Retrieval of aerosol optical depth over bare soil surfaces using time series of MODIS imagery

NASA Astrophysics Data System (ADS)

Yuan, Zhengwu; Yuan, Ranyin; Zhong, Bo

2014-11-01

Aerosol Optical Depth (AOD) is one of the key parameters which can not only reflect the characterization of atmospheric turbidity, but also identify the climate effects of aerosol. The current MODIS aerosol estimation algorithm over land is based on the "dark-target" approach which works only over densely vegetated surfaces. For non-densely vegetated surfaces (such as snow/ice, desert, and bare soil surfaces), this method will be failed. In this study, we develop an algorithm to derive AOD over the bare soil surfaces. Firstly, this method uses the time series of MODIS imagery to detect the " clearest" observations during the non-growing season in multiple years for each pixel. Secondly, the "clearest" observations after suitable atmospheric correction are used to fit the bare soil's bidirectional reflectance distribution function (BRDF) using Kernel model. As long as the bare soil's BRDF is established, the surface reflectance of "hazy" observations can be simulated. Eventually, the AOD over the bare soil surfaces are derived. Preliminary validation results by comparing with the ground measurements from AERONET at Xianghe sites show a good agreement.

Fabrication and characterization of SPR chips with the modified bovine serum albumin

NASA Astrophysics Data System (ADS)

Chen, Xing; Zhang, Lu-lu; Cui, Da-fu

2016-03-01

A facile surface plasmon resonance (SPR) chip is developed for small molecule determination and analysis. The SPR chip was prepared based on a self assembling principle, in which the modified bovine serum albumin (BSA) was directly self-assembled onto the bare gold surface. The surface morphology of the chip with the modified BSA was investigated by atomic force microscopy (AFM) and its optical properties were characterized. The surface binding capacity of the bare facile SPR chip with a uniform morphology is 8 times of that of the bare control SPR chip. Based on the experiments of immune reaction between cortisol antibody and cortisol derivative, the sensitivity of the facile SPR chip with the modified BSA is much higher than that of the control SPR chip with the un-modified BSA. The facile SPR chip has been successfully used to detect small molecules. The lowest detection limit is 5 ng/mL with a linear range of 5—100 ng/mL for cortisol analysis. The novel facile SPR chip can also be applied to detect other small molecules.

Variable effects of plant colonization on black slate uptake into microbial PLFAs

NASA Astrophysics Data System (ADS)

Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

2013-04-01

Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake, respectively. Our results prove that black slate degradation followed by carbon uptake takes place in situ. Results imply that plant colonization might additionally affect this process. Slight colonization with few plants increased slate derived carbon uptake in PLFAs of Gram-positive bacteria. Evidently, Gram-positive bacteria represented by specific PLFAs from the greened site held more ancient carbon than from the bare site. In contrast, no black slate derived carbon was used by microorganisms at the forested site with 2-3 times greater carbon content. Results suggest that the use of ancient slate derived carbon dominates mainly in early stages of microbial colonization of surfaces and that with increasing ecosystem development recycling of plant derived carbon dominates.

Irrigation scheduling, freeze warning and soil salinity detecting. [in Cameron County Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Correlations of multispectral scanner (MSS) digital data differences between vegetated and bare soil areas with salinity levels from the eight saline areas using MSS bands seven and ten in the infrared region were significant. Correlations were derived for Cameron County, Texas. Detection of saline soils may be possible, using either film density readings or multispectral scanner data, when the lower reflectance of vegetation on highly saline soil and the higher reflectance of vegetation on lower saline soil are considered by using film on MSS contrasts between vegetation and bare soil.

PO calculation for reduction in radar cross section of hypersonic targets using RAM

NASA Astrophysics Data System (ADS)

Liu, Song-hua; Guo, Li-xin; Pan, Wei-tao; Chen, Wei; Xiao, Yi-fan

2018-06-01

The radar cross section (RCS) reduction of hypersonic targets by radar absorbing materials (RAM) coating under different reentry cases is analyzed in the C and X bands frequency range normally used for radar detection. The physical optics method is extended to both the inhomogeneous plasma sheath and RAM layer present simultaneously. The simulation results show that the absorbing coating can reduce the RCS of the plasma cloaking system and its effectiveness is related to the maximum plasma frequency. Moreover, the amount of the RCS decrease, its maxima, and the corresponding optimal RAM thickness depend on the non-uniformity and parameters of the plasma sheath. In addition, the backward RCS of the flight vehicle shrouded by plasma shielding and man-made absorber is calculated and compared to the bare cone.

Multi-directional emission and detection of spin waves propagating in yttrium iron garnet with wavelengths down to about 100 nm

NASA Astrophysics Data System (ADS)

Maendl, Stefan; Grundler, Dirk

2018-05-01

We performed broadband spin-wave spectroscopy on 200 nm thick yttrium iron garnet containing arrays of partially embedded magnetic nanodisks. Using integrated coplanar waveguides (CPWs), we studied the excitation and transmission of spin waves depending on the presence of nanomagnet arrays of different lateral extensions. By means of the grating coupler effect, we excited spin waves propagating in multiple lateral directions with wavelengths down to 111 nm. They exhibited group velocities of up to 1 km/s. Detection of such short-wavelength spin waves was possible only in symmetrically designed emitter/detector configurations, not with a bare CPW. We report spin waves propagating between grating couplers under oblique angles exhibiting a wave vector component parallel to the CPW. The effective propagation distance amounted to about 80 μm. Such transmission signals were not addressed before and substantiate the versatility of the grating coupler effect for implementing nanomagnonic circuits.

Chemically-modified graphenes for oxidation of DNA bases: analytical parameters.

PubMed

Goh, Madeline Shuhua; Bonanni, Alessandra; Ambrosi, Adriano; Sofer, Zdeněk; Pumera, Martin

2011-11-21

We studied the electroanalytical performances of chemically-modified graphenes (CMGs) containing different defect densities and amounts of oxygen-containing groups, namely graphite oxide (GPO), graphene oxide (GO), thermally reduced graphene oxide (TR-GO) and electrochemically reduced graphene oxide (ER-GO) by comparing the sensitivity, selectivity, linearity and repeatability towards the oxidation of DNA bases. We have observed that for differential pulse voltammetric (DPV) detection of adenine and cytosine, all CMGs showed enhanced sensitivity to oxidation, while for guanine and thymine, ER-GO and TR-GO exhibited much improved sensitivity over bare glassy carbon (GC) as well as over GPO and GO. There is also significant selectivity enhancement when using GPO for adenine and TR-GO for thymine. Our results have uncovered that the differences in surface functionalities, structure and defects of various CMGs largely influence their electrochemical behaviour in detecting the oxidation of DNA bases. The findings in this report will provide a useful guide for the future development of label-free electrochemical devices for DNA analysis.

Effect of skin-transmitted vibration enhancement on vibrotactile perception.

PubMed

Tanaka, Yoshihiro; Ueda, Yuichiro; Sano, Akihito

2015-06-01

Vibration on skin elicited by the mechanical interaction of touch between the skin and an object propagates to skin far from the point of contact. This paper investigates the effect of skin-transmitted vibration on vibrotactile perception. To enhance the transmission of high-frequency vibration on the skin, stiff tape was attached to the skin so that the tape covered the bottom surface of the index finger from the periphery of the distal interphalangeal joint to the metacarpophalangeal joint. Two psychophysical experiments with high-frequency vibrotactile stimuli of 250 Hz were conducted. In the psychophysical experiments, discrimination and detection thresholds were estimated and compared between conditions of the presence or the absence of the tape (normal bare finger). A method of limits was applied for the detection threshold estimation, and the discrimination task using a reference stimulus and six test stimuli with different amplitudes was applied for the discrimination threshold estimation. The stimulation was given to bare fingertips of participants. Result showed that the detection threshold was enhanced by attaching the tape, and the discrimination threshold enhancement by attaching the tape was confirmed for participants who have relatively large discrimination threshold under normal bare finger. Then, skin-transmitted vibration was measured with an accelerometer with the psychophysical experiments. Result showed that the skin-transmitted vibration when the tape was attached to the skin was larger than that when normal bare skin. There is a correlation between the increase in skin-transmitted vibration and the enhancement of the discrimination threshold.

Nanoscale Au-In alloy-oxide core-shell particles as electrocatalysts for efficient hydroquinone detection

DOE PAGES

Sutter, E.; Tong, X.; Medina-Plaza, C.; ...

2015-10-09

The presence of hydroquinone (HQ), a phenol ubiquitous in nature and widely used in industry, needs to be monitored because of its toxicity to the environment. Here we demonstrate efficient detection of HQ using simple, fast, and noninvasive electrochemical measurements on indium tin oxide (ITO) electrodes modified with nanoparticles comprising bimetallic Au–In cores and mixed Au–In oxide shells. Whereas bare ITO electrodes show very low activity for the detection of HQ, their modification with Au–In core–shell nanoparticles induces a pronounced shift of the oxidation peak to lower potentials, i.e., facilitated oxidation. The response of the different electrodes was correlated withmore » the initial composition of the bimetallic nanoparticle cores, which in turn determined the amount of Au and In stabilized on the surface of the amorphous Au–In oxide shells available for the electrochemical reaction. While adding core–shell nanostructures with different compositions of the alloy core facilitates the electrocatalytic (reduction-) oxidation of HQ, the activity is highest for particles with AuIn cores (i.e., a Au:In ratio of 1). This optimal system is found to follow a single pathway, the two-electron oxidation of the quinone–hydroquinone couple, which gives rise to high oxidation peaks and is most effective in facilitating the electrode-to-analyte charge transfer and thus detection. The limits of detection (LOD) decreased when increasing the amount of Au exposed on the surface of the amorphous Au–In oxide shells. As a result the LODs were in the range of 10 –5 – 10 –6 M and were lower than those obtained using bulk Au.« less

Application Level Processing for Long-Lived and Information Rich Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Wilkins, R.; Gaura, E.; Brusey, J.

2013-12-01

A primary design goal in Wireless Sensor Networks (WSNs) is to ensure the longest possible node lifetime with the available power budget while still meeting application requirements. Since radio transmissions often consume the most power in WSN devices, it follows that a node should aim to maximise its lifetime by transmitting only the data or information required to enable the motivating application. Full raw data streams are often not required since summaries of data are sufficient to meet application needs summaries are often performed at a central point after collection). When raw data is not a requirement, it makes sense to perform as much application-specific processing on-node as possible to minimise the amount of transmissions a node must make. For example, in home environment monitoring, the amount of time a room spends within an acceptable temperature range is more important than the raw stream of temperature measurements. The work presents Bare Necessities (BN) which implements the calculation of application-specific summaries on-node. In the case of knowing the amount time a room spends within an acceptable temperature range, BN encodes the raw signal as a distribution over bins (e.g. a bin might comprise temperatures between 18 °C and 22 °C). BN conserves power by only transmitting when changes to the distribution occur only sending the bare necessities of information the end user is interested in (thus the algorithm name). In the case of home monitoring it has been shown that BN can lead to a packet transmission reduction of 99.98%, increasing a nodes lifetime by a factor of 14 when compared to sense-and-send nodes. A summary of the Bare Necessities process at the node.

Role of clothing in both accelerating and impeding dermal absorption of airborne SVOCs.

PubMed

Morrison, Glenn C; Weschler, Charles J; Bekö, Gabriel; Koch, Holger M; Salthammer, Tunga; Schripp, Tobias; Toftum, Jørn; Clausen, Geo

2016-01-01

To assess the influence of clothing on dermal uptake of semi-volatile organic compounds (SVOCs), we measured uptake of selected airborne phthalates for an individual wearing clean clothes or air-exposed clothes and compared these results with dermal uptake for bare-skinned individuals under otherwise identical experimental conditions. Using a breathing hood to isolate dermal from inhalation uptake, we measured urinary metabolites of diethylphthalate (DEP) and di-n-butylphthalate (DnBP) from an individual exposed to known concentrations of these compounds for 6 h in an experimental chamber. The individual wore either clean (fresh) cotton clothes or cotton clothes that had been exposed to the same chamber air concentrations for 9 days. For a 6-h exposure, the net amounts of DEP and DnBP absorbed when wearing fresh clothes were, respectively, 0.017 and 0.007 μg/kg/(μg/m(3)); for exposed clothes the results were 0.178 and 0.261 μg/kg/(μg/m(3)), respectively (values normalized by air concentration and body mass). When compared against the average results for bare-skinned participants, clean clothes were protective, whereas exposed clothes increased dermal uptake for DEP and DnBP by factors of 3.3 and 6.5, respectively. Even for non-occupational environments, wearing clothing that has adsorbed/absorbed indoor air pollutants can increase dermal uptake of SVOCs by substantial amounts relative to bare skin.

Gene Deletion in Barley Mediated by LTR-retrotransposon BARE

PubMed Central

Shang, Yi; Yang, Fei; Schulman, Alan H.; Zhu, Jinghuan; Jia, Yong; Wang, Junmei; Zhang, Xiao-Qi; Jia, Qiaojun; Hua, Wei; Yang, Jianming; Li, Chengdao

2017-01-01

A poly-row branched spike (prbs) barley mutant was obtained from soaking a two-rowed barley inflorescence in a solution of maize genomic DNA. Positional cloning and sequencing demonstrated that the prbs mutant resulted from a 28 kb deletion including the inflorescence architecture gene HvRA2. Sequence annotation revealed that the HvRA2 gene is flanked by two LTR (long terminal repeat) retrotransposons (BARE) sharing 89% sequence identity. A recombination between the integrase (IN) gene regions of the two BARE copies resulted in the formation of an intact BARE and loss of HvRA2. No maize DNA was detected in the recombination region although the flanking sequences of HvRA2 gene showed over 73% of sequence identity with repetitive sequences on 10 maize chromosomes. It is still unknown whether the interaction of retrotransposons between barley and maize has resulted in the recombination observed in the present study. PMID:28252053

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanée, 21-France).

PubMed

Landry, David; Dousset, Sylvie; Fournier, Jean-Claude; Andreux, Francis

2005-11-01

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide.

Grazing management effects on sediment, phosphorus, and pathogen loading of streams in cool-season grass pastures.

PubMed

Schwarte, Kirk A; Russell, James R; Kovar, John L; Morrical, Daniel G; Ensley, Steven M; Yoon, Kyoung-Jin; Cornick, Nancy A; Cho, Yong Il

2011-01-01

Erosion and runoff from pastures may lead to degradation of surface water. A 2-yr grazing study was conducted to quantify the effects of grazing management on sediment, phosphorus (P), and pathogen loading of streams in cool-season grass pastures. Six adjoining 12.1-ha pastures bisected by a stream in central Iowa were divided into three treatments: continuous stocking with unrestricted stream access (CSU), continuous stocking with restricted stream access (CSR), and rotational stocking (RS). Rainfall simulations on stream banks resulted in greater ( < 0.10) proportions of applied precipitation and amounts of sediment and P transported in runoff from bare sites than from vegetated sites across grazing treatments. Similar differences were observed comparing vegetated sites in CSU and RS pastures with vegetated sites in CSR pastures. Bovine enterovirus was shed by an average of 24.3% of cows during the study period and was collected in the runoff of 8.3 and 16.7% of runoff simulations on bare sites in CSU pastures in June and October of 2008, respectively, and from 8.3% of runoff simulations on vegetated sites in CSU pastures in April 2009. Fecal pathogens (bovine coronavirus [BCV], bovine rotavirus group A, and O157:H7) shed or detected in runoff were almost nonexistent; only BCV was detected in feces of one cow in August of 2008. Erosion of cut-banks was the greatest contributor of sediment and P loading to the stream; contributions from surface runoff and grazing animals were considerably less and were minimized by grazing management practices that reduced congregation of cattle by pasture streams. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

[Gender reassignment surgery in transsexualism from a urological perspective].

PubMed

Althaus, Peter

2006-01-01

The surgical treatment of transsexual patients can barely be called satisfactory. Poor quality surgical operations cause the life of the patients so treated to become unhappy. Transsexual surgery should only be performed in centres where a sufficient amount of experience has been gathered, and--what is equally important--an understanding amounting to affinity exists with the problem of transsexualism. There is a great need for better treatment methods. The present situation is far from being optimal.

The use of forward looking infrared to locate bird carcasses in agricultural areas

USGS Publications Warehouse

Healy, J.M.

2001-01-01

Helicopter-mounted Forward Looking Infrared has mainly been used for large animal censuses. I examined the use of this instrument in locating bird carcasses in agricultural fields to improve current carcass searching techniques. Mallard (Arias platyrhynchos) and northern bobwhite quail (Colinus virginianus) carcasses were measured with an infrared thermometer immediately following death and for 5 consecutive nights to determine the optimal time for detection. Preliminary flights were conducted to design a protocol that was used in test flights. Bird species (mallard versus quail) and cover type (bare ground versus short grass) were compared in the flights. Carcasses were recovered with the aid of Global Positioning Systems. Carcasses remained above ambient ground temperatures for all or part of night 1. Quail carcass temperatures decreased faster than mallard carcasses. In warmer weather, carcass temperatures increased 3-5 nights following death. In colder weather, carcasses were 1-2 C cooler than the ground after the first night. Mallard and quail carcasses were both detected on bare ground and short grass cover types with Forward Looking Infrared. The carcass recovery rates were 40% arid 30% on bare ground and short grass, respectively. There were no significant differences in detection for species or cover type. In warmer weather, carcasses could be detected for several hours following death and again 3-5 nights after death. Carcasses may be detected as objects cooler than the ground in colder weather. Forward Looking Infrared was successful in detecting mallard and quail carcasses. Further research should evaluate improved mapping techniques to enhance carcass recovery.

Polygalacturonase Gene Expression in Rutgers, rin, nor, and Nr Tomato Fruits 1

PubMed Central

DellaPenna, Dean; Kates, David S.; Bennett, Alan B.

1987-01-01

Polygalacturonase (PG) gene expression was studied in normally ripening tomato fruit (Lycopersicon esculentum Mill, cv Rutgers) and in three ripening-impaired mutants, rin, nor, and Nr. Normal and mutant fruit of identical chronological age were analyzed at 41, 49, and 62 days after pollination. These stages corresponded to mature-green, ripe, and overripe, respectively, for Rutgers. The amount of PG mRNA in Rutgers was highest at 49 days and accounted for 2.3% of the total mRNA mass but at 62 days had decreased to 0.004% of the total mRNA mass. In Nr, the amount of PG mRNA steadily increased between 41 and 62 days after pollination, reaching a maximum level of 0.5% of the total mRNA mass. The mutant nor exhibited barely detectable levels of PG mRNA at all stages tested. Surprisingly, PG mRNA, comprising approximately 0.06% of the mRNA mass, was detected in 49 day rin fruit. This mRNA accumulation occurred in the absence of elevated ethylene production by the fruit and resulted in the synthesis of enzymically active PG I. The different patterns of PG mRNA accumulation in the three mutants suggests that distinct molecular mechanisms contribute to reduced PG expression in each ripening-impaired mutant. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:16665727

The visible signal responsible for proton therapy dosimetry using bare optical fibers is not Čerenkov radiation.

PubMed

Darafsheh, Arash; Taleei, Reza; Kassaee, Alireza; Finlay, Jarod C

2016-11-01

Proton beam dosimetry using bare plastic optical fibers has emerged as a simple approach to proton beam dosimetry. The source of the signal in this method has been attributed to Čerenkov radiation. The aim of this work was a phenomenological study of the nature of the visible light responsible for the signal in bare fiber optic dosimetry of proton therapy beams. Plastic fiber optic probes embedded in solid water phantoms were irradiated with proton beams of energies 100, 180, and 225 MeV produced by a proton therapy cyclotron. Luminescence spectroscopy was performed by a CCD-coupled spectrometer. The spectra were acquired at various depths in phantom to measure the percentage depth dose (PDD) for each beam energy. For comparison, the PDD curves were acquired using a standard multilayer ion chamber device. In order to further analyze the contribution of the Čerenkov radiation in the spectra, Monte Carlo simulation was performed using fluka Monte Carlo code to stochastically simulate radiation transport, ionizing radiation dose deposition, and optical emission of Čerenkov radiation. The measured depth doses using the bare fiber are in agreement with measurements performed by the multilayer ion chamber device, indicating the feasibility of using bare fiber probes for proton beam dosimetry. The spectroscopic study of proton-irradiated fibers showed a continuous spectrum with a shape different from that of Čerenkov radiation. The Monte Carlo simulations confirmed that the amount of the generated Čerenkov light does not follow the radiation absorbed dose in a medium. The source of the optical signal responsible for the proton dose measurement using bare optical fibers is not Čerenkov radiation. It is fluorescence of the plastic material of the fiber.

A novel conducting poly(p-aminobenzene sulphonic acid)-based electrochemical sensor for sensitive determination of Sudan I and its application for detection in food stuffs.

PubMed

Li, Bang Lin; Luo, Jun Hua; Luo, Hong Qun; Li, Nian Bing

2015-04-15

In the present work, a new method for the determination of Sudan I has been developed based on a conducting poly(p-aminobenzene sulphonic acid) (poly(p-ABSA)) film modified electrode. The new electrochemical sensor showed strong accumulation ability and excellent electrocatalytic activity for Sudan I. Electrochemical oxidation signal of Sudan I at the poly(p-ABSA) modified glassy carbon electrode (poly(p-ABSA)/GCE) was significantly increased when compared to that at the bare GCE. The experimental conditions such as amount of alcohol, pH of buffer solution, accumulation time, and instrumental parameters for square wave anodic stripping voltammetry were optimised for the determination of Sudan I. Under optimum conditions, the linear regression equation of Sudan I was ip=1.868+0.1213c (ip: μA, c: μgL(-1), R=0.9981) from 1 to 500 μg L(-1) with a detection limit of 0.3 μg L(-1). Finally, this sensor was successfully employed to detect Sudan I in some hot chili and ketchup samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monte Carlo calculations of LR115 detector response to 222Rn in the presence of 220Rn.

PubMed

Nikezić, D; Yu, K N

2000-04-01

The sensitivities (in m) of bare LR115 detectors and detectors in diffusion chambers to 222Rn and 220Rn chains are calculated by the Monte Carlo method. The partial sensitivities of bare detectors to the 222Rn chain are larger than those to the 220Rn chain, which is due to the higher energies of alpha particles in the 220Rn chain and the upper energy limit for detection for the LR115 detector. However, the total sensitivities are approximately equal because 220Rn is always in equilibrium with its first progeny, which is not the case for the 222Rn chain. The total sensitivity of bare LR115 detectors to 222Rn chain depends linearly on the equilibrium factor. The overestimation in 222Rn measurements with bare detectors caused by 220Rn in air can reach 10% in normal environmental conditions. An analytical relationship between the equilibrium factor and the ratio between track densities on the bare detector and the detector enclosed in chamber is given in the last part of the paper. This ratio is also affected by 220Rn, which can disturb the determination of the equilibrium factor.

[Effects of soil crusts on surface hydrology in the semiarid Loess hilly area].

PubMed

Wei, Wei; Wen, Zhi; Chen, Li-Ding; Chen, Jin; Wu, Dong-Ping

2012-11-01

Soil crusts are distributed extensively in the Chinese Loess Plateau and play key roles in surface hydrological processes. In this study, a typical loess hilly region in Anjiagou catchment, Dingxi city, Gansu province was selected as the study region, and soil crusts in the catchment were investigated. Then, the hydrological effect of soil crusts was studied by using multi-sampling and hydrological monitoring experiments. Several key results were shown as follows. Firstly, compared with bared soil without crust cover, soil crusts can greatly reduce the bulk density, improve the porosity of soil, and raise the holding capacity of soil moisture which ranges from 1.4 to 1.9 times of that of bared soil. Secondly, the role of soil crust on rainfall interception was very significant. Moss crust was found to be strongest on rainfall interception, followed by synantectic crusts and lichen crusts. Bared soil without covering crusts was poorest in resisting rainfall splash. Thirdly, hydrological simulation experiments indicate that soil crusts play a certain positive role in promoting the water infiltration capacity, and the mean infiltration rate of the crusted soil was 2 times higher than that of the no-crust covered soils. While the accumulated infiltrated water amounts was also far higher than that of the bared soil.

Evaluation of barely visible indentation damage (BVID) in CF/EP sandwich composites using guided wave signals

NASA Astrophysics Data System (ADS)

Mustapha, Samir; Ye, Lin; Dong, Xingjian; Alamdari, Mehrisadat Makki

2016-08-01

Barely visible indentation damage after quasi-static indentation in sandwich CF/EP composites was assessed using ultrasonic guided wave signals. Finite element analyses were conducted to investigate the interaction between guided waves and damage, further to assist in the selection process of the Lamb wave sensitive modes for debonding identification. Composite sandwich beams and panels structures were investigated. Using the beam structure, a damage index was defined based on the change in the peak magnitude of the captured wave signals before and after the indentation, and the damage index was correlated with the residual deformation (defined as the depth of the dent), that was further correlated with the amount of crushing within the core. Both A0 and S0 Lamb wave modes showed high sensitivity to the presence of barely visible indentation damage with residual deformation of 0.2 mm. Furthermore, barely visible indentation damage was assessed in composite sandwich panels after indenting to 3 and 5 mm, and the damage index was defined, based on (a) the peak magnitude of the wave signals before and after indentation or (b) the mismatch between the original and reconstructed wave signals based on a time-reversal algorithm, and was subsequently applied to locate the position of indentation.

An electrochemical albumin-sensing system utilizing microfluidic technology

NASA Astrophysics Data System (ADS)

Huang, Chao-June; Lu, Chiu-Chun; Lin, Thong-Yueh; Chou, Tse-Chuan; Lee, Gwo-Bin

2007-04-01

This paper reports an integrated microfluidic chip capable of detecting the concentration of albumin in urine by using an electrochemical method in an automatic format. The integrated microfluidic chip was fabricated by using microelectromechanical system techniques. The albumin detection was conducted by using the electrochemical sensing method, in which the albumin in urine was detected by measuring the difference of peak currents between a bare reference electrode and an albumin-adsorption electrode. To perform the detection of the albumin in an automatic format, pneumatic microvalves and micropumps were integrated onto the microfluidic chip. The albumin sample and interference mixture solutions such as homovanillic acid, dopamine, norepinephrine and epinephrine were first stored in one of the three reservoirs. Then the solution comprising the albumin sample and interference solutions was transported to pass through the detection zone utilizing the pneumatic micropump. Experimental data showed that the developed system can successfully detect the concentration of the albumin in the existence of interference materials. When compared with the traditional albumin-sensing method, smaller amounts of samples were required to perform faster detection by using the integrated microfluidic chip. Additionally, the microfluidic chip integrated with pneumatic micropumps and microvalves facilitates the transportation of the samples in an automatic mode with lesser human intervention. The development of the integrated microfluidic albumin-sensing system may be promising for biomedical applications. Preliminary results of the current paper were presented at the 2nd International Meeting on Microsensors and Microsystems 2006 (National Cheng Kung University, Tainan, Taiwan, 15-18 January).

Indium tin oxide based chip for optical and electrochemical characterization of protein-cell interaction

NASA Astrophysics Data System (ADS)

Choi, Yong Hyun; Min, Junhong; Cho, Sungbo

2015-06-01

Analysis on the interaction between proteins and cells is required for understanding the cellular behaviour and response. In this article, we characterized the adhesion and growth of 293/GFP cells on fetal bovine serum (FBS) coated indium tin oxide (ITO) electrode. Using optical and electrochemical measurement, it was able to detect the adsorption of the protein on the surface of the ITO electrode dependent on the concentration of the protein in the immersing solution or the immersing time. An increase in the amount of the adsorbed serum protein resulted in a decrease in anodic peak current and an increase in the charge transfer resistance extracted from the equivalent circuit fitting analysis. More cells adhered and proliferated on the ITO electrode which was pre-immersed in FBS medium rather than bare electrode. The effect of the FBS on cell behaviors was reflected in the impedance monitoring of cells at 21.5 kHz.

Confined detection volume of fluorescence correlation spectroscopy by bare fiber probes.

PubMed

Lu, Guowei; Lei, Franck H; Angiboust, Jean-François; Manfait, Michel

2010-04-01

A fiber-tip-based near-field fluorescence correlation spectroscopy (FCS) has been developed for confining the detection volume to sub-diffraction-limited dimensions. This near-field FCS is based on near-field illumination by coupling a scanning near-field optical microscope (SNOM) to a conventional confocal FCS. Single-molecule FCS analysis at 100 nM Rhodamine 6G has been achieved by using bare chemically etched, tapered fiber tips. The detection volume under control of the SNOM system has been reduced over one order of magnitude compared to that of the conventional confocal FCS. Related factors influencing the near-field FCS performance are investigated and discussed in detail. In this proof-of-principle study, the preliminary experimental results suggest that the fiber-tip-based near-field FCS might be a good alternative to realize localized analysis at the single-molecule level.

Estimating preseason irrigation losses by characterizing evaporation of effective precipitation under bare soil conditions using large weighing lysimeters

USDA-ARS?s Scientific Manuscript database

Irrigation scheduling is one of the most cost effective means of conserving limited groundwater resources, particularly in semi-arid regions. Effective precipitation, or the net amount of water from precipitation that can be used in field water balance equations, is essential to accurate and effecti...

Masterpieces in the Hallways

ERIC Educational Resources Information Center

Downs, Philip; Patton-McFarren, Erin

2009-01-01

No matter how many bulletin boards, exit signs, motivational posters, and directional signage in a school, write the authors, there are always wall spaces that cry out for something to cover them. In 2006, when Cedar Canyon Elementary School opened its doors for the first time, the amount of bare wall space was noticeable even after putting up…

Thermal microwave emission from vegetated fields - A comparison between theory and experiment

NASA Technical Reports Server (NTRS)

Wang, J. R.; Shiue, J. C.; Dombrowski, M.; Chuang, S. L.; Shin, R. T.

1984-01-01

The radiometric measurements over bare field and fields covered with grass, soybean, corn, and alfalfa were made with 1.4- and 5-GHz microwave radiometers during August-October 1978. The measured results are compared with radiative transfer theory treating the vegetated fields as a two-layer random medium. It is found that the presence of a vegetation cover generally gives a higher brightness temperature T sub B than that expected from a bare soil. The amount of this T sub B excess increases with increase in the vegetation biomass and in the frequency of the observed radiation. The results of radiative transfer calculations, which include a parameter characterizing ground surface roughness, generally match well with the experimental data.

Paint removal using wheat starch blast media

NASA Astrophysics Data System (ADS)

Foster, Terry; Oestreich, John

1993-03-01

A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of cracks confirms better crack visibility with wheat starch media versus Type V or Type II plastic media. Testing of wheat starch media in several composite test programs, including fiberglass, Kevlar, and graphite-epoxy composites, showed no fiber damage. Process developments and production experience at the first U.S. aircraft stripping facility are also reviewed. Corporate and regional aircraft are being stripped in this three nozzle dry blast hanger.

Alcohol molecules adsorption on graphane nanosheets - A first-principles investigation

NASA Astrophysics Data System (ADS)

Nagarajan, V.; Chandiramouli, R.

2018-05-01

The geometric structure, electronic and adsorption properties of methanol, ethanol and 1-propanol molecules on hydrogenated graphene (graphane) were investigated using first-principles calculations. The stability of graphane base material is confirmed using formation energy and phonon band structures. The adsorption of alcohol molecules on bare graphane and hydrogen vacant graphane nanosheet is found to be prominent and the selectivity of alcohol molecules can be achieved using bare or hydrogen vacant graphane nanosheet. Moreover, the interaction of alcohol molecules on bare and hydrogen vacant graphane nanosheets is studied using the adsorption energy, energy band gap variation, Bader charge transfer and average energy band gap variation. The adsorption energy ranges from -0.149 to -0.383 eV upon alcohol adsorption. The energy gap varies from 4.71 to 2.62 eV for bare graphane and from 4.02 to 3.60 eV for hydrogen vacant graphane nanosheets upon adsorption of alcohol molecules. The adsorption properties of alcohol molecules provide useful information for the possible application of graphane nanosheet as a base material for the detection of alcohol molecules.

Species–specific contributions to moderate resolution vegetation indices derived from sub-decimeter aerial photography – Prospects for phenological monitoring

USDA-ARS?s Scientific Manuscript database

High spatial heterogeneity in ground cover, large amounts of exposed bare soil, and modest cover from shrubs and grasses in arid and semi-arid ecosystems challenge the integration of field observations of phenology and remotely sensed data to monitor changes in land surface phenology. This research ...

In Pakistan, the Problems that Money Can Bring

ERIC Educational Resources Information Center

Neelakantan, Shailaja

2007-01-01

Over the past four years, Pakistan's higher-education budget has increased more than sevenfold, to about $449-million. While that amounts to only 0.5 percent of Pakistan's gross domestic product, it is a big improvement from the days of barely enough to pay "measly salaries and basic bills." But for students, along with many of…

Training Next-Gen Data Superheroes

ERIC Educational Resources Information Center

Waters, John K.

2013-01-01

The latest data alert: By 2020, the amount of data generated daily will reach 40 zettabytes, or roughly 5,247 gigabytes for every person on earth. That's one of the findings in a new report published by IT industry analysts at IDC. The study casts doubt on the ability to capture the value of all this data, especially since schools barely tapped…

Amphiphilic Copolymers Shuttle Drugs Across the Blood-Brain Barrier.

PubMed

Clemens-Hemmelmann, Mirjam; Kuffner, Christiane; Metz, Verena; Kircher, Linda; Schmitt, Ulrich; Hiemke, Christoph; Postina, Rolf; Zentel, Rudolf

2016-05-01

Medical treatment of diseases of the central nervous system requires transport of drugs across the blood-brain barrier (BBB). Here, it is extended previously in vitro experiments with a model compound to show that the non-water-soluble and brain-impermeable drug domperidone (DOM) itself can be enriched in the brain by use of an amphiphilic copolymer as a carrier. This carrier consists of poly(N-(2-hydroxypropyl)-methacrylamide), statistically copolymerized with 10 mol% hydrophobic lauryl methacrylate, into whose micellar aggregates DOM is noncovalently absorbed. As tested in a BBB model efficient transport of DOM across, the BBB is achievable over a wide range of formulations, containing 0.8 to 35.5 wt% domperidone per copolymer. In neither case, the polymer itself is translocated across the BBB model. In vivo experiments in mice show that already 10 min after intraperitoneal injection of the polymer/domperidone (PolyDOM) formulation, domperidone can be detected in blood and in the brain. Highest serum and brain levels of domperidone are detected 40 min after injection. At that time point serum domperidone is increased 48-fold. Most importantly, domperidone is exclusively detectable in high amounts in the brain of PolyDOM injected mice and not in mice injected with bare domperidone. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantum dots electrochemical aptasensor based on three-dimensionally ordered macroporous gold film for the detection of ATP.

PubMed

Zhou, Jinjun; Huang, Haiping; Xuan, Jie; Zhang, Jianrong; Zhu, Jun-Jie

2010-10-15

A sensitive electrochemical aptasensor was successfully fabricated for the detection of adenosine triphosphate (ATP) by combining three-dimensionally ordered macroporous (3DOM) gold film and quantum dots (QDs). The 3DOM gold film was electrochemically fabricated with an inverted opal template, making the active surface area of the electrode up to 9.52 times larger than that of a classical bare flat one. 5′-thiolated ATP-binding aptamer (ABA) was first assembled onto the 3DOM gold film via sulfur–gold affinity. Then, 5′-biotinated complementary strand (BCS) was immobilized via hybridization reaction to form the DNA/DNA duplex. Since the tertiary structure of the aptamer was stabilized in the presence of target ATP, the duplex can be denatured to liberate BCS. The reaction was monitored by electrochemical stripping analysis of dissolved QDs which were bound to the residual BCS through biotin-streptavidin system. The decrease of peak current was proportional to the amount of ATP. The unique interconnected structure in 3DOM gold film along with the "built-in" preconcentration remarkably improved the sensitivity. ATP detection with high selectivity, wide linear dynamic range of 4 orders of magnitude and high sensitivity down to 0.01 nm were achieved. The results demonstrated that the novel strategy was feasible for sensitive ATP assay and provided a promising model for the detection of small molecules.

Chernozems microbial community under anthropogenic impact (Russia)

NASA Astrophysics Data System (ADS)

Ivashchenko, Kristina; Ananyeva, Nadezhda; Sushko, Sofia; Vasenev, Viacheslav

2017-04-01

Chernozems is important natural resource, which in the last decade under intense influence as a result of plowing and urbanization. The parameters of soil microbial community functioning might be identify some soil deterioration under the impacts. Our research was focused on assessment of microbial community status in different soil layers of virgin steppe, bare fallow and urban ecosystems (Kursk region). In each ecosystem, we chose randomly 3-5 spatially distributed sites, where soil samples were collected by auguring up to 0.5 m depth (each layer 10 cm thickness) and up to 1.5 m depth (0-10, 10-50, 50-100, 100-150 cm layers), totally 127 samples. The bulk density was measured for these soil layers. In all soil samples the microbial biomass carbon content (Cmic) was analyzed by substrate-induced respiration (SIR) method and basal respiration (BR) was assessed by CO2 rate production. The fungi-to-bacteria ratio (selective inhibition technique with antibiotics) was determined and portion of Cmic in soil organic carbon (Corg) content was calculated in topsoil (0-10 cm). The Corg (dichromate oxidation) and pHw (potentiometry) values were measured. The Cmic and BR profile pools were calculated using bulk density and thickness of studied layers. The Cmic (0-10 cm) was varied from 84 to 1954 µg C g-1 soil, in steppe it was on average 3-4 times higher than those in bare fallow and urban. The BR rate was amounted from 0.20 to 1.57 µg CO2-C g-1 soil h-1, however no significant difference between studied ecosystems was found. It was shown the relationship between Cmic, BR and Corg (the linear regression, R2=0.92 and 0.75, respectively, p<0.05). The Cmic / Corg ratio in steppe was on average 3.3%, it was significantly higher those bare fallow and urban (1.6 and 0.7%, respectively). The fungi-to-bacteria ratio was decreased along ecosystems row: virgin steppe>bare fallow>urban, and it was on average 6.0, 5.2 and 1.8, respectively. The Cmic profile pool (0.5 m) of steppe was reached up on average 206 g C m-2, and it was 2.0 and 2.5 times higher those bare fallow and urban, respectively. The BR profile pool (0.5 m) in steppe and bare fallow was reached up 5.9 and 5.8 g CO2-C m-2 d-1, respectively, it was on average 2 times higher urban. The Cmic profile pool (1.5 m) in steppe was amounted to 372 g C m-2, and it was essentially higher those in bare fallow and urban (138 and 140 g C m-2, respectively). The BR profile pool (1.5 m) was also decreased along ecosystems row: steppe> fallow>urban, and it was on average 13.0, 8.0 and 5.6 g CO2-C m-2 d-1, respectively. Thus, we found a significant decreasing soil microbial biomass content, its portion in soil Corg, fungi content, and the Cmic and BR profile pools along Chernozems' ecosystems gradient from natural (virgin steppe) to anthropogenically transformed (bare fallow, urban). It might be illustrated some deterioration of soil microbial community functioning under plowing and urbanization. This research was supported by RFBR grants Nos. 15-04-00915 and 16-34-00398

Interfacial nano-mixing in a miniaturised platform enables signal enhancement and in situ detection of cancer biomarkers.

PubMed

Wuethrich, Alain; Sina, Abu Ali Ibn; Ahmed, Mostak; Lin, Ting-Yun; Carrascosa, Laura G; Trau, Matt

2018-06-14

Interfacial biosensing performs the detection of biomolecules at the bare-metal interface for disease diagnosis by comparing how biological species derived from patients and healthy individuals interact with bare metal surfaces. This technique retrieves clinicopathological information without complex surface functionalisation which is a major limitation of conventional techniques. However, it is still challenging to detect subtle molecular changes by interfacial biosensing, and the detection often requires prolonged sensing times due to the slow diffusion process of the biomolecules towards the sensor surface. Herein, we report on a novel strategy for interfacial biosensing which involves in situ electrochemical detection under the action of an electric field-induced nanoscopic flow at nanometre distance to the sensing surface. This nanomixing significantly increases target adsorption, reduces sensing time, and enables the detection of small molecular changes with enhanced sensitivity. Using a multiplex electrochemical microdevice that enables nanomixing and in situ label-free electrochemical detection, we demonstrate the detection of multiple cancer biomarkers on the same device. We present data for the detection of aberrant phosphorylation in the EGFR protein and hypermethylation in the EN1 gene region. Our method significantly shortens the assay period (from 40 min and 20 min to 3 minutes for protein and DNA, respectively), increases the sensitivity by up to two orders of magnitude, and improves detection specificity.

Attenuation of soil microwave emissivity by corn and soybeans at 1.4 and 5 GHz

NASA Technical Reports Server (NTRS)

Jackson, Thomas J.; O'Neill, Peggy E.

1989-01-01

Theory and experiments have shown that passive microwave radiometers can be used to measure soil moisture. However, the presence of a vegetative cover alters the measurement that might be obtained under bare conditions. Deterministically accounting for the effect of vegetation and developing algorithms for extracting soil moisture from observations of a vegetable-soil complex present significant obstacles to the practical use of this approach. The presence of a vegetation canopy reduces the sensitivity of passive microwave instruments to soil moisture variations. The reduction in sensitivity, as compared to a bare-soil relationship, increases as microwave frequency increases, implying that the longest wavelength sensors should provide the most information. Sensitivity also decreases as the amount of vegetative wet biomass increases for a given type of vegetation.

Soil respiration in typical plant communities in the wetland surrounding the high-salinity Ebinur Lake

NASA Astrophysics Data System (ADS)

Li, Yanhong; Zhao, Mingliang; Li, Fadong

2018-03-01

Soil respiration in wetlands surrounding lakes is a vital component of the soil carbon cycle in arid regions. However, information remains limited on the soil respiration around highly saline lakes during the plant growing season. Here, we aimed to evaluate diurnal and seasonal variation in soil respiration to elucidate the controlling factors in the wetland of Ebinur Lake, Xinjiang Uygur Autonomous Region, western China. We used a soil carbon flux automatic analyzer (LI-840A) to measure soil respiration rates during the growing season (April to November) in two fields covered by reeds and tamarisk and one field with no vegetation (bare soil) from 2015 to 2016. The results showed a single peak in the diurnal pattern of soil respiration from 11:00 to 17:00 for plots covered in reeds, tamarisk, and bare soil, with minimum values being detected from 03:00 to 07:00. During the growing season, the soil respiration of reeds and tamarisk peaked during the thriving period (4.16 and 3.75 mmol•m-2•s-1, respectively), while that of bare soil peaked during the intermediate growth period (0.74 mmol•m-2•s-1). The soil respiration in all three plots was lowest during the wintering period (0.08, 0.09, and-0.87 mmol•m-2•s-1, respectively). Air temperature and relative humidity significantly influenced soil respiration. A significant linear relationship was detected between soil respiration and soil temperature for reeds, tamarisk, and bare soil. The average Q10 of reeds and tamarisk were larger than that of bare soil. However, soil moisture content was not the main factor controlling soil respiration. Soil respiration was negatively correlated with soil pH and soil salinity in all three plot types. In contrast, soil respiration was positively correlated with organic carbon. Overall, CO2 emissions and greenhouse gases had a relatively weak effect on the wetlands surrounding the highly saline Ebinur Lake.

Graphene quantum dots modified silicon nanowire array for ultrasensitive detection in the gas phase

NASA Astrophysics Data System (ADS)

Li, T. Y.; Duan, C. Y.; Zhu, Y. X.; Chen, Y. F.; Wang, Y.

2017-03-01

Si nanostructure-based gas detectors have attracted much attention due to their huge surface areas, relatively high carrier mobility, maneuverability for surface functionalization and compatibility to modern electronic industry. However, the unstable surface of Si, especially for the nanostructures in a corrosive atmosphere, hinders their sensitivity and reproducibility when used for detection in the gas phase. In this study, we proposed a novel strategy to fabricate a Si-based gas detector by using the vertically aligned Si nanowire (SiNW) array as a skeleton and platform, and decorated chemically inert graphene quantum dots (GQDs) to protect the SiNWs from oxidation and promote the carriers’ interaction with the analytes. The radial core-shell structures of the GQDs/SiNW array were then assembled into a resistor-based gas detection system and evaluated by using nitrogen dioxide (NO2) as the model analyte. Compared to the bare SiNW array, our novel sensor exhibited ultrahigh sensitivity for detecting trace amounts of NO2 with the concentration as low as 10 ppm in room temperature and an immensely reduced recovery time, which is of significant importance for their practical application. Meanwhile, strikingly, reproducibility and stability could also be achieved by showing no sensitivity decline after storing the GQDs/SiNW array in air for two weeks. Our results demonstrate that protecting the surface of the SiNW array with chemically inert GQDs is a feasible strategy to realize ultrasensitive detection in the gas phase.

Stopping of protons - Improved accuracy of the UCA model

NASA Astrophysics Data System (ADS)

Schiwietz, G.; Grande, P. L.

2012-02-01

Recent theoretical developments in the unitary convolution approximation (UCA) for electronic energy losses of bare and screened ions are presented. Examples are given for proton beams and rare-gas targets. For gas targets there exists a sufficient amount of experimental data on charge exchange, for pinpointing the largely unknown stopping-power contribution of electron-capture processes at low and intermediate energies.

Enhanced photocatalytic activity of nanocellulose supported zinc oxide composite for RhB dye as well as ciprofloxacin drug under sunlight/visible light

NASA Astrophysics Data System (ADS)

Tavker, Neha; Sharma, Manu

2018-05-01

Zinc oxide nanoparticles were synthesised from zinc acetate di-hydrate via co-precipitation method. Nanocellulose was isolated from agrowaste using chemo-mechanical treatments and characterized. Nanocellulose supported zinc oxide composites were prepared through in-situ method by adding different amounts of nanocellulose. The photocatalytic efficiency of pure Zno and nanocellulose supported ZnO was calculated using RhB dye under visible light and sun light. The composites which had nanocellulose in greater ratio showed higher degradation efficiency in sunlight rather than visible light for both; dye and drug. All the composites showed high rate of photodegradation compared to bare ZnO and bare nanocellulose. The enhancement in photocatalytic activity was observed maximum where the amount of cellulose was maximum. The maximum observed rate was 0.025 min-1 using Ciprofloxacin drug due to the increase in lifetime of Z4 sample delaying the electron and hole pair recombination. The degrading efficiency of nanocellulose supported zinc oxide (NC/ZnO) composite for RhB was found to be 35% in visible, 76% in sunlight and 75% for ciprofloxacin under sunlight.

DDT acceleration of mammary gland tumors induced in the male Sprague-Dawley rat by 2-acetamidophenanthrene.

PubMed

Scribner, J D; Mottet, N K

1981-01-01

2-Acetamidophenanthrene (AAP) yields adducts to rat liver DNA and RNA in amounts comparable to those found for the potent hepatocarcinogen 2-acetamidofluorene, but is not hepatocarcinogenic. This suggested that AAP might initiate liver tumors, but was incapable of causing their progression to a detectable state. To test this hypothesis, the protocol devised by Peraino was used, in which 21-day-old male Sprague-Dawley rats were fed 0.02% AAP in a grain diet for three weeks. this was followed by long-term feeding of 0.05% 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT). The mean latent period of all tumors (primarily mammary tumors) was reduced about six months by the DDT feeding. No tumors were found in rats treated with DDT only. Livers in all animals appeared normal at autopsy or on laparotomy, and showed barely detectable signs of toxicity upon histological examination. Thus, we have found that a once wide-spread environmental chemical acts as a tumor accelerator on a major target for human tumors. Because this finding is in the male rat, the significance of this result for breast cancer in women is uncertain.

Atomic layer deposition to prevent metal transfer from implants: An X-ray fluorescence study

NASA Astrophysics Data System (ADS)

Bilo, Fabjola; Borgese, Laura; Prost, Josef; Rauwolf, Mirjam; Turyanskaya, Anna; Wobrauschek, Peter; Kregsamer, Peter; Streli, Christina; Pazzaglia, Ugo; Depero, Laura E.

2015-12-01

We show that Atomic Layer Deposition is a suitable coating technique to prevent metal diffusion from medical implants. The metal distribution in animal bone tissue with inserted bare and coated Co-Cr alloys was evaluated by means of micro X-ray fluorescence mapping. In the uncoated implant, the migration of Co and Cr particles from the bare alloy in the biological tissues is observed just after one month and the number of particles significantly increases after two months. In contrast, no metal diffusion was detected in the implant coated with TiO2. Instead, a gradient distribution of the metals was found, from the alloy surface going into the tissue. No significant change was detected after two months of aging. As expected, the thicker is the TiO2 layer, the lower is the metal migration.

Graphene-bimetallic nanoparticle composites with enhanced electro-catalytic detection of bisphenol A

NASA Astrophysics Data System (ADS)

Pogacean, Florina; Biris, Alexandru R.; Socaci, Crina; Coros, Maria; Magerusan, Lidia; Rosu, Marcela-Corina; Lazar, Mihaela D.; Borodi, Gheorghe; Pruneanu, Stela

2016-12-01

This study brings for the first time novel knowledge about the synthesis by catalytic chemical vapor deposition with induction heating of graphene-bimetallic nanoparticle composites (Gr-AuCu and Gr-AgCu) and their morphological and structural characterization by transmission electron microscopy, Raman spectroscopy, and x-ray powder diffraction. Gold electrodes modified with the obtained materials exhibit an enhanced electro-catalytic effect towards one of the most encountered estrogenic disruptive chemicals, bisphenol A (BPA). The BPA behavior in varying pH solutions was investigated using the electrochemical quartz crystal microbalance, which allowed the accurate determination of the number of molecules involved in the oxidation process. The modified electrodes promote the oxidation of BPA at significantly lower potentials (0.66 V) compared to bare gold (0.78 V). In addition, the peak current density recorded with such electrodes greatly exceeded that obtained with bare gold (e.g. one order of magnitude larger, for a Au/Gr-AgCu electrode). The two modified electrodes have low detection limits, of 1.31 × 10-6 M and 1.91 × 10-6 M for Au/Gr-AgCu and Au/Gr-AuCu, respectively. The bare gold electrode has a higher detection limit of 5.1 × 10-6 M. The effect of interfering species (e.g. catechol and 3-nitrophenol) was also investigated. Their presence influenced not only the BPA peak potential, but also the peak current. With both modified electrodes, no peak currents were recorded below 3 × 10-5 M BPA.

Volumetric visualization of multiple-return LIDAR data: Using voxels

USGS Publications Warehouse

Stoker, Jason M.

2009-01-01

Elevation data are an important component in the visualization and analysis of geographic information. The creation and display of 3D models representing bare earth, vegetation, and surface structures have become a major focus of light detection and ranging (lidar) remote sensing research in the past few years. Lidar is an active sensor that records the distance, or range, of a laser usually fi red from an airplane, helicopter, or satellite. By converting the millions of 3D lidar returns from a system into bare ground, vegetation, or structural elevation information, extremely accurate, high-resolution elevation models can be derived and produced to visualize and quantify scenes in three dimensions. These data can be used to produce high-resolution bare-earth digital elevation models; quantitative estimates of vegetative features such as canopy height, canopy closure, and biomass; and models of urban areas such as building footprints and 3D city models.

Adsorption of quantum dots onto polymer and Gemini surfactant films: a quartz crystal microbalance study.

PubMed

Alejo, T; Merchán, M D; Velázquez, M M

2014-08-26

We used quartz crystal microbalance with dissipation to study the mechanical properties, the kinetics of adsorption, and the amount of CdSe quantum dots (QDs) adsorbed onto a SiO2 sensor, referred as bare sensor, onto the sensor modified with a film of the polymer poly(maleic anhydride-alt-1-octadecene), PMAO, or with a film of the Gemini surfactant ethyl-bis(dimethyl octadecyl ammonium bromide), abbreviated as 18-2-18. Results showed that when the sensor is coated with polymer or surfactant molecules, the coverage increases compared with that obtained for the bare sensor. On the other hand, rheological properties and kinetics of adsorption of QDs are driven by QD nanoparticles. Thus, the QD films present elastic behavior, and the elasticity values are independent of the molecule used as coating and similar to the elasticity value obtained for QDs films on the bare sensor. The QD adsorption is a two-step mechanism in which the fastest process is attributed to the QD adsorption onto the solid substrate and the slowest one is ascribed to rearrangement movements of the nanoparticles adsorbed at the surface.

IFATS Collection: Adipose-Derived Stromal Cells Improve the Foreign Body Response

PubMed Central

Prichard, Heather L.; Reichert, William; Klitzman, Bruce

2015-01-01

Many implanted devices fail due to the formation of an avascular capsule surrounding the device. Additionally, fat has long been known to promote healing and vascularization. The goals of this study were to identify potential mechanisms of the provascular actions of adipose-derived stromal cells (ASCs) and to improve implant biocompatibility. First, adult ASCs and fibroblasts from rats were attached to polyurethane and polystyrene in vitro and their cytokine secretion profile was analyzed. Secretion of vascular endothelial growth factor (VEGF) from ASCs was 10 –70 times higher than fibroblasts after 3 and 6 days. Next, polyurethane, bare and with cellular coatings, was implanted subcutaneously in rats. The fibrous capsule surrounding bare polyurethane implants was 17%–32% thicker and the amount of collagen was 27% greater than the capsule surrounding ASC-coated implants. Finally, the microvessel density adjacent to ASC-coated polyurethane was approximately 50%–80% higher than bare polyurethane. In summary, ASCs attached to polyurethane have a dramatically increased VEGF production compared with fibroblasts in vitro, and these cells also produce an increased microvessel density in the surrounding tissue when implanted subcutaneously in rats. PMID:18436858

New Indices to Evaluate the Effects of Rainfall Pattern on Runoff and Soil Loss under Different Vegetation in the Loess Plateau, China.

NASA Astrophysics Data System (ADS)

Liu, J.; Gao, G.; Jiao, L.; Fu, B.

2016-12-01

The rainfall amount, density and duration were commonly used to evaluate the influences of rainfall on runoff and soil loss, which could completely express the information of rainfall, especially rainfall pattern. In this study, the peak zone of rainfall intensity (PZRI) and intra-event intermittency of rainfall (IERI) were developed to detect the effects of rainfall pattern on runoff and soil loss under different land cover types in the Loess Plateau of China. The runoff and soil loss of three vegetation types (Prunus armeniaca, Artemisia sacrorum and Andropogon yunnanensis) and bare land were measured from 2012 to 2015. The PZRI was significantly correlated with average rainfall intensity (I) and maximum rainfall intensity in 30 minutes (I30). The runoff coefficient (RC) and soil loss were not significantly correlated with I, but they were significantly affected by I30 and PZRI (p<0.05). The greater value of IERI indicated more proportion of PZRI in rainfall duration, and there was positive correlation between IERI and RC. It was showed that the RC was most correlated with PZRI, whereas the correlation between soil loss and I30 was most significant under all cover types. This indicated that the changes of rainfall pattern had more effects on runoff than soil loss. In addition, the position of PZRI in the rainfall profile had an important role on runoff and soil loss. RC and soil loss under bare land was most sensitive to the occurrence period of rainfall peak, followed by Prunus armeniaca, Artemisia sacrorum and Andropogon yunnanensis.

Oxidation and hot corrosion of coated and bare oxide dispersion strengthened superalloy MA-755E

NASA Technical Reports Server (NTRS)

Glasgow, T. K.; Santoro, G. J.

1981-01-01

Cyclic hot corrosion and oxidation of an experimental oxide dispersion strengthened (ODS) superalloy MA-755E were conducted in a hot gas stream at Mach 0.3. The response of the ODS alloy, bare or with protective coatings, was similar to that of a conventional cast alloy, IN-792, in hot corrosion at 900 C. However, during oxidation at 1100 and 1150 C the ODS alloy differed from the cast alloy by developing a greater amount of subsurface porosity. Compared with a diffused aluminide coating, an electron beam vapor deposited NiCrAlY coating offered superior oxidation protection and decreased porosity formation. In additional testing, the tendency to form porosity was associated with the large grains of recrystallized powder metallurgy alloys but was independent of the presence of an oxide dispersion.

Erosion of mountain hiking trail over a seven-year period in Daisetsuzan National Park, central Hokkaido, Japan

Treesearch

Akemi Yoda; Teiji Watanabe

2000-01-01

Erosion of mountain hiking trails was investigated in Daisetsuzan National Park over a seven-year period. The amount and rate of erosion were different in the two typical landscape components. Cross-section diagrams revealed that trail depth became deeper in snowy vegetated areas than in wind-beaten bare ground areas. The existence and timing of runoff from snowmelt...

Ionic liquid-modified silica-coated magnetic nanoparticles: promising adsorbents for ultra-fast extraction of paraquat from aqueous solution.

PubMed

Latifeh, Farzad; Yamini, Yadollah; Seidi, Shahram

2016-03-01

In the present study, ionic liquid-modified silica-coated magnetic nanoparticles (Fe3O4@SiO2@IL) were synthesized and applied as adsorbents for extraction and determination of paraquat (PQ) followed by high-performance liquid chromatography. For assurance of the extraction efficiency, the obtained results were compared with those obtained by bared magnetic nanoparticles (MNPs). Experimental design and response surface methodology were used for optimization of different parameters which affect extraction efficiency of paraquat using both adsorbents. Under the optimized conditions, extraction recoveries in the range of 20-25 and 35-40 % with satisfactory repeatability values (RSDs%, n = 4) less than 5.0 % were obtained for bared MNPs and Fe3O4@SiO2@IL, respectively. The limits of detection were 0.1 and 0.25 μg/L using Fe3O4@SiO2@IL and bared MNPs, respectively. The linearity was obtained in the range of 0.25 to 25 μg/L and 0.5 to 25 μg/L for Fe3O4@SiO2@IL and bared MNPs, respectively, with the coefficients of determination better than 0.9950. Finally, Fe3O4@SiO2@IL was chosen as superior adsorbent due to more dispersion ability, higher extraction recovery, lower detection limit, as well as better linearity and repeatability. Calculated errors (%) were in the range of 3 to 10 % depicting acceptable accuracy for the analysis of PQ by the proposed method. Finally, the method was successfully applied for extraction and determination of PQ in some water and countryside soil samples.

Dextran hydrogel coated surface plasmon resonance imaging (SPRi) sensor for sensitive and label-free detection of small molecule drugs

NASA Astrophysics Data System (ADS)

Li, Shaopeng; Yang, Mo; Zhou, Wenfei; Johnston, Trevor G.; Wang, Rui; Zhu, Jinsong

2015-11-01

The label-free and sensitive detection of small molecule drugs on SPRi is still a challenging task, mainly due to the limited surface immobilization capacity of the sensor. In this research, a dextran hydrogel-coated gold sensor chip for SPRi was successfully fabricated via photo-cross-linking for enhanced surface immobilization capacity. The density of the dextran hydrogel was optimized for protein immobilization and sensitive small molecule detection. The protein immobilization capacity of the hydrogel was 10 times greater than a bare gold surface, and 20 times greater than an 11-mercaptoundecanoic acid (MUA) surface. Such a drastic improvement in immobilization capacity allowed the SPRi sensor to detect adequate response signals when probing small molecule binding events. The binding signal of 4 nM liquid-phase biotin to streptavidin immobilized on the dextran surface reached 435 RU, while no response was observed on bare gold or MUA surfaces. The dextran hydrogel-coated SPRi sensor was also applied in a kinetic study of the binding between an immunosuppressive drug (FK506) and its target protein (FKBP12) in a high-throughput microarray format. The measured binding affinity was shown to be consistent with reported literature values, and a detection limit of 0.5 nM was achieved.

Relationships between past and present pesticide applications and pollution at a watershed outlet: The case of a horticultural catchment in Martinique, French West Indies.

PubMed

Mottes, Charles; Lesueur Jannoyer, Magalie; Le Bail, Marianne; Guéné, Mathilde; Carles, Céline; Malézieux, Eric

2017-10-01

The understanding of factors affecting pesticide transfers to catchment outlet is still at a very early stage in tropical context, and especially on tropical volcanic context. We performed on-farm pesticide use surveys during 87 weeks and monitored pesticides in water weekly during 67 weeks at the outlet of a small catchment in Martinique. We identified three types of pollution. First, we showed long-term chronic pollution by chlordecone, diuron and metolachlor resulting from horticultural practices applied 5-20 years ago (quantification frequency higher than 80%). Second, we showed peak pollution. High amounts of propiconazole and fosthiazate applied at low frequencies caused river pollution peaks for weeks following a single application. Low amounts of diquat and diazinon applied at low frequencies also caused pollution peaks. The high amounts of glyphosate applied at high frequency resulted into pollution peaks by glyphosate and aminomethylphosphonic acid (AMPA) in 6 and 20% of the weeks. Any intensification of their uses will result in higher pollution levels. Third, relatively low amounts of glufosinate-ammonium, difenoconazol, spinosad and metaldehyde were applied at high frequencies. Unexpectedly, such pesticides remained barely detected (<1.5%) or undetected in water samples. We showed that AMPA, fosthiazate and propiconazole have serious leaching potential. They might result in future chronic pollution of shallow aquifers alimenting surface water. We prove that to avoid the past errors and decrease the risk of long-term pollution of water resources, it is urgent to reduce or stop the use of pesticides with leaching potential by changing agricultural practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early Changes of the Cortical Micro-Channel System in the Bare Area of the Joints of Patients With Rheumatoid Arthritis.

PubMed

Werner, David; Simon, David; Englbrecht, Matthias; Stemmler, Fabian; Simon, Christoph; Berlin, Andreas; Haschka, Judith; Renner, Nina; Buder, Thomas; Engelke, Klaus; Hueber, Axel J; Rech, Jürgen; Schett, Georg; Kleyer, Arnd

2017-08-01

To characterize the specific structural properties of the erosion-prone bare area of the human joint, and to search for early microstructural changes in this region during rheumatoid arthritis (RA). In the initial part of the study, human cadaveric hand joints were examined for exact localization of the bare area of the metacarpal heads, followed by detection of cortical micro-channels (CoMiCs) in this region by high-resolution peripheral quantitative computed tomography (HR-pQCT) and, after anatomic dissection, validation of the presence of CoMiCs by micro-computed tomography (micro-CT). In the second part of the study, the number and distribution of CoMiCs were analyzed in 107 RA patients compared to 105 healthy individuals of similar age and sex distribution. Investigation by HR-pQCT combined with adaptive thresholding allowed the detection of CoMiCs in the bare area of human cadaveric joints. The existence of CoMiCs in the bare area was additionally validated by micro-CT. In healthy individuals, the number of CoMiCs increased with age. RA patients showed significantly more CoMiCs compared to healthy individuals (mean ± SD 112.9 ± 54.7/joint versus 75.2 ± 41.9/joint; P < 0.001), with 20-49-year-old RA patients exhibiting similar numbers of CoMiCs as observed in healthy individuals older than age 65 years. Importantly, CoMiCs were already found in RA patients very early in their disease course, with enrichment in the erosion-prone radial side of the joint. CoMiCs represent a new form of structural change in the joints of patients with RA. Although the number of CoMiCs increases with age, RA patients develop CoMiCs much earlier in life, and such changes can even occur at the onset of the disease. CoMiCs therefore represent an interesting new opportunity to assess structural changes in RA. © 2017, American College of Rheumatology.

Dispersion and stability of bare hematite nanoparticles: effect of dispersion tools, nanoparticle concentration, humic acid and ionic strength

PubMed Central

Dickson, Dionne; Liu, Guangliang; Li, Chenzhong; Tachiev, Georgio; Cai, Yong

2012-01-01

The aggregation and sedimentation of iron oxide nanoparticles (IONPs) can significantly affect the mobility and reactivity of IONPs and subsequently influence the interaction between IONPs and environmental contaminants. Dispersing bare IONPs into a stable suspension within nanoscale range is an important step for studying the interaction of IONPs with contaminants (e.g., toxic metals). In this study, different techniques to disperse bare IONPs (vortex, bath sonication and probe ultrasonication) and the effects of important environmental factors such as dissolved organic matter and ionic strength on the stability of IONPs dispersions were investigated. Vortex minimally dispersed IONPs with hydrodynamic diameter outside the “nanosize range” (698–2400nm). Similar to vortex, bath sonication could not disperse IONPs efficiently. Probe ultrasonication was more effective at dispersing IONPs (50% or more) with hydrodynamic diameters ranging from 120–140 nm with minimal changes in size and sedimentation of IONPs for a prolonged period of time. Over the course of 168 hours, considerable amounts of IONPs remained dispersed in the presence and absence of low ionic strength (0.1 mM of NaCl) and 100 mg/L of humic acid (HA). These results indicate that IONPs can be broken down efficiently into “nanosize range” by probe ultrasonication and a degree of stability can be achieved without the use of synthetic modifiers to enhance colloidal stability. This dispersion tool could be used to develop a laboratory method to study the adsorption mechanism between dispersed bare IONPs and toxic contaminants. PMID:22289174

Evaluation of biodegradable paclitaxel-eluting nanofibre-covered metal stents for the treatment of benign cardia stricture in an experimental model.

PubMed

Zhu, Y-Q; Cui, W-G; Cheng, Y-S; Chang, J; Chen, N-W; Yan, L

2013-05-01

Benign strictures at the cardia are troublesome for patients and often require repeated endoscopic treatments. Paclitaxel can reduce fibrosis. This study evaluated a biodegradable paclitaxel-eluting nanofibre-covered metal stent for the treatment of benign cardia stricture in vitro and in vivo. Drug release was investigated in vitro at pH 7·4 and 4·0. Eighty dogs were divided randomly into four groups (each n = 20): controls (no stent), bare stent (retained for 1 week), and two drug-eluting stent (DES) groups with retention for either 1 week (DES-1w) or 4 weeks (DES-4w). Lower oesophageal sphincter pressure (LOSP) and 5-min barium height (5-mBH) were assessed before, immediately after stent deployment, at 1 week, and 1, 3 and 6 months later. Five dogs in each group were killed for histological examination at each follow-up point. Stent migration rates were similar (0 bare stent versus 2 DES; P = 0·548). The percentage and amount of paclitaxel released in vitro was higher at pH 4·0 than at pH 7·4. After 6 months, LOSP and 5-mBH were both improved in the DES-1w (P = 0·004 and P = 0·049) and DES-4w (both P < 0·001) groups compared with the bare-stent group, with better relief when the stent was retained for 4 weeks (P = 0·004 and P = 0·007). The DES was associated with a reduced peak inflammatory reaction and less scar formation compared with bare stents, especially when inserted for 4 weeks. The DES was more effective for the treatment of benign cardia stricture than bare stents in a canine model. Retention of the DES for 4 weeks led to a better clinical and pathological outcome than 1 week. © 2013 British Journal of Surgery Society Ltd. Published by John Wiley & Sons Ltd.

Thermal microwave emissions from vegetated fields: A comparison between theory and experiment. [Agricultural Research Center, Beltsville, MD.

NASA Technical Reports Server (NTRS)

Wang, J. R.; Shiue, J.; Chuang, S. L.; Dombrowski, M.

1980-01-01

The radiometric measurements over bare field and fields covered with grass, soybean, corn, and alfalfa were made with 1.4 GHz and 5 GHz microwave radiometers during August - October 1978. The measured results are compared with radiative transfer theory treating the vegetated fields as a two layer random medium. It is found that the presence of a vegetation cover generally gives a higher brightness temperature T(B) than that expected from a bare soil. The amount of this T(B) excess increases in the vegetation biomass and in the frequency of the observed radiation. The results of radiative transfer calculations generally match well with the experimental data, however, a detailed analysis also strongly suggests the need of incorporating soil surface roughness effect into the radiative transfer theory in order to better interpret the experimental data.

Dual frequency microwave radiometer measurements of soil moisture for bare and vegetated rough surfaces

NASA Technical Reports Server (NTRS)

Lee, S. L.

1974-01-01

Controlled ground-based passive microwave radiometric measurements on soil moisture were conducted to determine the effects of terrain surface roughness and vegetation on microwave emission. Theoretical predictions were compared with the experimental results and with some recent airborne radiometric measurements. The relationship of soil moisture to the permittivity for the soil was obtained in the laboratory. A dual frequency radiometer, 1.41356 GHz and 10.69 GHz, took measurements at angles between 0 and 50 degrees from an altitude of about fifty feet. Distinct surface roughnesses were studied. With the roughness undisturbed, oats were later planted and vegetated and bare field measurements were compared. The 1.4 GHz radiometer was less affected than the 10.6 GHz radiometer, which under vegetated conditions was incapable of detecting soil moisture. The bare surface theoretical model was inadequate, although the vegetation model appeared to be valid. Moisture parameters to correlate apparent temperature with soil moisture were compared.

