scholarly journals In Situ Bottom-up Synthesis of Porphyrin-Based Covalent Organic Frameworks

2019 ◽  
Vol 141 (50) ◽  
pp. 19560-19564 ◽  
Author(s):  
Elham Tavakoli ◽  
Arvin Kakekhani ◽  
Shayan Kaviani ◽  
Peng Tan ◽  
Mahdi Mohammadi Ghaleni ◽  
...  
Keyword(s):  
Covalent Organic Frameworks ◽  
Bottom Up

scholarly journals Bottom-up synthesis of chiral covalent organic frameworks and their bound capillaries for chiral separation

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Hai-Long Qian ◽  
Cheng-Xiong Yang ◽  
Xiu-Ping Yan
Keyword(s):  
Gas Chromatography ◽  
Chiral Separation ◽  
Capillary Columns ◽  
Organic Ligands ◽  
Covalent Organic Frameworks ◽  
Bottom Up ◽  
Repeatability And Reproducibility ◽  
Growth Approach ◽  
Chiral Gas Chromatography

Abstract Covalent organic frameworks (COFs) are a novel class of porous materials, and offer great potential for various applications. However, the applications of COFs in chiral separation and chiral catalysis are largely underexplored due to the very limited chiral COFs available and their challenging synthesis. Here we show a bottom-up strategy to construct chiral COFs and an in situ growth approach to fabricate chiral COF-bound capillary columns for chiral gas chromatography. We incorporate the chiral centres into one of the organic ligands for the synthesis of the chiral COFs. We subsequently in situ prepare the COF-bound capillary columns. The prepared chiral COFs and their bound capillary columns give high resolution for the separation of enantiomers with excellent repeatability and reproducibility. The proposed strategy provides a promising platform for the synthesis of chiral COFs and their chiral separation application.

scholarly journals Cell-free protein synthesis and in situ immobilization of deGFP-MatB in polymer microgels for malonate-to-malonyl CoA conversion

RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40588-40596
Author(s):  
Tony Köhler ◽  
Thomas Heida ◽  
Sandra Hoefgen ◽  
Niclas Weigel ◽  
Vito Valiante ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Genetic Information ◽  
In Situ Immobilization ◽  
Bottom Up ◽  
Free Protein ◽  
Malonyl Coa ◽  
Cell Free Protein Synthesis

We describe a bottom-up approach towards functional enzymes utilizing microgels as carriers for genetic information that enable cell-free protein synthesis, in situ immobilization, and utilization of functional deGFP-MatB.

scholarly journals Diffusion-induced in situ growth of covalent organic frameworks for composite membranes

2019 ◽  
Vol 7 (45) ◽  
pp. 25802-25807 ◽  
Author(s):  
Priyanka Manchanda ◽  
Stefan Chisca ◽  
Lakshmeesha Upadhyaya ◽  
Valentina-Elena Musteata ◽  
Mark Carrington ◽  
...  
Keyword(s):  
Reaction Times ◽  
Composite Membranes ◽  
Thin Layers ◽  
In Situ Growth ◽  
Covalent Organic Frameworks ◽  
Polymeric Support ◽  
Ambient Conditions ◽  
Induction Method ◽  
Covalent Organic Framework

Thin layers of a covalent organic framework (COF) have been synthesized on a flexible polymeric support using a new diffusion-induction method under ambient conditions in reaction times as short as 3 hours.

Bottom-up in situ formation of Fe3O4 nanocrystals in a porous carbon foam for lithium-ion battery anodes

2011 ◽  
Vol 21 (43) ◽  
pp. 17325 ◽  
Author(s):  
Taegyun Yoon ◽  
Changju Chae ◽  
Yang-Kook Sun ◽  
Xin Zhao ◽  
Harold H. Kung ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Porous Carbon ◽  
Lithium Ion ◽  
Carbon Foam ◽  
Bottom Up ◽  
In Situ Formation

In Situ Synthesis of Covalent Organic Frameworks (COFs) on Carbon Nanotubes and Graphenes by Sonochemical Reaction for CO2 Adsorbents

2015 ◽  
Vol 44 (4) ◽  
pp. 560-562 ◽  
Author(s):  
JongTae Yoo ◽  
SuHyun Lee ◽  
Shinsuke Hirata ◽  
ChaeRin Kim ◽  
Chang Kee Lee ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
In Situ Synthesis ◽  
Covalent Organic Frameworks ◽  
Sonochemical Reaction

scholarly journals On-Site Participation for Proto-Architectural Assemblies Encompassing Technology and Human Improvisation: “Fish Trap” and “Orchid” Architectural Interventions

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Peter Buš ◽  
Shi-Yen Wu ◽  
Ayça Tartar
Keyword(s):  
Computational Models ◽  
Design Strategy ◽  
Top Down ◽  
Bottom Up ◽  
Fish Trap ◽  
Human Needs ◽  
Qualitative Observation ◽  
Building System ◽  
Collaborative Improvisation

This research investigates the notion of builders’ on-site engagement to physically build architectural interventions based on their demands, spatial requirements, and collaborative improvisation enhanced with the principles of uniqueness and bespoke solutions which are previously explored in computational models. The paper compares and discusses two physical installations as proto-architectural assemblies testing two different designs and building approaches: the top-down predefined designers’ scenario contrary to bottom-up unpredictable improvisation. It encompasses a building strategy based on the discrete precut components assembled by builders themselves in situ. The paper evaluates both strategies in a qualitative observation and comparison defining advantages and limitations of the top-down design strategy in comparison with the decentralised bottom-up building system built by the builders themselves. As such, it outlines the position of a designer within the bottom-up building processes on-site. The paper argues that improvisation and builders’ direct engagement on-site lead to solutions that better reflect human needs and low-tech building principles incorporated can deliver unpredictable but convenient spatial scenarios.

