty in modeling the structure, characteristics of sensors, and the dynamic response information collected by the sensors is emphasized. A time domain system identification-based procedure is proposed to assess health of a structure at the finite element level in the presence of all major sources of uncertainty. It is denoted as the GILS-EKF-UI method. The method does not require information on excitation that caused the response and the noise-contaminated response information needs not be available at all dynamic degrees of freedom. The method is verified using computer generated analytical and actual measured response information emphasizing three items: (1) identification of the defect-free frame, (2) detection of location of a crack accurately within a defective element, and (3) detection of a crack using limited response information using the GILS-EKF-UI method.

We present for the first time, a fully integrated battery powered RFID integrated circuit (IC) for operation at ultrahigh frequency (UHF) and microwave bands. The battery powered RFID IC can also work as a passive RFID tag without a battery or when the battery has died (i.e., voltage has dropped below 1.3 V); this novel dual passive and battery operation allays one of the major drawbacks of currently available active tags, namely that the tag cannot be used once the battery has died. When powered by a battery, the current consumption is 700 nA at 1.5 V (400 nA if internal signals are not brought out on test pads). This ultra-low-power consumption permits the use of a very small capacity battery of 100 mA-hr for lifetimes exceeding ten years; as a result a battery tag that is very close to a passive tag both in form factor and cost is made possible. The chip is built on a 1-mum digital CMOS process with dual poly layers, EEPROM and Schottky diodes. The RF threshold power at 2.45 GHz is -19 dBm which is the lowest ever reported threshold power for RFID tags and has a range exceeding 3.5 m under FCC unlicensed operation at the 2.4-GHz microwave band. The low threshold is achieved with architectural choices and low-power circuit design techniques. At 915 MHz, based on the experimentally measured tag impedance (92-j837) and the threshold spec of the tag (200 mV), the theoretical minimum range is 24 m. The tag initially is in a "low-power" mode to conserve power and when issued the appropriate command, it operates in "full-power" mode. The chip has on-chip voltage regulators, clock and data recovery circuits, EEPROM and a digital state machine that implements the ISO 18000-4 B protocol in the "full-power" mode. We provide detailed explanation of the clock recovery circuits and the implementation of the binary sort algorithm, which includes a pseudorandom number generator. Other than the antenna board and a battery, no external components are used.

Kurokawa's method of calculating the power reflection coefficient from the Smith chart in the situation when one complex impedance is directly connected to another is applied to passive RFID tag design, where power reflection is important, as it determines the tag characteristics. The performance analysis of a specific RFID tag is presented together with experimental data, which is in close agreement with the theory.

A finite-element-based procedure is proposed to identify defects in existing structures and evaluate their extent at the local element level for the purpose of health assessment. The procedure is a time-domain system identification technique where input excitation is not required to identify a structure. It estimates the dynamic properties of a structure in terms of stiffness and damping at the element level in a finite-element representation. The method can be used to precisely locate a defective spot in an element. Although input excitation information is not required, examples are used to show that the algorithm is robust enough to identify a structure excited by different types of loading. Structures can be excited simultaneously by multiple loadings, and the response information can be noise-free or noise-contaminated. Defects can be small or relatively large. In all cases, the algorithm identified the structures correctly. The error in the identification is considerably smaller than that of other available methods where input excitation information is used to identify a structure. With the help of examples, it is shown that the algorithm can potentially be used as a nondestructive evaluation technique for health assessment of existing structures with minimum disruption of operations. Since the procedure is very simple and requires only a few seconds of response information, it is expected to be very economical and efficient.

A wireless fuel quantity indication system (FQIS) has been developed using an RFID-enabled sensing platform. The system comprises a fully passive tag, modified reader protocol, capacitive fuel probe, and auxiliary antenna for additional energy harvesting. Results of fluid testing show sensitivity to changes in fluid height of less than 0.25in. An RF-DC harvesting circuit was developed, which delivers up to 5dBm of input power through a remote radio frequency (RF) source. Testing was conducted in a loaded reverberation chamber to emulate the fuel tank environment. Results demonstrate feasibility of the remote source to power the sensor with less than 1W of maximum transmit power and under 100ms dwell time (100mW average power) into the tank. This indicates adequate coverage for large transport aircraft at safe operating levels with a sample rate of up to 1 sample/s.

