Read by QxMD icon Read

Co2 absorber

Vytas Reipa, Shannon K Hanna, Aaron Urbas, Lane Sander, John Elliott, Joseph Conny, Elijah J Petersen
As the production mass of multiwall carbon nanotubes (MWCNT) increases, the potential for human and environmental exposure to MWCNTs may also increase. We have shown that exposing an aqueous suspension of pristine MWCNTs to an intense oxidative treatment in an electrochemical reactor, equipped with an efficient hydroxyl radical generating Boron Doped Diamond (BDD) anode, leads to their almost complete mineralization. Thermal optical transmittance analysis showed a total carbon mass loss of over two orders of magnitude due to the electrochemical treatment, a result consistent with measurements of the degraded MWCNT suspensions using UV-vis absorbance...
April 26, 2018: Journal of Hazardous Materials
Fan Wang, Zhiquan Lin, Chongyun Shao, Qinling Zhou, Lei Zhang, Meng Wang, Danping Chen, Guojun Gao, Shikai Wang, Chunlei Yu, Lili Hu
The laser behavior of a centimeter-scale Er3+ /Al3+ codoped silica fiber with core numerical aperture and core diameter of 0.15 and 8 μm, respectively, is reported. The core glass was prepared by the sol-gel method combined with high-temperature sintering; it contained Er3+ ion concentration as high as 1.32×1020   ions/cm3 and an Al/Er mole ratio of 10. The high doping homogeneity of Er3+ ions in the fiber core was confirmed by an electron probe microanalyzer element scanning, long Er3+ :  I13/2 4 emission lifetime of 11...
May 15, 2018: Optics Letters
Claudia C Robayo-Torres, Marisela Diaz-Sotomayor, Bruce R Hamaker, Susan S Baker, Bruno P Chumpitazi, Antone R Opekun, Buford L Nichols
BACKGROUND AND HYPOTHESES: Human starch digestion is a multienzyme process involving 6 different enzymes: salivary and pancreatic α-amylase; sucrase and isomaltase (from sucrose-isomaltase [SI]), and maltase and glucoamylase (from maltase-glucoamylase [MGAM]). Together these enzymes cleave starch to smaller molecules ultimately resulting in the absorbable monosaccharide glucose. Approximately 80% of all mucosal maltase activity is accounted for by SI and the reminder by MGAM. Clinical studies suggest that starch may be poorly digested in those with congenital sucrase-isomaltase deficiency (CSID)...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Matthew E S Bracken, Nyssa J Silbiger, Genevieve Bernatchez, Cascade J B Sorte
Predicting the impacts of ocean acidification in coastal habitats is complicated by bio-physical feedbacks between organisms and carbonate chemistry. Daily changes in pH and other carbonate parameters in coastal ecosystems, associated with processes such as photosynthesis and respiration, often greatly exceed global mean predicted changes over the next century. We assessed the strength of these feedbacks under projected elevated CO2 levels by conducting a field experiment in 10 macrophyte-dominated tide pools on the coast of California, USA...
2018: PeerJ
Junea Leandro do Nascimento, Alex-Alan Furtado de Almeida, Joedson P Barroso, Pedro A O Mangabeira, Dário Ahnert, Artur G R Sousa, José Vitor S Silva, Virupax C Baligar
The objective of this study was to evaluate Cr toxicity in young plants of the CCN 51 Theobroma cacao genotype at different concentrations of Cr3+ in the soil (0, 100, 200, 400 and 600 mg kg-1 ) through physiological, ultrastructural, antioxidant and molecular changes. Doses of 400 and 600 mg Cr3+ kg-1 soil severely affected foliar gas exchange, promoted by damages in photosynthetic machinery evidenced by the decrease in CO2 fixation. Decreased expression of psbA and psbO genes, changes in enzymatic activity and lipid peroxidation also affected leaf gas exchange...
May 10, 2018: Ecotoxicology and Environmental Safety
Moritz F Kuehnel, Constantin D Sahm, Gaia Neri, Jonathan R Lee, Katherine L Orchard, Alexander J Cowan, Erwin Reisner
A precious metal and Cd-free photocatalyst system for efficient CO2 reduction in water is reported. The hybrid assembly consists of ligand-free ZnSe quantum dots (QDs) as a visible-light photosensitiser combined with a phosphonic acid-functionalised Ni(cyclam) catalyst, NiCycP. This precious metal-free photocatalyst system shows a high activity for aqueous CO2 reduction to CO (Ni-based TONCO > 120), whereas an anchor-free catalyst, Ni(cyclam)Cl2 , produced three times less CO. Additional ZnSe surface modification with 2-(dimethylamino)ethanethiol (MEDA) partially suppresses H2 generation and enhances the CO production allowing for a Ni-based TONCO of > 280 and more than 33% selectivity for CO2 reduction over H2 evolution, after 20 h visible light irradiation ( λ > 400 nm, AM 1...
