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Co2 absorber

Dong Yan, John Beardall, Kunshan Gao
Cell size has implications for the package effect in photon absorption as well as for metabolic scaling of metabolism. In this study, we have avoided species-related differences by using isolates of the marine planktonic diatom Coscinodiscus granii with cells of different sizes and grown at different light intensities to investigate their energy allocation strategies. To make full use of incident light, several fold variations in cellular chlorophyll a content were employed across cell size. This modulation of pigment-related light absorbance was deemed effective as similar light absorbing capacities were found in all treatments...
January 10, 2018: Photosynthesis Research
Shichen Lian, Mohamad S Kodaimati, Emily A Weiss
This paper describes the use of electrostatic assemblies of negatively charged colloidal CuInS2/ZnS quantum dot (QD) sensitizers and positively charged, trimethylamino-functionalized iron tetraphenylporphyrin catalysts (FeTMA) to photoreduce CO2 to CO in water, upon illumination with 450-nm light. This system achieves a turnover number (TON) of CO (per FeTMA) of 450 after 30 h of illumination, with a selectivity of 99%. Its sensitization efficiency (TON per Joule of photons absorbed) is a factor of eleven larger than the previous record for photosensitization of an iron porphyrin catalyst for this reaction, held by a system in which both QDs and metal porphyrin were uncharged...
January 3, 2018: ACS Nano
Rachel Steinhardt, Stanley C Hiew, Hemakesh Mohapatra, Du Nguyen, Zachary Oh, Richard Truong, Aaron Esser-Kahn
Designing new liquids for CO2 absorption is a challenge in CO2 removal. Here, achieving low regeneration energies while keeping high selectivity and large capacity are current challenges. Recent cooperative metal-organic frameworks have shown the potential to address many of these challenges. However, many absorbent systems and designs rely on liquid capture agents. We present herein a liquid absorption system which exhibits cooperative CO2 absorption isotherms. Upon introduction, CO2 uptake is initially suppressed, followed by an abrupt increase in absorption...
December 27, 2017: ACS Central Science
Pengrui Jin, Chuan Huang, Jiaxiang Li, Yadong Shen, Liao Wang
The wetting of hollow fibre membranes decreases the performance of the liquid-gas membrane contactor for CO2 capture in biogas upgrading. To solve this problem, in this work, a poly(vinylidene fluoride) (PVDF) hollow fibre membrane for a liquid-gas membrane contactor was coated with a superhydrophobic layer composed of a combination of hydrophobic SiO2 nanoparticles and polydimethylsiloxane (PDMS) by the method of spray deposition. A rough layer of SiO2 deposited on the PVDF membrane resulted in an enhanced surface hydrophobicity...
November 2017: Royal Society Open Science
Yan Gao, Shu-Cheng Zheng, Chao-Qun Zheng, Yue-Chen Shi, Xiao-Lu Xie, Ke-Jian Wang, Hai-Peng Liu
The gradual increase of CO2 concentration in the atmosphere, absorbed by the ocean surface water through air to sea equilibration termed ocean acidification (OA), leads to the decline of pH in seawater. It is not clear so far how the composition of fatty acids, particular the immune-related, in marine crustacean and the subsequent energy supply in marine ecosystem are affected by OA. The brine shrimp Artemia sinica is an open and common feed that provide essential fatty acids for mariculture. In this study, the fatty acids profiles of brine shrimp cultured under different lower pH levels of CO2 driven seawater were investigated...
December 26, 2017: Developmental and Comparative Immunology
Suramya Waidyanatha, Kristen Ryan, J Michael Sanders, Jacob D McDonald, Christopher J Wegerski, Melanie Doyle-Eisle, C Edwin Garner
β-N-methylamino-l-alanine (L-BMAA) is produced by cyanobacteria (blue-green algae). Human exposure to L-BMAA occurs via consumption of L-BMAA-contaminated water and food. It is speculated that exposure to L-BMAA, and subsequent brain accumulation, may contribute to an increased incidence of neurodegenerative diseases indicating the need to evaluate risk of L-BMAA exposure to humans. As an initial step in this process, we have evaluated disposition following a single or repeated gavage administration of 1, 10 or 100mg/kg [14C]L-BMAA in rats and mice...
December 14, 2017: Toxicology and Applied Pharmacology
Mohab Omer, Jan F A Hendrickx, Simon De Ridder, Alexander De Houwer, Rik Carette, Sofie De Cooman, Andre M De Wolf
Low fresh gas flows (FGFs) decrease the use of anesthetic gases, but increase CO2 absorbent usage. CO2 absorbent usage remains poorly quantified. The goal of this study is to determine canister life of 8 commercially available CO2 absorbent prepacks with the Zeus®. Pre-packed CO2 canisters of 8 different brands were tested in vitro: Amsorb Plus, Spherasorb, LoFloSorb, LithoLyme, SpiraLith, SpheraSorb, Drägersorb 800+, Drägersorb Free, and CO2ntrol. CO2 (160 mL min- 1) flowed into the tip of a 2 L breathing bag that was ventilated with a tidal volume of 500 mL, a respiratory rate of 10/min, and an I:E ratio of 1:1 using the controlled mechanical ventilation mode of the Zeus® (Dräger, Lubeck, Germany)...