An open-label study in 518 outpatients with major depression was performed by a collaborative group involving 105 psychiatrists in 22 cities in Mexico. The objectives of this study were to assess the tolerance and efficacy of venlafaxine, a new antidepressive drug, in outpatients in usual care settings. The two largest psychiatric medical associations approved the proposed protocol, and their chairmen coordinated the study. Patients had to comply with the diagnostic criteria for major depression as stated in the Diagnostic and Statistical Manual of Mental Disorders , 3rd edition, revised. The Hamilton Depression rating scale (21 items) and the Clinical Global Impressions (CGI) rating scale were used to assess a patient's clinical response to drug, which was prescribed in different doses (37.5 to 75 mg, 100 to 150 mg, and 175 to 300 mg) according to a patient's status at enrollment. Patients were followed for 6 weeks. A total of 435 patients (84%) completed the study. After 7 days of treatment with venlafaxine, there was a statistically significant improvement in patients with mild-to-moderate depression—those in the 37.5- to 75- mg group (mean CGI improvement, 3.8% to 38.2%) and in the 100- to 150-mg group (mean CGI improvement, 1.3% to 16.7%)—and by day 14 in patients with severe depression—those in the 175- to 300-mg group (mean CGI improvement at day 14, 1.8% to 20.0%). The efficacy of venlafaxine was assessed in all three groups by day 42, with statistically significant improvement observed after treatment with venlafaxine as compared with baseline. The adverse events most frequently associated with the use of venlafaxine were nausea (35.13%) and headache (17.95%), which did not differ in nature and intensity from that reported by other investigators. A total of 83 patients withdrew from the study; 50 of these dropped out due to an adverse event. Although the study design weakened the conclusions drawn from this study, in this 6-week, open-label, uncontrolled trial, venlafaxine appeared to be an efficacious, well-tolerated antidepressant in patients with major depression, with improvement generally detected in about 1 week.

Expressions for SO(4) invariant Euclidean QCD generating functionals are introduced which should produce nonvanishing gluon condensates. We consider first the loop expansion of the corresponding effectíve action searching for a description differing from the usual perturbation theory. At this level, we consider special free propagators which have off-diagonal long range order. The calculation of the polarization tensor leads to a gluon mass term which is proportional to the squared root of the finite value for 2>. The summation of all the one-loop contributions to the energy having only mass insertions, indicates the spontaneous generation of the condensate from the perturbative ground state in a way resembling the similar effect in the case of chromomagnetic field models.

In this paper, we describe a novel passive RFID system capable of direct tag-to-tag communication in the presence of external radio frequency field. Tags talk by modulating the external field and thus backscattering the commands to each other. We present the system concept and show its hardware implementation based on TI MSP430 microcontroller. We also provide the theoretical model for modulation depth vs. distance which agrees with experimental results (maximum tag-to-tag communication distance). Finally, we discuss possible applications and outline future work.

In this paper, we give an overview of spatial identification (determining position and velocity) of modulated backscatter UHF RFID tags using RF phase information. We describe three main techniques based on PDOA (Phase Difference of Arrival): TD (Time Domain), FD (Frequency Domain), and SD (Spatial Domain). The techniques are illustrated with modeling and simulation example in free space and in presence of multipath using a multi-ray channel model for amplitude and phase of the received tag signal in deterministic environment. We also present and discuss the experiments performed in a real RFID warehouse portal environment.

An innovative technique to assess structural health just after subjected to impulsive loadings (blasts, explosions, etc.) underdevelopment at the University of Arizona was experimentally verified and is presented in this paper. The authors called it the G eneralized I terative L east S quare E xtended K alman F ilter with U nknown I nput (GILS-EKF-UI) method. The system is represented by finite elements and a Kalman filter-based system identification (SI) technique is used to identify the system. Some of the major characteristics of the method are that it does not require information on input excitation and can identify a system with limited noise-contaminated response information measured at few node points. To implement the Kalman-filter based algorithm, the information on the input excitation and the initial state vector must be available. The authors proposed a two-stage approach. In the first stage, based on the limited measured response information available at the locations of the sensors, a substructure is identified. After the completion of the first stage, the input excitation information that caused the responses and the stiffness of all the elements in the substructure can be evaluated. Then, in stage 2, the Kalman-filter based algorithm is used to identify the whole structure. The experimental verification of the method is emphasized in this paper.Copyright © 2006 by ASME