Layer-by-layer self-assembled graphene oxide/silica microsphere composites as stationary phase for high performance liquid chromatography.

PubMed

Liang, Xiaojing; Liu, Shujuan; Song, Xinwang; Zhu, Yangwen; Jiang, Shengxiang

2012-11-21

Graphene oxide (GO) has been layer-by-layer assembled onto silica microspheres to form a GO/SiO(2) composite stationary phase. All the characterizations of GO/SiO(2) by elemental analysis, Raman spectroscopy and Fourier transformed infrared spectrometry confirmed that with the increase of the assembled layer, GO gradually increases on the silica surface. The chromatographic properties of bare SiO(2) and GO/SiO(2) with different GO assembled layers show that the amount of GO plays an important role in the separation of analytes. Only the appropriate amount of GO on SiO(2) can perform a good chromatographic separation. The comparison between chromatographic performances of bare SiO(2) column, GO/SiO(2)-2 column and C18 commercial column clearly show that GO/SiO(2)-2 and C18 columns obtained a better separation; GO/SiO(2)-2 exhibits a large π-electron system and C18 exhibits hydrophobicity. The eluting order, peak width and resolution of analyte on GO/SiO(2)-2 column was highly dependent on the size of its π-electron system, while on the C18 column the decisive factor is its hydrophobic property.

Effects of plastic mulches and high tunnel raspberry production systems on soil physicochemical quality indicators

NASA Astrophysics Data System (ADS)

Domagała-Świątkiewicz, Iwona; Siwek, Piotr

2018-01-01

In horticulture, degradable materials are desirable alternatives to plastic films. Our aim was to study the impact of soil plastic mulching on the soil properties in the high tunnel and open field production systems of raspberry. The raised beds were mulched with a polypropylene non-woven and two degradable mulches: polypropylene with a photodegradant and non-woven polylactide. The results indicated that the system of raspberry production, as well as the type of mulching had significant impact on soil organic carbon stock, moisture content and water stable aggregate amount. Soils taken from the open field system had a lower bulk density and water stability aggregation index, but higher organic carbon and capillary water content as compared to soils collected from high tunnel conditions. In comparison with the open field system, soil salinity was also found to be higher in high tunnel, as well as with higher P, Mg, Ca, S, Na and B content. Furthermore, mulch covered soils had more organic carbon amount than the bare soils. Soil mulching also enhanced the water capacity expressed as a volume of capillary water content. In addition, mulching improved the soil structure in relation to the bare soil, in particular, in open field conditions. The impact of the compared mulches on soil quality indicators was similar.

Before Immense Saturn

NASA Image and Video Library

2010-07-22

The moons Mimas and Janus seem insignificant in front of the immensity of Saturn in this NASA Cassini spacecraft image. Mimas is visible above the rings near the center; Janus is barely detectable as a tiny speck of light below the rings on the left.

Vegetation associated with different walking track types in the Kosciuszko alpine area, Australia.

PubMed

Hill, Wendy; Pickering, Catherine Marina

2006-01-01

Tourism infrastructure such as walking tracks can have negative effects on vegetation including in mountain regions. In the alpine area around continental Australia's highest mountain, Mt Kosciuszko (2228 m), there is a range of walking tracks (paved, gravel and raised steel mesh surfaces) in addition to an extensive network of informal/non-hardened tracks. Vegetation characteristics were compared between track types on/under tracks, on the track verge, and in the adjacent native vegetation. For a raised steel mesh walkway there was no difference in vegetation under the walkway, on the verge, and 3m away. In contrast, for a non-hardened track there was 35% bare ground on the track surface but no other detectable impacts. Gravel and paved tracks had distinct verges largely comprising bare ground and exotic species. For non-hardened tracks there was an estimated 270 m2 of disturbance per km of track. For wide gravel tracks the combined area of bare ground, exotic plants and gravel was estimated as 4290 m2 per km, while for narrow gravel tracks it was estimated as 2940 m2 per km. For paved tracks there was around 2680 m2 per km of damage. In contrast, there was no detectable effect of raised steel mesh walkway on vegetation highlighting some of the benefits of this surface over other track types.

Detection of the Pseudomonas Quinolone Signal (PQS) by cyclic voltammetry and amperometry using a boron doped diamond electrode.

PubMed

Zhou, Lin; Glennon, Jeremy D; Luong, John H T; Reen, F Jerry; O'Gara, Fergal; McSweeney, Christina; McGlacken, Gerard P

2011-10-07

2-Heptyl-3-hydroxy-4-quinolone, known as the Pseudomonas Quinolone Signal, is a key regulator of bacterial cooperative behaviour known as quorum sensing. A simple electrochemical strategy was employed for its sensitive detection using a bare boron-doped diamond electrode by cyclic voltammetry and amperometry. PQS (and potentially other quinolones) was then detected in cultures of P. aeruginosa pqsL(-) mutant strains. This journal is © The Royal Society of Chemistry 2011

Acquisition of Structure and Interpretation: Cases from Mandarin Bare and Non-Bare Noun Phrases

ERIC Educational Resources Information Center

Chang, Hsiang-Hua

2011-01-01

Children's production of bare nominals is universal. When acquiring languages disallowing bare nominals, children will develop from the bare to the non-bare stage. However, Mandarin nominals may appear bare or non-bare in various positions with all kinds of interpretations. This dissertation conducts two acquisition studies to examine the…

Detecting barely visible impact damages of honeycomb and laminate CFRP using digital shearography

NASA Astrophysics Data System (ADS)

Burkov, Mikhail; Lyubutin, Pavel; Byakov, Anton; Panin, Sergey

2017-12-01

The paper deals with testing of the developed shearographic device and signal processing software applied for nondestructive testing/evaluation (NDT/E) of carbon fiber reinforced polymers (CFRP). There were 4 types of test specimens: laminate CFRP, honeycomb CFRP, laminate CFRP with the channel stiffener, and laminate CFRP bolted with the aluminum plate. All the specimens were subjected to impact loading using the drop weight technique according to the ASTM D7136 standard in order to produce barely visible impact damages (BVID). The obtained shearograms easily reveal BVIDs as nonuniformities in strain fields. The results are analyzed and discussed in view of the sensitivity of shearography to delamination and debonding.

Bacterial and Fungal Communities in a Degraded Ombrotrophic Peatland Undergoing Natural and Managed Re-Vegetation

PubMed Central

Elliott, David R.; Caporn, Simon J. M.; Nwaishi, Felix; Nilsson, R. Henrik; Sen, Robin

2015-01-01

The UK hosts 15–19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat oligotrophy, re-vegetation recalcitrance, rhizosphere-microbe-soil interactions, C, N and P cycling, trajectory of restoration, and ecosystem service implications for peatland restoration. PMID:25969988

Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

PubMed

Elliott, David R; Caporn, Simon J M; Nwaishi, Felix; Nilsson, R Henrik; Sen, Robin

2015-01-01

The UK hosts 15-19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat oligotrophy, re-vegetation recalcitrance, rhizosphere-microbe-soil interactions, C, N and P cycling, trajectory of restoration, and ecosystem service implications for peatland restoration.

Hyperspectral Analysis for Standoff Detection of Dimethyl ...

EPA Pesticide Factsheets

Journal Article Detecting organophosphates in indoor settings requires more efficient and faster methods of surveying large surface areas than conventional approaches, which sample small surface areas followed by extraction and analysis. This study examined a standoff detection technique utilizing hyperspectral imaging for analysis of building materials in near-real time. In this proof-of-concept study, dimethyl methylphosphonate (DMMP) was applied to stainless steel and laminate coupons and spectra were collected during active illumination. Absorbance bands at approximately 1275 cm-1 and 1050 cm-1 were associated with phosphorus-oxygen double bond (P=O) and phosphorus-oxygen-carbon (P-O-C) bond stretches of DMMP, respectively. The magnitude of these bands increased linearly (r2 = 0.93) with DMMP across the full absorbance spectrum, between ν1 = 877 cm-1 to ν2 = 1262 cm-1. Comparisons between bare and contaminated surfaces on stainless steel using the spectral contrast angle technique indicated that the bare samples showed no sign of contamination, with large uniformly distributed contrast angles of 45˚-55˚, while the contaminated samples had smaller spectral contact angles of 40° in the uncontaminated region. The laminate contaminated region exhibited contact angles of < 25°. To the best of our knowledge, this is the first report to demonstrate that hyperspectral imaging can be used to detect DMMP on building materials, with detection levels similar to c

Comparison of Unmanned Aerial Vehicle Platforms for Assessing Vegetation Cover in Sagebrush Steppe Ecosystems

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

Robert P. Breckenridge; Maxine Dakins; Stephen Bunting

2011-09-01

In this study, the use of unmanned aerial vehicles (UAVs) as a quick and safe method for monitoring biotic resources was evaluated. Vegetation cover and the amount of bare ground are important factors in understanding the sustainability of many ecosystems and assessment of rangeland health. Methods that improve speed and cost efficiency could greatly improve how biotic resources are monitored on western lands. Sagebrush steppe ecosystems provide important habitat for a variety of species (including sage grouse and pygmy rabbit). Improved methods are needed to support monitoring these habitats because there are not enough resource specialists or funds available formore » comprehensive ground evaluations. In this project, two UAV platforms, fixed wing and helicopter, were used to collect still-frame imagery to assess vegetation cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to (1) estimate percent cover for six different vegetation types (shrub, dead shrub, grass, forb, litter, and bare ground) and (2) locate sage grouse using representative decoys. The field plots were located on the Idaho National Engineering (INL) site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetation cover. A software program called SamplePoint was used along with visual inspection to evaluate percent cover for the six cover types. Results were compared against standard field measurements to assess accuracy. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform to use. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.« less

Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents.

PubMed

Sigler, Matthias; Klötzer, Julia; Quentin, Thomas; Paul, Thomas; Möller, Oliver

2015-12-01

Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model. Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation. On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents. After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

Real-Time and Delayed Analysis of Tree and Shrub Cores as Indicators of Subsurface Volatile Organic Compound Contamination, Durham Meadows Superfund Site, Durham, Connecticut, August 29, 2006

USGS Publications Warehouse

Vroblesky, Don A.; Willey, Richard E.; Clifford, Scott; Murphy, James J.

2008-01-01

This study examined volatile organic compound concentrations in cores from trees and shrubs for use as indicators of vadose-zone contamination or potential vapor intrusion by volatile organic compounds into buildings at the Durham Meadows Superfund Site, Durham, Connecticut. The study used both (1) real-time tree- and shrub-core analysis, which involved field heating the core samples for 5 to 10 minutes prior to field analysis, and (2) delayed analysis, which involved allowing the gases in the cores to equilibrate with the headspace gas in the sample vials unheated for 1 to 2 days prior to analysis. General correspondence was found between the two approaches, indicating that preheating and field analysis of vegetation cores is a viable approach to real-time monitoring of subsurface volatile organic compounds. In most cases, volatile organic compounds in cores from trees and shrubs at the Merriam Manufacturing Company property showed a general correspondence to the distribution of volatile organic compounds detected in a soil-gas survey, despite the fact that most of the soil-gas survey data in close proximity to the relevant trees were collected about 3 years prior to the tree-core collection. Most of the trees cored at the Durham Meadows Superfund Site, outside of the Merriam Manufacturing Company property, contained no volatile organic compounds and were in areas where indoor air sampling and soil-gas sampling showed little or no volatile organic compound concentrations. An exception was tree DM11, which contained barely detectable concentrations of trichloroethene near a house where previous investigations found low concentrations of trichloroethene (0.13 to 1.2 parts per billion by volume) in indoor air and 7.7 micrograms per liter of trichloroethene in the ground water. The barely detectable concentration of trichloroethene in tree DM11 and the lack of volatile organic compound detection in nearby tree DM10 (adjacent to the well having 7.7 micrograms of trichloroethene) may be attributable to the relatively large depth to water (17.6 feet), the relatively low soil-vapor trichloroethene concentration, and the large amount of rainfall during and preceding the tree-coring event. The data indicate that real-time and delayed analyses of tree cores are viable approaches to examining subsurface volatile organic compound soil-gas or vadose-zone contamination at the Durham Meadows Superfund Site and other similar sites. Thus, the methods may have application for determining the potential for vapor intrusion into buildings.

Environmental and alloying effects on corrosion of metals and alloys

NASA Astrophysics Data System (ADS)

Liang, Dong

2009-12-01

In the first part of this project, corrosion studies were carried out on 304L stainless steel samples welded with Cr-free consumables, which were developed to minimize the concentration of chromate species in the weld fume. The corrosion properties of Ni-Cu and Ni-Cu-Pd Gas Tungsten Arc (GTA) welds and Shielded Metal Arc (SMA) welds are comparable to those of welds fabricated with SS308L consumable, which is the standard consumable for welding 304L. Although the breakdown potentials of the new welds from both welding processes are lower than that of the SS308L weld, the repassivation potential of these new welds is much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Our studies showed that the Ni-Cu and Ni-Cu-Pd welds are more resistant to crevice corrosion than SS308L welds, which is related to the high repassivation potential. Also, addition of Pd improved the corrosion resistance of the new welds, which is consistent with previous studies from button samples and bead-on-plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni-Cu-Pd welds can be a qualified substitute for SS308 weld. In the second part of this project, efforts are put on the connection between lab and field exposure tests because sometimes the correspondence between lab atmospheric corrosion tests (ASTM B117) and field exposures is poor as a result of differences in the critical conditions controlling chemical and electrochemical reactions on surfaces. Recent studies in atmospheric chemistry revealed the formation of extremely reactive species from interactions between UV light, chloride aerosols above oceans and oxidizing agents such as ozone or peroxide. Atmospheric corrosion of metals can be affected by these species which might be transported long distances in the atmosphere to locations far from oceans. However, these species could be missed in standard laboratory exposures such as ASTM B117. Initial efforts focused on the effects UV radiation, O3, relative humidity on the atmospheric corrosion of bare silver. Later work addressed the corrosion of silver samples deposited with NaCl particles. An exposure chamber that can simulate various environmental effects was built. The effects of UV radiation, O3, and relative humidity were varied separately while keeping the other factors the same level. The corrosion products were analyzed by the galvanostatic reduction method and characterization techniques such as SEM and EDS. It was found that both UV and O3 are necessary for fast corrosion on bare silver and this fast corrosion reaction results from atomic oxygen generated photodegradation of O3. In the presence of UV and O3, relative humidity has little effect on the atmospheric corrosion of bare silver in contrast to conventional atmospheric corrosion. The degree of corrosion is found to increase with O3 concentration. Moreover, a kinetic study of atmospheric corrosion of bare silver found that an incubation time for the atmospheric corrosion attack is needed. This incubation time is related to the chemisorption process of atomic oxygen. Though UV radiation can form reactive atomic oxygen which is more reactive than O3 alone as shown in the last chapter, the enhancement of corrosion by UV is limited for Ag with NaCl particles at low ozone concentration and high RH. The corrosion rate of silver with NaCl particles is found to increase with relative humidity, which is different than the case of bare silver. This indicates that different mechanisms control the atmospheric corrosion of silver. The incubation time for corrosion of silver with NaCl particles is shorter than for bare silver. This result from chemisorption of Cl 2 is favored over that of atomic oxygen. Interestingly, the total corrosion product of silver with NaCl particles is less than that of bare silver. This could be due to limited amount of NaCl and also higher oxidizing power of atomic oxygen. Finally, bare silver samples were exposed in salt spray chamber according to ASTM B117 up to 4 months. Very little corrosion products were detected after exposure, which is attributed to the lack of reactive species such as O and O3 in the environment. (Abstract shortened by UMI.)

Monopole search below the Parker limit with the MACRO detector at Gran Sasso

NASA Technical Reports Server (NTRS)

Tarle, G.

1985-01-01

The MACRO detector approved for the Gran Sasso Underground Laboratory in Italy will be the first capable of performing a definitive search for super-massive grand unified theory (GUT) monopoles at a level significantly below the Parker flux limit of 10 to the minus 15th power square centimeters Sr(-1) 5(-1). GUT monopoles will move at very low velocities (V approx. 0.001 c) relative to the Earth and a multifaceted detection technique is required to assume their unambiguous identification. Calculations of scintillator response to slow monopoles and measurements of scintillation efficiency for low energy protons have shown that bare monopoles and electrically charged monopoles moving at velocities as low as 5 x .0001 c will produce detectable scintillation signals. The time-of-flight between two thick (25 cm) liquid scintillation layers separated by 4.3m will be used in conjunction with waveform digitization of signals of extended duration in each thick scintillator to provide a redundant signature for slow penetrating particles. Limited streamer tubes filled with He and n-pentane will detect bare monopoles with velocities as low as 1 x 0.0001 c by exploiting monopole induced level mixing and the Penning effect.

TH-AB-209-02: Gadolinium Measurements in Human Bone Using in Vivo K X-Ray Fluorescence (KXRF) Technique

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

Mostafaei, F; Nie, L

Purpose: Improvement in an in vivo K x-ray fluorescence system, based on 109Cd source, for the detection of gadolinium (Gd) in bone has been investigated. Series of improvements to the method is described. Gd is of interest because of the extensive use of Gd-based contrast agents in MR imaging and the potential toxicity of Gd exposure. Methods: A set of seven bone equivalent phantoms with different amount of Gd concentrations (from 0–100 ppm) has been developed. Soft tissue equivalent plastic plates were used to simulate the soft tissue overlaying the tibia bone in an in vivo measurement. A new 5more » GBq 109Cd source was used to improve the source activity in comparison to the previous study (0.17 GBq). An improved spectral fitting program was utilized for data analysis. Results: The previous published minimum detection limit (MDL) for Gd doped phantom measurements using KXRF system was 3.3 ppm. In this study the MDL for bare bone phantoms was found to be 0.8 ppm. Our previous study used only three layers of plastic (0.32, 0.64 and 0.96 mm) as soft tissue equivalent materials and obtained the MDL of 4–4.8 ppm. In this study the plastic plates with more realistic thicknesses to simulate the soft tissue covering tibia bone (nine thicknesses ranging from 0.61–6.13 mm) were used. The MDLs for phantoms were determined to be 1.8–3.5 ppm. Conclusion: With the improvements made to the technology (stronger source, improved data analysis algorithm, realistic soft tissue thicknesses), the MDL of the KXRF system to measure Gd in bare bone was improved by a factor of 4.1. The MDL is at the level of the bone Gd concentration reported in literature. Hence, the system is ready to be tested on human subjects to investigate the use of bone Gd as a biomarker for Gd toxicity.« less

Highly selective colorimetric and electrochemical sensing of iron (III) using Nile red functionalized graphene film.

PubMed

Sadak, Omer; Sundramoorthy, Ashok K; Gunasekaran, Sundaram

2017-03-15

We report a highly selective method for identification and detection of iron (III) (ferric iron, Fe 3+ ) using Nile red (NR) as a complexing agent. Fe 3+ preferentially binds with NR in dimethylformamide (DMF)/water (1:1) solution over other cations such as Fe 2+ , Cu 2+ , Pb 2+ , Hg 2+ , Mn 2+ , Ni 2+ , Zn 2+ , Co 2+ and Cd 2+ at room temperature. In the presence of Fe 3+ , the color of NR solution changes from purple to dark brown, which is detectable with bare eyes. Using UV-vis spectroscopy, we could measure the amount of Fe 3+ in the sample solution by monitoring changes in absorption from 540 to 580nm; the linear range and the limit of detection are 30-1000µM and 24.9µM, respectively. Taking advantage of the NR selectivity, we treated partially oxidized graphene sheets (po-Gr) with NR to obtain po-Gr-NR dispersion by ultrasonication. The NR-treated po-Gr flakes (po-Gr-NR) were characterized by UV-vis, FT-IR, and Raman spectroscopies and FE-SEM, which indicated attachment of NR on po-Gr sheets. The po-Gr-NR hybrid film deposited glassy carbon electrode (po-Gr-NR/GCE) served as the Fe 3+ sensor. Differential pulse voltammetry was used to investigate the detection of Fe 3+ in 0.05M HCl+0.05M KCl solution. The linear range and the limit of detection of Fe 3+ were from 37.5nM to 21.53µM and 18.7nM, respectively. Furthermore, this sensor was successfully used to measure Fe 3+ content in red wine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of vegetation construction on runoff and sediment yield and runoff erosion ability on slope surface

NASA Astrophysics Data System (ADS)

Yang, Chun Xia; Xiao, PeiQing; Li, Li; Jiao, Peng

2018-06-01

Land consolidation measures affected the underlying surface erosion environment during the early stage of vegetation construction, and then had an impact on rainfall infiltration, erosion and sediment yield. This paper adopted the field simulated rainfall experiments to analyze the function that pockets site preparation measures affected on rainfall infiltration, runoff sediment yield and runoff erosion ability. The results showed that, the measures can delay the rainfall runoff formation time of the slope by 3'17" and 1'04" respectively. Compared with the same condition of the bare land and natural grassland. The rainfall infiltration coefficient each increased by 76.47% and 14.49%, and infiltration rate increased by 0.26 mm/min and 0.11mm/min respectively; The amount of runoff and sediment yield were reduced because of the pockets site preparation. The amount of runoff reducing rate were 33.51% and 30.49%, and sediment reduction rate were 81.35% and 65.66%, The sediment concentration was decreased by 71.99% and 50.58%; Runoff velocity of bare slope and natural grassland slope decreased by 38.12% and 34.59% respectively after pockets site preparation . The runoff erosion rate decreased by 67.92% and 79.68% respectively. The results will have a great significance for recognizing the effect of water and sediment reduction about vegetation and the existence of its plowing measures at the early period of restoration.

Image Processing Diagnostics: Emphysema

NASA Astrophysics Data System (ADS)

McKenzie, Alex

2009-10-01

Currently the computerized tomography (CT) scan can detect emphysema sooner than traditional x-rays, but other tests are required to measure more accurately the amount of affected lung. CT scan images show clearly if a patient has emphysema, but is unable by visual scan alone, to quantify the degree of the disease, as it appears merely as subtle, barely distinct, dark spots on the lung. Our goal is to create a software plug-in to interface with existing open source medical imaging software, to automate the process of accurately diagnosing and determining emphysema severity levels in patients. This will be accomplished by performing a number of statistical calculations using data taken from CT scan images of several patients representing a wide range of severity of the disease. These analyses include an examination of the deviation from a normal distribution curve to determine skewness, a commonly used statistical parameter. Our preliminary results show that this method of assessment appears to be more accurate and robust than currently utilized methods which involve looking at percentages of radiodensities in air passages of the lung.

Sensitive and selective determination of Cu2+ at D-penicillamine functionalized nano-cellulose modified pencil graphite electrode

NASA Astrophysics Data System (ADS)

Taheri, M.; Ahour, F.; Keshipour, S.

2018-06-01

A novel electrochemical sensor based on D-penicillamine anchored nano-cellulose (DPA-NC) modified pencil graphite electrode was fabricated and used for highly selective and sensitive determination of copper (II) ions in the picomolar concentration by square wave adsorptive stripping voltammetric (SWV) method. The modified electrode showed better and increased SWV response compared to the bare and NC modified electrodes which may be related to the porous structure of modifier along with formation of complex between Cu2+ ions and nitrogen or oxygen containing groups in DPA-NC. Optimization of various experimental parameters influence the performance of the sensor, were investigated. Under optimized condition, DPA-NC modified electrode was used for the analysis of Cu2+ in the concentration range from 0.2 to 50 pM, and a lower detection limit of 0.048 pM with good stability, repeatability, and selectivity. Finally, the practical applicability of DPA-NC-PGE was confirmed via measuring trace amount of Cu (II) in tap and river water samples.

Noncontact atomic force microscopy in liquid environment with quartz tuning fork and carbon nanotube probe

NASA Astrophysics Data System (ADS)

Kageshima, Masami; Jensenius, Henriette; Dienwiebel, Martin; Nakayama, Yoshikazu; Tokumoto, Hiroshi; Jarvis, Suzanne P.; Oosterkamp, Tjerk H.

2002-03-01

A force sensor for noncontact atomic force microscopy in liquid environment was developed by combining a multiwalled carbon nanotube (MWNT) probe with a quartz tuning fork. Solvation shells of octamethylcyclotetrasiloxane on a graphite surface were detected both in the frequency shift and dissipation. Due to the high aspect ratio of the CNT probe, the long-range background force was barely detectable in the solvation region.

A randomized control hands-on defibrillation study-Barrier use evaluation.

PubMed

Wampler, David; Kharod, Chetan; Bolleter, Scotty; Burkett, Alison; Gabehart, Caitlin; Manifold, Craig

2016-06-01

Chest compressions and defibrillation are the only therapies proven to increase survival in cardiac arrest. Historically, rescuers must remove hands to shock, thereby interrupting chest compressions. This hands-off time results in a zero blood flow state. Pauses have been associated with poorer neurological recovery. This was a blinded randomized control cadaver study evaluating the detection of defibrillation during manual chest compressions. An active defibrillator was connected to the cadaver in the sternum-apex configuration. The sham defibrillator was not connected to the cadaver. Subjects performed chest compressions using 6 barrier types: barehand, single and double layer nitrile gloves, firefighter gloves, neoprene pad, and a manual chest compression/decompression device. Randomized defibrillations (10 per barrier type) were delivered at 30 joules (J) for bare hand and 360J for all other barriers. After each shock, the subject indicated degree of sensation on a VAS scale. Ten subjects participated. All subjects detected 30j shocks during barehand compressions, with only 1 undetected real shock. All barriers combined totaled 500 shocks delivered. Five (1%) active shocks were detected, 1(0.2%) single layer of Nitrile, 3(0.6%) with double layer nitrile, and 1(0.2%) with the neoprene barrier. One sham shock was reported with the single layer nitrile glove. No shocks were detected with fire gloves or compression decompression device. All shocks detected barely perceptible (0.25(±0.05)cm on 10cm VAS scale). Nitrile gloves and neoprene pad prevent (99%) responder's detection of defibrillation of a cadaver. Fire gloves and compression decompression device prevented detection. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Hyperspectral analysis of seagrass in Redfish Bay, Texas

NASA Astrophysics Data System (ADS)

Wood, John S.

Remote sensing using multi- and hyperspectral imaging and analysis has been used in resource management for quite some time, and for a variety of purposes. In the studies to follow, hyperspectral imagery of Redfish Bay is used to discriminate between species of seagrasses found below the water surface. Water attenuates and reflects light and energy from the electromagnetic spectrum, and as a result, subsurface analysis can be more complex than that performed in the terrestrial world. In the following studies, an iterative process is developed, using ENVI image processing software and ArcGIS software. Band selection was based on recommendations developed empirically in conjunction with ongoing research into depth corrections, which were applied to the imagery bands (a default depth of 65 cm was used). Polygons generated, classified and aggregated within ENVI are reclassified in ArcGIS using field site data that was randomly selected for that purpose. After the first iteration, polygons that remain classified as 'Mixed' are subjected to another iteration of classification in ENVI, then brought into ArcGIS and reclassified. Finally, when that classification scheme is exhausted, a supervised classification is performed, using a 'Maximum Likelihood' classification technique, which assigned the remaining polygons to the classification that was most like the training polygons, by digital number value. Producer's Accuracy by classification ranged from 23.33 % for the 'MixedMono' class to 66.67% for the 'Bare' class; User's Accuracy by classification ranged from 22.58% for the 'MixedMono' class to 69.57% for the 'Bare' classification. An overall accuracy of 37.93% was achieved. Producers and Users Accuracies for Halodule were 29% and 39%, respectively; for Thalassia, they were 46% and 40%. Cohen's Kappa Coefficient was calculated at .2988. We then returned to the field and collected spectral signatures of monotypic stands of seagrass at varying depths and at three sensor levels: above the water surface, just below the air/water interface, and at the canopy position, when it differed from the subsurface position. Analysis of plots of these spectral curves, after applying depth corrections and Multiplicative Scatter Correction, indicates that there are detectable spectral differences between Halodule and Thalassia species at all three positions. Further analysis indicated that only above-surface spectral signals could reliably be used to discriminate between species, because there was an overlap of the standard deviations in the other two positions. A recommendation for wavelengths that would produce increased accuracy in hyperspectral image analysis was made, based on areas where there is a significant amount of difference between the mean spectral signatures, and no overlap of the standard deviations in our samples. The original hyperspectral imagery was reprocessed, using the bands recommended from the research above (approximately 535, 600, 620, 638, and 656 nm). A depth raster was developed from various available sources, which was resampled and reclassified to reflect values for water absorption and water scattering, which were then applied to each band using the depth correction algorithm. Processing followed the iterative classification methods described above. Accuracy for this round of processing improved; overall accuracy increased from 38% to 57%. Improvements were noted in Producer's Accuracy, with the 'Bare' vi classification increasing from 67% to 73%, Halodule increasing from 29% to 63%, Thalassia increasing slightly, from 46% to 50%, and 'MixedMono' improving from 23% to 42%. User's Accuracy also improved, with the 'Bare' class increasing from 69% to 70%, Halodule increasing from 39% to 67%, Thalassia increasing from 40% to 7%, and 'MixedMono' increasing from 22.5% to 35%. A very recent report shows the mean percent cover of seagrasses in Redfish Bay and Corpus Christi Bay combined for all species at 68.6%, and individually by species: Halodule 39.8%, Thalassia 23.7%, Syringodium 4%, Ruppia 1% and Halophila 0.1%. Our study classifies 15% as 'Bare', 23% Halodule, 18% Thalassia, and 2% Ruppia. In addition, we classify 5% as 'Mixed', 22% as 'MixedMono', 12% as 'Bare/Halodule Mix', and 3% 'Bare/Thalassia Mix'. Aggregating the 'Bare' and 'Bare/species' classes would equate to approximately 30%, very close to what this new study produces. Other classes are quite similar, when considering that their study includes no 'Mixed' classifications. This series of research studies illustrates the application and utility of hyperspectral imagery and associated processing to mapping shallow benthic habitats. It also demonstrates that the technology is rapidly changing and adapting, which will lead to even further increases in accuracy. Future studies with hyperspectral imaging should include extensive spectral field collection, and the application of a depth correction.

In Vitro Studies on the Degradability, Bioactivity, and Cell Differentiation of PRP/AZ31B Mg Alloys Composite Scaffold.

PubMed

Zou, Jian; Shi, Zhongmin; Xu, Hongwei; Li, Xiaolin

2017-01-01

In recent years, more and more methods have been developed to improve the bioactivity of the biodegradable materials in bone tissue regeneration. In present study, we used rat mesenchymal stem cells (rMSCs) to evaluate the outcomes of Mg alloys (AZ31B, Magnesium, and Aluminum) and Platelet-rich plasma (PRP)/Mg alloys on rMSCs biocompatibility and osteogenic differentiation. Water absorption experiments indicated that both bare AZ31B and PRP/AZ31B were capable of absorbing large amounts of water. But the water absorption ratio for PRP/AZ31B was significantly higher than that for bare AZ31B. The degradability experiments implied that both samples degraded at same speed. rMSCs on the surface of AZ31B distributed more and better than those on the AZ31B scaffold. In ALP activity experiment, the activity of rMSCs on the PRP/AZ31B was markedly higher than that on the AZ31B scaffolds on the 7th day and 14th day. qRT-PCR also showed that OPN and OCN were expressed in both samples. OPN and OCN expression in PRP/AZ31B sample were higher than those in bare AZ31B samples. In summary, the in vitro study implied that AZ31B combined with PRP could remarkably improve cell seeding, attachment, proliferation, and differentiation.

Adequate Hand Washing and Glove Use Are Necessary To Reduce Cross-Contamination from Hands with High Bacterial Loads.

PubMed

Robinson, Andrew L; Lee, Hyun Jung; Kwon, Junehee; Todd, Ewen; Rodriguez, Fernando Perez; Ryu, Dojin

2016-02-01

Hand washing and glove use are the main methods for reducing bacterial cross-contamination from hands to ready-to-eat food in a food service setting. However, bacterial transfer from hands to gloves is poorly understood, as is the effect of different durations of soap rubbing on bacterial reduction. To assess bacterial transfer from hands to gloves and to compare bacterial transfer rates to food after different soap washing times and glove use, participants' hands were artificially contaminated with Enterobacter aerogenes B199A at ∼9 log CFU. Different soap rubbing times (0, 3, and 20 s), glove use, and tomato dicing activities followed. The bacterial counts in diced tomatoes and on participants' hands and gloves were then analyzed. Different soap rubbing times did not significantly change the amount of bacteria recovered from participants' hands. Dicing tomatoes with bare hands after 20 s of soap rubbing transferred significantly less bacteria (P < 0.01) to tomatoes than did dicing with bare hands after 0 s of soap rubbing. Wearing gloves while dicing greatly reduced the incidence of contaminated tomato samples compared with dicing with bare hands. Increasing soap washing time decreased the incidence of bacteria recovered from outside glove surfaces (P < 0.05). These results highlight that both glove use and adequate hand washing are necessary to reduce bacterial cross-contamination in food service environments.

1-Meter Digital Elevation Model specification

USGS Publications Warehouse

Arundel, Samantha T.; Archuleta, Christy-Ann M.; Phillips, Lori A.; Roche, Brittany L.; Constance, Eric W.

2015-10-21

In January 2015, the U.S. Geological Survey National Geospatial Technical Operations Center began producing the 1-Meter Digital Elevation Model data product. This new product was developed to provide high resolution bare-earth digital elevation models from light detection and ranging (lidar) elevation data and other elevation data collected over the conterminous United States (lower 48 States), Hawaii, and potentially Alaska and the U.S. territories. The 1-Meter Digital Elevation Model consists of hydroflattened, topographic bare-earth raster digital elevation models, with a 1-meter x 1-meter cell size, and is available in 10,000-meter x 10,000-meter square blocks with a 6-meter overlap. This report details the specifications required for the production of the 1-Meter Digital Elevation Model.

DOING Physics--Physics Activities for Groups.

ERIC Educational Resources Information Center

Zwicker, Earl, Ed.

1985-01-01

Students are challenged to investigate a simple electric motor and to build their own model from a battery, wood block, clips, enameled copper wire, bare wire, and sandpaper. Through trial and error, several discoveries are made, including a substitute commutator and use of a radio to detect motor armature contact changes. (DH)

Differences between tethered polyelectrolyte chains adsorbed onto bare mica and hydrophobically modified mica, comparison with theory.

NASA Astrophysics Data System (ADS)

Balastre, Marc; Tamashiro, Mario N.; Hernandez, Ernesto; Pincus, Philip; Tirrell, Matthew

2001-03-01

End-grafted polymers generated from the adsorption of asymmetric diblock copolymers on solid surface play an important role in many areas of science and technology. While the small insoluble block acts as an anchor, the charged soluble block confers useful properties to the surface. This study looks at tethered layers of poly(styrene sulfonate)/poly(t-butyl styrene) (PtBS-PSS) adsorbed on both mica (hydrophilic) and octadecyltriethoxysilane (OTE) modified mica (hydrophobic). Normal compressing forces at two different constant grafting densities (bare and modified mica) were measured with the surface force apparatus and compared with theoretical prediction. The effect of salt concentration (Cs) upon the thickness of the self-assembled layers (Lo) was measured in each case. For adsorption of diblock copolymers onto OTE the resulting scaling relationship is much closer to the brush theory, Lo Cs-1/3. This result suggests that the adsorbed amount on mica is not high enough to form a brush.

Automation in airport security X-ray screening of cabin baggage: Examining benefits and possible implementations of automated explosives detection.

PubMed

Hättenschwiler, Nicole; Sterchi, Yanik; Mendes, Marcia; Schwaninger, Adrian

2018-10-01

Bomb attacks on civil aviation make detecting improvised explosive devices and explosive material in passenger baggage a major concern. In the last few years, explosive detection systems for cabin baggage screening (EDSCB) have become available. Although used by a number of airports, most countries have not yet implemented these systems on a wide scale. We investigated the benefits of EDSCB with two different levels of automation currently being discussed by regulators and airport operators: automation as a diagnostic aid with an on-screen alarm resolution by the airport security officer (screener) or EDSCB with an automated decision by the machine. The two experiments reported here tested and compared both scenarios and a condition without automation as baseline. Participants were screeners at two international airports who differed in both years of work experience and familiarity with automation aids. Results showed that experienced screeners were good at detecting improvised explosive devices even without EDSCB. EDSCB increased only their detection of bare explosives. In contrast, screeners with less experience (tenure < 1 year) benefitted substantially from EDSCB in detecting both improvised explosive devices and bare explosives. A comparison of all three conditions showed that automated decision provided better human-machine detection performance than on-screen alarm resolution and no automation. This came at the cost of slightly higher false alarm rates on the human-machine system level, which would still be acceptable from an operational point of view. Results indicate that a wide-scale implementation of EDSCB would increase the detection of explosives in passenger bags and automated decision instead of automation as diagnostic aid with on screen alarm resolution should be considered. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Radioactivities and gamma-rays from supernovae

NASA Technical Reports Server (NTRS)

Woosley, S. E.

1991-01-01

An account is given of the implications of several calculations relevant to the estimation of gamma-ray signals from various explosive astronomical phenomena. After discussing efforts to constrain the amounts of Ni-57 and Ti-44 produced in SN 1987A, attention is given to the production of Al-27 in massive stars and SNs. A 'delayed detonation' model of type Ia SNs is proposed, and the gamma-ray signal which may be expected when a bare white dwarf collapses directly into a neutron star is discussed.

A rapid electrochemical monitoring platform for sensitive determination of thiamethoxam based on β-cyclodextrin-graphene composite.

PubMed

Zhai, XingChen; Zhang, Hua; Zhang, Min; Yang, Xin; Gu, Cheng; Zhou, GuoPeng; Zhao, HaiTian; Wang, ZhenYu; Dong, AiJun; Wang, Jing

2017-08-01

A rapid monitoring platform for sensitive voltammetric detection of thiamethoxam residues is reported in the present study. A β-cyclodextrin-reduced graphene oxide composite was used as a reinforcing material in electrochemical determination of thiamethoxam. Compared with bare glassy carbon electrodes, the reduction peak currents of thiamethoxam at reduced graphene oxide/glassy carbon electrode and β-cyclodextrin-reduced graphene oxide/glassy carbon electrode were increased by 70- and 124-fold, respectively. The experimental conditions influencing voltammetric determination of thiamethoxam, such as the amount of β-cyclodextrin-reduced graphene oxide, solution pH, temperature, and accumulation time, were optimized. The reduction mechanism and binding affinity of this material is also discussed. Under optimal conditions, the reduction peak currents increased linearly between 0.5 µM and 16 µM concentration of thiamethoxam. The limit of detection was 0.27 µM on the basis of a signal-to-noise ratio of 3. When the proposed method was applied to brown rice in a recovery test, the recoveries were between 92.20% and 113.75%. The results were in good concordance with the high-performance liquid chromatography method. The proposed method therefore provides a promising and effective platform for sensitive and rapid determination of thiamethoxam. Environ Toxicol Chem 2017;36:1991-1997. © 2017 SETAC. © 2017 SETAC.

The rodent Research Animal Holding Facility as a barrier to environmental contamination

NASA Technical Reports Server (NTRS)

Savage, P. D., Jr.; Jahns, G. C.; Dalton, B. P.; Hogan, R. P.; Wray, A. E.

1989-01-01

The rodent Research Animal Holding Facility (RAHF), developed by NASA Ames Research Center (ARC) to separately house rodents in a Spacelab, was verified as a barrier to environmental contaminants during a 12-day biocompatibility test. Environmental contaminants considered were solid particulates, microorganisms, ammonia, and typical animal odors. The 12-day test conducted in August 1988 was designed to verify that the rodent RAHF system would adequately support and maintain animal specimens during normal system operations. Additional objectives of this test were to demonstrate that: (1) the system would capture typical particulate debris produced by the animal; (2) microorganisms would be contained; and (3) the passage of animal odors was adequately controlled. In addition, the amount of carbon dioxide exhausted by the RAHF system was to be quantified. Of primary importance during the test was the demonstration that the RAHF would contain particles greater than 150 micrometers. This was verified after analyzing collection plates placed under exhaust air ducts and and rodent cages during cage maintenance operations, e.g., waste tray and feeder changeouts. Microbiological testing identified no additional organisms in the test environment that could be traced to the RAHF. Odor containment was demonstrated to be less than barely detectable. Ammonia could not be detected in the exhaust air from the RAHF system. Carbon dioxide levels were verified to be less than 0.35 percent.

The rodent research animal holding facility as a barrier to environmental contamination

NASA Technical Reports Server (NTRS)

Savage, P. D., Jr.; Jahns, G. C.; Dalton, B. P.; Hogan, R. P.; Wray, A. E.

1989-01-01

The rodent Research Animal Holding Facility (RAHF), developed by NASA Ames Research Center (ARC) to separately house rodents in a Spacelab, was verified as a barrier to environmental contaminants during a 12-day biocompatibility test. Environmental contaminants considered were solid particulates, microorganisms, ammonia, and typical animal odors. The 12-day test conducted in August 1988 was designed to verify that the rodent RAHF system would adequately support and maintain animal specimens during normal system operations. Additional objectives of this test were to demonstrate that: (1) the system would capture typical particulate debris produced by the animal; (2) microorganisms would be contained; and (3) the passage of animal odors was adequately controlled. In addition, the amount of carbon dioxide exhausted by the RAHF system was to be quantified. Of primary importance during the test was the demonstration that the RAHF would contain particles greater than 150 micrometers. This was verified after analyzing collection plates placed under exhaust air ducts and rodent cages during cage maintenance operations, e.g., waste tray and feeder changeouts. Microbiological testing identified no additional organisms in the test environment that could be traced to the RAHF. Odor containment was demonstrated to be less than barely detectable. Ammonia could not be detected in the exhaust air from the RAHF system. Carbon dioxide levels were verified to be less than 0.35 percent.

Water deficit induces swainsonine of some locoweed taxa, but with no swainsonine-growth trade-off

USDA-ARS?s Scientific Manuscript database

Locoweeds (Astragalus and Oxytropis spp.) contain swainsonine (SWA), an alkaloid toxic to vertebrates. In two common-garden experiments, we studied three A. mollissimus varieties that vary in SWA levels (barely detectable SWA var. ‘thompsonae’, intermediate SWA var. ‘bigelovii’, and high SWA var. ‘m...

Very Large Scale Aerial (VLSA) imagery for assessing postfire bitterbrush recovery

Treesearch

Corey A. Moffet; J. Bret Taylor; D. Terrance Booth

2008-01-01

Very large scale aerial (VLSA) imagery is an efficient tool for monitoring bare ground and cover on extensive rangelands. This study was conducted to determine whether VLSA images could be used to detect differences in antelope bitterbrush (Purshia tridentata Pursh DC) cover and density among similar ecological sites with varying postfire recovery...

Ionic Segregation on Grain Boundaries in Thermally Grown Alumina Scales

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

Pint, Bruce A; Unocic, Kinga A

2012-01-01

This study first examined segregation behaviour in the alumina scale formed after 100 h at 1100 C on bare and MCrAlYHfSi-coated single-crystal superalloys with {approx}10 ppma La and Y. For the bare superalloy, Hf and Ti were detected on the grain boundaries of the inner columnar alumina layer. Increasing the oxidation temperature to 1200 C for 2 h did not change the segregation behavior. With the bond coating, both Y and Hf were segregated to the grain boundaries as expected. However, there was evidence of Ti-rich oxide particles near the gas interface suggesting that Ti diffused from the superalloy throughmore » the coating. To further understand these segregation observations with multiple dopants, other alumina-forming systems were examined. Alumina scale grain boundary co-segregation of Ti with Y is common for FeCrAl alloys. Co-segregation of Hf and Ti was observed in the scale formed on co-doped NiAl. No La segregation was detected in the scale formed on NiCrAl with only a 19 ppma La addition, however, the scale was adherent.« less

Deep convolutional neural network for classifying Fusarium wilt of radish from unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Ha, Jin Gwan; Moon, Hyeonjoon; Kwak, Jin Tae; Hassan, Syed Ibrahim; Dang, Minh; Lee, O. New; Park, Han Yong

2017-10-01

Recently, unmanned aerial vehicles (UAVs) have gained much attention. In particular, there is a growing interest in utilizing UAVs for agricultural applications such as crop monitoring and management. We propose a computerized system that is capable of detecting Fusarium wilt of radish with high accuracy. The system adopts computer vision and machine learning techniques, including deep learning, to process the images captured by UAVs at low altitudes and to identify the infected radish. The whole radish field is first segmented into three distinctive regions (radish, bare ground, and mulching film) via a softmax classifier and K-means clustering. Then, the identified radish regions are further classified into healthy radish and Fusarium wilt of radish using a deep convolutional neural network (CNN). In identifying radish, bare ground, and mulching film from a radish field, we achieved an accuracy of ≥97.4%. In detecting Fusarium wilt of radish, the CNN obtained an accuracy of 93.3%. It also outperformed the standard machine learning algorithm, obtaining 82.9% accuracy. Therefore, UAVs equipped with computational techniques are promising tools for improving the quality and efficiency of agriculture today.

Defect imaging in composite structures

NASA Astrophysics Data System (ADS)

Fromme, Paul; Endrizzi, Marco; Olivo, Alessandro

2018-04-01

Carbon fiber laminate composites offer advantages including a good strength to weight ratio for aerospace structures. However, manufacturing imperfections and impact during the operation and servicing of the aircraft can lead to barely visible and difficult to detect damage. Incorrect ply lay-up during the manufacturing process can result in fiber misalignment or in-plane and out-of-plane waviness. Impact, such as bird strike, during the service life can lead to delamination and cracking, reducing the load carrying capacity of the structure. Both ultrasonic and X-ray techniques have a good track record for the nondestructive testing of composite structures; for the latter, phase-based approaches provide additional advantages due to their enhanced sensitivity. Bulk and guided ultrasonic waves propagating in the composite panel were employed for defect imaging. Ultrasonic immersion C-scans of a composite panel with barely visible impact damage were taken to characterize the size and shape of damage (delamination). The first antisymmetric A0 Lamb wave mode was excited experimentally using piezoelectric transducers and measured using a laser vibrometer. X-ray phase-contrast and dark field imaging, implemented through the edge-illumination (EI) approach, were used for the detailed visualization of the damages in the composite material. The Edge-illumination approach is multi-modal and provides three representations of the sample: absorption, differential phase and dark-field. The latter is of particular interest to detect cracks and voids of dimensions that are smaller than the actual spatial resolution of the imaging system. Application examples for carbon fiber composite plates with barely visible impact damage are shown.

Ultra High Energy Cosmic Rays: Strangelets?

NASA Astrophysics Data System (ADS)

Xu, Ren-Xin; Wu, Fei

2003-06-01

The conjecture that ultra-high-energy cosmic rays (UHECRs) are actually strangelets is discussed. Besides the reason that strangelets can do as cosmic rays beyond the Greisen-Zatsepin-Kuzmin-cutoff, another argument to support the conjecture is addressed by the study of formation of TeV-scale microscopic black holes when UHECRs bombarding bare strange stars. It is proposed that the exotic quark surface of a bare strange star could be an effective astro-laboratory in the investigations of the extra dimensions and of the detection of ultra-high-energy neutrino fluxes. The flux of neutrinos (and other point-like particles) with energy larger than 2.3×1020 eV could be expected to be smaller than 10-26 cm-2 s-1 if there are two extra spatial dimensions.

Four pi calibration and modeling of a bare germanium detector in a cylindrical field source

NASA Astrophysics Data System (ADS)

Dewberry, R. A.; Young, J. E.

2012-05-01

In this paper we describe a 4π cylindrical field acquisition configuration surrounding a bare (unshielded, uncollimated) high purity germanium detector. We perform an efficiency calibration with a flexible planar source and model the configuration in the 4π cylindrical field. We then use exact calculus to model the flux on the cylindrical sides and end faces of the detector. We demonstrate that the model accurately represents the experimental detection efficiency compared to that of a point source and to Monte Carlo N-particle (MCNP) calculations of the flux. The model sums over the entire source surface area and the entire detector surface area including both faces and the detector's cylindrical sides. Agreement between the model and both experiment and the MCNP calculation is within 8%.

Impending rupture of saphenous vein graft aneurysm with floating fractured bare metal stent treated by coil embolization and covered stent implantation.

PubMed

Kodama, Atsuko; Kurita, Tairo; Kato, Osamu; Suzuki, Takahiko

2016-11-01

Aneurysmal degeneration of a saphenous vein graft (SVG) is a rare, but potentially fatal complication of coronary artery bypass graft (CABG) surgery. In this case report, a patient that had undergone prior CABG surgery and bare metal stent (BMS) implantation at the site of a stenotic SVG lesion presented at our hospital with chest pain, and an SVG aneurysm was detected at the previous BMS implantation site. In addition, the implanted BMS was fractured and floating in the SVG aneurysm. The SVG aneurysm was successfully occluded by percutaneous intervention, using a combination of distal covered stent deployment at the site of the anastomosis between the native coronary artery and the SVG and proximal coil embolization of the aneurysm.

Effect of Fluoride on the Morphology and Electrochemical Property of Co3O4 Nanostructures for Hydrazine Detection

PubMed Central

Gao, Wanlin; Wang, Qiang; Umar, Ahmad

2018-01-01

In this paper, we systematically investigated the influence of fluoride on the morphology and electrochemical property of Co3O4 nanostructures for hydrazine detection. The results showed that with the introduction of NH4F during the synthesis process of Co3O4, both Co(CO3)0.5(OH)·0.11H2O and Co(OH)F precursors would be generated. To understand the influence of F on the morphology and electrochemical property of Co3O4, three Co3O4 nanostructures that were respectively obtained from bare Co(CO3)0.5(OH)·0.11H2O, Co(OH)F and Co(CO3)0.5(OH)·0.11H2O mixtures and bare Co(OH)F were successfully synthesized. The electrochemical tests revealed the sensing performance of prepared Co3O4 nanostructures decreased with the increase in the fluoride contents of precursors. The more that dosages of NH4F were used, the higher crystallinity and smaller specific surface area of Co3O4 was gained. Among these three Co3O4 nanostructures, the Co3O4 that was obtained from bare Co(CO3)0.5(OH)·0.11H2O-based hydrazine sensor displayed the best performances, which exhibited a great sensitivity (32.42 μA·mM−1), a low detection limit (9.7 μΜ), and a wide linear range (0.010–2.380 mM), together with good selectivity, great reproducibility and longtime stability. To the best of our knowledge, it was revealed for the first time that the sensing performance of prepared Co3O4 nanostructures decreased with the increase in fluoride contents of precursors. PMID:29382161

CLICK: The new USGS center for LIDAR information coordination and knowledge

USGS Publications Warehouse

Stoker, Jason M.; Greenlee, Susan K.; Gesch, Dean B.; Menig, Jordan C.

2006-01-01

Elevation data is rapidly becoming an important tool for the visualization and analysis of geographic information. The creation and display of three-dimensional models representing bare earth, vegetation, and structures have become major requirements for geographic research in the past few years. Light Detection and Ranging (lidar) has been increasingly accepted as an effective and accurate technology for acquiring high-resolution elevation data for bare earth, vegetation, and structures. Lidar is an active remote sensing system that records the distance, or range, of a laser fi red from an airborne or space borne platform such as an airplane, helicopter or satellite to objects or features on the Earth’s surface. By converting lidar data into bare ground topography and vegetation or structural morphologic information, extremely accurate, high-resolution elevation models can be derived to visualize and quantitatively represent scenes in three dimensions. In addition to high-resolution digital elevation models (Evans et al., 2001), other lidar-derived products include quantitative estimates of vegetative features such as canopy height, canopy closure, and biomass (Lefsky et al., 2002), and models of urban areas such as building footprints and three-dimensional city models (Maas, 2001).

Using remote sensing and GIS to detect and monitor land use and land cover change in Dhaka Metropolitan of Bangladesh during 1960-2005.

PubMed

Dewan, Ashraf M; Yamaguchi, Yasushi

2009-03-01

This paper illustrates the result of land use/cover change in Dhaka Metropolitan of Bangladesh using topographic maps and multi-temporal remotely sensed data from 1960 to 2005. The Maximum likelihood supervised classification technique was used to extract information from satellite data, and post-classification change detection method was employed to detect and monitor land use/cover change. Derived land use/cover maps were further validated by using high resolution images such as SPOT, IRS, IKONOS and field data. The overall accuracy of land cover change maps, generated from Landsat and IRS-1D data, ranged from 85% to 90%. The analysis indicated that the urban expansion of Dhaka Metropolitan resulted in the considerable reduction of wetlands, cultivated land, vegetation and water bodies. The maps showed that between 1960 and 2005 built-up areas increased approximately 15,924 ha, while agricultural land decreased 7,614 ha, vegetation decreased 2,336 ha, wetland/lowland decreased 6,385 ha, and water bodies decreased about 864 ha. The amount of urban land increased from 11% (in 1960) to 344% in 2005. Similarly, the growth of landfill/bare soils category was about 256% in the same period. Much of the city's rapid growth in population has been accommodated in informal settlements with little attempt being made to limit the risk of environmental impairments. The study quantified the patterns of land use/cover change for the last 45 years for Dhaka Metropolitan that forms valuable resources for urban planners and decision makers to devise sustainable land use and environmental planning.

Catalyst-free "click" functionalization of polymer brushes preserves antifouling properties enabling detection in blood plasma.

PubMed

Parrillo, Viviana; de Los Santos Pereira, Andres; Riedel, Tomas; Rodriguez-Emmenegger, Cesar

2017-06-08

Progress in biosensors for clinical detection critically relies on modifications of the transducer surface to prevent non-specific adsorption from matrix components (i.e. antifouling) while supporting biomolecular recognition elements to capture the analyte. Such combination of properties presents a significant challenge. Hierarchically structured polymer brushes comprising an antifouling polymer bottom block and a functionalizable top block are proposed as a promising strategy to achieve this goal. We employed the catalyst-free strain-promoted alkyne-azide cycloaddition (SPAAC) "click" reaction to biofunctionalize antifouling polymer brushes without impairing their resistance to fouling. The functionalization was performed on the side chains along the top polymer block or only on the end-groups of the polymer brush. The immobilized amounts of bioreceptors (streptavidin followed by biotin-conjugated proteins) and the resistance to fouling from blood plasma of the surfaces obtained were evaluated via surface plasmon resonance. The end group functionalization approach resulted in very low immobilization of bioreceptor. On the other hand, the side group modification of a top polymer block led to immobilization of 83% of a monolayer of streptavidin. Following binding of a biotin-conjugated antibody (66 ng cm -2 ) the functionalized layer was able to reduce the fouling from undiluted human blood plasma by 89% in comparison with bare gold. Finally, the functionalized hierarchical polymer brushes were applied to the label-free detection of a model analyte in diluted human blood plasma, highlighting the potential for translation to medical applications. Copyright © 2017. Published by Elsevier B.V.

Multifunctional nanocomposites of Fe3O4-graphene-Au for repeated use in simultaneous adsorption, in situ SERS detection and catalytic reduction of 4-nitrophenol in water

NASA Astrophysics Data System (ADS)

Chen, Fenghua; Wang, Yongwei; Chen, Qingtao; Han, Lifeng; Chen, Zhijun; Fang, Shaoming

2014-12-01

This work is directed towards the synthesis of a ternary nanocomposite of Fe3O4-graphene-Au, i.e. Fe3O4 nanoparticles (˜300 nm in size) and Au nanoparticles (˜50 nm in size) loaded on the carbon basal planes of reduced graphene oxide, aimed for repeated use in simultaneous adsorption, in situ SERS detection and catalytic reduction of 4-nitrophenol (4-NP) in water, and also for recovering the useful reduction product of 4-aminophenol (4-AP). The results indicate that the amount of 4-NP and 4-AP absorbed to the prepared Fe3O4-graphene-Au nanocomposite can reach 170 mg g-1 and 447 mg g-1, respectively. The reduction reaction of 4-NP to 4-AP by NaBH4 with the Fe3O4-graphene-Au nanocomposite as a catalyst follows first-order kinetics with a rate constant (k) of about 0.4964 min-1, remarkably superior to the 0.1199 min-1 for the reduction reaction with the bare Au nanoparticles under the same conditions. In addition, in situ SERS can also be carried out to detect 4-NP and to monitor the reduction reaction with Fe3O4-graphene-Au as the substrate. Recycling of the composite can be achieved by simply applying an external magnetic field and the results demonstrate that it can be reused at least eight times with almost unaffected catalytic efficiency.

Empirical Model for Evaluating PM10 Concentration Caused by River Dust Episodes

PubMed Central

Lin, Chao-Yuan; Chiang, Mon-Ling; Lin, Cheng-Yu

2016-01-01

Around the estuary of the Zhuo-Shui River in Taiwan, the waters recede during the winter, causing an increase in bare land area and exposing a large amount of fine earth and sand particles that were deposited on the riverbed. Observations at the site revealed that when northeastern monsoons blow over bare land without vegetation or water cover, the fine particles are readily lifted by the wind, forming river dust, which greatly endangers the health of nearby residents. Therefore, determining which factors affect river dust and constructing a model to predict river dust concentration are extremely important in the research and development of a prototype warning system for areas at risk of river dust emissions. In this study, the region around the estuary of the Zhuo-Shui River (from the Zi-Qiang Bridge to the Xi-Bin Bridge) was selected as the research area. Data from a nearby air quality monitoring station were used to screen for days with river dust episodes. The relationships between PM10 concentration and meteorological factors or bare land area were analyzed at different temporal scales to explore the factors that affect river dust emissions. Study results showed that no single factor alone had adequate power to explain daily average or daily maximum PM10 concentration. Stepwise regression analysis of multiple factors showed that the model could not effectively predict daily average PM10 concentration, but daily maximum PM10 concentration could be predicted by a combination of wind velocity, temperature, and bare land area; the coefficient of determination for this model was 0.67. It was inferred that river dust episodes are caused by the combined effect of multiple factors. In addition, research data also showed a time lag effect between meteorological factors and hourly PM10 concentration. This characteristic was applied to the construction of a prediction model, and can be used in an early warning system for local residents. PMID:27271642

Empirical Model for Evaluating PM10 Concentration Caused by River Dust Episodes.

PubMed

Lin, Chao-Yuan; Chiang, Mon-Ling; Lin, Cheng-Yu

2016-06-02

Around the estuary of the Zhuo-Shui River in Taiwan, the waters recede during the winter, causing an increase in bare land area and exposing a large amount of fine earth and sand particles that were deposited on the riverbed. Observations at the site revealed that when northeastern monsoons blow over bare land without vegetation or water cover, the fine particles are readily lifted by the wind, forming river dust, which greatly endangers the health of nearby residents. Therefore, determining which factors affect river dust and constructing a model to predict river dust concentration are extremely important in the research and development of a prototype warning system for areas at risk of river dust emissions. In this study, the region around the estuary of the Zhuo-Shui River (from the Zi-Qiang Bridge to the Xi-Bin Bridge) was selected as the research area. Data from a nearby air quality monitoring station were used to screen for days with river dust episodes. The relationships between PM10 concentration and meteorological factors or bare land area were analyzed at different temporal scales to explore the factors that affect river dust emissions. Study results showed that no single factor alone had adequate power to explain daily average or daily maximum PM10 concentration. Stepwise regression analysis of multiple factors showed that the model could not effectively predict daily average PM10 concentration, but daily maximum PM10 concentration could be predicted by a combination of wind velocity, temperature, and bare land area; the coefficient of determination for this model was 0.67. It was inferred that river dust episodes are caused by the combined effect of multiple factors. In addition, research data also showed a time lag effect between meteorological factors and hourly PM10 concentration. This characteristic was applied to the construction of a prediction model, and can be used in an early warning system for local residents.

The relative importance of decomposition and transport mechanisms in accounting for C profiles

NASA Astrophysics Data System (ADS)

Guenet, B.; Eglin, T.; Vasilyeva, N.; Peylin, P.; Ciais, P.; Chenu, C.

2012-10-01

Soil is the major terrestrial reservoirs of carbon, and a substantial part of this carbon is stored in deep layers, typically deeper than 50 cm below the surface. Several studies underlined the quantitative importance of this deep Soil Organic Carbon (SOC) pool and models are needed to better understand this stock and its evolution under climate and land-uses changes. In this study, we test and compare 3 simple theoretical models of vertical transport for SOC against SOC profiles measurements from a long-term bare fallow experiment carried out by the Central-Chernozem State Natural Biosphere Reserve named after V.V. Alekhin, in the Kursk Region of Russia. The transport schemes tested are diffusion, advection or both diffusion and advection. They are coupled to two different formulations of soil carbon decomposition kinetics. The first formulation is a first order kinetics widely used in global SOC decomposition models; the second one links SOC decomposition rate to the amount of fresh organic matter, representing a "priming effect". Field data are from a set of three bare fallow plots where soil received no input during the past 20, 26 and 58 yr respectively. Parameters of the models were optimized using a Bayesian method. The best results are obtained when SOC decomposition is assumed to be controlled by fresh organic matter. In comparison to the first-order kinetic model, the "priming" model reduces the underestimation of SOC decomposition in the top layers and the over estimation in the deep layers. We also observe that the transport scheme that improved the fit with the data depends on the soil carbon mineralization formulation chosen. When soil carbon decomposition is modelled to depend on the fresh organic matter amount, the transport mechanisms which improves best the fit to the SOC profile data is the model representing both advection and diffusion. Interestingly, the older the bare fallow is, the lesser the need for diffusion is. This suggests that stabilized carbon may not be transported within the profile by the same mechanisms than more labile carbon.

The relative importance of decomposition and transport mechanisms in accounting for soil organic carbon profiles

NASA Astrophysics Data System (ADS)

Guenet, B.; Eglin, T.; Vasilyeva, N.; Peylin, P.; Ciais, P.; Chenu, C.

2013-04-01

Soil is the major terrestrial reservoir of carbon and a substantial part of this carbon is stored in deep layers, typically deeper than 50 cm below the surface. Several studies underlined the quantitative importance of this deep soil organic carbon (SOC) pool and models are needed to better understand this stock and its evolution under climate and land-uses changes. In this study, we tested and compared three simple theoretical models of vertical transport for SOC against SOC profiles measurements from a long-term bare fallow experiment carried out by the Central-Chernozem State Natural Biosphere Reserve in the Kursk Region of Russia. The transport schemes tested are diffusion, advection and both diffusion and advection. They are coupled to three different formulations of soil carbon decomposition kinetics. The first formulation is a first order kinetics widely used in global SOC decomposition models; the second one, so-called "priming" model, links SOC decomposition rate to the amount of fresh organic matter, representing the substrate interactions. The last one is also a first order kinetics, but SOC is split into two pools. Field data are from a set of three bare fallow plots where soil received no input during the past 20, 26 and 58 yr, respectively. Parameters of the models were optimised using a Bayesian method. The best results are obtained when SOC decomposition is assumed to be controlled by fresh organic matter (i.e., the priming model). In comparison to the first-order kinetic model, the priming model reduces the overestimation in the deep layers. We also observed that the transport scheme that improved the fit with the data depended on the soil carbon mineralisation formulation chosen. When soil carbon decomposition was modelled to depend on the fresh organic matter amount, the transport mechanism which improved best the fit to the SOC profile data was the model representing both advection and diffusion. Interestingly, the older the bare fallow is, the lesser the need for diffusion is, suggesting that stabilised carbon may not be transported within the profile by the same mechanisms than more labile carbon.

Electrical DNA biosensor using aluminium interdigitated electrode for E.Coli O157:H7 detection

NASA Astrophysics Data System (ADS)

Natasha, N. Z.; Rajapaksha, R. D. A. A.; Uda, M. N. A.; Hashim, U.

2017-09-01

Escherichia Coli (E.Coli) O157:H7 is the one of the most dangerous foodborne pathogens based diseases that presence in our daily life that causes illness and death increase every year. Aluminum Interdigitated Electrode (Al IDE) biosensor was introduced to detect E.Coli O157:H7 in earlier stage. In this paper we investigated ssDNA of E.Coli O157:H7 bacteria detection through electrical behavior of Al IDE sensor. The physical properties of Al IDE biosensor has been characterized using Low Power Microscope (LPM), High Power Microscope (HPM), Scanning Electron Microscope (SEM) and 3D Nano Profiler. The bare Al IDE was electrical characterized by using I-V measurement. The surface modification was accomplished by salinization using APTES and immobilization using Carboxylic Probe E.Coli which was the first step in preparing Al IDE biosensor. Geared up prepared biosensor was hybridized with complementary, non-complementary and single based mismatch ssDNA to confirmed specificity detection of E Coli O157:H7 ssDNA target. The Current - Voltage was performed for each step such as bare Al IDE, surface modification, immobilization and hybridization. Sensitivity measurement was accomplished using different concentration of complementary ssDNA target from 1 fM - 10 µM. Selectivity measurements was achieved using same concentration which was 10 µM concentration for complement, non-complement and mismatch E.Coli O157:H7 ssDNA target. It's totally proved that the Al IDE able to detect specific and small current down to Femtomolar concentration.

A reduced graphene oxide based electrochemical biosensor for tyrosine detection

NASA Astrophysics Data System (ADS)

Wei, Junhua; Qiu, Jingjing; Li, Li; Ren, Liqiang; Zhang, Xianwen; Chaudhuri, Jharna; Wang, Shiren

2012-08-01

In this paper, a ‘green’ and safe hydrothermal method has been used to reduce graphene oxide and produce hemin modified graphene nanosheet (HGN) based electrochemical biosensors for the determination of l-tyrosine levels. The as-fabricated HGN biosensors were characterized by UV-visible absorption spectra, fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TGA). The experimental results indicated that hemin was successfully immobilized on the reduced graphene oxide nanosheet (rGO) through π-π interaction. TEM images and EDX results further confirmed the attachment of hemin on the rGO nanosheet. Cyclic voltammetry tests were carried out for the bare glass carbon electrode (GCE), the rGO electrode (rGO/GCE), and the hemin-rGO electrode (HGN/GCE). The HGN/GCE based biosensor exhibits a tyrosine detection linear range from 5 × 10-7 M to 2 × 10-5 M with a detection limitation of 7.5 × 10-8 M at a signal-to-noise ratio of 3. The sensitivity of this biosensor is 133 times higher than that of the bare GCE. In comparison with other works, electroactive biosensors are easily fabricated, easily controlled and cost-effective. Moreover, the hemin-rGO based biosensors demonstrate higher stability, a broader detection linear range and better detection sensitivity. Study of the oxidation scheme reveals that the rGO enhances the electron transfer between the electrode and the hemin, and the existence of hemin groups effectively electrocatalyzes the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity and reduced costs.

A reduced graphene oxide based electrochemical biosensor for tyrosine detection.

PubMed

Wei, Junhua; Qiu, Jingjing; Li, Li; Ren, Liqiang; Zhang, Xianwen; Chaudhuri, Jharna; Wang, Shiren

2012-08-24

In this paper, a 'green' and safe hydrothermal method has been used to reduce graphene oxide and produce hemin modified graphene nanosheet (HGN) based electrochemical biosensors for the determination of l-tyrosine levels. The as-fabricated HGN biosensors were characterized by UV-visible absorption spectra, fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TGA). The experimental results indicated that hemin was successfully immobilized on the reduced graphene oxide nanosheet (rGO) through π-π interaction. TEM images and EDX results further confirmed the attachment of hemin on the rGO nanosheet. Cyclic voltammetry tests were carried out for the bare glass carbon electrode (GCE), the rGO electrode (rGO/GCE), and the hemin-rGO electrode (HGN/GCE). The HGN/GCE based biosensor exhibits a tyrosine detection linear range from 5 × 10(-7) M to 2 × 10(-5) M with a detection limitation of 7.5 × 10(-8) M at a signal-to-noise ratio of 3. The sensitivity of this biosensor is 133 times higher than that of the bare GCE. In comparison with other works, electroactive biosensors are easily fabricated, easily controlled and cost-effective. Moreover, the hemin-rGO based biosensors demonstrate higher stability, a broader detection linear range and better detection sensitivity. Study of the oxidation scheme reveals that the rGO enhances the electron transfer between the electrode and the hemin, and the existence of hemin groups effectively electrocatalyzes the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity and reduced costs.

Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdO x Membrane in Electrolyte-Insulator-Semiconductor Structure.

PubMed

Kumar, Pankaj; Maikap, Siddheswar; Qiu, Jian-Tai; Jana, Surajit; Roy, Anisha; Singh, Kanishk; Cheng, Hsin-Ming; Chang, Mu-Tung; Mahapatra, Rajat; Chiu, Hsien-Chin; Yang, Jer-Ren

2016-12-01

A 15-nm-thick GdO x membrane in an electrolyte-insulator-semiconductor (EIS) structure shows a higher pH sensitivity of 54.2 mV/pH and enzyme-free hydrogen peroxide (H2O2) detection than those of the bare SiO2 and 3-nm-thick GdO x membranes for the first time. Polycrystalline grain and higher Gd content of the thicker GdO x films are confirmed by transmission electron microscopy (TEM) and X-ray photo-electron spectroscopy (XPS), respectively. In a thicker GdO x membrane, polycrystalline grain has lower energy gap and Gd(2+) oxidation states lead to change Gd(3+) states in the presence of H2O2, which are confirmed by electron energy loss spectroscopy (EELS). The oxidation/reduction (redox) properties of thicker GdO x membrane with higher Gd content are responsible for detecting H2O2 whereas both bare SiO2 and thinner GdO x membranes do not show sensing. A low detection limit of 1 μM is obtained due to strong catalytic activity of Gd. The reference voltage shift increases with increase of the H2O2 concentration from 1 to 200 μM owing to more generation of Gd(3+) ions, and the H2O2 sensing mechanism has been explained as well.

Simultaneous detection of genetically modified organisms by multiplex ligation-dependent genome amplification and capillary gel electrophoresis with laser-induced fluorescence.

PubMed

García-Cañas, Virginia; Mondello, Monica; Cifuentes, Alejandro

2010-07-01

In this work, an innovative method useful to simultaneously analyze multiple genetically modified organisms is described. The developed method consists in the combination of multiplex ligation-dependent genome dependent amplification (MLGA) with CGE and LIF detection using bare-fused silica capillaries. The MLGA process is based on oligonucleotide constructs, formed by a universal sequence (vector) and long specific oligonucleotides (selectors) that facilitate the circularization of specific DNA target regions. Subsequently, the circularized target sequences are simultaneously amplified with the same couple of primers and analyzed by CGE-LIF using a bare-fused silica capillary and a run electrolyte containing 2-hydroxyethyl cellulose acting as both sieving matrix and dynamic capillary coating. CGE-LIF is shown to be very useful and informative for optimizing MLGA parameters such as annealing temperature, number of ligation cycles, and selector probes concentration. We demonstrate the specificity of the method in detecting the presence of transgenic DNA in certified reference and raw commercial samples. The method developed is sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 1% of GA21, 1% of MON863, and 1% of MON810 in maize samples with signal-to-noise ratios for the corresponding DNA peaks of 15, 12, and 26, respectively. These results demonstrate, to our knowledge for the first time, the great possibilities of MLGA techniques for genetically modified organisms analysis.

Heterogeneity of soil surface temperature induced by xerophytic shrub in a revegetated desert ecosystem, northwestern China

NASA Astrophysics Data System (ADS)

Zhang, Ya-Feng; Wang, Xin-Ping; Pan, Yan-Xia; Hu, Rui; Zhang, Hao

2013-06-01

Variation characteristics of the soil surface temperature induced by shrub canopy greatly affects the near-surface biological and biochemical processes in desert ecosystems. However, information regarding the effects of shrub upon the heterogeneity of soil surface temperature is scarce. Here we aimed to characterize the effects of shrub ( Caragana korshinskii) canopy on the soil surface temperature heterogeneity at areas under shrub canopy and the neighbouring bare ground. Diurnal variations of soil surface temperature were measured at areas adjacent to the shrub base (ASB), beneath the midcanopy (BMC), and in the bare intershrub spaces (BIS) at the eastern, southern, western and northern aspects of shrub, respectively. Results indicated that diurnal mean soil surface temperature under the C. korshinskii canopy (ASB and BMC) was significantly lower than in the BIS, with the highest in the BIS, followed by the BMC and ASB. The diurnal maximum and diurnal variations of soil surface temperatures under canopy vary strongly with different aspects of shrub with the diurnal variation in solar altitude, which could be used as cues to detect safe sites for under-canopy biota. A significant empirical linear relationship was found between soil surface temperature and solar altitude, suggesting an empirical predicator that solar altitude can serve for soil surface temperature. Lower soil surface temperatures under the canopy than in the bare intershrub spaces imply that shrubs canopy play a role of `cool islands' in the daytime in terms of soil surface temperature during hot summer months in the desert ecosystems characterized by a mosaic of sparse vegetation and bare ground.

14C-labeled organic amendments: Characterization in different particle size fractions and humic acids in a long-term field experiment

PubMed Central

Tatzber, Michael; Stemmer, Michael; Spiegel, Heide; Katzlberger, Christian; Landstetter, Claudia; Haberhauer, Georg; Gerzabek, Martin H.

2012-01-01

Knowledge about the stabilization of organic matter input to soil is essential for understanding the influence of different agricultural practices on turnover characteristics in agricultural soil systems. In this study, soil samples from a long-term field experiment were separated into silt- and clay-sized particles. In 1967, 14C labeled farmyard manure was applied to three different cropping systems: crop rotation, monoculture and permanent bare fallow. Humic acids (HAs) were extracted from silt- and clay-sized fractions and characterized using photometry, mid-infrared and fluorescence spectroscopy. Remaining 14C was determined in size fractions as well as in their extracted HAs. Yields of carbon and remaining 14C in HAs from silt-sized particles and Corg in clay-sized particles decreased significantly in the order: crop rotation > monoculture ≫ bare fallow. Thus, crop rotation not only had the largest overall C-pool in the experiment, but it also best stabilized the added manure. Mid-infrared spectroscopy could distinguish between HAs from different particle size soil fractions. With spectroscopic methods significant differences between the cropping systems were detectable in fewer cases compared to quantitative results of HAs (yields, 14C, Corg and Nt). The trends, however, pointed towards increased humification of HAs from bare fallow systems compared to crop rotation and monoculture as well as of HAs from clay-sized particles compared to silt-sized particles. Our study clearly shows that the largest differences were observed between bare fallow on one hand and monoculture and crop rotation on the other. PMID:23482702

14C-labeled organic amendments: Characterization in different particle size fractions and humic acids in a long-term field experiment.

PubMed

Tatzber, Michael; Stemmer, Michael; Spiegel, Heide; Katzlberger, Christian; Landstetter, Claudia; Haberhauer, Georg; Gerzabek, Martin H

2012-05-01

Knowledge about the stabilization of organic matter input to soil is essential for understanding the influence of different agricultural practices on turnover characteristics in agricultural soil systems. In this study, soil samples from a long-term field experiment were separated into silt- and clay-sized particles. In 1967, 14 C labeled farmyard manure was applied to three different cropping systems: crop rotation, monoculture and permanent bare fallow. Humic acids (HAs) were extracted from silt- and clay-sized fractions and characterized using photometry, mid-infrared and fluorescence spectroscopy. Remaining 14 C was determined in size fractions as well as in their extracted HAs. Yields of carbon and remaining 14 C in HAs from silt-sized particles and C org in clay-sized particles decreased significantly in the order: crop rotation > monoculture ≫ bare fallow. Thus, crop rotation not only had the largest overall C-pool in the experiment, but it also best stabilized the added manure. Mid-infrared spectroscopy could distinguish between HAs from different particle size soil fractions. With spectroscopic methods significant differences between the cropping systems were detectable in fewer cases compared to quantitative results of HAs (yields, 14 C, C org and N t ). The trends, however, pointed towards increased humification of HAs from bare fallow systems compared to crop rotation and monoculture as well as of HAs from clay-sized particles compared to silt-sized particles. Our study clearly shows that the largest differences were observed between bare fallow on one hand and monoculture and crop rotation on the other.

[Micro-community characteristics of vegetations in blowouts and depositional areas of Hulunbuir grassland, Inner Mongolia].

PubMed

Man, Liang; Hasi, Eerdun; Zhang, Ping; Yan, Xu; Xia, Xian-Dong

2008-10-01

By using traditional sampling methods, the micro-communities of vegetations in fixed, semi-bare, and bare blowouts of Hulunbuir grassland were investigated, and the investigation data were statistical analyzed. The results showed that the vegetation coverage decreased in the order of fixed blowout, semi-bare blowout, and bare blowout, and was lower than that of the primary vegetation Form. Stipa grandis. Potentilla acaulis and Kengia squarrosa were the dominant species in fixed blowout, with the coverage being 5%; while P. acaulis and Carex sp. were the dominant species in semi-bare blowout, with the coverage being 2%. The dominant species in depositional areas of semi-bare blowout were P. acaulis, K. squarrosa, Agropyron cristatum, and Thymus mongolicus, and the coverage was 4%. The dominant species on the southwest slope of bare blowout was Agriophyllum pungens. The middle depositional area of bare blowout was also occupied by A. pungens (coverage 4.7%), and the edge of it was dominated by A. cristatum (coverage 2.7%), Carex sp. (coverage 2.6%), and T. mongolicus (coverage 1.7%) from the edge of the depositional area to primary grassland. The mean species importance value in fixed, semi-bare, and bare blowouts was 12.64%, 13.38%, and 20.08%, while that in the depositional area of semi-bare blowout and in the middle and edge of bare blowout was 12.55%, 40.18%, and 11.15%, respectively.

Neutron detection with a NaI spectrometer using high-energy photons

NASA Astrophysics Data System (ADS)

Holm, Philip; Peräjärvi, Kari; Sihvonen, Ari-Pekka; Siiskonen, Teemu; Toivonen, Harri

2013-01-01

Neutrons can be indirectly detected by high-energy photons. The performance of a 4″×4″×16″ NaI portal monitor was compared to a 3He-based portal monitor with a comparable cross-section of the active volume. Measurements were performed with bare and shielded 252Cf and AmBe sources. With an optimum converter and moderator structure for the NaI detector, the detection efficiencies and minimum detectable activities of the portal monitors were similar. The NaI portal monitor preserved its detection efficiency much better with shielded sources, making the method very interesting for security applications. For heavily shielded sources, the NaI detector was 2-3 times more sensitive than the 3He-based detector.

Mitigation of greenhouse gas emission on abandoned peatlands by growing reed canary grass

NASA Astrophysics Data System (ADS)

Järveoja, J.; Laht, J.; Soosaar, K.; Maddison, M.; Ostonen, I.; Mander, Ü.

2012-04-01

We used combined closed-chamber and plant biomass techniques to study the impact of reed canary grass (RCG, Phalaris arundinacea) cultivation on greenhouse gas (GHG) fluxes and carbon balance of an abandoned peat extraction area in Lavassaare, Estonia (N58°34'20''; E24°23'15''). Three core study sites were chosen within the abandoned peat extraction area: (I) bare peat soil (abandoned and not planted site), (II) non-fertilized Phalaris site, (III) and fertilized Phalaris site (all on drained Fibric Histosols). In addition, (IV) the natural raised bog (Fibric Histosol) and (V) the cultivated fen meadow (drained Sapric Histosol) served as reference sites. The CO2, CH4 and N2O fluxes were determined using the closed-chamber method once a month from May 2010 to December 2011. White 60 L chambers made of PVC and sealed with a water-filled ring on the soil surface were installed in 5 replicates on each site. The gas was sampled 3 times per hour in 100 mL pre-evacuated glass bottles, and in the lab the gas concentrations were measured using the Shimadzu GC-2014 (ECD, FID) gas-chromatographic system combined with a Loftfield autosampler. Measurements of groundwater level and soil temperature (10, 20, 30, and 40 cm depths) were performed simultaneously. Biomass assessments of RCG were carried out just after maximal growth of macrophytes, in early September 2010, in April 2011 just after snow melt (time of minimum aboveground biomass), and again in September 2011. Aboveground biomass samples were collected from 1×1m plots. Belowground biomass samples were collected at a depth of 25 cm in 3 replicates adjacent to each chamber using a 10×10 cm auger. Samples were analyzed for N, P and C. Our results showed high nitrous oxide emissions (up to 541 μg N2O-N m-2 h-1) from the fen meadow and high methane emissions from the natural raised bog (up to 12915 μg CH4-C m-2 h-1). The low CH4 emission from the Phalaris plots and bare soil was due to the deeper water table (up to 85 cm below ground) and high sulfur concentration in peat (up to 23 g kg-1), which probably inhibited methanogenesis. The high CO2 emission on fertilized and non-fertilized Phalaris plots in comparison to the bare peat site was probably caused by: (1) the higher plant biomass: more dissolved C coming from roots and greater amount of fine root turnover, (2) the influence of fresh plant litter on the peat mineralization on Phalaris plots, and (3) inhibited mineralization by recalcitrant C of bare peat. Our results demonstrated that as a total, the Phalaris sites acted as net carbon sinks, sequestering C in the amount of 6929.5 and 6083.5 kg CO2-C ha-1 yr-1 on the fertilized and non-fertilized plots, respectively, whereas the bare peat site acted as a carbon source (emitting 687.5 kg CO2-C ha-1 yr-1).

Control of resonant wavelength from organic light-emitting materials by use of a Fabry-Perot microcavity structure.

PubMed

Jung, Boo Young; Kim, Nam Young; Lee, Changhee; Hwangbo, Chang Kwon; Seoul, Chang

2002-06-01

We report the fabrication of Fabry-Perot microcavity structures with the organic light-emitting material tris-(8-hydroxyquinoline) aluminum (Alq3) and derive their optical properties by measuring their photoluminescence (PL) and absorption. Silver and a TiO2-SiO2 multilayer were used as metal and dielectric reflectors, respectively, in a Fabry-Perot microcavity structure. Three types of microcavity were prepared: type A consisted of [air[Ag[Alq3]Ag]glass]; type B, of [air[dielectric[Alq3]dielectric]glass]; and type C, of [air[Ag[Alq2]dielectric]glass]. A bare Alq3 film of [air[Alq3]glass] had its PL peak near 514 nm, and its full width at half-maximum (FWHM) was 80 nm. The broad FWHM of a bare Alq3 film was reduced to 15-27.5, 7-10.5, and 16-16.6 nm for microcavity types A, B, and C, respectively. Also, we could control the PL peak of the microcavity structure by changing the spacer thickness, the amount of phase change on reflection, and the angle of incidence.

Fortissimo: A Japanese Space Test Of Bare Wire Anode Tethers

NASA Technical Reports Server (NTRS)

Johnson, Les; Fujii, H. A.; Sanmartin, J. R.

2008-01-01

A Japanese led international team is developing a suborbital test of orbital-motion-limited (OML) bare wire anode current collection for application to electrodynamic tether (EDT) propulsion. The tether is a tape with a width of 25 mm, thickness of 0.05 mm, and is 300 m in length. This will be the first space test of OML theory. The mission will launch in the summer of 2009 using an S520 Sounding Rocket. During ascent, and above approx. 100 km in attitude, the tape tether will be deployed at a rate of approx. 8 m/s. Once deployed, the tape tether will serve as an anode, collecting ionospheric electrons. The electrons will be expelled into space by a hollow cathode device, thereby completing the circuit and allowing current to flow. The total amount of current collected will be used to assess the validity of OML theory. This paper will describe the objectives of the proposed mission, the technologies to be employed, and the application of the results to future space missions using EDTs for propulsion or power generation.

Effect of Curvature on the Impact Damage Characteristics and Residual Strength of Composite Plates

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Starnes, James H., Jr.

1998-01-01

The results of a study of the response and failure characteristics of thin, cylindrically curved, composite plates subjected to low-speed impact damage are presented. The results indicate that the plate radius and the plate thickness are important structural parameters that influence the nonlinear response of a plate for a given amount of impact energy. Analytical and experimental contact-force results are compared for several plates and the results correlate well. The impact-energy levels required to cause damage initiation and barely visible impact damage are a function of the plate radius for a given plate thickness. The impact-energy levels required to initiate impact damage for plates with a certain range of radii are greater than plates with other radii. The contact-force results corresponding to these impact-energy levels follow a similar trend. Residual strength results for plates with barely visible impact damage suggest that the compression-after-impact residual strength is also a function of plate radius. The residual strength of impact-damaged flat plates appears to be lower than the residual strength of the corresponding cylindrically curved plates.

Benefits of High Strength Microalloyed Rebar

NASA Astrophysics Data System (ADS)

Wright, Michael

The amount of reinforcing bar (or "rebar") currently produced globally is estimated at over 400 million tons per year. With global infra-structure demands increasing, this production level is forecasted for continued expansion. Product requirements along with production levels are ever increasing, but as an industry there is minimal to no effort being put forth to produce a better product. Rather, rebar is being commoditized to a point where price is the only real consideration taken into account when purchasing rebar for major projects. This "pricing only" mentality results in a product that barely meets minimum standards.

Analysis of soil moisture extraction algorithm using data from aircraft experiments

NASA Technical Reports Server (NTRS)

Burke, H. H. K.; Ho, J. H.

1981-01-01

A soil moisture extraction algorithm is developed using a statistical parameter inversion method. Data sets from two aircraft experiments are utilized for the test. Multifrequency microwave radiometric data surface temperature, and soil moisture information are contained in the data sets. The surface and near surface ( or = 5 cm) soil moisture content can be extracted with accuracy of approximately 5% to 6% for bare fields and fields with grass cover by using L, C, and X band radiometer data. This technique is used for handling large amounts of remote sensing data from space.

Conceptual Design of an Electric Sail Technology Demonstration Mission Spacecraft

NASA Technical Reports Server (NTRS)

Wiegmann, Bruce M.

2017-01-01

There is great interest in examining the outer planets of our solar system and Heliopause region (edge of Solar System) and beyond regions of interstellar space by both the Planetary and Heliophysics communities. These needs are well docu-mented in the recent National Academy of Sciences Decadal Surveys. There is significant interest in developing revolutionary propulsion techniques that will enable such Heliopause scientific missions to be completed within 10 to15 years of the launch date. One such enabling propulsion technique commonly known as Electric Sail (E-Sail) propulsion employs positively charged bare wire tethers that extend radially outward from a rotating spacecraft spinning at a rate of one revolution per hour. Around the positively charged bare-wire tethers, a Debye Sheath is created once positive voltage is applied. This sheath stands off of the bare wire tether at a sheath diameter that is proportional to the voltage in the wire coupled with the flux density of solar wind ions within the solar system (or the location of spacecraft in the solar system. The protons that are expended from the sun (solar wind) at 400 to 800 km/sec are electrostatically repelled away from these positively charged Debye sheaths and propulsive thrust is produced via the resulting momentum transfer. The amount of thrust produced is directly proportional to the total wire length. The Marshall Space Flight Center (MSFC) Electric Sail team is currently funded via a two year Phase II NASA Innovative Advanced Concepts (NIAC) awarded in July 2015. The team's current activities are: 1) Developing a Particle in Cell (PIC) numeric engineering model from the experimental data collected at MSFC's Solar Wind Facility on the interaction between simulated solar wind interaction with a charged bare wire that can be applied to a variety of missions, 2) The development of the necessary tether deployers and tethers to enable successful de-ployment of multiple, multi km length bare tethers, 3) Controllability of the space-craft via a voltage bias to steer itself through the solar system to destinations of discovery. These activities once demonstrated analytically, will require a technology demonstration mission (TDM) around the year2020 to demonstrate that all systems work together seamlessly before a Heliophysics Electrostatic Rapid Transit System (HERTS) mission could be initiated. A notional TDM spacecraft that meets the requirements of such a mission will be showcased in this paper.

Evaluation of vacuum filter sock surface sample collection method for Bacillus spores from porous and non-porous surfaces.

PubMed

Brown, Gary S; Betty, Rita G; Brockmann, John E; Lucero, Daniel A; Souza, Caroline A; Walsh, Kathryn S; Boucher, Raymond M; Tezak, Matthew S; Wilson, Mollye C

2007-07-01

Vacuum filter socks were evaluated for recovery efficiency of powdered Bacillus atrophaeus spores from two non-porous surfaces, stainless steel and painted wallboard and two porous surfaces, carpet and bare concrete. Two surface coupons were positioned side-by-side and seeded with aerosolized Bacillus atrophaeus spores. One of the surfaces, a stainless steel reference coupon, was sized to fit into a sample vial for direct spore removal, while the other surface, a sample surface coupon, was sized for a vacuum collection application. Deposited spore material was directly removed from the reference coupon surface and cultured for enumeration of colony forming units (CFU), while deposited spore material was collected from the sample coupon using the vacuum filter sock method, extracted by sonication and cultured for enumeration. Recovery efficiency, which is a measure of overall transfer effectiveness from the surface to culture, was calculated as the number of CFU enumerated from the filter sock sample per unit area relative to the number of CFU enumerated from the co-located reference coupon per unit area. The observed mean filter sock recovery efficiency from stainless steel was 0.29 (SD = 0.14, n = 36), from painted wallboard was 0.25 (SD = 0.15, n = 36), from carpet was 0.28 (SD = 0.13, n = 40) and from bare concrete was 0.19 (SD = 0.14, n = 44). Vacuum filter sock recovery quantitative limits of detection were estimated at 105 CFU m(-2) from stainless steel and carpet, 120 CFU m(-2) from painted wallboard and 160 CFU m(-2) from bare concrete. The method recovery efficiency and limits of detection established in this work provide useful guidance for the planning of incident response environmental sampling for biological agents such as Bacillus anthracis.

Bare laser-synthesized Au-based nanoparticles as nondisturbing surface-enhanced Raman scattering probes for bacteria identification.

PubMed

Kögler, Martin; Ryabchikov, Yury V; Uusitalo, Sanna; Popov, Alexey; Popov, Anton; Tselikov, Gleb; Välimaa, Anna-Liisa; Al-Kattan, Ahmed; Hiltunen, Jussi; Laitinen, Riitta; Neubauer, Peter; Meglinski, Igor; Kabashin, Andrei V

2018-02-01

The ability of noble metal-based nanoparticles (NPs) (Au, Ag) to drastically enhance Raman scattering from molecules placed near metal surface, termed as surface-enhanced Raman scattering (SERS), is widely used for identification of trace amounts of biological materials in biomedical, food safety and security applications. However, conventional NPs synthesized by colloidal chemistry are typically contaminated by nonbiocompatible by-products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification. In this article, we explore novel ultrapure laser-synthesized Au-based nanomaterials, including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks of bacteria detection. We show that these Au-based nanomaterials can efficiently enhance Raman signals from model R6G molecules, while the enhancement factor depends on the content of Au in NP composition. Profiting from the observed enhancement and purity of laser-synthesized nanomaterials, we demonstrate successful identification of 2 types of bacteria (Listeria innocua and Escherichia coli). The obtained results promise less disturbing studies of biological systems based on good biocompatibility of contamination-free laser-synthesized nanomaterials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microspore development of three coniferous species: affinity of nuclei for flavonoids.

PubMed

Feucht, Walter; Treutter, Dieter; Dithmar, Heike; Polster, Jürgen

2008-12-01

The nuclear localization of blue-staining flavanols was investigated histochemically throughout microsporogenesis in yellow cypress (Callitropsis nootkatensis (D. Don) Oerst., formerly Cupressus nootkatensis), juniper (Juniperus communis L.) and yew (Taxus baccata L.). During meiotic development, both the cytoplasm and nuclei of microspores of all species contained varying amounts of flavanols; however, the flavanols were largely confined to the nuclei in microspores just released from tetrads. Quantification by HPLC analysis indicated that, in all species, catechin and epicatechin were the dominant nuclear flavanols. At the early free microspore stage, the nuclear flavanols were barely detectable in all species, but they increased fivefold on incubation in the presence of 0.1 mM benzylaminopurine (BA) or zeatin. Histochemical studies revealed that, in addition to non-fluorescing flavanols, microspores contained yellow-fluorescing flavonoids, which yielded a distinct HPLC flavonoid profile for each species. In yellow cypress, the hydrolyzed flavonoids were identified as quercetin, apigenin, kaempferol and luteolin, whereas only quercetin and myricetin were found in microspores of juniper and in anthers of yew. Application of a UV-VIS titration technique revealed that the aglycone quercetin seems to interact more strongly with histone H3 than either glycoside rutin or kaempferol.

Methodological approach to crime scene investigation: the dangers of technology

NASA Astrophysics Data System (ADS)

Barnett, Peter D.

1997-02-01

The visitor to any modern forensic science laboratory is confronted with equipment and processes that did not exist even 10 years ago: thermocyclers to allow genetic typing of nanogram amounts of DNA isolated from a few spermatozoa; scanning electron microscopes that can nearly automatically detect submicrometer sized particles of molten lead, barium and antimony produced by the discharge of a firearm and deposited on the hands of the shooter; and computers that can compare an image of a latent fingerprint with millions of fingerprints stored in the computer memory. Analysis of populations of physical evidence has permitted statistically minded forensic scientists to use Bayesian inference to draw conclusions based on a priori assumptions which are often poorly understood, irrelevant, or misleading. National commissions who are studying quality control in DNA analysis propose that people with barely relevant graduate degrees and little forensic science experience be placed in charge of forensic DNA laboratories. It is undeniable that high- tech has reversed some miscarriages of justice by establishing the innocence of a number of people who were imprisoned for years for crimes that they did not commit. However, this papers deals with the dangers of technology in criminal investigations.

Galectin-7 overexpression is associated with the apoptotic process in UVB-induced sunburn keratinocytes

PubMed Central

Bernerd, Francoise; Sarasin, Alain; Magnaldo, Thierry

1999-01-01

Galectin-7 is a β-galactoside binding protein specifically expressed in stratified epithelia and notably in epidermis, but barely detectable in epidermal tumors and absent from squamous carcinoma cell lines. Galectin-7 gene is an early transcriptional target of the tumor suppressor protein P53 [Polyak, K., Xia, Y., Zweier, J., Kinzler, K. & Vogelstein, B. (1997) Nature (London) 389, 300–305]. Because p53 transcriptional activity is increased by genotoxic stresses we have examined the possible effects of ultraviolet radiations (UVB) on galectin-7 expression in epidermal keratinocytes. The amounts of galectin-7 mRNA and protein are increased rapidly after UVB irradiation of epidermal keratinocytes. The increase of galectin-7 is parallel to P53 stabilization. UVB irradiation of skin reconstructed in vitro and of human skin ex vivo demonstrates that galectin-7 overexpression is associated with sunburn/apoptotic keratinocytes. Transfection of a galectin-7 expression vector results in a significant increase in terminal deoxynucleotidyltransferase-mediated UTP end labeling-positive keratinocytes. The present findings demonstrate a keratinocyte-specific protein involved in the UV-induced apoptosis, an essential process in the maintenance of epidermal homeostasis. PMID:10500176

Impact damage detection in sandwich composite structures using Lamb waves and laser vibrometry

NASA Astrophysics Data System (ADS)

Lamboul, B.; Passilly, B.; Roche, J.-M.; Osmont, D.

2013-01-01

This experimental study explores the feasibility of impact damage detection in composite sandwich structures using Lamb wave excitation and signals acquired with a laser Doppler vibrometer. Energy maps are computed from the transient velocity wave fields and used to highlight defect areas in impacted coupons of foam core and honeycomb core sandwich materials. The technique performs well for the detection of barely visible damage in this type of material, and is shown to be robust in the presence of wave reverberation. Defect extent information is not always readily retrieved from the obtained defect signatures, which depend on the wave - defect interaction mechanisms.

Algorithm-Based Motion Magnification for Video Processing in Urological Laparoscopy.

PubMed

Adams, Fabian; Schoelly, Reto; Schlager, Daniel; Schoenthaler, Martin; Schoeb, Dominik S; Wilhelm, Konrad; Hein, Simon; Wetterauer, Ulrich; Miernik, Arkadiusz

2017-06-01

Minimally invasive surgery is in constant further development and has replaced many conventional operative procedures. If vascular structure movement could be detected during these procedures, it could reduce the risk of vascular injury and conversion to open surgery. The recently proposed motion-amplifying algorithm, Eulerian Video Magnification (EVM), has been shown to substantially enhance minimal object changes in digitally recorded video that is barely perceptible to the human eye. We adapted and examined this technology for use in urological laparoscopy. Video sequences of routine urological laparoscopic interventions were recorded and further processed using spatial decomposition and filtering algorithms. The freely available EVM algorithm was investigated for its usability in real-time processing. In addition, a new image processing technology, the CRS iimotion Motion Magnification (CRSMM) algorithm, was specifically adjusted for endoscopic requirements, applied, and validated by our working group. Using EVM, no significant motion enhancement could be detected without severe impairment of the image resolution, motion, and color presentation. The CRSMM algorithm significantly improved image quality in terms of motion enhancement. In particular, the pulsation of vascular structures could be displayed more accurately than in EVM. Motion magnification image processing technology has the potential for clinical importance as a video optimizing modality in endoscopic and laparoscopic surgery. Barely detectable (micro)movements can be visualized using this noninvasive marker-free method. Despite these optimistic results, the technology requires considerable further technical development and clinical tests.

Analysis of total polyphenols in wines by FIA with highly stable amperometric detection using carbon nanotube-modified electrodes.

PubMed

Arribas, Alberto Sánchez; Martínez-Fernández, Marta; Moreno, Mónica; Bermejo, Esperanza; Zapardiel, Antonio; Chicharro, Manuel

2013-02-15

The use of glassy carbon electrodes (GCEs) modified with multi-walled carbon nanotube (CNT) films for the continuous monitoring of polyphenols in flow systems has been examined. The performance of these modified electrodes was evaluated and compared to bare GCE by cyclic voltammetry experiments and by flow injection analysis (FIA) with amperometric detection monitoring the response of gallic, caffeic, ferulic and p-coumaric acids in 0.050 M acetate buffer pH 4.5 containing 100 mM NaCl. The GCE modified with CNT dispersions in polyethyleneimine (PEI) provided lower overpotentials, higher sensitivity and much higher signal stability under a dynamic regime than bare GCEs. These properties allowed the estimation of the total polyphenol content in red and white wines with a remarkable long-term stability in the measurements despite the presence of potential fouling substances in the wine matrix. In addition, the versatility of the electrochemical methodology allowed the selective estimation of the easily oxidisable polyphenol fraction as well as the total polyphenol content just by tuning the detection potential at +0.30 or 0.70 V, respectively. The significance of the electrochemical results was demonstrated through correlation studies with the results obtained with conventional spectrophotometric assays for polyphenols (Folin-Ciocalteu, absorbance at 280 nm index and colour intensity index). Copyright © 2012 Elsevier Ltd. All rights reserved.

Electrochemical biosensor for Mycobacterium tuberculosis DNA detection based on gold nanotubes array electrode platform.

PubMed

Torati, Sri Ramulu; Reddy, Venu; Yoon, Seok Soo; Kim, CheolGi

2016-04-15

The template assisted electrochemical deposition technique was used for the synthesis of gold nanotubes array (AuNTsA). The morphological structure of the synthesized AuNTsA was observed by scanning electron microscopy and found that the individual nanotubes are around 1.5 μm in length with a diameter of 200 nm. Nanotubes are vertically aligned to the Au thick film, which is formed during the synthesis process of nanotubes. The electrochemical performance of the AuNTsA was compared with the bare Au electrode and found that AuNTsA has better electron transfer surface than bare Au electrode which is due to the high surface area. Hence, the AuNTsA was used as an electrode for the fabrication of DNA hybridization biosensor for detection of Mycobacterium Tuberculosis DNA. The DNA hybridization biosensor constructed by AuNTsA electrode was characterized by cyclic voltammetry technique with Fe(CN)6(3-/4-) as an electrochemical redox indicator. The selectivity of the fabricated biosensor was illustrated by hybridization with complementary DNA and non-complementary DNA with probe DNA immobilized AuNTsA electrode using methylene blue as a hybridization indicator. The developed electrochemical DNA biosensor shows good linear range of complementary DNA concentration from 0.01 ng/μL to 100 ng/μL with high detection limit. Copyright © 2015 Elsevier B.V. All rights reserved.

Ag-ZnO nanostructure for ANTA explosive molecule detection

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

Shaik, Ummar Pasha; Sangani, L. D. Varma; Gaur, Anshu

2016-05-23

Ag/ZnO nanostructure for surface enhanced Raman scattering application in the detection of ANTA explosive molecule is demonstrated. A highly rough ZnO microstructure was achieved by rapid thermal annealing of metallic Zn film. Different thickness Ag nanostructures are decorated over these ZnO microstructures by ion beam sputtering technique. Surface enhanced Raman spectroscopic studies carried out over Ag/ZnO substrates have shown three orders higher enhancement compared to bare Ag nanostructure deposited on the same substrate. The reasons behind such huge enhancement are discussed based on the morphology of the sample.

Searching for Life with Rovers: Exploration Methods & Science Results from the 2004 Field Campaign of the "Life in the Atacama" Project and Applications to Future Mars Missions

NASA Technical Reports Server (NTRS)

Cabrol, N. A.a; Wettergreen, D. S.; Whittaker, R.; Grin, E. A.; Moersch, J.; Diaz, G. Chong; Cockell, C.; Coppin, P.; Dohm, J. M.; Fisher, G.

2005-01-01

The Life In The Atacama (LITA) project develops and field tests a long-range, solarpowered, automated rover platform (Zo ) and a science payload assembled to search for microbial life in the Atacama desert. Life is barely detectable over most of the driest desert on Earth. Its unique geological, climatic, and biological evolution have created a unique training site for designing and testing exploration strategies and life detection methods for the robotic search for life on Mars.

A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

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

Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If themore » detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.« less

A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

DOE PAGES

Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

2017-06-13

An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If themore » detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.« less

Semi-conducting single-walled carbon nanotubes are detrimental when compared to metallic single-walled carbon nanotubes for electrochemical applications.

PubMed

Dong, Qi; Nasir, Muhammad Zafir Mohamad; Pumera, Martin

2017-10-18

As-synthetized single walled carbon nanotubes (SWCNTs) contain both metallic and semiconducting nanotubes. For the electronics, it is desirable to separate semiconducting SWCNTs (s-SWCNTs) from the metallic ones as s-SWCNTs provide desirable electronic properties. Here we test whether ultrapure semi-conducting single-walled carbon nanotubes (s-SWCNTs) provide advantageous electrochemical properties over the as prepared SWCNTs which contain a mixture of semiconducting and metallic CNTs. We test them as a transducer platform which enhanced the detection of target analytes (ascorbic acid, dopamine, uric acid) when compared to a bare glassy carbon (GC) electrode. Despite that, the two materials exhibit significantly different electrochemical properties and performances. A mixture of m-SWCNTs and s-SWCNTs demonstrated superior performance over ultrapure s-SWCNTs with greater peak currents and pronounced shift in peak potentials to lower values in cyclic and differential pulse voltammetry for the detection of target analytes. The mixture of m- and s-SWCNTs displayed about a 4 times improved heterogeneous electron transfer rate as compared to bare GC and a 2 times greater heterogeneous electron transfer rate than s-SWCNTs, demonstrating that ultrapure SWCNTs do not provide any major enhancement over the as prepared SWCNTs.

Evaluation of Precipitation Detection over Various Surfaces from Passive Microwave Imagers and Sounders

NASA Technical Reports Server (NTRS)

Munchak, S. Joseph; Skofronick-Jackson, Gail

2012-01-01

During the middle part of this decade a wide variety of passive microwave imagers and sounders will be unified in the Global Precipitation Measurement (GPM) mission to provide a common basis for frequent (3 hr), global precipitation monitoring. The ability of these sensors to detect precipitation by discerning it from non-precipitating background depends upon the channels available and characteristics of the surface and atmosphere. This study quantifies the minimum detectable precipitation rate and fraction of precipitation detected for four representative instruments (TMI, GMI, AMSU-A, and AMSU-B) that will be part of the GPM constellation. Observations for these instruments were constructed from equivalent channels on the SSMIS instrument on DMSP satellites F16 and F17 and matched to precipitation data from NOAA's National Mosaic and QPE (NMQ) during 2009 over the continuous United States. A variational optimal estimation retrieval of non-precipitation surface and atmosphere parameters was used to determine the consistency between the observed brightness temperatures and these parameters, with high cost function values shown to be related to precipitation. The minimum detectable precipitation rate, defined as the lowest rate for which probability of detection exceeds 50%, and the detected fraction of precipitation, are reported for each sensor, surface type (ocean, coast, bare land, snow cover) and precipitation type (rain, mix, snow). The best sensors over ocean and bare land were GMI (0.22 mm/hr minimum threshold and 90% of precipitation detected) and AMSU (0.26 mm/hr minimum threshold and 81% of precipitation detected), respectively. Over coasts (0.74 mm/hr threshold and 12% detected) and snow-covered surfaces (0.44 mm/hr threshold and 23% detected), AMSU again performed best but with much lower detection skill, whereas TMI had no skill over these surfaces. The sounders (particularly over water) benefited from the use of re-analysis data (vs. climatology) to set the a-priori atmospheric state and all instruments benefit from the use of a conditional snow cover emissivity database over land. It is recommended that real-time sources of these data be used in the operational GPM precipitation algorithms.

Spin Polarization and Quantum Spins in Au Nanoparticles

PubMed Central

Li, Chi-Yen; Karna, Sunil K.; Wang, Chin-Wei; Li, Wen-Hsien

2013-01-01

The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter. PMID:23989607

An activating G{sub s}{alpha} mutation is present in fibrous dysplasia of bone in the McCune-Albright syndrome

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

Shenker, A.; Weinstein, L.S.; Spiegel, A.M.

1994-09-01

McCune-Albright syndrome (MAS) is a sporadic disease characterized by polyostotic fibrous dysplasia, cafe-au-lait spots, and multiple endocrinopathies. The etiology of fibrous dysplasia is unknown. Activating mutations of codon 201 in the gene encoding the {alpha}-subunit of G{sub s}, the G-protein that stimulates adenylyl cyclase, have been found in all affected MAS tissues that have been studied. Initial attempts to amplify DNA from decalcified paraffin-embedded bone specimens from frozen surgical bone specimens from five MAS patients using polymerase chain reaction and allele-specific oligonucleotide hybridization. Most of the cells in four specimens of dysplastic bone contained a heterozygous mutation encoding substitution ofmore » Arg{sup 201} of G{sub s}{alpha} with His, but the mutation was barely detectable in peripheral blood specimens from the patients. Only a small amount of mutant allele was detected in a specimen of normal cortical bone from the fifth patient, although this patients had a high proportion of mutation in other, affected tissues. The mosaic distribution of mutant alleles is consistent with an embryological somatic cell mutation of the G{sub s}{alpha} gene in MAS. The presence of an activating mutation of G{sub s}{alpha} in osteoblastic progenitor cells may cause them to exhibit increased proliferation and abnormal differentiation, thereby producing the lesions of fibrous dysplasia. 43 refs., 2 figs.« less

Evaluation of selected spectral vegetation indices in senescent rangeland canopy using Landsat imagery

NASA Astrophysics Data System (ADS)

Striped Face-Collins, Marla

Grassland birds are diminishing more steadily and rapidly than other North American birds in general. The nesting success of some grassland bird species depends on the amount of nonproductive vegetation (NPV). To estimate NPV land managers are currently using the Robel pole visual obstruction reading methods. Researchers with the USDA Agricultural Research Service's (ARS) Northern Great Plains Research Laboratory in Mandan, ND, recently established statistical relationships between photosynthetic vegetation (PV), NPV and spectral vegetation indices (SVIs) derived from more sensitive and more detailed, but less accessible and more costly hyperspectral aerial imagery. This study is an extension of this previous work using spectral vegetation indices collected using the Landsat TM sensor, including simple ratios SWIR-SR (rho2215/rho 1650) and SR71 (rho2215 /rho485) to estimate the amount of NPV and bare ground cover, respectively.

Effect of pendent chains on the interfacial properties of thin polydimethylsiloxane (PDMS) networks.

PubMed

Landherr, Lucas J T; Cohen, Claude; Archer, Lynden A

2011-05-17

The interfacial properties of end-linked polydimethylsiloxane (PDMS) films on silicon are examined. Thin cross-linked PDMS films (∼10 μm thick) were synthesized over a self-assembled monolayer supported on a silicon wafer. By systematically varying the concentration of monofunctional PDMS in a mixture with telechelic precursor molecules, structures ranging from near-ideal elastic networks to poorly cross-linked networks composed of a preponderance of dangling/pendent chains were synthesized. Lateral force microscopy (LFM) employing bead probes was used to quantify the effect of network structure on the interfacial friction coefficient and residual force. Indentation measurements employing an AFM in force mode were used to characterize the elastic modulus and the pull-off force for the films as a function of pendent chain content. These measurements were complemented with conventional mechanical rheometry measurements on similar thick network films to determine their bulk rheological properties. All networks studied manifested interfacial friction coefficients substantially lower than that of bare silicon. PDMS networks with the lowest pendent chain content displayed friction coefficients close to 1 order of magnitude lower than that of bare silicon, whereas networks with the highest pendent chain content manifested friction coefficients about 3 times lower than that of bare silicon. At intermediate sliding velocities, a crossover in the interfacial friction coefficient was observed, wherein cross-linked PDMS films with the least amount of pendent chains exhibit the highest friction coefficient. These observations are discussed in terms of the structure of the films and relaxation dynamics of elastic strands and dangling chains in tethered network films.

Mulching as a means of exploiting dew for arid agriculture?

NASA Astrophysics Data System (ADS)

Graf, Alexander; Kuttler, Wilhelm; Werner, Julius

2008-03-01

A traditional mulching technique used in Lanzarote, Canary Islands, allows dry farming as well as pronounced water savings in irrigation. It is known to reduce evaporational losses, but is also supposed to enhance the nocturnal condensation of water vapour from the atmosphere. The mulch layer consists of porous volcanic rock fragments abundantly available on the island. The mulched surface is believed to cool rapidly and to be more hygroscopic than a bare soil surface. This was investigated during a field experiment conducted over 68 nights during different seasons in 2001 and 2002, as well as some simple laboratory measurements. It was found that nocturnal condensation on the mulch surface (max 0.33 mm) was lower than on the bare soil surface (max 0.57 mm) or any one of three alternative mulch substrates. However, a slightly stronger nocturnal cooling of the mulched as compared to the bare surface was present. It is shown that these contrary findings can be explained by the higher hygroscopicity of the dry loam soil, resulting in condensation gains beyond the strict definition of dew. Differences in plant-availability of non-hygroscopic dew water and hygroscopic water uptakes are discussed, and conditions under which mulching would show positive condensation effects are defined. This includes a theoretical section demonstrating that non-hygroscopic mulch layers of a proper thickness can provide small amounts of dew to plant roots at the mulch-soil interface. This condensation could also happen during the day and would be favoured by a high amplitude of the diurnal atmospheric moisture cycle.

Selenium volatilization in vegetated agricultural drainage sediment from the San Luis Drain, Central California.

PubMed

Bañuelos, G S; Lin, Z-Q; Arroyo, I; Terry, N

2005-09-01

The presence of large amounts of Se-laden agricultural drainage sediment in the San Luis Drain, Central California, poses a serious toxic threat to wildlife in the surrounding environment. Effective management of the drainage sediment becomes a practical challenge because the sediment is polluted with high levels of Se, B, and salts. This two-year field study was conducted to identify the best plant species that are salt and B tolerant and that have a superior ability of volatilizing Se from drainage sediment. The drainage sediment was mixed with clean soil, and vegetated with salado alfalfa (Medicago sativa 'salado'), salado grass (Sporobulus airoides 'salado'), saltgrass-turf (Distichlis spp. 'NYPA Turf'), saltgrass-forage (Distichlis spicata (L.) Greene), cordgrass (Spartina patens 'Flageo'), Leucaenia (Leucaena leucocephola), elephant grass (Pennistum purpureum), or wild type-Brassica (Brassica spp.). Results show that elephant grass produced the greatest amount of biomass and accumulated highest concentrations of B. Highest concentrations of Se, S, and Cl were observed in wild-type Brassica. Biogenic volatilization of Se by plants and soil microbes was greater in summer. Among the treatments, the mean daily rates of Se volatilization (microg Se m(-2)d(-1)) were wild-type Brassica (39) > saltgrass-turf (31) > cordgrass (27) > saltgrass forage (24) > elephant grass (22) > salado grass (21) > leucaenia (19) > salado alfalfa (14) > irrigated bare soil (11) > non-irrigated bare soil (6). Overall, rates of Se volatilization in drainage sediment were relatively low due to high levels of sulfate. To manage Se in drainage sediment by phytoremediation, the biological volatilization process needs to be enhanced substantially under field conditions.

Nanocapillaries for Open Tubular Chromatographic Separations of Proteins in Femtoliter to Picoliter Samples

PubMed Central

Wang, Xiayan; Cheng, Chang; Wang, Shili; Zhao, Meiping; Dasgupta, Purnendu K.; Liu, Shaorong

2009-01-01

We have recently examined the potential of bare nanocapillaries for free solution DNA separations and demonstrated efficiencies exceeding 106 theoretical plates/m. In the present work, we demonstrate the use of bare and hydroxypropylcellulose (HPC) coated open tubular nanocapillaries for protein separations. Using 1.5 μm inner diameter (i.d.) capillary columns, hydrodynamically injecting femto to picoliter (fL-pL) volumes of fluorescent or fluorescent dye labeled protein samples, utilizing a pneumatically pressurized chamber containing 1.0 mM sodium tetraborate solution eluent (typ. 200 psi) as the pump and performing on-column detection using a simple laser-induced fluorescence detector, we demonstrate efficiencies of close to a million theoretical plates/m while generating single digit μL volumes of waste for a complete chromatographic run. We achieve baseline resolution for a protein mixture consisting of transferrin, α-lactalbumin, insulin, and α -2-macroglobulin. PMID:19663450

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984 - April 1, 1985

DOE R&D Accomplishments Database

Smalley, R. E.

1985-01-01

There have been four major areas of concentration for the study of bare metal cluster beams: neutral cluster, chemical reactivity, cold cluster ion source development (both positive and negative), bare cluster ion ICR (ion cyclotron resonance) development, and photofragmentation studies of bare metal cluster ions.

Radio Frequency Detection and Characterization of Water-Ethanol Solution through Spiral-Coupled Passive Micro-Resonator Sensor.

PubMed

Koirala, Gyan Raj; Dhakal, Rajendra; Kim, Eun-Seong; Yao, Zhao; Kim, Nam-Young

2018-04-03

We present a microfabricated spiral-coupled passive resonator sensor realized through integrated passive device (IPD) technology for the sensitive detection and characterization of water-ethanol solutions. In order to validate the performance of the proposed device, we explicitly measured and analyzed the radio frequency (RF) characteristics of various water-ethanol solution compositions. The measured results showed a drift in the resonance frequency from 1.16 GHz for deionized (DI) water to 1.68 GHz for the solution containing 50% ethanol, whereas the rejection level given by the reflection coefficient decreased from -29.74 dB to -14.81 dB. The obtained limit of detection was 3.82% volume composition of ethanol in solution. The derived loaded capacitance was 21.76 pF for DI water, which gradually decreased to 8.70 pF for the 50% ethanol solution, and the corresponding relative permittivity of the solution decreased from 80.14 to 47.79. The dissipation factor increased with the concentration of ethanol in the solution. We demonstrated the reproducibility of the proposed sensor through iterative measures of the samples and the study of surface morphology. Successive measurement of different samples had no overlapping and had very minimum bias between RF characteristics for each measured sample. The surface profile for bare sensors was retained after the sample test, resulting a root mean square (RMS) value of 11.416 nm as compared to 10.902 nm for the bare test. The proposed sensor was shown to be a viable alternative to existing sensors for highly sensitive water-ethanol concentration detection.

Short-lived Rn-222 daughters in cryogenic liquids

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

Pelczar, Krzysztof; Frodyma, Nikodem; Wójcik, Marcin

In this paper a detection method of α emitters from {sup 222}Rn decay chain, present in cryogenic liquids, using bare Si-PIN diodes immersed in the liquids is presented. Properties of ionized {sup 222}Rn daughters deduced from conducted measurements are outlined. Life-time of positive ions was found to be of the order of 10 s, and nonzero content of electronegative ions was observed.

Using Lidar and color infrared imagery to successfully measure stand characteristics on the William B. Bankhead National Forest, Alabama

Treesearch

Jeffrey Stephens; Luben Dimov; Callie Schweitzer; Wubishet Tadesse

2008-01-01

Light detection and ranging (Lidar) and color infrared imagery (CIR) were used to quantify forest structure and to distinguish deciduous from coniferous trees for selected stands on the William B. Bankhead National Forest in Alabama. Lidar bare ground and vegetation point clouds were used to determine tree heights and tree locations. Lidar accuracy was assessed by...

Long period gratings in multimode optical fibers: application in chemical sensing

NASA Astrophysics Data System (ADS)

Thomas Lee, S.; Dinesh Kumar, R.; Suresh Kumar, P.; Radhakrishnan, P.; Vallabhan, C. P. G.; Nampoori, V. P. N.

2003-09-01

We propose and demonstrate a new technique for evanescent wave chemical sensing by writing long period gratings in a bare multimode plastic clad silica fiber. The sensing length of the present sensor is only 10 mm, but is as sensitive as a conventional unclad evanescent wave sensor having about 100 mm sensing length. The minimum measurable concentration of the sensor reported here is 10 nmol/l and the operating range is more than 4 orders of magnitude. Moreover, the detection is carried out in two independent detection configurations viz., bright field detection scheme that detects the core-mode power and dark field detection scheme that detects the cladding mode power. The use of such a double detection scheme definitely enhances the reliability and accuracy of the results. Furthermore, the cladding of the present fiber need not be removed as done in conventional evanescent wave fiber sensors.

30 CFR 57.12080 - Bare conductor guards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work or...

30 CFR 57.12080 - Bare conductor guards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work or...

30 CFR 77.515 - Bare signal or control wires; voltage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

30 CFR 77.515 - Bare signal or control wires; voltage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

Effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions.

PubMed

Lv, Dong; Zhu, Tianle; Liu, Runwei; Lv, Qingzhi; Sun, Ye; Wang, Hongmei; Liu, Yu; Zhang, Fan

2016-09-01

The effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions were systematically investigated in a cement production line in Beijing. The results show that co-processing the sewage sludge was helpful to reduce NOx emission, which primarily depends on the NH3 amount released from the sewage sludge. Meanwhile, NOx and NH3 concentrations in the flue gas have a negative correlation, and the contribution of feeding the sewage sludge to NOx removal decreased with the increase of injection amount of ammonia water in the SNCR system. Therefore, it is suggested that the injection amount of ammonia water in SNCR system may reduce to cut down the operating costs during co-processing the sewage sludge in cement kiln. In addition, the emission of total PAHs seems to increase with the increased amount of the sewage sludge feeding to the cement kiln. However, the distributions of PAHs were barely changed, and lower molecular weight PAHs were mainly distributed in gaseous phase, accounted for the major portion of PAHs when co-processing sewage sludge in cement kiln. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cure of beta-thalassaemia major by umbilical cord blood transplantation--a case report of Malaysia's first cord blood transplantation.

PubMed

Chan, L L; Lin, H P

1999-08-01

A 25-month-old boy with beta-thalassaemia major was presented with an opportunity for umbilical cord blood transplantation when his unborn sibling was diagnosed in utero to be a beta-thalassaemia carrier and also human leucocyte antigen compatible. A barely adequate amount of cord blood was collected at the birth of his sibling and infused into the patient after appropriate chemo-conditioning. Engraftment occurred without major complications. The subject is now alive and well 9 months post-transplant, thus marking our first success in umbilical cord blood transplantation.

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

Above- and belowground fluxes of CH4 from boreal shrubs and Scots pine

NASA Astrophysics Data System (ADS)

Halmeenmäki, Elisa; Heinonsalo, Jussi; Santalahti, Minna; Putkinen, Anuliina; Fritze, Hannu; Pihlatie, Mari

2016-04-01

Boreal upland forests are considered as an important sink for the greenhouse gas methane (CH4) due to CH4 oxidizing microbes in the soil. However, recent evidence suggests that vegetation can act as a significant source of CH4. Also, preliminary measurements indicate occasional emissions of CH4 above the tree canopies of a boreal forest. Nevertheless, the sources and the mechanisms of the observed CH4 emissions are still mostly unknown. Furthermore, the majority of CH4 flux studies have been conducted with the soil chamber method, thus not considering the role of the vegetation itself. We conducted a laboratory experiment to study separately the above- and belowground CH4 fluxes of bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), heather (Calluna vulgaris), and Scots pine (Pinus sylvestris), which were grown in microcosms. The above- and belowground fluxes of the plants were measured separately, and these fluxes were compared to fluxes of microcosms containing only humus soil. In addition to the flux measurements, we analysed the CH4 producing archaea (methanogens) and the CH4 consuming bacteria (methanotrophs) with the qPCR method to discover whether these microbes contribute to the CH4 exchange from the plant material and the soil. The results of the flux measurements indicate that the humus soil with roots of lingonberry, heather, and Scots pine consume CH4 compared to bare humus soil. Simultaneously, the shoots of heather and Scots pine emit small amounts of CH4. We did not find detectable amounts of methanogens from any of the samples, suggesting the produced CH4 could be of non-microbial origin, or produced by very small population of methanogens. Based on the first preliminary results, methanotrophs were present in all the studied plant species, and especially in high amounts in the rooted soils, thus implying that the methanotrophs could be responsible of the CH4 uptake in the root-soil systems.

Nighttime water absorption by a bare loess soil in a coastal desert

NASA Astrophysics Data System (ADS)

Ninari, N.; Berliner, P. R.

2003-04-01

The role of dew in arid and semi-arid ecosystems is considered to be of great importance. It can serve as a water source for the bacteria of biological crust, for plants and for small insects. The Negev Desert is a semiarid region characterized by winter rainfall with a very large inter-annual variability. Reports on measurements carried out in this area mention that up to 180 nights a year with dew were registered by a conventional Hiltner Dew Balance, with intensities that ranged from 0.1 to 0.2 mm per night (yielding a total of 15 mm per year, which is more than 10% of the total rainfall). The Hiltner dew balance is based on the continuous weighing of an artificial condensation plate that has a completely different energy balance from that of the soil surface above which it is installed. The Hiltner dew balance could, therefore, be considered as a ``potential dew" gauge, whose results are probably mainly correlated to atmospheric conditions. The prime objective of this work was, therefore, to quantify the amounts of dew deposition on the soil surface, and to compare these amounts to those measured by the Hiltner balance. Measurements were carried out at the Wadi Mashash Experimental Farm in the Negev. To estimate deposition and evaporation of dew, a micro-lysimeter (diameter: 20 cm; soil depth: 50 cm) with an undisturbed soil sample was installed flush with the soil surface. The following were continuously monitored: micro-lysimeter weight, incoming and reflected short wave radiation, net radiation, dry and wet bulb temperatures, wind speed, and soil heat flux. A Hiltner Dew Balance was placed close by as a reference to compare with previous measurements. Throughout the ``dew period" (spring, summer and fall), and at random intervals, soil samples were taken hourly during the whole night. The uppermost 10 cm of the soil was divided into 1 cm intervals, and the soil moisture content was measured (oven dry). During the above-mentioned night campaigns, no dew deposition could be visually detected on the soil surface. A mass gain was however registered with the ML and an increase in moisture content was observed. The Hiltner balance clearly underestimated dew deposition amounts. These results indicate that although no visual signs of dew deposition could be detected, moisture did penetrate into the soil.

Exotic Spartina alterniflora invasion alters ecosystem-atmosphere exchange of CH4 and N2O and carbon sequestration in a coastal salt marsh in China.

PubMed

Yuan, Junji; Ding, Weixin; Liu, Deyan; Kang, Hojeong; Freeman, Chris; Xiang, Jian; Lin, Yongxin

2015-04-01

Coastal salt marshes are sensitive to global climate change and may play an important role in mitigating global warming. To evaluate the impacts of Spartina alterniflora invasion on global warming potential (GWP) in Chinese coastal areas, we measured CH4 and N2O fluxes and soil organic carbon sequestration rates along a transect of coastal wetlands in Jiangsu province, China, including open water; bare tidal flat; and invasive S. alterniflora, native Suaeda salsa, and Phragmites australis marshes. Annual CH4 emissions were estimated as 2.81, 4.16, 4.88, 10.79, and 16.98 kg CH4 ha(-1) for open water, bare tidal flat, and P. australis, S. salsa, and S. alterniflora marshes, respectively, indicating that S. alterniflora invasion increased CH4 emissions by 57-505%. In contrast, negative N2O fluxes were found to be significantly and negatively correlated (P < 0.001) with net ecosystem CO2 exchange during the growing season in S. alterniflora and P. australis marshes. Annual N2O emissions were 0.24, 0.38, and 0.56 kg N2O ha(-1) in open water, bare tidal flat and S. salsa marsh, respectively, compared with -0.51 kg N2O ha(-1) for S. alterniflora marsh and -0.25 kg N2O ha(-1) for P. australis marsh. The carbon sequestration rate of S. alterniflora marsh amounted to 3.16 Mg C ha(-1) yr(-1) in the top 100 cm soil profile, a value that was 2.63- to 8.78-fold higher than in native plant marshes. The estimated GWP was 1.78, -0.60, -4.09, and -1.14 Mg CO2 eq ha(-1) yr(-1) in open water, bare tidal flat, P. australis marsh and S. salsa marsh, respectively, but dropped to -11.30 Mg CO2 eq ha(-1) yr(-1) in S. alterniflora marsh. Our results indicate that although S. alterniflora invasion stimulates CH4 emissions, it can efficiently mitigate increases in atmospheric CO2 and N2O along the coast of China. © 2014 John Wiley & Sons Ltd.

Bubble electrodeposition of gold porous nanocorals for the enzymatic and non-enzymatic detection of glucose.

PubMed

Sanzó, Gabriella; Taurino, Irene; Antiochia, Riccarda; Gorton, Lo; Favero, Gabriele; Mazzei, Franco; De Micheli, Giovanni; Carrara, Sandro

2016-12-01

Au nanocorals are grown on gold screen-printed electrodes (SPEs) by using a novel and simple one-step electrodeposition process. Scanning electron microscopy was used for the morphological characterization. The devices were assembled on a three-electrode SPE system, which is flexible and mass producible. The electroactive surface area, determined by cyclic voltammetry in sulphuric acid, was found to be 0.07±0.01cm(2) and 35.3±2.7cm(2) for bare Au and nanocoral Au, respectively. The nanocoral modified SPEs were used to develop an enzymatic glucose biosensor based on H2O2 detection. Au nanocoral electrodes showed a higher sensitivity of 48.3±0.9μA/(mMcm(2)) at +0.45V vs Ag|AgCl compared to a value of 24.6±1.3μA/(mMcm(2)) at +0.70V vs Ag|AgCl obtained with bare Au electrodes. However, the modified electrodes have indeed proven to be extremely powerful for the direct detection of glucose with a non-enzymatic approach. The results confirmed a clear peak observed by using nanocoral Au electrode even in the presence of chloride ions at physiological concentration. Amperometric study carried out at +0.15V vs Ag|AgCl in the presence of 0.12M NaCl showed a linear range for glucose between 0.1 and 13mM. Copyright © 2016. Published by Elsevier B.V.

L-band radar sensing of soil moisture. [Kern County, California

NASA Technical Reports Server (NTRS)

Chang, A. T. C.; Atwater, S.; Salomonson, V. V.; Estes, J. E.; Simonett, D. S.; Bryan, M. L.

1980-01-01

The performance of an L-band, 25 cm wavelength imaging synthetic aperture radar was assessed for soil moisture determination, and the temporal variability of radar returns from a number of agricultural fields was studied. A series of three overflights was accomplished over an agricultural test site in Kern County, California. Soil moisture samples were collected from bare fields at nine sites at depths of 0-2, 2-5, 5-15, and 15-30 cm. These gravimetric measurements were converted to percent of field capacity for correlation to the radar return signal. The initial signal film was optically correlated and scanned to produce image data numbers. These numbers were then converted to relative return power by linear interpolation of the noise power wedge which was introduced in 5 dB steps into the original signal film before and after each data run. Results of correlations between the relative return power and percent of field capacity (FC) demonstrate that the relative return power from this imaging radar system is responsive to the amount of soil moisture in bare fields. The signal returned from dry (15% FC) and wet (130% FC) fields where furrowing is parallel to the radar beam differs by about 10 dB.

Growth process and anticancer properties of gold nanorods.

PubMed

Zhang, Junyan; Wang, Mian; Webster, Thomas J

2017-09-01

Gold nanoparticles have been of great interest because of their unique optical properties, facile synthesis and conjugation. Among various shapes of gold nanoparticles, gold nanorods have been widely studied. They can be conjugated with different molecules for biomedical applications, such as tumor imaging and therapy. However, few researchers have studied the antitumor properties of bare gold nanorods. In this study, unfunctionalized gold nanorods were synthesized and tested on breast tumor cells. Results showed that the aspect ratio of gold nanorods could be easily influenced by both reaction time and the amount of silver nitrate in the growth solution. A new growth process is proposed here based on the UV-Vis spectra and TEM images of gold nanorods at different reaction times. More importantly, cell studies showed that within a certain concentration range, the gold nanorods can selectively kill tumor cells while having limited or little influence on healthy mammalian (dermal fibroblast) cells. Thus, this study shows promise for the use of bare gold nanorods for further study alone or in combination with photothermal treatment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2616-2621, 2017. © 2017 Wiley Periodicals, Inc.

Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Jeong, Heon Jae; Kim, Jun Woo; Jang, Dong Young; Shim, Joon Hyung

2015-09-01

Pt-Ru bi-metallic catalysts are synthesized by atomic layer deposition (ALD) of Ru surface-coating on sputtered Pt mesh. The catalysts are evaluated in direct ethanol solid oxide fuel cells (DESOFCs) in the temperature range of 300-500 °C. Island-growth of the ALD Ru coating is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analyses. The performance of the DESOFCs is evaluated based on the current-voltage output and electrochemical impedance spectroscopy. Genuine reduction of the polarization impedance, and enhanced power output with improved surface kinetics are achieved with the optimized ALD Ru surface-coating compared to bare Pt. The chemical composition of the Pt/ALD Ru electrode surface after fuel cell operation is analyzed via XPS. Enhanced cell performance is clearly achieved, attributed to the effective Pt/ALD Ru bi-metallic catalysis, including oxidation of Cdbnd O by Ru, and de-protonation of ethanol and cleavage of C-C bonds by Pt, as supported by surface morphology analysis which confirms formation of a large amount of carbon on bare Pt after the ethanol-fuel-cell test.

On the origin of the visible light responsible for proton dose measurement using plastic optical fibers

NASA Astrophysics Data System (ADS)

Darafsheh, Arash; Taleei, Reza; Kassaee, Alireza; Finlay, Jarod C.

2017-03-01

We experimentally and by means of Monte Carlo simulations investigated the origin of the visible signal responsible for proton therapy dose measurement using bare plastic optical fibers. Experimentally, the fiber optic probe, embedded in tissue-mimicking plastics, was irradiated with a proton beam produced by a proton therapy cyclotron and the luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze the emission spectrum of the fiber tip. Monte Carlo simulations were performed using FLUKA Monte Carlo code to stochastically simulate radiation transport, ionizing radiation dose deposition, and optical emission of Čerenkov radiation. The spectroscopic study of proton-irradiated plastic fibers showed a continuous spectrum with shape different from that of Čerenkov radiation. The Monte Carlo simulations confirmed that the amount of the generated Čerenkov light does not follow the radiation absorbed dose in a medium. Our results show that the origin of the optical signal responsible for the proton dose measurement using bare optical fibers is not Čerenkov radiation. Our results point toward a connection between the scintillation of the plastic material of the fiber and the origin of the signal responsible for dose measurement.

Heavy metal remediation with Ficus microcarpa through transplantation and its environmental risks through field scale experiment.

PubMed

Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Gu, Xiaowen Sophie

2018-02-01

The phytoremediation efficiency of various metals by Ficus microcarpa was evaluated through a real scale experiment in the present study. The root biomass production of the species varied significantly from 3.68 to 5.43 g because of the spatial heterogeneity of different metals. It would take 4-93 years to purify the excess Cd of the experimental site. Mercury was the most inflexible element which can barely be phytoremediated by F. microcarpa. After the species transplanted from the polluted soil to the clean site, Cd and Cu were transferred to the rhizosphere soil to different extent while the bulk soil was barely influenced. Relative to Cd and Cu, significantly fewer amounts of Pb and Hg were released. The highest concentrations of Cd, Cu, Hg and Pb in the clean soil were far below their corresponding safe thresholds for agricultural land after 3 months of the polluted plants were cultivated and metal concentrations of plant leaves were negligible, both indicated the low ecological risk of transplantation. Results from this study suggested a feasible disposal method for metal rich plants after phytoremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Developmental instability in Rhus copallinum L.: multiple stressors, years, and responses

USGS Publications Warehouse

Freeman, D. Carl; Brown, Michelle L.; Duda, Jeffrey J.; Graham, John H.; Emlen, John M.; Krzysik, Anthony J.; Balbach, Harold E.; Kovacic, Dave A.; Zak, John C.

2004-01-01

Developmental instability, as assessed by leaf fluctuating asymmetry and stem internode allometry, was examined at nine sites, representing three levels of disturbance, over multiple years. Site selection was based on land‐use disturbance classes related to training of mechanized infantry and other land management activities at Fort Benning, Georgia. Developmental instability varied among sites and years, and there was a strong site‐by‐year interaction for many traits. Indeed, depending on the year, the same site could be ranked as having the greatest and least amount of leaf fluctuating asymmetry. Burning a site the year prior to collecting the leaves profoundly influenced measures of leaf fluctuating asymmetry. In the absence of recent burning, leaf fluctuating asymmetry declined with increasing disturbance, but burning the year prior to collecting the leaves reversed this trend. Total plant cover, proportion of bare ground, and amount of plant litter influenced the amount of leaf asymmetry in a site‐dependent manner. Overall, burning influenced the levels of developmental instability more than either disturbance or microhabitat variables such as total plant cover, which should reflect competition in a plant’s immediate neighborhood.

Photoinduced deposition of gold nanoparticles on TiO2-WO3 nanotube films as efficient photoanodes for solar water splitting

NASA Astrophysics Data System (ADS)

Momeni, Mohamad Mohsen; Ghayeb, Yousef

2016-06-01

Gold-modified TiO2-WO3 nanotubes with different amounts of gold were obtained by two methods; photoassisted deposition and one-step electrochemical anodizing method. The morphology, crystallinity and elemental composition were studied by FE-SEM, XRD and EDX. The photoelectrochemical performance was examined under Xe light illumination in 1 M NaOH electrolyte. Characterization of the as-prepared TiO2-WO3 samples indicated that sodium tungstate concentration in anodizing solution significantly influenced the morphology and photoelectrochemical activity of fabricated films. Also, photoelectrochemical characterizations show that the photocatalytic activity of Au/TiO2-WO3 nanotubes was improved as compared with that of bare TiO2-WO3 nanotubes. The experimental results showed that the photocatalytic activities of Au/TiO2-WO3 were significantly affected by the amount of Au nanoparticles. The amount of gold nanoparticles was effectively controlled by time of photoreduction of the chloroauric acid solution. These new photoanodes showed enhanced high photocurrent density with good stability and are a highly promising photoanodes for photocatalytic hydrogen production.

A constructive nonlinear array (CNA) method for barely visible impact detection in composite materials

NASA Astrophysics Data System (ADS)

Malfense Fierro, Gian Piero; Meo, Michele

2017-04-01

Currently there are numerous phased array techniques such as Full Matrix Capture (FMC) and Total Focusing Method (TFM) that provide good damage assessment for composite materials. Although, linear methods struggle to evaluate and assess low levels of damage, while nonlinear methods have shown great promise in early damage detection. A sweep and subtraction evaluation method coupled with a constructive nonlinear array method (CNA) is proposed in order to assess damage specific nonlinearities, address issues with frequency selection when using nonlinear ultrasound imaging techniques and reduce equipment generated nonlinearities. These methods were evaluated using multiple excitation locations on an impacted composite panel with a complex damage (barely visible impact damage). According to various recent works, damage excitation can be accentuated by exciting at local defect resonance (LDR) frequencies; although these frequencies are not always easily determinable. The sweep methodology uses broadband excitation to determine both local defect and material resonances, by assessing local defect generated nonlinearities using a laser vibrometer it is possible to assess which frequencies excite the complex geometry of the crack. The dual effect of accurately determining local defect resonances, the use of an image subtraction method and the reduction of equipment based nonlinearities using CNA result in greater repeatability and clearer nonlinear imaging (NIM).

