Frequency domain FIR and IIR adaptive filters

NASA Technical Reports Server (NTRS)

Lynn, D. W.

1990-01-01

A discussion of the LMS adaptive filter relating to its convergence characteristics and the problems associated with disparate eigenvalues is presented. This is used to introduce the concept of proportional convergence. An approach is used to analyze the convergence characteristics of block frequency-domain adaptive filters. This leads to a development showing how the frequency-domain FIR adaptive filter is easily modified to provide proportional convergence. These ideas are extended to a block frequency-domain IIR adaptive filter and the idea of proportional convergence is applied. Experimental results illustrating proportional convergence in both FIR and IIR frequency-domain block adaptive filters is presented.

Boundary implications for frequency response of interval FIR and IIR filters

NASA Technical Reports Server (NTRS)

Bose, N. K.; Kim, K. D.

1991-01-01

It is shown that vertex implication results in parameter space apply to interval trigonometric polynomials. Subsequently, it is shown that the frequency responses of both interval FIR and IIR filters are bounded by the frequency responses of certain extreme filters. The results apply directly in the evaluation of properties of designed filters, especially because it is more realistic to bound the filter coefficients from above and below instead of determining those with infinite precision because of finite arithmetic effects. Illustrative examples are provided to show how the extreme filters might be easily derived in any specific interval FIR or IIR filter design problem.

Optimal design of a bank of spatio-temporal filters for EEG signal classification.

PubMed

Higashi, Hiroshi; Tanaka, Toshihisa

2011-01-01

The spatial weights for electrodes called common spatial pattern (CSP) are known to be effective in EEG signal classification for motor imagery based brain computer interfaces (MI-BCI). To achieve accurate classification in CSP, the frequency filter should be properly designed. To this end, several methods for designing the filter have been proposed. However, the existing methods cannot consider plural brain activities described with different frequency bands and different spatial patterns such as activities of mu and beta rhythms. In order to efficiently extract these brain activities, we propose a method to design plural filters and spatial weights which extract desired brain activity. The proposed method designs finite impulse response (FIR) filters and the associated spatial weights by optimization of an objective function which is a natural extension of CSP. Moreover, we show by a classification experiment that the bank of FIR filters which are designed by introducing an orthogonality into the objective function can extract good discriminative features. Moreover, the experiment result suggests that the proposed method can automatically detect and extract brain activities related to motor imagery.

Systolic Signal Processor/High Frequency Direction Finding

DTIC Science & Technology

1990-10-01

MUSIC ) algorithm and the finite impulse response (FIR) filter onto the testbed hardware was supported by joint sponsorship of the block and major bid...computational throughput. The systolic implementations of a four-channel finite impulse response (FIR) filter and multiple signal classification ( MUSIC ... MUSIC ) algorithm was mated to a bank of finite impulse response (FIR) filters and a four-channel data acquisition subsystem. A complete description

Optimal design of FIR triplet halfband filter bank and application in image coding.

PubMed

Kha, H H; Tuan, H D; Nguyen, T Q

2011-02-01

This correspondence proposes an efficient semidefinite programming (SDP) method for the design of a class of linear phase finite impulse response triplet halfband filter banks whose filters have optimal frequency selectivity for a prescribed regularity order. The design problem is formulated as the minimization of the least square error subject to peak error constraints and regularity constraints. By using the linear matrix inequality characterization of the trigonometric semi-infinite constraints, it can then be exactly cast as a SDP problem with a small number of variables and, hence, can be solved efficiently. Several design examples of the triplet halfband filter bank are provided for illustration and comparison with previous works. Finally, the image coding performance of the filter bank is presented.

Implementation of real-time digital signal processing systems

NASA Technical Reports Server (NTRS)

Narasimha, M.; Peterson, A.; Narayan, S.

1978-01-01

Special purpose hardware implementation of DFT Computers and digital filters is considered in the light of newly introduced algorithms and IC devices. Recent work by Winograd on high-speed convolution techniques for computing short length DFT's, has motivated the development of more efficient algorithms, compared to the FFT, for evaluating the transform of longer sequences. Among these, prime factor algorithms appear suitable for special purpose hardware implementations. Architectural considerations in designing DFT computers based on these algorithms are discussed. With the availability of monolithic multiplier-accumulators, a direct implementation of IIR and FIR filters, using random access memories in place of shift registers, appears attractive. The memory addressing scheme involved in such implementations is discussed. A simple counter set-up to address the data memory in the realization of FIR filters is also described. The combination of a set of simple filters (weighting network) and a DFT computer is shown to realize a bank of uniform bandpass filters. The usefulness of this concept in arriving at a modular design for a million channel spectrum analyzer, based on microprocessors, is discussed.

Integrating the ECG power-line interference removal methods with rule-based system.

PubMed

Kumaravel, N; Senthil, A; Sridhar, K S; Nithiyanandam, N

1995-01-01

The power-line frequency interference in electrocardiographic signals is eliminated to enhance the signal characteristics for diagnosis. The power-line frequency normally varies +/- 1.5 Hz from its standard value of 50 Hz. In the present work, the performances of the linear FIR filter, Wave digital filter (WDF) and adaptive filter for the power-line frequency variations from 48.5 to 51.5 Hz in steps of 0.5 Hz are studied. The advantage of the LMS adaptive filter in the removal of power-line frequency interference even if the frequency of interference varies by +/- 1.5 Hz from its normal value of 50 Hz over other fixed frequency filters is very well justified. A novel method of integrating rule-based system approach with linear FIR filter and also with Wave digital filter are proposed. The performances of Rule-based FIR filter and Rule-based Wave digital filter are compared with the LMS adaptive filter.

Novel programmable microwave photonic filter with arbitrary filtering shape and linear phase.

PubMed

Zhu, Xiaoqi; Chen, Feiya; Peng, Huanfa; Chen, Zhangyuan

2017-04-17

We propose and demonstrate a novel optical frequency comb (OFC) based microwave photonic filter which is able to realize arbitrary filtering shape with linear phase response. The shape of filter response is software programmable using finite impulse response (FIR) filter design method. By shaping the OFC spectrum using a programmable waveshaper, we can realize designed amplitude of FIR taps. Positive and negative sign of FIR taps are achieved by balanced photo-detection. The double sideband (DSB) modulation and symmetric distribution of filter taps are used to maintain the linear phase condition. In the experiment, we realize a fully programmable filter in the range from DC to 13.88 GHz. Four basic types of filters (lowpass, highpass, bandpass and bandstop) with different bandwidths, cut-off frequencies and central frequencies are generated. Also a triple-passband filter is realized in our experiment. To the best of our knowledge, it is the first demonstration of a programmable multiple passband MPF with linear phase response. The experiment shows good agreement with the theoretical result.

High-speed spectral calibration by complex FIR filter in phase-sensitive optical coherence tomography.

PubMed

Kim, Sangmin; Raphael, Patrick D; Oghalai, John S; Applegate, Brian E

2016-04-01

Swept-laser sources offer a number of advantages for Phase-sensitive Optical Coherence Tomography (PhOCT). However, inter- and intra-sweep variability leads to calibration errors that adversely affect phase sensitivity. While there are several approaches to overcoming this problem, our preferred method is to simply calibrate every sweep of the laser. This approach offers high accuracy and phase stability at the expense of a substantial processing burden. In this approach, the Hilbert phase of the interferogram from a reference interferometer provides the instantaneous wavenumber of the laser, but is computationally expensive. Fortunately, the Hilbert transform may be approximated by a Finite Impulse-Response (FIR) filter. Here we explore the use of several FIR filter based Hilbert transforms for calibration, explicitly considering the impact of filter choice on phase sensitivity and OCT image quality. Our results indicate that the complex FIR filter approach is the most robust and accurate among those considered. It provides similar image quality and slightly better phase sensitivity than the traditional FFT-IFFT based Hilbert transform while consuming fewer resources in an FPGA implementation. We also explored utilizing the Hilbert magnitude of the reference interferogram to calculate an ideal window function for spectral amplitude calibration. The ideal window function is designed to carefully control sidelobes on the axial point spread function. We found that after a simple chromatic correction, calculating the window function using the complex FIR filter and the reference interferometer gave similar results to window functions calculated using a mirror sample and the FFT-IFFT Hilbert transform. Hence, the complex FIR filter can enable accurate and high-speed calibration of the magnitude and phase of spectral interferograms.

High-speed spectral calibration by complex FIR filter in phase-sensitive optical coherence tomography

PubMed Central

Kim, Sangmin; Raphael, Patrick D.; Oghalai, John S.; Applegate, Brian E.

2016-01-01

Swept-laser sources offer a number of advantages for Phase-sensitive Optical Coherence Tomography (PhOCT). However, inter- and intra-sweep variability leads to calibration errors that adversely affect phase sensitivity. While there are several approaches to overcoming this problem, our preferred method is to simply calibrate every sweep of the laser. This approach offers high accuracy and phase stability at the expense of a substantial processing burden. In this approach, the Hilbert phase of the interferogram from a reference interferometer provides the instantaneous wavenumber of the laser, but is computationally expensive. Fortunately, the Hilbert transform may be approximated by a Finite Impulse-Response (FIR) filter. Here we explore the use of several FIR filter based Hilbert transforms for calibration, explicitly considering the impact of filter choice on phase sensitivity and OCT image quality. Our results indicate that the complex FIR filter approach is the most robust and accurate among those considered. It provides similar image quality and slightly better phase sensitivity than the traditional FFT-IFFT based Hilbert transform while consuming fewer resources in an FPGA implementation. We also explored utilizing the Hilbert magnitude of the reference interferogram to calculate an ideal window function for spectral amplitude calibration. The ideal window function is designed to carefully control sidelobes on the axial point spread function. We found that after a simple chromatic correction, calculating the window function using the complex FIR filter and the reference interferometer gave similar results to window functions calculated using a mirror sample and the FFT-IFFT Hilbert transform. Hence, the complex FIR filter can enable accurate and high-speed calibration of the magnitude and phase of spectral interferograms. PMID:27446666

The synergy between complex channel-specific FIR filter and spatial filter for single-trial EEG classification.

PubMed

Yu, Ke; Wang, Yue; Shen, Kaiquan; Li, Xiaoping

2013-01-01

The common spatial pattern analysis (CSP), a frequently utilized feature extraction method in brain-computer-interface applications, is believed to be time-invariant and sensitive to noises, mainly due to an inherent shortcoming of purely relying on spatial filtering. Therefore, temporal/spectral filtering which can be very effective to counteract the unfavorable influence of noises is usually used as a supplement. This work integrates the CSP spatial filters with complex channel-specific finite impulse response (FIR) filters in a natural and intuitive manner. Each hybrid spatial-FIR filter is of high-order, data-driven and is unique to its corresponding channel. They are derived by introducing multiple time delays and regularization into conventional CSP. The general framework of the method follows that of CSP but performs better, as proven in single-trial classification tasks like event-related potential detection and motor imagery.

Low-cost space-varying FIR filter architecture for computational imaging systems

NASA Astrophysics Data System (ADS)

Feng, Guotong; Shoaib, Mohammed; Schwartz, Edward L.; Dirk Robinson, M.

2010-01-01

Recent research demonstrates the advantage of designing electro-optical imaging systems by jointly optimizing the optical and digital subsystems. The optical systems designed using this joint approach intentionally introduce large and often space-varying optical aberrations that produce blurry optical images. Digital sharpening restores reduced contrast due to these intentional optical aberrations. Computational imaging systems designed in this fashion have several advantages including extended depth-of-field, lower system costs, and improved low-light performance. Currently, most consumer imaging systems lack the necessary computational resources to compensate for these optical systems with large aberrations in the digital processor. Hence, the exploitation of the advantages of the jointly designed computational imaging system requires low-complexity algorithms enabling space-varying sharpening. In this paper, we describe a low-cost algorithmic framework and associated hardware enabling the space-varying finite impulse response (FIR) sharpening required to restore largely aberrated optical images. Our framework leverages the space-varying properties of optical images formed using rotationally-symmetric optical lens elements. First, we describe an approach to leverage the rotational symmetry of the point spread function (PSF) about the optical axis allowing computational savings. Second, we employ a specially designed bank of sharpening filters tuned to the specific radial variation common to optical aberrations. We evaluate the computational efficiency and image quality achieved by using this low-cost space-varying FIR filter architecture.

Suppression of ITI by array head reading and 2D-equalization

NASA Astrophysics Data System (ADS)

Nakamura, Y.; Suzuto, R.; Osawa, H.; Okamoto, Y.; Kanai, Y.; Muraoka, H.

2017-05-01

Two-dimensional magnetic recording (TDMR) by shingled magnetic recording (SMR) draws attention as a next generation technology to increase the recording density in hard disk drive (HDD). It is shown that the two-dimensional finite impulse response (2D-FIR) filter provides gain the reproducing waveforms from an array head with 3 readers in the TDMR under a specification of 4 Tbit/inch.2 We evaluate the effect of the intertrack interference (ITI) reduction by 2D-FIR using the correlation between the real FIR filter output and the partial response class-I (PR1) signal corresponding to recording sequence by the computer simulation. The results show that the 2D-FIR filter is effective to mitigate ITI and improves the signal-to-noise ratio at the discriminate point by about 0.6 dB.

Comparison between hybrid feedforward-feedback, feedforward, and feedback structures for active noise control of fMRI noise.

PubMed

Reddy, Rajiv M; Panahi, Issa M S

2008-01-01

The performance of FIR feedforward, IIR feedforward, FIR feedback, hybrid FIR feedforward--FIR feedback, and hybrid IIR feedforward - FIR feedback structures for active noise control (ANC) are compared for an fMRI noise application. The filtered-input normalized least squares (FxNLMS) algorithm is used to update the coefficients of the adaptive filters in all these structures. Realistic primary and secondary paths of an fMRI bore are used by estimating them on a half cylindrical acrylic bore of 0.76 m (D)x1.52 m (L). Detailed results of the performance of the ANC system are presented in the paper for each of these structures. We find that the IIR feedforward structure produces most of the performance improvement in the hybrid IIR feedforward - FIR feedback structure and adding the feedback structure becomes almost redundant in the case of fMRI noise.

Optimized FPGA Implementation of Multi-Rate FIR Filters Through Thread Decomposition

NASA Technical Reports Server (NTRS)

Kobayashi, Kayla N.; He, Yutao; Zheng, Jason X.

2011-01-01

Multi-rate finite impulse response (MRFIR) filters are among the essential signal-processing components in spaceborne instruments where finite impulse response filters are often used to minimize nonlinear group delay and finite precision effects. Cascaded (multistage) designs of MRFIR filters are further used for large rate change ratio in order to lower the required throughput, while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original filter structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this innovation, an alternative representation and implementation technique called TD-MRFIR (Thread Decomposition MRFIR) is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original filter as done in the polyphase decomposition. A naive implementation of a decimation filter consisting of a full FIR followed by a downsampling stage is very inefficient, as most of the computations performed by the FIR state are discarded through downsampling. In fact, only 1/M of the total computations are useful (M being the decimation factor). Polyphase decomposition provides an alternative view of decimation filters, where the downsampling occurs before the FIR stage, and the outputs are viewed as the sum of M sub-filters with length of N/M taps. Although this approach leads to more efficient filter designs, in general the implementation is not straightforward if the numbers of multipliers need to be minimized. In TD-MRFIR, each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The filter is thus viewed as a finite collection of concurrent threads. Each of the threads completes when a convolution result (filter output value) is computed, and activated when the first input of the convolution becomes available. Thus, the new threads get spawned at exactly the rate of N/M, where N is the total number of taps, and M is the decimation factor. Existing threads retire at the same rate of N/M. The implementation of an MRFIR is thus transformed into a problem to statically schedule the minimum number of multipliers such that all threads can be completed on time. Solving the static scheduling problem is rather straightforward if one examines the Thread Decomposition Diagram, which is a table-like diagram that has rows representing computation threads and columns representing time. The control logic of the MRFIR can be implemented using simple counters. Instead of decomposing MRFIRs into subfilters as suggested by polyphase decomposition, the thread decomposition diagrams transform the problem into a familiar one of static scheduling, which can be easily solved as the input rate is constant.

Dichroic filters to protect milliwatt far-infrared detectors from megawatt ECRH radiation.

PubMed

Bertschinger, G; Endres, C P; Lewen, F; Oosterbeek, J W

2008-10-01

Dichroic filters have been used to shield effectively the far infrared (FIR) detectors at the interferometer/polarimeter on TEXTOR. The filters consist of metal foils with regular holes, the hole diameter, the mutual spacing and the thickness of the foils are chosen to transmit radiation at the design frequency with transmission >90%. The attenuation at the low frequency end of the bandpass filter is about 30 dB per octave, the high frequency transmission is between 20% and 40%. The filters have been used to block the stray radiation from the megawatt microwave heating beam to the detectors of the FIR interferometer, operating with power on the detector in the milliwatt range. If required, the low frequency attenuation can be still enhanced, without compromising the transmission in the passband. The FIR interferometer used for plasma density and position control is no longer disturbed by electromagnetic waves used for plasma heating.

Optimized FPGA Implementation of Multi-Rate FIR Filters Through Thread Decomposition

NASA Technical Reports Server (NTRS)

Zheng, Jason Xin; Nguyen, Kayla; He, Yutao

2010-01-01

Multirate (decimation/interpolation) filters are among the essential signal processing components in spaceborne instruments where Finite Impulse Response (FIR) filters are often used to minimize nonlinear group delay and finite-precision effects. Cascaded (multi-stage) designs of Multi-Rate FIR (MRFIR) filters are further used for large rate change ratio, in order to lower the required throughput while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original filter structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this paper, an alternative representation and implementation technique, called TD-MRFIR (Thread Decomposition MRFIR), is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original filter as done in the polyphase decomposition. Each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The filter is thus viewed as a finite collection of concurrent threads. The technical details of TD-MRFIR will be explained, first showing its applicability to the implementation of downsampling, upsampling, and resampling FIR filters, and then describing a general strategy to optimally allocate the number of filter taps. A particular FPGA design of multi-stage TD-MRFIR for the L-band radar of NASA's SMAP (Soil Moisture Active Passive) instrument is demonstrated; and its implementation results in several targeted FPGA devices are summarized in terms of the functional (bit width, fixed-point error) and performance (time closure, resource usage, and power estimation) parameters.

Fine-scale structure in the far-infrared Milky-Way

NASA Technical Reports Server (NTRS)

Waller, William H.; Wall, William F.; Reach, William T.; Varosi, Frank; Ebert, Rick; Laughlin, Gaylin; Boulanger, Francois

1995-01-01

This final report summarizes the work performed and which falls into five broad categories: (1) generation of a new data product (mosaics of the far-infrared emission in the Milky Way); (2) acquisition of associated data products at other wavelengths; (3) spatial filtering of the far-infrared mosaics and resulting images of the FIR fine-scale structure; (4) evaluation of the spatially filtered data; (5) characterization of the FIR fine-scale structure in terms of its spatial statistics; and (6) identification of interstellar counterparts to the FIR fine-scale structure.

Implementation of an FIR Band Pass Filter Using a Bit-Slice Processor.

DTIC Science & Technology

1987-06-01

R14 S IMPLEMENTATION OF AN FIR BND PASS FILTER USING A 1 /2 S" IT-SLICE PROCESSOR(U) NAVAL POSTGRADUATE SCOOL N UTEREY CA D W PURDY JUN 97...WILRSIFIED F/I 12/6mmhhmmhhmhhhhl EIIIIIIEIIIII IIIIIIEEIIIEI IIIIIIIIIIIIIl IIIIIIIIIIIIIu EIIIIIIIIIIIII - U󈧖 ~1I.25 1 .41.6 -qwr- -qw qw wV vw- .W sw...Ae 10 .w w ’ 1 - w* lo % % q* NAVAL POSTGRADUATE SCHOOL 0 Monterey, California 0 oi a ’: L t ",, I-’ ; OCT 0 �." THESIS IMPLEMENTATION OF AN FIR

A floating-point digital receiver for MRI.

PubMed

Hoenninger, John C; Crooks, Lawrence E; Arakawa, Mitsuaki

2002-07-01

A magnetic resonance imaging (MRI) system requires the highest possible signal fidelity and stability for clinical applications. Quadrature analog receivers have problems with channel matching, dc offset and analog-to-digital linearity. Fixed-point digital receivers (DRs) reduce all of these problems. We have demonstrated that a floating-point DR using large (order 124 to 512) FIR low-pass filters also overcomes these problems, automatically provides long word length and has low latency between signals. A preloaded table of finite impuls response (FIR) filter coefficients provides fast switching between one of 129 different one-stage and two-stage multrate FIR low-pass filters with bandwidths between 4 KHz and 125 KHz. This design has been implemented on a dual channel circuit board for a commercial MRI system.

Active field control (AFC) -electro-acoustic enhancement system using acoustical feedback control

NASA Astrophysics Data System (ADS)

Miyazaki, Hideo; Watanabe, Takayuki; Kishinaga, Shinji; Kawakami, Fukushi

2003-10-01

AFC is an electro-acoustic enhancement system using FIR filters to optimize auditory impressions, such as liveness, loudness, and spaciousness. This system has been under development at Yamaha Corporation for more than 15 years and has been installed in approximately 50 venues in Japan to date. AFC utilizes feedback control techniques for recreation of reverberation from the physical reverberation of the room. In order to prevent coloration problems caused by a closed loop condition, two types of time-varying control techniques are implemented in the AFC system to ensure smooth loop gain and a sufficient margin in frequency characteristics to prevent instability. Those are: (a) EMR (electric microphone rotator) -smoothing frequency responses between microphones and speakers by changing the combinations of inputs and outputs periodically; (b) fluctuating-FIR -smoothing frequency responses of FIR filters and preventing coloration problems caused by fixed FIR filters, by moving each FIR tap periodically on time axis with a different phase and time period. In this paper, these techniques are summarized. A block diagram of AFC using new equipment named AFC1, which has been developed at Yamaha Corporation and released recently in the US, is also presented.

Iterative design of one- and two-dimensional FIR digital filters. [Finite duration Impulse Response

NASA Technical Reports Server (NTRS)

Suk, M.; Choi, K.; Algazi, V. R.

1976-01-01

The paper describes a new iterative technique for designing FIR (finite duration impulse response) digital filters using a frequency weighted least squares approximation. The technique is as easy to implement (via FFT) and as effective in two dimensions as in one dimension, and there are virtually no limitations on the class of filter frequency spectra approximated. An adaptive adjustment of the frequency weight to achieve other types of design approximation such as Chebyshev type design is discussed.

Perfect blind restoration of images blurred by multiple filters: theory and efficient algorithms.

PubMed

Harikumar, G; Bresler, Y

1999-01-01

We address the problem of restoring an image from its noisy convolutions with two or more unknown finite impulse response (FIR) filters. We develop theoretical results about the existence and uniqueness of solutions, and show that under some generically true assumptions, both the filters and the image can be determined exactly in the absence of noise, and stably estimated in its presence. We present efficient algorithms to estimate the blur functions and their sizes. These algorithms are of two types, subspace-based and likelihood-based, and are extensions of techniques proposed for the solution of the multichannel blind deconvolution problem in one dimension. We present memory and computation-efficient techniques to handle the very large matrices arising in the two-dimensional (2-D) case. Once the blur functions are determined, they are used in a multichannel deconvolution step to reconstruct the unknown image. The theoretical and practical implications of edge effects, and "weakly exciting" images are examined. Finally, the algorithms are demonstrated on synthetic and real data.

Adaptive filtering with the self-organizing map: a performance comparison.

PubMed

Barreto, Guilherme A; Souza, Luís Gustavo M

2006-01-01

In this paper we provide an in-depth evaluation of the SOM as a feasible tool for nonlinear adaptive filtering. A comprehensive survey of existing SOM-based and related architectures for learning input-output mappings is carried out and the application of these architectures to nonlinear adaptive filtering is formulated. Then, we introduce two simple procedures for building RBF-based nonlinear filters using the Vector-Quantized Temporal Associative Memory (VQTAM), a recently proposed method for learning dynamical input-output mappings using the SOM. The aforementioned SOM-based adaptive filters are compared with standard FIR/LMS and FIR/LMS-Newton linear transversal filters, as well as with powerful MLP-based filters in nonlinear channel equalization and inverse modeling tasks. The obtained results in both tasks indicate that SOM-based filters can consistently outperform powerful MLP-based ones.

Robust adaptive extended Kalman filtering for real time MR-thermometry guided HIFU interventions.

PubMed

Roujol, Sébastien; de Senneville, Baudouin Denis; Hey, Silke; Moonen, Chrit; Ries, Mario

2012-03-01

Real time magnetic resonance (MR) thermometry is gaining clinical importance for monitoring and guiding high intensity focused ultrasound (HIFU) ablations of tumorous tissue. The temperature information can be employed to adjust the position and the power of the HIFU system in real time and to determine the therapy endpoint. The requirement to resolve both physiological motion of mobile organs and the rapid temperature variations induced by state-of-the-art high-power HIFU systems require fast MRI-acquisition schemes, which are generally hampered by low signal-to-noise ratios (SNRs). This directly limits the precision of real time MR-thermometry and thus in many cases the feasibility of sophisticated control algorithms. To overcome these limitations, temporal filtering of the temperature has been suggested in the past, which has generally an adverse impact on the accuracy and latency of the filtered data. Here, we propose a novel filter that aims to improve the precision of MR-thermometry while monitoring and adapting its impact on the accuracy. For this, an adaptive extended Kalman filter using a model describing the heat transfer for acoustic heating in biological tissues was employed together with an additional outlier rejection to address the problem of sparse artifacted temperature points. The filter was compared to an efficient matched FIR filter and outperformed the latter in all tested cases. The filter was first evaluated on simulated data and provided in the worst case (with an approximate configuration of the model) a substantial improvement of the accuracy by a factor 3 and 15 during heat up and cool down periods, respectively. The robustness of the filter was then evaluated during HIFU experiments on a phantom and in vivo in porcine kidney. The presence of strong temperature artifacts did not affect the thermal dose measurement using our filter whereas a high measurement variation of 70% was observed with the FIR filter.

A new method for fabrication of diamond-dust blocking filters

NASA Technical Reports Server (NTRS)

Collard, H. R.; Hogan, R. C.

1986-01-01

Thermal embedding of diamond dust onto a polyethylene-coated Al plate has been used to make a blocking filter for FIR applications. The Al plate is sandwiched between two Mylar 'blankets' and the air between the layers is removed by means of a small vacuum pump. After the polyethylene is heated and softened, the diamond dust is applied to the polyethylene coating using a brush. The optimum diamond dust grain sizes corresponding to polyethylene layer thicknesses of 9-12 microns are given in a table, and the application of the blocking filter to spectrometric measurements in the FIR is described. An exploded view diagram of the layered structure of the blocking filter is provided.

FIR filters for hardware-based real-time multi-band image blending

NASA Astrophysics Data System (ADS)

Popovic, Vladan; Leblebici, Yusuf

2015-02-01

Creating panoramic images has become a popular feature in modern smart phones, tablets, and digital cameras. A user can create a 360 degree field-of-view photograph from only several images. Quality of the resulting image is related to the number of source images, their brightness, and the used algorithm for their stitching and blending. One of the algorithms that provides excellent results in terms of background color uniformity and reduction of ghosting artifacts is the multi-band blending. The algorithm relies on decomposition of image into multiple frequency bands using dyadic filter bank. Hence, the results are also highly dependant on the used filter bank. In this paper we analyze performance of the FIR filters used for multi-band blending. We present a set of five filters that showed the best results in both literature and our experiments. The set includes Gaussian filter, biorthogonal wavelets, and custom-designed maximally flat and equiripple FIR filters. The presented results of filter comparison are based on several no-reference metrics for image quality. We conclude that 5/3 biorthogonal wavelet produces the best result in average, especially when its short length is considered. Furthermore, we propose a real-time FPGA implementation of the blending algorithm, using 2D non-separable systolic filtering scheme. Its pipeline architecture does not require hardware multipliers and it is able to achieve very high operating frequencies. The implemented system is able to process 91 fps for 1080p (1920×1080) image resolution.

Seedling Responses of Five Species of Western Conifers to Simulated Ambient Sulfur Dioxide Exposures

Treesearch

Theodor D. Leininger; Paul R. Miller; Susan L. Schilling; Paul H. Dunn

1991-01-01

Seedlings of ponderosa pine, Douglas-fir, white fir, Engelmann spruce, and subalpine fir were exposed continuously to charcoal-filtered (CF) air or one of three levels of a simulated ambient exposure typical of SO, pollution near smelters in the western United States. Seedlings were exposed during winter-spring experiments for 60 days to hourly means of 17, 38, and 54...

Cat Swarm Optimization algorithm for optimal linear phase FIR filter design.

PubMed

Saha, Suman Kumar; Ghoshal, Sakti Prasad; Kar, Rajib; Mandal, Durbadal

2013-11-01

In this paper a new meta-heuristic search method, called Cat Swarm Optimization (CSO) algorithm is applied to determine the best optimal impulse response coefficients of FIR low pass, high pass, band pass and band stop filters, trying to meet the respective ideal frequency response characteristics. CSO is generated by observing the behaviour of cats and composed of two sub-models. In CSO, one can decide how many cats are used in the iteration. Every cat has its' own position composed of M dimensions, velocities for each dimension, a fitness value which represents the accommodation of the cat to the fitness function, and a flag to identify whether the cat is in seeking mode or tracing mode. The final solution would be the best position of one of the cats. CSO keeps the best solution until it reaches the end of the iteration. The results of the proposed CSO based approach have been compared to those of other well-known optimization methods such as Real Coded Genetic Algorithm (RGA), standard Particle Swarm Optimization (PSO) and Differential Evolution (DE). The CSO based results confirm the superiority of the proposed CSO for solving FIR filter design problems. The performances of the CSO based designed FIR filters have proven to be superior as compared to those obtained by RGA, conventional PSO and DE. The simulation results also demonstrate that the CSO is the best optimizer among other relevant techniques, not only in the convergence speed but also in the optimal performances of the designed filters. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Fast digital zooming system using directionally adaptive image interpolation and restoration.

PubMed

Kang, Wonseok; Jeon, Jaehwan; Yu, Soohwan; Paik, Joonki

2014-01-01

This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.

Method and system for training dynamic nonlinear adaptive filters which have embedded memory

NASA Technical Reports Server (NTRS)

Rabinowitz, Matthew (Inventor)

2002-01-01

Described herein is a method and system for training nonlinear adaptive filters (or neural networks) which have embedded memory. Such memory can arise in a multi-layer finite impulse response (FIR) architecture, or an infinite impulse response (IIR) architecture. We focus on filter architectures with separate linear dynamic components and static nonlinear components. Such filters can be structured so as to restrict their degrees of computational freedom based on a priori knowledge about the dynamic operation to be emulated. The method is detailed for an FIR architecture which consists of linear FIR filters together with nonlinear generalized single layer subnets. For the IIR case, we extend the methodology to a general nonlinear architecture which uses feedback. For these dynamic architectures, we describe how one can apply optimization techniques which make updates closer to the Newton direction than those of a steepest descent method, such as backpropagation. We detail a novel adaptive modified Gauss-Newton optimization technique, which uses an adaptive learning rate to determine both the magnitude and direction of update steps. For a wide range of adaptive filtering applications, the new training algorithm converges faster and to a smaller value of cost than both steepest-descent methods such as backpropagation-through-time, and standard quasi-Newton methods. We apply the algorithm to modeling the inverse of a nonlinear dynamic tracking system 5, as well as a nonlinear amplifier 6.

FPGA-based fused smart sensor for dynamic and vibration parameter extraction in industrial robot links.

PubMed

Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

2010-01-01

Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA).

FPGA-Based Fused Smart Sensor for Dynamic and Vibration Parameter Extraction in Industrial Robot Links

PubMed Central

Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

2010-01-01

Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA). PMID:22319345

Extending the impulse response in order to reduce errors due to impulse noise and signal fading

NASA Technical Reports Server (NTRS)

Webb, Joseph A.; Rolls, Andrew J.; Sirisena, H. R.

1988-01-01

A finite impulse response (FIR) digital smearing filter was designed to produce maximum intersymbol interference and maximum extension of the impulse response of the signal in a noiseless binary channel. A matched FIR desmearing filter at the receiver then reduced the intersymbol interference to zero. Signal fades were simulated by means of 100 percent signal blockage in the channel. Smearing and desmearing filters of length 256, 512, and 1024 were used for these simulations. Results indicate that impulse response extension by means of bit smearing appears to be a useful technique for correcting errors due to impulse noise or signal fading in a binary channel.

A novel low-complexity digital filter design for wearable ECG devices

PubMed Central

Mehrnia, Alireza

2017-01-01

Wearable and implantable Electrocardiograph (ECG) devices are becoming prevailing tools for continuous real-time personal health monitoring. The ECG signal can be contaminated by various types of noise and artifacts (e.g., powerline interference, baseline wandering) that must be removed or suppressed for accurate ECG signal processing. Limited device size, power consumption and cost are critical issues that need to be carefully considered when designing any portable health monitoring device, including a battery-powered ECG device. This work presents a novel low-complexity noise suppression reconfigurable finite impulse response (FIR) filter structure for wearable ECG and heart monitoring devices. The design relies on a recently introduced optimally-factored FIR filter method. The new filter structure and several of its useful features are presented in detail. We also studied the hardware complexity of the proposed structure and compared it with the state-of-the-art. The results showed that the new ECG filter has a lower hardware complexity relative to the state-of-the-art ECG filters. PMID:28384272

A novel low-complexity digital filter design for wearable ECG devices.

PubMed

Asgari, Shadnaz; Mehrnia, Alireza

2017-01-01

Wearable and implantable Electrocardiograph (ECG) devices are becoming prevailing tools for continuous real-time personal health monitoring. The ECG signal can be contaminated by various types of noise and artifacts (e.g., powerline interference, baseline wandering) that must be removed or suppressed for accurate ECG signal processing. Limited device size, power consumption and cost are critical issues that need to be carefully considered when designing any portable health monitoring device, including a battery-powered ECG device. This work presents a novel low-complexity noise suppression reconfigurable finite impulse response (FIR) filter structure for wearable ECG and heart monitoring devices. The design relies on a recently introduced optimally-factored FIR filter method. The new filter structure and several of its useful features are presented in detail. We also studied the hardware complexity of the proposed structure and compared it with the state-of-the-art. The results showed that the new ECG filter has a lower hardware complexity relative to the state-of-the-art ECG filters.

Non-transmissible Sendai virus vector encoding c-myc suppressor FBP-interacting repressor for cancer therapy

PubMed Central

Matsushita, Kazuyuki; Shimada, Hideaki; Ueda, Yasuji; Inoue, Makoto; Hasegawa, Mamoru; Tomonaga, Takeshi; Matsubara, Hisahiro; Nomura, Fumio

2014-01-01

AIM: To investigate a novel therapeutic strategy to target and suppress c-myc in human cancers using far up stream element (FUSE)-binding protein-interacting repressor (FIR). METHODS: Endogenous c-Myc suppression and apoptosis induction by a transient FIR-expressing vector was examined in vivo via a HA-tagged FIR (HA-FIR) expression vector. A fusion gene-deficient, non-transmissible, Sendai virus (SeV) vector encoding FIR cDNA, SeV/dF/FIR, was prepared. SeV/dF/FIR was examined for its gene transduction efficiency, viral dose dependency of antitumor effect and apoptosis induction in HeLa (cervical squamous cell carcinoma) cells and SW480 (colon adenocarcinoma) cells. Antitumor efficacy in a mouse xenograft model was also examined. The molecular mechanism of the anti-tumor effect and c-Myc suppression by SeV/dF/FIR was examined using Spliceostatin A (SSA), a SAP155 inhibitor, or SAP155 siRNA which induce c-Myc by increasing FIR∆exon2 in HeLa cells. RESULTS: FIR was found to repress c-myc transcription and in turn the overexpression of FIR drove apoptosis through c-myc suppression. Thus, FIR expressing vectors are potentially applicable for cancer therapy. FIR is alternatively spliced by SAP155 in cancer cells lacking the transcriptional repression domain within exon 2 (FIR∆exon2), counteracting FIR for c-Myc protein expression. Furthermore, FIR forms a complex with SAP155 and inhibits mutual well-established functions. Thus, both the valuable effects and side effects of exogenous FIR stimuli should be tested for future clinical application. SeV/dF/FIR, a cytoplasmic RNA virus, was successfully prepared and showed highly efficient gene transduction in in vivo experiments. Furthermore, in nude mouse tumor xenograft models, SeV/dF/FIR displayed high antitumor efficiency against human cancer cells. SeV/dF/FIR suppressed SSA-activated c-Myc. SAP155 siRNA, potentially produces FIR∆exon2, and led to c-Myc overexpression with phosphorylation at Ser62. HA-FIR suppressed endogenous c-Myc expression and induced apoptosis in HeLa and SW480 cells. A c-myc transcriptional suppressor FIR expressing SeV/dF/FIR showed high gene transduction efficiency with significant antitumor effects and apoptosis induction in HeLa and SW480 cells. CONCLUSION: SeV/dF/FIR showed strong tumor growth suppression with no significant side effects in an animal xenograft model, thus SeV/dF/FIR is potentially applicable for future clinical cancer treatment. PMID:24764668

Enhancement of the Comb Filtering Selectivity Using Iterative Moving Average for Periodic Waveform and Harmonic Elimination

PubMed Central

Wu, Yan; Aarts, Ronald M.

2018-01-01

A recurring problem regarding the use of conventional comb filter approaches for elimination of periodic waveforms is the degree of selectivity achieved by the filtering process. Some applications, such as the gradient artefact correction in EEG recordings during coregistered EEG-fMRI, require a highly selective comb filtering that provides effective attenuation in the stopbands and gain close to unity in the pass-bands. In this paper, we present a novel comb filtering implementation whereby the iterative filtering application of FIR moving average-based approaches is exploited in order to enhance the comb filtering selectivity. Our results indicate that the proposed approach can be used to effectively approximate the FIR moving average filter characteristics to those of an ideal filter. A cascaded implementation using the proposed approach shows to further increase the attenuation in the filter stopbands. Moreover, broadening of the bandwidth of the comb filtering stopbands around −3 dB according to the fundamental frequency of the stopband can be achieved by the novel method, which constitutes an important characteristic to account for broadening of the harmonic gradient artefact spectral lines. In parallel, the proposed filtering implementation can also be used to design a novel notch filtering approach with enhanced selectivity as well. PMID:29599955

Equalization of nonlinear transmission impairments by maximum-likelihood-sequence estimation in digital coherent receivers.

PubMed

Khairuzzaman, Md; Zhang, Chao; Igarashi, Koji; Katoh, Kazuhiro; Kikuchi, Kazuro

2010-03-01

We describe a successful introduction of maximum-likelihood-sequence estimation (MLSE) into digital coherent receivers together with finite-impulse response (FIR) filters in order to equalize both linear and nonlinear fiber impairments. The MLSE equalizer based on the Viterbi algorithm is implemented in the offline digital signal processing (DSP) core. We transmit 20-Gbit/s quadrature phase-shift keying (QPSK) signals through a 200-km-long standard single-mode fiber. The bit-error rate performance shows that the MLSE equalizer outperforms the conventional adaptive FIR filter, especially when nonlinear impairments are predominant.

Orthonormal filters for identification in active control systems

NASA Astrophysics Data System (ADS)

Mayer, Dirk

2015-12-01

Many active noise and vibration control systems require models of the control paths. When the controlled system changes slightly over time, adaptive digital filters for the identification of the models are useful. This paper aims at the investigation of a special class of adaptive digital filters: orthonormal filter banks possess the robust and simple adaptation of the widely applied finite impulse response (FIR) filters, but at a lower model order, which is important when considering implementation on embedded systems. However, the filter banks require prior knowledge about the resonance frequencies and damping of the structure. This knowledge can be supposed to be of limited precision, since in many practical systems, uncertainties in the structural parameters exist. In this work, a procedure using a number of training systems to find the fixed parameters for the filter banks is applied. The effect of uncertainties in the prior knowledge on the model error is examined both with a basic example and in an experiment. Furthermore, the possibilities to compensate for the imprecise prior knowledge by a higher filter order are investigated. Also comparisons with FIR filters are implemented in order to assess the possible advantages of the orthonormal filter banks. Numerical and experimental investigations show that significantly lower computational effort can be reached by the filter banks under certain conditions.

An optimization of the FPGA/NIOS adaptive FIR filter using linear prediction to reduce narrow band RFI for the next generation ground-based ultra-high energy cosmic-ray experiment

NASA Astrophysics Data System (ADS)

Szadkowski, Zbigniew; Fraenkel, E. D.; Glas, Dariusz; Legumina, Remigiusz

2013-12-01

The electromagnetic part of an extensive air shower developing in the atmosphere provides significant information complementary to that obtained by water Cherenkov detectors which are predominantly sensitive to the muonic content of an air shower at ground. The emissions can be observed in the frequency band between 10 and 100 MHz. However, this frequency range is significantly contaminated by narrow-band RFI and other human-made distortions. The Auger Engineering Radio Array currently suppresses the RFI by multiple time-to-frequency domain conversions using an FFT procedure as well as by a set of manually chosen IIR notch filters in the time-domain. An alternative approach developed in this paper is an adaptive FIR filter based on linear prediction (LP). The coefficients for the linear predictor are dynamically refreshed and calculated in the virtual NIOS processor. The radio detector is an autonomous system installed on the Argentinean pampas and supplied from a solar panel. Powerful calculation capacity inside the FPGA is a factor. Power consumption versus the degree of effectiveness of the calculation inside the FPGA is a figure of merit to be minimized. Results show that the RFI contamination can be significantly suppressed by the LP FIR filter for 64 or less stages.

In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI

PubMed Central

Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

2013-01-01

Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a-priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency. PMID:23473798

Adaptively combined FIR and functional link artificial neural network equalizer for nonlinear communication channel.

PubMed

Zhao, Haiquan; Zhang, Jiashu

2009-04-01

This paper proposes a novel computational efficient adaptive nonlinear equalizer based on combination of finite impulse response (FIR) filter and functional link artificial neural network (CFFLANN) to compensate linear and nonlinear distortions in nonlinear communication channel. This convex nonlinear combination results in improving the speed while retaining the lower steady-state error. In addition, since the CFFLANN needs not the hidden layers, which exist in conventional neural-network-based equalizers, it exhibits a simpler structure than the traditional neural networks (NNs) and can require less computational burden during the training mode. Moreover, appropriate adaptation algorithm for the proposed equalizer is derived by the modified least mean square (MLMS). Results obtained from the simulations clearly show that the proposed equalizer using the MLMS algorithm can availably eliminate various intensity linear and nonlinear distortions, and be provided with better anti-jamming performance. Furthermore, comparisons of the mean squared error (MSE), the bit error rate (BER), and the effect of eigenvalue ratio (EVR) of input correlation matrix are presented.

In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI.

PubMed

Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

2013-05-15

Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency. Published by Elsevier B.V.

Predicting susceptibility of white fir during a drought-associated outbreak of the fir engraver, Scolytus centralis, in California

Treesearch

G.T. Ferrell; W.J. Otrosina; C.J. DeMars

1994-01-01

Phenotypic traits were compared with a vigor (growth efficiency) index for accuracy in predicting susceptibility of white fir, Abies concolor (Gord. & Glend.) Lindl., during a drought-associated outbreak of the fir engraver, Scolytus centralis LeC., in the central Sierra Nevada at Lake Tahoe, California.Predictor variables were estimated for 633 firs in six forest...

Power Spectral Density and Hilbert Transform

DTIC Science & Technology

2016-12-01

Fourier transform, Hilbert transform, digital filter , SDR 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER...terms. A very good approximation to the ideal Hilbert transform is a low-pass finite impulse response (FIR) filter . In Fig. 7, we show a real signal...220), converted to an analytic signal using a 255-tap Hilbert transform low-pass filter . For an ideal Hilbert

Dense grid sibling frames with linear phase filters

NASA Astrophysics Data System (ADS)

Abdelnour, Farras

2013-09-01

We introduce new 5-band dyadic sibling frames with dense time-frequency grid. Given a lowpass filter satisfying certain conditions, the remaining filters are obtained using spectral factorization. The analysis and synthesis filterbanks share the same lowpass and bandpass filters but have different and oversampled highpass filters. This leads to wavelets approximating shift-invariance. The filters are FIR, have linear phase, and the resulting wavelets have vanishing moments. The filters are designed using spectral factorization method. The proposed method leads to smooth limit functions with higher approximation order, and computationally stable filterbanks.

Quasi interpolation with Voronoi splines.

PubMed

Mirzargar, Mahsa; Entezari, Alireza

2011-12-01

We present a quasi interpolation framework that attains the optimal approximation-order of Voronoi splines for reconstruction of volumetric data sampled on general lattices. The quasi interpolation framework of Voronoi splines provides an unbiased reconstruction method across various lattices. Therefore this framework allows us to analyze and contrast the sampling-theoretic performance of general lattices, using signal reconstruction, in an unbiased manner. Our quasi interpolation methodology is implemented as an efficient FIR filter that can be applied online or as a preprocessing step. We present visual and numerical experiments that demonstrate the improved accuracy of reconstruction across lattices, using the quasi interpolation framework. © 2011 IEEE

An approach for fixed coefficient RNS-based FIR filter

NASA Astrophysics Data System (ADS)

Srinivasa Reddy, Kotha; Sahoo, Subhendu Kumar

2017-08-01

In this work, an efficient new modular multiplication method for {2k-1, 2k, 2k+1-1} moduli set is proposed to implement a residue number system (RNS)-based fixed coefficient finite impulse response filter. The new multiplication approach reduces the number of partial products by using pre-loaded product block. The reduction in partial products with the proposed modular multiplication improves the clock frequency and reduces the area and power as compared with the conventional modular multiplication. Further, the present approach eliminates a binary number to residue number converter circuit, which is usually needed at the front end of RNS-based system. In this work, two fixed coefficient filter architectures with the new modular multiplication approach are proposed. The filters are implemented using Verilog hardware description language. The United Microelectronics Corporation 90 nm technology library has been used for synthesis and the results area, power and delay are obtained with the help of Cadence register transfer level compiler. The power delay product (PDP) is also considered for performance comparison among the proposed filters. One of the proposed architecture is found to improve PDP gain by 60.83% as compared with the filter implemented with conventional modular multiplier. The filters functionality is validated with the help of Altera DSP Builder.

Research on signal processing of shock absorber test bench based on zero-phase filter

NASA Astrophysics Data System (ADS)

Wu, Yi; Ding, Guoqing

2017-10-01

The quality of force-displacement diagram is significant to help evaluate the performance of shock absorbers. Damping force sampling data is often interfered by Gauss white noise, 50Hz power interference and its harmonic wave during the process of testing; data de-noising has become the core problem of drawing true, accurate and real-time indicator diagram. The noise and interference can be filtered out through generic IIR or FIR low-pass filter, but addition phase lag of useful signal will be caused due to the inherent attribute of IIR and FIR filter. The paper uses FRR method to realize zero-phase digital filtering in a software way based on mutual cancellation of phase lag between the forward and reverse sequences after through the filter. High-frequency interference above 40Hz are filtered out completely and noise attenuation is more than -40dB, with no additional phase lag. The method is able to restore the true signal as far as possible. Theoretical simulation and practical test indicate high-frequency noises have been effectively inhibited in multiple typical speed cases, signal-to-noise ratio being greatly improved; the curve in indicator diagram has better smoothness and fidelity. The FRR algorithm has low computational complexity, fast running time, and can be easily transplanted in multiple platforms.

WE-D-204-02: Novel Method for Correcting Degradation of Sharpness of Liquid-Crystal Display Based On Modulation Transfer Function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tokurei, S; Department of Radiology, Yamaguchi University Hospital, Ube, Yamaguchi; Morishita, J

2015-06-15

Purpose: To develop a method for improving sharpness of images reproduced on liquid-crystal displays (LCDs) by compensating for the degradation of modulation transfer function (MTF) of the LCD. Methods: The inherent MTF of a color LCD (display MTF) was measured using a commercially available color digital camera. The frequency responses necessary to compensate for the resolution property of the LCD were calculated from the inverses of the display MTFs in both the horizontal and vertical directions. In addition, the inverses of the display MTFs were combined with the response of the human eye. The finite impulse response (FIR) filters weremore » computed by taking the inverse Fourier transform of the frequency responses, and the effects of the FIR filtering on both the resolution and noise properties of the displayed images were verified by measuring the MTF and Wiener spectrum (WS), respectively. The FIR filtering was then applied to the representation of digital bone and chest radiographs. Results: The FIR filtering improved the MTF values by up to almost 1.0 or greater over the frequency range of interest, while it minimally increased the WS values. Combining the inverses of the display MTFs with the response of the human eye led to further refinement of the MTF. Our method was successfully and beneficially applied to the image interpretation of bone radiographs. The resolution enhancement of chest radiographs, which include larger scattered radiation than bone radiographs, was easily perceived by incorporating the response of the human eye. In addition, no artifacts were observed on the processed images. Conclusion: Our proposed method to compensate for the degradation of the resolution properties of LCDs has the potential to improve the observer performance of radiologists when reading digital radiographs. This work was supported in part by grant from EIZO Corporation.« less

Exact reconstruction analysis/synthesis filter banks with time-varying filters

NASA Technical Reports Server (NTRS)

Arrowood, J. L., Jr.; Smith, M. J. T.

1993-01-01

This paper examines some of the analysis/synthesis issues associated with FIR time-varying filter banks where the filter bank coefficients are allowed to change in response to the input signal. Several issues are identified as being important in order to realize performance gains from time-varying filter banks in image coding applications. These issues relate to the behavior of the filters as transition from one set of filter banks to another occurs. Lattice structure formulations for the time varying filter bank problem are introduced and discussed in terms of their properties and transition characteristics.

A Multi Directional Perfect Reconstruction Filter Bank Designed with 2-D Eigenfilter Approach: Application to Ultrasound Speckle Reduction.

PubMed

Nagare, Mukund B; Patil, Bhushan D; Holambe, Raghunath S

2017-02-01

B-Mode ultrasound images are degraded by inherent noise called Speckle, which creates a considerable impact on image quality. This noise reduces the accuracy of image analysis and interpretation. Therefore, reduction of speckle noise is an essential task which improves the accuracy of the clinical diagnostics. In this paper, a Multi-directional perfect-reconstruction (PR) filter bank is proposed based on 2-D eigenfilter approach. The proposed method used for the design of two-dimensional (2-D) two-channel linear-phase FIR perfect-reconstruction filter bank. In this method, the fan shaped, diamond shaped and checkerboard shaped filters are designed. The quadratic measure of the error function between the passband and stopband of the filter has been used an objective function. First, the low-pass analysis filter is designed and then the PR condition has been expressed as a set of linear constraints on the corresponding synthesis low-pass filter. Subsequently, the corresponding synthesis filter is designed using the eigenfilter design method with linear constraints. The newly designed 2-D filters are used in translation invariant pyramidal directional filter bank (TIPDFB) for reduction of speckle noise in ultrasound images. The proposed 2-D filters give better symmetry, regularity and frequency selectivity of the filters in comparison to existing design methods. The proposed method is validated on synthetic and real ultrasound data which ensures improvement in the quality of ultrasound images and efficiently suppresses the speckle noise compared to existing methods.

Digital filtering implementations for the detection of broad spectral features by direct analysis of passive Fourier transform infrared interferograms.

PubMed

Tarumi, Toshiyasu; Small, Gary W; Combs, Roger J; Kroutil, Robert T

2004-04-01

Finite impulse response (FIR) filters and finite impulse response matrix (FIRM) filters are evaluated for use in the detection of volatile organic compounds with wide spectral bands by direct analysis of interferogram data obtained from passive Fourier transform infrared (FT-IR) measurements. Short segments of filtered interferogram points are classified by support vector machines (SVMs) to implement the automated detection of heated plumes of the target analyte, ethanol. The interferograms employed in this study were acquired with a downward-looking passive FT-IR spectrometer mounted on a fixed-wing aircraft. Classifiers are trained with data collected on the ground and subsequently used for the airborne detection. The success of the automated detection depends on the effective removal of background contributions from the interferogram segments. Removing the background signature is complicated when the analyte spectral bands are broad because there is significant overlap between the interferogram representations of the analyte and background. Methods to implement the FIR and FIRM filters while excluding background contributions are explored in this work. When properly optimized, both filtering procedures provide satisfactory classification results for the airborne data. Missed detection rates of 8% or smaller for ethanol and false positive rates of at most 0.8% are realized. The optimization of filter design parameters, the starting interferogram point for filtering, and the length of the interferogram segments used in the pattern recognition is discussed.

