Low back pain: conservative treatment with artificial shock absorbers.

PubMed

Wosk, J; Voloshin, A S

1985-03-01

A new method of conservative treatment for low back pain (LBP) was studied by follow-up investigation of 382 patients during the last five years. The attempt to reduce repetitive impulsive intervertebral impact in the troublesome S1-L5-4 area by significant improvement of the foot's attenuational capacity through artificial viscoelastic shock absorbing was prompted by the authors' work on decreased capability of LBP spines to attenuate axially propagated walking stresses. Viscoelastic shoe inserts were used in addition to light flexible shoes as artificial shock absorbing devices. Maximal amplitudes of bone oscillation during walking were reduced by about 40% by the viscoelastic inserts. Rapid and surprisingly significant improvement of pain syndrome and patient mobility occurred in about 80% of the patients. The accelerographic patterns recorded on a sacrum of patient with LBP were unusual for a healthy subject; they usually disappeared after treatment in LBP cases. Results suggested that poor walking impact attenuation was a true cause for prolonging intervertebral structures overstrain and consequent degeneration. It seemed logical that as spine damage could be explained primarily by prolonged impulsive overstrain, treatment must include viscoelastic inserts which increase foot shock absorbing capacity and help cushion the spine.

Microstructure Analysis of Bismuth Absorbers for Transition-Edge Sensor X-ray Microcalorimeters

NASA Astrophysics Data System (ADS)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2018-03-01

Given its large X-ray stopping power and low specific heat capacity, bismuth (Bi) is a promising absorber material for X-ray microcalorimeters and has been used with transition-edge sensors (TESs) in the past. However, distinct X-ray spectral features have been observed in TESs with Bi absorbers deposited with different techniques. Evaporated Bi absorbers are widely reported to have non-Gaussian low-energy tails, while electroplated ones do not show this feature. In this study, we fabricated Bi absorbers with these two methods and performed microstructure analysis using scanning electron microscopy and X-ray diffraction microscopy. The two types of material showed the same crystallographic structure, but the grain size of the electroplated Bi was about 40 times larger than that of the evaporated Bi. This distinction in grain size is likely to be the cause of their different spectral responses.

Sulfur oxide adsorbents and emissions control

DOEpatents

Li, Liyu [Richland, WA; King, David L [Richland, WA

2006-12-26

High capacity sulfur oxide absorbents utilizing manganese-based octahedral molecular sieve (Mn--OMS) materials are disclosed. An emissions reduction system for a combustion exhaust includes a scrubber 24 containing these high capacity sulfur oxide absorbents located upstream from a NOX filter 26 or particulate trap.

Surface structure and electrochemical characteristics of Ti-V-Cr bcc-type solid solution alloys sintered with Ni

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

Tsuji, Yoichiro; Yamamoto, Osamu; Matsuda, Hiromu

2000-07-01

Ti-V-Cr bcc-type solid solution alloys can absorb a large amount of hydrogen and be applied to active materials of the negative electrode in Ni-MH batteries. However, because of the insolubility of Ni into these alloys, the electrochemical characteristics like discharge capacity and cycle life were poor. In order to increase the discharge capacity of hydrogen absorbing alloy electrodes, Ti-V-Cr bcc-type alloy powders were sintered with Ni in order to form Ni contained surface layer on the alloy surface. As sintering temperature rose up, the surface composition changed from TiNi to Ti{sub 2}Ni. TiNi surface layer showed better electrochemical characteristics. Formore » the Ni adding method, Ni electroless plating was preferred because of good adhesion. As a result of optimized conditions, a discharge capacity of 570 mAh/g and an improvement of cycle life were achieved.« less

Can dual chlorophyll fluorescence excitation be used to assess the variation in the content of UV-absorbing phenolic compounds in leaves of temperate tree species along a light gradient?

PubMed

Barthod, Sandrine; Cerovic, Zoran; Epron, Daniel

2007-01-01

The present study assesses light-induced variations in phenolic compounds in leaves of saplings of two co-occurring temperate species (Acer platanoides L., and Fraxinus excelsior L.) along a light gradient using a new non-invasive optical method (Dualex). The Dualex-derived UV absorbance of leaf epidermis (the sum of the adaxial and abaxial faces, AUV) increased significantly with increasing light in both species. AUV values were correlated with absorbance of the leaf extract at 305 nm and 375 nm (A305 and A375) in both species with similar slopes for both species. However, a large difference in intercept was observed between the two species when A305 was regressed against AUV. Similarly, AUV values were well correlated with the amount of phenolics in the leaf extracts assessed by the Folin-Ciocalteu method, but slopes were significantly different for the two species. Thus, the UV-A epidermal transmittance, despite being a reliable indicator of the UV-screening capacity of the leaf epidermis, cannot be used for any quantitative estimate of UV-B screening capacity or of energetic requirement for leaf construction without a species-specific calibration.

Versatile fabrication of a superhydrophobic and ultralight cellulose-based aerogel for oil spillage clean-up.

PubMed

Zhang, Hui; Li, Yuqi; Xu, Yaoguang; Lu, Zexiang; Chen, Lihui; Huang, Liulian; Fan, Mizi

2016-10-12

To deal with marine oil spillage and chemical leakage issues, a highly efficient absorbent (cellulose based aerogel) with a low density (ρ < 0.034 g cm -3 , φ > 98.5%) and high mechanical strength was fabricated via a novel physical-chemical foaming method, plasma treatment and subsequent silane modification process. This aerogel has a perfect 3D skeleton and interconnected pores similar to honeycomb, which are favorable to oil adsorption and storage. More importantly, without introducing additional micro/nanoparticles, the rough micro/nano structure of the surface was directly constructed using plasma irradiation in this study. The low surface energy substrate was further introduced using a simple physical-soaking method and the resulting aerogel exhibited excellent superhydrophobicity (WCA > 156°) and superoleophilicity (OCA = 0°), which can selectively and efficiently absorb various oils or organic solvents from polluted water. In addition, this aerogel has a high storage capacity and absorption capacity (up to 4300% and 99% of its weight and volume, respectively). More interestingly, this aerogel exhibits excellent mechanical abrasion resistance and corrosion resistance even in strong acid, alkali solution and salt marine environment. The aerogel could be reused more than 30 times after removal of the absorbed oil by rinsing with ethanol.

Manipulating surface wettability and oil absorbency of diatomite depending on processing and ambient conditions

NASA Astrophysics Data System (ADS)

Özen, İlhan; Şimşek, Süleyman; Okyay, Gamze

2015-03-01

In this study, a diatomite sample, which is a natural inorganic mineral with inherently high water and oil absorption capacity, was subjected to grinding before surface modification. Afterwards, the diatomite surface was modified via facile methods using a fluorocarbon (FC) chemical and stearic acid (SA) in addition to the sol-gel fluorosilanization (FS) process. The water and oil wettability, and oil absorbency properties of the unmodified and modified diatomites were investigated in addition to diatomite characterizations such as chemical content, surface area, particle size distribution, morphology, and modification efficiency. It was revealed that the wettability was changed completely depending on the surface modification agent and the media used, while the oil absorbency property surprisingly did not change. On the other hand, the oil absorbency was worsened by the grinding process, whereas the wettability was not affected.

Better Absorbents for Ammonia Separation

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

Malmali, Mahdi; Le, Giang; Hendrickson, Jennifer

Making ammonia from renewable wind energy at a competitive price may be possible if the conventional ammonia condenser is replaced with an ammonia absorber. Such a process change requires an ammonia selective absorbent. Supported metal halide sorbents for this separation display outstanding dynamic capacity close to their equilibrium thermodynamic limits. Alkaline earth chlorides and bromides supported on silica and zeolite Y are the most promising. MgCl 2 and CaBr 2 at 40% loading on silica show capacities of 60-70 mg NH3/gsorbent at 150 °C and 4 bar. Overall, cations with smaller atomic numbers show more affinity to ammonia; bromides holdmore » ammonia more strongly than chlorides. Different solvents and metal halide mixtures do not show significant changes in the absorption capacity. Finally, these absorbents can be incorporated into ammonia reaction-absorption syntheses to achieve faster production rates.« less

Better Absorbents for Ammonia Separation

DOE PAGES

Malmali, Mahdi; Le, Giang; Hendrickson, Jennifer; ...

2018-03-30

Making ammonia from renewable wind energy at a competitive price may be possible if the conventional ammonia condenser is replaced with an ammonia absorber. Such a process change requires an ammonia selective absorbent. Supported metal halide sorbents for this separation display outstanding dynamic capacity close to their equilibrium thermodynamic limits. Alkaline earth chlorides and bromides supported on silica and zeolite Y are the most promising. MgCl 2 and CaBr 2 at 40% loading on silica show capacities of 60-70 mg NH3/gsorbent at 150 °C and 4 bar. Overall, cations with smaller atomic numbers show more affinity to ammonia; bromides holdmore » ammonia more strongly than chlorides. Different solvents and metal halide mixtures do not show significant changes in the absorption capacity. Finally, these absorbents can be incorporated into ammonia reaction-absorption syntheses to achieve faster production rates.« less

Oxygen radical absorbance capacity of phycocyanin and phycocyanobilin from the food supplement Aphanizomenon flos-aquae.

PubMed

Benedetti, Serena; Benvenuti, Francesca; Scoglio, Stefano; Canestrari, Franco

2010-02-01

The oxygen radical absorbance capacity (ORAC) assay has been widely used to quantify peroxyl radical scavenging capacity of pure antioxidant compounds and antioxidant plant/food extracts. However, it has never been applied to natural compounds derived from microalgae-based dietary supplements, namely, phycocyanin (PC) and phycocyanobilin (PCB), for which a strong radical scavenger activity has been documented. In this article, we applied the ORAC method to investigate the capacity of PC and PCB purified from the edible microalga Aphanizomenon flos-aquae to directly quench peroxyl radicals in comparison to well-known antioxidants molecules such as Trolox, ascorbic acid, and reduced glutathione. As a result, PCB was found to have the highest ORAC value (22.18 micromol of Trolox/micromol of compound), comparable to that of PC (20.33 micromol of Trolox/micromol of compound), hence confirming that PCB is mostly responsible for the scavenger activity of PC and making the protein a possible source of the antioxidant in vivo. Our data further corroborate the use of these natural compounds from A. flos-aquae as dietary antioxidant supplements in the treatment of clinical conditions related to oxidative stress.

Influence of the concentration of CO2 and SO2 on the absorption of CO2 by a lithium orthosilicate-based absorbent.

PubMed

Pacciani, R; Torres, J; Solsona, P; Coe, C; Quinn, R; Hufton, J; Golden, T; Vega, L F

2011-08-15

A novel, high temperature solid absorbent based on lithium orthosilicate (Li(4)SiO(4)) has shown promise for postcombustion CO(2) capture. Previous studies utilizing a clean, synthetic flue gas have shown that the absorbent has a high CO(2) capacity, >25 wt %, along with high absorption rates, lower heat of absorption and lower regeneration temperature than other solids such as calcium oxide. The current effort was aimed at evaluating the Li(4)SiO(4) based absorbent in the presence of contaminants found in typical flue gas, specifically SO(2), by cyclic exposure to gas mixtures containing CO(2), H(2)O (up to 25 vol. %), and SO(2) (up to 0.95 vol. %). In the absence of SO(2), a stable CO(2) capacity of ∼ 25 wt % over 25 cycles at 550 °C was achieved. The presence of SO(2), even at concentrations as low as 0.002 vol. %, resulted in an irreversible reaction with the absorbent and a decrease in CO(2) capacity. Analysis of SO(2)-exposed samples revealed that the absorbent reacted chemically and irreversibly with SO(2) at 550 °C forming Li(2)SO(4). Thus, industrial application would require desulfurization of flue gas prior to contacting the absorbent. Reactivity with SO(2) is not unique to the lithium orthosilicate material, so similar steps would be required for other absorbents that chemically react with SO(2).

Ultra-Sensitive Transition-Edge Sensors (TESs) for Far-IR/Submm Space-Borne Spectroscopy

NASA Technical Reports Server (NTRS)

Kenyon, M.; Day, P. K.; Bradford, C. M.; Bock, J .J.; Leduc, H. G.

2011-01-01

We have built surface micromachined thin-film metallized Si(x)N(y) optical absorbers for transition-edge sensors (TESs) suitable for the Background - Limited far-IR/Submm Spectrograph (BLISS). BLISS is a broadband (38 micrometers - 433 micrometers), grating spectrometer consisting of five wavebands each with a modest resolution of R (is) approx. 1000. Because BLISS requires the effective noise equivalent power (NEP) of the TES to be below 10 (exp 19) W/Hz(exp 1/2), our TESs consist of four long (1000 micrometers), narrow (0.4 micrometers ), and thin (0.25 micrometers ) Si(x) N(y) support beams that reduce the thermal conductance G between the substrate and the optical absorber. To reduce the heat capacity of the absorber and make the response time tau fast enough for BLISS, our absorbers are patterned into a mesh geometry with a fill factor of less than 10%. We use a bilayer of Ti/Au to make the effective impedance of the absorber match the impedance of the incoming radiation for each band. Measurements of the response time of the metallized absorbers to heat pulses show that their heat capacity exceeds the predictions of the Debye model. Our results are suggestive that the surface of the low pressure chemical vapor deposition (LPCVD) Si(x)N(y) used in the absorbers' construction is the source of microstates that dominate the heat capacity.

Preparation and Properties of a Novel Semi-IPN Slow-Release Fertilizer with the Function of Water Retention.

PubMed

Xiang, Yang; Ru, Xudong; Shi, Jinguo; Song, Jiang; Zhao, Haidong; Liu, Yaqing; Guo, Dongdong; Lu, Xin

2017-12-20

A new semi-interpenetrating polymer network (semi-IPN) slow-release fertilizer (SISRF) with water absorbency, based on the kaolin-g-poly(acrylic acid-co-acrylic amide) (kaolin-g-P(AA-co-AM)) network and linear urea-formaldehyde oligomers (UF), was prepared by solution polymerization. Nutrients phosphorus and potassium were supplied by adding dipotassium hydrogen phosphate during the preparation process. The structure and properties of SISRF were characterized by various characterization methods. SISRF showed excellent water absorbency of 68 g g -1 in tap water. The slow-release behavior of nutrients and water-retention capacity of SISRF were also measured. Meanwhile, the swelling kinetics was well described by a pseudo-second-order kinetics model. Results suggested the formation of SISRF with simultaneously good slow-release and water-retention capacity, which was expected to apply in modern agriculture and horticulture.

In-depth analysis and discussions of water absorption-typed high power laser calorimeter

NASA Astrophysics Data System (ADS)

Wei, Ji Feng

2017-02-01

In high-power and high-energy laser measurement, the absorber materials can be easily destroyed under long-term direct laser irradiation. In order to improve the calorimeter's measuring capacity, a measuring system directly using water flow as the absorber medium was built. The system's basic principles and the designing parameters of major parts were elaborated. The system's measuring capacity, the laser working modes, and the effects of major parameters were analyzed deeply. Moreover, the factors that may affect the accuracy of measurement were analyzed and discussed. The specific control measures and methods were elaborated. The self-calibration and normal calibration experiments show that this calorimeter has very high accuracy. In electrical calibration, the average correction coefficient is only 1.015, with standard deviation of only 0.5%. In calibration experiments, the standard deviation relative to a middle-power standard calorimeter is only 1.9%.

A facile and scalable method to prepare carbon nanotube-grafted-graphene for high performance Li-S battery

NASA Astrophysics Data System (ADS)

Wang, Q. Q.; Huang, J. B.; Li, G. R.; Lin, Z.; Liu, B. H.; Li, Z. P.

2017-01-01

A carbon nanotube-grafted-graphene (CNT-g-Gr) is developed for enhancements of electrical conduction and polysulfide (PS) absorption to improve rate performance and cycleability of lithium-sulfur battery. The CNT-g-Gr is prepared through CNT growth on Ni-deposited graphene sheet which is fabricated via pyrolysis of glucose in a molten salt. The obtained CNT-g-Gr shows much higher specific surface area and PS adsorption capability than graphene. The in-situ formed Ni nanoparticles on graphene sheet not only serve as the catalytic sites for CNT growth, but also function as the anchor-sites for polar PS absorption. The CNT-g-Gr contributes a superb PS adsorption capability arising from graphene and CNT absorbing weakly-polar PS species, and Ni nanoparticles absorbing the species with stronger polarity. The resultant Li-S battery with the CNT-g-Gr shows excellent cycleability and rate performance. A stable discharge capacity of 900 mAh g-1 (with low capacity degradation rate) and a rate capacity of 260 mAh g-1 at 30 C discharge rate have been achieved.

Removal of insoluble heavy metal sulfides from water.

PubMed

Banfalvi, Gaspar

2006-05-01

The necessity of heavy metal removal from wastewater has led to increasing interest in absorbents. We have developed a new approach to obtain high metal adsorption capacity by precipitating metal sulfides with sodium sulfide on the surface of bentonite and adhere them to the absorbent. This method allowed to remove approximately 90% of cadmium as CdS from 10(-4)-10(-6) M CdCl2 solutions. Additional reactions are related to the removal of excess sodium sulfide by the release of hydrogen sulfide and oxidation to sulfur using carbogen gas (5% CO2, 95% O2) followed by aeration.

Novel total antioxidant capacity index for dietary polyphenols and vitamins C and E, using their cupric ion reducing capability in the presence of neocuproine: CUPRAC method.

PubMed

Apak, Resat; Güçlü, Kubilay; Ozyürek, Mustafa; Karademir, Saliha Esin

2004-12-29

The chemical diversity of antioxidants makes it difficult to separate and quantify antioxidants from the vegetable matrix. Therefore, it is desirable to establish a method that can measure the total antioxidant activity level directly from vegetable extracts. The current literature clearly states that there is no "total antioxidant" as a nutritional index available for food labeling because of the lack of standard quantitation methods. Thus, this work reports the development of a simple, widely applicable antioxidant capacity index for dietary polyphenols and vitamins C and E, utilizing the copper(II)-neocuproine [Cu(II)-Nc] reagent as the chromogenic oxidizing agent. Because the copper(II) (or cupric) ion reducing ability of polyphenols is measured, the method is named by our research group "cupric reducing antioxidant capacity" abbreviated as the CUPRAC method. This method should be advantageous over the ferric reducing antioxidant power (FRAP) method because the redox chemistry of copper(II)-as opposed to that of ferric ion-involves faster kinetics. The method comprises mixing of the antioxidant solution (directly or after acid hydrolysis) with a copper(II) chloride solution, a neocuproine alcoholic solution, and an ammonium acetate aqueous buffer at pH 7 and subsequent measurement of the developed absorbance at 450 nm after 30 min. Because the color development is fast for compounds such as ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds were assayed after incubation at 50 degrees C on a water bath for 20 min [after Cu(II)-Nc reagent addition] so as to force the oxidation reaction to reach completion. The flavonoid glycosides were hydrolyzed to their corresponding aglycons by refluxing in 1.2 M HCl-containing 50% MeOH so as to exert maximal reducing power toward Cu(II)-Nc. Certain compounds also needed incubation after acid hydrolysis to fully exhibit their reducing capability. The CUPRAC antioxidant capacities of synthetic mixtures of antioxidants were experimentally measured as Trolox equivalents and compared to those theoretically found by making use of the principle of additivity of absorbances assuming no chemical interaction between the mixture constituents. Because ascorbic acid is not resistant to elevated temperature incubation, it should be assayed initially by measuring the absorbance (at 450 nm) difference of original and ascorbate oxidase-added mixture solutions at the end of 1 min of Cu(II)-Nc reagent addition. Thus, the total CUPRAC antioxidant capacity of a mixture containing various antioxidants should be that finally measured after a suitable combination of hydrolysis and incubation procedures, added to the initially measured capacity due to ascorbate. The antioxidant polyphenolic compounds tested demonstrate that the highest capacities in the CUPRAC method were observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accordance with theoretical expectations, because the number and position of the hydroxyl groups as well as the degree of conjugation of the whole molecule are important. The antioxidant potency of flavonoids is nearly proportional to the total number of -OH groups and is positively affected by the presence of an o-dihydroxy moiety in the B-ring. beta-Carotene, which did not react with the CUPRAC reagent in alcoholic aqueous medium, could be assayed in dichloromethane solvent. Linear calibration curves for ascorbic acid and flavonoids were redrawn in synthetic solutions containing a mixture of antioxidants, and also in real matrices such as grape and orange juices, green tea, and blackberry tea, showing an initial nonzero absorbance with the CUPRAC reagent. The parallellism of the linear calibration curves of pure compounds in a given complex matrix effectively demonstrated that there were no interferent chemical interactions among the solution constituents and that the antioxidant capacities of the tested antioxidants were additive. The CUPRAC reagent is reasonably selective, stable, easily accessible, and sensitive toward thiol-type oxidants, unlike the FRAP method. The reaction is carried out at nearly physiological pH as opposed to the unrealistic acidic pH of FRAP.

Enhancing the open space of Jabodetabek area, Indonesia

NASA Astrophysics Data System (ADS)

Wartaman, A. S.; Situmorang, R.; Suharto, B. B.

2018-01-01

Jabodetabek area is planned to be developed as a sustainable development region. The Government of Indonesia (GoI) committed in Paris Conference that the target of GHG emissions would be reduced by 29% up to 2030 with her own efforts and by 41% with supported by international assistance. This research attempts to apply specific methods such as stratified planting method to improve the quality of green open space by increasing the absorbed carbon level. The study showed that with the planting vegetation of stratified model, the total capacity of the mainland to absorb CO2 gas is quite significant increase with approximately 20% compared to that of homogeneous vegetation. The stratified planting model is worthwhile to achieve the commitment of the GoI mentioned above.

Research on temperature characteristics of laser energy meter absorber irradiated by ms magnitude long pulse laser

NASA Astrophysics Data System (ADS)

Li, Nan; Qiao, Chunhong; Fan, Chengyu; Zhang, Jinghui; Yang, Gaochao

2017-10-01

The research on temperature characteristics for large-energy laser energy meter absorber is about continuous wave (CW) laser before. For the measuring requirements of millisecond magnitude long pulse laser energy, the temperature characteristics for absorber are numerically calculated and analyzed. In calculation, the temperature field distributions are described by heat conduction equations, and the metal cylinder cavity is used for absorber model. The results show that, the temperature of absorber inwall appears periodic oscillation with pulse structure, the oscillation period and amplitude respectively relate to the pulse repetition frequency and single pulse energy. With the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and rises gradually with time. The factors to affect the temperature rise of absorber are single pulse energy, pulse width and repetition frequency. When the laser irradiation stops, the temperature between absorber inwall and outerwall will reach agreement rapidly. After special technology processing to enhance the capacity of resisting laser damage for absorber inwall, the ms magnitude long pulse laser energy can be obtained with the method of measuring the temperature of absorber outerwall. Meanwhile, by optimization design of absorber structure, when the repetition frequency of ms magnitude pulse laser is less than 10Hz, the energy of every pulse for low repetition frequency pulse sequence can be measured. The work offers valuable references for the design of ms magnitude large-energy pulse laser energy meter.

Schools' Capacity to Absorb a "Healthy School" Approach into Their Operations: Insights from a Realist Evaluation

ERIC Educational Resources Information Center

Deschesnes, Marthe; Drouin, Nathalie; Tessier, Caroline; Couturier, Yves

2014-01-01

Purpose: The purpose of this paper is to understand how a Canadian intervention based on a professional development (PD) model did or did not influence schools' capacities to absorb a Healthy School (HS) approach into their operations. This study is the second part of a research project: previously published results regarding this research…

Preparation of pure chitosan film using ternary solvents and its super absorbency.

PubMed

Wang, Xuejun; Lou, Tao; Zhao, Wenhua; Song, Guojun

2016-11-20

Chemical modification and graft copolymerization were commonly adopted to prepare super absorbent materials. However, physical microstructure of pure chitosan film was optimized to improve the water uptake capacity in this study. Chitosan films with micro-nanostructure were prepared by a ternary solvent system. The optimal process parameters are 1% acetic acid water solution: dioxane: dimethyl sulfoxide=90: 2.5: 7.5 (v/v/v) with chitosan concentration at 1.25% (w/v). The water uptake capacity of the chitosan film prepared under the optimal process parameters was 896g/g. The prepared chitosan films also exhibited high water uptake capacity in response to external stimuli such as temperature, pH and salt. This finding may provide another way for improving the water absorbency. The pure chitosan film may find potential applications especially in the fields of hygienic products and biomedicine due to its super water absorbency and nontoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline;

Improved fabrication techniques for infrared bolometers

NASA Technical Reports Server (NTRS)

Lange, A. E.; Kreysa, E.; Mcbride, S. E.; Richards, P. L.; Haller, E. E.

1983-01-01

Techniques are described for producing improved infrared bolometers from doped germanium. Ion implantation and sputter metalization have been used to make ohmic electrical contacts to Ge:Ga chips. This method results in a high yield of small monolithic bolometers with very little low-frequency noise. When one of these chips is used as the thermometric element of a composite bolometer, it must be bonded to a dielectric substrate. The thermal resistance of the conventional epoxy bond has been measured and found to be undesirably large. A procedure for soldering the chip to a metalized portion of the substrate is described which reduced this resistance. The contribution of the metal film absorber to the heat capacity of a composite bolometer has been measured. The heat capacity of a NiCr absorber at 1.3 K can dominate the bolometer performance. A Bi absorber has significantly lower heat capacity. A low temperature blackbody calibrator has been built to measure the optical responsivity of bolometers. A composite bolometer system with a throughput of approx. 0.1 sr sq cm was constructed using the new techniques. In negligible background it has an optical NEP of 3.6 10((exp -15) W/sq root of Hz at 1.0 K with a time constant of 20 ms. The noise in this bolometer is white above 2.5 Hz and is somewhat below the value predicted by thermodynamic equilibrium theory. It is in agreement with calculations based on a recent nonequilibrium theory.

Array of Bolometers for Submillimeter- Wavelength Operation

NASA Technical Reports Server (NTRS)

Bock, James; Turner, Anthony

2007-01-01

A feed-horn-coupled monolithic array of micromesh bolometers is undergoing development for use in a photometric camera. The array is designed for conducting astrophysical observations in a wavelength band centered at 350 m. The bolometers are improved versions of previously developed bolometers comprising metalized Si3N4 micromesh radiation absorbers coupled with neutron- transmutation-doped Ge thermistors. Incident radiation heats the absorbers above a base temperature, changing the electrical resistance of each thermistor. In the present array of improved bolometers (see figure), the thermistors are attached to the micromesh absorbers by indium bump bonds and are addressed by use of lithographed, vapor-deposited electrical leads. This architecture reduces the heat capacity and minimizes the thermal conductivity to 1/20 and 1/300, respectively, of earlier versions of these detectors, with consequent improvement in sensitivity and speed of response. The micromesh bolometers, intended to operate under an optical background set by thermal emission from an ambient-temperature space-borne telescope, are designed such that the random arrival of photons ("photon noise") dominates the noise sources arising from the detector and readout electronics. The micromesh is designed to be a highly thermally and optically efficient absorber with a limiting response time of about 100 s. The absorber and thermistor heat capacity are minimized in order to give rapid speed of response. Due to the minimization of the absorber volume, the dominant source of heat capacity arises from the thermistor.

Comparison of ozone-specific (OZAC) and oxygen radical (ORAC) antioxidant capacity assays for use with nasal lavage fluid.

PubMed

Rutkowski, Joseph M; Santiag, Lizzie Y; Ben-Jebria, Abdellaziz; Ultman, James S

2011-10-01

Antioxidants in respiratory mucus protect the underlying airway epithelium from damage by ozone (O(3)), a common outdoor air pollutant. To understand O(3)-antioxidant interactions and the variation of these interactions among individuals, in vitro assays are needed to measure the total antioxidant capacity of airway lavage fluid, a convenient source of (diluted) mucous samples. Here, we compare the oxygen radical absorbance capacity (ORAC), a general method that uses peroxyl radicals as a reactive substance, to the recently developed ozone specific antioxidant capacity (OZAC), a procedure that directly employs O(3). For prepared model mucous antioxidant solutions containing uric acid, ascorbic acid or glutathione, the ORAC and OZAC methods yielded comparable antioxidant capacities. The addition of EDTA or DETAPAC, necessary to prevent auto-oxidation of test solutions during the ORAC assay, unpredictably altered ORAC measurements. EDTA did not have a significant effect on OZAC measurements in either prepared uric acid or ascorbic acid solutions. When assessing antioxidant capacities of nasal lavage samples, the ORAC and OZAC assays were no longer comparable. Because the OZAC of nasal lavage samples was positively related to measured uric acid concentrations whereas the ORAC data were not, the OZAC method appears to provide more realistic mucous antioxidant capacities than the ORAC method. Copyright © 2011 Elsevier Ltd. All rights reserved.

Antioxidant capacity of different broccoli (Brassica oleracea) genotypes using the oxygen radical absorbance capacity (ORAC) assay.

PubMed

Kurilich, Anne C; Jeffery, Elizabeth H; Juvik, John A; Wallig, Matthew A; Klein, Barbara P

2002-08-28

Antioxidant capacity of hydrophilic and lipophilic extracts from eight broccoli genotypes was compared using the oxygen radical absorbance capacity (ORAC) assay. Each genotype was analyzed for carotenoid, tocopherol, ascorbic acid, and flavonoid content. Results indicate that the antioxidant capacity of hydrophilic extracts ranged from 65.8 to 121.6 micromol trolox equivalents (TE)/g of tissue, and the capacity of lipophilic extracts ranged from 3.9 to 17.5 micromol TE/g. Ascorbic acid and flavonoid content of the hydrophilic extracts did not explain the total variation in antioxidant capacity of those extracts, suggesting either the presence of other antioxidant components that have yet to be identified or that the known antioxidants are producing synergistic effects. The carotenoids did correlate with antioxidant capacity of the lipophilic extracts and accounted for the majority of the variability in that fraction. The variability in hydrophilic and lipophilic antioxidant capacity found among these genotypes suggests that potential efficacy from antioxidants will vary considerably from genotype to genotype.

High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

2015-01-01

Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and multifunctional operation. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flight-like, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station.

High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

2014-01-01

Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and adaptability to highly variable thermal environments. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flightlike, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station.

Improving CO2 permeation and separation performance of CO2-philic polymer membrane by blending CO2 absorbents

NASA Astrophysics Data System (ADS)

Cheng, Jun; Hu, Leiqing; Li, Yannan; Liu, Jianzhong; Zhou, Junhu; Cen, Kefa

2017-07-01

To research effects of CO2 absorption capacity and type of CO2 absorbent on the CO2 separation and free-volume properties of facilitated transport membranes, two types of CO2 absorbents, namely monoethanolamine (MEA) and ionic liquids (ILs:[P66614][Triz] and [P66614][2-Op]), were adopted. The CO2 absorption capacities of MEA, [P66614][Triz] and [P66614][2-Op] were about 0.561 mol CO2 per mol, 0.95 mol CO2 per mol and 1.60 mol CO2 per mol, respectively. All mean free-volume hole radiuses of membranes decreased after blending CO2 absorbents. After polymer membrane blended with two ILs, number of free-volume hole increased, resulting in modest increase of the fractional free volume. Both CO2 permeability and selectivity increased after blending MEA and ILs. The increasing range of CO2 permeability corresponded with CO2 absorption capacity of CO2 absorbents, and membrane blending with [P66614][2-Op] showed the highest CO2 permeability of 672.1 Barrers at 25 °C. Pebax/PEGDME membrane blending with MEA obtained the highest CO2/H2 and CO2/CH4 selectivity at 17.8 and 20.5, respectively.

A new test method for the evaluation of total antioxidant activity of herbal products.

PubMed

Zaporozhets, Olga A; Krushynska, Olena A; Lipkovska, Natalia A; Barvinchenko, Valentina N

2004-01-14

A new test method for measuring the antioxidant power of herbal products, based on solid-phase spectrophotometry using tetrabenzo-[b,f,j,n][1,5,9,13]-tetraazacyclohexadecine-Cu(II) complex immobilized on silica gel, is proposed. The absorbance of the modified sorbent (lambda(max) = 712 nm) increases proportionally to the total antioxidant activity of the sample solution. The method represents an attractive alternative to the mostly used radical scavenging capacity assays, because they generally require complex long-lasting stages to be carried out. The proposed test method is simple ("drop and measure" procedure is applied), rapid (10 min/sample), requires only the monitoring of time and absorbance, and provides good statistical parameters (s(r)

Perestroika and Change in Soviet Weapons Acquisition

DTIC Science & Technology

1990-06-01

attempted to transfer features of defense industry-mainly managers and methods-to the civilian sector to improve productivity and output. On assuming...to the defense complex absorbed defense managers ’ attention, diverted defense production capacity, and redirected new investment to food processing...equipment drew on additional management andproduction caaite and required more diversion of invest- mnet. Defense procurement reductions arising from

Comparative study of antioxidant properties and total phenolic content of 30 plant extracts of industrial interest using DPPH, ABTS, FRAP, SOD, and ORAC assays.

PubMed

Dudonné, Stéphanie; Vitrac, Xavier; Coutière, Philippe; Woillez, Marion; Mérillon, Jean-Michel

2009-03-11

Aqueous extracts of 30 plants were investigated for their antioxidant properties using DPPH and ABTS radical scavenging capacity assay, oxygen radical absorbance capacity (ORAC) assay, superoxide dismutase (SOD) assay, and ferric reducing antioxidant potential (FRAP) assay. Total phenolic content was also determined by the Folin-Ciocalteu method. Antioxidant properties and total phenolic content differed significantly among selected plants. It was found that oak (Quercus robur), pine (Pinus maritima), and cinnamon (Cinnamomum zeylanicum) aqueous extracts possessed the highest antioxidant capacities in most of the methods used, and thus could be potential rich sources of natural antioxidants. These extracts presented the highest phenolic content (300-400 mg GAE/g). Mate (Ilex paraguariensis) and clove (Eugenia caryophyllus clovis) aqueous extracts also showed strong antioxidant properties and a high phenolic content (about 200 mg GAE/g). A significant relationship between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants.

The development of national quality performance standards for disposable absorbent products for adult incontinence.

PubMed

Muller, Nancy; McInnis, Elaine

2013-09-01

Disposable absorbent products are widely used in inpatient care settings and in the community to manage adult urinary and fecal incontinence, but few product standards exist to help guide their production or optimal use. Increasing costs and reduced revenues have caused a number of states to evaluate absorbent product use among persons who receive care at home with the assistance of the Medicaid Waiver Program, further increasing concerns about the lack of product performance standards. To address these issues, the National Association For Continence (NAFC) formed a council of experts and key stakeholders with the objective of establishing national, independent quality performance standards for disposable absorbent products provided by states to Waiver Program recipients. The Council consisted of representatives from five purposefully selected states, technical directors from six nonwoven product manufacturers, an officer of the nonwoven manufactures trade association, a delegate from an academic nursing program and professional societies, a family caregiver, and a patient representative. Following a consensus method and guidelines for use, nine specific recommendations were developed, posted for public comment, and further refined. Final recommendations for product performance assessment include: rewet rate (a measure of a product's ability to withstand multiple incontinent episodes between changes), rate of acquisition (a measure of the speed at which urine is drawn away from the skin by a product, product retention capacity (a measure of a product's capacity to hold fluid without rewetting the skin), sizing options, absorbency levels, product safety, closure technology, breathable zones (a measure of the air permeability across a textile-like fabric at a controlled differential pressure), and elasticity. The Council also set values for and recommended four quantifiable parameters, and the testing methodology associated with each, to help consumers and states evaluate absorbent products (medium adult size): Maximum Rewet Rate: <1.0-2.0 g for briefs and <0.5-1.0 g for underwear; Maximum Rate of Acquisition: <50-60 seconds for briefs and <35-45 seconds for underwear; Minimum Retention Capacity: >250 g for standard briefs or underwear and >400 g for premium briefs or underwear; and Breathability of Zones: Minimum of >100 cubic feet per minute. As these recommendations are implemented, research is needed to evaluate the impact on both cost and quality of care for further refinement and modifications, particularly as technology and knowledge is advanced.

Design of a Conceptual Bumper Energy Absorber Coupling Pedestrian Safety and Low-Speed Impact Requirements

PubMed Central

Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Duan, Shuyong

2018-01-01

The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness (t u), side arc radius (R), and clamping boost beam thickness (t b) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels. PMID:29581728

Design of a Conceptual Bumper Energy Absorber Coupling Pedestrian Safety and Low-Speed Impact Requirements.

PubMed

Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Xiao, Zhi; Duan, Shuyong

2018-01-01

The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness ( t u ), side arc radius ( R ), and clamping boost beam thickness ( t b ) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels.

Analysis of antioxidant activities of common vegetables employing oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays: a comparative study.

PubMed

Ou, Boxin; Huang, Dejian; Hampsch-Woodill, Maureen; Flanagan, Judith A; Deemer, Elizabeth K

2002-05-22

A total of 927 freeze-dried vegetable samples, including 111 white cabbages, 59 carrots, 51 snap beans, 57 cauliflower, 33 white onions, 48 purple onions, 130 broccoli, 169 tomatoes, 25 beets, 88 peas, 88 spinach, 18 red peppers, and 50 green peppers, were analyzed using the oxygen radical absorption capacity (ORAC) and ferric reducing antioxidant capacity (FRAP) methods. The data show that the ORAC and FRAP values of vegetable are not only dependent on species, but also highly dependent on geographical origin and harvest time. The two antioxidant assay methods, ORAC and FRAP, also give different antioxidant activity trends. The discrepancy is extensively discussed based on the chemistry principles upon which these methods are built, and it is concluded that the ORAC method is chemically more relevant to chain-breaking antioxidants activity, while the FRAP has some drawbacks such as interference, reaction kinetics, and quantitation methods. On the basis of the ORAC results, green pepper, spinach, purple onion, broccoli, beet, and cauliflower are the leading sources of antioxidant activities against the peroxyl radicals.

Comparative polyphenolic content and antioxidant activities of Genista tinctoria L. and Genistella sagittalis (L.) Gams (Fabaceae).

PubMed

Hanganu, Daniela; Olah, Neli Kinga; Benedec, Daniela; Mocan, Andrei; Crisan, Gianina; Vlase, Laurian; Popica, Iulia; Oniga, Ilioara

2016-01-01

The aim of this study was focused on the polyphenolic composition and antioxidant capacity of Genista tinctoria L. and Genistella sagittalis (L.) Gams. A qualitative and quantitative characterization of the main phenolic compounds from the extracts were carried out using a HPLC-MS method. The total polyphenolic and flavonoid content was spectrophotometrically determined. The antioxidant activity towards various radicals generated in different systems was evaluated usingDPPH bleaching method, Trolox equivalent antioxidant capacity assay (TEAC) and Oxygen radical absorbance capacity (ORAC), and all indicated that G. tinctoria extract was more antioxidant than G. sagittalis extract.That was in good agreement with the total polyphenolic and flavonoidic content.Chlorogenic acid, p-coumaric acid, isoquercitrin and apigenin were identified in bothspecies. Caffeic acid, ferulic acid, hyperoside, rutin, quercitrin and luteolin were found only in G. tinctoria, while quercetin was determined in G. sagittalis.

Relationship between selected physicochemical properties of peaty-mucks soils and main absorbance bands of its FTIR spectra*

NASA Astrophysics Data System (ADS)

Boguta, Patrycja; Sokolowska, Zofia

2013-04-01

Peatlands are a large reservoir of organic matter that is responsible for sorption properties, structure of soils and microbial activity. However, most of the peatlands in Poland have been drained and subjected to agricultural use. Processes of such kind cause acceleration of peat mass transformation to mucks. Changes in peat evolution under melioration processes are mostly characterised by mineralisation and humification. The above processes lead to changes in the morphological, chemical, biological and physical properties of peat soils. Knowledge about changes of these parameters is very important in suitable application of conditions and fertilisers in order to improve agricultural value of soil. One of the indicators which could describe the changes in peat mass could be the water holding capacity index proposed by Gawlik. This parameter characterises the secondary transformation processes taking place in soils. Mucking processes are also well described by humification indexes and organic/inorganic carbon content. However, changes of above physical and physicochemical properties of soils are also connected with changes of chemical structure of organic matter contained in soil material. Organic matter is a significant component of organic soils and it influences such important parameters of all soil like sorptivity. So that, it is also valuable to control state of functional groups which determine sorption capacity of soil. One of the methods which could be applied in this case is observation of absorbance values of functional groups in infrared spectra of samples. This is quick and method but it could be used only in approximate way because of some content of ash and inorganic parts. Main aim of this work was attempt to find relationships beetwen selected physicochemical properties of peats soils and height of the most important infrared bands of these materials. 11 peaty-muck soils were taken from different places in Eastern part of Poland from deph 0-20cm. After homogenizing, selected parameters were determined for all samples. Content of organic carbon was investigated using TOC analyzer (MultiNC 2000, Analityk Jena), water holding capacity indexes were determined via centrifugation/ weighting method proposed by Gawlik, humification index was calculated using colorimetric method proposed by Springer. Infrared spectra were recorded for samples in form of pellets with KBr. Absorbance of the most important bands were measured: carboxylic for COO- as. (1619-1639cm-1), COO- sym. (1383 - 1387cm-1), COOH sym. (1240 - 1266cm-1) and phenolic groups for (~3389-3401cm-1). After this, relationships between all parameters were found. Results showed presence of statistically significant correlation between absorbance of functional groups and organic carbon content. This relation indicated that increase in organic carbon caused increase in functional groups of organic matter. No statistically significant correlation was found for relation of bands height and water holding capacity and humification index. *This work was partly supported by the National Science Centre in Poland, grant No. UMO-2011/03/N/NZ9/04239.

Food-processes wastewaters treatment using food solid-waste materials as adsorbents or absorbents

NASA Astrophysics Data System (ADS)

Rapti, Ilaira; Georgopoulos, Stavros; Antonopoulou, Maria; Konstantinou, Ioannis; Papadaki, Maria

2016-04-01

The wastewaters generated by olive-mills during the production of olive oil, wastewaters from a dairy and a cow-farm unit and wastewaters from a small food factory have been treated by means of selected materials, either by-products of the same units, or other solid waste, as absorbents or adsorbents in order to identify the capacity of those materials to remove organic load and toxicity from the aforementioned wastewaters. The potential of both the materials used as absorbents as well as the treated wastewaters to be further used either as fertilizers or for agricultural irrigation purposes are examined. Dry olive leaves, sheep wool, rice husks, etc. were used either in a fixed-bed or in a stirred batch arrangemen,t employing different initial concentrations of the aforementioned wastewaters. The efficiency of removal was assessed using scpectrophotometric methods and allium test phytotoxicity measurements. In this presentation the response of each material employed is shown as a function of absorbent/adsorbent quantity and kind, treatment time and wastewater kind and initial organic load. Preliminary results on the potential uses of the adsorbents/absorbents and the treated wastewaters are also shown. Keywords: Olive-mill wastewaters, dairy farm wastewaters, olive leaves, zeolite, sheep wool

Superabsorbent Polymers: An Idea Whose Time Has Come

NASA Astrophysics Data System (ADS)

Buchholz, Fredric L.

1996-06-01

Superabsorbent polymers are cross-linked polyelectrolytes. Because of their ionic nature and interconnected structure, they absorb large quantities of water and other aqueous solutions without dissolving. This makes them ideally suited as absorbents of body fluids in many personal care products sold today, including baby diapers, adult incontinence products, and feminine napkins. Several emerging applications are also described. A simple laboratory preparation of partially neutralized, cross-linked poly(acrylic acid) is given along with test methods suitable for measuring the absorption capacity of the product. Experiments are described that demonstrate the ability of a swelling gel to perform work, and the ability of a gel to exclude macromolecular solutes from diffusing into its porous, cross-linked structure.

Solutions to decrease a systematic error related to AAPH addition in the fluorescence-based ORAC assay.

PubMed

Mellado-Ortega, Elena; Zabalgogeazcoa, Iñigo; Vázquez de Aldana, Beatriz R; Arellano, Juan B

2017-02-15

Oxygen radical absorbance capacity (ORAC) assay in 96-well multi-detection plate readers is a rapid method to determine total antioxidant capacity (TAC) in biological samples. A disadvantage of this method is that the antioxidant inhibition reaction does not start in all of the 96 wells at the same time due to technical limitations when dispensing the free radical-generating azo initiator 2,2'-azobis (2-methyl-propanimidamide) dihydrochloride (AAPH). The time delay between wells yields a systematic error that causes statistically significant differences in TAC determination of antioxidant solutions depending on their plate position. We propose two alternative solutions to avoid this AAPH-dependent error in ORAC assays. Copyright © 2016 Elsevier Inc. All rights reserved.

Application of manual assessment of oxygen radical absorbent capacity (ORAC) for use in high throughput assay of "total" antioxidant activity of drugs and natural products.

PubMed

Price, Joseph A; Sanny, Charles G; Shevlin, Dennis

2006-01-01

Antioxidants are of particular interest in a spectrum of diseases, and thus are an active area of drug discovery and design. It is important to make considered choices as to which assay chemistry will best serve for particular investigations. We examined the manual oxygen radical absorbent capacity (ORAC) assay for "total" antioxidant activity, including a direct comparison to an alternative technique, the AOP-490 assay, using a panel of extracts from 12 phylogenetically unrelated algae. The AOP-490 assay was done per manufacturer's protocol. The ORAC assay was done by hand, in 96-well plates, not by machine as had been previously published. Our ORAC calculations were done using an in-experiment antioxidant standard curve. Results were reported as equivalents of the antioxidant Trolox, which was used as a standard. With the AOP-490 kit (from Oxis Research) widespread activity was found, but not in all samples. When the ORAC method was used to assay aliquots of the same extracts there was significant activity detected in all samples, and the rank order of activity by the two methods was not identical. The data showed the wide occurrence of antioxidants in algae. The standard curve with the manual ORAC assay was linear in the range tested (0-100 mM Trolox) and had excellent reproducibility. The importance of the beneficial effects of antioxidants is currently an area of active interest for drug development, and thus it is of great value to have an assay that is robust and approximates "total" antioxidant activity in a high throughput format. The ORAC (oxygen radical absorbent capacity) method was adapted to microplates and an eight-channel pipette and was more effective in detecting "total" antioxidant activity than the AOP-490 assay. These results might vary with other types of samples, and would depend on the active agents measured, but do suggest the practical value of the ORAC assay for any laboratory not ready for robotics but using manual 96-well format assays, and the utility of the ORAC assay for evaluating algal, and probably other samples as well.

Shock wave absorber having a deformable liner

DOEpatents

Youngdahl, C.K.; Wiedermann, A.H.; Shin, Y.W.; Kot, C.A.; Ockert, C.E.

1983-08-26

This invention discloses a shock wave absorber for a piping system carrying liquid. The absorber has a plastically deformable liner defining the normal flow boundary for an axial segment of the piping system, and a nondeformable housing is spaced outwardly from the liner so as to define a gas-tight space therebetween. The flow capacity of the liner generally corresponds to the flow capacity of the piping system line, but the liner has a noncircular cross section and extends axially of the piping system line a distance between one and twenty times the diameter thereof. Gas pressurizes the gas-tight space equal to the normal liquid pressure in the piping system. The liner has sufficient structural capacity to withstand between one and one-half and two times this normal liquid pressures; but at greater pressures it begins to plastically deform initially with respect to shape to a more circular cross section, and then with respect to material extension by circumferentially stretching the wall of the liner. A high energy shock wave passing through the liner thus plastically deforms the liner radially into the gas space and progressively also as needed in the axial direction of the shock wave to minimize transmission of the shock wave beyond the absorber.

UV-responsive nano-sponge for oil absorption and desorption

PubMed Central

Kim, Do Hyun; Jung, Min Chan; Cho, So-Hye; Kim, Sang Hoon; Kim, Ho-Young; Lee, Heon Ju; Oh, Kyu Hwan; Moon, Myoung-Woon

2015-01-01

Controlled surface wettability for oil has been intensively studied to remove industrial oil waste or oil spill pollution from seas or rivers. In particular, external stimuli-induced special wetting materials, such as photo-responsive TiO2, have attracted considerable attention for oil-water separation. In this study, a novel method is reported to fabricate a nano-sponge which is composed of hydrophobic hydrocarbon and hydrophilic TiO2 nanoparticles for oil absorption or desorption that are responsive to UV irradiation. The hydrocarbon in the nano-sponge could selectively absorb oil from water, whereas the absorbed oil is released into the water by TiO2 in response to UV irradiation. The nano-sponge functionalized porous polydimethylsiloxane released more than 98% of the absorbed crude oil with UV irradiation and air-bubbling. It could be continuously reused while maintaining a high absorption capacity and desorption efficiency without incurring secondary air or water pollution. This smart oil absorption/desorption methodology with excellent selectivity and recyclability with almost perfect removal of absorbed oil can be applied for oil-water separation, oil spill cleanup and reuse of spilled oil. PMID:26260470

Study of sound-absorbing properties of glass-fiber reinforced materials used in engineering

NASA Astrophysics Data System (ADS)

Egorova, V. E.; Habibova, R. R.; Shafigullin, L. N.

2017-09-01

Modern engineering makes high demands to the noise level in the passenger compartment or cabin of KAMAZ. An effective means of dealing with noise is to use sound absorbing materials produced by the automotive industry. To increase sound-absorbing capacity of materials and structures using glass fibre reinforced polyurethane foams (PUF) obtained by the technology Fiber Composite Spraying.

A new bipyrrole and some phenolic constituents in prunes (Prunus domestica L.) and their oxygen radical absorbance capacity (ORAC).

PubMed

Kayano, Shin-ichi; Kikuzaki, Hiroe; Ikami, Takao; Suzuki, Tomoo; Mitani, Takahiko; Nakatani, Nobuji

2004-04-01

Isolation and structural elucidation of prune constituents were performed and total 10 compounds were determined by NMR and MS analyses. A novel compound was identified to be 2-(5-hydroxymethyl-2',5'-dioxo-2',3',4',5'-tetrahydro-1'H-1,3'-bipyrrole)carbaldehyde, and 7 phenolic compounds were isolated from prunes for the first time. In addition, antioxidant activity of them was evaluated on the basis of the oxygen radical absorbance capacity (ORAC).

Correlation between charge input and cycle life of MgNi electrode for Ni-MH batteries

NASA Astrophysics Data System (ADS)

Ruggeri, Stéphane; Roué, Lionel

Amorphous MgNi material has been prepared by mechanically alloying magnesium and nickel powders for 10 h. Its cycle life as a negative electrode for nickel-metal hydride (Ni-MH) batteries has been studied with charge inputs varying from 0 to 600 mAh/g. For charge inputs lower than 400 mAh/g, the first cycle discharge capacity is superior to the charge input capacity. This surplus discharge capacity can be associated with the alloy oxidation to Mg(OH) 2 and Ni(OH) 2. For charge inputs higher than 400 mAh/g, the initial discharge capacity becomes inferior to the charge input capacity due to the progressive decrease of the charge efficiency related to the hydrogen evolution side reaction. From the second charge/discharge cycle, no additional discharge capacity appears and no discharge capacity degradation occurs for charge inputs inferior or equal to 233 mAh/g. In contrast, for higher charge input values, an important decay in the discharge capacity appears, which is accentuated with increasing charge input. The thresholds charge input of 233 mAh/g corresponds to an amount of hydrogen absorbed into the alloy of 0.8 wt.% (MgNiH 0.7). For higher absorbed hydrogen amounts, it is assumed that extended electrode pulverization occurs, which breaks the passive surface layer of Mg(OH) 2 formed during the first charge/discharge cycle. This creates unprotected fresh MgNi surfaces and consequently, leads to electrode capacity degradation. The stability of the MgNi electrode for absorbed hydrogen content lower than 0.8 wt.% may be related to its amorphous character, which favors a gradual volume expansion upon hydrogen absorption in contrast to crystalline compounds characterized by an abrupt α-to-β lattice expansion.

Influence of the target molecule on the oxygen radical absorbance capacity index: a comparison between alizarin red- and fluorescein-based methodologies.

PubMed

Martin, I; Aspée, A; Torres, P; Lissi, E; López-Alarcón, C

2009-12-01

A comparison of alizarin red (AR) and fluorescein (FL) as target molecules in oxygen radical absorbance capacity (ORAC)-like methods is reported. Galangin, apigenin, ferulic acid, and coumaric acid decreased AR initial consumption rate, whereas quercetin, kaempferol, luteolin, caffeic acid, and sinapic acid inhibited its consumption through an induction time, associated with a repair mechanism. On the other hand, all compounds protected FL with a clear induction time. AR was more selective and provides ORAC-AR values considerably smaller for compounds of low reactivity. The ORAC-AR value for luteolin was nearly 200 times that of coumaric acid. However, the ratio of ORAC-FL values for luteolin and coumaric acid was only 1.2. This different selectivity implies that AR provides ORAC values more related to reactivity than FL. ORAC-AR values of infusions were considerably smaller than the corresponding ORAC-FL values. These differences are interpreted in terms of the capacity of FL to generate induction times, irrespective of the reactivity of the additive. It is proposed that comparison of ORAC-AR and ORAC-FL values could afford a rough estimation of the average reactivity of the antioxidants titrated by the ORAC-FL methodology.

Variability of oxygen radical absorbance capacity (ORAC) in different animal species.

PubMed

Ninfali, P; Aluigi, G

1998-11-01

The oxygen radical absorbance capacity (ORAC) was measured both in whole (ORAC-T) and deproteinized (ORAC-AS) plasma samples of human, pig, cow, rabbit, dog, cat, sheep, horse, dolphin, turkey, guinea-hen and chicken. In the 12 species, ORAC-T data, expressed as micromoles of peroxyl radicals trapped by 11 of sample, were found scattered between 8,600 and 23,000 micromol/l. The species with the highest ORAC-T values were cat among mammals and chicken among avies. ORAC-AS values ranged between 600 and 2000 micromol/l, with the highest values found in dolphin and sheep among mammals, while chicken was first among avies. In the 12 species, the relative contribution of ORAC-AS in relation to ORAC-T ranged from 5% to 20%. Protein SH-groups and uric acid were measured in plasma of all species, but no significant correlation was found between thiols and ORAC-T values or between uric acid and ORAC-AS values. Our results show that: (1) the ORAC method is reproducible and sensitive enough to be used in the comparison of the peroxyl-radical absorbance capacity of protein and non-protein plasma components in different animal species; (2) both in mammals and in avies, there is a deep intra-class heterogeneity of ORAC-T and ORAC-AS values; (3) by considering most species, plasma proteins and lipoproteins account for about 85-90% of the overall peroxyl-radical trapping capacity. In the dolphin only, the protein contribution decreases to 80%; (4) uric acid accounts for about one-half of the ORAC-AS value in human, guinea-hen and for about one-third in chicken, while it provides a very limited contribution in other species. We conclude that species with the highest ORAC-T, like cat and chicken, or with the highest ORAC-AS, like dolphin, are interesting models to study the reasons of such a marked antioxidant defense in the plasma.

Role of catechins in the antioxidant capacity of an active film containing green tea, green coffee, and grapefruit extracts.

PubMed

Colon, M; Nerin, C

2012-10-03

The oxygen radical absorbance capacity (ORAC) method was used to characterize the antioxidant capacity of natural extracts of green tea, green coffee, and grapefruit. These natural extracts were incorporated into a plastic film layer, which was subsequently subjected to a free radical gas stream in order to determine the antioxidant capacity directly in the active film. The green tea extract (GTE) afforded the strongest antioxidant activity. To identify the active compounds in the extract, concentration of the diverse catechins in samples were determined by HPLC-UV analysis. The results showed that the content of catechins in the GTE is around 77% (w/w), the major components being (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (-)-epicatechin. A variation in the concentration profile of catechins was detected during the oxidation process. The chromatographic study demonstrated that (-)-gallocatechin, (-)- epigallocatechin, (+)-catechin, and (-)-catechin gallate exhibited the most radical scavenging.

Investigation into the energy-absorbing properties of multilayered circular thin-walled tube

NASA Astrophysics Data System (ADS)

Qi, Aidong; Liu, Chuanhua; Hu, Gongli; Gu, Hongjun

2002-05-01

With the rise in collision accident and the increase in requirement for resistance of blastproof structures in recent years, people attach much importance to the research and application of energy-absorbing device. In this paper the author calculates the specific strength, the specific hardness and ultimate internal force of a circular thin-walled tube by theoretic calculations, discusses the feasibility of using circular thin-walled tube as an energy-absorbing element, analyzes the energy-absorbing properties and the energy-absorbing mechanism through the energy-absorbing experiments using various materials and forms of arrangement, reaches the conclusion that the load-bearing capacity and energy-absorbing properties of multilayered tubes are superior to that of single tube, and puts forward the concept of 'grading tube'.

Antioxidant capacity of human blood plasma and human urine: simultaneous evaluation of the ORAC index and ascorbic acid concentration employing pyrogallol red as probe.

PubMed

Torres, P; Galleguillos, P; Lissi, E; López-Alarcón, C

2008-10-15

The oxygen radical absorbance capacity (ORAC) methodology has been employed to estimate the antioxidant capacity of human blood plasma and human urine using pyrogallol red (ORAC-PGR) as target molecule. Uric acid, reduced glutathione, human serum albumin, and ascorbic acid (ASC) inhibited the consumption of pyrogallol red, but only ASC generated an induction time. Human blood plasma and human urine protected efficiently pyrogallol red. In these assays, both biological fluids generated neat induction times that were removed by ascorbate oxidase. From these results, ORAC-PGR method could be proposed as a simple alternative to evaluate an ORAC index and, simultaneously, to estimate the concentration of ascorbic acid in human blood plasma or human urine.

Microwave impregnation of porous materials with thermal energy storage materials

DOEpatents

Benson, David K.; Burrows, Richard W.

1993-01-01

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Microwave impregnation of porous materials with thermal energy storage materials

DOEpatents

Benson, D.K.; Burrows, R.W.

1993-04-13

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Electrochemical sensing of total antioxidant capacity and polyphenol content in wine samples using amperometry online-coupled with microdialysis.

PubMed

Jakubec, Petr; Bancirova, Martina; Halouzka, Vladimir; Lojek, Antonin; Ciz, Milan; Denev, Petko; Cibicek, Norbert; Vacek, Jan; Vostalova, Jitka; Ulrichova, Jitka; Hrbac, Jan

2012-08-15

This work describes the method for total antioxidant capacity (TAC) and/or total content of phenolics (TCP) analysis in wines using microdialysis online-coupled with amperometric detection using a carbon microfiber working electrode. The system was tested on 10 selected wine samples, and the results were compared with total reactive antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and chemiluminescent determination of total antioxidant capacity (CL-TAC) methods using Trolox and catechin as standards. Microdialysis online-coupled with amperometric detection gives similar results to the widely used cyclic voltammetry methodology and closely correlates with ORAC and TRAP. The problem of electrode fouling is overcome by the introduction of an electrochemical cleaning step (1-2 min at the potential of 0 V vs Ag/AgCl). Such a procedure is sufficient to fully regenerate the electrode response for both red and white wine samples as well as catechin/Trolox standards. The appropriate size of microdialysis probes enables easy automation of the electrochemical TAC/TCP measurement using 96-well microtitration plates.

Shock Absorbing Helmets

NASA Technical Reports Server (NTRS)

1978-01-01

This paper presents a description of helmets used by football players that offer three times the shock-absorbing capacity of earlier types. An interior padding for the helmets, composed of Temper Foam, first used by NASA's Ames Research Center in the design of aircraft seats is described.

A novel automated direct measurement method for total antioxidant capacity using a new generation, more stable ABTS radical cation.

PubMed

Erel, Ozcan

2004-04-01

To develop a novel colorimetric and automated direct measurement method for total antioxidant capacity (TAC). A new generation, more stable, colored 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS(*+)) was employed. The ABTS(*+) is decolorized by antioxidants according to their concentrations and antioxidant capacities. This change in color is measured as a change in absorbance at 660 nm. This process is applied to an automated analyzer and the assay is calibrated with Trolox. The novel assay is linear up to 6 mmol Trolox equivalent/l, its precision values are lower than 3%, and there is no interference from hemoglobin, bilirubin, EDTA, or citrate. The method developed is significantly correlated with the Randox- total antioxidant status (TAS) assay (r = 0.897, P < 0.0001; n = 91) and with the ferric reducing ability of plasma (FRAP) assay (r = 0.863, P < 0.0001; n = 110). Serum TAC level was lower in patients with major depression (1.69 +/- 0.11 mmol Trolox equivalent/l) than in healthy subjects (1.75 +/- 0.08 mmol Trolox equivalent/l, P = 0.041). This easy, stable, reliable, sensitive, inexpensive, and fully automated method described can be used to measure total antioxidant capacity.

IN VITRO MEASUREMENT OF TOTAL ANTIOXIDANT CAPACITY OF CRATAEGUS MACRACANTHA LODD LEAVES.

PubMed

Miftode, Alina Monica; Stefanache, Alina; Spac, A F; Miftode, R F; Miron, Anca; Dorneanu, V

2016-01-01

Crataegus macracantha Lodd, family Rosaceae, is a very rare species in Europe, and unlike Crataegus monogyna is less investigated for pharmacologic activity. To analyze the ability of the lyophilisate of extract obtained from leaves of Crataegus macracantha Lodd (single plant at the Iaşi Botanical Garden) to capture free radicals in vitro. The lyophilisate obtained in Department of Pharmacognosy, Faculty of Pharmacy, "Grigore T. Popa" University of Medicine and Pharmacy Iaşi. The decreased absorbance of chromophore chlorpromazine radical cation in the presence of the lyophilized solutions was studied spectrophotometrically. The indicator radical cation, obtained by oxidation of chlorpromazine by potassium persulfate, has the maximum absorbance at 525 nm. Ascorbic acid was used as a standard antioxidant. The absorbance of radical solution was determined after the addition of a certain amount of lyophilisate at different time intervals. The antioxidant activity was calculated using the calibration curve obtained by plotting the variation in radical solution absorbance depending on ascorbic acid concentration. For each ascorbic acid concentration the area under the curve was calculated from plotting the percentage inhibition of the absorbance at two pre-established time intervals. The results confirm the antioxidant activity of the leaves of Crataegus Macracantha Lodd and by optimizing the proposed analytical methods the antiradical activity can be quickly evaluated with minimal reagent consumption.

