Eight new state records of aleyrodine whiteflies found in Clark County, Nevada and three newly described taxa (Hemiptera: Aleyrodidae, Aleyrodinae)

Eight new state records and the three newly described species are the subject of this publication. Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae: Aleyrodinae) were collected from 2003 through 2009 within the Las Vegas area of Clark County, Nevada to determine the occurrence of newly established species and host range and distribution. Prior to 2003 the following ten whiteflies were known to be established in Nevada: Aleuroglandulus subtilis Bondar, Aleuroplatus berbericolus Quaintance and Baker, Aleyrodes spiraeoides Quaintance, Bemisia tabaci (Gennadius), Dialeurodes citri (Ashmead), Siphoninus phillyreae (Haliday), Tetraleurodes mori (Quaintance), Trialeurodes abutiloneus (Haldeman), Trialeurodes packardi (Morrill), and Trialeurodes vaporariorum (Westwood). Based on collections made after 2003, eleven additional whitefly species were found in Nevada. Of these the following eight were described species from California and other western U.S. states: Aleuroparadoxus arctostaphyli Russell, Aleuroplatus gelatinosus (Cockerell), Aleuropleurocelus ceanothi (Sampson), Aleuropleurocelus nigrans (Bemis), Tetraleurodes quercicola Nakahara, Trialeurodes corollis (Penny), Trialeurodes eriodictyonis Russell, and Trialeurodes glacialis (Bemis). Three new species are described and illustrated: Aleuropleurocelus nevadensis Dooley sp. nov., Tetraleurodes quercophyllae Dooley sp. nov., and Trialeurodes pseudoblongifoliae Dooley sp. nov

Macroscale multimodal imaging reveals ancient painting production technology and the vogue in Greco-Roman Egypt.

Macroscale multimodal chemical imaging combining hyperspectral diffuse reflectance (400-2500 nm), luminescence (400-1000 nm), and X-ray fluorescence (XRF, 2 to 25 keV) data, is uniquely equipped for noninvasive characterization of heterogeneous complex systems such as paintings. Here we present the first application of multimodal chemical imaging to analyze the production technology of an 1,800-year-old painting and one of the oldest surviving encaustic ("burned in") paintings in the world. Co-registration of the data cubes from these three hyperspectral imaging modalities enabled the comparison of reflectance, luminescence, and XRF spectra at each pixel in the image for the entire painting. By comparing the molecular and elemental spectral signatures at each pixel, this fusion of the data allowed for a more thorough identification and mapping of the painting's constituent organic and inorganic materials, revealing key information on the selection of raw materials, production sequence and the fashion aesthetics and chemical arts practiced in Egypt in the second century AD

A Practical Class S Power Amplifier for High Frequency Transmitters

Digital signal processing (DSP) techniques are being incorporated in the design of modern power amplifiers (PA) and as the speed of DSP advances it is envisioned that DSP will develop to a point where algorithms will provide signals at RF particularly for switching amplifiers. The digital transmitter has many potential benefits such as the absence of aging or tuning problems, reconfigurability, programmability as well as ease of integration and testing. In this paper a new class S RF power amplifier architecture is proposed for use in high frequency transmitters and is not restricted by the requirement for the square wave modulator to have a sampling rate of 4 times the carrier frequency

Whitefly fauna of Clark County, Nevada.

The research presented here documents the whitefly fauna within the Las Vegas area in Clark County, Nevada, with information on the geology, host and plant communities in the area where the whiteflies were collected. Only specimens of the immature fourth stage (puparium) were observed and collected at Red Rock Canyon, Mount Charleston, and the Mojave Desert surrounding Las Vegas

Scintillation counters for slow neutrons

The suitability of boric oxide glass containing phosphorescent materials for use as scintillation counters for slow neutrons is investigated both theoretically and experimentally. A theory is developed which can be used for predicting counting efficiencies of the phosphor disks given optical data and neutron absorption properties of the materials present, and physical details of the experimental arrangement. This is compared to experiment in one case with good agreement. It is shown that there are serious practical difficulties in the use of a boric glass phosphor as a slow neutron detector

Efforts Towards a Validated Time-Domain Model of an Oscillating Water Column with Control Components

As part of the development process of a proposed offshore floating wind/wave platform, a scale-model testing programme has been carried out at a narrow tank facility on a single oscillating water column (OWC) device. Previous proof-ofconcept testing was performed on a scale model of the proposed platform comprising thirty-two OWCs with control components. That testing programme, implemented at the Hydraulic and Maritime Research Centre, demonstrated the feasibility of the concept. However, the large number of interacting components in this complex system results in difficulties when attempting to study and model numerically the hydrodynamic and thermodynamic processes at work within the OWCs during operation. In order to better study these processes, the subsequent phase of narrow tank testing was planned based on a single-chamber OWC model as described herein. This model was constructed with similar dimensions and cross-sectional profile to that of one OWC chamber in the larger model. Various control components can be added to and removed from the new model to investigate in a systematic fashion the effect of each component. Theory to numerically model the OWC in various configurations has been developed. A comparison between the tank test results and those obtained for a specific setup is presented

Improved Coding-Efficiency Two-Level Source Encoder for RF Switch-Mode Power Amplifiers

A ΣΔ-driven RF switch-mode power amplifier is inherently linear only when it has a two-level output. At the same time, a two-level output generates the largest amount of quantization noise. This brief analyzes the effect of nonequal level spacing in a three-level ΣΔ output and provides a method for shaping the corresponding error noise to regions outside the band of interest. Subsequently, the nonlinearity-shaping property is utilized to obtain an improved two-level drive signal based on three-levelΣΔmodulation. The new binary drive signal is proven to have better adjacent channel leakage ratio and higher coding efficiency than a conventional two-level ΣΔ modulator. In the investigated case, measured coding efficiency improves from 8.9% of the conventional two-level modulator to 21% of the modified two-level modulator

Utilizing Sparse-Aware Volterra for Power Amplifier Behavioral Modeling

This paper presents a method for reducing the number of weights in a time series behavioral model for a power amplifier. The least-absolute shrinkage and selection operator (Lasso) algorithm is used to reduce the kernel size, preserving the important kernels, while eliminating the less important kernels. The algorithm is evaluated on a behavioral model for a class AB amplifier, the algorithm reduces the number of weights by greater than 70% without degrading model performance by a significant amount