Supercritical fluid chromatographic resolution of water soluble isomeric carboxyl/amine terminated peptides facilitated via mobile phase water and ion pair formation.

PubMed

Patel, M A; Riley, F; Ashraf-Khorassani, M; Taylor, L T

2012-04-13

Both analytical scale and preparative scale packed column supercritical fluid chromatography (SFC) have found widespread applicability for chiral separations of multiple polar pharmaceutical candidates. However, SFC is rapidly becoming an achiral technique. More specifically, ion pair SFC is finding greater utility for separation of ionic analytes such as amine salts and organic sulfonates. The key to this success is, in part, the incorporation of additives such as trifluoroacetic acid and ammonium acetate into the mobile phase in association with a wide variety of both bonded silica stationary phases and high purity bare silica. Ion pairing SFC coupled with evaporative light scattering detection and mass spectrometric detection is presented here for the separation of water soluble, uncapped, isomeric peptide pairs that differ in amino acid arrangement. The separation is best achieved on either diol-bonded silica or bare silica with 1-5% (w/w) water as a significant ingredient in the mobile phase. Nitrogenous stationary phases such as 2-ethylpyridine, which had been very successful for the separation of capped peptides failed to yield the desired separation regardless of the mobile phase composition. A HILIC type retention mechanism is postulated for the separation of both isomeric uncapped peptide pairs. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterizing subcritical assemblies with time of flight fixed by energy estimation distributions

NASA Astrophysics Data System (ADS)

Monterial, Mateusz; Marleau, Peter; Pozzi, Sara

2018-04-01

We present the Time of Flight Fixed by Energy Estimation (TOFFEE) as a measure of the fission chain dynamics in subcritical assemblies. TOFFEE is the time between correlated gamma rays and neutrons, subtracted by the estimated travel time of the incident neutron from its proton recoil. The measured subcritical assembly was the BeRP ball, a 4.482 kg sphere of α-phase weapons grade plutonium metal, which came in five configurations: bare, 0.5, 1, and 1.5 in iron, and 1 in nickel closed fitting shell reflectors. We extend the measurement with MCNPX-PoliMi simulations of shells ranging up to 6 inches in thickness, and two new reflector materials: aluminum and tungsten. We also simulated the BeRP ball with different masses ranging from 1 to 8 kg. A two-region and single-region point kinetics models were used to model the behavior of the positive side of the TOFFEE distribution from 0 to 100 ns. The single region model of the bare cases gave positive linear correlations between estimated and expected neutron decay constants and leakage multiplications. The two-region model provided a way to estimate neutron multiplication for the reflected cases, which correlated positively with expected multiplication, but the nature of the correlation (sub or superlinear) changed between material types. Finally, we found that the areal density of the reflector shells had a linear correlation with the integral of the two-region model fit. Therefore, we expect that with knowledge of reflector composition, one could determine the shell thickness, or vice versa. Furthermore, up to a certain amount and thickness of the reflector, the two-region model provides a way of distinguishing bare and reflected plutonium assemblies.

Prediction of soil properties using imaging spectroscopy: Considering fractional vegetation cover to improve accuracy

NASA Astrophysics Data System (ADS)

Franceschini, M. H. D.; Demattê, J. A. M.; da Silva Terra, F.; Vicente, L. E.; Bartholomeus, H.; de Souza Filho, C. R.

2015-06-01

Spectroscopic techniques have become attractive to assess soil properties because they are fast, require little labor and may reduce the amount of laboratory waste produced when compared to conventional methods. Imaging spectroscopy (IS) can have further advantages compared to laboratory or field proximal spectroscopic approaches such as providing spatially continuous information with a high density. However, the accuracy of IS derived predictions decreases when the spectral mixture of soil with other targets occurs. This paper evaluates the use of spectral data obtained by an airborne hyperspectral sensor (ProSpecTIR-VS - Aisa dual sensor) for prediction of physical and chemical properties of Brazilian highly weathered soils (i.e., Oxisols). A methodology to assess the soil spectral mixture is adapted and a progressive spectral dataset selection procedure, based on bare soil fractional cover, is proposed and tested. Satisfactory performances are obtained specially for the quantification of clay, sand and CEC using airborne sensor data (R2 of 0.77, 0.79 and 0.54; RPD of 2.14, 2.22 and 1.50, respectively), after spectral data selection is performed; although results obtained for laboratory data are more accurate (R2 of 0.92, 0.85 and 0.75; RPD of 3.52, 2.62 and 2.04, for clay, sand and CEC, respectively). Most importantly, predictions based on airborne-derived spectra for which the bare soil fractional cover is not taken into account show considerable lower accuracy, for example for clay, sand and CEC (RPD of 1.52, 1.64 and 1.16, respectively). Therefore, hyperspectral remotely sensed data can be used to predict topsoil properties of highly weathered soils, although spectral mixture of bare soil with vegetation must be considered in order to achieve an improved prediction accuracy.

Measurements of dermal uptake of nicotine directly from air and clothing.

PubMed

Bekö, G; Morrison, G; Weschler, C J; Koch, H M; Pälmke, C; Salthammer, T; Schripp, T; Toftum, J; Clausen, G

2017-03-01

In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically "smoking" cigarettes, for three hours in a chamber while breathing clean air from head-enveloping hoods. The average nicotine concentration (420 μg/m 3 ) was comparable to the highest levels reported for smoking sections of pubs. Urine samples were collected immediately before exposure and 60 hour post-exposure for bare-skinned participants. For the clothed participant, post-exposure urine samples were collected for 24 hour. This participant then entered the chamber for another three-hour exposure wearing a hood and clothes, including a shirt that had been exposed for five days to elevated nicotine levels. The urine samples were analyzed for nicotine and two metabolites-cotinine and 3OH-cotinine. Peak urinary cotinine and 3OH-cotinine concentrations for the bare-skinned participants were comparable to levels measured among non-smokers in hospitality environments before smoking bans. The amount of dermally absorbed nicotine for each bare-skinned participant was conservatively estimated at 570 μg, but may have been larger. For the participant wearing clean clothes, uptake was ~20 μg, and while wearing a shirt previously exposed to nicotine, uptake was ~80 μg. This study demonstrates meaningful dermal uptake of nicotine directly from air or from nicotine-exposed clothes. The findings are especially relevant for children in homes with smoking or vaping. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Wave Amplitude Dependent Engineering Model of Propellant Slosh in Spherical Tanks

NASA Technical Reports Server (NTRS)

Brodnick, Jacob; Westra, Douglas G.; Eberhart, Chad J.; Yang, Hong Q.; West, Jeffrey S.

2016-01-01

Liquid propellant slosh is often a concern for the controllability of flight vehicles. Anti-slosh devices are traditionally included in propellant tank designs to limit the amount of sloshing allowed during flight. These devices and any necessary supports can be quite heavy to meet various structural requirements. Some of the burden on anti-slosh devices can be relieved by exploiting the nonlinear behavior of slosh waves in bare smooth wall tanks. A nonlinear regime slosh model for bare spherical tanks was developed through a joint analytical and experimental effort by NASA/MSFC. The developed slosh model accounts for the large damping inherent in nonlinear slosh waves which is more accurate and drives conservatism from vehicle stability analyses that use traditional bare tank slosh models. A more accurate slosh model will result in more realistic predicted slosh forces during flight reducing or removing the need for active controls during a maneuver or baffles in the tank design. Lower control gains and smaller or fewer tank baffles can reduce cost and system complexity while increasing vehicle performance. Both Computational Fluid Dynamics (CFD) simulation and slosh testing of three different spherical tank geometries were performed to develop the proposed slosh model. Several important findings were made during this effort in addition to determining the parameters to the nonlinear regime slosh model. The linear regime slosh damping trend for spherical tanks reported in NASA SP-106 was shown to be inaccurate for certain regions of a tank. Additionally, transition to the nonlinear regime for spherical tanks was only found to occur at very large wave amplitudes in the lower hemisphere and was a strong function of the propellant fill level in the upper hemisphere. The nonlinear regime damping trend was also found to be a function of the propellant fill level.

Radiative transfer model of snow for bare ice regions

NASA Astrophysics Data System (ADS)

Tanikawa, T.; Aoki, T.; Niwano, M.; Hosaka, M.; Shimada, R.; Hori, M.; Yamaguchi, S.

2016-12-01

Modeling a radiative transfer (RT) for coupled atmosphere-snow-bare ice systems is of fundamental importance for remote sensing applications to monitor snow and bare ice regions in the Greenland ice sheet and for accurate climate change predictions by regional and global climate models. Recently, the RT model for atmosphere-snow system was implemented for our regional and global climate models. However, the bare ice region where recently it has been expanded on the Greenland ice sheet due to the global warming, has not been implemented for these models, implying that this region leads miscalculations in these climate models. Thus, the RT model of snow for bare ice regions is needed for accurate climate change predictions. We developed the RT model for coupled atmosphere-snow-bare ice systems, and conducted a sensitivity analysis of the RT model to know the effect of snow, bare ice and geometry parameters on the spectral radiant quantities. The RT model considers snow and bare-ice inherent optical properties (IOPs), including snow grain size, air bubble size and its concentration and bare ice thickness. The conventional light scattering theory, Mie theory, was used for IOP calculations. Monte Carlo method was used for the multiple scattering. The sensitivity analyses showed that spectral albedo for the bare ice increased with increasing the concentration of the air bubble in the bare ice for visible wavelengths because the air bubble is scatterer with no absorption. For near infrared wavelengths, spectral albedo has no dependence on the air bubble due to the strong light absorption by ice. When increasing solar zenith angle, the spectral albedo were increased for all wavelengths. This is the similar trend with spectral snow albedo. Cloud cover influenced the bare ice spectral albedo by covering direct radiation into diffuse radiation. The purely diffuse radiation has an effective solar zenith angle near 50°. Converting direct into diffuse radiation reduces the effective solar zenith angle, resulting in reducing the spectral albedo. This is also the similar trend with spectral snow albedo. Further work should focus on the validation of the RT model using in situ measurement data through field and laboratory experiments.

Automated laser-based barely visible impact damage detection in honeycomb sandwich composite structures

NASA Astrophysics Data System (ADS)

Girolamo, D.; Girolamo, L.; Yuan, F. G.

2015-03-01

Nondestructive evaluation (NDE) for detection and quantification of damage in composite materials is fundamental in the assessment of the overall structural integrity of modern aerospace systems. Conventional NDE systems have been extensively used to detect the location and size of damages by propagating ultrasonic waves normal to the surface. However they usually require physical contact with the structure and are time consuming and labor intensive. An automated, contactless laser ultrasonic imaging system for barely visible impact damage (BVID) detection in advanced composite structures has been developed to overcome these limitations. Lamb waves are generated by a Q-switched Nd:YAG laser, raster scanned by a set of galvano-mirrors over the damaged area. The out-of-plane vibrations are measured through a laser Doppler Vibrometer (LDV) that is stationary at a point on the corner of the grid. The ultrasonic wave field of the scanned area is reconstructed in polar coordinates and analyzed for high resolution characterization of impact damage in the composite honeycomb panel. Two methodologies are used for ultrasonic wave-field analysis: scattered wave field analysis (SWA) and standing wave energy analysis (SWEA) in the frequency domain. The SWA is employed for processing the wave field and estimate spatially dependent wavenumber values, related to discontinuities in the structural domain. The SWEA algorithm extracts standing waves trapped within damaged areas and, by studying the spectrum of the standing wave field, returns high fidelity damage imaging. While the SWA can be used to locate the impact damage in the honeycomb panel, the SWEA produces damage images in good agreement with X-ray computed tomographic (X-ray CT) scans. The results obtained prove that the laser-based nondestructive system is an effective alternative to overcome limitations of conventional NDI technologies.

Mineral-bearing vesicle transport in sea urchin embryos.

PubMed

Vidavsky, Netta; Masic, Admir; Schertel, Andreas; Weiner, Steve; Addadi, Lia

2015-12-01

Sea urchin embryos sequester calcium from the sea water. This calcium is deposited in a concentrated form in granule bearing vesicles both in the epithelium and in mesenchymal cells. Here we use in vivo calcein labeling and confocal Raman spectroscopy, as well as cryo-FIB-SEM 3D structural reconstructions, to investigate the processes occurring in the internal cavity of the embryo, the blastocoel. We demonstrate that calcein stained granules are also present in the filopodial network within the blastocoel. Simultaneous fluorescence imaging and Raman spectroscopy show that these granules do contain a calcium mineral. By tracking the movements of these granules, we show that the granules in the epithelium and primary mesenchymal cells barely move, but those in the filopodial network move long distances. We could however not detect any unidirectional movement of the filopodial granules. We also show the presence of mineral containing multivesicular vesicles that also move in the filopodial network. We conclude that the filopodial network is an integral part of the mineral transport process, and possibly also for sequestering calcium and other ions. Although much of the sequestered calcium is deposited in the mineralized skeleton, a significant amount is used for other purposes, and this may be temporarily stored in these membrane-delineated intracellular deposits. Copyright © 2015 Elsevier Inc. All rights reserved.

Statistical correction of lidar-derived digital elevation models with multispectral airborne imagery in tidal marshes

USGS Publications Warehouse

Buffington, Kevin J.; Dugger, Bruce D.; Thorne, Karen M.; Takekawa, John Y.

2016-01-01

Airborne light detection and ranging (lidar) is a valuable tool for collecting large amounts of elevation data across large areas; however, the limited ability to penetrate dense vegetation with lidar hinders its usefulness for measuring tidal marsh platforms. Methods to correct lidar elevation data are available, but a reliable method that requires limited field work and maintains spatial resolution is lacking. We present a novel method, the Lidar Elevation Adjustment with NDVI (LEAN), to correct lidar digital elevation models (DEMs) with vegetation indices from readily available multispectral airborne imagery (NAIP) and RTK-GPS surveys. Using 17 study sites along the Pacific coast of the U.S., we achieved an average root mean squared error (RMSE) of 0.072 m, with a 40–75% improvement in accuracy from the lidar bare earth DEM. Results from our method compared favorably with results from three other methods (minimum-bin gridding, mean error correction, and vegetation correction factors), and a power analysis applying our extensive RTK-GPS dataset showed that on average 118 points were necessary to calibrate a site-specific correction model for tidal marshes along the Pacific coast. By using available imagery and with minimal field surveys, we showed that lidar-derived DEMs can be adjusted for greater accuracy while maintaining high (1 m) resolution.

Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

NASA Astrophysics Data System (ADS)

Kozai, Naofumi; Ohnuki, Toshihiko; Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro

2011-10-01

The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

New baseline environmental assessment of mosquito ecology in northern Haiti during increased urbanization

PubMed Central

Archer, Reginald S.; Alimi, Temitope O.; Arheart, Kristopher K.; Impoinvil, Daniel E.; Oscar, Roland; Fuller, Douglas O.; Qualls, Whitney A.

2015-01-01

The catastrophic 2010 earthquake in Port-au-Prince, Haiti, led to the large-scale displacement of over 2.3 million people, resulting in rapid and unplanned urbanization in northern Haiti. This study evaluated the impact of this unplanned urbanization on mosquito ecology and vector-borne diseases by assessing land use and change patterns. Land-use classification and change detection were carried out on remotely sensed images of the area for 2010 and 2013. Change detection identified areas that went from agricultural, forest, or bare-land pre-earthquake to newly developed and urbanized areas post-earthquake. Areas to be sampled for mosquito larvae were subsequently identified. Mosquito collections comprised five genera and ten species, with the most abundant species being Culex quinquefasciatus 35% (304/876), Aedes albopictus 27% (238/876), and Aedes aegypti 20% (174/876). All three species were more prevalent in urbanized and newly urbanized areas. Anopheles albimanus, the predominate malaria vector, accounted for less than 1% (8/876) of the collection. A set of spectral indices derived from the recently launched Landsat 8 satellite was used as covariates in a species distribution model. The indices were used to produce probability surfaces maps depicting the likelihood of presence of the three most abundant species within 30 m pixels. Our findings suggest that the rapid urbanization following the 2010 earthquake has increased the amount of area with suitable habitats for urban mosquitoes, likely influencing mosquito ecology and posing a major risk of introducing and establishing emerging vector-borne diseases. PMID:26047183

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

PubMed Central

2017-01-01

Due to their electrochemical and economical characteristics, pencil graphite electrodes (PGEs) gained in recent years a large applicability to the analysis of various types of inorganic and organic compounds from very different matrices. The electrode material of this type of working electrodes is constituted by the well-known and easy commercially available graphite pencil leads. Thus, PGEs are cheap and user-friendly and can be employed as disposable electrodes avoiding the time-consuming step of solid electrodes surface cleaning between measurements. When compared to other working electrodes PGEs present lower background currents, higher sensitivity, good reproducibility, and an adjustable electroactive surface area, permitting the analysis of low concentrations and small sample volumes without any deposition/preconcentration step. Therefore, this paper presents a detailed overview of the PGEs characteristics, designs and applications of bare, and electrochemically pretreated and chemically modified PGEs along with the corresponding performance characteristics like linear range and detection limit. Techniques used for bare or modified PGEs surface characterization are also reviewed. PMID:28255500

The Effects of Foam Thermal Protection System on the Damage Tolerance Characteristics of Composite Sandwich Structures for Launch Vehicles

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Hodge, A. J.; Jackson, J. R.

2011-01-01

For any structure composed of laminated composite materials, impact damage is one of the greatest risks and therefore most widely tested responses. Typically, impact damage testing and analysis assumes that a solid object comes into contact with the bare surface of the laminate (the outer ply). However, most launch vehicle structures will have a thermal protection system (TPS) covering the structure for the majority of its life. Thus, the impact response of the material with the TPS covering is the impact scenario of interest. In this study, laminates representative of the composite interstage structure for the Ares I launch vehicle were impact tested with and without the planned TPS covering, which consists of polyurethane foam. Response variables examined include maximum load of impact, damage size as detected by nondestructive evaluation techniques, and damage morphology and compression after impact strength. Results show that there is little difference between TPS covered and bare specimens, except the residual strength data is higher for TPS covered specimens.

Variations in thematic mapper spectra of soil related to tillage and crop residue management - Initial evaluation

NASA Technical Reports Server (NTRS)

Seeley, M. W.; Ruschy, D. L.; Linden, D. R.

1983-01-01

A cooperative research project was initiated in 1982 to study differences in thematic mapper spectral characteristics caused by variable tillage and crop residue practices. Initial evaluations of radiometric data suggest that spectral separability of variably tilled soils can be confounded by moisture and weathering effects. Separability of bare tilled soils from those with significant amounts of corn residue is enhanced by wet conditions, but still possible under dry conditions when recent tillage operations have occurred. In addition, thematic mapper data may provide an alternative method to study the radiant energy balance at the soil surface in conjunction with variable tillage systems.

Performance of Self-developing Radiography Films in LVR-15's Neutron Beams

NASA Astrophysics Data System (ADS)

Soltes, Jaroslav; Viererbl, Ladislav; Klupak, Vit; Vins, Miroslav; Michalcova, Bozena

In the search for a suitable detector for demonstration neutron radiography measurements on the zero-power VR-1 training reactor at the Czech Technical University in Prague, some options were considered. Due to the reactor's low power and spatial limitations, an easy and practical solution had to be found. Self-developing films represent a flexible detection tool in x-ray imaging. Therefore, the goal of this study was to evaluate their potential for neutron detection. For this purpose, bare and converter covered films were studied in the thermal and epithermal neutron beams at the LVR-15 research reactor in Rez, Czech Republic.

Electroreduction-based electrochemical-enzymatic redox cycling for the detection of cancer antigen 15-3 using graphene oxide-modified indium-tin oxide electrodes.

PubMed

Park, Seonhwa; Singh, Amardeep; Kim, Sinyoung; Yang, Haesik

2014-02-04

We compare herein biosensing performance of two electroreduction-based electrochemical-enzymatic (EN) redox-cycling schemes [the redox cycling combined with simultaneous enzymatic amplification (one-enzyme scheme) and the redox cycling combined with preceding enzymatic amplification (two-enzyme scheme)]. To minimize unwanted side reactions in the two-enzyme scheme, β-galactosidase (Gal) and tyrosinase (Tyr) are selected as an enzyme label and a redox enzyme, respectively, and Tyr is selected as a redox enzyme label in the one-enzyme scheme. The signal amplification in the one-enzyme scheme consists of (i) enzymatic oxidation of catechol into o-benzoquinone by Tyr and (ii) electroreduction-based EN redox cycling of o-benzoquinone. The signal amplification in the two-enzyme scheme consists of (i) enzymatic conversion of phenyl β-d-galactopyranoside into phenol by Gal, (ii) enzymatic oxidation of phenol into catechol by Tyr, and (iii) electroreduction-based EN redox cycling of o-benzoquinone including further enzymatic oxidation of catechol to o-benzoquinone by Tyr. Graphene oxide-modified indium-tin oxide (GO/ITO) electrodes, simply prepared by immersing ITO electrodes in a GO-dispersed aqueous solution, are used to obtain better electrocatalytic activities toward o-benzoquinone reduction than bare ITO electrodes. The detection limits for mouse IgG, measured with GO/ITO electrodes, are lower than when measured with bare ITO electrodes. Importantly, the detection of mouse IgG using the two-enzyme scheme allows lower detection limits than that using the one-enzyme scheme, because the former gives higher signal levels at low target concentrations although the former gives lower signal levels at high concentrations. The detection limit for cancer antigen (CA) 15-3, a biomarker of breast cancer, measured using the two-enzyme scheme and GO/ITO electrodes is ca. 0.1 U/mL, indicating that the immunosensor is highly sensitive.

Accuracy of EAARL lidar ground elevations using a bare-earth algorithm in marsh and beach grasses on the Chandeleur Islands, Louisiana

USGS Publications Warehouse

Doran, Kara S.; Sallenger, Asbury H.; Reynolds, Billy J.; Wright, C. Wayne

2010-01-01

The NASA Experimental Advanced Airborne Lidar (EAARL) is an airborne lidar (light detection and ranging) instrument designed to map coastal topography and bathymetry. The EAARL system has the capability to capture each laser-pulse return over a large signal range and can digitize the full waveform of the backscattered energy. Because of this ability to capture the full waveform, the EAARL system can map features such as coral reefs, beaches, coastal vegetation, and trees, where extreme variations in the laser backscatter are caused by different physical and optical characteristics. Post-processing of the EAARL data is accomplished using the Airborne Lidar Processing System (ALPS) (Nayegandhi and others, 2009). In ALPS, the waveform of the lidar is analyzed and split into first and last returns. The 'first returns' are indicative of vegetation-canopy height, or bare ground in the absence of vegetation, whereas 'last returns' typically represent 'bare-earth' elevations under vegetation. To test the accuracy of the first-return and bare-earth EAARL data, topographic and vegetation height surveys were conducted in the Chandeleur Islands, concurrent with an EAARL lidar survey and an aerial oblique-photographic survey from September 20 to 27, 2006. The Chandeleur Islands are a north-south-oriented chain of low-lying islands located approximately 100 kilometers east of the city of New Orleans, Louisiana. The islands are narrow north-south strips of land with marsh on the landward (west sides) and sandy beaches on their gulfward (east sides). Prior to Hurricane Katrina, which made landfall at Buras, Louisiana, as a Category 3 storm on August 29, 2005, prominent, 3- to 4-meter-high sand dunes were present in the northern Chandeleurs. The storm removed them, leaving post-storm island elevations of generally less than 2 meters above 0.0 NAVD88. This report is part of a study of the impact of Hurricane Katrina on the Chandeleur Islands using pre-storm and post-storm lidar surveys to detect morphological changes. The islands lost over 80 percent of their land area during Hurricane Katrina, and in the first 2 years following Katrina, many of the islands experienced continued shoreline retreat (Sallenger and others, 2007). In addition to land-area losses, the loss of dunes made the islands increasingly vulnerable to future storm impacts. The U.S. Geological Survey, along with partners in the Louisiana Department of Natural Resources and the U.S. Army Corps of Engineers, continues to monitor changes in shoreline position, land area, and elevation in the Chandeleur Islands.

Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

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

Kim, Charles Y., E-mail: charles.kim@duke.edu; Tandberg, Daniel J.; Rosenberg, Michael D.

2012-08-15

Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metalmore » stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.« less

Re-usable electrochemical glucose sensors integrated into a smartphone platform.

PubMed

Bandodkar, Amay J; Imani, Somayeh; Nuñez-Flores, Rogelio; Kumar, Rajan; Wang, Chiyi; Mohan, A M Vinu; Wang, Joseph; Mercier, Patrick P

2018-03-15

This article demonstrates a new smartphone-based reusable glucose meter. The glucose meter includes a custom-built smartphone case that houses a permanent bare sensor strip, a stylus that is loaded with enzyme-carbon composite pellets, and sensor instrumentation circuits. A custom-designed Android-based software application was developed to enable easy and clear display of measured glucose concentration. A typical test involves the user loading the software, using the stylus to dispense an enzymatic pellet on top of the bare sensor strip affixed to the case, and then introducing the sample. The electronic module then acquires and wirelessly transmits the data to the application software to be displayed on the screen. The deployed pellet is then discarded to regain the fresh bare sensor surface. Such a unique working principle allows the system to overcome challenges faced by previously reported reusable sensors, such as enzyme degradation, leaching, and hysteresis effects. Studies reveal that the enzyme loaded in the pellets are stable for up to 8 months at ambient conditions, and generate reproducible sensor signals. The work illustrates the significance of the pellet-based sensing system towards realizing a reusable, point-of-care sensor that snugly fits around a smartphone and which does not face issues usually common to reusable sensors. The versatility of this system allows it to be easily modified to detect other analytes for application in a wide range of healthcare, environmental and defense domains. Copyright © 2017 Elsevier B.V. All rights reserved.

New β-Cyclodextrin Entrapped in Polyethyleneimine Film-Modified Electrodes for Pharmaceutical Compounds Determination

PubMed Central

Fritea, Luminţa; Tertiş, Mihaela; Cristea, Cecilia; Săndulescu, Robert

2013-01-01

The electrochemical behavior of ascorbic acid and uric acid on glassy carbon bare electrodes and ones modified with β-cyclodextrin entrapped in polyethyleneimine film has been investigated using square wave voltammetry. The electrode modification was achieved in order to separate the voltammetric peaks of ascorbic acid and uric acid when present in the same solution. On the modified electrodes the potential of the oxidation peak of the ascorbic acid was shifted to more negative values by over 0.3 V, while in the case of uric acid, the negative potential shift was about 0.15 V compared to the bare glassy carbon electrode. When the two compounds were found together in the solution, on the bare electrode only a single broad signal was observed, while on the modified electrode the peak potentials of these two compounds were separated by 0.4 V. When the uric acid concentration remained constant, the peak intensity of the ascorbic acid is increased linearly with the concentration (r2 = 0.996) and when the ascorbic acid concentration remains constant, the peak intensity of the uric acid increased linearly with the concentration (r2 = 0.992). FTIR measurements supported the formation of inclusion complexes. In order to characterize the modification of the electrodes microscopic studies were performed. The modified electrodes were successfully employed for the determination of ascorbic acid in pharmaceutical formulations with a detection limit of 0.22 μM. PMID:24287544

Coral Skeletons Defend against Ultraviolet Radiation

PubMed Central

Reef, Ruth; Kaniewska, Paulina; Hoegh-Guldberg, Ove

2009-01-01

Background Many coral reef organisms are photosynthetic or have evolved in tight symbiosis with photosynthetic symbionts. As such, the tissues of reef organisms are often exposed to intense solar radiation in clear tropical waters and have adapted to trap and harness photosynthetically active radiation (PAR). High levels of ultraviolet radiation (UVR) associated with sunlight, however, represent a potential problem in terms of tissue damage. Methodology/Principal Findings By measuring UVR and PAR reflectance from intact and ground bare coral skeletons we show that the property of calcium carbonate skeletons to absorb downwelling UVR to a significant extent, while reflecting PAR back to the overlying tissue, has biological advantages. We placed cnidarians on top of bare skeletons and a UVR reflective substrate and showed that under ambient UVR levels, UVR transmitted through the tissues of cnidarians placed on top of bare skeletons were four times lower compared to their counterparts placed on a UVR reflective white substrate. In accordance with the lower levels of UVR measured in cnidarians on top of coral skeletons, a similar drop in UVR damage to their DNA was detected. The skeletons emitted absorbed UVR as yellow fluorescence, which allows for safe dissipation of the otherwise harmful radiation. Conclusions/Significance Our study presents a novel defensive role for coral skeletons and reveals that the strong UVR absorbance by the skeleton can contribute to the ability of corals, and potentially other calcifiers, to thrive under UVR levels that are detrimental to most marine life. PMID:19946361

Spatial variation and linkages of soil and vegetation in the Siberian Arctic tundra - coupling field observations with remote sensing data

NASA Astrophysics Data System (ADS)

Mikola, Juha; Virtanen, Tarmo; Linkosalmi, Maiju; Vähä, Emmi; Nyman, Johanna; Postanogova, Olga; Räsänen, Aleksi; Kotze, D. Johan; Laurila, Tuomas; Juutinen, Sari; Kondratyev, Vladimir; Aurela, Mika

2018-05-01

Arctic tundra ecosystems will play a key role in future climate change due to intensifying permafrost thawing, plant growth and ecosystem carbon exchange, but monitoring these changes may be challenging due to the heterogeneity of Arctic landscapes. We examined spatial variation and linkages of soil and plant attributes in a site of Siberian Arctic tundra in Tiksi, northeast Russia, and evaluated possibilities to capture this variation by remote sensing for the benefit of carbon exchange measurements and landscape extrapolation. We distinguished nine land cover types (LCTs) and to characterize them, sampled 92 study plots for plant and soil attributes in 2014. Moreover, to test if variation in plant and soil attributes can be detected using remote sensing, we produced a normalized difference vegetation index (NDVI) and topographical parameters for each study plot using three very high spatial resolution multispectral satellite images. We found that soils ranged from mineral soils in bare soil and lichen tundra LCTs to soils of high percentage of organic matter (OM) in graminoid tundra, bog, dry fen and wet fen. OM content of the top soil was on average 14 g dm-3 in bare soil and lichen tundra and 89 g dm-3 in other LCTs. Total moss biomass varied from 0 to 820 g m-2, total vascular shoot mass from 7 to 112 g m-2 and vascular leaf area index (LAI) from 0.04 to 0.95 among LCTs. In late summer, soil temperatures at 15 cm depth were on average 14 °C in bare soil and lichen tundra, and varied from 5 to 9 °C in other LCTs. On average, depth of the biologically active, unfrozen soil layer doubled from early July to mid-August. When contrasted across study plots, moss biomass was positively associated with soil OM % and OM content and negatively associated with soil temperature, explaining 14-34 % of variation. Vascular shoot mass and LAI were also positively associated with soil OM content, and LAI with active layer depth, but only explained 6-15 % of variation. NDVI captured variation in vascular LAI better than in moss biomass, but while this difference was significant with late season NDVI, it was minimal with early season NDVI. For this reason, soil attributes associated with moss mass were better captured by early season NDVI. Topographic attributes were related to LAI and many soil attributes, but not to moss biomass and could not increase the amount of spatial variation explained in plant and soil attributes above that achieved by NDVI. The LCT map we produced had low to moderate uncertainty in predictions for plant and soil properties except for moss biomass and bare soil and lichen tundra LCTs. Our results illustrate a typical tundra ecosystem with great fine-scale spatial variation in both plant and soil attributes. Mosses dominate plant biomass and control many soil attributes, including OM % and temperature, but variation in moss biomass is difficult to capture by remote sensing reflectance, topography or a LCT map. Despite the general accuracy of landscape level predictions in our LCT approach, this indicates challenges in the spatial extrapolation of some of those vegetation and soil attributes that are relevant for the regional ecosystem and global climate models.

Inclusion of Solar Elevation Angle in Land Surface Albedo Parameterization Over Bare Soil Surface.

PubMed

Zheng, Zhiyuan; Wei, Zhigang; Wen, Zhiping; Dong, Wenjie; Li, Zhenchao; Wen, Xiaohang; Zhu, Xian; Ji, Dong; Chen, Chen; Yan, Dongdong

2017-12-01

Land surface albedo is a significant parameter for maintaining a balance in surface energy. It is also an important parameter of bare soil surface albedo for developing land surface process models that accurately reflect diurnal variation characteristics and the mechanism behind the solar spectral radiation albedo on bare soil surfaces and for understanding the relationships between climate factors and spectral radiation albedo. Using a data set of field observations, we conducted experiments to analyze the variation characteristics of land surface solar spectral radiation and the corresponding albedo over a typical Gobi bare soil underlying surface and to investigate the relationships between the land surface solar spectral radiation albedo, solar elevation angle, and soil moisture. Based on both solar elevation angle and soil moisture measurements simultaneously, we propose a new two-factor parameterization scheme for spectral radiation albedo over bare soil underlying surfaces. The results of numerical simulation experiments show that the new parameterization scheme can more accurately depict the diurnal variation characteristics of bare soil surface albedo than the previous schemes. Solar elevation angle is one of the most important factors for parameterizing bare soil surface albedo and must be considered in the parameterization scheme, especially in arid and semiarid areas with low soil moisture content. This study reveals the characteristics and mechanism of the diurnal variation of bare soil surface solar spectral radiation albedo and is helpful in developing land surface process models, weather models, and climate models.

Optical characterization of nanoporous AAO sensor substrate

NASA Astrophysics Data System (ADS)

Kassu, Aschalew; Farley, Carlton W.; Sharma, Anup

2014-05-01

Nanoporous anodic aluminum oxide (AAO) has been investigated as an ideal and cost-effective chemical and biosensing platform. In this paper, we report the optical properties of periodic 100 micron thick nanoporous anodic alumina membranes with uniform and high density cylindrical pores penetrating the entire thickness of the substrate, ranging in size from 18 nm to 150 nm in diameter and pore periods from 44 nm to 243 nm. The surface geometry of the top and bottom surface of each membrane is studied using atomic force microscopy. The optical properties including transmittance, reflectance, and absorbance spectra on both sides of each substrate are studied and found to be symmetrical. It is observed that, as the pore size increases, the peak resonance intensity in transmittance decreases and in absorbance increases. The effects of the pore sizes on the optical properties of the bare nanoporous membranes and the benefit of using arrays of nanohole arrays with varying hole size and periodicity as a chemical sensing platform is also discussed. To characterize the optical sensing technique, transmittance and reflectance measurements of various concentrations of a standard chemical adsorbed on the bare nanoporous substrates are investigated. The preliminary results presented here show variation in transmittance and reflectance spectra with the concentration of the chemical used or the amount of the material adsorbed on the surface of the substrate.

ASRM process development in aqueous cleaning

NASA Technical Reports Server (NTRS)

Swisher, Bill

1992-01-01

Viewgraphs are included on process development in aqueous cleaning which is taking place at the Aerojet Advanced Solid Rocket Motor (ASRM) Division under a NASA Marshall Space and Flight Center contract for design, development, test, and evaluation of the ASRM including new production facilities. The ASRM will utilize aqueous cleaning in several manufacturing process steps to clean case segments, nozzle metal components, and igniter closures. ASRM manufacturing process development is underway, including agent selection, agent characterization, subscale process optimization, bonding verification, and scale-up validation. Process parameters are currently being tested for optimization utilizing a Taguci Matrix, including agent concentration, cleaning solution temperature, agitation and immersion time, rinse water amount and temperature, and use/non-use of drying air. Based on results of process development testing to date, several observations are offered: aqueous cleaning appears effective for steels and SermeTel-coated metals in ASRM processing; aqueous cleaning agents may stain and/or attack bare aluminum metals to various extents; aqueous cleaning appears unsuitable for thermal sprayed aluminum-coated steel; aqueous cleaning appears to adequately remove a wide range of contaminants from flat metal surfaces, but supplementary assistance may be needed to remove clumps of tenacious contaminants embedded in holes, etc.; and hot rinse water appears to be beneficial to aid in drying of bare steel and retarding oxidation rate.

The Bare Area of the Proximal Ulna: An Anatomic Study With Relevance to Chevron Osteotomy.

PubMed

Ao, Rongguang; Zhang, Xu; Li, Dejian; Chen, Fancheng; Zhou, Jianhua; Yu, Baoqing

2017-06-01

A chevron osteotomy of the ulna is widely used to obtain intra-articular access to the elbow in the treatment of type C distal humerus fractures. The trochlear notch of the proximal ulna is divided into 2 articular parts by the "bare area." Ideally, the olecranon osteotomy should be centered on the bare area to minimize damage to the joint cartilage. The goals of this study were to describe the anatomy of the bare area and design an ideal chevron-shaped osteotomy. We dissected 38 cadaver elbows and measured the width of the bare area, the distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area. We then designed a chevron osteotomy to stay within the bare area and measured the distance from the tip of the triceps insertion to the osteotomy apex as well as the angle of the osteotomy plane and the angle of the chevron cuts. The bare area existed in all 38 cadavers. The mean longitudinal and transverse widths were 4.0 mm (range, 1.0-8.6 mm) and 19.0 mm (range, 16.9-23.8 mm), respectively. The mean distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area was 19.0 mm (range, 16.0-23.0 mm). The mean transverse and longitudinal widths of the cortical notch were 3.0 mm (range, 1.6-4.5 mm) and 8.0 mm (range, 6.5-14.8 mm), respectively. The mean distance between the tip of the triceps insertion and the osteotomy apex was 22.0 mm (range, 18.0-24.0 mm) and the mean angle between the osteotomy surface and the vertical plane corresponding to the tangent plane was 20° (range, 10° to 25°). The mean angle of the V shape was 140° (range, 130° to 150°). Using the narrowest edge lacking cartilage (lateral or medial side) as a point of reference to locate the bare area, the designed chevron osteotomy entered the joint in the bare area in most specimens and decreased associated damage to the joint cartilage. This study describes the anatomy of the bare area and the design of the ideal chevron-shaped osteotomy to treat type C distal humerus fractures. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Optical filter for highlighting spectral features part I: design and development of the filter for discrimination of human skin with and without an application of cosmetic foundation.

PubMed

Nishino, Ken; Nakamura, Mutsuko; Matsumoto, Masayuki; Tanno, Osamu; Nakauchi, Shigeki

2011-03-28

Light reflected from an object's surface contains much information about its physical and chemical properties. Changes in the physical properties of an object are barely detectable in spectra. Conventional trichromatic systems, on the other hand, cannot detect most spectral features because spectral information is compressively represented as trichromatic signals forming a three-dimensional subspace. We propose a method for designing a filter that optically modulates a camera's spectral sensitivity to find an alternative subspace highlighting an object's spectral features more effectively than the original trichromatic space. We designed and developed a filter that detects cosmetic foundations on human face. Results confirmed that the filter can visualize and nondestructively inspect the foundation distribution.

Interdigitated electrode (IDE) for porcine detection based on titanium dioxide (TiO2) thin films

NASA Astrophysics Data System (ADS)

Nordin, N.; Hashim, U.; Azizah, N.

2016-07-01

Interdigited Electrode (IDE) porcine detection can be accomplished to authenticate the halal issue that has been a concern to Muslim not only in Malaysia but all around the world. The method used is photolithography that used the p-type photoresist on the spin coater with 2500 rpm. Bare IDEs device is deposited with Titanium Dioxide (TiO2) to improve the performance of the device. The result indicates that current-voltage (I-V) measurement of porcine probe line slightly above porcine target due to negative charges repelled each other. The IDE device can detect the porcine presence in food as lowest as 1.0 µM. Better performance of the device can be achieved with the replacement of gold deposited to trigger more sensitivity of the device.

A graphene-based electrochemical sensor for sensitive detection of paracetamol

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

Kang, Xinhuang; Wang, Jun; Wu, Hong

2010-05-15

An electrochemical sensor based on the electrocatalytic activity of functionalized graphene for sensitive detection of paracetamol is presented. The electrochemical behaviors of paracetamol on graphene-modified glassy carbon electrodes (GCEs) were investigated by cyclic voltammetry and square-wave voltammetry. The results showed that the graphene-modified electrode exhibited excellent electrocatalytic activity to paracetamol. A quasi-reversible redox process of paracetamol at the modified electrode was obtained, and the over-potential of paracetamol decreased significantly compared with that at the bare GCE. Such electrocatalytic behavior of graphene is attributed to its unique physical and chemical properties, e.g., subtle electronic characteristics, attractive π–π interaction, and strong adsorptivemore » capability. The sensor shows great promise for simple, sensitive, and quantitative detection of paracetamol.« less

Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

PubMed

Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

2016-10-20

The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysing land cover and land use change in the Matobo National Park and surroundings in Zimbabwe

NASA Astrophysics Data System (ADS)

Scharsich, Valeska; Mtata, Kupakwashe; Hauhs, Michael; Lange, Holger; Bogner, Christina

2016-04-01

Natural forests are threatened worldwide, therefore their protection in National Parks is essential. Here, we investigate how this protection status affects the land cover. To answer this question, we analyse the surface reflectance of three Landsat images of Matobo National Park and surrounding in Zimbabwe from 1989, 1998 and 2014 to detect changes in land cover in this region. To account for the rolling countryside and the resulting prominent shadows, a topographical correction of the surface reflectance was required. To infer land cover changes it is not only necessary to have some ground data for the current satellite images but also for the old ones. In particular for the older images no recent field study could help to reconstruct these data reliably. In our study we follow the idea that land cover classes of pixels in current images can be transferred to the equivalent pixels of older ones if no changes occurred meanwhile. Therefore we combine unsupervised clustering with supervised classification as follows. At first, we produce a land cover map for 2014. Secondly, we cluster the images with clara, which is similar to k-means, but suitable for large data sets. Whereby the best number of classes were determined to be 4. Thirdly, we locate unchanged pixels with change vector analysis in the images of 1989 and 1998. For these pixels we transfer the corresponding cluster label from 2014 to 1989 and 1998. Subsequently, the classified pixels serve as training data for supervised classification with random forest, which is carried out for each image separately. Finally, we derive land cover classes from the Landsat image in 2014, photographs and Google Earth and transfer them to the other two images. The resulting classes are shrub land; forest/shallow waters; bare soils/fields with some trees/shrubs; and bare light soils/rocks, fields and settlements. Subsequently the three different classifications are compared and land changes are mapped. The main changes are observable in the surroundings of the National Park, especially the common lands have lost their clear boundaries with time. In the National Park, the area of forest increases from 1989 to 2014 from 58% to 61% whereas the area of shrub land decreases by the same amount. The amount of each of the other two classes remains constant. These changes indicate an actual effect of the protection status of the National Park. In our study remote sensing data are the main source to evaluate the effects and the benefits of a protected area without on-side studies. This could be important for regions, where field studies are not possible because of insecure political conditions and only remote sensing data are available.

Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods

PubMed Central

Kadir, Mohamad Kamal Abdul; Tothill, Ibtisam E.

2010-01-01

An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a detection limit of 100 µg·L-1 for fumonisins. This was then transferred to the surface of a bare gold screen-printed electrode (SPGE) and detection was performed by chronoamperometry, monitoring the reaction of 3,3’,5,5’-Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H2O2) catalysed by HRP at −100 mV potential vs. onboard Ag-AgCl pseudo-reference electrode. The immunosensor exhibited detection limit of 5 µg·L−1 fumonisins with a dynamic range from 1 µg·L−1–1000 µg·L−1. The sensor also performed well in extracted corn samples. PMID:22069591

The Effects of Extravehicular Activity (EVA) Glove Pressure on Hand Strength

NASA Technical Reports Server (NTRS)

Mesloh, Miranda; England, Scott; Benson, Elizabeth; Thompson, Shelby; Rajulu, Sudhakar

2010-01-01

The purpose of this study was to characterize hand strength, while wearing a Phase VI Extravehicular Activity (EVA) glove in an Extravehicular Mobility Unit (EMU) suit. Three types of data were collected: hand grip, lateral pinch, and pulp-2 pinch, wider three different conditions: bare-handed, gloved with no Thermal Micrometeoroid Garment (TMG), and glove with TMG. In addition, during the gloved conditions, subjects were tested when unpressurized and pressurized (43 psi). As a percentage of bare-hand strength, the TMG condition showed reduction in grip strength to 55% unpressurized and 46% pressurized. Without the TMG, grip strength increased to 66% unpressurized and 58% pressurized of bare-hand strength. For lateral pinch strength, the reduction in strength was the same for both pressure conditions and with and without the TMG, about 8.5% of bare-hand Pulp-2 pinch strength with no TMG showed an increase to 122% unpressurized and 115% pressurized of bare-hand strength. While wearing the TMG, pulp-2 pinch strength was 115% of bare-hand strength for both pressure conditions.

Location of Bare Soil Surface and Soil Line on the RED-NIR Spectral Plane

NASA Astrophysics Data System (ADS)

Koroleva, P. V.; Rukhovich, D. I.; Rukhovich, A. D.; Rukhovich, D. D.; Kulyanitsa, A. L.; Trubnikov, A. V.; Kalinina, N. V.; Simakova, M. S.

2017-12-01

Soil as a separate natural body occupies certain area with its own set of spectral characteristics within the RED-NIR spectral space. This is an ellipse-shaped area, and its semi-major axis is the soil line for a satellite image. The spectral area for a bare soil surface is neighboring to the areas of black carbon, straw, vegetating plants, and missing RED-NIR values. A reliable separation of the bare soil surface within the spectral space is possible with the technology of spectral neighborhood of soil line. The accuracy of this method is 90%. The determination of the bare soil surface using vegetation indices, both relative (NDVI), and perpendicular (PVI), is incorrect; the accuracy of these methods does not exceed 65%, and for most of the survey seasons it may be lower than 50%. The flat part of the "tasseled cap" described as the soil line, is not a synonym for the area of the bare soil surface. The bare soil surface on the RED-NIR plots occupies significantly smaller areas than the area of soil line according to Kauth and Thomas.

Intrinsic stress evolution during amorphous oxide film growth on Al surfaces

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

Flötotto, D., E-mail: d.floetotto@is.mpg.de; Wang, Z. M.; Jeurgens, L. P. H.

2014-03-03

The intrinsic stress evolution during formation of ultrathin amorphous oxide films on Al(111) and Al(100) surfaces by thermal oxidation at room temperature was investigated in real-time by in-situ substrate curvature measurements and detailed atomic-scale microstructural analyses. During thickening of the oxide a considerable amount of growth stresses is generated in, remarkably even amorphous, ultrathin Al{sub 2}O{sub 3} films. The surface orientation-dependent stress evolutions during O adsorption on the bare Al surfaces and during subsequent oxide-film growth can be interpreted as a result of (i) adsorption-induced surface stress changes and (ii) competing processes of free volume generation and structural relaxation, respectively.

Finding Platinum-Coating Gaps On Titanium Anodes

NASA Technical Reports Server (NTRS)

Bodemeijer, Ronnald; Flowers, Cecil E.

1990-01-01

Simple procedure makes gaps visible to eye. New gap-detection method consists of plating thin layer of non-silver-colored metal like copper or gold on anode. Contrast in color between plated metal and bare anode material makes gaps stand out. If anode passes inspection, copper or gold plate removable by reversal of test-plating current. Remains to be determined whether test plating and removal damages anode. New method simpler and more economical than previous attempts to identify gaps in platinum.

eMethylsorb: electrochemical quantification of DNA methylation at CpG resolution using DNA-gold affinity interactions.

PubMed

Sina, Abu Ali Ibn; Howell, Sidney; Carrascosa, Laura G; Rauf, Sakandar; Shiddiky, Muhammad J A; Trau, Matt

2014-11-07

We report a simple electrochemical method referred to as "eMethylsorb" for the detection of DNA methylation. The method relies on the base dependent affinity interaction of DNA with gold. The methylation status of DNA is quantified by monitoring the electrochemical current as a function of the relative adsorption level of bisulphite treated DNA samples onto a bare gold electrode. This method can successfully distinguish methylated and unmethylated epigenotypes at single CpG resolution.

The Measurement of the Effects of Helmet Form on Sound Source Detection and Localization Using a Portable Four-Loudspeaker Test Array

DTIC Science & Technology

2013-05-01

to data collection, a rough estimate of each listener’s binaural hearing threshold (with a bare head) was obtained for each of the test frequencies...spectral information that allows disambiguation of binaural cues lies primarily in the higher frequencies. For the analysis shown in the second...Moore, 2012). The binaural cues of level and phase differences are fairly robust; however, they can only help to determine locations on the left-right

A putative functional MYB transcription factor induced by low temperature regulates anthocyanin biosynthesis in purple kale (Brassica Oleracea var. acephala f. tricolor).

PubMed

Zhang, Bin; Hu, Zongli; Zhang, Yanjie; Li, Yali; Zhou, Shuang; Chen, Guoping

2012-02-01

The purple kale (Brassica Oleracea var. acephala f. tricolor) is a mutation in kales, giving the mutant phenotype of brilliant purple color in the interior. Total anthocyanin analysis showed that the amount of anthocyanins in the purple kale was up to 1.73 mg g(-1) while no anthocyanin was detected in the white kale. To elucidate the molecular mechanism of the anthocyanin biosynthesis in the purple kale, we analyzed the expression of structural genes and some transcription factors associated with anthocyanin biosynthesis in the purple cultivar "Red Dove" and the white cultivar "White Dove". The result showed that nearly all the anthocyanin biosynthetic genes showed higher expression levels in the purple cultivar than in the white cultivar, especially for DFR and ANS, they were barely detected in the white cultivar. Interestingly, the fact that a R2R3 MYB transcription factor named BoPAP1 was extremely up-regulated in the purple kale and induced by low temperature attracted our attention. Further sequence analysis showed that BoPAP1 shared high similarity with AtPAP1 and BoMYB1. In addition, the anthocyanin accumulation in the purple kale is strongly induced by the low temperature stress. The total anthocyanin contents in the purple kale under low temperature were about 50-fold higher than the plants grown in the greenhouse. The expression of anthocyanin biosynthetic genes C4H, F3H, DFR, ANS and UFGT were all enhanced under the low temperature. These evidences strongly suggest that BoPAP1 may play an important role in activating the anthocyanin structural genes for the abundant anthocyanin accumulation in the purple kale.

Quantitative Imaging of D-2-Hydroxyglutarate in Selected Histological Tissue Areas by a Novel Bioluminescence Technique.

PubMed

Voelxen, Nadine F; Walenta, Stefan; Proescholdt, Martin; Dettmer, Katja; Pusch, Stefan; Mueller-Klieser, Wolfgang

2016-01-01

Patients with malignant gliomas have a poor prognosis with average survival of less than 1 year. Whereas in other tumor entities the characteristics of tumor metabolism are successfully used for therapeutic approaches, such developments are very rare in brain tumors, notably in gliomas. One metabolic feature characteristic of gliomas, in particular diffuse astrocytomas and oligodendroglial tumors, is the variable content of D-2-hydroxyglutarate (D2HG), a metabolite that was discovered first in this tumor entity. D2HG is generated in large amounts due to various "gain-of-function" mutations in the isocitrate dehydrogenases IDH1 and IDH2. Meanwhile, D2HG has been detected in several other tumor entities, including intrahepatic bile-duct cancer, chondrosarcoma, acute myeloid leukemia, and angioimmunoblastic T-cell lymphoma. D2HG is barely detectable in healthy tissue (<0.1 mM), but its concentration increases up to 35 mM in malignant tumor tissues. Consequently, the "oncometabolite" D2HG has gained increasing interest in the field of tumor metabolism. To facilitate its quantitative measurement without loss of spatial resolution at a microscopical level, we have developed a novel bioluminescence assay for determining D2HG in sections of snap-frozen tissue. The assay was verified independently by photometric tests and liquid chromatography/mass spectrometry. The novel technique allows the microscopically resolved determination of D2HG in a concentration range of 0-10 μmol/g tissue (wet weight). In combination with the already established bioluminescence imaging techniques for ATP, glucose, pyruvate, and lactate, the novel D2HG assay enables a comparative characterization of the metabolic profile of individual tumors in a further dimension.

Urinary cystatin C as a renal biomarker and its immunohistochemical localization in anti-GBM glomerulonephritis rats.

PubMed

Togashi, Yuko; Imura, Naoko; Miyamoto, Yohei

2013-11-01

The usefulness of urinary cystatin C for the early detection of renal damage in anti-glomerular basement membrane (GBM) glomerulonephritis rats was investigated and compared to other biomarkers (β2-microglobulin, calbindin, clusterin, epidermal growth factor (EGF), alpha-glutathione S-transferase (GST-α), mu-glutathione S-transferase (GST-μ), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), osteopontin, tissue inhibitor of metalloprotease-1 (TIMP-1), and vascular endothelial growth factor (VEGF)). Urinary levels of cystatin C increased in anti-GBM glomerulonephritis rats, whereas the conventional markers, plasma creatinine and UN did not, demonstrating its usefulness for the early detection of renal damage associated with anti-GBM glomerulonephritis. As well as cystatin C, urinary β2-microglobulin, clusterin, GST-α, GST-μ, KIM-1, and NGAL also had the potential to detect renal damage associated with anti-GBM glomerulonephritis. Furthermore, the immunohistochemical localization of cystatin C in the kidney was examined. Cystatin C expression was mainly observed in the proximal renal tubules in anti-GBM glomerulonephritis rats, and its expression barely changed with the progression of glomerulonephritis. Cystatin C expression was also observed in the tubular lumen of the cortex and medulla when glomerulonephritis was marked, which was considered to be characteristic of renal damage. In conclusion, urinary cystatin C, β2-microglobulin, clusterin, GST-α, GST-μ, KIM-1, and NGAL could be useful biomarkers of renal damage in anti-GBM glomerulonephritis rats. Immunohistochemical cystatin C expression in the proximal renal tubules was barely changed by the progression of glomerulonephritis, but it was newly observed in the tubular lumen when renal damage was apparent. Crown Copyright © 2013. Published by Elsevier GmbH. All rights reserved.

Bare eye detection of Hg(II) ions based on enzyme inhibition and using mercaptoethanol as a reagent to improve selectivity.

PubMed

He, Liuying; Lu, Yuexiang; Wang, Feiyang; Gao, Xinxin; Chen, Ying; Liu, Yueying

2018-02-13

The authors describe a colorimetric method for the determination of Hg 2+ ions based on the inhibition of the activity of the enzyme urease. The pH value of solution increases when urease hydrolyzes urea, which can be visualized by adding a pH indicator such as Phenol Red (PhR). Mercaptoethanol as a typical thiol is added to the system to improve selectivity because it binds metal ions and then - unlike the Hg 2+ mercaptoethanol complex - does not inhibit urease. Hence, the color of the pH indicator PhR turns from yellow to pink as the solution becomes alkaline. The Hg 2+ mercaptoethanol complex, in contrast, strongly inhibits urease and the color of the solution remains yellow. The findings were used to design a photometric assay based on the measurement of the ratio of absorptions of PhR at 558 nm and 430 nm. It has a linear response over the 25 to 40 nM Hg 2+ concentration range and a 5 nM detection limit. This is well below the guideline values of Hg 2+ specified by the US Environmental Protection Agency and the World Health Organization for drinking water (10 nM and 30 nM, respectively). The method was employed to the determination of Hg 2+ in water samples spiked with 10 nM levels of Hg 2+ where color changes still can be observed visually. Graphical Abstract Schematic presentation of a colorimetric method for the ultrasensitive detection of Hg 2+ based on the inhibition of urease activity. Mercaptoethanol is used to improve the selectivity. Even at Hg 2+ concentrations as low as 5 nM, the color change still can be easily observed by bare eyes.

Field and energy relations in continuum electrodynamics.

PubMed

Crenshaw, Michael E

2005-09-01

The bare, or fundamental, electric and magnetic fields in a linear medium are identified. Through the energy relations for the bare fields, the electric permittivity is shown to combine the effects of the enhanced energy density and the polarization reaction field. The macroscopic Maxwell equations are modified to be consistent with the constitutive relations for the bare fields.

78 FR 61000 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... To: OPERADORA Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU, S.A. DE C.V.; Linked To: ROOL EUROPE AG... REMF671011QH1 (Mexico) (individual) [SDNTK] (Linked To: OPERADORA Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU... Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU, S.A. DE C.V., Vallarta No. 2380, Col. Colinas De San...

Reconciling the MOLA, TES, and Neutron Observations of the North Polar CO2 Mass Budget on Mars

NASA Technical Reports Server (NTRS)

Haberle, R. M.; Mattingly, B.; Titus, T. N.

2003-01-01

There are now three independent observations of the CO2 polar cap mass budget of Mars' north polar cap. The first is based elevation changes detected by the Mars Orbiter Laser Altimeter (MOLA) on the Mars Global Surveyor (MGS). The second is based on MGS Thermal Emission Spectrometer (TES) broadband observations of the solar and infrared radiation fields at the top of the atmosphere. The third is based on neutron counts measured by the neutron spectrometer (NS) on Odyssey. The TES data are based on an energy balance. The net radiative loss (gain) in a column is balanced by latent heating due condensation (sublimation) of CO2. In calculating the mass budget, the other main energy sources, atmospheric heat transport and subsurface conduction, were neglected. At the pole, atmospheric heat transport is indeed a small term. However, subsurface heat conduction can be significant because at the North Pole water ice, which has a high thermal conductivity compared to bare soil, is a dominant component of the subsurface. Thus, heat conducted down into the ice during summer will slowly bleed back out during fall and winter reducing the amount of CO2 that condenses on the pole. We have taken a first cut at quantifying this effect by fitting a curve to Paige's estimates of the conducted energy flux in his analysis of Viking IRTM data.

Hyperion Studies Of Crop Stress In Mexico

NASA Technical Reports Server (NTRS)

Lobell, David B.; Asner, Gregory P.

2004-01-01

Satellite-based measurements of crop stress could provide much needed information for cropland management, especially in developing countries where other precision agriculture technologies are too expensive (Pierce and Nowak 1999; Robert 2002). For example, detection of areas that are nitrogen deficient or water stressed could guide fertilizer and water management decisions for all farmers within the swath of the satellite. Several approaches have been proposed to quantify canopy nutrient or water content based on spectral reflectance, most of which involve combinations of reflectance in the form of vegetation indices. While these indices are designed to maximize sensitivity to leaf chemistry, variations in other aspects of plant canopies may significantly impact remotely sensed reflectance. These confounding factors include variations in canopy structural properties (e.g., leaf area index, leaf angle distribution) as well as the extent of canopy cover, which determines the amount of exposed bare soil within a single pixel. In order to assess the utility of spectral indices for monitoring crop stress, it is therefore not only necessary to establish relationships at the leaf level, but also to test the relative importance of variations in other canopy attributes at the spatial scale of the remote sensing measurement. In this context, the relative importance of a given attribute will depend on (1) the sensitivity of the reflectance index to variation in the attribute and (2) the degree to which the attribute varies spatially and temporally.

Synthesis and spectroscopic characterization of gold nanoparticles via plasma-liquid interaction technique

NASA Astrophysics Data System (ADS)

Khatoon, N.; Yasin, H. M.; Younus, M.; Ahmed, W.; Rehman, N. U.; Zakaullah, M.; Iqbal, M. Zafar

2018-01-01

Fabrication of non-functionalized gold nanoparticles is interesting owing to their potential applications in sensing and biomedicine. We report on the synthesis of surfactant-free gold nanoparticles (AuNPs) by Plasma-Liquid Interaction (PLI) technique, using micro-atmospheric pressure D.C. plasma. The effects of discharge parameters, such as discharge current, precursor concentration and gas flow rates on the structure and morphology of AuNPs have been investigated. Optical Emission Spectroscopy (OES) was employed to estimate the UV radiation intensity and OH radical density. Scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) optical spectroscopy were employed to study the morphology and structure of AuNPs. The normalized intensities of UV radiation and OH radical density found to increase with increase in discharge current. We observed that the particle size can be tuned by controlling any of the following parameters: intensity of the UV radiation, OH radical density, and concentration of the Au precursor. Interestingly, we found that addition of 1% Ar in the feedstock gas results in formation of relatively uniform size distribution of nanoparticles. The surfactant-free AuNPs, due to their bare-surface, exhibit excellent surface-enhanced Raman scattering (SERS) properties. The SERS study of Rhodamine 6G using AuNPs as substrates, shows significant Raman enhancement and fluorescence quenching, which makes our technique a potentially powerful route to detection of trace amounts of dangerous explosives and other materials.

Comparison of ultraviolet detection and charged aerosol detection methods for liquid-chromatographic determination of protoescigenin.

PubMed

Filip, Katarzyna; Grynkiewicz, Grzegorz; Gruza, Mariusz; Jatczak, Kamil; Zagrodzki, Bogdan

2014-01-01

Escin, a complex mixture of pentacyclic triterpene saponins obtained from horse chestnut seeds extract (HCSE; Aesculus hippocastanum L.), constitutes a traditional herbal active substance of preparations (drugs) used for a treatment of chronic venous insufficiency and capillary blood vessel leakage. A new approach to exploitation of pharmacological potential of this saponin complex has been recently proposed, in which the β-escin mixture is perceived as a source of a hitherto unavailable raw material, pentacyclic triterpene aglycone-protoescigenin. Although many liquid chromatography methods are described in the literature for saponins determination, analysis of protoescigenin is barely mentioned. In this work, a new ultra-high performance liquid chromatography (UHPLC) method developed for protoescigenin quantification has been described. CAD (charged aerosol detection), as a relatively new detection method based on aerosol charging, has been applied in this method as an alternative to ultraviolet (UV) detection. The influence of individual parameters on CAD response and sensitivity was studied. The detection was performed using CAD and UV (200 nm) simultaneously and the results were compared with reference to linearity, accuracy, precision and limit of detection.

Dispersive detection of radio-frequency-dressed states

NASA Astrophysics Data System (ADS)

Jammi, Sindhu; Pyragius, Tadas; Bason, Mark G.; Florez, Hans Marin; Fernholz, Thomas

2018-04-01

We introduce a method to dispersively detect alkali-metal atoms in radio-frequency-dressed states. In particular, we use dressed detection to measure populations and population differences of atoms prepared in their clock states. Linear birefringence of the atomic medium enables atom number detection via polarization homodyning, a form of common path interferometry. In order to achieve low technical noise levels, we perform optical sideband detection after adiabatic transformation of bare states into dressed states. The balanced homodyne signal then oscillates independently of field fluctuations at twice the dressing frequency, thus allowing for robust, phase-locked detection that circumvents low-frequency noise. Using probe pulses of two optical frequencies, we can detect both clock states simultaneously and obtain population difference as well as the total atom number. The scheme also allows for difference measurements by direct subtraction of the homodyne signals at the balanced detector, which should technically enable quantum noise limited measurements with prospects for the preparation of spin squeezed states. The method extends to other Zeeman sublevels and can be employed in a range of atomic clock schemes, atom interferometers, and other experiments using dressed atoms.

Detecting ecosystem performance anomalies for land management in the upper colorado river basin using satellite observations, climate data, and ecosystem models

USGS Publications Warehouse

Gu, Yingxin; Wylie, B.K.

2010-01-01

This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005-2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using "percentage of bare soil" ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005-2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions. ?? 2010 by the authors.

Detecting Ecosystem Performance Anomalies for Land Management in the Upper Colorado River Basin Using Satellite Observations, Climate Data, and Ecosystem Models

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.

2010-01-01

This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005–2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using “percentage of bare soil” ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005–2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions.

Direct Electrodeposition of Gold Nanoparticles on Glassy Carbon Electrode for Selective Determination Catechol in the Presence of Hydroquinone.

PubMed

Jayakumar, C; Magdalane, C Maria; Kaviyarasu, K; Kulandainathan, M Anbu; Jeyaraj, Boniface; Maaza, M

2018-07-01

A simple and reliable voltammetric sensor for simultaneous determination of Catechol (CT) and Hydroquinone (HQ) was developed by electrodepositing the gold nanoparticles on the surface of the Glassy Carbon Electrode (GCE). The cyclic voltammograms in a mixed solution of CT and HQ have shown that the oxidation peaks become well resolved and were separated by 110 mV, although the bare GCE gave a single broad oxidation peak. Moreover, the oxidation peak currents of both CT and HQ were remarkably increased three times in comparison with the bare GCE. This makes gold nanoparticles deposited GCE a suitable candidate for the determination of these isomers. In the presence of 1 mM HQ isomer, the oxidation peak currents of differential pulse voltammograms are proportional to the concentration of CT in the range of 21 μM to 323 μM with limit of detection 3.0 μM (S/N = 3). The proposed sensor has some important advantages such as low cost, ease of preparation, good stability and high reproducibility.

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

S.O. Bader

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are releasedmore » from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be conservatively applied to confined CSNF assemblies.« less

Adsorption and Fenton regeneration of SBA-15 for di-(2-ethylhexyl) phthalate leached from PVC sheets by Gram-positive strains LHM1 and LHM2

NASA Astrophysics Data System (ADS)

Hwang, S.; Latorre, I.; Caban, M.; Soto, B.; Montalvo-Rodríguez, R.; Hernández-Maldonado, A.

2012-12-01

Bioleaching of Di-(2-ethylhexyl) phthalate (DEHP) from PVC sheets was studied with newly isolated, Gram-positive strains LHM1 and LHM2 capable of growing on DEHP as the sole carbon source. According to 16S rRNA gene analysis, strains LHM1 and LHM2 were closely related (more than 97% similarity) to Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. The biodeteriorated PVC sheets by the strains LHM1 and LHM2 had thicker biofilm development. Despite their metabolic capability of degrading DEHP as the sole carbon source, the strains LHM1 and LHM2 did not metabolize all DEHP leached out of the PVC sheets. Thermogravimetric analysis (TGA) showed that the biodeterioration by strains LHM1 and LHM2 resulted in less amount of and weakly bonded DEHP present in PVC sheets, in comparison to the virgin PVC sheet. Therefore, PVC biodeterioration by strains LHM1 and LHM2 might play an important role in stability of PVC sheets and fate and effect of leached DEHP on the environmental receptors. In response to this, an advanced adsorption with SBA-15 was assessed as a potential alternative DEHP remediation with arsenic as a co-contaminant. SBA-15 had an excellent arsenic adsorption showing >90% arsenic removal when arsenic was present as a singular contaminant. Adsorption effectiveness was irrelevant to the solid/liquid (S/L) ratio. However, when arsenic was present together with DEHP, arsenic adsorption to bare SBA-15 was reduced by 10 - 40%, with lesser S/L ratio having greater arsenic removal. On the contrary, bare SBA-15 only adsorbed ~30% of DEHP on average. When DEHP was present as a co-solute with arsenic, DEHP adsorption to bare SBA-15 was increased. For SBA-15 regeneration, adsorbed arsenic was recovered with EDTA elution, whereas adsorbed DEHP was destructed with Fenton oxidation.

Interdigitated electrode (IDE) for porcine detection based on titanium dioxide (TiO{sub 2}) thin films

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

Nordin, N.; Azizah, N.; Hashim, U., E-mail: uda@unimap.edu.my

2016-07-06

Interdigited Electrode (IDE) porcine detection can be accomplished to authenticate the halal issue that has been a concern to Muslim not only in Malaysia but all around the world. The method used is photolithography that used the p-type photoresist on the spin coater with 2500 rpm. Bare IDEs device is deposited with Titanium Dioxide (TiO{sub 2}) to improve the performance of the device. The result indicates that current-voltage (I-V) measurement of porcine probe line slightly above porcine target due to negative charges repelled each other. The IDE device can detect the porcine presence in food as lowest as 1.0 µM.more » Better performance of the device can be achieved with the replacement of gold deposited to trigger more sensitivity of the device.« less

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare...

30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wires and cables. 75.517-2 Section 75.517-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2011 CFR

2011-07-01

... wires and cables. 75.517-2 Section 75.517-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to...

Performance of Slash Pine Bare-Root Seedlings and Containerized Rooted Cuttings Planted on Five Dates in Louisiana

Treesearch

Alper Akgul; Michael G. Messina; Alan Wilson; Joe Weber

2004-01-01

Landowners are interested in extending the normal planting season, as well as the comparative field performance, of nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on field performance of two stock types of slash pine (Pinus elliottii Engelm.) was examined. Slash pine bare-root seedlings (BRS) and...