Selective Pyroelectric Detection of Millimetre Waves Using Ultra-Thin Metasurface Absorbers

PubMed Central

Kuznetsov, Sergei A.; Paulish, Andrey G.; Navarro-Cía, Miguel; Arzhannikov, Andrey V.

2016-01-01

Sensing infrared radiation is done inexpensively with pyroelectric detectors that generate a temporary voltage when they are heated by the incident infrared radiation. Unfortunately the performance of these detectors deteriorates for longer wavelengths, leaving the detection of, for instance, millimetre-wave radiation to expensive approaches. We propose here a simple and effective method to enhance pyroelectric detection of the millimetre-wave radiation by combining a compact commercial infrared pyro-sensor with a metasurface-enabled ultra-thin absorber, which provides spectrally- and polarization-discriminated response and is 136 times thinner than the operating wavelength. It is demonstrated that, due to the small thickness and therefore the thermal capacity of the absorber, the detector keeps the high response speed and sensitivity to millimetre waves as the original infrared pyro-sensor does against the regime of infrared detection. An in-depth electromagnetic analysis of the ultra-thin resonant absorbers along with their complex characterization by a BWO-spectroscopy technique is presented. Built upon this initial study, integrated metasurface absorber pyroelectric sensors are implemented and tested experimentally, showing high sensitivity and very fast response to millimetre-wave radiation. The proposed approach paves the way for creating highly-efficient inexpensive compact sensors for spectro-polarimetric applications in the millimetre-wave and terahertz bands. PMID:26879250

Assessment of salivary total antioxidant capacity in patients with primary untreated head and neck squamous cell carcinoma with ORAC.

PubMed

Wesołowski, Piotr; Zawada, Katarzyna; Wojtowicz, Andrzej; Strużycka, Izabela; Kamiński, Tomasz

2016-11-01

Oxidative DNA damage leads to abnormalities in endogenous cellular processes and constitutes a direct link between free radicals, antioxidants and squamous cell carcinoma (SCC). Oxygen radical absorbance capacity (ORAC) method is used to measure antioxidant capacity versus oxygen free radicals. There is no report on the application of ORAC to evaluate salivary antioxidant capacity in patients with head and neck SCC. This study investigated the relation between total antioxidant capacity of saliva, measured with ORAC method, and the incidence, location, size and histopathological grading of SCC. Salivary antioxidant capacity was assessed in 30 male and female patients with histopathologically confirmed oral and laryngeal SCC. Histopathological grading of SCC was based on WHO classification. Mean ORAC in patients with SCC was higher than the mean value in the control group. Statistically significant difference was observed in the study group versus the control group. No significant differences were observed for ORAC values in relation to histopathological grading, tumour size and spread to lymph nodes. The obtained results can advocate local compensatory mechanism in saliva in response to increased oxidative stress associated with primary tumour. ORAC can become an additional factor in head and neck SCC prognosis, but further investigation is required. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Removal of phenols from the water effluents of olive presses

NASA Astrophysics Data System (ADS)

Stamboliadis, Elias; Emejulu, Anthony; Pantelaki, Olga; Pentari, Despina; Petrakis, Evangelos

2012-11-01

The water effluents of olive presses contain a number of phenols that are hardly biodegradable and therefore constitute an environmental hazard, mainly in the Mediterranean countries. The present work presents the results obtained from the study of artificial solutions containing one kind of phenol, namely gallic acid that consists of the main type of phenols present. According to the experimental procedure, the phenol is removed from the water solution by absorption on different naturally occurring raw rock materials. The first material is caustic magnesia produced after the calcination of a magnesite sample from Macedonia, Greece, the second is a sample of sedimentary psammitic marl from the area of Chania, Crete, Greece, and the third solid absorbent is a bentonite sample from the island of Milos, Greece. According to the results obtained, magnesia seems to be by far the best absorbent, with an absorbing capacity of 3500 mg of phenol per gram, followed by the psammitic marl. The absorbing capacity of bentonite is almost negligible

Determination of total antioxidant capacity of milk by CUPRAC and ABTS methods with separate characterisation of milk protein fractions.

PubMed

Çekiç, Sema Demirci; Demir, Aslı; Başkan, Kevser Sözgen; Tütem, Esma; Apak, Reşat

2015-05-01

Most milk-applied antioxidant assays in literature are based on the isolation and quantification of individual antioxidative compounds, whereas total antioxidant capacity (TAC) gives a more holistic picture due to cooperative action of antioxidants. Recently, the cupric reducing antioxidant capacity (CUPRAC) method has been modified to measure the antioxidant capacities of thiol-containing proteins, where the classical ammonium acetate buffer - that may otherwise precipitate proteins- was replaced with concentrated urea buffer (able to expose embedded thiol groups of proteins to oxidative attack) adjusted to pH 7.0. Thus, antioxidant capacity of milk was investigated with two competing TAC assays, namely CUPRAC and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid))/persulphate, because only these assays were capable of evaluating protein contribution to the observed TAC value. As milk fat caused turbidity, experiments were carried out with skim milk or defatted milk samples. To determine TAC, modified CUPRAC method was applied to whole milk, separated and redissolved protein fractions, and the remaining liquid phase after necessary operations. Both TAC methods were investigated for their dilution sensitivity and antioxidant power assessment of separate milk fractions such as casein and whey. Proteins like β-lactoglobulin and casein (but not simple thiols) exhibited enhanced CUPRAC reactivity with surfactant (SDS) addition. Addition of milk protein fractions to whole skim milk produced significant 'negative-biased' deviations (up to -26% relative standard error) from TAC absorbance additivity in the application of the ABTS method, as opposed to that of the CUPRAC method less affected by chemical deviations from Beer's law thereby producing much smaller deviations from additivity (i.e. the property of additivity is valid when the measured TAC of a mixture is equal to the sum of individual antioxidant capacities of its constituents).

The cupric ion reducing antioxidant capacity and polyphenolic content of some herbal teas.

PubMed

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Esin Karademir, Saliha; Erçağ, Erol

2006-01-01

The total antioxidant capacity of the aqueous extracts of some endemic herbs-prepared as infusions by steeping these herbs in hot water--was assayed with bis(neocuproine)copper(II) chloride, also known as the cupric ion reducing antioxidant capacity (CUPRAC) reagent, which was easily accessible, rapid, stable and responsive to both hydrophilic and lipophilic antioxidants. The highest antioxidant capacities of some herbal teas available in the Turkish market were observed for scarlet pimpernel (Anagallis arvensis), sweet basil (Ocimum basilicum), green tea (Camellia sinensis) and lemon balm (Melissa officinalis), in this order (1.63, 1.18, 1.07, and 0.99 mmol trolox equivalent (TR)/g, respectively). For infusions prepared from ready-to-use tea bags, the CUPRAC values were highest for Ceylon blended ordinary tea (4.41), green tea with lemon (1.61), English breakfast ordinary tea (1.26) and green tea (0.94), all of which were manufactured types of C. sinensis. Following the strongest antioxidant herbs with capacities close to or slightly exceeding 1.0 mmol TR/g, sage, thyme, coriander, coltsfoot, blackberry and immortelle (Helichrysum) exhibited capacities around 0.5 mmol TR/g. The correlation of the Folin total phenolic content of herbal teas with their CUPRAC and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) total antioxidant capacities gave linear curves with correlation coefficients of 0.966 and 0.936, respectively, showing that the CUPRAC assay results better correlated with total phenolic content of herbal teas. Absorbance versus concentration data at different dilutions and upon standard additions of model antioxidant compounds (trolox and quercetin) to herbal tea infusions showed that the absorbances (at 450 nm of the CUPRAC method) due to different antioxidant compounds in herbal tea infusions were additive; that is, the tested antioxidants did not chemically interact to cause apparent deviations from Beer's law.

Mapping the Sloan Digital Sky Survey's Global Impact

NASA Astrophysics Data System (ADS)

Chen, Chaomei; Zhang, Jian; Vogeley, Michael S.

2009-07-01

The scientific capacity of a country is essential in todayâ's increasingly globalized science and technology ecosystem. Scientific capacity has four increasingly advanced levels of capabilities: absorbing, applying, creating, and retaining scientific knowledge. Moving to a advanced level requires additional skills and training. For example, it requires more specialized skills to apply scientific knowledge than to absorb knowledge. Similarly, making new discoveries requires more knowledge than applying existing procedures. Research has shown the importance of addressing specific, local problems while tapping into globally available expertise and resources. Accessing scientific knowledge is the first step towards absorbing knowledge. Low-income countries have increased their access to scientific literature on the Internet, but to what extent has this access led to more advanced levels of scientific capacity? Interdisciplinary and international collaboration may hold the key to creating and retaining knowledge. For example, creative ideas tend to be associated with inspirations originated from a diverse range of perspectives On the other hand, not all collaborations are productive. Assessing global science and technology needs to address both successes and failures and reasons behind them.

Measurement of xanthine oxidase inhibition activity of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method.

PubMed

Ozyürek, Mustafa; Bektaşoğlu, Burcu; Güçlü, Kubilay; Apak, Reşat

2009-03-16

Various dietary polyphenolics have been found to show an inhibitory effect on xanthine oxidase (XO) which mediates oxidative stress-originated diseases because of its ability to generate reactive oxygen species (ROS), including superoxide anion radical (O(2)(-)) and hydrogen peroxide. XO activity has usually been determined by following the rate of uric acid formation from xanthine-xanthine oxidase (X-XO) system using the classical XO activity assay (UV-method) at 295nm. Since some polyphenolics have strong absorption from the UV to visible region, XO-inhibitory activity of polyphenolics was alternatively determined without interference by directly measuring the formation of uric acid and hydrogen peroxide using the modified CUPRAC (cupric reducing antioxidant capacity) spectrophotometric method at 450nm. The CUPRAC absorbance of the incubation solution due to the reduction of Cu(II)-neocuproine reagent by the products of the X-XO system decreased in the presence of polyphenolics, the difference being proportional to the XO inhibition ability of the tested compound. The structure-activity relationship revealed that the flavones and flavonols with a 7-hydroxyl group such as apigenin, luteolin, kaempferol, quercetin, and myricetin inhibited XO-inhibitory activity at low concentrations (IC(50) values from 1.46 to 1.90microM), while the flavan-3-ols and naringin were less inhibitory. The findings of the developed method for quercetin and catechin in the presence of catalase were statistically alike with those of HPLC. In addition to polyphenolics, five kinds of herbs were evaluated for their XO-inhibitory activity using the developed method. The proposed spectrophotometric method was practical, low-cost, rapid, and could reliably assay uric acid and hydrogen peroxide in the presence of polyphenols (flavonoids, simple phenolic acids and hydroxycinnamic acids), and less open to interferences by UV-absorbing substances.

Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers.

PubMed

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektaşoğlu, Burcu; Bener, Mustafa

2010-01-01

Tests measuring the combined antioxidant effect of the nonenzymatic defenses in biological fluids may be useful in providing an index of the organism's capability to counteract reactive species known as pro-oxidants, resist oxidative damage, and combat oxidative stress-related diseases. The selected chromogenic redox reagent for the assay of human serum should be easily accessible, stable, selective, and respond to all types of biologically important antioxidants such as ascorbic acid, alpha-tocopherol, beta-carotene, reduced glutathione (GSH), uric acid, and bilirubin, regardless of chemical type or hydrophilicity. Our recently developed cupric reducing antioxidant capacity (CUPRAC) spectrophotometric method for a number of polyphenols and flavonoids using the copper(II)-neocuproine reagent in ammonium acetate buffer is now applied to a complete series of plasma antioxidants for the assay of total antioxidant capacity of serum, and the resulting absorbance at 450 nm is recorded either directly (e.g., for ascorbic acid, alpha-tocopherol, and glutathione) or after incubation at 50 degrees C for 20 min (e.g., for uric acid, bilirubin, and albumin), quantitation being made by means of a calibration curve. The lipophilic antioxidants, alpha-tocopherol and beta-carotene, are assayed in dichloromethane. Lipophilic antioxidants of serum are extracted with n-hexane from an ethanolic solution of serum subjected to centrifugation. Hydrophilic antioxidants of serum are assayed in the centrifugate after perchloric acid precipitation of proteins. The CUPRAC molar absorptivities, linear ranges, and TEAC (trolox equivalent antioxidant capacity) coefficients of the serum antioxidants are established, and the results are evaluated in comparison with the findings of the ABTS/TEAC reference method. The intra- and inter-assay coefficients of variation (CVs) are 0.7 and 1.5%, respectively, for serum. The CUPRAC assay proved to be efficient for glutathione and thiol-type antioxidants, for which the FRAP (ferric reducing antioxidant potency) test is basically nonresponsive. The additivity of absorbances of all the tested antioxidants confirmed that antioxidants in the CUPRAC test do not chemically interact among each other so as to cause an intensification or quenching of the theoretically expected absorbance, and that a total antioxidant capacity (TAC) assay of serum is possible. As a distinct advantage over other electron-transfer based assays (e.g., Folin, FRAP, ABTS, DPPH), CUPRAC is superior in regard to its realistic pH close to the physiological pH, favorable redox potential, accessibility and stability of reagents, and applicability to lipophilic antioxidants as well as hydrophilic ones. The CUPRAC procedure can also assay hydroxyl radicals, being the most reactive oxygen species (ROS). As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield TBARS test, we use p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of [Fe(II)+EDTA] with hydrogen peroxide. The produced hydroxyl radicals attack both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2 h. The CUPRAC absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreases in the presence of (.)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. The developed method is less lengthy, more specific, and of a higher yield than the classical TBARS assay.

Kevlar based nanofibrous particles as robust, effective and recyclable absorbents for water purification.

PubMed

Nie, Chuanxiong; Peng, Zihang; Yang, Ye; Cheng, Chong; Ma, Lang; Zhao, Changsheng

2016-11-15

Developing robust and recyclable absorbents for water purification is of great demand to control water pollution and to provide sustainable water resources. Herein, for the first time, we reported the fabrication of Kevlar nanofiber (KNF) based composite particles for water purification. Both the KNF and KNF-carbon nanotube composite particles can be produced in large-scale by automatic injection of casting solution into ethanol. The resulted nanofibrous particles showed high adsorption capacities towards various pollutants, including metal ions, phenylic compounds and various dyes. Meanwhile, the adsorption process towards dyes was found to fit well with the pseudo-second-order model, while the adsorption speed was controlled by intraparticle diffusion. Furthermore, the adsorption capacities of the nanofibrous particles could be easily recovered by washing with ethanol. In general, the KNF based particles integrate the advantages of easy production, robust and effective adsorption performances, as well as good recyclability, which can be used as robust absorbents to remove toxic molecules and forward the application of absorbents in water purification. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of antioxidant capacity of Chinese five-spice ingredients.

PubMed

Bi, Xinyan; Soong, Yean Yean; Lim, Siang Wee; Henry, Christiani Jeyakumar

2015-05-01

Phenolic compounds in spices were reportedly found to possess high antioxidant capacities (AOCs), which may prevent or reduce risk of human diseases such as cardiovascular disease, cancer and diabetes. The potential AOC of Chinese five-spice powder (consist of Szechuan pepper, fennel seed, cinnamon, star anise and clove) with varying proportion of individual spice ingredients was investigated through four standard methods. Our results suggest that clove is the major contributor to the AOC of the five-spice powder whereas the other four ingredients contribute to the flavour. For example, the total phenolic content as well as ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) values increased linearly with the clove percentage in five-spice powder. This observation opens the door to use clove in other spice mixtures to increase their AOC and flavour. Moreover, linear relationships were also observed between AOC and the total phenolic content of the 32 tested spice samples.

Phenolic composition and antioxidant properties of koose, a deep-fat fried cowpea cake.

PubMed

Apea-Bah, Franklin B; Serem, June C; Bester, Megan J; Duodu, Kwaku G

2017-12-15

Koose, a West African delicacy, is a side dish prepared by deep frying thick cowpea paste. The current research determined the effect of deep-fat frying of cowpea paste on its total phenolic content (TPC), phenolic composition and antioxidant properties. Four cowpea cultivars comprising two reddish-brown, a brownish-cream and cream phenotypes were used. Liquid chromatography-mass spectrometry was used to determine phenolic composition of the samples. TPC was determined using Folin-Ciocalteu method while radical scavenging capacities were by Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity and nitric oxide scavenging assays. The phenolic acids identified included benzoic and cinnamic acid derivatives. The predominant flavonoid classes were flavan-3-ols and flavonols. Deep-fat frying of the cowpea pastes decreased their TPC, radical scavenging capacities and total quantified flavonoids. The koose inhibited radical-induced oxidative cellular and DNA damage. It is concluded that koose is a potential functional food that can contribute to alleviating radical-induced oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selective Adsorption and Separation of Organic Dyes with Spherical Polyelectrolyte Brushes and Compressed Carbon Dioxide.

PubMed

Zhang, Rui; Yu, Zhenchuan; Wang, Lei; Shen, Qizhe; Hou, Xiaoyan; Guo, Xuhong; Wang, Junwei; Zhu, Xuedong; Yao, Yuan

2017-10-04

Dye-containing wastewater has caused serious environmental pollution. Herein, rationally designed spherical polyelectrolyte brushes (SPBs) with cationic charges, polystyrene-poly(2-aminoethylmethacrylate hydrochloride) (PS-PAEMH) as the absorbent, and compressed carbon dioxide as the antisolvent are proposed for the separation of the anionic dye eosin Y (EY) from a solution of mixed dyes. The adsorption behavior of EY onto PS-PAEMH was highly dependent on CO 2 pressure, contact time, and initial concentration. The maximum adsorption capacity of PS-PAEMH was 335.20 mg g -1 . FTIR and UV/Vis measurements proved that the electrostatic interactions between EY and PS-PAEMH played an important role in the absorbance process. The adsorption process fitted the pseudo-second-order kinetic model and Freundlich isotherm model very well. The combined dye and polymer brush could be easily separated through ion exchange by adding an aqueous solution of NaCl. Recovered PS-PAEMH retained a high adsorption capacity even after ten cycles of regeneration. This method provides a simple and effective way to separate ionic materials for environmental engineering. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reversible Assembly of Graphitic Carbon Nitride 3D Network for Highly Selective Dyes Absorption and Regeneration.

PubMed

Zhang, Yuye; Zhou, Zhixin; Shen, Yanfei; Zhou, Qing; Wang, Jianhai; Liu, Anran; Liu, Songqin; Zhang, Yuanjian

2016-09-27

Responsive assembly of 2D materials is of great interest for a range of applications. In this work, interfacial functionalized carbon nitride (CN) nanofibers were synthesized by hydrolyzing bulk CN in sodium hydroxide solution. The reversible assemble and disassemble behavior of the as-prepared CN nanofibers was investigated by using CO2 as a trigger to form a hydrogel network at first. Compared to the most widespread absorbent materials such as active carbon, graphene and previously reported supramolecular gel, the proposed CN hydrogel not only exhibited a competitive absorbing capacity (maximum absorbing capacity of methylene blue up to 402 mg/g) but also overcame the typical deficiencies such as poor selectivity and high energy-consuming regeneration. This work would provide a strategy to construct a 3D CN network and open an avenue for developing smart assembly for potential applications ranging from environment to selective extraction.

Efficient SO2 capture by amine functionalized PEG.

PubMed

Yang, Dezhong; Hou, Minqiang; Ning, Hui; Zhang, Jianling; Ma, Jun; Han, Buxing

2013-11-07

Polyethylene glycols (PEGs) are a class of non-toxic, non-volatile, biocompatible, and widely available polymers. In this work, we synthesized N-ethyl-N-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-2-aminoethanol (EE3AE) that combines the properties of PEG and amines, and N-decyl-N-ethyl-2-aminoethanol (DEAE). Their performances to capture SO2 were studied at different temperatures, pressures, and absorption times. The interaction between the absorbents and SO2 were characterized by NMR and FTIR techniques. It was demonstrated that both EE3AE and DEAE could absorb SO2 efficiently, and there existed chemical and physical interactions between the absorbents and SO2. In particular, the absorption capacity of EE3AE could be as high as 1.09 g SO2 per g EE3AE at 1 atm. The absorption capacity of EE3AE was much larger than that of DEAE because the ether group in the EE3AE interacted with SO2 more strongly than the alkyl group in the DEAE. The SO2 absorbed by EE3AE could be stripped out by bubbling N2 or by applying a vacuum and the EE3AE could be reused. Moreover, both absorbents exhibited a high SO2-CO2 selectivity.

Spectrophotometric Determination of Phenolic Antioxidants in the Presence of Thiols and Proteins.

PubMed

Avan, Aslı Neslihan; Demirci Çekiç, Sema; Uzunboy, Seda; Apak, Reşat

2016-08-12

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive to the probe reagent. In this study, three of the most common TAC determination methods, namely cupric ion reducing antioxidant capacity (CUPRAC), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt/trolox equivalent antioxidant capacity (ABTS/TEAC), and ferric reducing antioxidant power (FRAP), were tested for the assay of phenolics in the presence of selected thiol and protein compounds. Although the FRAP method is almost non-responsive to thiol compounds individually, surprising overoxidations with large positive deviations from additivity were observed when using this method for (phenols + thiols) mixtures. Among the tested TAC methods, CUPRAC gave the most additive results for all studied (phenol + thiol) and (phenol + protein) mixtures with minimal relative error. As ABTS/TEAC and FRAP methods gave small and large deviations, respectively, from additivity of absorbances arising from these components in mixtures, mercury(II) compounds were added to stabilize the thiol components in the form of Hg(II)-thiol complexes so as to enable selective spectrophotometric determination of phenolic components. This error compensation was most efficient for the FRAP method in testing (thiols + phenols) mixtures.

Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture

NASA Astrophysics Data System (ADS)

Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan

2017-05-01

Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

Diesel NO{sub x} reduction by plasma-regenerated absorbent beds

DOEpatents

Wallman, P.H.; Vogtlin, G.E.

1998-02-10

Reduction of NO{sub x} from diesel engine exhaust by use of plasma-regenerated absorbent beds is described. This involves a process for the reduction of NO{sub x} and particulates from diesel engines by first absorbing NO{sub x} onto a solid absorbent bed that simultaneously acts as a physical trap for the particulate matter, and second regenerating said solid absorbent by pulsed plasma decomposition of absorbed NO{sub x} followed by air oxidation of trapped particulate matter. The absorbent bed may utilize all metal oxides, but the capacity and the kinetics of absorption and desorption vary between different materials, and thus the composition of the absorbent bed is preferably a material which enables the combination of NO{sub x} absorption capability with catalytic activity for oxidation of hydrocarbons. Thus, naturally occurring or synthetically prepared materials may be utilized, particularly those having NO{sub x} absorption properties up to temperatures around 400 C which is in the area of diesel engine exhaust temperatures. 1 fig.

Performance of a hybrid chemical/mechanical heat pump

NASA Technical Reports Server (NTRS)

Silvestri, John J.; Scaringe, Robert P.; Grzyll, Lawrence R.

1990-01-01

The authors present the design and preliminary results of the performance of a hybrid chemical/mechanical, low-lift (20 C) heat pump. Studies have indicated that this heat pump has several advantages over the traditional single fluid vapor compression (reverse Rankine) heat pump. Included in these benefits are: 1) increased COPc due to the approximation of the cycle to the Lorenz cycle and due to the availability of the heat of solution, along with the heat of vaporization, to provide cooling; and 2) ease of variation in system cooling capacity by changing the fluid composition. The system performance is predicted for a variety of refrigerant-absorbent pairs. Cooling capacity is determined for systems operating with ammonia as the refrigerant and lithium nitrate and sodium thiocyanate as the absorbents and also with water as the refrigerant and magnesium chloride, potassium hydroxide, lithium bromide, sodium hydroxide, and sulfuric acid as the absorbents. Early indications have shown that the systems operating with water as the refrigerant operate at 2-4 times the capacity of the ammonia-refrigerant-based systems. Using existing working fluids in the proposed innovative design, a coefficient-of-performance improvement of 21 percent is possible when compared to the best vapor compression systems analyzed.

A New Remote-Sensing Method for Mine Detection using HPM Irradiation and IR Detection.

DTIC Science & Technology

1999-12-01

absorption of microwave energy by the mine. This signature appears at the soil surface after a brief time-delay from the start of HPM illumination. At...detection de cible, l’operation de teledetection, la capacite de detecter des cibles sous un ciel couvert avec peu de dependance du cycle solaire et la...the temperature of the sample depends on the microwave energy absorbed by the sample and varies inversely with the sample thermal heat capacity. The

Laparoscopic surgery for morbid obesity.

PubMed

Hallerbäck, B; Glise, H; Johansson, B; Johnson, E

1998-01-01

Morbid obesity, defined as a body mass index (BMI), i.e. weight (kg)/height (m2) over 36 for males and 38 for females, is a common condition and a threat for health, life and individual well being. Hitherto, surgery is the only effective treatment for weight reduction. Surgical methods can be malabsorptive, reducing the patients ability to absorb nutrients, or restrictive, reducing the capacity of food intake. Exclusively malabsorptive methods have been abandoned due to severe side effects. Restrictive methods, gastroplasties, reduces the compliance capacity of the stomach. Two types are performed laparoscopically, the vertical banded gastroplasty and the adjustable gastric banding. The proximal gastric by pass is also performed laparoscopically and is a combination of a restrictive proximal gastroplasty and a malabsorptive Roux-en-Y gastro-jejunal anastomosis. With laparoscopic adjustable gastric banding mean BMI was reduced from 41 kg/m2 to 33 kg/m2 (n = 43) after one year. Two years after surgery mean BMI was 30 kg/m2 (n = 16). The different operative techniques are further discussed in this paper.

Heat transfer capability of solar radiation in colored roof and influence on room thermal comfort

NASA Astrophysics Data System (ADS)

Syuhada, Ahmad; Maulana, Muhammad Ilham

2018-02-01

Colored zinc is the most widely used by people in Indonesia as the roof of the building. Each color has different heat absorption capability, the higher the absorption capacity of a roof will cause high room temperature. A high temperature in the room will cause the room is not thermally comfortable for activity. Lack of public knowledge about the ability of each color to absorb heat can cause errors in choosing the color of the roof of the building so that it becomes uncomfortable regarding thermal comfort. This study examined how big the ability of each color in influencing the heat absorption on the roof of the zinc. The purpose of this study is to examine which colors are the lowest to absorb radiation heat. This research used theexperimental method. Data collected by measuring the temperature of the environment above and below the colored tin roof, starting at 11:00 am until 15:00 pm. The zinc roofs tested in this study are zinc black, red zinc, green zinc, blue zinc, brown zinc, maroon zinc, orange zinc, zinc gray, zinc color chrome and zinc white color. The study results show that black and blackish colors will absorb more heat than other colors. While the color white or close to whitish color will absorb a slight heat.

Antioxidant potential, tannin and polyphenol contents of seed and pericarp of three Coffea species.

PubMed

Patay, Éva Brigitta; Sali, Nikolett; Kőszegi, Tamás; Csepregi, Rita; Balázs, Viktória Lilla; Németh, Tibor Sebastian; Németh, Tibor; Papp, Nóra

2016-04-01

To investigate the antioxidant activity, total phenolic and total tannin content of the pericarp and the seed of Coffea benghalensis (C. benghalensis) and Coffea liberica compared to Coffea arabica (C. arabica). The antioxidant potential, total tannin and polyphenol contents of the immature and mature seed and pericarp of C. benghalensis and Coffea liberica were quantified and compared to C. arabica. Enhanced chemiluminescence (ECL), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity, Folin-Ciocalteau method and total tannin content assays were used. Trolox equivalent (TE/g plant material) values obtained by ECL and DPPH methods showed loose correlation (r(2) = 0.587) while those measured by oxygen radical absorbance capacity assay were higher without correlation in each plant. A closer correlation was detected between the ECL method and the percentage antioxidant activity of the DPPH technique (r(2) = 0.610 7) in each species, however the immature pericarp of C. benghalensis showed much higher DPPH scavenging potential than was seen in the ECL assay. The immature pericarp of C. benghalensis expressed the highest tannin and polyphenol content, and a high polyphenol level was also detected in the immature seed of C. arabica. The immature pericarp of Bengal and Liberian coffees showed the largest amount of phenolic contents. The obtained data highlight the potential role of C. benghalensis as a new source of natural antioxidants and polyphenols compared to C. arabica. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

The effect of the elliptical ratio on the tubular energy absorber subjected to lateral loading under quasistatic conditions

NASA Astrophysics Data System (ADS)

Baroutaji, A.; Olabi, A. G.

2010-06-01

Tubular systems are proposed to be used as energy absorber because they are cheap and easy to manufacture; recently some researchers use the elliptical tube as energy absorber. In this work, the influence of elliptical ratio (r =D1/D2) on energy absorption capability and load carrying capacity and stress of mild steel elliptical tubes has been investigated both experimentally and numerically, the experimental analyses conducted by using Zwick Type BT1-FB050TN testing instrument. This machine is universal instrument for performing tensile test and compression test, Fig (1) and bending test and it is consider as an important machine for measuring the mechanical properties of materials and structures. The loading frame consist of two vertical lead screws, a moving crosshead and an upper and lower bearing plate which bears the load of the lead screws. The maximum capacity of the loading frame attached to the table mounted unit is 50KN In this study a velocity between 310mm/min was applied to the moving component to ensure the quasistatic conditions whereas velocities between 0.5mm/min and 15 mm/min have been used by many researchers to simulate the quasi-static lateral compression of tubes between various indenters [1-2]. In addition to the experimental work, computational method using ANSYS is used to predict the loading and response of such tubes where series of models was performed with elliptical ratios ranging from 0.5 to 1.5. Comparison of numerical and experimental forcedeflection response is presented. It has been found that with changing the elliptical ratio of the tube the loaddeflection curve change and this leads to change the energy absorbed by tube, the changing of the geometrical shape of the tube leads to change the volume of this tube and hence the mass. By reducing the elliptical ratio to 0.5 the tube will absorb 43.3% more energy and the system will gain 102% more in terms of specific energy, fig (2).

Combination of UV absorbance and electron donating capacity to assess degradation of micropollutants and formation of bromate during ozonation of wastewater effluents.

PubMed

Chon, Kangmin; Salhi, Elisabeth; von Gunten, Urs

2015-09-15

In this study, the changes in UV absorbance at 254 nm (UVA254) and electron donating capacity (EDC) were investigated as surrogate indicators for assessing removal of micropollutants and bromate formation during ozonation of wastewater effluents. To measure the EDC, a novel method based on size exclusion chromatography followed by a post-column reaction was developed and calibrated against an existing electrochemical method. Low specific ozone doses led to a more efficient abatement of EDC than of UVA254. This was attributed to the abatement of phenolic moieties in the dissolved organic matter (DOM), which lose their EDC upon oxidation, but are partially transformed into quinones, which still absorb in the measured UV range. For higher specific ozone doses, the relative EDC abatement was lower than the relative UVA abatement, which can be explained by the oxidation of UV absorbing moieties (e.g. non-activated aromatic compounds), which contribute less to EDC. The abatement of the selected micropollutants (i.e., 17α-ethinylestradiol (EE2), carbamazepine (CBZ), atenolol (ATE), bezafibrate (BZF), ibuprofen (IBU), and p-chlorobenzoic acid (pCBA)) varied significantly depending on their reactivity with ozone in the examined specific ozone dose range of 0-1.45 mgO3/mgDOC. The decrease of EE2 and CBZ with high ozone reactivity was linearly proportional to the reduction of the relative residuals of UVA254 and EDC. The abatement of ATE, BZF, IBU, and pCBA with intermediate to low ozone reactivities was not significant in a first phase (UVA254/UVA254,0 = 1.00-0.70; EDC/EDC0 = 1.00-0.56) while their abatement was more efficient than the degradation of the relative residual UVA254 and much more noticeable than the degradation of the relative residual EDC in a second phase (UVA254/UVA254,0 = 0.70-0.25; EDC/EDC0 = 0.56-0.25) because the partially destroyed UV absorbing and electron donating DOM moieties become recalcitrant to ozone attack. Bromate formation was pronounced for specific ozone doses >0.25 mgO3/mgDOC. At these ozone doses, the residual DOM competes less with bromide for ozone as the electron-rich DOM moieties are almost completely degraded. Overall, these results imply that a combination of the relative residual UVA254 and EDC more truly reflects the intrinsic reactivity of DOM associated with the removal of micropollutants and bromate formation than the single use of the UV absorbance-based surrogate indicators. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced optical absorbance and fabrication of periodic arrays on nickel surface using nanosecond laser

NASA Astrophysics Data System (ADS)

Fu, Jinxiang; Liang, Hao; Zhang, Jingyuan; Wang, Yibo; Liu, Yannan; Zhang, Zhiyan; Lin, Xuechun

2017-04-01

A hundred-nanosecond pulsed laser was employed to structure the nickel surface. The effects of laser spatial filling interval and laser scanning speed on the optical absorbance capacity and morphologies on the nickel surface were experimentally investigated. The black nickel surface covered with dense micro/nanostructured broccoli-like clusters with strong light trapping capacity ranging from the UV to the near IR was produced at a high laser scanning speed up to v=100 mm/s. The absorbance of the black nickel is as high as 98% in the UV range of 200-400 nm, more than 97% in the visible spectrum, ranging from 400 to 800 nm, and over 90% in the IR between 800 and 2000 nm. In addition, when the nickel surface was irradiated in two-dimensional crossing scans by laser with different processing parameters, self-organized and shape-controllable structures of three-dimensional (3D) periodic arrays can be fabricated. Compared with ultrafast laser systems previously used for such processing, the nanosecond fiber laser used in this work is more cost-effective, compact and allows higher processing rates. This nickel surface structured technique may be applicable in optoelectronics, batteries industry, solar/wave absorbers, and wettability materials.

Water holding capacity and evaporative loss from organic bedding materials used in livestock facilities

USDA-ARS?s Scientific Manuscript database

Physical and chemical characteristics of organic bedding materials determine how well they will absorb and retain moisture and may influence the environment in livestock facilities where bedding is used. The objective of this study was to determine water holding capacity (WHC) and rate of evaporativ...

Development of a prototype regeneration carbon dioxide absorber. [for use in EVA conditions

NASA Technical Reports Server (NTRS)

Patel, P. S.; Baker, B. S.

1977-01-01

A prototype regenerable carbon dioxide absorber was developed to maintain the environmental quality of the portable life support system. The absorber works on the alkali metal carbonate-bicarbonate solid-gas reaction to remove carbon dioxide from the atmosphere. The prototype sorber module was designed, fabricated, and tested at simulated extravehicular activity conditions to arrive at optimum design. The unit maintains sorber outlet concentration below 5 mm Hg. An optimization study was made with respect to heat transfer, temperature control, sorbent utilization, sorber life and regenerability, and final size of the module. Important parameters influencing the capacity of the final absorber unit were identified and recommendations for improvement were made.

The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock ( Theragra chalcogramma) skin

NASA Astrophysics Data System (ADS)

Zhuang, Yongliang; Li, Bafang; Zhao, Xue

2009-06-01

Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock ( Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.

Advances in the analytical methods for determining the antioxidant properties of honey: a review.

PubMed

Moniruzzaman, M; Khalil, M I; Sulaiman, S A; Gan, S H

2012-01-01

Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. In an effort to combat free radical activity, scientists are studying the effects of increasing individuals' antioxidant levels through diet and dietary supplements. Honey appears to act as an antioxidant in more ways than one. In the body, honey can mop up free radicals and contribute to better health. Various antioxidant activity methods have been used to measure and compare the antioxidant activity of honey. In recent years, DPPH (Diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), ORAC (The Oxygen Radical Absorbance Capacity), ABTS [2, 2-azinobis (3ehtylbenzothiazoline-6-sulfonic acid) diamonium salt], TEAC [6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox)-equivalent antioxidant capacity] assays have been used to evaluate antioxidant activity of honey. The antioxidant activity of honey is also measured by ascorbic acid content and different enzyme assays like Catalase (CAT), Glutathione Peroxidase (GPO), Superoxide Dismutase (SOD). Among the different methods available, methods that have been validated, standardized and widely reported are recommended.

Diesel NO.sub.x reduction by plasma-regenerated absorbend beds

DOEpatents

Wallman, P. Henrik; Vogtlin, George E.

1998-01-01

Reduction of NO.sub.x from diesel engine exhaust by use of plasma-regenerated absorbent beds. This involves a process for the reduction of NO.sub.x and particulates from diesel engines by first absorbing NO.sub.x onto a solid absorbent bed that simultaneously acts as a physical trap for the particulate matter, and second regenerating said solid absorbent by pulsed plasma decomposition of absorbed NO.sub.x followed by air oxidation of trapped particulate matter. The absorbent bed may utilize all metal oxides, but the capacity and the kinetics of absorption and desorption vary between different materials, and thus the composition of the absorbent bed is preferably a material which enables the combination of NO.sub.x absorption capability with catalytic activity for oxidation of hydrocarbons. Thus, naturally occurring or synthetically prepared materials may be utilized, particularly those having NO.sub.x absorption properties up to temperatures around 400.degree. C. which is in the area of diesel engine exhaust temperatures.

Plasmatic antioxidant capacity due to ascorbate using TEMPO scavenging and electron spin resonance.

PubMed

Piehl, Lidia L; Facorro, Graciela B; Huarte, Mónica G; Desimone, Martín F; Copello, Guillermo J; Díaz, Luis E; de Celis, Emilio Rubín

2005-09-01

Ascorbate is the most effective water-soluble antioxidant and its plasma concentration is usually measured by different methods including colorimetric assays, HPLC or capillary electrophoresis. Plasma antioxidant capacity is determined by indexes such as total reactive antioxidant potential, total antioxidant reactivity, oxygen radical absorbance capacity, etc. We developed an alternative method for the evaluation of the plasma antioxidant status due to ascorbate. TEMPO kinetics scavenging analyzed by ESR spectroscopy was performed on plasma samples in different antioxidant situations. Plasma ascorbate concentrations were determined by capillary electrophoresis. Ascorbyl radical levels were measured by ESR. Plasma reactivity with TEMPO (PR-T) reflected plasma ascorbate levels. Average PR-T for normal plasmas resulted 85+/-27 micromol/l (n=43). PR-T during ascorbic acid intake (1 g/day) increased to an average value of 130+/-20 micromol/l (p<0.001, n=20). PR-T correlated with the plasmatic ascorbate levels determined by capillary electrophoresis (r=0.92), presenting as an advantage the avoiding of the deproteination step. Plasma ascorbyl radical levels increase from 16+/-2 to 24+/-3 nmol/l (p<0.005, n=14) after ascorbate intake. PR-T could be considered as a measure of the plasmatic antioxidant capacity due to the plasma ascorbate levels and could be useful to investigate different antioxidant situations.

Improvement in botanical standardization of commercial freeze-dried herbal extracts by using the combination of antioxidant capacity and constituent marker concentrations.

PubMed

Ninfali, Paolino; Gennari, Lorenzo; Biagiotti, Enrica; Cangi, Francesca; Mattoli, Luisa; Maidecchi, Anna

2009-01-01

Botanical extracts are standardized to > or = 1 marker compounds (MCs). This standardization provides a certain level of quality control, but not complete quality assurance. Thus, industries are looking for other satisfactory systems to improve standardization. This study focuses on the standardization of herbal medicines by combining 2 parameters: the concentration of the MC and antioxidant capacity. Antioxidant capacity was determined with the oxygen radical absorbance capacity (ORAC) method and the concentrations of the MCs, by high-performance liquid chromatography. Total phenols were also determined by the Folin-Ciocolteau method. The ORAC values, expressed as micromol Trolox equivalents/100 g (ORAC %), of 12 commercial herbal extracts were related to the ORAC values of the respective pure MCs at the concentrations at which the MCs occur in products (ORAC-MC %). The ORAC % values of 11 extracts were higher than those of the respective MCs and the ratios ORAC-MC %/ORAC % ranged from 0.007 to 0.7, whereas in the case of Olea europaea leaves, the same ratio was 1.36. The ORAC parameters and their ratios, as well as the linear relationship between ORAC-MC % and ORAC %, are described and discussed as tools for improving the standardization of herbal products and detecting modifications due to herb processing and storage.

Ballistic performance of a Kevlar-29 woven fibre composite under varied temperatures

NASA Astrophysics Data System (ADS)

Soykasap, O.; Colakoglu, M.

2010-05-01

Armours are usually manufactured from polymer matrix composites and used for both military and non-military purposes in different seasons, climates, and regions. The mechanical properties of the composites depend on temperature, which also affects their ballistic characteristics. The armour is used to absorb the kinetic energy of a projectile without any major injury to a person. Therefore, besides a high strength and lightness, a high damping capacity is required to absorb the impact energy transferred by the projectile. The ballistic properties of a Kevlar 29/polyvinyl butyral composite are investigated under varied temperatures in this study. The elastic modulus of the composite is determined from the natural frequency of composite specimens at different temperatures by using a damping monitoring method. Then, the backside deformation of composite plates is analysed experimentally and numerically employing the finite-element program Abaqus. The experimental and numeric results obtained are in good agreement.

Similarity principles for the biology of pelagic animals

PubMed Central

Barenblatt, G. I.; Monin, A. S.

1983-01-01

A similarity principle is formulated according to which the statistical pattern of the pelagic population is identical in all scales sufficiently large in comparison with the molecular one. From this principle, a power law is obtained analytically for the pelagic animal biomass distribution over the animal sizes. A hypothesis is presented according to which, under fixed external conditions, the oxygen exchange intensity of an animal is governed only by its mass and density and by the specific absorbing capacity of the animal's respiratory organ. From this hypothesis a power law is obtained by the method of dimensional analysis for the exchange intensity mass dependence. The known empirical values of the exponent of this power law are interpreted as an indication that the oxygen-absorbing organs of the animals can be represented as so-called fractal surfaces. In conclusion the biological principle of the decrease in specific exchange intensity with increase in animal mass is discussed. PMID:16593327

Experimental and analytical study of high velocity impact on Kevlar/Epoxy composite plates

NASA Astrophysics Data System (ADS)

Sikarwar, Rahul S.; Velmurugan, Raman; Madhu, Velmuri

2012-12-01

In the present study, impact behavior of Kevlar/Epoxy composite plates has been carried out experimentally by considering different thicknesses and lay-up sequences and compared with analytical results. The effect of thickness, lay-up sequence on energy absorbing capacity has been studied for high velocity impact. Four lay-up sequences and four thickness values have been considered. Initial velocities and residual velocities are measured experimentally to calculate the energy absorbing capacity of laminates. Residual velocity of projectile and energy absorbed by laminates are calculated analytically. The results obtained from analytical study are found to be in good agreement with experimental results. It is observed from the study that 0/90 lay-up sequence is most effective for impact resistance. Delamination area is maximum on the back side of the plate for all thickness values and lay-up sequences. The delamination area on the back is maximum for 0/90/45/-45 laminates compared to other lay-up sequences.

Oxygen radical absorbance capacity of different varieties of strawberry and the antioxidant stability in storage.

PubMed

Li, Chunyang; Huang, Wu-Yang; Wang, Xing-Na; Liu, Wen-Xu

2013-01-25

Total antioxidant capacity of different varieties of strawberry (Ningfeng, Ningyu, Zijin 4, Toyonoka, Benihope, Sweet Charlie) in different developmental stages (including green unripe stages, half red stages, and red ripe stages) was investigated by oxygen radical absorbance capacity (ORAC) assay. In addition, effects of the antioxidant properties of strawberry stored at 4 °C or -18 °C for a period of five months were studied. The results showed that antioxidant capacity of strawberry changed based on tested part, developmental stage, variety, and time of collection. Calyces had significantly higher ORAC values compared with fruits. Strawberry fruits had higher ORAC values during the green unripe stages than the half red stages and red ripe stages. Strawberries got higher ORAC values during short-time storage, and then decreased during long-time storage. Samples stored at -18 °C exhibited higher antioxidant capacity than those stored at 4 °C, while vacuum treatment could further increase ORAC values. The results indicated the potential market role of strawberries as a functional food and could provide great value in preventing oxidation reaction in food processing and storage for the dietary industry.

Antioxidant activity of a new C-glycosylflavone from the leaves of Ficus microcarpa.

PubMed

Phan, Van Kiem; Nguyen, Xuan Cuong; Nguyen, Xuan Nhiem; Vu, Kim Thu; Ninh, Khac Ban; Chau, Van Minh; Bui, Huu Tai; Truong, Nam Hai; Lee, Sang Hyun; Jang, Hae Dong; Kim, Young Ho

2011-01-15

By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5μM Trolox equivalents at the concentration of 2.0μM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4μM. Copyright © 2010 Elsevier Ltd. All rights reserved.

Removal of Carmine from Aqueous Solution by Carbonated Hydroxyapatite Nanorods

PubMed Central

Liu, Guanxiong; Xue, Caibao; Zhu, Peizhi

2017-01-01

In this study, carbonated hydroxyapatite (CHA) nanorods were prepared by a novel hydrothermal method. The crystallinity and chemical structure of synthesized CHA nanorods was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. Carmine was selected as representative organic dyes to study the adsorption capacities of CHA nanorods. Mechanistic studies of carmine adsorption by CHA nanorods show that the adsorption processes both follow the pseudo-second-order kinetic model and fit the Langmuir isotherm model well. The CHA nanorods exhibited a high adsorption capacity of 85.51 mg/g for carmine at room-temperature. The experimental results prove that CHA nanorods can be promising absorbents for removing organic dye pollutants in wastewater from paper and textile plants. PMID:28587250

Spectrophotometric Determination of Phenolic Antioxidants in the Presence of Thiols and Proteins

PubMed Central

Avan, Aslı Neslihan; Demirci Çekiç, Sema; Uzunboy, Seda; Apak, Reşat

2016-01-01

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive to the probe reagent. In this study, three of the most common TAC determination methods, namely cupric ion reducing antioxidant capacity (CUPRAC), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt/trolox equivalent antioxidant capacity (ABTS/TEAC), and ferric reducing antioxidant power (FRAP), were tested for the assay of phenolics in the presence of selected thiol and protein compounds. Although the FRAP method is almost non-responsive to thiol compounds individually, surprising overoxidations with large positive deviations from additivity were observed when using this method for (phenols + thiols) mixtures. Among the tested TAC methods, CUPRAC gave the most additive results for all studied (phenol + thiol) and (phenol + protein) mixtures with minimal relative error. As ABTS/TEAC and FRAP methods gave small and large deviations, respectively, from additivity of absorbances arising from these components in mixtures, mercury(II) compounds were added to stabilize the thiol components in the form of Hg(II)-thiol complexes so as to enable selective spectrophotometric determination of phenolic components. This error compensation was most efficient for the FRAP method in testing (thiols + phenols) mixtures. PMID:27529232

Age Differences in Energy Absorption in the Upper Extremity During a Descent Movement: Implications for Arresting a Fall

PubMed Central

Stotz, Paula J.; Normandin, Sarah C.; Robinovitch, Stephen N.

2010-01-01

Background Falls are the number one cause of unintentional injury in older adults. The protective response of “breaking the fall” with the outstretched hand is often essential for avoiding injury to the hip and head. In this study, we compared the ability of young and older women to absorb the impact energy of a fall in the outstretched arms. Methods Twenty young (mean age = 21 years) and 20 older (M = 78 years) women were instructed to slowly lower their body weight, similar to the descent phase of a push-up, from body lean angles ranging from 15° to 90°. Measures were acquired of peak upper extremity energy absorption, arm deflection, and hand contact force. Results On average, older women were able to absorb 45% less energy in the dominant arm than young women (1.7 ± 0.5% vs 3.1 ± 0.4% of their body weight × body height; p < .001). These results suggest that, even when both arms participate equally, the average energy content of a forward fall exceeds by 5-fold the average energy that our older participants could absorb and exceeds by 2.7-fold the average energy that young participants could absorb. Conclusions During a descent movement that simulates fall arrest, the energy-absorbing capacity of the upper extremities in older women is nearly half that of young women. Absorbing the full energy of a fall in the upper extremities is a challenging task even for healthy young women. Strengthening of upper extremity muscles should enhance this ability and presumably reduce the risk for injury to the hip and head during a fall. PMID:19861641

High-Capacity Heat-Pipe Evaporator

NASA Technical Reports Server (NTRS)

Oren, J. A.; Duschatko, R. J.; Voss, F. E.; Sauer, L. W.

1989-01-01

Heat pipe with cylindrical heat-input surface has higher contact thermal conductance than one with usual flat surface. Cylindrical heat absorber promotes nearly uniform flow of heat into pipe at all places around periphery of pipe, helps eliminate hotspots on heat source. Lugs in aluminum pipe carry heat from outer surface to liquid oozing from capillaries of wick. Liquid absorbs heat, evaporates, and passes out of evaporator through interlug passages.

Role of the calcaneal heel pad and polymeric shock absorbers in attenuation of heel strike impact.

PubMed

Noe, D A; Voto, S J; Hoffmann, M S; Askew, M J; Gradisar, I A

1993-01-01

The capacity of the calcaneal heel pad, with and without augmentation by a polymeric shock absorbing material (Sorbothane 0050), to attenuate heel strike impulses has been studied using five fresh human cadaveric lower leg specimens. The specimens, instrumented with an accelerometer, were suspended and impacted with a hammer; a steel rod was similarly suspended and impacted. The calcaneal heel pad attenuated the peak accelerations by 80%. Attenuations of up to 93% were achieved by the shock absorbing material when tested against the steel rod; however, when tested in series with the calcaneal heel pad, the reduction in peak acceleration due to the shock absorbing material dropped to 18%. Any evaluation of the effectiveness of shock absorbing shoe materials must take into account their mechanical interaction with the body.

Metallic materials for mechanical damping capacity applications

NASA Astrophysics Data System (ADS)

Crăciun, R. C.; Stanciu, S.; Cimpoeșu, R.; (Dragoș Ursanu, A. I.; Manole, V.; Paraschiv, P.; Chicet, D. L.

2016-08-01

Some metallic materials exhibit good damping capacity of mechanical energy into thermal energy. This property along with the others metallic characteristics make this materials interesting for a big number of applications. These materials can be used as bumpers in different applications including automotive field. Beside grey cast iron and shape memory alloys few new metallic materials are presented for the supposition of high damping capacity. We analyze the causes that increase the internal friction of some metallic materials and possibilities to enhance this property through different mechanical, physical or chemical methods. Shape memory alloys, especially those based on copper, present a different damping capacity on martensite, austenite or transition state. In the transformation range M ↔A, which in case of copper base shape memory alloys is quite large, the metallic intelligent materials present a high internal friction, almost comparable with natural rubber behavior that can transform mechanical energy into thermal energy till a certain value of the external solicitation. These materials can be used as noise or small vibrations bumpers or even as shock absorbers in automotive industry.

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

DOE PAGES

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui; ...

2018-05-17

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

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

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Determination of total antioxidant capacity by a new spectrophotometric method based on Ce(IV) reducing capacity measurement.

PubMed

Ozyurt, Dilek; Demirata, Birsen; Apak, Resat

2007-02-28

Dietary antioxidants widely found in fruits and vegetables may serve the task of reducing oxidative damage in humans induced by free radicals and reactive oxygen species under 'oxidative stress' conditions. The aim of this work is to develop a simple, low-cost, sensitive, and diversely applicable indirect spectrophotometric method for the determination of total antioxidant capacity of several plants. The method is based on the oxidation of antioxidants with cerium(IV) sulfate in dilute sulfuric acid at room temperature. The Ce(IV) reducing capacity of the sample is measured under carefully adjusted conditions of oxidant concentration and pH such that only antioxidants and not other organic compounds would be oxidized. The spectrophotometric determination of the remaining Ce(IV) was performed after completion of reaction with antioxidants. Quercetin and gallic acid were used as standards for flavonoids and phenolic acids, respectively, and results of antioxidant measurements were reported as trolox equivalents. The developed procedure was successfully applied to the assay of total antioxidant capacity due to simple compounds such as trolox, quercetin, gallic acid, ascorbic acid, catechin, naringin, naringenin, caffeic acid, chlorogenic acid, ferulic acid, and p-coumaric acid, and due to phenolic acids and flavonoids in the arieal parts of nettle (Urtica Dioica L.). Blank correction of significantly absorbing plant extracts at 320nm could be made with the aid of spectrophotometric titration. Plant selection was made in respect to high antioxidant content, and extraction was made with water. The proposed method was reproducible, and the trolox equivalent antioxidant capacities (TEAC coefficients) of the tested antioxidant compounds were correlated to those found by reference methods such as ABTS and CUPRAC. Since the TEAC coefficients found with the proposed method of naringin-naringenin and rutin-catechin pairs were close to each other, this Ce(IV)-based assay probably caused the simultaneous hydrolysis of flavonoid glycosides to the corresponding aglycones and their subsequent oxidation such that the hydrolysis products exhibed antioxidant capacities roughly proportional the number of -OH groups contained in a molecule.

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties.

PubMed

Sharpe, Erica; Hua, Fang; Schuckers, Stephanie; Andreescu, Silvana; Bradley, Ryan

2016-02-01

A novel paper-based Nanoceria Reducing Antioxidant Capacity (NanoCerac) assay for antioxidant detection (Sharpe, Frasco, Andreescu, & Andreescu, 2012), has been adapted for the first time as a high-throughput method, in order to measure the effect of brewing conditions and re-infusion on the antioxidant capacity of twenty-four commercial green teas. The oxygen radical absorbance capacity (ORAC) assay, frequently applied to complex foods and beverages, was used as a comparator measure of antioxidant capacity. A novel measure of sustained antioxidant capacity, the total inherent antioxidant capacity (TI-NanoCerac and TI-ORAC) was measured by infusing each tea six times. Effects of brewing conditions (temperature, brew time, etc.) were assessed using one popular tea as a standard. Both NanoCerac and ORAC assays correlated moderately (R(2) 0.80 ± 0.19). The average first-brew NanoCerac, TI-NanoCerac, first-brew ORAC and TI-ORAC were: 0.73 ± 0.1 GAE/g tea; 2.4 ± 0.70 mmolGAE/g tea; 1.0 ± 0.3 mmolTE/g tea and 2.1 ± 0.71 mmolTE/g tea respectively. Brewing conditions including water temperature and infusion time significantly affected antioxidant capacity. The high-throughput adaptation of the original NanoCerac assay tested here offered advantages over ORAC, including portability and rapid analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Brewing Conditions on the Antioxidant Capacity of Twenty-four Commercial Green Tea Varieties

PubMed Central

Sharpe, Erica; Hua, Fang; Schuckers, Stephanie; Andreescu, Silvana; Bradley, Ryan

2015-01-01

A novel paper-based Nanoceria Reducing Antioxidant Capacity (NanoCerac) assay for antioxidant detection (Sharpe, Frasco, Andreescu, & Andreescu, 2012), has been adapted for the first time as a high-throughput method, in order to measure the effect of brewing conditions and re-infusion on the antioxidant capacity of twenty-four commercial green teas. The oxygen radical absorbance capacity (ORAC) assay, frequently applied to complex foods and beverages, was used as a comparator measure of antioxidant capacity. A novel measure of sustained antioxidant capacity, the total inherent antioxidant capacity (TI-NanoCerac and TI-ORAC) was measured by infusing each tea six times. Effects of brewing conditions (temperature, brew time, etc.) were assessed using one popular tea as a standard. Both NanoCerac and ORAC assays correlated moderately (R2 0.80 ± 0.19). The average first-brew NanoCerac, TI-NanoCerac, first-brew ORAC and TI-ORAC were: 0.73 ± 0.1 GAE/g tea ; 2.4 ± 0.70 mmol GAE/g tea; 1.0 ± 0.3 mmol TE/g tea and 2.1 ± 0.71 mmol TE/g tea respectively. Brewing conditions including water temperature and infusion time significantly affected antioxidant capacity. The high-throughput adaptation of the original NanoCerac assay tested here offered advantages over ORAC, including portability and rapid analysis. PMID:26304363

Application of a microplate-based ORAC-pyrogallol red assay for the estimation ofantioxidant capacity: First Action 2012.03.

PubMed

Ortiz, Rocío; Antilén, Mónica; Speisky, Hernán; Aliaga, Margarita E; López-Alarcón, Camilo; Baugh, Steve

2012-01-01

A method was developed for microplate-based oxygen radicals absorbance capacity (ORAC) using pyrogallol red (PGR) as probe (ORAC-PGR). The method was evaluated for linearity, precision, and accuracy. In addition, the antioxidant capacity of commercial beverages, such as wines, fruit juices, and iced teas, was measured. Linearity of the area under the curve (AUC) versus Trolox concentration plots was [AUC = (845 +/- 110) + (23 +/- 2) [Trolox, microM]; R = 0.9961, n = 19]. Analyses showed better precision and accuracy at the highest Trolox concentration (40 microM) with RSD and recovery (REC) values of 1.7 and 101.0%, respectively. The method also showed good linearity for red wine [AUC = (787 +/- 77) + (690 +/- 60) [red wine, microL/mL]; R = 0.9926, n = 17], precision and accuracy with RSD values from 1.4 to 8.3%, and REC values that ranged from 89.7 to 103.8%. Red wines showed higher ORAC-PGR values than white wines, while the ORAC-PGR index of fruit juices and iced teas presented a wide range of results, from 0.6 to 21.6 mM of Trolox equivalents. Product-to-product variability was also observed for juices of the same fruit, showing the differences between brands on the ORAC-PGR index.

Removal of Methylene Blue from aqueous solution using spent bleaching earth

NASA Astrophysics Data System (ADS)

Saputra, E.; Saputra, R.; Nugraha, M. W.; Irianty, R. S.; Utama, P. S.

2018-04-01

The waste from industrial textile waste is one of the environmental problems, it is required effective and efficient processing. In this study spent bleaching earth was used as absorbent. It was found that the absorbent was effective to remove methylene blue from aqueous solution with removal efficiency 99.97 % in 120 min. Several parameters such as pH, amount of absorbent loading, stirring speed are found as key factor influencing removal of methylene blue. The mechanism of adsorption was also studied, and it was found that Langmuir isotherm fitted to data of experiment with adsorption capacity 0.5 mg/g.

Oxidative damage, skin aging, antioxidants and a novel antioxidant rating system.

PubMed

Palmer, Debbie M; Kitchin, Jennifer Silverman

2010-01-01

It is believed that oxidative stress is caused by an imbalance between the production of reactive oxygen and a biological system's ability to neutralize the reactive intermediates. Oxidative damage occurs because of both intrinsic and extrinsic mechanisms. Together, intrinsic and extrinsic damage are the primary causes of skin aging. The skin uses a series of intrinsic antioxidants to protect itself from free radical damage. Naturally occurring extrinsic antioxidants have also been widely shown to offset and alleviate these changes. Unlike sunscreens, which have an SPF rating system to guide consumers in their purchases, there is no widely accepted method to choose antioxidant anti-aging products. ORAC (Oxygen Radical Absorbance Capacity) and ABEL-RAC (Analysis By Emitted Light-Relative Antioxidant Capacity), are both accepted worldwide as a standard measure of the antioxidant capacity of foods, and are rating systems that could be applied to all antioxidant skincare products. The standardization of antioxidant creams could revolutionize the cosmeceutical market and give physicians and consumers the ability to compare and choose effectively.

The ORAC/kcal ratio qualifies nutritional and functional properties of fruit juices, nectars, and fruit drinks.

PubMed

Ninfali, Paolino; Chiarabini, Andrea; Angelino, Donato

2014-09-01

Fruit beverages are source of antioxidants, but their sugar content plays an important role in the epidemic of obesity. In this study, we considered 32 fruit beverages consumed in Italy (13 fruit juices, 11 nectars, and 8 fruit drinks), which were analyzed for caloric intake, total phenols (TP), ascorbic acid, and antioxidant capacity (oxygen radical absorbance capacity (ORAC) method). Results showed that the caloric intake was almost completely provided by the sugar content, ranging from 5.5 to 19%. The ORAC/kcal ratio was taken as an indicator of the antioxidant performance of fruit beverages. Fruit juices containing berries, red orange, and goji showed the best performances, together with berries or pears nectars and fruit drinks made with rose hips or tea extracts. The 95% of antioxidant capacity was provided by TP, which showed a significant linear correlation with the net ORAC values. Overall, the results indicate that the ORAC/kcal ratio is a suitable parameter to rank the quality of fruit beverages.

Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities.

PubMed

Popoola, Olugbenga K; Marnewick, Jeanine L; Rautenbach, Fanie; Iwuoha, Emmanuel I; Hussein, Ahmed A

2015-09-18

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1-3) and six known (4-10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe(2+)-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.

A novel and simple ORAC methodology based on the interaction of Pyrogallol Red with peroxyl radicals.

PubMed

López-Alarcón, C; Lissi, E

2006-09-01

Oxygen radicals absorbance capacities (ORAC) indexes are frequently employed to characterize the radical trapping capacity of pure compounds and their complex mixtures. A drawback of ORAC values obtained using phycoerythrin, fluorescein (FL) or c-phycocyanin as targets, makes it possible to conclude that for very reactive compounds they are much more related to stoichiometric factors than to the reactivity of the tested compound. In the present paper, we propose a simple methodology, based on the bleaching of Pyrogallol Red (PGR) absorbance that provides ORAC indexes that are almost exclusively determined by the reactivity of the tested compounds. This difference is due to the high reactivity of PGR and the high concentrations of this compound employed in the experiments.

Preliminary assessment for DNA extraction on microfluidic channel

NASA Astrophysics Data System (ADS)

Gopinath, Subash C. B.; Hashim, Uda; Uda, M. N. A.

2017-03-01

The aim of this research is to extract, purify and yield DNA in mushroom from solid state mushroom sample by using fabricated continuous high-capacity sample delivery microfluidic through integrated solid state extraction based amino-coated silica bead. This device is made to specifically extract DNA in mushroom sample in continuous inflow process with energy and cost consumption. In this project, we present two methods of DNA extraction and purification which are by using centrifuge (complex and conventional method) and by using microfluidic biosensor (new and fast method). DNA extracted can be determined by using ultraviolet-visible spectroscopy (UV-VIS). The peak obtained at wavelength 260nm after measuring the absorbance of sample proves that DNA is successfully extracted from the mushroom.

Heaving buoys, point absorbers and arrays.