Clutter Mitigation in Echocardiography Using Sparse Signal Separation

PubMed Central

Yavneh, Irad

2015-01-01

In ultrasound imaging, clutter artifacts degrade images and may cause inaccurate diagnosis. In this paper, we apply a method called Morphological Component Analysis (MCA) for sparse signal separation with the objective of reducing such clutter artifacts. The MCA approach assumes that the two signals in the additive mix have each a sparse representation under some dictionary of atoms (a matrix), and separation is achieved by finding these sparse representations. In our work, an adaptive approach is used for learning the dictionary from the echo data. MCA is compared to Singular Value Filtering (SVF), a Principal Component Analysis- (PCA-) based filtering technique, and to a high-pass Finite Impulse Response (FIR) filter. Each filter is applied to a simulated hypoechoic lesion sequence, as well as experimental cardiac ultrasound data. MCA is demonstrated in both cases to outperform the FIR filter and obtain results comparable to the SVF method in terms of contrast-to-noise ratio (CNR). Furthermore, MCA shows a lower impact on tissue sections while removing the clutter artifacts. In experimental heart data, MCA obtains in our experiments clutter mitigation with an average CNR improvement of 1.33 dB. PMID:26199622

Heating of large format filters in sub-mm and fir space optics

NASA Astrophysics Data System (ADS)

Baccichet, N.; Savini, G.

2017-11-01

Most FIR and sub-mm space borne observatories use polymer-based quasi-optical elements like filters and lenses, due to their high transparency and low absorption in such wavelength ranges. Nevertheless, data from those missions have proven that thermal imbalances in the instrument (not caused by filters) can complicate the data analysis. Consequently, for future, higher precision instrumentation, further investigation is required on any thermal imbalances embedded in such polymer-based filters. Particularly, in this paper the heating of polymers when operating at cryogenic temperature in space will be studied. Such phenomenon is an important aspect of their functioning since the transient emission of unwanted thermal radiation may affect the scientific measurements. To assess this effect, a computer model was developed for polypropylene based filters and PTFE-based coatings. Specifically, a theoretical model of their thermal properties was created and used into a multi-physics simulation that accounts for conductive and radiative heating effects of large optical elements, the geometry of which was suggested by the large format array instruments designed for future space missions. It was found that in the simulated conditions, the filters temperature was characterized by a time-dependent behaviour, modulated by a small scale fluctuation. Moreover, it was noticed that thermalization was reached only when a low power input was present.

The discrete prolate spheroidal filter as a digital signal processing tool

NASA Technical Reports Server (NTRS)

Mathews, J. D.; Breakall, J. K.; Karawas, G. K.

1983-01-01

The discrete prolate spheriodall (DPS) filter is one of the glass of nonrecursive finite impulse response (FIR) filters. The DPS filter is superior to other filters in this class in that it has maximum energy concentration in the frequency passband and minimum ringing in the time domain. A mathematical development of the DPS filter properties is given, along with information required to construct the filter. The properties of this filter were compared with those of the more commonly used filters of the same class. Use of the DPS filter allows for particularly meaningful statements of data time/frequency resolution cell values. The filter forms an especially useful tool for digital signal processing.

An advanced real-time digital signal processing system for linear systems emulation, with special emphasis on network and acoustic response characterization

NASA Astrophysics Data System (ADS)

Gaydecki, Patrick; Fernandes, Bosco

2003-11-01

A fast digital signal processing (DSP) system is described that can perform real-time emulation of a wide variety of linear audio-bandwidth systems and networks, such as reverberant spaces, musical instrument bodies and very high order filter networks. The hardware design is based upon a Motorola DSP56309 operating at 110 million multiplication-accumulations per second and a dual-channel 24 bit codec with a maximum sampling frequency of 192 kHz. High level software has been developed to express complex vector frequency responses as both infinite impulse response (IIR) and finite impulse response (FIR) coefficients, in a form suitable for real-time convolution by the firmware installed in the DSP system memory. An algorithm has also been devised to express IIR filters as equivalent FIR structures, thereby obviating the potential instabilities associated with recursive equations and negating the traditional deficiencies of FIR filters respecting equivalent analogue designs. The speed and dynamic range of the system is such that, when sampling at 48 kHz, the frequency response can be specified to a spectral precision of 22 Hz when sampling at 10 kHz, this resolution increases to 0.9 Hz. Moreover, it is also possible to control the phase of any frequency band with a theoretical precision of 10-5 degrees in all cases. The system has been applied in the study of analogue filter networks, real-time Hilbert transformation, phase-shift systems and musical instrument body emulation, where it is providing valuable new insights into the understanding of psychoacoustic mechanisms.

A low-noise delta-sigma phase modulator for polar transmitters.

PubMed

Zhou, Bo

2014-01-01

A low-noise phase modulator, using finite-impulse-response (FIR) filtering embedded delta-sigma (ΔΣ) fractional-N phase-locked loop (PLL), is fabricated in 0.18 μ m CMOS for GSM/EDGE polar transmitters. A simplified digital compensation filter with inverse-FIR and -PLL features is proposed to trade off the transmitter noise and linearity. Experimental results show that the presented architecture performs RF phase modulation well with 20 mW power dissipation from 1.6 V supply and achieves the root-mean-square (rms) and peak phase errors of 4° and 8.5°, respectively. The measured and simulated phase noises of -104 dBc/Hz and -120 dBc/Hz at 400-kHz offset from 1.8-GHz carrier frequency are observed, respectively.

FPGA/NIOS Implementation of an Adaptive FIR Filter Using Linear Prediction to Reduce Narrow-Band RFI for Radio Detection of Cosmic Rays

NASA Astrophysics Data System (ADS)

Szadkowski, Zbigniew; Fraenkel, E. D.; van den Berg, Ad M.

2013-10-01

We present the FPGA/NIOS implementation of an adaptive finite impulse response (FIR) filter based on linear prediction to suppress radio frequency interference (RFI). This technique will be used for experiments that observe coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays. These experiments are designed to make a detailed study of the development of the electromagnetic part of air showers. Therefore, these radio signals provide information that is complementary to that obtained by water-Cherenkov detectors which are predominantly sensitive to the particle content of an air shower at ground. The radio signals from air showers are caused by the coherent emission due to geomagnetic and charge-excess processes. These emissions can be observed in the frequency band between 10-100 MHz. However, this frequency range is significantly contaminated by narrow-band RFI and other human-made distortions. A FIR filter implemented in the FPGA logic segment of the front-end electronics of a radio sensor significantly improves the signal-to-noise ratio. In this paper we discuss an adaptive filter which is based on linear prediction. The coefficients for the linear predictor (LP) are dynamically refreshed and calculated in the embedded NIOS processor, which is implemented in the same FPGA chip. The Levinson recursion, used to obtain the filter coefficients, is also implemented in the NIOS and is partially supported by direct multiplication in the DSP blocks of the logic FPGA segment. Tests confirm that the LP can be an alternative to other methods involving multiple time-to-frequency domain conversions using an FFT procedure. These multiple conversions draw heavily on the power consumption of the FPGA and are avoided by the linear prediction approach. Minimization of the power consumption is an important issue because the final system will be powered by solar panels. The FIR filter has been successfully tested in the Altera development kits with the EP4CE115F29C7 from the Cyclone IV family and the EP3C120F780C7 from the Cyclone III family at a 170 MHz sampling rate, a 12-bit I/O resolution, and an internal 30-bit dynamic range. Most of the slow floating-point NIOS calculations have been moved to the FPGA logic segments as extended fixed-point operations, which significantly reduced the refreshing time of the coefficients used in the LP. We conclude that the LP is a viable alternative to other methods such as non-adaptive methods involving digital notch filters or multiple time-to-frequency domain conversions using an FFT procedure.

A 128-Tap Highly Tunable CMOS IF Finite Impulse Response Filter for Pulsed Radar Applications

DOE PAGES

Mincey, John Stephen; Su, Eric C.; Silva-Martinez, Jose; ...

2018-02-28

A configurable-bandwidth (BW) filter is presented in this paper for pulsed radar applications. Also, to eliminate dispersion effects in the received waveform, a finite impulse response (FIR) topology is proposed, which has a measured standard deviation of an in-band group delay of 11 ns that is primarily dominated by the inherent, fully predictable delay introduced by the sample-and-hold. The filter operates at an IF of 20 MHz, and is tunable in BW from 1.5 to 15 MHz, which makes it optimal to be used with varying pulse widths in the radar. Employing a total of 128 taps, the FIR filtermore » provides greater than 50-dB sharp attenuation in the stopband in order to minimize all out-of-band noise in the low signal-to-noise received radar signal. Fabricated in a 0.18-μm silicon on insulator CMOS process, the proposed filter consumes approximately 3.5 mW/tap with a 1.8-V supply. Finally, a 20-MHz two-tone measurement with 200-kHz tone separation shows IIP3 greater than 8.5 dBm.« less

Adaptive feedforward control of non-minimum phase structural systems

NASA Astrophysics Data System (ADS)

Vipperman, J. S.; Burdisso, R. A.

1995-06-01

Adaptive feedforward control algorithms have been effectively applied to stationary disturbance rejection. For structural systems, the ideal feedforward compensator is a recursive filter which is a function of the transfer functions between the disturbance and control inputs and the error sensor output. Unfortunately, most control configurations result in a non-minimum phase control path; even a collocated control actuator and error sensor will not necessarily produce a minimum phase control path in the discrete domain. Therefore, the common practice is to choose a suitable approximation of the ideal compensator. In particular, all-zero finite impulse response (FIR) filters are desirable because of their inherent stability for adaptive control approaches. However, for highly resonant systems, large order filters are required for broadband applications. In this work, a control configuration is investigated for controlling non-minimum phase lightly damped structural systems. The control approach uses low order FIR filters as feedforward compensators in a configuration that has one more control actuator than error sensors. The performance of the controller was experimentally evaluated on a simply supported plate under white noise excitation for a two-input, one-output (2I1O) system. The results show excellent error signal reduction, attesting to the effectiveness of the method.

A 128-Tap Highly Tunable CMOS IF Finite Impulse Response Filter for Pulsed Radar Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mincey, John Stephen; Su, Eric C.; Silva-Martinez, Jose

A configurable-bandwidth (BW) filter is presented in this paper for pulsed radar applications. Also, to eliminate dispersion effects in the received waveform, a finite impulse response (FIR) topology is proposed, which has a measured standard deviation of an in-band group delay of 11 ns that is primarily dominated by the inherent, fully predictable delay introduced by the sample-and-hold. The filter operates at an IF of 20 MHz, and is tunable in BW from 1.5 to 15 MHz, which makes it optimal to be used with varying pulse widths in the radar. Employing a total of 128 taps, the FIR filtermore » provides greater than 50-dB sharp attenuation in the stopband in order to minimize all out-of-band noise in the low signal-to-noise received radar signal. Fabricated in a 0.18-μm silicon on insulator CMOS process, the proposed filter consumes approximately 3.5 mW/tap with a 1.8-V supply. Finally, a 20-MHz two-tone measurement with 200-kHz tone separation shows IIP3 greater than 8.5 dBm.« less

A Low-Noise Delta-Sigma Phase Modulator for Polar Transmitters

PubMed Central

Zhou, Bo

2014-01-01

A low-noise phase modulator, using finite-impulse-response (FIR) filtering embedded delta-sigma (ΔΣ) fractional-N phase-locked loop (PLL), is fabricated in 0.18 μm CMOS for GSM/EDGE polar transmitters. A simplified digital compensation filter with inverse-FIR and -PLL features is proposed to trade off the transmitter noise and linearity. Experimental results show that the presented architecture performs RF phase modulation well with 20 mW power dissipation from 1.6 V supply and achieves the root-mean-square (rms) and peak phase errors of 4° and 8.5°, respectively. The measured and simulated phase noises of −104 dBc/Hz and −120 dBc/Hz at 400-kHz offset from 1.8-GHz carrier frequency are observed, respectively. PMID:24719578

A minimax technique for time-domain design of preset digital equalizers using linear programming

NASA Technical Reports Server (NTRS)

Vaughn, G. L.; Houts, R. C.

1975-01-01

A linear programming technique is presented for the design of a preset finite-impulse response (FIR) digital filter to equalize the intersymbol interference (ISI) present in a baseband channel with known impulse response. A minimax technique is used which minimizes the maximum absolute error between the actual received waveform and a specified raised-cosine waveform. Transversal and frequency-sampling FIR digital filters are compared as to the accuracy of the approximation, the resultant ISI and the transmitted energy required. The transversal designs typically have slightly better waveform accuracy for a given distortion; however, the frequency-sampling equalizer uses fewer multipliers and requires less transmitted energy. A restricted transversal design is shown to use the least number of multipliers at the cost of a significant increase in energy and loss of waveform accuracy at the receiver.

Effects of leader topping and branch pruning on efficiency of Douglas-fir cone harvesting with a tree shaker.

Treesearch

D.L. Copes

1985-01-01

In 1983, a study was conducted to evaluate the effects of leader topping and branch pruning on the efficiency to tree shaking to remove Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) cones. Removal efficiency for three topping and pruning treatments averaged 69 percent, whereas for the uncut control treatment it was 62 percent. The treatment...

Efficient non-doped phosphorescent orange, blue and white organic light-emitting devices

NASA Astrophysics Data System (ADS)

Yin, Yongming; Yu, Jing; Cao, Hongtao; Zhang, Letian; Sun, Haizhu; Xie, Wenfa

2014-10-01

Efficient phosphorescent orange, blue and white organic light-emitting devices (OLEDs) with non-doped emissive layers were successfully fabricated. Conventional blue phosphorescent emitters bis [4,6-di-fluorophenyl]-pyridinato-N,C2'] picolinate (Firpic) and Bis(2,4-difluorophenylpyridinato) (Fir6) were adopted to fabricate non-doped blue OLEDs, which exhibited maximum current efficiency of 7.6 and 4.6 cd/A for Firpic and Fir6 based devices, respectively. Non-doped orange OLED was fabricated utilizing the newly reported phosphorescent material iridium (III) (pbi)2Ir(biq), of which manifested maximum current and power efficiency of 8.2 cd/A and 7.8 lm/W. The non-doped white OLEDs were achieved by simply combining Firpic or Fir6 with a 2-nm (pbi)2Ir(biq). The maximum current and power efficiency of the Firpic and (pbi)2Ir(biq) based white OLED were 14.8 cd/A and 17.9 lm/W.

Efficient non-doped phosphorescent orange, blue and white organic light-emitting devices.

PubMed

Yin, Yongming; Yu, Jing; Cao, Hongtao; Zhang, Letian; Sun, Haizhu; Xie, Wenfa

2014-10-24

Efficient phosphorescent orange, blue and white organic light-emitting devices (OLEDs) with non-doped emissive layers were successfully fabricated. Conventional blue phosphorescent emitters bis [4,6-di-fluorophenyl]-pyridinato-N,C(2')] picolinate (Firpic) and Bis(2,4-difluorophenylpyridinato) (Fir6) were adopted to fabricate non-doped blue OLEDs, which exhibited maximum current efficiency of 7.6 and 4.6 cd/A for Firpic and Fir6 based devices, respectively. Non-doped orange OLED was fabricated utilizing the newly reported phosphorescent material iridium (III) (pbi)₂Ir(biq), of which manifested maximum current and power efficiency of 8.2 cd/A and 7.8 lm/W. The non-doped white OLEDs were achieved by simply combining Firpic or Fir6 with a 2-nm (pbi)₂Ir(biq). The maximum current and power efficiency of the Firpic and (pbi)₂Ir(biq) based white OLED were 14.8 cd/A and 17.9 lm/W.

A multichannel nonlinear adaptive noise canceller based on generalized FLANN for fetal ECG extraction

NASA Astrophysics Data System (ADS)

Ma, Yaping; Xiao, Yegui; Wei, Guo; Sun, Jinwei

2016-01-01

In this paper, a multichannel nonlinear adaptive noise canceller (ANC) based on the generalized functional link artificial neural network (FLANN, GFLANN) is proposed for fetal electrocardiogram (FECG) extraction. A FIR filter and a GFLANN are equipped in parallel in each reference channel to respectively approximate the linearity and nonlinearity between the maternal ECG (MECG) and the composite abdominal ECG (AECG). A fast scheme is also introduced to reduce the computational cost of the FLANN and the GFLANN. Two (2) sets of ECG time sequences, one synthetic and one real, are utilized to demonstrate the improved effectiveness of the proposed nonlinear ANC. The real dataset is derived from the Physionet non-invasive FECG database (PNIFECGDB) including 55 multichannel recordings taken from a pregnant woman. It contains two subdatasets that consist of 14 and 8 recordings, respectively, with each recording being 90 s long. Simulation results based on these two datasets reveal, on the whole, that the proposed ANC does enjoy higher capability to deal with nonlinearity between MECG and AECG as compared with previous ANCs in terms of fetal QRS (FQRS)-related statistics and morphology of the extracted FECG waveforms. In particular, for the second real subdataset, the F1-measure results produced by the PCA-based template subtraction (TSpca) technique and six (6) single-reference channel ANCs using LMS- and RLS-based FIR filters, Volterra filter, FLANN, GFLANN, and adaptive echo state neural network (ESN a ) are 92.47%, 93.70%, 94.07%, 94.22%, 94.90%, 94.90%, and 95.46%, respectively. The same F1-measure statistical results from five (5) multi-reference channel ANCs (LMS- and RLS-based FIR filters, Volterra filter, FLANN, and GFLANN) for the second real subdataset turn out to be 94.08%, 94.29%, 94.68%, 94.91%, and 94.96%, respectively. These results indicate that the ESN a and GFLANN perform best, with the ESN a being slightly better than the GFLANN but about four times more computationally expensive than the GFLANN, which makes the GFLANN a good alternative for NI-FECG extraction.

Development of Software for a Lidar-Altimeter Processor

NASA Technical Reports Server (NTRS)

Rosenberg, Jacob S.; Trujillo, Carlos

2005-01-01

A report describes the development of software for a digital processor that operates in conjunction with a finite-impulse-response (FIR) chip in a spaceborne lidar altimeter. Processing is started by a laser-fire interrupt signal that is repeated at intervals of 25 ms. For the purpose of discriminating between returns from the ground and returns from such things as trees, buildings, and clouds, the software is required to scan digitized lidar-return data in reverse of the acquisition sequence in order to distinguish the last return pulse from within a commanded ground-return range window. The digitized waveform information within this range window is filtered through 6 matched filters, in the hardware electronics, in order to maximize the probability of finding echoes from sloped or rough terrain and minimize the probability of selecting cloud returns. From the data falling past the end of the range window, there is obtained a noise baseline that is used to calculate a threshold value for each filter. The data from each filter is analyzed by a complex weighting scheme and the filter with the greatest weight is selected. A region around the peak of the ground return pulse associated with the selected filter is placed in telemetry, as well as information on its location, height, and other characteristics. The software requires many uplinked parameters as input. Included in the report is a discussion of major software-development problems posed by the design of the FIR chip and the need for the software to complete its process within 20 ms to fit within the overall 25-ms cycle.

Analyses of Great Smoky Mountain Red Spruce Tree Ring Data

Treesearch

Paul C. van Deusen; [Editor

1988-01-01

Four different analyses of red spruce tree ring data from the Great Smoky Mountains are presented along with a description of the spruce/fir ecosystem.The analyses use several techniques including spatial analysis, fractals, spline detrending, and the Kalman filter.

Two-Dimensional Signal Processing, Optical Information Storage and Processing, and Electromagnetic Measurements

DTIC Science & Technology

1994-05-16

analysis of anisotropic grating diffraction, perfor- mance analysis of Givens rotation integrated optical interdigitated-electrode cross- channel Bragg...11. T. R. Gardos and R. M. Mersereau, "FIR filtering on a lattice with periodically deleted samples," Proc. 1991 IEEE Int. Conf. on Acoustics...pp. vol. 1, pp. 301-311, July 1992. 23. T. R. Gardos , K. Nayebi, and R. M. Mersereau, "Time domain analysis of multi- dimensional multi-rate filter

Using recurrence plot analysis for software execution interpretation and fault detection

NASA Astrophysics Data System (ADS)

Mosdorf, M.

2015-09-01

This paper shows a method targeted at software execution interpretation and fault detection using recurrence plot analysis. In in the proposed approach recurrence plot analysis is applied to software execution trace that contains executed assembly instructions. Results of this analysis are subject to further processing with PCA (Principal Component Analysis) method that simplifies number coefficients used for software execution classification. This method was used for the analysis of five algorithms: Bubble Sort, Quick Sort, Median Filter, FIR, SHA-1. Results show that some of the collected traces could be easily assigned to particular algorithms (logs from Bubble Sort and FIR algorithms) while others are more difficult to distinguish.

Concomitant expression of far upstream element (FUSE) binding protein (FBP) interacting repressor (FIR) and its splice variants induce migration and invasion of non-small cell lung cancer (NSCLC) cells.

PubMed

Müller, Benedikt; Bovet, Michael; Yin, Yi; Stichel, Damian; Malz, Mona; González-Vallinas, Margarita; Middleton, Alistair; Ehemann, Volker; Schmitt, Jennifer; Muley, Thomas; Meister, Michael; Herpel, Esther; Singer, Stephan; Warth, Arne; Schirmacher, Peter; Drasdo, Dirk; Matthäus, Franziska; Breuhahn, Kai

2015-11-01

Transcription factors integrate a variety of oncogenic input information, facilitate tumour growth and cell dissemination, and therefore represent promising therapeutic target structures. Because over-expression of DNA-interacting far upstream element binding protein (FBP) supports non-small cell lung cancer (NSCLC) migration, we asked whether its repressor, FBP-interacting repressor (FIR) is functionally inactivated and how FIR might affect NSCLC cell biology. Different FIR splice variants were highly expressed in the majority of NSCLCs, with the highest levels in tumours carrying genomic gains of chromosome 8q24.3, which contained the FIR gene locus. Nuclear FIR expression was significantly enriched at the invasion front of primary NSCLCs, but this did not correlate with tumour cell proliferation. FIR accumulation was associated with worse patient survival and tumour recurrence; in addition, FIR over-expression significantly correlated with lymph node metastasis in squamous cell carcinomas (SCCs). In vitro, we applied newly developed methods and modelling approaches for the quantitative and time-resolved description of the pro-migratory and pro-invasive capacities of SCC cells. siRNA-mediated silencing of all FIR variants significantly reduced the speed and directional movement of tumour cells in all phases of migration. Furthermore, sprouting efficiency and single cell invasiveness were diminished following FIR inhibition. Interestingly, the silencing of FIR isoforms lacking exon 2 (FIR(Δexon2)) alone was sufficient to reduce lateral migration and invasion. In summary, by using scale-spanning data derived from primary human tissues, quantitative cellular analyses and mathematical modelling, we have demonstrated that concomitant over-expression of FIR and its splice variants drives NSCLC migration and dissemination. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range

EPA Science Inventory

Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen to increase growth rates. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The objective ...

Evaluation and Analysis of a Multi-Band Transceiver for Next Generation Telemetry Applications

DTIC Science & Technology

2014-06-01

DDC ) BAND SELECTION Kintex FPGA DIGITAL RADIO RECEIVER DIGITAL RADIO TRANSMITTER ADC Fs < 225 MSPS Fs = 400 MHz RF BW = 36 MHz FREQ TRANSLATION VIA...MANAGER (MMCM) DIGITAL DOWN CONVERSION ( DDC ) BAND SELECTIVE FILTER Kintex FPGA DIGITAL RADIO RECEIVER DIGITAL RADIO TRANSMITTER FIR FINE TRANSLATION

Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3*

NASA Technical Reports Server (NTRS)

Malhotra, Sangeeta; Rhoads, James E.; Finkelstein, K.; Yang, Huan; Carilli, Chris; Combes, Francoise; Dassas, Karine; Finkelstein, Steven; Frye, Brenda; Gerin, Maryvonne;

Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3

NASA Astrophysics Data System (ADS)

Malhotra, Sangeeta; Rhoads, James E.; Finkelstein, K.; Yang, Huan; Carilli, Chris; Combes, Françoise; Dassas, Karine; Finkelstein, Steven; Frye, Brenda; Gerin, Maryvonne; Guillard, Pierre; Nesvadba, Nicole; Rigby, Jane; Shin, Min-Su; Spaans, Marco; Strauss, Michael A.; Papovich, Casey

2017-01-01

We observed the [C II] line in 15 lensed galaxies at redshifts 1 < z < 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C II] with Herschel. The [C II] luminosity in this sample ranges from 8 × 107 L⊙ to 3.7 × 109 L⊙ (after correcting for magnification), confirming that [C II] is a strong tracer of the ISM at high redshifts. The ratio of the [C II] line to the total far-infrared (FIR) luminosity serves as a measure of the ratio of gas to dust cooling and thus the efficiency of the grain photoelectric heating process. It varies between 3.3% and 0.09%. We compare the [C II]/FIR ratio to that of galaxies at z = 0 and at high redshifts and find that they follow similar trends. The [C II]/FIR ratio is lower for galaxies with higher dust temperatures. This is best explained if increased UV intensity leads to higher FIR luminosity and dust temperatures, but gas heating does not rise due to lower photoelectric heating efficiency. The [C II]/FIR ratio shows weaker correlation with FIR luminosity. At low redshifts highly luminous galaxies tend to have warm dust, so the effects of dust temperature and luminosity are degenerate. Luminous galaxies at high redshifts show a range of dust temperatures, showing that [C II]/FIR correlates most strongly with dust temperature. The [C II] to mid-IR ratio for the HELLO sample is similar to the values seen for low-redshift galaxies, indicating that small grains and PAHs dominate the heating in the neutral ISM, although some of the high [CII]/FIR ratios may be due to turbulent heating. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

HERSCHEL EXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTS z = 1–3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malhotra, Sangeeta; Rhoads, James E.; Yang, Huan

We observed the [C ii] line in 15 lensed galaxies at redshifts 1 < z < 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3 σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C ii] with Herschel . The [C ii] luminosity in this sample ranges from 8 × 10{sup 7} L {sub ⊙} to 3.7 × 10{sup 9} L {sub ⊙} (after correcting for magnification), confirming that [C ii] is a strong tracer of the ISM at high redshifts. The ratio of the [C ii] line to themore » total far-infrared (FIR) luminosity serves as a measure of the ratio of gas to dust cooling and thus the efficiency of the grain photoelectric heating process. It varies between 3.3% and 0.09%. We compare the [C ii]/FIR ratio to that of galaxies at z = 0 and at high redshifts and find that they follow similar trends. The [C ii]/FIR ratio is lower for galaxies with higher dust temperatures. This is best explained if increased UV intensity leads to higher FIR luminosity and dust temperatures, but gas heating does not rise due to lower photoelectric heating efficiency. The [C ii]/FIR ratio shows weaker correlation with FIR luminosity. At low redshifts highly luminous galaxies tend to have warm dust, so the effects of dust temperature and luminosity are degenerate. Luminous galaxies at high redshifts show a range of dust temperatures, showing that [C ii]/FIR correlates most strongly with dust temperature. The [C ii] to mid-IR ratio for the HELLO sample is similar to the values seen for low-redshift galaxies, indicating that small grains and PAHs dominate the heating in the neutral ISM, although some of the high [CII]/FIR ratios may be due to turbulent heating.« less

Spatio-Temporal Equalizer for a Receiving-Antenna Feed Array

NASA Technical Reports Server (NTRS)

Mukai, Ryan; Lee, Dennis; Vilnrotter, Victor

2010-01-01

A spatio-temporal equalizer has been conceived as an improved means of suppressing multipath effects in the reception of aeronautical telemetry signals, and may be adaptable to radar and aeronautical communication applications as well. This equalizer would be an integral part of a system that would also include a seven-element planar array of receiving feed horns centered at the focal point of a paraboloidal antenna that would be nominally aimed at or near the aircraft that would be the source of the signal that one seeks to receive (see Figure 1). This spatio-temporal equalizer would consist mostly of a bank of seven adaptive finite-impulse-response (FIR) filters one for each element in the array - and the outputs of the filters would be summed (see Figure 2). The combination of the spatial diversity of the feedhorn array and the temporal diversity of the filter bank would afford better multipath-suppression performance than is achievable by means of temporal equalization alone. The seven-element feed array would supplant the single feed horn used in a conventional paraboloidal ground telemetry-receiving antenna. The radio-frequency telemetry signals re ceiv ed by the seven elements of the array would be digitized, converted to complex baseband form, and sent to the FIR filter bank, which would adapt itself in real time to enable reception of telemetry at a low bit error rate, even in the presence of multipath of the type found at many flight test ranges.

High efficiency blue and white phosphorescent organic light emitting devices

NASA Astrophysics Data System (ADS)

Eom, Sang-Hyun

Organic light-emitting devices (OLEDs) have important applications in full-color flat-panel displays and as solid-state lighting sources. Achieving high efficiency deep-blue phosphorescent OLEDs (PHOLEDs) is necessary for high performance full-color displays and white light sources with a high color rendering index (CRI); however it is more challenging compared to the longer wavelength light emissions such as green and red due to the higher energy excitations for the deep-blue emitter as well as the weak photopic response of deep-blue emission. This thesis details several effective strategies to enhancing efficiencies of deep-blue PHOLEDs based on iridium(III) bis(4',6'-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6), which are further employed to demonstrate high efficiency white OLEDs by combining the deep-blue emitter with green and red emitters. First, we have employed 1,1-bis-(di-4-tolylaminophenyl) cyclohexane (TAPC) as the hole transporting material to enhance electron and triplet exciton confinement in Fir6-based PHOLEDs, which increased external quantum efficiency up to 18 %. Second, dual-emissive-layer (D-EML) structures consisting of an N,N -dicarbazolyl-3,5-benzene (mCP) layer doped with 4 wt % FIr6 and a p-bis (triphenylsilyly)benzene (UGH2) layer doped with 25 wt % FIr6 was employed to maximize exciton generation in the emissive layer. Combined with the p-i-n device structure, high power efficiencies of (25 +/- 2) lm/W at 100 cd/m2 and (20 +/- 2) lm/W at 1000 cd/m 2 were achieved. Moreover, the peak external quantum efficiency of (20 +/- 1) % was achieved by employing tris[3-(3-pyridyl)mesityl]borane (3TPYMB) as the electron transporting material, which further improves the exciton confinement in the emissive layer. With Cs2CO3 doping in the 3TPYMB layer to greatly increase its electrical conductivity, a peak power efficiency up to (36 +/- 2) lm/W from the deep-blue PHOLED was achieved, which also maintains Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.28). High efficiency white PHOLEDs are also demonstrated by incorporating green and red phosphorescent emitters together with the deep-blue emitter FIr6. Similar to the FIr6-only devices, the D-EML structure with high triplet energy charge transport materials leads to a maximum external quantum efficiency of (19 +/- 1) %. Using the p-i-n device structure, a peak power efficiency of (40 +/- 2) lm/W and (36 +/- 2) lm/W at 100 cd/m2 were achieved, and the white PHOLED possesses a CRI of 79 and CIE coordinates of (0.37, 0.40). The limited light extraction from the planar-type OLEDs is also one of the remaining challenges to the OLED efficiency. Here we have developed a simple soft lithography technique to fabricate a transparent, close-packed hemispherical microlens arrays. The application of such microlens arrays to the glass surface of the large-area fluorescent OLEDs enhanced the light extraction efficiency up to (70 +/- 7)%. It is also shown that the light extraction efficiency of the OLEDs is affected by microlens contact angle, OLEDs size, and detailed layer structure of the OLEDs.

Financial feasibility of marker-aided selection in Douglas-fir.

Treesearch

G.R. Johnson; N.C. Wheeler; S.H. Strauss

2000-01-01

The land area required for a marker-aided selection (MAS) program to break-even (i.e., have equal costs and benefits) was estimated using computer simulation for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Pacific Northwestern United States. We compared the selection efficiency obtained when using an index that included the...

Characterizing root-associated fungal communities and soils of Douglas-fir (Pseudotsuga menziesii) stands that naturally produce Oregon white truffles (Tuber oregonense and Tuber gibbosum).

PubMed

Benucci, Gian Maria Niccolò; Lefevre, Charles; Bonito, Gregory

2016-07-01

Many truffle species in the genus Tuber are endemic to North America. Some of these have commercial value such as Tuber oregonense and Tuber gibbosum, commonly known as Oregon white truffles. Most of what is known about the ecology of these truffles comes from observational data. These truffle species form ectomycorrhizas with Douglas-fir (Pseudotsuga menziesii) and sometimes fruit abundantly in early successional forest regrowth. The goal of this study was to characterize fungal communities and soils associated with truffle-producing Douglas-fir sites. We extracted DNA from roots of five trees at four different truffle-producing Douglas-fir sites (n = 20). We amplified the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA (nrDNA) and sequenced amplicons with 454 pyrosequencing. After quality filtering, we assembled 15,713 sequences into 150 fungal operational taxonomic units (OTUs). Pezizomycetes (Tuber and Pyronemataceae) were the most abundant taxa detected followed by Helotiales. Agaricomycetes represented most by Thelephoraceae, Russulaceae, and Inocybaceae were also abundant. A total of five Tuber species were detected. T. oregonense was the most abundant OTU, followed by T. gibbosum and Wilcoxina mikolae. Fungal root endophytes were also detected and well represented by Chalara and Phialocephala spp. Fungal community structure and soil chemistry differed between sites. This study represents the first characterization of the fungal communities in Douglas-fir stands producing Oregon white truffles. We found that Tuber species can be dominant ectomycorrhizal symbionts of Douglas-fir. Truffle fungi are also important in forest health, food webs, and as a non-timber forest resource that can contribute to rural economies.

Seed invasion filters and forest fire severity

Treesearch

Tom R. Cottrell; Paul F. Hessburg; Jonathan A. Betz

2008-01-01

Forest seed dispersal is altered after fire. Using seed traps, we studied impacts of fire severity on timing of seed dispersal, total seed rain, and seed rain richness in patches of high and low severity fire and unburned Douglas-fir (Pseudotsuga menziesii) forests in the Fischer and Tyee fire complexes in the eastern Washington Cascades. Unburned...

Next-Generation A/D Sampler ADS3000+ for VLBI2010

NASA Technical Reports Server (NTRS)

Takefuji, Kazuhiro; Takeuchi, Hiroshi; Tsutsumi, Masanori; Koyama, Yasuhiro

2010-01-01

A high-speed A/D sampler, called ADS3000+, has been developed in 2008, which can sample one analog signal up to 4 Gbps to versatile Linux PC. After A/D conversion, the ADS3000+ can perform digital signal processing such as real-time DBBC (Digital Base Band Conversion) and FIR filtering such as simple CW RFI filtering using the installed FPGAs. A 4 Gsps fringe test with the ADS3000+ has been successfully performed. The ADS3000+ will not exclusively be used for VLBI but will also be employed in other applications.

Compact Focal Plane Assembly for Planetary Science

NASA Technical Reports Server (NTRS)

Brown, Ari; Aslam, Shahid; Huang, Wei-Chung; Steptoe-Jackson, Rosalind

2013-01-01

A compact radiometric focal plane assembly (FPA) has been designed in which the filters are individually co-registered over compact thermopile pixels. This allows for construction of an ultralightweight and compact radiometric instrument. The FPA also incorporates micromachined baffles in order to mitigate crosstalk and low-pass filter windows in order to eliminate high-frequency radiation. Compact metal mesh bandpass filters were fabricated for the far infrared (FIR) spectral range (17 to 100 microns), a game-changing technology for future planetary FIR instruments. This fabrication approach allows the dimensions of individual metal mesh filters to be tailored with better than 10- micron precision. In contrast, conventional compact filters employed in recent missions and in near-term instruments consist of large filter sheets manually cut into much smaller pieces, which is a much less precise and much more labor-intensive, expensive, and difficult process. Filter performance was validated by integrating them with thermopile arrays. Demonstration of the FPA will require the integration of two technologies. The first technology is compact, lightweight, robust against cryogenic thermal cycling, and radiation-hard micromachined bandpass filters. They consist of a copper mesh supported on a deep reactive ion-etched silicon frame. This design architecture is advantageous when constructing a lightweight and compact instrument because (1) the frame acts like a jig and facilitates filter integration with the FPA, (2) the frame can be designed so as to maximize the FPA field of view, (3) the frame can be simultaneously used as a baffle for mitigating crosstalk, and (4) micron-scale alignment features can be patterned so as to permit high-precision filter stacking and, consequently, increase the filter bandwidth and sharpen the out-of-band rolloff. The second technology consists of leveraging, from another project, compact and lightweight Bi0.87Sb0.13/Sb arrayed thermopiles. These detectors consist of 30-layer thermopiles deposited in series upon a silicon nitride membrane. At 300 K, the thermopile arrays are highly linear over many orders of magnitude of incident IR power, and have a reported specific detectivity that exceeds the requirements imposed on future mission concepts. The bandpass filter array board is integrated with a thermopile array board by mounting both boards on a machined aluminum jig.

A periodic spatio-spectral filter for event-related potentials.

PubMed

Ghaderi, Foad; Kim, Su Kyoung; Kirchner, Elsa Andrea

2016-12-01

With respect to single trial detection of event-related potentials (ERPs), spatial and spectral filters are two of the most commonly used pre-processing techniques for signal enhancement. Spatial filters reduce the dimensionality of the data while suppressing the noise contribution and spectral filters attenuate frequency components that most likely belong to noise subspace. However, the frequency spectrum of ERPs overlap with that of the ongoing electroencephalogram (EEG) and different types of artifacts. Therefore, proper selection of the spectral filter cutoffs is not a trivial task. In this research work, we developed a supervised method to estimate the spatial and finite impulse response (FIR) spectral filters, simultaneously. We evaluated the performance of the method on offline single trial classification of ERPs in datasets recorded during an oddball paradigm. The proposed spatio-spectral filter improved the overall single-trial classification performance by almost 9% on average compared with the case that no spatial filters were used. We also analyzed the effects of different spectral filter lengths and the number of retained channels after spatial filtering. Copyright © 2016. Published by Elsevier Ltd.

Artifact removal from EEG signals using adaptive filters in cascade

NASA Astrophysics Data System (ADS)

Garcés Correa, A.; Laciar, E.; Patiño, H. D.; Valentinuzzi, M. E.

2007-11-01

Artifacts in EEG (electroencephalogram) records are caused by various factors, like line interference, EOG (electro-oculogram) and ECG (electrocardiogram). These noise sources increase the difficulty in analyzing the EEG and to obtaining clinical information. For this reason, it is necessary to design specific filters to decrease such artifacts in EEG records. In this paper, a cascade of three adaptive filters based on a least mean squares (LMS) algorithm is proposed. The first one eliminates line interference, the second adaptive filter removes the ECG artifacts and the last one cancels EOG spikes. Each stage uses a finite impulse response (FIR) filter, which adjusts its coefficients to produce an output similar to the artifacts present in the EEG. The proposed cascade adaptive filter was tested in five real EEG records acquired in polysomnographic studies. In all cases, line-frequency, ECG and EOG artifacts were attenuated. It is concluded that the proposed filter reduces the common artifacts present in EEG signals without removing significant information embedded in these records.

Far infrared filters for the Galileo-Jupiter and other missions

NASA Technical Reports Server (NTRS)

Seeley, J. S.; Hunneman, R.; Whatley, A.

1981-01-01

Progress in the development of FIR multilayer interference filters for the net flux radiometer and photopolarizing radiometer to be carried on board the Galileo mission to Jupiter is reported. The multilayer interference technique has been extended to the region above 40 microns by the use of PbTe/II-VI materials in hard-coated combination, with the thickest layers composed of CdSe QWOT at 74 microns and PbTe QWOT. Improvements have also been obtained in filters below 20 microns on the basis of the Chebyshev stack design. A composite filter cutting on steeply at 40 microns has been designed which employs a thin crystal quartz substrate, shorter wavelength absorption in ZnS and As2S3 thin films, and supplementary multilayer interference. Finally, absorptive filters have been developed based on II-VI compounds in multilayer combination with KRS-5 (or 6) on a KRS-5 (or 6) substrate

Compact Micromachined Bandpass Filters for Infrared Planetary Spectroscopy

NASA Technical Reports Server (NTRS)

Brown, Ari D.; Aslam, Shahid; Chervenak, James A.; Huang, Wei-Chung; Merrell, Willie; Quijada, Manuel

2011-01-01

The thermal instrument strawman payload of the Jupiter Europa Orbiter on the Europa Jupiter Science Mission will map out thermal anomalies, the structure, and atmospheric conditions of Europa and Jupiter within the 7-100 micron spectral range. One key requirement for the payload is that the mass cannot exceed 3.7 kg. Consequently, a new generation of light-weight miniaturized spectrometers needs to be developed. On the path toward developing these spectrometers is development of ancillary miniaturized spectroscopic components. In this paper, we present a strategy for making radiation hard and low mass FIR band pass metal mesh filters. Our strategy involves using MEMS-based fabrication techniques, which will permit the quasi-optical filter structures to be made with micron-scale precision. This will enable us to achieve tight control over both the pass band of the filter and the micromachined silicon support structure architecture, which will facilitate integration of the filters for a variety of applications.

Do trees smart from ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Douglas-firs near Eatonville, Washington - 70 miles south of Seattle - are getting doses of ozone pollution at levels regularly found in Los Angeles. Ozone levels of 220 parts per billion (ppb) can make your eyes smart and give your Aunt Edna a doozy of a headache. University of Washington researchers are now trying to find if Douglas-fir is adversely affected by 220 ppb of ozone. They are also studying whether individual branches can reveal how whole trees respond to pollutants. Studying entire trees is tough so researchers hope to take the pulse of a tree by examining its branches.more » At the university's experimental forest, researchers have placed 12-foot-tall plastic-covered corrals around six Douglas-firs, each nine or 10 years old and up to 15 feet tall. Three of the trees receive filtered air while three others are blasted with 220 ppb of ozone for eight hours each day. Four individual branches on each tree are encased in their own plastic chambers. Two are dosed with filtered air and two with ozone. To date, the UW research is the only study in the US combining branch chambers with whole tree measurements. Now in its second year, the experiment is expected to yield information about growth and foliage health by measuring respiration, chlorophyll, photosynthesis, and nutrient uptake. Loss of tree vigor could lead to increased problems with pathogens and insects. In the summer of '88, surprisingly high levels of ozone - up to 196 ppb - were detected in forests downwind from Seattle, worse than the urban areas themselves.« less

Device model for pixelless infrared image up-converters based on polycrystalline graphene heterostructures

NASA Astrophysics Data System (ADS)

Ryzhii, V.; Shur, M. S.; Ryzhii, M.; Karasik, V. E.; Otsuji, T.

2018-01-01

We developed a device model for pixelless converters of far/mid-infrared radiation (FIR/MIR) images into near-infrared/visible (NIR/VIR) images. These converters use polycrystalline graphene layers (PGLs) immersed in the van der Waals materials integrated with a light emitting diode (LED). The PGL serves as an element of the PGL infrared photodetector (PGLIP) sensitive to the incoming FIR/MIR due to the interband absorption. The spatially non-uniform photocurrent generated in the PGLIP repeats (mimics) the non-uniform distribution (image) created by the incident FIR/MIR. The injection of the nonuniform photocurrent into the LED active layer results in the nonuniform NIR/VIR image reproducing the FIR/MIR image. The PGL and the entire layer structure are not deliberately partitioned into pixels. We analyze the characteristics of such pixelless PGLIP-LED up-converters and show that their image contrast transfer function and the up-conversion efficiency depend on the PGL lateral resistivity. The up-converter exhibits high photoconductive gain and conversion efficiency when the lateral resistivity is sufficiently high. Several teams have successfully demonstrated the large area PGLs with the resistivities varying in a wide range. Such layers can be used in the pixelless PGLIP-LED image up-converters. The PGLIP-LED image up-converters can substantially surpass the image up-converters based on the quantum-well infrared photodetector integrated with the LED. These advantages are due to the use of the interband FIR/NIR absorption and a high photoconductive gain in the GLIPs.

Effects of water suspension and wet-dry cycling on fertility of Douglas-fir pollen.

Treesearch

Donald L. Copes; Nan C. Vance

2000-01-01

Studies were made to determine how long Douglas-fir pollen remains viable after suspension in cool water form 0 to 34 days. Linear regression analysis of in vivo and in vitro tests indicated that filled seed efficiency and pollen viability, respectively, decreased about 3 percent per day. The relation may have been nonlinear the first 6 days, as little decrease...

Genetic variation in tree structure and its relation to size in Douglas-fir: I. Biomass partitioning, foliage efficiency, stem form, and wood density.

Treesearch

J.B. St. Clair

1994-01-01

Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found in size, biomass partitioning, and wood density, and genetic gains may be...

Dowel-nut connection in Douglas-fir peeler cores

Treesearch

Ronald W. Wolfe; John R. King; Agron Gjinolli

As part of an effort to encourage more efficient use of small-diameter timber, the Forest Products Laboratory cooperated with Geiger Engineers in a study of the structural properties of Douglas-fir peeler cores and the efficacy of a bdowel-nutc connection detail for application in the design of a space frame roof system. A 44.5-mm- (1.75-in.-) diameter dowel-nut...

Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range

Treesearch

Eladio H. Cornejo-Oviedo; Steven L. Voelker; Douglas B. Mainwaring; Douglas A. Maguire; Frederick C. Meinzer; J. Renée Brooks

2017-01-01

Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen (N) to increase growth rates, but only about ⅔ of all stands respond. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The primary objective of this study was...

A Comparative Analysis of Digital and Passive Filters for IFOC based Induction Motor Drive (EV) fed through ZSI

NASA Astrophysics Data System (ADS)

Bedi, Tarun; Heema, Dave; Singh, Dheerendra

2018-03-01

It is known that harmonics are generated in any power electronics based application. Since presence of harmonics is not desirable, it is necessary to remove the harmonics. The IFOC is based on stator current regulation, and the stator currents are sensed and used in the speed control algorithm. The current needs to be free from noise and harmonics for accurate further processing. In this paper, a passive analog filter, as well as a 50th order FIR filter is designed in MATLAB and implemented in Code Composer Studio to remove noise and distortion, and a comparative analysis has been done, for the speed control of an induction motor fed through ZSI, for electric vehicle application.

Joint polarization tracking and channel equalization based on radius-directed linear Kalman filter

NASA Astrophysics Data System (ADS)

Zhang, Qun; Yang, Yanfu; Zhong, Kangping; Liu, Jie; Wu, Xiong; Yao, Yong

2018-01-01

We propose a joint polarization tracking and channel equalization scheme based on radius-directed linear Kalman filter (RD-LKF) by introducing the butterfly finite-impulse-response (FIR) filter in our previously proposed RD-LKF method. Along with the fast polarization tracking, it can also simultaneously compensate the inter-symbol interference (ISI) effects including residual chromatic dispersion and polarization mode dispersion. Compared with the conventional radius-directed equalizer (RDE) algorithm, it is demonstrated experimentally that three times faster convergence speed, one order of magnitude better tracking capability, and better BER performance is obtained in polarization division multiplexing 16 quadrature amplitude modulation system. Besides, the influences of the algorithm parameters on the convergence and the tracking performance are investigated by numerical simulation.

Emissions from prescribed burning of timber slash piles in Oregon

NASA Astrophysics Data System (ADS)

Aurell, Johanna; Gullett, Brian K.; Tabor, Dennis; Yonker, Nick

2017-02-01

Emissions from burning piles of post-harvest timber slash (Douglas-fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5), black carbon, ultraviolet absorbing PM, elemental/organic carbon, filter-based metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins/dibenzofurans (PCDD/PCDF), and volatile organic compounds (VOCs) were sampled to determine emission factors, the amount of pollutant formed per amount of biomass burned. The effect on emissions from covering the piles with polyethylene (PE) sheets to prevent fuel wetting versus uncovered piles was also determined. Results showed that the uncovered ("wet") piles burned with lower combustion efficiency and higher emission factors for VOCs, PM2.5, PCDD/PCDF, and PAHs. Removal of the PE prior to ignition, variation of PE size, and changing PE thickness resulted in no statistical distinction between emissions. Results suggest that dry piles, whether covered with PE or not, exhibited statistically significant lower emissions than wet piles due to better combustion efficiency.

Zero-phase FIR filters: Blessing or curse?

NASA Astrophysics Data System (ADS)

Scherbaum, Frank

These are exciting times for observational seismology. State-of-the-art broadband seismometers now easily cover a frequency band of more than one hundred seconds to several tens of Hertz in a single sensor. Commonly available data loggers provide a dynamic range exceeding 120 dB. Ground motion amplitudes differing by more than 6 orders of magnitude can be simultaneously recorded without distortion.

A SNP resource for Douglas-fir: de novo transcriptome assembly and SNP detection and validation.

PubMed

Howe, Glenn T; Yu, Jianbin; Knaus, Brian; Cronn, Richard; Kolpak, Scott; Dolan, Peter; Lorenz, W Walter; Dean, Jeffrey F D

2013-02-28

Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauca) are native to North America, the coastal variety is also widely planted for timber production in Europe, New Zealand, Australia, and Chile. Our main goal was to develop a SNP resource large enough to facilitate genomic selection in Douglas-fir breeding programs. To accomplish this, we developed a 454-based reference transcriptome for coastal Douglas-fir, annotated and evaluated the quality of the reference, identified putative SNPs, and then validated a sample of those SNPs using the Illumina Infinium genotyping platform. We assembled a reference transcriptome consisting of 25,002 isogroups (unique gene models) and 102,623 singletons from 2.76 million 454 and Sanger cDNA sequences from coastal Douglas-fir. We identified 278,979 unique SNPs by mapping the 454 and Sanger sequences to the reference, and by mapping four datasets of Illumina cDNA sequences from multiple seed sources, genotypes, and tissues. The Illumina datasets represented coastal Douglas-fir (64.00 and 13.41 million reads), interior Douglas-fir (80.45 million reads), and a Yakima population similar to interior Douglas-fir (8.99 million reads). We assayed 8067 SNPs on 260 trees using an Illumina Infinium SNP genotyping array. Of these SNPs, 5847 (72.5%) were called successfully and were polymorphic. Based on our validation efficiency, our SNP database may contain as many as ~200,000 true SNPs, and as many as ~69,000 SNPs that could be genotyped at ~20,000 gene loci using an Infinium II array-more SNPs than are needed to use genomic selection in tree breeding programs. Ultimately, these genomic resources will enhance Douglas-fir breeding and allow us to better understand landscape-scale patterns of genetic variation and potential responses to climate change.

A SNP resource for Douglas-fir: de novo transcriptome assembly and SNP detection and validation

PubMed Central

2013-01-01

Background Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauca) are native to North America, the coastal variety is also widely planted for timber production in Europe, New Zealand, Australia, and Chile. Our main goal was to develop a SNP resource large enough to facilitate genomic selection in Douglas-fir breeding programs. To accomplish this, we developed a 454-based reference transcriptome for coastal Douglas-fir, annotated and evaluated the quality of the reference, identified putative SNPs, and then validated a sample of those SNPs using the Illumina Infinium genotyping platform. Results We assembled a reference transcriptome consisting of 25,002 isogroups (unique gene models) and 102,623 singletons from 2.76 million 454 and Sanger cDNA sequences from coastal Douglas-fir. We identified 278,979 unique SNPs by mapping the 454 and Sanger sequences to the reference, and by mapping four datasets of Illumina cDNA sequences from multiple seed sources, genotypes, and tissues. The Illumina datasets represented coastal Douglas-fir (64.00 and 13.41 million reads), interior Douglas-fir (80.45 million reads), and a Yakima population similar to interior Douglas-fir (8.99 million reads). We assayed 8067 SNPs on 260 trees using an Illumina Infinium SNP genotyping array. Of these SNPs, 5847 (72.5%) were called successfully and were polymorphic. Conclusions Based on our validation efficiency, our SNP database may contain as many as ~200,000 true SNPs, and as many as ~69,000 SNPs that could be genotyped at ~20,000 gene loci using an Infinium II array—more SNPs than are needed to use genomic selection in tree breeding programs. Ultimately, these genomic resources will enhance Douglas-fir breeding and allow us to better understand landscape-scale patterns of genetic variation and potential responses to climate change. PMID:23445355

Vegetation control effects on untreated wood, crude cellulose and holocellulose 𗉝C of early and latewood in 3- to 5-year-old rings of Douglas-fir

Treesearch

Adrian Ares; Constance A Harrington; Thomas A. Terry; Joseph M. Kraft

2009-01-01

The stable carbon (C) composition of tree rings expressed as 13C, is a measure of intrinsic water-use efficiency and can indicate the occurrence of past water shortages for tree growth. We examined 13C in 3- to 5-year-old rings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees...

Low power adder based auditory filter architecture.