Modeling the Hydrologic Response to Changes in Groundcover Conditions Caused by Fire Disturbances

NASA Astrophysics Data System (ADS)

Kikinzon, E.; Atchley, A. L.; Coon, E.; Middleton, R. S.

2016-12-01

Climate change and fire suppression increase wildfire activity, which alters ecosystem functions and can significantly impact hydrological response. Both wildfire and prescribed burns reduce groundcover, affect top layers of subsurface, and change the structure of overland flow pathways. To understand respective effects on surface and subsurface hydrology, it is imperative to accurately represent surface-subsurface interface pre and post-fire, and to model physical processes in groundcover components. We show mechanistic models used to describe physics in two key types of groundcover, litter and duff, in Advanced Terrestrial Simulator (ATS). Litter is considered to be a part of vegetative canopy covering the surface. It has associated water storage capacity, which allows simulating interception and drainage, and its thickness is used to evaluate surface roughness with potential effect of slowing overland flow compared to bare soil. Duff on the other hand is incorporated into the subsurface, thus requiring meshing and discretization capability to support complex geometries including pinchouts, which is necessary both for achieving desired mesh resolution and portraying bare soil patches without adversely affecting the time scale. As part of the subsurface, duff has its own hydrologic and water retention properties used to resolve infiltration and saturation limited runoff generation, run on, and infiltration processes. This enables the use of ATS for fine scale modeling of integrated hydrology with adequate representation of groundcover influence. To isolate the impact of changing groundcover, we consider a simple hill slope and study the hydrological response to varying amount and geometries of groundcover. To cover landscape characteristics produced by a wide variety of fire conditions, from high intensity to low intensity fire impacts, we simulate hydrologic response to precipitation events over a number of typical geometries and with fine control over amounts of two described types of groundcover. We then analyze hydrological sensitivity to presence or absence of particular groundcover types, their respective patchiness, and possible changes in overland flow pathways.

The Low Backscattering Objects Classification in Polsar Image Based on Bag of Words Model Using Support Vector Machine

NASA Astrophysics Data System (ADS)

Yang, L.; Shi, L.; Li, P.; Yang, J.; Zhao, L.; Zhao, B.

2018-04-01

Due to the forward scattering and block of radar signal, the water, bare soil, shadow, named low backscattering objects (LBOs), often present low backscattering intensity in polarimetric synthetic aperture radar (PolSAR) image. Because the LBOs rise similar backscattering intensity and polarimetric responses, the spectral-based classifiers are inefficient to deal with LBO classification, such as Wishart method. Although some polarimetric features had been exploited to relieve the confusion phenomenon, the backscattering features are still found unstable when the system noise floor varies in the range direction. This paper will introduce a simple but effective scene classification method based on Bag of Words (BoW) model using Support Vector Machine (SVM) to discriminate the LBOs, without relying on any polarimetric features. In the proposed approach, square windows are firstly opened around the LBOs adaptively to determine the scene images, and then the Scale-Invariant Feature Transform (SIFT) points are detected in training and test scenes. The several SIFT features detected are clustered using K-means to obtain certain cluster centers as the visual word lists and scene images are represented using word frequency. At last, the SVM is selected for training and predicting new scenes as some kind of LBOs. The proposed method is executed over two AIRSAR data sets at C band and L band, including water, bare soil and shadow scenes. The experimental results illustrate the effectiveness of the scene method in distinguishing LBOs.

Detection of damaged areas caused by the oil extraction in a steppe region using winter landsat imagery

NASA Astrophysics Data System (ADS)

Mjachina, Ksenya; Hu, Zhiyong; Chibilyev, Alexander

2018-01-01

Oil production in a steppe region disturbs the landscape and damages the steppe ecosystem. The objective of this research was to detect areas damaged by oil production in an oil field within the Russian Volga-Ural steppe region using winter Landsat imagery. We developed a practicable and effective approach using winter snow season multispectral Landsat satellite imagery. To this end, we applied seven algorithms of spectral or texture-based transformation: K-means, maximum likelihood estimation, topsoil grain size index, soil brightness, normalized differential snow index, tasselled cap, and co-occurrence measures. The co-occurrence texture measure variance shows the optimal result of identifying damaged areas. The unique feature of our method is that it can differentiate damaged areas from the bare soil of cropland within a cold steppe region where the area damaged by oil production is mixed with bare (fallow) croplands that have a polygonal shape similar to well pads. Such similarities can lead to confusion in object-based classification. Using the co-occurrence measures, we found that from 1988 to 2015, damaged area is nearly three times as big in the peak period of the oil field development (2001 and 2009) as in 1988. Landscape fragmentation also peaked in 2001 and 2009. Our approach for this project is useful and cost effective regular monitoring of damages from oil production for both the Volga-Ural steppe region and other cold steppe regions.

A multi-scale evaluation of pack stock effects on subalpine meadow plant communities in the Sierra Nevada

USGS Publications Warehouse

Lee, Steven R.; Berlow, Eric L.; Ostoja, Steven M.; Brooks, Matthew L.; Génin, Alexandre; Matchett, John R.; Hart, Stephen C.

2017-01-01

We evaluated the influence of pack stock (i.e., horse and mule) use on meadow plant communities in Sequoia and Yosemite National Parks in the Sierra Nevada of California. Meadows were sampled to account for inherent variability across multiple scales by: 1) controlling for among-meadow variability by using remotely sensed hydro-climatic and geospatial data to pair stock use meadows with similar non-stock (reference) sites, 2) accounting for within-meadow variation in the local hydrology using in-situ soil moisture readings, and 3) incorporating variation in stock use intensity by sampling across the entire available gradient of pack stock use. Increased cover of bare ground was detected only within “dry” meadow areas at the two most heavily used pack stock meadows (maximum animals per night per hectare). There was no difference in plant community composition for any level of soil moisture or pack stock use. Increased local-scale spatial variability in plant community composition (species dispersion) was detected in “wet” meadow areas at the two most heavily used meadows. These results suggest that at the meadow scale, plant communities are generally resistant to the contemporary levels of recreational pack stock use. However, finer-scale within-meadow responses such as increased bare ground or spatial variability in the plant community can be a function of local-scale hydrological conditions. Wilderness managers can improve monitoring of disturbance in Sierra Nevada meadows by adopting multiple plant community indices while simultaneously considering local moisture regimes.

Fabrication of a LRET-based upconverting hybrid nanocomposite for turn-on sensing of H2O2 and glucose

NASA Astrophysics Data System (ADS)

Wu, Shuang; Kong, Xiang-Juan; Cen, Yao; Yuan, Jing; Yu, Ru-Qin; Chu, Xia

2016-04-01

Blood glucose detecting has aroused considerable attention because diabetes mellitus has become a worldwide publish health problem. Herein, we construct an exceptionally simple upconverting hybrid nanocomposite, composed of DNA-templated Ag nanoparticles (DNA-AgNPs) and NaYF4:Yb/Tm@NaYF4 core-shell upconversion nanoparticles (UCNPs), for the sensing of H2O2 and glucose. In this design, UCNPs with bared surface act as the donor, and DNA-AgNPs serve as efficient quenchers. DNA-AgNPs can be directly assembled on the bared surface of UCNPs, which further decreases the distance of donor-to-acceptor. The formation of DNA-AgNPs/UCNP nanocomposite results in luminescence quenching of UCNP by DNA-AgNPs through luminescence resonance energy transfer (LRET). Upon H2O2 addition, AgNPs can be etched and transformed into Ag+, leading to inhibition of the LRET process and causing the recovery of upconversion luminescence. Based on the conversion of glucose into H2O2 by glucose oxidase, the DNA-AgNPs/UCNP nanocomposite can also be exploited for glucose sensing. Moreover, due to the non-autofluorescence offered by UCNPs, the approach developed can be applied to monitor glucose levels in human serum samples with satisfactory results.Blood glucose detecting has aroused considerable attention because diabetes mellitus has become a worldwide publish health problem. Herein, we construct an exceptionally simple upconverting hybrid nanocomposite, composed of DNA-templated Ag nanoparticles (DNA-AgNPs) and NaYF4:Yb/Tm@NaYF4 core-shell upconversion nanoparticles (UCNPs), for the sensing of H2O2 and glucose. In this design, UCNPs with bared surface act as the donor, and DNA-AgNPs serve as efficient quenchers. DNA-AgNPs can be directly assembled on the bared surface of UCNPs, which further decreases the distance of donor-to-acceptor. The formation of DNA-AgNPs/UCNP nanocomposite results in luminescence quenching of UCNP by DNA-AgNPs through luminescence resonance energy transfer (LRET). Upon H2O2 addition, AgNPs can be etched and transformed into Ag+, leading to inhibition of the LRET process and causing the recovery of upconversion luminescence. Based on the conversion of glucose into H2O2 by glucose oxidase, the DNA-AgNPs/UCNP nanocomposite can also be exploited for glucose sensing. Moreover, due to the non-autofluorescence offered by UCNPs, the approach developed can be applied to monitor glucose levels in human serum samples with satisfactory results. Electronic supplementary information (ESI) available: Experimental details and supplementary figures. See DOI: 10.1039/c6nr00470a

Characterizing near-surface CO2 conditions before injection - Perspectives from a CCS project in the Illinois Basin, USA

USGS Publications Warehouse

Locke, R.A.; Krapac, I.G.; Lewicki, J.L.; Curtis-Robinson, E.

2011-01-01

The Midwest Geological Sequestration Consortium is conducting a large-scale carbon capture and storage (CCS) project in Decatur, Illinois, USA to demonstrate the ability of a deep saline formation to store one million tonnes of carbon dioxide (CO2) from an ethanol facility. Beginning in early 2011, CO2 will be injected at a rate of 1,000 tonnes/day for three years into the Mount Simon Sandstone at a depth of approximately 2,100 meters. An extensive Monitoring, Verification, and Accounting (MVA) program has been undertaken for the Illinois Basin Decatur Project (IBDP) and is focused on the 0.65 km2 project site. Goals include establishing baseline conditions to evaluate potential impacts from CO2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO2. MVA efforts are being conducted pre-, during, and post- CO2 injection. Soil and net CO2 flux monitoring has been conducted for more than one year to characterize near-surface CO2 conditions. More than 2,200 soil CO2 flux measurements have been manually collected from a network of 118 soil rings since June 2009. Three ring types have been evaluated to determine which type may be the most effective in detecting potential CO 2 leakage. Bare soil, shallow-depth rings were driven 8 cm into the ground and were prepared to minimize surface vegetation in and near the rings. Bare soil, deep-depth rings were prepared similarly, but were driven 46 cm. Natural-vegetation, shallow-depth rings were driven 8 cm and are most representative of typical vegetation conditions. Bare-soil, shallow-depth rings had the smallest observed mean flux (1.78 ??mol m-2 s-1) versus natural-vegetation, shallow-depth rings (3.38 ??mol m-2 s-1). Current data suggest bare ring types would be more sensitive to small CO2 leak signatures than natural ring types because of higher signal to noise ratios. An eddy covariance (EC) system has been in use since June 2009. Baseline data from EC monitoring is being used to characterize pre-injection conditions, and may then be used to detect changes in net exchange CO2 fluxes (Fc) that could be the result of CO2 leakage into the near-surface environment during or following injection. When injection at IBDP begins, soil and net CO2 monitoring efforts will have established a baseline of near-surface conditions that will be important to help demonstrate the effectiveness of storage activities. ?? 2011 Published by Elsevier Ltd.

Albedo of cold sea ice with precipitated salt on the tropical ocean of Snowball Earth: field measurements and laboratory experiments

NASA Astrophysics Data System (ADS)

Light, B.; Black, T.; Carns, R.; Brandt, R.; Dadic, R.; Warren, S.

2012-04-01

During the initial freezing of the tropical ocean on Snowball Earth, the first ice to form would be sea ice, which contains salt within liquid brine inclusions. At temperatures below -23 C, significant amounts of salt begin to crystallize within the brine inclusions. These crystals scatter light, increasing the ice albedo. The most abundant salt is hydrohalite, NaCl.2H2O. A dry tropical atmosphere promoting ice surface sublimation would cause a salt crust to be left on the surface as a lag deposit. Such a high-albedo surface could be crucial during the snowball initiation. These processes must be considered when assigning albedos to sea ice in a climate model of Snowball Earth. Precipitation of salt within brine inclusions was observed on windswept bare ice of McMurdo Sound at the coast of Antarctica (78 S) in late winter. Consequently the albedo was higher at lower temperature. The precipitation process exhibited hysteresis, with hydrohalite precipitating at about -30 C and dissolving at about -23 C. The causes of the hysteresis are being investigated in laboratory experiments; they may involve biological macromolecules. Nowhere on the modern Earth does sea ice undergo sublimation at low temperatures for long enough to develop a salt crust before the summer melt begins, so this process is being investigated in our laboratory. A 1000-liter tank is used to grow artificial sea ice, and a system has been built to measure its albedo. A diffusely reflecting hemispherical dome of diameter 1.2 m is placed on top of the tank and illuminated from within. The interior of the dome illuminates the ice surface as well as serving as a platform for detecting the incident and backscattered radiance fields. The diffusely reflecting surfaces of the ice and the dome make it straightforward to estimate incoming and reflected irradiance as angular integrals of the radiance measurements. The albedo of the bare, cold (below -23 C) ice is 0.8 at visible wavelengths, decreasing toward the near-infrared but remaining higher than that of warmer ice. The salt crust has very high albedo, >0.9 for wavelengths 300-1000 nm, and remains much higher than snow across the near-infrared. Halite (NaCl) is nonabsorptive throughout the solar spectrum, but the hydrohalite crust contains two waters of hydration and does show water-absorption features at 1500 and 2000 nm, as expected. When the crust was warmed to -20 C, saline puddles formed and the albedo dropped dramatically. The spectral albedos are integrated over wavelength, using a solar spectrum appropriate for the tropical snowball ocean, to obtain broadband albedos. Preliminary values for the broadband albedos are 0.89 for the salt crust, 0.56 for bare subeutectic ice without a crust, and 0.32 for puddled melting ice.

Tectonic and neotectonic framework of the Yucca Mountain Region

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

Schweickert, R.A.

1992-09-30

Highlights of major research accomplishments concerned with the tectonics and neotectonics of the Yucca Mountain Region include: structural studies in Grapevine Mountains, Bullfrog Hills, and Bare Mountain; recognition of significance of pre-Middle Miocene normal and strike-slip faulting at Bare Mountain; compilation of map of quaternary faulting in Southern Amargosa Valley; and preliminary paleomagnetic analysis of Paleozoic and Cenozoic units at Bare Mountain.

Final Report for Emergency Stabilization and Rehabilitation Treatment Monitoring of the Keeney Pass, Cow Hollow, Double Mountain, and Farewell Bend Fires

USGS Publications Warehouse

Wirth, Troy A.; Pyke, David A.

2009-01-01

A strategy for monitoring post-fire seedings in the sagebrush steppe of the Intermountain West was developed and used to monitor four example fires in the Vale, Oregon District of the Bureau of Land Management (BLM). We began to develop a potential approach by (1) reviewing previous vegetation monitoring manuals produced by the Federal government to determine what techniques and approaches had been approved for use, and (2) monitoring a set of example fire rehabilitation projects from 2006 through 2008. We reviewed seven vegetation monitoring manuals approved for use by the Federal government. From these seven manuals, we derived a set of design elements appropriate for monitoring post-fire rehabilitation and stabilization projects. These design elements consisted of objectives, stratification, control plots, random sampling, data quality, and statistical analysis. Additionally, we chose three quantitative vegetation field procedures that were objective and repeatable to be used in conjunction with these six design elements. During the spring and summer of 2006 to 2008, U.S. Geological Survey personnel monitored vegetation in seven post-fire seeding treatments in four burned areas in the Vale district of the BLM in eastern Oregon. Treatments monitored included a native and non-native seeding in each of the Farewell Bend, Double Mountain, and Keeney Pass fires, and a native seeding at the Cow Hollow fire. All fires occurred in 2005. There generally was a low level of plant establishment for all seedings by 2008. The quantitative objective established by the BLM was to achieve 5 seeded grass plants/m2 by the end of 3 years as a result of the seeding. There was an estimated 3.97 and 6.28 plants/m2 in 2006 and 1.06 and 0.85 plants/m2 seeded perennial grasses in 2008 from the Keeney Pass non-native and native seeding, respectively. The Cow Hollow seeding resulted in the lowest establishment of perennial seeded grasses of the four project areas with 0.69 plants/m2 in 2006 and 0.09 plants/m2 in 2008. Density of seeded perennial grasses at the Double Mountain non-native and native seeding were 2.72 and 3.86 plants/m2 in 2006 and 0.90 and 1.74 plants/m2 in 2008, respectively. The Farewell Bend non-native seeding resulted in 5.62 plants/m2 in 2006 and 0.42 plants/m2 in 2008 while the native seeding had 2.22 seeded grass plants/m2 in 2006 and 0.44 plants/m2 by 2008. The primary reason for low level of establishment on most treatments except the Cow Hollow seeding was most likely the unfavorable timing and amount of precipitation in 2007 and 2008. Measurements of density within the first 3 years provide the best estimate of initial seeding success. Increases in cover due to the seedings were not detectable in the first 3 years following seeding in this monitoring effort. Changes in cover resulting from the treatments may be detectable in cases where the seedings were very successful in the first 3 years following seeding, but in areas with lower annual average precipitation, may not occur consistently. As a result, cover of seeded species may not be a good indication of seeding success in the early years after treatment. However, cover is useful for monitoring initial patterns of abundance of naturally recovering vegetation, exotic annual grasses and forbs, and bare ground. Cover measurements at these four sites revealed patterns common to most of the treatment areas in cover of litter, bare ground, and exotic annuals in response to drill seeding and weather patterns. There was a rapid increase in litter at all treatments after the fire. Additionally, there was less litter in treatment plots than in the control plots in 2006 probably due to the mechanical action of the seed drill. There also was a corresponding decrease in bare ground from 2006 to 2008. Initially, higher bare ground cover at treatment plots appears to be due to the mechanical action of the seed drill. Cover of annual grasses, primarily Bromus tectorum,

Quantifying vegetation distribution and structure using high resolution drone-based structure-from-motion photogrammetry

NASA Astrophysics Data System (ADS)

Zhang, J.; Okin, G.

2017-12-01

Vegetation is one of the most important driving factors of different ecosystem processes in drylands. The structure of vegetation controls the spatial distribution of moisture and heat in the canopy and the surrounding area. Also, the structure of vegetation influences both airflow and boundary layer resistance above the land surface. Multispectral satellite remote sensing has been widely used to monitor vegetation coverage and its change; however, it can only capture 2D images, which do not contain the vertical information of vegetation. In situ observation uses different methods to measure the structure of vegetation, and their results are accurate; however, these methods are laborious and time-consuming, and susceptible to undersampling in spatial heterogeneity. Drylands are sparsely covered by short plants, which allows the drone fly at a relatively low height to obtain ultra-high resolution images. Structure-from-motion (SfM) is a photogrammetric method that was proved to produce 3D model based on 2D images. Drone-based remote sensing can obtain the multiangle images for one object, which can be used to constructed 3D models of vegetation in drylands. Using these images detected by the drone, the orthomosaics and digital surface model (DSM) can be built. In this study, the drone-based remote sensing was conducted in Jornada Basin, New Mexico, in the spring of 2016 and 2017, and three derived vegetation parameters (i.e., canopy size, bare soil gap size, and plant height) were compared with those obtained with field measurement. The correlation coefficient of canopy size, bare soil gap size, and plant height between drone images and field data are 0.91, 0.96, and 0.84, respectively. The two-year averaged root-mean-square error (RMSE) of canopy size, bare soil gap size, and plant height between drone images and field data are 0.61 m, 1.21 m, and 0.25 cm, respectively. The two-year averaged measure error (ME) of canopy size, bare soil gap size, and plant height between drone images and field data are 0.02 m, -0.03, and -0.1 m, respectively. These results indicate a good agreement between drone-based remote sensing and field measurement.

TiO2 nanotubes with different spacing, Fe2O3 decoration and their evaluation for Li-ion battery application.

PubMed

Ozkan, Selda; Cha, Gihoon; Mazare, Anca; Schmuki, Patrik

2018-05-11

In the present work, we report on the use of organized TiO 2 nanotube (NT) layers with a regular intertube spacing for the growth of highly defined α-Fe 2 O 3 nano-needles in the interspace. These α-Fe 2 O 3 decorated TiO 2 NTs are then explored for Li-ion battery applications and compared to classic close-packed (CP) NTs that are decorated with various amounts of nanoscale α-Fe 2 O 3 . We show that NTs with tube-to-tube spacing allow uniform decoration of individual NTs with regular arrangements of hematite nano-needles. The tube spacing also facilitates the electrolyte penetration as well as yielding better ion diffusion. While bare CP NTs show a higher capacitance of 71 μAh cm -2 compared to bare spaced NTs with a capacitance of 54 μAh cm -2 , the hierarchical decoration with secondary metal oxide, α-Fe 2 O 3 , remarkably enhances the Li-ion battery performance. Namely, spaced NTs with α-Fe 2 O 3 decoration have an areal capacitance of 477 μAh cm -2 , i.e. they have nearly ∼8 times higher capacitance. However, the areal capacitance of CP NTs with α-Fe 2 O 3 decoration saturates at 208 μAh cm -2 , i.e. is limited to ∼3 times increase.

The Separability of Morphological Processes from Semantic Meaning and Syntactic Class in Production of Single Words: Evidence from the Hebrew Root Morpheme.

PubMed

Deutsch, Avital

2016-02-01

In the present study we investigated to what extent the morphological facilitation effect induced by the derivational root morpheme in Hebrew is independent of semantic meaning and grammatical information of the part of speech involved. Using the picture-word interference paradigm with auditorily presented distractors, Experiment 1 compared the facilitation effect induced by semantically transparent versus semantically opaque morphologically related distractor words (i.e., a shared root) on the production latency of bare nouns. The results revealed almost the same amount of facilitation for both relatedness conditions. These findings accord with the results of the few studies that have addressed this issue in production in Indo-European languages, as well as previous studies in written word perception in Hebrew. Experiment 2 compared the root's facilitation effect, induced by morphologically related nominal versus verbal distractors, on the production latency of bare nouns. The results revealed a facilitation effect of similar size induced by the shared root, regardless of the distractor's part of speech. It is suggested that the principle that governs lexical organization at the level of morphology, at least for Hebrew roots, is form-driven and independent of semantic meaning. This principle of organization crosses the linguistic domains of production and written word perception, as well as grammatical organization according to part of speech.

TiO2 nanotubes with different spacing, Fe2O3 decoration and their evaluation for Li-ion battery application

NASA Astrophysics Data System (ADS)

Ozkan, Selda; Cha, Gihoon; Mazare, Anca; Schmuki, Patrik

2018-05-01

In the present work, we report on the use of organized TiO2 nanotube (NT) layers with a regular intertube spacing for the growth of highly defined α-Fe2O3 nano-needles in the interspace. These α-Fe2O3 decorated TiO2 NTs are then explored for Li-ion battery applications and compared to classic close-packed (CP) NTs that are decorated with various amounts of nanoscale α-Fe2O3. We show that NTs with tube-to-tube spacing allow uniform decoration of individual NTs with regular arrangements of hematite nano-needles. The tube spacing also facilitates the electrolyte penetration as well as yielding better ion diffusion. While bare CP NTs show a higher capacitance of 71 μAh cm-2 compared to bare spaced NTs with a capacitance of 54 μAh cm-2, the hierarchical decoration with secondary metal oxide, α-Fe2O3, remarkably enhances the Li-ion battery performance. Namely, spaced NTs with α-Fe2O3 decoration have an areal capacitance of 477 μAh cm-2, i.e. they have nearly ˜8 times higher capacitance. However, the areal capacitance of CP NTs with α-Fe2O3 decoration saturates at 208 μAh cm-2, i.e. is limited to ˜3 times increase.

On the contribution of atmospheric moisture to dew formation

NASA Astrophysics Data System (ADS)

Garratt, J. R.; Segal, M.

1988-09-01

The relative contributions of dewfall (a flux of water vapour from air to surface) and distillation (a flux of water vapour from soil to canopy) to dew formation on closed canopy and bare soil surfaces are assessed, and the dependence of dew amount upon wind speed, absolute temperature, atmospheric stability, relative humidity, soil characteristics and cloudiness, all of which are significant factors, is evaluated. Some of these evaluations provide refinements to similar ones given in Monteith (1961). High dewfall rates are usually ≲0.06 mm hr-1 over canopy or bare soil, though upon a canopy under soil-saturated and air-saturated conditions, rates of dew formation may reach 0.07 0.09 mm hr-1 with contributions from distillation. Various sets of observations are reanalyzed to illustrate the importance of the horizontal advection of moisture in the nocturnal boundary layer (NBL) to observed high rates of dew formation arising from the atmospheric contribution of water vapour (dewfall). These locally observed high dewfall rates must be the result of small-scale or mesoscale horizontal advection of moisture in the NBL, since the humidity changes within the typically shallow NBL required to balance the loss of water at the surface are not observed. Over extensive areas of uniform surface (horizontal scales ≫10 km), such continuously high dewfall rates could only be balanced by a local supply of atmospheric moisture since advection of moisture would necessarily be small.

Trend Assessment of Spatio-Temporal Change of Tehran Heat Island Using Satellite Images

NASA Astrophysics Data System (ADS)

Saradjian, M. R.; Sherafati, Sh.

2015-12-01

Numerous investigations on Urban Heat Island (UHI) show that land cover change is the main factor of increasing Land Surface Temperature (LST) in urban areas, especially conversion of vegetation and bare soil to concrete, asphalt and other man-made structures. On the other hand, other human activities like those which cause to burning fossil fuels, that increase the amount of carbon dioxide, may raise temperature in global scale in comparison with small scales (urban areas). In this study, multiple satellite images with different spatial and temporal resolutions have been used to determine Land Surface Temperature (LST) variability in Tehran metropolitan area. High temporal resolution of AVHRR images have been used as the main data source when investigating temperature variability in the urban area. The analysis shows that UHI appears more significant at afternoon and night hours. But the urban class temperature is almost equal to its surrounding vegetation and bare soil classes at around noon. It also reveals that there is no specific difference in UHI intense during the days throughout the year. However, it can be concluded that in the process of city expansion in years, UHI has been grown both spatially and in magnitude. In order to locate land-cover types and relate them to LST, Thematic Mapper (TM) images have been exploited. The influence of elevation on the LST has also been studied, using digital elevation model derived from SRTM database.

Incorporation of metal-organic framework HKUST-1 into porous polymer monolithic capillary columns to enhance the chromatographic separation of small molecules.

PubMed

Yang, Shengchao; Ye, Fanggui; Lv, Qinghui; Zhang, Cong; Shen, Shufen; Zhao, Shulin

2014-09-19

Metal-organic framework (MOF) HKUST-1 nanoparticles have been incorporated into poly(glycidyl methacrylate-co-ethylene dimethacrylate) (HKUST-1-poly(GMA-co-EDMA)) monoliths to afford stationary phases with enhanced chromatographic performance of small molecules in the reversed phase capillary liquid chromatography. The effect of HKUST-1 nanoparticles in the polymerization mixture on the performance of the monolithic column was explored in detail. While the bare poly(GMA-co-EDMA) monolith exhibited poor resolution (Rs<1.0) and low efficiency (800-16,300plates/m), addition of a small amount of HKUST-1 nanoparticles to the polymerization mixture provide high increased resolution (Rs≥1.3) and high efficiency ranged from 16,300 to 44,300plates/m. Chromatographic performance of HKUST-1-poly(GMA-co-EDMA) monolith was demonstrated by separation of various analytes including polycyclic aromatic hydrocarbons, ethylbenzene and styrene, phenols and aromatic acids using a binary polar mobile phase (CH3CN/H2O). The HKUST-1-poly(GMA-co-EDMA) monolith displayed enhanced hydrophobic and π-π interaction characteristics in the reversed phase separation of test analytes compared to the bare poly(GMA-co-EDMA) monolith. The experiment results showed that HKUST-1-poly(GMA-co-EDMA) monoliths are an alternative to enhance the chromatographic separation of small molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

A study of the management strategies for river aeolian dust inhibition at the estuary of Zhuo-shui River

NASA Astrophysics Data System (ADS)

Tsai, S. F.; Lin, C. Y.

2014-12-01

With the characteristics of humidity in summer and drought in winter, there existing lots of bare lands due to the decline of water level cause large amounts of aeolian dust and environmental deterioration during the monsoon seasons in central Taiwan. How to adopt effective measures to inhibit the damage of dust is an essential issue. This study selected the serious dust-affected section of Zhuo-shui river (bridge Zi-qiang to Xi-bin) to delineate the areas of potential aeolian dust occurrence, explore the relationship between elevation and water level determined from return period analysis, submit the countermeasures for dust inhibition at the bare lands and/or cultivated areas, and address the responsibilities of related authority offices for dust prevention by means of literature review. The return period of inundation for the areas of potential aeolian dust occurrence is 1.1 years. Engineering of dust prevention with highly unit price are not recommended due to could be destroyed annually. The deposition sites of a river are usually located at the convex bank, which with silt texture and high salinity are not suitable for cultivation, are delineated as the areas of potential aeolian dust occurrence. Besides technology consideration in dust prevention, this study also examined the related articles of river management to integrate a comprehensive vision for better riverside environment and air quality.

Electrochemical sensing of bisphenol using a multilayer graphene nanobelt modified photolithography patterned platinum electrode

NASA Astrophysics Data System (ADS)

Karthick Kannan, Padmanathan; Hu, Chunxiao; Morgan, Hywel; Moshkalev, Stanislav A.; Sekhar Rout, Chandra

2016-09-01

An electrochemical sensor has been developed for the detection of Bisphenol-A (BPA) using photolithographically patterned platinum electrodes modified with multilayer graphene nanobelts (GNB). Compared to bare electrodes, the GNB modified electrode exhibited enhanced BPA oxidation current, due to the high effective surface area and high adsorption capacity of the GNB. The sensor showed a linear response over the concentration range from 0.5 μM-9 μM with a very low limit of detection = 37.33 nM. In addition, the sensor showed very good stability and reproducibility with good specificity, demonstrating that GNB is potentially a new material for the development of a practical BPA electrochemical sensor with application in both industrial and plastic industries.

Glycosides of the Neurotoxin Tutin in Toxic Honeys Are from Coriaria arborea Phloem Sap, Not Insect Metabolism.

PubMed

Watkins, Oliver C; Joyce, Nigel I; Gould, Nick; Perry, Nigel B

2018-04-27

Some honeys contain the neurotoxin tutin (1) plus hyenanchin (2), 2-(β-d-glucopyranosyl)tutin (3), and 2-[6'-(α-d-glucopyranosyl)-β-d-glucopyranosyl]tutin (4). These honeys are made by bees collecting honeydew from passionvine hoppers feeding on the sap of tutu plants ( Coriaria spp.). We report a LC-MS study showing that all these picrotoxanes are of plant, not insect, origin. Hyenanchin was barely detectable and the diglucoside was not detectable in C. arborea leaves, but tutu phloem sap contained all four compounds at concentrations up to the highest found in honeydew. It is proposed that the diglucoside may function as a transport form of tutin, analogous to sucrose transport in phloem.

Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

NASA Astrophysics Data System (ADS)

Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

2016-04-01

Dryland systems currently cover ˜40% of the world's land surface and are still expanding as a consequence of human impact and global change. In contrast to that, information on their role in global biochemical processes is limited, probably induced by the presumption that their sparse vegetation cover plays a negligible role in global balances. However, spaces between the sparse shrubs are not bare, but soils are mostly covered by biological soil crusts (biocrusts). These biocrust communities belong to the oldest life forms, resulting from an assembly between soil particles and cyanobacteria, lichens, bryophytes, and algae plus heterotrophic organisms in varying proportions. Depending on the dominating organism group, cyanobacteria-, lichen-, and bryophyte-dominated biocrusts are distinguished. Besides their ability to restrict soil erosion they fix atmospheric carbon and nitrogen, and by doing this they serve as a nutrient source in strongly depleted dryland ecosystems. In this study we show that a fraction of the nitrogen fixed by biocrusts is metabolized and subsequently returned to the atmosphere in the form of nitric oxide (NO) and nitrous acid (HONO). These gases affect the radical formation and oxidizing capacity within the troposphere, thus being of particular interest to atmospheric chemistry. Laboratory measurements using dynamic chamber systems showed that dark cyanobacteria-dominated crusts emitted the largest amounts of NO and HONO, being ˜20 times higher than trace gas fluxes of nearby bare soil. We showed that these nitrogen emissions have a biogenic origin, as emissions of formerly strongly emitting samples almost completely ceased after sterilization. By combining laboratory, field, and satellite measurement data we made a best estimate of global annual emissions amounting to ˜1.1 Tg of NO-N and ˜0.6 Tg of HONO-N from biocrusts. This sum of 1.7 Tg of reactive nitrogen emissions equals ˜20% of the soil release under natural vegetation according to the latest IPCC report. In summary, our measurements show that dryland emissions of nitrogen oxides are largely driven by biocrusts and not by the underlying soil. As precipitation patterns, which influence biocrust activity, are affected by climate change, alterations in global nitrogen oxide emissions are to be expected. Thus, the role of biocrusts in the global cycling of reactive nitrogen needs to be followed and also implemented in regional and global models of biogeochemistry, air chemistry and climate.

3D laser measurements of bare and shod feet during walking.

PubMed

Novak, Boštjan; Možina, Janez; Jezeršek, Matija

2014-01-01

This article presents a new system for 3D foot-shape measurements during walking. It is based on the laser-triangulation, multiple-line-illumination and color-modulation techniques. It consists of a walking stage and four measuring modules that simultaneously acquire the foot shape from the top, bottom and side views. The measuring speed is 30 fps. Custom-developed software makes it possible to analyze the foot's dimensions at an arbitrary cross-section by means of the width, height, girth and section orientation. Six subjects were measured during bare and shod walking, and the bare foot and the outside dimensions of the footwear during the entire stance phase are presented. The relative measurement repeatability of a single subject is 0.5% for bare foot and 1% for shod foot. This means that it is possible to study the differences between various influences on the foot-shape dynamics, such as a bare/shod foot, different loading conditions and the shoe's stiffness condition. Copyright © 2014 Elsevier B.V. All rights reserved.

Very late stent thrombosis in a bare-metal stent, 9 years after implantation.

PubMed

Almasswary, Adel A

2009-06-01

Very late bare-metal stent thrombosis occurring beyond one year after stenting is uncommon. We report a case of bare-metal stent thrombosis presenting as acute myocardial infarction. The patient's stent was implanted 9 years ago, however, he was not adherent to his antiplatelet therapy (aspirin). This case highlights the importance of antiplatelet therapy in patients with stents even many years after implantation.

Instructive Video Retrieval for Surgical Skill Coaching Using Attribute Learning

DTIC Science & Technology

2015-06-28

dance, sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited automated...including dance, sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited...sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited automated feed- back to a

Research to lessen the amounts of curing agents in processed meat through use of rock salt and carbon monoxide

NASA Astrophysics Data System (ADS)

Sakata, R.; Takeda, S.; Kinoshita, Y.; Waga, M.

2017-09-01

This study was carried out to examine the reddening of meat products due to the addition of natural yellow salt (YS) and carbon monoxide (CO). Following YS or NaCl addition at 2% to pork subsequent to nitrite (0∼100 ppm) treatment, color development due to this addition was analyzed visually. Heme pigment content in the meat was also determined spectrophotometrically. YS was found to bring about greater reddening than NaCl, indicating residual nitrite and nitrate content to be significantly higher in meat containing YS, through the amount of either was quite small. The amount of nitrite required for a red color to develop was noted to vary significantly from one meat product to another. CO treatment of pork caused the formation of carboxy myoglobin (COMb) with consequent reddening of the meat. COMb was shown to be heat-stable and form stably at pH 5.0 to ∼8.0 and to be extractable with water, but was barely extractable at all with acetone. Nitric oxide was found to have greater affinity toward myoglobin (Mb) than CO. Nitrosyl Mb was noted to be stable in all meat products examined. CO was seen to be capable of controlling the extent of lipid oxidation.

Single-ion adsorption and switching in carbon nanotubes

DOE PAGES

Bushmaker, Adam W.; Oklejas, Vanessa; Walker, Don; ...

2016-01-25

Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes,more » by the mechanism of ion potentialinduced carrier depletion, which is supported by density functional and Landauer transport theory. Lastly, our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.« less

Ultrasound biomicroscopic findings in hallerman-streiff syndrome.

PubMed

Sato, Miho; Terasaki, Hiroko; Amano, Emil; Okamoto, Yoko; Miyake, Yozo

2002-01-01

To demonstrate the usefulness of ultrasound biomicroscopy in detecting the morphological changes in the lens caused by the spontaneous absorption of lens material and to detect fundus abnormalities in a patient with Hallermann-Streiff syndrome. Case report of an infant diagnosed at the age of 2 months as having Hallermann-Streiff syndrome. Spontaneous lens absorption occurred during the course of follow-up and was detected only by ultrasound biomicroscopy after the patient was prepared for cataract surgery. The changes in the anterior chamber depth and lens shapes were documented by ultrasound biomicroscopy. Retinal folds that were barely observable by conventional ophthalmoscopy because of a dense cataract were clearly shown by ultrasound biomicroscopy. Ultrasound biomicroscopy can be used to examine the lenses of eyes that are not observable with conventional optical instruments. Ultrasound biomicroscopy can also be used to study the posterior segment of microphthalmic eyes. We recommend preoperative ultrasound biomicroscopy to prevent unnecessary anesthesia and surgical preparation.

A comparative analysis to quantify the biogeochemical and biogeophysical cooling effects on climate of a white mustard cover crop

NASA Astrophysics Data System (ADS)

Ferlicoq, Morgan; Ceschia, Eric; Brut, Aurore; Tallec, Tiphaine; Carrer, Dominique; Pique, Gaetan; Ferroni, Nicole

2017-04-01

During the COP21, agriculture was recognised as a strategic sector and an opportunity to strengthen climate mitigation. In particular, the "4 per 1000" initiative relies upon solutions that refer to agro-ecology, conservation agriculture, … that could lead to increase carbon storage. Among those agro-ecology practices, including cover crops during fallow periods is considered as a fundamental agronomic lever for storing carbon. However, if biogeochemical benefits of cover-crops (CC) have already been addressed, their biogeophysical effects on climate have never been quantified and compared to biogeochemical effects. This comparative study (CC vs. bare soil), quantified and compared biogeochemical (including carbon storage) and biophysical effects (albedo and energy partitioning effect) of CC on climate. An experimental campaign was performed in 2013 in Southwest France, during the fallow period following a winter-wheat crop (and before a maize). The experimental plot was divided in two: the northern part was maintained in bare soil (BS) while white-mustard (WM) was grown during 3-months on the southern part. On each subplot, continuous measurements of CO2, latent and sensible fluxes (by eddy covariance) and solar radiation were acquired. Also, N2O emissions were measured by means of automatic chambers on each subplots. Moreover, by using a Life-Cycle-Analysis approach, each component of the greenhouse gas budget (GHGB) was quantified for each subplot, including emissions associated to field operations (FO). To quantify the albedo induced radiative forcing (RFα) caused by the white-mustard, the bare soil subplot was used as a reference state (IPCC, 2007). Finally, the net radiative forcing for each subplot was calculated as the sum of biogeochemical and biogeophysical (albedo effect) radiative forcing. The white-mustard allowed a net CO2 fixation of 63 g C-eq.m-2, corresponding to 20% of the net annual CO2 flux that year (-332 g C-eq.m-2). Through the WM seeds, the amount of C imported to the field increased by 2 g C-eq.m-2. As the white-mustard was buried and used as green manure for the next cash crop, the amount of C exported (when harvesting winter-wheat) was unchanged. Thus, the WM improved the NECB and reinforced the sink effect by 65 g C-eq.m-2. Nevertheless, growing a CC leads to additional emissions associated to FO. They represented only 3 g C-eq.m-2 and can therefore be considered negligible. However, N2O emissions were reduced during the WM development. Finally, the GHGB of the WM subplot (-73 g C-eq.m-2) was a significant sink while the GHGB of the BS subplot was close to neutral (-12 g C-eq.m-2). By increasing surface albedo, the WM induced a biogeophysical cooling effect (-81 g C-eq.m-2) equivalent to the GHGB of the WM subplot. In other words, the white-mustard cooling effect (compared to bare soil) is doubled if both biogeochemical and RFα are considered. This cooling effect was reinforced by the 53% increase in latent heat flux during the WM development. Finally, we estimated that the albedo cooling effect could be increased by 5-fold by maintaining the WM during 6-months. We conclude that through both biogeochemical and biogeophysical effects, cover crops represent a strong mitigation potential.

Sensitivity enhancement of capacitive tumor necrosis factor-α detection by deposition of nanoparticles on interdigitated electrode

NASA Astrophysics Data System (ADS)

Yagati, Ajay Kumar; Park, Jinsoo; Kim, Jungsuk; Ju, Heongkyu; Chang, Keun-A.; Cho, Sungbo

2016-06-01

An interdigitated electrodes (IDE) modified with gold nanoparticles (AuNPs) was fabricated to enhance the capacitive detection of tumor necrosis factor-α (TNF-α) and compared with a bare IDE. A TNF-α immunosensor was developed by covalently conjugating TNF-α antibodies with 3-mercaptopropionic acid by a carbodiimide/N-hydroxysuccinimide reaction on the AuNP/IDE. After the application of human serum samples containing various concentrations of TNF-α to the sensing electrode, changes in both the impedance spectrum and the electrode interfacial capacitance were measured. The capacitance changes were dependent on the TNF-α concentration in the range of 1 pg ml-1 to 10 ng ml-1, and the device had the calculated detection limit of 0.83 pg ml-1. The developed AuNP/IDE-based immunosensor was successfully used for the capacitive detection of the binding of TNF-α to its antibody, and was found to be feasible for the analysis of TNF-α in human blood serum.

A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs

PubMed Central

Kao, Kun-Wei; Hsu, Ming-Che; Chang, Yuh-Hwa; Gwo, Shangjr; Yeh, J. Andrew

2012-01-01

An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air. PMID:22969342

Application of the Nimbus 5 ESMR to rainfall detection over land surfaces

NASA Technical Reports Server (NTRS)

Meneely, J. M.

1975-01-01

The ability of the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR) to detect rainfall over land surfaces was evaluated. The ESMR brightness temperatures (Tb sub B) were compared with rainfall reports from climatological stations for a limited number of rain events over portions of the U.S. The greatly varying emissivity of land surfaces precludes detection of actively raining areas. Theoretical calculations using a ten-layer atmospheric model showed this to be an expected result. Detection of rain which had fallen was deemed feasible over certain types of land surfaces by comparing the Tb sub B fields before and after the rain fell. This procedure is reliable only over relatively smooth terrain having a substantial fraction of bare soil, such as exists in major agricultural regions during the dormant or early growing seasons. Soil moisture budgets were computed at selected sites to show how the observed emissivity responded to changes in the moisture content of the upper soil zone.

Graphene decorated microelectrodes for simultaneous detection of ascorbic, dopamine, and folic acids by means of chemical vapor deposition

NASA Astrophysics Data System (ADS)

Namdar, N.; Hassanpour Amiri, M.; Dehghan Nayeri, F.; Gholizadeh, A.; Mohajerzadeh, S.

2015-09-01

In this paper, high quality and large area graphene layers were synthesized using thermal chemical vapour deposition on copper foil substrates. We use graphene incorporated electrodes to measure simultaneously ascorbic acid, dopamine and folic acid. Cyclic voltammetry and differential pulse voltammetry methods were used to evaluate electrochemical behaviour of the grown graphene layers. The graphene-modified electrode shows large electrochemical potential difference compared to bare gold electrodes with higher current responses. Also our fabricated electrodes configuration can be used easily for microfluidic analysis.

Hybrid Materials for Thermal Management in Thin Films and Bulk Composites

DTIC Science & Technology

2012-02-01

enamel  that  cures  via  oxidative...polymerization   in   air  ( Enamel ),  a  waterborne  flat   latex  that  cures  by  coalescing  while  air  drying  (Flat...Wood   Bare   Primer   Primer   +  KPF6     Bare   Primer   Primer   +  KPF6     Bare   Primer   Enamel  

Consistency of temporal and habitat-related differences among assemblages of fish in coastal lagoons

NASA Astrophysics Data System (ADS)

Gray, Charles A.; Rotherham, Douglas; Johnson, Daniel D.

2011-12-01

The consistency of habitat-related differences in coastal lagoon fish assemblages was assessed across different spatial and temporal scales. Multimesh gillnets were used to sample assemblages of fish on a monthly basis for 1-year in three habitats (shallow seagrass, shallow bare and deep substrata) at two locations (>1 km apart), in each of two coastal lagoons (approximately 500 km apart), in southeastern Australia. A total of 48 species was sampled with 34 species occurring in both lagoons and in all three habitats; species caught in only one lagoon or habitat occurred in low numbers. Ten species dominated assemblages and accounted for more than 83% of all individuals sampled. In both lagoons, assemblages in the deep habitat consistently differed to those in the shallow strata (regardless of habitat). Several species were caught more frequently or in larger numbers in the deep habitat. Assemblages in the two shallow habitats did not differ consistently and were dominated by the same species and sizes of fish, possibly due to habitat heterogeneity and the scale and method of sampling. Within each lagoon, very few between location differences in assemblages within each habitat were observed. Consistent differences in assemblages were detected between lagoons for the shallow bare and deep habitats, indicating there were some intrinsic differences in ichthyofauna between lagoons. Assemblages in spring differed to those in summer, which differed to those in winter for the shallow bare habitat in both lagoons, and the deep habitat in only one lagoon. Fish-habitat relationships are complex and differences in the fish fauna between habitats were often temporally inconsistent. This study highlights the need for greater testing of habitat relationships in space and time to assess the generality of observations and to identify the processes responsible for structuring assemblages.

Diurnal emissivity dynamics in bare versus biocrusted sand dunes.

PubMed

Rozenstein, Offer; Agam, Nurit; Serio, Carmine; Masiello, Guido; Venafra, Sara; Achal, Stephen; Puckrin, Eldon; Karnieli, Arnon

2015-02-15

Land surface emissivity (LSE) in the thermal infrared depends mainly on the ground cover and on changes in soil moisture. The LSE is a critical variable that affects the prediction accuracy of geophysical models requiring land surface temperature as an input, highlighting the need for an accurate derivation of LSE. The primary aim of this study was to test the hypothesis that diurnal changes in emissivity, as detected from space, are larger for areas mostly covered by biocrusts (composed mainly of cyanobacteria) than for bare sand areas. The LSE dynamics were monitored from geostationary orbit by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) over a sand dune field in a coastal desert region extending across both sides of the Israel-Egypt political borderline. Different land-use practices by the two countries have resulted in exposed, active sand dunes on the Egyptian side (Sinai), and dunes stabilized by biocrusts on the Israeli side (Negev). Since biocrusts adsorb more moisture from the atmosphere than bare sand does, and LSE is affected by the soil moisture, diurnal fluctuations in LSE were larger for the crusted dunes in the 8.7 μm channel. This phenomenon is attributed to water vapor adsorption by the sand/biocrust particles. The results indicate that LSE is sensitive to minor changes in soil water content caused by water vapor adsorption and can, therefore, serve as a tool for quantifying this effect, which has a large spatial impact. As biocrusts cover vast regions in deserts worldwide, this discovery has repercussions for LSE estimations in deserts around the globe, and these LSE variations can potentially have considerable effects on geophysical models from local to regional scales. Copyright © 2014 Elsevier B.V. All rights reserved.

Critical screening in the one- and two-electron Yukawa atoms

NASA Astrophysics Data System (ADS)

Montgomery, H. E.; Sen, K. D.; Katriel, Jacob

2018-02-01

The one- and two-electron Yukawa atoms, also referred to as the Debye-Hückel or screened Coulomb atoms, have been topics of considerable interest both for intrinsic reasons and because of their relevance to terrestrial and astrophysical plasmas. At sufficiently high screening the one-electron Yukawa atom ceases to be bound. Some calculations appeared to suggest that as the screening increases in the ground state of the two-electron Yukawa atom (in which both the one-particle attraction and the interparticle repulsion are screened) the two electrons are detached simultaneously, at the same screening constant at which the one-electron atom becomes unbound. Our results rule this scenario out, offering an alternative that is not less interesting. In particular, it is found that for Z <1 a mild amount of screening actually increases the binding energy of the second electron. At the nuclear charge Zc≈0.911028 ... , at which the bare Coulomb two-electron atom becomes unbound, and even over a range of lower nuclear charges, an appropriate amount of screening gives rise to a bound two-electron system.

Three-year results of the VIBRANT trial of VIABAHN endoprosthesis versus bare nitinol stent implantation for complex superficial femoral artery occlusive disease.

PubMed

Geraghty, Patrick J; Mewissen, Mark W; Jaff, Michael R; Ansel, Gary M

2013-08-01

The predominant mode of bare nitinol stent failure is diffuse in-stent restenosis, and failure rates correlate to the length and complexity of the treated lesion. Addition of an expanded polytetrafluoroethylene lining to a nitinol stent frame, as found in the VIABAHN endoprosthesis, mitigates the ingrowth of intimal hyperplasia. We compared the long-term outcomes of complex superficial femoral artery disease intervention using the VIABAHN endoprosthesis to those obtained with bare nitinol stent implantation. One hundred forty-eight patients with symptomatic complex superficial femoral artery disease (TransAtlantic Inter-Society Consensus I class C and D lesions, accompanied by intermittent claudication or ischemic rest pain) were randomized to endovascular intervention using either bare nitinol stent implantation (76 patients) or nonheparin-bonded VIABAHN endoprosthesis deployment (72 patients). Patency, limb hemodynamics, and quality of life were evaluated at 1, 6, 12, 24, and 36 months following intervention. The average treated lesion measured 18 ± 8 cm in length, and 58.8% of lesions displayed segmental or complete occlusion. At 3 years, primary patency rates (defined by peak systolic velocity ratio ≤ 2.0 and no target lesion revascularization) did not significantly differ between patients treated with the VIABAHN stent graft and those who received a bare nitinol stent (24.2% vs 25.9%; P = .392). Stent fractures were significantly more common in bare nitinol stents (50.0%) than in the VIABAHN endoprostheses (2.6%). Primary-assisted patency rates were higher in those receiving bare nitinol stents than the VIABAHN stent graft (88.8% vs 69.8%; P = .04), although secondary patency rates did not differ between bare nitinol stent and stent graft recipients (89.3% vs 79.5%; P = .304). There were no instances of procedure-related mortality or amputation. The hemodynamic improvement and quality measures improved equally in both groups. The long-term outcomes of complex superficial femoral artery disease intervention using the VIABAHN endograft and bare nitinol stents are similar. Although primary patency rates are low in both study arms, excellent primary-assisted and secondary patency rates were achieved, with sustained augmentation of limb perfusion and quality-of-life measures. Patency rates diminish most rapidly in the first year after device implantation. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

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

Krokidis, Miltiadis, E-mail: mkrokidis@hotmail.com; Fanelli, Fabrizio; Orgera, Gianluigi

The purpose of this study was to compare the clinical effectiveness of expanded polytetrafluoroethylene/fluorinated-ethylene-propylene (ePTFE/FEP)-covered stents with that of uncovered nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer. Eighty patients were enrolled in a prospective randomized study. Bare nitinol stents were used in half of the patients, and ePTFE/FEP-covered stents were used in the remaining patients. Patency, survival, complications, and mean cost were calculated in both groups. Mean patency was 166.0 {+-} 13.11 days for the bare-stent group and 234.0 {+-} 20.87 days for the covered-stent group (p = 0.007). Primary patency rates atmore » 3, 6, and 12 months were 77.5, 69.8, and 69.8% for the bare-stent group and 97.5, 92.2, and 87.6% for the covered-stent group, respectively. Mean secondary patency was 123.7 {+-} 22.5 days for the bare-stent group and 130.3 {+-} 21.4 days for the covered-stent group. Tumour ingrowth occurred exclusively in the bare-stent group in 27.5% of cases (p = 0.002). Median survival was 203.2 {+-} 11.8 days for the bare-stent group and 247.0 {+-} 20 days for the covered-stent group (p = 0.06). Complications and mean cost were similar in both groups. Regarding primary patency and ingrowth rate, ePTFE/FEP-covered stents have shown to be significantly superior to bare nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer and pose comparable cost and complications. Use of a covered stent does not significantly influence overall survival rate; nevertheless, the covered endoprosthesis seems to offer result in fewer reinterventions and better quality of patient life.« less

Effectiveness of liquid soap vs. chlorhexidine gluconate for the removal of Clostridium difficile from bare hands and gloved hands.

PubMed

Bettin, K; Clabots, C; Mathie, P; Willard, K; Gerding, D N

1994-11-01

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile. C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student's t test. On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P = NS) and fingers (log10 CFU, 2.4 and 2.5, P = NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P < .01) and palms (log10 CFU 1.5 and 2.0, P < .01), but not finger/thumbtips (log10 CFU 1.6 with each, P = NS). Residual C difficile counts were lower on gloved hands than bare hands (P < 0.01 to < 0.0001). The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

Characterization of Emissions of Volatile Organic Compounds from Interior Alkyd Paint.

PubMed

Fortmann, Roy; Roache, Nancy; Chang, John C S; Guo, Zhishi

1998-10-01

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9-C12); C8-C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m 3 were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variables, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data.

Characterization of emissions of volatile organic compounds from interior alkyd paint.

PubMed

Fortmann, R; Roache, N; Chang, J C; Guo, Z

1998-10-01

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9-C12); C8-C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m3 were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variable, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data.

Carpeting in hospitals: an epidemiological evaluation.

PubMed Central

Anderson, R L; Mackel, D C; Stoler, B S; Mallison, G F

1982-01-01

Epidemiological and microbiological studies were conducted in a hospital room with carpet (CR) and in one with carpet (NCR). Microbiological profiles were determined with specimens obtained from patients admitted to these rooms. Patient records were reviewed to note infection status and other case identities. Eleven-millimeter cylindrical core samples of carpet were obtained, and swab template techniques were used on the bare floor for subsequent enumeration and identification of contaminating microorganisms. In each sampling period, higher microbial counts per square inch (1 in(2) = ca 6.452 cm(2)) were measured for the carpet than for the bare floor. Recovery rates of Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli were higher from carpet samples than from bare floor samples. Typable organisms (such as E. coli, Pseudomonas aeruginosa, K. pneumoniae, and Staphylococcus aureus) obtained from patients were also more frequently recovered from the carpet than from the bare flooring. Patients who stayed in the CR were shown to be colonized with the same types of organisms as those initially recovered from the carpet. However, no statistically significant differences were found in patients in the CR versus NCR in colonization with all typable and nontypable organisms first found on the floor. Disease in patients was found not to be associated with organisms found as contaminants of the carpet or the bare floor. Air above carpeting contained more consistent concentrations of organisms than air above the bare flooring. PMID:7076814

Partitioning Carbon Dioxide Emission and Assessing Dissolved Organic Carbon Leaching of a Drained Peatland Cultivated with Pineapple at Saratok, Malaysia

PubMed Central

Lim Kim Choo, Liza Nuriati; Ahmed, Osumanu Haruna

2014-01-01

Pineapples (Ananas comosus (L.) Merr.) cultivation on drained peats could affect the release of carbon dioxide (CO2) into the atmosphere and also the leaching of dissolved organic carbon (DOC). Carbon dioxide emission needs to be partitioned before deciding on whether cultivated peat is net sink or net source of carbon. Partitioning of CO2 emission into root respiration, microbial respiration, and oxidative peat decomposition was achieved using a lysimeter experiment with three treatments: peat soil cultivated with pineapple, bare peat soil, and bare peat soil fumigated with chloroform. Drainage water leached from cultivated peat and bare peat soil was also analyzed for DOC. On a yearly basis, CO2 emissions were higher under bare peat (218.8 t CO2 ha/yr) than under bare peat treated with chloroform (205 t CO2 ha/yr), and they were the lowest (179.6 t CO2 ha/yr) under cultivated peat. Decreasing CO2 emissions under pineapple were attributed to the positive effects of photosynthesis and soil autotrophic activities. An average 235.7 mg/L loss of DOC under bare peat suggests rapid decline of peat organic carbon through heterotrophic respiration and peat decomposition. Soil CO2 emission depended on moderate temperature fluctuations, but it was not affected by soil moisture. PMID:25215335

a Framework of Change Detection Based on Combined Morphologica Features and Multi-Index Classification

NASA Astrophysics Data System (ADS)

Li, S.; Zhang, S.; Yang, D.

2017-09-01

Remote sensing images are particularly well suited for analysis of land cover change. In this paper, we present a new framework for detection of changing land cover using satellite imagery. Morphological features and a multi-index are used to extract typical objects from the imagery, including vegetation, water, bare land, buildings, and roads. Our method, based on connected domains, is different from traditional methods; it uses image segmentation to extract morphological features, while the enhanced vegetation index (EVI), the differential water index (NDWI) are used to extract vegetation and water, and a fragmentation index is used to the correct extraction results of water. HSV transformation and threshold segmentation extract and remove the effects of shadows on extraction results. Change detection is performed on these results. One of the advantages of the proposed framework is that semantic information is extracted automatically using low-level morphological features and indexes. Another advantage is that the proposed method detects specific types of change without any training samples. A test on ZY-3 images demonstrates that our framework has a promising capability to detect change.

Bed load tracer mobility in a mixed bedrock/alluvial channel

NASA Astrophysics Data System (ADS)

Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.

2017-04-01

The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate bed load transport during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial sediment cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.

Synthesis, characterization and antibacterial activity of superparamagnetic nanoparticles modified with glycol chitosan

NASA Astrophysics Data System (ADS)

Inbaraj, Baskaran Stephen; Tsai, Tsung-Yu; Chen, Bing-Huei

2012-02-01

Iron oxide nanoparticles (IONPs) were synthesized by coprecipitation of iron salts in alkali media followed by coating with glycol chitosan (GC-coated IONPs). Both bare and GC-coated IONPs were subsequently characterized and evaluated for their antibacterial activity. Comparison of Fourier transform infrared spectra and thermogravimetric data of bare and GC-coated IONPs confirmed the presence of GC coating on IONPs. Magnetization curves showed that both bare and GC-coated IONPs are superparamagnetic and have saturation magnetizations of 70.3 and 59.8 emu g-1, respectively. The IONP size was measured as ~8-9 nm by transmission electron microscopy, and their crystal structure was assigned to magnetite from x-ray diffraction patterns. Both bare and GC-coated IONPs inhibited the growths of Escherichia coli ATCC 8739 and Salmonella enteritidis SE 01 bacteria better than the antibiotics linezolid and cefaclor, as evaluated by the agar dilution assay. GC-coated IONPs showed higher potency against E. coli O157:H7 and Staphylococcus aureus ATCC 10832 than bare IONPs. Given their biocompatibility and antibacterial properties, GC-coated IONPs are a potential nanomaterial for in vivo applications.

Spectral methods to detect surface mines

NASA Astrophysics Data System (ADS)

Winter, Edwin M.; Schatten Silvious, Miranda

2008-04-01

Over the past five years, advances have been made in the spectral detection of surface mines under minefield detection programs at the U. S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD). The problem of detecting surface land mines ranges from the relatively simple, the detection of large anti-vehicle mines on bare soil, to the very difficult, the detection of anti-personnel mines in thick vegetation. While spatial and spectral approaches can be applied to the detection of surface mines, spatial-only detection requires many pixels-on-target such that the mine is actually imaged and shape-based features can be exploited. This method is unreliable in vegetated areas because only part of the mine may be exposed, while spectral detection is possible without the mine being resolved. At NVESD, hyperspectral and multi-spectral sensors throughout the reflection and thermal spectral regimes have been applied to the mine detection problem. Data has been collected on mines in forest and desert regions and algorithms have been developed both to detect the mines as anomalies and to detect the mines based on their spectral signature. In addition to the detection of individual mines, algorithms have been developed to exploit the similarities of mines in a minefield to improve their detection probability. In this paper, the types of spectral data collected over the past five years will be summarized along with the advances in algorithm development.

LiDAR-Assisted identification of an active fault near Truckee, California

USGS Publications Warehouse

Hunter, L.E.; Howle, J.F.; Rose, R.S.; Bawden, G.W.

2011-01-01

We use high-resolution (1.5-2.4 points/m2) bare-earth airborne Light Detection and Ranging (LiDAR) imagery to identify, map, constrain, and visualize fault-related geomorphology in densely vegetated terrain surrounding Martis Creek Dam near Truckee, California. Bare-earth LiDAR imagery reveals a previously unrecognized and apparently youthful right-lateral strike-slip fault that exhibits laterally continuous tectonic geomorphic features over a 35-km-long zone. If these interpretations are correct, the fault, herein named the Polaris fault, may represent a significant seismic hazard to the greater Truckee-Lake Tahoe and Reno-Carson City regions. Three-dimensional modeling of an offset late Quaternary terrace riser indicates a minimum tectonic slip rate of 0.4 ?? 0.1 mm/yr.Mapped fault patterns are fairly typical of regional patterns elsewhere in the northern Walker Lane and are in strong coherence with moderate magnitude historical seismicity of the immediate area, as well as the current regional stress regime. Based on a range of surface-rupture lengths and depths to the base of the seismogenic zone, we estimate a maximum earthquake magnitude (M) for the Polaris fault to be between 6.4 and 6.9.

[Microeukaryotic biodiversity in the waste ore samples surrounding an acid mine drainage lake].

PubMed

Li, Si-Yuan; Hao, Chun-Bo; Wang, Li-Hua; Lü, Zheng; Zhang, Li-Na; Liu, Ying; Feng, Chuan-Ping

2013-10-01

The abandoned mineral samples were collected in an acid mine drainage area in Anhui Province. Molecular ecological methods were used to construct 18S rDNA clone libraries after analyzing the main physicochemical parameters, and then the microeukaryotic diversity and community structure in the acid mine drainage area were studied. The results showed that the region was strongly acidic (pH <3), and the concentrations of Fe, SO2-(4), P, NO-(3) -N showed the same trend, all higher in the bare waste ore samples PD and 1 M than in the vegetation covered samples LW and XC. Four eukaryotic phyla were detected in the abandoned mineral samples: Ascomycota, Basidiomycota, Glomeromycota and Arthropoda. Glomeromycota can form an absolute symbiotic relationship with the plant, and it was a key factor for early plant to adapt the terrestrial environment. The biodiversity of the vegetation covered samples LW and XC, which contained Glomeromycota, was much higher than that of the bare abandoned rock samples PD and 1 M. Moreover, many sequences in the libraries were closely related to some isolated strains, which are tolerant to low pH and heavy metals, such as Penicillium purpurogenum, Chaetothyriales sp. and Staninwardia suttonii.

Taking single virus detection and sizing to the limit with molecular sensitivity: the birth of nanoplasmonic-microcavity hybrid sensors

NASA Astrophysics Data System (ADS)

Arnold, S.

2013-03-01

The BioPhotonics community is buzzing at the prospect that ulta-small bio-nanoparticles such as Polio virus and protein can be detected label-free in their native state and sized one at a time. As the awareness that the claim of label-free single protein sensing through the frequency shift of a bare microcavity by A.M. Armani et al in Science in 2007 fades from lack of independent experimental confirmation or a viable physical mechanism to account for the magnitude of the reported wavelength shifts, a new approach has captured the community's interest. It is a product of a marriage between nano-optics and micro-photonics, and is poised to take label-free sensing to the limit.

A multi-scale evaluation of pack stock effects on subalpine meadow plant communities in the Sierra Nevada

PubMed Central

Berlow, Eric L.; Ostoja, Steven M.; Brooks, Matthew L.; Génin, Alexandre; Matchett, John R.; Hart, Stephen C.

2017-01-01

We evaluated the influence of pack stock (i.e., horse and mule) use on meadow plant communities in Sequoia and Yosemite National Parks in the Sierra Nevada of California. Meadows were sampled to account for inherent variability across multiple scales by: 1) controlling for among-meadow variability by using remotely sensed hydro-climatic and geospatial data to pair stock use meadows with similar non-stock (reference) sites, 2) accounting for within-meadow variation in the local hydrology using in-situ soil moisture readings, and 3) incorporating variation in stock use intensity by sampling across the entire available gradient of pack stock use. Increased cover of bare ground was detected only within “dry” meadow areas at the two most heavily used pack stock meadows (maximum animals per night per hectare). There was no difference in plant community composition for any level of soil moisture or pack stock use. Increased local-scale spatial variability in plant community composition (species dispersion) was detected in “wet” meadow areas at the two most heavily used meadows. These results suggest that at the meadow scale, plant communities are generally resistant to the contemporary levels of recreational pack stock use. However, finer-scale within-meadow responses such as increased bare ground or spatial variability in the plant community can be a function of local-scale hydrological conditions. Wilderness managers can improve monitoring of disturbance in Sierra Nevada meadows by adopting multiple plant community indices while simultaneously considering local moisture regimes. PMID:28609464

Seroprevalences of Specific IgG Antibodies to Measles, Mumps, and Rubella in Korean Infants.

PubMed

Cho, Hye Kyung; Lee, Hyunju; Kim, Han Wool; Kim, Sung Soon; Kang, Hae Ji; Kim, In Tae; Kim, Kyung Hyo

2016-12-01

In this study, the seroprevalences of measles, mumps, and rubella antibodies in infants were determined to assess the immunization strategy and control measures for these infectious diseases. Serum samples from infants < 1 year of age and their mothers were collected to measure the concentrations of specific IgG antibodies to measles, mumps, and rubella by enzyme-linked immunosorbent assay. For selected infant serum samples, measles-specific neutralizing antibody levels were determined by using the plaque reduction neutralization test. The sera from 295 of infants and 80 of their mothers were analyzed. No infants had past measles, mumps, or rubella infections. Almost all infants < 2 months of age were positive for measles and rubella IgG antibodies. However, seroprevalence of measles and rubella antibodies decreased with age, and measles IgG and rubella IgG were barely detectable after 4 months of age. The seroprevalence of mumps antibodies was lower than that of measles and rubella antibodies in infants ≤ 4 months old, and mumps IgG was barely detectable after 2 months of age. The seropositivity of measles-specific neutralizing antibody was 63.6% in infants aged 2 months and undetectable in infants ≥ 6 months old. Because the seropositivity rates of measles, mumps, and rubella antibodies were low after the first few months of age in Korean infants, active immunization with vaccines is strongly recommended for infants aged 6-11 months when measles is epidemic. Timely administration of the first dose of measles-mumps-rubella vaccine at 12 months of age should be encouraged in non-epidemic situations.

Seroprevalences of Specific IgG Antibodies to Measles, Mumps, and Rubella in Korean Infants

PubMed Central

2016-01-01

In this study, the seroprevalences of measles, mumps, and rubella antibodies in infants were determined to assess the immunization strategy and control measures for these infectious diseases. Serum samples from infants < 1 year of age and their mothers were collected to measure the concentrations of specific IgG antibodies to measles, mumps, and rubella by enzyme-linked immunosorbent assay. For selected infant serum samples, measles-specific neutralizing antibody levels were determined by using the plaque reduction neutralization test. The sera from 295 of infants and 80 of their mothers were analyzed. No infants had past measles, mumps, or rubella infections. Almost all infants < 2 months of age were positive for measles and rubella IgG antibodies. However, seroprevalence of measles and rubella antibodies decreased with age, and measles IgG and rubella IgG were barely detectable after 4 months of age. The seroprevalence of mumps antibodies was lower than that of measles and rubella antibodies in infants ≤ 4 months old, and mumps IgG was barely detectable after 2 months of age. The seropositivity of measles-specific neutralizing antibody was 63.6% in infants aged 2 months and undetectable in infants ≥ 6 months old. Because the seropositivity rates of measles, mumps, and rubella antibodies were low after the first few months of age in Korean infants, active immunization with vaccines is strongly recommended for infants aged 6–11 months when measles is epidemic. Timely administration of the first dose of measles-mumps-rubella vaccine at 12 months of age should be encouraged in non-epidemic situations. PMID:27822935

Early detection of Candida albicans biofilms at porous electrodes.