PubMed

Falnes, Johannes; Hals, Jørgen

2012-01-28

Absorption of wave energy may be considered as a phenomenon of interference between incident and radiated waves generated by an oscillating object; a wave-energy converter (WEC) that displaces water. If a WEC is very small in comparison with one wavelength, it is classified as a point absorber (PA); otherwise, as a 'quasi-point absorber'. The latter may be a dipole-mode radiator, for instance an immersed body oscillating in the surge mode or pitch mode, while a PA is so small that it should preferably be a source-mode radiator, for instance a heaving semi-submerged buoy. The power take-off capacity, the WEC's maximum swept volume and preferably also its full physical volume should be reasonably matched to the wave climate. To discuss this matter, two different upper bounds for absorbed power are applied in a 'Budal diagram'. It appears that, for a single WEC unit, a power capacity of only about 0.3 MW matches well to a typical offshore wave climate, and the full physical volume has, unfortunately, to be significantly larger than the swept volume, unless phase control is used. An example of a phase-controlled PA is presented. For a sizeable wave-power plant, an array consisting of hundreds, or even thousands, of mass-produced WEC units is required.

Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

NASA Astrophysics Data System (ADS)

Dang, Xugang; Chen, Hui; Shan, Zhihua

2017-07-01

One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

Antioxidant Peptides Identified from Ovotransferrin by the ORAC Method Did Not Show Anti-Inflammatory and Antioxidant Activities in Endothelial Cells.

PubMed

Jahandideh, Forough; Chakrabarti, Subhadeep; Davidge, Sandra T; Wu, Jianping

2016-01-13

Oxygen radical absorbance capacity (ORAC) is a widely used method of measuring antioxidant capacities of various antioxidant components. Surprisingly, 16 antioxidant peptides previously identified from egg protein ovotransferrin using the ORAC method did not show any anti-inflammatory and antioxidant activities in cells. After simulated gastro-intestinal digestion (GID), several peptide digests significantly reduced the expression of tumor necrosis factor-α (TNF-α)-induced pro-inflammatory intercellular cell adhesion molecule-1 (ICAM-1) by 65.7 ± 10.4% and vascular cell adhesion molecule-1 (VCAM-1) by 53.5 ± 9.6% to 61.0 ± 14.5%, but only GWNI reduced TNF-α-activated superoxide generation by 71.0 ± 12.9% when tested with dihydroethidium (DHE) assay. Mass spectrometer analysis identified two new peptides, GWN and GW, in the GWNI digest; however, only GW reduced TNF-α-induced VCAM-1 expression (64.3 ± 20.6%) significantly compared to the TNF-α treated cells. Our study suggested that ORAC lacked biological relevance in assessing bioactive peptides.

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

NASA Astrophysics Data System (ADS)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2017-11-01

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth, and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. We show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

DOE PAGES

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; ...

2017-11-08

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

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

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Programmable flow system for automation of oxygen radical absorbance capacity assay using pyrogallol red for estimation of antioxidant reactivity.

PubMed

Ramos, Inês I; Gregório, Bruno J R; Barreiros, Luísa; Magalhães, Luís M; Tóth, Ildikó V; Reis, Salette; Lima, José L F C; Segundo, Marcela A

2016-04-01

An automated oxygen radical absorbance capacity (ORAC) method based on programmable flow injection analysis was developed for the assessment of antioxidant reactivity. The method relies on real time spectrophotometric monitoring (540 nm) of pyrogallol red (PGR) bleaching mediated by peroxyl radicals in the presence of antioxidant compounds within the first minute of reaction, providing information about their initial reactivity against this type of radicals. The ORAC-PGR assay under programmable flow format affords a strict control of reaction conditions namely reagent mixing, temperature and reaction timing, which are critical parameters for in situ generation of peroxyl radical from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). The influence of reagent concentrations and programmable flow conditions on reaction development was studied, with application of 37.5 µM of PGR and 125 mM of AAPH in the flow cell, guaranteeing first order kinetics towards peroxyl radicals and pseudo-zero order towards PGR. Peroxyl-scavenging reactivity of antioxidants, bioactive compounds and phenolic-rich beverages was estimated employing the proposed methodology. Recovery assays using synthetic saliva provided values of 90 ± 5% for reduced glutathione. Detection limit calculated using the standard antioxidant compound Trolox was 8 μM. RSD values were <3.4 and <4.9%, for intra and inter-assay precision, respectively. Compared to previous batch automated ORAC assays, the developed system also accounted for high sampling frequency (29 h(-1)), low operating costs and low generation of waste. Copyright © 2015 Elsevier B.V. All rights reserved.

Converting to DEA/MDEA mix ups sweetening capacity

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

Spears, M.L.; Hagan, K.M.; Bullin, J.A.

1996-08-12

Mixing amines can be the best method for increasing capacity or improving efficiency in an amine sweetening unit. In many cases, it may be possible simply to add a second amine to the existing solution on the fly, or as the unit is running. Union Pacific Resources` Bryan, Tex., gas plant provides one example. The plant was converted from diethanolamine (DEA) to a DEA/MDEA (methyl DEA) mixture after analysis by TSWEET, a process-simulation program. After conversion, CO{sub 2} levels in the sales gas fell to less than pipeline specifications. Data were taken for the absorber at a constant amine circulationmore » of 120 gpm. A comparison of the performance data to the values calculated by the program proved the accuracy of TSWEET. The conversion and performance of the plant are described.« less

Lessons Learned From Transitioning PEPFAR Track 1.0 Care and Treatment Programs: Case Studies in Financial Management Capacity Building in Zambia and Botswana.

PubMed

Kuehn, Chuck; Tidwell, George; Vhugen, Jann; Sharma, Anjali

2015-01-01

In 2008, the United States government mandated transition of internationally managed HIV care and treatment programs to local country ownership. Three case studies illustrate the US Health Resources Services Administration's fiscal assessment and technical assistance (TA) processes to strengthen local organizations' capabilities to absorb and manage United States government funding. Review of initial, TA and follow-up reports reveal that the 1 Botswanan and 2 Zambian organizations closed 10 of 17 financial capacity gaps, with Health Resources Services Administration assisting on 2. Zambian organizations requested and absorbed targeted TA on the basis of the consultant's desk review, their finance staff revised fiscal policies and procedures, and accordingly trained other staff. In Botswana, delays in integrating recommendations necessitated on-site TA for knowledge building and role modeling. Organizational maturity may explain differences in responsiveness, ownership, and required TA approaches. Clarifying expectations of capacity building, funding agreement, and nonmonetary donor involvement can help new organizations determine and act on intervening actions.

Effects of oolong tea on plasma antioxidative capacity in mice loaded with restraint stress assessed using the oxygen radical absorbance capacity (ORAC) assay.

PubMed

Kurihara, Hiroshi; Fukami, Harukazu; Asami, Sumio; Toyoda, Yoshiko; Nakai, Masaaki; Shibata, Hiroshi; Yao, Xin-Sheng

2004-07-01

In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.

Polyaniline-stabilized electromagnetic wave absorption composites of reduced graphene oxide on magnetic carbon nanotube film

NASA Astrophysics Data System (ADS)

Li, Jinsong; Duan, Yan; Lu, Weibang; Chou, Tsu-Wei

2018-04-01

A multi-layered composite with exceptionally high electromagnetic wave-absorbing capacity and performance stability was fabricated via the facile electrophoresis of a reduced graphene oxide network on carbon nanotube (CNT)-Fe3O4-polyaniline (PANI) film. Minimum reflection loss (RL) of -53.2 dB and absorbing bandwidth of 5.87 GHz (< -10 dB) are achieved, surpassing most recently reported CNT- and graphene-based absorbers. In particular, comparing to the original composites, the minimum RL and bandwidth (< -10 dB) maintains 82.5% and 99.7%, respectively, after 20 h charge/discharge cycling, demonstrating high environmental suitability.

Hexagonal Hollow Tube Based Energy Absorbing Crash Buffers for Roadside Fixed Objects

NASA Astrophysics Data System (ADS)

Uddin, M. S.; Amirah Shafie, Nurul; Zivkovic, Grad

2017-03-01

The purpose of this study was to investigate the deformation of the energy absorbing hexagonal hollow tubes in a lateral compression. The aim is to design cost effective and high energy-absorbing buffer systems, which are capable of controlling out-of-control vehicles in high-speed zones. A nonlinear quasi-static finite element analysis was applied to determine the deformation and energy absorption capacity. The main parameters in the design were diameter and wall thickness of the tubes. Experimental test simulating the lateral compressive loading on a single tube was performed. Results show that as the diameter and the thickness increase, the deformation strength increases. Hexagonal tube with diameter of 219 mm and thickness of 4 mm is shown to have the highest energy absorption capability. Compared to existing cylindrical and octagonal shapes, the hexagonal tubes show the highest energy absorption capacity. Hexagonal tubes therefore can be regarded as a potential candidate for buffer designs in high speed zones. In addition, they would be compact, cost effective and facilitate ease of installation.

Assessing the resilience of urban areas to traffic-related air pollution: Application in Greater Paris.

PubMed

Cariolet, Jean-Marie; Colombert, Morgane; Vuillet, Marc; Diab, Youssef

2018-02-15

Recent studies report that outdoor air pollution will become the main environmental cause of premature death over the next few decades (OECD, 2012; WHO, 2014; World Bank, 2016). Cities are considered hot spots and urban populations are particularly exposed. There is therefore an urgent need to adapt urban systems and urban design to tackle this issue. While most European cities have introduced measures to reduce emissions, action is still required to reduce concentrations and exposure, and a holistic approach to urban design is badly needed. The concept of urban resilience, defined by Holling (1987) as the ability of a city to absorb a disturbance while maintaining its functions and structures, may offer a new paradigm for tackling urban air pollution. We propose to adapt the concept of urban resilience to outdoor air pollution. A method has been developed to assess the resilience of an urban area to outdoor air pollution. Three "resilience capacities" have been identified: the capacity of an urban area to decrease air pollution emissions, the capacity to decrease concentrations and the capacity to decrease exposure. The calculation is based on the analysis of urban design, defined as the pattern of buildings as well as the structural elements that define an urban area (urban morphology; transport network, services and land use). For each resilience capacity, indicators are calculated using a Geographic Information System (GIS) and a grid-based approach. This method has been implemented in the Greater Paris area within a 500m grid-cell system. Greater Paris is one of the densest urban areas in Europe and experiences high air pollution levels. The proposed "quick scan" method helps to localize areas where specific action is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Cross-Cultural Absorptive Capacity in the Effectiveness of In-Country Cross-Cultural Training

ERIC Educational Resources Information Center

Tarique, Ibraiz; Caligiuri, Paula

2009-01-01

Based on the theory of absorptive capacity, this study examines the following question. In the context of cross-cultural training, can the amount of previously accumulated cultural knowledge affect the ability of a trainee to absorb further learning about a new culture, thus enhancing total knowledge and presumably cross-cultural adjustment?…

Evaluation of synergistic antioxidant potential of complex mixtures using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR).

PubMed

Parker, Tory L; Miller, Samantha A; Myers, Lauren E; Miguez, Fernando E; Engeseth, Nicki J

2010-01-13

Previous research has demonstrated that certain combinations of compounds result in a decrease in toxic or pro-oxidative effects, previously noted when compounds were administered singly. Thus, there is a need to study many complex interactions further. Two in vitro techniques [electron paramagnetic resonance (EPR) and oxygen radical absorbance capacity (ORAC) assays] were used in this study to assess pro- and antioxidant capacity and synergistic potential of various compounds. Rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar solution were evaluated individually at various concentrations and in all 26 possible combinations at concentrations found in certain foods (honey or papaya), both before and after simulated digestion. EPR results indicated sugar-containing combinations provided significantly higher antioxidant capacity; those combinations containing sugars and ascorbic acid demonstrated synergistic potential. The ORAC assay suggested additive effects, with some combinations having synergistic potential, although fewer combinations were significantly synergistic after digestion. Finally, ascorbic acid, caffeic acid, quercetin, and urate were evaluated at serum-achievable levels. EPR analysis did not demonstrate additive or synergistic potential, although ORAC analysis did, principally in combinations containing ascorbic acid.

Self-assembly of defect-rich graphene oxide nanosheets with Na2Ti3O7 nanowires and their superior absorptive capacity to toxic dyes

NASA Astrophysics Data System (ADS)

Sun, Yibai; Fu, Wanlin; Dai, Yunqian; Huang, Yiyang; Zhou, Jie; Huang, Chengqian; Yang, Chongya; Huang, Meiyou; Ma, Rongwei; Lin, Baoping

2017-06-01

Graphene sheets, a flexible 2D material with excellent absorptive capacity, have great potential as absorbing materials. However, this material has always suffered from irreversible aggregation and thus loses the abundant active sites and large surface area. In this paper, large-scale graphene oxide (GO) sheets were cut and reduced to tiny reduced graphene oxide (RGO) sheets by a cell-break sonicator, for producing numerous defects, which are the center of chemisorption. Furthermore, sodium titanate nanowires functioned as a framework to help to disperse the tiny RGO sheets uniformly. And, in turn, the flexible tiny RGO sheets glued robust nanowires into a free-standing membrane. This novel composite membrane exhibited an ultra-high decoloration efficiency of 99.8% of rhodamine B in a continuous flow mode, and an outstanding absorptive capability of 1.30 × 10-2 mol g-1 correlated to RGO content in batch reaction, which is about two orders of magnitude higher than other reported graphene-based absorbents. In addition, an efficient and feasible method without any heat treatment for regenerating the membrane is illustrated, and the recycled membrane retains superior decoloration efficiency. The excellent absorptive performance indicates the framework-based disperse strategy has great potential for the construction and application of defect-rich graphene.

Total antioxidant capacity of the Korean diet

PubMed Central

Han, Jeong-Hwa; Lee, Hye-Jin; Cho, Mi Ran; Chang, Namsoo; Kim, Yuri; Oh, Se-Young

2014-01-01

BACKGROUND/OBJECTIVES The objective of this study was to measure and/or estimate the total antioxidant capacity of the Korean diet. MATERIALS/METHODS Eighty-one plant foods that were expected to exhibit rather high antioxidant activities were selected from the Korean diet using the Fifth Korean National Health and Nutrition Survey (KNHANES V). These foods were categorized into 11 food groups: cereals, potatoes, legumes, nuts, vegetables, kimchies, mushrooms, fruits, fruit juices, sea weeds, and oils. The foods were mixed in the proportions specified in traditional Korean recipes and analyzed. The measured indicators for antioxidant capacities were total phenolics, 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC). RESULTS Total phenolics were high in the fruit juices, nuts, vegetables, and fruits; and the average DPPH, ORAC, and TEAC values were high in the vegetables, fruits, fruit juices, and nuts. The correlation coefficient between the content of total phenolics of each food and the in vitro antioxidant capacity was relatively high at 0.851. The intake of total phenolics per capita per day in the Republic of Korea was estimated to be 127 mg. The total dietary antioxidant capacity (TDAC) values, which were obtained from the total antioxidant capacity of each food, taking into account the intake of each food, were 20,763, 54,335, and 876.4 µmol of Trolox equivalents using the DPPH, ORAC, and TEAC methods, respectively. The food group that contributed the most to the Korean TDAC was cereals at 39.7%, followed by fruits and vegetables at 27.8% and 13.9%, respectively. The contribution of legumes, nuts, fruit juices, and mushrooms was quite minimal at less than 2% each. CONCLUSIONS The content of total phenolics and the antioxidant capacity of the Korean diet are significantly correlated and the high contributing food groups are cereals, fruits, and vegetables. PMID:24741403

An Overview on Impact Behaviour and Energy Absorption of Collapsible Metallic and Non-Metallic Energy Absorbers used in Automotive Applications

NASA Astrophysics Data System (ADS)

Shinde, R. B.; Mali, K. D.

2018-04-01

Collapsible impact energy absorbers play an important role of protecting automotive components from damage during collision. Collision of the two objects results into the damage to one or both of them. Damage may be in the form of crack, fracture and scratch. Designers must know about how the material and object behave under impact event. Owing to above reasons different types of collapsible impact energy absorbers are developed. In the past different studies were undertaken to improve such collapsible impact energy absorbers. This article highlights such studies on common shapes of collapsible impact energy absorber and their impact behaviour under the axial compression. The literature based on studies and analyses of effects of different geometrical parameters on the crushing behaviour of impact energy absorbers is presented in detail. The energy absorber can be of different shape such as circular tube, square tube, and frustums of cone and pyramids. The crushing behaviour of energy absorbers includes studies on crushing mechanics, modes of deformation, energy absorbing capacity, effect on peak and mean crushing load. In this work efforts are made to cover major outcomes from past studies on such behavioural parameters. Even though the major literature reviewed is related to metallic energy absorbers, emphasis is also laid on covering literature on use of composite tube, fiber metal lamination (FML) member, honeycomb plate and functionally graded thickness (FGT) tube as a collapsible impact energy absorber.

Molecular dynamics and a spectroscopic study of sulfur dioxide absorption by an ionic liquid and its mixtures with PEO.

PubMed

Hoher, Karina; Cardoso, Piercarlo F; Lepre, Luiz F; Ando, Rômulo A; Siqueira, Leonardo J A

2016-10-19

An investigation comprising experimental techniques (absorption capacity of SO 2 and vibrational spectroscopy) and molecular simulations (thermodynamics, structure, and dynamics) has been performed for the polymer poly(ethylene oxide) (PEO), the ionic liquid butyltrimethylammonium bis(trifluoromethylsulfonyl)imide ([N 4111 ][Tf 2 N]) and their mixtures as sulfur dioxide (SO 2 ) absorbing materials. The polymer PEO has higher capacity to absorb SO 2 than the neat ionic liquid, whereas the mixtures presented intermediary absorption capacities. The band assigned to the symmetric stretching band of SO 2 at ca. 1140 cm -1 , which is considered a spectroscopic probe for the strength of SO 2 interactions with its neighborhood, shifts to lower wavenumbers as more negative total interaction energy values of SO 2 were evaluated from the simulations. The solvation free energy of SO 2 , ΔG sol , correlates linearly with the absorption capacity of SO 2 . The negative values of ΔG sol are due to negative and positive values of enthalpy and entropy, respectively. In the ionic liquid, SO 2 weakens the cation-anion interactions, whereas in the mixture with a high content of PEO these interactions are slightly increased. Such effects were correlated with the relative population of cisoid and transoid conformers of Tf 2 N anions as revealed by Raman spectroscopy. Moreover, the presence of SO 2 in the systems provokes the increase of diffusion coefficients of the absorbing species in comparison with the systems without the gas. Proper to the slow dynamics of the polymer, the diffusion coefficient of ions and SO 2 diminishes with the increase of the PEO content.

Simplified method for creating a density-absorbed dose calibration curve for the low dose range from Gafchromic EBT3 film.

PubMed

Gotanda, Tatsuhiro; Katsuda, Toshizo; Gotanda, Rumi; Kuwano, Tadao; Akagawa, Takuya; Tanki, Nobuyoshi; Tabuchi, Akihiko; Shimono, Tetsunori; Kawaji, Yasuyuki

2016-01-01

Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber in that the dosimetry process is time-consuming for creating a density-absorbed dose calibration curve. The purpose of this study was the development of a simplified method of creating a density-absorbed dose calibration curve from radiochromic film within a short time. This simplified method was performed using Gafchromic EBT3 film with a low energy dependence and step-shaped Al filter. The simplified method was compared with the standard method. The density-absorbed dose calibration curves created using the simplified and standard methods exhibited approximately similar straight lines, and the gradients of the density-absorbed dose calibration curves were -32.336 and -33.746, respectively. The simplified method can obtain calibration curves within a much shorter time compared to the standard method. It is considered that the simplified method for EBT3 film offers a more time-efficient means of determining the density-absorbed dose calibration curve within a low absorbed dose range such as the diagnostic range.

Simplified method for creating a density-absorbed dose calibration curve for the low dose range from Gafchromic EBT3 film

PubMed Central

Gotanda, Tatsuhiro; Katsuda, Toshizo; Gotanda, Rumi; Kuwano, Tadao; Akagawa, Takuya; Tanki, Nobuyoshi; Tabuchi, Akihiko; Shimono, Tetsunori; Kawaji, Yasuyuki

2016-01-01

Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber in that the dosimetry process is time-consuming for creating a density-absorbed dose calibration curve. The purpose of this study was the development of a simplified method of creating a density-absorbed dose calibration curve from radiochromic film within a short time. This simplified method was performed using Gafchromic EBT3 film with a low energy dependence and step-shaped Al filter. The simplified method was compared with the standard method. The density-absorbed dose calibration curves created using the simplified and standard methods exhibited approximately similar straight lines, and the gradients of the density-absorbed dose calibration curves were −32.336 and −33.746, respectively. The simplified method can obtain calibration curves within a much shorter time compared to the standard method. It is considered that the simplified method for EBT3 film offers a more time-efficient means of determining the density-absorbed dose calibration curve within a low absorbed dose range such as the diagnostic range. PMID:28144120

Efficient removal of tetracycline with KOH-activated graphene from aqueous solution

PubMed Central

Sun, Yiran; Yu, Fei

2017-01-01

Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g−1) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid–liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid–liquid ratio and coexisting ions (Cu2+, CrO42−) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions. PMID:29291064

Fabrication of cellulose-based aerogels from waste newspaper without any pretreatment and their use for absorbents.

PubMed

Jin, Chunde; Han, Shenjie; Li, Jingpeng; Sun, Qingfeng

2015-06-05

Cellulose-based aerogel (CBA) was prepared from waste newspaper (WNP) without any pretreatment using 1-allyl-3-methyimidazolium chloride (AmImCl) as a solvent via regeneration and an environmentally friendly freeze-drying method. After being treated with trimethylchlorosilane (TMCS) via a simple thermal chemical vapor deposition process, the resulting CBAs were rendered both hydrophobic and oleophilic. Successful silanization on the surface of the porous CBA was verified by a variety of techniques including scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and water contact angle (WCA) measurements. As a result, the silane-coated, interconnected CBAs not only exhibited good absorption performance for oils (e.g., waste engine oil), but also showed absorption capacity for organic solvents such as chloroform (with a representative weight gain ranging from 11 to 22 times of their own dry weight), making them diversified absorbents for potential applications including sewage purification. Copyright © 2015 Elsevier Ltd. All rights reserved.

Green and facile fabrication of carbon aerogels from cellulose-based waste newspaper for solving organic pollution.

PubMed

Han, Shenjie; Sun, Qingfeng; Zheng, Huanhuan; Li, Jingpeng; Jin, Chunde

2016-01-20

Carbon-based aerogel fabricated from waste biomass is a potential absorbent material for solving organic pollution. Herein, the lightweight, hydrophobic and porous carbon aerogels (CAs) have been synthesized through freezing-drying and post-pyrolysis by using waste newspaper as the only raw materials. The as-prepared CAs exhibited a low density of 18.5 mg cm(-3) and excellent hydrophobicity with a water contact angle of 132° and selective absorption for organic reagents. The absorption capacity of CA for organic compounds can be 29-51 times its own weight. Moreover, three methods (e.g., squeezing, combustion, and distillation) can be employed to recycle CA and harvest organic pollutants. Combined with waste biomass as raw materials, green and facile fabrication process, excellent hydrophobicity and oleophilicity, CA used as an absorbent material has great potential in application of organic pollutant solvents absorption and environmental protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simple and Low-Cost Dual-Band Printed Microwave Absorber for 2.4- and 5-GHz-Band Applications

NASA Astrophysics Data System (ADS)

Khoomwong, Ekajit; Phongcharoenpanich, Chuwong

2017-10-01

In this research, a dual-band thin printed-circuit-board (PCB) microwave absorber has been proposed for applications in 2.4 and 5 GHz frequency bands. Each unit cell of the absorber consists of a square ring and a thick cross-dipole, augmented with the tuning elements. In the design process, numerical simulations were performed for the optimal characteristics of the absorber and an absorber prototype was fabricated using the simple print-transferring and etching process. The measured absorption bandwidths (50 %) of 170 MHz (2.36-2.53 GHz) and 830 MHz (5.09-5.92 GHz) were achieved for the first and second bands, respectively, with the wideband characteristic at the second operating band. The absorption rates near the center frequencies (2.45 and 5.5 GHz) were respectively 97.85 % and 97.76 %. The simulation and measured results are in good agreement. Furthermore, the incidence-angle dependencies of the absorber were of moderately wide angles with the absorption capacity of at least 50 % for both operating bands. The proposed absorber is suitable for a variety of applications requiring absorption in the 2.4/5 GHz bands.

Nutritional Composition and Antioxidant Capacity in Edible Flowers: Characterisation of Phenolic Compounds by HPLC-DAD-ESI/MSn

PubMed Central

Navarro-González, Inmaculada; González-Barrio, Rocío; García-Valverde, Verónica; Bautista-Ortín, Ana Belén; Periago, María Jesús

2014-01-01

Edible flowers are commonly used in human nutrition and their consumption has increased in recent years. The aim of this study was to ascertain the nutritional composition and the content and profile of phenolic compounds of three edible flowers, monks cress (Tropaeolum majus), marigold (Tagetes erecta) and paracress (Spilanthes oleracea), and to determine the relationship between the presence of phenolic compounds and the antioxidant capacity. Proximate composition, total dietary fibre (TDF) and minerals were analysed according to official methods: total phenolic compounds (TPC) were determined with Folin-Ciocalteu’s reagent, whereas antioxidant capacity was evaluated using Trolox Equivalent Antioxidant Capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. In addition, phenolic compounds were characterised by HPLC-DAD-MSn. In relation to the nutritional value, the edible flowers had a composition similar to that of other plant foods, with a high water and TDF content, low protein content and very low proportion of total fat—showing significant differences among samples. The levels of TPC compounds and the antioxidant capacity were significantly higher in T. erecta, followed by S. oleracea and T. majus. Thirty-nine different phenolic compounds were tentatively identified, with flavonols being the major compounds detected in all samples, followed by anthocyanins and hydroxycynnamic acid derivatives. In T. erecta small proportions of gallotannin and ellagic acid were also identified. PMID:25561232

Role of alkoxyl radicals on the fluorescein-based ORAC (Oxygen Radical Absorbance Capacity) assay.

PubMed

Dorta, E; Atala, E; Aspee, A; Speisky, H; Lissi, E; Lopez-Alarcon, C

2014-10-01

During the last decades the ORAC (Oxygen Radical Absorbance Capacity) assay has been widely employed to evaluate the in vitro antioxidant capacity of polyphenol-rich fruits, vegetables and beverages. The method employs fluorescein (FLH) as target molecule and AAPH (2,2'-azo-bis(2-amidinopropane)dihydrochloride) as the source of peroxyl radicals (ROO•). The protection of FLH, afforded by antioxidants (XH), is often characterized by kinetic profiles with clear lag times (LT), which are directly associated with the stoichiometry (n) of the XH-ROO• reaction. However, even for simple phenolic compounds, the LT measured imply large n values (defined as the number of ROO• moles trapped by each antioxidant molecule) which cannot be explained by a simple reaction mechanism. Nonetheless, they can be explained when considering the formation of alkoxyl radicals (RO•) from the recombination of two AAPH-derived ROO•. In the present work, we provide kinetic data showing that, in the zero order kinetic limit of FLH consumption, there is a low reaction rate incompatible with total trapping of ROO•. Thus, the consumption of FLH should be mostly related to its reaction with RO•. In addition, we present data regarding the assumption that in competitive measurements, the LT is due to efficient trapping of the ROO• by the added phenols, leading to high n values (1.7 to 23) for mono and polyphenols. These values are not in agreement with kinetic studies of the antioxidant consumption mediated by the presence of AAPH carried out by HPLC-DAD technique, which imply a competition by RO•. The results suggest that the use of FLH as probe at low concentrations give, for several antioxidants, ORAC values mainly related to their reaction towards RO• radicals instead of primary ROO•radicals. Copyright © 2014. Published by Elsevier Inc.

Lyophilization closures for protein based drugs.

PubMed

DeGrazio, F; Flynn, K

1992-01-01

Rubber stopper formulations which are currently used as lyophilization stoppers vary widely in their capacities to absorb and release moisture. Release of moisture from the stopper over the shelf life of the product may result in drug degradation for extremely low cake weight products. The degree to which rubber formulations absorb water is dependent upon the components of these formulations. Independently, polymers and fillers absorb water during autoclave cycles to varying levels depending upon such factors as the solubility, structure, possibility of chemical reactions and impurity levels of these materials. Once combined into a stopper formulation, the raw materials can react to form species which further promote absorption. Data is presented comparing the absorption characteristics of low versus high absorbent rubber formulations. The release of moisture from these formulas when stoppered on vials containing dry product is also discussed.

Solar air heaters and their applications

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1977-01-01

The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

Photothermally tunable silicon-microring-based optical add-drop filter through integrated light absorber.

PubMed

Chen, Xi; Shi, Yuechun; Lou, Fei; Chen, Yiting; Yan, Min; Wosinski, Lech; Qiu, Min

2014-10-20

An optically pumped thermo-optic (TO) silicon ring add-drop filter with fast thermal response is experimentally demonstrated. We propose that metal-insulator-metal (MIM) light absorber can be integrated into silicon TO devices, acting as a localized heat source which can be activated remotely by a pump beam. The MIM absorber design introduces less thermal capacity to the device, compared to conventional electrically-driven approaches. Experimentally, the absorber-integrated add-drop filter shows an optical response time of 13.7 μs following the 10%-90% rule (equivalent to a exponential time constant of 5 μs) and a wavelength shift over pump power of 60 pm/mW. The photothermally tunable add-drop filter may provide new perspectives for all-optical routing and switching in integrated Si photonic circuits.

Rapid-Response Low Infrared Emission Broadband Ultrathin Plasmonic Light Absorber

PubMed Central

Tagliabue, Giulia; Eghlidi, Hadi; Poulikakos, Dimos

2014-01-01

Plasmonic nanostructures can significantly advance broadband visible-light absorption, with absorber thicknesses in the sub-wavelength regime, much thinner than conventional broadband coatings. Such absorbers have inherently very small heat capacity, hence a very rapid response time, and high light power-to-temperature sensitivity. Additionally, their surface emissivity can be spectrally tuned to suppress infrared thermal radiation. These capabilities make plasmonic absorbers promising candidates for fast light-to-heat applications, such as radiation sensors. Here we investigate the light-to-heat conversion properties of a metal-insulator-metal broadband plasmonic absorber, fabricated as a free-standing membrane. Using a fast IR camera, we show that the transient response of the absorber has a characteristic time below 13 ms, nearly one order of magnitude lower than a similar membrane coated with a commercial black spray. Concurrently, despite the small thickness, due to the large absorption capability, the achieved absorbed light power-to-temperature sensitivity is maintained at the level of a standard black spray. Finally, we show that while black spray has emissivity similar to a black body, the plasmonic absorber features a very low infra-red emissivity of almost 0.16, demonstrating its capability as selective coating for applications with operating temperatures up to 400°C, above which the nano-structure starts to deform. PMID:25418040

Effect of topical sunscreens on the UV-radiation-induced suppression of the alloactivating capacity in human skin in vivo.

PubMed

van Praag, M C; Out-Luyting, C; Claas, F H; Vermeer, B J; Mommaas, A M

1991-10-01

Exposure of mice or humans to solar or artificial ultraviolet radiation (UV) has been shown to induce a number of changes in the immune system that may influence their susceptibility to skin tumors. The protective effect of sunscreens on these changes is not clear. Thirty-two patients with a variety of dermatoses routinely undergoing treatment with standard UVB (n = 19) or PUVA (n = 13) therapy were studied. One of the two tested sunscreens or its vehicle was applied to the right flexor forearm immediately prior to each total-body UV exposure. Epidermal sheets were obtained by the suction-blister method from the left flexor forearm before treatment and from both flexor forearms after 4 weeks of photo- or photochemotherapy and used as stimulator epidermal cells (EC) in the mixed epidermal cell-lymphocyte reaction (MECLR). After 4 weeks of either UVB or PUVA therapy the MECLR responses on EC from both arms were markedly decreased. Neither the tested sunscreens nor their vehicles prevented the UV-induced suppression of the alloactivating capacity. The failure of sunscreens to protect against the UV-induced suppression of the alloactivating capacity could be explained in two ways. First, the energy not absorbed by the sunscreen could be sufficient to induce suppression of the alloactivating capacity. An alternative explanation could be systemic immune suppression by UV. In order to discriminate between these possibilities only the right forearms of 10 healthy volunteers, treated with a sunscreen or its vehicle, were irradiated with UVB during 4 weeks. In this manner systemic immune suppression by UVB could be excluded. This experiment resulted in a similar suppression of the MECLR responses, as induced by total body UVB irradiation, without any protection by the sunscreen. Apparently, the UV dose not absorbed by the sunscreen was capable to induce suppression of the alloactivating capacity. Our results indicate that people protected from sunburn by sunscreens may be exposed to UV for a long period of time, and thereby subject themselves to its immunosuppressive action.

Flower-like BiOI microsphere/Ni@C nanocapsule hybrid composites and their efficient microwave absorbing activity

NASA Astrophysics Data System (ADS)

Liu, Xianguo; Yu, Jieyi; Cui, Caiyun; Sun, Yuping; Li, Xiaolong; Li, Zhenxing

2018-07-01

At present, microwave absorbers are prepared by dispersing absorbing nanomaterials in a binder, which can lead to the aggregation of nanomaterials in the binder and further affect the optimization of the absorption performances. Hybrid micro/nano-scale structures are beneficial for buffering agglomeration phenomena and the construction of multiple interfaces. Here, Ni@C nanocapsules are conjugated onto flower-like BiOI microspheres, forming micro/nano-scale hybrid composites. The multiple interfaces between BiOI microspheres and Ni@C nanocapsules can bring enhanced dielectric loss and increased attenuation constant, resulting in the enhancement of absorption capacity (the optimal reflection loss reaches  ‑61.35 dB), increased width of the effective absorption band (the maximum effective bandwidth, f Emax , is 5.86 GHz) and the reduction of absorption thickness (the thickness corresponding to f Emax is 1.7 mm). This study highlights a simple idea for the optimization of electromagnetic absorbing performance, which is of great significance in the development of microwave absorbers.

Program for the exploitation of unused NASA patents

NASA Technical Reports Server (NTRS)

Fay, R. J.

1972-01-01

The program to exploit unused NASA patents through the use of a multidisciplinary approach involving faculty students, and research staff is reported. NASA patents were screened for their applicability outside the space program, specific applications were identified, and the technical and commercial feasibility of these applications was established. Also application of this technology by governmental agencies outside the space program was sought. The program was specifically interested in energy absorbing devices such as those developed for lunar soft landings. These energy absorbing devices absorb large amounts of mechanical energy but are, in general, not reusable. Some of these devices can also operate as structural elements until their structural load capacity is exceeded and they become activated as energy absorbers. The capability of these devices to operate as structural elements and as energy absorbing devices makes them candidates for many applications in the fields of transportation and materials handling safety where accidents take a large toll in human injury and property damage.

Investigation on a mechanical vibration absorber with tunable piecewise-linear stiffness

NASA Astrophysics Data System (ADS)

Shui, Xin; Wang, Shimin

2018-02-01

The design and characterization of a mechanical vibration absorber are addressed. A distinctive feature of the absorber is its tunable piecewise-linear stiffness, which is realized by means of a slider with two stop-blocks installed constraining the bilateral deflections of the elastic support. A new analytical approach named as the equivalent stiffness technique (EST) is introduced and then employed to obtain the analytical relations of the frequency, amplitude and phase with a view to exhibit a more comprehensive characterization of the absorber. Experiments are conducted to demonstrate the feasibility of the design. The experimental data show good agreement with the analytical results. The final results indicate that the tunable stiffness absorber (TSA) possesses a typical nonlinear characteristic at each given position of the slider, and its stiffness can be tuned in real time over a wide range by adjusting the slider position. Hence the TSA has a large optimum vibration-absorption range together with a wide suppression band around each optimal position, which contributes to its excellent capacity of vibration absorption.

The Photostabilizing Effect of Grape Seed Extract on Three Common Sunscreen Absorbers.

PubMed

Martincigh, Bice S; Ollengo, Moses A

2016-11-01

The photostabilizing ability of grape seed extract on three common sunscreen absorbers, 2-ethylhexyl-p-methoxycinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS, and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract. All sunscreens showed an improved photostability in the extract. The inherent photo-instability of BMDBM when exposed to UV radiation was almost eliminated in the presence of grape seed extract. A mixture of all three sunscreens in the extract showed very high photostability and a red shift covering the entire UVB and UVA regions, thereby improving the broad-spectrum protection. The incorporation of grape seed extract in sunscreen and other cosmetic formulations for topical application boosts photoprotection by stabilizing the UV filters and enhancing broad-spectrum coverage. This in turn helps in reducing the amounts of absorbers and other additives incorporated in a sunscreen product and consequently lowers the risk of an unprecedented buildup of photoproducts whose toxicities are currently unknown. © 2016 The American Society of Photobiology.

Shock absorbency of factors in the shoe/heel interaction--with special focus on role of the heel pad.

PubMed

Jørgensen, U; Bojsen-Møller, F

1989-06-01

The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

Infrared bolometers with silicon nitride micromesh absorbers

NASA Technical Reports Server (NTRS)

Bock, J. J.; Turner, A. D.; DelCastillo, H. M.; Beeman, J. W.; Lange, A. E.; Mauskopf, P. D.

1996-01-01

Sensitive far infrared and millimeter wave bolometers fabricated from a freestanding membrane of low stress silicon nitride are reported. The absorber, consisting of a metallized silicon nitride micromesh thermally isolated by radial legs of silicon nitride, is placed in an integrating cavity to efficiently couple to single mode or multiple mode infrared radiation. This structure provides low heat capacity, low thermal conduction and minimal cross section to energetic particles. A neutron transmutation doped Ge thermister is bump bonded to the center of the device and read out with evaporated Cr-Au leads. The limiting performance of the micromesh absorber is discussed and the recent results obtained from a 300 mK cold stage are summarized.

Pine Bark and Green Tea Concentrated Extracts: Antioxidant Activity and Comprehensive Characterization of Bioactive Compounds by HPLC–ESI-QTOF-MS

PubMed Central

Cádiz-Gurrea, María de la Luz; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

2014-01-01

The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC–ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin–Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents. PMID:25383680

Pine bark and green tea concentrated extracts: antioxidant activity and comprehensive characterization of bioactive compounds by HPLC-ESI-QTOF-MS.

PubMed

de la Luz Cádiz-Gurrea, María; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

2014-11-06

The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin-Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents.

Method of absorbance correction in a spectroscopic heating value sensor

DOEpatents

Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

2013-09-17

A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

Biomass carbon composited FeS2 as cathode materials for high-rate rechargeable lithium-ion battery

NASA Astrophysics Data System (ADS)

Xu, Xin; Meng, Zhen; Zhu, Xueling; Zhang, Shunlong; Han, Wei-Qiang

2018-03-01

Pyrite FeS2 has long been used as commercial primary lithium batteries at room temperature. To achieve rechargeable FeS2 battery, biomass-carbon@FeS2 composites are prepared using green and renewable auricularia auricula as carbon source through the process of carbonization and sulfuration. The auricularia auricula has strong swelling characteristics to absorb aqueous solution which can effectively absorb Fe ions into its body. FeS2 homogeneously distributed in biomass carbon matrix performs high electronic and ionic conductivity. The specific capacity of biomass-carbon@FeS2 composites remains 850 mAh g-1 after 80 cycles at 0.5C and 700 mAh g-1 at the rate of 2C after 150 cycles. Biomass-carbon@FeS2 composites exhibit high-rate capacity in lithium-ion battery.

Production and Structural Investigation of Polyethylene Composites with Modified Kaolin

NASA Astrophysics Data System (ADS)

Domka, L.; Malicka, A.; Stachowiak, N.

2008-08-01

The study was undertaken to evaluate the effect of the filler (kaolin) modification with silane coupling agents on the properties of the polyethylene (HDPE Hostalen ACP 5831) composites. Powder mineral fillers are added to polymers to modify the properties of the latter and to reduce the cost of their production. A very important factor is the filler dispersion in the polymer matrix. Kaolin modified with 3-methacryloxypropyltrimethoxysilane and pure kaolin were characterised by surface area, pore size, water absorbing capacity, paraffin oil absorbing capacity, bulk density, scanning electron microscopy observations and X-ray diffraction measurements. Their performance was characterised by determination of the mechanical resistance upon static stretching and tearing, and their structure was observed in scanning electron microscopy images. The results were compared to those obtained for the composites with unmodified filler and pure HDPE.

Metal-organic frameworks as potential shock absorbers: the case of the highly flexible MIL-53(Al).

PubMed

Yot, Pascal G; Boudene, Zoubeyr; Macia, Jasmine; Granier, Dominique; Vanduyfhuys, Louis; Verstraelen, Toon; Van Speybroeck, Veronique; Devic, Thomas; Serre, Christian; Férey, Gérard; Stock, Norbert; Maurin, Guillaume

2014-08-28

The mechanical energy absorption ability of the highly flexible MIL-53(Al) MOF material was explored using a combination of experiments and molecular simulations. A pressure-induced transition between the large pore and the closed pore forms of this solid was revealed to be irreversible and associated with a relatively large energy absorption capacity. Both features make MIL-53(Al) the first potential MOF candidate for further use as a shock absorber.

Removal of benzocaine from water by filtration with activated carbon

USGS Publications Warehouse

Howe, G.E.; Bills, T.D.; Marking, L.L.

1990-01-01

Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

Dietary quebracho tannins are not absorbed, but increase the antioxidant capacity of liver and plasma in sheep.

PubMed

López-Andrés, Patricia; Luciano, Giuseppe; Vasta, Valentina; Gibson, Trevor M; Biondi, Luisa; Priolo, Alessandro; Mueller-Harvey, Irene

2013-08-01

A total of sixteen lambs were divided into two groups and fed two different diets. Of these, eight lambs were fed a control diet (C) and eight lambs were fed the C diet supplemented with quebracho tannins (C+T). The objective of the present study was to assess whether dietary quebracho tannins can improve the antioxidant capacity of lamb liver and plasma and if such improvement is due to a direct transfer of phenolic compounds or their metabolites, to the animal tissues. Feed, liver and plasma samples were purified by solid-phase extraction (SPE) and analysed by liquid chromatography-MS for phenolic compounds. Profisitinidin compounds were identified in the C+T diet. However, no phenolic compounds were found in lamb tissues. The liver and the plasma from lambs fed the C+T diet displayed a greater antioxidant capacity than tissues from lambs fed the C diet, but only when samples were not purified with SPE. Profisetinidin tannins from quebracho seem not to be degraded or absorbed in the gastrointestinal tract. However, they induced antioxidant effects in animal tissues.

Reexamination of the ORAC assay: effect of metal ions.

PubMed

Nkhili, E; Brat, P

2011-05-01

The oxygen radical absorbance capacity (ORAC) assay method has been employed extensively in the field of antioxidant and oxidative stress. It uses fluorescein as probe for oxidation by peroxyl radical. Hundreds of reports have been published on the use of this method to determine antioxidant capacity in food and biological samples. The question is whether the results of all these reports are influenced by antioxidant autoxidation, which occurs during the ORAC test. Indeed, the presence of metal ions in the studied matrix will influence antioxidant stability, thereby leading to the underestimation of their antioxidant properties. Ethylenediaminetetraacetic acid hydrate (EDTA) can be used as a metal complexation agent. This paper examines the effect of the addition of EDTA on the ORAC values of pure compounds (quercetin, ascorbic, and dehydroascorbic acid) and five food juices (kiwi, orange, tomato, red grape, and apple). Metal complexation by EDTA (80 μM) clearly increased the ORAC values, given that the antioxidant was protected against rapid autoxidation incited by trace metal ions within samples and then by free radicals. Our finding also undoubtedly demonstrated that the number of literature values is potentially underestimated.

Super water-absorbing new material from chitosan, EDTA and urea.

PubMed

Narayanan, Abathodharanan; Dhamodharan, Raghavachari

2015-12-10

A new, super water-absorbing, material is synthesized by the reaction between chitosan, EDTA and urea and named as CHEDUR. CHEDUR is probably formed through the crosslinking of chitosan molecules (CH) with the EDTA-urea (EDUR) adduct that is formed during the reaction. CHEDUR as well as the other products formed in control reactions are characterized extensively. CHEDUR exhibits a very high water uptake capacity when compared with chitosan, chitosan-EDTA adduct, as well as a commercial diaper material. A systematic study was done to find the optimum composition as well as reaction conditions for maximum water absorbing capacity. CHEDUR can play a vital role in applications that demand the rapid absorption and slow release of water such as agriculture, as a three in one new material for the slow release of urea, water and other metal ions that can be attached through the EDTA component. The other potential advantage of CHEDUR is that it can be expected to degrade in soil based on its chitosan backbone. The new material with rapid and high water uptake could also find potential applications as biodegradable active ingredient of the diaper material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimization of X-ray Absorbers for TES Microcalorimeters

NASA Technical Reports Server (NTRS)

Iyomoto, Naoko; Sadleir, John E.; Figueroa-Feliciano, Enectali; Saab, Tarek; Bandler, Simon; Kilbourne, Caroline; Chervenak, James; Talley, Dorothy; Finkbeiner, Fred; Brekosky, Regis

2004-01-01

We have investigated the thermal, electrical, and structural properties of Bi and BiCu films that are being developed as X-ray absorbers for transition-edge sensor (TES) microcalorimeter arrays for imaging X-ray spectroscopy. Bi could be an ideal material for an X-ray absorber due to its high X-ray stopping power and low heat capacity, but it has a low thermal conductivity, which can result in position dependence of the pulses in the absorber. In order to improve the thermal conductivity, we added Cu layers in between the Bi layers. We measured electrical and thermal conductivities of the films around 0.1 K(sub 1) the operating temperature of the TES calorimeter, to examine the films and to determine the optimal thickness of the Cu layer. From the electrical conductivity measurements, we found that the Cu is more resistive on the Bi than on a Si substrate. Together with an SEM picture of the Bi surface, we concluded that the rough surface of the Bi film makes the Cu layer resistive when the Cu layer is not thick enough t o fill in the roughness. From the thermal conductivity measurements, we determined the thermal diffusion constant to be 2 x l0(exp 3) micrometers squared per microsecond in a film that consists of 2.25 micrometers of Bi and 0.1 micrometers of Cu. We measured the position dependence in the film and found that its thermal diffusion constant is too low to get good energy resolution, because of the resistive Cu layer and/or possibly a very high heat capacity of our Bi films. We show plans to improve the thermal diffusion constant in our BiCu absorbers.

Influence of gamma radiation on the physicochemical and rheological properties of sterculia gum polysaccharides

NASA Astrophysics Data System (ADS)

Singh, Baljit; Sharma, Vikrant

2013-11-01

Keeping in view the influence of gamma radiation on the physiochemical properties of the polysaccharides and their importance in the food and pharmaceutical industry, in the present study attempt has been made to investigate the effects of absorbed dose on FTIR, XRD, SEMs, absorbance, pH, solubility, water absorption capacity, emulsion stability and rheology of sterculia gum. Increase in solubility and decrease in swellability of gum has been observed on increasing the absorbed dose. The emulsion stability has improved for the gum sample irradiated with total dose of 8.1±0.2 kGy. Apparent viscosity of gum solution first increased with increase in dose from 0 to 8.1±0.2 kGy than decreased with regular trends with further increase in total absorbed dose. Flow behavior of gum solution shifted to Newtonian from non-Newtonian with increasing the dose.

Multifunctional Composite Nanofibers for Smart Structures

DTIC Science & Technology

2011-10-13

low cost. It is coated onto the surface of CNF to use as a supercapacitor cathode. The high porosity and surface area of nanofiber composite...SiNP fusion, pulverization, and capacity loss can be minimized during electrochemical cycling. Carbon is also ductile in absorbing the mechanical...b) Figure 2 Core-shell CNF/Si composite with a thin layer of carbon shell coating on SiNP (a) and the capacity of both

Concepts of Resilience for Coastal Systems

DTIC Science & Technology

2015-11-06

respond to, and adapt to changing conditions and to withstand and recover rapidly from disruptions with minimal damage.” Urban Land Institute, “After...AR5/images/uploads/WGIIAR5-Glossary_FGD.pdf “The capacity of a social- ecological system to cope with a hazardous event or disturbance, responding or...dunes, wetlands Ecological Resilience The capacity of a system to absorb disturbance and reorganize while undergoing change Ecological Resilience

Evaluation of oxygen radical absorbance capacity in kampo medicine.

PubMed

Nishimura, Ko; Osawa, Toshihiko; Watanabe, Kenji

2011-01-01

Antioxidant capacity of food has come to be shown in terms of oxygen radical absorbance capacity (ORAC) mainly on vegetables or fruit. However, the evaluation of Kampo in terms of ORAC has not yet been accomplished. It is important that such an investigation is also conducted for Kampo medicine. We measured the ORAC value of almost all the available Kampo formulas used in the Japanese National health insurance system and examined the ORAC value both for the daily prescription, and also the crude herb ingredients. The ORAC value of Kampo medicine ranged 4.65-5913 units/day. The ORAC value was high in Kampo formulas including Rhei Rhizoma, and was relatively high in Kampo formulas including anti-inflammatory herbs other than Rhei Rhizoma. The ORAC value was also high in Kampo formulas including crude herbs that have relaxation effects. The ORAC value of a crude herb would seem to not be fixed but be dependent on combination with other crude herbs from the comparison of different herbs added to the basic Kampo medicine. These results suggest variability and complexity of the antioxidant capacity of Kampo medicine within the similar range of food. On the other hand, investigation of the compound changes of various crude herbs with ORAC may lead to the elucidation of the action mechanism of Kampo medicine.

[Reason for dormancy of Cuscuta chinensis seed and solving method].

PubMed

Wang, Xuemin; He, Jiaqing; Cai, Jing; Dong, Zhenguo

2010-02-01

To study the reason for the deep dormancy of the aged Cuscuta chinensis seed and find the solving method. The separated and combined treatments were applied in the orthogonal designed experiments. The aged seed had well water-absorbency; the water and ethanol extracts of the seeds showed an inhibition effect on germination capacity of the seeds. The main reason for the deep dormancy of aged C. chinensis seed is the inhibitors existed in seed. There are two methods to solve the problem. The seeds is immersed in 98% of H2SO4 for 2 min followed by 500 mg x L(-1) of GA3 treatment for 60 min, or in 100 mg x L(-1) of NaOH for 20 min followed by 500 mg x L(-1) of GA3 treatment for 120 min.

Can plant-based natural flax replace mineral-based basalt and synthetic E-glass for fibre reinforced polymer tubular energy absorbers? A comparative study on quasi-static axial crushing

NASA Astrophysics Data System (ADS)

Yan, Libo; Wang, Bo; Kasal, Bohumil

2017-12-01

Using plant-based natural fibres to substitute glass fibres as reinforcement of composite materials is of particular interest due to their economic, technical and environmental significance. One potential application of plant-based natural fibre reinforced polymer (FRP) composites is in automotive engineering as crushable energy absorbers. Current study experimentally investigated and compared the energy absorption efficiency of plant-based natural flax, mineral-based basalt and glass FRP composite tubular energy absorbers subjected to quasi-static axial crushing. The effects of number of flax fabric layer, the use of foam-filler and the type of fibre materials on the crashworthiness characteristics and energy absorption capacities were discussed. In addition, the failure mechanisms of the hollow and foam-filled flax, basalt and glass FRP tubes in quasi-static axial crushing were analysed and compared. The test results showed that the energy absorption capabilities of both hollow and foam-filled energy absorbers made of flax were superior to the corresponding energy absorbers made of basalt and were close to energy absorbers made of glass. This study therefore indicated that flax fibre has the great potential to be suitable replacement of basalt and glass fibres for crushable energy absorber application.

Preparation of new diatomite-chitosan composite materials and their adsorption properties and mechanism of Hg(II).

PubMed

Fu, Yong; Xu, Xiaoxu; Huang, Yue; Hu, Jianshe; Chen, Qifan; Wu, Yaoqing

2017-12-01

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet-visible (UV-Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g -1 .

Preparation of new diatomite–chitosan composite materials and their adsorption properties and mechanism of Hg(II)

PubMed Central

Fu, Yong; Xu, Xiaoxu; Huang, Yue; Hu, Jianshe; Chen, Qifan; Wu, Yaoqing

2017-01-01

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet–visible (UV–Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g−1. PMID:29308226

Neutron absorbers and methods of forming at least a portion of a neutron absorber

DOEpatents

Guillen, Donna P; Porter, Douglas L; Swank, W David; Erickson, Arnold W

2014-12-02

Methods of forming at least a portion of a neutron absorber include combining a first material and a second material to form a compound, reducing the compound into a plurality of particles, mixing the plurality of particles with a third material, and pressing the mixture of the plurality of particles and the third material. One or more components of neutron absorbers may be formed by such methods. Neutron absorbers may include a composite material including an intermetallic compound comprising hafnium aluminide and a matrix material comprising pure aluminum.

Implanted Silicon Resistor Layers for Efficient Terahertz Absorption

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Abrahams, J.; Allen, C. A.; Benford, D. J.; Henry, R.; Stevenson, T.; Wollack, E.; Moseley, S. H.

2005-01-01

Broadband absorption structures are an essential component of large format bolometer arrays for imaging GHz and THz radiation. We have measured electrical and optical properties of implanted silicon resistor layers designed to be suitable for these absorbers. Implanted resistors offer a low-film-stress, buried absorber that is robust to longterm aging, temperature, and subsequent metals processing. Such an absorber layer is readily integrated with superconducting integrated circuits and standard micromachining as demonstrated by the SCUBA II array built by ROE/NIST (1). We present a complete characterization of these layers, demonstrating frequency regimes in which different recipes will be suitable for absorbers. Single layer thin film coatings have been demonstrated as effective absorbers at certain wavelengths including semimetal (2,3), thin metal (4), and patterned metal films (5,6). Astronomical instrument examples include the SHARC II instrument is imaging the submillimeter band using passivated Bi semimetal films and the HAWC instrument for SOFIA, which employs ultrathin metal films to span 1-3 THz. Patterned metal films on spiderweb bolometers have also been proposed for broadband detection. In each case, the absorber structure matches the impedance of free space for optimal absorption in the detector configuration (typically 157 Ohms per square for high absorption with a single or 377 Ohms per square in a resonant cavity or quarter wave backshort). Resonant structures with -20% bandwidth coupled to bolometers are also under development; stacks of such structures may take advantage of instruments imaging over a wide band. Each technique may enable effective absorbers in imagers. However, thin films tend to age, degrade or change during further processing, can be difficult to reproduce, and often exhibit an intrinsic granularity that creates complicated frequency dependence at THz frequencies. Thick metal films are more robust but the requirement for patterning can limit their absorption at THz frequencies and their heat capacity can be high. patterned absorber structures that offer low heat capacity, absence of aging, and uniform, predictable behavior at THz frequencies. We have correlated DC electrical and THz optical measurements of a series of implanted layers and studied their frequency dependence of optical absorption from .3 to 10 THz at cryogenic temperatures. We have modeled the optical response to determine the suitability of the implanted silicon resistor as a function of resistance in the range 10 Ohms/sq to 300 Ohms/sq.

GIS and agent based spatial-temporal simulation modeling for assessing tourism social carrying capacity: a study on Mount Emei scenic area, China

NASA Astrophysics Data System (ADS)

Zhang, Renjun

2007-06-01

Each scenic area can sustain a specific level of acceptance of tourist development and use, beyond which further development can result in socio-cultural deterioration or a decline in the quality of the experience gained by visitors. This specific level is called carrying capacity. Social carrying capacity can be defined as the maximum level of use (in terms of numbers and activities) that can be absorbed by an area without an unacceptable decline in the quality of experience of visitors and without an unacceptable adverse impact on the society of the area. It is difficult to assess the carrying capacity, because the carrying capacity is determined by not only the number of visitors, but also the time, the type of the recreation, the characters of each individual and the physical environment. The objective of this study is to build a spatial-temporal simulation model to simulate the spatial-temporal distribution of tourists. This model is a tourist spatial behaviors simulator (TSBS). Based on TSBS, the changes of each visitor's travel patterns such as location, cost, and other states data are recoded in a state table. By analyzing this table, the intensity of the tourist use in any area can be calculated; the changes of the quality of tourism experience can be quantized and analyzed. So based on this micro simulation method the social carrying capacity can be assessed more accurately, can be monitored proactively and managed adaptively. In this paper, the carrying capacity of Mount Emei scenic area is analyzed as followed: The author selected the intensity of the crowd as the monitoring Indicators. it is regarded that longer waiting time means more crowded. TSBS was used to simulate the spatial-temporal distribution of tourists. the average of waiting time all the visitors is calculated. And then the author assessed the social carrying capacity of Mount Emei scenic area, found the key factors have impacted on social carrying capacity. The results show that the TSBS-aided method for assessing carrying capacity is dynamic, quantifiable and more accurate.

Superconducting High Energy Resolution Gamma-ray Spectrometers

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

Chow, D T

2002-02-22

We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an active negative feedback bias. We demonstrated the effects of active bias such as additional pulse shortening, reduction ofmore » TES change in temperature during a pulse, and linearization of energy response at low energy. Linearization at higher energy is possible with optimized heat capacities and thermal conductivities of the microcalorimeter. However, the current fabrication process has low control and repeatability over the thermal properties. Thus, optimization of the detector performance is difficult until the fabrication process is improved. Currently, several efforts are underway to better control the fabrication of our gamma-ray spectrometers. We are developing a full-wafer process to produce TES films. We are investigating the thermal conductivity and surface roughness of thicker SiN membranes. We are exploring alternative methods to couple the absorber to the TES film for reproducibility. We are also optimizing the thermal conductivities within the detector to minimize two-element phonon noise. We are experimenting with different absorber materials to optimize absorption efficiency and heat capacity. We are also working on minimizing Johnson noise from the E S shunt and SQUID amplifier noise. We have shown that our performance, noise, and active bias models agree very well with measured data from several microcalorimeters. Once the fabrication improvements have been implemented, we have no doubt that our gamma-ray spectrometer will achieve even more spectacular results.« less

Hydrolates from lavender (Lavandula angustifolia)--their chemical composition as well as aromatic, antimicrobial and antioxidant properties.

PubMed

Prusinowska, Renata; Śmigielski, Krzysztof; Stobiecka, Agnieszka; Kunicka-Styczyńska, Alina

2016-01-01

It was shown that the method for obtaining hydrolates from lavender (Lavandula angustifolia) influences the content of active compounds and the aromatic, antimicrobial and antioxidant properties of the hydrolates. The content of volatile organic compounds ranged from 9.12 to 97.23 mg/100 mL of hydrolate. Lavender hydrolate variants showed low antimicrobial activity (from 0% to 0.05%). The radical scavenging activity of DPPH was from 3.6 ± 0.5% to 3.8 ± 0.6% and oxygen radical absorbance capacity (ORAC(FL)) results were from 0 to 266 μM Trolox equivalent, depending on the hydrolate variant.

Carbon felt interlayer derived from rice paper and its synergistic encapsulation of polysulfides for lithium-sulfur batteries

NASA Astrophysics Data System (ADS)

Yang, Kai; Zhong, Lei; Guan, Ruiteng; Xiao, Min; Han, Dongmei; Wang, Shuanjin; Meng, Yuezhong

2018-05-01

Lithium-sulfur (Li-S) batteries have remarkably high theoretical specific capacity as promising candidates for next-generation energy storage. However, the "polysulfides shuttle" effect hampers its commercial application. Here, we use a kind of rice paper as a raw material to get inorganic oxides doping carbon felt by the facile carbonization method, and then modified by a simple coating process using poly (fluorenyl ether ketone) and Super P slurry. The special structure of the carbon felt derived from rice paper and its modified layer endow the final electronic conductive interlayer with inherent polysulfides absorbents and ion Coulombic repulsion functions, respectively, which show synergistic effect for trapping polysulfides. As an interlayer of Li-S batteries, the obtained carbon felt/poly (fluorenyl ether ketone)& Super P (CFSS) interlayer shows excellent electrochemical performance in improving specific capacity and decreasing polarization. The batteries with CFSS interlayer exhibit a high capacity of 837 mA h g-1 at 2.0 C and a high initial capacity of 1073.4 mA h g-1 and good capacity retention of 824.5 mA h g-1 after 500 cycles at 0.5 C. CFSS interlayer also shows excellent anti-self-discharge performance. Therefore, the simple and economical CFSS interlayer can be considered as a promising component for high performance Li-S batteries.

Adaptation of the ORAC assay to the common laboratory equipment and subsequent application to antioxidant plastic films.

PubMed

Bentayeb, K; Vera, P; Rubio, C; Nerin, C

2009-06-01

The oxygen radical absorbance capacity (ORAC) method has been adapted to the instrumental laboratory and optimized for the determination of the antioxidant capacity of a novel active packaging. As the ORAC assay requires the monitorization of a reaction at controlled temperature by means of the fluorescence signal decrease over time, specific instrumental is usually necessary. In this work, a common liquid chromatographic device has been adapted to perform the ORAC assay, leaving it accessible to any laboratory. Using this adaptation, five different essential oils have been determined resulting in the following antioxidant order: clove (2.66 g Trolox per gram of essential oil), oregano (2.25), cinnamon (1.93), rosemary (1.66), and ginger (1.47). After incorporating the essential oils to the film, its antioxidant capacity has also been checked and related to the concentration of essential oil as well as the thickness of the active film. The results point out that for the same amount of essential oil incorporated measured as grams per square meter, thicker films have more antioxidant capacity than the thinner and more concentrated ones. Furthermore, the antioxidant capacity found in the films was always higher than expected taking into account the amount of essential oil incorporated. Some likely explanations have been proposed, leading to the improvement of the antioxidant film under development.

Antioxidative activity of lactobacilli measured by oxygen radical absorbance capacity.