PubMed

Rahiman, P F Khaleelur; Jayanthi, V S

2014-01-01

Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

Reception of Multiple Telemetry Signals via One Dish Antenna

NASA Technical Reports Server (NTRS)

Mukai, Ryan; Vilnrotter, Victor

2010-01-01

A microwave aeronautical-telemetry receiver system includes an antenna comprising a seven-element planar array of receiving feed horns centered at the focal point of a paraboloidal dish reflector that is nominally aimed at a single aircraft or at multiple aircraft flying in formation. Through digital processing of the signals received by the seven feed horns, the system implements a method of enhanced cancellation of interference, such that it becomes possible to receive telemetry signals in the same frequency channel simultaneously from either or both of two aircraft at slightly different angular positions within the field of view of the antenna, even in the presence of multipath propagation. The present system is an advanced version of the system described in Spatio- Temporal Equalizer for a Receiving-Antenna Feed Array NPO-43077, NASA Tech Briefs, Vol. 34, No. 2 (February 2010), page 32. To recapitulate: The radio-frequency telemetry signals received by the seven elements of the array are digitized, converted to complex baseband form, and sent to a spatio-temporal equalizer that consists mostly of a bank of seven adaptive finite-impulse-response (FIR) filters (one for each element in the array) plus a unit that sums the outputs of the filters. The combination of the spatial diversity of the feedhorn array and the temporal diversity of the filter bank affords better multipath suppression performance than is achievable by means of temporal equalization alone. The FIR filter bank adapts itself in real time to enable reception of telemetry at a low bit error rate, even in the presence of frequency-selective multipath propagation like that commonly found at flight-test ranges. The combination of the array and the filter bank makes it possible to constructively add multipath incoming signals to the corresponding directly arriving signals, thereby enabling reductions in telemetry bit-error rates.

Recursive inversion of externally defined linear systems by FIR filters

NASA Technical Reports Server (NTRS)

Bach, Ralph E., Jr.; Baram, Yoram

1989-01-01

The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least-squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problem of system identification and compensation.

Direct Sequence Spread Spectrum (DSSS) Receiver, User Manual

DTIC Science & Technology

2008-01-01

sampled data is clocked in to correlator data registers and a comparison is made between the code and data register contents, producing a correlation ...symbol (equal to the processing gain Gp ) but need not be otherwise synchronised with the spreading codes . This allows a very long and noise- like PRBS...and Q channels are independently but synchronously sampled . Complex Real ADC FIR Filter Interpolator Acquisition Correlators

Design of adaptive control systems by means of self-adjusting transversal filters

NASA Technical Reports Server (NTRS)

Merhav, S. J.

1986-01-01

The design of closed-loop adaptive control systems based on nonparametric identification was addressed. Implementation is by self-adjusting Least Mean Square (LMS) transversal filters. The design concept is Model Reference Adaptive Control (MRAC). Major issues are to preserve the linearity of the error equations of each LMS filter, and to prevent estimation bias that is due to process or measurement noise, thus providing necessary conditions for the convergence and stability of the control system. The controlled element is assumed to be asymptotically stable and minimum phase. Because of the nonparametric Finite Impulse Response (FIR) estimates provided by the LMS filters, a-priori information on the plant model is needed only in broad terms. Following a survey of control system configurations and filter design considerations, system implementation is shown here in Single Input Single Output (SISO) format which is readily extendable to multivariable forms. In extensive computer simulation studies the controlled element is represented by a second-order system with widely varying damping, natural frequency, and relative degree.

Remote sensing of atmospheric chemistry; Proceedings of the Meeting, Orlando, FL, Apr. 1-3, 1991

NASA Technical Reports Server (NTRS)

Mcelroy, James L. (Editor); Mcneal, Robert J. (Editor)

1991-01-01

The present volume on remote sensing of atmospheric chemistry discusses special remote sensing space observations and field experiments to study chemical change in the atmosphere, network monitoring for detection of stratospheric chemical change, stratospheric chemistry studies, and the combining of model, in situ, and remote sensing in atmospheric chemistry. Attention is given to the measurement of tropospheric carbon monoxide using gas filter radiometers, long-path differential absorption measurements of tropospheric molecules, air quality monitoring with the differential optical absorption spectrometer, and a characterization of tropospheric methane through space-based remote sensing. Topics addressed include microwave limb sounder experiments for UARS and EOS, an overview of the spectroscopy of the atmosphere using an FIR emission experiment, the detection of stratospheric ozone trends by ground-based microwave observations, and a FIR Fabry-Perot spectrometer for OH measurements.

Equalizing secondary path effects using the periodicity of fMRI acoustic noise.

PubMed

Kannan, Govind; Milani, Ali A; Panahi, Issa; Briggs, Richard

2008-01-01

Non-minimum phase secondary path has a direct effect on achieving a desired noise attenuation level in active noise control (ANC) systems. The adaptive noise canceling filter is often a causal FIR filter which may not be able to sufficiently equalize the effect of a non-minimum phase secondary path, since in theory only a non-causal filter can equalize it. However a non-causal stable filter can be found to equalize the non-minimum phase effect of secondary path. Realization of non-causal stable filters requires knowledge of future values of input signal. In this paper we develop methods for equalizing the non-minimum phase property of the secondary path and improving the performance of an ANC system by exploiting the periodicity of fMRI acoustic noise. It has been shown that the scanner noise component is highly periodic and hence predictable which enables easy realization of non-causal filtering. Improvement in performance due to the proposed methods (with and without the equalizer) is shown for periodic fMRI acoustic noise.

An active structural acoustic control approach for the reduction of the structure-borne road noise

NASA Astrophysics Data System (ADS)

Douville, Hugo; Berry, Alain; Masson, Patrice

2002-11-01

The reduction of the structure-borne road noise generated inside the cabin of an automobile is investigated using an Active Structural Acoustic Control (ASAC) approach. First, a laboratory test bench consisting of a wheel/suspension/lower suspension A-arm assembly has been developed in order to identify the vibroacoustic transfer paths (up to 250 Hz) for realistic road noise excitation of the wheel. Frequency Response Function (FRF) measurements between the excitation/control actuators and each suspension/chassis linkage are used to characterize the different transfer paths that transmit energy through the chassis of the car. Second, a FE/BE model (Finite/Boundary Elements) was developed to simulate the acoustic field of an automobile cab interior. This model is used to predict the acoustic field inside the cabin as a response to the measured forces applied on the suspension/chassis linkages. Finally, an experimental implementation of ASAC is presented. The control approach relies on the use of inertial actuators to modify the vibration behavior of the suspension and the automotive chassis such that its noise radiation efficiency is decreased. The implemented algorithm consists of a MIMO (Multiple-Input-Multiple-Output) feedforward configuration with a filtered-X LMS algorithm using an advanced reference signal (width FIR filters) using the Simulink/Dspace environment for control prototyping.

Acquisition, Image and Data Compression.

DTIC Science & Technology

1983-04-30

considered, self well to the freq.ency hcppe! signal arpli’a- ,i n. This loop aol Itn i ociltei w’efors are hown in Firs. la,h. 71;n r’tine wav ’-f, m...thei siiiillaiieiuts spacie midi slllitial tre(tivelicy 26. 1). .ui-.u.ii m~ill It. V. K. N’iu.a~ kiar Appl. Ot IS, ti673 filtering tt i-I ) sit .imls

Adaptive clutter rejection filters for airborne Doppler weather radar applied to the detection of low altitude windshear

NASA Technical Reports Server (NTRS)

Keel, Byron M.

1989-01-01

An optimum adaptive clutter rejection filter for use with airborne Doppler weather radar is presented. The radar system is being designed to operate at low-altitudes for the detection of windshear in an airport terminal area where ground clutter returns may mask the weather return. The coefficients of the adaptive clutter rejection filter are obtained using a complex form of a square root normalized recursive least squares lattice estimation algorithm which models the clutter return data as an autoregressive process. The normalized lattice structure implementation of the adaptive modeling process for determining the filter coefficients assures that the resulting coefficients will yield a stable filter and offers possible fixed point implementation. A 10th order FIR clutter rejection filter indexed by geographical location is designed through autoregressive modeling of simulated clutter data. Filtered data, containing simulated dry microburst and clutter return, are analyzed using pulse-pair estimation techniques. To measure the ability of the clutter rejection filters to remove the clutter, results are compared to pulse-pair estimates of windspeed within a simulated dry microburst without clutter. In the filter evaluation process, post-filtered pulse-pair width estimates and power levels are also used to measure the effectiveness of the filters. The results support the use of an adaptive clutter rejection filter for reducing the clutter induced bias in pulse-pair estimates of windspeed.

Fast Image Restoration for Spatially Varying Defocus Blur of Imaging Sensor

PubMed Central

Cheong, Hejin; Chae, Eunjung; Lee, Eunsung; Jo, Gwanghyun; Paik, Joonki

2015-01-01

This paper presents a fast adaptive image restoration method for removing spatially varying out-of-focus blur of a general imaging sensor. After estimating the parameters of space-variant point-spread-function (PSF) using the derivative in each uniformly blurred region, the proposed method performs spatially adaptive image restoration by selecting the optimal restoration filter according to the estimated blur parameters. Each restoration filter is implemented in the form of a combination of multiple FIR filters, which guarantees the fast image restoration without the need of iterative or recursive processing. Experimental results show that the proposed method outperforms existing space-invariant restoration methods in the sense of both objective and subjective performance measures. The proposed algorithm can be employed to a wide area of image restoration applications, such as mobile imaging devices, robot vision, and satellite image processing. PMID:25569760

Fundamentals handbook of electrical and computer engineering. Volume 1 Circuits fields and electronics

NASA Astrophysics Data System (ADS)

Chang, S. S. L.

State of the art technology in circuits, fields, and electronics is discussed. The principles and applications of these technologies to industry, digital processing, microwave semiconductors, and computer-aided design are explained. Important concepts and methodologies in mathematics and physics are reviewed, and basic engineering sciences and associated design methods are dealt with, including: circuit theory and the design of magnetic circuits and active filter synthesis; digital signal processing, including FIR and IIR digital filter design; transmission lines, electromagnetic wave propagation and surface acoustic wave devices. Also considered are: electronics technologies, including power electronics, microwave semiconductors, GaAs devices, and magnetic bubble memories; digital circuits and logic design.

End-point controller design for an experimental two-link flexible manipulator using convex optimization

NASA Technical Reports Server (NTRS)

Oakley, Celia M.; Barratt, Craig H.

1990-01-01

Recent results in linear controller design are used to design an end-point controller for an experimental two-link flexible manipulator. A nominal 14-state linear-quadratic-Gaussian (LQG) controller was augmented with a 528-tap finite-impulse-response (FIR) filter designed using convex optimization techniques. The resulting 278-state controller produced improved end-point trajectory tracking and disturbance rejection in simulation and experimentally in real time.

Two-Dimensional Signal Processing, Optical Information Storage and Processing, and Electromagnetic Measurements

DTIC Science & Technology

1992-07-15

Modeling SENIOR PRINCIPAL INVESTIGATOR: R. M. Mersereau, Regents’ Professor SCIENTIFIC PERSONNEL: F. J. Malassenet, (Ph.D. received, Dec. 1991) T. R. Gardos ...multiprocessor environment. RESEARCH ACCOMPLISHMENTS: Students Gardos , Martucci, Rao, and Truong were partially supported using funds supplied by Georgia...pp. 21- 56, 1991. [4] T. R. Gardos and R. M. Mersereau, "FIR Filtering on a Lattice with Periodically Deleted Samples," Proc. 1991 IEEE Int. Conf

Study of quadrature FIR filters for extraction of low-frequency instantaneous information in biophysical signals

NASA Astrophysics Data System (ADS)

Arce-Guevara, Valdemar E.; Alba-Cadena, Alfonso; Mendez, Martín O.

Quadrature bandpass filters take a real-valued signal and output an analytic signal from which the instantaneous amplitude and phase can be computed. For this reason, they represent a useful tool to extract time-varying, narrow-band information from electrophysiological signals such as electroencephalogram (EEG) or electrocardiogram. One of the defining characteristics of quadrature filters is its null response to negative frequencies. However, when the frequency band of interest is close to 0 Hz, a careless filter design could let through negative frequencies, producing distortions in the amplitude and phase of the output. In this work, three types of quadrature filters (Ideal, Gabor and Sinusoidal) have been evaluated using both artificial and real EEG signals. For the artificial signals, the performance of each filter was measured in terms of the distortion in amplitude and phase, and sensitivity to noise and bandwidth selection. For the real EEG signals, a qualitative evaluation of the dynamics of the synchronization between two EEG channels was performed. The results suggest that, while all filters under study behave similarly under noise, they differ in terms of their sensitivity to bandwidth choice. In this study, the Sinusoidal filter showed clear advantages for the estimation of low-frequency EEG synchronization.

Soil phosphorus functional fractions and tree tissue nutrient concentrations influenced by stand density in subtropical Chinese fir plantation forests

PubMed Central

Fang, Xiang-Min; Zhang, Xiu-Lan; Zong, Ying-Ying; Zhang, Yang; Wan, Song-Ze; Bu, Wen-Sheng

2017-01-01

Stand density regulation is an important measure of plantation forest management, and phosphorus (P) is often the limiting factor of tree productivity, especially in the subtropics and tropics. However, the stand density influence on ecosystem P cycling is unclear in Chinese fir (Cunninghamia lanceolata) plantations of subtropical China. We collected rhizosphere and bulk soils, leaves and twigs with different ages and roots with different orders to measure P and nitrogen (N) variables in Chinese fir plantations with low density (LDCF) and high density (HDCF) at Fujian and Hunan provinces of subtropical China. Rhizosphere soil labile P, slow P, occluded P and extractable P were higher in LDCF than HDCF at two sites. Meanwhile, P and N concentrations of 1-year-old leaves and twigs were higher in LDCF than HDCF and leaf N/P ratio generally increased with increasing leaf age at two sites. Rhizosphere vs. bulk soil labile P and occluded P were greater in LDCF than HDCF at Fujian. Nitrogen resorption efficiencies (NRE) of leaves and twigs were higher in LDCF than HDCF at Fujian, while their P resorption efficiencies (PRE) were not different between two densities at two sites. The average NRE of leaves (41.7%) and twigs (65.6%) were lower than the corresponding PRE (67.8% and 78.0%, respectively). Our results suggest that reducing stem density in Chinese fir plantations might be helpful to increase soil active P supplies and meet tree nutrient requirements. PMID:29073278

A Dynamic Attitude Measurement System Based on LINS

PubMed Central

Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

2014-01-01

A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

A model of head-related transfer functions based on a state-space analysis

NASA Astrophysics Data System (ADS)

Adams, Norman Herkamp

This dissertation develops and validates a novel state-space method for binaural auditory display. Binaural displays seek to immerse a listener in a 3D virtual auditory scene with a pair of headphones. The challenge for any binaural display is to compute the two signals to supply to the headphones. The present work considers a general framework capable of synthesizing a wide variety of auditory scenes. The framework models collections of head-related transfer functions (HRTFs) simultaneously. This framework improves the flexibility of contemporary displays, but it also compounds the steep computational cost of the display. The cost is reduced dramatically by formulating the collection of HRTFs in the state-space and employing order-reduction techniques to design efficient approximants. Order-reduction techniques based on the Hankel-operator are found to yield accurate low-cost approximants. However, the inter-aural time difference (ITD) of the HRTFs degrades the time-domain response of the approximants. Fortunately, this problem can be circumvented by employing a state-space architecture that allows the ITD to be modeled outside of the state-space. Accordingly, three state-space architectures are considered. Overall, a multiple-input, single-output (MISO) architecture yields the best compromise between performance and flexibility. The state-space approximants are evaluated both empirically and psychoacoustically. An array of truncated FIR filters is used as a pragmatic reference system for comparison. For a fixed cost bound, the state-space systems yield lower approximation error than FIR arrays for D>10, where D is the number of directions in the HRTF collection. A series of headphone listening tests are also performed to validate the state-space approach, and to estimate the minimum order N of indiscriminable approximants. For D = 50, the state-space systems yield order thresholds less than half those of the FIR arrays. Depending upon the stimulus uncertainty, a minimum state-space order of 7≤N≤23 appears to be adequate. In conclusion, the proposed state-space method enables a more flexible and immersive binaural display with low computational cost.

Filter design for cancellation of baseline-fluctuation in needle EMG recordings.

PubMed

Rodríguez-Carreño, I; Malanda-Trigueros, A; Gila-Useros, L; Navallas-Irujo, J; Rodríguez-Falces, J

2006-01-01

Appropriate cancellation of the baseline fluctuation (BLF) is an important issue when recording EMG signals as it may degrade signal quality and distort qualitative and quantitative analysis. We present a novel filter-design approach for automatic cancellation of the BLF based on several signal processing techniques used sequentially. The methodology is to estimate the spectral content of the BLF, and then to use this estimation to design a high-pass FIR filter that cancel the BLF present in the signal. Two merit figures are devised for measuring the degree of BLF present in an EMG record. These figures are used to compare our method with the conventional approach, which naively considers the baseline course to be of constant (without any fluctuation) potential shift. Applications of the technique on real and simulated EMG signals show the superior performance of our approach in terms of both visual inspection and the merit figures.

A comparison of coupled biogeophysical and biogeochemical dynamics across a precipitation gradient in Oregon using data assimilation

NASA Astrophysics Data System (ADS)

Pettijohn, J. C.; Law, B. E.; Williams, M. D.; Stoekli, R.; Thornton, P. E.; Thomas, C. K.; Hudiburg, T. W.; Martin, J.

2010-12-01

We present results from our coupled biophysical - biochemical model data fusion (MDF) analysis across a climatic gradient in Oregon, USA, using data from a coast-range Douglas-fir (US-Fir; 2006-2008) and a semi-arid ponderosa pine (US-Me2; 2002-2008) AmeriFlux site. Our MDF scheme couples the Ensemble Kalman Filter (EnKF) with the National Center for Atmospheric Research (NCAR) Community Land Model with Carbon-Nitrogen coupling (CLM-CN, version 3.5). Assimilated data includes continuous eddy covariance measurements of forest-atmosphere CO2 (NEE, net ecosystem exchange) and water vapor fluxes (λE, latent heat flux), chamber-based soil respiratory flux, soil moisture and temperature, snow depth (US-Me2), MODIS-derived 8 day LAI, and carbon and nitrogen pools. We quantify the ecosystem carbon and nitrogen budgets, partition NEE and λE fluxes, and thus increase confidence in multi-scale controls on CO2 and water vapor exchange. The MDF did a better job predicting NEE than λE at both sites (r2 = 0.86 for NEE at both sites; λE r2 = 0.65 and 0.63 at the US-ME2 and US-Fir sites, respectively) partly due to a weighting scheme we prescribed for NEE. The distribution of carbon and nitrogen differed significantly between sites, with total ecosystem carbon (vegetation, detritus, soil) of the US-Fir site being about 1.4 times higher than the US-Me2 site (35 kg C m-2 vs. 25 kg C m-2). Mean NEE over overlapping water years ‘07-‘08 was -495 gC m-2 at the US-Me2 site as opposed to -809 gC m-2 at the US-Fir site, nearly a two-fold difference in C uptake across this precipitation gradient. Average GPP and ecosystem respiration (Re) over these two water years were both ~1.7x greater at the US-Fir site, with 1712 gC m^-2 and 1217 gC m-2, respectively, at the US-Me2 site vs. 2841 gC m-2 and 2032 gC m-2 at the US-Fir. Autotrophic respiration contributed 79% and 72% to the Re flux at the US-Me2 and US-Fir sites, respectively, with total soil respiration contributing 53% and 58% to Re. While a comparison of observed and MDF environmental response functions suggests both root-zone soil moisture and leaf-to-air VPD photosynthetic controls at both sites, the MDF did not impose CLM-CN’s soil stress upon photosynthesis at the US-Fir site, suggesting the apparent soil moisture response arises from correlations with other driving variables such as VPD. In summary, we demonstrate that MDF analysis can help constrain coupled ecosystem carbon and water dynamics by combining long-term ecosystem measurements by incorporating necessary measurement and model uncertainties.

Time Delay Estimation

DTIC Science & Technology

1976-04-09

of the signal and noise remain HH ***^-^*--~ 53 h, to r(Mc) h2(r» r(we) Figure 3-2 Sy&toetric Impulse Response for Two FIR Linear Phase...Inputs x,y and Outputs x.j. , 15 2-2 Linear System with Impulse Response h("r) 23 2-3 Model of Error Resulting from Linearly Filtering x(t) to...Corrupted with Additive Noise 42 2-6 Model of Directional Signal Corrupted with Additive Noise and Processed .... 45 2-7 Source Driving Two

Derivative information recovery by a selective integration technique

NASA Technical Reports Server (NTRS)

Johnson, M. A.

1974-01-01

A nonlinear stationary homogeneous digital filter DIRSIT (derivative information recovery by a selective integration technique) is investigated. The spectrum of a quasi-linear discrete describing function (DDF) to DIRSIT is obtained by a digital measuring scheme. A finite impulse response (FIR) approximation to the quasi-linearization is then obtained. Finally, DIRSIT is compared with its quasi-linear approximation and with a standard digital differentiating technique. Results indicate the effects of DIRSIT on a wide variety of practical signals.

Parental GCA testing: how many crosses per parent?

Treesearch

G.R. Johnson

1998-01-01

The impact of increasing the number of crosses per parent (k) on the efficiency of roguing seed orchards (backwards selection, i.e., reselection of parents) was examined by using Monte Carlo simulation. Efficiencies were examined in light of advanced-generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) tree improvement programs where...

A new design approach to MMI-based (de)multiplexers

NASA Astrophysics Data System (ADS)

Yueyu, Xiao; Sailing, He

2004-09-01

A novel design method of the wavelength (de)multiplexer is presented. The output spectral response of a (de)multiplexer is designed from the view of FIR filters. Avoiding laborious mathematic analysis, the (de)multiplexer is analyzed and designed in this explicit and simple method. A four channel (de)multiplexer based on multimode interference (MMI) is designed as an example. The result obtained agrees with that of the commonly used method, and is verified by a finite difference beam propagation method (FDBPM) simulation.

Report on Contract F05611-76-90203. Volume I.

DTIC Science & Technology

1976-01-01

The most serious of these assumptions used in the development of the algorithms was that the sensors in use are much better than they really are...This was not the fault of the AFIT personnel, since the algo- rithus they developed used the best information about the sensors which they had at the...phase response for the first FIR filters. In the region trom 0.01 Hz to 0.1 liz the tiltmeter controls the servo. However, above 0. Ili the seismo-neter

Differential Frequency Hopping (DFH) Modulation for Underwater Acoustic Communications and Networking

DTIC Science & Technology

2009-10-09

trains the coefficients c of a finite impulse response (FIR) filter by gradient descent. The coefficients at iteration k + 1 are computed with the update... absorption . Figure 9 shows the reflection loss as a function of grazing angle for this bottom model. Note that below 30◦ this bottom model predicts...less than 1 dB loss per ray bounce. 11 Figure 9: Jackson bottom reflection loss for sand at 15 kHz Absorption Loss The absorption loss in the medium was

Static and Dynamic Characteristics of DC-DC Converter Using a Digital Filter

NASA Astrophysics Data System (ADS)

Kurokawa, Fujio; Okamatsu, Masashi

This paper presents the regulation and dynamic characteristics of the dc-dc converter with digital PID control, the minimum phase FIR filter or the IIR filter, and then the design criterion to improve the dynamic characteristics is discussed. As a result, it is clarified that the DC-DC converter using the IIR filter method has superior performance characteristics. The regulation range is within 1.3%, the undershoot against the step change of the load is less than 2% and the transient time is less than 0.4ms with the IIR filter method. In this case, the switching frequency is 100kHz and the step change of the load R is from 50 Ω to 10 Ω. Further, the superior characteristics are obtained when the first gain, the second gain and the second cut-off frequency are relatively large, and the first cut-off frequency and the passing frequency are relatively low. Moreover, it is important that the gain strongly decreases at the second cut-off frequency because the upper band pass frequency range must be always less than half of the sampling frequency based on the sampling theory.

Dwarf mistletoe affects whole-tree water relations of Douglas fir and western larch primarily through changes in leaf to sapwood ratios.

PubMed

Sala, Anna; Carey, Eileen V; Callaway, Ragan M

2001-01-01

Dwarf mistletoes induce abnormal growth patterns and extreme changes in the biomass allocation of their hosts as well as directly parasitizing them for resources. Because biomass allocation can affect the resource use and efficiency of conifers, we studied the influences of dwarf mistletoe infection on above-ground biomass allocation of Douglas fir and western larch, and the consequences of such changes on whole-tree water use and water relations. Sap flow, tree water potentials, leaf:sapwood area ratios (A L :A S ), leaf carbon isotope ratios, and nitrogen content were measured on Douglas fir and western larch trees with various degrees of mistletoe infection during the summer of 1996 in western Montana. Heavy dwarf mistletoe infection on Douglas fir and western larch was related to significant increases in A L :A S . Correspondingly, water transport dynamics were altered in infected trees, but responses were different for the two species. Higher A L :A S ratios in heavily infected Douglas firs were offset by increases in sapwood area-based sap flux densities (Q SW ) such that leaf area-based sap flux densities (Q L ) and predawn leaf water potentials at the end of the summer did not change significantly with mistletoe infection. Small (but statistically insignificant) decreases of Q L for heavily infected Douglas firs were enough to offset increases in leaf area such that whole-tree water use was similar for uninfected and heavily infected trees. Increased A L :A S ratios of heavily infected western larch were not offset by increases of Q SW . Consequently, Q L was reduced, which corresponded with significant decreases of water potential at the end of the summer. Furthermore, mistletoe-infection-related changes in A L :A S as a function of tree size resulted in greater whole-tree water use for large infected larches than for large uninfected trees. Such changes may result in further depletion of limited soil water resources in mature infected stands late in the growing season. Foliage from infected trees of both species had lower water use efficiencies than non-infected trees. Our results demonstrate substantial changes of whole-tree processes related to mistletoe infection, and stress the importance of integrating whole-tree physiological and structural processes to fully understand the mechanisms by which pathogens suppress forest productivity.

Design and implementation of a multiband digital filter using FPGA to extract the ECG signal in the presence of different interference signals.

PubMed

Aboutabikh, Kamal; Aboukerdah, Nader

2015-07-01

In this paper, we propose a practical way to synthesize and filter an ECG signal in the presence of four types of interference signals: (1) those arising from power networks with a fundamental frequency of 50Hz, (2) those arising from respiration, having a frequency range from 0.05 to 0.5Hz, (3) muscle signals with a frequency of 25Hz, and (4) white noise present within the ECG signal band. This was done by implementing a multiband digital filter (seven bands) of type FIR Multiband Least Squares using a digital programmable device (Cyclone II EP2C70F896C6 FPGA, Altera), which was placed on an education and development board (DE2-70, Terasic). This filter was designed using the VHDL language in the Quartus II 9.1 design environment. The proposed method depends on Direct Digital Frequency Synthesizers (DDFS) designed to synthesize the ECG signal and various interference signals. So that the synthetic ECG specifications would be closer to actual ECG signals after filtering, we designed in a single multiband digital filter instead of using three separate digital filters LPF, HPF, BSF. Thus all interference signals were removed with a single digital filter. The multiband digital filter results were studied using a digital oscilloscope to characterize input and output signals in the presence of differing sinusoidal interference signals and white noise. Copyright © 2015 Elsevier Ltd. All rights reserved.

Douglas-Fir Seedlings Exhibit Metabolic Responses to Increased Temperature and Atmospheric Drought

PubMed Central

Jansen, Kirstin; Du, Baoguo; Kayler, Zachary; Siegwolf, Rolf; Ensminger, Ingo; Rennenberg, Heinz; Kammerer, Bernd; Jaeger, Carsten; Schaub, Marcus; Kreuzwieser, Jürgen; Gessler, Arthur

2014-01-01

In the future, periods of strongly increased temperature in concert with drought (heat waves) will have potentially detrimental effects on trees and forests in Central Europe. Norway spruce might be at risk in the future climate of Central Europe. However, Douglas-fir is often discussed as an alternative for the drought and heat sensitive Norway spruce, because some provenances are considered to be well adapted to drier and warmer conditions. In this study, we identified the physiological and growth responses of seedlings from two different Douglas-fir provenances to increased temperature and atmospheric drought during a period of 92 days. We analysed (i) plant biomass, (ii) carbon stable isotope composition as an indicator for time integrated intrinsic water use efficiency, (iii) apparent respiratory carbon isotope fractionation as well as (iv) the profile of polar low molecular metabolites. Plant biomass was only slightly affected by increased temperatures and atmospheric drought but the more negative apparent respiratory fractionation indicated a temperature-dependent decrease in the commitment of substrate to the tricarboxylic acid cycle. The metabolite profile revealed that the simulated heat wave induced a switch in stress protecting compounds from proline to polyols. We conclude that metabolic acclimation successfully contributes to maintain functioning and physiological activity in seedlings of both Douglas-fir provenances under conditions that are expected during heat waves (i.e. elevated temperatures and atmospheric drought). Douglas-fir might be a potentially important tree species for forestry in Central Europe under changing climatic conditions. PMID:25436455

Enchanced interference cancellation and telemetry reception in multipath environments with a single paraboic dish antenna using a focal plane array

NASA Technical Reports Server (NTRS)

Vilnrotter, Victor A. (Inventor); Mukai, Ryan (Inventor)

2011-01-01

An Advanced Focal Plane Array ("AFPA") for parabolic dish antennas that exploits spatial diversity to achieve better channel equalization performance in the presence of multipath (better than temporal equalization alone), and which is capable of receiving from two or more sources within a field-of-view in the presence of multipath. The AFPA uses a focal plane array of receiving elements plus a spatio-temporal filter that keeps information on the adaptive FIR filter weights, relative amplitudes and phases of the incoming signals, and which employs an Interference Cancelling Constant Modulus Algorithm (IC-CMA) that resolves multiple telemetry streams simultaneously from the respective aero-nautical platforms. This data is sent to an angle estimator to calculate the target's angular position, and then on to Kalman filters FOR smoothing and time series prediction. The resulting velocity and acceleration estimates from the time series data are sent to an antenna control unit (ACU) to be used for pointing control.

Signal propagation in cortical networks: a digital signal processing approach.

PubMed

Rodrigues, Francisco Aparecido; da Fontoura Costa, Luciano

2009-01-01

This work reports a digital signal processing approach to representing and modeling transmission and combination of signals in cortical networks. The signal dynamics is modeled in terms of diffusion, which allows the information processing undergone between any pair of nodes to be fully characterized in terms of a finite impulse response (FIR) filter. Diffusion without and with time decay are investigated. All filters underlying the cat and macaque cortical organization are found to be of low-pass nature, allowing the cortical signal processing to be summarized in terms of the respective cutoff frequencies (a high cutoff frequency meaning little alteration of signals through their intermixing). Several findings are reported and discussed, including the fact that the incorporation of temporal activity decay tends to provide more diversified cutoff frequencies. Different filtering intensity is observed for each community in those networks. In addition, the brain regions involved in object recognition tend to present the highest cutoff frequencies for both the cat and macaque networks.

The ISS Fluids Integrated Rack (FIR): a Summary of Capabilities

NASA Astrophysics Data System (ADS)

Gati, F.; Hill, M. E.

2002-01-01

The Fluids Integrated Rack (FIR) is a modular, multi-user scientific research facility that will fly in the U.S. laboratory module, Destiny, of the International Space Station (ISS). The FIR will be one of the two racks that will make up the Fluids and Combustion Facility (FCF) - the other being the Combustion Integrated Rack (CIR). The ISS will provide the FCF with the necessary resources, such as power and cooling. While the ISS crew will be available for experiment operations, their time will be limited. The FCF is, therefore, being designed for autonomous operations and remote control operations. Control of the FCF will be primarily through the Telescience Support Center (TSC) at the Glenn Research Center. The FCF is being designed to accommodate a wide range of combustion and fluids physics experiments within the ISS resources and constraints. The primary mission of the FIR, however, is to accommodate experiments from four major fluids physics disciplines: Complex Fluids; Multiphase Flow and Heat Transfer; Interfacial Phenomena; and Dynamics and Stability. The design of the FIR is flexible enough to accommodate experiments from other science disciplines such as Biotechnology. The FIR flexibility is a result of the large volume dedicated for experimental hardware, easily re-configurable diagnostics that allow for unique experiment configurations, and it's customizable software. The FIR will utilize six major subsystems to accommodate this broad scope of fluids physics experiments. The major subsystems are: structural, environmental, electrical, gaseous, command and data management, and imagers and illumination. Within the rack, the FIR's structural subsystem provides an optics bench type mechanical interface for the precise mounting of experimental hardware; including optical components. The back of the bench is populated with FIR avionics packages and light sources. The interior of the rack is isolated from the cabin through two rack doors that are hinged near the top and bottom of the rack. Transmission of micro-gravity disturbances to and from the rack is minimized through the Active Rack Isolation System (ARIS). The environmental subsystem will utilize air and water to remove heat generated by facility and experimental hardware. The air will be circulated throughout the rack and will be cooled by an air-water heat exchanger. Water will be used directly to cool some of the FIR components and will also be available to cool experiment hardware as required. The electrical subsystem includes the Electrical Power Control Unit (EPCU), which provides 28 VDC and 120 VDC power to the facility and the experiment hardware. The EPCU will also provide power management and control functions, as well as fault protection capabilities. The FIR will provide access to the ISS gaseous nitrogen and vacuum systems. These systems are available to support experiment operations such as the purging of experimental cells, creating flows within experimental cells and providing dry conditions where needed. The FIR Command and Data Management subsystem (CDMS) provides command and data handling for both facility and experiment hardware. The Input Output Processor (IOP) provides the overall command and data management functions for the rack including downlinking or writing data to removable drives. The IOP will also monitor the health and status of the rack subsystems. The Image Processing and Storage Units (IPSU) will perform diagnostic control and image data acquisition functions. An IPSU will be able to control a digital camera, receive image data from that camera and process/ compress image data as necessary. The Fluids Science and Avionics Package (FSAP) will provide the primary control over an experiment. The FSAP contains various computer boards/cards that will perform data and control functions. To support the imaging needs, cameras and illumination sources will be available to the investigator. Both color analog and black and white digital cameras with lenses are expected. These cameras will be capable of high resolution and, separately, frame rates up to 32,000 frames per second. Lenses for these cameras will provide both microscopic and macroscopic views. The FIR will provide two illumination sources, a 532 nm Nd:YAG laser and a white light source, both with adjustable power output. The FIR systems are being designed to maximize the amount of science that can be done on-orbit. Experiments will be designed and efficiently operated. Each individual experiment must determine the best configuration of utilizing facility capabilities and resources with augmentation of specific experiment hardware. Efficient operations will be accomplished via a combination of on-orbit physical component change-outs or processing by the crew, and software updates via ground commanding or by the crew. Careful coordination by ground and on-orbit personnel regarding the on-orbit storage and downlinking of image data will also be very important.

Instantaneous and Frequency-Warped Signal Processing Techniques for Auditory Source Separation.

NASA Astrophysics Data System (ADS)

Wang, Avery Li-Chun

This thesis summarizes several contributions to the areas of signal processing and auditory source separation. The philosophy of Frequency-Warped Signal Processing is introduced as a means for separating the AM and FM contributions to the bandwidth of a complex-valued, frequency-varying sinusoid p (n), transforming it into a signal with slowly-varying parameters. This transformation facilitates the removal of p (n) from an additive mixture while minimizing the amount of damage done to other signal components. The average winding rate of a complex-valued phasor is explored as an estimate of the instantaneous frequency. Theorems are provided showing the robustness of this measure. To implement frequency tracking, a Frequency-Locked Loop algorithm is introduced which uses the complex winding error to update its frequency estimate. The input signal is dynamically demodulated and filtered to extract the envelope. This envelope may then be remodulated to reconstruct the target partial, which may be subtracted from the original signal mixture to yield a new, quickly-adapting form of notch filtering. Enhancements to the basic tracker are made which, under certain conditions, attain the Cramer -Rao bound for the instantaneous frequency estimate. To improve tracking, the novel idea of Harmonic -Locked Loop tracking, using N harmonically constrained trackers, is introduced for tracking signals, such as voices and certain musical instruments. The estimated fundamental frequency is computed from a maximum-likelihood weighting of the N tracking estimates, making it highly robust. The result is that harmonic signals, such as voices, can be isolated from complex mixtures in the presence of other spectrally overlapping signals. Additionally, since phase information is preserved, the resynthesized harmonic signals may be removed from the original mixtures with relatively little damage to the residual signal. Finally, a new methodology is given for designing linear-phase FIR filters which require a small fraction of the computational power of conventional FIR implementations. This design strategy is based on truncated and stabilized IIR filters. These signal-processing methods have been applied to the problem of auditory source separation, resulting in voice separation from complex music that is significantly better than previous results at far lower computational cost.

Using indicator plants to assess susceptibility of Californian red fir and white fir to the fir engraver beetle

Treesearch

George T. Ferrell

1986-01-01

Using a Vegetation Drought Index (VDI) for estimating the susceptibility of California red and white firs to the fir engraver beetle (Scolytus venttralis) was evaluated in northern California forests where these true firs (Abies species) occur in mixed conifer and true fir stands. Midway through the summer drought, true fir...

An Efficient Implementation For Real Time Applications Of The Wigner-Ville Distribution

NASA Astrophysics Data System (ADS)

Boashash, Boualem; Black, Peter; Whitehouse, Harper J.

1986-03-01

The Wigner-Ville Distribution (WVD) is a valuable tool for time-frequency signal analysis. In order to implement the WVD in real time an efficient algorithm and architecture have been developed which may be implemented with commercial components. This algorithm successively computes the analytic signal corresponding to the input signal, forms a weighted kernel function and analyses the kernel via a Discrete Fourier Transform (DFT). To evaluate the analytic signal required by the algorithm it is shown that the time domain definition implemented as a finite impulse response (FIR) filter is practical and more efficient than the frequency domain definition of the analytic signal. The windowed resolution of the WVD in the frequency domain is shown to be similar to the resolution of a windowed Fourier Transform. A real time signal processsor has been designed for evaluation of the WVD analysis system. The system is easily paralleled and can be configured to meet a variety of frequency and time resolutions. The arithmetic unit is based on a pair of high speed VLSI floating-point multiplier and adder chips. Dual operand buses and an independent result bus maximize data transfer rates. The system is horizontally microprogrammed and utilizes a full instruction pipeline. Each microinstruction specifies two operand addresses, a result location, the type of arithmetic and the memory configuration. input and output is via shared memory blocks with front-end processors to handle data transfers during the non access periods of the analyzer.

Linear Phase Sharp Transition BPF to Detect Noninvasive Maternal and Fetal Heart Rate.

PubMed

Marchon, Niyan; Naik, Gourish; Pai, K R

2018-01-01

Fetal heart rate (FHR) detection can be monitored using either direct fetal scalp electrode recording (invasive) or by indirect noninvasive technique. Weeks before delivery, the invasive method poses a risk factor to the fetus, while the latter provides accurate fetal ECG (FECG) information which can help diagnose fetal's well-being. Our technique employs variable order linear phase sharp transition (LPST) FIR band-pass filter which shows improved stopband attenuation at higher filter orders. The fetal frequency fiduciary edges form the band edges of the filter characterized by varying amounts of overlap of maternal ECG (MECG) spectrum. The one with the minimum maternal spectrum overlap was found to be optimum with no power line interference and maximum fetal heart beats being detected. The improved filtering is reflected in the enhancement of the performance of the fetal QRS detector (FQRS). The improvement has also occurred in fetal heart rate obtained using our algorithm which is in close agreement with the true reference (i.e., invasive fetal scalp ECG). The performance parameters of the FQRS detector such as sensitivity (Se), positive predictive value (PPV), and accuracy (F 1 ) were found to improve even for lower filter order. The same technique was extended to evaluate maternal QRS detector (MQRS) and found to yield satisfactory maternal heart rate (MHR) results.

Cryogenic bolometric systems

NASA Astrophysics Data System (ADS)

Kangas, Miikka Matias

The big bang, early galaxy formation, the interstellar medium, and high z galaxy cluster evolution are all science objectives that are studied in the far infrared (FIR). The cosmological parameters that describe the universe are encoded in anisotropies in the Cosmic Microwave Background (CMB), and can be extracted from precision subdegree angular resolution FIR maps. Cryogenic bolometers are well suited for these science objectives, and are evolving rapidly today. A cryogenic bolometric system is made up of a few building blocks, which can be modularized or integrated depending on the maturity of the scientific field they are used for. Integration of systems increases with the maturity of the technology. The basic building blocks are the bolometer, the cryogenics, the dewar, the optics, the filters, and electronics. The electronics can be further subdivided into room temperature back-end and cryogenic front-end electronics. The electronics are often partly integrated into the dewar. The dewar is part of the support structure, and only the subkelvin portion the dewar is referred to as cryogenics here. Each of these can be a sophisticated engineering feat on their own, and this dissertation revolves around the development of several of these elements. The microfabrication sequence for a free standing micromesh detector was developed. Polarization preserving photometer optics and filters were constructed and tested. A test dewar mechanical and optical structure was created to test single pixel photometers prior to mounting in the flight dewar. A modular flight dewar capable of holding an array of photometers and adaptable to a number of different cryogenics schemes and detector arrays was engineered and constructed. A zero gravity dilution refrigerator coil was constructed and tested. A corrugated platelet array concept was designed and tested. Metal mesh filter design and fabrication techniques were developed. Kevlar isolator structures were improved to work in subkelvin dewars, and detector modules that mounted the bolometer chips to the photometer tubes were created. These subsystems underwent testing to compare the predicted behavior and actual performance.

Climate-related trends in sapwood biophysical properties in two conifers: avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance.

PubMed

Barnard, David M; Meinzer, Frederick C; Lachenbruch, Barbara; McCulloh, Katherine A; Johnson, Daniel M; Woodruff, David R

2011-04-01

In the Pacific north-west, the Cascade Mountain Range blocks much of the precipitation and maritime influence of the Pacific Ocean, resulting in distinct climates east and west of the mountains. The current study aimed to investigate relationships between water storage and transport properties in populations of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) adapted to both climates. Sapwood thickness, capacitance, vulnerability to embolism, and axial and radial conductivity were measured on samples collected from trunks of mature trees. The sapwood of ponderosa pine was three to four times thicker than Douglas-fir. Radial conductivity was higher in west-side populations of both species, but axial conductivity was higher in the east-side populations and in Douglas-fir. Eastern populations of both species had sapwood that was more vulnerable to embolism than west-side populations. Sapwood capacitance was similar between species, but was about twice as great in east-side populations (580 kg m⁻³ MPa⁻¹) as in west-side populations (274 kg m⁻³ MPa⁻¹). Capacitance was positively correlated with both mean embolism pressure and axial conductivity across species and populations, suggesting that coordinated adjustments in xylem efficiency, safety and water storage capacity may serve to avoid embolism along a gradient of increasing aridity. © 2011 Blackwell Publishing Ltd.

Rooting cuttings from douglas-fir, white-fir, and California red fir christmas trees

Treesearch

C. M. Blankensop; R. Z. Callaham

1960-01-01

Christmas tree growers in California have asked geneticists to help improve the characteristics of the - wild species they are cultivating. The preferred Christmas trees of California are Shasta red fir (Abies magnifica A. Murr.), white fir (A. concolor (Gord. & Glend.) Lindl.), and Douglas-fir (Pseudotsuga...

Collection of biological and non-biological particles by new and used filters made from glass and electrostatically charged synthetic fibers.

PubMed

Raynor, P C; Kim, B G; Ramachandran, G; Strommen, M R; Horns, J H; Streifel, A J

2008-02-01

Synthetic filters made from fibers carrying electrostatic charges and fiberglass filters that do not carry electrostatic charges are both utilized commonly in heating, ventilating, and air-conditioning (HVAC) systems. The pressure drop and efficiency of a bank of fiberglass filters and a bank of electrostatically charged synthetic filters were measured repeatedly for 13 weeks in operating HVAC systems at a hospital. Additionally, the efficiency with which new and used fiberglass and synthetic filters collected culturable biological particles was measured in a test apparatus. Pressure drop measurements adjusted to equivalent flows indicated that the synthetic filters operated with a pressure drop less than half that of the fiberglass filters throughout the test. When measured using total ambient particles, synthetic filter efficiency decreased during the test period for all particle diameters. For particles 0.7-1.0 mum in diameter, efficiency decreased from 92% to 44%. It is hypothesized that this reduction in collection efficiency may be due to charge shielding. Efficiency did not change significantly for the fiberglass filters during the test period. However, when measured using culturable biological particles in the ambient air, efficiency was essentially the same for new filters and filters used for 13 weeks in the hospital for both the synthetic and fiberglass filters. It is hypothesized that the lack of efficiency reduction for culturable particles may be due to their having higher charge than non-biological particles, allowing them to overcome the effects of charge shielding. The type of particles requiring capture may be an important consideration when comparing the relative performance of electrostatically charged synthetic and fiberglass filters. Electrostatically charged synthetic filters with high initial efficiency can frequently replace traditional fiberglass filters with lower efficiency in HVAC systems because properly designed synthetic filters offer less resistance to air flow. Although the efficiency of charged synthetic filters at collecting non-biological particles declined substantially with use, the efficiency of these filters at collecting biological particles remained steady. These findings suggest that the merits of electrostatically charged synthetic HVAC filters relative to fiberglass filters may be more pronounced if collection of biological particles is of primary concern.

Price projections for selected grades of Douglas-fir, coast hem-fir, inland hem-fir, and ponderosa pine lumber.

Treesearch

Richard W. Haynes; Roger D. Fight

1992-01-01

Grade-specific price projections were developed for Douglas-fir, coast hem-fir, inland hem-fir, and ponderosa pine lumber. These grade-specific price projections can be used in evaluating management practices that will affect the quality of saw logs produced under various management regimes.

Comparison of leaf gas exchange and stable isotope signature of water-soluble compounds along canopy gradients of co-occurring Douglas-fir and European beech.

PubMed

Bögelein, Rebekka; Hassdenteufel, Martin; Thomas, Frank M; Werner, Willy

2012-07-01

Combined δ(13) C and δ(18) O analyses of water-soluble leaf and twig phloem material were used to determine intrinsic water-use efficiency (iWUE) and variability of stomatal conductance at different crown positions in adult European beech (Fagus sylvatica) and Douglas-fir (Pseudotsuga menziesii) trees. Simultaneous gas exchange measurements allowed evaluation of the differences in calculating iWUE from leaf or phloem water-soluble compounds, and comparison with a semi-quantitative dual isotope model to infer variability of net photosynthesis (A(n) ) between the investigated crown positions. Estimates of iWUE from δ(13) C of leaf water-soluble organic matter (WSOM) outperformed the estimates from phloem compounds. In the beech crown, δ(13) C of leaf WSOM coincided clearly with gas exchange measurements. The relationship was not as reliable in the Douglas-fir. The differences in δ(18) O between leaf and phloem material were found to correlate with stomatal conductance. The semi-quantitative model approach was applicable for comparisons of daily average A(n) between different crown positions and trees. Intracanopy gradients were more pronounced in the beech than in the Douglas-fir, which reached higher values of iWUE at the respective positions, particularly under dry air conditions. © 2012 Blackwell Publishing Ltd.

Weather and tree growth associated with white fir mortality caused by fir engraver and roundheaded fir borer

Treesearch

George T. Ferrell; Ralph C. Hall

1975-01-01

White fir (Abides concolor [Cord. & Glend.] Lindl.) stands in Western North America periodically suffer extensive tree mortality caused by outbreaks of the fir engraver bark beetle (Scolytus ventralis Lec.). The cambial zone of the boles infested by S. ventralis is also colonized by the roundheaded fir borer...

Nanotechnology Infrared Optics for Astronomy Missions

NASA Technical Reports Server (NTRS)

Smith, Howard A.; Stringfellow, Guy (Technical Monitor)

2002-01-01

The program "Nanotechnology Infrared Optics for Astronomy Missions" will design and develop new, nanotechnology techniques for infrared optical devices suitable for use in NASA space missions. The proposal combines expertise from the Smithsonian Astrophysical Observatory, the Naval Research Laboratory, the Goddard Space Flight Center, and the Physics Department at the Queen Mary and Westfield College in London, now relocated to the University of Cardiff, Cardiff, Wales. The method uses individually tailored metal grids, and layered stacks of metal mesh grids, both inductive (free-standing) and capacitive (substrate-mounted), to produce various kinds of filters. The program has the following goals: (1) Model FIR filter properties using electric-circuit analogs, and near-field, EM diffraction calculations; (2) Prototype fabrication of meshes on various substrates, with various materials, and of various dimensions; (3) Test of filter prototypes, and iterate with the modeling programs; (4) Travel to related sites, including trips to Washington, D.C. (location of NRL and GSFC), London (location of QMW), Cardiff, Wales, and Rome (location of ISO PMS project headquarters); (5) Produce ancillary science, including publication of both testing on mesh performance and infrared astronomical science.

Nanotechnology Infrared Optics for Astronomy Missions

NASA Technical Reports Server (NTRS)

Smith, Howard A.; Frogel, Jay (Technical Monitor)

2003-01-01

The program "Nanotechnology Infrared Optics for Astronomy Missions" will design and develop new, nanotechnology techniques for infrared optical devices suitable for use in NASA space missions. The proposal combines expertise from the Smithsonian Astrophysical Observatory, the Naval Research Laboratory, the Goddard Space Flight Center, and the Physics Department at the Queen Mary and Westfield College in London, now relocated to the University of Cardiff, Cardiff, Wales. The method uses individually tailored metal grids and layered stacks of metal mesh grids, both inductive (freestanding) and capacitive (substrate-mounted), to produce various kinds of filters. The program has the following goals: 1) Model FIR filter properties using electric-circuit analogs and near-field, EM diffraction calculations. 2) Prototype fabrication of meshes on various substrates, with various materials, and of various dimensions. 3) Test filter prototypes and iterate with the modeling programs. 4) Travel to related sites, including trips to Washington, D.C. (location of NRL and GSFC), London (location of QMW), Cardiff, Wales, and Rome (location of ISO PMS project headquarters). 5) Produce ancillary science, including both publication of testing on mesh performance and infrared astronomical science.

Study of Interpolated Timing Recovery Phase-Locked Loop with Linearly Constrained Adaptive Prefilter for Higher-Density Optical Disc

NASA Astrophysics Data System (ADS)

Kajiwara, Yoshiyuki; Shiraishi, Junya; Kobayashi, Shoei; Yamagami, Tamotsu

2009-03-01

A digital phase-locked loop (PLL) with a linearly constrained adaptive filter (LCAF) has been studied for higher-linear-density optical discs. LCAF has been implemented before an interpolated timing recovery (ITR) PLL unit in order to improve the quality of phase error calculation by using an adaptively equalized partial response (PR) signal. Coefficient update of an asynchronous sampled adaptive FIR filter with a least-mean-square (LMS) algorithm has been constrained by a projection matrix in order to suppress the phase shift of the tap coefficients of the adaptive filter. We have developed projection matrices that are suitable for Blu-ray disc (BD) drive systems by numerical simulation. Results have shown the properties of the projection matrices. Then, we have designed the read channel system of the ITR PLL with an LCAF model on the FPGA board for experiments. Results have shown that the LCAF improves the tilt margins of 30 gigabytes (GB) recordable BD (BD-R) and 33 GB BD read-only memory (BD-ROM) with a sufficient LMS adaptation stability.

Adaptive Identification and Control of Flow-Induced Cavity Oscillations

NASA Technical Reports Server (NTRS)

Kegerise, M. A.; Cattafesta, L. N.; Ha, C.

2002-01-01

Progress towards an adaptive self-tuning regulator (STR) for the cavity tone problem is discussed in this paper. Adaptive system identification algorithms were applied to an experimental cavity-flow tested as a prerequisite to control. In addition, a simple digital controller and a piezoelectric bimorph actuator were used to demonstrate multiple tone suppression. The control tests at Mach numbers of 0.275, 0.40, and 0.60 indicated approx. = 7dB tone reductions at multiple frequencies. Several different adaptive system identification algorithms were applied at a single freestream Mach number of 0.275. Adaptive finite-impulse response (FIR) filters of orders up to N = 100 were found to be unsuitable for modeling the cavity flow dynamics. Adaptive infinite-impulse response (IIR) filters of comparable order better captured the system dynamics. Two recursive algorithms, the least-mean square (LMS) and the recursive-least square (RLS), were utilized to update the adaptive filter coefficients. Given the sample-time requirements imposed by the cavity flow dynamics, the computational simplicity of the least mean squares (LMS) algorithm is advantageous for real-time control.

Financial analysis of early stand treatments in southwest Oregon.