One of the major problems facing RFID systems today is that of tags not being read, resulting in reduced tag identification rates. This is more likely to happen as large number of tags is present in a small enclosure. We examine one of the causes for missed tags, namely coupling between adjacent tags. We present a theoretical explanation for the cause of coupling between tags and the mechanism by which it causes tags not to be identified. The concept of using a volatile state storage cell is examined. We study how state storage helps to eliminate missed tags, using the ISO 18000-6B protocol as an illustrative example. Experimental results using chips that have state storage capability are presented and we compare identification rates with and without using state storage. It is seen that when state storage is used, all tags are identified and is vastly superior to tag identification without state storage. For the first time, we present results showing how indispensable the concept of state storage is for passive RFID operation. The concept is readily extended to any protocol for passive RFID operation.

A stacked antenna front-end for RFIDs is presented. Schottky diode based voltage doubler charge pumps are used on the front-end. The use of schottky diodes permits broadband operation for UHF (915MHz) as well as Microwave (2.45GHz). The entire chip has a low power EEPROM, digital state machine, clock recovery and data demodulation circuits; and the chip implements the ISO 18000-6B protocol for passive UHF (915MHz) operation. The chip is built on n-well, dual poly digital process with schottky diodes and EEPROM and comparisons are made between an unoptimized front-end built on 1um and an optimized front-end built on a 0.35 process. We provide a theoretical derivation for the superior orientational performance of a stacked antenna transponder as compared to a single antenna transponder. The tag front-end impedance is measured at UHF and Microwave bands for various powers and the threshold power for the tag is calculated. Based on the threshold power measured, the range of the tag is estimated and the omni-directional superiority of a stacked dipole is shown.

The differential radar cross-section (RCS) of an RFID tag is an important parameter which determines the power of the modulated backscattered tag signal. The vector differential RCS of an RFID tag as seen by the reader is analysed and, for the first time, compared with experimental results in UHF band.

Subsurface drainage systems are commonly installed in agricultural areas to remove the excess soil water. Knowledge of the position of the existing drainage network is often lacking. This complicates 1) the understanding of increased leaching and offsite release of nutrients and in turn the development of eutrophication mitigation strategies and 2) retrofitting the new drain lines within the existing drainage system to increase drainage efficiency. The conventional methods of drainage mapping include the use of tile probe and trenching equipment, which are invasive, laborious and often inefficient to apply at large spatial scales. Recent technological developments in non-destructive techniques (NDT) provide a potential alternative solution. In this study, we explore the suitability of unmanned aerial vehicle (UAV) imagery collected using three different cameras (visible-color, multispectral and thermal infrared) and a ground penetrating radar (GPR) for subsurface drainage mapping. Both these techniques are complementary in terms of their usage, applicability and the properties they measure. While UAV imagery is useful in measuring surface soil and plant properties and the flights can cover large areas in limited time, the GPR works the best to understand subsurface variation in soil electrical properties and is comparatively hard to employ across large areas. Both these techniques were applied at three different sites near Mount Gilead, OH; Clayton, MI and Palmyra, MI in the Midwest U.S. At the Mount Gilead site, it was possible to delineate the location of drainage pipes using both the UAV imagery and GPR, hence, providing a suitable validation technique and depth information. At the Clayton site, while UAV imagery was successful on the western part of the field, GPR proved to be useful in the eastern part where the UAV imagery failed to capture the drainage pipe locations. At the Palmyra site, less to no success was observed in finding the drain lines using UAV imagery, while good success was achieved using the GPR. Although UAV imagery seems to be an attractive solution for mapping subsurface drainage systems as it is cost-effective and can cover large field areas, the results suggest the usefulness of GPR to complement the UAV imagery as both a mapping and validation technique. Future research focuses on understanding the dependence of the UAV imagery and GPR on the soil type, crop residue, tillage practice, ground wetness level and rainfall event prior to the surveys with the aim of developing guidelines in relation to the choice of sensor for subsurface drainage mapping.