PubMed

Congdon, Robert B; Feldberg, Alexander S; Ben-Yakar, Natalie; McGee, Dennis; Ober, Christopher; Sammakia, Bahgat; Sadik, Omowunmi A

2013-02-15

We describe the development of an electrochemical sensor for early detection of biofilm using Candida albicans. The electrochemical sensor used the ability of biofilms to accept electrons from redox mediators relative to the number of metabolically active cells present. Cyclic voltammetry and differential pulse voltammetry techniques were used to monitor the redox reaction of K(3)Fe(CN)(6) at porous reticulated vitreous carbon (RVC) (238.7 cm(2)) working electrodes versus Ag/AgCl reference. A shift in the peak potential occurred after 12 h of film growth, which is attributed to the presence of C. albicans. Moreover, the intensity of the ferricyanide reduction peak first increased as C. albicans deposited onto the porous electrodes at various growth times. The peak current subsequently decreased at extended periods of growth of 48 h. The reduction in peak current was attributed to the biofilm reaching its maximum growth thickness, which correlated with the maximum number of metabolically active cells. The observed diffusion coefficients for the bare RVC and biofilm-coated electrodes were 2.2 × 10(-3) and 7.0 × 10(-6) cm(2)/s, respectively. The increase in diffusivity from the bare electrode to the biofilm-coated electrode indicated some enhancement of electron transfer mediated by the biofilm to the porous electrode. Verification of the growth of biofilm was achieved using scanning electron microcopy and laser scanning confocal imaging microscopy. Validation with conventional plating techniques confirmed that the correlation (R(2) = 0.9392) could be achieved between the electrochemical sensors data and colony-forming units. Copyright © 2012 Elsevier Inc. All rights reserved.

Voltammetric studies of Azathioprine on the surface of graphite electrode modified with graphene nanosheets decorated with Ag nanoparticles.

PubMed

Asadian, Elham; Iraji Zad, Azam; Shahrokhian, Saeed

2016-01-01

By using graphene nanosheets decorated with Ag nanoparticles (AgNPs-G) as an effective approach for the surface modification of pyrolytic graphite electrode (PGE), a sensing platform was fabricated for the sensitive voltammetric determination of Azathioprine (Aza). The prepared AgNPs-G nanosheets were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and Raman spectroscopy techniques. The electrochemical behavior of Aza was investigated by means of cyclic voltammetry. Comparing to the bare PGE, a remarkable enhancement was observed in the response characteristics of Aza on the surface of the modified electrode (AgNPs-G/PGE) as well as a noticeable decrease in its reduction overpotential. These results can be attributed to the incredible enlargement in the microscopic surface area of the electrode due to the presence of graphene nanosheets together with strong adsorption of Aza on its surface. The effect of experimental parameters such as accumulation time, the amount of modifier suspension and pH of the supporting electrolyte were also optimized toward obtaining the maximum sensitivity. Under the optimum conditions, the calibration curve studies demonstrated that the peak current increased linearly with Aza concentrations in the range of 7 × 10(-7) to 1 × 10(-4)mol L(-1) with the detection limit of 68 nM. Further experiments revealed that the modified electrode can be successfully applied for the accurate determination of Aza in pharmaceutical preparations. Copyright © 2015 Elsevier B.V. All rights reserved.

Small cysteine-rich antifungal proteins from radish: their role in host defense.

PubMed Central

Terras, F R; Eggermont, K; Kovaleva, V; Raikhel, N V; Osborn, R W; Kester, A; Rees, S B; Torrekens, S; Van Leuven, F; Vanderleyden, J

1995-01-01

Radish seeds have previously been shown to contain two homologous, 5-kD cysteine-rich proteins designated Raphanus sativus-antifungal protein 1 (Rs-AFP1) and Rs-AFP2, both of which exhibit potent antifungal activity in vitro. We now demonstrate that these proteins are located in the cell wall and occur predominantly in the outer cell layers lining different seed organs. Moreover, Rs-AFPs are preferentially released during seed germination after disruption of the seed coat. The amount of released proteins is sufficient to create a microenvironment around the seed in which fungal growth is suppressed. Both the cDNAs and the intron-containing genomic regions encoding the Rs-AFP preproteins were cloned. Transcripts (0.55 kb) hybridizing with an Rs-AFP1 cDNA-derived probe were present in near-mature and mature seeds. Such transcripts as well as the corresponding proteins were barely detectable in healthy uninfected leaves but accumulated systemically at high levels after localized fungal infection. The induced leaf proteins (designated Rs-AFP3 and Rs-AFP4) were purified and shown to be homologous to seed Rs-AFPs and to exert similar antifungal activity in vitro. A chimeric Rs-AFP2 gene under the control of the constitutive cauliflower mosaic virus 35S promoter conferred enhanced resistance to the foliar pathogen Alternaria longipes in transgenic tobacco. The term "plant defensins" is proposed to denote these defense-related proteins. PMID:7780308

Geodetic Earth Observation

NASA Astrophysics Data System (ADS)

Rothacher, Markus

2017-04-01

Mankind is constantly threatened by a variety of natural disasters and global change phenomena. In order to be able to better predict and assess these catastrophic and disastrous events a continuous observation and monitoring of the causative Earth processes is a necessity. These processes may happen in time scales from extremely short (earthquakes, volcano eruptions, land slides, ...) to very long (melting of ice sheets, sea level change, plate tectonics, ...). Appropriate monitoring and early warning systems must allow, therefore, the detection and quantification of catastrophic events in (near) real-time on the one hand and the reliable identification of barely noticeable, but crucial long-term trends (e.g., sea level rise) on the other hand. The Global Geodetic Observing System (GGOS), established by the International Association of Geodesy (IAG) in 2003, already now contributes in a multitude of ways to meet this challenge, e.g., by providing a highly accurate and stable global reference frame, without which the measurement of a sea level rise of 2-3 mm/y would not be possible; by measuring displacements in near real-time and deformations over decades that offer valuable clues to plate tectonics, earthquake processes, tsunamis, volcanos, land slides, and glaciers dynamics; by observing the mass loss of ice sheets with gravity satellite missions; and by estimating essential variables such as the amount of water vapor in the troposphere relevant for weather predictions and climate and the content of free electrons in the ionosphere crucial for space weather.

Subcellular localization and compartmentation of thiamine derivatives in rat brain.

PubMed

Bettendorff, L; Wins, P; Lesourd, M

1994-05-26

The subcellular distribution of thiamine derivatives in rat brain was studied. Thiamine diphosphate content was highest in the mitochondrial and synaptosomal fractions, and lowest in microsomal, myelin and cytosolic fractions. Only 3-5% of total thiamine diphosphate was bound to transketolase, a cytosolic enzyme. Thiamine triphosphate was barely detectable in the microsomal and cytosolic fraction, but synaptosomes were slightly enriched in this compound compared to the crude homogenate. Both myelin and mitochondrial fractions contained significant amounts of thiamine triphosphate. In order to estimate the relative turnover rates of these compounds, the animals received an intraperitoneal injection of either [14C]thiamine or [14C]sulbutiamine (isobutyrylthiamine disulfide) 1 h before decapitation. The specific radioactivities of thiamine compounds found in the brain decreased in the order: thiamine > thiamine triphosphate > thiamine monophosphate > thiamine diphosphate. Incorporation of radioactivity into thiamine triphosphate was more marked with [14C]sulbutiamine than with [14C]thiamine. The highest specific radioactivity of thiamine diphosphate was found in the cytosolic fraction of the brain, though this pool represents less than 10% of total thiamine diphosphate. Cytosolic thiamine diphosphate had a twice higher specific radioactivity when [14C]sulbutiamine was used as precursor compared with thiamine though no significant differences were found in the other cellular compartments. Our results suggest the existence of two thiamine diphosphate pools: the bound cofactor pool is essentially mitochondrial and has a low turnover; a much smaller cytosolic pool (6-7% of total TDP) of high turnover is the likely precursor of thiamine triphosphate.

SU-D-19A-05: The Dosimetric Impact of Using Xoft Axxent® Electronic Brachytherapy Source TG-43 Dosimetry Parameters for Treatment with the Xoft 30 Mm Diameter Vaginal Applicator

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

Simiele, S; Micka, J; Culberson, W

2014-06-01

Purpose: A full TG-43 dosimetric characterization has not been performed for the Xoft Axxent ® electronic brachytherapy source (Xoft, a subsidiary of iCAD, San Jose, CA) within the Xoft 30 mm diameter vaginal applicator. Currently, dose calculations are performed using the bare-source TG-43 parameters and do not account for the presence of the applicator. This work focuses on determining the difference between the bare-source and sourcein- applicator TG-43 parameters. Both the radial dose function (RDF) and polar anisotropy function (PAF) were computationally determined for the source-in-applicator and bare-source models to determine the impact of using the bare-source dosimetry data. Methods:more » MCNP5 was used to model the source and the Xoft 30 mm diameter vaginal applicator. All simulations were performed using 0.84p and 0.03e cross section libraries. All models were developed based on specifications provided by Xoft. The applicator is made of a proprietary polymer material and simulations were performed using the most conservative chemical composition. An F6 collision-kerma tally was used to determine the RDF and PAF values in water at various dwell positions. The RDF values were normalized to 2.0 cm from the source to accommodate the applicator radius. Source-in-applicator results were compared with bare-source results from this work as well as published baresource results. Results: For a 0 mm source pullback distance, the updated bare-source model and source-in-applicator RDF values differ by 2% at 3 cm and 4% at 5 cm. The largest PAF disagreements were observed at the distal end of the source and applicator with up to 17% disagreement at 2 cm and 8% at 8 cm. The bare-source model had RDF values within 2.6% of the published TG-43 data and PAF results within 7.2% at 2 cm. Conclusion: Results indicate that notable differences exist between the bare-source and source-in-applicator TG-43 simulated parameters. Xoft Inc. provided partial funding for this work.« less

Comparisons between gouge and bare surface friction of serpentinite at seismic slip velocities: Implications for dynamic weakening of gouge-bearing faults

NASA Astrophysics Data System (ADS)

Proctor, B.; Mitchell, T. M.; Hirth, G.; Goldsby, D. L.; Di Toro, G.; Zorzi, F.

2013-12-01

High-velocity friction (HVF) experiments on bare rock surfaces have revealed various dynamic weakening processes (e.g., flash weakening, gel weakening, melt lubrication) that likely play a fundamental role in coseismic fault weakening. However, faults generally contain a thin layer of gouge separating the solid wallrocks, thus it is important to understand how the presence of gouge modifies the efficiency of these weakening processes at seismic slip rates. We explored the frictional behavior of bare surfaces and powdered samples of an antigorite-rich serpentinite (ARS) and a lizardite-rich serpentinite (LRS) at earthquake slip rates. HVF experiments were conducted with slip displacements ranging from ~0.5 to 2m, at velocities ranging from 0.002m/s to 6.5 m/s, and with normal stresses ranging from 2-22 MPa for gouge and 5-100MPa for bare surfaces. Our results demonstrate that the friction coefficient (μ) of powdered serpentine is significantly larger than that of bare surfaces under otherwise identical conditions. Bare surface friction decreases over a weakening distance of a few centimeters to a nominally steady-state value of ~0.1 at velocities greater than 0.1m/s. The nominal steady-state friction decreases non-linearly with increasing normal stress from 0.14 to 0.045 at 5 and ~100MPa respectfully at a slip velocity of 1m/s. Additionally, the recovery of frictional strength during deceleration depends on total displacement; samples slipped for ~50mm recover faster than samples slipped for ~0.5m. Microstructural analysis of bare surfaces deformed at the highest normal stresses revealed translucent glass-like material on the slip surfaces and XRD analysis of wear material revealed an increasing presence of olivine and enstatite with increasing normal stress. In contrast, gouge requires an order of magnitude higher velocity than bare surfaces to induce frictional weakening, has a larger weakening distance and higher steady state friction values for equivalent deformation conditions. Furthermore, we observe a strong normal stress dependence of the nominal steady state friction and the weakening distance of ARS and LRS gouge from 0.51 to 0.39 and from 25-10cm at 4MPa and 22MPa, respectfully, for at a slip velocity of 1m/s. Strain was localized onto a shear surface in the range of 100-300 microns wide in all gouge samples deformed at >10cm/s and XRD analyses revealed the presence of olivine and enstatite in samples with the most weakening and none in samples with no weakening. Our results indicate that dynamic weakening occurs in gouge at low normal stress in response to strain localization and shear heating of the slip surface. However, because more initial displacement is required to localize strain, weakening initiates at higher velocities and after larger weakening distances than bare surfaces. At higher normal stress, localization occurs after less displacement and the differences between gouge and bare-surface friction diminish; extrapolation of our data suggests that the behavior of serpentine gouge will approach that of bare surfaces at normal stresses ≥60 MPa.

5. American elevator looking east barely visible behind American malt ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. American elevator looking east barely visible behind American malt house with Russell-Miller flour mill to right (now Eonacara and idle). - American Elevator, 87 Childs Street, Buffalo, Erie County, NY

Recent Advances in Laser-Ablative Synthesis of Bare Au and Si Nanoparticles and Assessment of Their Prospects for Tissue Engineering Applications.

PubMed

Al-Kattan, Ahmed; Nirwan, Viraj P; Popov, Anton; Ryabchikov, Yury V; Tselikov, Gleb; Sentis, Marc; Fahmi, Amir; Kabashin, Andrei V

2018-05-24

Driven by surface cleanness and unique physical, optical and chemical properties, bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising materials for the development of advanced biomedical platforms related to biosensing, bioimaging and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for tissue engineering applications. This review is aimed at the description of our recent progress in laser synthesis of bare Si and Au NPs and their testing as functional modules (additives) in innovative scaffold platforms intended for tissue engineering tasks.

Algorithms used in the Airborne Lidar Processing System (ALPS)

USGS Publications Warehouse

Nagle, David B.; Wright, C. Wayne

2016-05-23

The Airborne Lidar Processing System (ALPS) analyzes Experimental Advanced Airborne Research Lidar (EAARL) data—digitized laser-return waveforms, position, and attitude data—to derive point clouds of target surfaces. A full-waveform airborne lidar system, the EAARL seamlessly and simultaneously collects mixed environment data, including submerged, sub-aerial bare earth, and vegetation-covered topographies.ALPS uses three waveform target-detection algorithms to determine target positions within a given waveform: centroid analysis, leading edge detection, and bottom detection using water-column backscatter modeling. The centroid analysis algorithm detects opaque hard surfaces. The leading edge algorithm detects topography beneath vegetation and shallow, submerged topography. The bottom detection algorithm uses water-column backscatter modeling for deeper submerged topography in turbid water.The report describes slant range calculations and explains how ALPS uses laser range and orientation measurements to project measurement points into the Universal Transverse Mercator coordinate system. Parameters used for coordinate transformations in ALPS are described, as are Interactive Data Language-based methods for gridding EAARL point cloud data to derive digital elevation models. Noise reduction in point clouds through use of a random consensus filter is explained, and detailed pseudocode, mathematical equations, and Yorick source code accompany the report.

Mine tailings composition in a historic site: implications for ecological restoration.

PubMed

Courtney, R

2013-02-01

Ecological restoration, using tolerant plant species and nutrient additions, is a low-cost option to decrease environmental risks associated with mine tailings. An attempt was previously made to establish such a vegetation cover on an abandoned tailings facility in Southern Ireland. Historically, the tailings site has been prone to dusting and is a potential source of contamination to the surrounding environment. The site was examined to determine the success of the previous restoration plan used to revegetate the site and to determine its suitability for further restoration. Three distinct floristic areas were identified (grassland, poor grassland and bare area) based on herbage compositions and elemental analysis. Surface and subsurface samples were taken to characterise tailings from within these areas of the tailings site. The pH of bare surface tailings (pH, 2.7) was significantly more acidic (p < 0.5) than in other areas. Additionally, negligible net neutralising potential resulted in the tailings being hostile to plant growth. Total metal concentrations in tailings were high (c. 10,000 mg kg(-1) for Pb and up to 20,000 mg kg(-1) for Zn). DTPA-extractable Zn and Pb were 16 and 11 % of the total amount, respectively. Metal content in grasses growing on some areas of the tailings were elevated and demonstrated the inability of the tailings to support sustainable plant growth. Due to the inherently hostile characteristics of these areas, future restoration work will employ capping with a barrier layer.

Sub-Chandrasekhar-mass White Dwarf Detonations Revisited

NASA Astrophysics Data System (ADS)

Shen, Ken J.; Kasen, Daniel; Miles, Broxton J.; Townsley, Dean M.

2018-02-01

The detonation of a sub-Chandrasekhar-mass white dwarf (WD) has emerged as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. Recent studies have suggested that the rapid transfer of a very small amount of helium from one WD to another is sufficient to ignite a helium shell detonation that subsequently triggers a carbon core detonation, yielding a “dynamically driven double-degenerate double-detonation” SN Ia. Because the helium shell that surrounds the core explosion is so minimal, this scenario approaches the limiting case of a bare C/O WD detonation. Motivated by discrepancies in previous literature and by a recent need for detailed nucleosynthetic data, we revisit simulations of naked C/O WD detonations in this paper. We disagree to some extent with the nucleosynthetic results of previous work on sub-Chandrasekhar-mass bare C/O WD detonations; for example, we find that a median-brightness SN Ia is produced by the detonation of a 1.0 {M}ȯ WD instead of a more massive and rarer 1.1 {M}ȯ WD. The neutron-rich nucleosynthesis in our simulations agrees broadly with some observational constraints, although tensions remain with others. There are also discrepancies related to the velocities of the outer ejecta and light curve shapes, but overall our synthetic light curves and spectra are roughly consistent with observations. We are hopeful that future multidimensional simulations will resolve these issues and further bolster the dynamically driven double-degenerate double-detonation scenario’s potential to explain most SNe Ia.

Influence of catchment-scale military land use on stream physical and organic matter variables in small Southeaster Plains Catchments (USA)

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

Maloney, Kelly

2005-01-01

We conducted a 3-year study designed to examine the relationship between disturbance from military land use and stream physical and organic matter variables within 12 small (<5.5 km2) Southeastern Plains catchments at the Fort Benning Military Installation, Georgia, USA. Primary land-use categories were based on percentages of bare ground and road cover and nonforested land (grasslands, sparse vegetation, shrublands, fields) in catchments and natural catchments features, including soils (% sandy soils) and catchment size (area). We quantified stream flashiness (determined by slope of recession limbs of storm hydrographs), streambed instability (measured by relative changes in bed height over time), organicmore » matter storage [coarse wood debris (CWD) relative abundance, benthic particulate organic matter (BPOM)] and stream-water dissolved organic carbon concentration (DOC). Stream flashiness was positively correlated with average storm magnitude and percent of the catchment with sandy soil, whereas streambed instability was related to percent of the catchment containing nonforested (disturbed) land. The proportions of in-stream CWD and sediment BPOM, and stream-water DOC were negatively related to the percent of bare ground and road cover in catchments. Collectively, our results suggest that the amount of catchment disturbance causing denuded vegetation and exposed, mobile soil is (1) a key terrestrial influence on stream geomorphology and hydrology and (2) a greater determinant of in-stream organic matter conditions than is natural geomorphic or topographic variation (catchment size, soil type) in these systems.« less

Enhanced production of bioethanol from waste of beer fermentation broth at high temperature through consecutive batch strategy by simultaneous saccharification and fermentation.

PubMed

Khattak, Waleed Ahmad; Khan, Taous; Ha, Jung Hwan; Ul-Islam, Mazhar; Kang, Min-Kyung; Park, Joong Kon

2013-10-10

Malt hydrolyzing enzymes and yeast glycolytic and fermentation enzymes in the waste from beer fermentation broth (WBFB) were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A new 'one-pot consecutive batch strategy' was developed for efficient bio-ethanol production by simultaneous saccharification and fermentation (SSF) using WBFB without additional enzymes, microbial cells, or carbohydrates. Bio-ethanol production was conducted in batches using WBFB supernatant in the first phase at 25-67°C and 50rpm, followed by the addition of 3% WBFB solid residue to the existing culture broth in the second phase at 67°C. The ethanol production increased from 50 to 102.5g/L when bare supernatant was used in the first phase, and then to 219g ethanol/L in the second phase. The amount of ethanol obtained using this strategy was almost equal to that obtained using the original WBFB containing 25% solid residue at 33°C, and more than double that obtained when bare supernatant was used. Microscopic and gel electrophoresis studies revealed yeast cell wall degradation and secretion of cellular material into the surrounding medium. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) supported the existence of enzymes in WBFB involved in bioethanol production at elevated temperatures. The results of this study will provide insight for the development of new strategies for biofuel production. Copyright © 2013 Elsevier Inc. All rights reserved.

Polyethyleneimine assisted-two-step polymerization to develop surface imprinted cryogels for lysozyme purification.

PubMed

Erol, Kadir; Köse, Kazım; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

2016-10-01

Surface imprinting strategy is one of the promising approaches to synthesize plastic antibodies while overcoming the problems in the protein imprinting research. In this study, we focused our attentions on developing two-step polymerization to imprint on the bare surface employing polyethyleneimine (PEI) assisted-coordination of template molecules, lysozyme. For this aim, we firstly synthesized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA) cryogels as a bare structure. Then, we immobilized PEI onto the cryogels through the addition reaction between GMA and PEI molecules. After that, we determined the amount of free amine (NH2) groups of PEI molecules, subsequently immobilized methacrylate functionalities onto the half of them and another half was used to chelate Cu(II) ions as a mediator between template, lysozyme and PEI groups. After the characterization of the materials developed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and the micro-computed tomography (μCT), we optimized the lysozyme adsorption conditions from aqueous solution. Before performing lysozyme purification from chicken egg white, we evaluated the effects of pH, interaction time, the initial lysozyme concentration, temperature and ionic strength on the lysozyme adsorption. Moreover, the selectivity of surface imprinted cryogels was examined against cytochrome c and bovine serum albumin (BSA) as the competitors. Finally, the mathematical modeling, which was applied to describe the adsorption process, showed that the experimental data is very well-fitted to the Langmuir adsorption isotherm. Copyright © 2016 Elsevier B.V. All rights reserved.

Nest site preferences of the Woodlark (Lullula arborea) and its association with artificial nest predation

NASA Astrophysics Data System (ADS)

Buehler, Roman; Bosco, Laura; Arlettaz, Raphaël; Jacot, Alain

2017-01-01

The Woodlark is an insectivorous bird, which is listed as a priority species in Switzerland. In Valais, a stronghold of this species in the country, the birds breed in intensively managed vineyards and show a preference for parcels with ground vegetation during territory establishment. As a ground-breeder, the species is highly vulnerable to nest predation by avian and mammal predators. The aims of our study were firstly to investigate nest site preferences of the woodlark within vineyards and secondly to compare the predation risk of artificial nests dependent of ground vegetation structure. Our results point out that the Woodlark prefers patches of tall and dense ground cover within vegetated vineyard parcels and avoids parcels that have been treated with herbicides. In a follow-up experiment we conducted a study comparing the predation rate of artificial nests between bare parcels (<20% vegetated area) and vegetated parcels (>40% vegetated area). Artificial nests equipped with one quail egg were distributed pairwise between two adjacent parcels that fulfilled the upper criteria and were monitored by trail cameras during 10-12 days. Predation rate was generally low (4 predation events) and only occurred in bare parcels. These data indicate that conspicuousness of avian nests may be decreased in vegetated parcels and that the amount of vegetation can lower the predation risk on ground breeding birds - another indication for the importance of ground vegetation for a successful conservation of the endangered Woodlark in Swiss vineyards.

SUMMARY OF PROGRESS ON THE STUDY OF BETA TREATMENT OF URANIUM, SEPTEMBER 1 TO NOVEMBER 30, 1960

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

Russell, R.B.

Studies were made of the variables affecting the growth index (G/sub 3/) and grain size of beta-treated uranium. The effect of time and temperature in the beta phase on G/sub 3/ was somewhat clarified. The range of beta treatment conditions was a heating of 2 to 64 min in molten salt at 690 to 760 l C and oil quenching. Both bare and sealed discs were studied. It was found that G/sub 3/ is affected by time only by small increments toward G/sub 3/ = 0 for 2 to 5 min; after this time G/sub 3/ is not expected tomore » increase significantly. The G/sub 3/ values in discs protected from molten salt increase during this period by the same amount as bare discs. An investigation of thermal data for 1 7/8-in.-dia rod and for 3-in. OD bY 2 1/2-in. ID tube showed that there is little difference in cooling rate between a warm (55 l C) oil quench and a roomtemperature oil quench, whereas the cooling rate in warm (55 l C) water is definitely less than in cold (13 l C) water. Grain size and G/sub 3/ data are presented for a 1 7/8-in.-dia cold(12 l C) water-quenched rod and a 1 7/32-in.-dia 23 l C oilquenched rod. (P.C.H.)« less

Graphene nanoplatelets induced tailoring in photocatalytic activity and antibacterial characteristics of MgO/graphene nanoplatelets nanocomposites

NASA Astrophysics Data System (ADS)

Arshad, Aqsa; Iqbal, Javed; Siddiq, M.; Mansoor, Qaisar; Ismail, M.; Mehmood, Faisal; Ajmal, M.; Abid, Zubia

2017-01-01

The synthesis, physical, photocatalytic, and antibacterial properties of MgO and graphene nanoplatelets (GNPs) nanocomposites are reported. The crystallinity, phase, morphology, chemical bonding, and vibrational modes of prepared nanomaterials are studied. The conductive nature of GNPs is tailored via photocatalysis and enhanced antibacterial activity. It is interestingly observed that the MgO/GNPs nanocomposites with optimized GNPs content show a significant photocatalytic activity (97.23% degradation) as compared to bare MgO (43%) which makes it the potential photocatalyst for purification of industrial waste water. In addition, the effect of increased amount of GNPs on antibacterial performance of nanocomposites against pathogenic micro-organisms is researched, suggesting them toxic. MgO/GNPs 25% nanocomposite may have potential applications in waste water treatment and nanomedicine due its multifunctionality.

Fabrication of Amine-Modified Magnetite-Electrochemically Reduced Graphene Oxide Nanocomposite Modified Glassy Carbon Electrode for Sensitive Dopamine Determination

PubMed Central

He, Quanguo; Liu, Jun; Liu, Xiaopeng; Li, Guangli; Chen, Dongchu; Deng, Peihong; Liang, Jing

2018-01-01

Amine-modified magnetite (NH2–Fe3O4)/reduced graphene oxide nanocomposite modified glassy carbon electrodes (NH2–Fe3O4/RGO/GCEs) were developed for the sensitive detection of dopamine (DA). The NH2-Fe3O4/RGO/GCEs were fabricated using a drop-casting method followed by an electrochemical reduction process. The surface morphologies, microstructure and chemical compositions of the NH2–Fe3O4 nanoparticles (NPs), reduced graphene oxide (RGO) sheets and NH2–Fe3O4/RGO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The electrochemical behaviors of DA on the bare and modified GCEs were investigated in phosphate buffer solution (PBS) by cyclic voltammetry (CV). Compared with bare electrode and RGO/GCE, the oxidation peak current (ipa) on the NH2–Fe3O4/RGO/GCE increase significantly, owing to the synergistic effect between NH2–Fe3O4 NPs and RGO sheets. The oxidation peak currents (ipa) increase linearly with the concentrations of DA in the range of 1 × 10−8 mol/L – 1 × 10−7 mol/L, 1 × 10−7 mol/L – 1 × 10−6 mol/L and 1 × 10−6 mol/L – 1 × 10−5 mol/L. The detection limit is (4.0 ± 0.36) ×10−9 mol/L (S/N = 3). Moreover, the response peak currents of DA were hardly interfered with the coexistence of ascorbic acid (AA) and uric acid (UA). The proposed NH2–Fe3O4/RGO/GCE is successfully applied to the detection of dopamine hydrochloride injections with satisfactory results. Together with low cost, facile operation, good selectivity and high sensitivity, the NH2–Fe3O4/RGO/GCEs have tremendous prospects for the detection of DA in various real samples. PMID:29584682

Considerations for Achieving Cross-Platform Point Cloud Data Fusion across Different Dryland Ecosystem Structural States

PubMed Central

Swetnam, Tyson L.; Gillan, Jeffrey K.; Sankey, Temuulen T.; McClaran, Mitchel P.; Nichols, Mary H.; Heilman, Philip; McVay, Jason

2018-01-01

Remotely sensing recent growth, herbivory, or disturbance of herbaceous and woody vegetation in dryland ecosystems requires high spatial resolution and multi-temporal depth. Three dimensional (3D) remote sensing technologies like lidar, and techniques like structure from motion (SfM) photogrammetry, each have strengths and weaknesses at detecting vegetation volume and extent, given the instrument's ground sample distance and ease of acquisition. Yet, a combination of platforms and techniques might provide solutions that overcome the weakness of a single platform. To explore the potential for combining platforms, we compared detection bias amongst two 3D remote sensing techniques (lidar and SfM) using three different platforms [ground-based, small unmanned aerial systems (sUAS), and manned aircraft]. We found aerial lidar to be more accurate for characterizing the bare earth (ground) in dense herbaceous vegetation than either terrestrial lidar or aerial SfM photogrammetry. Conversely, the manned aerial lidar did not detect grass and fine woody vegetation while the terrestrial lidar and high resolution near-distance (ground and sUAS) SfM photogrammetry detected these and were accurate. UAS SfM photogrammetry at lower spatial resolution under-estimated maximum heights in grass and shrubs. UAS and handheld SfM photogrammetry in near-distance high resolution collections had similar accuracy to terrestrial lidar for vegetation, but difficulty at measuring bare earth elevation beneath dense herbaceous cover. Combining point cloud data and derivatives (i.e., meshes and rasters) from two or more platforms allowed for more accurate measurement of herbaceous and woody vegetation (height and canopy cover) than any single technique alone. Availability and costs of manned aircraft lidar collection preclude high frequency repeatability but this is less limiting for terrestrial lidar, sUAS and handheld SfM. The post-processing of SfM photogrammetry data became the limiting factor at larger spatial scale and temporal repetition. Despite the utility of sUAS and handheld SfM for monitoring vegetation phenology and structure, their spatial extents are small relative to manned aircraft. PMID:29379511

Considerations for Achieving Cross-Platform Point Cloud Data Fusion across Different Dryland Ecosystem Structural States.

PubMed

Swetnam, Tyson L; Gillan, Jeffrey K; Sankey, Temuulen T; McClaran, Mitchel P; Nichols, Mary H; Heilman, Philip; McVay, Jason

2017-01-01

Remotely sensing recent growth, herbivory, or disturbance of herbaceous and woody vegetation in dryland ecosystems requires high spatial resolution and multi-temporal depth. Three dimensional (3D) remote sensing technologies like lidar, and techniques like structure from motion (SfM) photogrammetry, each have strengths and weaknesses at detecting vegetation volume and extent, given the instrument's ground sample distance and ease of acquisition. Yet, a combination of platforms and techniques might provide solutions that overcome the weakness of a single platform. To explore the potential for combining platforms, we compared detection bias amongst two 3D remote sensing techniques (lidar and SfM) using three different platforms [ground-based, small unmanned aerial systems (sUAS), and manned aircraft]. We found aerial lidar to be more accurate for characterizing the bare earth (ground) in dense herbaceous vegetation than either terrestrial lidar or aerial SfM photogrammetry. Conversely, the manned aerial lidar did not detect grass and fine woody vegetation while the terrestrial lidar and high resolution near-distance (ground and sUAS) SfM photogrammetry detected these and were accurate. UAS SfM photogrammetry at lower spatial resolution under-estimated maximum heights in grass and shrubs. UAS and handheld SfM photogrammetry in near-distance high resolution collections had similar accuracy to terrestrial lidar for vegetation, but difficulty at measuring bare earth elevation beneath dense herbaceous cover. Combining point cloud data and derivatives (i.e., meshes and rasters) from two or more platforms allowed for more accurate measurement of herbaceous and woody vegetation (height and canopy cover) than any single technique alone. Availability and costs of manned aircraft lidar collection preclude high frequency repeatability but this is less limiting for terrestrial lidar, sUAS and handheld SfM. The post-processing of SfM photogrammetry data became the limiting factor at larger spatial scale and temporal repetition. Despite the utility of sUAS and handheld SfM for monitoring vegetation phenology and structure, their spatial extents are small relative to manned aircraft.

Very-to-barely remote sensing of prehistoric features under tephra in Central America

NASA Technical Reports Server (NTRS)

Sheets, Payson D.

1991-01-01

A wide variety of remote sensing instruments have been utilized to attempt to detect archaeological features under volcanic ash in Central America. Some techniques have not been successful, such as seismic refraction, for reasons that are not difficult to understand. Others have been very successful and provide optimism for archaeologists witnessing the destruction of unburied sites throughout Central America. The sudden burial of buildings, gardens, and footpaths by volcanic ash can preserve them extremely well providing a rich data base for understanding human life and culture at certain points in time.

Watching Galaxy Evolution in High Definition

NASA Technical Reports Server (NTRS)

Rigby, Jane

2011-01-01

As Einstein predicted, mass deflects light. In hundreds of known cases, "gravitational lenses" have deflected, distorted, and amplified images of galaxies or quasars behind them. As such, gravitational lensing is a way to "cheat" at studying how galaxies evolve, because lensing can magnify galaxies by factors of 10--100 times, transforming them from objects we can barely detect to bright objects we can study in detail. I'll summarize new results from a comprehensive program, using multi-wavelength, high-quality spectroscopy, to study how galaxies formed stars at redshifts of 1--3, the epoch when most of the Universe's stars were formed.

Watching Galaxy Evolution in High Definition

NASA Technical Reports Server (NTRS)

Rigby, Jane R.

2012-01-01

As Einstein predicted, mass deflects light. In hundreds of known cases, "gravitational lenses" have deflected, distorted, and amplified images of galaxies or quasars behind them. As such, gravitational lensing is a way to "cheat" at studying how galaxies evolve, because lensing can magnify galaxies by factors of 10-100 times, transforming them from objects we can barely detect to bright objects we can study in detail. I'll summarize new results from a comprehensive program, using multi-wavelength, high-quality spectroscopy, to study how galaxies formed stars at redshifts of 1-3, the epoch when most of the Universe's stars were formed.

Strain distribution in thin concrete pavement panels under three-point loading to failure with pre-pulse-pump Brillouin optical time domain analysis (Presentation Video)

NASA Astrophysics Data System (ADS)

Bao, Yi; Cain, John; Chen, Yizheng; Huang, Ying; Chen, Genda; Palek, Leonard

2015-04-01

Thin concrete panels reinforced with alloy polymer macro-synthetic fibers have recently been introduced to rapidly and cost-effectively improve the driving condition of existing roadways by laying down a fabric sheet on the roadways, casting a thin layer of concrete, and then cutting the layer into panels. This study is aimed to understand the strain distribution and potential crack development of concrete panels under three-point loading. To this end, six full-size 6ft×6ft×3in concrete panels were tested to failure in the laboratory. They were instrumented with three types of single-mode optical fiber sensors whose performance and ability to measure the strain distribution and detect cracks were compared. Each optical fiber sensor was spliced and calibrated, and then attached to a fabric sheet using adhesive. A thin layer of mortar (0.25 ~ 0.5 in thick) was cast on the fabric sheet. The three types of distributed sensors were bare SM-28e+ fiber, SM-28e+ fiber with a tight buffer, and concrete crack cable, respectively. The concrete crack cable consisted of one SM-28e+ optical fiber with a tight buffer, one SM-28e+ optical fiber with a loose buffer for temperature compensation, and an outside protective tight sheath. Distributed strains were collected from the three optical fiber sensors with pre-pulse-pump Brillouin optical time domain analysis in room temperature. Among the three sensors, the bare fiber was observed to be most fragile during construction and operation, but most sensitive to strain change or micro-cracks. The concrete crack cable was most rugged, but not as sensitive to micro-cracks and robust in micro-crack measurement as the bare fiber. The ruggedness and sensitivity of the fiber with a tight buffer were in between the bare fiber and the concrete crack cable. The strain distribution resulted from the three optical sensors are in good agreement, and can be applied to successfully locate cracks in the concrete panels. It was observed that the three types of fibers were functional until the concrete panels have experienced inelastic deformation, making the distributed strain sensing technology promising for real applications in pavement engineering.

Outcomes with various drug eluting or bare metal stents in patients with diabetes mellitus: mixed treatment comparison analysis of 22 844 patient years of follow-up from randomised trials

PubMed Central

Kumar, Sunil; Fusaro, Mario; Amoroso, Nicholas; Kirtane, Ajay J; Byrne, Robert A; Williams, David O; Slater, James; Cutlip, Donald E; Feit, Frederick

2012-01-01

Objectives To evaluate the efficacy and safety of currently used drug eluting stents compared with each other and compared with bare metal stents in patients with diabetes. Design Mixed treatment comparison meta-analysis. Data sources and study selection PubMed, Embase, and CENTRAL were searched for randomised clinical trials, until April 2012, of four durable polymer drug eluting stents (sirolimus eluting stents, paclitaxel eluting stents, everolimus eluting stents, and zotarolimus eluting stents) compared with each other or with bare metal stents for the treatment of de novo coronary lesions and enrolling at least 50 patients with diabetes. Primary outcomes Efficacy (target vessel revascularisation) and safety (death, myocardial infarction, stent thrombosis). Results From 42 trials with 22 844 patient years of follow-up, when compared with bare metal stents (reference rate ratio 1) all of the currently used drug eluting stents were associated with a significant reduction in target vessel revascularisation (37% to 69%), though the efficacy varied with the type of stent (everolimus eluting stents∼sirolimus eluting stents>paclitaxel eluting stents∼zotarolimus eluting stent>bare metal stents). There was about an 87% probability that everolimus eluting stents were the most efficacious compared with all others, though there were limited usable data for the zotarolimus eluting Resolute stent in patients with diabetes. Moreover, there was no increased risk of any safety outcome (including very late stent thrombosis) with any drug eluting stents compared with bare metal stents. There was about a 62% probability that the everolimus eluting stent was the safest stent for the outcome of “any” stent thrombosis. Conclusions Among patients with diabetes treated with coronary stents all currently available drug eluting stents were efficacious without compromising safety compared with bare metal stents. There were relative differences among the drug eluting stents, such that the everolimus eluting stent was the most efficacious and safe. PMID:22885395

GREAT-a randomized controlled trial comparing HydroSoft/HydroFrame and bare platinum coils for endovascular aneurysm treatment: procedural safety and core-lab-assessedangiographic results.

PubMed

Taschner, Christian A; Chapot, René; Costalat, Vincent; Machi, Paolo; Courthéoux, Patrick; Barreau, Xavier; Berge, Jérôme; Pierot, Laurent; Kadziolka, Kryzsztof; Jean, Betty; Blanc, Raphaël; Biondi, Alessandra; Brunel, Hervé; Gallas, Sophie; Berlis, Ansgar; Herbreteau, Denis; Berkefeld, Joachim; Urbach, Horst; El Shikh, Samer; Fiehler, Jens; Desal, Hubert; Graf, Erika; Bonafé, Alain

2016-08-01

Hybrid hydrogel-platinum coils (HydroCoil) have proven effective for endovascular aneurysm treatment. To overcome technical limitations (coil stiffness, time restriction for placement), a second generation of softer hydrogel coils has been brought to clinical practice (HydroSoft, HydroFrame). We report on procedural safety and core-lab-assessed angiographic results from an open-label multicenter randomized controlled trial. Web-based randomization occurred in 15 medical centers in France and seven in Germany between coil embolization with second-generation hydrogel coils and treatment with any bare platinum coil. Assist devices could be used as clinically required. Primary endpoint is a composite outcome including major aneurysm recurrence and poor clinical outcome at 18 months follow-up. Five hundred thirteen patients were randomized (hydrogel n = 256, bare platinum n = 257). Twenty patients were excluded for missing informed consent and nine patients for treatment related criteria. Four hundred eighty-four patients were analyzed as randomized (hydrogel n = 243, bare platinum n = 241). Two hundred eight had ruptured aneurysms (43 %). Prespecified procedural complications occurred in 58 subjects (hydrogel n = 28, bare platinum n = 30, p = 0.77). The 14-day mortality rate was 2.1 % in both arms of the study. The median calculated packing densities for aneurysms assigned to hydrogel and bare platinum were 39 and 31 % respectively (p < 0.001). No statistically significant differences were found between arms in the post procedural angiographic occlusion rate (p = 0.8). Second-generation hydrogel coils can be used in a wide spectrum of aneurysms with a risk profile equivalent to bare platinum. Packing density was significantly higher in aneurysms treated with hydrogel coils. http://www.germanctr.de , DRKS00003132.

Effects of rainfall patterns and land cover on the subsurface flow generation of sloping Ferralsols in southern China

PubMed Central

Yang, Jie; Tang, Chongjun; Chen, Lihua; Liu, Yaojun; Wang, Lingyun

2017-01-01

Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land) in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface flows associated with bare land. PMID:28792507

Richard E. Smalley, Buckminsterfullerene (the Buckyball), and Nanotubes

Science.gov Websites

: 723-730; July 1997 Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984  – April 1, 1985 Includes early cold ion beam technology research Supersonic Bare Metal Cluster Beams

Radiometric measurements over bare and vegetated fields at 1.4 GHz and 5 GHz frequencies. [Beltsville Agricultural Research Center, Maryland

NASA Technical Reports Server (NTRS)

Wang, J. R.; Mcmurtrey, J. E., III; Engman, E. T.; Jackson, T. J.; Schmugge, T. J.; Gould, W. I.; Glazar, W. S.; Fuchs, J. E. (Principal Investigator)

1981-01-01

Microwave emission from bare and vegetated fields was measured with dual polarized radiometers at 1.4 GHz and 5 GHz frequencies. The measured brightness temperatures over bare fields are shown to compare favorably with those calculated from radiative transfer theory with two constant parameters characterizing surface roughness effect. The presence of vegetation cover is found to reduce the sensitivity to soil moisture variation. This sensitivity reduction is generally pronounced the denser, the vegetation cover and the higher the frequency of observation. The effect of vegetation cover is also examined with respect to the measured polarization factor at both frequencies. With the exception of dry corn fields, the measured polarization factor over vegetated fields is found appreciably reduced compared to that over bare fields. A much larger reduction in this factor is found at 5GHz than at 1.4GHz frequency.

The structures of bare and deuterated Co{sub 19}

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

Parks, E.K.; Riley, S.J.

1997-07-01

The structures of bare Co{sub 19} and deuterated Co{sub 19}D{sub m} clusters are examined by the chemical probe method, and earlier assignments of bare Co{sub 19} as an fcc octahedron are reconsidered. New experimental measurements of the reactivity of Co{sub 19} with ammonia, nitrogen, and deuterium are presented, and together with earlier measurements of the reactivity with water suggest that bare Co{sub 19} has an hcp structure (D{sub 3h} symmetry). The adsorption of deuterium on Co{sub 19} is found to proceed in steps, leading to successive saturation levels at Co{sub 19}D{sub 4}, Co{sub 19}D{sub 14}, and Co{sub 19}D{sub 18}. Usingmore » binding rules derived from earlier studies of larger cobalt and nickel clusters, possible D-atom binding sites on Co{sub 19}D{sub m} (both fcc and hcp) are proposed.« less

Detection of early stage large scale landslides in forested areas by 2 m LiDAR DEM analysis. The example of Portainé (Central Pyrenees)

NASA Astrophysics Data System (ADS)

Guinau, Marta; Ortuño, Maria; Calvet, Jaume; Furdada, Glòria; Bordonau, Jaume; Ruiz, Antonio; Camafort, Miquel

2016-04-01

Mass movements have been classically detected by field inspection and air-photo interpretation. However, airborne LiDAR has significant potential for generating high-resolution digital terrain models, which provide considerable advantages over conventional surveying techniques. In this work, we present the identification and characterization of six slope failures previously undetected in the Orri massif, at the core of the Pyrenean range. The landforms had not been previously detected and were identified by the analysis of high resolution 2 m LiDAR derived bared earth topography. Most of the scarps within these failures are not detectable by photo interpretation or the analysis of 5 m resolution topographic maps owing to their small heights (ranging between 0.5 and 2 m) and their location within forest areas. 2D and 3D visualization of hillshade maps with different sun azimuths, allowed to obtain the overall picture of the scarp assemblage and to analyze the geometry and location of the scarps with respect to the slope and the structural fabric. Near 120 scarps were mapped and interpreted as part of slow gravitational deformation, incipient slow flow affecting a colluvium, rotational rock-sliding and slope creep. Landforms interpreted as incipient slow flow affecting a colluvium have headscarps with horse-shoe shape and superficial (< 20 m) basal planes whereas sackung features have open headscarps and basal planes that are likely located at 200-250 m maximum depth. Other distinctive features are toppling or extensive scarps, double ridges and rock rotational landslides. The sharpness of the scarps suggests their recent activity, which may pose a potential risk for the Port-Ainé sky resort users and facilities. These results suggest that the systematic analysis of 2 m LIDAR derived bared earth topography would significantly help in the rapid detection and mapping of early stage slope deformations in high mountain areas, which could contribute to 1) a better understanding of the spatial controlling factors and 2) obtaining rapid diagnosis of the state of the slopes, critical for the proper forecast of future catastrophic failures. This presentation is supported by the Spanish Ministry of Science and Innovation project CHARMA: CHAracterization and ContRol of MAss Movements. A Challenge for Geohazard Mitigation (CGL2013-40828-R).

PVT-NG sensor final report.

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

Mitchell, Dean James; Brusseau, Charles A.

2012-01-01

This document is a final report for the polyvinyl toluene (PVT) neutron-gamma (PVT-NG) project, which was sponsored by the Domestic Nuclear Detection Office (DNDO). The PVT-NG sensor uses PVT detectors for both gamma and neutron detection. The sensor exhibits excellent spectral resolution and gain stabilization, which are features that are beneficial for detection of both gamma-ray and neutron sources. In fact, the ability to perform isotope identification based on spectra that were measured by the PVT-NG sensor was demonstrated. As described in a previous report, the neutron sensitivity of the first version of the prototype was about 25% less thanmore » the DNDO requirement of 2.5 cps/ng for bare Cf-252. This document describes design modifications that were expected to improve the neutron sensitivity by about 50% relative to the PVT-NG prototype. However, the project was terminated before execution of the design modifications after portal vendors demonstrated other technologies that enable neutron detection without the use of He-3. Nevertheless, the PVT-NG sensor development demonstrated several performance goals that may be useful in future portal designs.« less

Detecting Damage in Composite Material Using Nonlinear Elastic Wave Spectroscopy Methods

NASA Astrophysics Data System (ADS)

Meo, Michele; Polimeno, Umberto; Zumpano, Giuseppe

2008-05-01

Modern aerospace structures make increasing use of fibre reinforced plastic composites, due to their high specific mechanical properties. However, due to their brittleness, low velocity impact can cause delaminations beneath the surface, while the surface may appear to be undamaged upon visual inspection. Such damage is called barely visible impact damage (BVID). Such internal damages lead to significant reduction in local strengths and ultimately could lead to catastrophic failures. It is therefore important to detect and monitor damages in high loaded composite components to receive an early warning for a well timed maintenance of the aircraft. Non-linear ultrasonic spectroscopy methods are promising damage detection and material characterization tools. In this paper, two different non-linear elastic wave spectroscopy (NEWS) methods are presented: single mode nonlinear resonance ultrasound (NRUS) and nonlinear wave modulation technique (NWMS). The NEWS methods were applied to detect delamination damage due to low velocity impact (<12 J) on various composite plates. The results showed that the proposed methodology appear to be highly sensitive to the presence of damage with very promising future NDT and structural health monitoring applications.

Selective attention and the auditory vertex potential. I - Effects of stimulus delivery rate. II - Effects of signal intensity and masking noise

NASA Technical Reports Server (NTRS)

Schwent, V. L.; Hillyard, S. A.; Galambos, R.

1976-01-01

The effects of varying the rate of delivery of dichotic tone pip stimuli on selective attention measured by evoked-potential amplitudes and signal detectability scores were studied. The subjects attended to one channel (ear) of tones, ignored the other, and pressed a button whenever occasional targets - tones of a slightly higher pitch were detected in the attended ear. Under separate conditions, randomized interstimulus intervals were short, medium, and long. Another study compared the effects of attention on the N1 component of the auditory evoked potential for tone pips presented alone and when white noise was added to make the tones barely above detectability threshold in a three-channel listening task. Major conclusions are that (1) N1 is enlarged to stimuli in an attended channel only in the short interstimulus interval condition (averaging 350 msec), (2) N1 and P3 are related to different modes of selective attention, and (3) attention selectivity in multichannel listening task is greater when tones are faint and/or difficult to detect.

Rapid Surface Enhanced Raman Scattering (SERS) Detection of Sibutramine Hydrochloride in Pharmaceutical Capsules with a β-Cyclodextrin- Ag/Polyvivnyl Alcohol Hydrogel Substrate.

PubMed

Ouyang, Lei; Jiang, Zuyan; Wang, Nan; Zhu, Lihua; Tang, Heqing

2017-07-10

Sibutramine hydrochloride (SH) is a banned weight-loss drug, but its illegal addition to health products is still rampant. This suggests a very urgent need for a fast and precise detection method for SH. Surface Enhanced Raman Scattering (SERS) is a promising candidate for this purpose, but the weak affinity between SH and bare metal limits its direct SERS detection. In the present work, β-cyclodextrin was capped in situ onto the surface of Ag nanoparticles to function as a scaffold to capture SH. The obtained Ag nanoparticles were encapsulated into polyvinyl alcohol (PVA) to fabricate a SERS active hydrogel with excellent reproducibility. A facile SERS strategy based on such substrate was proposed for trace SH quantification with a linear range of 7.0-150.0 µg·mL -1 , and a detection limit low to 3.0 µg·mL -1 . It was applied to analyze seven types of commercial slimming capsules with satisfactory results, showing good prospect for real applications.

Rapid Surface Enhanced Raman Scattering (SERS) Detection of Sibutramine Hydrochloride in Pharmaceutical Capsules with a β-Cyclodextrin- Ag/Polyvivnyl Alcohol Hydrogel Substrate

PubMed Central

Ouyang, Lei; Jiang, Zuyan; Wang, Nan; Zhu, Lihua; Tang, Heqing

2017-01-01

Sibutramine hydrochloride (SH) is a banned weight-loss drug, but its illegal addition to health products is still rampant. This suggests a very urgent need for a fast and precise detection method for SH. Surface Enhanced Raman Scattering (SERS) is a promising candidate for this purpose, but the weak affinity between SH and bare metal limits its direct SERS detection. In the present work, β-cyclodextrin was capped in situ onto the surface of Ag nanoparticles to function as a scaffold to capture SH. The obtained Ag nanoparticles were encapsulated into polyvinyl alcohol (PVA) to fabricate a SERS active hydrogel with excellent reproducibility. A facile SERS strategy based on such substrate was proposed for trace SH quantification with a linear range of 7.0–150.0 µg·mL–1, and a detection limit low to 3.0 µg·mL−1. It was applied to analyze seven types of commercial slimming capsules with satisfactory results, showing good prospect for real applications. PMID:28698502

Simultaneous Automatic Electrochemical Detection of Zinc, Cadmium, Copper and Lead Ions in Environmental Samples Using a Thin-Film Mercury Electrode and an Artificial Neural Network

PubMed Central

Kudr, Jiri; Nguyen, Hoai Viet; Gumulec, Jaromir; Nejdl, Lukas; Blazkova, Iva; Ruttkay-Nedecky, Branislav; Hynek, David; Kynicky, Jindrich; Adam, Vojtech; Kizek, Rene

2015-01-01

In this study a device for automatic electrochemical analysis was designed. A three electrodes detection system was attached to a positioning device, which enabled us to move the electrode system from one well to another of a microtitre plate. Disposable carbon tip electrodes were used for Cd(II), Cu(II) and Pb(II) ion quantification, while Zn(II) did not give signal in this electrode configuration. In order to detect all mentioned heavy metals simultaneously, thin-film mercury electrodes (TFME) were fabricated by electrodeposition of mercury on the surface of carbon tips. In comparison with bare electrodes the TMFEs had lower detection limits and better sensitivity. In addition to pure aqueous heavy metal solutions, the assay was also performed on mineralized rock samples, artificial blood plasma samples and samples of chicken embryo organs treated with cadmium. An artificial neural network was created to evaluate the concentrations of the mentioned heavy metals correctly in mixture samples and an excellent fit was observed (R2 = 0.9933). PMID:25558996

Alternative states of a semiarid grassland ecosystem: implications for ecosystem services

USGS Publications Warehouse

Miller, Mark E.; Belote, R. Travis; Bowker, Matthew A.; Garman, Steven L.

2011-01-01

Ecosystems can shift between alternative states characterized by persistent differences in structure, function, and capacity to provide ecosystem services valued by society. We examined empirical evidence for alternative states in a semiarid grassland ecosystem where topographic complexity and contrasting management regimes have led to spatial variations in levels of livestock grazing. Using an inventory data set, we found that plots (n = 72) cluster into three groups corresponding to generalized alternative states identified in an a priori conceptual model. One cluster (biocrust) is notable for high coverage of a biological soil crust functional group in addition to vascular plants. Another (grass-bare) lacks biological crust but retains perennial grasses at levels similar to the biocrust cluster. A third (annualized-bare) is dominated by invasive annual plants. Occurrence of grass-bare and annualized-bare conditions in areas where livestock have been excluded for over 30 years demonstrates the persistence of these states. Significant differences among all three clusters were found for percent bare ground, percent total live cover, and functional group richness. Using data for vegetation structure and soil erodibility, we also found large among-cluster differences in average levels of dust emissions predicted by a wind-erosion model. Predicted emissions were highest for the annualized-bare cluster and lowest for the biocrust cluster, which was characterized by zero or minimal emissions even under conditions of extreme wind. Results illustrate potential trade-offs among ecosystem services including livestock production, soil retention, carbon storage, and biodiversity conservation. Improved understanding of these trade-offs may assist ecosystem managers when evaluating alternative management strategies.

Laboratory tests of oviposition by the African malaria mosquito, Anopheles gambiae, on dark soil as influenced by presence or absence of vegetation

PubMed Central

Huang, Juan; Walker, Edward D; Otienoburu, Philip E; Amimo, Fred; Vulule, John; Miller, James R

2006-01-01

Background Physical objects like vegetation can influence oviposition by mosquitoes on soil or water substrates. Anopheles gambiae s. l. is generally thought to utilize puddles over bare soil as its prime larval habitat and to avoid standing water populated with vegetation. In Kisian, Kenya near Kisumu, water often pools in grassy drainage areas both during and after periods of infrequent rains, when typical puddle habitats become scarce because of drying. This raised the question of whether An. gambiae has the behavioural flexibility to switch ovipositional sites when puddles over bare soil are unavailable. Methods To test whether presence and height of grasses influenced oviposition, wild-caught gravid An. gambiae s. l. were offered paired choices between wet, bare soil and wet soil populated with mixed grasses or grasses of differing height. No-choice tests were also conducted by giving females either grassy soil or bare soil. Results In choice tests, females laid four times more eggs on bare, wet soil than soil populated with grasses. However in no-choice tests, egg output was not significantly different whether grasses were present or not. Females laid significantly more eggs on soil populated with short grass than with medium, or tall grass. Conclusion This work shows An. gambiae s. l. has the capacity to oviposit into grassy aquatic habitats when typical puddles over bare soil are unavailable. This knowledge will need to be considered in the design and implementation of programmes aimed at reducing malaria transmission by suppression of An. gambiae s. l. immatures. PMID:17038187

Digital image processing of nanometer-size metal particles on amorphous substrates

NASA Technical Reports Server (NTRS)

Soria, F.; Artal, P.; Bescos, J.; Heinemann, K.

1989-01-01

The task of differentiating very small metal aggregates supported on amorphous films from the phase contrast image features inherently stemming from the support is extremely difficult in the nanometer particle size range. Digital image processing was employed to overcome some of the ambiguities in evaluating such micrographs. It was demonstrated that such processing allowed positive particle detection and a limited degree of statistical size analysis even for micrographs where by bare eye examination the distribution between particles and erroneous substrate features would seem highly ambiguous. The smallest size class detected for Pd/C samples peaks at 0.8 nm. This size class was found in various samples prepared under different evaporation conditions and it is concluded that these particles consist of 'a magic number' of 13 atoms and have cubooctahedral or icosahedral crystal structure.

Noninvasive Optical Tracking of Red Fluorescent Protein-Expressing Cancer Cells in a Model of Metastatic Breast Cancer 1*

PubMed Central

Winnard, Paul T; Kluth, Jessica B; Raman, Venu

2006-01-01

Abstract We have evaluated the use of the Xenogen IVIS 200 imaging system for real-time fluorescence protein-based optical imaging of metastatic progression in live animals. We found that green fluorescent protein-expressing cells (100 x 106) were not detectable in a mouse cadaver phantom experiment. However, a 10-fold lower number of tdTomato-expressing cells were easily detected. Mammary fat pad xenografts of stable MDA-MB-231-tdTomato cells were generated for the imaging of metastatic progression. At 2 weeks postinjection, barely palpable tumor burdens were easily detected at the sites of injection. At 8 weeks, a small contralateral mammary fat pad metastasis was imaged and, by 13 weeks, metastases to lymph nodes were detectable. Metastases with nodular composition were detectable within the rib cage region at 15 weeks. 3-D image reconstructions indicated that the detection of fluorescence extended to approximately 1 cm below the surface. A combination of intense tdTomato fluorescence, imaging at ≥ 620 nm (where autofluorescence is minimized), and the sensitivity of the Xenogen imager made this possible. This study demonstrates the utility of the noninvasive optical tracking of cancer cells during metastatic progression with endogenously expressed fluorescence protein reporters using detection wavelengths of ≥ 620 nm. PMID:17032496

Generation and detection of pulsed T-rays for use in the study of biological and bioterrorism issues

NASA Astrophysics Data System (ADS)

Jedju, Thomas M.; Bosacchi, Bruno; Warren, Warren S.; Nahata, Ajay; Kuenstner, Todd

2004-09-01

Terahertz (T-rays) spectroscopy has recently emerged as a powerful method to access a heretofore barely explored region of the electromagnetic spectrum where fundamental molecular resonances occur. Besides their importance for fundamental research, these resonances could be used as signatures in the identification of molecular species and as sensitive probes in a wide variety of molecular processes. In this paper we consider the potential of THz spectroscopy in the application to relevant biomedical and homeland security problems such as the analysis of normal and diseased tissues and the detection of toxic biomolecules. As examples, we present preliminary experimental data which suggest that THz spectroscopy: 1) can discriminate between cancerous and normal tissue, and 2) can reveal the presence of foreign substances hidden in an envelope and even allow their specific identification. This capability is of particular relevance as a straightforward homeland security tool for the detection of anthrax and other biotoxic molecules.

Detection of Bovine Leukemia Virus in Brains of Cattle with a Neurological Syndrome: Pathological and Molecular Studies

PubMed Central

D'Angelino, Rubens Henrique Ramos; Pituco, Edviges Maristela; Villalobos, Eliana Monteforte Cassaro; Harakava, Ricardo; Gregori, Fábio

2013-01-01

Bovine leukemia virus (BLV) was investigated in the central nervous system (CNS) of cattle with neurological syndrome. A total of 269 CNS samples were submitted to nested-PCR (BLV env gene gp51), and the viral genotypes were identified. The nested-PCR was positive in 4.8% (13/269) CNS samples, with 2.7% (2/74) presenting at histological examination lesions of nonpurulent meningoencephalitis (NPME), whereas 5.6% (11/195) not presenting NPME (P > 0.05). No samples presented lymphosarcoma. The PCR products (437 bp) were sequenced and submitted to phylogenetic analysis by neighbor-joining and maximum composite likelihood methods, and genotypes 1, 5, and 6 were detected, corroborating other South American studies. The genotype 6 barely described in Brazil and Argentina was more frequently detected in this study. The identity matrices showed maximum similarity (100%) among some samples of this study and one from Argentina (FJ808582), recovered from GenBank. There was no association among the genotypes and NPME lesions. PMID:23710448

New duel fluorescent "on-off" and colorimetric sensor for Copper(II): Copper(II) binds through N coordination and pi cation interaction to sensor.

PubMed

Kumar, Jutika; Bhattacharyya, Pradip K; Das, Diganta Kumar

2015-03-05

Schiff base derived from naphthylamine and benzil (L) binds to two Cu(2+) ions, one by coordination through N of the Schiff base and another by pi cation interaction through benzil rings. This bonding pattern determined by DFT calculation has been proved by matching electronic spectrum obtained from TDDFT calculation to the experimental one. L acts as "on-off" fluorescent and bare eye detectable colorimetric (purple color) sensor for Cu(2+) ion over the metal ions - Na(+), K(+), Ca(2+) Mn(2+), Co(2+) Ni(2+), Zn(2+), Pb(2+), Cd(2+), Hg(2+), Ag(+), Hg(2+) and Al(3+) in 1:1 v/v CH3CN:H2O. These metal ions do not interfere the fluorescent/colorimetric sensing. As fluorescent sensor the linear range of detection is 5×10(-5) to 3×10(-4)M and detection limit 10(-5)M. Copyright © 2014 Elsevier B.V. All rights reserved.

New duel fluorescent 'on-off' and colorimetric sensor for Copper(II): Copper(II) binds through N coordination and pi cation interaction to sensor

NASA Astrophysics Data System (ADS)

Kumar, Jutika; Bhattacharyya, Pradip K.; Das, Diganta Kumar

2015-03-01

Schiff base derived from naphthylamine and benzil (L) binds to two Cu2+ ions, one by coordination through N of the Schiff base and another by pi cation interaction through benzil rings. This bonding pattern determined by DFT calculation has been proved by matching electronic spectrum obtained from TDDFT calculation to the experimental one. L acts as "on-off" fluorescent and bare eye detectable colorimetric (purple color) sensor for Cu2+ ion over the metal ions - Na+, K+, Ca2+ Mn2+, Co2+ Ni2+, Zn2+, Pb2+, Cd2+, Hg2+, Ag+, Hg2+ and Al3+ in 1:1 v/v CH3CN:H2O. These metal ions do not interfere the fluorescent/colorimetric sensing. As fluorescent sensor the linear range of detection is 5 × 10-5 to 3 × 10-4 M and detection limit 10-5 M.

A Multi-Level Decision Fusion Strategy for Condition Based Maintenance of Composite Structures

PubMed Central

Sharif Khodaei, Zahra; Aliabadi, M.H.

2016-01-01

In this work, a multi-level decision fusion strategy is proposed which weighs the Value of Information (VoI) against the intended functions of a Structural Health Monitoring (SHM) system. This paper presents a multi-level approach for three different maintenance strategies in which the performance of the SHM systems is evaluated against its intended functions. Level 1 diagnosis results in damage existence with minimum sensors covering a large area by finding the maximum energy difference for the guided waves propagating in pristine structure and the post-impact state; Level 2 diagnosis provides damage detection and approximate localization using an approach based on Electro-Mechanical Impedance (EMI) measures, while Level 3 characterizes damage (exact location and size) in addition to its detection by utilising a Weighted Energy Arrival Method (WEAM). The proposed multi-level strategy is verified and validated experimentally by detection of Barely Visible Impact Damage (BVID) on a curved composite fuselage panel. PMID:28773910

Nearest Neighbor Averaging and its Effect on the Critical Level and Minimum Detectable Concentration for Scanning Radiological Survey Instruments that Perform Facility Release Surveys.

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

Fournier, Sean Donovan; Beall, Patrick S; Miller, Mark L

2014-08-01

Through the SNL New Mexico Small Business Assistance (NMSBA) program, several Sandia engineers worked with the Environmental Restoration Group (ERG) Inc. to verify and validate a novel algorithm used to determine the scanning Critical Level (L c ) and Minimum Detectable Concentration (MDC) (or Minimum Detectable Areal Activity) for the 102F scanning system. Through the use of Monte Carlo statistical simulations the algorithm mathematically demonstrates accuracy in determining the L c and MDC when a nearest-neighbor averaging (NNA) technique was used. To empirically validate this approach, SNL prepared several spiked sources and ran a test with the ERG 102F instrumentmore » on a bare concrete floor known to have no radiological contamination other than background naturally occurring radioactive material (NORM). The tests conclude that the NNA technique increases the sensitivity (decreases the L c and MDC) for high-density data maps that are obtained by scanning radiological survey instruments.« less

Applying the RUSLE and the USLE-M on hillslopes where runoff production during an erosion event is spatially variable

NASA Astrophysics Data System (ADS)

Kinnell, P. I. A.

2014-11-01

The assumption that runoff is produced uniformly over the eroding area underlies the traditional use of Universal Soil Loss Equation (USLE) and the revised version of it, the RUSLE. However, although the application of the USLE/RUSLE to segments on one dimensional hillslopes and cells on two-dimensional hillslopes is based on the assumption that each segment or cell is spatially uniform, factors such as soil infiltration, and hence runoff production, may vary spatially between segments or cells. Results from equations that focus on taking account of spatially variable runoff when applying the USLE/RUSLE and the USLE-M, the modification of the USLE/RUSLE that replaces the EI30 index by the product of EI30 and the runoff ratio, in hillslopes during erosion events where runoff is not produced uniformly were compared on a hypothetical a 300 m long one-dimensional hillslope with a spatially uniform gradient. Results were produced for situations where all the hillslope was tilled bare fallow and where half of the hillslope was cropped with corn and half was tilled bare fallow. Given that the erosive stress within a segment or cell depends on the volume of surface water flowing through the segment or cell, soil loss can be expected to increase not only with distance from the point where runoff begins but also directly with runoff when it varies about the average for the slope containing the segment or cell. The latter effect was achieved when soil loss was predicted using the USLE-M but not when the USLE/RUSLE slope length factor for a segment using an effective upslope length that varies with the ratio of the upslope runoff coefficient and the runoff coefficient for the slope to the bottom of the segment or cell was used. The USLE-M also predicted deposition to occur in a segment containing corn when an area with tilled bare fallow soil existed immediately upslope of it because the USLE-M models erosion on runoff and soil loss plots as a transport limited system. In a comparison of the USLE-M and RUSLE2, the form of the RUSLE that uses a daily time step in modeling rainfall erosion on one-dimensional hillslopes in the USA, on a 300 m long 9% hillslope where management changed from bare fallow to corn midway down the slope, the USLE-M predicted greater deposition in the bottom segment than predicted by RUSLE2. In addition, the USLE-M approach predicted that the deposition that occurred when the slope gradient changed from 9% to 4.5% midway down the slope was much greater than the amount predicted using RUSLE2.

Modeling Linkages Between Effective Impervious Surface and Urban Vegetation Productivity in Semi-arid Environments

NASA Astrophysics Data System (ADS)

Shields, C. A.; Tague, C.

2010-12-01

With a majority of the world's population now living in urban areas, the role of vegetation in urban ecosystems warrants increased attention. We address the question of how the fine scale (<5m) spatial arrangement of impervious surfaces affects water available to vegetation, which in turn can significantly impact the productivity of vegetation and uptake of C and N. To gain insight into how landscape features influence vegetation productivity, we use a coupled ecohydrogic model to estimate impacts of the amount and arrangement of impervious surfaces on vegetation water use. We use the model to explore how concepts from research in natural semi-arid ecosystems can be applied in the urban context. Ecological research in semi-arid ecosystems has shown that the arrangement of vegetated and bare surfaces plays a key role in regulating both runoff and ecosystem water use and productivity. Systems that include a mixture of bare and vegetated surfaces, for example, tend to show less runoff and more productivity than those with more homogeneous cover. In some instances, patchiness of bare and vegetated surfaces is more important than total vegetated area in determining rates of runoff and vegetation use of rainfall. In an urban context, impervious surfaces can be viewed as analogous to the bare surfaces present in undeveloped ecosystems. We consider not only the total impervious area (TIA), but also the effect of impervious area with a direct hydrologic connection to the stream network, effective impervious area (EIA). While increases in total impervious area (TIA) have been widely shown to impact catchment hydrology, the role of effective impervious area (EIA) has been less extensively studied. A consensus is emerging from the literature that EIA is as important or even more important than TIA as an indicator of catchment response to urbanization. Ecohydrologic models offer a tool to quantify the role of EIA on water availability and plant productivity and demonstrate the potential of urban areas to act as C or N sinks (and minimize the impacts such as increased storm runoff and degraded downstream water quality). We explore the relative roles of TIA and EIA on water availability and plant productivity in a semi-arid urban environment through a series of modeling exercises. The Regional HydroEcological Simulation System (RHESSys) is used to model a range of impervious surface and vegetation scenarios on a test hillslope in the Mission Creek catchment in Santa Barbara CA. Results indicate that reduced EIA can indeed act to mitigate the impact of TIA on water available to plants. We then implement a modification to the RHESSys model that incorporates patch scale estimates of EIA into simulations of the entire Mission Creek catchment, allowing us to quantify likely catchment-scale impacts of altering EIA.