March 7, 2018: Chemical Science
Tao Sun, Shubin Li, Xinyu Song, Jinjin Diao, Lei Chen, Weiwen Zhang
Photosynthetic cyanobacteria are important primary producers and model organisms for studying photosynthesis and elements cycling on earth. Due to the ability to absorb sunlight and utilize carbon dioxide, cyanobacteria have also been proposed as renewable chassis for carbon-neutral "microbial cell factories". Recent progresses on cyanobacterial synthetic biology have led to the successful production of more than two dozen of fuels and fine chemicals directly from CO2 , demonstrating their potential for scale-up application in the future...
May 2, 2018: Biotechnology Advances
Alexey L Kaledin, Darren M Driscoll, Diego Troya, Daniel L Collins-Wildman, Craig L Hill, John R Morris, Djamaladdin G Musaev
The impact of ambient gas molecules (X), NO2 , CO2 and SO2 on the structure, stability and decontamination activity of Cs8 Nb6 O19 polyoxometalate was studied computationally and experimentally. It was found that Cs8 Nb6 O19 absorbs these molecules more strongly than it adsorbs water and Sarin (GB) and that these interactions hinder nerve agent decontamination. The impacts of diamagnetic CO2 and SO2 molecules on polyoxoniobate Cs8 Nb6 O19 were fundamentally different from that of NO2 radical. At ambient temperatures, weak coordination of the first NO2 radical to Cs8 Nb6 O19 conferred partial radical character on the polyoxoniobate and promoted stronger coordination of the second NO2 adsorbent to form a stable diamagnetic Cs8 Nb6 O19 /(NO2 )2 species...
February 28, 2018: Chemical Science
Hao Yang, Manmilan Singh, Jacob Schaefer
A humidity-swing polymeric sorbent captures CO2 from ambient air at room temperature simply by changing the humidity level. To date there has been no direct experimental evidence to characterize the chemical mechanism for this process. In this report we describe the use of solid-state NMR to study the humidity-swing CO2 absorption/desorption cycle directly. We find that at low humidity levels CO2 is absorbed as HCO3-. At high humidity levels, HCO3- is replaced by hydrated OH- and the absorbed CO2 is released...
May 1, 2018: Chemical Communications: Chem Comm
Sebastian Henke, Michael T Wharmby, Gregor Kieslich, Inke Hante, Andreas Schneemann, Yue Wu, Dominik Daisenberger, Anthony K Cheetham
We investigate the pressure-dependent mechanical behaviour of the zeolitic imidazolate framework ZIF-4 (M(im)2 ; M2+ = Co2+ or Zn2+ , im- = imidazolate) with high pressure, synchrotron powder X-ray diffraction and mercury intrusion measurements. A displacive phase transition from a highly compressible open pore ( op ) phase with continuous porosity (space group Pbca , bulk modulus ∼1.4 GPa) to a closed pore ( cp ) phase with inaccessible porosity (space group P 21 / c , bulk modulus ∼3.3-4.9 GPa) is triggered by the application of mechanical pressure...
February 14, 2018: Chemical Science
Yasuomi Yamazaki, Osamu Ishitani
Photofunctional trinuclear complexes containing three different central metals, i.e. Os(ii), Re(i) and Ru(ii), were synthesised for the first time using stepwise Mizoroki-Heck reactions. The vinylene groups in the bridging ligands of the Os(ii)-Re(i)-Ru(ii) trinuclear complexes were selectively reduced by photochemical hydrogenation in moderate yield, affording novel supramolecular photocatalysts which can absorb a wide range of visible light up to 730 nm and induce CO2 reduction with high selectivity and durability...
January 28, 2018: Chemical Science
Serguei Koulikov, Sergey Assonov, Ales Fajgelj, Pieter Tans
The manuscript explores some advantages and limitations of laser based optical spectroscopy, aimed at achieving robust, high-reproducibility 13 C16 O2 and 12 C16 O2 ratio determinations on the VPDB-CO2 δ13 C scale by measuring the absorbance of line pairs of 13 C16 O2 and 12 C16 O2 . In particular, the sensitivities of spectroscopic lines to both pressure (P) and temperature (T) are discussed. Based on the considerations and estimations presented, a level of reproducibility of the 13 C16 O2 /12 C16 O2 ratio determinations may be achieved of about 10-6 ...
July 1, 2018: Talanta
Vivek K Arora, Joe R Melton
The terrestrial biosphere currently absorbs about 30% of anthropogenic CO2 emissions. This carbon uptake over land results primarily from vegetation's response to increasing atmospheric CO2 but other factors also play a role. Here we show that since the 1930s increasing population densities and cropland area have decreased global area burned, consistent with the charcoal record and recent satellite-based observations. The associated reduced wildfire emissions from increase in cropland area do not enhance carbon uptake since natural vegetation that is spared burning was deforested anyway...