PubMed

Saide, J A O; Gilliland, S E

2005-04-01

The reducing ability and antioxidative activity of some species of Lactobacillus were compared under in vitro conditions. Cultures of Lactobacillus delbrueckii ssp. lactis, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and Lactobacillus casei were grown at 37 degrees C in de Man, Rogosa, Sharpe (MRS) broth supplemented with 0.5% 2,3,5 triphenyl tetrazolium chloride (TTC) to evaluate reducing activity. Reduced TTC was extracted from the cultures with acetone, and the intensity of the red color measured colorimetrically at 485 nm was an indication of reducing activity. The lactobacilli varied significantly in relative ability to reduce TTC when grown in MRS broth for 15 h. The relative amounts of growth as indicated by pH values at 18 h appeared to influence the amount of reduction. Antioxidative activity was evaluated by the ability of the whole cells or the cell-free extracts from cultures to protect a protein from being attacked by free radicals. These analyses were performed using the oxygen radical absorbance capacity method. All cultures tested exhibited some degree of antioxidative activity. Among the treatments, the cell-free extracts from cells grown in MRS broth exhibited significantly higher values than did whole cells. There was no apparent relationship between the reducing and antioxidative activities of the cultures evaluated. The results from this study show that these cultures can provide a source of dietary antioxidants. Furthermore, selection of cultures that produce antioxidants as starters could provide yet another health or nutritional benefit from cultured or culture-containing dairy products.

Non-enzymatic antioxidant capacity (NEAC) estimated by two different dietary assessment methods and its relationship with NEAC plasma levels.

PubMed

Carrión-García, Cayetano Javier; Guerra-Hernández, Eduardo J; García-Villanova, Belén; Molina-Montes, Esther

2017-06-01

We aimed to quantify and compare dietary non-enzymatic antioxidant capacity (NEAC), estimated using two dietary assessment methods, and to explore its relationship with plasma NEAC. Fifty healthy subjects volunteer to participate in this study. Two dietary assessment methods [a food frequency questionnaire (FFQ) and a 24-hour recall (24-HR)] were used to collect dietary information. Dietary NEAC, including oxygen radical absorbance capacity (ORAC), total polyphenols, ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity, was estimated using several data sources of NEAC content in food. NEAC status was measured in fasting blood samples using the same assays. We performed nonparametric Spearman's correlation analysis between pairs of dietary NEAC (FFQ and 24-HR) and diet-plasma NEAC, with and without the contribution of coffee's NEAC. Partial correlation analysis was used to estimate correlations regardless of variables potentially influencing these relationships. FFQ-based NEAC and 24-HR-based NEAC were moderately correlated, with correlation coefficients ranging from 0.54 to 0.71, after controlling for energy intake, age and sex. Statistically significant positive correlations were found for dietary FRAP, either derived from the FFQ or the 24-HR, with plasma FRAP (r ~ 0.30). This weak, albeit statistically significant, correlation for FRAP was mostly present in the fruits and vegetables food groups. Plasma ORAC without proteins and 24-HR-based total ORAC were also positively correlated (r = 0.35). The relationship between dietary NEAC and plasma FRAP and ORAC suggests the dietary NEAC may reflect antioxidant status despite its weak in vivo potential, supporting further its use in oxidative stress-related disease epidemiology.

Development of a low-cost optical sensor for cupric reducing antioxidant capacity measurement of food extracts.

PubMed

Bener, Mustafa; Ozyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

2010-05-15

A low-cost optical sensor using an immobilized chromogenic redox reagent was devised for measuring the total antioxidant level in a liquid sample without requiring sample pretreatment. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly colored Cu(I)-Nc chelate as a result of reaction with antioxidants was measured at 450 nm. The sensor gave a linear response over a wide concentration range of standard antioxidant compounds. The trolox equivalent antioxidant capacity (TEAC) values of various antioxidants reported in this work using the optical sensor-based "cupric reducing antioxidant capacity" (CUPRAC) assay were comparable to those of the standard solution-based CUPRAC assay, showing that the immobilized Cu(II)-Nc reagent retained its reactivity toward antioxidants. Common food ingredients like oxalate, citrate, fruit acids, and reducing sugars did not interfere with the proposed sensing method. This assay was validated through linearity, additivity, precision, and recovery, demonstrating that the assay is reliable and robust. The developed optical sensor was used to screen total antioxidant capacity (TAC) of some commercial fruit juices without preliminary treatment and showed a promising potential for the preparation of antioxidant inventories of a wide range of food plants.

Bioaccessible Antioxidants in Milk Fermented by Bifidobacterium longum subsp. longum Strains

PubMed Central

Gagnon, Mérilie; Savard, Patricia; Rivière, Audrey; LaPointe, Gisèle

2015-01-01

Bifidobacterium longum subsp. longum is among the dominant species of the human gastrointestinal microbiota and could thus have potential as probiotics. New targets such as antioxidant properties have interest for beneficial effects on health. The objective of this study was to evaluate the bioaccessibility of antioxidants in milk fermented by selected B. longum subsp. longum strains during in vitro dynamic digestion. The antioxidant capacity of cell extracts from 38 strains, of which 32 belong to B. longum subsp. longum, was evaluated with the ORAC (oxygen radical absorbance capacity) method. On the basis of screening and gene sequence typing by multilocus locus sequence analysis (MLSA), five strains were chosen for fermenting reconstituted skim milk. Antioxidant capacity varied among the strains tested (P = 0.0009). Two strains of B. longum subsp. longum (CUETM 172 and 171) showed significantly higher ORAC values than the other bifidobacteria strains. However, there does not appear to be a relationship between gene sequence types and antioxidant capacity. The milk fermented by each of the five strains selected (CUETM 268, 172, 245, 247, or PRO 16-10) did not have higher initial ORAC values compared to the nonfermented milk samples. However, higher bioaccessibility of antioxidants in fermented milk (175–358%) was observed during digestion. PMID:25802836

Thermal conductance of and heat generation in tire-pavement interface and effect on aircraft braking

NASA Technical Reports Server (NTRS)

Miller, C. D.

1976-01-01

A finite-difference analysis was performed on temperature records obtained from a free rolling automotive tire and from pavement surface. A high thermal contact conductance between tire and asphalt was found on a statistical basis. Average slip due to squirming between tire and asphalt was about 1.5 mm. Consequent friction heat was estimated as 64 percent of total power absorbed by bias-ply, belted tire. Extrapolation of results to aircraft tire indicates potential braking improvement by even moderate increase of heat absorbing capacity of runway surface.

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

Caldwell, M.M.; Eissenstat, D.M.; Richards, J.H.

Two species of Agropyron grass differed strikingly in their capacity to compete for phosphate in soil interspaces shared with a common competitor, the sagebrush Artemisia tridentata. Of the total phosphorus-32 and -33 absorbed by Artemisia, 86% was from the interspace shared with Agropyron spicatum and only 14% from that shared with Agropyron desertorum. Actively absorbing mycorrhizal roots of Agropyron and Artemisia were present in both interspaces, where competition for the labeled phosphate occurred. The results have important implications about the way in which plants compete for resources below ground in both natural plant communities and agricultural intercropping systems.

2011 Resilience and Law Panel Session

EPA Science Inventory

Resilience is the capacity of a complex system of people and nature to absorb perturbations without collapsing. It provides a conceptual framework for the integration of natural resource management with ecological responses. Achieving the goal of sustainability is complicated b...

Methods for applying microchannels to separate methane using liquid absorbents, especially ionic liquid absorbents from a mixture comprising methane and nitrogen

DOEpatents

Tonkovich, Anna Lee Y [Dublin, OH; Litt, Robert D [Westerville, OH; Dongming, Qiu [Dublin, OH; Silva, Laura J [Plain City, OH; Lamont, Micheal Jay [Plain City, OH; Fanelli, Maddalena [Plain City, OH; Simmons, Wayne W [Plain city, OH; Perry, Steven [Galloway, OH

2011-10-04

Methods of using microchannel separation systems including absorbents to improve thermal efficiency and reduce parasitic power loss. Energy is typically added to desorb methane and then energy or heat is removed to absorb methane using a working solution. The working solution or absorbent may comprise an ionic liquid, or other fluids that demonstrate a difference in affinity between methane and nitrogen in a solution.

Diagnosis of Cell Death by Means of Infrared Spectroscopy

PubMed Central

Zelig, Udi; Kapelushnik, Joseph; Moreh, Raymond; Mordechai, Shaul; Nathan, Ilana

2009-01-01

Abstract Fourier transform infrared (FTIR) spectroscopy has been established as a fast spectroscopic method for biochemical analysis of cells and tissues. In this research we aimed to investigate FTIR's utility for identifying and characterizing different modes of cell death, using leukemic cell lines as a model system. CCRF-CEM and U937 leukemia cells were treated with arabinoside and doxorubicin apoptosis inducers, as well as with potassium cyanide, saponin, freezing-thawing, and H2O2 necrosis inducers. Cell death mode was determined by various gold standard biochemical methods in parallel with FTIR-microscope measurements. Both cell death modes exhibit large spectral changes in lipid absorbance during apoptosis and necrosis; however, these changes are similar and thus cannot be used to distinguish apoptosis from necrosis. In contrast to the above confounding factor, our results reveal that apoptosis and necrosis can still be distinguished by the degree of DNA opaqueness to infrared light. Moreover, these two cell death modes also can be differentiated by their infrared absorbance, which relates to the secondary structure of total cellular protein. In light of these findings, we conclude that, because of its capacity to monitor multiple biomolecular parameters, FTIR spectroscopy enables unambiguous and easy analysis of cell death modes and may be useful for biochemical and medical applications. PMID:19804743

Assessing the Effects of Water Deficit on Photosynthesis Using Parameters Derived from Measurements of Leaf Gas Exchange and of Chlorophyll a Fluorescence

PubMed Central

Urban, Laurent; Aarrouf, Jawad; Bidel, Luc P. R.

2017-01-01

Water deficit (WD) is expected to increase in intensity, frequency and duration in many parts of the world as a consequence of global change, with potential negative effects on plant gas exchange and growth. We review here the parameters that can be derived from measurements made on leaves, in the field, and that can be used to assess the effects of WD on the components of plant photosynthetic rate, including stomatal conductance, mesophyll conductance, photosynthetic capacity, light absorbance, and efficiency of absorbed light conversion into photosynthetic electron transport. We also review some of the parameters related to dissipation of excess energy and to rerouting of electron fluxes. Our focus is mainly on the techniques of gas exchange measurements and of measurements of chlorophyll a fluorescence (ChlF), either alone or combined. But we put also emphasis on some of the parameters derived from analysis of the induction phase of maximal ChlF, notably because they could be used to assess damage to photosystem II. Eventually we briefly present the non-destructive methods based on the ChlF excitation ratio method which can be used to evaluate non-destructively leaf contents in anthocyanins and flavonols. PMID:29312367

Assessing the Effects of Water Deficit on Photosynthesis Using Parameters Derived from Measurements of Leaf Gas Exchange and of Chlorophyll a Fluorescence.

PubMed

Urban, Laurent; Aarrouf, Jawad; Bidel, Luc P R

2017-01-01

Water deficit (WD) is expected to increase in intensity, frequency and duration in many parts of the world as a consequence of global change, with potential negative effects on plant gas exchange and growth. We review here the parameters that can be derived from measurements made on leaves, in the field, and that can be used to assess the effects of WD on the components of plant photosynthetic rate, including stomatal conductance, mesophyll conductance, photosynthetic capacity, light absorbance, and efficiency of absorbed light conversion into photosynthetic electron transport. We also review some of the parameters related to dissipation of excess energy and to rerouting of electron fluxes. Our focus is mainly on the techniques of gas exchange measurements and of measurements of chlorophyll a fluorescence (ChlF), either alone or combined. But we put also emphasis on some of the parameters derived from analysis of the induction phase of maximal ChlF, notably because they could be used to assess damage to photosystem II. Eventually we briefly present the non-destructive methods based on the ChlF excitation ratio method which can be used to evaluate non-destructively leaf contents in anthocyanins and flavonols.

[Study of Cervical Exfoliated Cell's DNA Quantitative Analysis Based on Multi-Spectral Imaging Technology].

PubMed

Wu, Zheng; Zeng, Li-bo; Wu, Qiong-shui

2016-02-01

The conventional cervical cancer screening methods mainly include TBS (the bethesda system) classification method and cellular DNA quantitative analysis, however, by using multiple staining method in one cell slide, which is staining the cytoplasm with Papanicolaou reagent and the nucleus with Feulgen reagent, the study of achieving both two methods in the cervical cancer screening at the same time is still blank. Because the difficulty of this multiple staining method is that the absorbance of the non-DNA material may interfere with the absorbance of DNA, so that this paper has set up a multi-spectral imaging system, and established an absorbance unmixing model by using multiple linear regression method based on absorbance's linear superposition character, and successfully stripped out the absorbance of DNA to run the DNA quantitative analysis, and achieved the perfect combination of those two kinds of conventional screening method. Through a series of experiment we have proved that between the absorbance of DNA which is calculated by the absorbance unmixxing model and the absorbance of DNA which is measured there is no significant difference in statistics when the test level is 1%, also the result of actual application has shown that there is no intersection between the confidence interval of the DNA index of the tetraploid cells which are screened by using this paper's analysis method when the confidence level is 99% and the DNA index's judging interval of cancer cells, so that the accuracy and feasibility of the quantitative DNA analysis with multiple staining method expounded by this paper have been verified, therefore this analytical method has a broad application prospect and considerable market potential in early diagnosis of cervical cancer and other cancers.

Evaluation of Biologically Active Compounds from Calendula officinalis Flowers using Spectrophotometry

PubMed Central

2012-01-01

Background This study aimed to quantify the active biological compounds in C. officinalis flowers. Based on the active principles and biological properties of marigolds flowers reported in the literature, we sought to obtain and characterize the molecular composition of extracts prepared using different solvents. The antioxidant capacities of extracts were assessed by using spectrophotometry to measure both absorbance of the colorimetric free radical scavenger 2,2-diphenyl-1-picrylhydrazyl (DPPH) as well as the total antioxidant potential, using the ferric reducing power (FRAP) assay. Results Spectrophotometric assays in the ultraviolet-visible (UV-VIS) region enabled identification and characterization of the full range of phenolic and flavonoids acids, and high-performance liquid chromatography (HPLC) was used to identify and quantify phenolic compounds (depending on the method of extraction). Methanol ensured more efficient extraction of flavonoids than the other solvents tested. Antioxidant activity in methanolic extracts was correlated with the polyphenol content. Conclusions The UV-VIS spectra of assimilator pigments (e.g. chlorophylls), polyphenols and flavonoids extracted from the C. officinalis flowers consisted in quantitative evaluation of compounds which absorb to wavelengths broader than 360 nm. PMID:22540963

Decorating MOF-Derived Nanoporous Co/C in Chain-Like Polypyrrole (PPy) Aerogel: A Lightweight Material with Excellent Electromagnetic Absorption

PubMed Central

Sun, Xiaodong; Lv, Xuliang; Sui, Mingxu; Weng, Xiaodi; Li, Xiaopeng; Wang, Jijun

2018-01-01

To clear away the harmful effects of the increment of electromagnetic pollution, high performance absorbers with appropriate impedance matching and strong attenuation capacity are strongly desired. In this study, a chain-like PPy aerogel decorated with MOF-derived nanoporous Co/C (Co/C@PPy) has been successfully prepared by a self-assembled polymerization method. With a filler loading ratio of 10 wt %, the composite of Co/C@PPy could achieve a promising electromagnetic absorption performance both in intensity and bandwidth. An optimal reflection loss value of −44.76 dB is achieved, and the effective bandwidth (reflection loss lower than −10 dB) is as large as 6.56 GHz. Furthermore, a composite only loaded with 5 wt % Co/C@PPy also achieves an effective bandwidth of 5.20 GHz, which is even better than numerous reported electromagnetic absorption (EA) materials. The result reveals that the as-fabricated Co/C@PPy—with high absorption intensity, broad bandwidth, and light weight properties—can be utilized as a competitive absorber. PMID:29751650

Evolutionary dynamics of fluctuating populations with strong mutualism

NASA Astrophysics Data System (ADS)

Chotibut, Thiparat; Nelson, David

2013-03-01

Evolutionary game theory with finite interacting populations is receiving increased attention, including subtle phenomena associated with number fluctuations, i.e., ``genetic drift.'' Models of cooperation and competition often utilize a simplified Moran model, with a strictly fixed total population size. We explore a more general evolutionary model with independent fluctuations in the numbers of two distinct species, in a regime characterized by ``strong mutualism.'' The model has two absorbing states, each corresponding to fixation of one of the two species, and allows exploration of the interplay between growth, competition, and mutualism. When mutualism is favored, number fluctuations eventually drive the system away from a stable fixed point, characterized by cooperation, to one of the absorbing states. Well-mixed populations will thus be taken over by a single species in a finite time, despite the bias towards cooperation. We calculate both the fixation probability and the mean fixation time as a function of the initial conditions and carrying capacities in the strong mutualism regime, using the method of matched asymptotic expansions. Our results are compared to computer simulations.

Decorating MOF-Derived Nanoporous Co/C in Chain-Like Polypyrrole (PPy) Aerogel: A Lightweight Material with Excellent Electromagnetic Absorption.

PubMed

Sun, Xiaodong; Lv, Xuliang; Sui, Mingxu; Weng, Xiaodi; Li, Xiaopeng; Wang, Jijun

2018-05-11

To clear away the harmful effects of the increment of electromagnetic pollution, high performance absorbers with appropriate impedance matching and strong attenuation capacity are strongly desired. In this study, a chain-like PPy aerogel decorated with MOF-derived nanoporous Co/C (Co/C@PPy) has been successfully prepared by a self-assembled polymerization method. With a filler loading ratio of 10 wt %, the composite of Co/C@PPy could achieve a promising electromagnetic absorption performance both in intensity and bandwidth. An optimal reflection loss value of −44.76 dB is achieved, and the effective bandwidth (reflection loss lower than −10 dB) is as large as 6.56 GHz. Furthermore, a composite only loaded with 5 wt % Co/C@PPy also achieves an effective bandwidth of 5.20 GHz, which is even better than numerous reported electromagnetic absorption (EA) materials. The result reveals that the as-fabricated Co/C@PPy—with high absorption intensity, broad bandwidth, and light weight properties—can be utilized as a competitive absorber.

Molecularly Imprinted Polymer of Colocynthin, An Effective Tool for Quality Control of Citrullus colocynthis Extracts.

PubMed

Farid, Ramezani; Mahnaz, Khanavi; Ardekani Mohammad Reza, Shams; Börje, Sellergren; Mahdieh, Eftekhari; Hossein, Rastegar; Maryam, Shekarchi

2017-01-01

Different parts of Colocynth, Citrullus colocynthis (L.) Schrad., are used in traditional phytotherapy and homeopathy. In our new approach, a molecularly imprinted polymer was synthesized to absorb colocynthin, the major plant marker, and its capability was evaluated using HPLC-UV. A new method was considered to achieve optimal conditions. FT-infrared, N2 adsorption porosimetry, fluorescent and scanning electron microscopy and thermo gravimetric profile of the polymers were studied. The imprinted polymer was applied as molecularly imprinted solid phase extraction sorbent to enrich colocynthin from colocynth oil extract, a traditional medicine dosage form. The imprinted polymer showed high capacity and affinity toward colocynthin. Physical assessments demonstrated no major differences between imprinted and nonimprinted polymers. The imprinted polymer was able to absorb colocynthin more efficiently than non-imprinted and control simple solvent extraction from the real sample. In conclusion, this polymer is capable of being applied as a promising adsorbent for analysis of colocynth traditional medicine products. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sabah snake grass extract pre-processing: Preliminary studies in drying and fermentation

NASA Astrophysics Data System (ADS)

Solibun, A.; Sivakumar, K.

2016-06-01

Clinacanthus nutans (Burm. F.) Lindau which also known as ‘Sabah Snake Grass’ among Malaysians have been studied in terms of its medicinal and chemical properties in Asian countries which is used to treat various diseases from cancer to viral-related diseases such as varicella-zoster virus lesions. Traditionally, this plant has been used by the locals to treat insect and snake bites, skin rashes, diabetes and dysentery. In Malaysia, the fresh leaves of this plant are usually boiled with water and consumed as herbal tea. The objectives of this study are to determine the key process parameters for Sabah Snake Grass fermentation which affect the chemical and biological constituent concentrations within the tea, extraction kinetics of fermented and unfermented tea and the optimal process parameters for the fermentation of this tea. Experimental methods such as drying, fermenting and extraction of C.nutans leaves were conducted before subjecting them to analysis of antioxidant capacity. Conventional oven- dried (40, 45 and 50°C) and fermented (6, 12 and 18 hours) whole C.nutans leaves were subjected to tea infusion extraction (water temperature was 80°C, duration was 90 minutes) and the sample liquid was extracted for every 5th, 10th, 15th, 25th, 40th, 60th and 90th minute. Analysis for antioxidant capacity and total phenolic content (TPC) were conducted by using 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) and Folin-Ciocaltheu reagent, respectively. The 40°C dried leaves sample produced the highest phenolic content at 0.1344 absorbance value in 15 minutes of extraction while 50°C dried leaves sample produced 0.1298 absorbance value in 10 minutes of extraction. The highest antioxidant content was produced by 50°C dried leaves sample with absorbance value of 1.6299 in 5 minutes of extraction. For 40°C dried leaves sample, the highest antioxidant content could be observed in 25 minutes of extraction with the absorbance value of 1.1456. The largest diameter of disc that could be observed at 18 hours of fermentation sample had a pile size of 3 cm that had expanded to 5.9 cm of diameter which indicated the microbe's growth.

Energy Absorption of Expansion Tube Considering Local Buckling Characteristics

NASA Astrophysics Data System (ADS)

Ahn, Kwang-Hyun; Kim, Jin-Sung; Huh, Hoon

This paper deals with the crash energy absorption and the local buckling characteristics of the expansion tube during the tube expanding processes. In order to improve energy absorption capacity of expansion tubes, local buckling characteristics of an expansion tube must be considered. The local buckling load and the absorbed energy during the expanding process were calculated for various types of tubes and punch shapes with finite element analysis. The energy absorption capacity of the expansion tube is influenced by the tube and the punch shape. The material properties of tubes are also important parameter for energy absorption. During the expanding process, local buckling occurs in some cases, which causes significant decreasing the absorbed energy of the expansion tube. Therefore, it is important to predict the local buckling load accurately to improve the energy absorption capacity of the expansion tube. Local buckling takes place relatively easily at the large punch angle and expansion ratio. Local buckling load is also influenced by both the tube radius and the thickness. In prediction of the local buckling load, modified Plantema equation was used for strain hardening and strain rate hardening. The modified Plantema equation shows a good agreement with the numerical result.

Simultaneous purification and storage of hydrogen

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

Hynek, S.; Fuller, W.; Weber, R.

1998-08-01

Specially coated magnesium particles have been shown to selectively absorb hydrogen from a hydrogen-rich gas stream such as reformate. These coated magnesium particles can store the absorbed hydrogen as required and subsequently deliver pure hydrogen, just as uncoated magnesium particles can. These coated magnesium particles could be used in a device that accepts a steady stream of reformate, as from a methane reformer, stores the selectively absorbed hydrogen indefinitely, and delivers purified hydrogen on demand. Unfortunately, this coating (magnesium nitride) has been shown to degrade over a period of several weeks, so that the magnesium within evidences progressively lower storagemore » capacity. The authors are investigating two other coatings, one of which might be applicable to hydridable metals other than magnesium, to replace magnesium nitride.« less

Amino acid composition and antioxidant capacity of Spanish honeys.

PubMed

Pérez, Rosa Ana; Iglesias, María Teresa; Pueyo, Encarnación; Gonzalez, Montserrat; de Lorenzo, Cristina

2007-01-24

The amino acid composition of 53 honey samples from Spain, consisting of 39 floral, 5 honeydew, and 9 blend honeys, has been determined. Physicochemical characteristics, polyphenolic content, amino acid composition, and estimation of the radical scavenging capacity against the stable free radical DPPH of the honey samples were analyzed. The resulting data have been statistically evaluated. The results showed that pH, acidity, net absorbance, electrical conductivity, and total polyphenolic contents of the honeys showed a strong correlation with the radical scavenging capacity. The correlation between the radical scavenging capacity of honey and amino acid contents was high with 18 of the 20 amino acids detected, with correlation values higher than those obtained for polyphenolic content. These results suggest that the amino acid composition of honey is an indicator of the sample's scavenging capacity.

Research on calorimeter for high-power microwave measurements.

PubMed

Ye, Hu; Ning, Hui; Yang, Wensen; Tian, Yanmin; Xiong, Zhengfeng; Yang, Meng; Yan, Feng; Cui, Xinhong

2015-12-01

Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an "inline" calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an "offline" calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations and a "cold test" on a 9.3 GHz klystron show that the "inline" calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device's power capacity is approximately 0.9 GW. The same experiments were also carried out for the "offline" calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the "cold tests," and the experiments show good agreement.

Low Drag Porous Ship with Superhydrophobic and Superoleophilic Surface for Oil Spills Cleanup.

PubMed

Wang, Gang; Zeng, Zhixiang; Wang, He; Zhang, Lin; Sun, Xiaodong; He, Yi; Li, Longyang; Wu, Xuedong; Ren, Tianhui; Xue, Qunji

2015-12-02

To efficiently remove and recycle oil spills, we construct aligned ZnO nanorod arrays on the surface of the porous stainless steel wire mesh to fabricate a porous unmanned ship (PUS) with properties of superhydrophobicity, superoleophilicity, and low drag by imitating the structure of nonwetting leg of water strider. The superhydrophobicity of the PUS is stable, which can support 16.5 cm water column with pore size of 100 μm. Water droplet can rebound without adhesion. In the process of oil/water separation, when the PUS contacts with oil, the oil is quickly pulled toward and penetrates into the PUS automatically. The superhydrophobicity and low water adhesion force of the PUS surface endow the PUS with high oil recovery capacity (above 94%) and drag-reducing property (31% at flowing velocity of 0.38m/s). In addition, the PUS has good corrosion resistance and reusability. We further investigate the wetting behavior of water and oil, oil recovery capacity, drag-reducing property, and corrosion resistance of the PUS after oil absorbed. The PUS surface changes significantly from superhydrophobic to hydrophobic after absorbing oil. However, the oil absorbed PUS possesses better drag-reducing property and corrosion resistance due to the changes of the motion state of the water droplets.

Removal of heavy metal Cu(II) in simulated aquaculture wastewater by modified palygorskite.

PubMed

Cao, Jia-Shun; Wang, Cheng; Fang, Fang; Lin, Jun-Xiong

2016-12-01

Palygorskite (PAL) is a good heavy metal adsorbent due to its high surface area, low cost, and environmentally compatibility. But the natural PAL has limited its adsorption capacity and selectivity. In this study, a cost-effective and readily-generated absorbent, l-threonine-modified palygorskite (L-PAL), was used and its performance for Cu(II) removal in simulated aquaculture wastewater was evaluated. After preparation, L-PAL was characterized by using Fourier transform infrared spectroscopy, scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis. The impacts of pH, adsorbent dosage, contact time, and initial Cu(II) concentration on the adsorption capacity of L-PAL were examined. The Cu(II) adsorption capacity on L-PAL was enhanced almost 10 times than that of raw PAL. The adsorption isotherms of Cu(II) fit the Langmuir isotherms, and the adsorption kinetics was dominated by the pseudo-second-order model. The thermodynamic parameters at four temperatures were calculated, which indicated that the adsorption was spontaneous and endothermic. The adsorption mechanism involves complexation, chelation, electrostatic attraction, and micro-precipitation. Furthermore, L-PAL is shown to have a high regeneration capacity. These results indicate that L-PAL is a cheap and promising absorbent for Cu(II) removal and hold potential to be used for aquaculture wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxygen radical absorbance capacity (ORAC) and exercise-induced oxidative stress in trotters.

PubMed

Kinnunen, Susanna; Hyyppä, Seppo; Lehmuskero, Arja; Oksala, Niku; Mäenpää, Pekka; Hänninen, Osmo; Atalay, Mustafa

2005-12-01

Strenuous exercise is a potent inducer of oxidative stress, which has been suggested to be associated with disturbances in muscle homeostasis, fatigue and injury. There is no comprehensive or uniform view of the antioxidant status in horses. We have previously shown that moderate exercise induces protein oxidation in trotters. The aim of this study was to measure the antioxidative capacity of the horse in relation to different antioxidant components and oxidative stress markers after a single bout of moderate exercise to elucidate the mechanisms of antioxidant protection in horses. Eight clinically normal and regularly trained standard-bred trotters were treadmill-exercised for 53 min at moderate intensity. Blood samples were collected prior to and immediately after exercise and at 4 and 24 h of recovery. Muscle biopsies from the middle gluteal muscle were taken before exercise and after 4 h of recovery. Acute induction of oxygen radical absorbance capacity (ORAC) did not prevent exercise-induced oxidative stress, which was demonstrated by increased lipid hydroperoxides (LPO). Pre-exercise ORAC levels were, however, a determinant of total glutathione content of the blood after 4 and 24 h of recovery. Furthermore, baseline ORAC level correlated negatively with 4-h recovery LPO levels. Our results imply that horses are susceptible to oxidative stress, but a stronger antioxidant capacity may improve coping with exercise-induced oxidative stress.

Evaluation of Oxygen Radical Absorbance Capacity in Kampo Medicine

PubMed Central

Nishimura, Ko; Osawa, Toshihiko; Watanabe, Kenji

2011-01-01

Antioxidant capacity of food has come to be shown in terms of oxygen radical absorbance capacity (ORAC) mainly on vegetables or fruit. However, the evaluation of Kampo in terms of ORAC has not yet been accomplished. It is important that such an investigation is also conducted for Kampo medicine. We measured the ORAC value of almost all the available Kampo formulas used in the Japanese National health insurance system and examined the ORAC value both for the daily prescription, and also the crude herb ingredients. The ORAC value of Kampo medicine ranged 4.65–5913 units/day. The ORAC value was high in Kampo formulas including Rhei Rhizoma, and was relatively high in Kampo formulas including anti-inflammatory herbs other than Rhei Rhizoma. The ORAC value was also high in Kampo formulas including crude herbs that have relaxation effects. The ORAC value of a crude herb would seem to not be fixed but be dependent on combination with other crude herbs from the comparison of different herbs added to the basic Kampo medicine. These results suggest variability and complexity of the antioxidant capacity of Kampo medicine within the similar range of food. On the other hand, investigation of the compound changes of various crude herbs with ORAC may lead to the elucidation of the action mechanism of Kampo medicine. PMID:19126557

Reversible capture of SO2 through functionalized ionic liquids.

PubMed

Yang, Dezhong; Hou, Minqiang; Ning, Hui; Ma, Jun; Kang, Xinchen; Zhang, Jianling; Han, Buxing

2013-07-01

Emission of SO2 in flue gas from the combustion of fossil fuels leads to severe environmental problems. Exploration of green and efficient methods to capture SO2 is an interesting topic, especially at lower SO2 partial pressures. In this work, ionic liquids (ILs) 1-(2-diethylaminoethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Et2 NEMim][Tf2 N]) and 1-(2-diethylaminoethyl)-3-methylimidazolium tetrazolate ([Et2 NEMim][Tetz]) were synthesized. The performances of the two ILs to capture SO2 were studied under different conditions. It was demonstrated that the ILs were very efficient for SO2 absorption. The [Et2 NEMim][Tetz] IL designed in this work could absorb 0.47 g(SO2)g(IL)(-1) at 0.0101 MPa SO2 partial pressure, which is the highest capacity reported to date under the same conditions. The main reason for the large capacity was that both the cation and the anion could capture SO2 chemically. In addition, the IL could easily be regenerated, and the very high absorption capacity and rapid absorption/desorption rates were not changed over five repeated cycles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Absorber for terahertz radiation management

DOEpatents

Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

2015-12-08

A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

A new flavonol glycoside from the medicinal halophyte Suaeda fruticosa.

PubMed

Oueslati, Samia; Ksouri, Riadh; Pichette, André; Lavoie, Serge; Girard-Lalancette, Karl; Mshvildadze, Vakhtang; Abdelly, Chedly; Legault, Jean

2014-01-01

A new flavonol glycoside, namely 3-(α-rhamnopyranosyl-(1 → 2)-[β-xylopyranosyl-(1 → 6)]-β-glucopyranosyloxy) isorhamnetin was reported from methanol extracts of aerial parts of Suaeda fruticosa for the first time. In this work, liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify this new compound. Structure was elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC and (1)H-(1)H COSY. Antioxidant potentialities of a pure compound were evaluated. The estimation of antioxidant capacities using oxygen radical absorbance capacity (ORAC method) and a cell based-assay (WS1) indicated that this new flavonol exhibited the highest antioxidant activities with an ORAC value of 5.0 ± 0.3 μmol Trolox/μmol and inhibited the tBH-induced oxidation of 2',7'-dichlorofluorescin with an IC50 value of 4.9 ± 0.6 μM.

Superabsorbent nanocomposite synthesis of cellulose from rice husk grafted poly(acrylate acid-co-acrylamide)/bentonite

NASA Astrophysics Data System (ADS)

Helmiyati; Abbas, G. H.; Kurniawan, S.

2017-04-01

Superabsorbent nanocomposite synthesis of cellulose rice husk as the backbone with free radical polymerization method in copolymerization grafted with acrylic acid and acrylamide monomer. The cellulose was isolated from rice husk with mixture of toluene and ethanol and then hemicellulose and lignin were removed by using potassium hydroxide 4% and hydrogen peroxide 2%. The obtained cellulose rendement was 37.85%. The functional group of lignin analyzed by FTIR spectra was disappeared at wavenumber 1724 cm-1. Crystal size of the obtained isolated cellulose analyzed by XRD diffraction pattern was 34.6 nm, indicated the nanocrystal structure. Copolymerization was performed at temperature of 70°C with flow nitrogen gas. Initiator and crosslinking agent used were potassium persulfate and N‧N-methylene-bis-acrylamide. The swelling capacity of water and urea showed the results was quite satisfactory, the maximum swelling capacity in urea and water were 611.700 g/g and 451.303 g/g, respectively, and can be applied in agriculture to absorb water and urea fertilizer.

Chitosan, the marine functional food, is a potent adsorbent of humic acid.

PubMed

Chen, Jeen-Kuan; Yeh, Chao-Hsien; Wang, Lian-Chen; Liou, Tzong-Horng; Shen, Chia-Rui; Liu, Chao-Lin

2011-12-01

Chitosan is prepared by the deacetylation of chitin, the second-most abundant biopolymer in nature, and has applicability in the removal of dyes, heavy metals and radioactive waste for pollution control. In weight-reduction remedies, chitosan is used to form hydrogels with lipids and to depress the intestinal absorption of lipids. In this study, an experimental method was implemented to simulate the effect of chitosan on the adsorption of humic acid in the gastrointestinal tract. The adsorption capacity of chitosan was measured by its adsorption isotherm and analyzed using the Langmuir equation. The results showed that 3.3 grams of humic acid was absorbed by 1 gram of chitosan. The adsorption capacity of chitosan was much greater than that of chitin, diethylaminoethyl-cellulose or activated charcoal. Cellulose and carboxymethyl-cellulose, a cellulose derivative with a negative charge, could not adsorb humic acid in the gastrointestinal tract. This result suggests that chitosan entraps humic acid because of its positive charge.

Visualization of electrochemically driven solid-state phase transformations using operando hard X-ray spectro-imaging

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

Li, Linsen; Chen-Wiegart, Yu-chen Karen; Wang, Jiajun

In situ techniques with high temporal, spatial and chemical resolution are key to understand ubiquitous solid-state phase transformations, which are crucial to many technological applications. Hard X-ray spectro-imaging can visualize electrochemically driven phase transformations but demands considerably large samples with strong absorption signal so far. Here we show a conceptually new data analysis method to enable operando visualization of mechanistically relevant weakly absorbing samples at the nanoscale and study electrochemical reaction dynamics of iron fluoride, a promising high-capacity conversion cathode material. In two specially designed samples with distinctive microstructure and porosity, we observe homogeneous phase transformations during both discharge andmore » charge, faster and more complete Li-storage occurring in porous polycrystalline iron fluoride, and further, incomplete charge reaction following a pathway different from conventional belief. In conclusion, these mechanistic insights provide guidelines for designing better conversion cathode materials to realize the promise of high-capacity lithium-ion batteries.« less

Preparation and oil absorption properties of magnetic melamine sponge

NASA Astrophysics Data System (ADS)

Lei, LUO; Jia-qi, HU; Na, LV

2017-12-01

The magnetic melamine sponge (MS-Fe3O4) with magnetic response and high hydrophobicity was fabricated by two-step method. First, the magnetic nano-particles were fixed on the skeleton of melamine sponge (MS) using 3-hydroxytyramine hydrochloride and 1-dodecanethiol, then hydrophobicity modified with octadecyltrichlorosilane (OTS). The structures and chemical compositions of MS and MS-Fe3O4 were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The wettability of the sample was obtained by using contact angle analysis system. MS-Fe3O4 endowed with outstanding selectivity and excellent oil absorption capacities, which can be widely used in absorbing various sorts of oil. The oil absorption capacities for crude oil, diesel oil, lubricating oil, soybean oil and peanut oil were 71g/g, 51g/g, 62g/g, 54g/g, 57g/g. In addition, MS-Fe3O4 showed excellent recyclability which can be forecasted as an ideal candidate for oil-water separation.

Green synthesis of amphipathic graphene aerogel constructed by using the framework of polymer-surfactant complex for water remediation

NASA Astrophysics Data System (ADS)

Cao, Jingjing; Wang, Ziyuan; Yang, Xianhou; Tu, Jing; Wu, Ronglan; Wang, Wei

2018-06-01

Graphene aerogels have been extensively studied in water treatment and oil remediation. We report a mild and green method to prepare a 3D-columnar graphene aerogel. The aerogel was synthesized by using polyvinyl alcohol (PVA) and stearic acid (SA) as crosslinking agents to construct a framework of reduced graphene oxide (RGO). The interaction between PVA, SA, and stacked RGO sheets created a mechanically very robust aerogel. The aerogel possesses ultra-light performance with the destiny ranging from 4.9 to 10 mg cm-3. The aerogel also demonstrated ultrafast oil absorption, good fire-resistance, and excellent mechanical properties. The adsorptive capacities are in the range of 105-250 times of its original weight for various organic liquids after the absorption. The aerogel also exhibited a strong durability and reusability, and after ten cycles of absorbing-squeezing, the adsorptive capacity is nearly unchanged, indicating potential application in practical oil remediation.

Visualization of electrochemically driven solid-state phase transformations using operando hard X-ray spectro-imaging

DOE PAGES

Li, Linsen; Chen-Wiegart, Yu-chen Karen; Wang, Jiajun; ...

2015-04-20

In situ techniques with high temporal, spatial and chemical resolution are key to understand ubiquitous solid-state phase transformations, which are crucial to many technological applications. Hard X-ray spectro-imaging can visualize electrochemically driven phase transformations but demands considerably large samples with strong absorption signal so far. Here we show a conceptually new data analysis method to enable operando visualization of mechanistically relevant weakly absorbing samples at the nanoscale and study electrochemical reaction dynamics of iron fluoride, a promising high-capacity conversion cathode material. In two specially designed samples with distinctive microstructure and porosity, we observe homogeneous phase transformations during both discharge andmore » charge, faster and more complete Li-storage occurring in porous polycrystalline iron fluoride, and further, incomplete charge reaction following a pathway different from conventional belief. In conclusion, these mechanistic insights provide guidelines for designing better conversion cathode materials to realize the promise of high-capacity lithium-ion batteries.« less

Chitosan, the Marine Functional Food, Is a Potent Adsorbent of Humic Acid

PubMed Central

Chen, Jeen-Kuan; Yeh, Chao-Hsien; Wang, Lian-Chen; Liou, Tzong-Horng; Shen, Chia-Rui; Liu, Chao-Lin

2011-01-01

Chitosan is prepared by the deacetylation of chitin, the second-most abundant biopolymer in nature, and has applicability in the removal of dyes, heavy metals and radioactive waste for pollution control. In weight-reduction remedies, chitosan is used to form hydrogels with lipids and to depress the intestinal absorption of lipids. In this study, an experimental method was implemented to simulate the effect of chitosan on the adsorption of humic acid in the gastrointestinal tract. The adsorption capacity of chitosan was measured by its adsorption isotherm and analyzed using the Langmuir equation. The results showed that 3.3 grams of humic acid was absorbed by 1 gram of chitosan. The adsorption capacity of chitosan was much greater than that of chitin, diethylaminoethyl-cellulose or activated charcoal. Cellulose and carboxymethyl-cellulose, a cellulose derivative with a negative charge, could not adsorb humic acid in the gastrointestinal tract. This result suggests that chitosan entraps humic acid because of its positive charge. PMID:22363235

Antioxidant Compound Extraction from Maqui (Aristotelia chilensis [Mol] Stuntz) Berries: Optimization by Response Surface Methodology

PubMed Central

Quispe-Fuentes, Issis; Vega-Gálvez, Antonio; Campos-Requena, Víctor H.

2017-01-01

The optimum conditions for the antioxidant extraction from maqui berry were determined using a response surface methodology. A three level D-optimal design was used to investigate the effects of three independent variables namely, solvent type (methanol, acetone and ethanol), solvent concentration and extraction time over total antioxidant capacity by using the oxygen radical absorbance capacity (ORAC) method. The D-optimal design considered 42 experiments including 10 central point replicates. A second-order polynomial model showed that more than 89% of the variation is explained with a satisfactory prediction (78%). ORAC values are higher when acetone was used as a solvent at lower concentrations, and the extraction time range studied showed no significant influence on ORAC values. The optimal conditions for antioxidant extraction obtained were 29% of acetone for 159 min under agitation. From the results obtained it can be concluded that the given predictive model describes an antioxidant extraction process from maqui berry.

Coupling Monte Carlo simulations with thermal analysis for correcting microdosimetric spectra from a novel micro-calorimeter

NASA Astrophysics Data System (ADS)

Fathi, K.; Galer, S.; Kirkby, K. J.; Palmans, H.; Nisbet, A.

2017-11-01

The high uncertainty in the Relative Biological Effectiveness (RBE) values of particle therapy beam, which are used in combination with the quantity absorbed dose in radiotherapy, together with the increase in the number of particle therapy centres worldwide necessitate a better understating of the biological effect of such modalities. The present novel study is part of performance testing and development of a micro-calorimeter based on Superconducting QUantum Interference Devices (SQUIDs). Unlike other microdosimetric detectors that are used for investigating the energy distribution, this detector provides a direct measurement of energy deposition at the micrometre scale, that can be used to improve our understanding of biological effects in particle therapy application, radiation protection and environmental dosimetry. Temperature rises of less than 1μK are detectable and when combined with the low specific heat capacity of the absorber at cryogenic temperature, extremely high energy deposition sensitivity of approximately 0.4 eV can be achieved. The detector consists of 3 layers: tissue equivalent (TE) absorber, superconducting (SC) absorber and silicon substrate. Ideally all energy would be absorbed in the TE absorber and heat rise in the superconducting layer would arise due to heat conduction from the TE layer. However, in practice direct particle absorption occurs in all 3 layers and must be corrected for. To investigate the thermal behaviour within the detector, and quantify any possible correction, particle tracks were simulated employing Geant4 (v9.6) Monte Carlo simulations. The track information was then passed to the COMSOL Multiphysics (Finite Element Method) software. The 3D heat transfer within each layer was then evaluated in a time-dependent model. For a statistically reliable outcome, the simulations had to be repeated for a large number of particles. An automated system has been developed that couples Geant4 Monte Carlo output to COMSOL for determining the expected distribution of proton tracks and their thermal contribution within the detector. The correction factor for a 3.8 MeV proton pencil beam was determined and applied to the expected spectra. The corrected microdosimetric spectra was shown to have a good agreement with the ideal spectra.

General design method of ultra-broadband perfect absorbers based on magnetic polaritons.

PubMed

Liu, Yuanbin; Qiu, Jun; Zhao, Junming; Liu, Linhua

2017-10-02

Starting from one-dimensional gratings and the theory of magnetic polaritons (MPs), we propose a general design method of ultra-broadband perfect absorbers. Based on the proposed design method, the obtained absorber can keep the spectrum-average absorptance over 99% at normal incidence in a wide range of wavelengths; this work simultaneously reveals the robustness of the absorber to incident angles and polarization angles of incident light. Furthermore, this work shows that the spectral band of perfect absorption can be flexibly extended to near the infrared regime by adjusting the structure dimension. The findings of this work may facilitate the active design of ultra-broadband absorbers based on plasmonic nanostructures.

Thermally-Resilient, Broadband Optical Absorber from UV-to-IR Derived from Carbon Nanostructures and Method of Making the Same

NASA Technical Reports Server (NTRS)

Kaul, Anupama B. (Inventor); Coles, James B. (Inventor)

2015-01-01

A monolithic optical absorber and methods of making same. The monolithic optical absorber uses an array of mutually aligned carbon nanotubes that are grown using a PECVD growth process and a structure that includes a conductive substrate, a refractory template layer and a nucleation layer. Monolithic optical absorbers made according to the described structure and method exhibit high absorptivity, high site densities (greater than 10.sup.9 nanotubes/cm.sup.2), very low reflectivity (below 1%), and high thermal stability in air (up to at least 400.degree. C.). The PECVD process allows the application of such absorbers in a wide variety of end uses.

Chemical and cellular antioxidant activity of phytochemicals purified from olive mill waste waters.

PubMed

Angelino, Donato; Gennari, Lorenzo; Blasa, Manuela; Selvaggini, Roberto; Urbani, Stefania; Esposto, Sonia; Servili, Maurizio; Ninfali, Paolino

2011-03-09

The isolation and identification of a phytocomplex from olive mill waste waters (OMWW) was achieved. The isolated phytocomplex is made up of the following three phenolic compounds: hydroxytyrosol (3,4-DHPEA), tyrosol (p-HPEA) and the dialdehydic form of decarboxymethyl elenolic acid, linked with (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA). The purification of this phytocomplex was reached by partial dehydration of the OMWW, followed by liquid-liquid extraction with ethyl acetate and middle pressure liquid chromatography (MPLC) on a Sephadex LH-20 column. The phytocomplex accounted for 6% of the total phenolic content of the OMWW. The phytocomplex and individual compounds were tested for antioxidant capacity by the oxygen radical absorbance capacity (ORAC) method. The ORAC phytocomplex produced 10,000 ORAC units/g dry weight, whereas the cellular antioxidant activity, measured by the cellular antioxidant activity in red blood cell (CAA-RBC) method, demonstrated that the phytocomplex and all of the components are able to permeate the cell membrane thus exhibiting antioxidant activity inside the red blood cells. Our phytocomplex could be employed in the formulation of fortified foods and nutraceuticals, with the goal to obtain substantial health protective effects due to the suitable combination of the component molecules.

Antioxidant and Anti-Osteoporosis Activities of Chemical Constituents of the Stems of Zanthoxylum piperitum.

PubMed

Yang, Seo Young; Lee, Sang-Hyun; Tai, Bui Huu; Jang, Hae-Dong; Kim, Young Ho

2018-02-18

Two new lignans, zanthoxyloside C ( 1 ) and zanthoxyloside D ( 2 ), together with nine known compounds comprising lignans ( 3 - 5 ), flavonoids ( 6 - 8 ), and phenolics ( 9 - 11 ), were isolated from the methanol extract of the stems of Zanthoxylum piperitum. All isolates were evaluated for their antioxidant and anti-osteoporotic activities using oxygen radical absorbance capacity (ORAC), cupric reducing antioxidant capacity (CUPRAC), and tartrate-resistant acid phosphatase (TRAP) assays. Compounds 7 - 10 showed peroxyl radical-scavenging capacities and 4 , 6 - 7 , and 9 showed reducing capacities. Moreover, compounds 3 , 6 - 9 , and 11 significantly suppressed TRAP activities. These results indicated that the stems of Z. piperitum could be an excellent source for natural antioxidant and anti-osteoporosis.

Anomalous electronic heat capacity of copper nanowires at sub-Kelvin temperatures

NASA Astrophysics Data System (ADS)

Viisanen, K. L.; Pekola, J. P.

2018-03-01

We have measured the electronic heat capacity of thin film nanowires of copper and silver at temperatures 0.1-0.3 K; the films were deposited by standard electron-beam evaporation. The specific heat of the Ag films of sub-100-nm thickness agrees with the bulk value and the free-electron estimate, whereas that of similar Cu films exceeds the corresponding reference values by one order of magnitude. The origin of the anomalously high heat capacity of copper films remains unknown for the moment. Based on the small heat capacity at low temperatures and the possibility to devise a tunnel probe thermometer on it, metal films form a promising absorber material, e.g., for microwave photon calorimetry.

Method of Synthesizing a Novel Absorbent Titanosilicate Material (UPRM-5)

NASA Technical Reports Server (NTRS)

Hernandez-Maldonado, Arturo (Inventor); Primera-Pedrozo, Jose N (Inventor)

2013-01-01

A titanium silicate variant named UPRM-5 was prepared using tetraethylammonium hydroxide as a structure-directing agent (SDA). Successful detemplation was achieved via ion exchange with NH4Cl. Effective functionalization was obtained after ion exchanging the detemplated material using SrCl2 and BaCl2. Adsorption of CO2 at 25 deg C in Sr(-) and Ba-UPRM-5 materials activated at different temperatures. For low partial pressures, the observed CO2 adsorption capacities increased as follows: NH4-UPRM-5 less than Sr-UPRM-5 less than Ba-UPRM-5. Both the Sr(-) and Ba-UPRM-5 materials exhibited outstanding selectivity for CO2 over CH4, N2 and O2.

Protein determination: a comparison of several methods.

PubMed

Hocman, G; Palkovic, M

1977-01-01

A comparison of four methods for the determination of total proteins is presented from the following points of view: - sensitivity; - specificity; - amount of work, chemicals, time and equipment needed for the performance of the determination. The following tests have been examined; Tombs' (absorbancy at 210 nm); Waddell's (difference in absorbancy between 215 and 225 nm); Warburg's (absorbancy at 280 nm); Lowry's (absorbancy at 500 nm after the reaction with phenol reagent). The authors recommend Tombs' method for its outstanding sensitivity, specificity and simplicity as the best of the four.

Use of a New Simltaneous Absorbance-Fluorescene Instrument to Monitor Hydraluic Fracture Mining Waste Water to Prevent Drinking Water Contamination

NASA Astrophysics Data System (ADS)

Gilmore, A. M.

2013-05-01

Recently, the issue of waste water effuse from oil and gas mining, especially that including hydraulic fracturing, has resurfaced on the news and the political atmosphere as an area of concern. One of the key concerns is drinking water contamination from the hydraulic fracturing chemicals and chemicals contained in the water introduced into the well at high-pressure and the flowback and produced water associate with the petroleum product extraction. The key to successfully meeting drinking water safety requirements lies in the drinking water treatment plant's ability to deal with often dramatic source-water variations in natural organic matter (NOM) content that can react during disinfection with high levels of chloride and bromide found in hydraulic facture waste water to form toxc disinfection by-products (DBPs). Importantly, the brominated DBP species are particularly dangerous. Whereas the regulated levels of NOM can roughly determined by measuring total organic carbon (TOC), often this parameter does not provide rapid or cost-effective qualitative or quantitative assessment of the various humic, fulvic and other aromatic NOM components associated with DBP formation. However, two main optical techniques namely UV absorbance and fluorescence excitation-emission mapping can be used for rapid assessment with precise identification of humic and fulvic components that cause DBPs. This study presents data from a new type of instrument which simultaneously measures the UV-VIS absorbance spectrum and EEM. The rapid absorbance-EEM is facilitated by a single system that is more than 100 time faster than conventional scanning absorbance and fluorescence optical benches. The new system can continuously collect EEMs and absorbance spectra at a rate often greater than 1 per min with the extra capacity to monitor the UV254 absorbance and fluorescence emission spectrum excited at 254 nm in 4 ms intervals (an equivalent scan rate of 5.5 million nm/min). The EEM spectral data is corrected for all instrumental response factors including concentration dependent inner-filter effects. The accumulated EEM data sets can be modeled using conventional peak identification, PARAFAC and or PCA analysis of the fractionated samples to predict the trihalomethane forming potential (THMFP). Moreover, the instrument and methods can be used to identify and quantify hundreds of chemicals including oils, PAHs and other key chemicals of concern from hydraulic fracturing practices.

CO2: Adsorption on palagonite and the Martian regolith

NASA Technical Reports Server (NTRS)

Zent, Aaron P.; Fanale, Fraser P.; Postawko, Susan E.

1987-01-01

Possible scenarios for the evolution of the Martian climate are discussed. In the interest of determining an upper limit on the absorptive capacity of the Martian regolith, researchers examined the results of Fanale and Cannon (1971, 1974) for CO2 adsorption on nontronite and basalt. There appeared to be a strong proportionality between the capacity of the absorbent and its specific surface area. A model of the Martian climate is given that allows the researchers to make some estimates of exchangeable CO2 abundances.

Superb electromagnetic wave-absorbing composites based on large-scale graphene and carbon nanotube films.

PubMed

Li, Jinsong; Lu, Weibang; Suhr, Jonghwan; Chen, Hang; Xiao, John Q; Chou, Tsu-Wei

2017-05-24

Graphene has sparked extensive research interest for its excellent physical properties and its unique potential for application in absorption of electromagnetic waves. However, the processing of stable large-scale graphene and magnetic particles on a micrometer-thick conductive support is a formidable challenge for achieving high reflection loss and impedance matching between the absorber and free space. Herein, a novel and simple approach for the processing of a CNT film-Fe 3 O 4 -large scale graphene composite is studied. The Fe 3 O 4 particles with size in the range of 20-200 nm are uniformly aligned along the axial direction of the CNTs. The composite exhibits exceptionally high wave absorption capacity even at a very low thickness. Minimum reflection loss of -44.7 dB and absorbing bandwidth of 4.7 GHz at -10 dB are achieved in composites with one-layer graphene in six-layer CNT film-Fe 3 O 4 prepared from 0.04 M FeCl 3 . Microstructural and theoretical studies of the wave-absorbing mechanism reveal a unique Debye dipolar relaxation with an Eddy current effect in the absorbing bandwidth.

Capacity and degree of iodine absorbed and enriched by vegetable from soil.

PubMed

Weng, Huan-Xin; Weng, Jing-Ke; Yong, Wen-Bin; Sun, Xiang-Wu; Zhong, Hang

2003-01-01

To understand the biogeochemical transfer of iodine, the absorbability and bioaccumulation of iodine in tested vegetables (radish, spinach and Chinese cabbage) are examined by applying iodic fertilizer composed of kelp and diatomaceous earth. The experimental results show that when iodine in soil is not excessive, the concentrations of iodine in tested vegetables increase as the content of iodine in soil increases. The absorbability and enrichment degree of iodine in various vegetables and in various parts of the same vegetable a redifferent, which explains that the concentration of iodine in plant is determined by the plant type and the physiological action of plant. The patience order of tested vegetables to excessive iodine is Chinese cabbage > spinach > radish. These results have theoretical and practical significance in opening up a new way for ameliorating poor iodine environment with artificial means.

Method of absorbing UF.sub.6 from gaseous mixtures in alkamine absorbents

DOEpatents

Lafferty, Robert H.; Smiley, Seymour H.; Radimer, Kenneth J.

1976-04-06

A method of recovering uranium hexafluoride from gaseous mixtures employing as an absorbent a liquid composition at least one of the components of which is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2.

Alkaline extraction of phenolic compounds from intact sorghum kernels

USDA-ARS?s Scientific Manuscript database

An aqueous sodium hydroxide solution was employed to extract phenolic compounds from whole grain sorghum without decortication or grinding as determined by Oxygen Radical Absorbance Capacity (ORAC). The alkaline extract ORAC values were more stable over 32 days compared to neutralized and freeze dri...

Heavy metal absorbing Thioether-functionalized ligands derived from vegetable oils

USDA-ARS?s Scientific Manuscript database

Sulfur-functionalized vegetable oils containing thioether groups have been shown to effectively remove Ag+ from aqueous solution. Interestingly, the absorption capacity differs depending upon the choice of which vegetable oil precursor is functionalized. In this study, we will provide data for oils ...

Miniaturized and direct spectrophotometric multi-sample analysis of trace metals in natural waters.

PubMed

Albendín, Gemma; López-López, José A; Pinto, Juan J

2016-03-15

Trends in the analysis of trace metals in natural waters are mainly based on the development of sample treatment methods to isolate and pre-concentrate the metal from the matrix in a simpler extract for further instrumental analysis. However, direct analysis is often possible using more accessible techniques such as spectrophotometry. In this case a proper ligand is required to form a complex that absorbs radiation in the ultraviolet-visible (UV-Vis) spectrum. In this sense, the hydrazone derivative, di-2-pyridylketone benzoylhydrazone (dPKBH), forms complexes with copper (Cu) and vanadium (V) that absorb light at 370 and 395 nm, respectively. Although spectrophotometric methods are considered as time- and reagent-consuming, this work focused on its miniaturization by reducing the volume of sample as well as time and cost of analysis. In both methods, a micro-amount of sample is placed into a microplate reader with a capacity for 96 samples, which can be analyzed in times ranging from 5 to 10 min. The proposed methods have been optimized using a Box-Behnken design of experiments. For Cu determination, concentration of phosphate buffer solution at pH 8.33, masking agents (ammonium fluoride and sodium citrate), and dPKBH were optimized. For V analysis, sample (pH 4.5) was obtained using acetic acid/sodium acetate buffer, and masking agents were ammonium fluoride and 1,2-cyclohexanediaminetetraacetic acid. Under optimal conditions, both methods were applied to the analysis of certified reference materials TMDA-62 (lake water), LGC-6016 (estuarine water), and LGC-6019 (river water). In all cases, results proved the accuracy of the method. Copyright © 2015 Elsevier Inc. All rights reserved.

Container and method for absorbing and reducing hydrogen concentration

DOEpatents

Wicks, George G.; Lee, Myung W.; Heung, Leung K.

2001-01-01

A method for absorbing hydrogen from an enclosed environment comprising providing a vessel; providing a hydrogen storage composition in communication with a vessel, the hydrogen storage composition further comprising a matrix defining a pore size which permits the passage of hydrogen gas while blocking the passage of gaseous poisons; placing a material within the vessel, the material evolving hydrogen gas; sealing the vessel; and absorbing the hydrogen gas released into the vessel by the hydrogen storage composition. A container for absorbing evolved hydrogen gas comprising: a vessel having an interior and adapted for receiving materials which release hydrogen gas; a hydrogen absorbing composition in communication with the interior, the composition defining a matrix surrounding a hydrogen absorber, the matrix permitting the passage of hydrogen gas while excluding gaseous poisons; wherein, when the vessel is sealed, hydrogen gas, which is released into the vessel interior, is absorbed by the hydrogen absorbing composition.

Study on the millimeter-wave scale absorber based on the Salisbury screen

NASA Astrophysics Data System (ADS)

Yuan, Liming; Dai, Fei; Xu, Yonggang; Zhang, Yuan

2018-03-01

In order to solve the problem on the millimeter-wave scale absorber, the Salisbury screen absorber is employed and designed based on the RL. By optimizing parameters including the sheet resistance of the surface resistive layer, the permittivity and the thickness of the grounded dielectric layer, the RL of the Salisbury screen absorber could be identical with that of the theoretical scale absorber. An example is given to verify the effectiveness of the method, where the Salisbury screen absorber is designed by the proposed method and compared with the theoretical scale absorber. Meanwhile, plate models and tri-corner reflector (TCR) models are constructed according to the designed result and their scattering properties are simulated by FEKO. Results reveal that the deviation between the designed Salisbury screen absorber and the theoretical scale absorber falls within the tolerance of radar Cross section (RCS) measurement. The work in this paper has important theoretical and practical significance in electromagnetic measurement of large scale ratio.

Development of arrays of position-sensitive microcalorimeters for Constellation-X

NASA Astrophysics Data System (ADS)

Smith, Stephen J.; Bandler, Simon R.; Brekosky, Regis P.; Brown, Ari-D.; Chervenak, James A.; Eckart, Megan E.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, F. Scott; Sadleir, John E.

2008-07-01

We are developing arrays of position-sensitive transition-edge sensor (PoST) X-ray detectors for future astronomy missions such as NASA's Constellation-X. The PoST consists of multiple absorbers thermally coupled to one or more transition-edge sensor (TES). Each absorber element has a different thermal coupling to the TES. This results in a distribution of different pulse shapes and enables position discrimination between the absorber elements. PoST's are motivated by the desire to achieve the largest possible focal plane area with the fewest number of readout channels and are ideally suited to increasing the Constellation-X focal plane area, without comprising on spatial sampling. Optimizing the performance of PoST's requires careful design of key parameters such as the thermal conductances between the absorbers, TES and the heat sink, as well as the absorber heat capacities. Our new generation of PoST's utilizes technology successfully developed on high resolution (~ 2.5 eV) single pixels arrays of Mo/Au TESs, also under development for Constellation-X. This includes noise mitigation features on the TES and low resistivity electroplated absorbers. We report on the first experimental results from new one-channel, four-pixel, PoST's or 'Hydras', consisting of composite Au/Bi absorbers. We have achieved full-width-at-half-maximum energy resolution of between 5-6 eV on all four Hydra pixels with an exponential decay time constant of 620 μs. Straightforward position discrimination by means of rise time is also demonstrated.

Multilayer graphene-based metasurfaces: robust design method for extremely broadband, wide-angle, and polarization-insensitive terahertz absorbers.

PubMed

Rahmanzadeh, Mahdi; Rajabalipanah, Hamid; Abdolali, Ali

2018-02-01

In this study, by using an equivalent circuit method, a polarization-insensitive terahertz (THz) absorber based on multilayer graphene-based metasurfaces (MGBMs) is systematically designed, providing an extremely broad absorption bandwidth (BW). The proposed absorber is a compact, three-layer structure, comprising square-, cross-, and circular-shaped graphene metasurfaces embedded between three separator dielectrics. The equivalent-conductivity method serves as a parameter retrieval technique to characterize the graphene metasurfaces as the components of the proposed circuit model. Good agreement is observed between the full-wave simulations and the equivalent-circuit predictions. The optimum MGBM absorber exhibits >90% absorbance in an extremely broad frequency band of 0.55-3.12 THz (BW=140%). The results indicate a significant BW enhancement compared with both the previous metal- and graphene-based THz absorbers, highlighting the capability of the designed MGBM absorber. To clarify the physical mechanism of absorption, the surface current and the electric-field distributions, as well as the power loss density of each graphene metasurface, are monitored and discussed. The MGBM functionality is evaluated under a wide range of incident wave angles to prove that the proposed absorber is omnidirectional and polarization-insensitive. These superior performances guarantee the applicability of the MGBM structure as an ultra-broadband absorber for various THz applications.