Gadolinium Chelate Safety in Pregnancy: Barely Detectable Gadolinium Levels in the Juvenile Nonhuman Primate after in Utero Exposure.

PubMed

Prola-Netto, Joao; Woods, Mark; Roberts, Victoria H J; Sullivan, Elinor L; Miller, Christina Ann; Frias, Antonio E; Oh, Karen Y

2018-01-01

Purpose To determine whether gadolinium remains in juvenile nonhuman primate tissue after maternal exposure to intravenous gadoteridol during pregnancy. Materials and Methods Gravid rhesus macaques and their offspring (n = 10) were maintained, as approved by the institutional animal care and utilization committee. They were prospectively studied as part of a pre-existing ongoing research protocol to evaluate the effects of maternal malnutrition on placental and fetal development. On gestational days 85 and 135, they underwent placental magnetic resonance imaging after intravenous gadoteridol administration. Amniocentesis was performed on day 135 prior to administration of the second dose of gadoteridol. After delivery, the offspring were followed for 7 months. Tissue samples from eight different organs and from blood were harvested from each juvenile macaque. Gadolinium levels were measured by using inductively coupled plasma mass spectrometry. Results Gadolinium concentration in the amniotic fluid was 0.028 × 10 -5 %ID/g (percentage injected dose per gram of tissue) 50 days after administration of one gadoteridol dose. Gadolinium was most consistently detected in the femur (mean, 2.5 × 10 -5 %ID/g; range, [0.81-4.1] × 10 -5 %ID/g) and liver (mean, 0.15 × 10 -5 %ID/g; range, [0-0.26] × 10 -5 %ID/g). Levels were undetectable in the remaining sampled tissues, with the exception of one juvenile skin sample (0.07 × 10 -5 %ID/g), one juvenile spleen sample (0.039 × 10 -5 %ID/g), and one juvenile brain (0.095 × 10 -5 %ID/g) and kidney (0.13 × 10 -5 %ID/g) sample. Conclusion The presence of gadoteridol in the amniotic fluid after maternal injection enables confirmation that it crosses the placenta. Extremely low levels of gadolinium are found in juvenile macaque tissues after in utero exposure to two doses of gadoteridol, indicating that a very small amount of gadolinium persists after delivery. © RSNA, 2017.

A visual assay and spectrophotometric determination of LLM-105 explosive using detection of gold nanoparticle aggregation at two pH values.

PubMed

He, Yi; Cheng, Yang

2016-08-01

We report a simple, rapid, and sensitive assay for visual and spectrophotometric detection of the 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) explosive. The assay is based on different interactions between LLM-105 and gold nanoparticle (AuNP) dispersions at two pH values, leading to the formation of dispersed or aggregated AuNPs. Two AuNP dispersions at two pH values were applied to recognize and detect LLM-105 instead of traditional AuNP dispersion under an aptotic pH to improve the anti-interference ability. The developed assay showed excellent sensitivity with a detection limit of 3 ng/mL, and the presence of as low as 0.2 μg/mL LLM-105 can be directly detected with the bare eye. This sensitivity is about six orders of magnitude higher than that of the reported traditional assays. Additionally, the assay exhibited good selectivity toward LLM-105 over other explosives, sulfur-containing compounds, and amines. Graphical abstract A simple, sensitive, and selective assay for LLM-105 was developed based on the pH-dependent interaction between the LLM-105 explosive and gold nanoparticle dispersion.

Antennas in matter: Fundamentals, theory, and applications

NASA Technical Reports Server (NTRS)

King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

1981-01-01

The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis.

PubMed

Palmerini, Tullio; Biondi-Zoccai, Giuseppe; Della Riva, Diego; Stettler, Christoph; Sangiorgi, Diego; D'Ascenzo, Fabrizio; Kimura, Takeshi; Briguori, Carlo; Sabatè, Manel; Kim, Hyo-Soo; De Waha, Antoinette; Kedhi, Elvin; Smits, Pieter C; Kaiser, Christoph; Sardella, Gennaro; Marullo, Antonino; Kirtane, Ajay J; Leon, Martin B; Stone, Gregg W

2012-04-14

The relative safety of drug-eluting stents and bare-metal stents, especially with respect to stent thrombosis, continues to be debated. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to accurately estimate treatment differences between stents. We compared the risk of thrombosis between bare-metal and drug-eluting stents. For this network meta-analysis, randomised controlled trials comparing different drug-eluting stents or drug-eluting with bare-metal stents currently approved in the USA were identified through Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted. 49 trials including 50,844 patients randomly assigned to treatment groups were analysed. 1-year definite stent thrombosis was significantly lower with cobalt-chromium everolimus eluting stents (CoCr-EES) than with bare-metal stents (odds ratio [OR] 0·23, 95% CI 0·13-0·41). The significant difference in stent thrombosis between CoCr-EES and bare-metal stents was evident as early as 30 days (OR 0·21, 95% CI 0·11-0·42) and was also significant between 31 days and 1 year (OR 0·27, 95% CI 0·08-0·74). CoCr-EES were also associated with significantly lower rates of 1-year definite stent thrombosis compared with paclitaxel-eluting stents (OR 0·28, 95% CI 0·16-0·48), permanent polymer-based sirolimus-eluting stents (OR 0·41, 95% CI 0·24-0·70), phosphorylcholine-based zotarolimus-eluting stents (OR 0·21, 95% CI 0·10-0·44), and Resolute zotarolimus-eluting stents (OR 0·14, 95% CI 0·03-0·47). At 2-year follow-up, CoCr-EES were still associated with significantly lower rates of definite stent thrombosis than were bare-metal (OR 0·35, 95% CI 0·17-0·69) and paclitaxel-eluting stents (OR 0·34, 95% CI 0·19-0·62). No other drug-eluting stent had lower definite thrombosis rates compared with bare-metal stents at 2-year follow-up. In randomised studies completed to date, CoCr-EES has the lowest rate of stent thrombosis within 2 years of implantation. The finding that CoCr-EES also reduced stent thrombosis compared with bare-metal stents, if confirmed in future randomised trials, represents a paradigm shift. The Cardiovascular Research Foundation. Copyright © 2012 Elsevier Ltd. All rights reserved.

To the Application of LiDAR to Detect the Geological Structures in Sulphurets Property, British Columbia, Canada

NASA Astrophysics Data System (ADS)

Koohzare, A.; Rezaeian, M.; McIntosh, A.

2009-05-01

The Kerr Sulphurets property in North Western British Columbia has been explored primarily as a placer gold holding since the 1880s; and, potentially includes one of Canada's largest gold deposits (e.g. the Mitchell Zone). The Sulphurets camp has been classified by Taylor in 2007 as a prominent global epithermal high-sulphidation subtype with 10 million tonnes of ore (reserves + production) containing approximately 10 g/t gold. The geological and geophysical observations of this deposit indicate intrusion- related mineralized veins which are known to overlap as the result of structural complexities. Faulting predates mineralization and alteration and dramatically dominates the location of the mineralization for this porphyry- epithermal high-sulphidation deposit (Britton and Alldrick 1988, British Columbia Ministry of Energy, Mines and Petroleum Resources, 1992; Margolis, 1993). However, the surface trace of these structures and lineaments within the site is obscured by vegetation, glacial cover and steep topographic relief. We used high resolution LiDAR airborne bare-earth sensing (vegetative data deleted) in an effort to detect the surface geological features and lineaments in the Kerr Sulphurets site. The LiDAR flight was designed to acquire high density data with 2 points per square meter using a 150 kHz multipulse system. High resolution LiDAR data provides a level of detail not achievable by other digital terrain modelling techniques, whether extracted from aerial photography, low-resolution topographic contour maps, 10-30 meter USGS, or SRTM digital elevation models. LiDAR bare-earth data spectacularly revealed hidden geological structures within the property district, which in turn assisted in identifying the high potential zones for mineralization in Sulphurets.

A deep X-ray view of the bare AGN Ark 120. III. X-ray timing analysis and multiwavelength variability

NASA Astrophysics Data System (ADS)

Lobban, A. P.; Porquet, D.; Reeves, J. N.; Markowitz, A.; Nardini, E.; Grosso, N.

2018-03-01

We present the spectral/timing properties of the bare Seyfert galaxy Ark 120 through a deep ˜420 ks XMM-Newton campaign plus recent NuSTAR observations and a ˜6-month Swift monitoring campaign. We investigate the spectral decomposition through fractional rms, covariance and difference spectra, finding the mid- to long-time-scale (˜day-year) variability to be dominated by a relatively smooth, steep component, peaking in the soft X-ray band. Additionally, we find evidence for variable Fe K emission redward of the Fe Kα core on long time-scales, consistent with previous findings. We detect a clearly defined power spectrum which we model with a power law with a slope of α ˜ 1.9. By extending the power spectrum to lower frequencies through the inclusion of Swift and Rossi X-ray Timing Explorer data, we find tentative evidence of a high-frequency break, consistent with existing scaling relations. We also explore frequency-dependent Fourier time lags, detecting a negative (`soft') lag for the first time in this source with the 0.3-1 keV band lagging behind the 1-4 keV band with a time delay, τ, of ˜900 s. Finally, we analyse the variability in the optical and ultraviolet (UV) bands using the Optical/UV Monitor onboard XMM-Newton and the Ultra-Violet/Optical Telescope onboard Swift and search for time-dependent correlations between the optical/UV/X-ray bands. We find tentative evidence for the U-band emission lagging behind the X-rays with a time delay of τ = 2.4 ± 1.8 d, which we discuss in the context of disc reprocessing.

Comparative performances of a bare graphite-polyurethane composite electrode unmodified and modified with graphene and carbon nanotubes in the electrochemical determination of escitalopram.

PubMed

Baccarin, Marina; Cervini, Priscila; Cavalheiro, Eder Tadeu Gomes

2018-02-01

A bare composite graphite-polyurethane electrode (EGPU) and two other modified with graphene (EGPU-GR) and functionalized multi-walled carbon nanotubes (EGPU-CNTs) were prepared and compared regarding their voltammetric response to escitalopran (EST). The modifiers were characterized by Raman spectroscopy and the resulting electrode materials by contact angle measurements with a hydrophilicity character in the ascending order for the composites: GPU > GPU-GR > GPU-CNTs and scanning electron microscopy (SEM). The electroactive areas of the EGPU, EGPU-GR, and EGPU-CNTs were 0.065, 0.080, and 0.092cm 2 , respectively, calculated from the chronocoulometry using K 3 [Fe(CN) 6 ] as a probe and the Cottrell equation. The cyclic voltammograms obtained for EST indicated irreversible electrochemical behavior, with an anodic peak at ca. +0.80V (νs. SCE). These measurements were carried out with the three electrodes, and comparison of the analytical responses led to the EGPU-GR electrode being selected for use in the subsequent experiments. Under optimal conditions, square wave and differential pulse voltammetry at EGPU-GR presented linear dynamic ranges between 1.5 × 10 -6 and 1.2 × 10 -5 mol L -1 , with a detection limit of 2.5 × 10 -7 molL -1 (SWV) and 1.5 × 10 -6 and 1.2 × 10 -5 molL -1 , with a detection limit of 3.2 × 10 -7 molL -1 (DPV) for EST. The proposed method was applied for the quantification of EST in synthetic urine and cerebrospinal fluid samples, offering advantages including simplicity of fabrication, no requirement for analyte preconcentration and surface renewal, fast response, and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

UV-induced photocatalytic degradation of aqueous acetaminophen: the role of adsorption and reaction kinetics.

PubMed

Basha, Shaik; Keane, David; Nolan, Kieran; Oelgemöller, Michael; Lawler, Jenny; Tobin, John M; Morrissey, Anne

2015-02-01

Nanostructured titania supported on activated carbon (AC), termed as integrated photocatalytic adsorbents (IPCAs), were prepared by ultrasonication and investigated for the photocatalytic degradation of acetaminophen (AMP), a common analgesic and antipyretic drug. The IPCAs showed high affinity towards AMP (in dark adsorption studies), with the amount adsorbed proportional to the TiO2 content; the highest adsorption was at 10 wt% TiO2. Equilibrium isotherm studies showed that the adsorption followed the Langmuir model, indicating the dependence of the reaction on an initial adsorption step, with maximum adsorption capacity of 28.4 mg/g for 10 % TiO2 IPCA. The effects of initial pH, catalyst amount and initial AMP concentration on the photocatalytic degradation rates were studied. Generally, the AMP photodegradation activity of the IPCAs was better than that of bare TiO2. Kinetic studies on the photocatalytic degradation of AMP under UV suggest that the degradation followed Langmuir-Hinshelwood (L-H) kinetics, with an adsorption rate constant (K) that was considerably higher than the photocatalytic rate constant (k r), indicating that the photocatalysis of AMP is the rate-determining step during the adsorption/photocatalysis process.

The Impact of Time Delay on the Content of Discussions at a Computer-Mediated Conference

NASA Astrophysics Data System (ADS)

Huntley, Byron C.; Thatcher, Andrew

2008-11-01

This study investigates the relationship between the content of computer-mediated discussions and the time delay between online postings. The study aims to broaden understanding of the dynamics of computer-mediated discussion regarding the time delay and the actual content of computer-mediated discussions (knowledge construction, social aspects, amount of words and number of postings) which has barely been researched. The computer-mediated discussions of the CybErg 2005 virtual conference served as the sample for this study. The Interaction Analysis Model [1] was utilized to analyze the level of knowledge construction in the content of the computer-mediated discussions. Correlations have been computed for all combinations of the variables. The results demonstrate that knowledge construction, social aspects and amount of words generated within postings were independent of, and not affected by, the time delay between the postings and the posting from which the reply was formulated. When greater numbers of words were utilized within postings, this was typically associated with a greater level of knowledge construction. Social aspects in the discussion were found to neither advantage nor disadvantage the overall effectiveness of the computer-mediated discussion.

Study of Microstructure and Mechanical Properties of Particulate Reinforced Aluminum Matrix Composite Foam

NASA Astrophysics Data System (ADS)

Kumar, Suresh; Pandey, O. P.

Metal foams cellular metals have gained an important role in the field of metallurgy, though barely a few decades old. Aluminum composite foam exhibit unique properties such as light weight, blast palliation, sound absorption, high energy absorption, and flame resistance. In the present investigation the effect of variation in the amount of CaCO3 as blowing agent on the microstructure and wear behavior of LM13 alloy foams has been studied. The blowing agent was blended in highly viscous semi-solid melt by stirring process. The process parameters that influence the formation of bubbles like the melt temperature, size and amount of blowing agent and its distribution has been optimized to get uniform size foams. The distribution behavior of blowing agent is influenced by the melt viscosity and stirring speed. For packaging application, the dry sliding wear behavior of the prepared foam was investigated by using a pin on disc method at applied loads of 9.8, 19.6 and 29.4 N at room temperature. The results indicate that the wear rate is dependent on the cell size and cell wall thickness of the foam.

Influence of crop residues on trifluralin mineralization in a silty clay loam soil.

PubMed

Farenhorst, Annemieke

2007-01-01

Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day(-1) in soil with 16% A to 2.89E-02 day(-1) in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.

Corrosion of bare carbon steel as a passive sensor to assess moisture availability for biological activity in Atacama Desert soils.

PubMed

Cáceres, Luis; Davila, Alfonso F; Soliz, Alvaro; Saldivia, Jessica

2018-02-28

Here we consider that the corrosion of polished bared metal coupons can be used as a passive sensor to detect or identify the lower limit of water availability suitable for biological activity in Atacama Desert soils or solid substrates. For this purpose, carbon steel coupons were deposited at selected sites along a west-east transect and removed at predetermined times for morphological inspection. The advantage of this procedure is that the attributes of the oxide layer (corrosion extent, morphology and oxide phases) can be considered as a fingerprint of the atmospheric moisture history at a given time interval. Two types of coupons were used, long rectangular shaped ones that were half-buried in a vertical position, and square shaped ones that were deposited on the soil surface. The morphological attributes observed by SEM inspection were found to correlate to the so-called humectation time which is determined from local meteorological parameters. The main finding was that the decreasing trend of atmospheric moisture along the transect was closely related to corrosion behaviour and water soil penetration. For instance, at the coastal site oxide phases formed on the coupon surface rapidly evolve into well-crystallized species, while at the driest inland site Lomas Bayas only amorphous oxide was observed on the coupons.

Numerical solution of the exact cavity equations of motion for an unstable optical resonator.

PubMed

Bowers, M S; Moody, S E

1990-09-20

We solve numerically, we believe for the first time, the exact cavity equations of motion for a realistic unstable resonator with a simple gain saturation model. The cavity equations of motion, first formulated by Siegman ["Exact Cavity Equations for Lasers with Large Output Coupling," Appl. Phys. Lett. 36, 412-414 (1980)], and which we term the dynamic coupled modes (DCM) method of solution, solve for the full 3-D time dependent electric field inside the optical cavity by expanding the field in terms of the actual diffractive transverse eigenmodes of the bare (gain free) cavity with time varying coefficients. The spatially varying gain serves to couple the bare cavity transverse modes and to scatter power from mode to mode. We show that the DCM method numerically converges with respect to the number of eigenmodes in the basis set. The intracavity intensity in the numerical example shown reaches a steady state, and this steady state distribution is compared with that computed from the traditional Fox and Li approach using a fast Fourier transform propagation algorithm. The output wavefronts from both methods are quite similar, and the computed output powers agree to within 10%. The usefulness and advantages of using this method for predicting the output of a laser, especially pulsed lasers used for coherent detection, are discussed.

Corrosion of Bare Carbon Steel as a Passive Sensor to Assess Moisture Availability for Biological Activity in Atacama Desert Soils

NASA Technical Reports Server (NTRS)

Caceres, Luis; Davila, Alfonso F.; Soliz, Alvaro; Saldivia, Jessica

2018-01-01

In this work we suggest the corrosion of polished bared metal coupons as a passive sensor to detect or identify the lower limit of water availability that could be suitable for biological activity in the Atacama Desert on soil or solid substrates. For this purpose, carbon steel coupons were deposited in selected sites along a west-east transect and removed at predetermined times for morphological inspection. The advantage of this procedure is that the attributes of the oxide layer (corrosion extent, morphology and oxide phases) can be considered as a fingerprint of the atmospheric moisture history at a given time interval. Two types of coupons were used, a long rectangular shape that are half-buried in a vertical position, and square shape that are deposited on the soil surface. The morphological attributes observed by SEM inspection is correlated to the so-called humectation time which is determined from local meteorological parameters. The main result is that the decreasing trend of atmospheric moisture along the transect is closely related to corrosion behavior and water soil penetration. For instance, while in the coastal site oxide phases formed on the coupon surface rapidly evolve to well- crystallized species, in the driest inland site Lomas Bayas only amorphous oxide is observed.

Electrocatalytic Oxidation of Ascorbic Acid Using a Poly(aniline-co-m-ferrocenylaniline) Modified Glassy Carbon Electrode

PubMed Central

Chairam, Sanoe; Sriraksa, Worawit; Amatatongchai, Maliwan; Somsook, Ekasith

2011-01-01

A poly(aniline-co-m-ferrocenylaniline) was successfully synthesized on a glassy carbon electrode (GCE) by electrochemical copolymerization using a scan potential range from −0.3 to +0.9 V (vs. Ag/AgCl) in 0.5 M H2SO4 containing 30% acetonitrile (ACN), 0.1 M aniline (Ani) and 0.005 M m-ferrocenyaniline (m-FcAni). The field emission scanning electron microscope (FESEM) and electrochemical methods were used to characterize the poly(Ani-co-m-FcAni) modified electrode. The poly(Ani-co-m-FcAni)/GCE exhibited excellent electrocatalytic oxidation of ascorbic acid (AA) in citrate buffer solution (CBS, pH 5.0). The anodic peak potential of AA was shifted from +0.55 V at the bare GCE to +0.25 V at the poly(Ani-co-m-FcAni)/GCE with higher current responses than those seen on the bare GCE. The scan number at the 10th cycle was selected as the maximum scan cycle in electrochemical polymerization. The limit of detection (LOD) was estimated to be 2.0 μM based on the signal-to-noise ratio (S/N = 3). The amperometric responses demonstrated an excellent selectivity for AA determination over glucose (Glu) and dopamine (DA). PMID:22346636

Fabrication of copper decorated tungsten oxide-titanium oxide nanotubes by photochemical deposition technique and their photocatalytic application under visible light

NASA Astrophysics Data System (ADS)

Momeni, Mohamad Mohsen

2015-12-01

Copper decorated WO3-TiO2 nanotubes (Cu/WTNs) with a high photocatalytic activity were prepared by anodizing and photochemical deposition. Highly ordered WO3-TiO2 nanotubes (WTNs) on pure titanium foils were successfully fabricated by electrochemical anodizing and copper deposited on these nanotubes (Cu/WTNs) by photoreduction method. The resulting samples were characterized by various methods. Only the anatase phase was detected by X-ray diffraction analysis. The presence of copper in the structure of thin films was confirmed by energy dispersive X-ray spectrometry and X-ray diffraction. The extension of optical absorption into the visible region of as-prepared films was indicated by UV/Vis spectroscopy. The degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of the obtained samples. Results showed that the photocatalytic activity of Cu/WTNs samples is higher than bare WTNs sample. Kinetic research showed that the reaction rate constant of Cu/WTNs is approximately 2.5 times higher than the apparent reaction rate constant of bare WTNs. These results not only offer an economical method for constructing Cu/WTNs photocatalysts, but also shed new insight on the rational design of a low cost and high-efficiency photocatalyst for environmental remediation.

Site-directed introduction of disulfide groups on antibodies for highly sensitive immunosensors.

PubMed

Acero Sánchez, Josep Ll; Fragoso, Alex; Joda, Hamdi; Suárez, Guillaume; McNeil, Calum J; O'Sullivan, Ciara K

2016-07-01

The interface between the sample and the transducer surface is critical to the performance of a biosensor. In this work, we compared different strategies for covalent self-assembly of antibodies onto bare gold substrates by introducing disulfide groups into the immunoglobulin structure, which acted as anchor molecules able to chemisorb spontaneously onto clean gold surfaces. The disulfide moieties were chemically introduced to the antibody via the primary amines, carboxylic acids, and carbohydrates present in its structure. The site-directed modification via the carbohydrate chains exhibited the best performance in terms of analyte response using a model system for the detection of the stroke marker neuron-specific enolase. SPR measurements clearly showed the potential for creating biologically active densely packed self-assembled monolayers (SAMs) in a one-step protocol compared to both mixed SAMs of alkanethiol compounds and commercial immobilization layers. The ability of the carbohydrate strategy to construct an electrochemical immunosensor was investigated using electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) transduction. Graphical Abstract Left: Functionalization strategies of bare gold substrates via direct bio-SAM using disulfide-containing antibody chemically modified via their primary amines (A), carbohydrates (B) and carboxylic acids (C). Right: Dependence of the peak height with NSE concentration at NSE21-CHO modified electrochemical immunosensor. Inset: Logarithmic calibration plot.

Graphene-containing PCL- coated Porous 13-93B3 Bioactive Glass Scaffolds for Bone Regeneration

NASA Astrophysics Data System (ADS)

Türk, Mert; Deliormanlı, Aylin M.

2018-04-01

Borate-based 13-93B3 bioactive glass scaffolds were coated with the graphene-containing poly-caprolactone (PCL) solution to prepare electrically conductive composites for biomedical applications. Results revealed that electrical conductivity of the scaffolds increased with increasing concentration of graphene nanoparticles. Significant difference was not observed in hydroxyapatite forming ability of the bare and the graphene-containing scaffolds immersed in simulated body fluid. In vitro cytotoxicity experiments (XTT tests) showed that pre-osteoblastic MC3T3-E1 cell viability percentages of the graphene- containing samples was higher than control group samples after 7 days of incubation. However, a decrease in cell viability rates was obtained after 14 days of incubation for samples coated with PCL containing graphene starting from 3 wt%. Additionally, results obtained in the live-dead assay were consistent with the results of XTT tests. A higher ALP activity was detected in cells cultured on the graphene-containing borate glass scaffolds than those on the bare PCL coated 13-93B3 scaffolds suggesting the presence of graphene nanopowders stimulated an early stage of osteoblastic differentiation. SEM analysis showed that MC3T3-E1 cells exhibited a flat appearance and spread out through the surface in all groups of scaffolds starting from 3 days of incubation.

Fast synthesis of platinum nanopetals and nanospheres for highly-sensitive non-enzymatic detection of glucose and selective sensing of ions

NASA Astrophysics Data System (ADS)

Taurino, Irene; Sanzó, Gabriella; Mazzei, Franco; Favero, Gabriele; de Micheli, Giovanni; Carrara, Sandro

2015-10-01

Novel methods to obtain Pt nanostructured electrodes have raised particular interest due to their high performance in electrochemistry. Several nanostructuration methods proposed in the literature use costly and bulky equipment or are time-consuming due to the numerous steps they involve. Here, Pt nanostructures were produced for the first time by one-step template-free electrodeposition on Pt bare electrodes. The change in size and shape of the nanostructures is proven to be dependent on the deposition parameters and on the ratio between sulphuric acid and chloride-complexes (i.e., hexachloroplatinate or tetrachloroplatinate). To further improve the electrochemical properties of electrodes, depositions of Pt nanostructures on previously synthesised Pt nanostructures are also performed. The electroactive surface areas exhibit a two order of magnitude improvement when Pt nanostructures with the smallest size are used. All the biosensors based on Pt nanostructures and immobilised glucose oxidase display higher sensitivity as compared to bare Pt electrodes. Pt nanostructures retained an excellent electrocatalytic activity towards the direct oxidation of glucose. Finally, the nanodeposits were proven to be an excellent solid contact for ion measurements, significantly improving the time-stability of the potential. The use of these new nanostructured coatings in electrochemical sensors opens new perspectives for multipanel monitoring of human metabolism.

Spectral analysis method for detecting an element

DOEpatents

Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

2008-02-12

A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

Chemical, biological, radiological, and nuclear decontamination: Recent trends and future perspective

PubMed Central

Kumar, Vinod; Goel, Rajeev; Chawla, Raman; Silambarasan, M.; Sharma, Rakesh Kumar

2010-01-01

Chemical, biological, radiological, and nuclear (CBRN) decontamination is the removal of CBRN material from equipment or humans. The objective of the decontamination is to reduce radiation burden, salvage equipment, and materials, remove loose CBRN contaminants, and fix the remaining in place in preparation for protective storage or permanent disposal work activities. Decontamination may be carried out using chemical, electrochemical, and mechanical means. Like materials, humans may also be contaminated with CBRN contamination. Changes in cellular function can occur at lower radiation doses and exposure to chemicals. At high dose, cell death may take place. Therefore, decontamination of humans at the time of emergency while generating bare minimum waste is an enormous task requiring dedication of large number of personnel and large amount of time. General principles of CBRN decontamination are discussed in this review with emphasis on radiodecontamination. PMID:21829318

Dark soliton past a finite-size obstacle

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

Bilas, Nicolas; Pavloff, Nicolas

2005-09-15

We consider the collision of a dark soliton with an obstacle in a quasi-one-dimensional Bose condensate. We show that in many respects the soliton behaves as an effective classical particle of mass twice the mass of a bare particle, evolving in an effective potential which is a convolution of the actual potential describing the obstacle. Radiative effects beyond this approximation are also taken into account. The emitted waves are shown to form two counterpropagating wave packets, both moving at the speed of sound. We determine, at leading order, the total amount of radiation emitted during the collision and compute themore » acceleration of the soliton due to the collisional process. It is found that the radiative process is quenched when the velocity of the soliton reaches the velocity of sound in the system.« less

A prospective randomized study for efficacy of an uncovered double bare metal stent compared to a single bare metal stent in malignant biliary obstruction.

PubMed

Lee, Hyun Jik; Chung, Moon Jae; Park, Jeong Yup; Park, Seung Woo; Nam, Chung Mo; Song, Si Young; Bang, Seungmin

2017-08-01

A biliary self-expandable metal stent (SEMS) is commonly used to relieve malignant biliary obstruction. The aim of this study was to compare the efficacy of a conventional uncovered SEMS with that of a newly developed uncovered double bare metal stent in reducing the risk of stent occlusion caused by tumor ingrowth. We performed a prospective, open-labeled, randomized trial in 71 patients at Severance Hospital, Yonsei University College of Medicine from June 2013 to June 2014. Patients with inoperable malignant biliary obstruction were included and randomized to receive an uncovered single bare metal stent (SBSs; S&G Biotech Inc.), an uncovered single bare metal stent (SBSt; Taewoong Medical), or an uncovered double bare metal stent (DBS; S&G Biotech Inc.). The mean age was 66.6 years (range, 35-83), and 42 (59.2%) were male. The mean duration of stent patency was 212 days (±152) in the DBS group (n = 24) compared with 124 days (±98) in the SBSs group (n = 23; P = 0.022 for noninferiority) and 116 days (±79) in the SBSt group (n = 24; P = 0.010 for noninferiority). There were no differences in the incidences of early and delayed complications or migration. The newly developed DBS is noninferior to the conventional uncovered SEMSs on duration of stent patency and tumor ingrowth occurred less frequently in the DBS group. This might decrease the need for reintervention and offer a better quality of life. The trial is registered with Clinicaltrials.gov no: NCT01869894.

Evaluation of Bare Ground on Rangelands using Unmanned Aerial Vehicles

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

Robert P. Breckenridge; Maxine Dakins

2011-01-01

Attention is currently being given to methods that assess the ecological condition of rangelands throughout the United States. There are a number of different indicators that assess ecological condition of rangelands. Bare Ground is being considered by a number of agencies and resource specialists as a lead indicator that can be evaluated over a broad area. Traditional methods of measuring bare ground rely on field technicians collecting data along a line transect or from a plot. Unmanned aerial vehicles (UAVs) provide an alternative to collecting field data, can monitor a large area in a relative short period of time, andmore » in many cases can enhance safety and time required to collect data. In this study, both fixed wing and helicopter UAVs were used to measure bare ground in a sagebrush steppe ecosystem. The data were collected with digital imagery and read using the image analysis software SamplePoint. The approach was tested over seven different plots and compared against traditional field methods to evaluate accuracy for assessing bare ground. The field plots were located on the Idaho National Laboratory (INL) site west of Idaho Falls, Idaho in locations where there is very little disturbance by humans and the area is grazed only by wildlife. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.« less

Temperature responses of carbon monoxide and hydrogen uptake by vegetated and unvegetated volcanic cinders

PubMed Central

King, Caitlin E; King, Gary M

2012-01-01

Ecosystem succession on a large deposit of volcanic cinders emplaced on Kilauea Volcano in 1959 has resulted in a mosaic of closed-canopy forested patches and contiguous unvegetated patches. Unvegetated and unshaded surface cinders (Bare) experience substantial diurnal temperature oscillations ranging from moderate (16 °C) to extreme (55 °C) conditions. The surface material of adjacent vegetated patches (Canopy) experiences much smaller fluctuations (14–25 °C) due to shading. To determine whether surface material from these sites showed adaptations by carbon monoxide (CO) and hydrogen (H2) consumption to changes in ambient temperature regimes accompanying succession, we measured responses of CO and H2 uptake to short-term variations in temperature and long-term incubations at elevated temperature. Based on its broader temperature optimum and lower activation energy, Canopy H2 uptake was less sensitive than Bare H2 uptake to temperature changes. In contrast, Bare and Canopy CO uptake responded similarly to temperature during short-term incubations, indicating no differences in temperature sensitivity. However, during extended incubations at 55 °C, CO uptake increased for Canopy but not Bare material, which indicated that the former was capable of thermal adaptation. H2 uptake for material from both sites was completely inhibited at 55 °C throughout extended incubations. These results indicated that plant development during succession did not elicit differences in short-term temperature responses for Bare and Canopy CO uptake, in spite of previously reported differences in CO oxidizer community composition, and differences in average daily and extreme temperatures. Differences associated with vegetation due to succession did, however, lead to a notable capacity for thermophilic CO uptake by Canopy but not Bare material. PMID:22258097

Temperature responses of carbon monoxide and hydrogen uptake by vegetated and unvegetated volcanic cinders.

PubMed

King, Caitlin E; King, Gary M

2012-08-01

Ecosystem succession on a large deposit of volcanic cinders emplaced on Kilauea Volcano in 1959 has resulted in a mosaic of closed-canopy forested patches and contiguous unvegetated patches. Unvegetated and unshaded surface cinders (Bare) experience substantial diurnal temperature oscillations ranging from moderate (16 °C) to extreme (55 °C) conditions. The surface material of adjacent vegetated patches (Canopy) experiences much smaller fluctuations (14-25 °C) due to shading. To determine whether surface material from these sites showed adaptations by carbon monoxide (CO) and hydrogen (H(2)) consumption to changes in ambient temperature regimes accompanying succession, we measured responses of CO and H(2) uptake to short-term variations in temperature and long-term incubations at elevated temperature. Based on its broader temperature optimum and lower activation energy, Canopy H(2) uptake was less sensitive than Bare H(2) uptake to temperature changes. In contrast, Bare and Canopy CO uptake responded similarly to temperature during short-term incubations, indicating no differences in temperature sensitivity. However, during extended incubations at 55 °C, CO uptake increased for Canopy but not Bare material, which indicated that the former was capable of thermal adaptation. H(2) uptake for material from both sites was completely inhibited at 55 °C throughout extended incubations. These results indicated that plant development during succession did not elicit differences in short-term temperature responses for Bare and Canopy CO uptake, in spite of previously reported differences in CO oxidizer community composition, and differences in average daily and extreme temperatures. Differences associated with vegetation due to succession did, however, lead to a notable capacity for thermophilic CO uptake by Canopy but not Bare material.

Understanding Life Cycle Assessment: Applications for OSWER's Land and Materials Managment

EPA Science Inventory

The Office of Superfund Remediation and Technology Innovation (OSRTI) is hosting an informative webcast presentation by Jane Bare, expert on Life Cycle Impact Assessment (LCIA) in EPA's Office of Research and Development. Ms. Bare's presentation will provide an overview of LCIA, ...

Exploiting Defect Clustering to Screen Bare Die for Infant Mortality Failure: An Experimental Study

NASA Technical Reports Server (NTRS)

Lakin, David R., II; Singh, Adit D.

1999-01-01

We present the first experimental results to establish that a binning strategy based on defect clustering can be used to screen bare die for early life failures. The data for this study comes from the SEMATECH test methods experiment.

Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

NASA Astrophysics Data System (ADS)

Taskjelle, Torbjørn; Hudson, Stephen R.; Granskog, Mats A.; Hamre, Børge

2017-09-01

Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400-900 nm) were found to be on average 0.15-0.20 under bare ice, and 0.39-0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice). This large difference is due to the highly scattering surface scattering layer (SSL) increasing the albedo of the bare ice.

Effect of varying Nd:YAG laser fiber tips on porcine dermal tissue

NASA Astrophysics Data System (ADS)

Pergadia, Vani R.; Vari, Sandor G.; Snyder, Wendy J.; Duffy, J. T.; Weiss, Andrew B.; Fishbein, Michael C.; Thomas, Reem; Shi, Wei-Qiang; Tausend, Kevin J.; Grundfest, Warren S.

1994-02-01

We evaluated the effect of the 600 micrometers bare (flat tip) and 600/100 micrometers conical tip fibers on porcine skin. We compared their effect in both the continuous-wave (cw) and pulsed (P) modes (20 ms ON/OFF) at 20 W to that of the electrocautery at 100 W in the pure and blend 3 modes. On 11 farmer pigs, 6 cuts were made for each parameter combination. The samples were processed for histological evaluation. The cutting depth, cutting width, and total thermal damage (carbonization, coagulation and denaturation) were recorded for each parameter combination. The results show that the 600/100 micrometers conical fiber provides deeper resective capabilities than the 600 micrometers bare and electrocautery. In addition, the 600/100 micrometers conical tip fiber allows for narrower cuts with significantly less thermal necrosis when compared to the 600 micrometers bare and electrocautery. The results indicate that there is an advantage to using the sculptured tip fiber for creating incisions when compared to the bare fiber and electrocautery.

Applications of the silicon wafer direct-bonding technique to electron devices

NASA Astrophysics Data System (ADS)

Furukawa, K.; Nakagawa, A.

1990-01-01

A silicon wafer direct-bonding (SDB) technique has been developed. A pair of bare silicon wafers, as well as an oxidized wafer pair, are bonded throughout the wafer surfaces without any bonding material. Conventional semiconductor device processes can be used for the bonded wafers, since the bonded interface is stable thermally, chemically, mechanically and electrically. Therefore, the SDB technique is very attractive, and has been applied to several kinds of electron devices. Bare silicon to bare silicon bonding is an alternative for epitaxial growth. A thick, high quality and high resistivity layer on a low resistivity substrate was obtained without autodoping. 1800 V insulated gate bipolar transistors were developed using these SDB wafers. No electrical resistance was observed at the bonded bare silicon interfaces. If oxidized wafers are bonded, the two wafers are electrically isolated, providing silicon on insulator (SOI) wafers. Dielectrically isolated photodiode arrays were fabricated on the SOI wafers and 500 V power IC's are now being developed.

Bacterial repopulation of drinking water pipe walls after chlorination.

PubMed

Mathieu, Laurence; Francius, Grégory; El Zein, Racha; Angel, Edith; Block, Jean-Claude

2016-09-01

The short-term kinetics of bacterial repopulation were evaluated after chlorination of high-density polyethylene (HDPE) colonized with drinking water biofilms and compared with bare HDPE surfaces. The effect of chlorination was partial as a residual biofilm persisted and was time-limited as repopulation occurred immediately after water resupply. The total number of bacteria reached the same levels on both the bare and chlorinated biofilm-fouled HDPE after a seven-day exposure to drinking water. Due to the presence of a residual biofilm, the hydrophobicity of chlorinated biofilm-fouled surface exhibited much lower adhesion forces (2.1 nN) compared to bare surfaces (8.9 nN). This could explain the rapid repopulation after chlorination, with a twofold faster bacterial accumulation rate on the bare HDPE surface. γ-Proteobacteria dominated the early stages of repopulation of both surfaces and a shift in the dominance occurred over the colonization time. Such observations define a timescale for cleaning frequency in industrial environments and guidelines for a rinsing procedure using drinking water.

Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

NASA Technical Reports Server (NTRS)

Sasscer, D. S.; Morgan, T. O.; Rivera, C.; Ernst, R.; Scott, A. C.; Summerson, T. J.

1982-01-01

Bare 3004 tubes, 7072 Alclad 3004 tubes, and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr). Pitting did not occur in bare 3003 and 3004 samples during the six month test. Pitting did occur to varying degrees in the Alclad and zinc diffusion treated material, but did not penetrate to the base metal. Biofouling countermeasures (intermittent chlorination and brushing) did not affect the corrosion rates to any significant extent. Intermittent chlorination at a level of 0.5 ppm for 28 minutes daily controlled microbiofouling of the samples but did not prevent the development of a macrobiofouling community in areas of the plumbing with low flow.

Test of Lorentz and CPT violation with short baseline neutrino oscillation excesses

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Huelsnitz, W.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Ouedraogo, S.; Patterson, R. B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R. G.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2013-01-01

The sidereal time dependence of MiniBooNE νe and νbare appearance data is analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov (K-S) test shows both the νe and νbare appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the νe appearance data prefer a sidereal time-independent solution, and the νbare appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10-20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for νμ →νe and νbarμ →νbare oscillations. The fit values and limits of combinations of SME coefficients are provided.

Near-edge wrack effects on bare sediments: Small scale variation matters in the monitoring of sandy beaches.

PubMed

MacMillan, Mitchell R; Tummon Flynn, Paula; Duarte, Cristian; Quijón, Pedro A

2016-12-01

The influence of wrack on sandy beach communities is well-documented but its effect on bare sediments located immediately beyond its edge has not yet been tested. This study aimed to explore these effects by surveying bare sediments located at increasing distances (0.5-2 m) from the wrack in five sandy beaches on Prince Edward Island, Atlantic Canada. In addition, we tested the influence of wrack with a field manipulation using wrack patches made up of rockweed bundles. The survey indicated that a modest but significant number of amphipods and beetles occupied bare sediments located 0.5 m from the edge of the wrack, but that those numbers dropped in sediments 1 m away and farther. The outcome of the field manipulation showed a similar pattern. Although small in spatial scale, our results have implications for the monitoring sandy beaches affected by scattered as well as heavy wrack input. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of tiny amounts of fissile materials in large-sized containers with radioactive waste

NASA Astrophysics Data System (ADS)

Batyaev, V. F.; Skliarov, S. V.

2018-01-01

The paper is devoted to non-destructive control of tiny amounts of fissile materials in large-sized containers filled with radioactive waste (RAW). The aim of this work is to model an active neutron interrogation facility for detection of fissile ma-terials inside NZK type containers with RAW and determine the minimal detectable mass of U-235 as a function of various param-eters: matrix type, nonuniformity of container filling, neutron gen-erator parameters (flux, pulse frequency, pulse duration), meas-urement time. As a result the dependence of minimal detectable mass on fissile materials location inside container is shown. Nonu-niformity of the thermal neutron flux inside a container is the main reason of the space-heterogeneity of minimal detectable mass in-side a large-sized container. Our experiments with tiny amounts of uranium-235 (<1 g) confirm the detection of fissile materials in NZK containers by using active neutron interrogation technique.

Probing dynamics and mechanism of exchange process of quaternary ammonium dimeric surfactants, 14-s-14, in the presence of conventional surfactants.

PubMed

Liu, Jun; Jiang, Yan; Chen, Hong; Mao, Shi Zhen; Du, You Ru; Liu, Mai Li

2012-12-27

In this Article, we investigated effects of different types of conventional surfactants on exchange dynamics of quaternary ammonium dimeric surfactants, with chemical formula C(14)H(29)N(+)(CH(3))(2)- (CH(2))(s)-N(+)(CH(3))(2)C(14)H(29)·2Br(-), or 14-s-14 for short. Two nonionic surfactants, TritonX-100 (TX-100) and polyethylene glycol (23) laurylether (Brij-35), and one cationic surfactant, n-tetradecyltrimethyl ammonium bromide (TTAB), and one ionic surfactant, sodium dodecyl sulfate (SDS) were chosen as typical conventional surfactants. Exchange rates of 14-s-14 (s = 2, 3, and 4) between the micelle form and monomer in solution were detected by two NMR methods: one-dimensional (1D) line shape analysis and two-dimensional (2D) exchange spectroscopy (EXSY). Results show that the nonionic surfactants (TX-100 and Brij-35), the cationic surfactant (TTAB), and the ionic surfactant (SDS) respectively accelerated, barely influenced, and slowed the exchange rate of 14-s-14. The effect mechanism was investigated by the self-diffusion experiment, relaxation time measurements (T(2)/T(1)), the fluorescence experiment (I(1)/I(3)) and observed chemical shift variations. Results reveal that, nonionic conventional surfactants (TX-100 and Brij-35) loosened the molecule arrangement and decreased hydrophobic interactions in the micelle, and thus accelerated the exchange rate of 14-s-14. The cationic conventional surfactant (TTAB) barely changed the molecule arrangement and thus barely influenced the exchange rate of 14-s-14. The ionic conventional surfactant (SDS) introduced the electrostatic attraction effect, tightened the molecule arrangement, and increased hydrophobic interactions in the micelle, and thus slowed down the exchange rate of 14-s-14. Additionally, the two-step exchange mechanism of 14-s-14 in the mixed solution was revealed through interesting variation tendencies of exchange rates of 14-s-14.

Implications of climate change for evaporation from bare soils in a Mediterranean environment.

PubMed

Aydin, Mehmet; Yano, Tomohisa; Evrendilek, Fatih; Uygur, Veli

2008-05-01

The purpose of this study was to predict quantitative changes in evaporation from bare soils in the Mediterranean climate region of Turkey in response to the projections of a regional climate model developed in Japan (hereafter RCM). Daily RCM data for the estimation of reference evapotranspiration (ETr) and soil evaporation were obtained for the periods of 1994--2003 and 2070--2079. Potential evaporation (Ep) from bare soils was calculated using the Penman-Monteith equation with a surface resistance of zero. Simulation of actual soil evaporation (Ea) was carried out using Aydin model (Aydin et al., Ecological Modelling 182:91-105, 2005) combined with Aydin and Uygur (2006, A model for estimating soil water potential of bare fields. In Proceedings of the 18th International Soil Meeting (ISM) on Soils Sustaining Life on Earth, Managing Soil and Technology, Sanliurfa, 477-480pp.) model of predicting soil water potential at the top surface layer of a bare soil, after performances of Aydin model (R2 = 94.0%) and Aydin and Uygur model (R2 = 97.6) were tested. The latter model is based on the relations among potential soil evaporation, hydraulic diffusivity, and soil wetness, with some simplified assumptions. Input parameters of the model are simple and easily obtainable such as climatic parameters used to compute the potential soil evaporation, average diffusivity for the drying soil, and volumetric water content at field capacity. The combination of Aydin and Aydin and Uygur models appeared to be useful in estimating water potential of soils and Ea from bare soils, with only a few parameters. Unlike ETr and Ep projected to increase by 92 and 69 mm (equivalent to 8.0 and 7.3% increases) due to the elevated evaporative demand of the atmosphere, respectively, Ea from bare soils is projected to reduce by 50 mm (equivalent to a 16.5% decrease) in response to a decrease in rainfall by 46% in the Mediterranean region of Turkey by the 2070s predicted by RCM, and consequently, to decreased soil wetness in the future.

Correlation between landscape fragmentation and sandy desertification: a case study in Horqin Sandy Land, China.

PubMed

Ge, Xiaodong; Dong, Kaikai; Luloff, A E; Wang, Luyao; Xiao, Jun; Wang, Shiying; Wang, Qian

2016-01-01

The exact roles of landscape fragmentation on sandy desertification are still not fully understood, especially with the impact of different land use types in spatial dimension. Taking patch size and shape into consideration, this paper selected the Ratio of Patch Size and the Fractal Dimension Index to establish a model that reveals the association between the area of bare sand land and the fragmentation of different land use types adjacent to bare sand land. Results indicated that (1) grass land and arable land contributed the most to landscape fragmentation processes in the regions adjacent to bare sand land during the period 1980 to 2010. Grass land occupied 54 % of the region adjacent to bare sand land in 1980. The Ratio of Patch Size of grass land decreased from 1980 to 2000 and increased after 2000. The Fractal Dimension Index of grass increased during the period 1980 to 1990 and decreased after 1990. Arable land expanded significantly during this period. The Ratio of Patch Size of arable land increased from 1980 to 1990 and decreased since 1990. The Fractal Dimension Index of arable land increased from 1990 to 2000 and decreased after 2000. (2) The Ratio of Patch Size and the Fractal Dimension Index were significantly related to the area of bare sand land. The role of landscape fragmentation was not linear to sandy desertification. There were both positive and negative effects of landscape fragmentation on sandy desertification. In 1980, the Ratio of Patch Size and the Fractal Dimension Index were negatively related to the area of bare sand land, showing that the landscape fragmentation and regularity of patches contributed to the expansion of sandy desertification. In 1990, 2000, and 2010, the Ratio of Patch Size and the Fractal Dimension Index were mostly positively related to the area of bare sand land, showing the landscape fragmentation and regularity of patches contributed to the reversion of sandy desertification in this phase. The absolute values of the coefficients were the highest for grass land in the regression models, so that grass land had the most important influence on sandy desertification.

Gold nanoparticles on titanium and interaction with prototype protein.

PubMed

Padmos, J Daniel; Duchesne, Paul; Dunbar, Michael; Zhang, Peng

2010-10-01

Modifying titanium (Ti) implant surfaces with functional proteins can strengthen the interface between prosthesis and bone. A prototype system was developed using gold nanoparticles (AuNPs) to immobilize proteins onto Ti. An electroless (galvanic displacement) deposition method was first used to form AuNPs of controlled size and coverage on commercial Ti foil (giving Ti-AuNPs). Parameters were then modified to create two groups of discs (n = 26) with different average AuNP diameters. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the morphology and surface structure of Ti-AuNPs. To study the interaction of Ti-AuNPs with proteins, Ti discs (n = 8) modified with plain AuNPs and discs (n = 8) modified with thiol (HS--R--COOH)-functionalized AuNPs were treated with lysozyme solution. The amount and activity of the lysozyme on the discs were examined with Micro-BCA and enzymatic assays. Lysozyme was immobilized onto the discs, and the assays showed that the discs with thiol-functionalized AuNPs, discs with bare AuNPs, and Ti controls had average lysozyme adsorptions of 23 x 10(4), 2.3 x 10(4), and 5.7 x 10(4) microg/m2, respectively. The activity assays showed that 21.5, 18.4, and 12.5% of the adsorbed lysozyme was active on the discs with thiol-functionalized AuNPs, discs with bare AuNPs, and Ti controls, respectively. This technique holds promise for binding functional biomolecules to surgical implants, hence possibly creating implant surfaces that react to their local environment. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

Morphology control, defect engineering and photoactivity tuning of ZnO crystals by graphene oxide--a unique 2D macromolecular surfactant.

PubMed

Pan, Xiaoyang; Yang, Min-Quan; Xu, Yi-Jun

2014-03-28

Zinc oxide (ZnO) nanostructured materials have received significant attention because of their unique physicochemical and electronic properties. In particular, the functional properties of ZnO are strongly dependent on its morphology and defect structure, particularly for a semiconductor ZnO-based photocatalyst. Here, we demonstrate a simple strategy for simultaneous morphology control, defect engineering and photoactivity tuning of semiconductor ZnO by utilizing the unique surfactant properties of graphene oxide (GO) in a liquid phase. By varying the amount of GO added during the synthesis process, the morphology of ZnO gradually evolves from a one dimensional prismatic rod to a hexagonal tube-like architecture while GO is converted into reduced GO (RGO). In addition, the introduction of GO can create oxygen vacancies in the lattice of ZnO crystals. As a result, the absorption edge of the wide band gap semiconductor ZnO is effectively extended to the visible light region, which thus endows the RGO-ZnO nanocomposites with visible light photoactivity; in contrast, the bare ZnO nanorod is only UV light photoactive. The synergistic integration of the unique morphology and the presence of oxygen vacancies imparts the RGO-ZnO nanocomposite with remarkably enhanced visible light photoactivity as compared to bare ZnO and its counterpart featuring different structural morphologies and the absence of oxygen vacancies. Our promising results highlight the versatility of the 2D GO as a solution-processable macromolecular surfactant to fabricate RGO-semiconductor nanocomposites with tunable morphology, defect structure and photocatalytic performance in a system-materials-engineering way.

Effects of the Carrier-Envelope Phase in the Multiphoton Ionization Regime

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

Nakajima, Takashi; Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581; Watanabe, Shuntaro

2006-06-02

We theoretically investigate the effects of the carrier-envelope phase of few-cycle laser pulses in the multiphoton ionization regime. For atoms with low ionization potential, total ionization yield barely exhibits phase dependence, as expected. However, population of some bound states clearly shows phase dependence. This implies that the measurement of the carrier-envelope phase would be possible through the photoemission between bound states without energy-and-angle-resolved photoelectron detection. The considered scheme could be particularly useful to measure the carrier-envelope phase for a light source without an amplifier, such as a laser oscillator, which cannot provide sufficient pulse energy to induce tunneling ionization.

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Electricity Surface...

DETAIL VIEW, SOUTH PORTICO. THE BARE GROUND BENEATH THE PORTICO’S ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW, SOUTH PORTICO. THE BARE GROUND BENEATH THE PORTICO’S CENTER BAY DISCLOSES THE LOCATION OF A REMOVED STAIR. THE ORIGINAL FRAME STAIRCASES UP TO THE PORTICO EXTENDED FROM THE EAST AND WEST SIDES - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

FREE-WATER DEPTH AS A MANAGEMENT TOOL FOR CONSTRUCTED WETLANDS

EPA Science Inventory

Marsh plants in constructed wetlands have shown the capacity to remove unwanted pollutants from storm water runoff. The plants can be established at the site from bare roots. However, plant growth from bare roots can be restricted by the elevated water depths. Using several wa...

Genetics Home Reference: bare lymphocyte syndrome type II

MedlinePlus

... 6. Citation on PubMed Gobin SJ, Peijnenburg A, van Eggermond M, van Zutphen M, van den Berg R, van den Elsen PJ. The RFX complex is crucial ... D, Szöllosi J, Jenei A. Bare lymphocyte syndrome: an opportunity to discover our immune system. Immunol Lett. ...

Protoporphyrin IX Content Correlates with Activity of Photobleaching Herbicides

PubMed Central

Becerril, Jose M.; Duke, Stephen O.

1989-01-01

Several laboratories have demonstrated recently that photobleaching herbicides such as acifluorfen and oxadiazon cause accumulation of protoporphyrin IX (PPIX), a photodynamic pigment capable of herbicidal activity. We investigated, in acifluorfen-treated tissues, the in vivo stability of PPIX, the kinetics of accumulation, and the correlation between concentration of PPIX and herbicidal damage. During a 20 hour dark period, PPIX levels rose from barely detectable concentrations to 1 to 2 nanomoles per 50 cucumber (Cucumis sativus L.) cotyledon discs treated with 10 micromolar acifluorfen. When placed in 500 micromoles per square meter per second PAR, PPIX levels decayed logarithmically, with an initial half-life of about 2.5 hours. PPIX levels at each time after exposure to light correlated positively with the cellular damage that occurred during the following 1 hour in both green and yellow (tentoxin-treated) cucumber cotyledon tissues. PPIX levels in discs incubated for 20 hours in darkness correlated positively with the acifluorfen concentration in which they were incubated. In cucumber, the level of herbicidal damage caused by several p-nitrodiphenyl other herbicides, a p-chlorodiphenylether herbicide, and oxadiazon correlated positively with the amount of PPIX induced to accumulate by each of the herbicide treatments. Similar results were obtained with acifluorfen-treated pigweed and velvetleaf primary leaf tissues. In cucumber, PPIX levels increased within 15 and 30 minutes after exposure of discs to 10 micromolar acifluorfen in the dark and light, respectively. These data strengthen the view that PPIX is responsible for all or a major part of the photobleaching activity of acifluorfen and related herbicides. PMID:16666869

GD3- and O-acetylated GD3-gangliosides in the GM2 synthase-deficient mouse brain and their immunohistochemical localization

PubMed Central

Matsuda, Junko; Vanier, Marie T.; Popa, Iuliana; Portoukalian, Jacques; Suzuki, Kunihiko

2006-01-01

Gangliosides in the brain of the knockout mouse deficient in the activity of β1,4 N-acetylgalactosaminyl transferase (β1,4 GalNAc-T)(GM2 synthase) consisted of nearly exclusively of GM3- and GD3-gangliosides as expected from the known substrate specificity of the enzyme and in confirmation of the initial reports from two laboratories that generated the mutant mouse experimentally. The total molar amount of gangliosides was approximately 30% higher in the mutant mouse brain than that in the wild-type brain. However, contrary to the initial reports, one-fourth of total GD3-ganglioside was O-acetylated. It reacted positively with an anti-O-acetylated GD3 monoclonal antibody and disappeared with a corresponding increase in GD3-ganglioside after mild alkaline treatment. The absence of O-acetylated GD3 in the initial reports can be explained by the saponification step included in their analytical procedures. Although quantitatively much less and identification tentative, we also detected GT3 and O-acetylated GT3. Anti-GD3 and anti-O-acetylated GD3 monoclonal antibodies gave positive reactions in the brain of mutant mouse as expected from the analytical results. Either antibody barely stained wild-type brain except for immunoreactivity of GD3 in the cerebellar Purkinje cells. The distributions of GD3 and O-acetylated GD3 in the brain of mutant mouse were similar but differential localization was noted in the cerebellar Purkinje cells and cerebral cortex. PMID:25792782

Damage criticality and inspection concerns of composite-metallic aircraft structures under blunt impact

NASA Astrophysics Data System (ADS)

Zou, D.; Haack, C.; Bishop, P.; Bezabeh, A.

2015-04-01

Composite aircraft structures such as fuselage and wings are subject to impact from many sources. Ground service equipment (GSE) vehicles are regarded as realistic sources of blunt impact damage, where the protective soft rubber is used. With the use of composite materials, blunt impact damage is of special interest, since potential significant structural damage may be barely visible or invisible on the structure's outer surface. Such impact can result in local or non-local damage, in terms of internal delamination in skin, interfacial delamination between stiffeners and skin, and fracture of internal reinforced component such as stringers and frames. The consequences of these events result in aircraft damage, delays, and financial cost to the industry. Therefore, it is necessary to understand the criticality of damage under this impact and provide reliable recommendations for safety and inspection technologies. This investigation concerns a composite-metallic 4-hat-stiffened and 5-frame panel, designed to represent a fuselage structure panel generic to the new generation of composite aircraft. The test fixtures were developed based on the correlation between finite element analyses of the panel model and the barrel model. Three static tests at certain amount of impact energy were performed, in order to improve the understanding of the influence of the variation in shear ties, and the added rotational stiffness. The results of this research demonstrated low velocity high mass impacts on composite aircraft fuselages beyond 82.1 kN of impact load, which may cause extensive internal structural damage without clear visual detectability on the external skin surface.

Dispersive microextraction based on water-coated Fe₃O₄ followed by gas chromatography-mass spectrometry for determination of 3-monochloropropane-1,2-diol in edible oils.

PubMed

Zhao, Qin; Wei, Fang; Xiao, Neng; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

2012-06-01

In the present work, we developed a novel dispersive microextraction technique by combining the advantages of liquid-phase microextraction (LPME) and magnetic solid-phase extraction (MSPE). In this method, trace amount of water directly absorbed on bare Fe₃O₄ to form water-coated Fe₃O₄ (W-Fe₃O₄) and rapid extraction can be achieved while W-Fe₃O₄ dispersed in the sample solution. The analyte adsorbed W-Fe₃O₄ can be easily collected and isolated from sample solution by application of a magnet. It was worth noting that in the proposed method water was used as extractant and Fe₃O₄ served as the supporter and retriever of water. The performance of the method was evaluated by extraction of 3-monochloropropane-1,2-diol (3-MCPD) from edible oils. The extracted 3-MCPD was then derived by a silylanization reagent (1-trimethylsilylimidazole) before gas chromatography-mass spectrometry (GC-MS) analysis. Several parameters that affected the extraction and derivatization efficiency were investigated. Our results showed that the limit of detection for 3-MCPD was 1.1 ng/g. The recoveries in spiked oil samples were in the range of 70.0-104.9% with the RSDs less than 5.6% (intra-day) and 6.4% (inter-day). Taken together, the simple, rapid and cost-effective method developed in current study, offers a potential application for the extraction and preconcentration of hydrophilic analytes from complex fatty samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Hydrocyclone/Filter for Concentrating Biomarkers from Soil

NASA Technical Reports Server (NTRS)

Ponce, Adrian; Obenhuber, Donald

2008-01-01

The hydrocyclone-filtration extractor (HFE), now undergoing development, is a simple, robust apparatus for processing large amounts of soil to extract trace amounts of microorganisms, soluble organic compounds, and other biomarkers from soil and to concentrate the extracts in amounts sufficient to enable such traditional assays as cell culturing, deoxyribonucleic acid (DNA) analysis, and isotope analysis. Originally intended for incorporation into a suite of instruments for detecting signs of life on Mars, the HFE could also be used on Earth for similar purposes, including detecting trace amounts of biomarkers or chemical wastes in soils.

Probing Biological Processes on Supported Lipid Bilayers with Single-Walled Carbon Nanotube Field-Effect Transistors

NASA Astrophysics Data System (ADS)

Zhou, Xinjian; Moran-Mirabal, Jose Manuel; Craighead, Harold; McEuen, Paul

2006-03-01

We have formed supported lipid bilayers (SLBs) by small unilamellar vesicle fusion on substrates containing single-walled carbon nanotube field-effect transistors (SWNT-FETs). We are able to detect the self-assembly of SLBs electrically with SWNT-FETs since their threshold voltages are shifted by this event. The SLB fully covers the NT surface and lipid molecules can diffuse freely in the bilayer surface across the NT. To study the interactions of important biological entities with receptors imbedded within the membrane, we have also integrated a membrane protein, GT1b ganglioside, in the bilayer. While bare gangliosides can diffuse freely across the NT, interestingly the NT acts as a diffusion barrier for the gangliosides when they are bound with tetanus toxin. This experiment opens the possibility of using SWNT-FETs as biosensors for label-free detection.

Catechol-chitosan redox capacitor for added amplification in electrochemical immunoanalysis.

PubMed

Yan, Kun; Liu, Yi; Guan, Yongguang; Bhokisham, Narendranath; Tsao, Chen-Yu; Kim, Eunkyoung; Shi, Xiao-Wen; Wang, Qin; Bentley, William E; Payne, Gregory F

2018-05-22

Antibodies are common recognition elements for molecular detection but often the signals generated by their stoichiometric binding must be amplified to enhance sensitivity. Here, we report that an electrode coated with a catechol-chitosan redox capacitor can amplify the electrochemical signal generated from an alkaline phosphatase (AP) linked immunoassay. Specifically, the AP product p-aminophenol (PAP) undergoes redox-cycling in the redox capacitor to generate amplified oxidation currents. We estimate an 8-fold amplification associated with this redox-cycling in the capacitor (compared to detection by a bare electrode). Importantly, this capacitor-based amplification is generic and can be coupled to existing amplification approaches based on enzyme-linked catalysis or magnetic nanoparticle-based collection/concentration. Thus, the capacitor should enhance sensitivities in conventional immunoassays and also provide chemical to electrical signal transduction for emerging applications in molecular communication. Copyright © 2018 Elsevier B.V. All rights reserved.

Multithreaded hybrid feature tracking for markerless augmented reality.

PubMed

Lee, Taehee; Höllerer, Tobias

2009-01-01

We describe a novel markerless camera tracking approach and user interaction methodology for augmented reality (AR) on unprepared tabletop environments. We propose a real-time system architecture that combines two types of feature tracking. Distinctive image features of the scene are detected and tracked frame-to-frame by computing optical flow. In order to achieve real-time performance, multiple operations are processed in a synchronized multi-threaded manner: capturing a video frame, tracking features using optical flow, detecting distinctive invariant features, and rendering an output frame. We also introduce user interaction methodology for establishing a global coordinate system and for placing virtual objects in the AR environment by tracking a user's outstretched hand and estimating a camera pose relative to it. We evaluate the speed and accuracy of our hybrid feature tracking approach, and demonstrate a proof-of-concept application for enabling AR in unprepared tabletop environments, using bare hands for interaction.

Electrocatalytic response of poly(cobalt tetraaminophthalocyanine)/multi-walled carbon nanotubes-Nafion modified electrode toward sulfadiazine in urine*

PubMed Central

Hong, Xiao-ping; Zhu, Yan; Zhang, Yan-zhen

2012-01-01

A highly sensitive amperometric sulfadiazine sensor fabricated by electrochemical deposition of poly(cobalt tetraaminophthalocyanine) (poly(CoIITAPc)) on the surface of a multi-walled carbon nanotubes-Nafion (MWCNTs-Nafion) modified electrode is described. This electrode showed a very attractive performance by combining the advantages of CoIITAPc, MWCNTs, and Nafion. Compared with the bare glassy carbon electrode (GCE) and the MWCNTs-Nafion modified electrode, the electrocatalytic activity of poly(CoIITAPc)-coated MWCNTs-Nafion GCE generated greatly improved electrochemical detections toward sulfadiazine including low oxidation potential, high current responses, and good anti-fouling performance. The oxidation peak currents of sulfadiazine obtained on the new modified electrode increased linearly while increasing the concentration of sulfadiazine from 0.5 to 43.5 μmol/L with the detection limit of 0.17 μmol/L. PMID:22661213

Reflectance of vegetation, soil, and water. [in Hidalgo County, Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A study was conducted in a 340-acre (139 hectares) field of grain sorghum (Sorghum bicolor (L.) Moench) to determine if multispectral data from ERTS-1 could be used to detect differences in chlorophyll concentration between iron-deficient (chlorotic) and apparently normal (green) grain sorghum. Chlorotic sorghum areas 2.8 acres (1.1 hectares) or larger in size were identified on a computer printout of band 5 data which contains the chlorophyll absorption band at the 0.65 micron wavelength. ERTS resolution is sufficient for practical applications in detecting iron-deficient sorghum in otherwise uniform fields. The first classification map of the study county has been produced. Vegetation (crops), rangeland, bare soil, water, and an undefined (all other) category occupied 15.2, 45.0, 19.1, 0.02, and 20.6% of the land area, respectively.

Prospects for Characterizing the Atmosphere of Proxima Centauri b

NASA Astrophysics Data System (ADS)

Kreidberg, Laura; Loeb, Abraham

2016-11-01

The newly detected Earth-mass planet in the habitable zone of Proxima Centauri could potentially host life—if it has an atmosphere that supports surface liquid water. We show that thermal phase curve observations with the James Webb Space Telescope (JWST) from 5-12 μm can be used to test for the existence of such an atmosphere. We predict the thermal variation for a bare rock versus a planet with 35% heat redistribution to the nightside and show that a JWST phase curve measurement can distinguish between these cases at 4σ confidence, assuming photon-limited precision. We also consider the case of an Earth-like atmosphere, and find that the 9.8 μm ozone band could be detected with longer integration times (a few months). We conclude that JWST observations have the potential to put the first constraints on the possibility of life around the the solar system’s nearest star.

Spatial and temporal variability of hyperspectral signatures of terrain

NASA Astrophysics Data System (ADS)

Jones, K. F.; Perovich, D. K.; Koenig, G. G.

2008-04-01

Electromagnetic signatures of terrain exhibit significant spatial heterogeneity on a range of scales as well as considerable temporal variability. A statistical characterization of the spatial heterogeneity and spatial scaling algorithms of terrain electromagnetic signatures are required to extrapolate measurements to larger scales. Basic terrain elements including bare soil, grass, deciduous, and coniferous trees were studied in a quasi-laboratory setting using instrumented test sites in Hanover, NH and Yuma, AZ. Observations were made using a visible and near infrared spectroradiometer (350 - 2500 nm) and hyperspectral camera (400 - 1100 nm). Results are reported illustrating: i) several difference scenes; ii) a terrain scene time series sampled over an annual cycle; and iii) the detection of artifacts in scenes. A principal component analysis indicated that the first three principal components typically explained between 90 and 99% of the variance of the 30 to 40-channel hyperspectral images. Higher order principal components of hyperspectral images are useful for detecting artifacts in scenes.

Immunological multimetal deposition for rapid visualization of sweat fingerprints.

PubMed

He, Yayun; Xu, Linru; Zhu, Yu; Wei, Qianhui; Zhang, Meiqin; Su, Bin

2014-11-10

A simple method termed immunological multimetal deposition (iMMD) was developed for rapid visualization of sweat fingerprints with bare eyes, by combining the conventional MMD with the immunoassay technique. In this approach, antibody-conjugated gold nanoparticles (AuNPs) were used to specifically interact with the corresponding antigens in the fingerprint residue. The AuNPs serve as the nucleation sites for autometallographic deposition of silver particles from the silver staining solution, generating a dark ridge pattern for visual detection. Using fingerprints inked with human immunoglobulin G (hIgG), we obtained the optimal formulation of iMMD, which was then successfully applied to visualize sweat fingerprints through the detection of two secreted polypeptides, epidermal growth factor and lysozyme. In comparison with the conventional MMD, iMMD is faster and can provide additional information than just identification. Moreover, iMMD is facile and does not need expensive instruments. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of the Sting Nematode, Belonolaimus longicaudalus, on Young Citrus Trees.