December 13, 2017: Journal of Clinical Monitoring and Computing
James Barber
The biological energy cycle of our planet is driven by photosynthesis whereby sunlight is absorbed by chlorophyll and other accessory pigments. The excitation energy is then efficiently transferred to a reaction centre where charge separation occurs in a few picoseconds. In the case of photosystem II (PSII), the energy of the charge transfer state is used to split water into oxygen and reducing equivalents. This is accomplished by the relatively low energy content of four photons of visible light. PSII is a large multi-subunit membrane protein complex embedded in the lipid environment of the thylakoid membranes of plants, algae and cyanobacteria...
January 2017: Quarterly Reviews of Biophysics
Bing Yu, Lichun Li, Hai Yu, Marcel Maeder, Graeme Puxty, Qi Yang, Paul H M Feron, William Owen Conway, Zuliang Chen
CO2 capture processes involving absorbent scrubbing will play a vital role in large scale industrial CO2 emissions reductions into the future. Despite the relative maturity of amine based absorbent technologies, few have attempted to examine the fundamental chemistry of di-amines in detail due to the complex reaction mechanisms. In an effort to advance this understanding we report here the determination of the kinetic and equilibrium constants for a simple linear di-amine N,N-dimethylethylenediamine (DMEDA) via stopped-flow spectrophotometric and 1H/13C NMR titrations at 25...
December 7, 2017: Environmental Science & Technology
Lennart T Bach, Santiago Alvarez-Fernandez, Thomas Hornick, Annegret Stuhr, Ulf Riebesell
The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA). OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3) for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm) in five of them while the other five served as controls (380 μatm)...
2017: PloS One
Jesús Alberto Pérez-Romero, Yanina Lorena Idaszkin, Bernardo Duarte, Alexandra Baeta, João Carlos Marques, Susana Redondo-Gómez, Isabel Caçador, Enrique Mateos-Naranjo
A glasshouse experiment was designed to investigate the effect of the co-occurrence of 400 and 700ppm CO2 at 0, 15 and 45mM Cu on the Cu-tolerance of C4 cordgrass species Spartina densiflora, by measuring growth, gas exchange, efficiency of PSII, pigments profiles, antioxidative enzyme activities and nutritional balance. Our results revealed that the rising atmospheric CO2 mitigated growth reduction imposed by Cu in plants grown at 45mM Cu, leading to leaf Cu concentration bellow than 270mgKg-1 Cu, caused by an evident dilution effect...
November 23, 2017: Journal of Plant Physiology
Adrianna Nogalska, Adrianna Zukowska, Ricard Garcia-Valls
The aim of these studies is to evaluate the ambient CO2 capture abilities of the membrane contactor system in the same conditions as leafs, such as ambient temperature, pressure and low CO2 concentration, where the only driving force is the concentration gradient. The polysulfone membrane employed was made by a phase inversion process and characterized by ESEM micrographs which were used to determine the thickness, asymmetry and pore size. Besides, the porosity of the membrane was measured from the membrane and polysulfone density correlation and the hydrophobicity was analyzed by contact angle measurements...
November 24, 2017: Science of the Total Environment
William F Martin, Donald A Bryant, J Thomas Beatty
The origin and early evolution of photosynthesis are reviewed from an ecophysiological perspective. Earth's first ecosystems were chemotrophic, fueled by geological H2 at hydrothermal vents, and required flavin-based electron bifurcation to reduce ferredoxin for CO2 fixation. Chlorophyll-based phototrophy (chlorophototrophy) allowed autotrophs to generate reduced ferredoxin without electron bifurcation, providing them access to reductants other than H2. Because high-intensity, short-wavelength electromagnetic radiation at Earth's surface would have been damaging for the first chlorophyll (Chl)-containing cells, photosynthesis probably arose at hydrothermal vents under low-intensity, long-wavelength geothermal light...
November 21, 2017: FEMS Microbiology Reviews
Shunsuke Sato, Takeo Arai, Takeshi Morikawa
We successfully developed a highly efficient electrode for CO2 reduction using a Ru-complex catalyst ([Ru]) supported on carbon paper coated with multi-walled carbon nanotubes (CPCNT/[Ru]). The CPCNT/[Ru] electrode promoted the CO2 reduction reaction in aqueous solution near the theoretical potential, and produced formate linearly with a current density of greater than 0.9 mA/cm2 at -0.15 V (vs. RHE) for at least 24 hours. Due to the outstandingly low overpotential, a monolithic tablet-shaped photo-device was realized by coupling the CPCNT/[Ru] catalyst with amorphous SiGe-jn as a light absorber and IrOx as a water oxidation catalyst, and the device produced formate from CO2 and water in a single-compartment reactor...