The additive properties of Oxygen Radical Absorbance Capacity (ORAC) assay: the case of essential oils.

PubMed

Bentayeb, Karim; Vera, Paula; Rubio, Carlos; Nerín, Cristina

2014-04-01

The ORAC assay is applied to measure the antioxidant capacity of foods or dietary supplements. Sometimes, the manufacturers claim antioxidant capacities that may not correspond to the constituents of the product. These statements are sheltered by the general understanding that antioxidants might exhibit synergistic properties, but this is not necessarily true when dealing with ORAC assay values. This contribution applies the ORAC assay to measure the antioxidant capacity of ten essential oils typically added to foodstuffs: citronella, dill, basil, red thyme, thyme, rosemary, oregano, clove and cinnamon. The major components of these essential oils were twenty-one chemicals in total. After a preliminary discrimination, the antioxidant capacity of eugenol, carvacrol, thymol, α-pinene, limonene and linalool was determined. The results showed that 72-115% of the antioxidant capacity of the essential oils corresponded to the addition of the antioxidant capacity of their constituents. Thus, the ORAC assay showed additive properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made from Camellia sinensis in China

PubMed Central

Zhao, Chunjian; Li, Chunying; Liu, Shuaihua; Yang, Lei

2014-01-01

Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R 2 = 0.67–0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG). PMID:25243234

High-strain rate tensile characterization of graphite platelet reinforced vinyl ester based nanocomposites using split-Hopkinson pressure bar

NASA Astrophysics Data System (ADS)

Pramanik, Brahmananda

The dynamic response of exfoliated graphite nanoplatelet (xGnP) reinforced and carboxyl terminated butadiene nitrile (CTBN) toughened vinyl ester based nanocomposites are characterized under both dynamic tensile and compressive loading. Dynamic direct tensile tests are performed applying the reverse impact Split Hopkinson Pressure Bar (SHPB) technique. The specimen geometry for tensile test is parametrically optimized by Finite Element Analysis (FEA) using ANSYS Mechanical APDLRTM. Uniform stress distribution within the specimen gage length has been verified using high-speed digital photography. The on-specimen strain gage installation is substituted by a non-contact Laser Occlusion Expansion Gage (LOEG) technique for infinitesimal dynamic tensile strain measurements. Due to very low transmitted pulse signal, an alternative approach based on incident pulse is applied for obtaining the stress-time history. Indirect tensile tests are also performed combining the conventional SHPB technique with Brazilian disk test method for evaluating cylindrical disk specimens. The cylindrical disk specimen is held snugly in between two concave end fixtures attached to the incident and transmission bars. Indirect tensile stress is estimated from the SHPB pulses, and diametrical transverse tensile strain is measured using LOEG. Failure diagnosis using high-speed digital photography validates the viability of utilizing this indirect test method for characterizing the tensile properties of the candidate vinyl ester based nanocomposite system. Also, quasi-static indirect tensile response agrees with previous investigations conducted using the traditional dog-bone specimen in quasi-static direct tensile tests. Investigation of both quasi-static and dynamic indirect tensile test responses show the strain rate effect on the tensile strength and energy absorbing capacity of the candidate materials. Finally, the conventional compressive SHPB tests are performed. It is observed that both strength and energy absorbing capacity of these candidate material systems are distinctively less under dynamic tension than under compressive loading. Nano-reinforcement appears to marginally improve these properties for pure vinyl ester under dynamic tension, although it is found to be detrimental under dynamic compression.

SORPTION, DIFFUSION AND PERMEATION OF 1,1,1- TRICHLOROETHANE THROUGH ADSORBENT-FILLED POLYMERIC MEMBRANES

EPA Science Inventory

Addition of hydrophobic absorbents such as activated carbon into polymeric mebranes increased the sorption capacity for 1,1,1-trichloroethane premeability of the mebranes used in the Pervaporation mode. Water permeability also increased for all filled membranes due to increased w...

Research on calorimeter for high-power microwave measurements

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

Ye, Hu; Ning, Hui; Yang, Wensen

2015-12-15

Based on measurement of the volume increment of polar liquid that is a result of heating by absorbed microwave energy, two types of calorimeters with coaxial capacitive probes for measurement of high-power microwave energy are designed in this paper. The first is an “inline” calorimeter, which is placed as an absorbing load at the end of the output waveguide, and the second is an “offline” calorimeter that is placed 20 cm away from the radiation horn of the high-power microwave generator. Ethanol and high density polyethylene are used as the absorbing and housing materials, respectively. Results from both simulations andmore » a “cold test” on a 9.3 GHz klystron show that the “inline” calorimeter has a measurement range of more than 100 J and an energy absorption coefficient of 93%, while the experimental results on a 9.3 GHz relativistic backward-wave oscillator show that the device’s power capacity is approximately 0.9 GW. The same experiments were also carried out for the “offline” calorimeter, and the results indicate that it can be used to eliminate the effects of the shock of the solenoid on the measurement curves and that the device has a higher power capacity of 2.5 GW. The results of the numerical simulations, the “cold tests,” and the experiments show good agreement.« less

Silicon nitride Micromesh Bolometer Array for Submillimeter Astrophysics.

PubMed

Turner, A D; Bock, J J; Beeman, J W; Glenn, J; Hargrave, P C; Hristov, V V; Nguyen, H T; Rahman, F; Sethuraman, S; Woodcraft, A L

2001-10-01

We present the design and performance of a feedhorn-coupled bolometer array intended for a sensitive 350-mum photometer camera. Silicon nitride micromesh absorbers minimize the suspended mass and heat capacity of the bolometers. The temperature transducers, neutron-transmutation-doped Ge thermistors, are attached to the absorber with In bump bonds. Vapor-deposited electrical leads address the thermistors and determine the thermal conductance of the bolometers. The bolometer array demonstrates a dark noise-equivalent power of 2.9 x 10(-17) W/ radicalHz and a mean heat capacity of 1.3 pJ/K at 390 mK. We measure the optical efficiency of the bolometer and feedhorn to be 0.45-0.65 by comparing the response to blackbody calibration sources. The bolometer array demonstrates theoretical noise performance arising from the photon and the phonon and Johnson noise, with photon noise dominant under the design background conditions. We measure the ratio of total noise to photon noise to be 1.21 under an absorbed optical power of 2.4 pW. Excess noise is negligible for audio frequencies as low as 30 mHz. We summarize the trade-offs between bare and feedhorn-coupled detectors and discuss the estimated performance limits of micromesh bolometers. The bolometer array demonstrates the sensitivity required for photon noise-limited performance from a spaceborne, passively cooled telescope.

Characterization and identification of microorganisms by FT-IR microspectrometry

NASA Astrophysics Data System (ADS)

Ngo-Thi, N. A.; Kirschner, C.; Naumann, D.

2003-12-01

We report on a novel FT-IR approach for microbial characterization/identification based on a light microscope coupled to an infrared spectrometer which offers the possibility to acquire IR-spectra of microcolonies containing only few hundred cells. Microcolony samples suitable for FT-IR microspectroscopic measurements were obtained by a replica technique with a stamping device that transfers spatially accurate cells of microcolonies growing on solid culture plates to a special, IR-transparent or reflecting stamping plate. High quality spectra could be recorded either by applying the transmission/absorbance or the reflectance/absorbance mode of the infrared microscope. Signal to noise ratios higher than 1000 were obtained for microcolonies as small as 40 μm in diameter. Reproducibility levels were established that allowed species and strain identification. The differentiation and classification capacity of the FT-IR microscopic technique was tested for different selected microorganisms. Cluster and factor analysis methods were used to evaluate the complex spectral data. Excellent discrimination between bacteria and yeasts, and at the same time Gram-negative and Gram-positive bacterial strains was obtained. Twenty-two selected strains of different species within the genus Staphylococcus were repetitively measured and could be grouped into correct species cluster. Moreover, the results indicated that the method allows also identifications at the subspecies level. Additionally, the new approach allowed spectral mapping analysis of single colonies which provided spatially resolved characterization of growth heterogeneity within complex microbial populations such as colonies.

An improved method for determination of refractive index of absorbing films: A simulation study

NASA Astrophysics Data System (ADS)

Özcan, Seçkin; Coşkun, Emre; Kocahan, Özlem; Özder, Serhat

2017-02-01

In this work an improved version of the method presented by Gandhi was presented for determination of refractive index of absorbing films. In this method local maxima of consecutive interference order in transmittance spectrum are used. The method is based on the minimizing procedure leading to the determination of interference order accurately by using reasonable Cauchy parameters. It was tested on theoretically generated transmittance spectrum of absorbing film and the details of the minimization procedure were discussed.

Chemical evaluation, antioxidant capacity, and consumer acceptance of several oak infusions.

PubMed

Rocha-Guzmán, Nuria Elizabeth; Medina-Medrano, Jose Roberto; Gallegos-Infante, José Alberto; Gonzalez-Laredo, Rubén Francisco; Ramos-Gómez, Minerva; Reynoso-Camacho, Rosalía; Guzmán-Maldonado, Horacio; González-Herrera, Silvia Marina

2012-02-01

As part of an ongoing screening on natural products, 4 oak leaves were analyzed as potential nutraceutical beverages. The phenolic composition, antioxidant capacity, and sensory preferences of leaves infusions from Quercus resinosa, Q. sideroxyla, Q. eduadii, and Q. durifolia in comparison with 2 commercial green teas were investigated. Herbal infusions from oak leaves and Green teas (1%, 80 °C, 10 min) were evaluated for total polyphenol content (TPC), total flavonoid content (TFC), HPLC analysis, trolox equivalent antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC), soluble solids, pH, color, and consumer preference analysis. Q. resinosa leaves infusions have shown the highest TPC, TEAC, and ORAC values but they have attained the lowest preference score. Quercus leaves infusions with higher content of gallic acid and catechins showed best antioxidant capacity but lower consumer preference. © 2012 Institute of Food Technologists®

Potential Water Retention Capacity as a Factor in Silage Effluent Control: Experiments with High Moisture By-product Feedstuffs.

PubMed

Razak, Okine Abdul; Masaaki, Hanada; Yimamu, Aibibula; Meiji, Okamoto

2012-04-01

The role of moisture absorptive capacity of pre-silage material and its relationship with silage effluent in high moisture by-product feedstuffs (HMBF) is assessed. The term water retention capacity which is sometimes used in explaining the rate of effluent control in ensilage may be inadequate, since it accounts exclusively for the capacity of an absorbent incorporated into a pre-silage material prior to ensiling, without consideration to how much the pre-silage material can release. A new terminology, 'potential water retention capacity' (PWRC), which attempts to address this shortcoming, is proposed. Data were pooled from a series of experiments conducted separately over a period of five years using laboratory silos with four categories of agro by-products (n = 27) with differing moisture contents (highest 96.9%, lowest 78.1% in fresh matter, respectively), and their silages (n = 81). These were from a vegetable source (Daikon, Raphanus sativus), a root tuber source (potato pulp), a fruit source (apple pomace) and a cereal source (brewer's grain), respectively. The pre-silage materials were adjusted with dry in-silo absorbents consisting wheat straw, wheat or rice bran, beet pulp and bean stalks. The pooled mean for the moisture contents of all pre-silage materials was 78.3% (±10.3). Silage effluent decreased (p<0.01), with increase in PWRC of pre-silage material. The theoretical moisture content and PWRC of pre-silage material necessary to stem effluent flow completely in HMBF silage was 69.1% and 82.9 g/100 g in fresh matter, respectively. The high correlation (r = 0.76) between PWRC of ensiled material and silage effluent indicated that the latter is an important factor in silage-effluent relationship.

Numerical study for identification of influence of energy absorption and frontal crush for vehicle crashworthiness

NASA Astrophysics Data System (ADS)

Suman, Shwetabh; Shah, Haard; Susarla, Vaibhav; Ravi, K.

2017-11-01

According to the statistics it has been seen that everyday nearly 400 people are killed due to road accidents. Due to this it has become an important concern to concentrate on the safety of the passengers which can be done by improving the crashworthiness of the vehicle. During the impact, a large amount of energy is released which if not absorbed, will be transmitted to the passenger compartment. For the safety of the passenger this energy has to be absorbed. Front rail is one of the main energy absorbing components in the vehicle front structure. When it comes to the structure and material of the part or component of the vehicle that is to be designed for crash, it is done based on three parameters: Specific Energy of Absorption, Mass of the front rail and maximum crush force. In this work, we are considering different internal geometries with different materials to increase the energy absorbing capacity of the front rail. Based on the extensive analysis carried aluminium seizes to be the opt material for frontal crash.

Time-dependent photon migration imaging

NASA Astrophysics Data System (ADS)

Sevick, Eva M.; Wang, NaiGuang; Chance, Britton

1992-02-01

Recently, the application of both time- and frequency-resolved fluorescence techniques for the determination of photon migration characteristics in strongly scattering media has been used to characterize the optical properties in strongly scattering media. Specifically, Chance and coworkers have utilized measurement of photon migration characteristics to determine tissue hemoglobin absorbance and ultimately oxygenation status in homogeneous tissues. In this study, we present simulation results and experimental measurements for both techniques to show the capacity of time-dependent photon migration characteristics to image optically obscure absorbers located in strongly scattering media. The applications of time-dependent photon imaging in the biomedical community include imaging of light absorbing hematomas, tumors, hypoxic tissue volumes, and other tissue abnormalities. Herein, we show that the time-resolved parameter of mean photon path length, , and the frequency- resolved parameter of phase-shift, (theta) , can be used similarly to obtain three dimensional information of absorber position from two-dimensional measurements. Finally, we show that unlike imaging techniques that monitor the intensity of light without regard to the migration characteristics, the resolution of time-dependent photon migration measurements is enhanced by tissue scattering, further potentiating their use for biomedical imaging.

An antibacterial and absorbable silk-based fixation material with impressive mechanical properties and biocompatibility

NASA Astrophysics Data System (ADS)

Shi, Chenglong; Pu, Xiaobing; Zheng, Guan; Feng, Xinglong; Yang, Xuan; Zhang, Baoliang; Zhang, Yu; Yin, Qingshui; Xia, Hong

2016-11-01

Implant-associated infections and non-absorbing materials are two important reasons for a second surgical procedure to remove internal fixation devices after an orthopedic internal fixation surgery. The objective of this study was to produce an antibacterial and absorbable fixation screw by adding gentamicin to silk-based materials. The antibacterial activity was assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in vitro by plate cultivation and scanning electron microscopy (SEM). We also investigated the properties, such as the mechanical features, swelling properties, biocompatibility and degradation, of gentamicin-loaded silk-based screws (GSS) in vitro. The GSS showed significant bactericidal effects against S. aureus and E. coli. The antibacterial activity remained high even after 4 weeks of immersion in protease solution. In addition, the GSS maintained the remarkable mechanical properties and excellent biocompatibility of pure silk-based screws (PSS). Interestingly, after gentamicin incorporation, the degradation rate and water-absorbing capacity increased and decreased, respectively. These GSS provide both impressive material properties and antibacterial activity and have great potential for use in orthopedic implants to reduce the incidence of second surgeries.

Reconsidering Language Orientation for Undergraduate Singers

ERIC Educational Resources Information Center

Paver, Barbara E.

2009-01-01

Foreign language lyric diction is a compulsory subject in all undergraduate vocal performance degrees in universities. However, the effectiveness of its teaching depends on the capacity of students to absorb the material, for which many are largely unprepared, due to their lack of previous language study. Further, native speakers of North American…

Electrically tunable metasurface perfect absorbers for ultrathin mid-infrared optical modulators.

PubMed

Yao, Yu; Shankar, Raji; Kats, Mikhail A; Song, Yi; Kong, Jing; Loncar, Marko; Capasso, Federico

2014-11-12

Dynamically reconfigurable metasurfaces open up unprecedented opportunities in applications such as high capacity communications, dynamic beam shaping, hyperspectral imaging, and adaptive optics. The realization of high performance metasurface-based devices remains a great challenge due to very limited tuning ranges and modulation depths. Here we show that a widely tunable metasurface composed of optical antennas on graphene can be incorporated into a subwavelength-thick optical cavity to create an electrically tunable perfect absorber. By switching the absorber in and out of the critical coupling condition via the gate voltage applied on graphene, a modulation depth of up to 100% can be achieved. In particular, we demonstrated ultrathin (thickness < λ0/10) high speed (up to 20 GHz) optical modulators over a broad wavelength range (5-7 μm). The operating wavelength can be scaled from the near-infrared to the terahertz by simply tailoring the metasurface and cavity dimensions.

Dynamic tuning of optical absorbers for accelerated solar-thermal energy storage.

PubMed

Wang, Zhongyong; Tong, Zhen; Ye, Qinxian; Hu, Hang; Nie, Xiao; Yan, Chen; Shang, Wen; Song, Chengyi; Wu, Jianbo; Wang, Jun; Bao, Hua; Tao, Peng; Deng, Tao

2017-11-14

Currently, solar-thermal energy storage within phase-change materials relies on adding high thermal-conductivity fillers to improve the thermal-diffusion-based charging rate, which often leads to limited enhancement of charging speed and sacrificed energy storage capacity. Here we report the exploration of a magnetically enhanced photon-transport-based charging approach, which enables the dynamic tuning of the distribution of optical absorbers dispersed within phase-change materials, to simultaneously achieve fast charging rates, large phase-change enthalpy, and high solar-thermal energy conversion efficiency. Compared with conventional thermal charging, the optical charging strategy improves the charging rate by more than 270% and triples the amount of overall stored thermal energy. This superior performance results from the distinct step-by-step photon-transport charging mechanism and the increased latent heat storage through magnetic manipulation of the dynamic distribution of optical absorbers.

Integrated Microcalorimeters Using Ir TES And Sn Mushroom Absorbers

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

Chen, C.; Bogorin, D.; Galeazzi, M.

2006-09-07

Cryogenic microcalorimeters have the potential to meet the requirements of future x-ray missions. The University of Miami has recently started a program to fabricate fully integrated microcalorimeter arrays. We deposit high purity iridium thin film as Transition Edge Sensors (TES). We chose iridium because it has a bulk transition temperature of 112 mK and we expect single layer TES to have good reproducibility and long term stability. Also we use integrated tin film in a mushroom geometry as the absorbers to get high filling factor, low heat capacity and easy array manufacturing process. We present here our preliminary results inmore » both areas.« less

Using tea stalk lignocellulose as an adsorbent for separating decaffeinated tea catechins.

PubMed

Ye, J H; Jin, J; Liang, H L; Lu, J L; Du, Y Y; Zheng, X Q; Liang, Y R

2009-01-01

Lignocelluloses prepared from woody tea stalk, pine sawdust and sugarcane bagasse were used as adsorbents to isolate decaffeinated catechins from tea extracts and compared with synthetic macroporous resin HPD 600. HPD 600 had the highest adsorption capacity to catechins, followed by tea stalk lignocellulose while lignocelluloses of pine sawdust and bagasse the least. Tea stalk lignocellulose absorbed preferentially tea catechins and showed a good selectivity. HPD 600 absorbed caffeine and tea catechins simultaneously. The kinetics data of tea stalk lignocellulose showed a good fit with the Langmuir isotherm model. It is considered that tea stalk lignocellulose is an alternative low-cost adsorbent for preparing decaffeinated tea catechins.

The effect of filler addition and oven temperature to the antioxidant quality in the drying of Physalis angulata fruit extract obtained by subcritical water extraction

NASA Astrophysics Data System (ADS)

Susanti, R. F.; Christianto, G.

2016-01-01

Physalis angulata or ceplukan is medicinal herb, which grows naturally in Indonesia. It has been used in traditional medicine to treat several diseases. It is also reported to have antimycobacterial, antileukemic, antipyretic. In this research, Pysalis angulata fruit was investigated for its antioxidant capacity. In order to avoid the toxic organic solvent commonly used in conventional extraction, subcritical water extraction method was used. During drying, filler which is inert was added to the extract. It can absorb water and change the oily and sticky form of extract to powder form. The effects of filler types, concentrations and drying temperatures were investigated to the antioxidant quality covering total phenol, flavonoid and antioxidant activity. The results showed that total phenol, flavonoid and antioxidant activity were improved by addition of filler because the drying time was shorter compared to extract without filler. Filler absorbs water and protects extract from exposure to heat during drying. The combination between high temperature and shorter drying time are beneficial to protect the antioxidant in extract. The type of fillers investigation showed that aerosil gave better performance compared to Microcrystalline Celullose (MCC).

Suitability of optical, physical and chemical measurements for detection of changes in bacterial drinking water quality.

PubMed

Ikonen, Jenni; Pitkänen, Tarja; Miettinen, Ilkka T

2013-10-25

In this study, different optical, physical and chemical measurements were tested for their capacity to detect changes in water quality. The tests included UV-absorbance at 254 nm, absorbance at 420 nm, turbidity, particle counting, temperature, pH, electric conductivity (EC), free chlorine concentration and ATP concentration measurements. Special emphasis was given to investigating the potential for measurement tools to detect changes in bacterial concentrations in drinking water. Bacterial colony counts (CFU) and total bacterial cell counts (TBC) were used as reference methods for assessing the bacterial water quality. The study consists of a series of laboratory scale experiments: monitoring of regrowth of Pseudomonas fluorescens, estimation of the detection limits for optical measurements using Escherichia coli dilutions, verification of the relationships by analysing grab water samples from various distribution systems and utilisation of the measurements in the case of an accidentally contaminated distribution network. We found significant correlations between the tested measurements and the bacterial water quality. As the bacterial contamination of water often co-occurs with the intrusion of matrixes containing mainly non-bacterial components, the tested measurement tools can be considered to have the potential to rapidly detect any major changes in drinking water quality.

Suitability of Optical, Physical and Chemical Measurements for Detection of Changes in Bacterial Drinking Water Quality

PubMed Central

Ikonen, Jenni; Pitkänen, Tarja; Miettinen, Ilkka T.

2013-01-01

In this study, different optical, physical and chemical measurements were tested for their capacity to detect changes in water quality. The tests included UV-absorbance at 254 nm, absorbance at 420 nm, turbidity, particle counting, temperature, pH, electric conductivity (EC), free chlorine concentration and ATP concentration measurements. Special emphasis was given to investigating the potential for measurement tools to detect changes in bacterial concentrations in drinking water. Bacterial colony counts (CFU) and total bacterial cell counts (TBC) were used as reference methods for assessing the bacterial water quality. The study consists of a series of laboratory scale experiments: monitoring of regrowth of Pseudomonas fluorescens, estimation of the detection limits for optical measurements using Escherichia coli dilutions, verification of the relationships by analysing grab water samples from various distribution systems and utilisation of the measurements in the case of an accidentally contaminated distribution network. We found significant correlations between the tested measurements and the bacterial water quality. As the bacterial contamination of water often co-occurs with the intrusion of matrixes containing mainly non-bacterial components, the tested measurement tools can be considered to have the potential to rapidly detect any major changes in drinking water quality. PMID:24284353

Measurement of wavelength-dependent extinction to distinguish between absorbing and nonabsorbing aerosol particulates

NASA Technical Reports Server (NTRS)

Portscht, R.

1977-01-01

Measurements of spectral transmission factors in smoky optical transmission paths reveal a difference between wavelength exponents of the extinction cross section of high absorption capacity and those of low absorption capacity. A theoretical explanation of this behavior is presented. In certain cases, it is possible to obtain data on the absorption index of aerosol particles in the optical path by measuring the spectral decadic extinction coefficient at, at least, two wavelengths. In this manner it is possible, for instance, to distinguish smoke containing soot from water vapor.

Rethinking capacity building for knowledge mobilisation: developing multilevel capabilities in healthcare organisations.

PubMed

Kislov, Roman; Waterman, Heather; Harvey, Gill; Boaden, Ruth

2014-11-15

Knowledge mobilisation in healthcare organisations is often carried out through relatively short-term projects dependent on limited funding, which raises concerns about the long-term sustainability of implementation and improvement. It is becoming increasingly recognised that the translation of research evidence into practice has to be supported by developing the internal capacity of healthcare organisations to engage with and apply research. This process can be supported by external knowledge mobilisation initiatives represented, for instance, by professional associations, collaborative research partnerships and implementation networks. This conceptual paper uses empirical and theoretical literature on organisational learning and dynamic capabilities to enhance our understanding of intentional capacity building for knowledge mobilisation in healthcare organisations. The discussion is structured around the following three themes: (1) defining and classifying capacity building for knowledge mobilisation; (2) mechanisms of capability development in organisational context; and (3) individual, group and organisational levels of capability development. Capacity building is presented as a practice-based process of developing multiple skills, or capabilities, belonging to different knowledge domains and levels of complexity. It requires an integration of acquisitive learning, through which healthcare organisations acquire knowledge and skills from knowledge mobilisation experts, and experience-based learning, through which healthcare organisations adapt, absorb and modify their knowledge and capabilities through repeated practice. Although the starting point for capability development may be individual-, team- or organisation-centred, facilitation of the transitions between individual, group and organisational levels of learning within healthcare organisations will be needed. Any initiative designed to build capacity for knowledge mobilisation should consider the subsequent trajectory of newly developed knowledge and skills within the recipient healthcare organisations. The analysis leads to four principles underpinning a practice-based approach to developing multilevel knowledge mobilisation capabilities: (1) moving from 'building' capacity from scratch towards 'developing' capacity of healthcare organisations; (2) moving from passive involvement in formal education and training towards active, continuous participation in knowledge mobilisation practices; (3) moving from lower-order, project-specific capabilities towards higher-order, generic capabilities allowing healthcare organisations to adapt to change, absorb new knowledge and innovate; and (4) moving from single-level to multilevel capability development involving transitions between individual, group and organisational learning.

Exotensioned structural members with energy-absorbing effects

DOEpatents

Brockwell, Michael Ian

2014-01-07

Structural members having enhanced load bearing capacity per unit mass include a skeleton structure formed from strips of material. Notches may be placed on the strips and a weave of tensile material placed in the notches and woven around the skeleton structure. At least one pair of structural members can be jointed together to provide very strong joints due to a weave patterns of tensile material, such as Kevlar, that distributes stress throughout the structure, preventing stress from concentrating in one area. Methods of manufacturing such structural members include molding material into skeletons of desired cross section using a matrix of molding segments. Total catastrophic failures in composite materials are substantially avoided and the strength to weight ratio of structures can be increased.

Exotensioned structural members with energy-absorbing effects

DOEpatents

Brockwell, Michael Ian

2017-08-22

Structural members having enhanced load bearing capacity per unit mass include a skeleton structure formed from strips of material. Notches may be placed on the strips and a weave of tensile material placed in the notches and woven around the skeleton structure. At least one pair of structural members can be jointed together to provide very strong joints due to a weave patterns of tensile material, such as Kevlar, that distributes stress throughout the structure, preventing stress from concentrating in one area. Methods of manufacturing such structural members include molding material into skeletons of desired cross section using a matrix of molding segments. Total catastrophic failures in composite materials are substantially avoided and the strength to weight ratio of structures can be increased.

Exotensioned structural members with energy-absorbing effects

DOEpatents

Brockwell, Michael Ian

2015-08-11

Structural members having enhanced load bearing capacity per unit mass include a skeleton structure formed from strips of material. Notches may be placed on the strips and a weave of tensile material placed in the notches and woven around the skeleton structure. At least one pair of structural members can be jointed together to provide very strong joints due to a weave patterns of tensile material, such as Kevlar, that distributes stress throughout the structure, preventing stress from concentrating in one area. Methods of manufacturing such structural members include molding material into skeletons of desired cross section using a matrix of molding segments. Total catastrophic failures in composite materials are substantially avoided and the strength to weight ratio of structures can be increased.

Positron Spectroscopy of Nanodiamonds after Hydrogen Sorption

PubMed Central

Laptev, Roman; Abzaev, Yuri; Lider, Andrey; Ivashutenko, Alexander

2018-01-01

The structure and defects of nanodiamonds influence the hydrogen sorption capacity. Positronium can be used as a sensor for detecting places with the most efficient capture of hydrogen atoms. Hydrogenation of carbon materials was performed from gas atmosphere. The concentration of hydrogen absorbed by the sample depends on the temperature and pressure. The concentration 1.2 wt % is achieved at the temperature of 243 K and the pressure of 0.6 MPa. The hydrogen saturation of nanodiamonds changes the positron lifetime. Increase of sorption cycle numbers effects the positron lifetime, as well as the parameters of the Doppler broadening of annihilation line. The electron-positron annihilation being a sensitive method, it allows detecting the electron density fluctuation of the carbon material after hydrogen saturation. PMID:29324712

Establishing traceability of photometric absorbance values for accurate measurements of the haemoglobin concentration in blood

NASA Astrophysics Data System (ADS)

Witt, K.; Wolf, H. U.; Heuck, C.; Kammel, M.; Kummrow, A.; Neukammer, J.

2013-10-01

Haemoglobin concentration in blood is one of the most frequently measured analytes in laboratory medicine. Reference and routine methods for the determination of the haemoglobin concentration in blood are based on the conversion of haeme, haemoglobin and haemiglobin species into uniform end products. The total haemoglobin concentration in blood is measured using the absorbance of the reaction products. Traceable absorbance measurement values on the highest metrological level are a prerequisite for the calibration and evaluation of procedures with respect to their suitability for routine measurements and their potential as reference measurement procedures. For this purpose, we describe a procedure to establish traceability of spectral absorbance measurements for the haemiglobincyanide (HiCN) method and for the alkaline haematin detergent (AHD) method. The latter is characterized by a higher stability of the reaction product. In addition, the toxic hazard of cyanide, which binds to the iron ion of the haem group and thus inhibits the oxygen transport, is avoided. Traceability is established at different wavelengths by applying total least-squares analysis to derive the conventional quantity values for the absorbance from the measured values. Extrapolation and interpolation are applied to get access to the spectral regions required to characterize the Q-absorption bands of the HiCN and AHD methods, respectively. For absorbance values between 0.3 and 1.8, the contributions of absorbance measurements to the total expanded uncertainties (95% level of confidence) of absorbance measurements range from 1% to 0.4%.

Enhancing heat capacity of colloidal suspension using nanoscale encapsulated phase-change materials for heat transfer.

PubMed

Hong, Yan; Ding, Shujiang; Wu, Wei; Hu, Jianjun; Voevodin, Andrey A; Gschwender, Lois; Snyder, Ed; Chow, Louis; Su, Ming

2010-06-01

This paper describes a new method to enhance the heat-transfer property of a single-phase liquid by adding encapsulated phase-change nanoparticles (nano-PCMs), which absorb thermal energy during solid-liquid phase changes. Silica-encapsulated indium nanoparticles and polymer-encapsulated paraffin (wax) nanoparticles have been made using colloid method, and suspended into poly-alpha-olefin (PAO) and water for potential high- and low-temperature applications, respectively. The shells prevent leakage and agglomeration of molten phase-change materials, and enhance the dielectric properties of indium nanoparticles. The heat-transfer coefficients of PAO containing indium nanoparticles (30% by mass) and water containing paraffin nanoparticles (10% by mass) are 1.6 and 1.75 times higher than those of corresponding single-phase fluids. The structural integrity of encapsulation allows repeated use of such nanoparticles for many cycles in high heat generating devices.

Method and apparatus for selectively annealing heterostructures using microwave

NASA Technical Reports Server (NTRS)

Atwater, Harry A. (Inventor); Brain, Ruth A. (Inventor); Barmatz, Martin B. (Inventor)

1998-01-01

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Method and apparatus for selectively annealing heterostructures using microwaves

NASA Technical Reports Server (NTRS)

Atwater, Harry A. (Inventor); Brain, Ruth A. (Inventor); Barmatz, Martin B. (Inventor)

1998-01-01

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Corrosion resistant neutron absorbing coatings

DOEpatents

Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

2012-05-29

A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

Corrosion resistant neutron absorbing coatings

DOEpatents

Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

2013-11-12

A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

Chemical composition and physicochemical properties of Phaeodactylum tricornutum microalgal residual biomass.

PubMed

German-Báez, L J; Valdez-Flores, M A; Félix-Medina, J V; Norzagaray-Valenzuela, C D; Santos-Ballardo, D U; Reyes-Moreno, C; Shelton, L M; Valdez-Ortiz, A

2017-12-01

The production of photosynthetic biofuels using microalgae is a promising strategy to combat the use of non-renewable energy sources. The microalgae residual biomass is a waste by-product of biofuel production; however, it could prove to have utility in the development of sustainable nutraceuticals and functional foods. In this study, a comprehensive characterisation of the under-utilised Phaeodactylum tricornutum microalgae residual biomass is presented. Proximal composition, antioxidant capacity (using three different antioxidant assays; oxygen radical absorbance capacity; radical cation activity, ABTS; and radical scavenging activity, DPPH), and total phenolic content of free and bound polyphenols were determined. Additionally, the physicochemical properties of water activity, pH, water absorption index, water solubility index, and dispersibility were evaluated. Results revealed that P. tricornutum microalgae residual biomass exhibits a relatively high protein and carbohydrate content, with values of 36.67% and 46.78%, respectively; and most carbohydrates were found as total dietary fibre (45.57%), of which insoluble dietary fibre was the most predominant (43.54%). Antioxidant capacity values for total phytochemicals of 106.22, 67.93, 9.54 µM TE g -1 dw were determined by oxygen radical absorbance capacity, ABTS, and DPPH assays, respectively. Total phenolic content was found to be 2.90 mg GAE g -1 dw. Interestingly, antioxidant capacity and total phenolic content were higher in bound than in free phytochemical extracts. The physicochemical analysis showed P. tricornutum microalgae residual biomass to have suitable properties for the generation of a beverage with Aw, pH, water absorption index, water solubility index, and dispersibility values of 0.45, 7.12, 3.40 g gel g -1  dw, 2.5 g solids 100 g -1  dw, and 90%, respectively. Hence, P. tricornutum microalgae residual biomass could be considered a potential source of bioactive compounds suitable for the production of functional food exhibiting antioxidant capacity and high dietary fibre content.

Coupled-rearrangement-channels calculation of the three-body system under the absorbing boundary condition

NASA Astrophysics Data System (ADS)

Iwasaki, M.; Otani, R.; Ito, M.; Kamimura, M.

2016-05-01

We formulate the method of the absorbing boundary condition (ABC) in the coupled-rearrangement-channels variational method (CRCMV) for the three-body problem. In the present study, we handle the simple three-boson system, and the absorbing potential is introduced in the Jacobi coordinate in the individual rearrangement channels. The resonance parameters and the strength of the monopole breakup are compared with the complex scaling method (CSM). We have found that the CRCVM + ABC method nicely works in the threebody problem with the rearrangement channels.

Method for Non-Invasive Determination of Chemical Properties of Aqueous Solutions

NASA Technical Reports Server (NTRS)

Jones, Alan (Inventor); Thomas, Nathan A. (Inventor); Todd, Paul W. (Inventor)

2016-01-01

A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.

Determination of antioxidants by a novel on-line HPLC-cupric reducing antioxidant capacity (CUPRAC) assay with post-column detection.

PubMed

Celik, Saliha Esin; Ozyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

2010-07-26

A novel on-line HPLC-cupric reducing antioxidant capacity (CUPRAC) method was developed for the selective determination of polyphenols (flavonoids, simple phenolic and hydroxycinnamic acids) in complex plant matrices. The method combines chromatographic separation, constituent analysis, and post-column identification of antioxidants in plant extracts. The separation of polyphenols was performed on a C18 column using gradient elution with two different mobile phase solutions, i.e., MeOH and 0.2% o-phosphoric acid. The HPLC-separated antioxidant polyphenols in the extracts react with copper(II)-neocuproine (Cu(II)-Nc) reagent in a post-column reaction coil to form a derivative. The reagent is reduced by antioxidants to the copper(I)-neocuproine (Cu(I)-Nc) chelate having maximum absorption at 450 nm. The negative peaks of antioxidant constituents were monitored by measuring the increase in absorbance due to Cu(I)-Nc. The detection limits of polyphenols at 450 nm (in the range of 0.17-3.46 microM) after post-column derivatization were comparable to those at 280 nm UV detection without derivatization. The developed method was successfully applied to the identification of antioxidant compounds in crude extracts of Camellia sinensis, Origanum marjorana and Mentha. The method is rapid, inexpensive, versatile, non-laborious, uses stable reagents, and enables the on-line qualitative and quantitative estimation of antioxidant constituents of complex plant samples. Copyright 2010 Elsevier B.V. All rights reserved.

Wide band design on the scaled absorbing material filled with flaky CIPs

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Yuan, Liming; Gao, Wei; Wang, Xiaobing; Liang, Zichang; Liao, Yi

2018-02-01

The scaled target measurement is an important method to get the target characteristic. Radar absorbing materials are widely used in the low detectable target, considering the absorbing material frequency dispersion characteristics, it makes designing and manufacturing scaled radar absorbing materials on the scaled target very difficult. This paper proposed a wide band design method on the scaled absorbing material of the thin absorption coating with added carbonyl iron particles. According to the theoretical radar cross section (RCS) of the plate, the reflection loss determined by the permittivity and permeability was chosen as the main design factor. Then, the parameters of the scaled absorbing materials were designed using the effective medium theory, and the scaled absorbing material was constructed. Finally, the full-size coating plate and scaled coating plates (under three different scale factors) were simulated; the RCSs of the coating plates were numerically calculated and measured at 4 GHz and a scale factor of 2. The results showed that the compensated RCS of the scaled coating plate was close to that of the full-size coating plate, that is, the mean deviation was less than 0.5 dB, and the design method for the scaled material was very effective.

Nanostructured Lipid Carriers (NLC) as Vehicles for Topical Administration of Sesamol: In Vitro Percutaneous Absorption Study and Evaluation of Antioxidant Activity.

PubMed

Puglia, Carmelo; Lauro, Maria Rosaria; Offerta, Alessia; Crascì, Lucia; Micicchè, Lucia; Panico, Anna Maria; Bonina, Francesco; Puglisi, Giovanni

2017-03-01

Sesamol is a natural phenolic compound extracted from Sesamum indicum seed oil. Sesamol is endowed with several beneficial effects, but its use as a topical agent is strongly compromised by unfavorable chemical-physical properties. Therefore, to improve its characteristics, the aim of the present work was the formulation of nanostructured lipid carriers as drug delivery systems for topical administration of sesamol.Two different nanostructured lipid carrier systems have been produced based on the same solid lipid (Compritol® 888 ATO) but in a mixture with two different kinds of oil phase such as Miglyol® 812 (nanostructured lipid carrier-M) and sesame oil (nanostructured lipid carrier-PLUS). Morphology and dimensional distribution of nanostructured lipid carriers have been characterized by differential scanning calorimetry and photon correlation spectroscopy, respectively. The release pattern of sesamol from nanostructured lipid carriers was evaluated in vitro determining drug percutaneous absorption through excised human skin. Furthermore, an oxygen radical absorbance capacity assay was used to determine their antioxidant activity.From the results obtained, the method used to formulate nanostructured lipid carriers led to a homogeneous dispersion of particles in a nanometric range. Sesamol has been encapsulated efficiently in both nanostructured lipid carriers, with higher encapsulation efficiency values (> 90 %) when sesame oil was used as the oil phase (nanostructured lipid carrier-PLUS). In vitro evidences show that nanostructured lipid carrier dispersions were able to control the rate of sesamol diffusion through the skin, with respect to the reference formulations.Furthermore, the oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of sesamol, especially when vehiculated by nanostructured lipid carrier-PLUS. Georg Thieme Verlag KG Stuttgart · New York.

Magnetic graphene dispersive solid phase extraction combining high performance liquid chromatography for determination of fluoroquinolones in foods.

PubMed

He, Xin; Wang, Geng Nan; Yang, Kun; Liu, Hui Zhi; Wu, Xia Jun; Wang, Jian Ping

2017-04-15

In this study, a magnetic graphene-based dispersive solid phase extraction method was developed that was combined with high performance liquid chromatography to determine the residues of fluoroquinolone drugs in foods of animal origin. During the experiments, several parameters possible influencing the extraction performance were optimized (amount of magnetic graphene, sample pH, extraction time and elution solution). This extraction method showed high absorption capacities (>6800ng) and high enrichment factors (68-79-fold) for seven fluoroquinolones. Furthermore, this absorbent could be reused for at least 40 times. The limits of detection were in the range of 0.05-0.3ng/g, and the recoveries from the standards fortified blank samples (bovine milk, chicken muscle and egg) were in the range of 82.4-108.5%. Therefore, this method could be used as a simple and sensitive tool to determine the residues of fluoroquinolones in foods of animal origin. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimized ultra-high-pressure-assisted extraction of procyanidins from lychee pericarp improves the antioxidant activity of extracts.

PubMed

Zhang, Ruifen; Su, Dongxiao; Hou, Fangli; Liu, Lei; Huang, Fei; Dong, Lihong; Deng, Yuanyuan; Zhang, Yan; Wei, Zhencheng; Zhang, Mingwei

2017-08-01

To establish optimal ultra-high-pressure (UHP)-assisted extraction conditions for procyanidins from lychee pericarp, a response surface analysis method with four factors and three levels was adopted. The optimum conditions were as follows: 295 MPa pressure, 13 min pressure holding time, 16.0 mL/g liquid-to-solid ratio, and 70% ethanol concentration. Compared with conventional ethanol extraction and ultrasonic-assisted extraction methods, the yields of the total procyanidins, flavonoids, and phenolics extracted using the UHP process were significantly increased; consequently, the oxygen radical absorbance capacity and cellular antioxidant activity of UHP-assisted lychee pericarp extracts were substantially enhanced. LC-MS/MS and high-performance liquid chromatography quantification results for individual phenolic compounds revealed that the yield of procyanidin compounds, including epicatechin, procyanidin A2, and procyanidin B2, from lychee pericarp could be significantly improved by the UHP-assisted extraction process. This UHP-assisted extraction process is thus a practical method for the extraction of procyanidins from lychee pericarp.

Influence of finishing systems on hydrophilic and lipophilic oxygen radical absorbance capacity (ORAC) in beef.

PubMed

Wu, C; Duckett, S K; Neel, J P S; Fontenot, J P; Clapham, W M

2008-11-01

The aim of this research was to: (1) develop a reliable extraction procedure and assay to determine antioxidant activity in meat products, and (2) assess the effect of beef finishing system (forage-finished: alfalfa, pearl millet or mixed pastures vs. concentrate-finished) on longissimus muscle antioxidant activity. The effect of extraction method (ethanol concentration and extraction time), protein removal, and sample preparation method (pulverization or freeze drying) were first evaluated to develop an antioxidant assay for meat products. Beef extracts prepared with low ethanol concentrations (20%) demonstrated higher hydrophilic ORAC. Protein removal prior to extraction reduced hydrophilic ORAC values. Sample preparation method influenced both hydrophilic and lipophilic ORAC, with pulverized samples containing higher hydrophilic and lipophilic ORAC values. Beef cattle finishing system (Forage: alfalfa, pearl millet, or natural pasture vs. concentrates) had little impact on muscle hydrophilic ORAC, but muscle from forage finished beef contained greater lipophilic ORAC. In addition, broiling of steaks reduced hydrophilic ORAC.

Study of Polyphenol Content and Antioxidant Capacity of Myrianthus Arboreus (Cecropiaceae) Root Bark Extracts

PubMed Central

Kasangana, Pierre Betu; Haddad, Pierre Selim; Stevanovic, Tatjana

2015-01-01

In order to evaluate the therapeutic potential of polyphenolic extracts from root bark of M. arboreus, we have determined the content of various polyphenols in aqueous and ethanol (EtOH) extract as well as two sub-fractions of the latter: ethyl acetate (EAc) and hexane (Hex). The total phenols, flavonoids, hydroxycinnamic acids and proanthocyanidins have been determined for all studied extracts/fractions by spectrophotometric methods. Both TP content (331.5 ± 2.5 mg GAE/g) and HCA content (201 ± 1.5 mg CAE/g) were determined to be the highest in EAc fraction of EtOH extract. All studied extracts were however determined to have a low content in flavonoids. The determination of antioxidant capacities of the studied extracts has also been performed by the following in vitro antioxidant tests: DPPH scavenging, phosphomolybdenum method and oxygen radical absorbance (ORACFl and ORACPRG) assay. The results of the DPPH free radical and ORACFl assays showed that there is no significant difference between the EAc fraction and Oligopin®, but the EAc fraction exhibited the highest antioxidant capacity as determined by the phosphomolybdenium method. In addition, the EtOH extract was determined to have the same antioxidant efficiency as the synthetic antioxidant BHT or commercial extract Oligopin® by phosphomolybdenum method. On the other hand, a positive correlation (r < 0.6) was found between different classes of polyphenols and the results of the phosphomolybdenum method, ORACFl as well as ORACPRG, except for the DPPH assay, for which a negative correlation was indicated (r < 0.62). Interestingly, it seems that the content in hydroxycinnamic acids played a big role in all assays with r < 0.9. According to the present study, EAc fraction and EtOH extract should be further studied for the potential use in the pharmaceutical and food industry. PMID:26783713

Relationship between H2 sorption properties and aqueous corrosion mechanisms in A2Ni7 hydride forming alloys (A = Y, Gd or Sm)

NASA Astrophysics Data System (ADS)

Charbonnier, Véronique; Monnier, Judith; Zhang, Junxian; Paul-Boncour, Valérie; Joiret, Suzanne; Puga, Beatriz; Goubault, Lionel; Bernard, Patrick; Latroche, Michel

2016-09-01

Intermetallic compounds A2B7 (A = rare earth, B = transition metal) are of interest for Ni-MH batteries. Indeed they are able to absorb hydrogen reversibly and exhibit good specific capacity in electrochemical route. To understand the effect of rare earth on properties of interest such as thermodynamic, cycling stability and corrosion, we synthesized and studied three compounds: Y2Ni7, Gd2Ni7 and Sm2Ni7. Using Sieverts' method, we plot P-c-isotherms up to 10 MPa and study hydride stability upon solid-gas cycling. Electrochemical cycling was also performed, as well as calendar and cycling corrosion study. Corrosion products were characterized by means of X-ray diffraction, electron diffraction, Raman micro-spectroscopy and scanning and transmission electron microscopies. Magnetic measurements were also performed to calculate corrosion rates. A corrosion mechanism, based on the nature of corrosion products, is proposed. By combining results from solid-gas cycling, electrochemical cycling and corrosion study, we attribute the loss in capacity either to corrosion or loss of crystallinity.

Antioxidant capacity index based on gold nanoparticles formation. Application to extra virgin olive oil samples.

PubMed

Della Pelle, Flavio; Vilela, Diana; González, María Cristina; Lo Sterzo, Claudio; Compagnone, Darío; Del Carlo, Michele; Escarpa, Alberto

2015-07-01

A simple gold nanoparticles (AuNPs) based colorimetric assay for the antioxidant activity determination has been developed. The AuNP formation is mediated by extra virgin olive oil (EVOO's) endogenous polyphenols; the reaction is described by a sigmoidal curve. The ratio KAuNPs/Xc(50) (slope of the linear part of the sigmoid/concentration at half value of the absorbance) was found to be the optimal parameter to report the antioxidant capacity with respect to the single KAuNPs or Xc(50) values. The obtained data demonstrated that the compounds with ortho-diphenols functionality are most active in reducing gold (III) to gold (0). Thus, intermediate activity was found for gallic acid, while tyrosol (mono-phenols) had a significant lower activity than the others antioxidant compounds (at least one order of magnitude). In the analysis of olive oil samples, a significant correlation among classical methods used to determine antioxidant activity and the proposed parameter was found with R values in the 0.96-0.97 range. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low Temperature Sorbents for Removal of Sulfur Compounds from Fluid Feed Streams

DOEpatents

Siriwardane, Ranjani

2004-06-01

A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

Planning in the Face of Uncertainty: Habitat Mapping that Supports Social-Ecological Networks and Resilient Estuaries

EPA Science Inventory

Estuaries are located at the nexus of fresh and salt water, making them inherently dynamic. However, many land uses have reduced the natural capacity of estuaries and their floodplains to absorb changes in sea-level, precipitation regimes, and storminess. Land use planning that r...

Polymer/reduced graphene oxide functionalized sponges as superabsorbents for oil removal and recovery.

PubMed

Periasamy, Arun Prakash; Wu, Wen-Ping; Ravindranath, Rini; Roy, Prathik; Lin, Guan-Lin; Chang, Huan-Tsung

2017-01-30

Polyurethane dish-washing (PU-DW) sponges are functionalized sequentially with polyethylenimine (PEI) and graphene oxide (GO) to form PEI/reduced graphene oxide (RGO) PU-DW sponges. The PEI/RGO PU-DW sponge consists of PEI/RGO sheets having numerous pores, with diameters ranging from 236 to 254nm. To further enhance hydrophobicity and absorption capacity of oil, PEI/RGO PU-DW sponge is further coated with 20% phenyltrimethoxysilane (PTMOS). The PTMOS/PEI/RGO PU-DW sponge absorbs various oils within 20s, with maximum absorption capacity values of 880% and 840% for bicycle chain oil and motorcycle engine oil, respectively. The absorbed oils were released completely by squeezing or immersed in hexane. The PTMOS/PEI/RGO PU-DW sponge efficiently separates oil/water mixtures through a flowing system. Having the advantages of faster absorption rate, reusability, and low cost, the PTMOS/PEI/RGO PU-DW sponge holds great potential as a superabsorbent for efficient removal and recovery of oil spills as well as for the separation of oil/water mixtures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alkyl chitosan film-high strength, functional biomaterials.

PubMed

Lu, Li; Xing, Cao; Xin, Shen; Shitao, Yu; Feng, Su; Shiwei, Liu; Fusheng, Liu; Congxia, Xie

2017-11-01

Biofilm with strong tensile strength is a topic item in the area of tissue engineering, medicine engineering, and so forth. Here we introduced an alkyl chitosan film with strong tensile strength and its possibility for an absorbable anticoagulation material in vivo was tested in the series of blood test, such as dynamic coagulation time, plasma recalcification time and hemolysis. Alkyl chitosan film was a better biomaterial than traditional chitosan film in the anticoagulation, tissue compatibility and cell compatibility. The unique trait of alkyl chitosan film may be for its greater contact angle and hydrophobicity ability to reduce the adsorption capacity for the blood component and the activity of fibrinolytic enzymes, enhance the antibacterial capacity than chitosan film. Moreover, none of chitosan film or butyl chitosan film exhibited quick inflammation or other disadvantage and degraded quickly by implanted test. Therefore, Alkyl chitosan film is of prospective properties as an implantable, absorbable agent for tissue heals, and this material need further research. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3034-3041, 2017. © 2017 Wiley Periodicals, Inc.

Identification of phenolic compounds in petals of nasturtium flowers (Tropaeolum majus) by high-performance liquid chromatography coupled to mass spectrometry and determination of oxygen radical absorbance capacity (ORAC).

PubMed

Garzón, G Astrid; Manns, David C; Riedl, Ken; Schwartz, Steven J; Padilla-Zakour, Olga

2015-02-18

The contents and profile of polyphenols were analyzed in edible petals of nasturtium flowers (Tropaeolum majus) of three colors, and their oxygen radical absorbance capacities (ORAC) were compared. Three primary anthocyanins (ACNs) and 15 non-ACN phenolic compounds including hydroxycinammic acids (HCAs) and flavonoids (myricetin, quercetin, and kaempferol derivatives) were detected. Anthocyanin concentration was within 31.9 ± 21.7 and 114.5 ± 2.3 mg cyanidin-3-glucoside (cy-3-glu)/100 g fresh weight (FW) in yellow and red petals, respectively. The concentration of HCAs varied between 33.3 ± 7.1 and 235.6 ± 8.1 mg chlorogenic acid equivalents/100 g FW for red and yellow flowers, respectively. Red flowers had the highest level of flavonoids (315.1 ± 2.4 mg myricetin equivalents/100 g FW) and the highest ORAC radical-scavenging activity. These results show the diversity and abundance of polyphenolic compounds in nasturtium flowers, which could be the basis for applications in functional foods, cosmetics, and pharmaceuticals.

High-throughput assay of oxygen radical absorbance capacity (ORAC) using a multichannel liquid handling system coupled with a microplate fluorescence reader in 96-well format.

PubMed

Huang, Dejian; Ou, Boxin; Hampsch-Woodill, Maureen; Flanagan, Judith A; Prior, Ronald L

2002-07-31

The oxygen radical absorbance capacity (ORAC) assay has been widely accepted as a standard tool to measure the antioxidant activity in the nutraceutical, pharmaceutical, and food industries. However, the ORAC assay has been criticized for a lack of accessibility due to the unavailability of the COBAS FARA II analyzer, an instrument discontinued by the manufacturer. In addition, the manual sample preparation is time-consuming and labor-intensive. The objective of this study was to develop a high-throughput instrument platform that can fully automate the ORAC assay procedure. The new instrument platform consists of a robotic eight-channel liquid handling system and a microplate fluorescence reader. By using the high-throughput platform, the efficiency of the assay is improved with at least a 10-fold increase in sample throughput over the current procedure. The mean of intra- and interday CVs was

Chemical composition, aroma evaluation, and oxygen radical absorbance capacity of volatile oil extracted from Brassica rapa cv. "yukina" used in Japanese traditional food.

PubMed

Usami, Atsushi; Motooka, Ryota; Takagi, Ayumi; Nakahashi, Hiroshi; Okuno, Yoshiharu; Miyazawa, Mitsuo

2014-01-01

The chemical composition of the volatile oil extracted from the aerial parts of Brassica rapa cv. "yukina" was analyzed using GC-MS, GC-PFPD, and GC-O. A total of 50 compounds were identified. The most prominent constituents were (E)-1,5-heptadiene (40.27%), 3-methyl-3-butenenitrile (25.97%) and 3-phenylpropanenitrile (12.41%). With regard to aroma compounds, 12 compounds were identified by GC-O analysis. The main aroma-active compounds were dimethyl tetrasulfide (sulphury-cabbage, FD = 64), 3-phenylpropanenitrile (nutty, FD = 64), 3-methylindole (pungent, FD = 64), and methional (potato, FD = 32). The antioxidant activity of the aroma-active compounds of the oil was determined using an oxygen radical absorbance capacity (ORAC) assay using fluorescein as the fluorescent probe. The ORAC values were found to be 785 ± 67 trolox equivalents (μmol TE/g) for B. rapa cv. "yukina" oil. The results obtained showed that the volatile oil extracted from the aerial parts is a good dietary source of antioxidants.

Antioxidant activity evaluation of new dosage forms as vehicles for dehydrated vegetables.

PubMed

Romero-de Soto, María Dolores; García-Salas, Patricia; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio; Fernández-Campos, Francisco; Clares-Naveros, Beatriz

2013-06-01

A dehydrated vegetables mixture loaded in four pharmaceutical dosage forms as powder, effervescent granulate, sugar granulate and gumdrops were investigated for their antioxidant capacity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging capacity assay, oxygen radical absorbance capacity assay and ferric reducing antioxidant potential assay. Total phenolic content of dehydrated vegetables powder mixture was also measured by the Folin-Ciocalteu method, so as to evaluate its contribution to their total antioxidant function. The effect of different temperatures on stability of these systems after 90 days storage was also evaluated. These formulations presented strong antioxidant properties and high phenolic content (279 mg gallic acid equivalent/g of sample) and thus could be potential rich sources of natural antioxidants. Antioxidant properties differed significantly among selected formulations (p < 0.05). Generally, the losses were lower in samples stored under refrigeration. To interpret the antioxidant properties a kinetic approach was performed. Degradation kinetics for the phenolic content and antioxidant capacity followed a zero-order function. Effervescent granulate was the formulation which underwent faster degradation. Contrary, sugar granulate and gumdrops were much more slowly. Time required to halve the initial amount of phenolic compounds was 589 ± 45 days for samples stored at 4 º C, and 312 ± 16 days for samples stored at room temperature. These developed dosage forms are new and innovative approach for vegetable intakes in population with special requirements providing an improvement in the administration of vegetables and fruits.

SU-E-CAMPUS-I-06: Y90 PET/CT for the Instantaneous Determination of Both Target and Non-Target Absorbed Doses Following Hepatic Radioembolization

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

Pasciak, A; Kao, J

2014-06-15

Purpose The process of converting Yttrium-90 (Y90) PET/CT images into 3D absorbed dose maps will be explained. The simple methods presented will allow the medical physicst to analyze Y90 PET images following radioembolization and determine the absorbed dose to tumor, normal liver parenchyma and other areas of interest, without application of Monte-Carlo radiation transport or dose-point-kernel (DPK) convolution. Methods Absorbed dose can be computed from Y90 PET/CT images based on the premise that radioembolization is a permanent implant with a constant relative activity distribution after infusion. Many Y90 PET/CT publications have used DPK convolution to obtain 3D absorbed dose maps.more » However, this method requires specialized software limiting clinical utility. The Local Deposition method, an alternative to DPK convolution, can be used to obtain absorbed dose and requires no additional computer processing. Pixel values from regions of interest drawn on Y90 PET/CT images can be converted to absorbed dose (Gy) by multiplication with a scalar constant. Results There is evidence that suggests the Local Deposition method may actually be more accurate than DPK convolution and it has been successfully used in a recent Y90 PET/CT publication. We have analytically compared dose-volume-histograms (DVH) for phantom hot-spheres to determine the difference between the DPK and Local Deposition methods, as a function of PET scanner point-spread-function for Y90. We have found that for PET/CT systems with a FWHM greater than 3.0 mm when imaging Y90, the Local Deposition Method provides a more accurate representation of DVH, regardless of target size than DPK convolution. Conclusion Using the Local Deposition Method, post-radioembolization Y90 PET/CT images can be transformed into 3D absorbed dose maps of the liver. An interventional radiologist or a Medical Physicist can perform this transformation in a clinical setting, allowing for rapid prediction of treatment efficacy by comparison to published tumoricidal thresholds.« less

Efficient absorption of SO2 with low-partial pressures by environmentally benign functional deep eutectic solvents.

PubMed

Zhang, Kai; Ren, Shuhang; Hou, Yucui; Wu, Weize

2017-02-15

Sulfur dioxide (SO 2 ) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO 2 from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and l-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO 2 with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO 2 efficiently. SO 2 absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332mol SO 2 /mol HBA for Bet+EG DES and 0.820mol SO 2 /mol HBA for L-car+EG DES at 40°C with a SO 2 partial pressure of 0.02atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO 2 by DESs was studied by FT-IR, 1 H NMR and 13 C NMR spectra. It was found that there are strong acid-base interactions between SO 2 and -COO - on HBA. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental Results and Modeling of Low-Heat-Capacity TES Microcalorimeters for Soft-X-ray Spectroscopy

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

Eckart, Megan E.; NASA Postdoctoral Program Fellow; Adams, Joseph S.

2009-12-16

Transition-edge-sensor (TES) X-ray microcalorimeters have mostly been targeted at mid-band energies from 0.05-10 keV and high energies to above 100 keV. However, many other optimizations are possible. Here we present results from devices optimized for soft X-ray applications. For spectroscopy below 1 keV, the X-ray stopping power and heat capacity (C) of the TES itself are high enough that we can omit a separate absorber. The resulting devices have low C and the best-achievable energy resolution should be under 1 eV. We are interested in pursuing such devices primarily for astrophysical applications and laboratory astrophysics at LLNL's Electron-Beam Ion Trap.more » To this end, we have studied arrays in which 'bare' TESs are interspersed with broad-band pixels that have absorbers. By extending the absorbers to cover the area where the leads contact the low-energy pixels, we have eliminated a significant source of non-Gaussian detector response. The bare devices are in a different regime from our typical devices in that C is ten times lower and the conductance to the bath is four times lower. We have explored this regime through simultaneous fitting of noise and impedance data. These data cannot be fit by the simple model we employ to describe our typical broad-band devices. In this contribution we present X-ray spectra and the results from modeling.« less

Development of a primary standard for absorbed dose from unsealed radionuclide solutions

NASA Astrophysics Data System (ADS)

Billas, I.; Shipley, D.; Galer, S.; Bass, G.; Sander, T.; Fenwick, A.; Smyth, V.

2016-12-01

Currently, the determination of the internal absorbed dose to tissue from an administered radionuclide solution relies on Monte Carlo (MC) calculations based on published nuclear decay data, such as emission probabilities and energies. In order to validate these methods with measurements, it is necessary to achieve the required traceability of the internal absorbed dose measurements of a radionuclide solution to a primary standard of absorbed dose. The purpose of this work was to develop a suitable primary standard. A comparison between measurements and calculations of absorbed dose allows the validation of the internal radiation dose assessment methods. The absorbed dose from an yttrium-90 chloride (90YCl) solution was measured with an extrapolation chamber. A phantom was developed at the National Physical Laboratory (NPL), the UK’s National Measurement Institute, to position the extrapolation chamber as closely as possible to the surface of the solution. The performance of the extrapolation chamber was characterised and a full uncertainty budget for the absorbed dose determination was obtained. Absorbed dose to air in the collecting volume of the chamber was converted to absorbed dose at the centre of the radionuclide solution by applying a MC calculated correction factor. This allowed a direct comparison of the analytically calculated and experimentally determined absorbed dose of an 90YCl solution. The relative standard uncertainty in the measurement of absorbed dose at the centre of an 90YCl solution with the extrapolation chamber was found to be 1.6% (k  =  1). The calculated 90Y absorbed doses from published medical internal radiation dose (MIRD) and radiation dose assessment resource (RADAR) data agreed with measurements to within 1.5% and 1.4%, respectively. This study has shown that it is feasible to use an extrapolation chamber for performing primary standard absorbed dose measurements of an unsealed radionuclide solution. Internal radiation dose assessment methods based on MIRD and RADAR data for 90Y have been validated with experimental absorbed dose determination and they agree within the stated expanded uncertainty (k  =  2).

Data in support of antioxidant activities of the non-extractable fraction of dried persimmon (Diospyros kaki Thunb.).