Treesearch

Helge Eng; K. Norman Johnson; Roger D. Fight

1990-01-01

Management guidelines for economically efficient early stand treatments were developed by identifying treatments that would maximize financial returns over the rotation for coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in southwest Oregon. Short rotations and low stand densities (trees per acre) gave...

Silvics of grand fir

Treesearch

Marvin W. Foiles

1959-01-01

Grand fir (Abies grandis) is one of the two balsam firs found in the northern Rocky Mountain region and one of seven in the Pacific Northwest. Except in the southern part of its range, where it is often confused with white fir (Abies concolor), it is distinguished from other firs in its range by its needles, which are distinctly two-ranked. Grand fir differs...

Growth classification systems for red fir and white fir in northern California

Treesearch

George T. Ferrell

1983-01-01

Selected crown and bole characteristics were predictor variables in growth classification equations developed for California red fir, Shasta red fir, and white fir in northern California. Individual firs were classified on the basis of percent basal area increment (PCTBAI ) as Class 1 (≤ 1 pct), Class 2 (> 1 pct and ≤ 3 pct), or Class 3 (> 3...

Fir dwarf mistletoe (FIDL).

Treesearch

Gregory M. Filip; Jerome S. Beatty; Robert L. Mathiasen

2000-01-01

Fir dwarf mistletoe (Arceuthobium abietinum Engelmann ex Munz) is a common and damaging parasite of white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), and California red fir (A. magnifica A. Murr.) in the western...

Damage from wind and other causes in mixed white fir-red fir stands adjacent to clearcuttings

Treesearch

Donald T. Gordon

1973-01-01

Damage to timber surrounding clearcuttings and in one light selection cutting in mixed white fir-red fir stands was monitored for 6 years in northeastern California. In some years, bark beetles apparently killed more trees than did wind damage, but in two of the study years, severe wind storms caused much damage. One storm produced mainly break-age, apparently...

Height-related trends in leaf xylem anatomy and shoot hydraulic characteristics in a tall conifer: safety versus efficiency in water transport.

PubMed

Woodruff, D R; Meinzer, F C; Lachenbruch, B

2008-01-01

Hydraulic vulnerability of Douglas-fir (Pseudotsuga menziesii) branchlets decreases with height, allowing shoots at greater height to maintain hydraulic conductance (K shoot) at more negative leaf water potentials (Psi l). To determine the basis for this trend shoot hydraulic and tracheid anatomical properties of foliage from the tops of Douglas-fir trees were analysed along a height gradient from 5 to 55 m. Values of Psi l at which K shoot was substantially reduced, declined with height by 0.012 Mpa m(-1). Maximum K shoot was reduced by 0.082 mmol m(-2) MPa(-1) s(-1) for every 1 m increase in height. Total tracheid lumen area per needle cross-section, hydraulic mean diameter of leaf tracheid lumens, total number of tracheids per needle cross-section and leaf tracheid length decreased with height by 18.4 microm(2) m(-1), 0.029 microm m(-1), 0.42 m(-1) and 5.3 microm m(-1), respectively. Tracheid thickness-to-span ratio (tw/b)2 increased with height by 1.04 x 10(-3) m(-1) and pit number per tracheid decreased with height by 0.07 m(-1). Leaf anatomical adjustments that enhanced the ability to cope with vertical gradients of increasing xylem tension were attained at the expense of reduced water transport capacity and efficiency, possibly contributing to height-related decline in growth of Douglas fir.

Rapid prototyping and evaluation of programmable SIMD SDR processors in LISA

NASA Astrophysics Data System (ADS)

Chen, Ting; Liu, Hengzhu; Zhang, Botao; Liu, Dongpei

2013-03-01

With the development of international wireless communication standards, there is an increase in computational requirement for baseband signal processors. Time-to-market pressure makes it impossible to completely redesign new processors for the evolving standards. Due to its high flexibility and low power, software defined radio (SDR) digital signal processors have been proposed as promising technology to replace traditional ASIC and FPGA fashions. In addition, there are large numbers of parallel data processed in computation-intensive functions, which fosters the development of single instruction multiple data (SIMD) architecture in SDR platform. So a new way must be found to prototype the SDR processors efficiently. In this paper we present a bit-and-cycle accurate model of programmable SIMD SDR processors in a machine description language LISA. LISA is a language for instruction set architecture which can gain rapid model at architectural level. In order to evaluate the availability of our proposed processor, three common baseband functions, FFT, FIR digital filter and matrix multiplication have been mapped on the SDR platform. Analytical results showed that the SDR processor achieved the maximum of 47.1% performance boost relative to the opponent processor.

Radial growth of grand fir and Douglas-fir 10 years after defoliation by the Douglas-fir tussock moth in the Blue Mountains outbreak.

Treesearch

Boyd E. Wickman

1986-01-01

Radial-growth recovery related to amount of tree defoliation was measured 10 years after a severe outbreak of Douglas-fir tussock moth (Orgyia pseudotsugata (McDunnough). For the period 1978-82, growth of qrand fir surpassed and was significantly greater than in the preoutbreak period, 1968-72. Douglas-fir growth during the postoutbreak period...

Reconsidering price projections for selected grades of Douglas-fir, coast hem-fir, inland hem-fir, and ponderosa pine lumber.

Treesearch

Richard W. Haynes; Roger D. Fight

2004-01-01

Grade-specific price projections were once again developed for Douglas-fir, coast hem-fir, inland hem-fir, and ponderosa pine lumber. These grade-specific price projections can be used to demonstrate the returns to land management of practices that lead to high-quality logs that produce a larger proportion of high grades of lumber. The price ratios among low, medium,...

Douglas-fir tussock moth- and Douglas-fir beetle-caused mortality in a ponderosa pine/Douglas-fir forest in the Colorado Front Range, USA

Treesearch

Jose F. Negron; Ann M. Lynch; Willis C. Schaupp; Vladimir Bocharnikov

2014-01-01

An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir...

AmeriFlux CA-Na1 New Brunswick - 1967 Balsam Fir - Nashwaak Lake Site 01 (Mature balsam fir forest)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourque, Charles P.-A.

This is the AmeriFlux version of the carbon flux data for the site CA-Na1 New Brunswick - 1967 Balsam Fir - Nashwaak Lake Site 01 (Mature balsam fir forest). Site Description - immature balsam fir forest

Remote pedestrians detection at night time in FIR Image using contrast filtering and locally projected region based CNN

NASA Astrophysics Data System (ADS)

Kim, Taehwan; Kim, Sungho

2017-02-01

This paper presents a novel method to detect the remote pedestrians. After producing the human temperature based brightness enhancement image using the temperature data input, we generates the regions of interest (ROIs) by the multiscale contrast filtering based approach including the biased hysteresis threshold and clustering, remote pedestrian's height, pixel area and central position information. Afterwards, we conduct local vertical and horizontal projection based ROI refinement and weak aspect ratio based ROI limitation to solve the problem of region expansion in the contrast filtering stage. Finally, we detect the remote pedestrians by validating the final ROIs using transfer learning with convolutional neural network (CNN) feature, following non-maximal suppression (NMS) with strong aspect ratio limitation to improve the detection performance. In the experimental results, we confirmed that the proposed contrast filtering and locally projected region based CNN (CFLP-CNN) outperforms the baseline method by 8% in term of logaveraged miss rate. Also, the proposed method is more effective than the baseline approach and the proposed method provides the better regions that are suitably adjusted to the shape and appearance of remote pedestrians, which makes it detect the pedestrian that didn't find in the baseline approach and are able to help detect pedestrians by splitting the people group into a person.

Impact of the air filtration on indoor particle concentration by using combination filters in offices building

NASA Astrophysics Data System (ADS)

Kabrein, H.; Hariri, A.; Leman, A. M.; Noraini, N. M. R.; Yusof, M. Z. M.; Afandi, A.

2017-09-01

Heating ventilation and air conditioning system (HVAC) is very important for offices building and human health. The combining filter method was used to reduce the air pollution indoor such as that particulate matter and gases pollution that affected in health and productivity. Using particle filters in industrial HVAC systems (factories and manufacturing process) does not enough to remove all the indoor pollution. The main objective of this study is to investigate the impact of combination filters for particle and gases removal efficiency. The combining method is by using two filters (particulate filter pre-filter and carbon filter) to reduce particle matter and gases respectively. The purpose of this study is to use minimum efficiency reporting value (MERV filter) rating 13 and activated carbon filter (ACF) to remove indoor air pollution and controlling the air change rate to enhance the air quality and energy saving. It was concluded that the combination filter showed good removal efficiency of particle up to 90.76% and 89.25% for PM10 and PM2.5 respectively. The pressure drop across the filters was small compared with the high-efficiency filters. The filtration efficiency of combination filters after three months’ was better than efficiency by the new MERV filter alone.

Design parameters of a resonant infrared photoconductor with unity quantum efficiency

NASA Technical Reports Server (NTRS)

Farhoomand, Jam; Mcmurray, Robert E., Jr.

1991-01-01

This paper proposes a concept of a resonant infrared photoconductor that has characteristics of 100 percent quantum efficiency, high photoconductive gain, and very low noise equivalent power. Central to this concept is an establishment of a high-finesse absorption cavity internal to the detector element. A theoretical analysis is carried out, demonstrating this concept and providing some design guidelines. A Ge:Ga FIR detector is presently being fabricated using this approach.

The long-term performance of electrically charged filters in a ventilation system.

PubMed

Raynor, Peter C; Chae, Soo Jae

2004-07-01

The efficiency and pressure drop of filters made from polyolefin fibers carrying electrical charges were compared with efficiency and pressure drop for filters made from uncharged glass fibers to determine if the efficiency of the charged filters changed with use. Thirty glass fiber filters and 30 polyolefin fiber filters were placed in different, but nearly identical, air-handling units that supplied outside air to a large building. Using two kinds of real-time aerosol counting and sizing instruments, the efficiency of both sets of filters was measured repeatedly for more than 19 weeks while the air-handling units operated almost continuously. Pressure drop was recorded by the ventilation system's computer control. Measurements showed that the efficiency of the glass fiber filters remained almost constant with time. However, the charged polyolefin fiber filters exhibited large efficiency reductions with time before the efficiency began to increase again toward the end of the test. For particles 0.6 microm in diameter, the efficiency of the polyolefin fiber filters declined from 85% to 45% after 11 weeks before recovering to 65% at the end of the test. The pressure drops of the glass fiber filters increased by about 0.40 in. H2O, whereas the pressure drop of the polyolefin fiber filters increased by only 0.28 in. H2O. The results indicate that dust loading reduces the effectiveness of electrical charges on filter fibers. Copyright 2004 JOEH, LLC

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

Fir Engraver (FIDL)

Treesearch

George T. Ferrell

1986-01-01

The fir engraver, Scolytus ventralis LeConte, belongs to the family of insects called bark beetles, which live between the bark and wood of host trees. A wide-ranging, native beetle, the fir engraver attacks most species of fir in the Western United States. Epidemics can cause severe tree mortality. From 1977 to 1978, for example, the fir engraver killed an estimated 1...

Heart Rots of Red and White Firs

Treesearch

J.W. Kimmey; H.H. Jr. Bynum

1961-01-01

Heart rots, caused by fungi that attack the heartwood of living trees, are responsible for the greatest volume loss sustained by California red fir (Abies magnifica A. Murr.) and white fir (A. concolor (Gord. and Glend.) Lindl.). These two firs comprise 25 percent of the commercial timber of California. More than 13 percent of the volume in these firs is useless cull...

The identification of Douglas-fir wood

Treesearch

Forest Products Laboratory (U.S.)

1963-01-01

Douglas-fir is one of the largest, most abundant and widely distributed species of trees native to North America, and next to the southern yellow pines, it is cut in the greatest quantities of any wood of commercial importance. It belongs to the coniferous family and is, therefore, a softwood. Other names for Douglas -fir are red fir, yellow fir, Oregon pine, Puget...

Weather, logging, and tree growth associated with fir engraver attack scars in white fir

Treesearch

George T. Ferrell

1973-01-01

The boles of 32 recently killed, and 41 living, white fir were examined for embedded fir engraver (Scolytus ventralis) attack scars. Of 287 scars found in annual rings for the years 1934-69, only 2 to 3 percent represented reproductively successful attacks. Trends in scar abundance were directly correlated with trends in white fir killed by ...

Wideband aperture array using RF channelizers and massively parallel digital 2D IIR filterbank

NASA Astrophysics Data System (ADS)

Sengupta, Arindam; Madanayake, Arjuna; Gómez-García, Roberto; Engeberg, Erik D.

2014-05-01

Wideband receive-mode beamforming applications in wireless location, electronically-scanned antennas for radar, RF sensing, microwave imaging and wireless communications require digital aperture arrays that offer a relatively constant far-field beam over several octaves of bandwidth. Several beamforming schemes including the well-known true time-delay and the phased array beamformers have been realized using either finite impulse response (FIR) or fast Fourier transform (FFT) digital filter-sum based techniques. These beamforming algorithms offer the desired selectivity at the cost of a high computational complexity and frequency-dependant far-field array patterns. A novel approach to receiver beamforming is the use of massively parallel 2-D infinite impulse response (IIR) fan filterbanks for the synthesis of relatively frequency independent RF beams at an order of magnitude lower multiplier complexity compared to FFT or FIR filter based conventional algorithms. The 2-D IIR filterbanks demand fast digital processing that can support several octaves of RF bandwidth, fast analog-to-digital converters (ADCs) for RF-to-bits type direct conversion of wideband antenna element signals. Fast digital implementation platforms that can realize high-precision recursive filter structures necessary for real-time beamforming, at RF radio bandwidths, are also desired. We propose a novel technique that combines a passive RF channelizer, multichannel ADC technology, and single-phase massively parallel 2-D IIR digital fan filterbanks, realized at low complexity using FPGA and/or ASIC technology. There exists native support for a larger bandwidth than the maximum clock frequency of the digital implementation technology. We also strive to achieve More-than-Moore throughput by processing a wideband RF signal having content with N-fold (B = N Fclk/2) bandwidth compared to the maximum clock frequency Fclk Hz of the digital VLSI platform under consideration. Such increase in bandwidth is achieved without use of polyphase signal processing or time-interleaved ADC methods. That is, all digital processors operate at the same Fclk clock frequency without phasing, while wideband operation is achieved by sub-sampling of narrower sub-bands at the the RF channelizer outputs.

Disturbed alternative splicing of FIR (PUF60) directed cyclin E overexpression in esophageal cancers.

PubMed

Ogura, Yukiko; Hoshino, Tyuji; Tanaka, Nobuko; Ailiken, Guzhanuer; Kobayashi, Sohei; Kitamura, Kouichi; Rahmutulla, Bahityar; Kano, Masayuki; Murakami, Kentarou; Akutsu, Yasunori; Nomura, Fumio; Itoga, Sakae; Matsubara, Hisahiro; Matsushita, Kazuyuki

2018-05-01

Overexpression of alternative splicing of far upstream element binding protein 1 (FUBP1) interacting repressor (FIR; poly(U) binding splicing factor 60 [PUF60]) and cyclin E were detected in esophageal squamous cell carcinomas (ESCC). Accordingly, the expression of FBW7 was examined by which cyclin E is degraded as a substrate via the proteasome system. Expectedly, FBW7 expression was decreased significantly in ESCC. Conversely, c-myc gene transcriptional repressor FIR (alias PUF60; U2AF-related protein) and its alternative splicing variant form (FIRΔexon2) were overexpressed in ESCC. Further, anticancer drugs (cis-diaminedichloroplatinum/cisplatin [CDDP] or 5-fluorouracil [5-FU]) and knockdown of FIR by small interfering RNA (siRNA) increased cyclin E while knockdown of FIRΔexon2 by siRNA decreased cyclin E expression in ESCC cell lines (TE1, TE2, and T.Tn) or cervical SCC cells (HeLa cells). Especially, knockdown of SAP155 (SF3b1), a splicing factor required for proper alternative splicing of FIR pre-mRNA, decreased cyclin E. Therefore, disturbed alternative splicing of FIR generated FIR/FIRΔexon2 with cyclin E overexpression in esophageal cancers, indicating that SAP155 siRNA potentially rescued FBW7 function by reducing expression of FIR and/or FIRΔexon2. Remarkably, Three-dimensional structure analysis revealed the hypothetical inhibitory mechanism of FBW7 function by FIR/FIRΔexon2, a novel mechanism of cyclin E overexpression by FIR/FIRΔexon2-FBW7 interaction was discussed. Clinically, elevated FIR expression potentially is an indicator of the number of lymph metastases and anti-FIR/FIRΔexon2 antibodies in sera as cancer diagnosis, indicating chemical inhibitors of FIR/FIRΔexon2-FBW7 interaction could be potential candidate drugs for cancer therapy. In conclusion, elevated cyclin E expression was, in part, induced owing to potential FIR/FIRΔexon2-FBW7 interaction in ESCC.

Far infrared promotes wound healing through activation of Notch1 signaling.

PubMed

Hsu, Yung-Ho; Lin, Yuan-Feng; Chen, Cheng-Hsien; Chiu, Yu-Jhe; Chiu, Hui-Wen

2017-11-01

The Notch signaling pathway is critically involved in cell proliferation, differentiation, development, and homeostasis. Far infrared (FIR) has an effect that promotes wound healing. However, the underlying molecular mechanisms are unclear. In the present study, we employed in vivo and HaCaT (a human skin keratinocyte cell line) models to elucidate the role of Notch1 signaling in FIR-promoted wound healing. We found that FIR enhanced keratinocyte migration and proliferation. FIR induced the Notch1 signaling pathway in HaCaT cells and in a microarray dataset from the Gene Expression Omnibus database. We next determined the mRNA levels of NOTCH1 in paired normal and wound skin tissues derived from clinical patients using the microarray dataset and Ingenuity Pathway Analysis software. The result indicated that the Notch1/Twist1 axis plays important roles in wound healing and tissue repair. In addition, inhibiting Notch1 signaling decreased the FIR-enhanced proliferation and migration. In a full-thickness wound model in rats, the wounds healed more rapidly and the scar size was smaller in the FIR group than in the light group. Moreover, FIR could increase Notch1 and Delta1 in skin tissues. The activation of Notch1 signaling may be considered as a possible mechanism for the promoting effect of FIR on wound healing. FIR stimulates keratinocyte migration and proliferation. Notch1 in keratinocytes has an essential role in FIR-induced migration and proliferation. NOTCH1 promotes TWIST1-mediated gene expression to assist wound healing. FIR might promote skin wound healing in a rat model. FIR stimulates keratinocyte migration and proliferation. Notch1 in keratinocytes has an essential role in FIR-induced migration and proliferation. NOTCH1 promotes TWIST1-mediated gene expression to assist wound healing. FIR might promote skin wound healing in a rat model.

Silvical characteristics of balsam fir (Abies balsamea)

Treesearch

Arthur C. Hart

1959-01-01

Balsam fir takes its name from the Latin word for balm. Some people know the tree as the Balm-of-Gilead fir. It has also been called the blister fir, because of the bark blisters that yield Canada balsam, a resin that is used for, among other things, mounting microscope slides. The needles of balsam fir have a spicy aroma that Donald Culross Peattie has called "...

Seed maturity in white fir and red fir

Treesearch

William W. Oliver

1974-01-01

White fir and red fir seed collected over a 2-month period in northern California was tested for germination of fresh and stratified seed. Ratio of embryo length to embryo cavity length was found to be the most useful index of seed maturity for white and red fir. Cone specific gravity also was correlated with nearly all measures of seed germination. Data suggest that...

Differential susceptibility of white fir provenances to the fir engraver and its fungal symbiont in northern California

Treesearch

G.T. Ferrell; W.J. Otrosina

1996-01-01

The fir engraver, Scolytus ventralis LeC., attacks white fir, Abies concolor (Gord. and Glend.) Lindl., and other true firs, Abies spp., in western North America. The biology, attack behavior, and ecology of this bark beetle were recently summarized by Berryman and Ferrell (1988). During the summer flight season, the attacking beetles bore into the cambial zone of...

Planck's view on the spectrum of the Sunyaev-Zeldovich effect

NASA Astrophysics Data System (ADS)

Erler, Jens; Basu, Kaustuv; Chluba, Jens; Bertoldi, Frank

2018-05-01

We present a detailed analysis of the stacked frequency spectrum of a large sample of galaxy clusters using Planck data, together with auxiliary data from the AKARI and IRAS missions. Our primary goal is to search for the imprint of relativistic corrections to the thermal Sunyaev-Zeldovich effect (tSZ) spectrum, which allow to measure the temperature of the intracluster medium. We remove Galactic and extragalactic foregrounds with a matched filtering technique, which is validated using simulations with realistic mock data sets. The extracted spectra show the tSZ signal at high significance and reveal an additional far-infrared (FIR) excess, which we attribute to thermal emission from the galaxy clusters themselves. This excess FIR emission from clusters is accounted for in our spectral model. We are able to measure the tSZ relativistic corrections at 2.2σ by constraining the mean temperature of our cluster sample to 4.4^{+2.1}_{-2.0} keV. We repeat the same analysis on a subsample containing only the 100 hottest clusters, for which we measure the mean temperature to be 6.0^{+3.8}_{-2.9} keV, corresponding to 2.0σ. The temperature of the emitting dust grains in our FIR model is constrained to ≃20 K, consistent with previous studies. Control for systematic biases is done by fitting mock clusters, from which we also show that using the non-relativistic spectrum for SZ signal extraction will lead to a bias in the integrated Compton parameter Y, which can be up to 14% for the most massive clusters. We conclude by providing an outlook for the upcoming CCAT-prime telescope, which will improve upon Planck with lower noise and better spatial resolution.

Demonstrating a New Census of Infrared Galaxies with ALMA (DANCING-ALMA). I. FIR Size and Luminosity Relation at z = 0-6 Revealed with 1034 ALMA Sources

NASA Astrophysics Data System (ADS)

Fujimoto, Seiji; Ouchi, Masami; Shibuya, Takatoshi; Nagai, Hiroshi

2017-11-01

We present the large statistics of the galaxy effective radius R e in the rest-frame far-infrared (FIR) wavelength {R}{{e}({FIR})} obtained from 1627 Atacama Large Millimeter/submillimeter Array (ALMA) 1 mm band maps that become public by 2017 July. Our ALMA sample consists of 1034 sources with the star formation rate ˜ 100{--}1000 {M}⊙ {{yr}}-1 and the stellar mass ˜ {10}10{--}{10}11.5 {M}⊙ at z = 0-6. We homogeneously derive {R}{{e}({FIR})} and FIR luminosity L FIR of our ALMA sources via the uv-visibility method with the exponential disk model, carefully evaluating selection and measurement incompletenesses by realistic Monte-Carlo simulations. We find that there is a positive correlation between {R}{{e}({FIR})} and L FIR at the >99% significance level. The best-fit power-law function, {R}{{e}({FIR})}\\propto {L}{FIR}α , provides α =0.28+/- 0.07, and shows that {R}{{e}({FIR})} at a fixed L FIR decreases toward high redshifts. The best-fit α and the redshift evolution of {R}{{e}({FIR})} are similar to those of R e in the rest-frame UV (optical) wavelength {R}{{e}({UV})} ({R}{{e}({Opt}.)}) revealed by Hubble Space Telescope (HST) studies. We identify that our ALMA sources have significant trends of {R}{{e}({FIR})}≲ {R}{{e}({UV})} and {R}{{e}({Opt}.)}, which suggests that the dusty starbursts take place in compact regions. Moreover, {R}{{e}({FIR})} of our ALMA sources is comparable to {R}{{e}({Opt}.)} of quiescent galaxies at z ˜ 1-3 as a function of stellar mass, supporting the evolutionary connection between these two galaxy populations. We also investigate rest-frame UV and optical morphologies of our ALMA sources with deep HST images, and find that ˜30%-40% of our ALMA sources are classified as major mergers. This indicates that dusty starbursts are triggered by not only the major mergers but also the other mechanism(s).

A 1-channel 3-band wide dynamic range compression chip for vibration transducer of implantable hearing aids.

PubMed

Kim, Dongwook; Seong, Kiwoong; Kim, Myoungnam; Cho, Jinho; Lee, Jyunghyun

2014-01-01

In this paper, a digital audio processing chip which uses a wide dynamic range compression (WDRC) algorithm is designed and implemented for implantable hearing aids system. The designed chip operates at a single voltage of 3.3V and drives a 16 bit parallel input and output at 32 kHz sample. The designed chip has 1-channel 3-band WDRC composed of a FIR filter bank, a level detector, and a compression part. To verify the performance of the designed chip, we measured the frequency separations of bands and compression gain control to reflect the hearing threshold level.

Arithmetic Circuit Verification Based on Symbolic Computer Algebra

NASA Astrophysics Data System (ADS)

Watanabe, Yuki; Homma, Naofumi; Aoki, Takafumi; Higuchi, Tatsuo

This paper presents a formal approach to verify arithmetic circuits using symbolic computer algebra. Our method describes arithmetic circuits directly with high-level mathematical objects based on weighted number systems and arithmetic formulae. Such circuit description can be effectively verified by polynomial reduction techniques using Gröbner Bases. In this paper, we describe how the symbolic computer algebra can be used to describe and verify arithmetic circuits. The advantageous effects of the proposed approach are demonstrated through experimental verification of some arithmetic circuits such as multiply-accumulator and FIR filter. The result shows that the proposed approach has a definite possibility of verifying practical arithmetic circuits.

Combustion characteristics of Douglas Fir planer shavings. Technical progress report No. 4, September 16, 1977--September 15, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Junge, D.C.

1978-12-01

Significant quantities of wood residue fuels are presently being used in industrial steam generating facilities. Recent studies indicate that substantial additional quantities of wood residue fuels are available for energy generation in the form of steam and/or electricity. A limited data base on the combustion characteristics of wood residue fuels has resulted in the installation and operation of inefficient combustion systems for these fuels. This investigation of the combustion characteristics of wood residue fuels was undertaken to provide a data base which could be used to optimize the combustion of such fuels. Optimization of the the combustion process in industrialmore » boilers serves to improve combustion efficiency and to reduce air pollutant emissions generated in the combustion process. This report presents data on the combustion characteristics of Douglas Fir planer shavings. The data were obtained in a pilot scale combustion test facility at Oregon State Univerisity. Other technical reports present data on the combustion characteristics of: Douglas Fir bark, Red Alder sawdust, Red Alder bark, Ponderosa pine bark, Hemlock bark, and Eastern White Pine bark. An executive summary report is also available which compares the combustion characteristics of the various fuel species.« less

Transcriptome Changes in Douglas-fir (Pseudotsuga menziesii) Induced by Exposure to Diesel Emissions Generated with CeO2 Nanoparticle Fuel Additive

EPA Science Inventory

When cerium oxide nanoparticles are added to diesel fuel, fuel burning efficiency increases, producing emissions (DECe) with characteristics that differ from conventional diesel exhaust (DE). It has previously been shown that DECe induces more adverse pulmonary effects in rats on...

Reconstructing the calibrated strain signal in the Advanced LIGO detectors

NASA Astrophysics Data System (ADS)

Viets, A. D.; Wade, M.; Urban, A. L.; Kandhasamy, S.; Betzwieser, J.; Brown, Duncan A.; Burguet-Castell, J.; Cahillane, C.; Goetz, E.; Izumi, K.; Karki, S.; Kissel, J. S.; Mendell, G.; Savage, R. L.; Siemens, X.; Tuyenbayev, D.; Weinstein, A. J.

2018-05-01

Advanced LIGO’s raw detector output needs to be calibrated to compute dimensionless strain h(t) . Calibrated strain data is produced in the time domain using both a low-latency, online procedure and a high-latency, offline procedure. The low-latency h(t) data stream is produced in two stages, the first of which is performed on the same computers that operate the detector’s feedback control system. This stage, referred to as the front-end calibration, uses infinite impulse response (IIR) filtering and performs all operations at a 16 384 Hz digital sampling rate. Due to several limitations, this procedure currently introduces certain systematic errors in the calibrated strain data, motivating the second stage of the low-latency procedure, known as the low-latency gstlal calibration pipeline. The gstlal calibration pipeline uses finite impulse response (FIR) filtering to apply corrections to the output of the front-end calibration. It applies time-dependent correction factors to the sensing and actuation components of the calibrated strain to reduce systematic errors. The gstlal calibration pipeline is also used in high latency to recalibrate the data, which is necessary due mainly to online dropouts in the calibrated data and identified improvements to the calibration models or filters.

Novel mathematical algorithm for pupillometric data analysis.

PubMed

Canver, Matthew C; Canver, Adam C; Revere, Karen E; Amado, Defne; Bennett, Jean; Chung, Daniel C

2014-01-01

Pupillometry is used clinically to evaluate retinal and optic nerve function by measuring pupillary response to light stimuli. We have developed a mathematical algorithm to automate and expedite the analysis of non-filtered, non-calculated pupillometric data obtained from mouse pupillary light reflex recordings, obtained from dynamic pupillary diameter recordings following exposure of varying light intensities. The non-filtered, non-calculated pupillometric data is filtered through a low pass finite impulse response (FIR) filter. Thresholding is used to remove data caused by eye blinking, loss of pupil tracking, and/or head movement. Twelve physiologically relevant parameters were extracted from the collected data: (1) baseline diameter, (2) minimum diameter, (3) response amplitude, (4) re-dilation amplitude, (5) percent of baseline diameter, (6) response time, (7) re-dilation time, (8) average constriction velocity, (9) average re-dilation velocity, (10) maximum constriction velocity, (11) maximum re-dilation velocity, and (12) onset latency. No significant differences were noted between parameters derived from algorithm calculated values and manually derived results (p ≥ 0.05). This mathematical algorithm will expedite endpoint data derivation and eliminate human error in the manual calculation of pupillometric parameters from non-filtered, non-calculated pupillometric values. Subsequently, these values can be used as reference metrics for characterizing the natural history of retinal disease. Furthermore, it will be instrumental in the assessment of functional visual recovery in humans and pre-clinical models of retinal degeneration and optic nerve disease following pharmacological or gene-based therapies. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Risk-rating systems for mature red fir and white fir in northern California

Treesearch

George T. Ferrell

1980-01-01

On the basis of crown and bole characteristics, risk-rating systems to predict the probability that a tree will die within 5 years were developed for mature red fir and white fir in northern California. The systems apply to firs at least 10 inches (25.4 cm) in diameter-at-breast-height (d.b.h.), growing in mature stands, with the original overstory at least partially...

Assessing the susceptibility of white fir to the fir engraver, Scolytus ventralis Lec. (Coleoptera: Scolytidae), using fungal inoculation

Treesearch

G.T. Ferrell; W.J. Otrosina; C.J. DeMars

1993-01-01

A method of assessing susceptibility of white fir, Abies concolor (Gord. and Glend.) Lindl., by fungal inoculation was tested during an outbreak of the fir engraver beetle, Scolytus ventralis LeC., at Lake Tahoe, California, in 1987 through 1989.A total of 592 firs growing in six forest stands containing trees infested by the beetle were inoculated with the mutualistic...

Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

PubMed

Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

2015-11-15

In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Allelochemicals and activities in a replanted Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) tree ecosystem.

PubMed

Kong, C H; Chen, L C; Xu, X H; Wang, P; Wang, S L

2008-12-24

Autotoxicity is a major reason for replant problems in managed tree ecosystems. Studies have related phenolics-based allelochemicals to autotoxicity. We selected a 20-year-old replanted Chinese fir [Cunninghamia lancealata (Lamb.) Hook] tree ecosystem to isolate, identify, determine the biological activity of, and quantify soil phytotoxins. Eight common phenolics (coumarin, vanillin, isovanillin, and p-hydroxybenzoic, vanillic, benzoic, cinnamic, and ferulic acids), friedelin, and a novel cyclic dipeptide (6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane-2,5-diketone) were obtained by using the bioassay-guided isolation technique from toxic soil of the replanted Chinese fir tree ecosystem. Chemical structures were determined by spectroscopic means, including 2D-NMR (COSY, HMQC, HMBC, and NOESY) experiments. High concentrations of soil phenolics and friedelin were observed in the natural evergreen broadleaf forest (CK) rather than in the Chinese fir tree ecosystem. The phenolics and friedelin were not phytotoxic to Chinese fir trees. However, the cyclic dipeptide inhibited Chinese fir growth at soil concentrations determined in the replanted Chinese fir tree ecosystem. There was a significantly higher soil concentration of cyclic dipeptide in the replanted Chinese fir tree ecosystem than in a fresh Chinese fir tree ecosystem. The results suggest that phenolics and friedelin are not key allelochemicals since they are weakly phytotoxic and are detected in low concentrations in the replanted Chinese fir tree ecosystem, while cyclic dipeptide is a highly active allelochemical with a phytotoxic effect that limits offspring growth in the replanted Chinese fir tree ecosystem. The discovery of cyclic dipeptide, as well as a further understanding of its potential action mechanism in the replanted Chinese fir tree ecosystem, may contribute to solving the replant problems in managed tree ecosystems.

Precommercial thinning in mixed-species conifer plantations affected by armillaria and heterobasidion root diseases in West-Central Oregon and Washington: 30-year results

Treesearch

Gregory M. Filip; Joshua J. Bronson; Kristen L. Chadwick; Jeremy B. Filip; Susan J. Frankel; Donald J. Goheen; Ellen M. Goheen; Sylvia R. Mori; Angel L. Saavedra

2015-01-01

Four 10- to 20-year-old plantations were precommercially thinned to determine the effects on tree growth and mortality caused by armillaria and heterobasidion root diseases. The plantations represented different species compositions with one each of (1) coastal Douglas-fir and noble fir, (2) Douglas-fir and western hemlock, (3) pure Douglas-fir, and (4) Shasta red fir...

Hybridization of a Rocky Mountain fir (Abies concolor) and a Mexican fir (Abies religiosa).

Treesearch

J.B. St. Clair; W.B. Critchfield

1988-01-01

Interspecific crosses of Abies religiosa (HBK.) Schlecht. & Cham. (oyamel) with Abies concolor (Gord. & Glend.) Lindle. ex Hildebr. var. concolor (white fir) and Abies magnifica A. Murr. (California red fir) were undertaken to explore the relationships between these species. The...

Inhibition of the growth of Alexandrium tamarense by algicidal substances in Chinese fir (Cunninghamia lanceolata).

PubMed

Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye; Zhang, Xin-Lian; Qi, Yu-Zao

2009-10-01

The wood sawdust from Chinese fir (Cunninghamia lanceolata) exhibited stronger inhibition on the growth of Alexandrium tamarense than those from alder (Alnus cremastogyne), pine (Pinus massoniana), birch (Betula alnoides) and sapele (Entandrophragma cylindricum). The water extract, acetone-water extract and essential oil from fir sawdust were all shown to inhibit the growth of A. tamarense. The inhibition of fir essential oil was the strongest among all the above wood sources while the half effective concentration was only 0.65 mg/L. These results suggested that the fir essential oil may play an important role in the algicidal effect of Chinese fir.

Successful Training of Filtering Mechanisms in Multiple Object Tracking Does Not Transfer to Filtering Mechanisms in a Visual Working Memory Task: Behavioral and Electrophysiological Evidence

ERIC Educational Resources Information Center

Arend, Anna M.; Zimmer, Hubert D.

2012-01-01

In this training study, we aimed to selectively train participants' filtering mechanisms to enhance visual working memory (WM) efficiency. The highly restricted nature of visual WM capacity renders efficient filtering mechanisms crucial for its successful functioning. Filtering efficiency in visual WM can be measured via the lateralized change…

Hybridization of a Rocky Mountain fir (Abies concolor) and a Mexican fir (Abies religiosa)

Treesearch

J. B. St. Clair; W. B. Critchfield

1988-01-01

Interspecific crosses of Abies religiosa (HBK.) Schlecht. & Cham, (oyamel) with Abies concolor (Gord. & Glend.) Lindl. ex Hildebr. var. concolor (white fir) and Abies magnifica A. Murr. (California red fir) were undertaken to explore the relationships between these species. The cross...

User's guide to the Douglas-fir beetle impact model

Treesearch

Michael A. Marsden; Bov B. Eav; Matthew K. Thompson

1993-01-01

Douglas-fir beetle (Dendroctonus pseudotsugae Hopk.) occurs throughout the range of its principal host, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). At epidemic levels, the beetle causes considerable mortality in large-diameter Douglas-fir trees. Wind storms, drought, fire, and other factors have been reported as precedent...

Douglas-Fir Tussock Moth

Treesearch

Boyd E. Wickman; Richard R. Mason; Galen C. Trostle

1981-01-01

The Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) is an important defoliator of true firs and Douglas-fir in Western North America. Severe tussock moth outbreaks have occurred in British Columbia, Idaho, Washington, Oregon, Nevada, California, Arizona, and New Mexico, but the area subject to attack is more extensive

Effects of far-infrared radiation on heart rate variability and central manifestations in healthy subjects: a resting-fMRI study.

PubMed

Lin, Yii-Jeng; Kung, Yen-Ying; Kuo, Wen-Jui; Niddam, David M; Cheng, Chou-Ming; Chou, Chih-Che; Yeh, Tzu-Chen; Hsieh, Jen-Chuen; Chiu, Jen-Hwey

2015-01-01

The aim of this study was to investigate the autonomic responses and central manifestations by peripheral FIR stimulation. Ten subjects (mean ± SD age 26.2 ± 3.52 years) received FIR stimulation at left median nerve territory for 40 min. Electrocardiograph was continuously recorded and heart rate variability (HRV) were analyzed. By using a 3 T-MRI scanner, three sessions of resting-state functional magnetic resonance images (fMRI) were acquired, namely, before (baseline-FIR), immediately after (IA-FIR) and 15 min after FIR was turned off (Post-FIR). The fractional amplitude of low-frequency (0.01-0.08 Hz) fluctuation (fALFF) of each session to evaluate the intensity of resting-brain activity in each session was analyzed. Our results showed that FIR stimulation induced significant HRV responses such as an increasing trend of nLF and LF/HF ratio, while FIR increased fALFF in right superior front gyrus, middle frontal gyrus and decreased the resting brain activity at fusiform gyrus, extrastriae cortex, inferior temporal gyrus and middle temporal gyrus, especially 15 min after FIR was turned off. We conclude that the central manifestation and the autonomic responses are prominent during and after FIR stimulation, which provide important mechanistic explanation on human disorder treated by such energy medicine.

Noble fir: a bibliography with abstracts.

Treesearch

Jerry F. Franklin

1962-01-01

This bibliography on noble fir (Abies procera Rehd.) includes both North American and European references. Its purpose is to list articles for those interested in the species; the most important references have been abstracted. An article concerning California red fir and one concerning Shasta red fir are included, as their silvical characteristics...

User's guide to the douglas-fir beetle impact model. Forest Service general technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marsden, M.A.; Eav, B.B.; Thompson, M.K.

1994-09-01

Douglas-fir beetle occurs throughout the range of its principal host, Douglas-fir. At epidemic levels, the beetle causes considerable mortality in large-diameter Douglas-fir trees. Wind storms, drought, fire, and other factors have been reported as precendent conditions for epidemics of Douglas-fir beetle. An impact model has been developed to simulate tree mortality during such epidemics. The model has been linked to the Stand Prognosis Model (Forest Vegetation Simulator). This is a guide for using the model.

Test of precoat filtration technology for treatment of swimming pool water.

PubMed

Christensen, Morten Lykkegaard; Klausen, Morten Møller; Christensen, Peter Vittrup

2018-02-01

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite ® and Aquatec perlite) and cellulose fibers (Arbocel ® ), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, P.R.; Gregory, W.S.

1985-04-01

Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the samemore » (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released.« less

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China.

PubMed

Liu, Xin; Fu, Zhiyuan; Zhang, Bo; Zhai, Lu; Meng, Miaojing; Lin, Jie; Zhuang, Jiayao; Wang, G Geoff; Zhang, Jinchi

2018-09-30

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO 3 - in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO 3 - increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO 3 - concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO 3 - concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China. Copyright © 2018. Published by Elsevier Inc.

Less than 50% nitrogen retention 1-year after high N additions to Pacific Northwest Douglas-fir forests

NASA Astrophysics Data System (ADS)

Michelsen-Correa, S.; Harrison, R. B.

2017-12-01

In Pacific Northwest forests, N is known to be a limiting nutrient particularly in Douglas-fir (Pseudotsuga menziesii) ecosystems. Fertilizers are commonly applied to increase productivity in commercially managed forests. Despite known N limitations, Douglas-fir uptake of applied fertilizers is typically low and highly variable depending on environmental site conditions of a particular forest. We measured N recovery within a 1-year time frame at five sites using a fertilizer enriched in 15N as a tracer. Comparisons were also made between Enhanced Efficiency Fertilizers (EEFs) and an unformulated urea fertilizer to determine if N recovery is improved with fertilizers designed to limit volatile losses of ammonia. Retention was low across all sites and fertilizer types with a mean of 39.0% recovered after 1-year. The largest fertilizer pool was the top 20cm of mineral soil. The use of EFFs as a management tool to improve N use efficiency at the five sites in our study is not supported by our results as no significant differences in total 1-year N recovery or tree uptake of N were observed between treatments. The low N recovery after 1-year but simultaneous increases in above ground biomass support a model of N loss where the ecosystem can continue to accumulate biomass with simultaneous leaching and gaseous losses of N. This conclusion contrasts with the commonly held assumption that fertilization of N limited Douglas-fir forests, should yield negligible losses of N and high recovery of the applied fertilizer. Additionally, we conclude that management decisions regarding fertilizer use efficiency and the benefits of fertilization need to be site specific due to the variable N recovery rates based on site factors as opposed to fertilizer treatment type. Finally, despite differences in the size of available soil N pools the amount of N recovered in the above group pools (i.e. bole wood and foliage) were not significantly different between sites. N uptake by the plants pools may have been at its maximum, thus additional N in the soil pools would not make a difference in terms of productivity over just one year. It remains to be seen what the longer-term impacts of the fertilizer treatments are, as the sites with a larger reservoir of plant available N are expected to maintain their growth rates for longer than the sites with lower N recovery.

[Community stability for spruce-fir forest at different succession stages in Changbai Mountains, Northeast China].

PubMed

Zhang, Meng-tao; Zhang, Qing; Kang, Xin-gang; Yang, Ying-jun; Xu, Guang; Zhang, Li-xin

2015-06-01

Based on the analysis of three forest communities (polar-birch secondary forest, spruce-fir mixed forest, spruce-fir near pristine forest) in Changbai Mountains, a total of 22 factors of 5 indices, including the population regeneration, soil fertility (soil moisture and soli nutrient), woodland productivity and species diversity that reflected community characteristics were used to evaluate the stability of forest community succession at different stages by calculating subordinate function values of a model based on fuzzy mathematics. The results that the indices of population regeneration, soli nutrient, woodland productivity and species diversity were the highest in the spruce-fir mixed forest, and the indices of soil moisture were the highest in the spruce-fir near-pristine forest. The stability of three forest communities was in order of natural spruce-fir mixed forest > spruce-fir near pristine forest > polar-birch secondary forest.

Efficiency analysis of color image filtering

NASA Astrophysics Data System (ADS)

Fevralev, Dmitriy V.; Ponomarenko, Nikolay N.; Lukin, Vladimir V.; Abramov, Sergey K.; Egiazarian, Karen O.; Astola, Jaakko T.

2011-12-01

This article addresses under which conditions filtering can visibly improve the image quality. The key points are the following. First, we analyze filtering efficiency for 25 test images, from the color image database TID2008. This database allows assessing filter efficiency for images corrupted by different noise types for several levels of noise variance. Second, the limit of filtering efficiency is determined for independent and identically distributed (i.i.d.) additive noise and compared to the output mean square error of state-of-the-art filters. Third, component-wise and vector denoising is studied, where the latter approach is demonstrated to be more efficient. Fourth, using of modern visual quality metrics, we determine that for which levels of i.i.d. and spatially correlated noise the noise in original images or residual noise and distortions because of filtering in output images are practically invisible. We also demonstrate that it is possible to roughly estimate whether or not the visual quality can clearly be improved by filtering.

Predicting postfire Douglas-fir beetle attacks and tree mortality in the northern Rocky Mountains

Treesearch

Sharon Hood; Barbara Bentz

2007-01-01

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were monitored for 4 years following three wildfires. Logistic regression analyses were used to develop models predicting the probability of attack by Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins, 1905) and the probability of Douglas-fir mortality within 4 years following...

Losses associated with Douglas-fir and true fir tops killed by western spruce budworm in eastern Washington.

Treesearch

Paul E. Aho

1984-01-01

A sample of 133 Douglas-firs (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and 69 true firs (Abies spp.) with dead tops caused by defoliation by the western spruce budworm (Choristoneura occidentalis Freeman) were felled, dissected, and examined for height loss and incidence and...

Composition of root pressure exudate from conifers.

Treesearch

D.O. Ketchie; W. Lopushinsky

1981-01-01

Root pressure exudates collected from detopped seedlings of Douglas-fir, grand fir, noble fir, Pacific silver fir, ponderosa pine, lodgepole pine, and Engelmann spruce were analyzed for sugars, amino acids, organic acids, nitrogen, potassium, calcium, and magnesium. Sugar concentrations ranged from 0.10 percent to 5 percent, and included glucose, sucrose, fructose, and...

Effects of fir sawyer beetle on spatial structure of Siberian fir stands

Treesearch

Vladimir L. Gavrikov; Valentina P. Vetrova

1991-01-01

Insects not only use plants for food and habitat; they also change plant populations by influencing their structure and dynamics. This influence is evidenced in the alteration of the spatial structure of a stand. The fir sawyer, Monochamus urussovi Fisch. (Coleoptera: Cerambycidae), is the most abundant xylophagous insect injuring siberian fir,...

Timing of aerial surveys for the balsam woolly aphid

Treesearch

W.J. Buckhorn; Paul G. Lauterbach

1957-01-01

An outbreak of the balsam woolly aphid (Chermes piceae Ratz.) is damaging and killing Pacific silver fir, subalpine fir, and grand fir extensively in western Washington and Oregon. It is most serious in southern Washington where an outbreak on Pacific silver fir was discovered in 1954. Since effective methods for controlling this insect under...

Biological Degradation of Chinese Fir with Trametes Versicolor (L.) Lloyd

PubMed Central

Chen, Meiling; Wang, Chuangui; Fei, Benhua; Ma, Xinxin; Zhang, Bo; Zhang, Shuangyan; Huang, Anmin

2017-01-01

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) has been an important afforestation species in northeast China. It has obvious defects of buckling and cracking easily, which are caused by its chemical components. Trametes versicolor (L.) Lloyd, a white-rot fungus, can decompose the cellulose, hemicellulose, and lignin in the wood. White-rot fungus was used to biologically degrade Chinese fir wood. The effects of different degradation time on the Chinese fir wood’s mechanical properties, micromorphology, chemical components, and crystallinity were studied. The results showed that the heartwood of Chinese fir was more durable than the sapwood and the durability class of Chinese fir was III. Trametes versicolor (L.) Lloyd had a greater influence on the mechanical properties (especially with respect to the modulus of elasticity (MOE)) for the sapwood. Trametes versicolor (L.) Lloyd degraded Chinese fir and colonized the lumen of various wood cell types in Chinese fir, penetrated cell walls via pits, caused erosion troughs and bore holes, and removed all cell layers. The ability of white-rot fungus to change the chemical composition mass fraction for Chinese fir was: hemicellulose > lignin > cellulose. The durability of the chemical compositions was: lignin > cellulose > hemicellulose. The crystallinity of the cellulose decreased and the mean size of the ordered (crystalline) domains increased after being treated by white-rot fungus. PMID:28773191

Tracking Diurnal Variation in Photosynthetic Down-Regulation Using Low Cost Spectroscopic Instrumentation

PubMed Central

van Leeuwen, Martin; Kremens, Robert L.; van Aardt, Jan

2015-01-01

Photosynthetic light-use efficiency (LUE) has gained wide interest as an input to modeling forest gross primary productivity (GPP). The photochemical reflectance index (PRI) has been identified as a principle means to inform LUE-based models, using airborne and satellite-based observations of canopy reflectance. More recently, low-cost electronics have become available with the potential to provide for dense in situ time-series measurements of PRI. A recent design makes use of interference filters to record light transmission within narrow wavebands. Uncertainty remains as to the dynamic range of these sensors and performance under low light conditions, the placement of the reference band, and methodology for reflectance calibration. This paper presents a low-cost sensor design and is tested in a laboratory set-up, as well in the field. The results demonstrate an excellent performance against a calibration standard (R2 = 0.9999) and at low light conditions. Radiance measurements over vegetation demonstrate a reversible reduction in green reflectance that was, however, seen in both the reference and signal wavebands. Time-series field measurements of PRI in a Douglas-fir canopy showed a weak correlation with eddy-covariance-derived LUE and a significant decline in PRI over the season. Effects of light quality, bidirectional scattering effects, and possible sensor artifacts on PRI are discussed. PMID:25951342

Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters.

PubMed

Stephens, B; Siegel, J A

2013-12-01

This work uses an in situ filter test method to measure the size-resolved removal efficiency of indoor-generated ultrafine particles (approximately 7-100 nm) for six new commercially available filters installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC filters were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel filters (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media filters (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine particles (UFP) sizes with the lowest rated filters (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated filter (MERV 16). The deeper bed filters generally achieved higher removal efficiencies than the panel filters, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new filters and other inputs from real buildings shows that MERV 13-16 filters could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency filters, depending in part on particle size. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Association of Far-Infrared Radiation Therapy and Ankle-Brachial Index of Patients on Hemodialysis with Peripheral Artery Occlusive Disease

PubMed Central

Chen, Szu-Chia; Lee, Mei-Yueh; Huang, Jiun-Chi; Kuo, I-Ching; Mai, Hsiu-Chin; Kuo, Po-Lin; Chang, Jer-Ming; Hwang, Shang-Jyh; Chen, Hung-Chun

2016-01-01

Background and Aim: The ankle-brachial index (ABI) is recognized to be a good marker for atherosclerosis, and is useful in the diagnosis of peripheral artery occlusive disease (PAOD) which is prevalent among patients on hemodialysis (HD). Methods: This randomized trial aimed to evaluate the effect of far-infrared radiation (FIR) therapy on ABI in HD patients with PAOD. PAOD was defined as patients with ABI < 0.95. One hundred and eight HD patients were enrolled, including 50 in the control group and 58 in the FIR group. A WS TY101 FIR emitter was applied for 40 minutes during each HD session, three times per week for six months. The ABI was measured before and after the FIR therapy. Results: Regardless of FIR therapy, the bilateral ABI decreased (in the FIR group, left: 0.88±0.22 to 0.85±0.24, p = 0.188; right: 0.92±0.20 to 0.90±0.23, p = 0.372; in control group, left: 0.91±0.23 to 0.88±0.21, p = 0144; right: 0.93±0.17 to 0.89±0.21, p = 0.082). Multivariate logistic analysis of the FIR group revealed that high uric acid (odds ratio [OR]: 2.335; 95% confidence interval [CI]: 1.117-4.882; p=0.024) and aspirin use (OR: 16.463; 95% CI: 1.787-151.638; p=0.013) were independently associated with increased bilateral ABI after FIR therapy. Conclusions: This study demonstrates that ABI is not increased after FIR therapy in HD patients with PAOD. However, in the FIR group, patients with higher uric acid level or those who used aspirin have increased bilateral ABI after FIR therapy. PMID:27994503

Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany.

PubMed

Vitali, Valentina; Büntgen, Ulf; Bauhus, Jürgen

2017-12-01

Improving our understanding of the potential of forest adaptation is an urgent task in the light of predicted climate change. Long-term alternatives for susceptible yet economically important tree species such as Norway spruce (Picea abies) are required, if the frequency and intensity of summer droughts will continue to increase. Although Silver fir (Abies alba) and Douglas fir (Pseudotsuga menziesii) have both been described as drought-tolerant species, our understanding of their growth responses to drought extremes is still limited. Here, we use a dendroecological approach to assess the resistance, resilience, and recovery of these important central Europe to conifer species the exceptional droughts in 1976 and 2003. A total of 270 trees per species were sampled in 18 managed mixed-species stands along an altitudinal gradient (400-1200 m a.s.l.) at the western slopes of the southern and central Black Forest in southwest Germany. While radial growth in all species responded similarly to the 1976 drought, Norway spruce was least resistant and resilient to the 2003 summer drought. Silver fir showed the overall highest resistance to drought, similarly to Douglas fir, which exhibited the widest growth rings. Silver fir trees from lower elevations were more drought prone than trees at higher elevations. Douglas fir and Norway spruce, however, revealed lower drought resilience at higher altitudes. Although the 1976 and 2003 drought extremes were quite different, Douglas fir maintained consistently the highest radial growth. Although our study did not examine population-level responses, it clearly indicates that Silver fir and Douglas fir are generally more resistant and resilient to previous drought extremes and are therefore suitable alternatives to Norway spruce; Silver fir more so at higher altitudes. Cultivating these species instead of Norway spruce will contribute to maintaining a high level of productivity across many Central European mountain forests under future climate change. © 2017 John Wiley & Sons Ltd.