PubMed

Kaplan, D T

1985-10-01

The sting nematode, Belonolaimus longicaudatus, was associated with poor growth of citrus in a central Florida nursery. Foliage of trees was sparse and chlorotic. Affected rootstocks included Changsha and Cleopatra mandarin orange; Flying Dragon, Rubidoux, and Jacobsen trifoliate orange; Macrophylla and Milam lemon; Palestine sweet lime; sour orange; and the hybrids - Carrizo, Morton, and Rusk citrange and Swingle citrumelo. Root symptoms included apical swelling, development of swollen terminals containing 3-5 apical meristems and hyperplastic tissue, coarse roots, and a reduction in the number of fibrous roots. Population densities as high as 392 sting nematodes per liter soil were detected, with 80% of the population occurring in the top 30 cm of soil; however, nematodes were detected to 107 cm deep. Although an ectoparasite, the nematode was closely associated with citrus root systems and was transported with bare root nursery stock. Disinfestation was accomplished by hot water treatment (49 C for 5 minutes).

FlowShape: a runoff connectivity index for patched environments, based on shape and orientation of runoff sources

NASA Astrophysics Data System (ADS)

Callegaro, Chiara; Malkinson, Dan; Ursino, Nadia; Wittenberg, Lea

2016-04-01

The properties of vegetation cover are recognized to be a key factor in determining runoff processes and yield over natural areas. Still, how the actual vegetation spatial distribution affects these processes is not completely understood. In Mediterranean semi-arid regions, patched landscapes are often found, with clumped vegetation, grass or shrubs, surrounded by bare soil patches. These two phases produce a sink-source system for runoff, as precipitation falling over bare areas barely infiltrates and rather flows downslope. In contrast, vegetated patches have high infiltrability and can partially retain the runon water. We hypothesize that, at a relatively small scale, the shape and orientation of bare soil patches with respect to the runoff flow direction is a significant for the connectivity of the runoff flow paths, and consequently for runoff values. We derive an index, FlowShape, which is candidate to be a good proxy for runoff connectivity and thus runoff production in patched environments. FlowShape is an area-weighted average of the geometrical properties of each bare soil patch. Eight experimental plots in northern Israel were monitored during 2 years after a wildfire which occurred in 2006. Runoff was collected and measured - along with rainfall depth - after each rainfall event, at different levels of vegetation cover corresponding to post-fire recovery of vegetation and seasonality. We obtained a good correlation between FlowShape and the runoff coefficient, at two conditions: a minimal percentage of vegetation cover over the plot, and minimal rainfall depth. Our results support the hypothesis that the spatial distribution of the two phases (vegetation and bare soil) in patched landscapes dictates, at least partially, runoff yield. The correlation between the runoff coefficient and FlowShape, which accounts for shape and orientation of soil patches, is higher than the correlation between the runoff coefficient and the bare soil percentage alone. Besides that, the existence of a vegetation cover threshold under which FlowShape loses correlation with runoff yield, suggests that different processes occur at different levels of vegetation cover. On bare or almost bare plots, runoff flows as a sheet, and small isolated plants do not impose a directionality to the flow or interrupt runoff connectivity. On the other hand, rainfall depth - and possibly rainfall intensity - also affect the hydrological processes of infiltration and runoff production, and thus the applicability of any purely geometrical index. We compared the correlation to runoff coefficient with the FlowShape and FlowLength, a well-known index for runoff connectivity (Mayor et al., 2008) which is defined as the average of runoff flow paths over the plot. As microtopography was not available, our plots were idealized as planar hillslopes. We found that FlowShape is a better predictor than FlowLength for runoff yield over our experimental plots.

Growth performance, haematological traits, meat variables, and effects of treadmill and transport stress in veal calves supplied different amounts of iron.

PubMed

Lindt, F; Blum, J W

1994-06-01

Effects of serum iron (Fe), haematological variables and on blood lactate levels before and after treadmill exercise or transport to the slaughterhouse, on meat traits, and on growth performance of feeding milk replacer (MR), planned to contain 10, 20, 30, 40, 50 or 80 mg Fe/kg, were studied in veal calves. If supplied less than 50 mg Fe/kg MR, calves developed hypoferraemia and anaemia, the degree of which was dependent on Fe intake. Serum Fe concentration, saturation of transferrin with Fe and the degree of anaemia in calves fed 20 or 10 mg Fe/kg MR were nearly identical. Serum Fe concentration and haematological traits barely changed in calves fed 50 mg Fe/kg MR during the growth trail, but serum Fe concentration increased when MR contained 80 mg Fe/kg in calves fed 50 or more Fe/kg MR. Growth performance was smaller in calves fed 10 mg Fe/kg MR than in those fed greater amounts of Fe/kg MR. Carcass taxation was inversely related to Fe intake. In conclusion, MR containing only 10 mg Fe/kg caused marked anaemia and reduced growth performance. Feeding MR with only 20 mg Fe/kg is not necessarily sufficient to prevent development of severe anaemia. Feeding MR with 50 mg Fe/kg would seem to be physiologically the most appropriate amount of Fe for veal calves, but was too high for acceptable carcass taxation.

The biological and electrical trade-offs related to the thickness of conducting polymers for neural applications.

PubMed

Baek, Sungchul; Green, Rylie A; Poole-Warren, Laura A

2014-07-01

Poly(3,4-ethylenedioxythiophene) (PEDOT) films have attracted substantial interest as coatings for platinum neuroprosthetic electrodes due to their excellent chemical stability and electrical properties. This study systematically examined PEDOT coatings formed with different amounts of charge and dopant ions, and investigated the combination of surface characteristics that were optimal for neural cell interactions. PEDOT samples were fabricated by varying the electrodeposition charge from 0.05 to 1 C cm(-2). Samples were doped with either poly(styrenesulfonate), tosylate (pTS) or perchlorate. Scanning electron micrographs revealed that both thickness and nodularity increased as the charge used to produce the sample was increased, and larger dopants produced smoother films across all thicknesses. X-ray photoelectron spectroscopy confirmed that the amount of charge directly corresponded to the thickness and amount of dopant in the samples. Additionally, with increased thickness and nodularity, the electrochemical properties of all PEDOT coatings improved. However, neural cell adhesion and outgrowth assays revealed that there is a direct biological tradeoff related to the thickness and nodularity. Cell attachment, growth and differentiation was poorer on the thicker, rougher samples, but thin, less nodular PEDOT films exhibited significant improvements over bare platinum. PEDOT/pTS fabricated with a charge density of <0.1Ccm(-2) provided superior electrochemical and biological properties over conventional platinum electrodes and would be the most suitable conducting polymer for neural interface applications. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Erratum: Correction to: Polarisation vision: overcoming challenges of working with a property of light we barely see

NASA Astrophysics Data System (ADS)

Foster, James J.; Temple, Shelby E.; How, Martin J.; Daly, Ilse M.; Sharkey, Camilla R.; Wilby, David; Roberts, Nicholas W.

2018-06-01

In "Polarisation vision: overcoming challenges of working with a property of light we barely see" (Foster et al. 2018) we provide a basic description of how Stokes parameters can be estimated and used to calculate the angle of polarisation (AoP).

Evaluation of interior and exterior latex paints : final report.

DOT National Transportation Integrated Search

1979-10-01

The wood panels that have only one coat of paint over bare wood and one coat of paint over primed wood are continuing to show sighs of deterioration. The wood panels that have two coats of paint over bare wood and two coats of paint over primed wood ...

Grazing intensity and spatial heterogeneity in bare soil in a grazing-resistant grassland

USDA-ARS?s Scientific Manuscript database

Spatial patterns in rangeland vegetation serve as indicators of rangeland condition and are an important component of wildlife habitat. We illustrate the use of very-large-scale aerial photography (VLSA) to quantify spatial patterns in bare soil of the northeastern Colorado shortgrass steppe. Using ...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

A Management Information System for Bare Base Civil Engineering Commanders

DTIC Science & Technology

1988-09-01

initial beddown stage. The purpose of this research was to determine the feasibility of developing a microcomputer based management information system (MIS...the software best suited to synthesize four of the categories into a prototype field MIS. Keyword: Management information system , Bare bases, Civil engineering, Data bases, Information retrieval.

Simultaneous Detection of Dopamine and Uric Acid Using a Poly(l-lysine)/Graphene Oxide Modified Electrode

PubMed Central

Zhang, Yuehua; Lei, Wu; Xu, Yujuan; Xia, Xifeng; Hao, Qingli

2016-01-01

A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA. For the simultaneous detection of DA and UA, the detection limits of 0.021 and 0.074 μM were obtained, while 0.031 and 0.018 μM were obtained as the detection limits for the selective detection of UA and DA, using DPV in the linear concentration ranges of 0.5 to 20.0 and 0.5 to 35 μM, respectively. In addition, the PLL/GO/GCE demonstrated good reproducibility, long-term stability, excellent selectivity and negligible interference of ascorbic acid (AA). The proposed modified electrode was successfully implemented in the simultaneous detection of DA and UA in human blood serum, urine and dopamine hydrochloride injection with satisfactory results. PMID:28335305

Standoff detection of trace amounts of solids by nonlinear Raman spectroscopy using shaped femtosecond pulses

NASA Astrophysics Data System (ADS)

Katz, O.; Natan, A.; Silberberg, Y.; Rosenwaks, S.

2008-04-01

We demonstrate a single-beam, standoff (>10m) detection and identification of various materials including minute amounts of explosives under ambient light conditions. This is obtained by multiplex coherent anti-Stokes Raman scattering spectroscopy (CARS) using a single femtosecond phase-shaped laser pulse. We exploit the strong nonresonant background for amplification of the backscattered resonant CARS signals by employing a homodyne detection scheme. The simple and highly sensitive spectroscopic technique has a potential for hazardous materials standoff detection applications.

Choline and Inositol Distribution in Algae and Fungi1

PubMed Central

Ikawa, Miyoshi; Borowski, Paul T.; Chakravarti, Ashima

1968-01-01

Inositol and choline were present in varying amounts among the species of Rhodophyta, Phaeophyta, Chlorophyta, and Euglenophyta examined. However, in the two members of the order Fucales (division Phaeophyta) examined, no detectable amounts of choline were found. In contrast, the species of Cyanophyta examined contained no detectable amounts of either choline or inositol. All species of the fungal classes Phycomyceteae, Ascomyceteae, and Basidiomyceteae collected contained both inositol and choline in varying amounts. The red, brown, and blue-green algae usually contained much less inositol and choline than do plant and animals sources, but the fungi and the algae Chlorella and Euglena contained amounts comparable to those present in plant sources. PMID:5647522

Radar reflectivity of bare and vegetation-covered soil

NASA Technical Reports Server (NTRS)

Ulaby, F. T.; Dobson, M. C.; Bradley, G. A.

1981-01-01

Radar sensitivity to soil moisture content has been investigated experimentally for bare and vegetation-covered soil using detailed spectral measurements obtained by a truck-mounted radar spectrometer in the 1-8 GHz band and by airborne scatterometer observations at 1.6, 4.75, and 13.3 GHz. It is shown that radar can provide quantitative information on the soil moisture content of both bare and vegetation-covered soil. The observed soil moisture is in the form of the soil matric potential or a related quantity such as the percent of field capacity. The depth of the monitored layer varies from 1 cm for very wet soil to about 15 cm for very dry soil.

Bare Quantum Null Energy Condition.

PubMed

Fu, Zicao; Marolf, Donald

2018-02-16

The quantum null energy condition (QNEC) is a conjectured relation between a null version of quantum field theory energy and derivatives of quantum field theory von Neumann entropy. In some cases, divergences cancel between these two terms and the QNEC is intrinsically finite. We study the more general case here where they do not and argue that a QNEC can still hold for bare (unrenormalized) quantities. While the original QNEC applied only to locally stationary null congruences in backgrounds that solve semiclassical theories of quantum gravity, at least in the formal perturbation theory at a small Planck length, the quantum focusing conjecture can be viewed as the special case of our bare QNEC for which the metric is on shell.

Bare Quantum Null Energy Condition

NASA Astrophysics Data System (ADS)

Fu, Zicao; Marolf, Donald

2018-02-01

The quantum null energy condition (QNEC) is a conjectured relation between a null version of quantum field theory energy and derivatives of quantum field theory von Neumann entropy. In some cases, divergences cancel between these two terms and the QNEC is intrinsically finite. We study the more general case here where they do not and argue that a QNEC can still hold for bare (unrenormalized) quantities. While the original QNEC applied only to locally stationary null congruences in backgrounds that solve semiclassical theories of quantum gravity, at least in the formal perturbation theory at a small Planck length, the quantum focusing conjecture can be viewed as the special case of our bare QNEC for which the metric is on shell.

Magnetic moment evolution and spin freezing in doped BaFe2As2

DOE PAGES

Pelliciari, Jonathan; Huang, Yaobo; Ishii, Kenji; ...

2017-08-14

Fe-K β X-ray emission spectroscopy measurements reveal an asymmetric doping dependence of the magnetic moments μ bare in electron- and hole-doped BaFe 2As 2. At low temperature, μ bare is nearly constant in hole-doped samples, whereas it decreases upon electron doping. Increasing temperature substantially enhances μ bare in the hole-doped region, which is naturally explained by the theoretically predicted crossover into a spin-frozen state. Our measurements demonstrate the importance of Hund’s-coupling and electronic correlations, especially for hole-doped BaFe 2As 2, as well as the inadequacy of a fully localized or fully itinerant description of the 122 family of Fe pnictides.

Coseismic fault zone deformation caused by the 2014 Mw=6.2 Nagano-ken-hokubu, Japan, earthquake on the Itoigawa-Shizuoka Tectonic Line revealed with differential LiDAR

NASA Astrophysics Data System (ADS)

Toda, S.; Ishimura, D.; Homma, S.; Mukoyama, S.; Niwa, Y.

2015-12-01

The Mw = 6.2 Nagano-ken-hokubu earthquake struck northern Nagano, central Japan, on November 22, 2014, and accompanied a 9-km-long surface rupture mostly along the previously mapped N-NW trending Kamishiro fault, one of the segments of the 150-km-long Itoigawa-Shizuoka Tectonic Line active fault system. While we mapped the rupture and measured vertical displacement of up to 80 cm at the field, interferometric synthetic aperture radar (InSAR) shows densely spaced fringes on the hanging wall side, suggesting westward or uplift movement associated with thrust faulting. The mainshock focal mechanism and aftershock hypocenters indicate the source fault dips to the east but the InSAR images cannot exactly differentiate between horizontal and vertical movements and also lose coherence within and near the fault zone itself. To reveal near-field deformation and shallow fault slip, here we demonstrate a differential LiDAR analysis using a pair of 1 m-resolution pre-event and post-event bare Earth digital terrain models (DTMs) obtained from commercial LiDAR provider. We applied particle image velocity (PIV) method incorporating elevation change to obtain 3-D vectors of coseismic displacements (Mukoyama, 2011, J. Mt. Sci). Despite sporadic noises mostly due to local landslides, we detected up to 1.5 m net movement at the tip of the hanging wall, more than the field measurement of 80 cm. Our result implies that a 9-km-long rupture zone is not a single continuous fault but composed of two bow-shaped fault strands, suggesting a combination of shallow fault dip and modest amount (< 1.5 m) of slip. Eastward movement without notable subsidence on the footwall also supports the low angle fault dip near the surface, and significant fault normal contraction, observed as buckled cultural features across the fault zone. Secondary features, such as subsidiary back-thrust faults confirmed at the field, are also visible as a significant contrast of vector directions and slip amounts.

Midkine is expressed by infiltrating macrophages in in-stent restenosis in hypercholesterolemic rabbits.

PubMed

Narita, Hiroshi; Chen, Sen; Komori, Kimihiro; Kadomatsu, Kenji

2008-06-01

Neointimal hyperplasia is strikingly suppressed in an endothelium injury model in mice deficient in the growth factor midkine. Knockdown of midkine expression by means of antisense oligonucleotide or small interfering RNA has been shown to lead to suppression of neointimal hyperplasia in a balloon injury model and a rabbit vein graft model; therefore, midkine is an essential factor for neointimal hyperplasia. These findings, however, do not necessarily apply to the function of midkine in vascular stenoses such as in-stent restenosis, because human vascular stenosis is often accompanied by atherosclerosis. We investigated midkine expression in the neointima induced by implantation of a bare metal stent in the atheromatous lesions of hypercholesterolemic rabbits. We analyzed midkine expression during a THP-1 cell differentiation and in peritoneal macrophages exposed to low-density lipoprotein or oxidized low-density lipoprotein. Midkine expression reached the maximum level within 7 days after stenting and was detected in infiltrating macrophages. Differentiation of THP-1 cells to macrophage-like cells did not trigger midkine expression. Neither low-density lipoprotein nor oxidized low-density lipoprotein enhanced midkine expression in peritoneal macrophages that had been activated by thioglycollate, although these cells expressed a significant amount of midkine. The results indicate that macrophages are the major source of midkine in the atherosclerotic neointima. The amount of midkine expressed in macrophages may be sufficient (ie, further enhancement of the expression is not necessary) for the pathogenesis, because oxidized low-density lipoprotein stimulation did not induce the midkine expression. The growth factor midkine is induced during vascular stenosis in mouse and rat models with normal diet. Knockdown of midkine expression suppresses neointimal hyperplasia. The vascular response after stenting differs from that after balloon injury in that the inflammation is more prolonged and the accumulation of macrophages is more abundant in stent-injured vessel. We found here that macrophages are the major source of midkine in the atherosclerotic neointima of in-stent restenosis in hypercholesterolemic rabbits. Our data suggest that midkine has an important role in in-stent restenosis of atherosclerotic vessels and is a candidate molecular target to prevent in-stent restenosis.

Determination of Biogenic Amines in Seawater Using Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection.

PubMed

Gubartallah, Elbaleeq A; Makahleh, Ahmad; Quirino, Joselito P; Saad, Bahruddin

2018-05-08

A rapid and green analytical method based on capillary electrophoresis with capacitively coupled contactless conductivity detection (C⁴D) for the determination of eight environmental pollutants, the biogenic amines (putrescine, cadaverine, spermidine, spermine, tyramine, 2-phenylamine, histamine and tryptamine), is described. The separation was achieved under normal polarity mode at 24 °C and 25 kV with a hydrodynamic injection (50 mbar for 5 s) and using a bare fused-silica capillary (95 cm length × 50 µm i.d.) (detection length of 10.5 cm from the outlet end of the capillary). The optimized background electrolyte consisted of 400 mM malic acid. C⁴D parameters were set at a fixed amplitude (50 V) and frequency (600 kHz). Under the optimum conditions, the method exhibited good linearity over the range of 1.0⁻100 µg mL −1 ( R ² ≥ 0.981). The limits of detection based on signal to noise (S/N) ratios of 3 and 10 were ≤0.029 µg mL −1 . The method was used for the determination of seawater samples that were spiked with biogenic amines. Good recoveries (77⁻93%) were found.

Surface-induced brightness temperature variations and their effects on detecting thin cirrus clouds using IR emission channels in the 8-12 micrometer region

NASA Technical Reports Server (NTRS)

Gao, Bo-Cai; Wiscombe, W. J.

1993-01-01

A method for detecting cirrus clouds in terms of brightness temperature differences between narrow bands at 8, 11, and 12 mu m has been proposed by Ackerman et al. (1990). In this method, the variation of emissivity with wavelength for different surface targets was not taken into consideration. Based on state-of-the-art laboratory measurements of reflectance spectra of terrestrial materials by Salisbury and D'Aria (1992), we have found that the brightness temperature differences between the 8 and 11 mu m bands for soils, rocks and minerals, and dry vegetation can vary between approximately -8 K and +8 K due solely to surface emissivity variations. We conclude that although the method of Ackerman et al. is useful for detecting cirrus clouds over areas covered by green vegetation, water, and ice, it is less effective for detecting cirrus clouds over areas covered by bare soils, rocks and minerals, and dry vegetation. In addition, we recommend that in future the variation of surface emissivity with wavelength should be taken into account in algorithms for retrieving surface temperatures and low-level atmospheric temperature and water vapor profiles.

Optimization of a chemical identification algorithm

NASA Astrophysics Data System (ADS)

Chyba, Thomas H.; Fisk, Brian; Gunning, Christin; Farley, Kevin; Polizzi, Amber; Baughman, David; Simpson, Steven; Slamani, Mohamed-Adel; Almassy, Robert; Da Re, Ryan; Li, Eunice; MacDonald, Steve; Slamani, Ahmed; Mitchell, Scott A.; Pendell-Jones, Jay; Reed, Timothy L.; Emge, Darren

2010-04-01

A procedure to evaluate and optimize the performance of a chemical identification algorithm is presented. The Joint Contaminated Surface Detector (JCSD) employs Raman spectroscopy to detect and identify surface chemical contamination. JCSD measurements of chemical warfare agents, simulants, toxic industrial chemicals, interferents and bare surface backgrounds were made in the laboratory and under realistic field conditions. A test data suite, developed from these measurements, is used to benchmark algorithm performance throughout the improvement process. In any one measurement, one of many possible targets can be present along with interferents and surfaces. The detection results are expressed as a 2-category classification problem so that Receiver Operating Characteristic (ROC) techniques can be applied. The limitations of applying this framework to chemical detection problems are discussed along with means to mitigate them. Algorithmic performance is optimized globally using robust Design of Experiments and Taguchi techniques. These methods require figures of merit to trade off between false alarms and detection probability. Several figures of merit, including the Matthews Correlation Coefficient and the Taguchi Signal-to-Noise Ratio are compared. Following the optimization of global parameters which govern the algorithm behavior across all target chemicals, ROC techniques are employed to optimize chemical-specific parameters to further improve performance.

Hierarchical structural health monitoring system combining a fiber optic spinal cord network and distributed nerve cell devices

NASA Astrophysics Data System (ADS)

Minakuchi, Shu; Tsukamoto, Haruka; Takeda, Nobuo

2009-03-01

This study proposes novel hierarchical sensing concept for detecting damages in composite structures. In the hierarchical system, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with the optical fiber network through transducing mechanisms. The distributed "sensory nerve cell" devices detect the damage, and the fiber optic "spinal cord" network gathers damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of the hierarchical sensing system thorough comparison with existing fiber optic based systems and nerve systems in the animal kingdom. Then, in order to validate the proposed sensing concept, impact damage detection system for the composite structure was proposed. The sensor devices were developed based on Comparative Vacuum Monitoring (CVM) system and the Brillouin based distributed strain sensing was utilized to gather the damage signals from the distributed devices. Finally a verification test was conducted using prototype devices. Occurrence of barely visible impact damage was successfully detected and it was clearly indicated that the hierarchical system has better repairability, higher robustness, and wider monitorable area compared to existing systems utilizing embedded optical fiber sensors.

Land cover change detection of Hatiya Island, Bangladesh, using remote sensing techniques

NASA Astrophysics Data System (ADS)

Kumar, Lalit; Ghosh, Manoj Kumer

2012-01-01

Land cover change is a significant issue for environmental managers for sustainable management. Remote sensing techniques have been shown to have a high probability of recognizing land cover patterns and change detection due to periodic coverage, data integrity, and provision of data in a broad range of the electromagnetic spectrum. We evaluate the applicability of remote sensing techniques for land cover pattern recognition, as well as land cover change detection of the Hatiya Island, Bangladesh, and quantify land cover changes from 1977 to 1999. A supervised classification approach was used to classify Landsat Enhanced Thematic Mapper (ETM), Thematic Mapper (TM), and Multispectral Scanner (MSS) images into eight major land cover categories. We detected major land cover changes over the 22-year study period. During this period, marshy land, mud, mud with small grass, and bare soil had decreased by 85%, 46%, 44%, and 24%, respectively, while agricultural land, medium forest, forest, and settlement had positive changes of 26%, 45%, 363%, and 59%, respectively. The primary drivers of such landscape change were erosion and accretion processes, human pressure, and the reforestation and land reclamation programs of the Bangladesh Government.

Erodibility of and dust emissions from bare soil surfaces in the North American Southwest

USDA-ARS?s Scientific Manuscript database

Native plant communities throughout the Southwestern United States are subject to increased abiotic stress due to climate change. As native grass cover is replaced by shrubs, more bare soil surface is susceptible to erosion by wind. The dust record for the last 20 years indicates that wind erosion...

75 FR 30750 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

...-AA09 Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR AGENCY: Coast Guard, DHS... procedures on the Baring Cross Railroad Drawbridge across the Arkansas Waterway at mile 119.6 at Little Rock....123(b) state that the draw of the Baring Cross Railroad Drawbridge, mile 119.6, at Little Rock, AR is...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

Genericity Distinctions and the Interpretation of Determiners in Second Language Acquisition

ERIC Educational Resources Information Center

Ionin, Tania; Montrul, Silvina; Kim, Ji-Hye; Philippov, Vadim

2011-01-01

English uses three types of generic NPs: bare plurals ("Lions are dangerous"), definite singulars ("The lion is dangerous"), and indefinite singulars ("A lion is dangerous"). These three NP types are not interchangeable: definite singulars and bare plurals can have generic reference at the NP-level, while indefinite singulars are compatible only…

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

Bare Forms and Lexical Insertions in Code-Switching: A Processing-Based Account

ERIC Educational Resources Information Center

Owens, Jonathan

2005-01-01

Bare forms (or [slashed O] forms), uninflected lexical L2 insertions in contexts where the matrix language expects morphological marking, have been recognized as an anomaly in different approaches to code-switching. Myers-Scotton (1997, 2002) has explained their existence in terms of structural incongruity between the matrix and embedded…

Split Personality: Assessing the Potential for Organizational Identity in Reinforcing U.S. Military Jointness

DTIC Science & Technology

2015-07-17

company name’ ( logo ) ‘parent company name’ ( logo ) ‘business unit name’ ‘parent company name’ ( logo ) ‘specialization’ Example Barings Barings...26 in times of war when it seemed apparent that force goals would not be met. Most useful, however, is his recognition of an overall pattern of

Alternatives to preplant soil fumigation for Western forest nurseries.

Treesearch

Diane M. Hildebrand; Jeffrey K. Stone; Robert L. James; Susan J. Frankel

2004-01-01

Field trials at six bare-root forest tree nurseries in the Western United States compared cultural treatments including timing and depth of sowing; bare fallow (with and without periodic tilling); organic amendments including sawdust, composts, and cover crops; mulches including pine needles, sawdust, and rice straw; and fumigation with methyl bromide/chloropicrin or...

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan

PubMed Central

Chen, P.; Tsay, T.T.

2006-01-01

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region. PMID:19259538

Spectral characteristics and the extent of paleosols of the Palouse formation

NASA Technical Reports Server (NTRS)

Frazier, B. E.; Busacca, A.; Cheng, Y.; Wherry, D.; Hart, J.; Gill, S.

1986-01-01

Spectral relationships were investigated for several bare soil fields which were in summer fallow rotation on the date of the imagery. Printouts of each band were examined and compared to aerial photography. Bands with dissimilar reflectance patterns for known areas were then combined using ratio techniques which were proven useful in other studies (Williams, 1983). Selected ratios were Thematic Mapper (TM) 1/TM4, TM3/TM4, and TM5/TM4. Cluster analyses and Baysian and Fastclass classifier images were produced using the three ratio images. Plots of cluster analysis outputs revealed distinct groupings of reflectance data representing green crops, ripened crops, soil and green plants, and bare soil. Bare soil was represented by a line of clusters on plots of the ratios TM5/TM4 and TM3/TM4. The soil line was investigated further to determine factors involved in the distributin of clusters alone the line. The clusters representing the bare soil line were also studied by plotting the Tm5/TM4, TM1/TM4 dimension. A total of 76 soil samples were gathered and analyzed for organic carbon.

Initial Adsorption of Fe on an Ethanol-Saturated Si(111)7 × 7 Surface: Statistical Analysis in Scanning Tunneling Microscopy

NASA Astrophysics Data System (ADS)

Yang, Haoyu; Hattori, Ken

2018-03-01

We studied the initial stage of iron deposition on an ethanol-saturated Si(111)7 × 7 surface at room temperature using scanning tunneling microscopy (STM). The statistical analysis of the Si adatom height at empty states for Si(111)-C2H5OH before and after the Fe deposition showed different types of adatoms: type B (before the deposition) and type B' (after the deposition) assigned to bare adatoms, type D and type D' to C2H5O-terminated adatoms, and type E' to adatoms with Fe. The analysis of the height distribution revealed the protection of the molecule termination for the Fe capture at the initial stage. The analysis also indicated the preferential capture of a single Fe atom to a bare center-adatom rather than a bare corner-adatom which remain after the C2H5OH saturation, but no selectivity was observed in faulted and unfaulted half unit-cells. This is the first STM-based report proving that a remaining bare adatom, but not a molecule-terminated adatom, captures a metal.

Portable chamber measurements of evapotranspiration at the Amargosa Desert Research Site near Beatty, Nye County, Nevada, 2003-06

USGS Publications Warehouse

Garcia, C. Amanda; Johnson, Michael J.; Andraski, Brian J.; Halford, Keith J.; Mayers, C. Justin

2008-01-01

Portable chamber measurements of evapotranspiration (ET) were made at the U.S. Geological Survey's Amargosa Desert Research Site in southern Nevada to help quantify component- and landscape-scale contributions to ET in an arid environment. Evapotranspiration data were collected approximately every 3 months from 2003 to 2006. Chamber measurements of ET were partitioned into bare-soil evaporation and mixed-species transpiration components. The component-scale ET fluxes from native shrubs typically surpassed those from bare soil by as much as a factor of four. Component-scale ET fluxes were extrapolated to landscape-scale ET using a one-layer, multi-component canopy model. Landscape-scale ET fluxes predominantly were controlled by bare-soil evaporation. Bare soil covered 94 percent of the landscape on average and contributed about 70 percent of the landscape-scale vapor flux. Creosote bush, an evergreen shrub, accounted for about 90 percent of transpiration on average due to its dominance across the landscape (80 percent of the 6 percent shrub cover) and evergreen character.

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

David C. Anderson, Lloyd T. Desotell, David B. Hudson, Gregory J. Shott, Vefa Yucel

Since January 2001, drainage lysimeter studies have been conducted at Yucca Flat, on the Nevada Test Site, in support of an evapotranspirative cover design. Yucca Flat has an arid climate with average precipitation of 16.5 cm annually. The facility consists of six drainage lysimeters 3 m in diameter, 2.4 m deep, and backfilled with a single layer of native soil. The bottom of each lysimeter is sealed and equipped with a small drain that enables direct measurement of saturated drainage. Each lysimeter has eight time-domain reflectometer probes to measure moisture content-depth profiles paired with eight heat-dissipation probes to measure soil-watermore » potential depth profiles. Sensors are connected to dataloggers which are remotely accessed via a phone line. The six lysimeters have three different surface treatments: two are bare-soil; two were revegetated with native species (primarily shadscale, winterfat, ephedra, and Indian rice grass); and two were allowed to revegetate naturally with such species as Russian thistle, halogeton, tumblemustard and cheatgrass. Beginning in October 2003, one half of the paired cover treatments (one bare soil, one invader species, and one native species) were irrigated with an amount of water equal to two times the natural precipitation to achieve a three times natural precipitation treatment. From October 2003 through December 2005, all lysimeters received 52.8 cm precipitation, and the four irrigated lysimeters received an extra 105.6 cm of irrigation. No drainage has occurred from any of the nonirrigated lysimeters, but moisture has accumulated at the bottom of the bare-soil lysimeter and the native-plant lysimeter. All irrigated lysimeters had some drainage. The irrigated baresoil lysimeter had 48.3 cm of drainage or 26.4 percent of the combined precipitation and applied irrigation for the entire monitoring record. The irrigated invader species lysimeter had 5.8 cm of drainage, about 3.2 percent of the combined precipitation and applied irrigation. An irrigation valve failure caused an additional 50.8 cm of irrigation to be applied to the irrigated native plant lysimeter. There has been 29.3 cm of drainage from this lysimeter, which is 11.5 percent of the total applied water. Approximately 40 percent of the drainage from the irrigated native plant lysimeter occurred within four weeks of the valve failure.« less

Electrophoretic deposition of colloidal particles on Mg with cytocompatibility, antibacterial performance, and corrosion resistance.

PubMed

Sun, Jiadi; Zhu, Ye; Meng, Long; Chen, Peng; Shi, Tiantian; Liu, Xiaoya; Zheng, Yufeng

2016-11-01

Magnesium (Mg) has recently received increasing attention due to its unique biological performance, including cytocompatibility, antibacterial and biodegradable properties. However, rapid corrosion in physiological environment and potential toxicity limits its clinical applications. To improve the corrosion resistance meanwhile not compromise other excellent performance, self-assembled colloidal particles were deposited onto magnesium surfaces in ethanol by a simple and effective electrophoretic deposition (EPD) method. The fabricated functional nanostructured coatings were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analyses, and scanning electron microscopy (SEM). The electrochemical test, pH value, and Mg ion concentration data show that the corrosion resistance of Mg samples is enhanced appreciably after surface treatment. In vitro cellular response and antibacterial capability of the modified Mg substrates are performed. Significantly increased cell adhesion and viability are observed from the coated Mg samples, and the amounts of adherent bacteria on the treated Mg surfaces diminish remarkably compared to the bare Mg. Furthermore, the bare and coated Mg samples were implanted in New Zealand white rabbits for 12 weeks to examine the in vivo long-term corrosion performance and in situ inflammation behavior. The experiment results confirmed that compared with bare Mg substrate the corrosion and foreign-body reactions of the coated Mg samples were suppressed. The above results suggested that our coatings, which effectively enhance the biocompatibility, antimicrobial properties, and corrosion resistance of Mg substrate, provide a simple and practical strategy to expedite clinical acceptance of biodegradableMg and its alloys. Biomedical Mg metals have been considered as promising biodegradable implants because of their intended functions, such as cytocompatibility, antibacterial, and biodegradable properties. However, rapid corrosion in physiological environment limits their clinical applications. Alloying and surface coatings have been used to reduce the degradation rate. But this would compromise other excellent performance of Mg samples, including antibacterial and anti-inflammatory activity. Thus, while the rapid degradation of Mg samples must be solved, good antibacterial property and acceptable cytocompatibility are also necessary. In this study, polymer-based coatings were fabricated on Mg surfaces by electrophoretic deposition of poly(isobornyl acrylate-co-dimethylaminoethyl methacrylate)/tannic acid (P(ISA-co-DMA)/TA) colloidal particles. It suggested that the coating materials effectively improved the biocompatibility, antimicrobial behavior, and corrosion resistance of biomedical Mg. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Spectral mixture analyses of hyperspectral data acquired using a tethered balloon

USGS Publications Warehouse

Chen, Xuexia; Vierling, Lee

2006-01-01

Tethered balloon remote sensing platforms can be used to study radiometric issues in terrestrial ecosystems by effectively bridging the spatial gap between measurements made on the ground and those acquired via airplane or satellite. In this study, the Short Wave Aerostat-Mounted Imager (SWAMI) tethered balloon-mounted platform was utilized to evaluate linear and nonlinear spectral mixture analysis (SMA) for a grassland-conifer forest ecotone during the summer of 2003. Hyperspectral measurement of a 74-m diameter ground instantaneous field of view (GIFOV) attained by the SWAMI was studied. Hyperspectral spectra of four common endmembers, bare soil, grass, tree, and shadow, were collected in situ, and images captured via video camera were interpreted into accurate areal ground cover fractions for evaluating the mixture models. The comparison between the SWAMI spectrum and the spectrum derived by combining in situ spectral data with video-derived areal fractions indicated that nonlinear effects occurred in the near infrared (NIR) region, while nonlinear influences were minimal in the visible region. The evaluation of hyperspectral and multispectral mixture models indicated that nonlinear mixture model-derived areal fractions were sensitive to the model input data, while the linear mixture model performed more stably. Areal fractions of bare soil were overestimated in all models due to the increased radiance of bare soil resulting from side scattering of NIR radiation by adjacent grass and trees. Unmixing errors occurred mainly due to multiple scattering as well as close endmember spectral correlation. In addition, though an apparent endmember assemblage could be derived using linear approaches to yield low residual error, the tree and shade endmember fractions calculated using this technique were erroneous and therefore separate treatment of endmembers subject to high amounts of multiple scattering (i.e. shadows and trees) must be done with caution. Including the short wave infrared (SWIR) region in the hyperspectral and multispectral endmember data significantly reduced the Pearson correlation coefficient values among endmember spectra. Therefore, combination of visible, NIR, and SWIR information is likely to further improve the utility of SMA in understanding ecosystem structure and function and may help narrow uncertainties when utilizing remotely sensed data to extrapolate trace glas flux measurements from the canopy scale to the landscape scale.

Transport, retention, and long-term release behavior of polymer-coated silver nanoparticles in saturated quartz sand: The impact of natural organic matters and electrolyte.

PubMed

Hou, Jun; Zhang, Mingzhi; Wang, Peifang; Wang, Chao; Miao, Lingzhan; Xu, Yi; You, Guoxiang; Lv, Bowen; Yang, Yangyang; Liu, Zhilin

2017-10-01

This study investigated the transport and long-term release of stabilized silver nanoparticles (AgNPs), including polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) and bare AgNPs (Bare-AgNPs), in the presence of natural organic matters (NOMs; both humic acids (HA) and alginate (Alg)) and an electrolyte (Ca 2+ ) in a sand-packed column. Very low breakthrough rate (C/C 0 ) of AgNPs (below 0.04) occurred in the absence of NOM and the electrolyte. Increasing the concentration of NOM and decreasing the influent NOM solution's ionic strength (IS) reduced the retention of AgNPs. The reduced NP retention at high NOM and low IS was mainly attributed to the increased energy barrier between the AgNPs and the sand grain surface. Notably, the retention of PVP-AgNPs was enhanced at high Alg concentration and low IS, which mainly resulted from the improved hydrophobicity that could increase the interaction between the PVP-AgNPs and the collector. The total release amount of PVP-AgNPs (10.03%, 9.50%, 28.42%, 6.37%) and Bare-AgNPs (3.28%, 2.58%, 10.36%, 1.54%) were gained when exposed to four kinds of NOM solutions, including deionized water, an electrolyte solution (1 mM Ca 2+ ), HA with an electrolyte (1 mM Ca 2+ ), and a Alg (40 mg/L) solution with an electrolyte (1 mM Ca 2+ ). The long-term release of retained silver nanoparticles in the quartz sand was mostly through the form of released Ag NPs. The factors that increased the mobility of AgNPs in quartz sand could improve the release of the AgNPs. The release of AgNPs had no significant change in the presence Ca 2+ but were increased in the presence of HA. The Alg slightly decreased the release of AgNPs by increasing the hydrophobicity of AgNPs. The results of the study indicated that all the tested NOM and Ca 2+ have prominent influence on the transport and long-term release behavior of silver nanoparticles in saturated quartz sand. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anthraquinones isolated from the browned Chinese chestnut kernels (Castanea mollissima blume)

NASA Astrophysics Data System (ADS)

Zhang, Y. L.; Qi, J. H.; Qin, L.; Wang, F.; Pang, M. X.

2016-08-01

Anthraquinones (AQS) represent a group of secondary metallic products in plants. AQS are often naturally occurring in plants and microorganisms. In a previous study, we found that AQS were produced by enzymatic browning reaction in Chinese chestnut kernels. To find out whether non-enzymatic browning reaction in the kernels could produce AQS too, AQS were extracted from three groups of chestnut kernels: fresh kernels, non-enzymatic browned kernels, and browned kernels, and the contents of AQS were determined. High performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) methods were used to identify two compounds of AQS, rehein(1) and emodin(2). AQS were barely exists in the fresh kernels, while both browned kernel groups sample contained a high amount of AQS. Thus, we comfirmed that AQS could be produced during both enzymatic and non-enzymatic browning process. Rhein and emodin were the main components of AQS in the browned kernels.

Rapid water disinfection over a Ag/AgBr/covalent triazine-based framework composite under visible light.

PubMed

Li, Liuyi; Li, Xiaofen; Cheng, Zhi; Bi, Jinhong; Liang, Shijing; Zhang, Zizhong; Yu, Yan; Wu, Ling

2018-05-22

Development of visible-light-induced and rapid water disinfection is of significant importance. Covalent triazine-based frameworks (CTFs) with pre-designable structures and favorable semiconductive behaviors hold great promise for photocatalytic water disinfection. Here, we report an Ag/AgBr/CTF composite with a layered structure, which serves as an efficient photocatalyst for rapid water disinfection. Water disinfection with >99.99% inactivation of Escherichia coli within 12 min was achieved by using a small amount of Ag/AgBr/CTF under visible light irradiation. The inactivation efficiency of Ag/AgBr/CTF was ∼10 times better than that of bare Ag/AgBr. Rapid water disinfection by the Ag/AgBr/CTF composite mainly results from the greatly improved generation of reactive oxygen species through the synergistic effects among the three components and the affinity of CTF to the cell wall of bacteria.

Boron nitride nanotube reinforced polylactide-polycaprolactone copolymer composite: mechanical properties and cytocompatibility with osteoblasts and macrophages in vitro.

PubMed

Lahiri, Debrupa; Rouzaud, Francois; Richard, Tanisha; Keshri, Anup K; Bakshi, Srinivasa R; Kos, Lidia; Agarwal, Arvind

2010-09-01

Biodegradable polylactide-polycaprolactone copolymer (PLC) has been reinforced with 0, 2 and 5wt.% boron nitride nanotubes (BNNTs) for orthopedic scaffold application. Elastic modulus of the PLC-5wt.% BNNT composite, evaluated through nanoindentation technique, shows a 1370% increase. The same amount of BNNT addition to PLC enhances the tensile strength by 109%, without any adverse effect on the ductility up to 240% elongation. Interactions of the osteoblasts and macrophages with bare BNNTs prove them to be non-cytotoxic. PLC-BNNT composites displayed increased osteoblast cell viability as compared to the PLC matrix. The addition of BNNTs also resulted in an increase in the expression levels of the Runx2 gene, the main regulator of osteoblast differentiation. These results indicate that BNNT is a potential reinforcement for composites for orthopedic applications. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Engine Yaw Augmentation for Hybrid-Wing-Body Aircraft via Optimal Control Allocation Techniques

NASA Technical Reports Server (NTRS)

Taylor, Brian R.; Yoo, Seung Yeun

2011-01-01

Asymmetric engine thrust was implemented in a hybrid-wing-body non-linear simulation to reduce the amount of aerodynamic surface deflection required for yaw stability and control. Hybrid-wing-body aircraft are especially susceptible to yaw surface deflection due to their decreased bare airframe yaw stability resulting from the lack of a large vertical tail aft of the center of gravity. Reduced surface deflection, especially for trim during cruise flight, could reduce the fuel consumption of future aircraft. Designed as an add-on, optimal control allocation techniques were used to create a control law that tracks total thrust and yaw moment commands with an emphasis on not degrading the baseline system. Implementation of engine yaw augmentation is shown and feasibility is demonstrated in simulation with a potential drag reduction of 2 to 4 percent. Future flight tests are planned to demonstrate feasibility in a flight environment.

Autonomous Laser-Powered Vehicle

NASA Technical Reports Server (NTRS)

Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

2017-01-01

An autonomous laser-powered vehicle designed to autonomously penetrate through ice caps of substantial (e.g., kilometers) thickness by melting a path ahead of the vehicle as it descends. A high powered laser beam is transmitted to the vehicle via an onboard bare fiber spooler. After the beam enters through the dispersion optics, the beam expands into a cavity. A radiation shield limits backscatter radiation from heating the optics. The expanded beam enters the heat exchanger and is reflected by a dispersion mirror. Forward-facing beveled circular grooves absorb the reflected radiant energy preventing the energy from being reflected back towards the optics. Microchannels along the inner circumference of the beam dump heat exchanger maximize heat transfer. Sufficient amount of fiber is wound on the fiber spooler to permit not only a descent but also to permit a sample return mission by inverting the vehicle and melting its way back to the surface.

Spectrum-enhanced Au@ZnO plasmonic nanoparticles for boosting dye-sensitized solar cell performance

NASA Astrophysics Data System (ADS)

Liu, Qisheng; Wei, Yunwei; Shahid, Malik Zeeshan; Yao, Mingming; Xu, Bo; Liu, Guangning; Jiang, Kejian; Li, Cuncheng

2018-03-01

Spectrum-enhanced Au@ZnO plasmonic nanoparticles (NPs) are developed for fabrication of the dye-sensitized solar cells (DSSCs), and their remarkable enhanced performances are achieved due to Surface Plasmon Resonance (SPR) effects. When being doped different blended amounts of the Au@ZnO NPs within the photoanode layers, various enhanced effects in the SPR-based DSSCs are exhibited. Compared with the power conversion efficiency (PCE, 7.50%) achieved for bare DSSC, device with doped Au@ZnO NPs of 1.93% delivers the top PCE of 8.91%, exhibiting about 20% enhancement. To elaborate the charge transfer process in the Au@ZnO NPs blended DSSCs, the photoluminescence (PL), electrochemical impedance spectra (EIS), etc are performed. We find that both the enhanced SPR absorption properties and the suppressed recombination process of charges contribute much to the improved performance of Au@ZnO-incorporated DSSCs.

High-efficient photo-electron transport channel in SiC constructed by depositing cocatalysts selectively on specific surface sites for visible-light H{sub 2} production

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

Wang, Da; Peng, Yuan; Wang, Qi

2016-04-18

Control cocatalyst location on a metal-free semiconductor to promote surface charge transfer for decreasing the electron-hole recombination is crucial for enhancing solar energy conversion. Based on the findings that some metals have an affinity for bonding with the specific atoms of polar semiconductors at a heterostructure interface, we herein control Pt deposition selectively on the Si sites of a micro-SiC photocatalyst surface via in-situ photo-depositing. The Pt-Si bond forming on the interface constructs an excellent channel, which is responsible for accelerating photo-electron transfer from SiC to Pt and then reducing water under visible-light. The hydrogen production is enhanced by twomore » orders of magnitude higher than that of bare SiC, and 2.5 times higher than that of random-depositing nano-Pt with the same loading amount.« less

New immiscible refrigeration lubricant for HFCs

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

Sunami, Motoshi; Takigawa, Katsuya; Suda, Satoshi

1995-12-31

This study examines the capability of a family of very low-viscosity alkylbenzenes (AB) used in high-side rotary compressors for HFCs. In the development of refrigeration lubricants for HFCs, miscibility is one of the most important problems to be solved. Therefore, PAG (polyalkylene glycols) and POE (polyol esters), which have good miscibility, have been applied in new HFC applications. However, it is difficult for these lubricants to maintain long-term durability in high-side rotary compressors. In friction tests under high HFC pressure, ABs with much lower viscosities than mineral oil maintained a much stronger oil film than the combination of mineral oil/R-12more » or POE/HFCs. These results were also proven by compressor durability tests. From the study of the solubility of ABs and HFCs, it is suggested that the total amount of refrigerant can be reduced because HFCs are barely soluble with ABs inside the high-side shell.« less

Room temperature strong light-matter coupling in three dimensional terahertz meta-atoms

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

Paulillo, B., E-mail: bruno.paulillo@u-psud.fr; Manceau, J.-M., E-mail: jean-michel.manceau@u-psud.fr; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr

2016-03-07

We demonstrate strong light-matter coupling in three dimensional terahertz meta-atoms at room temperature. The intersubband transition of semiconductor quantum wells with a parabolic energy potential is strongly coupled to the confined circuital mode of three-dimensional split-ring metal-semiconductor-metal resonators that have an extreme sub-wavelength volume (λ/10). The frequency of these lumped-element resonators is controlled by the size and shape of the external antenna, while the interaction volume remains constant. This allows the resonance frequency to be swept across the intersubband transition and the anti-crossing characteristic of the strong light-matter coupling regime to be observed. The Rabi splitting, which is twice themore » Rabi frequency (2Ω{sub Rabi}), amounts to 20% of the bare transition at room temperature, and it increases to 28% at low-temperature.« less

Large Area Crop Inventory Experiment (LACIE). LACIE phase 1 and phase 2 accuracy assessment. [Kansas, Texas, Minnesota, Montana, and North Dakota

NASA Technical Reports Server (NTRS)

1978-01-01

The author has identified the following significant results. The initial CAS estimates, which were made for each month from April through August, were considerably higher than the USDA/SRS estimates. This was attributed to: (1) the practice of considering bare ground as potential wheat and counting it as wheat; (2) overestimation of the wheat proportions in segments having only a small amount of wheat; and (3) the classification of confusion crops as wheat. At the end of the season most of the segments were reworked using improved methods based on experience gained during the season. In particular, new procedures were developed to solve the three problems listed above. These and other improvements used in the rework experiment resulted in at-harvest estimates that were much closer to the USDA/SRS estimates than those obtained during the regular season.

Selective growth of Ge nanowires by low-temperature thermal evaporation.

PubMed

Sutter, Eli; Ozturk, Birol; Sutter, Peter

2008-10-29

High-quality single-crystalline Ge nanowires with electrical properties comparable to those of bulk Ge have been synthesized by vapor-liquid-solid growth using Au growth seeds on SiO(2)/Si(100) substrates and evaporation from solid Ge powder in a low-temperature process at crucible temperatures down to 700 °C. High nanowire growth rates at these low source temperatures have been identified as being due to sublimation of GeO from substantial amounts of GeO(2) on the powder. The Ge nanowire synthesis from GeO is highly selective at our substrate temperatures (420-500 °C), i.e., occurs only on Au vapor-liquid-solid growth seeds. For growth of nanowires of 10-20 µm length on Au particles, an upper bound of 0.5 nm Ge deposition was determined in areas of bare SiO(2)/Si substrate without Au nanoparticles.

Stretchable nanocomposite electrodes with tunable mechanical properties by supersonic cluster beam implantation in elastomers

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

Borghi, F.; Podestà, A.; Milani, P., E-mail: pmilani@mi.infn.it

We demonstrate the fabrication of gold-polydimethylsiloxane nanocomposite electrodes, by supersonic cluster beam implantation, with tunable Young's modulus depending solely on the amount of metal clusters implanted in the elastomeric matrix. We show both experimentally and by atomistic simulations that the mechanical properties of the nanocomposite can be maintained close to that of the bare elastomer for significant metal volume concentrations. Moreover, the elastic properties of the nanocomposite, as experimentally characterized by nanoindentation and modeled with molecular dynamics simulations, are also well described by the Guth-Gold classical model for nanoparticle-filled rubbers, which depends on the presence, concentration, and aspect ratio ofmore » metal nanoparticles, and not on the physical and chemical modification of the polymeric matrix due to the embedding process. The elastic properties of the nanocomposite can therefore be determined and engineered a priori, by controlling only the nanoparticle concentration.« less

Analyses of protein corona on bare and silica-coated gold nanorods against four mammalian cells.

PubMed

Das, Minakshi; Yi, Dong Kee; An, Seong Soo A

2015-01-01

The purpose of this study was to investigate the mechanisms responsible for the toxic effects of gold nanorods (AuNRs). Here, a comprehensive study was performed by examining the effects of bare (uncoated) AuNRs and AuNRs functionalized with silica (SiO2-AuNRs) against various mammalian cell lines, including cervical cancer cells, fibroblast cells, human umbilical vein endothelial cells, and neuroblastoma cells. The interactions between AuNRs and mammalian cells were investigated with cell viability and mortality assays. Dihydrorhodamine-123 assay was carried out for evaluating reactive oxygen species (ROS) generation, along with mass spectroscopy analysis for determining the composition of the protein corona. Our results suggest that even the lowest concentrations of AuNRs (0.7 μg/mL) induced ROS production leading to cell mortality. On the other hand, cellular viability and ROS production were maintained even at a higher concentration of SiO2-coated AuNRs (12 μg/mL). The increased production of ROS by AuNRs seemed to cause the toxicity observed in all four mammalian cell types. The protein corona on the bare AuNRs did not appear to reduce ROS generation; however, different compositions of the protein corona on bare and SiO2-coated AuNRs may affect cellular behavior differently. Therefore, it was determined that SiO2-coated AuNRs would be more advantageous than bare AuNRs for cellular applications.

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

Kulkarni, Gourihar R.; Zhang, Kai; Zhao, Chun

Changes in the ice nucleation characteristics of atmospherically relevant mineral dust particles due to nitric acid coating are not well understood. Further, the atmospheric implications of dust coating on ice-cloud properties under different assumptions of primary ice nucleation mechanisms are unknown. We investigated ice nucleation ability of Arizona test dust, illite, K-feldspar and quartz as a function of temperature (-25 to -30°C) and relative humidity with respect to water (75 to 110%). Particles were size selected at 250 nm and transported (bare or coated) to the ice nucleation chamber to determine the fraction of particles nucleating ice at various temperaturemore » and water saturation conditions. All dust nucleated ice at water-subsaturated conditions, but the coated particles showed a reduction in their ice nucleation ability compared to bare particles. However, at water-supersaturated conditions, we observed that bare and coated particles had nearly similar ice nucleation characteristics. X-ray diffraction patterns indicated that structural properties of bare dust particles modified after acid treatment. We found that lattice parameters were slightly different, but crystallite sizes of the coated particles were reduced compared to bare particles. Next, single-column model results show that simulated ice crystal number concentrations mostly depends upon fraction of particles that are coated, primary ice nucleation mechanisms, and the competition between ice nucleation mechanisms to nucleate ice. In general, we observed that coating modify the ice-cloud properties and the picture of ice and mixed-phase cloud evolution is complex when different primary ice nucleation mechanisms are competing for fixed water vapor mass.« less

Analysis of ProSEDS Test of Bare-Tether Collection

NASA Technical Reports Server (NTRS)

Sanmartin, J. R.; Lorenzini, E. C.; Estes, R. D.; Charro, M.; Cosmo, M. L.

2003-01-01

NASA's tether experiment ProSEDS will be placed in orbit on board a Delta-II rocket to test bare-tether electron collection, deorbiting of the rocket second stage, and the system dynamic stability. ProSEDS performance will vary because ambient conditions change along the orbit and tether-circuit bulk elements at the cathodic end follow the step-by-step sequence for the current cycles of operating modes (open-circuit, shunt and resistor modes for primary cycles; shunt and battery modes for secondary cycles). In this work we discuss expected ProSEDS values of the ratio L,/L*, which jointly with cathodic bulk elements determines bias and current tether profiles; L, is tether length, and L* (changing with tether temperature and ionospheric plasma density and magnetic field) is a characteristic length gauging ohmic versus baretether collection impedances. We discuss how to test bare-tether electron collection during primary cycles, using probe measurements of plasma density, measurements of cathodic current in resistor and shunt modes, and an estimate of tether temperature based on ProSEDS orbital position at the particular cycle concerned. We discuss how a temperature misestimate might occasionally affect the test of bare-tether collection, and how introducing the battery mode in some primary cycles, for an additional current measurement, could obviate the need of a temperature estimate. We also show how to test bare-tether collection by estimating orbit-decay rate from measurements of cathodic current for the shunt and battery modes of secondary cycles.

A label-free photoelectrochemical biosensor for urokinase-type plasminogen activator detection based on a g-C3N4/CdS nanocomposite.

PubMed

Liu, Xing-Pei; Chen, Jing-Shuai; Mao, Chang-Jie; Niu, He-Lin; Song, Ji-Ming; Jin, Bao-Kang

2018-09-26

Herein, we established a novel ultrasensitive photoelectrochemical biosensor for detecting urokinase-type plasminogen activator (u-PA), based on a g-C 3 N 4 /CdS nanocomposite. The prepared nanocomposite was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible absorption spectroscopy, and Fourier transform infrared spectroscopy, thus indicating that the nanocomposite was prepared successfully. In the typical process, the prepared nanocomposite was deposited on the surface of a bare FTO electrode. After being air-dried, the g-C 3 N 4 /CdS nanocomposite modified electrode was successively incubated with antibody against urokinase-type plasminogen activator and the blocking agent BSA to produce a photoelectrochemical biosensor for u-PA. In the presence of target u-PA antigen, the photocurrent response of the prepared biosensor electrode decreased significantly. The proposed novel photoelectrochemical biosensor exhibited good sensitivity, specificity, and reproducibility for u-PA detection, and a low detection limit of 33 fg mL -1 , ranging from 1 μg mL -1 -0.1 pg mL -1 . The proposed strategy should provide a promising method for detection of other biomarkers. Copyright © 2018 Elsevier B.V. All rights reserved.

Plasmonics Enhanced Smartphone Fluorescence Microscopy.

PubMed

Wei, Qingshan; Acuna, Guillermo; Kim, Seungkyeum; Vietz, Carolin; Tseng, Derek; Chae, Jongjae; Shir, Daniel; Luo, Wei; Tinnefeld, Philip; Ozcan, Aydogan

2017-05-18

Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.

Electrochemical detection of uric acid via uricase-immobilized graphene oxide.

PubMed

Omar, Muhamad Nadzmi; Salleh, Abu Bakar; Lim, Hong Ngee; Ahmad Tajudin, Asilah

2016-09-15

Measurement of the uric acid level in the body can be improved by biosensing with respect to the accuracy, sensitivity and time consumption. This study has reported the immobilization of uricase onto graphene oxide (GO) and its function for electrochemical detection of uric acid. Through chemical modification of GO using 1-ethyl-3-(dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (NHS) as cross-linking reagents, the enzyme activity of the immobilized uricase was much comparable to the free enzyme with 88% of the activity retained. The modified GO-uricase (GOU) was then subjected to electrocatalytic detection of uric acid (UA) via cyclic voltammetry (CV). For that reason, a glassy carbon electrode (GCE) was modified by adhering the GO along with the immobilized uricase to facilitate the redox reaction between the enzyme and the substrate. The modified GOU/GCE outperformed a bare electrode through the electrocatalytic activity with an amplified electrical signal for the detection of UA. The electrocatalytic response showed a linear dependence on the UA concentration ranging from 0.02 to 0.49 mM with a detection limit of 3.45 μM at 3σ/m. The resulting biosensor also exhibited a high selectivity towards UA in the presence of other interference as well as good reproducibility. Copyright © 2016 Elsevier Inc. All rights reserved.

Design and optimization of a nanoprobe comprising amphiphilic chitosan colloids and Au-nanorods: Sensitive detection of human serum albumin in simulated urine

NASA Astrophysics Data System (ADS)

Jean, Ren-Der; Larsson, Mikael; Cheng, Wei-Da; Hsu, Yu-Yuan; Bow, Jong-Shing; Liu, Dean-Mo

2016-12-01

Metallic nanoparticles have been utilized as analytical tools to detect a wide range of organic analytes. In most reports, gold (Au)-based nanosensors have been modified with ligands to introduce selectivity towards a specific target molecule. However, in a recent study a new concept was presented where bare Au-nanorods on self-assembled carboxymethyl-hexanoyl chitosan (CHC) nanocarriers achieved sensitive and selective detection of human serum albumin (HSA) after manipulation of the solution pH. Here this concept was further advanced through optimization of the ratio between Au-nanorods and CHC nanocarriers to create a nanotechnology-based sensor (termed CHC-AuNR nanoprobe) with an outstanding lower detection limit (LDL) for HSA. The CHC-AuNR nanoprobe was evaluated in simulated urine solution and a LDL as low as 1.5 pM was achieved at an estimated AuNR/CHC ratio of 2. Elemental mapping and protein adsorption kinetics over three orders of magnitude in HSA concentration confirmed accumulation of HSA on the nanorods and revealed the adsorption to be completed within 15 min for all investigated concentrations. The results suggest that the CHC-AuNR nanoprobe has potential to be utilized for cost-effective detection of analytes in complex liquids.

Infrared techniques for detecting carbonization at onset of device failure

NASA Astrophysics Data System (ADS)

Farr, Norman; Sinofsky, Edward L.

1997-05-01

We describe the design, and development of an infrared detection system which detects the onset of carbonization of fluoropolymers in the presence of up to 60 watts of 1.06 micrometer laser energy. This system is used to shut down a therapeutic laser system before significant damage is done to a laser delivery device and patient. Black body radiation emitting from the diffusion tip is transmitted, backwards, through the same optical fiber as the therapeutic wavelength. Using a high power 1.06 micrometer laser mirror at 45 degrees, most of the 1.06 micrometer light is reflected while the black body radiation is passed to a holographic notch filter which further filters the signal. Still more filtering was needed before the 1.1 to 2 micrometer signal could be detected within the presence the therapeutic light using an extended indium gallium arsenide photodetector. There was still a significant detected offset which increased with laser power which necessitated a means to automatically null the offset for different laser power settings. The system is designed to be used with any unmodified laser system. It interfaces directly to or in series with most common external safety interlocks and can be used with various diffusing tips, probes or bare fibers.

Highly Sensitive GMO Detection Using Real-Time PCR with a Large Amount of DNA Template: Single-Laboratory Validation.

PubMed

Mano, Junichi; Hatano, Shuko; Nagatomi, Yasuaki; Futo, Satoshi; Takabatake, Reona; Kitta, Kazumi

2018-03-01

Current genetically modified organism (GMO) detection methods allow for sensitive detection. However, a further increase in sensitivity will enable more efficient testing for large grain samples and reliable testing for processed foods. In this study, we investigated real-time PCR-based GMO detection methods using a large amount of DNA template. We selected target sequences that are commonly introduced into many kinds of GM crops, i.e., 35S promoter and nopaline synthase (NOS) terminator. This makes the newly developed method applicable to a wide range of GMOs, including some unauthorized ones. The estimated LOD of the new method was 0.005% of GM maize events; to the best of our knowledge, this method is the most sensitive among the GM maize detection methods for which the LOD was evaluated in terms of GMO content. A 10-fold increase in the DNA amount as compared with the amount used under common testing conditions gave an approximately 10-fold reduction in the LOD without PCR inhibition. Our method is applicable to various analytical samples, including processed foods. The use of other primers and fluorescence probes would permit highly sensitive detection of various recombinant DNA sequences besides the 35S promoter and NOS terminator.

Response of Surface Soil Hydrology to the Micro-Pattern of Bio-Crust in a Dry-Land Loess Environment, China

PubMed Central

Wei, Wei; Yu, Yun; Chen, Liding

2015-01-01

The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes. PMID:26207757

Response of Surface Soil Hydrology to the Micro-Pattern of Bio-Crust in a Dry-Land Loess Environment, China.

PubMed

Wei, Wei; Yu, Yun; Chen, Liding

2015-01-01

The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes.

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

Wheat, C.G.; Mottl, M.J.

Warm hydrothermal springs were discovered on Baby Bare, which is an isolated basement outcrop on 3.5 Ma-old crust on the eastern flank of the Juan de Fuca Ridge. The authors have sampled these spring waters from a manned submersible, along with associated sediment pore waters from 48 gravity and piston cores. Systematic variations in the chemical composition of these waters indicate that hydrothermal reactions in basement at moderate temperatures remove Na, K, Li, Rb, Mg, TCO{sub 2}, alkalinity, and phosphate from the circulating seawater and leach Ca, Sr, Si, B, and Mn from the oceanic crust; and that reactions withmore » the turbidite sediment surrounding Baby Bare remove Na, Li, Mg, Ca, Sr, and sulfate from the pore water while producing ammonium and Si and both producing and consuming phosphate, nitrate, alkalinity, Mn, and Fe. K, Rb, and B are relatively unreactive in the sediment column. The composition of altered seawater in basement at Baby Bare is similar to the inferred composition of 58 C formation water from crust nearly twice as old (5.9 Ma) on the southern flank of the Costa Rica Rift. The Baby Bare fluids also exhibit the same directions of net elemental transfer between basalt and seawater as solutions produced in laboratory experiments at a similar temperature, and complement compositional changes form seawater observed in seafloor basalts altered at cool to moderate temperatures. The common parameter among the two ridge flanks and experiments is temperature, suggesting that the residence time of seawater in the two ridge-flank sites is sufficiently long for the solutions to equilibrate with altered basalt. The authors use the Baby Bare spring water to estimate upper limits on the global fluxes of 14 elements at warm ridge-flank sites such as Baby Bare. Maximum calculated fluxes of Mg, Ca, sulfate, B, and K may equal or exceed 25% of the riverine flux, and such sites may represent the missing, high K/Rb sink required for the K budget.« less

Strategies for leukemic biomarker detection using long-range surface plasmon-polaritons

NASA Astrophysics Data System (ADS)

Krupin, O.; Wang, C.; Berini, P.

2014-09-01

The suitability and use of long-range surface plasmon-polaritons for leukemic biomarker detection is discussed. A novel optical biosensor comprised of gold straight waveguides embedded in CYTOP with an etched microfluidic channel was tested for detecting leukemia in patient serum. Gold surface functionalization involved the interaction of protein G (PG) with antibodies by first adsorbing PG on bare gold and then antibodies (Immunoglobulin G, IgG). Differentiation between healthy and leukemia patients was based on the difference in ratios of Ig kappa (Igκ) and Ig lambda (Igλ) light chains in both serums. The ratio for a normal patient is ~1.4 - 2, whereas for a leukemia patient this ratio is altered. As a receptor (primary antibodies), goat anti-human anti-IgGκ and anti-IgGλ were used to functionalize the surface. Diluted normal and leukemia patient serums were tested over the aforementioned surfaces. The ratios of mass surface densities of IgGκ:IgGλ for normal serum (NS) and patient serum (PS) were found to be 1.55 and 1.92 respectively.

Damage detection in composites using nonlinear ultrasonically modulated thermography

NASA Astrophysics Data System (ADS)

Malfense Fierro, G.-P.; Dionysopoulos, D.; Meo, M.; Ciampa, F.

2018-03-01

This paper proposes a novel nonlinear ultrasonically stimulated thermography technique for a quick and reliable assessment of material damage in carbon fibre reinforced plastic (CFRP) composite materials. The proposed nondestructive evaluation (NDE) method requires narrow sweep ultrasonic excitation using contact piezoelectric transducers in order to identify dual excitation frequencies associated with the damage resonance. High-amplitude signals and higher harmonic generation are necessary conditions for an accurate identification of these two input frequencies. Dual periodic excitation using high- and low-frequency input signals was then performed in order to generate frictional heating at the crack location that was measured by an infrared (IR) camera. To validate this concept, an impact damaged CFRP composite panel was tested and the experimental results were compared with traditional flash thermography. A laser vibrometer was used to investigate the response of the material with dual frequency excitation. The proposed nonlinear ultrasonically modulated thermography successfully detected barely visible impact damage in CFRP composites. Hence, it can be considered as an alternative to traditional flash thermography and thermosonics by allowing repeatable detection of damage in composites.

An embedded fibre optic sensor for impact damage detection in composite materials

NASA Astrophysics Data System (ADS)

Glossop, Neil David William

1989-09-01

A structurally embedded fiber optic damage detection sensor for composite materials is described. The system is designed specifically for the detection of barely visible damage resulting from low velocity impacts in Kevlar-epoxy laminates. By monitoring the light transmission properties of optical fiber embedded in the composite, it was shown that the integrity of the material can be accurately determined. The effect of several parameters on the sensitivity of the system was investigated, including the effect of the optical fiber orientation and depth of embedding within the composite. A novel surface was also developed for the optical fibers to ensure they will fracture at the requisite damage level. The influence of the optical fiber sensors on the tensile and compressive material properties and on the impact resistance of the laminate was also studied. Extensive experimental results from impact tests are reported and a numerical model of the impact event is presented which is able to predict and model the damage mechanism and sensor system. A new and powerful method of nondestructive evaluation for translucent composite materials based on image enhanced backlighting is also described.

Preparation of β-cyclodextrin entrapped graphite composite for sensitive detection of dopamine.

PubMed

Palanisamy, Selvakumar; Sakthinathan, S; Chen, Shen-Ming; Thirumalraj, Balamurugan; Wu, Tsung-Han; Lou, Bih-Show; Liu, Xiaoheng

2016-01-01

A simple dopamine (DA) electrochemical sensor was developed based on a screen-printed carbon electrode (SPCE) modified with β-cyclodextrin entrapped graphite (GR/β-CD) composite for the first time. The polar hydroxyl groups on the β-CD rims interact with polar groups of edges of GR sheets resulting into the high dispersion ability of GR in β-CD solution. The GR/β-CD modified electrode exhibited a higher electrochemical response to DA with a lower oxidation potential (0.224V) than that of bare/β-CD (0.38V) and GR (0.525V) modified SPCEs, revealing an excellent electro-oxidation behavior of GR/β-CD composite toward DA. Under optimum conditions, the fabricated sensor detects the DA in the linear concentration range from 0.1 to 58.5μM with a limit of detection of 0.011μM and the sensitivity of 1.27±0.02μAμM(-1)cm(-2). The fabricated sensor also exhibits the excellent repeatability, practicality, reproducibility, storage stability along with acceptable selectivity. Copyright © 2015 Elsevier Ltd. All rights reserved.