PubMed

Matsumura, Yoko; Ito, Toshihiro; Yano, Hisakazu; Kita, Eiji; Mikasa, Keiichi; Okada, Masatoshi; Furutani, Azusa; Murono, Yuka; Shibata, Mitsuru; Nishii, Yasue; Kayano, Shin-Ichi

2016-09-01

This data article is related to the research article entitled, "Antioxidant potential in non-extractable fraction of dried persimmon (Diospyros kaki Thunb.)" (Matsumura et al., 2016) [1]. We investigated antioxidant activities of the non-extractable fraction of dried persimmon fruits in vitro and in vivo. We evaluated both extracted fraction and non-extractable fraction, and reported that non-extractable fraction may possess significantly antioxidant potential in vivo on the basis of the oxygen radical absorbance capacity (ORAC). We showed our experimental raw data about antioxidant capacity of dried persimmon, plasma triglycerides (TG) and HDL-cholesterol (HDL-C), and this data article might contribute to evaluate real antioxidant capacity of other fruits and vegetables.

Dyes removal from water using low cost absorbents

NASA Astrophysics Data System (ADS)

Giraldo, S.; Ramirez, A. P.; Ulloa, M.; Flórez, E.; Y Acelas, N.

2017-12-01

In this study, the removal capacity of low cost adsorbents during the adsorption of Methylene Blue (MB) and Congo Red (CR) at different concentrations (50 and 100mg·L-1) was evaluated. These adsorbents were produced from wood wastes (cedar and teak) by chemical activation (ZnCl2). Both studied materials, Activated Cedar (AC) and activated teak (AT) showed a good fit of their experimental data to the pseudo second order kinetic model and Langmuir isotherms. The maximum adsorption capacities for AC were 2000.0 and 444.4mg·g-1 for MB and CR, respectively, while for AT, maximum adsorption capacities of 1052.6 and 86.4mg·g-1 were found for MB and CR, respectively.

Oxygen radical absorbance capacity (ORAC) and phenolic and anthocyanin concentrations in fruit and leaf tissues of highbush blueberry.

PubMed

Ehlenfeldt, M K; Prior, R L

2001-05-01

Antioxidant capacity, as measured by oxygen radical absorbance capacity (ORAC), and total phenolic and total anthocyanin contents were evaluated in fruit tissues of 87 highbush blueberry (Vacciniumcorymbosum L.) and species-introgressed highbush blueberry cultivars. ORAC and phenolic levels were evaluated in leaf tissues of the same materials. Average values for ORAC, phenolics, and anthocyanins in fruit were 15.9 ORAC units, 1.79 mg/g (gallic acid equivalents), and 0.95 mg/g (cyanidin-3-glucoside equivalents), respectively. Cv. Rubel had the highest ORAC per gram of fresh weight values, at 31.1 units, and cv. Elliott had the highest values on the basis of ORAC per square centimeter of surface area. In leaf tissue, values for both ORAC and phenolics were significantly higher than in fruit tissue, with mean values of 490 ORAC units and 44.80 mg/g (gallic acid equivalents), respectively. Leaf ORAC had a low, but significant, correlation with fruit phenolics and anthocyanins, but not with fruit ORAC. An analysis of ORAC values versus calculated midparent values in 11 plants from the 87-cultivar group in which all parents were tested suggested that, across cultivars, ORAC inheritance is additive. An investigation of ORAC values in a family of 44 cv. Rubel x Duke seedlings showed negative epistasis for ORAC values, suggesting Rubel may have gene combinations contributing to ORAC that are broken up during hybridization.

Hybrid mode-scattering/sound-absorbing segmented liner system and method

NASA Technical Reports Server (NTRS)

Walker, Bruce E. (Inventor); Hersh, Alan S. (Inventor); Rice, Edward J. (Inventor)

1999-01-01

A hybrid mode-scattering/sound-absorbing segmented liner system and method in which an initial sound field within a duct is steered or scattered into higher-order modes in a first mode-scattering segment such that it is more readily and effectively absorbed in a second sound-absorbing segment. The mode-scattering segment is preferably a series of active control components positioned along the annulus of the duct, each of which includes a controller and a resonator into which a piezoelectric transducer generates the steering noise. The sound-absorbing segment is positioned acoustically downstream of the mode-scattering segment, and preferably comprises a honeycomb-backed passive acoustic liner. The invention is particularly adapted for use in turbofan engines, both in the inlet and exhaust.

High speed fabrication of absorbance-enhanced micro-nanostructures on nickel surface using hundred-nanosecond pulsed laser

NASA Astrophysics Data System (ADS)

Fu, Jinxiang; Zhang, Jingyuan; Liang, Hao; Wang, Yibo; Zhang, Zhiyan; Liu, Yannan; Lin, Xuechun

2017-01-01

We report the generation of micro-nanostructures on nickel surface using a pulsed laser with pulse duration of 100/200 ns. The blacken nickel, which is covered with dense broccoli-like clusters having strong light trapping capacity covering broad spectrum (200-2000 nm), can be produced at a high laser scanning speed up to 100 mm/s. The absorbance of the blacken nickel can be over 98% in the UV, more than 97% in the visible, and over 90% in the near IR. In addition, by treating the nickel surface with two crossing scans of the laser, highly organized and shape-controllable periodic arrays of hump-craters can be fabricated.

Impedance approach to designing efficient vibration energy absorbers

NASA Astrophysics Data System (ADS)

Bobrovnitskii, Y. I.; Morozov, K. D.; Tomilina, T. M.

2017-03-01

The concept introduced previously by the authors on the best sound absorber having the maximum allowable efficiency in absorbing the energy of an incident sound field has been extended to arbitrary linear elastic media and structures. Analytic relations have been found for the input impedance characteristics that the best vibrational energy absorber should have. The implementation of these relations is the basis of the proposed impedance method of designing efficient vibration and noise absorbers. We present the results of a laboratory experiment that confirms the validity of the obtained theoretical relations, and we construct the simplest best vibration absorber. We also calculate the parameters and demonstrate the efficiency of a dynamic vibration absorber as the best absorber.

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

DOEpatents

Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

1994-11-29

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

Fabrication of X-ray Microcalorimeter Focal Planes Composed of Two Distinct Pixel Types.

PubMed

Wassell, E J; Adams, J S; Bandler, S R; Betancourt-Martinez, G L; Chiao, M P; Chang, M P; Chervenak, J A; Datesman, A M; Eckart, M E; Ewin, A J; Finkbeiner, F M; Ha, J Y; Kelley, R; Kilbourne, C A; Miniussi, A R; Sakai, K; Porter, F; Sadleir, J E; Smith, S J; Wakeham, N A; Yoon, W

2017-06-01

We are developing superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting specifications of X-ray imaging spectrometers including high count-rate, high energy resolution, and large field-of-view. In particular, a focal plane composed of two sub-arrays: one of fine-pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit (X-IFU) instrument on the European Space Agency's Athena mission. We have based the sub-arrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all gold X-ray absorber on 50 and 75 micron scales where the Mo/Au TES sits atop a thick metal heatsinking layer have shown high resolution and can accommodate high count-rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au and an added bismuth layer in a 250 micron square absorber. To tune the parameters of each sub-array requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single ion milling step. We demonstrate methods for integrating heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each sub-array, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (T c ) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these "hybrid" arrays will be presented.

Fabrication of X-ray Microcalorimeter Focal Planes Composed of Two Distinct Pixel Types

PubMed Central

Wassell, E. J.; Adams, J. S.; Bandler, S. R.; Betancourt-Martinez, G. L.; Chiao, M. P.; Chang, M. P.; Chervenak, J. A.; Datesman, A. M.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Ha, J. Y.; Kelley, R.; Kilbourne, C. A.; Miniussi, A. R.; Sakai, K.; Porter, F.; Sadleir, J. E.; Smith, S. J.; Wakeham, N. A.; Yoon, W.

2017-01-01

We are developing superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting specifications of X-ray imaging spectrometers including high count-rate, high energy resolution, and large field-of-view. In particular, a focal plane composed of two sub-arrays: one of fine-pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit (X-IFU) instrument on the European Space Agency’s Athena mission. We have based the sub-arrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all gold X-ray absorber on 50 and 75 micron scales where the Mo/Au TES sits atop a thick metal heatsinking layer have shown high resolution and can accommodate high count-rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au and an added bismuth layer in a 250 micron square absorber. To tune the parameters of each sub-array requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single ion milling step. We demonstrate methods for integrating heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each sub-array, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (Tc) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these “hybrid” arrays will be presented. PMID:28804229

Fabrication of X-ray Microcalorimeter Focal Planes Composed of Two Distinct Pixel Types

NASA Technical Reports Server (NTRS)

Wassell, Edward J.; Adams, Joseph S.; Bandler, Simon R.; Betancour-Martinez, Gabriele L; Chiao, Meng P.; Chang, Meng Ping; Chervenak, James A.; Datesman, Aaron M.; Eckart, Megan E.; Ewin, Audrey J.;

New bone formation in a bone defect associated to dental implant using absorbable or non-absorbable membrane in a dog model

PubMed Central

Lopez, Maria de Almeida; Olate, Sergio; Lanata-Flores, Antonio; Pozzer, Leandro; Cavalieri-Pereira, Lucas; Cantín, Mario; Vásquez, Bélgica; de Albergaria-Barbosa, José

2013-01-01

The aim of this research was to determine the bone formation capacity in fenestration defects associated with dental implants using absorbable and non-absorbable membranes. Six dogs were used in the study. In both tibias of each animal 3 implants were installed, and around these 5 mm circular defects were created. The defects were covered with absorbable membranes (experimental group 1), non-absorbable membranes (experimental group 2), and the third defect was not covered (control group). At 3 and 8 weeks post-surgery, the animals were euthanized and the membranes with the bone tissue around the implants were processed for histological analysis. The statistical analysis was conducted with Tukey’s test, considering statistical significance when p<0.1. Adequate bone repair was observed in the membrane-covered defects. At 3 weeks, organization of the tissue, bone formation from the periphery of the defect and the absence of inflammatory infiltrate were observed in both experimental groups, but the defect covered with absorbable membrane presented statistically greater bone formation. At 8 weeks, both membrane-covered defects showed adequate bone formation without significant differences, although they did in fact present differences with the control defect in both periods (p>0.1). In the defects without membrane, continuous connective tissue invasions and bone repair deficiency were observed. There were no significant differences in the characteristics and volume of the neoformed bone in the defects around the implants covered by the different membranes, whereas the control defects produced significantly less bone. The use of biological membranes contributes to bone formation in three-wall defects. PMID:24228090

Development of arrays of position-sensitive microcalorimeters for Constellation-X

NASA Technical Reports Server (NTRS)

Smith, S. J.; Bandler, S. R.; Brekosky, R. P.; Brown, A.-D.; Chervenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Kolbourne, C. A.;

Method for making an aluminum or copper substrate panel for selective absorption of solar energy

NASA Technical Reports Server (NTRS)

Roberts, M. L.; Sharpe, M. H.; Krupnick, A. C. (Inventor)

1978-01-01

A panel is described for selectively absorbing solar energy comprising an aluminum substrate. A zinc layer was covered by a layer of nickel and an outer layer of solar energy absorbing nickel oxide or a copper substrate with a nickel layer. A layer of solar energy absorbing nickel oxide distal from the copper substrate was included. A method for making these panels is disclosed.

Chiral monolithic absorbent constructed by optically active helical-substituted polyacetylene and graphene oxide: preparation and chiral absorption capacity.

PubMed

Li, Weifei; Wang, Bo; Yang, Wantai; Deng, Jianping

2015-02-01

Chiral monolithic absorbent is successfully constructed for the first time by using optically active helical-substituted polyacetylene and graphene oxide (GO). The preparative strategy is facile and straightforward, in which chiral-substituted acetylene monomer (Ma), cross-linker (Mb), and alkynylated GO (Mc) undergo copolymerization to form the desired monolithic absorbent in quantitative yield. The resulting monoliths are characterized by circular dichroism, UV-vis absorption, scanning electron microscopy (SEM), FT-IR, Raman, energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), XPS, and thermogravimetric analysis (TGA) techniques. The polymer chains derived from Ma form chiral helical structures and thus provide optical activity to the monoliths, while GO sheets contribute to the formation of porous structures. The porous structure enables the monolithic absorbents to demonstrate a large swelling ratio in organic solvents, and more remarkably, the helical polymer chains provide optical activity and further enantio-differentiating absorption ability. The present study establishes an efficient and versatile methodology for preparing novel functional materials, in particular monolithic chiral materials based on substituted polyacetylene and GO. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of Multilayer Laminated Film and Absorbent of Vacuum Insulation Panel for Use at High Temperature

NASA Astrophysics Data System (ADS)

Araki, Kuninari; Echigoya, Wataru; Tsuruga, Toshimitsu; Kamoto, Daigorou; Matsuoka, Shin-Ichi

For the energy saving regulation and larger capacity, Vacuum Insulation Panel (VIP) has been used in refrigerators with urethane foam in recent years. VIP for low temperature is constructed by laminated plastic film, using heat welding of each neighboring part for keeping vacuum, so that the performance decrement is very large under high temperature. But recently high efficiency insulation material is desired for high temperature water holding devices (automatic vending machine, heat pump water heater, electric hot-water pot water, etc.), and we especially focused on cost and ability of the laminated plastic film and absorbent for high temperature VIP. We measured the heatproof temperature of plastic films and checked the amount of water vapor and out coming gas on temperature-programmed adsorption in absorbent. These results suggest the suitable laminated film and absorbent system for VIP use at high temperature, and the long-term reliability was evaluated by measuring thermal conductivity of high temperature. As a result it was found that high-retort pouch of CPP (cast polypropylene film) and adding of aluminum coating are the most suitable materials for use in the welded layers of high-temperature VIPs (105°C).

A comparative study of an ABC and an artificial absorber for truncating finite element meshes

NASA Technical Reports Server (NTRS)

Oezdemir, T.; Volakis, John L.

1993-01-01

The type of mesh termination used in the context of finite element formulations plays a major role on the efficiency and accuracy of the field solution. The performance of an absorbing boundary condition (ABC) and an artificial absorber (a new concept) for terminating the finite element mesh was evaluated. This analysis is done in connection with the problem of scattering by a finite slot array in a thick ground plane. The two approximate mesh truncation schemes are compared with the exact finite element-boundary integral (FEM-BI) method in terms of accuracy and efficiency. It is demonstrated that both approximate truncation schemes yield reasonably accurate results even when the mesh is extended only 0.3 wavelengths away from the array aperture. However, the artificial absorber termination method leads to a substantially more efficient solution. Moreover, it is shown that the FEM-BI method remains quite competitive with the FEM-artificial absorber method when the FFT is used for computing the matrix-vector products in the iterative solution algorithm. These conclusions are indeed surprising and of major importance in electromagnetic simulations based on the finite element method.

Aspects of fabrication aluminium matrix heterophase composites by suspension method

NASA Astrophysics Data System (ADS)

Dolata, A. J.; Dyzia, M.

2012-05-01

Composites with an aluminium alloy matrix (AlMMC) exhibit several advantageous properties such as good strength, stiffness, low density, resistance and dimensional stability to elevated temperatures, good thermal expansion coefficient and particularly high resistance to friction wear. Therefore such composites are more and more used in modern engineering constructions. Composites reinforced with hard ceramic particles (Al2O3, SiC) are gradually being implemented into production in automotive or aircraft industries. Another application of AlMMC is in the electronics industry, where the dimensional stability and capacity to absorb and remove heat is used in radiators. However the main problems are still: a reduction of production costs, developing methods of composite material tests and final product quality assessment, standardisation, development of recycling and mechanical processing methods. AlMMC production technologies, based on liquid-phase methods, and the shaping of products by casting methods, belong to the cheapest production methods. Application of a suspension method for the production of composites with heterophase reinforcement may turn out to be a new material and technological solution. The article presents the material and technological aspects of the transfer procedures for the production of composite suspensions from laboratory scale to a semi-industrial scale.

Comparative studies of bioactive organosulphur compounds and antioxidant activities in garlic (Allium sativum L.), elephant garlic (Allium ampeloprasum L.) and onion (Allium cepa L.).

PubMed

Kim, Sunyoung; Kim, Dan-Bi; Jin, Wenjie; Park, Junghyuck; Yoon, Wonjin; Lee, Yunyeol; Kim, Soyoung; Lee, Sanghee; Kim, Sungsoo; Lee, Ok-Hwan; Shin, Dongbin; Yoo, Miyoung

2018-05-01

We evaluated organosulphur compounds in Allium vegetables, including garlic, elephant garlic and onion, using high-performance liquid chromatography. Among organosulphur compounds, elephant garlic had considerable γ-glutamyl peptides, and garlic had the highest alliin content. Onion had low level of organosulphur compounds than did elephant garlic and garlic. In addition, antioxidant capacities were evaluated by oxygen radical absorbance capacity (ORAC) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The results showed that garlic had the highest antioxidant capacity, followed by elephant garlic and onion. Furthermore, a positive correlation was observed between antioxidant activities and organosulphur compounds (R > 0.77). Therefore, our results indicate that there was a close relationship between antioxidant capacity and organosulphur compounds in Allium vegetables.

Gas storage using fullerene based adsorbents

NASA Technical Reports Server (NTRS)

Mikhael, Michael G. (Inventor); Loutfy, Raouf O. (Inventor); Lu, Xiao-Chun (Inventor); Li, Weijiong (Inventor)

2000-01-01

This invention is directed to the synthesis of high bulk density high gas absorption capacity adsorbents for gas storage applications. Specifically, this invention is concerned with novel gas absorbents with high gravimetric and volumetric gas adsorption capacities which are made from fullerene-based materials. By pressing fullerene powder into pellet form using a conventional press, then polymerizing it by subjecting the fullerene to high temperature and high inert gas pressure, the resulting fullerene-based materials have high bulk densities and high gas adsorption capacities. By pre-chemical modification or post-polymerization activation processes, the gas adsorption capacities of the fullerene-based adsorbents can be further enhanced. These materials are suitable for low pressure gas storage applications, such as oxygen storage for home oxygen therapy uses or on-board vehicle natural gas storage. They are also suitable for storing gases and vapors such as hydrogen, nitrogen, carbon dioxide, and water vapor.

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

CHUGH, Devesh; Gluesenkamp, Kyle R; Abdelaziz, Omar

In this study, development of a novel system for combined water heating, dehumidification, and space evaporative cooling is discussed. Ambient water vapor is used as a working fluid in an open system. First, water vapor is absorbed from an air stream into an absorbent solution. The latent heat of absorption is transferred into the process water that cools the absorber. The solution is then regenerated in the desorber, where it is heated by a heating fluid. The water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser.more » The condensed water can then be used in an evaporative cooling process to cool the dehumidified air exiting the absorber, or it can be drained if primarily dehumidification is desired. Essentially, this open absorption cycle collects space heat and transfers it to process water. This technology is enabled by a membrane-based absorption/desorption process in which the absorbent is constrained by hydrophobic vapor-permeable membranes. Constraining the absorbent film has enabled fabrication of the absorber and desorber in a plate-and-frame configuration. An air stream can flow against the membrane at high speed without entraining the absorbent, which is a challenge in conventional dehumidifiers. Furthermore, the absorption and desorption rates of an absorbent constrained by a membrane are greatly enhanced. Isfahani and Moghaddam (Int. J. Heat Mass Transfer, 2013) demonstrated absorption rates of up to 0.008 kg/m2s in a membrane-based absorber and Isfahani et al. (Int. J. Multiphase Flow, 2013) have reported a desorption rate of 0.01 kg/m2s in a membrane-based desorber. The membrane-based architecture also enables economical small-scale systems, novel cycle configurations, and high efficiencies. The absorber, solution heat exchanger, and desorber are fabricated on a single metal sheet. In addition to the open arrangement and membrane-based architecture, another novel feature of the cycle is recovery of the solution heat energy exiting the desorber by process water (a process-solution heat exchanger ) rather than the absorber exiting solution (the conventional solution heat exchanger ). This approach has enabled heating the process water from an inlet temperature of 15 C to 57 C (conforming to the DOE water heater test standard) and interfacing the process water with absorbent on the opposite side of a single metal sheet encompassing the absorber, process-solution heat exchanger, and desorber. The system under development has a 3.2 kW water heating capacity and a target thermal coefficient of performance (COP) of 1.6.« less

Phenolic Compounds of Cereals and Their Antioxidant Capacity.

PubMed

Van Hung, Pham

2016-01-01

Phenolic compounds play an important role in health benefits because of their highly antioxidant capacity. In this review, total phenolic contents (TPCs), phenolic acid profile and antioxidant capacity of the extracted from wheat, corn, rice, barley, sorghum, rye, oat, and millet, which have been recently reported, are summarized. The review shows clearly that cereals contain a number of phytochemicals including phenolics, flavonoids, anthocyanins, etc. The phytochemicals of cereals significantly exhibit antioxidant activity as measured by trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging, reducing power, oxygen radical absorbance capacity (ORAC), inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol and DNA, Rancimat, inhibition of photochemilumenescence (PCL), and iron(II) chelation activity. Thus, the consumption of whole grains is considered to have significantly health benefits in prevention from chronic diseases such as cardiovascular disease, diabetes, and cancer because of the contribution of phenolic compounds existed. In addition, the extracts from cereal brans are considered to be used as a source of natural antioxidants.

Doctorate Holders outside the Academy in Finland: Academic Engagement and Industry-Specific Competence

ERIC Educational Resources Information Center

Haapakorpi, Arja

2017-01-01

In Finland, doctoral employment outside the academy has been increasing. Universities can no longer absorb the numbers in the doctoral labour force and research and development (R&D) policy emphasises the need for specialised research capacity in non-academic sectors; the highest academic degree is assumed to add value. However, the transition…

Higher iron pearl millet (Pennisetum glaucum L.) provides more absorbable iron that is limited by increased polyphenolic content

USDA-ARS?s Scientific Manuscript database

Background: Our objective was to compare the capacity of iron (Fe) biofortified and standard pearl millet (Pennisetum glaucum L.) to deliver Fe for hemoglobin (Hb) synthesis. Pearl millet is the most widely grown type of millet. It is common primarily in West Africa and the Indian subcontinent, and ...

Influence of the electromagnetic parameters on the surface wave attenuation in thin absorbing layers

NASA Astrophysics Data System (ADS)

Li, Yinrui; Li, Dongmeng; Wang, Xian; Nie, Yan; Gong, Rongzhou

2018-05-01

This paper describes the relationships between the surface wave attenuation properties and the electromagnetic parameters of radar absorbing materials (RAMs). In order to conveniently obtain the attenuation constant of TM surface waves over a wide frequency range, the simplified dispersion equations in thin absorbing materials were firstly deduced. The validity of the proposed method was proved by comparing with the classical dispersion equations. Subsequently, the attenuation constants were calculated separately for the absorbing layers with hypothetical relative permittivity and permeability. It is found that the surface wave attenuation properties can be strongly tuned by the permeability of RAM. Meanwhile, the permittivity should be appropriate so as to maintain high cutoff frequency. The present work provides specific methods and designs to improve the attenuation performances of radar absorbing materials.

Composite neutron absorbing coatings for nuclear criticality control

DOEpatents

Wright, Richard N.; Swank, W. David; Mizia, Ronald E.

2005-07-19

Thermal neutron absorbing composite coating materials and methods of applying such coating materials to spent nuclear fuel storage systems are provided. A composite neutron absorbing coating applied to a substrate surface includes a neutron absorbing layer overlying at least a portion of the substrate surface, and a corrosion resistant top coat layer overlying at least a portion of the neutron absorbing layer. An optional bond coat layer can be formed on the substrate surface prior to forming the neutron absorbing layer. The neutron absorbing layer can include a neutron absorbing material, such as gadolinium oxide or gadolinium phosphate, dispersed in a metal alloy matrix. The coating layers may be formed by a plasma spray process or a high velocity oxygen fuel process.

High strain rate and quasi-static tensile behaviour of Ti-6Al-4V after cyclic damage

NASA Astrophysics Data System (ADS)

Galán López, J.; Verleysen, P.; Degrieck, J.

2012-08-01

It is common that energy absorbing structural elements are subjected to a number of loading cycles before a crash event. Several studies have shown that previous fatigue can significantly influence the tensile properties of some materials, and hence the behaviour of structural elements made of them. However, when the capacity of absorbing energy of engineering materials is determined, fresh material without any fatigue damage is most often used. This study investigates the effect of fatigue damage on the dynamic tensile properties of Ti-6Al-4V in thin-sheet form. Results are completed with tests at quasi-static strain rates and observations of the fracture surfaces, and compared with results obtained from other alloys and steel grades. The experiments show that the dynamic properties of Ti-6Al-4V are not affected by a number of fatigue loading cycles high enough to significantly reduce the energy absorbing capabilities of EDM machined samples.

Model of radiation transmittance by inorganic fouling on UV reactor lamp sleeves.

PubMed

Wait, Isaac W; Blatchley, Ernest R

2010-11-01

The efficacy of UV disinfection of water depends on the ability of radiation to pass from UV lamps through the quartz sleeves that encase them; the accumulation of metal-containing foulants on sleeve surfaces inhibits disinfection by absorbing radiation that would otherwise be available for inactivation. In a series of experiments, the composition and quantity of sleeve foulants were studied relative to water chemistry and sleeve transmittance. Findings indicate that iron and calcium dominate fouling, with elevated fouling activity by iron, aluminum, manganese, and zinc. A regression-based modeling approach was used to characterize and quantify the effects of foulant metals on UV absorbance. The molar extinction coefficient for iron was found to be more than 3 times greater than that of calcium. Iron's relatively high activity in fouling reactions, elevated capacity to absorb UV, and reduced solubility under oxidizing conditions makes it a fouling precursor of particular concern, with respect to potential for sleeve fouling in UV reactors.

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1981-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Chemical heat pump

DOEpatents

Greiner, Leonard

1984-01-01

A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

Phenolic Profiling and Antioxidant Capacity of Eugenia uniflora L. (Pitanga) Samples Collected in Different Uruguayan Locations

PubMed Central

Baenas, Nieves; Gironés-Vilaplana, Amadeo; Cesio, María Verónica; Heinzen, Horacio

2018-01-01

The use of nutrient-rich foods to enhance the wellness, health and lifestyle habits of consumers is globally encouraged. Native fruits are of great interest as they are grown and consumed locally and take part of the ethnobotanic knowledge of the population. Pitanga is an example of a native fruit from Uruguay, consumed as a jelly or an alcoholic beverage. Pitanga has a red-violet pigmentation, which is a common trait for foods that are a good source of antioxidants. Hence, fruits from different Uruguayan regions were analyzed via miniaturized sample preparation method, HPLC-DAD-ESI/MSn and RP-HPLC-DAD techniques to identify and quantify phenolic compounds, respectively. The antioxidant capacity was evaluated via DPPH and ORAC (Oxygen Radical Absorbance Capacity) assays. A multivariate linear regression was applied to correlate the observed antioxidant capacity with the phenolic content. Furthermore, Principal Components Analysis was performed to highlight characteristics between the various samples studied. The main results indicated differences between northern and southern Uruguayan samples. Delphinidin-3-hexoside was present in southern samples (mean of 293.16 µmol/100 g dry weight (DW)) and absent in the sample collected in the north (sample 3). All the samples contain high levels of cyanidin-3-hexoside, but a noticeable difference was found between the northern sample (150.45 µmol/100 g DW) and the southern sample (1121.98 µmol/100 g DW). The antioxidant capacity (mean ORAC of 56370 µmol Trolox®/100 g DW) were high in all the samples compared to the Food and Drug Administration (FDA) database of similar berry-fruits. The results of this study highlight the nutraceutical value of a native fruit that has not been exploited until now. PMID:29695116

Phenolic Profiling and Antioxidant Capacity of Eugenia uniflora L. (Pitanga) Samples Collected in Different Uruguayan Locations.

PubMed

Migues, Ignacio; Baenas, Nieves; Gironés-Vilaplana, Amadeo; Cesio, María Verónica; Heinzen, Horacio; Moreno, Diego A

2018-04-24

The use of nutrient-rich foods to enhance the wellness, health and lifestyle habits of consumers is globally encouraged. Native fruits are of great interest as they are grown and consumed locally and take part of the ethnobotanic knowledge of the population. Pitanga is an example of a native fruit from Uruguay, consumed as a jelly or an alcoholic beverage. Pitanga has a red-violet pigmentation, which is a common trait for foods that are a good source of antioxidants. Hence, fruits from different Uruguayan regions were analyzed via miniaturized sample preparation method, HPLC-DAD-ESI/MS n and RP-HPLC-DAD techniques to identify and quantify phenolic compounds, respectively. The antioxidant capacity was evaluated via DPPH and ORAC (Oxygen Radical Absorbance Capacity) assays. A multivariate linear regression was applied to correlate the observed antioxidant capacity with the phenolic content. Furthermore, Principal Components Analysis was performed to highlight characteristics between the various samples studied. The main results indicated differences between northern and southern Uruguayan samples. Delphinidin-3-hexoside was present in southern samples (mean of 293.16 µmol/100 g dry weight (DW)) and absent in the sample collected in the north (sample 3). All the samples contain high levels of cyanidin-3-hexoside, but a noticeable difference was found between the northern sample (150.45 µmol/100 g DW) and the southern sample (1121.98 µmol/100 g DW). The antioxidant capacity (mean ORAC of 56370 µmol Trolox ® /100 g DW) were high in all the samples compared to the Food and Drug Administration (FDA) database of similar berry-fruits. The results of this study highlight the nutraceutical value of a native fruit that has not been exploited until now.

Lipophilic and hydrophilic antioxidant capacities of common foods in the United States.

PubMed

Wu, Xianli; Beecher, Gary R; Holden, Joanne M; Haytowitz, David B; Gebhardt, Susan E; Prior, Ronald L

2004-06-16

Both lipophilic and hydrophilic antioxidant capacities were determined using the oxygen radical absorbance capacity (ORAC(FL)) assay with fluorescein as the fluorescent probe and 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator on over 100 different kinds of foods, including fruits, vegetables, nuts, dried fruits, spices, cereals, infant, and other foods. Most of the foods were collected from four different regions and during two different seasons in U.S. markets. Total phenolics of each sample were also measured using the Folin-Ciocalteu reagent. Hydrophilic ORAC(FL) values (H-ORAC(FL)) ranged from 0.87 to 2641 micromol of Trolox equivalents (TE)/g among all of the foods, whereas lipophilic ORAC(FL) values (L-ORAC(FL)) ranged from 0.07 to 1611 micromol of TE/g. Generally, L-ORAC(FL) values were <10% of the H-ORAC(FL) values except for a very few samples. Total antioxidant capacity was calculated by combining L-ORAC(FL) and H-ORAC(FL). Differences of ORAC(FL) values in fruits and vegetables from different seasons and regions were relatively large for some foods but could not be analyzed in detail because of the sampling scheme. Two different processing methods, cooking and peeling, were used on selected foods to evaluate the impact of processing on ORAC(FL). The data demonstrated that processing can have significant effects on ORAC(FL). Considering all of the foods analyzed, the relationship between TP and H-ORAC(FL) showed a very weak correlation. Total hydrophilic and lipophilic antioxidant capacity intakes were calculated to be 5558 and 166 micromol of TE/day, respectively, on the basis of data from the USDA Continuing Survey of Food Intakes by Individuals (1994-1996).

Cupric ion reducing antioxidant capacity assay for food antioxidants: vitamins, polyphenolics, and flavonoids in food extracts.

PubMed

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektas Oğlu, Burcu; Bener, Mustafa

2008-01-01

Antioxidants are health beneficial compounds through their combat with reactive oxygen and nitrogen species and free radicals that may cause tissue damage leading to various diseases. This work reports the development of a simple and widely applicable antioxidant capacity index for dietary polyphenols, vitamins C and E, and plasma antioxidants utilizing the copper(II)-neocuproine (Cu(II)-Nc) reagent as the chromogenic oxidizing agent. This novel method based on an electron-transfer mechanism was named by our research group as 'cupric reducing antioxidant capacity', abbreviated as the CUPRAC method. The method is comprised of mixing the antioxidant solution with aqueous copper(II) chloride, alcoholic neocuproine, and ammonium acetate aqueous buffer at pH 7, and subsequently measuring the developed absorbance at 450 nm after 30 min. Since the color development is fast for compounds like ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds are assayed after incubation at 50 degrees C on a water bath for 20 min. The flavonoid glycosides are hydrolyzed to their corresponding aglycones by refluxing in 1.2 M: HCl-containing 50% MeOH so as to exert maximal reducing power towards Cu(II)-Nc. The CUPRAC antioxidant capacities of synthetic mixtures are equal to the sum of individual capacities of antioxidant constituents, indicating lack of chemical deviations from Beer's law. Tests on antioxidant polyphenols demonstrate that the highest CUPRAC capacities are observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accord with the number and position of the -OH groups as well the conjugation level of the molecule. The parallelism of the linear calibration curves of pure antioxidants in water and in a given complex matrix (plant extract) demonstrates that there are no chemical interactions of interferent nature among the solution constituents, and that the antioxidant capacities of the tested antioxidants are additive, in conformity to the Beer's law. For individual determination of ascorbic acid in fruit juices with a modified CUPRAC procedure, flavonoids are pre-extracted as their La(III) complexes prior to assay. For apricot extracts, a modified version of the CUPRAC assay based on anion exchange separation at pH 3 is applied, since sulfited-dried sample extracts contain the hydrosulfite anion interfering with the determination. For herbal tea infusions, the standard CUPRAC protocol is applied. The CUPRAC reagent is stable, easily accessible, low-cost, and is sensitive toward thiol-type antioxidants unlike FRAP. The reaction is carried out at nearly physiological pH as opposed to the acidic pH of FRAP or to the alkaline pH of Folin methods, constituting a basic advantage for the realistic assay of biological fluids.

Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

DOEpatents

Phillips, Benjamin A.; Zawacki, Thomas S.

1996-11-05

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

Physicochemical, melissopalynological and antioxidant properties of artisanal honeys from Lebanon.

PubMed

Jaafar, Katherine; Haidar, Janay; Kuraydiyyah, Sawsan; Ghaddar, Tarek; Knio, Khouzama; Ismail, Baraem; Toufeili, Imad

2017-07-01

Sixteen honeydew and 15 floral honeys from Lebanon were analyzed for pollen spectra and physicochemical parameters. A total of 37 families and 67 taxa were recorded with the honeybees producing honeydew honey exhibiting a more diverse foraging behavior than those making floral honeys. The honeydew and floral honeys exhibited differences in moisture content, pH, electrical conductivity, color, protein and Maillard reaction products. The honeydew honeys contained more total phenols, had higher antioxidant contents, and displayed higher antioxidant capacities than the floral samples in the Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity, inhibition of superoxide dismutase activity and protection of red blood cells against hemolysis assays. The honey samples exhibited higher antioxidant capacities, in the aforementioned assays, than their corresponding methanol-extractable phenol fractions although the differences did not reach statistical significance in the floral samples. The relative antioxidant capacity indices which integrate measures of antioxidant capacity from the different assays of the honey samples and their corresponding extracts exhibited similar patterns ( r  = 0.9774, 0.9937) thereby indicating that the antioxidative behavior of the entire honeys is mirrored by their methanol-extractable phenolic fractions.

Absorbable magnesium-based stent: physiological factors to consider for in vitro degradation assessments

PubMed Central

Wang, Juan; Smith, Christopher E.; Sankar, Jagannathan; Yun, Yeoheung; Huang, Nan

2015-01-01

Absorbable metals have been widely tested in various in vitro settings using cells to evaluate their possible suitability as an implant material. However, there exists a gap between in vivo and in vitro test results for absorbable materials. A lot of traditional in vitro assessments for permanent materials are no longer applicable to absorbable metallic implants. A key step is to identify and test the relevant microenvironment and parameters in test systems, which should be adapted according to the specific application. New test methods are necessary to reduce the difference between in vivo and in vitro test results and provide more accurate information to better understand absorbable metallic implants. In this investigative review, we strive to summarize the latest test methods for characterizing absorbable magnesium-based stent for bioabsorption/biodegradation behavior in the mimicking vascular environments. Also, this article comprehensively discusses the direction of test standardization for absorbable stents to paint a more accurate picture of the in vivo condition around implants to determine the most important parameters and their dynamic interactions. PMID:26816631

Advances in Small Pixel TES-Based X-Ray Microcalorimeter Arrays for Solar Physics and Astrophysics

NASA Technical Reports Server (NTRS)

Bandler, S. R.; Adams, J. S.; Bailey, C. N.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.;

[Internal fixation treatment of multiple rib fractures with absorbable rib-connecting-pins under epidural anesthesia].

PubMed

Liu, Jinliang; Li, Keyao; Ju, Zhenlong; Bai, Yan

2011-03-01

To study the indications, methods and experience of absorbable rib-connecting-pins fixation in the treatment of multiple rib fractures. 52 cases with multiple rib fractures were performed internal fixation with absorbable rib-connecting-pins under epidural anesthesia. All cases were followed up for 1 to 12 months, with an average of 5 months. All fractures were achieved healing in 3 to 6 months after the operation and were not found chest wall deformity. Absorbable rib-connecting-pins fixation is a simple and effective method and worthies recommending to perform operation for the appropriate cases with multiple rib fractures.

Nonlinear vibration absorption for a flexible arm via a virtual vibration absorber

NASA Astrophysics Data System (ADS)

Bian, Yushu; Gao, Zhihui

2017-07-01

A semi-active vibration absorption method is put forward to attenuate nonlinear vibration of a flexible arm based on the internal resonance. To maintain the 2:1 internal resonance condition and the desirable damping characteristic, a virtual vibration absorber is suggested. It is mathematically equivalent to a vibration absorber but its frequency and damping coefficients can be readily adjusted by simple control algorithms, thereby replacing those hard-to-implement mechanical designs. Through theoretical analyses and numerical simulations, it is proven that the internal resonance can be successfully established for the flexible arm, and the vibrational energy of flexible arm can be transferred to and dissipated by the virtual vibration absorber. Finally, experimental results are presented to validate the theoretical predictions. Since the proposed method absorbs rather than suppresses vibrational energy of the primary system, it is more convenient to reduce strong vibration than conventional active vibration suppression methods based on smart material actuators with limited energy output. Furthermore, since it aims to establish an internal vibrational energy transfer channel from the primary system to the vibration absorber rather than directly respond to external excitations, it is especially applicable for attenuating nonlinear vibration excited by unpredictable excitations.

Liftoff process for exfoliation of thin film photovoltaic devices and back contact formation

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

Haight, Richard A.; Hannon, James B.; Oida, Satoshi

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu--Zn--Sn--S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Antioxidant activity and phenolic compositions of lentil (Lens culinaris var. Morton) extract and its fractions

PubMed Central

Zou, Yanping; Chang, Sam K.C.; Gu, Yan; Qian, Steven Y.

2011-01-01

Phenolic compounds were extracted from Morton lentils using acidified aqueous acetone. The crude Morton extract (CME) was applied onto a macroresin column and desorbed by aqueous methanol to obtain a semi-purified Morton extract (SPME). The SPME was further fractionated over Sephadex LH-20 column into five main fractions (Fr I – Fr V). The phytochemical contents such as total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the CME, SPME, and its fractions were examined by colorimetric methods. Antioxidant activity of extracts and fractions were screened by DPPH scavenging activity, trolox equivalent antioxidant capacity (TEAC), ferric reduced antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC) methods. In addition, the compositions of active fractions were determined by HPLC-DAD and HPLC-MS methods. Results showed that fraction enriched in condensed tannins (Fr V) exhibited significantly higher value of TPC, CTC and higher antioxidant activity as compared to the crude extract, SPME and low-molecular-weight fractions (Fr I – IV). Eighteen compounds existed in those fractions, and seventeen were tentatively identified by UV and MS spectra. HPLC-MS analysis revealed Fr II contained mainly kaempferol glycoside, Fr III and Fr IV mainly contained flavonoid glycosides, and Fr V was composed of condensed tannins. The results suggested that extract of Morton lentils is a promising source of antioxidant phenolics, and may be used as a dietary supplement for health promotion. PMID:21332205

Potential Water Retention Capacity as a Factor in Silage Effluent Control: Experiments with High Moisture By-product Feedstuffs

PubMed Central

Razak, Okine Abdul; Masaaki, Hanada; Yimamu, Aibibula; Meiji, Okamoto

2012-01-01

The role of moisture absorptive capacity of pre-silage material and its relationship with silage effluent in high moisture by-product feedstuffs (HMBF) is assessed. The term water retention capacity which is sometimes used in explaining the rate of effluent control in ensilage may be inadequate, since it accounts exclusively for the capacity of an absorbent incorporated into a pre-silage material prior to ensiling, without consideration to how much the pre-silage material can release. A new terminology, ‘potential water retention capacity’ (PWRC), which attempts to address this shortcoming, is proposed. Data were pooled from a series of experiments conducted separately over a period of five years using laboratory silos with four categories of agro by-products (n = 27) with differing moisture contents (highest 96.9%, lowest 78.1% in fresh matter, respectively), and their silages (n = 81). These were from a vegetable source (Daikon, Raphanus sativus), a root tuber source (potato pulp), a fruit source (apple pomace) and a cereal source (brewer’s grain), respectively. The pre-silage materials were adjusted with dry in-silo absorbents consisting wheat straw, wheat or rice bran, beet pulp and bean stalks. The pooled mean for the moisture contents of all pre-silage materials was 78.3% (±10.3). Silage effluent decreased (p<0.01), with increase in PWRC of pre-silage material. The theoretical moisture content and PWRC of pre-silage material necessary to stem effluent flow completely in HMBF silage was 69.1% and 82.9 g/100 g in fresh matter, respectively. The high correlation (r = 0.76) between PWRC of ensiled material and silage effluent indicated that the latter is an important factor in silage-effluent relationship. PMID:25049587

Methods for absorbing neutrons

DOEpatents

Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

2012-07-24

A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

Comprehensive Evaluation of the Antioxidant Potential of Coastal Dune Mushroom Species from the Southwest of France.

PubMed

Smolskaite, Lina; Talou, Thierry; Venskutonis, Petras Rimantas

2016-01-01

Numerous mushroom species are used as food and for medicinal purposes; however, many species that may contain bioactive compounds remain underinvestigated. In this study, the antioxidant properties of extracts sequentially isolated with cyclohexane, dichloromethane, and methanol from 25 costal dune mushroom species collected in the southwestern region of France were evaluated based on their radical scavenging capacity, ferric-reducing antioxidant power, oxygen radical absorbance capacity, and Folin-Ciocalteu-determined total phenolic content. Overall, the antioxidant potential of dried mushrooms was assessed using integrated antioxidant scores. The highest antioxidant capacity values were demonstrated by the Cortinarius infractus, Agaricus coniferarum, A. menieri, and A. freirei species. These results may foster further studies of the selected mushroom species to valorize their nutritional and medicinal properties.

Geomaterials: their application to environmental remediation

PubMed Central

Yamada, Hirohisa; Tamura, Kenji; Watanabe, Yujiro; Iyi, Nobuo; Morimoto, Kazuya

2011-01-01

Geomaterials are materials inspired by geological systems originating from the billion years long history of the Earth. This article reviews three important classes of geomaterials. The first one is smectites—layered silicates with a cation-exchange capacity. Smectites are useful for removing pollutants and as intercalation compounds, catalysts and polymer nanocomposites. The second class is layered double hydroxides (LDHs). They have an anion-exchange capacity and are used as catalysts, catalyst precursors, sorbents and scavengers for halogens. The third class of geomaterials is zeolites—microporous materials with a cation-exchange capacity which are used for removing harmful cations. Zeolite composites with LDHs can absorb ammonium and phosphate ions in rivers and lakes, whereas zeolite/apatite composites can immobilize the radioactive iodine. These geomaterials are essential for environmental remediation. PMID:27877455

Active chemisorption sites in functionalized ionic liquids for carbon capture.

PubMed

Cui, Guokai; Wang, Jianji; Zhang, Suojiang

2016-07-25

Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined.

Significance of the oceanic CO2 sink for national carbon accounts

PubMed Central

McNeil, Ben I

2006-01-01

Background Under the United Nations convention on the law of the sea (1982), each participating country maintains exclusive economic and environmental rights within the oceanic region extending 200 nm from its coastline, known as the Exclusive Economic Zone (EEZ). Although the ocean within each EEZ has a vast capacity to absorb anthropogenic CO2 and therefore potentially be used as a carbon sink, it is not mentioned within the Kyoto Protocol most likely due to inadequate quantitative estimates. Here, I use two methods to estimate the anthropogenic CO2 storage and uptake for a typically large EEZ (Australia). Results Depending on whether the Antarctic territory is included I find that during the 1990s between 30–40% of Australia's fossil-fuel CO2 emissions were absorbed by its own EEZ. Conclusion This example highlights the potential significance of the EEZ carbon sink for national carbon accounts. However, this 'natural anthropogenic CO2 sink' could be used as a disincentive for certain nations to reduce their anthropogenic CO2 emissions, which would ultimately dampen global efforts to reduce atmospheric CO2 concentrations. Since the oceanic anthropogenic CO2 sink has limited ability to be controlled by human activities, current and future international climate change policies should have an explicit 'EEZ' clause excluding its use within national carbon accounts. PMID:16930461

Preparation and Properties of C/C Hollow Spheres and the Energy Absorption Capacity of the Corresponding Aluminum Syntactic Foams.

PubMed

Yu, Qiyong; Zhao, Yan; Dong, Anqi; Li, Ye

2018-06-12

The present study focuses on the preparation and characterization of lab-scale aluminum syntactic foams (ASFs) filled with hollow carbon spheres (HCSs). A new and original process for the fabrication of HCSs was explored. Firstly, expanded polystyrene beads with an average diameter of 6 mm and coated with carbon fibers/thermoset phenolic resin were produced by the “rolling ball” method. In the next step, the spheres were cured and post-cured, and then carbonized at 1050 °C under vacuum to form the HCSs. The porosity in the shell of the HCSs was decreased by increasing the number of impregnation⁻carbonization cycles. The aluminum syntactic foams were fabricated by casting the molten aluminum into a crucible filled with HCSs. The morphology of the hollow spheres before and after carbonization was investigated by scanning electron microscope (SEM). The compressive properties of the ASF were tested and the energy absorption capacities were calculated according to stress⁻strain curves. The results showed that the ASF filled with HCSs which had been treated by more cycles of impregnation⁻carbonization had higher energy absorption capacity. The aluminum syntactic foam absorbed 34.9 MJ/m³ (28.8 KJ/Kg) at 60% strain, which was much higher than traditional closed cell aluminum foams without particles. The HCSs have a promising future in producing a novel family of metal matrix syntactic foams.

Controllable Synthesis of Tetraethylenepentamine Modified Graphene Foam (TEPA-GF) for the Removal of Lead ions

NASA Astrophysics Data System (ADS)

Han, Zhuo; Tang, Zhihong; Sun, Yuhang; Yang, Junhe; Zhi, Linjie

2015-11-01

3D graphene foam for water purification has become pervasive recently, not only because it has high specific surface area for adsorption capacity, but also it is easily separated from solution after adsorption. However, it is still challenging because it is hard to improve the adsorption capacity as well as maintain the high mechanical strength. To overcome the challenge, Tetraethylenepentamine modified Graphene Foam (TEPA-GF) was synthesized via a one-step hydrothermal method by using GO and TEPA as raw materials. TEPA acted as both cross-linker to combine GO sheets together and reductant of GO during hydrothermal process. Results indicated that the resultant hydrogel’s formation was highly dependent on the mass ratio of TEPA to GO, they cross-linked into a stable hydrogel with perfect cylindrical only when MTEPA: MGO ≥ 1. What’s more, the highest mechanical strength of GF happened at the mass ratio of MTEPA: MGO = 3, which was up to 0.58 kPa. It was worth noting that TEPA-GF demonstrated high adsorption capacity for lead ions, which reached as high as 304.9 mg g-1, much higher than that of other absorbents. Furthermore, TEPA-GF was easily separated from water after adsorption of Pb2+, making it a great potential material for water purification.

Antioxidant Capacity and Polyphenolic Composition as Quality Indicators for Aqueous Infusions of Salvia officinalis L. (sage tea).

PubMed

Walch, Stephan G; Tinzoh, Laura Ngaba; Zimmermann, Benno F; Stühlinger, Wolf; Lachenmeier, Dirk W

2011-01-01

Sage (Salvia officinalis L.) is used as an herbal medicinal product, with the most typical form of application as infusion with boiling water (sage tea). The well-established traditional uses include symptomatic treatment of mild dyspeptic complaints, the treatment of inflammations in the mouth and the throat, and relief of excessive sweating and relief of minor skin inflammations. In this study, sage teas prepared from commercially available products were chemically analyzed for polyphenolic content using liquid chromatography, for antioxidant potential using the oxygen radical absorbance capacity method, and for the Folin-Ciocalteu (FC) index. The sage teas showed a high variation for all parameters studied (up to 20-fold differences for rosmarinic acid). Univariate and multivariate analyses showed that the antioxidant potential, which varied between 0.4 and 1.8 mmol trolox equivalents/100 mL, was highly dependent on rosmarinic acid and its derivatives. The FC index also showed a high correlation to these polyphenols, and could therefore be used as a screening parameter for sage tea quality. The considerable differences in polyphenolic composition and antioxidant capacity between the brands lead to a demand for quality standardization, especially if these sage teas are to be used for therapeutic purposes. Further research also appears to be necessary to characterize the dose-benefit relationship, as sage may also contain a constituent (thujone) with potentially adverse effects.

Fabrication of CIS Absorber Layers with Different Thicknesses Using A Non-Vacuum Spray Coating Method.

PubMed

Diao, Chien-Chen; Kuo, Hsin-Hui; Tzou, Wen-Cheng; Chen, Yen-Lin; Yang, Cheng-Fu

2014-01-03

In this study, a new thin-film deposition process, spray coating method (SPM), was investigated to deposit the high-densified CuInSe₂ absorber layers. The spray coating method developed in this study was a non-vacuum process, based on dispersed nano-scale CuInSe₂ precursor and could offer a simple, inexpensive, and alternative formation technology for CuInSe₂ absorber layers. After spraying on Mo/glass substrates, the CuInSe₂ thin films were annealed at 550 °C by changing the annealing time from 5 min to 30 min in a selenization furnace, using N₂ as atmosphere. When the CuInSe₂ thin films were annealed, without extra Se or H₂Se gas used as the compensation source during the annealing process. The aim of this project was to investigate the influence of annealing time on the densification and crystallization of the CuInSe₂ absorber layers to optimize the quality for cost effective solar cell production. The thickness of the CuInSe₂ absorber layers could be controlled as the volume of used dispersed CuInSe₂-isopropyl alcohol solution was controlled. In this work, X-ray diffraction patterns, field emission scanning electron microscopy, and Hall parameter measurements were performed in order to verify the quality of the CuInSe₂ absorber layers obtained by the Spray Coating Method.

Advanced neutron absorber materials

DOEpatents

Branagan, Daniel J.; Smolik, Galen R.

2000-01-01

A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

Flavonol content in the water extract of the mulberry (Morus alba L.) leaf and their antioxidant capacities.

PubMed

Kim, Gyo-Nam; Jang, Hae-Dong

2011-08-01

The biological activities of the mulberry (Morus alba L.) leaf have been attributed to its flavonoid content. The water extract of the mulberry leaf (WEML) was prepared by autoclaving at 121 °C for 15 min, and the flavonol content of the WEML was determined by HPLC The WEML contained 4 flavonols in the following order: quercetin-3-β-D-glucose (QT-G) > quercetin-3-O-glucose-6″-acetate (QT-GA) > rutin (RT) > quercetin (QT). In the oxygen radical absorbance capacity (ORAC) assay, QT had the highest peroxyl radical-scavenging capacity and a similar hydroxyl radical-scavenging capacity as its glycosides (QT-G, QT-GA, and RT). QT exhibited a stronger cellular antioxidant capacity (CAC) against 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH)- and Cu²⁺-induced oxidative stress in HepG2 cells compared to its glycosides, indicating that the intracellular antioxidant capacity of QT and its glycosides may depend upon both the permeability across the cell membrane and the peroxyl or hydroxyl radical-scavenging capacity. The information presented might be used for developing mulberry leaf-based functional foods. © 2011 Institute of Food Technologists®

An experimental-finite element analysis on the kinetic energy absorption capacity of polyvinyl alcohol sponge.

PubMed

Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

2014-06-01

Polyvinyl alcohol (PVA) sponge is in widespread use for biomedical and tissue engineering applications owing to its biocompatibility, availability, relative cheapness, and excellent mechanical properties. This study reports a novel concept of design in energy absorbing materials which consist in the use of PVA sponge as an alternative reinforcement material to enhance the energy loss of impact loads. An experimental study is carried out to measure the mechanical properties of the PVA sponge under uniaxial loading. The kinetic energy absorption capacity of the PVA sponge is computed by a hexahedral finite element (FE) model of the steel ball and bullet through the LS-DYNA code under impact load at three different thicknesses (5, 10, 15mm). The results show that a higher sponge thickness invokes a higher energy loss of the steel ball and bullet. The highest energy loss of the steel ball and bullet is observed for the thickest sponge with 160 and 35J, respectively. The most common type of traumatic brain injury in which the head subject to impact load causes the brain to move within the skull and consequently brain hemorrhaging. These results suggest the application of the PVA sponge as a great kinetic energy absorber material compared to commonly used expanded polystyrene foams (EPS) to absorb most of the impact energy and reduces the transmitted load. The results might have implications not only for understanding of the mechanical properties of PVA sponge but also for use as an alternative reinforcement material in helmet and packaging material design. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of an Mg-Based Alloy with High Hydriding and Dehydriding Rates and Large Hydrogen Storage Capacity by Adding TaF5.

PubMed

Kwak, Young Jun; Lee, Seong Ho; Song, Myoung Youp

2018-09-01

A sample with a composition of 95 wt% Mg + 5 wt% TaF5 (named Mg-5TaF5) was prepared by reactive mechanical grinding. The activation of Mg-5TaF5 was not necessary, and Mg-5TaF5 had an effective hydrogen storage capacity (the quantity of hydrogen absorbed for 60 min) larger than 5 wt%. At the first cycle (n = 1), the sample absorbed 4.50 wt% H for 10 min and 5.06 wt% H for 60 min at 593 K under 12 bar H2. At n = 1, the sample desorbed 1.58 wt% H for 10 min and 4.93 wt% H for 60 min at 593 K under 1.0 bar H2. The Mg-5TaF5 sample dehydrided at n = 3 contained MgF2 and Ta2H. The hydriding-dehydriding cycling of the sample, which forms MgF2 and Ta2H by reaction with hydrogen, is considered to produce defects on the surface of and inside the Mg particles, to create clean surfaces, and to reduce the particle size of Mg, due to the repetition of expansion with hydrogen absorption and contraction with hydrogen release. Mg-5TaF5 had a higher hydriding rate and a higher dehydriding rate after an incubation period and greater quantities of hydrogen absorbed and desorbed for 60 min than Mg-10TaF5, Mg-10MnO, or Mg-10Fe2O3.

Real-time measurement and monitoring of absorbed dose for electron beams

NASA Astrophysics Data System (ADS)

Korenev, Sergey; Korenev, Ivan; Rumega, Stanislav; Grossman, Leon

2004-09-01

The real-time method and system for measurement and monitoring of absorbed dose for industrial and research electron accelerators is considered in the report. The system was created on the basis of beam parameters method. The main concept of this method consists in the measurement of dissipated kinetic energy of electrons in the irradiated product, determination of number of electrons and mass of irradiated product in the same cell by following calculation of absorbed dose in the cell. The manual and automation systems for dose measurements are described. The systems are acceptable for all types of electron accelerators.

Point-particle method to compute diffusion-limited cellular uptake.

PubMed

Sozza, A; Piazza, F; Cencini, M; De Lillo, F; Boffetta, G

2018-02-01

We present an efficient point-particle approach to simulate reaction-diffusion processes of spherical absorbing particles in the diffusion-limited regime, as simple models of cellular uptake. The exact solution for a single absorber is used to calibrate the method, linking the numerical parameters to the physical particle radius and uptake rate. We study the configurations of multiple absorbers of increasing complexity to examine the performance of the method by comparing our simulations with available exact analytical or numerical results. We demonstrate the potential of the method to resolve the complex diffusive interactions, here quantified by the Sherwood number, measuring the uptake rate in terms of that of isolated absorbers. We implement the method in a pseudospectral solver that can be generalized to include fluid motion and fluid-particle interactions. As a test case of the presence of a flow, we consider the uptake rate by a particle in a linear shear flow. Overall, our method represents a powerful and flexible computational tool that can be employed to investigate many complex situations in biology, chemistry, and related sciences.

Simultaneous Spectrophotometric Determination of Elbasvir and Grazoprevir in a Pharmaceutical Preparation.

PubMed

Attia, Khalid A M; El-Abasawi, Nasr M; El-Olemy, Ahmed; Abdelazim, Ahmed H

2018-03-01

Three UV spectrophotometric methods have been developed for the simultaneous determination of two new Food and Drug Administration-approved drugs, elbasvir (EBV) and grazoprevir (GRV), in their combined pharmaceutical dosage form. These methods include dual wavelength (DW), classic least-squares (CLS), and principal component regression (PCR). To achieve the DW method, two wavelengths were chosen for each drug in a way to ensure the difference in absorbance was zero from one drug to the other. GRV revealed equal absorbance at 351 and 315 nm, for which the distinctions in absorbance were measured for the determination of EBV. In the same way, distinctions in absorbance at 375 and 334.5 nm were measured for the determination of GRV. Alternatively, the CLS and PCR models were applied to the spectra analysis because the synchronous inclusion of many unreal wavelengths rather than using a single wavelength greatly increased the precision and predictive ability of the methods. The proposed methods were successfully applied to the assay of these drugs in their pharmaceutical formulation. The obtained results were statistically compared with manufacturing methods. The results conclude that there was no significant difference between the proposed methods and the manufacturing method with respect to accuracy and precision.

Core--strategy leading to high reversible hydrogen storage capacity for NaBH4.

PubMed

Christian, Meganne L; Aguey-Zinsou, Kondo-François

2012-09-25

Owing to its high storage capacity (10.8 mass %), sodium borohydride (NaBH(4)) is a promising hydrogen storage material. However, the temperature for hydrogen release is high (>500 °C), and reversibility of the release is unachievable under reasonable conditions. Herein, we demonstrate the potential of a novel strategy leading to high and stable hydrogen absorption/desorption cycling for NaBH(4) under mild pressure conditions (4 MPa). By an antisolvent precipitation method, the size of NaBH(4) particles was restricted to a few nanometers (<30 nm), resulting in a decrease of the melting point and an initial release of hydrogen at 400 °C. Further encapsulation of these nanoparticles upon reaction of nickel chloride at their surface allowed the synthesis of a core--shell nanostructure, NaBH(4)@Ni, and this provided a route for (a) the effective nanoconfinement of the melted NaBH(4) core and its dehydrogenation products, and (b) reversibility and fast kinetics owing to short diffusion lengths, the unstable nature of nickel borohydride, and possible modification of reaction paths. Hence at 350 °C, a reversible and steady hydrogen capacity of 5 mass % was achieved for NaBH(4)@Ni; 80% of the hydrogen could be desorbed or absorbed in less than 60 min, and full capacity was reached within 5 h. To the best of our knowledge, this is the first time that such performances have been achieved with NaBH(4). This demonstrates the potential of the strategy in leading to major advancements in the design of effective hydrogen storage materials from pristine borohydrides.

Influence of Fruit Ripening on Color, Organic Acid Contents, Capsaicinoids, Aroma Compounds, and Antioxidant Capacity of Shimatogarashi (Capsicum frutescens).

PubMed

Manikharda; Takahashi, Makoto; Arakaki, Mika; Yonamine, Kaoru; Hashimoto, Fumio; Takara, Kensaku; Wada, Koji

2018-01-01

Shimatogarashi (Capsicum frutescens) is a typical chili pepper domesticated in southern Japan. Important traits of Shimatogarashi peppers, such as color; proportion of organic acids, capsaicinoids, and aromatic compounds; and antioxidant activity in three stages of maturity (green (immature), orange (turning), and red (mature) stages) were characterized. The results indicated that the concentration of organic acids, including ascorbic, citric, and malic acid, increased during ripening. In addition, the amount of capsaicinoids, which are responsible for the pungent taste of chili peppers, increased as the fruit matured to the orange and red stages. The volatile compound profile of Shimatogarashi was dominated by the presence of esters, which mainly contributed to fruity notes. The total amount of volatile compounds analyzed by gas chromatography-headspace solid-phase microextraction (GC-HS-SPME), especially esters, decreased as the fruit changed in color from green to red. This was in contrast to the amount of terpenoids, especially limonene, which increased at the red stage, denoting a change in flavor from fruity to a more citrus-like aroma. Based on the total phenolic content (TPC), the oxygen radical absorbance capacity (ORAC) and the diphenylpicrylhydrazyl (DPPH) free radical method, the antioxidant capacity of Shimatogarashi showed an increase at the mature red stage. However, while the red stage showed higher pungency and antioxidant capacity as well as an attractive color, the results of aromatic compound analysis revealed that the immature green stage had the advantages of having pleasant fruity smell, making it suitable for use in condiments.

Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor

DOEpatents

Dhere, Neelkanth G.; Kadam, Ankur A.

2009-12-15

A method of forming a CIGSS absorber layer includes the steps of providing a metal precursor, and selenizing the metal precursor using diethyl selenium to form a selenized metal precursor layer (CIGSS absorber layer). A high efficiency solar cell includes a CIGSS absorber layer formed by a process including selenizing a metal precursor using diethyl selenium to form the CIGSS absorber layer.

Method for Bacterial Growth and Ammonia Production and Effect of Inhibitory Substances in Disposable Absorbent Hygiene Products.