MicroRNA-134 Contributes to Glucose-Induced Endothelial Cell Dysfunction and This Effect Can Be Reversed by Far-Infrared Irradiation

PubMed Central

Wang, Yen-Li; Chang, Shih-Ting; Liao, Ko-Hsun; Lo, Hung-Hao; Chiu, Ya-Lin; Hsieh, Tsung-Han; Huang, Tse-Shun; Lin, Chin-Sheng; Cheng, Shu-Meng; Cheng, Cheng-Chung

2016-01-01

Diabetes mellitus (DM) is a metabolic disease that is increasing worldwide. Furthermore, it is associated with the deregulation of vascular-related functions, which can develop into major complications among DM patients. Endothelial colony forming cells (ECFCs) have the potential to bring about medical repairs because of their post-natal angiogenic activities; however, such activities are impaired by high glucose- (HG) and the DM-associated conditions. Far-infrared radiation (FIR) transfers energy as heat that is perceived by the thermoreceptors in human skin. Several studies have revealed that FIR improves vascular endothelial functioning and boost angiogenesis. FIR has been used as anti-inflammatory therapy and as a clinical treatment for peripheral circulation improvement. In addition to vascular repair, there is increasing evidence to show that FIR can be applied to a variety of diseases, including cardiovascular disorders, hypertension and arthritis. Yet mechanism of action of FIR and the biomarkers that indicate FIR effects remain unclear. MicroRNA-134 (miR-134-5p) was identified by small RNA sequencing as being increased in high glucose (HG) treated dfECFCs (HG-dfECFCs). Highly expressed miR-134 was also validated in dmECFCs by RT-qPCR and it is associated with impaired angiogenic activities of ECFCs. The functioning of ECFCs is improved by FIR treatment and this occurs via a reduction in the level of miR-134 and an increase in the NRIP1 transcript, a direct target of miR-134. Using a mouse ischemic hindlimb model, the recovery of impaired blood flow in the presence of HG-dfECFCs was improved by FIR pretreatment and this enhanced functionality was decreased when there was miR-134 overexpression in the FIR pretreated HG-dfECFCs. In conclusion, our results reveal that the deregulation of miR-134 is involved in angiogenic defects found in DM patients. FIR treatment improves the angiogenic activity of HG-dfECFCs and dmECFCs and FIR has potential as a treatment for DM. Detection of miR-134 expression in FIR-treated ECFCs should help us to explore further the effectiveness of FIR therapy. PMID:26799933

MicroRNA-134 Contributes to Glucose-Induced Endothelial Cell Dysfunction and This Effect Can Be Reversed by Far-Infrared Irradiation.

PubMed

Wang, Hsei-Wei; Su, Shu-Han; Wang, Yen-Li; Chang, Shih-Ting; Liao, Ko-Hsun; Lo, Hung-Hao; Chiu, Ya-Lin; Hsieh, Tsung-Han; Huang, Tse-Shun; Lin, Chin-Sheng; Cheng, Shu-Meng; Cheng, Cheng-Chung

2016-01-01

Diabetes mellitus (DM) is a metabolic disease that is increasing worldwide. Furthermore, it is associated with the deregulation of vascular-related functions, which can develop into major complications among DM patients. Endothelial colony forming cells (ECFCs) have the potential to bring about medical repairs because of their post-natal angiogenic activities; however, such activities are impaired by high glucose- (HG) and the DM-associated conditions. Far-infrared radiation (FIR) transfers energy as heat that is perceived by the thermoreceptors in human skin. Several studies have revealed that FIR improves vascular endothelial functioning and boost angiogenesis. FIR has been used as anti-inflammatory therapy and as a clinical treatment for peripheral circulation improvement. In addition to vascular repair, there is increasing evidence to show that FIR can be applied to a variety of diseases, including cardiovascular disorders, hypertension and arthritis. Yet mechanism of action of FIR and the biomarkers that indicate FIR effects remain unclear. MicroRNA-134 (miR-134-5p) was identified by small RNA sequencing as being increased in high glucose (HG) treated dfECFCs (HG-dfECFCs). Highly expressed miR-134 was also validated in dmECFCs by RT-qPCR and it is associated with impaired angiogenic activities of ECFCs. The functioning of ECFCs is improved by FIR treatment and this occurs via a reduction in the level of miR-134 and an increase in the NRIP1 transcript, a direct target of miR-134. Using a mouse ischemic hindlimb model, the recovery of impaired blood flow in the presence of HG-dfECFCs was improved by FIR pretreatment and this enhanced functionality was decreased when there was miR-134 overexpression in the FIR pretreated HG-dfECFCs. In conclusion, our results reveal that the deregulation of miR-134 is involved in angiogenic defects found in DM patients. FIR treatment improves the angiogenic activity of HG-dfECFCs and dmECFCs and FIR has potential as a treatment for DM. Detection of miR-134 expression in FIR-treated ECFCs should help us to explore further the effectiveness of FIR therapy.

Far-infrared radiation acutely increases nitric oxide production by increasing Ca{sup 2+} mobilization and Ca{sup 2+}/calmodulin-dependent protein kinase II-mediated phosphorylation of endothelial nitric oxide synthase at serine 1179

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jung-Hyun; Lee, Sangmi; Cho, Du-Hyong

Highlights: •Far-infrared (FIR) radiation increases eNOS-Ser{sup 1179} phosphorylation and NO production in BAEC. •CaMKII and PKA mediate FIR-stimulated increases in eNOS-Ser{sup 1179} phosphorylation. •FIR increases intracellular Ca{sup 2+} levels. •Thermo-sensitive TRPV Ca{sup 2+} channels are unlikely to be involved in the FIR-mediated eNOS-Ser{sup 1179} phosphorylation pathway. -- Abstract: Repeated thermal therapy manifested by far-infrared (FIR) radiation improves vascular function in both patients and mouse model with coronary heart disease, but its underlying mechanism is not fully understood. Using FIR as a thermal therapy agent, we investigate the molecular mechanism of its effect on endothelial nitric oxide synthase (eNOS) activity andmore » NO production. FIR increased the phosphorylation of eNOS at serine 1179 (eNOS-Ser{sup 1179}) in a time-dependent manner (up to 40 min of FIR radiation) in bovine aortic endothelial cells (BAEC) without alterations in eNOS expression. This increase was accompanied by increases in NO production and intracellular Ca{sup 2+} levels. Treatment with KN-93, a selective inhibitor of Ca{sup 2+}/calmodulin-dependent protein kinase II (CaMKII) and H-89, a protein kinase A inhibitor, inhibited FIR radiation-stimulated eNOS-Ser{sup 1179} phosphorylation. FIR radiation itself also increased the temperature of culture medium. As transient receptors potential vanilloid (TRPV) ion channels are known to be temperature-sensitive calcium channels, we explore whether TRPV channels mediate these observed effects. Reverse transcription-PCR assay revealed two TRPV isoforms in BAEC, TRPV2 and TRPV4. Although ruthenium red, a pan-TRPV inhibitor, completely reversed the observed effect of FIR radiation, a partial attenuation (∼20%) was found in cells treated with Tranilast, TRPV2 inhibitor. However, ectopic expression of siRNA of TRPV2 showed no significant alteration in FIR radiation-stimulated eNOS-Ser{sup 1179} phosphorylation. This study suggests that FIR radiation increases NO production via increasing CaMKII-mediated eNOS-Ser{sup 1179} phosphorylation but TRPV channels may not be involved in this pathway. Our results may provide the molecular mechanism by which FIR radiation improves endothelial function.« less

Determination of permeability of ultra-fine cupric oxide aerosol through military filters and protective filters

NASA Astrophysics Data System (ADS)

Kellnerová, E.; Večeřa, Z.; Kellner, J.; Zeman, T.; Navrátil, J.

2018-03-01

The paper evaluates the filtration and sorption efficiency of selected types of military combined filters and protective filters. The testing was carried out with the use of ultra-fine aerosol containing cupric oxide nanoparticles ranging in size from 7.6 nm to 299.6 nm. The measurements of nanoparticles were carried out using a scanning mobility particle sizer before and after the passage through the filter and a developed sampling device at the level of particle number concentration approximately 750000 particles·cm-3. The basic parameters of permeability of ultra-fine aerosol passing through the tested material were evaluated, in particular particle size, efficiency of nanoparticle capture by filter, permeability coefficient and overall filtration efficiency. Results indicate that the military filter and particle filters exhibited the highest aerosol permeability especially in the nanoparticle size range between 100–200 nm, while the MOF filters had the highest permeability in the range of 200 to 300 nm. The Filter Nuclear and the Health and Safety filter had 100% nanoparticle capture efficiency and were therefore the most effective. The obtained measurement results have shown that the filtration efficiency over the entire measured range of nanoparticles was sufficient; however, it was different for particular particle sizes.

Trapping Douglas-fir beetle (Dendroctonus pseudotsugae) with pheromone baited multiple-funnel traps does not reduce Douglas-fir (Pseudotsuga menziesii) mortality

Treesearch

R.A. Progar; N. Sturdevant; M.J. Rinella

2010-01-01

Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (DFB) causes considerable mortality to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North American forests. We evaluated the use of semiochemical-baited multiple-funnel traps for the protection of small, high-value stands of trees, such as those occurring...

Size of Douglas-fir trees in relation to distance from a mixed red alder - Douglas-fir stand

Treesearch

R.E. Miller; D.L. Reukema; T.A. Max

1993-01-01

Variation in diameter, height, and stem volume of 57-year-old Douglas-fir(Pseudotsuga menziesii var. menziesii (Mirb.) Franco) was related to distance of these trees from a 27 m wide strip in the same Douglas-fir plantation that had been interplanted with red alder (Alnus rubra Bong.). Within the...

HOW to Identify and Manage Needlecast Diseases on Balsam Fir

Treesearch

Mike Albers; Jana Albers; Jane Cummings Carlson; Linda Haugen; Nancy Wenner

1996-01-01

Needlecast diseases are common in balsam fir stands and Christmas tree plantations in the northeastern and north central United States and in southern Ontario, Quebec, and New Brunswick. Three different needlecast fungi, Lirula nervata, Lirula mirabilis and Isthmiella faullii, cause similar disease symptoms on balsam fir. These diseases may affect other firs planted in...

Ten-year risk-rating systems for California red fir and white fir: development and use

Treesearch

George T. Ferrell

1989-01-01

Logistic regression equations predicting the probability that a tree will die from natural causes--insects, diseases, intertree competition--within 10 years have been developed for California red fir (Abies magnifica) and white fir (A. concolor). The equations, like those with a 5-year prediction period already developed for these...

Diagnosis of Annosus Root Disease in Mixed Conifer Forests in the Northwestern United States

Treesearch

Craig L. Schmitt

1989-01-01

Recognizing annosus root disease affecting conifers in northwestern United States forests is discussed. Field diagnosis can bemade by observing characteristic stand patterns, wood stain and decay, ectotrophic mycelium, and sporophores. Most seriously affected trees include hemlocks, grand fir, white fir and Pacific silver fir. Ponderosa pine and other true firs may...

Decay of subalpine fir in Colorado

Treesearch

Thomas E. Hinds; Frank G. Hawksworth; Ross W. Davidson

1960-01-01

Spruce-fir is one of the major forest types in the central Rocky Mountains. Engelmann spruce, Picea engelmanni Parry, is usually the predominant species with subalpine fir, Abies lasiocarpa (Hook. ) Nutt., making up one-fourth or less of the total volume. Lodgepole pine, Pinus contorta Dougl. ex Loud., is frequently present at the lower elevations of the spruce-fir...

Stability of nuclear DNA content among divergent and isolated populations of Fraser fir

Treesearch

L.D. Auckland; J.S. Johnston; H.J. Price; F.E. Bridgwater

2001-01-01

Fraser fir (Abies fraseri (Pursh) Poir.) is an endemic species consisting of six major disjunct populations in the Appalachian Mountains, U.S.A. Nuclear DNA content was measured with laser flow cytometry to determine if genome size differences could be detected among the disjunct populations of Fraser fir and its close relatives, balsam fir

Altitudinal gradients of bryophyte diversity and community assemblage in southern Appalachian spruce-fir forests

Treesearch

Sarah E. Stehn; Christopher R. Webster; Janice M. Glime; Michael A. Jenkins

2010-01-01

Ground-layer plant communities in spruce-fir forests of the southern Appalachians have likely undergone significant change since the widespread death of canopy Fraser fir (Abies fraseri) caused by the exotic balsam woolly adelgid (Adelges piceae). Bryophytes comprise an important part of the ground-layer flora in the spruce-fir...

A SYNCHRONIZED FIR/VUV LIGHT SOURCE AT JEFFERSON LAB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephen Benson, David Douglas, George Neil, Michelle D. Shinn, Gwyn Williams

We describe a dual free-electron laser (FEL) configuration on the UV Demo FEL at Jefferson Lab that allows simultaneous lasing at FIR/THz and UV wavelengths. The FIR/THz source would be an FEL oscillator with a short wiggler providing nearly diffraction-limited pulses with pulse energy exceeding 50 microJoules. The FIR source would use the exhaust beam from a UVFEL. The coherent harmonics in the VUV from the UVFEL are out-coupled through a hole. The FIR source uses a shorter resonator with either hole or edge coupling to provide very high power FIR pulses. Simulations indicate excel-lent spectral brightness in the FIRmore » region with over 100 W/cm-1 output.« less

Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room

PubMed Central

Ma, Huan; Shen, Henggen; Shui, Tiantian; Li, Qing; Zhou, Liuke

2016-01-01

Size- and time-dependent aerodynamic behaviors of indoor particles, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3–3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 104 m3/m2. The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-filter (PR) or the active carbon granule filter (CF) was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE) showed maximum single-pass efficiency for PM1.0 (88.6%), PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4–0.65 μm) exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in school office buildings. PMID:26742055

Multichannel spatial auditory display for speech communications

NASA Technical Reports Server (NTRS)

Begault, D. R.; Erbe, T.; Wenzel, E. M. (Principal Investigator)

1994-01-01

A spatial auditory display for multiple speech communications was developed at NASA/Ames Research Center. Input is spatialized by the use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positions at 30 degrees azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6-7 dB when the signal was spatialized to 60 or 90 degrees azimuth positions.

Multi-channel spatial auditory display for speech communications

NASA Astrophysics Data System (ADS)

Begault, Durand; Erbe, Tom

1993-10-01

A spatial auditory display for multiple speech communications was developed at NASA-Ames Research Center. Input is spatialized by use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four letter call signs used by launch personnel at NASA, against diotic speech babble. Spatial positions at 30 deg azimuth increments were evaluated. The results from eight subjects showed a maximal intelligibility improvement of about 6 to 7 dB when the signal was spatialized to 60 deg or 90 deg azimuth positions.

Multichannel spatial auditory display for speech communications.

PubMed

Begault, D R; Erbe, T

1994-10-01

A spatial auditory display for multiple speech communications was developed at NASA/Ames Research Center. Input is spatialized by the use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positions at 30 degrees azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6-7 dB when the signal was spatialized to 60 or 90 degrees azimuth positions.

Multichannel Spatial Auditory Display for Speed Communications

NASA Technical Reports Server (NTRS)

Begault, Durand R.; Erbe, Tom

1994-01-01

A spatial auditory display for multiple speech communications was developed at NASA/Ames Research Center. Input is spatialized by the use of simplifiedhead-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positions at 30 degree azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6-7 dB when the signal was spatialized to 60 or 90 degree azimuth positions.

Multi-channel spatial auditory display for speech communications

NASA Technical Reports Server (NTRS)

Begault, Durand; Erbe, Tom

1993-01-01

A spatial auditory display for multiple speech communications was developed at NASA-Ames Research Center. Input is spatialized by use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four letter call signs used by launch personnel at NASA, against diotic speech babble. Spatial positions at 30 deg azimuth increments were evaluated. The results from eight subjects showed a maximal intelligibility improvement of about 6 to 7 dB when the signal was spatialized to 60 deg or 90 deg azimuth positions.

EFFECT OF LOADING DUST TYPE ON THE FILTRATION EFFICIENCY OF ELECTROSTATICALLY CHARGED FILTERS

EPA Science Inventory

The paper gives results of an evaluation of the effect of loading dust type on the filtration efficiency of electrostatically charged filters. Three types of filters were evaluated: a rigid-cell filter charged using an electrodynamic spinning process, a pleated-panel filter cha...

Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

NASA Astrophysics Data System (ADS)

Voigt, Claudia; Jäckel, Eva; Taina, Fabio; Zienert, Tilo; Salomon, Anton; Wolf, Gotthard; Aneziris, Christos G.; Le Brun, Pierre

2017-02-01

The influence of filter surface chemistry on the filtration efficiency of cast aluminum alloys was evaluated for four different filter coating compositions (Al2O3—alumina, MgAl2O4—spinel, 3Al2O3·2SiO2—mullite, and TiO2—rutile). The tests were conducted on a laboratory scale with a filtration pilot plant, which facilitates long-term filtration tests (40 to 76 minutes). This test set-up allows the simultaneous use of two LiMCAs (before and after the filter) for the determination of the efficiency of inclusion removal. The four tested filter surface chemistries exhibited good thermal stability and mechanical robustness after 750 kg of molten aluminum had been cast. All four filter types exhibited a mean filtration efficiency of at least 80 pct. However, differences were also observed. The highest filtration efficiencies were obtained with alumina- and spinel-coated filter surfaces (>90 pct), and the complete removal of the largest inclusions (>90 µm) was observed. The efficiency was slightly lower with mullite- and rutile-coated filter surfaces, in particular for large inclusions. These observations are discussed in relation to the properties of the filters, in particular in terms of, for example, the surface roughness.

Architecture of the wood-wide web: Rhizopogon spp. genets link multiple Douglas-fir cohorts.

PubMed

Beiler, Kevin J; Durall, Daniel M; Simard, Suzanne W; Maxwell, Sheri A; Kretzer, Annette M

2010-01-01

*The role of mycorrhizal networks in forest dynamics is poorly understood because of the elusiveness of their spatial structure. We mapped the belowground distribution of the fungi Rhizopogon vesiculosus and Rhizopogon vinicolor and interior Douglas-fir trees (Pseudotsuga menziesii var. glauca) to determine the architecture of a mycorrhizal network in a multi-aged old-growth forest. *Rhizopogon spp. mycorrhizas were collected within a 30 x 30 m plot. Trees and fungal genets were identified using multi-locus microsatellite DNA analysis. Tree genotypes from mycorrhizas were matched to reference trees aboveground. Two trees were considered linked if they shared the same fungal genet(s). *The two Rhizopogon species each formed 13-14 genets, each colonizing up to 19 trees in the plot. Rhizopogon vesiculosus genets were larger, occurred at greater depths, and linked more trees than genets of R. vinicolor. Multiple tree cohorts were linked, with young saplings established within the mycorrhizal network of Douglas-fir veterans. A strong positive relationship was found between tree size and connectivity, resulting in a scale-free network architecture with small-world properties. *This mycorrhizal network architecture suggests an efficient and robust network, where large trees play a foundational role in facilitating conspecific regeneration and stabilizing the ecosystem.

Variation in short-term and long-term responses of photosynthesis and isoprenoid-mediated photoprotection to soil water availability in four Douglas-fir provenances

PubMed Central

Junker, Laura Verena; Kleiber, Anita; Jansen, Kirstin; Wildhagen, Henning; Hess, Moritz; Kayler, Zachary; Kammerer, Bernd; Schnitzler, Jörg-Peter; Kreuzwieser, Jürgen; Gessler, Arthur; Ensminger, Ingo

2017-01-01

For long-lived forest tree species, the understanding of intraspecific variation among populations and their response to water availability can reveal their ability to cope with and adapt to climate change. Dissipation of excess excitation energy, mediated by photoprotective isoprenoids, is an important defense mechanism against drought and high light when photosynthesis is hampered. We used 50-year-old Douglas-fir trees of four provenances at two common garden experiments to characterize provenance-specific variation in photosynthesis and photoprotective mechanisms mediated by essential and non-essential isoprenoids in response to soil water availability and solar radiation. All provenances revealed uniform photoprotective responses to high solar radiation, including increased de-epoxidation of photoprotective xanthophyll cycle pigments and enhanced emission of volatile monoterpenes. In contrast, we observed differences between provenances in response to drought, where provenances sustaining higher CO2 assimilation rates also revealed increased water-use efficiency, carotenoid-chlorophyll ratios, pools of xanthophyll cycle pigments, β-carotene and stored monoterpenes. Our results demonstrate that local adaptation to contrasting habitats affected chlorophyll-carotenoid ratios, pool sizes of photoprotective xanthophylls, β-carotene, and stored volatile isoprenoids. We conclude that intraspecific variation in isoprenoid-mediated photoprotective mechanisms contributes to the adaptive potential of Douglas-fir provenances to climate change. PMID:28071755

Combined selective emitter and filter for high performance incandescent lighting

NASA Astrophysics Data System (ADS)

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle; Ilic, Ognjen; Soljačić, Marin; Wang, Evelyn N.

2017-08-01

The efficiency of incandescent light bulbs (ILBs) is inherently low due to the dominant emission at infrared wavelengths, diminishing its popularity today. ILBs with cold-side filters that transmit visible light but reflect infrared radiation back to the filament can surpass the efficiency of state-of-the-art light-emitting diodes (LEDs). However, practical challenges such as imperfect geometrical alignment (view factor) between the filament and cold-side filters can limit the maximum achievable efficiency and make the use of cold-side filters ineffective. In this work, we show that by combining a cold-side optical filter with a selective emitter, the effect of the imperfect view factor between the filament and filter on the system efficiency can be minimized. We experimentally and theoretically demonstrate energy savings of up to 67% compared to a bare tungsten emitter at 2000 K, representing a 34% improvement over a bare tungsten filament with a filter. Our work suggests that this approach can be competitive with LEDs in both luminous efficiency and color rendering index (CRI) when using selective emitters and filters already demonstrated in the literature, thus paving the way for next-generation high-efficiency ILBs.

Combined selective emitter and filter for high performance incandescent lighting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle

The efficiency of incandescent light bulbs (ILBs) is inherently low due to the dominant emission at infrared wavelengths, diminishing its popularity today. ILBs with cold-side filters that transmit visible light but reflect infrared radiation back to the filament can surpass the efficiency of state-of-the- art light-emitting diodes (LEDs). However, practical challenges such as imperfect geometrical alignment (view factor) between the filament and cold-side filters can limit the maximum achievable efficiency and make the use of cold-side filters ineffective. Here in this work, we show that by combining a cold-side optical filter with a selective emitter, the effect of the imperfectmore » view factor between the filament and filter on the system efficiency can be minimized. We experimentally and theoretically demonstrate energy savings of up to 67% compared to a bare tungsten emitter at 2000 K, representing a 34% improvement over a bare tungsten filament with a filter. Our work suggests that this approach can be competitive with LEDs in both luminous efficiency and color rendering index (CRI) when using selective emitters and filters already demonstrated in the literature, thus paving the way for next-generation high-efficiency ILBs.« less

Combined selective emitter and filter for high performance incandescent lighting

DOE PAGES

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle; ...

2017-09-01

The efficiency of incandescent light bulbs (ILBs) is inherently low due to the dominant emission at infrared wavelengths, diminishing its popularity today. ILBs with cold-side filters that transmit visible light but reflect infrared radiation back to the filament can surpass the efficiency of state-of-the- art light-emitting diodes (LEDs). However, practical challenges such as imperfect geometrical alignment (view factor) between the filament and cold-side filters can limit the maximum achievable efficiency and make the use of cold-side filters ineffective. Here in this work, we show that by combining a cold-side optical filter with a selective emitter, the effect of the imperfectmore » view factor between the filament and filter on the system efficiency can be minimized. We experimentally and theoretically demonstrate energy savings of up to 67% compared to a bare tungsten emitter at 2000 K, representing a 34% improvement over a bare tungsten filament with a filter. Our work suggests that this approach can be competitive with LEDs in both luminous efficiency and color rendering index (CRI) when using selective emitters and filters already demonstrated in the literature, thus paving the way for next-generation high-efficiency ILBs.« less

Testing Air-Filtering Systems

PubMed Central

Songer, Joseph R.; Sullivan, James F.; Hurd, James W.

1963-01-01

A procedure was developed for evaluating high-efficiency filters mounted in exhaust ducts at the National Animal Disease Laboratory. An aerosol of the test organism, Escherichia coli B T3 bacteriophage, was generated in a chamber attached to a ceiling exhaust register in concentrations of at least 1000 viable organisms per ft3 of air. Samples were collected from both the pre- and postfilter areas, and the number of organisms per ft3 of air was determined. The efficiency of the filter was calculated from these figures. A total of 269 high-efficiency filters were tested. Of these, 249 had efficiencies of 98% or greater. The remaining 20, with efficiencies of less than 98%, were repaired and retested. No filter was accepted with an efficiency of less than 98%. Images Fig. 2 PMID:14063779

Discrete wavelet transform: a tool in smoothing kinematic data.

PubMed

Ismail, A R; Asfour, S S

1999-03-01

Motion analysis systems typically introduce noise to the displacement data recorded. Butterworth digital filters have been used to smooth the displacement data in order to obtain smoothed velocities and accelerations. However, this technique does not yield satisfactory results, especially when dealing with complex kinematic motions that occupy the low- and high-frequency bands. The use of the discrete wavelet transform, as an alternative to digital filters, is presented in this paper. The transform passes the original signal through two complementary low- and high-pass FIR filters and decomposes the signal into an approximation function and a detail function. Further decomposition of the signal results in transforming the signal into a hierarchy set of orthogonal approximation and detail functions. A reverse process is employed to perfectly reconstruct the signal (inverse transform) back from its approximation and detail functions. The discrete wavelet transform was applied to the displacement data recorded by Pezzack et al., 1977. The smoothed displacement data were twice differentiated and compared to Pezzack et al.'s acceleration data in order to choose the most appropriate filter coefficients and decomposition level on the basis of maximizing the percentage of retained energy (PRE) and minimizing the root mean square error (RMSE). Daubechies wavelet of the fourth order (Db4) at the second decomposition level showed better results than both the biorthogonal and Coiflet wavelets (PRE = 97.5%, RMSE = 4.7 rad s-2). The Db4 wavelet was then used to compress complex displacement data obtained from a noisy mathematically generated function. Results clearly indicate superiority of this new smoothing approach over traditional filters.

Far-infrared protects vascular endothelial cells from advanced glycation end products-induced injury via PLZF-mediated autophagy in diabetic mice

PubMed Central

Chen, Cheng-Hsien; Chen, Tso-Hsiao; Wu, Mei-Yi; Chou, Tz-Chong; Chen, Jia-Rung; Wei, Meng-Jun; Lee, San-Liang; Hong, Li-Yu; Zheng, Cai-Mei; Chiu, I-Jen; Lin, Yuh-Feng; Hsu, Ching-Min; Hsu, Yung-Ho

2017-01-01

The accumulation of advanced glycation end products (AGEs) in diabetic patients induces vascular endothelial injury. Promyelocytic leukemia zinc finger protein (PLZF) is a transcription factor that can be activated by low-temperature far-infrared (FIR) irradiation to exert beneficial effects on the vascular endothelium. In the present study, we investigated the influence of FIR-induced PLZF activation on AGE-induced endothelial injury both in vitro and in vivo. FIR irradiation inhibited AGE-induced apoptosis in human umbilical vein endothelial cells (HUVECs). PLZF activation increased the expression of phosphatidylinositol-3 kinases (PI3K), which are important kinases in the autophagic signaling pathway. FIR-induced PLZF activation led to autophagy in HUVEC, which was mediated through the upregulation of PI3K. Immunofluorescence staining showed that AGEs were engulfed by HUVECs and localized to lysosomes. FIR-induced autophagy promoted AGEs degradation in HUVECs. In nicotinamide/streptozotocin-induced diabetic mice, FIR therapy reduced serum AGEs and AGEs deposition at the vascular endothelium. FIR therapy also reduced diabetes-induced inflammatory markers in the vascular endothelium and improved vascular endothelial function. These protective effects of FIR therapy were not found in PLZF-knockout mice. Our data suggest that FIR-induced PLZF activation in vascular endothelial cells protects the vascular endothelium in diabetic mice from AGE-induced injury. PMID:28071754

Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions.

PubMed

Huang, R; Agranovski, I; Pyankov, O; Grinshpun, S

2008-04-01

Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approximately 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +/- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. Recirculated air in HVAC systems used for indoor air quality control in buildings often contains considerable number of viable bioaerosol particles because of limited efficiency of the filters installed in these systems. In the present study, we investigated - using aerosolized bacterial cells, bacterial and fungal spores, and virus-carrying particles - a novel idea of enhancing the performance of a low-efficiency HVAC filter utilizing continuous emission of unipolar ions in the filter vicinity. The findings described in this paper, together with our previously published results for non-biological particles, demonstrate the feasibility of the newly developed approach.

Natural regeneration 10 years after a Douglas-fir tussock moth outbreak in northeastern Oregon.

Treesearch

B.E. Wickman; K.W. Seidel; G. Lynn Star

1986-01-01

A survey of natural regeneration 10 years after severe grand fir mortality caused by an outbreak of Douglas-fir tussock moth was conducted in the Wenaha-Tucannon Wilderness in the Blue Mountains of northeastern Oregon. Seedling stocking was only moderate, but seedling density was adequate where present. Grand fir is dominating both preoutbreak and postoutbreak...

Douglas-fir growth and yield: research 1909-1960.

Treesearch

R.O. Curtis; D.D. Marshall

2004-01-01

Systematic research on growth and yield of Douglas-fir began in 1909. This line of early research evolved over time and culminated in publication of USDA Bulletin 201, The Yield of Douglas-fir in the Pacific Northwest. B201 had an enormous influence on development of Douglas-fir forestry and was arguably the most influential single research publication ever produced in...

Symptoms associated with inoculation of stems on living Douglas-fir and Grand Fir Trees with Phytophthora ramorum

Treesearch

Gary Chastagner; Kathy Riley; Katie Coats; Marianne Elliott; Annie DeBauw; Norm Dart

2010-01-01

To obtain a better understanding of the potential risk of infection and colonization of living Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis) stems, the stems on over 150 trees of each species were inoculated at a Christmas tree farm near Los Gatos, California. This study had the following objectives: 1)...

Decay in white fir top-killed by Douglas-fir tussock moth.

Treesearch

Boyd E. Wickman; Robert F. Scharpf

1972-01-01

Stands heavily defoliated in 1936-37 by the Douglas-fir tussock moth, Hemerocampa pseudotsugata McD., at Mammoth Lakes, California, were studied to determine the incidence and extent of decay in top-damaged trees. This was done by dissecting the tops of trees felled during logging. Comparisons were made with white fir in a nearby logged area that was...

Growth of White fir after Douglas-fir tussock moth outbreaks: long-term records in the Sierra Nevada.

Treesearch

Boyd E. Wickman

1986-01-01

Radial growth of white fir trees, Abies concolor (Gord. and Glend.) Lindl. ex Hildebr., defoliated almost 30 years ago by Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), in the central Sierra Nevada was compared with 22 years of growth prior to the outbreak. There was little difference in growth between the two...

Little response of true fir saplings to understory shrub removal

Treesearch

William W. Oliver; Fabian C.C. Uzoh

2002-01-01

The ability of white fir and California red fir to become established, persist, and eventually dominate montane shrub fields is well known. When the firs have eventually dominated do the understory shrubs continue to inhibit growth? In a small study in the southern Cascade Range of northeastern California, we tested the growth response of a thinned stand of saplings to...

Environmental characteristics of the Grand Fir Mosaic and adjacent habitat types

Treesearch

Dennis E. Ferguson; John C. Byrne

2000-01-01

Grand Fir Mosaic habitats differ from adjacent forest habitats in their slow rate of secondary succession to woody vegetation. Remote monitoring stations were used to sample the environment at a Grand Fir Mosaic site and three adjacent habitat types. The Grand Fir Mosaic site has shorter growing seasons, cooler temperatures, and more soil moisture than the other sites...

Mortality patterns following spruce budworm infestation in unprotected spruce-fir forests in Maine

Treesearch

Dale S. Solomon; Lianjun Zhang; Thomas B. Brann; David S. Larrick

2003-01-01

Cumulative and annual mortality of red spruce (Picea rubens Sarg.) and balsam fir [Abies balsamea (L) Mill.] were examined over a 10 yr period to follow the mortality patterns in unprotected spruce-fir forests in northern Maine. Different mortality patterns were determined based on stand composition classes and merchantability classes. In general, balsam fir was more...

Early development of matched planted and naturally regenerated Douglas-fir stands after slash burning in the Cascade Range.

Treesearch

R.E. Miller; R.E. Bigley; S. Webster

1993-01-01

We compared matched planted and naturally regenerated plots in 35- to 38- year-old Douglas-fir (Pseudotsuga menziesii var. menziesii) stands at seven locations in western Washington and Oregon. Total number of live stems is similar, but stands planted to Douglas fir average 26 more live stemslac of Douglas-fir and 39 fewer...

Tree Biomass Estimation of Chinese fir (Cunninghamia lanceolata) Based on Bayesian Method

PubMed Central

Zhang, Jianguo

2013-01-01

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) is the most important conifer species for timber production with huge distribution area in southern China. Accurate estimation of biomass is required for accounting and monitoring Chinese forest carbon stocking. In the study, allometric equation was used to analyze tree biomass of Chinese fir. The common methods for estimating allometric model have taken the classical approach based on the frequency interpretation of probability. However, many different biotic and abiotic factors introduce variability in Chinese fir biomass model, suggesting that parameters of biomass model are better represented by probability distributions rather than fixed values as classical method. To deal with the problem, Bayesian method was used for estimating Chinese fir biomass model. In the Bayesian framework, two priors were introduced: non-informative priors and informative priors. For informative priors, 32 biomass equations of Chinese fir were collected from published literature in the paper. The parameter distributions from published literature were regarded as prior distributions in Bayesian model for estimating Chinese fir biomass. Therefore, the Bayesian method with informative priors was better than non-informative priors and classical method, which provides a reasonable method for estimating Chinese fir biomass. PMID:24278198

Tree biomass estimation of Chinese fir (Cunninghamia lanceolata) based on Bayesian method.

PubMed

Zhang, Xiongqing; Duan, Aiguo; Zhang, Jianguo

2013-01-01

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) is the most important conifer species for timber production with huge distribution area in southern China. Accurate estimation of biomass is required for accounting and monitoring Chinese forest carbon stocking. In the study, allometric equation W = a(D2H)b was used to analyze tree biomass of Chinese fir. The common methods for estimating allometric model have taken the classical approach based on the frequency interpretation of probability. However, many different biotic and abiotic factors introduce variability in Chinese fir biomass model, suggesting that parameters of biomass model are better represented by probability distributions rather than fixed values as classical method. To deal with the problem, Bayesian method was used for estimating Chinese fir biomass model. In the Bayesian framework, two priors were introduced: non-informative priors and informative priors. For informative priors, 32 biomass equations of Chinese fir were collected from published literature in the paper. The parameter distributions from published literature were regarded as prior distributions in Bayesian model for estimating Chinese fir biomass. Therefore, the Bayesian method with informative priors was better than non-informative priors and classical method, which provides a reasonable method for estimating Chinese fir biomass.

Ecophysiology and growth of advance red spruce and balsam fir regeneration after partial cutting in yellow birch-conifer stands.

PubMed

Dumais, Daniel; Prévost, Marcel

2008-08-01

We investigated ecophysiological and growth responses of short (0.4 to 1.3 m in height) advance regeneration of red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea L.) six years after removal of 0, 40, 50, 60 and 100% of the overstory basal area (BA) in two yellow birch-conifer stands. Partial cuts significantly increased stomatal conductance of red spruce only. Light-saturated photosynthesis (leaf-area basis) of both species increased with BA removal, but unlike red spruce, specific leaf area (SLA) of balsam fir decreased with increased cutting intensity. Partial cuts appreciably increased the concentration of N and Ca in red spruce and balsam fir foliage, respectively, and resulted in decreased foliar concentrations of K in red spruce and Mg in balsam fir. The height and lateral growth of both species increased with BA removal, although partial cuts were more beneficial to balsam fir. The data suggest that short advance regeneration of red spruce and balsam fir can coexist under partial overstory conditions, but balsam fir has physiological characteristics and a capacity for morphological adjustment (SLA) that places it at an advantage when in competition with red spruce.

Dual-Emission SG7@MOF Sensor via SC-SC Transformation: Enhancing the Formation of Excimer Emission and the Range and Sensitivity of Detection.

PubMed

Fu, Hong-Ru; Wu, Xiao-Xia; Ma, Lu-Fang; Wang, Fei; Zhang, Jian

2018-05-30

In this study, a water stable metal-organic framework FIR-53 is applied as a single-crystal container for anion exchange. The exceptional chemical stability and low crystallographic symmetry of FIR-53 makes it possible to determine anionic guests. Through ion exchange and single-crystal to single-crystal (SC-SC) transformation, 8-hydroxypyrene-1,3,6-trisulfonate (SG7, solvent green 7, ion form as SG7 3- ) is introduced into the pores of FIR-53 to obtain SG7@FIR-53. Because of the spatial confinement and partition effect, SG7@FIR-53 shows the bright exciter emission of SG7 ions. Interestingly, the composite SG7@FIR-53 exhibits a sensitive fluorescence quenching response against Cr 2 O 7 2- and MnO 4 - in aqueous solution. Especially, the detection limit toward MnO 4 - is as low as 0.12 ppb, which is the smallest value to date. Moreover, the prepared SG7@FIR-53 film also displays a broad response to nitro explosives in vapor/aqueous phase. Compared with the results of FIR-53, the range and sensitivity were greatly improved.

WATER AND METHANOL MASER ACTIVITIES IN THE NGC 2024 FIR 6 REGION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Minho; Kang, Miju; Byun, Do-Young

The NGC 2024 FIR 6 region was observed in the water maser line at 22 GHz and the methanol class I maser lines at 44, 95, and 133 GHz. The water maser spectra displayed several velocity components and month-scale time variabilities. Most of the velocity components may be associated with FIR 6n, while one component was associated with FIR 4. A typical lifetime of the water maser velocity components is about eight months. The components showed velocity fluctuations with a typical drift rate of about 0.01 km s{sup -1} day{sup -1}. The methanol class I masers were detected toward FIRmore » 6. The methanol emission is confined within a narrow range around the systemic velocity of the FIR 6 cloud core. The methanol masers suggest the existence of shocks driven by either the expanding H II region of FIR 6c or the outflow of FIR 6n.« less

Washable antimicrobial polyester/aluminum air filter with a high capture efficiency and low pressure drop.

PubMed

Choi, Dong Yun; Heo, Ki Joon; Kang, Juhee; An, Eun Jeong; Jung, Soo-Ho; Lee, Byung Uk; Lee, Hye Moon; Jung, Jae Hee

2018-06-05

Here, we introduce a reusable bifunctional polyester/aluminum (PET/Al) air filter for the high efficiency simultaneous capture and inactivation of airborne microorganisms. Both bacteria of Escherichia coli and Staphylococcus epidermidis were collected on the PET/Al filter with a high efficiency rate (∼99.99%) via the electrostatic interactions between the charged bacteria and fibers without sacrificing pressure drop. The PET/Al filter experienced a pressure drop approximately 10 times lower per thickness compared with a commercial high-efficiency particulate air filter. As the Al nanograins grew on the fibers, the antimicrobial activity against airborne E. coli and S. epidermidis improved to ∼94.8% and ∼96.9%, respectively, due to the reinforced hydrophobicity and surface roughness of the filter. Moreover, the capture and antimicrobial performances were stably maintained during a cyclic washing test of the PET/Al filter, indicative of its reusability. The PET/Al filter shows great potential for use in energy-efficient bioaerosol control systems suitable for indoor environments. Copyright © 2018 Elsevier B.V. All rights reserved.

Space-frame connection for small-diameter round timber

Treesearch

Ronald W. Wolfe; Agron E. Gjinolli; John R. King

2000-01-01

To promote more efficient use of small-diameter timber, research efforts are being focused on the development and evaluation of connection methods that can be easily applied to non-standard round wood profiles. This report summarizes an evaluation of a bdowel-nut connectionc as an option for the use of Douglas-fir peeler cores in three-dimensional truss or bspace-...

Methodology for modeling the microbial contamination of air filters.

PubMed

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter.

Adenovirus-mediated FIR demonstrated TP53-independent cell-killing effect and enhanced antitumor activity of carbon-ion beams.

PubMed

Kano, M; Matsushita, K; Rahmutulla, B; Yamada, S; Shimada, H; Kubo, S; Hiwasa, T; Matsubara, H; Nomura, F

2016-01-01

Combination therapy of carbon-ion beam with the far upstream element-binding protein (FBP)-interacting repressor, FIR, which interferes with DNA damage repair proteins, was proposed as an approach for esophageal cancer treatment with low side effects regardless of TP53 status. In vivo therapeutic antitumor efficacy of replication-defective adenovirus (E1 and E3 deleted adenovirus serotype 5) encoding human FIR cDNA (Ad-FIR) was demonstrated in the tumor xenograft model of human esophageal squamous cancer cells, TE-2. Bleomycin (BLM) is an anticancer agent that introduces DNA breaks. The authors reported that Ad-FIR involved in the BLM-induced DNA damage repair response and thus applicable for other DNA damaging agents. To examine the effect of Ad-FIR on DNA damage repair, BLM, X-ray and carbon-ion irradiation were used as DNA damaging agents. The biological effects of high linear energy transfer (LET) radiotherapy used with carbon-ion irradiation are more expansive than low-LET conventional radiotherapy, such as X-rays or γ rays. High LET radiotherapy is suitable for the local control of tumors because of its high relative biological effectiveness. Ad-FIR enhanced BLM-induced DNA damage indicated by γH2AX in vitro. BLM treatment increased endogenous nuclear FIR expression in TE-2 cells, and P27Kip1 expression was suppressed by TP53 siRNA and BLM treatment. Further, Ad-FIRΔexon2, a dominant-negative form of FIR that lacks exon2 transcriptional repression domain, decreased Ku86 expression. The combination of Ad-FIR and BLM in TP53 siRNA increased DNA damage. Additionally, Ad-FIR showed synergistic cell toxicity with X-ray in vitro and significantly increased the antitumor efficacy of carbon-ion irradiation in the xenograft mouse model of TE-2 cells (P=0.03, Mann-Whitney's U-test) and was synergistic with the sensitization enhancement ratio (SER) value of 1.15. Therefore, Ad-FIR increased the cell-killing activity of the carbon-ion beam that avoids late-phase severe adverse effects independently of the TP53 status in vitro. Our findings indicated the feasibility of the combination of Ad-FIR with DNA damaging agents for future esophageal cancer treatment.

A key to arboreal spiders of Douglas-fir and true fir forests of the Pacific Northwest.

Treesearch

A.R. Moldenke; B.L. Fichter; W.P. Stephen; C.E. Griswold

1987-01-01

This illustrated key for identifying spiders inhabiting true fir and Douglas-fir is based on extensive collections from throughout the three North American Pacific Coast States. Details of the age classes present at budburst and the season in which to expect adults are presented for all species. This paper is written for people unfamiliar as well as familiar with...

Stand and tree characteristics influencing density of fir engraver beetle attack scars in white fir

Treesearch

George T. Ferrell

1973-01-01

Density of embedded scars resulting from old fir engraver (Scolytus ventralis Lec.) attacks was assessed in 3,430 bole cross sections cut from 603 white firs growing in both cutover and in virgin old-growth stands in northern California. Mean scar density was directly related to percentage of mature stand removed by logging and was higher in...

Mortality of spruce and fir in Maine in 1976-78 due to the spruce budworm outbreak

Treesearch

Donald W. Seegrist; Stanford L. Arner

1982-01-01

The spruce budworm population in Maine's spruce-fir forests has been at epidemic levels since the early 1970's. Spruce-fir mortality in 1976-78 is compared with predictions of what mortality would have been had the natural mortality rates remained at the levels experienced before the budworm outbreak. It appears that mortality of spruce and fir has increased...

Impact of the first recorded outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata, in southern California and the extent of its distribution in the Pacific Southwest region

Treesearch

Tom W. Coleman; Michael I. Jones; Beatrice Courtial; Andrew D. Graves; Meghan Woods; Alain Roques; Steven J. Seybold

2014-01-01

The Douglas-fir tussock moth (DFTM), Orgyia pseudotsugata McDunnough (Lepidoptera:Erebidae: Lymantriinae), is a native western North American defoliator of true fir, Abies spp. Mill., and Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. We investigated the population genetics and impact associated with the first recorded...

Estimating extent of mortality associated with the Douglas-fir beetle in the Central and Northern Rockies

Treesearch

Jose F. Negron; Willis C. Schaupp; Kenneth E. Gibson; John Anhold; Dawn Hansen; Ralph Thier; Phil Mocettini

1999-01-01

Data collected from Douglas-fir stands infected by the Douglas-fir beetle in Wyoming, Montana, Idaho, and Utah, were used to develop models to estimate amount of mortality in terms of basal area killed. Models were built using stepwise linear regression and regression tree approaches. Linear regression models using initial Douglas-fir basal area were built for all...

Combustion characteristics of eastern white pine bark and Douglas fir planer shavings. Technical Progress Report No. 5, September 16, 1977--September 15, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Junge, D.C.

1978-12-01

Significant quantities of wood residue fuels are presently being used in industrial steam generating facilities. Recent studies indicate that substantial additional quantities of wood residue fuels are available for energy generation in the form of steam and/or electricity. A limited data base on the combustion characteristics of wood residue fuels has resulted in the installation and operation of inefficient combustion systems for these fuels. This investigation of the combustion characteristics of wood residue fuels was undertaken to provide a data base which could be used to optimize the combustion of such fuels. Optimization of the combustion process in industrial boilersmore » serves to improve combustion efficiency and to reduce air pollutant emissions generated in the combustion process. Data are presented on the combustion characteristics of eastern white pine bark mixed with Douglas fir planer shavings.« less

Plasticity in physiological traits in conifers: implications for response to climate change in the western U.S.

PubMed

Grulke, N E

2010-06-01

Population variation in ecophysiological traits of four co-occurring montane conifers was measured on a large latitudinal gradient to quantitatively assess their potential for response to environmental change. White fir (Abies concolor) had the highest variability, gross photosynthetic rate (Pg), and foliar carbon (C) and nitrogen (N) content. Despite low water use efficiency (WUE), stomatal conductance (gs) of fir was the most responsive to unfavorable environmental conditions. Pinus lambertiana exhibited the least variability in Pg and WUE, and is likely to be the most vulnerable to environmental changes. Pinus ponderosa had an intermediate level of variability, and high needle growth at its higher elevational limits. Pinus Jeffreyi also had intermediate variability, but high needle growth at its southern latitudinal and lower elevational limits. The attributes used to assess tree vigor were effective in predicting population vulnerability to abiotic (drought) and biotic (herbivore) stresses. Published by Elsevier Ltd.

Recent Advances in Laboratory Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbons: PAHs in the Far Infrared

NASA Technical Reports Server (NTRS)

Mattioda, Andrew L.; Ricca, Alessandra; Tucker, Jonathan; Boersma, Christiaan; Bauschlicher, Charles, Jr.; Allamandola, Louis J.

2010-01-01

Over 25 years of observations and laboratory work have shown that the mid-IR spectra of a majority of astronomical sources are dominated by emission features near 3.3, 6.2, 7.7, and 11.2 microns, which originate in free polycyclic aromatic hydrocarbon (PAH) molecules. PAHs dominate the mid-IR emission from many galactic and extragalactic objects. As such, this material tracks a wide variety of astronomical processes, making this spectrum a powerful probe of the cosmos Apart from bands in the mid-IR, PAHs have bands spanning the Far-IR (FIR) and emission from these FIR features should be present in astronomical sources showing the Mid-IR PAH bands. However, with one exception, the FIR spectral characteristics are known only for a few neutral small PAHs trapped in salt pellets or oils at room temperature, data which is not relevant to astrophysics. Furthermore, since most emitting PAHs responsible for the mid-IR astronomical features are ionized, the absence of any experimental or theoretical PAH ion FIR spectra will make it impossible to correctly interpret the FIR data from these objects. In view of the upcoming Herschel space telescope mission and SOFIA's FIR airborne instrumentation, which will pioneer the FIR region, it is now urgent to obtain PAH FIR spectra. This talk will present an overview recent advances in the laboratory spectroscopy of PAHs, Highlighting the FIR spectroscopy along with some quantum calculations.

Removal of particulate matter emitted from a subway tunnel using magnetic filters.

PubMed

Son, Youn-Suk; Dinh, Trieu-Vuong; Chung, Sang-Gwi; Lee, Jai-Hyo; Kim, Jo-Chun

2014-01-01

We removed particulate matter (PM) emitted from a subway tunnel using magnetic filters. A magnetic filter system was installed on the top of a ventilation opening. Magnetic field density was increased by increasing the number of permanent magnet layers to determine PM removal characteristics. Moreover, the fan's frequency was adjusted from 30 to 60 Hz to investigate the effect of wind velocity on PM removal efficiency. As a result, PM removal efficiency increased as the number of magnetic filters or fan frequency increased. We obtained maximum removal efficiency of PM10 (52%), PM2.5 (46%), and PM1 (38%) at a 60 Hz fan frequency using double magnetic filters. We also found that the stability of the PM removal efficiency by the double filter (RSD, 3.2-5.8%) was higher than that by a single filter (10.9-24.5%) at all fan operating conditions.

Fifteen-year results from a Grand fir-Shasta red fir spacing study.

Treesearch

K.W. Seidel

1987-01-01

A 43-year-old, even-aged stand of advance reproduction of grand fir and Shasta red fir in central Oregon responded to release and thinning with diameter and height growth two to three times the prerelease rate. The response began the first growing season after the overstory was killed with 2,4-D. Diameter growth during the second and third 5-year periods after release...

Tree growth in thinned and unthinned White fir stands 20 years after a Douglas-fir tussock moth outbreak.

Treesearch

Boyd E. Wickman

1988-01-01

Twenty-year postoutbreak growth was compared in thinned and unthinned, severely defoliated stands. Basal area of unthinned white fir has declined 37 percent and pine basal area has increased 32 percent since 1964. The stand thinned in 1960 has the lowest basal area in the study area, but the greatest tree growth before and after the outbreak. All defoliated fir are...

Evolutionary history and population genetics of fraser fir and intermediate fir, southern Appalachian endemic conifers imperiled by an exotic pest and climate change

Treesearch

Kevin M. Potter; John Frampton; Sedley Josserand; C. Dana. Nelson

2010-01-01

Two Abies (true fir) taxa are endemic to high elevations of the Appalachian Mountains, where both are restricted to small populations and are imperiled by the same exotic insect. Fraser fir (Abies fraseri) exists in a handful of island-like populations on mountain ridges in the southern Appalachians of North Carolina, Tennessee and...

A preliminary study of the deterioration of alder and Douglas-fir chips in outdoor piles.

Treesearch

Ernest. Wright

1954-01-01

In the fall of 1952, E. E. Matson of the Pacific Northwest Forest and Range Experiment Station learned that the Fir-Tex Insulating Board Company bf St. Helens, Oregon was considering mixing alder with Douglas-fir chips for outside storage. Since alder heartwood i s more susceptible to decay than that of Douglas-fir, the question arose whether mixing the two might...

The Far Infrared Earth

NASA Technical Reports Server (NTRS)

Harries, John; Carli, Bruno; Rizzi, Rolando; Serio, Carmine; Mlynczak, Martin G.; Palchetti, Luca; Maestri, T.; Brindley, H.; Masiello, Guido

2007-01-01

The paper presents a review of the far infrared (FIR) properties of the Earth's atmosphere, and the role of these properties in climate. These properties have been relatively poorly understood, and it is one of the purposes of this review to demonstrate that, in recent years, we have made great strides in improving this understanding. Seen from space, the Earth is a cool object, with an effective emitting temperature of about 255 K. This contrasts with a global mean surface temperature of 288 K, and is due primarily to strong absorption of outgoing longwave energy by water vapour, carbon dioxide and clouds (especially ice). A large fraction of this absorption occurs in the FIR, and so the Earth is effectively a FIR planet. The FIR is important in a number of key climate processes, for example the water vapour and cloud feedbacks (especially ice clouds). The FIR is also a spectral region which can be used to remotely sense and retrieve atmospheric composition in the presence of ice clouds. Recent developments in instrumentation have allowed progress in each of these areas, which are described, and proposals for a spaceborne FIR instrument are being formulated. It is timely to review the FIR properties of the clear and cloudy atmosphere, the role of FIR processes in climate, and its use in observing our planet from space.