November 27, 2017: Nanotechnology
Xiao-Ping Yi, Ya-Li Zhang, He-Sheng Yao, Ji-Mei Han, Wah Soon Chow, Da-Yong Fan, Wang-Feng Zhang
To clarify the influence of water deficit on the functionality of the photosynthetic apparatus of cotton plants, leaf gas exchange, chlorophyll a fluorescence, and P700 redox state were examined in field-grown cotton Gossypium hirsutum L. cv. Xinluzao 45. In addition, we measured changes in the P515 signal and analyzed the activity of ATP synthase and the trans-thylakoid proton gradient (ΔpH). With increasing water deficit, the net CO2 assimilation rate (AN) and stomatal conductance (gs) significantly decreased, but the maximum quantum efficiency of PSII photochemistry (Fv/Fm) did not change...
November 10, 2017: Journal of Plant Physiology
Timothy R Fennell, James M Mathews, Rodney W Snyder, Yang Hong, Scott L Watson, Sherry R Black, Barry S McIntyre, Suramya Waidyanatha
1. 2-Ethylhexyl-p-methoxycinnamate (EHMC) is commonly used as an ingredient in sunscreens, resulting in potential oral and dermal exposure in humans. 2. Clearance and metabolism of EHMC in hepatocytes and disposition and metabolism of EHMC in rodents following oral (8 to 800 mg/kg) intravenous (IV) (8 mg/kg), or dermal (0.8 to 80 mg/kg representing 0.1 to 10% formulation concentration) exposure to [(14)C]EHMC were investigated in rats and mice. 3. EHMC was rapidly cleared from rat and mouse hepatocytes (half-life ≤ 3...
November 7, 2017: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
Mingxing Sun, Yutao Wang, Lei Shi
Agricultural straw-based pulp making plays a vital role in pulp and paper industry, especially in forest deficient countries such as China. However, the environmental performance of straw-based pulp has scarcely been studied. A life cycle assessment on wheat straw-based pulp making in China was conducted to fill of the gaps in comprehensive environmental assessments of agricultural straw-based pulp making. On average, the global warming potential (GWP), GWP excluding biogenic carbon, acidification potential and eutrophication potential of wheat straw based pulp making are 2299kg CO2-eq, 4550kg CO2-eq, 16...
October 27, 2017: Science of the Total Environment
Haiping Yang, Daqian Wang, Bin Li, Zhiwei Zeng, Lei Qu, Wennan Zhang, Hanping Chen
The effects of potassium (K) salts loading on CaO on the H2 production from pyrolysis-gasification of wheat straw were investigated. The loading of 0.25 wt% KCl could significantly enhance the CO2 absorption capability of CaO. The CO2 concentration in the product gas decreased sharply from 20.83 to 11.70 vol%, and the H2 concentration increased from 48.2 to 55.5 vol%. While the loading of 0.25 wt% K2CO3/K2SO4 inhibited the enhancing effect of CaO. Further increasing the loading of KCl on CaO, the CO2 absorption of CaO declined, but the catalytic effect of KCl on the gasification process was promoted...
October 24, 2017: Bioresource Technology
Nana L Christensen, Steen Jakobsen, Anna C Schacht, Ole L Munk, Aage K O Alstrup, Lars P Tolbod, Hendrik J Harms, Søren Nielsen, Lars C Gormsen
INTRODUCTION: Despite the decades long use of [(11)C]palmitate positron emission tomography (PET)/computed tomography in basic metabolism studies, only personal communications regarding dosimetry and biodistribution data have been published. METHODS: Dosimetry and biodistribution studies were performed in 2 pigs and 2 healthy volunteers by whole-body [(11)C]palmitate PET scans. Metabolite studies were performed in 40 participants (healthy and with type 2 diabetes) under basal and hyperinsulinemic conditions...
January 2017: Molecular Imaging
A Mashari, L Fedorko, J A Fisher, M Klein, M Wąsowicz, M Meineri
BACKGROUND: A volatile anaesthetic (VA) reflector can reduce VA consumption (VAC) at the cost of fine control of its delivery and CO2 accumulation. A digital in-line vaporizer and a second CO2 absorber circumvent both of these limitations. We hypothesized that the combination of a VA reflector with an in-line vaporizer would yield substantial VA conservation, independent of fresh gas flow (FGF) in a circle circuit, and provide fine control of inspired VA concentrations. METHOD: Prospective observational study on six Yorkshire pigs...
October 25, 2017: Acta Anaesthesiologica Scandinavica
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