PubMed

Forsgren-Brusk, Ulla; Yhlen, Birgitta; Blomqvist, Marie; Larsson, Peter

The purpose of this study was to evaluate a pragmatic laboratory method to provide a technique for developing incontinence products better able to reduce malodor when used in the clinical setting. Bacterial growth and bacterially formed ammonia in disposable absorbent incontinence products was measured by adding synthetic urine inoculated with bacteria to test samples cut from the crotch area of the product. The inhibitory effect's of low pH (4.5 and 4.9) and 3 antimicrobial substances-chlorhexidine, polyhexamethylene biguanide (PHMB), and thymol-at 2 concentrations each, were studied. From the initial inocula of 3.3 log colony-forming units per milliliter (cfu/mL) at baseline, the bacterial growth of the references increased to 5.0 to 6.0 log cfu/mL at 6 hours for Escherichia coli, Proteus mirabilis, and Enterococcus faecalis. At 12 hours there was a further increase to 7.0 to 8.9 log cfu/mL. Adjusting the pH of the superabsorbent in the incontinence product from 6.0 to pH 4.5 and pH 4.9 significantly (P < .05) inhibited the bacterial growth rates, in most cases, both at 6 and 12 hours. The effect was most pronounced at pH 4.5. Chlorhexidine had significant (P < .05) inhibitory effect on E. coli and E. faecalis, and at 12 hours also on P. mirabilis. For PHMB and thymol the results varied. At 6 hours, the ammonia concentration in the references (pH 6.0) was 200 to 300 ppm and it was 1500 to 1600 ppm at 8 hours. At pH 4.5, no or little ammonia production was measured at 6 and 8 hours. At pH 4.9, there was a significant reduction (P < .01). Chlorhexidine and PHMB exerted a significant (P < .01 or P < .001) inhibitory effect on ammonia production at both concentrations and at 6 and 8 hours. Thymol 0.003% and 0.03% showed inhibitory effect at both 6 hours (P < .01 or P < .001) and at 8 hours (P < .05 or P < .001). The method described in this study can be used to compare the ability of various disposable absorbent products to inhibit bacterial growth and ammonia production. This technique, we describe, provides a pragmatic method for assessing the odor-inhibiting capacity of specific incontinence products.

Addressing Information Proliferation: Applications of Information Extraction and Text Mining

ERIC Educational Resources Information Center

Li, Jingjing

2013-01-01

The advent of the Internet and the ever-increasing capacity of storage media have made it easy to store, deliver, and share enormous volumes of data, leading to a proliferation of information on the Web, in online libraries, on news wires, and almost everywhere in our daily lives. Since our ability to process and absorb this information remains…

Measurement, monitoring, and verification: make it work!

Treesearch

Coeli M. Hoover

2011-01-01

The capacity of forests to absorb and store carbon is certainly, as the authors note, an important tool in the greenhouse gas mitigation toolbox. Our understanding of what elements can make forest carbon offset projects successful has grown a great deal over time, as the global community has come to understand that forest degradation and conversion are the result of a...

Applications of hydrogels in the nursery and during outplanting

Treesearch

Thomas D. Landis; Diane L. Haase

2012-01-01

Hydrogels have a variety of potential uses including application to plants in the nursery and at the time of outplanting. Absorptive capacity of these gels is influenced by their chemical and physical composition as well as the ion concentration of the liquid being absorbed. The most common uses for hydrogels in nurseries or during outplanting are incorporation or root...

Mission Connect Mild TBI Translational Research Consortium

DTIC Science & Technology

2009-08-01

and only minimally effective in-vivo. Initially, we identified carbon nanomaterials as potent antioxidants using a chemical ORAC assay. We...radical absorbency capacity ( ORAC ) assay using a chemical source for the oxygen radical (,′-azodiisobutyramidine dihydrochloride) (Table 1). We...nanomaterials determined with a chemically based ORAC assay.a Nanomaterial Trolox Equivalents (TE) Trolox Mass Equivalents (TME) p-SWCNT 14046 5.02

Improving Reading Comprehension in Kindergarten through 3rd Grade: IES Practice Guide. NCEE 2010-4038

ERIC Educational Resources Information Center

Shanahan, Timothy; Callison, Kim; Carriere, Christine; Duke, Nell K.; Pearson, P. David; Schatschneider, Christopher; Torgesen, Joseph

2010-01-01

Strong reading comprehension skills are central not only to academic and professional success, but also to a productive social and civic life. These skills build the capacity to learn independently, to absorb information on a variety of topics, to enjoy reading, and to experience literature more deeply. Despite the growing demand for highly…

Relationship between the structures of flavonoids and oxygen radical absorbance capacity values: a quantum chemical analysis.

PubMed

Zhang, Di; Liu, Yixiang; Chu, Le; Wei, Ying; Wang, Dan; Cai, Shengbao; Zhou, Feng; Ji, Baoping

2013-02-28

Various radical-scavenging activities (RSA) assessment assays are based on discrete mechanisms and on using different radical sources. Few studies have analyzed the structural significance of flavonoids in their peroxyl radical activities in the oxygen radical absorbance capacity (ORAC) assay. In this study, the RSA of 13 flavonoids in two ORAC assays with different probes (fluorescein and pyrogallol red) were investigated. Neither O-H bond dissociation enthalpy nor ionization potential values of flavonoids correlated with ORAC values. The proton affinity (PA) and electron transfer enthalpy (ETE) values, which were obtained via the sequential proton-loss electron-transfer mechanism, were significantly associated with the ORAC(pyrogallol Red) and ORAC(fluorescein) assays, respectively. Thus, PA represented the kinetic aspect of RSA, whereas ETE reflected the RSA extent. The PA values and the most acidic sites of flavonoids were affected by intramolecular electronic interactions, H-bonding, 3-hydroxyl group in the C ring, and conjugation systems. The stability of the deprotonated flavonoid determined the ETE value. Apart from the PA and ETE values in the first oxidation step of flavonoids, the PA and ETE values in the second oxidation step also affected the ORAC values of flavonoids.

Oil spills abatement: factors affecting oil uptake by cellulosic fibers.

PubMed

Payne, Katharine C; Jackson, Colby D; Aizpurua, Carlos E; Rojas, Orlando J; Hubbe, Martin A

2012-07-17

Wood-derived cellulosic fibers prepared in different ways were successfully employed to absorb simulated crude oil, demonstrating their possible use as absorbents in the case of oil spills. When dry fibers were used, the highest sorption capacity (six parts of oil per unit mass of fiber) was shown by bleached softwood kraft fibers, compared to hardwood bleached kraft and softwood chemithermomechanical pulp(CTMP) fibers. Increased refining of CTMP fibers decreased their oil uptake capacity. When the fibers were soaked in water before exposure to the oil, the ability of the unmodified kraft fibers to sorb oil was markedly reduced, whereas the wet CTMP fibers were generally more effective than the wet kraft fibers. Predeposition of lignin onto the surfaces of the bleached kraft fibers improved their ability to take up oil when wet. Superior ability to sorb oil in the wet state was achieved by pretreating the kraft fibers with a hydrophobic sizing agent, alkenylsuccinic anhydride (ASA). Contact angle tests on a model cellulose surface showed that some of the sorption results onto wetted fibers could be attributed to the more hydrophobic nature of the fibers after treatment with either lignin or ASA.

Facile synthesis and lithium storage properties of a porous NiSi2/Si/carbon composite anode material for lithium-ion batteries.

PubMed

Jia, Haiping; Stock, Christoph; Kloepsch, Richard; He, Xin; Badillo, Juan Pablo; Fromm, Olga; Vortmann, Britta; Winter, Martin; Placke, Tobias

2015-01-28

In this work, a novel, porous structured NiSi2/Si composite material with a core-shell morphology was successfully prepared using a facile ball-milling method. Furthermore, the chemical vapor deposition (CVD) method is deployed to coat the NiSi2/Si phase with a thin carbon layer to further enhance the surface electronic conductivity and to mechanically stabilize the whole composite structure. The morphology and porosity of the composite material was evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption measurements (BJH analysis). The as-prepared composite material consists of NiSi2, silicon, and carbon phases, in which the NiSi2 phase is embedded in a silicon matrix having homogeneously distributed pores, while the surface of this composite is coated with a carbon layer. The electrochemical characterization shows that the porous and core-shell structure of the composite anode material can effectively absorb and buffer the immense volume changes of silicon during the lithiation/delithiation process. The obtained NiSi2/Si/carbon composite anode material displays an outstanding electrochemical performance, which gives a stable capacity of 1272 mAh g(-1) for 200 cycles at a charge/discharge rate of 1C and a good rate capability with a reversible capacity of 740 mAh g(-1) at a rate of 5C.

Rate-based congestion control in networks with smart links, revision. B.S. Thesis - May 1988

NASA Technical Reports Server (NTRS)

Heybey, Andrew Tyrrell

1990-01-01

The author uses a network simulator to explore rate-based congestion control in networks with smart links that can feed back information to tell senders to adjust their transmission rates. This method differs in a very important way from congestion control in which a congested network component just drops packets - the most commonly used method. It is clearly advantageous for the links in the network to communicate with the end users about the network capacity, rather than the users unilaterally picking a transmission rate. The components in the middle of the network, not the end users, have information about the capacity and traffic in the network. The author experiments with three different algorithms for calculating the control rate to feed back to the users. All of the algorithms exhibit problems in the form of large queues when simulated with a configuration modeling the dynamics of a packet-voice system. However, the problems are not with the algorithms themselves, but with the fact that feedback takes time. If the network steady-state utilization is low enough that it can absorb transients in the traffic through it, then the large queues disappear. If the users are modified to start sending slowly, to allow the network to adapt to a new flow without causing congestion, a greater portion of the network's bandwidth can be used.

Coupled-rearrangement-channels calculation of the three-body system under the absorbing boundary condition

NASA Astrophysics Data System (ADS)

Iwasaki, M.; Otani, R.; Ito, M.; Kamimura, M.

2016-06-01

We formulate the absorbing boundary condition (ABC) in the coupled rearrangement-channels variational method (CRCVM) for the three-body problem. The absorbing potential is introduced in the system of the identical three-bosons, on which the boson symmetry is explicitly imposed by considering the rearrangement channels. The resonance parameters and the strength of the monopole breakup are calculated by the CRCVM + ABC method, and the results are compared with the complex scaling method (CSM). We have found that the results of the ABC method are consistent with the CSM results. The effect of the boson symmetry, which is often neglected in the calculation of the triple α reactions, is also discussed.

A-TEEMTM, a new molecular fingerprinting technique: simultaneous absorbance-transmission and fluorescence excitation-emission matrix method

NASA Astrophysics Data System (ADS)

Quatela, Alessia; Gilmore, Adam M.; Steege Gall, Karen E.; Sandros, Marinella; Csatorday, Karoly; Siemiarczuk, Alex; (Ben Yang, Boqian; Camenen, Loïc

2018-04-01

We investigate the new simultaneous absorbance-transmission and fluorescence excitation-emission matrix method for rapid and effective characterization of the varying components from a mixture. The absorbance-transmission and fluorescence excitation-emission matrix method uniquely facilitates correction of fluorescence inner-filter effects to yield quantitative fluorescence spectral information that is largely independent of component concentration. This is significant because it allows one to effectively monitor quantitative component changes using multivariate methods and to generate and evaluate spectral libraries. We present the use of this novel instrument in different fields: i.e. tracking changes in complex mixtures including natural water, wine as well as monitoring stability and aggregation of hormones for biotherapeutics.

Optimization of the acoustic absorption coefficients of certain functional absorbents

NASA Technical Reports Server (NTRS)

Pocsa, V.; Biborosch, L.; Veres, A.; Halpert, E.; Lorian, R.; Botos, T.

1974-01-01

The sound absorption coefficients of some functional absorbents (mineral wool plates) are determined by the reverberation chamber method. The influence of the angle of inclination of the sound absorbing material with respect to the surface to be treated is analyzed as well as the influence of the covering index, defined as the ratio of the designed area of a plate and the area of the treated surface belonging to another plate. As compared with the conventional method of applying sound-absorbing plates, the analyzed structures have a higher technological and economical efficiency. The optimum structure corresponds to an angle of inclination of 15 deg and a covering index of 0.8.

Absorption-emission optrode and methods of use thereof

DOEpatents

Hirschfeld, T.B.

1990-05-29

A method and apparatus are described for monitoring the physical and chemical properties of a sample fluid by measuring an optical signal generated by a fluorescent substance and modulated by an absorber substance. The emission band of the fluorescent substance overlaps the absorption band of the absorber substance, and the degree of overlap is dependent on the physical and chemical properties of the sample fluid. The fluorescent substance and absorber substance are immobilized on a substrate so that an effective number of molecules thereof are sufficiently close for resonant energy transfer to occur, thereby providing highly efficient modulation of the fluorescent emissions of the fluorescent substance by the absorber substance. 4 figs.

Sodium metabisulfite–induced polymerization of sickle cell hemoglobin incubated in the extracts of three medicinal plants (Anacardium occidentale, Psidium guajava, and Terminalia catappa)

PubMed Central

Chikezie, Paul Chidoka

2011-01-01

Background: The exploitation and utilization of vast varieties of herbal extracts may serve as alternative measures to deter aggregation of deoxygenated sickle cell hemoglobin (deoxyHbS) molecules. Objective: The present in vitro study ascertained the capacity of three medicinal plants, namely, Anacardium occidentale, Psidium guajava, and Terminalia catappa, to alter polymerization of HbS. Materials and Methods: Spectrophotometric method was used to monitor the level of polymerization of hemolysate HbS molecules treated with sodium metabisulfite (Na2 S2 O5) at a regular interval of 30 s for a period of 180 s in the presence of separate aqueous extracts of A. occidentale, P. guajava, and T. catappa. At time intervals of 30 s, the level of polymerization was expressed as percentage of absorbance relative to the control sample at the 180th s. Results: Although extracts of the three medicinal plants caused significant (P < 0.05) reduction in polymerization of deoxyHbS molecules, the corresponding capacity in this regard diminished with increase in incubation time. Aqueous extract of P. guajava exhibited the highest capacity to reduced polymerization of deoxyHbS molecules. Whereas at t > 60 s, extract concentration of 400 mg% of A. occidentale activated polymerization of deoxyHbS molecules by 6.23±1.34, 14.53±1.67, 21.15±1.89, and 24.42±1.09%, 800 mg% of T. catappa at t > 30 s gave values of 2.50±1.93, 5.09±1.96, 10.00±0.99, 15.38±1.33, and 17.31±0.97%. Conclusion: The capacity of the three medicinal plants to interfere with polymerization of deoxyHbS molecules depended on the duration of incubation and concentration of the extracts. PMID:21716622

Adsorption and kinetics study of manganesse (II) in waste water using vertical column method by sugar cane bagasse

NASA Astrophysics Data System (ADS)

Zaini, H.; Abubakar, S.; Rihayat, T.; Suryani, S.

2018-03-01

Removal of heavy metal content in wastewater has been largely done by various methods. One effective and efficient method is the adsorption method. This study aims to reduce manganese (II) content in wastewater based on column adsorption method using absorbent material from bagasse. The fixed variable consisted of 50 g adsorbent, 10 liter adsorbate volume, flow rate of 7 liters / min. Independent variable of particle size with variation 10 – 30 mesh and contact time with variation 0 - 240 min and respon variable concentration of adsorbate (ppm), pH and conductivity. The results showed that the adsorption process of manganese metal is influenced by particle size and contact time. The adsorption kinetics takes place according to pseudo-second order kinetics with an equilibrium adsorption capacity (qe: mg / g) for 10 mesh adsorbent particles: 0.8947; 20 mesh adsorbent particles: 0.4332 and 30 mesh adsorbent particles: 1.0161, respectively. Highest removal efficience for 10 mesh adsorbent particles: 49.22% on contact time 60 min; 20 mesh adsorbent particles: 35,25% on contact time 180 min and particle 30 mesh adsorbent particles: 51,95% on contact time 150 min.

Development of a Safe and Effective Skin Decontamination System: Demonstration and Validation

DTIC Science & Technology

1987-02-01

Solids Capacity Capacitymonths "C Abe t % AC=4_E9Z FP mecrlg 0a 25 0.10 89.5 340.5 0.320 1 25 0.01 90.0 343.5 - 2 25 0.01 90.5 323.0 0.150 3 25 0.01...Basicity/Acidity b Kin I UV Abs - Kinetic Iodine Ultraviolet Absorbance C ND no data I I I I I I - 51 - Table 15 Accelerated Storaae Stability...Results on Amberfard XE-556 Lot EOJ3937 Reactive Time, Temp, Extract- Solids, Acidity, Basicity, B/A Kin I Capacity, d C ables.% % mea/g meaqg R UV Abs mea

Improving the antioxidant functionality of Citrus junos Tanaka (yuzu) fruit juice by underwater shockwave pretreatment.

PubMed

Kuraya, Eisuke; Nakada, Shina; Touyama, Akiko; Itoh, Shigeru

2017-02-01

Citrus junos Tanaka (yuzu) has a strong characteristic aroma, and hence, yuzu juice is used in a number of Japanese foods. We herein evaluated the functional compounds of yuzu juice to investigate whether underwater shockwave pretreatment affects its functionality. Employing the shockwave pretreatment at an increased discharge and energy of 3.5kV and 4.9kJ, respectively, resulted in an increase in the flavanone glycoside content and oxygen radical absorbance capacity (ORAC). The ORAC value of yuzu juice cultivated in Rikuzentakata increased approximately 1.7 times upon underwater shockwave pretreatment. The treatment method proposed herein exhibited reliable and good performance for the extraction of functional and antioxidant chemicals in yuzu fruits, and was comparable with traditional squeezing methods. The high applicability and reliability of this technique for improving the antioxidant functionality of yuzu fruit juice was demonstrated, confirming the potential for application to a wide range of food extraction processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of different cooking methods on nutritional value and antioxidant activity of cultivated mushrooms.

PubMed

Roncero-Ramos, Irene; Mendiola-Lanao, Mónica; Pérez-Clavijo, Margarita; Delgado-Andrade, Cristina

2017-05-01

Influence of culinary treatments (boiling, microwaving, grilling, and deep frying) on proximate composition and antioxidant capacity of cultivated mushrooms (Agaricus bisporus, Lentinula edodes, Pleurotus ostreatus, and Pleurotus eryngii) was studied. Proximate composition was affected by the cooking method and the mushrooms species. Frying induced more severe losses in protein, ash, and carbohydrates content but increased the fat and energy. Boiling improved the total glucans content by enhancing the β-glucans fraction. A significant decrease was detected in the antioxidant activity especially after boiling and frying, while grilled and microwaved mushrooms reached higher values of antioxidant activity. Maillard reaction products could be partially responsible, as supported by the absorbance values measured at 420 nm. Since cooking techniques clearly influence the nutritional attributes of mushrooms, the proper selection of treatments is a key factor to prevent/reduce nutritional losses. Microwaving and grilling were established as the best processes to maintain the nutritional profile of mushrooms.

Computation of scattering matrix elements of large and complex shaped absorbing particles with multilevel fast multipole algorithm

NASA Astrophysics Data System (ADS)

Wu, Yueqian; Yang, Minglin; Sheng, Xinqing; Ren, Kuan Fang

2015-05-01

Light scattering properties of absorbing particles, such as the mineral dusts, attract a wide attention due to its importance in geophysical and environment researches. Due to the absorbing effect, light scattering properties of particles with absorption differ from those without absorption. Simple shaped absorbing particles such as spheres and spheroids have been well studied with different methods but little work on large complex shaped particles has been reported. In this paper, the surface Integral Equation (SIE) with Multilevel Fast Multipole Algorithm (MLFMA) is applied to study scattering properties of large non-spherical absorbing particles. SIEs are carefully discretized with piecewise linear basis functions on triangle patches to model whole surface of the particle, hence computation resource needs increase much more slowly with the particle size parameter than the volume discretized methods. To improve further its capability, MLFMA is well parallelized with Message Passing Interface (MPI) on distributed memory computer platform. Without loss of generality, we choose the computation of scattering matrix elements of absorbing dust particles as an example. The comparison of the scattering matrix elements computed by our method and the discrete dipole approximation method (DDA) for an ellipsoid dust particle shows that the precision of our method is very good. The scattering matrix elements of large ellipsoid dusts with different aspect ratios and size parameters are computed. To show the capability of the presented algorithm for complex shaped particles, scattering by asymmetry Chebyshev particle with size parameter larger than 600 of complex refractive index m = 1.555 + 0.004 i and different orientations are studied.

Additive manufacturing of RF absorbers

NASA Astrophysics Data System (ADS)

Mills, Matthew S.

The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

Multi-target determination of organic ultraviolet absorbents in organism tissues by ultrasonic assisted extraction and ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Peng, Xianzhi; Jin, Jiabin; Wang, Chunwei; Ou, Weihui; Tang, Caiming

2015-03-06

A sensitive and reliable method was developed for multi-target determination of 13 most widely used organic ultraviolet (UV) absorbents (including UV filters and UV stabilizers) in aquatic organism tissues. The organic UV absorbents were extracted using ultrasonic-assisted extraction, purified via gel permeation chromatography coupled with silica gel column chromatography, and determined by ultra-high performance liquid chromatography-tandem mass spectrometry. Recoveries of the UV absorbents from organism tissues mostly ranged from 70% to 120% from fish filet with satisfactory reproducibility. Method quantification limits were 0.003-1.0ngg(-1) dry weight (dw) except for 2-ethylhexyl 4-methoxycinnamate. This method has been applied to analysis of the UV absorbents in wild and farmed aquatic organisms collected from the Pearl River Estuary, South China. 2-Hydroxy-4-methoxybenzophenone and UV-P were frequently detected in both wild and farmed marine organisms at low ngg(-1)dw. 3-(4-Methylbenzylidene)camphor and most of the benzotriazole UV stabilizers were also frequently detected in maricultured fish. Octocrylene and 2-ethylhexyl 4-methoxycinnamate were not detected in any sample. This work lays basis for in-depth study about bioaccumulation and biomagnification of the UV absorbents in marine environment. Copyright © 2015 Elsevier B.V. All rights reserved.

A "two-objective, one-area" procedure in absorption microphotometry and its application using an inverted microscope.

PubMed

Chaubal, K A

1988-08-01

A 'two-objective, one-area' method and related equations are suggested to measure absorbance of microscopic stained objects. In such work, the measuring field invariably includes an image of the object and some clear area surrounding the image. The total intensity in the two areas is measured photometrically, using two different objectives, and substituted in the equation for absorbance. The equation is independent of the term representing intensity from the clear area and hence the error in the measurement of absorbance is reduced. The limitations of the 'two-objective, one-area' method are discussed and its pragmatic operation described with an experimental setup involving an inverted microscope. The method permits measurement of intensity in a part of a stained cell while the rest of the cell remains in the field of view. The method is applied to measure absorbance in Giemsa stained ascites cells and Feulgen stained liver and Human Amnion cells.

Copolymer natural latex in concrete: Dynamic evaluation through energy dissipation of polymer modified concrete

NASA Astrophysics Data System (ADS)

Andayani, Sih Wuri; Suratman, Rochim; Imran, Iswandi; Mardiyati

2018-05-01

Portland cement concrete have been used in construction due to its strength and ecomical value. But it has some limitations, such low flexural strength, low tensile strength, low chemical resistant and etc. Due to its limitations in flexural and tensile strength, Portland cement concrete more susceptible by seismic force. There are some methods for improving its limitations. Polymer addition into concrete mixture could be one of solution for improving the flexural and tensile strength, in aiming to get erthquake resistant properties. Also, the eartquake resistant could be achieved by improving energy dissipation capacity. In this research, the earthquake resistant evalution was approached from dynamic evaluation through energy dissipation capacity, after polymer addition as concrete additives. The polymers were natural latex (Indonesian naural resource) grafted with styrene and methacrylate, forming copolymer - natural latex methacrylate (KOLAM) and copolymer - natural latex styrene (KOLAS). They were added into concrete mixture resulting polymer modified concrete. The composition of polymer are 1%, 5% and 10% weight/weight of cement. The higher capacity of energy dissipation will give more capability in either absorbing or dissipating energy, and it was predicted would give better earthquake resistant.. The use of KOLAM gave better performance than KOLAS in energy dissipation capacity. It gave about 46% for addition of 1% w/w compared to Portland cement concrete. But for addition 5% w/w and 10% w/w, they gave about 7% and 5% higher energy dissipation capacity. The KOLAM addition into concrete mixture would reduce the maximum impact load with maximumabout 35% impact load reducing after 1% w/w addition. The higher concentration of KOLAM in concrete mixture, lower reducing of impact load, they were about 4% and 3% for KOLAM 5% and 10%. For KOLAS addition in any compositions, there were no positive trend either in energy dissipation capacity or impact load properties, compared to Portland cement concrete.

Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

DOEpatents

Walker, Richard J.

1986-01-01

A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

Thin-film solar cell fabricated on a flexible metallic substrate

DOEpatents

Tuttle, John R.; Noufi, Rommel; Hasoon, Falah S.

2006-05-30

A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate

DOEpatents

Tuttle, J. R.; Noufi, R.; Hasoon, F. S.

2006-05-30

A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

Techniques for measuring intercepted and absorbed PAR in corn canopies

NASA Technical Reports Server (NTRS)

Gallo, K. P.; Daughtry, C. S. T.

1984-01-01

The quantity of radiation potentially available for photosynthesis that is captured by the crop is best described as absorbed photosynthetically active radiation (PAR). Absorbed PAR (APAR) is the difference between descending and ascending fluxes. The four components of APAR were measured above and within two planting densities of corn (Zea mays L.) and several methods of measuring and estimating APAR were examined. A line quantum sensor that spatially averages the photosynthetic photon flux density provided a rapid and portable method of measuring APAR. PAR reflectance from the soil (Typic Argiaquoll) surface decreased from 10% to less than 1% of the incoming PAR as the canopy cover increased. PAR reflectance from the canopy decreased to less than 3% at maximum vegetative cover. Intercepted PAR (1 - transmitted PAR) generally overestimated absorbed PAR by less than 4% throughout most of the growing season. Thus intercepted PAR appears to be a reasonable estimate of absorbed PAR.

Design of High Resolution Soft X-Ray Microcalorimeters Using Magnetic Penetration Thermometers

NASA Technical Reports Server (NTRS)

Busch. Sarah; Balvin, Manuel; Bandler, Simon; Denis, Kevin; Finkbeiner, Fred; Porst, Jan-Patrick; Sadlier, Jack; Smith, Stephen; Stevenson, Thomas

2012-01-01

We have designed high-resolution soft x-ray microcalorimeters using magnetic penetration thermometers (MPTs) in an array of pixels covering a total of 2 square centimeters to have a resolving power of 300 at energies around 300 eV. This performance is desirable for studying the soft x-ray background from the warm hot intergalactic medium. MPT devices have small sensor heat capacity and high responsivities, which makes them excellent detector technology for attempting to attain sub-eV resolution. We are investigating the feasibility of pixels with absorbers that are 625 x 625 square micrometers, up to 1 x 1 square millimeters in area and 0.35 micrometer thick and thinner. Our tests have shown that suspended gold absorbers 0.35 micrometers thick (RRR = 6.7) are feasible to fabricate. We modeled the thermal diffusion from such thin gold over the size of a 625 x 625 square micrometer absorber, and conclude that the effect of the thermalization on the resolution of a 300 eV photon is an additional approximately 0.2 eV FWHM of broadening. We discuss the thermal effects of small absorber attachment sterns on solid substrate, as well as considerations for multiplexed readout. We will present the progress we have made towards building and testing this soft x-ray detector.

Analysis of Urban Forest Needs as Anthropogenic (CO2) Gas Absorbent in Semarang City

NASA Astrophysics Data System (ADS)

Febriani, Anisa Putri; Retnaningsih Soeprobowati, Tri; Maryono

2018-02-01

Green open space in cities in significant needs to maintenance environment quality. On of the critical function is to absorb increasing number of gas CO2. Therefore, developing urban forest in cities is very importance. The objective of the study is to determine the area of urban forest as CO2 gas anthropogenic absorb which is formed from fuel, diesel fuel, liquid petroleum gas. The study consists of (1) Analyzing the number of CO2 gas emission by calculating the needs of petroleum and gas based on the number of population, (2) Analyzing the power of gas absorption, (3) Measuring the air concentration of CO2 gas ambient based on daily traffic activities. This study shown that from year 2013 to year 2017, the increasing of urban forest is not so significant. For year 2013 the green open space in Semarang City are 373.67 hectares (7.5 percent from Semarang City area), consists of 239 parks, 11 public cemeteries, production forests, community forests, and urban forests, however the area of urban forest is not increase. The study assess that Antidesmabunius is one of the green species which high absorb capacity planted for Semarang. This trees produce 31,31 ton annually. This study proposed to fostering Antidesmabunius as one principle threes in Semarang urban forest.

High-throughput analysis of bergamot essential oil by fast solid-phase microextraction-capillary gas chromatography-flame ionization detection.

PubMed

Tranchida, Peter Quinto; Presti, Maria Lo; Costa, Rosaria; Dugo, Paola; Dugo, Giovanni; Mondello, Luigi

2006-01-20

The advantages of using a narrow-bore column in headspace solid-phase microextraction-gas chromatographic (HS-SPME-GC) analysis are investigated. An automated rapid HS-SPME-GC method for the determination of volatile compounds in a complex sample (bergamot essential oil) was developed. A low-capacity (7 microm) SPME fibre was employed, enabling a short equilibration time (15 min). The absorbed volatile compounds were then separated in 12.5 min on a 10 m x 0.1 mm I.D. capillary. The fast GC method was characterized by relatively moderate GC parameters (head pressure: 173 kPa; temperature program rate: 12 degrees C/min). The employment of the low-capacity fibre also suited the reduced sample capacity of the capillary employed, hence column overloading was avoided. Analytical repeatibility was determined in terms of retention times (maximum RSD: 0.32%) and peak areas (maximum RSD: 9.80%). The results obtained were compared to those derived from a conventional HS-SPME-GC (a 30 microm SPME fibre and 0.25 mm I.D. capillary were used) application on the same sample. In this respect, a great reduction of analytical time was obtained both with regard to the conventional SPME equilibration and GC run times, which both required 50 min. Peak resolution was altogether comparable in both applications. Although a slight loss in terms of sensitivity was observed in the rapid approach (generally within the 25-50% range), this did not impair the detection of all peaks of interest. Finally, the selectivities of the 30 and 7 microm fibres were evaluated and, as expected, these were in good agreement.

Antioxidant properties of aqueous and ethanolic extracts of tara (Caesalpinia spinosa) pods in vitro and in model food emulsions.

PubMed

Skowyra, Monika; Falguera, Víctor; Gallego, Gabriela; Peiró, Sara; Almajano, María Pilar

2014-03-30

The successful replacement of some synthetic food antioxidants by safe natural antioxidants has fostered intensive search for new vegetable sources of antioxidants. In our study the phenol and flavonoid content of extracts of tara pods was determined. The antioxidant activity was also studied by three different analytical assays: the measurement of scavenging capacity against a radical ABTS⁺ , the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP). All analyzed samples showed a good antioxidant capacity, but the use of a solution of ethanol 75% in a 1 h ultrasonic process allowed achieving the greatest quantity of phenolics (0.464 mg gallic acid equivalent (GAE) g⁻¹ dry weight (DW) ) and the highest antioxidant activity measured by the ABTS⁺ and ORAC methods (10.17 and 4.29 mmol L⁻¹ Trolox equivalents (TE) g⁻¹ DW, respectively). The best method for efficient extraction of flavonoids (3.08 mg catechin equivalent (CE) g⁻¹ DW) was a 24 h maceration in cold water. Two extracts obtained with ethanol 75% and water were added to a model food system (oil-in-water emulsion) and the oxidative stability was studied during storage at 38 °C. Oxidation was monitored by determination of the peroxide value. The addition of 48 µg mL⁻¹ ethanol extract to the emulsion delayed oxidation to the same extent as 17.8 µg mL⁻¹ of Trolox, while water extract was only effective in the early stages of the oxidation process. The results of this study indicate that ethanolic tara extracts may be suitable for use in food, cosmetic and nutraceutical applications. © 2013 Society of Chemical Industry.

Determination of Complex Microcalorimeter Parameters with Impedance Measurements

NASA Technical Reports Server (NTRS)

Saab, T.; Bandler, S. R.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Iyomoto, N.; Kelley, R.; Kilbourne, C. A.; Lindeman, M. A.; Porter, F. S.;

Accumulation of phenolic compounds in in vitro cultures and wild plants of Lavandula viridis L'Hér and their antioxidant and anti-cholinesterase potential.

PubMed

Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B; Romano, Anabela

2013-07-01

In this study, we evaluated the phenolic profile, antioxidant and anti-cholinesterase potential of different extracts from wild plants and in vitro cultures of Lavandula viridis L'Hér. The HPLC-DAD analysis allowed the identification and quantification of 3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids, and luteolin and pinocembrin. Water/ethanol extract from in vitro cultures contained the highest amount of the identified phenolic compounds (51652.92 mg/kg). To investigate the antioxidant activity we used Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity, Fe(2+) chelation activity and the inhibition of Fe(2+)-induced lipid peroxidation in mouse brain homogenates (in vitro). Overall, all the extracts from both wild plants and in vitro cultures exhibited ability to scavenge free radicals, to chelate Fe(2+) and to protect against lipid peroxidation. In addition, the extracts from L. viridis were active in inhibiting both acetylcholinesterase and butyrylcholinesterase (Ellman's method). Our findings suggest that L. viridis in vitro cultures represent a promising alternative for the production of active metabolites with antioxidant and anti-cholinesterase activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Uncertainty analysis for absorbed dose from a brain receptor imaging agent

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

Aydogan, B.; Miller, L.F.; Sparks, R.B.

Absorbed dose estimates are known to contain uncertainties. A recent literature search indicates that prior to this study no rigorous investigation of uncertainty associated with absorbed dose has been undertaken. A method of uncertainty analysis for absorbed dose calculations has been developed and implemented for the brain receptor imaging agent {sup 123}I-IPT. The two major sources of uncertainty considered were the uncertainty associated with the determination of residence time and that associated with the determination of the S values. There are many sources of uncertainty in the determination of the S values, but only the inter-patient organ mass variation wasmore » considered in this work. The absorbed dose uncertainties were determined for lung, liver, heart and brain. Ninety-five percent confidence intervals of the organ absorbed dose distributions for each patient and for a seven-patient population group were determined by the ``Latin Hypercube Sampling`` method. For an individual patient, the upper bound of the 95% confidence interval of the absorbed dose was found to be about 2.5 times larger than the estimated mean absorbed dose. For the seven-patient population the upper bound of the 95% confidence interval of the absorbed dose distribution was around 45% more than the estimated population mean. For example, the 95% confidence interval of the population liver dose distribution was found to be between 1.49E+0.7 Gy/MBq and 4.65E+07 Gy/MBq with a mean of 2.52E+07 Gy/MBq. This study concluded that patients in a population receiving {sup 123}I-IPT could receive absorbed doses as much as twice as large as the standard estimated absorbed dose due to these uncertainties.« less

Exact analytic flux distributions for two-dimensional solar concentrators.

PubMed

Fraidenraich, Naum; Henrique de Oliveira Pedrosa Filho, Manoel; Vilela, Olga C; Gordon, Jeffrey M

2013-07-01

A new approach for representing and evaluating the flux density distribution on the absorbers of two-dimensional imaging solar concentrators is presented. The formalism accommodates any realistic solar radiance and concentrator optical error distribution. The solutions obviate the need for raytracing, and are physically transparent. Examples illustrating the method's versatility are presented for parabolic trough mirrors with both planar and tubular absorbers, Fresnel reflectors with tubular absorbers, and V-trough mirrors with planar absorbers.

A new optical method coupling light polarization and Vis-NIR spectroscopy to improve the measured absorbance signal's quality of soil samples.

NASA Astrophysics Data System (ADS)

Gobrecht, Alexia; Bendoula, Ryad; Roger, Jean-Michel; Bellon-Maurel, Véronique

2014-05-01

Visible - Near-infrared spectroscopy (Vis-NIRS) is now commonly used to measure different physical and chemical parameters of soils, including carbon content. However, prediction model accuracy is insufficient for Vis-NIRS to replace routine laboratory analysis. One of the biggest issues this technique is facing up to is light scattering due to soil particles. It causes departure in the assumed linear relationship between the Absorbance spectrum and the concentration of the chemicals of interest as stated by Beer-Lambert's Law, which underpins the calibration models. Therefore it becomes essential to improve the metrological quality of the measured signal in order to optimize calibration as light/matter interactions are at the basis of the resulting linear modeling. Optics can help to mitigate scattering effect on the signal. We put forward a new optical setup coupling linearly polarized light with a Vis-NIR spectrometer to free the measured spectra from multi-scattering effect. The corrected measured spectrum was then used to compute an Absorbance spectrum of the sample, using Dahm's Equation in the frame of the Representative Layer Theory. This method has been previously tested and validated on liquid (milk+ dye) and powdered (sand + dye) samples showing scattering (and absorbing) properties. The obtained Absorbance was a very good approximation of the Beer-Lambert's law absorbance. Here, we tested the method on a set of 54 soil samples to predict Soil Organic Carbon content. In order to assess the signal quality improvement by this method, we built and compared calibration models using Partial Least Square (PLS) algorithm. The prediction model built from new Absorbance spectrum outperformed the model built with the classical Absorbance traditionally obtained with Vis-NIR diffuse reflectance. This study is a good illustration of the high influence of signal quality on prediction model's performances.

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

PubMed

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe; Kim, Tae-Il; Yi, Won-Jin

2015-03-01

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

Effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme in bean (Phaseolus vulgaris L.) grown under different nitrogen conditions.

PubMed

Pinto, M E; Casati, P; Hsu, T P; Ku, M S; Edwards, G E

1999-02-01

The effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme have been examined in different cultivars of Phaseolous vulgaris L. grown under 1 and 12 mM nitrogen. Low nitrogen nutrition reduces chlorophyll and soluble protein contents in the leaves and thus the photosynthesis rate and dry-matter accumulation. Chlorophyll, soluble protein and Rubisco contents and photosynthesis rate are not significantly altered by ambient levels of UV-B radiation (17 microW m-2, 290-320 nm, 4 h/day for one week). Comparative studies show that under high nitrogen, UV-B radiation slightly enhances leaf expansion and dry-matter accumulation in cultivar Pinto, but inhibits these parameters in Vilmorin. These results suggest that the UV-B effect on growth is mediated through leaf expansion, which is particularly sensitive to UV-B, and that Pinto is more tolerant than Vilmorin. The effect of UV-B radiation on UV-B-absorbing compounds and on NADP-malic enzyme (NADP-ME) activity is also examined. Both UV-B radiation and low-nitrogen nutrition enhance the content of UV-B-absorbing compounds, and among the three cultivars used, Pinto exhibits the highest increases and Arroz the lowest. The same trend is observed for the specific activity and content of NADP-ME. On a leaf-area basis, the amount of UV-B-absorbing compounds is highly correlated with the enzyme activity (r2 = 0.83), suggesting that NADP-ME plays a key role in biosynthesis of these compounds. Furthermore, the higher sensitivity of Vilmorin than Pinto to UV-B radiation appears to be related to the activity of NADP-ME and the capacity of the plants to accumulate UV-B-absorbing compounds.

Age differences in energy absorption in the upper extremity during a descent movement: implications for arresting a fall.

PubMed

Sran, Meena M; Stotz, Paula J; Normandin, Sarah C; Robinovitch, Stephen N

2010-03-01

Falls are the number one cause of unintentional injury in older adults. The protective response of "breaking the fall" with the outstretched hand is often essential for avoiding injury to the hip and head. In this study, we compared the ability of young and older women to absorb the impact energy of a fall in the outstretched arms. Twenty young (mean age = 21 years) and 20 older (M = 78 years) women were instructed to slowly lower their body weight, similar to the descent phase of a push-up, from body lean angles ranging from 15 degrees to 90 degrees . Measures were acquired of peak upper extremity energy absorption, arm deflection, and hand contact force. On average, older women were able to absorb 45% less energy in the dominant arm than young women (1.7 +/- 0.5% vs 3.1 +/- 0.4% of their body weight x body height; p < .001). These results suggest that, even when both arms participate equally, the average energy content of a forward fall exceeds by 5-fold the average energy that our older participants could absorb and exceeds by 2.7-fold the average energy that young participants could absorb. During a descent movement that simulates fall arrest, the energy-absorbing capacity of the upper extremities in older women is nearly half that of young women. Absorbing the full energy of a fall in the upper extremities is a challenging task even for healthy young women. Strengthening of upper extremity muscles should enhance this ability and presumably reduce the risk for injury to the hip and head during a fall.

Fabrication of CIS Absorber Layers with Different Thicknesses Using A Non-Vacuum Spray Coating Method

PubMed Central

Diao, Chien-Chen; Kuo, Hsin-Hui; Tzou, Wen-Cheng; Chen, Yen-Lin; Yang, Cheng-Fu

2014-01-01

In this study, a new thin-film deposition process, spray coating method (SPM), was investigated to deposit the high-densified CuInSe2 absorber layers. The spray coating method developed in this study was a non-vacuum process, based on dispersed nano-scale CuInSe2 precursor and could offer a simple, inexpensive, and alternative formation technology for CuInSe2 absorber layers. After spraying on Mo/glass substrates, the CuInSe2 thin films were annealed at 550 °C by changing the annealing time from 5 min to 30 min in a selenization furnace, using N2 as atmosphere. When the CuInSe2 thin films were annealed, without extra Se or H2Se gas used as the compensation source during the annealing process. The aim of this project was to investigate the influence of annealing time on the densification and crystallization of the CuInSe2 absorber layers to optimize the quality for cost effective solar cell production. The thickness of the CuInSe2 absorber layers could be controlled as the volume of used dispersed CuInSe2-isopropyl alcohol solution was controlled. In this work, X-ray diffraction patterns, field emission scanning electron microscopy, and Hall parameter measurements were performed in order to verify the quality of the CuInSe2 absorber layers obtained by the Spray Coating Method. PMID:28788451

Visible absorbance spectra: A basis for in situ and passive remote sensing of phytoplankton concentration and community composition

NASA Technical Reports Server (NTRS)

Farmer, F. H.; Jarrett, O., Jr.; Brown, C. A., Jr.

1983-01-01

The concentration and composition of phytoplankton populations are measured by an optical method which can be used either in situ or remotely. This method is based upon the in vivo light absorption characteristics of phytoplankton. To provide a data base for testing assumptions relative to the proposed method, visible absorbance spectra of pure cultures of 20 marine phytoplankton were obtained under laboratory conditions. Descriptive and analytical statistics were computed for the absorbance spectra and were used to make comparisons between members of major taxonomic groups and between groups. Spectral variation between the members of the major taxonomic groups was observed to be considerably less than the spectral variation between these groups. In several cases the differences between the mean absorbance spectra of major taxonomic groups are significant enough to be detected with passive remote sensing techniques.

Mycosporine-Like Amino Acids: Relevant Secondary Metabolites. Chemical and Ecological Aspects

PubMed Central

Carreto, Jose I.; Carignan, Mario O.

2011-01-01

Taxonomically diverse marine, freshwater and terrestrial organisms have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing substances called mycosporine-like amino acids (MAAs) as part of an overall strategy to diminish the direct and indirect damaging effects of environmental ultraviolet radiation (UVR). Whereas the enzymatic machinery to synthesize MAAs was probably inherited from cyanobacteria ancestors via the endosymbionts hypothesis, metazoans lack this biochemical pathway, but can acquire and metabolize these compounds by trophic transference, symbiotic or bacterial association. In this review we describe the structure and physicochemical properties of MAAs, including the recently discovered compounds and the modern methods used for their isolation and identification, updating previous reviews. On this basis, we review the metabolism and distribution of this unique class of metabolites among marine organism. PMID:21556168

Flower-, wire-, and sheet-like MnO2-deposited diatomites: Highly efficient absorbents for the removal of Cr(VI).

PubMed

Du, Yucheng; Wang, Liping; Wang, Jinshu; Zheng, Guangwei; Wu, Junshu; Dai, Hongxing

2015-03-01

Flower-, wire-, and sheet-like MnO2-deposited diatomites have been prepared using a hydrothermal method with Mn(Ac)2, KMnO4 and/or MnSO4 as Mn source and diatomite as support. Physical properties of the materials were characterized by means of numerous analytical techniques, and their behaviors in the adsorption of chromium(VI) were evaluated. It is shown that the MnO2-deposited diatomite samples with different morphologies possessed high surface areas and abundant surface hydroxyl groups (especially the wire-like MnO2/diatomite sample). The wire-like MnO2/diatomite sample showed the best performance in the removal of Cr(VI), giving the maximum Cr(VI) adsorption capacity of 101 mg/g. Copyright © 2014. Published by Elsevier B.V.

Determining Beta Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Hu, Xiao; Kaplan, David; Cebe, Peggy

2007-03-01

We report a study of self-assembled beta pleated sheets in Bombyx mori silk fibroin films using thermal analysis and infrared spectroscopy. Crystallization of beta pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally, or by exposure to methanol. The fractions of secondary structural components including random coils, alpha helices, beta pleated sheets, turns, and side chains, were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. As crystalline beta sheets form, the heat capacity increment from the TMDSC trace at Tg is systematically decreased and is linearly well correlated with beta sheet content determined from FSD. This analysis of beta sheet content can serve as an alternative to X-ray methods and may have wide applicability to other crystalline beta sheet forming proteins.

Applying an analytical method to study neutron behavior for dosimetry

NASA Astrophysics Data System (ADS)

Shirazi, S. A. Mousavi

2016-12-01

In this investigation, a new dosimetry process is studied by applying an analytical method. This novel process is associated with a human liver tissue. The human liver tissue has compositions including water, glycogen and etc. In this study, organic compound materials of liver are decomposed into their constituent elements based upon mass percentage and density of every element. The absorbed doses are computed by analytical method in all constituent elements of liver tissue. This analytical method is introduced applying mathematical equations based on neutron behavior and neutron collision rules. The results show that the absorbed doses are converged for neutron energy below 15MeV. This method can be applied to study the interaction of neutrons in other tissues and estimating the absorbed dose for a wide range of neutron energy.

Betalains, Phenols and Antioxidant Capacity in Cactus Pear [Opuntia ficus-indica (L.) Mill.] Fruits from Apulia (South Italy) Genotypes.

PubMed

Albano, Clara; Negro, Carmine; Tommasi, Noemi; Gerardi, Carmela; Mita, Giovanni; Miceli, Antonio; De Bellis, Luigi; Blando, Federica

2015-04-01

Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with orange fruit, from the Salento area, in Apulia (South Italy). In order to quantitate betanin in cactus pear fruit extracts (which is difficult by HPLC because of the presence of two isomers, betanin and isobetanin, and the lack of commercial standard with high purity), betanin was purified from Amaranthus retroflexus inflorescence, characterized by the presence of a single isomer. The purple cactus pear variety showed very high betanin content, with higher levels of phenolics, vitamin C, and antioxidant capacity (TEAC) than the orange variety. These findings confirm the potential for exploiting the autochthonous biodiversity of cactus pear fruits. In particular, the purple variety could be an interesting source of colored bioactive compounds which not only have coloring potential, but are also an excellent source of dietary antioxidant components which may have beneficial effects on consumers' health.

Anthocyanins, phenolics, and antioxidant capacity in diverse small fruits: vaccinium, rubus, and ribes.

PubMed

Moyer, Richard A; Hummer, Kim E; Finn, Chad E; Frei, Balz; Wrolstad, Ronald E

2002-01-30

Fruits from 107 genotypes of Vaccinium L., Rubus L., and Ribes L., were analyzed for total anthocyanins (ACY), total phenolics (TPH), and antioxidant capacities as determined by oxygen radical absorbing capacity (ORAC) and ferric reducing antioxidant power (FRAP). Fruit size was highly correlated (r = 0.84) with ACY within Vaccinium corymbosum L., but was not correlated to ACY across eight other Vaccinium species, or within 27 blackberry hybrids. Certain Vaccinium and Ribes fruits with pigmented flesh were lower in ACY, TPH, ORAC, and FRAP compared to those values in berries with nonpigmented flesh. ORAC values ranged from 19 to 131 micromol Trolox equivalents/g in Vaccinium, from 13 to 146 in Rubus, and from 17 to 116 in Ribes. Though ACY may indicate TPH, the range observed in ACY/TPH ratios precludes prediction of ACY from TPH and vice versa for a single genotype. In general, TPH was more highly correlated to antioxidant capacity than ACY was. This study demonstrates the wide diversity of phytochemical levels and antioxidant capacities within and across three genera of small fruit.

Side branch absorber for exhaust manifold of two-stroke internal combustion engine

DOEpatents

Harris, Ralph E [San Antonio, TX; Broerman, III, Eugene L.; Bourn, Gary D [Laramie, WY

2011-01-11

A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

DOEpatents

Crane, Thomas W.

1986-01-01

The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

DOEpatents

Crane, T.W.

1983-12-21

The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

DOEpatents

Phillips, Benjamin A.; Zawacki, Thomas S.

1996-12-03

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

DOEpatents

Phillips, B.A.; Zawacki, T.S.

1998-07-21

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

DOEpatents

Phillips, Benjamin A.; Zawacki, Thomas S.

1998-07-21

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

Green light drives leaf photosynthesis more efficiently than red light in strong white light: revisiting the enigmatic question of why leaves are green.

PubMed

Terashima, Ichiro; Fujita, Takashi; Inoue, Takeshi; Chow, Wah Soon; Oguchi, Riichi

2009-04-01

The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic capacity profile. In strong white light, therefore, the quantum yield of photosynthesis would be lower in the upper chloroplasts, located near the illuminated surface, than that in the lower chloroplasts. Because green light can penetrate further into the leaf than red or blue light, in strong white light, any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a greater extent than would additional red or blue light. Based on the assessment of effects of the additional monochromatic light on leaf photosynthesis, we developed the differential quantum yield method that quantifies efficiency of any monochromatic light in white light. Application of this method to sunflower leaves clearly showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light. The green leaf should have a considerable volume of chloroplasts to accommodate the inefficient carboxylation enzyme, Rubisco, and deliver appropriate light to all the chloroplasts. By using chlorophylls that absorb green light weakly, modifying mesophyll structure and adjusting the Rubisco/chlorophyll ratio, the leaf appears to satisfy two somewhat conflicting requirements: to increase the absorptance of photosynthetically active radiation, and to drive photosynthesis efficiently in all the chloroplasts. We also discuss some serious problems that are caused by neglecting these intra-leaf profiles when estimating whole leaf electron transport rates and assessing photoinhibition by fluorescence techniques.

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation

PubMed Central

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe

2015-01-01

Purpose We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). Materials and Methods The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. Results VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). Conclusion It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method. PMID:25793178

Quantum capacity of quantum black holes

NASA Astrophysics Data System (ADS)

Adami, Chris; Bradler, Kamil

2014-03-01

The fate of quantum entanglement interacting with a black hole has been an enduring mystery, not the least because standard curved space field theory does not address the interaction of black holes with matter. We discuss an effective Hamiltonian of matter interacting with a black hole that has a precise analogue in quantum optics and correctly reproduces both spontaneous and stimulated Hawking radiation with grey-body factors. We calculate the quantum capacity of this channel in the limit of perfect absorption, as well as in the limit of a perfectly reflecting black hole (a white hole). We find that the white hole is an optimal quantum cloner, and is isomorphic to the Unruh channel with positive quantum capacity. The complementary channel (across the horizon) is entanglement-breaking with zero capacity, avoiding a violation of the quantum no-cloning theorem. The black hole channel on the contrary has vanishing capacity, while its complement has positive capacity instead. Thus, quantum states can be reconstructed faithfully behind the black hole horizon, but not outside. This work sheds new light on black hole complementarity because it shows that black holes can both reflect and absorb quantum states without violating the no-cloning theorem, and makes quantum firewalls obsolete.

Impact of the Maillard reaction on the antioxidant capacity of bovine lactoferrin.

PubMed

Joubran, Yousef; Mackie, Alan; Lesmes, Uri

2013-12-15

Studies raise the notion that the Maillard reaction (MR) may be harnessed to modify the antioxidant capacity of alimentary proteins. However, little is known about the impact of MR on bioactive proteins. Glucose and fructose were used as model moieties reacting with lactoferrin (LF). UV absorbance and SDS-PAGE analyses were used to monitor MR progression during 36 h of mild thermal processing (60 °C, 79% RH). FTIR and CD did not reveal changes in LF structure; However, dynamic light scattering showed MR increased mean particle sizes and sample turbidity at 3

Some observations on soil freezing in forest and range lands of the Pacific Northwest.

Treesearch

Charles E. Hale

1950-01-01

It is well known that freezing and thawing of the surface soil and humus greatly affect their capacity to absorb water. Post and Dreibelbis (1) in Ohio reported that percolation was materially reduced or ceased entirely when the frost depth was three inches or greater. They also stated that "freezing of the surface soil undoubtedly has considerable influence on...

Antioxidative properties of functional polyphenols and their metabolites assessed by an ORAC assay.

PubMed

Ishimoto, Hidekazu; Tai, Akihiro; Yoshimura, Morio; Amakura, Yoshiaki; Yoshida, Takashi; Hatano, Tsutomu; Ito, Hideyuki

2012-01-01

We compared the antioxidative activities of polyphenol metabolites with those of intact functional polyphenols by an assay of the oxygen radical absorbance capacity (ORAC). The metabolites of ellagitannin geraniin, chlorogenic acid, and (-)-epigallocatechin gallate displayed more potent antioxidative activity than their respective original compounds. Our findings suggest that these metabolites may play important roles as biological antioxidants after their consumption.

High Speed Blood and Transfusion Equipment

DTIC Science & Technology

2013-10-14

absorption process is entirely reversible. By heating the absorber the ammonia refrigerant is removed from the salt in the vapor phase . The...ligand quantity decreased, the heating capacity would also consistently diminish. However, with the monovariant attribute a single pulse of the...limit, implying perfect heat transfer with no heat losses, can accommodate a volumetric flow rate of blood up to approximately 360 cc/min. When operating

Absorbed dose measurement in low temperature samples:. comparative methods using simulated material

NASA Astrophysics Data System (ADS)

Garcia, Ruth; Harris, Anthony; Winters, Martell; Howard, Betty; Mellor, Paul; Patil, Deepak; Meiner, Jason

2004-09-01

There is a growing need to reliably measure absorbed dose in low temperature samples, especially in the pharmaceutical and tissue banking industries. All dosimetry systems commonly used in the irradiation industry are temperature sensitive. Radiation of low temperature samples, such as those packaged with dry ice, must therefore take these dosimeter temperature effects into consideration. This paper will suggest a method to accurately deliver an absorbed radiation dose using dosimetry techniques designed to abrogate the skewing effects of low temperature environments on existing dosimetry systems.

Liquid carbon dioxide absorbents, methods of using the same, and related system

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

Perry, Robert James; Soloveichik, Grigorii Lev; Rubinsztajn, Malgorzata Iwona

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO 2 or have a high-affinity for CO 2, and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO 2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

Power maximization of a point absorber wave energy converter using improved model predictive control

NASA Astrophysics Data System (ADS)

Milani, Farideh; Moghaddam, Reihaneh Kardehi

2017-08-01

This paper considers controlling and maximizing the absorbed power of wave energy converters for irregular waves. With respect to physical constraints of the system, a model predictive control is applied. Irregular waves' behavior is predicted by Kalman filter method. Owing to the great influence of controller parameters on the absorbed power, these parameters are optimized by imperialist competitive algorithm. The results illustrate the method's efficiency in maximizing the extracted power in the presence of unknown excitation force which should be predicted by Kalman filter.

Liquid carbon dioxide absorbents, methods of using the same, and related systems

DOEpatents

O'Brien, Michael Joseph; Perry, Robert James; Lam, Tunchiao Hubert; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lewis, Larry Neil; Rubinsztajn, Malgorzata Iwona; Hancu, Dan

2016-09-13

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO.sub.2 or have a high-affinity for CO.sub.2; and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO.sub.2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

A Wide Band Absorbing Material Design Using Band-Pass Frequency Selective Surface

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Xu, Qiang; Liu, Ting; Zheng, Dianliang; Zhou, Li

2018-03-01

Based on the high frequency advantage characteristics of the Fe based absorbing coating, a method for designing the structure of broadband absorbing structure by using frequency selective surface (FSS) is proposed. According to the transmission and reflection characteristic of the different size FSS structure, the frequency variation characteristic was simulated. Secondly, the genetic algorithm was used to optimize the high frequency broadband absorbing materials, including the single and double magnetic layer material. Finally, the absorbing characteristics in iron layer were analyzed as the band pass FSS structure was embedded, the results showed that the band-pass FSS had the influence on widening the absorbing frequency. As the FSS was set as the bottom layer, it was effective to achieve the good absorbing property in low frequency and the high frequency absorbing performance was not weakened, because the band-pass FSS led the low frequency absorption and the high frequency shielding effect. The results of this paper are of guiding significance for designing and manufacturing the broadband absorbing materials.

Comparison of artificial absorbing boundaries for acoustic wave equation modelling

NASA Astrophysics Data System (ADS)

Gao, Yingjie; Song, Hanjie; Zhang, Jinhai; Yao, Zhenxing

2017-12-01

Absorbing boundary conditions are necessary in numerical simulation for reducing the artificial reflections from model boundaries. In this paper, we overview the most important and typical absorbing boundary conditions developed throughout history. We first derive the wave equations of similar methods in unified forms; then, we compare their absorbing performance via theoretical analyses and numerical experiments. The Higdon boundary condition is shown to be the best one among the three main absorbing boundary conditions that are based on a one-way wave equation. The Clayton and Engquist boundary is a special case of the Higdon boundary but has difficulty in dealing with the corner points in implementaion. The Reynolds boundary does not have this problem but its absorbing performance is the poorest among these three methods. The sponge boundary has difficulties in determining the optimal parameters in advance and too many layers are required to achieve a good enough absorbing performance. The hybrid absorbing boundary condition (hybrid ABC) has a better absorbing performance than the Higdon boundary does; however, it is still less efficient for absorbing nearly grazing waves since it is based on the one-way wave equation. In contrast, the perfectly matched layer (PML) can perform much better using a few layers. For example, the 10-layer PML would perform well for absorbing most reflected waves except the nearly grazing incident waves. The 20-layer PML is suggested for most practical applications. For nearly grazing incident waves, convolutional PML shows superiority over the PML when the source is close to the boundary for large-scale models. The Higdon boundary and hybrid ABC are preferred when the computational cost is high and high-level absorbing performance is not required, such as migration and migration velocity analyses, since they are not as sensitive to the amplitude errors as the full waveform inversion.

Large silver-cadmium technology program

NASA Technical Reports Server (NTRS)

Charlip, S.; Lerner, S.

1971-01-01

The effects of varying cell design on operation factors on the electrochemical performance of sealed, silver-cadmium cells were determined. A factorial experiment was conducted for all test cells constructed with organic separators. Three operating factors were evaluated: temperature, depth of discharge, and charge rate. The six construction factors considered were separator, absorber, electrolyte quantity, cadmium electrode type, cadmium-to-silver ratio, and auxiliary electrode. Test cells of 4 ampere-hour capacity were fabricated and cycled. The best performing cells, on a 94 minute orbit, at 40% depth of discharge, were those containing silver-treated fibrous sausage casings as the separator, and Teflon-ated, pressed cadmium electrodes. Cycling data of cells with inorganic separators (Astroset) are given. Best performance was shown by cells with nonwoven nylon absorbers. Rigid inorganic separators provided the best barrier to silver migration.

Polymer alloys with balanced heat storage capacity and engineering attributes and applications thereof

DOEpatents

Soroushian, Parviz

2002-01-01

A thermoplastic polymer of relatively low melt temperature is blended with at least one of thermosets, elastomers, and thermoplastics of relatively high melt temperature in order to produce a polymer blend which absorbs relatively high quantities of latent heat without melting or major loss of physical and mechanical characteristics as temperature is raised above the melting temperature of the low-melt-temperature thermoplastic. The polymer blend can be modified by the addition of at least one of fillers, fibers, fire retardants, compatibilisers, colorants, and processing aids. The polymer blend may be used in applications where advantage can be taken of the absorption of excess heat by a component which remains solid and retains major fractions of its physical and mechanical characteristics while absorbing relatively high quantities of latent heat.

All-optical switching of silicon disk resonator based on photothermal effect in metal-insulator-metal absorber.

PubMed

Shi, Yuechun; Chen, Xi; Lou, Fei; Chen, Yiting; Yan, Min; Wosinski, Lech; Qiu, Min

2014-08-01

Efficient narrowband light absorption by a metal-insulator-metal (MIM) structure can lead to high-speed light-to-heat conversion at a micro- or nanoscale. Such a MIM structure can serve as a heater for achieving all-optical light control based on the thermo-optical (TO) effect. Here we experimentally fabricated and characterized a novel all-optical switch based on a silicon microdisk integrated with a MIM light absorber. Direct integration of the absorber on top of the microdisk reduces the thermal capacity of the whole device, leading to high-speed TO switching of the microdisk resonance. The measurement result exhibits a rise time of 2.0 μs and a fall time of 2.6 μs with switching power as low as 0.5 mW; the product of switching power and response time is only about 1.3  mW·μs. Since no auxiliary elements are required for the heater, the switch is structurally compact, and its fabrication is rather easy. The device potentially can be deployed for new kinds of all-optical applications.

ZnCl 2- and NH 4Cl-hydroponics gel electrolytes for zinc-carbon batteries

NASA Astrophysics Data System (ADS)

Khalid, N. H.; Ismail, Y. M. Baba; Mohamad, A. A.

Absorbency testing is used to determine the percentage of ZnCl 2 or NH 4Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl 2 or NH 4Cl solution decreases with increasing solution concentration. The conductivity of ZnCl 2- and NH 4Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm -1 at 3 M ZnCl 2 and 7 M NH 4Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 Ω, a maximum power density of 12.7 and 12.2 mW cm -2, and a short-circuit current density of 29.1 and 33.9 mA cm -2 for ZnCl 2- and NH 4Cl-HPG electrolytes, respectively.

Radical cystectomy with W-shaped orthotopic ileal neobladder constructed with non-absorbable titanium staples-long term follow-up.