Far-infrared suppresses skin photoaging in ultraviolet B-exposed fibroblasts and hairless mice.

PubMed

Chiu, Hui-Wen; Chen, Cheng-Hsien; Chen, Yi-Jie; Hsu, Yung-Ho

2017-01-01

Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Collagen, which is one of the main building blocks of human skin, is regulated by collagen synthesis and collagen breakdown. Autophagy was found to block the epidermal hyperproliferative response to UVB and may play a crucial role in preventing skin photoaging. In the present study, we investigated whether far-infrared (FIR) therapy can inhibit skin photoaging via UVB irradiation in NIH 3T3 mouse embryonic fibroblasts and SKH-1 hairless mice. We found that FIR treatment significantly increased procollagen type I through the induction of the TGF-β/Smad axis. Furthermore, UVB significantly enhanced the expression of matrix metalloproteinase-1 (MMP-1) and MMP-9. FIR inhibited UVB-induced MMP-1 and MMP-9. Treatment with FIR reversed UVB-decreased type I collagen. In addition, FIR induced autophagy by inhibiting the Akt/mTOR signaling pathway. In UVB-induced skin photoaging in a hairless mouse model, FIR treatment resulted in decreased skin thickness in UVB irradiated mice and inhibited the degradation of collagen fibers. Moreover, FIR can increase procollagen type I via the inhibition of MMP-9 and induction of TGF-β in skin tissues. Therefore, our study provides evidence for the beneficial effects of FIR exposure in a model of skin photoaging.

The FCF Fluids Integrated Rack: Microgravity Fluid Physics Experimentation on Board the ISS

NASA Technical Reports Server (NTRS)

Gati, Frank G.; Hill, Myron E.; SaintOnge, Tom (Technical Monitor)

2001-01-01

The Fluids Integrated Rack (FIR) is a modular, multi-user scientific research facility that will fly in the U.S. laboratory module, Destiny, of the International Space Station (ISS). The FIR will be one of the racks that will constitute the Fluids and Combustion Facility (FCF). The ISS will provide the FCF and therefore the FIR with the necessary resources, such as power and cooling, so that the FIR can carry out its primary mission of accommodating fluid physics science experiments. This paper discusses the mission, design, and the capabilities of the FIR in carrying out research on the ISS.

The heating of dust in starburst galaxies: The contribution of the nonionizing radiation

NASA Technical Reports Server (NTRS)

Calzetti, D.; Bohlin, R. C.; Kinney, Anne L.; Storchi-Bergmann, T.; Heckman, Timothy M.

1995-01-01

The IUE UV and optical spectra and the far-infrared (FIR) IRAS flux densities of a sample of starburst and blue compact galaxies are used to investigate the relationship between dust obscuration and dust emission. The amount of dust obscuration at UV wavelengths correlates with the FIR-to-blue ratio; and an analysis of the correlation indicates that not only the ionizing but also the nonionizing radiation contribute to the FIR emission. The amount of UV and optical energy lost to dust obscuration accounts for most of the cool dust FIUR emission and for about 70% of the warm dust FIR emission. The remaining 30% of the warm dust FIR flux is probably due to dust emission from regions of star formation which are embedded in opaque giant molecular clouds and do not contribute to the integrated UV and optical spectrum. The use of the FIR emission as an indicator of high-mass star formation rate in star-forming galaxies can be problematic, since the contribution to the FIR flux from cool dust emission heated by relatively old stars is nonnegligible.

Preparation of Fiber Based Binder Materials to Enhance the Gas Adsorption Efficiency of Carbon Air Filter.

PubMed

Lim, Tae Hwan; Choi, Jeong Rak; Lim, Dae Young; Lee, So Hee; Yeo, Sang Young

2015-10-01

Fiber binder adapted carbon air filter is prepared to increase gas adsorption efficiency and environmental stability. The filter prevents harmful gases, as well as particle dusts in the air from entering the body when a human inhales. The basic structure of carbon air filter is composed of spunbond/meltblown/activated carbon/bottom substrate. Activated carbons and meltblown layer are adapted to increase gas adsorption and dust filtration efficiency, respectively. Liquid type adhesive is used in the conventional carbon air filter as a binder material between activated carbons and other layers. However, it is thought that the liquid binder is not an ideal material with respect to its bonding strength and liquid flow behavior that reduce gas adsorption efficiency. To overcome these disadvantages, fiber type binder is introduced in our study. It is confirmed that fiber type binder adapted air filter media show higher strip strength, and their gas adsorption efficiencies are measured over 42% during 60 sec. These values are higher than those of conventional filter. Although the differential pressure of fiber binder adapted air filter is relatively high compared to the conventional one, short fibers have a good potential as a binder materials of activated carbon based air filter.

Modeling of submicrometer aerosol penetration through sintered granular membrane filters.

PubMed

Marre, Sonia; Palmeri, John; Larbot, André; Bertrand, Marielle

2004-06-01

We present a deep-bed aerosol filtration model that can be used to estimate the efficiency of sintered granular membrane filters in the region of the most penetrating particle size. In this region the capture of submicrometer aerosols, much smaller than the filter pore size, takes place mainly via Brownian diffusion and direct interception acting in synergy. By modeling the disordered sintered grain packing of such filters as a simple cubic lattice, and mapping the corresponding 3D connected pore volume onto a discrete cylindrical pore network, the efficiency of a granular filter can be estimated, using new analytical results for the efficiency of cylindrical pores. This model for aerosol penetration in sintered granular filters includes flow slip and the kinetics of particle capture by the pore surface. With a unique choice for two parameters, namely the structural tortuosity and effective kinetic coefficient of particle adsorption, this semiempirical model can account for the experimental efficiency of a new class of "high-efficiency particulate air" ceramic membrane filters as a function of particle size over a wide range of filter thickness and texture (pore size and porosity) and operating conditions (face velocity).

Effect of filter designs on hydraulic properties and well efficiency.

PubMed

Kim, Byung-Woo

2014-09-01

To analyze the effect of filter pack arrangement on the hydraulic properties and the well efficiency of a well design, a step drawdown was conducted in a sand-filled tank model. Prior to the test, a single filter pack (SFP), granule only, and two dual filter packs (DFPs), type A (granule-pebble) and type B (pebble-granule), were designed to surround the well screen. The hydraulic properties and well efficiencies related to the filter packs were evaluated using the Hazen's, Eden-Hazel's, Jacob's, and Labadie-Helweg's methods. The results showed that the hydraulic properties and well efficiency of the DFPs were higher than those of a SFP, and the clogging effect and wellhead loss related to the aquifer material were the lowest owing to the grain size and the arrangement of the filter pack. The hydraulic conductivity of the DFPs types A and B was about 1.41 and 6.43 times that of a SFP, respectively. In addition, the well efficiency of the DFPs types A and B was about 1.38 and 1.60 times that of the SFP, respectively. In this study, hydraulic property and well efficiency changes were observed according to the variety of the filter pack used. The results differed from the predictions of previous studies on the grain-size ratio. Proper pack-aquifer ratios and filter pack arrangements are primary factors in the construction of efficient water wells, as is the grain ratio, intrinsic permeability (k), and hydraulic conductivity (K) between the grains of the filter packs and the grains of the aquifer. © 2014, National Ground Water Association.

[In vitro comparison of epidural bacteria filters permeability and screening scanning electron microscopy].

PubMed

Sener, Aysin; Erkin, Yuksel; Sener, Alper; Tasdogen, Aydin; Dokumaci, Esra; Elar, Zahide

2015-01-01

Epidural catheter bacteria filters are barriers in the patient-controlled analgesia/anaesthesia for preventing contamination at the epidural insertion site. The efficiency of these filters varies according to pore sizes and materials. The bacterial adhesion capability of the two filters was measured in vitro experiment. Adhesion capacities for standard Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853) strains of the two different filters (Portex and Rusch) which have the same pore size were examined. Bacterial suspension of 0.5 Mc Farland was placed in the patient-controlled analgesia pump, was filtered at a speed of 5mL/h. in continuous infusion for 48h and accumulated in bottle. The two filters were compared with colony counts of bacteria in the filters and bottles. At the same time, the filters and adhered bacteria were monitored by scanning electron microscope. Electron microscopic examination of filters showed that the Portex filter had a granular and the Rusch filter fibrillary structure. Colony counting from the catheter and bottle showed that both of the filters have significant bacterial adhesion capability (p<0.001). After the bacteria suspension infusion, colony countings showed that the Portex filter was more efficient (p<0.001). There was not any difference between S. aureus and P. aeruginosa bacteria adhesion. In the SEM monitoring after the infusion, it was physically shown that the bacteria were adhered efficiently by both of the filters. The granular structured filter was found statistically and significantly more successful than the fibrial. Although the pore sizes of the filters were same - of which structural differences shown by SEM were the same - it would not be right to attribute the changes in the efficiencies to only structural differences. Using microbiological and physical proofs with regard to efficiency at the same time has been another important aspect of this experiment. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

In vitro comparison of epidural bacteria filters permeability and screening scanning electron microscopy.

PubMed

Sener, Aysin; Erkin, Yuksel; Sener, Alper; Tasdogen, Aydin; Dokumaci, Esra; Elar, Zahide

2015-01-01

Epidural catheter bacteria filters are barriers in the patient-controlled analgesia/anaesthesia for preventing contamination at the epidural insertion site. The efficiency of these filters varies according to pore sizes and materials. The bacterial adhesion capability of the two filters was measured in vitro experiment. Adhesion capacities for standard Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853) strains of the two different filters (Portex and Rusch) which have the same pore size were examined. Bacterial suspension of 0.5 Mc Farland was placed in the patient-controlled analgesia pump, was filtered at a speed of 5 mL/h. in continuous infusion for 48 h and accumulated in bottle. The two filters were compared with colony counts of bacteria in the filters and bottles. At the same time, the filters and adhered bacteria were monitored by scanning electron microscope. Electron microscopic examination of filters showed that the Portex filter had a granular and the Rusch filter fibrillary structure. Colony counting from the catheter and bottle showed that both of the filters have significant bacterial adhesion capability (p<0.001). After the bacteria suspension infusion, colony countings showed that the Portex filter was more efficient (p<0.001). There was not any difference between S. aureus and P. aeruginosa bacteria adhesion. In the SEM monitoring after the infusion, it was physically shown that the bacteria were adhered efficiently by both of the filters. The granular structured filter was found statistically and significantly more successful than the fibrial. Although the pore sizes of the filters were same - of which structural differences shown by SEM were the same - it would not be right to attribute the changes in the efficiencies to only structural differences. Using microbiological and physical proofs with regard to efficiency at the same time has been another important aspect of this experiment. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Methodology for Modeling the Microbial Contamination of Air Filters

PubMed Central

Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

2014-01-01

In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter. PMID:24523908

Lumber recovery and deterioration of beetle-killed douglas-fir and grand fir in the Blue Mountains of eastern Oregon. Forest Service general technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parry, D.L.; Filip, G.M.; Willits, S.A.

1996-09-01

The purpose of this study was to determine the effect of time since death over a 4-year period on the amount of usable product volume and value, and to determine the species of fungi associated with wood deterioration in the stems of Douglas-fir and grand fir trees killed by bark beetles in northeastern Oregon.

Growth of suppressed grand fir and Shasta red fir in central Oregon after release and thinning—10-year results.

Treesearch

Kenneth W. Seidel

1983-01-01

A 43-year-old, even-aged stand of advance reproduction of grand fir and Shasta red fir in central Oregon responded to release and thinning with diameter and height growth two to three times the prerelease rate. The response began immediately after the overstory was killed with 2,4-D. Diameter growth during the second 5 years after release increased significantly over...

Lumber recovery and deterioration of beetle-killed Douglas-fir and grand fir in the Blue Mountains of eastern Oregon.

Treesearch

Dean L. Parry; Gregory M. Filip; Susan A. Willits; Catherine G. Parks

1996-01-01

The purpose of this study was to determine the effect of time since death over a 4-year period on the amount of usable product volume and value, and to determine the species of fungi associated with wood deterioration in the stems of Douglas-fir and grand fir trees killed by bark beetles in northeastern Oregon. Sap rot, caused principally by Cryptoporus...

Tunable far infrared laser spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blake, G.A.; Laughlin, K.B.; Cohen, R.C.

The state of the art in far infrared (FIR) spectroscopy is reviewed. The development of tunable, coherent FIR radiation sources is discussed. Applications of tunable FIR laser spectrometers for measurement of rotational spectra and dipole moments of molecular ions and free radicals, vibration-rotation-tunneling (VRT) spectra of weakly bound complexes, and vibration-rotation spectra of linear carbon clusters are presented. A detailed description of the Berkeley tunable FIR laser spectrometers is presented in the following article.

Far infrared radiation (FIR): its biological effects and medical applications

PubMed Central

Vatansever, Fatma; Hamblin, Michael R.

2013-01-01

Far infrared (FIR) radiation (λ = 3–100 μm) is a subdivision of the electromagnetic spectrum that has been investigated for biological effects. The goal of this review is to cover the use of a further sub-division (3– 12 μm) of this waveband, that has been observed in both in vitro and in vivo studies, to stimulate cells and tissue, and is considered a promising treatment modality for certain medical conditions. Technological advances have provided new techniques for delivering FIR radiation to the human body. Specialty lamps and saunas, delivering pure FIR radiation (eliminating completely the near and mid infrared bands), have became safe, effective, and widely used sources to generate therapeutic effects. Fibers impregnated with FIR emitting ceramic nanoparticles and woven into fabrics, are being used as garments and wraps to generate FIR radiation, and attain health benefits from its effects. PMID:23833705

High performance incandescent lighting using a selective emitter and nanophotonic filters

NASA Astrophysics Data System (ADS)

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle; Ilic, Ognjen; Soljačić, Marin; Wang, Evelyn N.

2017-09-01

Previous approaches for improving the efficiency of incandescent light bulbs (ILBs) have relied on tailoring the emitted spectrum using cold-side interference filters that reflect the infrared energy back to the emitter while transmitting the visible light. While this approach has, in theory, potential to surpass light-emitting diodes (LEDs) in terms of luminous efficiency while conserving the excellent color rendering index (CRI) inherent to ILBs, challenges such as low view factor between the emitter and filter, high emitter (>2800 K) and filter temperatures and emitter evaporation have significantly limited the maximum efficiency. In this work, we first analyze the effect of non-idealities in the cold-side filter, the emitter and the view factor on the luminous efficiency. Second, we theoretically and experimentally demonstrate that the loss in efficiency associated with low view factors can be minimized by using a selective emitter (e.g., high emissivity in the visible and low emissivity in the infrared) with a filter. Finally, we discuss the challenges in achieving a high performance and long-lasting incandescent light source including the emitter and filter thermal stability as well as emitter evaporation.

The Influence of Grain Refiners on the Efficiency of Ceramic Foam Filters

NASA Astrophysics Data System (ADS)

Towsey, Nicholas; Schneider, Wolfgang; Krug, Hans-Peter; Hardman, Angela; Keegan, Neil J.

An extensive program of work has been carried out to evaluate the efficiency of ceramic foam filters under carefully controlled conditions. Work reported at previous TMS meetings showed that in the absence of grain refiners, ceramic foam filters have the capacity for high filtration efficiency and consistent, reliable performance. The current phase of the investigation focuses on the impact grain refiner additions have on filter performance. The high filtration efficiencies obtained using 50 or 80ppi CFF's in the absence of grain refiners diminish when Al-3%Ti-1%B grain refiners are added. This, together with the impact of incoming inclusion loading on filter performance and the level of grain refiner addition are considered in detail. The new generation Al-3%Ti-0.15%C grain refiner has also been included. At typical addition levels (1kg/tonne) the effect on filter efficiency is similar to that for TiB2based grain refiners. The work was again conducted on a production scale using AA1050 alloy. Metal quality was determined using LiMCA and PoDFA. Spent filters were also analysed.

Wood density-moisture profiles in old-growth Douglas-fir and western hemlock.

Treesearch

W.Y. Pong; Dale R. Waddell; Lambert Michael B.

1986-01-01

Accurate estimation of the weight of each load of logs is necessary for safe and efficient aerial logging operations. The prediction of green density (lb/ft3) as a function of height is a critical element in the accurate estimation of tree bole and log weights. Two sampling methods, disk and increment core (Bergstrom xylodensimeter), were used to measure the density-...

Climate-related trends in sapwood biophysical properties in two conifers: avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance

Treesearch

David M. Barnard; Frederick C. Meinzer; Barbara Lachenbruch; Katherine A. McCulloh; Daniel M. Johnson; David R. Woodruff

2011-01-01

In the Pacific north-west, the Cascade Mountain Range blocks much of the precipitation and maritime influence of the Pacific Ocean, resulting in distinct climates east and west of the mountains. The current study aimed to investigate relationships between water storage and transport properties in populations of Douglas-fir (Pseudotsuga menziesii)...

A Radio Study of the Ultra-luminous FIR Galaxy NGC 6240

NASA Astrophysics Data System (ADS)

Colbert, E.; Wilson, A. S.; Bland-Hawthorn, J.

1993-05-01

A number of galaxies observed in the IRAS mission are noted to emit ~ 99% of their bolometric flux in the FIR, with FIR luminosities in excess of 10(11) Lsun. The interacting galaxy NGC 6240 has often been referred to as the ``proto-typical'' ultra-luminous (L_FIR >~ 10(12) Lsun) FIR galaxy. The origin of the FIR excess remains a disputed subject in the literature. New observations of NGC 6240 were taken with the VLA at 20cm in the B-configuration, and at 3.6cm in the A-configuration. No significant radio emission was detected from or near the possible ultra-massive ``dark core'' hypothesized by Bland-Hawthorn et. al. (1991); however, approximately 30% of Seyfert galaxies have 20 cm radio luminosities weaker than the upper limit derived from the radio maps. The non-thermal radio emission from luminous FIR galaxies is tightly correlated with the FIR emission. Previous radio observations of NGC 6240 revealed two compact, steep-spectrum nuclear sources, nearly coincident with the two nuclear sources seen in optical images. The 2 images from the new VLA observations and 5 images from previous VLA observations are used to identify the morphological and spectral features of the strong, compact components in the nuclear regions (<~ 1.5 kpc; D=100 Mpc) and of the weaker ``clumps'' of diffuse emission south and west (>~ 3 kpc) from the nucleus. Feasible explanations for the radio emission are discussed. The models that have been proposed in the literature for the FIR excess of NGC 6240 are evaluated for consistency with the observed radio emission.

RADIO IMAGING OF THE NGC 2024 FIR 5/6 REGION: A HYPERCOMPACT H II REGION CANDIDATE IN ORION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Minho; Kang, Miju; Lee, Jeong-Eun, E-mail: minho@kasi.re.kr

The NGC 2024 FIR 5/6 region was observed in the 6.9 mm continuum with an angular resolution of about 1.5 arcsec. The 6.9 mm continuum map shows four compact sources, FIR 5w, 5e, 6c, and 6n, as well as an extended structure of the ionization front associated with the optical nebulosity. FIR 6c has a source size of about 0.4 arcsec or 150 AU. The spectral energy distribution (SED) of FIR 6c is peculiar: rising steeply around 6.9 mm and flat around 1 mm. The possibility of a hypercompact H II region is explored. If the millimeter flux of FIRmore » 6c comes from hot ionized gas heated by a single object at the center, the central object may be a B1 star of about 5800 solar luminosities and about 13 solar masses. The 6.9 mm continuum of FIR 6n may be a mixture of free-free emission and dust continuum emission. Archival data show that both FIR 6n and 6c exhibit water maser activity, suggesting the existence of shocked gas around them. The 6.9 mm continuum emission from FIR 5w has a size of about 1.8 arcsec or 760 AU. The SEDs suggest that the 6.9 mm emission of FIR 5w and 5e comes from dust, and the masses of the dense molecular gas are about 0.6 and 0.5 solar masses, respectively.« less

In situ fabrication of depth-type hierarchical CNT/quartz fiber filters for high efficiency filtration of sub-micron aerosols and high water repellency

NASA Astrophysics Data System (ADS)

Li, Peng; Zong, Yichen; Zhang, Yingying; Yang, Mengmeng; Zhang, Rufan; Li, Shuiqing; Wei, Fei

2013-03-01

We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions.We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions. Electronic supplementary information (ESI) available: Schematic of the synthesis process of the CNT/QF filter; typical size distribution of atomized polydisperse NaCl aerosols used for air filtration testing; images of a QF filter and a CNT/QF filter; SEM image of a CNT/QF filter after 5 minutes of sonication in ethanol; calculation of porosity and filter specific area. See DOI: 10.1039/c3nr34325a

Movement of elements into the atmosphere from coniferous trees in subalpine forests of colorado and Idaho

USGS Publications Warehouse

Curtin, G.C.; King, H.D.; Mosier, E.L.

1974-01-01

Exudates from conifer trees, presumably consisting largely of volatile materials, were sampled at 19 subalpine localitites in Colorado and Idaho where anomalous amounts of several metals were determined in vegetation and mull during previous geochemical testing. The trees sampled were lodgepole pine (Pinus contorta), Engelmann spruce (Picea engelmannii) and Douglas fir (Pseudotsuga menziesii). The condensed exudates were passed through No. 40 Whatman filters, and through 5-micron, 0.45-micron, and 0.05-micron average-pore-diameter membrane filters, evaporated to dryness, and each residue was ashed and analyzed by a semiquantitative spectrographic method. The ashed residues of the exudates contain lithium, beryllium, boron, sodium, magnesium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, arsenic, strontium, yttrium, zirconium, molybdenum, silver, lead, bismuth, cadmium, tin, antimony, barium, and lanthanum. The presence of these elements suggests that volatile exudates from vegetation are a medium for the transport of elements in the biogeochemical cycle in subalpine environments. Thus, air sampling and analysis of aerosols derived from volatile exudates may be a useful tool in geochemical exploration. ?? 1974.

Continuous Mass Measurement on Conveyor Belt

NASA Astrophysics Data System (ADS)

Tomobe, Yuki; Tasaki, Ryosuke; Yamazaki, Takanori; Ohnishi, Hideo; Kobayashi, Masaaki; Kurosu, Shigeru

The continuous mass measurement of packages on a conveyor belt will become greatly important. In the mass measurement, the sequence of products is generally random. An interesting possibility of raising throughput of the conveyor line without increasing the conveyor belt speed is offered by the use of two or three conveyor belt scales (called a multi-stage conveyor belt scale). The multi-stage conveyor belt scale can be created which will adjust the conveyor belt length to the product length. The conveyor belt scale usually has maximum capacities of less than 80kg and 140cm, and achieves measuring rates of more than 150 packages per minute and more. The output signals from the conveyor belt scale are always contaminated with noises due to vibrations of the conveyor and the product to be measured in motion. In this paper an employed digital filter is of Finite Impulse Response (FIR) type designed under the consideration on the dynamics of the conveyor system. The experimental results on the conveyor belt scale suggest that the filtering algorithms are effective enough to practical applications to some extent.

Programmable noise bandwidth reduction by means of digital averaging

NASA Technical Reports Server (NTRS)

Poklemba, John J. (Inventor)

1993-01-01

Predetection noise bandwidth reduction is effected by a pre-averager capable of digitally averaging the samples of an input data signal over two or more symbols, the averaging interval being defined by the input sampling rate divided by the output sampling rate. As the averaged sample is clocked to a suitable detector at a much slower rate than the input signal sampling rate the noise bandwidth at the input to the detector is reduced, the input to the detector having an improved signal to noise ratio as a result of the averaging process, and the rate at which such subsequent processing must operate is correspondingly reduced. The pre-averager forms a data filter having an output sampling rate of one sample per symbol of received data. More specifically, selected ones of a plurality of samples accumulated over two or more symbol intervals are output in response to clock signals at a rate of one sample per symbol interval. The pre-averager includes circuitry for weighting digitized signal samples using stored finite impulse response (FIR) filter coefficients. A method according to the present invention is also disclosed.

7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

Code of Federal Regulations, 2012 CFR

2012-01-01

... willow *Sequoia sempervirens Coast redwood *Syringa vulgaris Lilac *Taxus baccata European yew... Phytophthora ramorum: Abies concolor White fir Abies grandis Grand fir Abies magnifica Red fir Acer circinatum...

7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

Code of Federal Regulations, 2013 CFR

2013-01-01

... willow *Sequoia sempervirens Coast redwood *Syringa vulgaris Lilac *Taxus baccata European yew... Phytophthora ramorum: Abies concolor White fir Abies grandis Grand fir Abies magnifica Red fir Acer circinatum...

7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

Code of Federal Regulations, 2014 CFR

2014-01-01

... willow *Sequoia sempervirens Coast redwood *Syringa vulgaris Lilac *Taxus baccata European yew... Phytophthora ramorum: Abies concolor White fir Abies grandis Grand fir Abies magnifica Red fir Acer circinatum...

7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

Code of Federal Regulations, 2010 CFR

2010-01-01

... willow *Sequoia sempervirens Coast redwood *Syringa vulgaris Lilac *Taxus baccata European yew... Phytophthora ramorum: Abies concolor White fir Abies grandis Grand fir Abies magnifica Red fir Acer circinatum...

7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

Code of Federal Regulations, 2011 CFR

2011-01-01

... willow *Sequoia sempervirens Coast redwood *Syringa vulgaris Lilac *Taxus baccata European yew... Phytophthora ramorum: Abies concolor White fir Abies grandis Grand fir Abies magnifica Red fir Acer circinatum...

Efficiency of different air filter types for pig facilities at laboratory scale

PubMed Central

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs. PMID:29028843

Efficiency of different air filter types for pig facilities at laboratory scale.

PubMed

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Truyen, Uwe; Speck, Stephanie

2017-01-01

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove aerosol containing equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), bovine enterovirus 1 (BEV), Actinobacillus pleuropneumoniae (APP), and Staphylococcus (S.) aureus from air. Depending on the filter prototype and utilisation, the airflow was set at 1,800 m3/h (combination of upstream prefilter and fiberglass filter) or 80 m3/h (filter mat). The pathogens were aerosolized and their concentration was determined in front of and behind the filter by culture or quantitative real-time RT-PCR. Furthermore, survival of the pathogens over time in the filter material was determined. Bacteria were most efficiently filtered with a reduction rate of up to 99.9% depending on the filter used. An approximately 98% reduction was achieved for the viruses tested. Viability or infectivity of APP or PRRSV in the filter material decreased below the detection limit after 4 h and 24 h, respectively, whereas S. aureus was still culturable after 4 weeks. Our results demonstrate that pathogens can efficiently be reduced by air filtration. Consequently, air filtration combined with other strict biosecurity measures markedly reduces the risk of introducing airborne transmitted pathogens to animal facilities. In addition, air filtration might be useful in reducing bioaerosols within a pig barn, hence improving respiratory health of pigs.

Al-Coated Conductive Fiber Filters for High-Efficiency Electrostatic Filtration: Effects of Electrical and Fiber Structural Properties.

PubMed

Choi, Dong Yun; An, Eun Jeong; Jung, Soo-Ho; Song, Dong Keun; Oh, Yong Suk; Lee, Hyung Woo; Lee, Hye Moon

2018-04-10

Through the direct decomposition of an Al precursor ink AlH 3 {O(C 4 H 9 ) 2 }, we fabricated an Al-coated conductive fiber filter for the efficient electrostatic removal of airborne particles (>99%) with a low pressure drop (~several Pascals). The effects of the electrical and structural properties of the filters were investigated in terms of collection efficiency, pressure drop, and particle deposition behavior. The collection efficiency did not show a significant correlation with the extent of electrical conductivity, as the filter is electrostatically charged by the metallic Al layers forming electrical networks throughout the fibers. Most of the charged particles were collected via surface filtration by Coulombic interactions; consequently, the filter thickness had little effect on the collection efficiency. Based on simulations of various fiber structures, we found that surface filtration can transition to depth filtration depending on the extent of interfiber distance. Therefore, the effects of structural characteristics on collection efficiency varied depending on the degree of the fiber packing density. This study will offer valuable information pertaining to the development of a conductive metal/polymer composite air filter for an energy-efficient and high-performance electrostatic filtration system.

Far-infrared properties of cluster galaxies

NASA Technical Reports Server (NTRS)

Bicay, M. D.; Giovanelli, R.

1987-01-01

Far-infrared properties are derived for a sample of over 200 galaxies in seven clusters: A262, Cancer, A1367, A1656 (Coma), A2147, A2151 (Hercules), and Pegasus. The IR-selected sample consists almost entirely of IR normal galaxies, with Log of L(FIR) = 9.79 solar luminosities, Log of L(FIR)/L(B) = 0,79, and Log of S(100 microns)/S(60 microns) = 0.42. None of the sample galaxies has Log of L(FIR) greater than 11.0 solar luminosities, and only one has a FIR-to-blue luminosity ratio greater than 10. No significant differences are found in the FIR properties of HI-deficient and HI-normal cluster galaxies.

A resolved two-way coupled CFD/6-DOF approach for predicting embolus transport and the embolus-trapping efficiency of IVC filters.

PubMed

Aycock, Kenneth I; Campbell, Robert L; Manning, Keefe B; Craven, Brent A

2017-06-01

Inferior vena cava (IVC) filters are medical devices designed to provide a mechanical barrier to the passage of emboli from the deep veins of the legs to the heart and lungs. Despite decades of development and clinical use, IVC filters still fail to prevent the passage of all hazardous emboli. The objective of this study is to (1) develop a resolved two-way computational model of embolus transport, (2) provide verification and validation evidence for the model, and (3) demonstrate the ability of the model to predict the embolus-trapping efficiency of an IVC filter. Our model couples computational fluid dynamics simulations of blood flow to six-degree-of-freedom simulations of embolus transport and resolves the interactions between rigid, spherical emboli and the blood flow using an immersed boundary method. Following model development and numerical verification and validation of the computational approach against benchmark data from the literature, embolus transport simulations are performed in an idealized IVC geometry. Centered and tilted filter orientations are considered using a nonlinear finite element-based virtual filter placement procedure. A total of 2048 coupled CFD/6-DOF simulations are performed to predict the embolus-trapping statistics of the filter. The simulations predict that the embolus-trapping efficiency of the IVC filter increases with increasing embolus diameter and increasing embolus-to-blood density ratio. Tilted filter placement is found to decrease the embolus-trapping efficiency compared with centered filter placement. Multiple embolus-trapping locations are predicted for the IVC filter, and the trapping locations are predicted to shift upstream and toward the vessel wall with increasing embolus diameter. Simulations of the injection of successive emboli into the IVC are also performed and reveal that the embolus-trapping efficiency decreases with increasing thrombus load in the IVC filter. In future work, the computational tool could be used to investigate IVC filter design improvements, the effect of patient anatomy on embolus transport and IVC filter embolus-trapping efficiency, and, with further development and validation, optimal filter selection and placement on a patient-specific basis.

Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO(2) assimilation and growth in Douglas-fir.

PubMed

Saffell, Brandy J; Meinzer, Frederick C; Voelker, Steven L; Shaw, David C; Brooks, J Renée; Lachenbruch, Barbara; McKay, Jennifer

2014-07-01

Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years. © 2013 John Wiley & Sons Ltd.

Far-infrared suppresses skin photoaging in ultraviolet B-exposed fibroblasts and hairless mice

PubMed Central

Chiu, Hui-Wen; Chen, Cheng-Hsien; Chen, Yi-Jie; Hsu, Yung-Ho

2017-01-01

Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Collagen, which is one of the main building blocks of human skin, is regulated by collagen synthesis and collagen breakdown. Autophagy was found to block the epidermal hyperproliferative response to UVB and may play a crucial role in preventing skin photoaging. In the present study, we investigated whether far-infrared (FIR) therapy can inhibit skin photoaging via UVB irradiation in NIH 3T3 mouse embryonic fibroblasts and SKH-1 hairless mice. We found that FIR treatment significantly increased procollagen type I through the induction of the TGF-β/Smad axis. Furthermore, UVB significantly enhanced the expression of matrix metalloproteinase-1 (MMP-1) and MMP-9. FIR inhibited UVB-induced MMP-1 and MMP-9. Treatment with FIR reversed UVB-decreased type I collagen. In addition, FIR induced autophagy by inhibiting the Akt/mTOR signaling pathway. In UVB-induced skin photoaging in a hairless mouse model, FIR treatment resulted in decreased skin thickness in UVB irradiated mice and inhibited the degradation of collagen fibers. Moreover, FIR can increase procollagen type I via the inhibition of MMP-9 and induction of TGF-β in skin tissues. Therefore, our study provides evidence for the beneficial effects of FIR exposure in a model of skin photoaging. PMID:28301572

Harmonised information exchange between decentralised food composition database systems.

PubMed

Pakkala, H; Christensen, T; de Victoria, I Martínez; Presser, K; Kadvan, A

2010-11-01

The main aim of the European Food Information Resource (EuroFIR) project is to develop and disseminate a comprehensive, coherent and validated data bank for the distribution of food composition data (FCD). This can only be accomplished by harmonising food description and data documentation and by the use of standardised thesauri. The data bank is implemented through a network of local FCD storages (usually national) under the control and responsibility of the local (national) EuroFIR partner. The implementation of the system based on the EuroFIR specifications is under development. The data interchange happens through the EuroFIR Web Services interface, allowing the partners to implement their system using methods and software suitable for the local computer environment. The implementation uses common international standards, such as Simple Object Access Protocol, Web Service Description Language and Extensible Markup Language (XML). A specifically constructed EuroFIR search facility (eSearch) was designed for end users. The EuroFIR eSearch facility compiles queries using a specifically designed Food Data Query Language and sends a request to those network nodes linked to the EuroFIR Web Services that will most likely have the requested information. The retrieved FCD are compiled into a specifically designed data interchange format (the EuroFIR Food Data Transport Package) in XML, which is sent back to the EuroFIR eSearch facility as the query response. The same request-response operation happens in all the nodes that have been selected in the EuroFIR eSearch facility for a certain task. Finally, the FCD are combined by the EuroFIR eSearch facility and delivered to the food compiler. The implementation of FCD interchange using decentralised computer systems instead of traditional data-centre models has several advantages. First of all, the local partners have more control over their FCD, which will increase commitment and improve quality. Second, a multicentred solution is more economically viable than the creation of a centralised data bank, because of the lack of national political support for multinational systems.

Detecting Structural Failures Via Acoustic Impulse Responses

NASA Technical Reports Server (NTRS)

Bayard, David S.; Joshi, Sanjay S.

1995-01-01

Advanced method of acoustic pulse reflectivity testing developed for use in determining sizes and locations of failures within structures. Used to detect breaks in electrical transmission lines, detect faults in optical fibers, and determine mechanical properties of materials. In method, structure vibrationally excited with acoustic pulse (a "ping") at one location and acoustic response measured at same or different location. Measured acoustic response digitized, then processed by finite-impulse-response (FIR) filtering algorithm unique to method and based on acoustic-wave-propagation and -reflection properties of structure. Offers several advantages: does not require training, does not require prior knowledge of mathematical model of acoustic response of structure, enables detection and localization of multiple failures, and yields data on extent of damage at each location.

Adaptive frequency-domain equalization in digital coherent optical receivers.

PubMed

Faruk, Md Saifuddin; Kikuchi, Kazuro

2011-06-20

We propose a novel frequency-domain adaptive equalizer in digital coherent optical receivers, which can reduce computational complexity of the conventional time-domain adaptive equalizer based on finite-impulse-response (FIR) filters. The proposed equalizer can operate on the input sequence sampled by free-running analog-to-digital converters (ADCs) at the rate of two samples per symbol; therefore, the arbitrary initial sampling phase of ADCs can be adjusted so that the best symbol-spaced sequence is produced. The equalizer can also be configured in the butterfly structure, which enables demultiplexing of polarization tributaries apart from equalization of linear transmission impairments. The performance of the proposed equalization scheme is verified by 40-Gbits/s dual-polarization quadrature phase-shift keying (QPSK) transmission experiments.

Symmetric convolution of asymmetric multidimensional sequences using discrete trigonometric transforms.

PubMed

Foltz, T M; Welsh, B M

1999-01-01

This paper uses the fact that the discrete Fourier transform diagonalizes a circulant matrix to provide an alternate derivation of the symmetric convolution-multiplication property for discrete trigonometric transforms. Derived in this manner, the symmetric convolution-multiplication property extends easily to multiple dimensions using the notion of block circulant matrices and generalizes to multidimensional asymmetric sequences. The symmetric convolution of multidimensional asymmetric sequences can then be accomplished by taking the product of the trigonometric transforms of the sequences and then applying an inverse trigonometric transform to the result. An example is given of how this theory can be used for applying a two-dimensional (2-D) finite impulse response (FIR) filter with nonlinear phase which models atmospheric turbulence.

PHYSICAL EFFECTS OCCURRING DURING GENERATION AND AMPLIFICATION OF LASER RADIATION: Enhancement of the efficiency of flashlamp-pumped lasers by conversion of the spectral composition of the exciting radiation

NASA Astrophysics Data System (ADS)

Levin, M. B.; Cherkasov, A. S.

1989-02-01

An account is given of the published investigations of ways of increasing the efficiency of flashlamp-pumped lasers by frequency conversion of the exciting radiation with the aid of luminescent filters. An analysis is made of the method for calculating the efficiency of luminescent filters absorbing short-wavelength radiation and reemitting it in the absorption region of the active medium. It is shown that the use of rhodamine 6G and other phosphors as luminescent filters can double the efficiency of neodymium glass lasers, increase the efficiency of YAG:Nd3+ lasers by a factor of 1.5, and improve the efficiency of lasers activated with Ti3+ by more than an order of magnitude. The use of luminescent filters in dye lasers can double the efficiency and make it possible to reach average output powers of hundreds of watts. Promising materials for luminescent filters are considered and margins for increasing their efficiency are analyzed. The main results are reported of studies of plasma pump-spectrum converters and it is shown that promising results can be expected by combining luminescent filters and an optimized plasma converter system in an "optical boiler" enclosure.

Variation in short-term and long-term responses of photosynthesis and isoprenoid-mediated photoprotection to soil water availability in four Douglas-fir provenances

DOE PAGES

Junker, Laura Verena; Kleiber, Anita; Jansen, Kirstin; ...

2017-01-10

For long-lived forest tree species, the understanding of intraspecific variation among populations and their response to water availability can reveal their ability to cope with and adapt to climate change. Dissipation of excess excitation energy, mediated by photoprotective isoprenoids, is an important defense mechanism against drought and high light when photosynthesis is hampered. We used 50-year-old Douglas-fir trees of four provenances at two common garden experiments to characterize provenance-specific variation in photosynthesis and photoprotective mechanisms mediated by essential and non-essential isoprenoids in response to soil water availability and solar radiation. All provenances revealed uniform photoprotective responses to high solar radiation,more » including increased de-epoxidation of photoprotective xanthophyll cycle pigments and enhanced emission of volatile monoterpenes. In contrast, we observed differences between provenances in response to drought, where provenances sustaining higher CO2 assimilation rates also revealed increased water-use efficiency, carotenoid-chlorophyll ratios, pools of xanthophyll cycle pigments, β-carotene and stored monoterpenes. Our results demonstrate that local adaptation to contrasting habitats affected chlorophyll-carotenoid ratios, pool sizes of photoprotective xanthophylls, β-carotene, and stored volatile isoprenoids. We conclude that intraspecific variation in isoprenoid-mediated photoprotective mechanisms contributes to the adaptive potential of Douglas-fir provenances to climate change.« less

Variation in short-term and long-term responses of photosynthesis and isoprenoid-mediated photoprotection to soil water availability in four Douglas-fir provenances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Junker, Laura Verena; Kleiber, Anita; Jansen, Kirstin

For long-lived forest tree species, the understanding of intraspecific variation among populations and their response to water availability can reveal their ability to cope with and adapt to climate change. Dissipation of excess excitation energy, mediated by photoprotective isoprenoids, is an important defense mechanism against drought and high light when photosynthesis is hampered. We used 50-year-old Douglas-fir trees of four provenances at two common garden experiments to characterize provenance-specific variation in photosynthesis and photoprotective mechanisms mediated by essential and non-essential isoprenoids in response to soil water availability and solar radiation. All provenances revealed uniform photoprotective responses to high solar radiation,more » including increased de-epoxidation of photoprotective xanthophyll cycle pigments and enhanced emission of volatile monoterpenes. In contrast, we observed differences between provenances in response to drought, where provenances sustaining higher CO2 assimilation rates also revealed increased water-use efficiency, carotenoid-chlorophyll ratios, pools of xanthophyll cycle pigments, β-carotene and stored monoterpenes. Our results demonstrate that local adaptation to contrasting habitats affected chlorophyll-carotenoid ratios, pool sizes of photoprotective xanthophylls, β-carotene, and stored volatile isoprenoids. We conclude that intraspecific variation in isoprenoid-mediated photoprotective mechanisms contributes to the adaptive potential of Douglas-fir provenances to climate change.« less

Active Control of Wind Tunnel Noise

NASA Technical Reports Server (NTRS)

Hollis, Patrick (Principal Investigator)

1991-01-01

The need for an adaptive active control system was realized, since a wind tunnel is subjected to variations in air velocity, temperature, air turbulence, and some other factors such as nonlinearity. Among many adaptive algorithms, the Least Mean Squares (LMS) algorithm, which is the simplest one, has been used in an Active Noise Control (ANC) system by some researchers. However, Eriksson's results, Eriksson (1985), showed instability in the ANC system with an ER filter for random noise input. The Restricted Least Squares (RLS) algorithm, although computationally more complex than the LMS algorithm, has better convergence and stability properties. The ANC system in the present work was simulated by using an FIR filter with an RLS algorithm for different inputs and for a number of plant models. Simulation results for the ANC system with acoustic feedback showed better robustness when used with the RLS algorithm than with the LMS algorithm for all types of inputs. Overall attenuation in the frequency domain was better in the case of the RLS adaptive algorithm. Simulation results with a more realistic plant model and an RLS adaptive algorithm showed a slower convergence rate than the case with an acoustic plant as a delay plant. However, the attenuation properties were satisfactory for the simulated system with the modified plant. The effect of filter length on the rate of convergence and attenuation was studied. It was found that the rate of convergence decreases with increase in filter length, whereas the attenuation increases with increase in filter length. The final design of the ANC system was simulated and found to have a reasonable convergence rate and good attenuation properties for an input containing discrete frequencies and random noise.

The Fluids Integrated Rack and Light Microscopy Module Integrated Capabilities

NASA Technical Reports Server (NTRS)

Motil, Susan M.; Gati, Frank; Snead, John H.; Hill, Myron E.; Griffin, DeVon W.

2003-01-01

The Fluids Integrated Rack (FIR), a facility class payload, and the Light Microscopy Module (LMM), a subrack payload, are scheduled to be launched in 2005. The LMM integrated into the FIR will provide a unique platform for conducting fluids and biological experiments on ISS. The FIR is a modular, multi-user scientific research facility that will fly in the U.S. laboratory module, Destiny, of the International Space Station (ISS). The first payload in the FIR will be the Light Microscopy Module (LMM). The LMM is planned as a remotely controllable, automated, on-orbit microscope subrack facility, allowing flexible scheduling and control of fluids and biology experiments within the FIR. Key diagnostic capabilities for meeting science requirements include video microscopy to observe microscopic phenomena and dynamic interactions, interferometry to make thin film measurements with nanometer resolution, laser tweezers for particle manipulation, confocal microscopy to provide enhanced three-dimensional visualization of structures, and spectrophotometry to measure photonic properties of materials. The LMM also provides experiment sample containment for frangibles and fluids. This paper will provide a description of the current FIR and LMM designs, planned capabilities and key features. In addition a brief description of the initial five experiments planned for LMM/FIR will be provided.

High Efficiency Particulate Air (HEPA) Filter Generation, Characterization, and Disposal Experiences at the Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coffey, D. E.

2002-02-28

High Efficiency Particulate Air filtration is an essential component of the containment and ventilation systems supporting the research and development activities at the Oak Ridge National Laboratory. High Efficiency Particulate Air filters range in size from 7.6cm (3 inch) by 10.2 cm (4 inch) cylindrical shape filters to filter array assemblies up to 2.1 m (7 feet) high by 1.5 m (5 feet) wide. Spent filters are grouped by contaminates trapped in the filter media and become one of the components in the respective waste stream. Waste minimization and pollution prevention efforts are applied for both radiological and non-radiological applications.more » Radiological applications include laboratory hoods, glove boxes, and hot cells. High Efficiency Particulate Air filters also are generated from intake or pre-filtering applications, decontamination activities, and asbestos abatement applications. The disposal avenues include sanitary/industrial waste, Resource Conservation and Recovery Act and Toxic Substance Control Act, regulated waste, solid low-level waste, contact handled transuranic, and remote handled transuranic waste. This paper discusses characterization and operational experiences associated with the disposal of the spent filters across multiple applications.« less

Price projections for selected grades of Douglas-fir lumber.

Treesearch

Richard W. Haynes; Thomas D. Fahey; Roger D. Fight

1988-01-01

Grade-specific price projections were developed for Douglas-fir lumber produced in the Douglas-fir region. These grade-specific price projections can be used as an aid in evaluating management practices that will affect the quality of saw logs that are produced.

Predictions of fire behavior and resistance to control: for use with photo series for the Douglas fir-hemlock type and the coastal Douglas-fir-hardwood type.

Treesearch

David V. SANDBERG; Franklin R. Ward

1981-01-01

This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Coastal Douglas-fir—Hemlock Type, Coastal Douglas-fir—Hardwood Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-051....

Fluids and Combustion Facility: Fluids Integrated Rack Modal Model Correlation

NASA Technical Reports Server (NTRS)

McNelis, Mark E.; Suarez, Vicente J.; Sullivan, Timothy L.; Otten, Kim D.; Akers, James C.

2005-01-01

The Fluids Integrated Rack (FIR) is one of two racks in the Fluids and Combustion Facility on the International Space Station. The FIR is dedicated to the scientific investigation of space system fluids management supporting NASA s Exploration of Space Initiative. The FIR hardware was modal tested and FIR finite element model updated to satisfy the International Space Station model correlation criteria. The final cross-orthogonality results between the correlated model and test mode shapes was greater than 90 percent for all primary target modes.

High Efficiency, Transparent, Reusable, and Active PM2.5 Filters by Hierarchical Ag Nanowire Percolation Network.

PubMed

Jeong, Seongmin; Cho, Hyunmin; Han, Seonggeun; Won, Phillip; Lee, Habeom; Hong, Sukjoon; Yeo, Junyeob; Kwon, Jinhyeong; Ko, Seung Hwan

2017-07-12

Air quality has become a major public health issue in Asia including China, Korea, and India. Particulate matters are the major concern in air quality. We present the first environmental application demonstration of Ag nanowire percolation network for a novel, electrical type transparent, reusable, and active PM2.5 air filter although the Ag nanowire percolation network has been studied as a very promising transparent conductor in optoelectronics. Compared with previous particulate matter air filter study using relatively weaker short-range intermolecular force in polar polymeric nanofiber, Ag nanowire percolation network filters use stronger long-range electrostatic force to capture PM2.5, and they are highly efficient (>99.99%), transparent, working on an active mode, low power consumption, antibacterial, and reusable after simple washing. The proposed new particulate matter filter can be applied for a highly efficient, reusable, active and energy efficient filter for wearable electronics application.

Efficiency of several micro-fiber glass filters for recovery of poliovirus from tape water.

PubMed Central

Payment, P; Trudel, M

1979-01-01

Micro-fiber glass filters from Gelman, Filterite, Johns-Manville, and Whatman were compared with Millipore membrane filters on the basis of their virus adsorbancy, flow rate, clogging resistance, and virus concentration efficiency by using tap water at 2 nephelometric turbidity units. As virus adsorbants the Johns-Manville D39, Filterite 0.25-micron, Filterite 0.45-micron, and Millipore 0.45-micron filters were the most efficient, retaining more than 99% of the added virus in water at pH 3.5 and 0.0005 M aluminum chloride. The Johns-Manville D79 and D49 filters retained 92 and 96% of the virus, respectively, whereas the Whatman GF-D, Whatman GF-F, Gelman A-E, and Millipore AP-20 filters retained only 28, 78, 56, and 34% of the virus, respectively. The best flow rate and clogging resistance were obtained with the Johns-Manville D79 filter or with this filter acting as a prefilter to the Johns-Manville D49, Johns-Manville D39, or Filterite 0.45-micron filter. Finally, poliovirus experimentally seeded in 20 liters of tape water was recovered from Johns-Manville D79-Johns-Manville D39 or Johns-Manville D79-Filterite 0.45 micron 142-mm filter combinations was a efficiencies of 86 and 85%, respectively. PMID:231414

EFFICIENCY OF THE FILTERS AGAINST RADIOACTIVE AEROSOL. ON THE RADIOACTIVE CONTAMINATION AND ITS REMOVAL (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miura, T.; Kimura, K.

1959-12-01

Dust filters were examined using a radioactive solidaerosol, decay product daughters of Rn/sup 220/. An examination with a thermal precipitator revealed that the major part of particles in the radioactive aerosol were smaller than 0.5 mu in diameter. Twenty-one kinds of filters were tested. The filtering efficiency was highest in asbestos fiber filters. A radioautographic examination revealed that the radioactive substance penetrated as deep as 1.4 to 1.5 mm into the filter layer. (auth)

Comparison of MERV 16 and HEPA filters for cab filtration of underground mining equipment.

PubMed

Cecala, A B; Organiscak, J A; Noll, J D; Zimmer, J A

2016-08-01

Significant strides have been made in optimizing the design of filtration and pressurization systems used on the enclosed cabs of mobile mining equipment to reduce respirable dust and provide the best air quality to the equipment operators. Considering all of the advances made in this area, one aspect that still needed to be evaluated was a comparison of the efficiencies of the different filters used in these systems. As high-efficiency particulate arrestance (HEPA) filters provide the highest filtering efficiency, the general assumption would be that they would also provide the greatest level of protection to workers. Researchers for the U.S. National Institute for Occupational Safety and Health (NIOSH) speculated, based upon a previous laboratory study, that filters with minimum efficiency reporting value, or MERV rating, of 16 may be a more appropriate choice than HEPA filters in most cases for the mining industry. A study was therefore performed comparing HEPA and MERV 16 filters on two kinds of underground limestone mining equipment, a roof bolter and a face drill, to evaluate this theory. Testing showed that, at the 95-percent confidence level, there was no statistical difference between the efficiencies of the two types of filters on the two kinds of mining equipment. As the MERV 16 filters were less restrictive, provided greater airflow and cab pressurization, cost less and required less-frequent replacement than the HEPA filters, the MERV 16 filters were concluded to be the optimal choice for both the roof bolter and the face drill in this comparative-analysis case study. Another key finding of this study is the substantial improvement in the effectiveness of filtration and pressurization systems when using a final filter design.

Comparison of MERV 16 and HEPA filters for cab filtration of underground mining equipment

PubMed Central

Cecala, A.B.; Organiscak, J.A.; Noll, J.D.; Zimmer, J.A.

2016-01-01

Significant strides have been made in optimizing the design of filtration and pressurization systems used on the enclosed cabs of mobile mining equipment to reduce respirable dust and provide the best air quality to the equipment operators. Considering all of the advances made in this area, one aspect that still needed to be evaluated was a comparison of the efficiencies of the different filters used in these systems. As high-efficiency particulate arrestance (HEPA) filters provide the highest filtering efficiency, the general assumption would be that they would also provide the greatest level of protection to workers. Researchers for the U.S. National Institute for Occupational Safety and Health (NIOSH) speculated, based upon a previous laboratory study, that filters with minimum efficiency reporting value, or MERV rating, of 16 may be a more appropriate choice than HEPA filters in most cases for the mining industry. A study was therefore performed comparing HEPA and MERV 16 filters on two kinds of underground limestone mining equipment, a roof bolter and a face drill, to evaluate this theory. Testing showed that, at the 95-percent confidence level, there was no statistical difference between the efficiencies of the two types of filters on the two kinds of mining equipment. As the MERV 16 filters were less restrictive, provided greater airflow and cab pressurization, cost less and required less-frequent replacement than the HEPA filters, the MERV 16 filters were concluded to be the optimal choice for both the roof bolter and the face drill in this comparative-analysis case study. Another key finding of this study is the substantial improvement in the effectiveness of filtration and pressurization systems when using a final filter design. PMID:27524838

Litter dynamics in two Sierran mixed conifer forests. I. Litterfall and decomposition rates

USGS Publications Warehouse

Stohlgren, Thomas J.