April 17, 2018: Nature Communications
Gabriel Martins da Rosa, Michele Greque de Morais, Jorge Alberto Vieira Costa
This study aimed to assess the growth of Chlorella strains isolated from adverse environments at various concentrations of monoethanolamine (MEA), evaluating the CO2 fixation and macromolecule production. For this purpose, the green algae Chlorella sp. and Chlorella fusca LEB 111 were tested against five concentrations of MEA: 50, 75, 100, 200 and 300 mg L-1 . The strain C. fusca LEB 111 exhibited higher tolerance to MEA as well as higher accumulation of dissolved inorganic carbon and efficiency of CO2 utilization (approximately 37...
April 13, 2018: Bioresource Technology
Piercarlo Fortunato Cardoso, Juan S L C Fernandez, Luiz Fernando Lepre, Rômulo Augusto Ando, Margarida F Costa Gomes, Leonardo J A Siqueira
The properties of mixtures of butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N4111 ][NTf2 ], with poly(ethyleneglycol) dimethyl ether, PEO, were described as a function of PEO chain size by molecular dynamics simulations. Both PEO chain size and mixture composition revealed to play a significant role in determining the structure and the dynamics of the fluids. The remarkably higher viscosity observed for mixtures composed by 0.25 mole fraction of PEO was attributed to the increase in the gauche population of OCCO dihedral of the polyether of longer chains...
April 7, 2018: Journal of Chemical Physics
Aishling Dunne, Colm Delaney, Aoife McKeon, Pavel Nesterenko, Brett Paull, Fernando Benito-Lopez, Dermot Diamond, Larisa Florea
Micro-capillaries, capable of light-regulated binding and qualitative detection of divalent metal ions in continuous flow, have been realised through functionalisation with spiropyran photochromic brush-type coatings. Upon irradiation with UV light, the coating switches from the passive non-binding spiropyran form to the active merocyanine form, which binds different divalent metal ions (Zn2+ , Co2+ , Cu2+ , Ni2+ , Cd2+ ), as they pass through the micro-capillary. Furthermore, the merocyanine visible absorbance spectrum changes upon metal ion binding, enabling the ion uptake to be detected optically...
April 4, 2018: Sensors
Haibo Zhai, Edward S Rubin
This study develops an integrated technical and economic modeling framework to investigate the feasibility of ionic liquids (ILs) for pre-combustion carbon capture. The IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is modeled as a potential physical solvent for CO2 capture at integrated gasification combined cycle (IGCC) power plants. The analysis reveals that the energy penalty of the IL-based capture system comes mainly from the process and product streams compression and solvent pumping, while the major capital cost components are the compressors and absorbers...
March 28, 2018: Environmental Science & Technology
Tsuyoshi Yamaguchi, Ryuya Ando, Koji Yoshida, Toshio Yamaguchi, Hiroshi Machida
Shear viscosity of concentrated aqueous solutions of alkylaminoethanols was determined with changing the length of the alkyl chain and the concentration of dissolved CO2 . The viscosity increased with increasing the CO2 loading, reflecting the strengthening of the intermolecular electrostatic interaction. The dependence of the viscosity on both temperature and CO2 loading was described by a modified version of Vogel-Fulchar-Tammann equation. Compared at the same volume concentration of CO2 , the viscosity increased with increasing the alkyl chain lengths, and the dependence on the alkyl chain length increased with the CO2 loading...
April 12, 2018: Journal of Physical Chemistry. B
Awanish Kumar, Pannuru Venkatesu
Mixtures of ionic liquids (ILs) have attracted our attention because of their extraordinary performances in extraction technologies and in absorbing large amount of CO2 gas. It has been observed that when two or more ILs are mixed in different proportions, a new solvent is obtained which is much better than that of each component of ILs from which the mixture is obtained. Within a mixture of ILs, several unidentified interactions occur among several ions which give rise to unique solvent properties to the mixture...
March 16, 2018: Biophysical Reviews
Roberto Raga, Alberto Pivato, Maria Cristina Lavagnolo, Laura Megido, Raffaello Cossu
In this study, a top cover system is investigated as a control for emissions during the aftercare of new landfills and for old landfills where biogas energy production might not be profitable. Different materials were studied as landfill cover system in lab-scale columns: mechanical-biological pretreated municipal solid waste (MBP); mechanical-biological pretreated biowaste (PB); fine (PBSf ) and coarse (PBSc ) mechanical-biological pretreated mixtures of biowaste and sewage sludge, and natural soil (NS). The effectiveness of these materials in removing methane and sulphur compounds from a gas stream was tested, even coupled with activated carbon membranes...
March 2018: Journal of Environmental Sciences (China)
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"