PubMed

Kravchick, Sergey; Lobik, Leonid; Paz, Adrian; Stepnov, Eugeny; Ben-Dor, David; Cytron, Shmuel

2013-01-01

We retrospectively assessed our experience with the W-shaped orthotopic ileal pouch, which was constructed with non-absorbable titanium staples. For these purpose, we discuss the results of bladder capacity, urinary continence and early and long-term postoperative complications. We included in the study 17 patients who underwent radical cystoprostatectomy followed by construction of an orthotopic W-shaped ileal pouch between October 2000 and November 2009. A 65-70 cm segment of ileum was isolated and prearranged into a W-configuration, leaving two 10 cm intact segments on both sides of the ileal fragment. In our technique we entirely anatomized all adjacent limbs in order to create a sphere-shaped pouch. The ureters were directly anastomized to both intact segments of the ileal division. All our patients underwent pouchscopy 6 months after operation and annually. Mean operative time for neobladder reconstruction and ureteral anastomoses was 87 ± 7.67 minutes. In one patient a leak from the ileo-ileal anastomosis was confirmed on the 3rd day after operation. In 2 cases unilateral stricture of the ureteral-neobladder anastomosis was documented. Staple lines were mostly covered with ileal mucosa after 6 months. The mean functional bladder capacity was 340 ± 27.6 mL and 375 ± 43.4 mL at 6 and 12 months, respectively. First-year daytime and nighttime continence was good and acceptable in 90% and 78% of patients, while it increased to 95% during the 2nd year. The long term follow-up shows that non-absorbable titanium staples can be safely used for creation of an orthotopic ileal neobladder. However, these data should be further validated in a larger series of patients.

A radiobiological model of metastatic burden reduction for molecular radiotherapy: application to patients with bone metastases

NASA Astrophysics Data System (ADS)

Denis-Bacelar, Ana M.; Chittenden, Sarah J.; Murray, Iain; Divoli, Antigoni; McCready, V. Ralph; Dearnaley, David P.; O'Sullivan, Joe M.; Johnson, Bernadette; Flux, Glenn D.

2017-04-01

Skeletal tumour burden is a biomarker of prognosis and survival in cancer patients. This study proposes a novel method based on the linear quadratic model to predict the reduction in metastatic tumour burden as a function of the absorbed doses delivered from molecular radiotherapy treatments. The range of absorbed doses necessary to eradicate all the bone lesions and to reduce the metastatic burden was investigated in a cohort of 22 patients with bone metastases from castration-resistant prostate cancer. A metastatic burden reduction curve was generated for each patient, which predicts the reduction in metastatic burden as a function of the patient mean absorbed dose, defined as the mean of all the lesion absorbed doses in any given patient. In the patient cohort studied, the median of the patient mean absorbed dose predicted to reduce the metastatic burden by 50% was 89 Gy (interquartile range: 83-105 Gy), whilst a median of 183 Gy (interquartile range: 107-247 Gy) was found necessary to eradicate all metastases in a given patient. The absorbed dose required to eradicate all the lesions was strongly correlated with the variability of the absorbed doses delivered to multiple lesions in a given patient (r  =  0.98, P  <  0.0001). The metastatic burden reduction curves showed a potential large reduction in metastatic burden for a small increase in absorbed dose in 91% of patients. The results indicate the range of absorbed doses required to potentially obtain a significant survival benefit. The metastatic burden reduction method provides a simple tool that could be used in routine clinical practice for patient selection and to indicate the required administered activity to achieve a predicted patient mean absorbed dose and reduction in metastatic tumour burden.

Micro-hybrid electric vehicle application of valve-regulated lead-acid batteries in absorbent glass mat technology: Testing a partial-state-of-charge operation strategy

NASA Astrophysics Data System (ADS)

Schaeck, S.; Stoermer, A. O.; Hockgeiger, E.

The BMW Group has launched two micro-hybrid functions in high volume models in order to contribute to reduction of fuel consumption in modern passenger cars. Both the brake energy regeneration (BER) and the auto-start-stop function (ASSF) are based on the conventional 14 V vehicle electrical system and current series components with only little modifications. An intelligent control algorithm of the alternator enables recuperative charging in braking and coasting phases, known as BER. By switching off the internal combustion engine at a vehicle standstill the idling fuel consumption is effectively reduced by ASSF. By reason of economy and package a lead-acid battery is used as electrochemical energy storage device. The BMW Group assembles valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology in the micro-hybrid electrical power system since special challenges arise for the batteries. By field data analysis a lower average state-of-charge (SOC) due to partial state-of-charge (PSOC) operation and a higher cycling rate due to BER and ASSF are confirmed in this article. Similar to a design of experiment (DOE) like method we present a long-term lab investigation. Two types of 90 Ah VRLA AGM batteries are operated with a test bench profile that simulates the micro-hybrid vehicle electrical system under varying conditions. The main attention of this lab testing is focused on capacity loss and charge acceptance over cycle life. These effects are put into context with periodically refresh charging the batteries in order to prevent accelerated battery aging due to hard sulfation. We demonstrate the positive effect of refresh chargings concerning preservation of battery charge acceptance. Furthermore, we observe moderate capacity loss over 90 full cycles both at 25 °C and at 3 °C battery temperature.

NEUTRONIC REACTOR CONTROL

DOEpatents

Metcalf, H.E.

1958-10-14

Methods of controlling reactors are presented. Specifically, a plurality of neutron absorber members are adjustably disposed in the reactor core at different distances from the center thereof. The absorber members extend into the core from opposite faces thereof and are operated by motive means coupled in a manner to simultaneously withdraw at least one of the absorber members while inserting one of the other absorber members. This feature effects fine control of the neutron reproduction ratio by varying the total volume of the reactor effective in developing the neutronic reaction.

Skeletal dosimetry based on µCT images of trabecular bone: update and comparisons

NASA Astrophysics Data System (ADS)

Kramer, R.; Cassola, V. F.; Vieira, J. W.; Khoury, H. J.; de Oliveira Lira, C. A. B.; Robson Brown, K.

2012-06-01

Two skeletal dosimetry methods using µCT images of human bone have recently been developed: the paired-image radiation transport (PIRT) model introduced by researchers at the University of Florida (UF) in the US and the systematic-periodic cluster (SPC) method developed by researchers at the Federal University of Pernambuco in Brazil. Both methods use µCT images of trabecular bone (TB) to model spongiosa regions of human bones containing marrow cavities segmented into soft tissue volumes of active marrow (AM), trabecular inactive marrow and the bone endosteum (BE), which is a 50 µm thick layer of marrow on all TB surfaces and on cortical bone surfaces next to TB as well as inside the medullary cavities. With respect to the radiation absorbed dose, the AM and the BE are sensitive soft tissues for the induction of leukaemia and bone cancer, respectively. The two methods differ mainly with respect to the number of bone sites and the size of the µCT images used in Monte Carlo calculations and they apply different methods to simulate exposure from radiation sources located outside the skeleton. The PIRT method calculates dosimetric quantities in isolated human bones while the SPC method uses human bones embedded in the body of a phantom which contains all relevant organs and soft tissues. Consequently, the SPC method calculates absorbed dose to the AM and to the BE from particles emitted by radionuclides concentrated in organs or from radiation sources located outside the human body in one calculation step. In order to allow for similar calculations of AM and BE absorbed doses using the PIRT method, the so-called dose response functions (DRFs) have been developed based on absorbed fractions (AFs) of energy for electrons isotropically emitted in skeletal tissues. The DRFs can be used to transform the photon fluence in homogeneous spongiosa regions into absorbed dose to AM and BE. This paper will compare AM and BE AFs of energy from electrons emitted in skeletal tissues calculated with the SPC and the PIRT method and AM and BE absorbed doses and AFs calculated with PIRT-based DRFs and with the SPC method. The results calculated with the two skeletal dosimetry methods agree well if one takes the differences between the two models properly into account. Additionally, the SPC method will be updated with larger µCT images of TB.

Step-scan differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS): a spectral deconvolution method for weak absorber detection in the presence of strongly overlapping background absorptions.

PubMed

Liu, Lixian; Mandelis, Andreas; Huan, Huiting; Michaelian, Kirk H

2017-04-01

The determination of small absorption coefficients of trace gases in the atmosphere constitutes a challenge for analytical air contaminant measurements, especially in the presence of strongly absorbing backgrounds. A step-scan differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS) method was developed to suppress the coherent external noise and spurious photoacoustic (PA) signals caused by strongly absorbing backgrounds. The infrared absorption spectra of acetylene (C₂H₂) and local air were used to verify the performance of the step-scan DFTIR-PAS method. A linear amplitude response to C₂H₂ concentrations from 100 to 5000 ppmv was observed, leading to a theoretical detection limit of 5 ppmv. The differential mode was capable of eliminating the coherent noise and dominant background gas signals, thereby revealing the presence of the otherwise hidden C₂H₂ weak absorption. Thus, the step-scan DFTIR-PAS modality was demonstrated to be an effective approach for monitoring weakly absorbing gases with absorption bands overlapped by strongly absorbing background species.

Preparation and microwave absorption properties of honeycomb core structures coated with composite absorber

NASA Astrophysics Data System (ADS)

Luo, Hui; Chen, Fu; Wang, Fang; Wang, Xian; Dai, Weiyong; Hu, Sheng; Gong, Rongzhou

2018-05-01

Honeycomb structure coated with paraffin filled with composite of graphene and flaky carbonyl iron powder (FCIP) as lossy filler have been studied. The composite of graphene/FCIP with different weight ratio were synthesized via mechanical milling, the electromagnetic properties of the samples were measured by transmission/reflection method in the frequency range of 8-12 GHz. The microwave absorbing properties of the microwave absorbing honeycomb structure (MAHS) and microwave absorbing honeycomb sandwich structure (MAHSS) were studied based on the Finite Element Method with periodical boundary conditions. The matching layer on the top of the honeycomb sandwich structure can enhanced the microwave absorption properties. It was shown that a light weight and broadband MAHSS could be implemented with the use of the magnetic material and dielectric material.

Ecologically friendly ways to clean up oil spills in harbor water areas: crude oil and diesel sorption behavior of natural sorbents.

PubMed

Paulauskiene, Tatjana

2018-04-01

This work aimed to evaluate the sorption capacity of natural sorbents (wool, moss, straw, peat) and their composites during the sorption of crude oil and of diesel overspread on the water surface. The work presents the research results of the maximum sorption capacity of the sorbents/their composites using crude oil/diesel; the sorption capacity of the sorbents/their composites when crude oil/diesel is spilled on the water surface; and the research results of the unrealized part of the crude oil/diesel in the sorbents. The results of the analysis showed that all the sorbents and their composites have their selectivity to crude oil less than 50%. Also the results showed that the distribution of diesel and water in the sorbents and their composites is very different compared with the distribution of crude oil during the sorption analyses. In total, the diesel in the liquid mass absorbed by the straw and the peat amounted to 17 and 20%, respectively. This shows that these sorbents are much more selective for water but not for diesel. A larger part of the diesel was in the liquid amount absorbed by the composites-up to 33%. Accordingly, the use of these composites in watery environments is much more effective than the use of individual sorbents. The composition of sorbents in the composite enhanced both the hydrophobic and the oleophilic properties; as a result, a more effective removal of the diesel and oil from the water surface was achieved.

Synthesis of polymer ion-exchange hydrogels under γ - irradiation 60Co

NASA Astrophysics Data System (ADS)

Le, V. M.; Zhevnyak, V. D.; Pak, V. Kh; Ananev, V. A.; Borodin, U. V.

2015-04-01

We have reported earlier about the modification of ion-exchange hydrogel under the influence of gamma radiation. The optimal absorbed dose of irradiation had been choosen for radiation modification of polymer hydrogels by ionits to produce products with a high content of the gel - fractions and sufficient mechanical properties. The dependence of the static exchange capacity of hydrogels on the type of ionit and its fractional composition had been studied. The dependence of the static exchange capacity of the quantitative composition of the ionit in the volume of the hydrogel had been investigated. The ion-exchange medical eye lenses had been made under selected conditions of synthesis. Their sorption properties had been studied.

Multi-domain boundary element method for axi-symmetric layered linear acoustic systems

NASA Astrophysics Data System (ADS)

Reiter, Paul; Ziegelwanger, Harald

2017-12-01

Homogeneous porous materials like rock wool or synthetic foam are the main tool for acoustic absorption. The conventional absorbing structure for sound-proofing consists of one or multiple absorbers placed in front of a rigid wall, with or without air-gaps in between. Various models exist to describe these so called multi-layered acoustic systems mathematically for incoming plane waves. However, there is no efficient method to calculate the sound field in a half space above a multi layered acoustic system for an incoming spherical wave. In this work, an axi-symmetric multi-domain boundary element method (BEM) for absorbing multi layered acoustic systems and incoming spherical waves is introduced. In the proposed BEM formulation, a complex wave number is used to model absorbing materials as a fluid and a coordinate transformation is introduced which simplifies singular integrals of the conventional BEM to non-singular radial and angular integrals. The radial and angular part are integrated analytically and numerically, respectively. The output of the method can be interpreted as a numerical half space Green's function for grounds consisting of layered materials.

Report on objective ride quality evaluation

NASA Technical Reports Server (NTRS)

Wambold, J. C.; Park, W. H.

1974-01-01

The correlation of absorbed power as an objective ride measure to the subjective evaluation for the bus data was investigated. For some individual bus rides the correlations were poor, but when a sufficient number of rides was used to give reasonable sample base, an excellent correlation was obtained. The following logarithmical function was derived: S = 1.7245 1n (39.6849 AP), where S = one subjective rating of the ride; and AP = the absorbed power in watts. A six-degree-of-freedom method developed for aircraft data was completed. Preliminary correlation of absorbed power with ISO standards further enhances the bus ride and absorbed power correlation numbers since the AP's obtained are of the same order of magnitude for both correlations. While it would then appear that one could just use ISO standards, there is no way to add the effect of three degrees of freedom. The absorbed power provides a method of adding the effects due to the three major directions plus the pitch and roll.

Absorber for wakefield interference management at the entrance of the wiggler of a free electron laser

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

Marchlik, Matthew; Biallas, George Herman

A method for managing the broad band microwave and TeraHertz (THz) radiation in a free electron laser (FEL) having a wiggler producing power in the electromagnetic spectrum. The method includes placement of broadband microwave and TeraHertz (THz) radiation absorbers on the upstream end of the wiggler. The absorbers dampen the bounced back, broad band microwave and THz radiation returning from the surfaces outside the nose of the cookie-cutter and thus preventing broadening of the electron beam pulse's narrow longitudinal energy distribution. Broadening diminishes the ultimate laser power from the wiggler. The broadband microwave and THz radiation absorbers are placed onmore » either side of the slot in the cookie-cutter that shapes the wake field wave of the electron pulse to the slot shape of the wiggler chamber aperture. The broad band microwave and THz radiation absorber is preferably a non-porous pyrolytic grade of graphite with small grain size.« less

Review of reconstruction of radiation incident air kerma by measurement of absorbed dose in tooth enamel with EPR.

PubMed

Wieser, A

2012-03-01

Electron paramagnetic resonance dosimetry with tooth enamel has been proved to be a reliable method to determine retrospectively exposures from photon fields with minimal detectable doses of 100 mGy or lower, which is lower than achievable with cytogenetic dose reconstruction methods. For risk assessment or validating dosimetry systems for specific radiation incidents, the relevant dose from the incident has to be calculated from the total absorbed dose in enamel by subtracting additional dose contributions from the radionuclide content in teeth, natural external background radiation and medical exposures. For calculating organ doses or evaluating dosimetry systems the absorbed dose in enamel from a radiation incident has to be converted to air kerma using dose conversion factors depending on the photon energy spectrum and geometry of the exposure scenario. This paper outlines the approach to assess individual dose contributions to absorbed dose in enamel and calculate individual air kerma of a radiation incident from the absorbed dose in tooth enamel.

Spectrally-engineered solar thermal photovoltaic devices

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

Lenert, Andrej; Bierman, David; Chan, Walker

A solar thermal photovoltaic device, and method of forming same, includes a solar absorber and a spectrally selective emitter formed on either side of a thermally conductive substrate. The solar absorber is configured to absorb incident solar radiation. The solar absorber and the spectrally selective emitter are configured with an optimized emitter-to-absorber area ratio. The solar thermal photovoltaic device also includes a photovoltaic cell in thermal communication with the spectrally selective emitter. The spectrally selective emitter is configured to permit high emittance for energies above a bandgap of the photovoltaic cell and configured to permit low emittance for energies belowmore » the bandgap.« less

Optimal active vibration absorber: Design and experimental results

NASA Technical Reports Server (NTRS)

Lee-Glauser, Gina; Juang, Jer-Nan; Sulla, Jeffrey L.

1992-01-01

An optimal active vibration absorber can provide guaranteed closed-loop stability and control for large flexible space structures with collocated sensors/actuators. The active vibration absorber is a second-order dynamic system which is designed to suppress any unwanted structural vibration. This can be designed with minimum knowledge of the controlled system. Two methods for optimizing the active vibration absorber parameters are illustrated: minimum resonant amplitude and frequency matched active controllers. The Controls-Structures Interaction Phase-1 Evolutionary Model at NASA LaRC is used to demonstrate the effectiveness of the active vibration absorber for vibration suppression. Performance is compared numerically and experimentally using acceleration feedback.

Dietary total antioxidant capacity from different assays in relation to serum C-reactive protein among young Japanese women

PubMed Central

2012-01-01

Background The association between dietary total antioxidant capacity (TAC) from different assays and serum C-reactive protein (CRP) has not been assessed in non-Western populations. We examined the association between dietary TAC and serum CRP concentration in young Japanese women using different four TAC assays. Methods The subjects were 443 young Japanese women aged 18–22 years. Dietary TAC was assessed with a self-administered diet history questionnaire and the TAC value of each food using the following four assays: ferric reducing ability of plasma (FRAP); oxygen radical absorbance capacity (ORAC); Trolox equivalent antioxidant capacity (TEAC); and total radical-trapping antioxidant parameter (TRAP). Serum CRP concentrations were measured by highly sensitive nephelometry. Results The major contributor to dietary TAC was green, barley, and oolong tea (FRAP: 53%, ORAC: 45%, TEAC: 36%, and TRAP: 44%). The prevalence of elevated CRP concentrations (≥ 1 mg/L) was 5.6%. TAC from FRAP was inversely associated with serum CRP concentrations (adjusted odds ratio [OR] for elevated CRP concentration in high [compared with low] dietary TAC group: 0.39 [95% confidence interval (CI): 0.16-0.98]; P = 0.04). TAC from ORAC was inversely associated with CRP, although the association was not significant (OR: 0.48 [95% CI: 0.20-1.14]; P = 0.10). TAC from TEAC was inversely associated with CRP (OR: 0.32 [95% CI: 0.12-0.82]; P = 0.02), as was TAC from TRAP (OR: 0.31 [95% CI: 0.12-0.81]; P = 0.02). Conclusions Dietary TAC was inversely associated with serum CRP concentration in young Japanese women regardless of assay. Further studies are needed in other populations to confirm these results. PMID:23110638

Phycourobilin in trichromatic phycocyanin from oceanic cyanobacteria is formed post-translationally by a phycoerythrobilin lyase-isomerase.

PubMed

Blot, Nicolas; Wu, Xian-Jun; Thomas, Jean-Claude; Zhang, Juan; Garczarek, Laurence; Böhm, Stephan; Tu, Jun-Ming; Zhou, Ming; Plöscher, Matthias; Eichacker, Lutz; Partensky, Frédéric; Scheer, Hugo; Zhao, Kai-Hong

2009-04-03

Most cyanobacteria harvest light with large antenna complexes called phycobilisomes. The diversity of their constituting phycobiliproteins contributes to optimize the photosynthetic capacity of these microorganisms. Phycobiliprotein biosynthesis, which involves several post-translational modifications including covalent attachment of the linear tetrapyrrole chromophores (phycobilins) to apoproteins, begins to be well understood. However, the biosynthetic pathway to the blue-green-absorbing phycourobilin (lambda(max) approximately 495 nm) remained unknown, although it is the major phycobilin of cyanobacteria living in oceanic areas where blue light penetrates deeply into the water column. We describe a unique trichromatic phycocyanin, R-PC V, extracted from phycobilisomes of Synechococcus sp. strain WH8102. It is evolutionarily remarkable as the only chromoprotein known so far that absorbs the whole wavelength range between 450 and 650 nm. R-PC V carries a phycourobilin chromophore on its alpha-subunit, and this can be considered an extreme case of adaptation to blue-green light. We also discovered the enzyme, RpcG, responsible for its biosynthesis. This monomeric enzyme catalyzes binding of the green-absorbing phycoerythrobilin at cysteine 84 with concomitant isomerization to phycourobilin. This reaction is analogous to formation of the orange-absorbing phycoviolobilin from the red-absorbing phycocyanobilin that is catalyzed by the lyase-isomerase PecE/F in some freshwater cyanobacteria. The fusion protein, RpcG, and the heterodimeric PecE/F are mutually interchangeable in a heterologous expression system in Escherichia coli. The novel R-PC V likely optimizes rod-core energy transfer in phycobilisomes and thereby adaptation of a major phytoplankton group to the blue-green light prevailing in oceanic waters.

A Versatile CuII Metal-Organic Framework Exhibiting High Gas Storage Capacity with Selectivity for CO2 : Conversion of CO2 to Cyclic Carbonate and Other Catalytic Abilities.

PubMed

De, Dinesh; Pal, Tapan K; Neogi, Subhadip; Senthilkumar, S; Das, Debasree; Gupta, Sayam Sen; Bharadwaj, Parimal K

2016-03-01

A linear tetracarboxylic acid ligand, H 4 L, with a pendent amine moiety solvothermally forms two isostructural metal-organic frameworks (MOFs) L M (M=Zn II , Cu II ). Framework L Cu can also be obtained from L Zn by post- synthetic metathesis without losing crystallinity. Compared with L Zn , the L Cu framework exhibits high thermal stability and allows removal of guest solvent and metal-bound water molecules to afford the highly porous, L Cu '. At 77 K, L Cu ' absorbs 2.57 wt % of H 2 at 1 bar, which increases significantly to 4.67 wt % at 36 bar. The framework absorbs substantially high amounts of methane (238.38 cm 3  g -1 , 17.03 wt %) at 303 K and 60 bar. The CH 4 absorption at 303 K gives a total volumetric capacity of 166 cm 3  (STP) cm -3 at 35 bar (223.25 cm 3  g -1 , 15.95 wt %). Interestingly, the NH 2 groups in the linker, which decorate the channel surface, allow a remarkable 39.0 wt % of CO 2 to be absorbed at 1 bar and 273 K, which comes within the dominion of the most famous MOFs for CO 2 absorption. Also, L Cu ' shows pronounced selectivity for CO 2 absorption over CH 4 , N 2 , and H 2 at 273 K. The absorbed CO 2 can be converted to value-added cyclic carbonates under relatively mild reaction conditions (20 bar, 120 °C). Finally, L Cu ' is found to be an excellent heterogeneous catalyst in regioselective 1,3-dipolar cycloaddition reactions ("click" reactions) and provides an efficient, economic route for the one-pot synthesis of structurally divergent propargylamines through three-component coupling of alkynes, amines, and aldehydes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In Vivo Biotransformation Rates of Organic Chemicals in Fish: Relationship with Bioconcentration and Biomagnification Factors.

PubMed

Lo, Justin C; Letinski, Daniel J; Parkerton, Thomas F; Campbell, Dave A; Gobas, Frank A P C

2016-12-20

In vivo dietary bioaccumulation experiments for 85 hydrophobic organic substances were conducted to derive the in vivo gastrointestinal biotransformation rates, somatic biotransformation rates, bioconcentration factors (BCF), and biomagnification factors (BMF) for improving methods for bioaccumulation assessment and to develop an in vivo biotransformation rate database for QSAR development and in vitro to in vivo biotransformation rate extrapolation. The capacity of chemicals to be biotransformed in fish was found to be highly dependent on the route of exposure. Somatic biotransformation was the dominant pathway for most chemicals absorbed via the respiratory route. Intestinal biotransformation was the dominant metabolic pathway for most chemicals absorbed via the diet. For substances not biotransformed or transformed exclusively in the body of the fish, the BCF and BMF appeared to be closely correlated. For substances subject to intestinal biotransformation, the same correlation did not apply. We conclude that intestinal biotransformation and bioavailability in water can modulate the relationship between the BCF and BMF. This study also supports a fairly simple rule of thumb that may be useful in the interpretation of dietary bioaccumulation tests; i.e., chemicals with a BMF L of <1 tend to exhibit BCFs based on either the freely dissolved (BCF WW,fd ) or the total concentration (BCF WW,t ) of the chemical in the water that is less than 5000.

Functionalized three-dimensional graphene sponges for highly efficient crude and diesel oil adsorption.

PubMed

Bagoole, Oscar; Rahman, Md Mahfuzur; Shah, Sohail; Hong, Haiping; Chen, Hang; Al Ghaferi, Amal; Younes, Hammad

2018-06-02

Modified Hummer's method has been used in this study to synthesize graphene oxide (GO) solution that was utilized for the fabrication of three-dimensional (3D) graphene sponges and their subsequent functionalization through a low-cost and facile vapor-based surface enhancement approach. The functionalized 3D-graphene sponge is an excellent absorbent, which can remove more than 3300 wt.% of crude oil (calculated with respect to the original sorbent mass). The functionalization of the obtained graphene sponges with trichloro (1H,1H,2H,2H-perfluorooctyl)silane enhanced their wettability properties due to the super-hydrophobic nature of the resulting materials characterized by the contact angles in water greater than 150°. Furthermore, their elastic compression modulus (estimated by conducting a series of compression tests) was about 22.3 kPa. The equilibrium modeling of the oil removal process, which was performed by plotting Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms, confirmed the properties of the fabricated 3D graphene sponges as exceptional absorbents for crude and diesel oil, which could be attributed to the oleophilic nature of graphene. Moreover, the obtained 3D graphene sponges could be regenerated via heat treatment, which was conducted to release the adsorbed species. After five adsorption-desorption cycles, the sorption capacity of the produced 3D graphene sponges towards crude oil reached 95% of the initial value.

Strength Enhancement of Car Front Bumper for Slow Speed Impact by FEA Method as per IIHS Regulation

NASA Astrophysics Data System (ADS)

Sonawane, Chandrakant Rameshchandra; Shelar, Ajit Lavaji

2017-05-01

Low speed collisions happen significantly due to on road slow moving heavy traffic as well as during parking of vehicles. The bumpers are provided in front and back side of a vehicle has two main purposes: first is to absorb the energy generated during these kinds of slow speed impacts and secondly to protect the expensive parts like main engine parts, radiators and connected engine cooling mechanism, headlights, taillights, etc, by slowing down the vehicles. The problem often in various cars bumper is that they doesn't line-up vertically during low speed impact and leads to damage of various parts which are costly to repair. Many a times bumper design does not have sufficient capacity to absorb the energy generated during these impact. Guideline by International Institute Highway Safety (IIHS) regulation provides useful insight for such low speed impact study. In this paper, slow speed impact test were conducted as per IIHS regulation in three positions namely central impact, left hand corner impact and right hand corner impact. Parameters including bumper material, shape, thickness and impact condition are analyzed using fine element analysis (FEA) to enhance crashworthiness design in low speed impact. Then the vehicle front structure has been modified suitably. It has been observed that lining up the front metal bumper with suitable stiffness provides the best result which ultimately reduces the damage to the vehicle parts.

Cr(VI) Adsorption on Red Mud Modified by Lanthanum: Performance, Kinetics and Mechanisms

PubMed Central

Cui, You-Wei; Li, Jie; Du, Zhao-Fu; Peng, Yong-Zhen

2016-01-01

Water pollution caused by the highly toxic metal hexavalent chromium (Cr(VI)) creates significant human health and ecological risks. In this study, a novel adsorbent was used to treat Cr(VI)-containing wastewater; the adsorbent was prepared using red mud (RM) generated from the alumina production industry and the rare earth element lanthanum. This study explored adsorption performance, kinetics, and mechanisms. Results showed that the adsorption kinetics of the RM modified by lanthanum (La-RM), followed the pseudo-second-order model, with a rapid adsorption rate. Cr(VI) adsorption was positively associated with the absorbent dose, pH, temperature, and initial Cr(VI) concentration; coexisting anions had little impact. The maximum Cr(VI) adsorption capacity was 17.35 mg/g. Cr(VI) adsorption on La-RM was a mono-layer adsorption pattern, following the Langmuir isotherm model. Thermodynamic parameters showed the adsorption was spontaneous and endothermic. The adsorption of Cr(VI) on La-RM occurred as a result of LaOCl formation on the RM surface, which in turn further reacted with Cr(VI) in the wastewater. This study highlighted a method for converting industrial waste into a valuable material for wastewater treatment. The novel absorbent could be used as a potential adsorbent for treating Cr(VI)-contaminating wastewater, due to its cost-effectiveness and high adsorption capability. PMID:27658113

Clinical pharmacokinetic drug interaction studies of gabapentin enacarbil, a novel transported prodrug of gabapentin, with naproxen and cimetidine

PubMed Central

Lal, Ritu; Sukbuntherng, Juthamas; Luo, Wendy; Vicente, Virna; Blumenthal, Robin; Ho, Judy; Cundy, Kenneth C

2010-01-01

AIM Gabapentin enacarbil, a transported prodrug of gabapentin, provides sustained, dose-proportional exposure to gabapentin. Unlike gabapentin, the prodrug is absorbed throughout the intestinal tract by high-capacity nutrient transporters, including mono-carboxylate transporter-1 (MCT-1). Once absorbed, gabapentin enacarbil is rapidly hydrolyzed to gabapentin, which is subsequently excreted by renal elimination via organic cation transporters (OCT2). To examine the potential for drug–drug interactions at these two transporters, the pharmacokinetics of gabapentin enacarbil were evaluated in healthy adults after administration alone or in combination with either naproxen (an MCT-1 substrate) or cimetidine (an OCT2 substrate). METHODS Subjects (n= 12 in each study) received doses of study drug until steady state was achieved; 1200 mg gabapentin enacarbil each day, followed by either naproxen (500 mg twice daily) or cimetidine (400 mg four times daily) followed by the combination. RESULTS When gabapentin enacarbil was co-administered with naproxen, gabapentin Css,max increased by, on average, 8% and AUC by, on average, 13%. When gabapentin enacarbil was co-administered with cimetidine, gabapentin AUCss increased by 24% and renal clearance of gabapentin decreased. Co-administration with gabapentin enacarbil did not affect naproxen or cimetidine exposure. Gabapentin enacarbil was generally well tolerated. CONCLUSIONS No gabapentin enacarbil dose adjustment is needed with co-administration of naproxen or cimetidine. PMID:20573085

Preparation and properties of a coated slow-release and water-retention biuret phosphoramide fertilizer with superabsorbent.

PubMed

Jin, Shuping; Yue, Guoren; Feng, Lei; Han, Yuqi; Yu, Xinghai; Zhang, Zenghu

2011-01-12

In this investigation, a novel water-insoluble slow-release fertilizer, biuret polyphosphoramide (BPAM), was formulated and synthesized from urea, phosphoric acid (H(3)PO(4)), and ferric oxide (Fe(2)O(3)). The structure of BPAM was characterized by Fourier transform infrared (FTIR) spectroscopy. Subsequently, a coated slow-release BPAM fertilizer with superabsorbent was prepared by ionic cross-linked carboxymethylchitosan (the core), acrylic acid, acrylamide, and active carbon (the coating). The variable influences on the water absorbency were investigated and optimized. Component analysis results showed that the coated slow-release BPAM contained 5.66% nitrogen and 11.7% phosphorus. The property of water retention, the behavior of slow release of phosphorus, and the capacity of adsorption of cations were evaluated, and the results revealed that the product not only had good slow-release property and excellent water retention capacity but also higher adsorption capacities of cations in saline soil.

Characterization of polyphenols and evaluation of antioxidant capacity in grape pomace of the cv. Malbec.

PubMed

Antoniolli, Andrea; Fontana, Ariel R; Piccoli, Patricia; Bottini, Rubén

2015-07-01

Low molecular weight polyphenols (LMW-PPs) and anthocyanins, along with the antioxidant capacity, were assessed in grape pomace extract (GPE) of red grape (Vitis vinifera L.) cv. Malbec. Twenty-six phenolics (13 LMW-PPs and 13 anthocyanins) were characterized and quantified by HPLC-MWD and UPLC-ESI-MS. The maximum concentrations of LMW-PPs corresponded to the flavanols (+)-catechin and (-)-epicatechin, whereas malvidin-3-glucoside was the most abundant anthocyanin. Piceatannol, a stilbene analogue to resveratrol with higher antioxidant activity, was firstly identified and quantified in GPE of the cv. Malbec. The antioxidant activity for Malbec GPE determined by oxygen radical absorbance capacity (ORAC) assay was 2,756 μmol TEg(-1) GPE. Therefore, the data reported sustain the use of winemaking by-products as a cheap source of phenolic compounds suitable for biotechnological applications, as a strategy for sustainable oenology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Changes in growth and antioxidant status of alfalfa sprouts during sprouting as affected by gamma irradiation of seeds.

PubMed

Fan, Xuetong; Thayer, Donald W; Sokorai, Kimberly J B

2004-03-01

Viking 3000 alfalfa seeds irradiated with gamma rays to doses of 0, 1, 2, 3, or 4 kGy were sprouted and allowed to grow for up to 8 days at 23 degrees C. Germination, growth (yield and length), antioxidant capacity, and ascorbic acid (AA) were measured during sprouting. Results showed percent germination of the seeds and the rates of growth of the sprouts were inversely related to the radiation dose absorbed by the seeds. Both antioxidant capacity and AA content expressed on a fresh weight basis decreased during growth of the sprouts. Sprouts grown from irradiated seeds had greater antioxidant capacity and AA content on a fresh weight basis than those grown from nonirradiated seeds. However, when the nutritive values were expressed on a per gram of seed basis, irradiation had no effect on the nutritive values of sprouts.

A bone marrow toxicity model for 223Ra alpha-emitter radiopharmaceutical therapy

NASA Astrophysics Data System (ADS)

Hobbs, Robert F.; Song, Hong; Watchman, Christopher J.; Bolch, Wesley E.; Aksnes, Anne-Kirsti; Ramdahl, Thomas; Flux, Glenn D.; Sgouros, George

2012-05-01

Ra-223, an α-particle emitting bone-seeking radionuclide, has recently been used in clinical trials for osseous metastases of prostate cancer. We investigated the relationship between absorbed fraction-based red marrow dosimetry and cell level-dosimetry using a model that accounts for the expected localization of this agent relative to marrow cavity architecture. We show that cell level-based dosimetry is essential to understanding potential marrow toxicity. The GEANT4 software package was used to create simple spheres representing marrow cavities. Ra-223 was positioned on the trabecular bone surface or in the endosteal layer and simulated for decay, along with the descendants. The interior of the sphere was divided into cell-size voxels and the energy was collected in each voxel and interpreted as dose cell histograms. The average absorbed dose values and absorbed fractions were also calculated in order to compare those results with previously published values. The absorbed dose was predominantly deposited near the trabecular surface. The dose cell histogram results were used to plot the percentage of cells that received a potentially toxic absorbed dose (2 or 4 Gy) as a function of the average absorbed dose over the marrow cavity. The results show (1) a heterogeneous distribution of cellular absorbed dose, strongly dependent on the position of the cell within the marrow cavity; and (2) that increasing the average marrow cavity absorbed dose, or equivalently, increasing the administered activity resulted in only a small increase in potential marrow toxicity (i.e. the number of cells receiving more than 4 or 2 Gy), for a range of average marrow cavity absorbed doses from 1 to 20 Gy. The results from the trabecular model differ markedly from a standard absorbed fraction method while presenting comparable average dose values. These suggest that increasing the amount of radioactivity may not substantially increase the risk of toxicity, a result unavailable to the absorbed fraction method of dose calculation.

Microcapsule and methods of making and using microcapsules

DOEpatents

Okawa, David C.; Pastine, Stefan J.; Zettl, Alexander K.; Frechet, Jean M.J.

2014-09-02

An embodiment of a microcapsule includes a shell surrounding a space, a liquid within the shell, and a light absorbing material within the liquid. An embodiment of a method of making microcapsules includes forming a mixture of a light absorbing material and an organic solution. An emulsion of the mixture and an aqueous solution is then formed. A polymerization agent is added to the emulsion, which causes microcapsules to be formed. Each microcapsule includes a shell surrounding a space, a liquid within the shell, and light absorbing material within the liquid. An embodiment of a method of using microcapsules includes providing phototriggerable microcapsules within a bulk material. Each of the phototriggerable microcapsules includes a shell surrounding a space, a chemically reactive material within the shell, and a light absorbing material within the shell. At least some of the phototriggerable microcapsules are exposed to light, which causes the chemically reactive material to release from the shell and to come into contact with bulk material.

EUV multilayer defect compensation (MDC) by absorber pattern modification: from theory to wafer validation

NASA Astrophysics Data System (ADS)

Pang, Linyong; Hu, Peter; Satake, Masaki; Tolani, Vikram; Peng, Danping; Li, Ying; Chen, Dongxue

2011-11-01

According to the ITRS roadmap, mask defects are among the top technical challenges to introduce extreme ultraviolet (EUV) lithography into production. Making a multilayer defect-free extreme ultraviolet (EUV) blank is not possible today, and is unlikely to happen in the next few years. This means that EUV must work with multilayer defects present on the mask. The method proposed by Luminescent is to compensate effects of multilayer defects on images by modifying the absorber patterns. The effect of a multilayer defect is to distort the images of adjacent absorber patterns. Although the defect cannot be repaired, the images may be restored to their desired targets by changing the absorber patterns. This method was first introduced in our paper at BACUS 2010, which described a simple pixel-based compensation algorithm using a fast multilayer model. The fast model made it possible to complete the compensation calculations in seconds, instead of days or weeks required for rigorous Finite Domain Time Difference (FDTD) simulations. Our SPIE 2011 paper introduced an advanced compensation algorithm using the Level Set Method for 2D absorber patterns. In this paper the method is extended to consider process window, and allow repair tool constraints, such as permitting etching but not deposition. The multilayer defect growth model is also enhanced so that the multilayer defect can be "inverted", or recovered from the top layer profile using a calibrated model.

Waters of Hydration of Cupric Hydrates: A Comparison between Heating and Absorbance Methods

ERIC Educational Resources Information Center

Barlag, Rebecca; Nyasulu, Frazier

2011-01-01

The empirical formulas of four cupric hydrates are determined by measuring the absorbance in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of absorbance versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C.E.; Benson, D.K.

1996-02-06

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbent material, such as FeO, VO{sub 2}, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbent material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbent material melts glass in the portions of both glass sheets that are adjacent the absorbent material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbent material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbent material to source energy power and welding heat needed, the process can be made self-stopping. 8 figs.

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C. Edwin; Benson, David K.

1996-01-01

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbant material, such as FeO, VO.sub.2, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbant material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbant material melts glass in the portions of both glass sheets that are adjacent the absorbant material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbant material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbant material to source energy power and welding heat needed, the process can be made self-stopping.

Getting and Keeping Students' Brains Energized and Eager

ERIC Educational Resources Information Center

Stormon-Flynn, Mary

2011-01-01

A brain has the capacity to absorb a great deal of information and can make decisions about what role or roles, major or minor, that data will play in its life. While it is most likely true that we learn one new thing every day, our brain, the controller of our thoughts, can decide what number of new things we can learn and remember each day. As I…

Bran data of total flavonoid and total phenolic contents, oxygen radical absorbance capacity, and profiles of proanthocyanidins and whole grain physical traits of 32 red and purple rice varieties

USDA-ARS?s Scientific Manuscript database

Phytochemicals in red and purple bran rice have potential health benefit to humans. We determined the phytochemicals in brans of 32 red and purple global rice varieties. The description of the origin and physical traits of the whole grain (color, length, width, thickness and 100-kernel weight) of th...

High Operating Temperature Barrier Infrared Detector with Tailorable Cutoff Wavelength

NASA Technical Reports Server (NTRS)

Ting, David Z. (Inventor); Hill, Cory J. (Inventor); Seibel, Alexander (Inventor); Bandara, Sumith Y. (Inventor); Gunapala, Sarath D. (Inventor)

2015-01-01

A barrier infrared detector with absorber materials having selectable cutoff wavelengths and its method of manufacture is described. A GaInAsSb absorber layer may be grown on a GaSb substrate layer formed by mixing GaSb and InAsSb by an absorber mixing ratio. A GaAlAsSb barrier layer may then be grown on the barrier layer formed by mixing GaSb and AlSbAs by a barrier mixing ratio. The absorber mixing ratio may be selected to adjust a band gap of the absorber layer and thereby determine a cutoff wavelength for the barrier infrared detector. The absorber mixing ratio may vary along an absorber layer growth direction. Various contact layer architectures may be used. In addition, a top contact layer may be isolated into an array of elements electrically isolated as individual functional detectors that may be used in a detector array, imaging array, or focal plane array.

Model-Based Radiation Dose Correction for Yttrium-90 Microsphere Treatment of Liver Tumors With Central Necrosis

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

Liu, Ching-Sheng; Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Lin, Ko-Han

Purpose: The objectives of this study were to model and calculate the absorbed fraction {phi} of energy emitted from yttrium-90 ({sup 90}Y) microsphere treatment of necrotic liver tumors. Methods and Materials: The tumor necrosis model was proposed for the calculation of {phi} over the spherical shell region. Two approaches, the semianalytic method and the probabilistic method, were adopted. In the former method, the range--energy relationship and the sampling of electron paths were applied to calculate the energy deposition within the target region, using the straight-ahead and continuous-slowing-down approximation (CSDA) method. In the latter method, the Monte Carlo PENELOPE code wasmore » used to verify results from the first method. Results: The fraction of energy, {phi}, absorbed from {sup 90}Y by 1-cm thickness of tumor shell from microsphere distribution by CSDA with complete beta spectrum was 0.832 {+-} 0.001 and 0.833 {+-} 0.001 for smaller (r{sub T} = 5 cm) and larger (r{sub T} = 10 cm) tumors (where r is the radii of the tumor [T] and necrosis [N]). The fraction absorbed depended mainly on the thickness of the tumor necrosis configuration, rather than on tumor necrosis size. The maximal absorbed fraction {phi} that occurred in tumors without central necrosis for each size of tumor was different: 0.950 {+-} 0.000, and 0.975 {+-} 0.000 for smaller (r{sub T} = 5 cm) and larger (r{sub T} = 10 cm) tumors, respectively (p < 0.0001). Conclusions: The tumor necrosis model was developed for dose calculation of {sup 90}Y microsphere treatment of hepatic tumors with central necrosis. With this model, important information is provided regarding the absorbed fraction applicable to clinical {sup 90}Y microsphere treatment.« less

Hybrid Encapsulated Ionic Liquids for Post-Combustion Carbon Dioxide (CO 2) Capture

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

Brennecke, Joan; Degnan, Thomas; McCready, Mark

Ionic liquids (ILs) and Phase Change Ionic Liquids (PCILs) are excellent materials for selective removal of carbon dioxide from dilute post-combustion streams. However, they are typically characterized as having high viscosities, which impairs their effectiveness due to mass transfer limitations, caused by the high viscosities. In this project, we are examining the benefits of encapsulating ILs and PCILs in thin polymeric shells to produce particles of approximately 100 to 600 μm in diameter that can be used in a fluidized bed absorber. The particles are produced by microencapsulation of the ILs and PCILs in CO 2-permeable polymer shells. Here wemore » report on the synthesis of the IL and PCIL materials, measurements of thermophysical properties including CO 2 capacity and reprotonation equilibrium and kinetics, encapsulation of the ILs and PCILs, mechanical and thermodynamic testing of the encapsulated materials, development of a rate based model of the absorber, and the design of a laboratory scale unit to test the encapsulated particles for CO 2 capture ability and efficiency. We show that the IL/PCIL materials can be successfully encapsulated, that they retain CO 2 uptake capacity, and that the uptake rates are increased relative to a stagnant sample of IL liquid or PCIL powder.« less

An Investigation on Axial Deformation Behavior of Thin-Wall Unfilled and Filled Tube with Aluminum Alloy (Al-Si7Mg) Foam Reinforced with SiC Particles

NASA Astrophysics Data System (ADS)

Kumaraswamidhas, L. A.; Rajak, Dipen Kumar; Das, S.

2016-08-01

The objective of this research is to produce superior quality aluminum alloy foam with low relative density and higher resistance against compression deformation. This investigation has studied crash energy capacities of unfilled and filled aluminum alloy foams in mild steel tubes. The foam has been prepared by the melt route process with an addition of 5wt.% silicon carbide particles. The fabricated aluminum alloy foams were characterized by field emission scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and Material Pro analyzer. It was observed that the foam-filled tubes could absorb more energy as compared to the unfilled tubes before reaching the complete densification point. Also, the aluminum alloy foams had better energy absorption capacity during the crash or impact loading. This article demonstrates the excellent ability of aluminum alloy foam application in the field where there is a need to absorb crash energy. It is to be noted that the amount of energy absorption will be greater for low-density foam filled in thin-wall rectangular section tubes. We have seen an increasing trend in the application of aluminum foams inside the thin-wall mild steel tubes for maximum energy absorption.

Development of a semi-active dynamic vibration absorber for longitudinal vibration of propulsion shaft system based on magnetorheological elastomer

NASA Astrophysics Data System (ADS)

Liu, Gaoyu; Lu, Kun; Zou, Donglin; Xie, Zhongliang; Rao, Zhushi; Ta, Na

2017-07-01

The control of the longitudinal pulsating force and the vibration generated is very important to improve the stealth performance of a submarine. Magnetorheological elastomer (MRE) is a kind of intelligent composite material, whose mechanical properties can be continuously, rapidly and reversibly controlled by an external magnetic field. It can be used as variable-stiffness components in the design of a semi-active dynamic vibration absorber (SDVA), which is one of the effective means of longitudinal vibration control. In this paper, an SDVA is designed based on the MRE’s magnetic-induced variable stiffness characteristic. Firstly, a mechanical model of the propulsion shaft system with the SDVA is proposed, theoretically discussed and numerically validated. Then, the mechanical performance of the MRE under different magnetic fields is tested. In addition, the magnetic circuit and the overall structure of the SDVA are designed. Furthermore, electromagnetic and thermodynamic simulations are carried out to guarantee the structural design. The frequency shift property of the SDVA is found through dynamic simulations and validated by a frequency shift experiment. Lastly, the vibration absorption capacity of the SDVA is investigated. The results show that the magnetorheological effect of the MRE and the frequency shift of the SDVA are obvious; the SDVA has relatively acceptable vibration absorption capacity.

New adaptive method to optimize the secondary reflector of linear Fresnel collectors

DOE PAGES

Zhu, Guangdong

2017-01-16

Performance of linear Fresnel collectors may largely depend on the secondary-reflector profile design when small-aperture absorbers are used. Optimization of the secondary-reflector profile is an extremely challenging task because there is no established theory to ensure superior performance of derived profiles. In this work, an innovative optimization method is proposed to optimize the secondary-reflector profile of a generic linear Fresnel configuration. The method correctly and accurately captures impacts of both geometric and optical aspects of a linear Fresnel collector to secondary-reflector design. The proposed method is an adaptive approach that does not assume a secondary shape of any particular form,more » but rather, starts at a single edge point and adaptively constructs the next surface point to maximize the reflected power to be reflected to absorber(s). As a test case, the proposed optimization method is applied to an industrial linear Fresnel configuration, and the results show that the derived optimal secondary reflector is able to redirect more than 90% of the power to the absorber in a wide range of incidence angles. Here, the proposed method can be naturally extended to other types of solar collectors as well, and it will be a valuable tool for solar-collector designs with a secondary reflector.« less

New adaptive method to optimize the secondary reflector of linear Fresnel collectors

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

Zhu, Guangdong

Performance of linear Fresnel collectors may largely depend on the secondary-reflector profile design when small-aperture absorbers are used. Optimization of the secondary-reflector profile is an extremely challenging task because there is no established theory to ensure superior performance of derived profiles. In this work, an innovative optimization method is proposed to optimize the secondary-reflector profile of a generic linear Fresnel configuration. The method correctly and accurately captures impacts of both geometric and optical aspects of a linear Fresnel collector to secondary-reflector design. The proposed method is an adaptive approach that does not assume a secondary shape of any particular form,more » but rather, starts at a single edge point and adaptively constructs the next surface point to maximize the reflected power to be reflected to absorber(s). As a test case, the proposed optimization method is applied to an industrial linear Fresnel configuration, and the results show that the derived optimal secondary reflector is able to redirect more than 90% of the power to the absorber in a wide range of incidence angles. Here, the proposed method can be naturally extended to other types of solar collectors as well, and it will be a valuable tool for solar-collector designs with a secondary reflector.« less

Branched GAX cycle gas fired heat pump

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

Erickson, D.C.; Anand, G.; Papar, R.A.

1996-12-31

GAX absorption heat pump cycles are characterized by the Generator Absorber Heat eXchange (GAX) between the high temperature end of the absorber and the low temperature end of the generator. The improved thermodynamic performance of the basic GAX cycle coupled with its mechanical simplicity has attracted substantial interest in using this cycle for gas-cooling. However, to be competitive in a cooling dominated market, the cycle has to achieve high cooling performance and also low installed cost. The Branched GAX (BGAX) cycle promises higher cooling performance using similar components as the basic GAX cycle and an additional solution pump. By increasingmore » the solution flow rate at the hot end of the absorber, the BGAX cycle makes more complete use of the temperature overlap. As a result, less external heat is supplied and higher COPs are obtained. A breadboard prototype of the BGAX cycle has been developed and is now operating. A novel thermosyphon cooled absorber eliminates the need for the outdoor hydronic loop, and reduces cost by 10%. Other component improvements yield another 10% cost reduction. The breadboard prototype has operated for more than 200 hours. Gas cooling COP = 0.87 has been consistently achieved at 30.6 C (87 F) ambient conditions. At the 35 C (95 F) ambient capacity rating condition, a cooling load of 4.5 refrigeration tons was achieved at a cycle COP = 0.95.« less

System and method for treatment of a flue gas

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

Spiry, Irina Pavlovna; Wood, Benjamin Rue; Singh, Surinder Prabhjot

A method for treatment of a flue gas involves feeding the flue gas and a lean solvent to an absorber. The method further involves reacting the flue gas with the lean solvent within the absorber to generate a clean flue gas and a rich solvent. The method also involves feeding the clean flue gas from the absorber and water from a source, to a wash tower to separate a stripped portion of the lean solvent from the clean flue gas to generate a washed clean flue gas and a mixture of the water and the stripped portion of the leanmore » solvent. The method further involves treating at least a portion of the mixture of the water and the stripped portion of the lean solvent via a separation system to separate the water from the stripped portion of the lean solvent.« less

Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

Shock Isolation Elements Testing for High Input Loadings. Volume III. Mechanical Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*SPRINGS, (*SHOCK(MECHANICS), REDUCTION), TORSION BARS, ELASTOMERS, DAMPING, EQUATIONS OF MOTION, MODEL TESTS, TEST METHODS, NUCLEAR EXPLOSIONS, HARDENING.

Heat pipe cooling for scramjet engines

NASA Technical Reports Server (NTRS)

Silverstein, Calvin C.

1986-01-01

Liquid metal heat pipe cooling systems have been investigated for the combustor liner and engine inlet leading edges of scramjet engines for a missile application. The combustor liner is cooled by a lithium-TZM molybdenum annular heat pipe, which incorporates a separate lithium reservoir. Heat is initially absorbed by the sensible thermal capacity of the heat pipe and liner, and subsequently by the vaporization and discharge of lithium to the atmosphere. The combustor liner temperature is maintained at 3400 F or less during steady-state cruise. The engine inlet leading edge is fabricated as a sodium-superalloy heat pipe. Cooling is accomplished by radiation of heat from the aft surface of the leading edge to the atmosphere. The leading edge temperature is limited to 1700 F or less. It is concluded that heat pipe cooling is a viable method for limiting scramjet combustor liner and engine inlet temperatures to levels at which structural integrity is greatly enhanced.

Control of water and nutrients using a porous tube - A method for growing plants in space

NASA Technical Reports Server (NTRS)

Dreschel, Thomas W.; Sager, John C.

1989-01-01

A plant nutrient delivery system that uses a microporous, hydrophilic tube was developed with potential application for crop production in the microgravity of space. The tube contains a nutrient solution and delivers it to the roots. Pumps attached to the tubing create a very small suction that holds the solution within the tube. This system was used to grow wheat for 107 d in a controlled environment at suctions of 0.40, 1.48, or 2.58 kPa. The water absorbed through the pores of the tube by baby diaper sections decreased as suction increased. Correspondingly, final plant biomass, seed number, and spikelet number also tended to decrease as suction increased. The reduced yield at higher suction suggests that the plants experienced water stress, although all suctions were below those typical of soils at field capacity.

Synthesis and application of acrylamide-maleic anhydride copolymer for solid phase extraction

NASA Astrophysics Data System (ADS)

Teng, Xiaoxiao; Niu, Yabo; Xie, Zhihai; Cai, Qing

2018-03-01

A new absorbent of acrylamide-maleic anhydride copolymer (PAMMA) for preconcentration of metal ions was synthesized. This PAMMA was applied for enrichment and determination of Al3+, Cu2+, Cd2+ and Pb2+ in table salt by ICP-OES. The maximum uptake capacities of PAMMA were 6.49, 5.84, 5.34 and 7.49 mg g‑1 for Al3+, Cu2+, Cd2+ and Pb2+, respectively. The limit of detection was 0.31, 0.26, 0.43, and 0.12 μg L‑1, and the RSD (relative standard deviations, n=6) was 1.5%, 3.7%, 3.0% and 2.6% for Al3+, Cu2+, Cd2+ and Pb2+, respectively. The presented method was used for simultaneous detecting of Al3+, Cu2+, Cd2+ and Pb2+ in table salt with the recoveries from 95.0% to 103%.

Erection of duct-like graphitic carbon nitride with enhanced photocatalytic activity for ACB photodegradation

NASA Astrophysics Data System (ADS)

Muhmood, Tahir; Xia, Mingzhu; Lei, Wu; Wang, Fengyun

2018-02-01

Novel duct graphitic carbon nitride (DCN) was successfully prepared using the temperature control method in a quartz tube furnace from commercially available melamine and evaluated against the photo-degradation of latent organic pollutants, acarbose (ACB). These prepared materials were characterized by UV-Vis spectroscopy, Fourier transform infrared spectra, x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy and scanning electron microscopy. The characterization results indicated that the synthesized material was in the form of a duct-like structure and has greater adsorption capacity and photocatalytic ability as compared to traditionally synthesized graphitic carbon nitride materials. The DCN split theACB completely into many intermediates, which were depicted in the HPLC-MS spectrum for knowing the acarbose photo-degrdation pathway. The duct-like morphology of graphitic carbon nitride has improved properties, such as increasing the surface area and decelerating the e -/h + recombination, which increase the light absorbance ability with enhanced photoactivity.

Adsorption characteristics of hexavalent chromium on HCB/TiO2

NASA Astrophysics Data System (ADS)

Zhang, Li; Zhang, Yonggang

2014-10-01

Sol-gel method was adopted to prepare HCB/TiO2 and its adsorption ability of hexavalent chromium, Cr(VI), and removal from aqueous solution were investigated. The samples were characterized by Power X-ray diffraction (XRD) and a transmission electron microscope (TEM) which showed that the TiO2 was deposited on the surface of HCB. FTIR was used to identify the changes of the surface functional groups before and after adsorption. Potentiometric titration method was used to characterize the zero charge (pHpzc) characteristics of the surface of HCB/TiO2 which showed more acidic functional groups containing. Batch experiments showed that initial pH, absorbent dosage, contact time and initial concentration of Cr(VI) were important parameters for the Cr(VI) adsorption studies. The Freundlich isotherm model better reflected the experimental data better. Cr(VI) adsorption process followed the pseudo-second order kinetic model, which illustrated chemical adsorption. The thermodynamic parameters, such as Gibbs free energy (ΔG), changes in enthalpy change (ΔH) and changes in entropy change (ΔS) were also evaluated. Negative value of free energy occurred at temperature range of 25-45 °C, so Cr(VI) adsorption by HCB/TiO2 is spontaneous. Desorption results showed that the adsorption capacity could maintain 80% after five cycles. The maximum adsorption capacity for Cr(VI) was at 27.33 mg g-1 in an acidic medium, of which the value is worth comparable with other low-cost adsorbents.

Analytical parameters of the microplate-based ORAC-pyrogallol red assay.

PubMed

Ortiz, Rocío; Antilén, Mónica; Speisky, Hernán; Aliaga, Margarita E; López-Alarcón, Camilo

2011-01-01

The analytical parameters of the microplate-based oxygen radicals absorbance capacity (ORAC) method using pyrogallol red (PGR) as probe (ORAC-PGR) are presented. In addition, the antioxidant capacity of commercial beverages, such as wines, fruit juices, and iced teas, is estimated. A good linearity of the area under the curve (AUC) versus Trolox concentration plots was obtained [AUC = (845 +/- 110) + (23 +/- 2) [Trolox, microM], R = 0.9961, n = 19]. QC experiments showed better precision and accuracy at the highest Trolox concentration (40 microM) with RSD and REC (recuperation) values of 1.7 and 101.0%, respectively. When red wine was used as sample, the method also showed good linearity [AUC = (787 +/- 77) + (690 +/- 60) [red wine, microL/mL]; R = 0.9926, n = 17], precision and accuracy with RSD values from 1.4 to 8.3%, and REC values that ranged from 89.7 to 103.8%. Additivity assays using solutions containing gallic acid and Trolox (or red wine) showed an additive protection of PGR given by the samples. Red wines showed higher ORAC-PGR values than white wines, while the ORAC-PGR index of fruit juices and iced teas presented a great variability, ranging from 0.6 to 21.6 mM of Trolox equivalents. This variability was also observed for juices of the same fruit, showing the influence of the brand on the ORAC-PGR index. The ORAC-PGR methodology can be applied in a microplate reader with good linearity, precision, and accuracy.

Automated Absorber Attachment for X-ray Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Moseley, S.; Allen, Christine; Kilbourne, Caroline; Miller, Timothy M.; Costen, Nick; Schulte, Eric; Moseley, Samuel J.

2007-01-01

Our goal is to develop a method for the automated attachment of large numbers of absorber tiles to large format detector arrays. This development includes the fabrication of high quality, closely spaced HgTe absorber tiles that are properly positioned for pick-and-place by our FC150 flip chip bonder. The FC150 also transfers the appropriate minute amount of epoxy to the detectors for permanent attachment of the absorbers. The success of this development will replace an arduous, risky and highly manual task with a reliable, high-precision automated process.

Liquid absorbent solutions for separating nitrogen from natural gas

DOEpatents

Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Lyon, David K.; Miller, Warren K.

2000-01-01

Nitrogen-absorbing and -desorbing compositions, novel ligands and transition metal complexes, and methods of using the same, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

Sorbents for High Temperature Removal of Arsenic from Coal-Derived Synthesis Gas

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

Alptekin, G.O.; Copeland, R.; Dubovik, M.

2002-09-20

Gasification technologies convert coal and other heavy feedstocks into synthesis gas feed streams that can be used in the production of a wide variety of chemicals, ranging from hydrogen through methanol, ammonia, acetic anhydride, dimethyl ether (DME), methyl tertiary butyl ether (MTBE), high molecular weight liquid hydrocarbons and waxes. Syngas can also be burned directly as a fuel in advanced power cycles to generate electricity with very high efficiency. However, the coal-derived synthesis gas contains a myriad of trace contaminants that may poison the catalysts that are used in the downstream manufacturing processes and may also be regulated in powermore » plant emissions. Particularly, the catalysts used in the conversion of synthesis gas to methanol and other liquid fuels (Fischer-Tropsch liquids) have been found to be very sensitive to the low levels of poisons, especially arsenic, that are present in the synthesis gas from coal. TDA Research, Inc. (TDA) is developing an expendable high capacity, low-cost chemical absorbent to remove arsenic from coal-derived syngas. Unlike most of the commercially available sorbents that physically adsorb arsenic, TDA's sorbent operates at elevated temperatures and removes the arsenic through chemical reaction. The arsenic content in the coal gas stream is reduced to ppb levels with the sorbent by capturing and stabilizing the arsenic gas (As4) and arsenic hydrides (referred to as arsine, AsH3) in the solid state. To demonstrate the concept of high temperature arsenic removal from coal-derived syngas, we carried out bench-scale experiments to test the absorption capacity of a variety of sorbent formulations under representative conditions. Using on-line analysis techniques, we monitored the pre- and post-breakthrough arsine concentrations over different sorbent samples. Some of these samples exhibited pre-breakthrough arsine absorption capacity over 40% wt. (capacity is defined as lb of arsenic absorbed/lb of sorbent), while maintaining an arsine outlet concentration at less than 10 ppb.« less

Sun and Shade leaves, SIF, and Photosynthetic Capacity

NASA Astrophysics Data System (ADS)

Berry, J. A.; Badgley, G.

2016-12-01

Recent advances in retrieval of solar induced chlorophyll fluorescence (SIF) have opened up new possibilities for remote sensing of canopy physiology and structure. To date most of the emphasis has been placed on SIF as an indicator of stress and photosynthetic capacity. However, it is clear that canopy structure can also have an influence. To this point, simulations of SIF in land surface models tend to under predict observed variation in SIF. Also, large, systematic differences in SIF from different canopy types seem to correlate well with the photosynthetic capacity of these canopies. SIF emissions from pampered crops can be several-fold that from evergreen, needle-leaf forests. Yet, these may have similar vegetation indices and absorb a similar fraction of incident PAR. SIF photons produced in a conifer canopy do have a lower probability of escaping its dense, clumped foliage. However, this does not explain the correlated differences in photosynthetic rate and SIF. It is useful, in this regard, to consider the separate contributions of sun and shade leaves to the SIF emitted by a canopy. Sun leaves tend to be displayed to intercept the direct solar beam, and these highly illuminated leaves are often visible from above the canopy. Sun leaves produce more SIF and a large fraction of it escapes. Therefore, the intensity of SIF may be a sensitive indicator of the partitioning of absorbed PAR to sun and shade leaves. Many models account tor the different photosynthetic capacity of sun and shade leaves in calculating canopy responses. However, the fraction of leaves in each category is usually parameterized by an assumed leaf angle distribution (e.g. spherical). In reality, the sun/shade fraction can vary over a wide range, and it has been difficult to measure. SIF and possibly near-IR reflectance of canopies can be used to specify this key parameter with obvious importance to understanding photosynthetic rate.