1988-01-01

Litterfall was measured for 4 years and leaf litter decomposition rates were studied for 3.6 years in two mixed conifer forest (giant sequoia-fir and fir-pine) in the southern Sierra Nevada of California. The giant sequoia-fir forest (GS site) was dominated by giant sequoia (Sequoiadendron giganteum (Lindl.) Buchh.), white fir (Abies concolor Lindl. & Gord.), and sugar pine (Pinus lambertiana Dougl.). The fir-pine forest (FP site) was dominated by white fir, sugar pine, and incense cedar (Calocedrus decurrens (Torr.) Florin). Litterfall, including large woody debris -1•year-1 compared with 4355 kg•ha-1•year-1 at the FP site (3.4:1). In the GS site, leaf litter decomposition after 3.6 years was slowest for giant sequoia (28.2% mass loss), followed by sugar pine (34.3%) and white fie (45.1%). In the FP site, mass loss was slowest for sugar pine (40.0%), followed by white fir (45.1%), while incense cedar showed the greatest mass loss (56.9%) after 3.6 years. High litterfall rates of large woody debris (i.e., 2.5-15.2 cm diameter) and slow rates of leaf litter decomposition in the giant sequoia-fir forest type may result in higher litter accumulation rates than in the fir-pine type. Leaf litter times to 95% decay for the GS and FP sites were 30 and 27 years, respectively, if the initial 0.7-year period (a short period of rapid mass decay) was ignored in the calculation. A mass balance approach for total litterfall (<15.2 cm diameter) decomposition yielded lower decay constants than did the litterbag study and therefore longer times to 95% decay (57 years for the GS site and 62 years for the FP site).

Electrospun Magnetic Nanoparticle-Decorated Nanofiber Filter and Its Applications to High-Efficiency Air Filtration.

PubMed

Kim, Juyoung; Chan Hong, Seung; Bae, Gwi Nam; Jung, Jae Hee

2017-10-17

Filtration technology has been widely studied due to concerns about exposure to airborne dust, including metal oxide nanoparticles, which cause serious health problems. The aim of these studies has been to develop mechanisms for the continuous and efficient removal of metal oxide dusts. In this study, we introduce a novel air filtration system based on the magnetic attraction force. The filtration system is composed of a magnetic nanoparticle (MNP)-decorated nanofiber (MNP-NF) filter. Using a simple electrospinning system, we fabricated continuous and smooth electrospun nanofibers with evenly distributed Fe 3 O 4 MNPs. Our electrospun MNP-NF filter exhibited high particle collection efficiency (∼97% at 300 nm particle size) compared to the control filter (w/o MNPs, ∼ 68%), with a ∼ 64% lower pressure drop (∼17 Pa) than the control filter (∼27 Pa). Finally, the filter quality factors of the MNP-NF filter were 4.7 and 11.9 times larger than those of the control filter and the conventional high-efficiency particulate air filters (>99% and ∼269 Pa), respectively. Furthermore, we successfully performed a field test of our MNP-NF filter using dust from a subway station tunnel. This work suggests that our novel MNP-NF filter can be used to facilitate effective protection against hazardous metal oxide dust in real environments.

Aboveground growth interactions of paired conifer seedlings in close proximity

Treesearch

Warren D. Devine; Timothy B. Harrington

2011-01-01

Where belowground resources are relatively abundant, naturally established trees sometimes occur in very close proximity to one another. We conducted a two-year study to assess the aboveground interactions between Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis) and noble fir (Abies procera)...

Early genetic testing of coastal Douglas-fir for Swiss needle cast tolerance.

Treesearch

Fatih Temel; G.R. Johnson; W.T. Adams

2005-01-01

The possibility of early testing coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) for Swiss needle cast (SNC; caused by Phaeocryptopus gaeumannii (Rohde) Petrak) tolerance was investigated using 55 Douglas-fir families from western Oregon. Seedlings were inoculated with P...

Technology Development of Miniaturized Far-Infrared Sources for Biomolecular Spectroscopy

NASA Technical Reports Server (NTRS)

Kono, Junichiro

2003-01-01

The objective of this project was to develop a purely solid-state based, thus miniaturized, far-infrared (FIR) (also known as terahertz (THz)) wave source using III-V semiconductor nanostructures for biomolecular detection and sensing. Many biomolecules, such as DNA and proteins, have distinct spectroscopic features in the FIR wavelength range as a result of vibration-rotation-tunneling motions and various inter- and intra-molecule collective motions. Spectroscopic characterization of such molecules requires narrow linewidth, sufficiently high power, tunable (in wavelength), and coherent FIR sources. Unfortunately, the FIR frequency is one of the least technologically developed ranges in the electromagnetic spectrum. Currently available FIR sources based on non-solid state technology are bulky, inefficient, and very often incoherent. In this project we investigated antimonide based compound semiconductor (ABCS) nanostructures as the active medium to generate FIR radiation. The final goal of this project was to demonstrate a semiconductor THz source integrated with a pumping diode laser module to achieve a compact system for biomolecular applications.

Spectral Energy Distribution of Far-infrared Bright Quasar Sample in the Lockman Hole

NASA Astrophysics Data System (ADS)

Dai, Y.; Huang, J.-S.; Omont, A.; Hatziminaoglou, E.; Willmer, C.; Fazio, G.; Elvis, M.; Bergeron, J.; Rigopoulou, D.; Perez-Fournon, I.

2011-10-01

The far-infrared (FIR) properties of Quasi-Stellar Objects (QSOs) is important in connecting the Starburst (SB) and Active Galactic Nucleus (AGN) activities. Therefore, we constructed a 24 μ m selected QSO sample to study their FIR behavior. All sources were spectroscopically identified from MMT or the Sloan Digital Sky Survey (SDSS) as broadline quasars. Of the total ˜330 sources, 37 have secure FIR detections in the Herschel-HERMES field. We compared their SEDs to previous QSO templates, and found that those FIR bright quasars differ from existing AGNs only by an additional dust component(s). Further studies on the origin for the FIR emission reveals the relative roles starburst and AGN play in powering the dust emission, based on the dust temperature, FIR luminosity, and the shapes of individual SEDs. The dust temperatures have a wide range from 20K to 80K with a median of ˜ 30K, indicating homogeneous heating mechanisms that could later be related to the origin of these cold dust emissions.

Enhanced spectral efficiency using bandwidth switchable SAW filtering for mobile satellite communications systems

NASA Technical Reports Server (NTRS)

Peach, Robert; Malarky, Alastair

1990-01-01

Currently proposed mobile satellite communications systems require a high degree of flexibility in assignment of spectral capacity to different geographic locations. Conventionally this results in poor spectral efficiency which may be overcome by the use of bandwidth switchable filtering. Surface acoustic wave (SAW) technology makes it possible to provide banks of filters whose responses may be contiguously combined to form variable bandwidth filters with constant amplitude and phase responses across the entire band. The high selectivity possible with SAW filters, combined with the variable bandwidth capability, makes it possible to achieve spectral efficiencies over the allocated bandwidths of greater than 90 percent, while retaining full system flexibility. Bandwidth switchable SAW filtering (BSSF) achieves these gains with a negligible increase in hardware complexity.

[Method for concentration determination of mineral-oil fog in the air of workplace].

PubMed

Xu, Min; Zhang, Yu-Zeng; Liu, Shi-Feng

2008-05-01

To study the method of concentration determination of mineral-oil fog in the air of workplace. Four filter films such as synthetic fabric filter film, beta glass fiber filter film, chronic filter paper and microporous film were used in this study. Two kinds of dust samplers were used to collect the sample, one sampling at fast flow rate in a short time and the other sampling at slow flow rate with long duration. Subsequently, the filter membrane was weighed with electronic analytical balance. According to sampling efficiency and incremental size, the adsorbent ability of four different filter membranes was compared. When the flow rate was between 10 approximately 20 L/min and the sampling time was between 10 approximately 15 min, the average sampling efficiency of synthetic fabric filter film was 95.61% and the increased weight ranged from 0.87 to 2.60 mg. When the flow rate was between 10 approximately 20 L/min and sampling time was between 10 approximately 15 min, the average sampling efficiency of beta glass fiber filter film was 97.57% and the increased weight was 0.75 approximately 2.47 mg. When the flow rate was between 5 approximately 10 L/min and the sampling time between 10 approximately 20 min, the average sampling efficiency of chronic filter paper and microporous film was 48.94% and 63.15%, respectively and the increased weight was 0.75 approximately 2.15 mg and 0.23 approximately 0.85 mg, respectively. When the flow rate was 3.5 L/min and the sampling time was between 100 approximately 166 min, the average sampling efficiency of filter film were 94.44% and 93.45%, respectively and the average increased weight was 1.28 mg for beta glass fiber filter film and 0.78 mg for beta glass fiber filter film and synthetic fabric synthetic fabric filter film. The average sampling efficiency of chronic filter paper and microporous film were 37.65% and 88.21%, respectively. The average increased weight was 4.30 mg and 1.23 mg, respectively. Sampling with synthetic fabric filter film and beta glass fiber filter film is credible, accurate, simple and feasible for determination of the concentration of mineral-oil fog in workplaces.

MR image reconstruction via guided filter.

PubMed

Huang, Heyan; Yang, Hang; Wang, Kang

2018-04-01

Magnetic resonance imaging (MRI) reconstruction from the smallest possible set of Fourier samples has been a difficult problem in medical imaging field. In our paper, we present a new approach based on a guided filter for efficient MRI recovery algorithm. The guided filter is an edge-preserving smoothing operator and has better behaviors near edges than the bilateral filter. Our reconstruction method is consist of two steps. First, we propose two cost functions which could be computed efficiently and thus obtain two different images. Second, the guided filter is used with these two obtained images for efficient edge-preserving filtering, and one image is used as the guidance image, the other one is used as a filtered image in the guided filter. In our reconstruction algorithm, we can obtain more details by introducing guided filter. We compare our reconstruction algorithm with some competitive MRI reconstruction techniques in terms of PSNR and visual quality. Simulation results are given to show the performance of our new method.

Local Volume Hi Survey: the far-infrared radio correlation

NASA Astrophysics Data System (ADS)

Shao, Li; Koribalski, Bärbel S.; Wang, Jing; Ho, Luis C.; Staveley-Smith, Lister

2018-06-01

In this paper we measure the far-infrared (FIR) and radio flux densities of a sample of 82 local gas-rich galaxies, including 70 "dwarf" galaxies (M* < 109 M⊙), from the Local Volume HI Survey (LVHIS), which is close to volume limited. It is found that LVHIS galaxies hold a tight linear FIR-radio correlation (FRC) over four orders of magnitude (F_1.4GHz ∝ F_FIR^{1.00± 0.08}). However, for detected galaxies only, a trend of larger FIR-to-radio ratio with decreasing flux density is observed. We estimate the star formation rate by combining UV and mid-IR data using empirical calibration. It is confirmed that both FIR and radio emission are strongly connected with star formation but with significant non-linearity. Dwarf galaxies are found radiation deficient in both bands, when normalized by star formation rate. It urges a "conspiracy" to keep the FIR-to-radio ratio generally constant. By using partial correlation coefficient in Pearson definition, we identify the key galaxy properties associated with the FIR and radio deficiency. Some major factors, such as stellar mass surface density, will cancel out when taking the ratio between FIR and radio fluxes. The remaining factors, such as HI-to-stellar mass ratio and galaxy size, are expected to cancel each other due to the distribution of galaxies in the parameter space. Such cancellation is probably responsible for the "conspiracy" to keep the FRC alive.

Fir Decline and Mortality in the Southern Siberian Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

2016-01-01

Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata))were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (1825),convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width(TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies)have a high impact on current TRW (r 0.600.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest steppe)and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

PubMed

Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

2017-03-01

Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

Veneer recovery from peeler-grade Douglas-fir logs in western Washington.

Treesearch

E.H. Clarke; A.C. Knauss

1957-01-01

As Douglas-fir plywood production continues to expand, increased demands will be made for all grades of peelable Douglas-fir logs. Thus, it becomes increasingly important to know the veneer-grade recovery expected so that timber and logs can be more accurately appraised.

Biological research by optically pumped far infrared lasers

NASA Astrophysics Data System (ADS)

Zhengyu, Mi

1989-05-01

The FIR breeding for paddy rice, black bean and wheat, the chlorophyll mutation of paddy rice induced by optically pumped FIR laser, etc., are presented. The results of SDS electrophoresis analysis of soluble proteins of Drosophita melanrgaster irradiated by optically pumped FIR laser are described and discussed.

Dwarf mistletoe-infected red fir: growth after release

Treesearch

Robert F. Scharpf

1979-01-01

Release cutting, live crown ratio, diameter-at-breast height, and dwarf mistletoe (Arceuthobium abietinum f. sp. magnificae). acted to affect radial and height growth of red firs (Abies magnifica A. Murr.). Infected and noninfected red firs responded well to release as expressed by increased radial growth: growth...

Growing corkbark fir and subalpine fir for nursery production

USDA-ARS?s Scientific Manuscript database

This bulletin is largely based on research conducted at the University of Idaho during 2000-2009. Corkbark and subalpine fir have desirable characteristics for Christmas tree and landscape use, including soft, fragrant foliage that ranges from dark green to silvery or bluish-green. Depending on seed...

Evolutionary history of two endemic Appalachian conifers revealed using microsatellite markers

Treesearch

Kevin M. Potter; John Frampton; Sedley A. Josserand; C. Dana Nelson

2010-01-01

Fraser fir (Abies fraseri [Pursh] Poir.) and intermediate fir (Abies balsamea [L.] Mill. var. phanerolepis Fern.) exist in small populations in the Appalachian highlands of the southeastern United States. We used ten nuclear microsatellite markers to quantify genetic variation within Fraser fir and intermediate...

PATHFINDER ATOMIC POWER PLANT. FILTRATION OF ALUMINUM CORROSION PRODUCTS PRODUCED IN HIGH-TEMPERATURE, HIGH PURITY WATER SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noble, J.H.; Davie, R.L.

1961-05-01

Filter tests were conducted to determine the most suitable filter for removing large quantities of aluminum corrosion product (boehmite) from reactor water. Filters tested included the following: wire-wound, sintered filter elements, sintered ceramic fllter elements, cotton stringwound filter elements, felted-cotton filter elements, cation resin, adsorption resin, diatomaceous earth precoat filter, and a wood-cellulose precoat filter. Parameters measured were flow rate, filter-influent and -effluent boehmite concentration, pressure drop, and final filter load. The pressure drop and efficiency of the filters was correlated with boehmite load. Boehmite deposits on filters as a nonporous gelatinous cake, and causes a rapidly increasing pressure drop.more » Tests indicate that the optimum load with filter elements and precoat filters is achieved at a pressure drop of 25 psi. Very little additional load can be obtained by operating to a higher pressure drop. Of the filters tested, the precoat filter snd 40 to 60 mesh cation resin were the more effective in removing boehmite. The efficiency of the precoat filter was in excess of 99%, and the efficiency of the cation resin was for the most part in excess of 95%. For various reasons, the other filters were eliminated from final consideration. The test program and available literature indicated that an element type precoat filter using wood cellulose as the precoat media would be most suitable for the proposed application. (auth)« less

New insights into the interstellar medium of the dwarf galaxy IC 10: connection between magnetic fields, the radio-infrared correlation and star formation

NASA Astrophysics Data System (ADS)

Basu, Aritra; Roychowdhury, Sambit; Heesen, Volker; Beck, Rainer; Brinks, Elias; Westcott, Jonathan; Hindson, Luke

2017-10-01

We present the highest sensitivity and angular resolution study at 0.32 GHz of the dwarf irregular galaxy IC 10, observed using the Giant Metrewave Radio Telescope, probing ˜45 pc spatial scales. We find the galaxy-averaged radio continuum spectrum to be relatively flat, with a spectral index α = -0.34 ± 0.01 (Sν ∝ να), mainly due to a high contribution from free-free emission. At 0.32 GHz, some of the H II regions show evidence of free-free absorption as they become optically thick below ˜0.41 GHz with corresponding free electron densities of ˜ 11-22 cm- 3. After removing the free-free emission, we studied the radio-infrared (IR) relations on 55, 110 and 165 pc spatial scales. We find that on all scales the non-thermal emission at 0.32 and 6.2 GHz correlates better with far-infrared (FIR) emission at 70 μm than mid-IR emission at 24 μm. The dispersion of the radio-FIR relation arises due to variations in both magnetic field and dust temperature, and decreases systematically with increasing spatial scale. The effect of cosmic ray transport is negligible as cosmic ray electrons were only injected ≲5 Myr ago. The average magnetic field strength (B) of 12 μG in the disc is comparable to that of large star-forming galaxies. The local magnetic field is strongly correlated with local star formation rate (SFR) as B ∝ SFR0.35 ± 0.03, indicating a starburst-driven fluctuation dynamo to be efficient (˜10 per cent) in amplifying the field in IC 10. The high spatial resolution observations presented here suggest that the high efficiency of magnetic field amplification and strong coupling with SFR likely sets up the radio-FIR correlation in cosmologically young galaxies.

77 FR 2930 - Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-20

... certain power turbine (PT) blade fir-tree roots. This proposed AD would require removing the affected PT... detected geometric non-conformities on blade fir-tree roots. The technical investigations carried out by... was prompted by the detection of geometric non- conformities on PT blade fir-tree roots. We are...

Dwarf Mistletoe on Red Fir . . . infection and control in understory stands

Treesearch

Robert F. Scharpf

1969-01-01

Height and age of understory red fir (Abies magnifica A. Murr.) were related to dwarf mistletoe (Arceuthobiilm campylopodum f. abietinum) infection from the surrounding overstory red fir on four National Forests in California. Percentage of trees infected and intensity of infection increased significantly as height of understory...

Fraser fir stand structure in the Black Mountains of North Carolina

Treesearch

Rachael H. McManamay; Lynn M. Resle; James B. Campbell

2010-01-01

Over the past several decades, naturally occurring populations of Fraser fir (Abies fraseri [Pursh.] Poir) have experienced devastating mortality rates due to attack by the exotic insect, balsam woolly adelgid (BWA) (Adelges piceae Ratz.). The decline in Fraser fir is particularly concerning because its natural geographic...

Belowground competition from overstory trees influences Douglas-fir sapling morphology in thinned stands

Treesearch

Warren D. Devine; Timothy B. Harrington

2009-01-01

We evaluated effects of belowground competition on morphology of naturally established coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) saplings in 60- to 80-year-old thinned Douglas-fir stands in southwestern Washington. We separately quantified belowground competition from overstory and understory sources...

AmeriFlux CA-Cha New Brunswick - Charlie Lake site 01 (immature balsam fir forest to be thinned in year 3)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourque, Charles

This is the AmeriFlux version of the carbon flux data for the site CA-Cha New Brunswick - Charlie Lake site 01 (immature balsam fir forest to be thinned in year 3). Site Description - mature balsam fir forest

Jet Drying of Southern Pine and Douglas-Fir: Exploratory Study

Treesearch

Howard N. Rosen

1978-01-01

Southern pine and Douglas-fir boards, containing both heart- and sapwood and 1.75 inches thick, were jet dried at temperatures from 160 to 400 F and air velocities from 3,000 to 9,000 fmp. Jet drying was more effective for southern pine than for Douglas-fir.

A forest health inventory assessment of red fir (Abies magnifica) in upper montane California

Treesearch

Leif Mortenson; Andrew N. Gray; David C. Shaw

2015-01-01

We investigated the forest health of red fir (Abies magnifica) and how it compared with commonly-associated species Jeffrey pine (Pinus jeffreyi), lodgepole pine (Pinus contorta) and white fir (Abies concolor) in the upper montane forests of California. We evaluated tree mortality rates...

Response of different white fir geographic provenances to Trichosporium symbioticum inoculation in California

Treesearch

William J. Otrosina; Stanley J. Zarnoch

2012-01-01

We inoculated the fir engraver (Scolytus ventralis LeConte) associated fungus Trichosporium symbioticum Wright onto 56 white fir (Abies concolor (Gordon & Glend.) Lindl. ex Hildebr.) trees planted in a common garden study near Camino, California, that represented five geographic provenances of this species....

Saddle Bag Mountain Research Natural Area: guidebook supplement 34.

Treesearch

Reid Schuller; Ronald L. Exeter

2007-01-01

This guidebook describes the Saddle Bag Mountain Research Natural Area, a 121-ha (300-ac) tract established to represent an old-growth remnant of Pacific silver fir (Abies amabilis) and western hemlock (Tsuga heterophylla) forest in the Oregon Coast Range. Pacific silver fir and noble fir (Abies procera)...

Madrone duff and the natural regeneration of Douglas-fir.

Treesearch

Don Minore

1987-01-01

Excellent natural regeneration of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) often occurs under canopies of Pacific madrone (Arbutus menziesii Pursh), but the effects of madrone duff on regeneration are poorly understood. A field experiment was conducted in a thinned Douglas-fir stand in southwestern Oregon to see if...

Dwarfmistletoe of Douglas-fir

Treesearch

Donald P. Graham

1961-01-01

Dwarfmistletoe (Arceuthobium douglasii Engelm.), one of the most destructive enemies of Douglas-fir, causes serious losses in many stands. This parasitic plant is present almost everywhere within the range of Douglas-fir in the northern, central, and southern Rockies. It is abundant in eastern Washington and Oregon and is common in southwestern Oregon and northern...

Truffle abundance and mycophagy by northern flying squirrels in eastern Washington forests.

Treesearch

John F. Lehmkuhl; Laura E. Gould; Efren Cazares; David R. Hosford

2004-01-01

Although much is known about truffle abundance and rodent mycophagy in mesic Douglas-fir forests in the Pacific Northwest, few data are available for dry interior montane forests dominated by ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and grand fir (Abies grandis). Our objective...

Douglas-fir displays a range of growth responses to temperature, water, and Swiss needle cast in western Oregon, USA

EPA Science Inventory

Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC ...

Graft union formation in Douglas-fir.

Treesearch

D.L. Copes

1969-01-01

Greenhouse-grown Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) graft unions were examined between 2 and 84 days after grafting. Room temperature was maintained at 60-70 F throughout the growing season. In most respects grafts of Douglas-fir followed development patterns previously reported for spruce and pine grafts, but specific differences...

Design and analysis of optically pumped submillimeter waveguide maser amplifiers and oscillators

NASA Technical Reports Server (NTRS)

Galantowicz, T. A.

1975-01-01

The design and experimental measurements are described of an optically pumped far-infrared (FIR) waveguide maser; preliminary measurements on a FIR waveguide amplifier are presented. The FIR maser was found to operate satisfactorily in a chopped CW mode using either methanol (CH3OH) or acetonitrile (CH3CN) as the active molecule. Two other gases, difluoroethane and difluoroethylene, produced an unstable output with high threshold and low output power when operated in the chopped CW mode. Experimental measurements include FIR output versus cavity length, output beam pattern, output power versus pressure, and input power. The FIR output was the input to an amplifier which was constructed similar to the oscillator. An increase of 10% in output power was noted on the 118.8 microns line of methanol.

Simulations of a FIR Oscillator with Large Slippage parameter at Jefferson Lab for FIR/UV pump-probe experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, Stephen V.; Campbell, L. T.; McNeil, B.W.T.

We previously proposed a dual FEL configuration on the UV Demo FEL at Jefferson Lab that would allow simultaneous lasing at FIR and UV wavelengths. The FIR source would be an FEL oscillator with a short wiggler providing diffraction-limited pulses with pulse energy exceeding 50 microJoules, using the exhaust beam from a UVFEL as the input electron beam. Since the UV FEL requires very short pulses, the input to the FIR FEL is extremely short compared to a slippage length and the usual Slowly Varying Envelope Approximation (SVEA) does not apply. We use a non-SVEA code to simulate this systemmore » both with a small energy spread (UV laser off) and with large energy spread (UV laser on).« less

The Dust Content and Opacity of Actively Star-Forming Galaxies

NASA Technical Reports Server (NTRS)

Calzetti, Daniela; Armus, Lee; Bohlin, Ralph C.; Kinney, Anne L.; Koornneef, Jan; Storchi-Bergmann, Thaisa

2000-01-01

We present far-infrared (FIR) photometry at 150 and 205 micron(s) of eight low-redshift starburst galaxies obtained with the Infrared Space Observatory (ISO) ISOPHOT. Five of the eight galaxies are detected in both wave bands, and these data are used, in conjunction with IRAS archival photometry, to model the dust emission at lambda approximately greater than 40 microns. The FIR spectral energy distributions (SEDs) are best fitted by a combination of two modified Planck functions, with T approx. 40 - 55 K (warm dust) and T approx. 20-23 K (cool dust) and with a dust emissivity index epsilon = 2. The cool dust can be a major contributor to the FIR emission of starburst galaxies, representing up to 60% of the total flux. This component is heated not only by the general interstellar radiation field, but also by the starburst itself. The cool dust mass is up to approx. 150 times larger than the warm dust mass, bringing the gas-to-dust ratios of the starbursts in our sample close to Milky Way values, once resealed for the appropriate metallicity. The ratio between the total dust FIR emission in the range 1-1000 microns and the IRAS FIR emission in the range 40 - 120 microns is approx. 1.75, with small variations from galaxy to galaxy. This ratio is about 40% larger than previously inferred from data at millimeter wavelengths. Although the galaxies in our sample are generally classified as "UV bright," for four of them the UV energy emerging shortward of 0.2 microns is less than 15% of the FIR energy. On average, about 30% of the bolometric flux is coming out in the UV-to-near-IR wavelength range; the rest is emitted in the FIR. Energy balance calculations show that the FIR emission predicted by the dust reddening of the UV-to-near-IR stellar emission is within a factor of approx. 2 of the observed value in individual galaxies and within 20% when averaged over a large sample. If our sample of local starbursts is representative of high-redshift (z approx. greater than 1), UV - bright star-forming galaxies, these galaxies' FIR emission will be generally undetected in submillimeter surveys, unless: (1) their bolometric luminosity is comparable to or larger than that of ultraluminous FIR galaxies and (2) their FIR SED contains a cool dust component.

Efficient color display using low-absorption in-pixel color filters

NASA Technical Reports Server (NTRS)

Wang, Yu (Inventor)

2000-01-01

A display system having a non-absorbing and reflective color filtering array and a reflector to improve light utilization efficiency. One implementation of the color filtering array uses a surface plasmon filter having two symmetric metal-dielectric interfaces coupled with each other to produce a transmission optical wave at a surface plasmon resonance wavelength at one interface from a p-polarized input beam on the other interface. Another implementation of the color filtering array uses a metal-film interference filter having two dielectric layers and three metallic films.

Desiccation by Foliar Deposition of Hygroscopic Aerosols may link Air Pollution to Forest Decline and Tree Mortality associated with Global-Change-Type Drought

NASA Astrophysics Data System (ADS)

Burkhardt, J.; Grantz, D. A.; Hunsche, M.; Pariyar, S.; Sutton, M. A.; Zinsmeister, D.

2016-12-01

Leaf surfaces are a major sink for atmospheric aerosol deposition. Plants benefit from aerosol associated nutrients and are able to increase deposition by leaf surface micromorphology. Recent studies have shown that deposited hygroscopic aerosols can also influence plant water relations. This might be an important issue even for remote forest ecosystems, given the strong anthropogenic influence on aerosol production and efficient atmospheric transport. We study processes of aerosol deposition to plant surfaces and their impact on water relations and drought tolerance, both for experimental particle amendment and for aerosol exclusion in filtered air (FA). FA plants experience an environment with < 10% concentration of hygroscopic aerosols compared to ambient air (AA), but no difference in trace gases. Increasing particle concentration leads to decreasing water use efficiency and increasing minimum epidermal conductance (gmin; a measure of uncontrolled water loss inversely related to drought tolerance). After particle amendment, anisohydric beech seedlings increased transpiration and maintained photosynthesis, while isohydric pine seedlings maintained transpiration and tended to reduce photosynthesis. FA seedlings of pine, oak, and fir showed lower gmin than corresponding AA seedlings. The results support the concept of hydraulic activation of stomata (HAS) and an associated wick action caused by leaf surface particles. Concentrated salt solutions formed by hygroscopicity even in unsaturated air may create a thin liquid film that penetrates the stomatal pore, allowing evaporation of liquid water at the leaf surface. Increased gmin suggests the significance of this process under ambient conditions. The direct impact of air pollution on plant drought tolerance is poorly integrated in current scenarios of forest decline and tree mortality, but might represent an important component.

Facile Preparation of Nanostructured, Superhydrophobic Filter Paper for Efficient Water/Oil Separation

PubMed Central

Wang, Jianhua; Wong, Jessica X. H.; Kwok, Honoria; Li, Xiaochun; Yu, Hua-Zhong

2016-01-01

In this paper, we present a facile and cost-effective method to obtain superhydrophobic filter paper and demonstrate its application for efficient water/oil separation. By coupling structurally distinct organosilane precursors (e.g., octadecyltrichlorosilane and methyltrichlorosilane) to paper fibers under controlled reaction conditions, we have formulated a simple, inexpensive, and efficient protocol to achieve a desirable superhydrophobic and superoleophilic surface on conventional filter paper. The silanized superhydrophobic filter paper showed nanostructured morphology and demonstrated great separation efficiency (up to 99.4%) for water/oil mixtures. The modified filter paper is stable in both aqueous solutions and organic solvents, and can be reused multiple times. The present study shows that our newly developed binary silanization is a promising method of modifying cellulose-based materials for practical applications, in particular the treatment of industrial waste water and ecosystem recovery. PMID:26982055

Developing particulate thin filter using coconut fiber for motor vehicle emission

NASA Astrophysics Data System (ADS)

Wardoyo, A. Y. P.; Juswono, U. P.; Riyanto, S.

2016-03-01

Amounts of motor vehicles in Indonesia have been recognized a sharply increase from year to year with the increment reaching to 22 % per annum. Meanwhile motor vehicles produce particulate emissions in different sizes with high concentrations depending on type of vehicles, fuels, and engine capacity. Motor Particle emissions are not only to significantly contribute the atmosphric particles but also adverse to human health. In order to reduce the particle emission, it is needed a filter. This study was aimed to develop a thin filter using coconut fiber to reduce particulate emissions for motor vehicles. The filter was made of coconut fibers that were grinded into power and mixed with glues. The filter was tested by the measurements of particle concentrations coming out from the vehicle exhaust directly and the particle concentrations after passing through the filter. The efficiency of the filter was calculated by ratio of the particle concentrations before comming in the filter to the particle conentrations after passing through the filter. The results showed that the efficiency of the filter obtained more than 30 %. The efficiency increases sharply when a number of the filters are arranged paralelly.

Oxygenation dynamics of sepsis patients undergoing far-infrared intervention based on near-infrared spectroscopy.

PubMed

Chuang, Kuei-Hung; Chuang, Ming-Lung; Sia, Sung-Kien; Sun, Chia-Wei

2017-03-01

Near-infrared spectroscopy (NIRS; continuous wave type) is a noninvasive tool for detecting the relative change of oxyhemoglobin and deoxyhemoglobin. To make this change, intervention methods must be applied. This study determined the hemodynamics of 44 healthy participants and 35 patients with sepsis during exposure to FIR as a novel physical intervention approach. Local microcirculation of their brachioradialis was monitored during exposure and recovery through NIRS. The variations in blood flow and microvascular reaction were determined by conducting paired and unpaired t tests. The oxyhemoglobin levels of the healthy participants increased continuously, even during recovery. In contrast to expextations, the oxyhemoglobin levels of the patients plateaued after only 5 min of FIR illumination. The proposed method has potential applications for ensuring efficient treatment and facilitating doctors in diagnosing the functions of vessels in intensive care units. Mapping diagrams of HbO 2 in healthy males and males with sepsis illustrated unique scenarios during the process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ectomycorrhizal fungi associated with ponderosa pine and Douglas-fir: a comparison of species richness in native western North American forests and Patagonian plantations from Argentina.

PubMed

Barroetaveña, C; Cázares, E; Rajchenberg, M

2007-07-01

The putative ectomycorrhizal fungal species registered from sporocarps associated with ponderosa pine and Douglas-fir forests in their natural range distribution (i.e., western Canada, USA, and Mexico) and from plantations in south Argentina and other parts of the world are listed. One hundred and fifty seven taxa are reported for native ponderosa pine forests and 514 taxa for native Douglas-fir forests based on available literature and databases. A small group of genera comprises a high proportion of the species richness for native Douglas-fir (i.e., Cortinarius, Inocybe, and Russula), whereas in native ponderosa pine, the species richness is more evenly distributed among several genera. The comparison between ectomycorrhizal species richness associated with both trees in native forests and in Patagonia (Argentina) shows far fewer species in the latter, with 18 taxa for the ponderosa pine and 15 for the Douglas-fir. Epigeous species richness is clearly dominant in native Douglas-fir, whereas a more balanced relation epigeous/hypogeous richness is observed for native ponderosa pine; a similar trend was observed for Patagonian plantations. Most fungi in Patagonian Douglas-fir plantations have not been recorded in plantations elsewhere, except Suillus lakei and Thelephora terrestris, and only 56% of the fungal taxa recorded in Douglas-fir plantations around the world are known from native forests, the other taxa being new associations for this host, suggesting that new tree + ectomycorrhizal fungal taxa associations are favored in artificial situations as plantations.

Fir Decline and Mortality in the Southern Siberian Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

2016-01-01

Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata)) were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (18 deg to 25 deg), convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width (TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies) have a high impact on current TRW (r = 0.60 to 0.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest- steppe) and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

RADIO OBSERVATIONS OF THE STAR FORMATION ACTIVITIES IN THE NGC 2024 FIR 4 REGION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Minho; Kang, Miju; Lee, Jeong-Eun, E-mail: minho@kasi.re.kr

Star formation activities in the NGC 2024 FIR 4 region were studied by imaging centimeter continuum sources and water maser sources using several archival data sets from the Very Large Array. The continuum source VLA 9 is elongated in the northwest–southeast direction, consistent with the FIR 4 bipolar outflow axis, and has a flat spectrum in the 6.2–3.6 cm interval. The three water maser spots associated with FIR 4 are also distributed along the outflow axis. One of the spots is located close to VLA 9, and another one is close to an X-ray source. Examinations of the positions ofmore » compact objects in this region suggest that the FIR 4 cloud core contains a single low-mass protostar. VLA 9 is the best indicator of the protostellar position. VLA 9 may be a radio thermal jet driven by this protostar, and it is unlikely that FIR 4 contains a high-mass young stellar object (YSO). A methanol 6.7 GHz maser source is located close to VLA 9, at a distance of about 100 AU. The FIR 4 protostar must be responsible for the methanol maser action, which suggests that methanol class II masers are not necessarily excited by high-mass YSOs. Also discussed are properties of other centimeter continuum sources in the field of view and the water masers associated with FIR 6n. Some of the continuum sources are radio thermal jets, and some are magnetically active young stars.« less

Survey for balsam woolly adegid in Washington and Oregon.

Treesearch

I. Ragenovich; B. Willhite; R. Mitchell; D. Overhulser; K. Ripley

2002-01-01

Balsam woolly adelgid (BWA) is an introduced insect that has had a significant impact on Abies tree species in the Pacific Northwest. During the late 1950s and 1960s, it caused extensive mortality of grand fir (A. grandis), subalpine fir (A. lasiocarpa), and silver fir (A. amabilis), particularly in the...

Relationship between self-fertility, allocation of growth, and inbreeding depression in three coniferous species.

Treesearch

Frank C. Sorensen

1999-01-01

Mortality and growth of self and outcross families of three wind-pollinated, mixed-mating, long-lived conifers, Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), and noble fir (Abies procera) were followed from outplanting to age 26 (25 for noble fir) in spaced plantings at a common...

Pulp quality from small-diameter trees.

Treesearch

G.C. Myers; S. Kumar; R.R. Gustafson; R.J. Barbour; S.M. Abubakr

1997-01-01

Kraft and thermomechanical (TMP) pulps were prepared and evaluated from lodgepole pine and mixed Douglas-fir/western larch sawmill residue chips; lodgepole pine, Douglas-fir, and western larch submerchantable logs; and lodgepole pine, Douglas-fir, and western larch small trees and tops. Kraft pulp from small trees and tops was identical to that from submerchantable...

Population dynamics of dwarf mistletoe on young true firs in the central Sierra Nevada, California

Treesearch

Robert E Scharpf; J. R. Jr. Parmeter

1982-01-01

Young red firs (Abies magnifica A. Murr.) and white firs (A. concolor [Gord. & Glend.] Lindl. ex Hildebr.) on the Stanislaus National Forest, California, were inoculated with seeds of dwarf mistletoe (Arceuthobium abietinum) for 5 successive years. Only 3 to 4 percent of about 7000 seeds placed on branches...

Growth of bear-damaged trees in a mixed plantation of Douglas-fir and red alder.

Treesearch

Richard E. Miller; Harry W. Anderson; Donald L. Reukema; Timothy A. Max

2007-01-01

Incidence and effects of tree damage by black bear (Ursus americanus altifrontalis) in a 50-year-old, coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantation are described. Bears girdled or partially girdled 35 dominant or codominant Douglas-fir trees per acre, but only in that...

Forest tree improvement in California-1970

Treesearch

M. Thompson Conkle

1972-01-01

Foresters in California were surveyed in 1970 to determine the extent of artificial regeneration and tree improvement efforts in the State. Seeding of Douglas-fir was the prevailing practice in the North Coast. Inland areas were being planted with conifers, including ponderosa, Jeffrey, Monterey, and sugar pines, Douglas-fir, and red and white firs. Manpower devoted to...

Conversion of SPORL pretreated Douglas fir forest residues into microbial lipids with oleaginous yeasts

USDA-ARS?s Scientific Manuscript database

Douglas fir is the dominant commercial tree grown in the United States. In this study Douglas fir residue was converted to single cell oils using oleaginous yeasts. Monosaccharides were extracted from the woody biomass by pretreating with sulfite and dilute sulfuric acid (SPORL process) and hydrol...

A SNP resource for douglas-fir: de novo transcriptome assembly and SNP detection and validation

Treesearch

Glenn R. Howe; Jianbin Yu; Brian Knaus; Richard Cronn; Scott Kolpak; Peter Dolan; W. Walter Lorenz; Jeffrey F.D. Dean

2013-01-01

Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauco) are native to North America, the coastal variety is...

First report of Phytophthora ramorum infecting grand fir in California

Treesearch

K.L. Riley; G.A. Chastagner

2011-01-01

Phytophthora ramorum was detected on grand fir in 2003 and 2005 in a Christmas tree plantation near Los Gatos, CA, in association with infected California bay laurel. Isolates derived from stem lesions were used to inoculate grand fir seedlings in two tests. Isolations from lesions on inoculated plants were positive for P. ramorum...

Climate and growth rate as related to an outbreak of silver fir beetles.

Treesearch

Gerard M. Thomas

1957-01-01

In 1947, an outbreak of silver fir beetles, Pseudohylesinus grandis Sw. and P. granulatus (Lec.), was discovered in northwestern Washington. The epidemic flourished for the next six years, killing some 525 million board-feet of Pacific silver fir, Abies amabilis (Dougl.) Forbes. Prior to 1947, the silver...

Shelterwood regeneration of true fir: conclusion after 8 years

Treesearch

Robert J. Laacke; Jeanne H. Tomascheski

1986-01-01

Shelterwood cuttings on Swain Mountain Experimental Forest were measured to determine performance six to eight years after the shelterwood cutting and before shelterwood removal. Use of appropriate selecting criteria minimized windthrow of seed trees. Regeneration remained red fir, even where the major seed source was white fir. Density of seed trees may affect...

Photo guide for appraising downed woody fuels in Montana forests: Interior ponderosa pine, ponderosa pine - larch - Douglas-fir, larch - Douglas-fir, and interior Douglas-fir cover types

Treesearch

William C. Fischer

1981-01-01

Four series of color photographs show different levels of downed woody material resulting from natural processes in four forest cover types in Montana. Each photo is supplemented by fuel inventory data and potential fire behavior ratings.

Douglas-fir tussock moth: an annotated bibliography.

Treesearch

Robert W. Campbell; Lorna C. Youngs

1978-01-01

This annotated bibliography includes references to 338 papers. Each deals in some way with either the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), or a related species. Specifically, 210 publications and 82 unpublished documents make some reference, at least, to the Douglas-fir tussock moth; 55 are concerned with other species in...

Survival, frost susceptibility, growth, and disease resistance of corkbark and subalpine fir grown for landscape and Christmas trees

USDA-ARS?s Scientific Manuscript database

Trees from six corkbark fir (Abies lasiocarpa var. arizonica) and 10 subalpine fir (A. lasiocarpa var. lasiocarpa) seed sources were grown at the University of Idaho Sandpoint Research and Extension Center (SREC) and two commercial nurseries in Idaho and Oregon. Post transplant mortality was highest...

Multi-decadal establishment for single-cohort Douglas-fir forests

Treesearch

James A. Freund; Jerry F. Franklin; Andrew J. Larson; James A. Lutz

2014-01-01

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have...

Mammoth lakes revisited—50 years after a Douglas-fir tussock moth outbreak.

Treesearch

Boyd E. Wickman; G. Lynn Starr

1990-01-01

For five decades after an outbreak of Douglas-fir tussock moth (Orgyia pseudotsugata (McDunnough)), radial growth of defoliated white fir trees (Abies concolor (Gord. & Glend.) Lindl.), was significantly greater than that of nondefoliated host trees nearby. The increased growth probably was due to the thinning effect of...

Recursive time-varying filter banks for subband image coding

NASA Technical Reports Server (NTRS)

Smith, Mark J. T.; Chung, Wilson C.

1992-01-01

Filter banks and wavelet decompositions that employ recursive filters have been considered previously and are recognized for their efficiency in partitioning the frequency spectrum. This paper presents an analysis of a new infinite impulse response (IIR) filter bank in which these computationally efficient filters may be changed adaptively in response to the input. The filter bank is presented and discussed in the context of finite-support signals with the intended application in subband image coding. In the absence of quantization errors, exact reconstruction can be achieved and by the proper choice of an adaptation scheme, it is shown that IIR time-varying filter banks can yield improvement over conventional ones.

Analysis of conifer forest regeneration using Landsat Thematic Mapper data

NASA Technical Reports Server (NTRS)

Fiorella, Maria; Ripple, William J.

1995-01-01

Landsat Thematic Mapper (TM) data were used to evaluate young conifer stands in the western Cascade Mountains of Oregon. Regression and correlation analyses were used to describe the relationships between TM band values and age of young Douglas-fir stands (2 to 35 years old). Spectral data from well regenerated Douglas-fir stands were compared to those of poorly regenerated conifer stands. TM bands 1, 2, 3, 5, 6, and 7 were inversely correlated with the age (r greater than or equal to -0.80) of well regenerated Douglas-fir stands. Overall, the 'structural index' (TM 4/5 ratio) had the highest correlation to age of Douglas-fir stands (r = 0.96). Poorly regenerated stands were spectrally distinct from well regenerated Douglas-fir stands after the stands reached an age of approximately 15 years.

Accurate thermometry based on the red and green fluorescence intensity ratio in NaYF₄: Yb, Er nanocrystals for bioapplication.

PubMed

Liu, Lixin; Qin, Feng; Lv, Tianquan; Zhang, Zhiguo; Cao, Wenwu

2016-10-15

A biological temperature measurement method based on the fluorescence intensity ratio (FIR) was developed to reduce uncertainty. The upconversion luminescence of NaYF₄:Yb, Er nanocrystals was studied as a function of temperature around the physiologically relevant range of 300-330 K. We found that the green-green FIR Fe and red-green FIR (I₆₆₀/I₅₄₀) varied linearly as temperature increased. The thermometric uncertainties using the two FIRs were discussed and were determined to be almost constant at 0.6 and 0.09 K for green-green and red-green, respectively. The lower thermometric uncertainty comes from the intense signal-to-noise ratio of the measured FIRs owing to their comparable fluorescence intensities.

VizieR Online Data Catalog: PACS photometry of FIR faint stars (Klaas+, 2018)

NASA Astrophysics Data System (ADS)

Klaas, U.; Balog, Z.; Nielbock, M.; Mueller, T. G.; Linz, H.; Kiss, Cs.

2018-01-01

70, 100 and 160um photometry of FIR faint stars from PACS scan map and chop/nod measurements. For scan maps also the photometry of the combined scan and cross-scan maps (at 160um there are usually two scan and cross-scan maps each as complements to the 70 and 100um maps) is given. Note: Not all stars have measured fluxes in all three filters. Scan maps: The main observing mode was the point-source mini-scan-map mode; selected scan map parameters are given in column mparam. An outline of the data processing using the high-pass filter (HPF) method is presented in Balog et al. (2014ExA....37..129B). Processing proceeded from Herschel Science Archive SPG v13.1.0 level 1 products with HIPE version 15 build 165 for 70 and 100um maps and from Herschel Science Archive SPG v14.2.0 level 1 products with HIPE version 15 build 1480 for 160um maps. Fluxes faper were obtained by aperture photometry with aperture radii of 5.6, 6.8 and 10.7 arcsec for the 70, 100 and 160um filter, respectively. Noise per pixel sigpix was determined with the histogram method, described in this paper, for coverage values greater than or equal to 0.5*maximum coverage. The number of map pixels (1.1, 1.4, and 2.1 arcsec pixel size, respectively) inside the photometric aperture is Naper = 81.42, 74.12, and 81.56, respectively. The corresponding correction factors for correlated noise are fcorr = 3.13, 2.76, and 4.12, respectively. The noise for the photometric aperture is calculated as sig_aper=sqrt(Naper)*fcorr*sigpix. Signal-to-noise ratios are determined as S/N=faper/sigaper. Aperture-correction factors to derive the total flux are caper = 1.61, 1.56 and 1.56 for the 70, 100 and 160um filter, respectively. Applied colour-correction factors for a 5000K black-body SED are cc = 1.016, 1.033, and 1.074 for the 70, 100, and 160um filter, respectively. The final stellar flux is derived as fstar=faper*caper/cc. Maximum and minimum FWHM of the star PSF are determined by an elliptical fit of the intensity profile. Chop/nod observations: The chop/nod point-source mode is described in this paper. An outline of the data processing is presented in Nielbock et al. (2013ExA....36..631N). Processing proceeded from Herschel Science Archive SPG v11.1.0 level 1 products with HIPE version 13 build 2768. Gyro correction was applied for most of the cases to improve the pointing reconstruction performance. Fluxes faper were obtained by aperture photometry with aperture radii of 5.6, 6.8 and 10.7 arcsec for the 70, 100 and 160um filter, respectively. Noise per pixel sigpix was determined with the histogram method, described in this paper, for coverage values greater than or equal to 0.5*maximum coverage. The number of map pixels (1.1, 1.4, and 2.1 arcsec pixel size, respectively) inside the photometric aperture is Naper = 81.42, 74.12, and 81.56, respectively. The corresponding correction factors for correlated noise are fcorr = 6.33, 4.22, and 7.81, respectively. The noise for the photometric aperture is calculated as sigaper=sqrt(Naper)*fcorr*sigpix. Signal-to-noise ratios are determined as S/N=faper/sigaper. Aperture-correction factors to derive the total flux are caper = 1.61, 1.56 and 1.56 for the 70, 100 and 160um filter, respectively. Applied colour-correction factors for a 5000K black-body SED are cc = 1.016, 1.033, and 1.074 for the 70, 100, and 160um filter, respectively. Maximum and minimum FWHM of the star PSF are determined by an elliptical fit of the intensity profile. (7 data files).

On optimal infinite impulse response edge detection filters

NASA Technical Reports Server (NTRS)

Sarkar, Sudeep; Boyer, Kim L.

1991-01-01

The authors outline the design of an optimal, computationally efficient, infinite impulse response edge detection filter. The optimal filter is computed based on Canny's high signal to noise ratio, good localization criteria, and a criterion on the spurious response of the filter to noise. An expression for the width of the filter, which is appropriate for infinite-length filters, is incorporated directly in the expression for spurious responses. The three criteria are maximized using the variational method and nonlinear constrained optimization. The optimal filter parameters are tabulated for various values of the filter performance criteria. A complete methodology for implementing the optimal filter using approximating recursive digital filtering is presented. The approximating recursive digital filter is separable into two linear filters operating in two orthogonal directions. The implementation is very simple and computationally efficient, has a constant time of execution for different sizes of the operator, and is readily amenable to real-time hardware implementation.

Herschel/PACS far-IR spectral imaging of a jet from an intermediate mass protostar in the OMC-2 region

NASA Astrophysics Data System (ADS)

González-García, B.; Manoj, P.; Watson, D. M.; Vavrek, R.; Megeath, S. T.; Stutz, A. M.; Osorio, M.; Wyrowski, F.; Fischer, W.; Tobin, J. J.; Sánchez-Portal, M.; Diaz Rodriguez, A. K.; Wilson, T. L.

2016-11-01

We present the first detection of a jet in the far-IR [O I] lines from an intermediate mass protostar. This jet was detected in a Herschel/PACS spectral mapping study in the [O I] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reveals the presence of an extended photodissociation region (PDR) and a narrow, but intense jet connecting the two protostars. The jet seen in [O I] emission is spatially aligned with the Spitzer/IRAC 4.5 μm jet and the CO (6-5) molecular outflow centered on FIR 3. The mass-loss rate derived from the total [O I] 63 μm line luminosity of the jet is 7.7 × 10-6M⊙ yr-1, more than an order of magnitude higher than that measured for typical low-mass class 0 protostars. The implied accretion luminosity is significantly higher than the observed bolometric luminosity of FIR 4, indicating that the [O I] jet is unlikely to be associated with FIR 4. We argue that the peak line emission seen toward FIR 4 originates in the terminal shock produced by the jet driven by FIR 3. The higher mass-loss rate that we find for FIR 3 is consistent with the idea that intermediate-mass protostars drive more powerful jets than their low-mass counterparts. Our results also call into question the nature of FIR 4. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The final reduced Herschel data used in this paper (FITS) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A26

The effects of clearcut logging on stream biology of the North Fork of Caspar Creek, Jackson Demonstration State Forest, Fort Bragg, CA--1986 to 1994

Treesearch

Richard L. Bottorff; Allen W. Knight

1996-01-01

The dense coniferous forests of the North Coast Range of California have been harvested for valuable redwood (Sequoia sempervirens), Douglas fir (Pseudotsuga menziesii), and other tree species for more than 100 years. Initially, the primary focus of logging activities was to efficiently fall the trees and transport them to the mill site without much concern for the...

Landsat thematic mapper attitude data processing

NASA Technical Reports Server (NTRS)

Sehn, G. J.; Miller, S. F.

1984-01-01

The Landsat 4 and 5 satellites carry a new, high resolution, seven band thematic mapper imaging instrument. The spacecraft also carry two types of attitude sensors: a gyroscopic internal reference unit (IRU) which senses angular rate from dc to about 2 Hz, and an AC-coupled angular displacement sensor (ADS) measuring angular deviation above 2 Hz. A description of the derivation of the crossover network used to combine and equalize the IRU and ADS data is made. Also described are the digital data processing algorithms which produce the time history of the satellites' attitude motion including the finite impulse response (FIR) implementation of G and F filters; the resampling (interpolation/decimation) and synchronization of the IRU and ADS data; and the axis rotations required as a result of the on-board sensor locations on three orthogonal axes.

Space-time adaptive decision feedback neural receivers with data selection for high-data-rate users in DS-CDMA systems.

PubMed

de Lamare, Rodrigo C; Sampaio-Neto, Raimundo

2008-11-01

A space-time adaptive decision feedback (DF) receiver using recurrent neural networks (RNNs) is proposed for joint equalization and interference suppression in direct-sequence code-division multiple-access (DS-CDMA) systems equipped with antenna arrays. The proposed receiver structure employs dynamically driven RNNs in the feedforward section for equalization and multiaccess interference (MAI) suppression and a finite impulse response (FIR) linear filter in the feedback section for performing interference cancellation. A data selective gradient algorithm, based upon the set-membership (SM) design framework, is proposed for the estimation of the coefficients of RNN structures and is applied to the estimation of the parameters of the proposed neural receiver structure. Simulation results show that the proposed techniques achieve significant performance gains over existing schemes.

Optical systolic solutions of linear algebraic equations

NASA Technical Reports Server (NTRS)

Neuman, C. P.; Casasent, D.

1984-01-01

The philosophy and data encoding possible in systolic array optical processor (SAOP) were reviewed. The multitude of linear algebraic operations achievable on this architecture is examined. These operations include such linear algebraic algorithms as: matrix-decomposition, direct and indirect solutions, implicit and explicit methods for partial differential equations, eigenvalue and eigenvector calculations, and singular value decomposition. This architecture can be utilized to realize general techniques for solving matrix linear and nonlinear algebraic equations, least mean square error solutions, FIR filters, and nested-loop algorithms for control engineering applications. The data flow and pipelining of operations, design of parallel algorithms and flexible architectures, application of these architectures to computationally intensive physical problems, error source modeling of optical processors, and matching of the computational needs of practical engineering problems to the capabilities of optical processors are emphasized.

Herschel-PACS photometry of faint stars for sensitivity performance assessment and establishment of faint FIR primary photometric standards

NASA Astrophysics Data System (ADS)

Klaas, U.; Balog, Z.; Nielbock, M.; Müller, T. G.; Linz, H.; Kiss, Cs.

2018-05-01

Aims: Our aims are to determine flux densities and their photometric accuracy for a set of seventeen stars that range in flux from intermediately bright (≲2.5 Jy) to faint (≳5 mJy) in the far-infrared (FIR). We also aim to derive signal-to-noise dependence with flux and time, and compare the results with predictions from the Herschel exposure-time calculation tool. Methods: We obtain aperture photometry from Herschel-PACS high-pass-filtered scan maps and chop/nod observations of the faint stars. The issues of detection limits and sky confusion noise are addressed by comparison of the field-of-view at different wavelengths, by multi-aperture photometry, by special processing of the maps to preserve extended emission, and with the help of large-scale absolute sky brightness maps from AKARI. This photometry is compared with flux-density predictions based on photospheric models for these stars. We obtain a robust noise estimate by fitting the flux distribution per map pixel histogram for the area around the stars, scaling it for the applied aperture size and correcting for noise correlation. Results: For 15 stars we obtain reliable photometry in at least one PACS filter, and for 11 stars we achieve this in all three PACS filters (70, 100, 160 μm). Faintest fluxes, for which the photometry still has good quality, are about 10-20 mJy with scan map photometry. The photometry of seven stars is consistent with models or flux predictions for pure photospheric emission, making them good primary standard candidates. Two stars exhibit source-intrinsic far-infrared excess: β Gem (Pollux), being the host star of a confirmed Jupiter-size exoplanet, due to emission of an associated dust disk, and η Dra due to dust emission in a binary system with a K1 dwarf. The investigation of the 160 μm sky background and environment of four sources reveals significant sky confusion prohibiting the determination of an accurate stellar flux at this wavelength. As a good model approximation, for nine stars we obtain scaling factors of the continuum flux models of four PACS fiducial standards with the same or quite similar spectral type. We can verify a linear dependence of signal-to-noise ratio (S/N) with flux and with square root of time over significant ranges. At 160 μm the latter relation is, however, affected by confusion noise. Conclusions: The PACS faint star sample has allowed a comprehensive sensitivity assessment of the PACS photometer. Accurate photometry allows us to establish a set of five FIR primary standard candidates, namely α Ari, ɛ Lep, ω Cap, HD 41047 and 42 Dra, which are 2-20 times fainter than the faintest PACS fiducial standard (γ Dra) with absolute accuracy of <6%. For three of these primary standard candidates, essential stellar parameters are known, meaning that a dedicated flux model code may be run. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables A.3 to A.5 and B.1 to B.3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/613/A40

Added Value of Far-Infrared Radiometry for Ice Cloud Remote Sensing

NASA Astrophysics Data System (ADS)

Libois, Q.; Blanchet, J. P.; Ivanescu, L.; S Pelletier, L.; Laurence, C.

2017-12-01

Several cloud retrieval algorithms based on satellite observations in the infrared have been developed in the last decades. However, most of these observations only cover the midinfrared (MIR, λ < 15 μm) part of the spectrum, and none are available in the far-infrared (FIR, λ ≥ 15 μm). Recent developments in FIR sensors technology, though, now make it possible to consider spaceborne remote sensing in the FIR. Here we show that adding a few FIR channels with realistic radiometric performances to existing spaceborne narrowband radiometers would significantly improve their ability to retrieve ice cloud radiative properties. For clouds encountered in the polar regions and the upper troposphere, where the atmosphere above clouds is sufficiently transparent in the FIR, using FIR channels would reduce by more than 50% the uncertainties on retrieved values of optical thickness, effective particle diameter, and cloud top altitude. This would somehow extend the range of applicability of current infrared retrieval methods to the polar regions and to clouds with large optical thickness, where MIR algorithms perform poorly. The high performance of solar reflection-based algorithms would thus be reached in nighttime conditions. Using FIR observations is a promising venue for studying ice cloud microphysics and precipitation processes, which is highly relevant for cirrus clouds and convective towers, and for investigating the water cycle in the driest regions of the atmosphere.

[Effects of conversion of natural broad-leaved forest to Chinese fir plantation on soil respiration in subtropical China].

PubMed

Zhang, Rui; Bai, Yang; Liu, Juan; Jiang, Pei-kun; Zhou, Guo-mo; Wu, Jia-sen; Tong, Zhi-peng; Li, Yong-fu

2015-10-01

Soil CO2 effluxes in natural broad-leaved forest and the conversed Chinese fir plantation in Linglong Mountains Scenic of Zhejiang Province were evaluated by using static closed chamber and gas chromatography method. The results showed that soil CO2 efflux showed consistent seasonal dynamics in natural broad-leaved forest and Chinese fir plantation, with the maximums observed in summer and autumn, the minimums in winter and spring. Soil CO2 effluxes were 20.0-111.3 and 4.1-118.6 mg C . m-2 . h-1 in natural broad-leaved forest and Chinese fir plantation, respectively. The cumulative soil CO2 emission of natural broad-leaved forest (16.46 t CO2 . hm-2 . a-1) was significantly higher than that of Chinese fir plantation (11.99 t CO2 . hm-2 . a-1). Soil moisture did not affect soil CO2 efflux. There was a significant relationship between soil CO2 efflux and soil temperature at 5 cm depth. There was no significant relationship between soil CO2 efflux of natural broad-leaved forest and water soluble organic carbon content, while water soluble organic carbon content affected significantly soil CO2 efflux in Chinese fir plantation. Converting the natural broad-leaved forest to Chinese fir plantation reduced soil CO2 efflux significantly but improved the sensitivity of soil respiration to environmental factors.

Crumb rubber filtration: a potential technology for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2006-05-01

The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between removal efficiency and filter depth. Higher filtration rate resulted in lower removal efficiency and higher head loss. Compared with conventional granular media filters, crumb rubber filters required less backwash, and developed lower head loss. Consequently crumb rubber filters could be run for a longer time or allow a higher filtration rate. The results also indicate that the crumb rubber filtration alone did not achieve the target removal of invasive species. However, crumb rubber filtration could potentially be used as a primary treatment technology to enhance the efficiency of a secondary treatment process (e.g., disinfection).

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

29 CFR 1910.134 - Respiratory protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... impact and penetration. High efficiency particulate air (HEPA) filter means a filter that is at least 99... as a high efficiency particulate air (HEPA) filter, or an air-purifying respirator equipped with a... frequency of respirator use (including use for rescue and escape); (C) The expected physical work effort; (D...

Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO2 assimilation and growth in Douglas-fir

EPA Science Inventory

Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible...

Documentation of the Douglas-fir tussock moth outbreak-population model.

Treesearch

J.J. Colbert; W. Scott Overton; Curtis. White

1979-01-01

Documentation of three model versions: the Douglas-fir tussock moth population-branch model on (1) daily temporal resolution, (2) instart temporal resolution, and (3) the Douglas-fir tussock moth stand-outbreak model; the hierarchical framework and the conceptual paradigm used are described. The coupling of the model with a normal-stand model is discussed. The modeling...

Host resistance screening for balsam woolly adelgid: A comparison of seedlings from 12 fir species

Treesearch

Leslie Newton; John Frampton; Fred Hain

2012-01-01

The balsam woolly adelgid, Adelges piceae (Hemiptera: Adelgidae) (BWA), first reported on Fraser fir, Abies fraseri (Pursh) Poiret, on Mount Mitchell in 1955 (Amman 1966, Boyce 1955), is a major pest in Christmas tree plantations and in native stands. Nearly all Fraser fir Christmas trees produced in North Carolina...

Development of spruce-fir stands following spruce beetle outbreaks

Treesearch

J. M. Schmid; T. E. Hinds

1974-01-01

Logged and unlogged stands of Engelmann spruce-subalpine fir were evaluated in spruce beetle outbreak areas infested about 15, 25, 50, and 100 years ago. Seedling regeneration was generally adequate except in heavily logged areas, although seedlings were often damaged, apparently by animals. Species composition was dramatically altered in favor of fir in the unlogged...

Guide to understory burning in ponderosa pine-larch-fir forests in the Intermountain West

Treesearch

Bruce M. Kilgore; George A. Curtis

1987-01-01

Summarizes the objectives, prescriptions, and techniques used in prescribed burning beneath the canopy of ponderosa pine stands, and stands of ponderosa pine mixed with western larch, Douglas-fir, and grand fir. Information was derived from 12 districts in two USDA Forest Service Regions and seven National Forests in Montana and Oregon.

Rx for Abies: silvicultural options for diseased firs in Oregon and Washington.

Treesearch

G.M. Filip; C.L. Schmitt

1990-01-01

The true firs are important species in Oregon and Washington forests, but root diseases, stem decays, and dwarf mistletoes cause more mortality, growth loss, and cull in these species than in any other. This paper consolidates research, observations, and management techniques for diseases of true firs, especially the effects of silvicultural activities on root diseases...

Resource use and clonal differences in attack rate by the Douglas-fir seed chalcid, Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), in France

Treesearch

Nancy Rappaport; Alain Roques

1991-01-01

The within-cone distribution of Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), the Douglas-fir seed chalcid, infesting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] cones from north-central France was compared with that in samples from California. Results indicate that the mid-region of cones was more intensively...

Decay losses associated with wounds in commercially thinned true fir stands in northern California.

Treesearch

Paul E. Aho; Gary Fiddler; Gregory M. Filip

1989-01-01

A total of 562 white firs (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) and red firs (A. magnifica A. Murr.) with logging wounds were felled, dissected, and analyzed for infection and decay in 28 commercially thinned stands on the Klamath and Tahoe National Forests in California. On the Klamath National Forest, decay...

Veneer recovery from Douglas-fir logs.

Treesearch

E.H. Clarke; A.C. Knauss

1957-01-01

During 1956, the Pacific Northwest Forest and Range Experiment Station made a series of six veneer-recovery studies in the Douglas-fir region of Oregon and Washington. The net volume of logs involved totaled approximately 777 M board-feet. Purpose of these studies was to determine volume recovery, by grade of veneer, from the four principal grades of Douglas-fir logs...

Financial analysis of pruning coast Douglas-fir.

Treesearch

Roger D. Fight; James M. Cahlll; Thomas D. Fahey; Thomas A. Snellgrove

1987-01-01

Pruning of coast Douglas-fir was evaluated; recent product recovery information for pruned and unpruned logs for both sawn and peeled products was used. Dimensions of pruned and unpruned trees were simulated with the Douglas-fir stand simulator (DFSIM). Results are presented for a range of sites, ages at time of pruning, ages at time of harvest, product prices, and...

What's in your Douglas-fir bark?

Treesearch

M. Gabriela Buamscha; James E. Altland

2008-01-01

Douglas-fir bark is a common waste product of forest industry, and has potential use as a substrate in container nurseries. Douglas-fir bark (DFB) is strongly acidic and contains amounts of phosphorus, potassium, iron, copper and manganese within or above the levels recommended for growing container crops. As the pH of DFB decreases, electrical conductivity and amounts...

A pioneer exotic tree search for the Douglas-fir region.

Treesearch

Roy R. Silen; Donald L. Olson

1992-01-01

After three-quarters of a century of introduction of 152 conifer and broadleaf species, no promising candidate exotic was found for the Douglas-fir region. Growth curves spanning 50 years or longer are figured for many species. Firs, pines, larches, spruces, hemlocks, and cedars originating in northwestern North America had superior growth rates to those from other...

Behavior of ground vegetation under a partially cut stand of Douglas-fir.

Treesearch

Kenneth W. Krueger

1960-01-01

Environmental changes resulting from logging in the Douglas-fir region often create ideal growing conditions for many woody and herbaceous plants. A rapid increase of brush and low vegetation, in turn, can seriously hinder efforts to establish a new stand. Consequently, one argument against partial cutting in Douglas-fir (Pseudotsuga menziesii) is...

Mortality and growth of dwarf mistletoe-infected red and white fir and the efficacy of thinning for reducing associated losses

Treesearch

H. K. Mehl; S. R. Mori; S. J. Frankel; D. M. Rizzo

2013-01-01

In managed forests dominated by true fir (Abies) species, stands are often restocked using understory trees retained during timber harvest, making the effects of dwarf mistletoe (Arceuthobium spp.) infestation on small true fir a concern. This study examined the response of small red (A. magnifica) and...

Dwarf mistletoe in red and white firs in California–23 to 28 years after inoculation

Treesearch

John R. Parmeter Jr.; Robert F. Scharpf

1989-01-01

Spread and buildup of dwarf mistletoe, Arceuthobium abietinum, was studied on inoculated white fir, Abies concolor, and red fir, A. magnifica, in northern California for 23 to 28 years. At the end of these studies (1986), and in the absence of overstory infection, 13 of 23 trees had dwarf mistletoe populations...

Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca) populations. III. Central Idaho

Treesearch

Gerald E. Rehfeldt

1983-01-01

Rehfeldt, Gerald E. 1983. Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca) populations. III. Central Idaho. Canadian Journal of Forest Research. 13: 626-632. Growth, phenology, and cold hardiness of seedlings from 74 populations of Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) from central Idaho were compared in four...

Field performance of stress-laminated highway bridges constructed with glued laminated timber

Treesearch

J.P. Wacker

2004-01-01

This paper summarizes the field performance of three stress-laminated deck timber bridges located in Wisconsin, New York, and Arizona. The deck superstructures of these single-span highway bridges is comprised of full-span glued laminated timber (glulam) beam laminations manufactured with southern pine, hem fir/red maple combination, and/or Douglas fir lumber species....

Growth of white firs defoliated by Modoc budworm in northeastern California

Treesearch

George T. Ferrell

1980-01-01

Open-grown, pole-sized white firs defoliated by Modoc budwonn (Choristoneura viridis) in northeastern California in the years 1959-62 and 1973-75 suffered only minor growth reductions and topkilling compared with the effects that more protracted budworm outbreaks have had elsewhere on their conifer hosts. Growth index analysis indicated that the firs...

A model to estimate noble fir bough weight.

Treesearch

Keith A. Blatner; Roger D. Fight; Nan Vance; Mark Savage; Roger. Chapman

2005-01-01

The harvesting of noble fir (Abies procera) for the production of Christmas wreaths and related products has been a mainstay of the nontimber forest products industry in the Pacific Northwest (PNW) for decades. Although noble fir is the single most important bough product harvested in the PNW, little or no work has been published concerning the...

Efficient Decoding With Steady-State Kalman Filter in Neural Interface Systems

PubMed Central

Malik, Wasim Q.; Truccolo, Wilson; Brown, Emery N.; Hochberg, Leigh R.

2011-01-01

The Kalman filter is commonly used in neural interface systems to decode neural activity and estimate the desired movement kinematics. We analyze a low-complexity Kalman filter implementation in which the filter gain is approximated by its steady-state form, computed offline before real-time decoding commences. We evaluate its performance using human motor cortical spike train data obtained from an intracortical recording array as part of an ongoing pilot clinical trial. We demonstrate that the standard Kalman filter gain converges to within 95% of the steady-state filter gain in 1.5 ± 0.5 s (mean ± s.d.). The difference in the intended movement velocity decoded by the two filters vanishes within 5 s, with a correlation coefficient of 0.99 between the two decoded velocities over the session length. We also find that the steady-state Kalman filter reduces the computational load (algorithm execution time) for decoding the firing rates of 25 ± 3 single units by a factor of 7.0 ± 0.9. We expect that the gain in computational efficiency will be much higher in systems with larger neural ensembles. The steady-state filter can thus provide substantial runtime efficiency at little cost in terms of estimation accuracy. This far more efficient neural decoding approach will facilitate the practical implementation of future large-dimensional, multisignal neural interface systems. PMID:21078582

EXPLAINING THE [C II]157.7 {mu}m DEFICIT IN LUMINOUS INFRARED GALAXIES-FIRST RESULTS FROM A HERSCHEL/PACS STUDY OF THE GOALS SAMPLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz-Santos, T.; Armus, L.; Howell, J. H.

We present the first results of a survey of the [C II]157.7 {mu}m emission line in 241 luminous infrared galaxies (LIRGs) comprising the Great Observatories All-sky LIRG Survey (GOALS) sample, obtained with the PACS instrument on board the Herschel Space Observatory. The [C II] luminosities, L{sub [C{sub II]}}, of the LIRGs in GOALS range from {approx}10{sup 7} to 2 Multiplication-Sign 10{sup 9} L{sub Sun }. We find that LIRGs show a tight correlation of [C II]/FIR with far-IR (FIR) flux density ratios, with a strong negative trend spanning from {approx}10{sup -2} to 10{sup -4}, as the average temperature of dustmore » increases. We find correlations between the [C II]/FIR ratio and the strength of the 9.7 {mu}m silicate absorption feature as well as with the luminosity surface density of the mid-IR emitting region ({Sigma}{sub MIR}), suggesting that warmer, more compact starbursts have substantially smaller [C II]/FIR ratios. Pure star-forming LIRGs have a mean [C II]/FIR {approx} 4 Multiplication-Sign 10{sup -3}, while galaxies with low polycyclic aromatic hydrocarbon (PAH) equivalent widths (EWs), indicative of the presence of active galactic nuclei (AGNs), span the full range in [C II]/FIR. However, we show that even when only pure star-forming galaxies are considered, the [C II]/FIR ratio still drops by an order of magnitude, from 10{sup -2} to 10{sup -3}, with {Sigma}{sub MIR} and {Sigma}{sub IR}, implying that the [C II]157.7 {mu}m luminosity is not a good indicator of the star formation rate (SFR) for most local LIRGs, for it does not scale linearly with the warm dust emission most likely associated to the youngest stars. Moreover, even in LIRGs in which we detect an AGN in the mid-IR, the majority (2/3) of galaxies show [C II]/FIR {>=} 10{sup -3} typical of high 6.2 {mu}m PAH EW sources, suggesting that most AGNs do not contribute significantly to the FIR emission. We provide an empirical relation between the [C II]/FIR and the specific SFR for star-forming LIRGs. Finally, we present predictions for the starburst size based on the observed [C II] and FIR luminosities which should be useful for comparing with results from future surveys of high-redshift galaxies with ALMA and CCAT.« less

Light Microscopy Module Imaging Tested and Demonstrated

NASA Technical Reports Server (NTRS)

Gati, Frank

2004-01-01

The Fluids Integrated Rack (FIR), a facility-class payload, and the Light Microscopy Module (LMM), a subrack payload, are integrated research facilities that will fly in the U.S. Laboratory module, Destiny, aboard the International Space Station. Both facilities are being engineered, designed, and developed at the NASA Glenn Research Center by Northrop Grumman Information Technology. The FIR is a modular, multiuser scientific research facility that is one of two racks that make up the Fluids and Combustion Facility (the other being the Combustion Integrated Rack). The FIR has a large volume dedicated for experimental hardware; easily reconfigurable diagnostics, power, and data systems that allow for unique experiment configurations; and customizable software. The FIR will also provide imagers, light sources, power management and control, command and data handling for facility and experiment hardware, and data processing and storage. The first payload in the FIR will be the LMM. The LMM integrated with the FIR is a remotely controllable, automated, on-orbit microscope subrack facility, with key diagnostic capabilities for meeting science requirements--including video microscopy to observe microscopic phenonema and dynamic interactions, interferometry to make thin-film measurements with nanometer resolution, laser tweezers to manipulate micrometer-sized particles, confocal microscopy to provide enhanced three-dimensional visualization of structures, and spectrophotometry to measure the photonic properties of materials. Vibration disturbances were identified early in the LMM development phase as a high risk for contaminating the science microgravity environment. An integrated FIR-LMM test was conducted in Glenn's Acoustics Test Laboratory to assess mechanical sources of vibration and their impact to microscopic imaging. The primary purpose of the test was to characterize the LMM response at the sample location, the x-y stage within the microscope, to vibration emissions from the FIR and LMM support structures.

DCT based interpolation filter for motion compensation in HEVC

NASA Astrophysics Data System (ADS)

Alshin, Alexander; Alshina, Elena; Park, Jeong Hoon; Han, Woo-Jin

2012-10-01

High Efficiency Video Coding (HEVC) draft standard has a challenging goal to improve coding efficiency twice compare to H.264/AVC. Many aspects of the traditional hybrid coding framework were improved during new standard development. Motion compensated prediction, in particular the interpolation filter, is one area that was improved significantly over H.264/AVC. This paper presents the details of the interpolation filter design of the draft HEVC standard. The coding efficiency improvements over H.264/AVC interpolation filter is studied and experimental results are presented, which show a 4.0% average bitrate reduction for Luma component and 11.3% average bitrate reduction for Chroma component. The coding efficiency gains are significant for some video sequences and can reach up 21.7%.

Severe leaching of calcium ions from fir needles caused by acid fog.

PubMed

Igawa, Manabu; Kase, Toshiyuki; Satake, Kosuke; Okochi, Hiroshi

2002-01-01

We have measured the components of the throughfall under fir trees (Abies firma) in the field around Mt. Oyama, where the forest appears to be declining, for the period 1994-1998. Exposure experiments of a simulated acid fog to fir twigs were performed under field conditions. There was a similarity between the acid response in the field and that in the laboratory. In both studies, the severe leaching of calcium ions from the needle surface was caused by exposure to acid fog. We also applied acid fog to fir seedlings over 1 year and observed a decrease in the growth of the seedlings due to this application in the dormant season. These results suggest that the severe leaching of calcium ions due to acid fog may cause the deficiency of calcium and be responsible for the decline of the fir trees.

Ultrasmall multi-channel resonant-tunneling filter using mode gap of width-tuned photonic-crystal waveguide.

PubMed

Shinya, Akihiko; Mitsugi, Satoshi; Kuramochi, Eiichi; Notomi, Masaya

2005-05-30

We have devised an ultra-small multi-channel drop filter based on a two-port resonant tunneling system in a two-dimensional photonic crystal with a triangular air-hole lattice. This filter does not require careful consideration of the interference process to achieve a high dropping efficiency. First we develop three-port systems based on a two-port resonant tunneling filter. Next we devise a multi-port channel drop filter by cascading these three-port systems. In this paper, we demonstrate a ten-channel drop filter with an 18 mum device size by 2D-FDTD calculation, and a three-port resonant tunneling filter with 65+/- 20 % dropping efficiency by experiment.

Effects of MERV 16 filters and routine work practices on enclosed cabs for reducing respirable dust and DPM exposures in an underground limestone mine

PubMed Central

Noll, J.D.; Cecala, A.B.; J.A.Organiscak; Rider, J.P.

2015-01-01

An effective technique to minimize miners’ respirable dust and diesel exposure on mobile mining equipment is to place mine operators in enclosed cabs with designed filtration and pressurization systems. Many factors affect the performance of these enclosed cab systems, and one of the most significant factors is the effectiveness of the filtration system. High-efficiency particulate air (HEPA)-type filters are typically used because they are highly efficient at capturing all types and sizes of particles, including those in the submicron range such as diesel particulate matter (DPM). However, in laboratory tests, minimum efficiency reporting value (MERV) 16 filters have proven to be highly efficient for capturing DPM and respirable dust. Also, MERV 16 filters can be less restrictive to cab airflow and less expensive than HEPA filters. To verify their effectiveness in the field, MERV 16 filters were used in the enclosed cab filtration system on a face drill and roof bolting mining machine and tested at an underground limestone mine. Test results showed that DPM and respirable dust concentrations were reduced by more than 90% when the cabs were properly sealed. However, when the cab door was opened periodically throughout the shift, the reduction efficiency of the MERV 16 filters was reduced to 80% on average. PMID:26236044

Coarse woody debris in a Southern Appalachian spruce-fir forest of the Great Smoky Mountains National Park

Treesearch

Anita K. Rose; N.S. Nicholas

2008-01-01

Spruce-fir forests in the southern Appalachian Mountains receive high atmospheric nitrogen inputs and have high nitrate levels in soil solution and streamwater. High levels of excess nitrogen have been associated with reduced tree vigor. Additionally, the balsam woolly adelgid (Adelges piceae Ratz.) has killed the majority of endemic Fraser fir [

An examination of the genetic control of Douglas-fir vascular tissue phytochemicals: implications for black bear foraging.

Treesearch

Bruce A. Kimball; G.R. Johnson; Dale L. Nolte; Doreen L. Griffin

1999-01-01

Silvicultural practices can influence black bear (Ursus americanus) foraging preferences for Douglas-fir (Pseudotsuga menziesii) cambial-zone vascular tissues, but little is known about the role of genetics. To study the impact of genetic selection, vascular tissue samples were collected from Douglas-fir trees in six half-sib families from five...

Early survival and height growth of Douglas-fir and lodgepole pine seedlings and variations in site factors following treatment of logging residues.

Treesearch

W. Lopushlnsky; D. Zabowskl; T.D. Anderson

1992-01-01

Logging residues were broadcast burned, piled and burned, removed, or left in place after clearcutting in a high-elevation subalpine fir (Abies lasiocarpa (Hook.) Nutt.) lodgepole pine (Pinus contorta Dougl. ex Loud.) forest in north-central Washington. Survival, height growth and foliar nutrient content of planted Douglas-fir...

Assessing the effects of vegetation types on carbon storage fifteen years after reforestation on a Chinese fir site

Treesearch

Qinkui Wang; Silong Wang; Jianwei Zhang

2009-01-01

Forest ecosystems play a significant role in sequestering carbon (C) in biomass and soils. Plantations established in subtropical China since the 1980s, mainly of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) in monocultures, have proved to be major C sinks. However, information is lacking about whether mixing Chinese fir with broadleaved tree...

Conifer-Ceanothus interactions influence tree growth before and after shrub removal in a forest plantation in the western Cascade Mountains, USA.

Treesearch

Heather E. Erickson; Constance A. Harrington

2006-01-01

Ceanothus velutinous is often considered to be an aggressive competitor with young conifers in the western United States. Using a conifer (noble fir, Pacific silver fir, Douglas-fir, and western hemlock) plantation in western WA where Ceanothus had become established, we assessed how conifer-shrub crown interactions affected...

Probability of infestation and extent of mortality associated with the Douglas-fir beetle in the Colorado Front Range

Treesearch

Jose F. Negron

1998-01-01

Infested and uninfested areas within Douglas fir, Pseudotsuga menziesii Mirb.. Franco, stands affected by the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk. were sampled in the Colorado Front Range, CO. Classification tree models were built to predict probabilities of infestation. Regression trees and linear regression analysis were used to model amount of tree...

How to identify brooms in Douglas-fir caused by dwarf mistletoe.

Treesearch

Robert O. Tinnin; Donald M. Knutson

1985-01-01

Dwarf mistletoe causes obvious brooms in Douglas-fir. The brooms are the easiest means of recognizing the presence of dwarf mistletoe; however, dwarf mistletoe is not the only cause of brooming in Douglas-fir. Therefore, accurate identification of dwarf mistletoe brooms is important. If no evidence of aerial shoots can be found in the brooms, and if the brooms occur...

Within-stand spatial distribution of tree mortality caused by the Douglas-Fir beetle (Coleoptera: Scolytidae)

Treesearch

Jose F. Negron; John A. Anhold; A. Steve Munson

2001-01-01

The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, causes considerable mortality in Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, forests. Within-stand distribution of mortality was examined in affected stands using geostatistical techniques. A 10 x 10 m grid was established in two 4-ha study sites. Live and beetle-killed host basal area was measured at...

A ponderosa pine-grand fir spacing study in central Oregon: results after 10 years.

Treesearch

K.W. Seidel

1985-01-01

The 10-year growth response from an initial spacing study established in a ponderosa pine (Pinus ponderosa Dougl, ex Laws.) and grand fir (Abies grandis (Dougl. ex D. Don) Lindl.) plantation was measured in central Oregon. The study was designed to compare the growth rates of pure pine, pure fir, and a 50-percent mixture of...

Seedfall and seed viability within artificial canopy gaps in a western Washington douglas-fir forest

Treesearch

Warren D. Devine; Timothy B. Harrington

2015-01-01

Seedfall of coast Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) has been studied at the forest edge-clearcut interface and in small canopy gaps, but it has not been evaluated in gap sizes that would be typical of a group-selection method of regeneration. In a mature Douglas-fir forest in the Puget Sound...

Site index curves for white fir in the southwestern United States developed using a guide curve method

Treesearch

Robert L. Mathiasen; William K. Olsen; Carleton B. Edminster

2006-01-01

Site index curves for white fir (Abies concolor) in Arizona, New Mexico, and southwestern Colorado were developed using height-age measurements and an estimated guide curve and 95% confidence intervals for individual predictions. The curves were developed using height-age data for 1,048 white firs from 263 study sites distributed across eight...

White fur lumber recovery at a western Washington sawmill.

Treesearch

E.E. Matson

1957-01-01

In April 1956 a study was made in western Washington to determine grades of lumber that could be expected from silver fir (Abies amabilis) and grand fir (Abies grandis) which are grouped together the lumber industry and sold as white fir. At the sawmill where the study was made, none of the lumber is seasoned and most of it is...

True fir spacing and yield trials—20-year update

Treesearch

Robert O. Curtis

2013-01-01

This report updates data and comparisons from previous reports (Curtis and others 2000, Curtis 2008) on a series of precommercial thinning and yield trials in high-elevation true fir–hemlock stands, using data from the 12 replicates for which 20-year data are now available. The stands were varying mixtures of Pacific silver fir (Abies amabilis (Douglas ex Loudon)...

Natural regeneration of Douglas-fir and associated species using modified clear-cutting systems in the Oregon Cascades.

Treesearch

Jerry F. Franklin

1963-01-01

Clear cutting is the standard harvesting system in old-growth Douglas-fir (Pseudotsuga menziesii) forests in the Pacific Northwest. Usually these clear cuts are in "staggered settings" of 15 to 80 acres with the surrounding stand left uncut to provide seed and serve as a firebreak. However, satisfactory natural regeneration of Douglas-fir...

Flight periodicity of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae: Scolytinae) in Colorado, U.S.A

Treesearch

Jose F. Negron; Willis C. Schaupp; Lee Pederson

2011-01-01

There are about 500 species of bark beetles (Coleoptera: Curculionidae: Scolytinae) in the United States (Wood 1982). A number of them are important disturbance agents in forested ecosystems, occasionally creating large tracts of dead trees. One eruptive species is the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, which utilizes Douglas-fir, Pseudotsuga...

Thinning balsam fir thickets with soil sterilants

Treesearch

Arthur C. Hart

1961-01-01

Under certain conditions that we do not yet fully understand, balsam fir has a tendency to form dense thickets that cause stagnation of growth. This condition is common throughout the spruce-fir region, and it presents the landowner with one of his most perplexing management problems. A typical thicket averaging 15 feet tall may contain 5,000 to 10,000 stems per acre (...

Selected yield tables for plantations and natural stands in Inland Northwest Forests

Treesearch

Albert R. Stage; David L. Renner; Roger C. Chapman

1988-01-01

Yields arrayed by site index and age have been tabulated for plantations of 500 trees per acre, with five thinning regimes, for Douglas-fir, grand fir, and western larch. Yields were also tabulated for naturally regenerated stands of the grand fir-cedar-hemlock ecosystem of the Inland Empire. All yields were estimated with the Prognosis Model for Stand Development,...

Changes in wood product proportions in the Douglas-fir region with respect to size, age, and time.

Treesearch

R.A. Monserud; X. Zhou

2007-01-01

We examine both the variation and the changing proportions of different wood products obtained from trees and logs in the Douglas-fir region of the Northwestern United States. Analyses are based on a large product recovery database covering over 40 years of recovery studies; 13 studies are available for Douglas-fir (Pseudotsuga menziesii (Mirb.)...

Five-year field trials using preservative-treated, second-growth Douglas-fir exposed in ground contact in Australia

Treesearch

Rodney C. De Groot; Douglas M. Crawford; Jack Norton; John Keith

2000-01-01

The durability of preservative-treated stakes of second-growth Coastal Douglas-fir was evaluated in a field plot in northern Queensland, Australia. Results from this field trial indicate that second-growth Douglas-fir can be treated with preservatives to meet Australian standards and will provide long-term durability in adverse environments. Data presented indicate...

Height growth and site index curves for Douglas-fir on dry sites in the Willamette National Forest.

Treesearch

Joseph E Means; Mary E. Helm

1985-01-01

Equations and curves are presented for estimating height and site index of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) on hot, dry sites in the Willamette National Forest in western Oregon. The equations are based on the dissected stems of 27 trees. The curves differ from those previously published for Douglas-fir. Instructions are presented...

Annosus Root Disease in True Firs in Northern and Central California National Forests

Treesearch

G. W. Slaughter; J. R. Parmeter Jr.

1989-01-01

True fir stands in California (3.5 million acres) were surveyed during 1979-1980 to estimate the prevalence of infection by Heterobasidion annosum, and to determine stand and tree characteristics associated with the occurrence of annosus root disease. Approximately 4 percent (1.46 billion board-feet) of the live true firs were estimated to be...

Stand development 18 years after gap creation in a uniform Douglas-fir plantation

Treesearch

Robert O. Curtis; Constance A. Harrington; Leslie C. Brodie

2017-01-01

This report gives early results, 18 years after treatment and 30 years after planting, from a trial of early thinning and gap creation intended to increase biodiversity in a very uniform extensive Douglas-fir plantation. Gap creation has introduced canopy irregularity and a substantial hemlock component into what was originally a very uniform pure Douglas-fir...

The distribution of genets and their nuclear composition reveal the dynamics of establishment and survival of Heterobasidion annosum in white fir stands

Treesearch

M. Garbelotto; F.W. Cobb; T.D. Bruns; W. Otrosina; T. Popenuck; Garey Slaughter

1998-01-01

The structure of Heterobasidiom annosum populations in white fir was studied in 15 mixed conifer sites of central and northern California. Areas selected for the study displayed mortality of white fir trees in enlarging discrete patches (mortality centers). At each site, fungal genotypes were defined by somatic compatibility tests...

Fir sawyer beetle-Siberian fir interaction modeling: resistance of fir stands to insect outbreaks

Treesearch

Tamara M. Ovtchinnikova; Victor V. Kiselev

1991-01-01

Entomological monitoring is part of a total ecological monitoring system. Its purpose is the identification, prognosis, and estimation of forest ecosystem impacts induced by insects. The entomological monitoring of a forest is based on a clear understanding of the role played by insects in forest ecosystems. The patterns of insect population dynamics in space and time...

Source identification of western Oregon Douglas-fir wood cores using mass spectrometry and random forest classification.

PubMed

Finch, Kristen; Espinoza, Edgard; Jones, F Andrew; Cronn, Richard

2017-05-01

We investigated whether wood metabolite profiles from direct analysis in real time (time-of-flight) mass spectrometry (DART-TOFMS) could be used to determine the geographic origin of Douglas-fir wood cores originating from two regions in western Oregon, USA. Three annual ring mass spectra were obtained from 188 adult Douglas-fir trees, and these were analyzed using random forest models to determine whether samples could be classified to geographic origin, growth year, or growth year and geographic origin. Specific wood molecules that contributed to geographic discrimination were identified. Douglas-fir mass spectra could be differentiated into two geographic classes with an accuracy between 70% and 76%. Classification models could not accurately classify sample mass spectra based on growth year. Thirty-two molecules were identified as key for classifying western Oregon Douglas-fir wood cores to geographic origin. DART-TOFMS is capable of detecting minute but regionally informative differences in wood molecules over a small geographic scale, and these differences made it possible to predict the geographic origin of Douglas-fir wood with moderate accuracy. Studies involving DART-TOFMS, alone and in combination with other technologies, will be relevant for identifying the geographic origin of illegally harvested wood.

FIR statistics of paired galaxies

NASA Technical Reports Server (NTRS)

Sulentic, Jack W.

1990-01-01

Much progress has been made in understanding the effects of interaction on galaxies (see reviews in this volume by Heckman and Kennicutt). Evidence for enhanced emission from galaxies in pairs first emerged in the radio (Sulentic 1976) and optical (Larson and Tinsley 1978) domains. Results in the far infrared (FIR) lagged behind until the advent of the Infrared Astronomy Satellite (IRAS). The last five years have seen numerous FIR studies of optical and IR selected samples of interacting galaxies (e.g., Cutri and McAlary 1985; Joseph and Wright 1985; Kennicutt et al. 1987; Haynes and Herter 1988). Despite all of this work, there are still contradictory ideas about the level and, even, the reality of an FIR enhancement in interacting galaxies. Much of the confusion originates in differences between the galaxy samples that were studied (i.e., optical morphology and redshift coverage). Here, the authors report on a study of the FIR detection properties for a large sample of interacting galaxies and a matching control sample. They focus on the distance independent detection fraction (DF) statistics of the sample. The results prove useful in interpreting the previously published work. A clarification of the phenomenology provides valuable clues about the physics of the FIR enhancement in galaxies.

Space Shuttle Main Engine High Pressure Fuel Turbopump Turbine Blade Cracking

NASA Technical Reports Server (NTRS)

Lee, Henry

1988-01-01

The analytical results from two-dimensional (2D) and three-dimensional (3D) finite element model investigations into the cracking of Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) first- and second-stage turbine blades are presented. Specifically, the initiation causes for transverse cracks on the pressure side of the firststage blade fir tree lobes and face/corner cracks on the downstream fir tree face of the second-state blade are evaluated. Because the blade material, MAR-M-246 Hf (DS), is highly susceptible to hydrogen embrittlement in the -100 F to 400 F thermal environment, a steady-state condition (full power level = 109 percent) rather than a start-up or shut-down transient was considered to be the most likely candidate for generating a high-strain state in the fir tree areas. Results of the analyses yielded strain levels on both first- and second-stage blade fir tree regions that are of a magnitude to cause hydrogen assisted low cycle fatigue cracking. Also evident from the analysis is that a positive margin against fir tree cracking exists for the planned design modifications, which include shot peening for both first- and second-stage blade fir tree areas.

Fabrication of an anti-viral air filter with SiO₂-Ag nanoparticles and performance evaluation in a continuous airflow condition.

PubMed

Joe, Yun Haeng; Woo, Kyoungja; Hwang, Jungho

2014-09-15

In this study, SiO2 nanoparticles surface coated with Ag nanoparticles (SA particles) were fabricated to coat a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter were evaluated against aerosolized bacteriophage MS2 in a continuous air flow condition. A mathematical approach was developed to measure the anti-viral ability of the filter with various virus deposition times. Moreover, two quality factors based on the anti-viral ability of the filter, and a traditional quality factor based on filtration efficiency, were calculated. The filtration efficiency and pressure drop increased with decreasing media velocity and with increasing SA particle coating level. The anti-viral efficiency also increased with increasing SA particle coating level, and decreased by with increasing virus deposition time. Consequently, SA particle coating on a filter does not have significant effects on filtration quality, and there is an optimal coating level to produce the highest anti-viral quality. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectrum splitting metrics and effect of filter characteristics on photovoltaic system performance.

PubMed

Russo, Juan M; Zhang, Deming; Gordon, Michael; Vorndran, Shelby; Wu, Yuechen; Kostuk, Raymond K

2014-03-10

During the past few years there has been a significant interest in spectrum splitting systems to increase the overall efficiency of photovoltaic solar energy systems. However, methods for comparing the performance of spectrum splitting systems and the effects of optical spectral filter design on system performance are not well developed. This paper addresses these two areas. The system conversion efficiency is examined in detail and the role of optical spectral filters with respect to the efficiency is developed. A new metric termed the Improvement over Best Bandgap is defined which expresses the efficiency gain of the spectrum splitting system with respect to a similar system that contains the highest constituent single bandgap photovoltaic cell. This parameter indicates the benefit of using the more complex spectrum splitting system with respect to a single bandgap photovoltaic system. Metrics are also provided to assess the performance of experimental spectral filters in different spectrum splitting configurations. The paper concludes by using the methodology to evaluate spectrum splitting systems with different filter configurations and indicates the overall efficiency improvement that is possible with ideal and experimental designs.

Performance of biomorphic Silicon Carbide as particulate filter in diesel boilers.

PubMed

Orihuela, M Pilar; Gómez-Martín, Aurora; Becerra, José A; Chacartegui, Ricardo; Ramírez-Rico, Joaquín

2017-12-01

Biomorphic Silicon Carbide (bioSiC) is a novel porous ceramic material with excellent mechanical and thermal properties. Previous studies have demonstrated that it may be a good candidate for its use as particle filter media of exhaust gases at medium or high temperature. In order to determine the filtration efficiency of biomorphic Silicon Carbide, and its adequacy as substrate for diesel particulate filters, different bioSiC-samples have been tested in the flue gases of a diesel boiler. For this purpose, an experimental facility to extract a fraction of the boiler exhaust flow and filter it under controlled conditions has been designed and built. Several filter samples with different microstructures, obtained from different precursors, have been tested in this bench. The experimental campaign was focused on the measurement of the number and size of particles before and after placing the samples. Results show that the initial efficiency of filters made from natural precursors is severely determined by the cutting direction and associated microstructure. In biomorphic Silicon Carbide derived from radially cut wood, the initial efficiency of the filter is higher than 95%. Nevertheless, when the cut of the wood is axial, the efficiency depends on the pore size and the permeability, reaching in some cases values in the range 70-90%. In this case, the presence of macropores in some of the samples reduces their efficiency as particle traps. In continuous operation, the accumulation of particles within the porous media leads to the formation of a soot cake, which improves the efficiency except in the case when extra-large pores exist. For all the samples, after a few operation cycles, capture efficiency was higher than 95%. These experimental results show the potential for developing filters for diesel boilers based on biomorphic Silicon Carbide. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crew size affects fire fighting efficiency: A progress report on time studies of the fire fighting job.

Treesearch

Donald N. Matthews

1940-01-01

Fire fighting is still largely a hand-work job in the heavy cover and fuel conditions and rugged topography of the Douglas fir region, in spite of recent advances that have been made in %he use of machinery. Controlling a fire in this region requires immense amounts of work per unit of fire perimeter, so that large numbers of men are required to attack all but the...

Micron-pore-sized metallic filter tube membranes for filtration of particulates and water purification.

PubMed

Phelps, T J; Palumbo, A V; Bischoff, B L; Miller, C J; Fagan, L A; McNeilly, M S; Judkins, R R

2008-07-01

Robust filtering techniques capable of efficiently removing particulates and biological agents from water or air suffer from plugging, poor rejuvenation, low permeance, and high backpressure. Operational characteristics of pressure-driven separations are in part controlled by the membrane pore size, charge of particulates, transmembrane pressure and the requirement for sufficient water flux to overcome fouling. With long term use filters decline in permeance due to filter-cake plugging of pores, fouling, or filter deterioration. Though metallic filter tube development at ORNL has focused almost exclusively on gas separations, a small study examined the applicability of these membranes for tangential filtering of aqueous suspensions of bacterial-sized particles. A mixture of fluorescent polystyrene microspheres ranging in size from 0.5 to 6 microm in diameter simulated microorganisms in filtration studies. Compared to a commercial filter, the ORNL 0.6 microm filter averaged approximately 10-fold greater filtration efficiency of the small particles, several-fold greater permeance after considerable use and it returned to approximately 85% of the initial flow upon backflushing versus 30% for the commercial filter. After filtering several liters of the particle-containing suspension, the ORNL composite filter still exhibited greater than 50% of its initial permeance while the commercial filter had decreased to less than 20%. When considering a greater filtration efficiency, greater permeance per unit mass, greater percentage of rejuvenation upon backflushing (up to 3-fold), and likely greater performance with extended use, the ORNL 0.6 microm filters can potentially outperform the commercial filter by factors of 100-1,000 fold.

An Efficient Index Dissemination in Unstructured Peer-to-Peer Networks

NASA Astrophysics Data System (ADS)

Takahashi, Yusuke; Izumi, Taisuke; Kakugawa, Hirotsugu; Masuzawa, Toshimitsu

Using Bloom filters is one of the most popular and efficient lookup methods in P2P networks. A Bloom filter is a representation of data item indices, which achieves small memory requirement by allowing one-sided errors (false positive). In the lookup scheme besed on the Bloom filter, each peer disseminates a Bloom filter representing indices of the data items it owns in advance. Using the information of disseminated Bloom filters as a clue, each query can find a short path to its destination. In this paper, we propose an efficient extension of the Bloom filter, called a Deterministic Decay Bloom Filter (DDBF) and an index dissemination method based on it. While the index dissemination based on a standard Bloom filter suffers performance degradation by containing information of too many data items when its dissemination radius is large, the DDBF can circumvent such degradation by limiting information according to the distance between the filter holder and the items holders, i. e., a DDBF contains less information for faraway items and more information for nearby items. Interestingly, the construction of DDBFs requires no extra cost above that of standard filters. We also show by simulation that our method can achieve better lookup performance than existing ones.

Development of a filter to prevent infections with spore-forming bacteria in injecting drug users.

PubMed

Alhusein, Nour; Scott, Jenny; Kasprzyk-Hordern, Barbara; Bolhuis, Albert

2016-12-01

In heroin injectors, there have been a number of outbreaks caused by spore-forming bacteria, causing serious infections such as anthrax or botulism. These are, most likely, caused by injecting contaminated heroin, and our aim was to develop a filter that efficiently removes these bacteria and is also likely to be acceptable for use by people who inject drugs (i.e. quick, simple and not spoil the hit). A prototype filter was designed and different filter membranes were tested to assess the volume of liquid retained, filtration time and efficiency of the filter at removing bacterial spores. Binding of active ingredients of heroin to different types of membrane filters was determined using a highly sensitive analytical chemistry technique. Heroin samples that were tested contained up to 580 bacteria per gramme, with the majority being Bacillus spp., which are spore-forming soil bacteria. To remove these bacteria, a prototype filter was designed to fit insulin-type syringes, which are commonly used by people who inject drugs (PWIDs). Efficient filtration of heroin samples was achieved by combining a prefilter to remove particles and a 0.22 μm filter to remove bacterial spores. The most suitable membrane was polyethersulfone (PES). This membrane had the shortest filtration time while efficiently removing bacterial spores. No or negligible amounts of active ingredients in heroin were retained by the PES membrane. This study successfully produced a prototype filter designed to filter bacterial spores from heroin samples. Scaled up production could produce an effective harm reduction tool, especially during outbreaks such as occurred in Europe in 2009/10 and 2012.

[Research on removal efficiency of Cd (II)-bearing wastewater by sulfate-reducing biological filter].

PubMed

Wu, Xuan; Tan, Ke-Yan; Hu, Xi-Jia; Gu, Yun; Yang, Hong

2014-04-01

At the temperature of 18.0-22.3 degrees C, biological carriers were produce from pure SRB and zeolite by the embedding immobilized method, and a sulfate-reducing biological filter filled with filter carriers was built to treat cadmium-containing wastewater. Experimental research on removal efficiency of Cd2+, COD and SO4(2-) in wastewater by the biological filter was carried out after SRB domestication. Results show that cadmium can be removed satisfactorily from wastewater using SRB by the biological filter filled with sulfate-reducing bacteria. When the filtration rate was 0.4 m x h(-1) and the cadmium concentration in wastewater was not more than 15 mg x L(-1), the processing efficiency was the best. In the formal running period, the removal rates of Cd2+, COD and SO4(2-) by the biological filter were more than 99%, 75% and 50%. The effluent Cd2+ concentration was less than 0.1 mg x L(-1), which could meet the cadmium emission requirements in the wastewater quality standards for discharge to municipal sewers (CJ 343-2010). The removal of Cd2+, COD and SO4(2-) by biological filter mainly occurs in the top 60 cm of the filter bed during stable operation. When the filtration rate was less than 0.6 m x h(-1), Cd(2+) can be removed by the biological filter with high efficiency and stability.

An efficient implementation of a high-order filter for a cubed-sphere spectral element model

NASA Astrophysics Data System (ADS)

Kang, Hyun-Gyu; Cheong, Hyeong-Bin

2017-03-01

A parallel-scalable, isotropic, scale-selective spatial filter was developed for the cubed-sphere spectral element model on the sphere. The filter equation is a high-order elliptic (Helmholtz) equation based on the spherical Laplacian operator, which is transformed into cubed-sphere local coordinates. The Laplacian operator is discretized on the computational domain, i.e., on each cell, by the spectral element method with Gauss-Lobatto Lagrange interpolating polynomials (GLLIPs) as the orthogonal basis functions. On the global domain, the discrete filter equation yielded a linear system represented by a highly sparse matrix. The density of this matrix increases quadratically (linearly) with the order of GLLIP (order of the filter), and the linear system is solved in only O (Ng) operations, where Ng is the total number of grid points. The solution, obtained by a row reduction method, demonstrated the typical accuracy and convergence rate of the cubed-sphere spectral element method. To achieve computational efficiency on parallel computers, the linear system was treated by an inverse matrix method (a sparse matrix-vector multiplication). The density of the inverse matrix was lowered to only a few times of the original sparse matrix without degrading the accuracy of the solution. For better computational efficiency, a local-domain high-order filter was introduced: The filter equation is applied to multiple cells, and then the central cell was only used to reconstruct the filtered field. The parallel efficiency of applying the inverse matrix method to the global- and local-domain filter was evaluated by the scalability on a distributed-memory parallel computer. The scale-selective performance of the filter was demonstrated on Earth topography. The usefulness of the filter as a hyper-viscosity for the vorticity equation was also demonstrated.

Six-year growth of Douglas-fir saplings after manual or herbicide release from coastal shrub competition.

Treesearch

William I. Stein

1999-01-01

Survival and growth of planted Douglas-fir (Pseudotsuga menziesii) saplings and associated shrubs were observed for 6 years after seven release treatments had been applied, side by, side on four areas in the Coast Range of Oregon. Four times as much Douglas-fir volume as in the control was produced by one manual cutting of shrubs, which also...

Foliage Consumption by 6th-Instar Spruce Budworm Larvae, Choristoneura fumiferana (Clem.) Feeding on Balsam Fir and White Spruce

Treesearch

A.W.  Thomas

1983-01-01

Female larvae ate about 1.5 times as much foliage as male larvae. Larvae ate significantly less old foliage than current foliage. Balsam fir current foliage was eaten in greater quantitities than any other foliage; white spruce current and balsam fir old were eaten to the same extent; very little old white spruce was eaten.

Stereo photo series for quantifying forest residues in the Douglas-Fir-Hemlock type of the Willamette National Forest.

Treesearch

Roger D. Ottmar; Colin C. Hardy; Robert E. Vihnanek

1990-01-01

A series of stereo photographs displays a range of residue loadings for harvested units in the Douglas-fir-western hemlock cover type common to the Willamette National Forest. Postburn residue levels are also represented for the Douglas-fir-western hemlock types. Information with each photo includes measured quadratic means and weights for various size classes, woody...

White fir stands killed by tussock moth...70-mm. color photography aids detection

Treesearch

Steven L. Wert; Boyd E. Wickman

1968-01-01

The use of large-scale 70 mm. aerial photography proved to be an effective technique for detecting trees in white fir stands killed by Douglas-fir tussock moth in northeastern California. Correlations between ground and photo estimates of dead trees were high. But correlations between such estimates of lesser degrees of tree damage--thin tops and topkill--were much...

Genetic diversity and seed production in Santa Lucia fir (Abies bracteata),a relict of the Miocene broadleaved evergreen forest

Treesearch

F. Thomas Ledig; Paul D. Hodgskiss; David R. Johnson

2006-01-01

Santa Lucia fir (Abies bracteata), is a unique fir, the sole member of the subgenus Pseudotorreya. It is a relict of the Miocene broadleaved evergreen sclerophyll forest, and is now restricted to a highly fragmented range in the Santa Lucia Mountains of central coastal California. Expected heterozygosity for 30 isozyme loci in 18 enzyme systems...

Optimal uneven-aged stocking guides: an application to spruce-fir stands in New England

Treesearch

Jeffrey H. Gove; Mark J. Ducey

2014-01-01

Management guides for uneven-aged forest stands periodically need to be revisited and updated based on new information and methods. The current silvicultural guide for uneven-aged spruce-fir management in Maine and the northeast (Frank, R.M. and Bjorkbom, J.C. 1973 A silvicultural guide for spruce-fir in the northeast. General Technical Report NE-6, Forest Service. U.S...