scholarly journals CO<sub>2</sub> and its correlation with CO at a rural site near Beijing: implications for combustion efficiency in China

2010 ◽  
Vol 10 (18) ◽  
pp. 8881-8897 ◽  
Author(s):  
Y. Wang ◽  
J. W. Munger ◽  
S. Xu ◽  
M. B. McElroy ◽  
J. Hao ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Statistical Significance ◽  
Northern China ◽  
The United States ◽  
Combustion Efficiency ◽  
Rural Site ◽  
Bottom Up ◽  
Air Masses ◽  
Diurnal Cycles

Abstract. Although China has surpassed the United States as the world's largest carbon dioxide emitter, in situ measurements of atmospheric CO2 have been sparse in China. This paper analyzes hourly CO2 and its correlation with CO at Miyun, a rural site near Beijing, over a period of 51 months (Dec 2004 through Feb 2009). The CO2-CO correlation analysis evaluated separately for each hour of the day provides useful information with statistical significance even in the growing season. We found that the intercept, representing the initial condition imposed by global distribution of CO2 with influence of photosynthesis and respiration, exhibits diurnal cycles differing by season. The background CO2 (CO2,b) derived from Miyun observations is comparable to CO2 observed at a Mongolian background station to the northwest. Annual growth of overall mean CO2 at Miyun is estimated at 2.7 ppm yr−1 while that of CO2,b is only 1.7 ppm yr−1 similar to the mean growth rate at northern mid-latitude background stations. This suggests a relatively faster increase in the regional CO2 sources in China than the global average, consistent with bottom-up studies of CO2 emissions. For air masses with trajectories through the northern China boundary layer, mean winter CO2/CO correlation slopes (dCO2/dCO) increased by 2.8 ± 0.9 ppmv/ppmv or 11% from 2005–2006 to 2007–2008, with CO2 increasing by 1.8 ppmv. The increase in dCO2/dCO indicates improvement in overall combustion efficiency over northern China after winter 2007, attributed to pollution reduction measures associated with the 2008 Beijing Olympics. The observed CO2/CO ratio at Miyun is 25% higher than the bottom-up CO2/CO emission ratio, suggesting a contribution of respired CO2 from urban residents as well as agricultural soils and livestock in the observations and uncertainty in the emission estimates.

scholarly journals A numerical evaluation of global oceanic emissions of α-pinene and isoprene

2010 ◽  
Vol 10 (4) ◽  
pp. 2007-2015 ◽  
Author(s):  
G. Luo ◽  
F. Yu
Keyword(s):  
Numerical Evaluation ◽  
Input Data ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Top Down ◽  
Mixing Processes ◽  
Bottom Up ◽  
Phytoplankton Communities ◽  
Oceanic Emissions

Abstract. A numerical evaluation of global oceanic emissions of α-pinene and isoprene based on both "bottom-up" and "top-down" methods is presented. We infer that the global "bottom-up" oceanic emissions of α-pinene and isoprene are 0.013 TgC yr−1 and 0.32 TgC yr−1, respectively. By constraining global chemistry model simulations with the shipborne measurement of Organics over the Ocean Modifying Particles in both Hemispheres summer cruise, we derived the global "top-down" oceanic α-pinene source of 29.5 TgC yr−1 and isoprene source of 11.6 TgC yr−1. Both the "bottom-up" and "top-down" values are subject to large uncertainties. The incomplete understanding of the in-situ phytoplankton communities and their range of emission potentials significantly impact the estimated global "bottom-up" oceanic emissions, while the estimated total amounts of the global "top-down" oceanic sources can be influenced by emission parameterizations, model and input data spatial resolutions, boundary layer mixing processes, and the treatments of chemical reactions. The global oceanic α-pinene source and its impact on organic aerosol formation is significant based on "top-down" method, but is negligible based on "bottom-up" approach. Our research highlights the importance of carrying out further research (especially measurements) to resolve the large offset in the derived oceanic organic emission based on two different approaches.

scholarly journals Top-down and Bottom-up aerosol-cloud-closure: towards understanding sources of uncertainty in deriving cloud radiative flux

2017 ◽  
Author(s):  
Kevin J. Sanchez ◽  
Greg C. Roberts ◽  
Radiance Calmer ◽  
Keri Nicoll ◽  
Eyal Hashimshoni ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Radiative Flux ◽  
Research Station ◽  
Top Down ◽  
Bottom Up ◽  
Airborne Measurements ◽  
Aerosol Cloud ◽  
Microphysical Properties ◽  
Holistic Understanding

Abstract. Top-down and bottom-up aerosol-cloud-radiative flux closures were conducted at the Mace Head atmospheric research station in Galway, Ireland in August 2015. This study is part of the BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding) European collaborative project, with the goal of understanding key processes affecting aerosol-cloud-radiative flux closures to improve future climate predictions and develop sustainable policies for Europe. Instrument platforms include ground-based, unmanned aerial vehicles (UAV), and satellite measurements of aerosols, clouds and meteorological variables. The ground-based and airborne measurements of aerosol size distributions and cloud condensation nuclei (CCN) concentration were used to initiate a 1D microphysical aerosol-cloud parcel model (ACPM). UAVs were equipped for a specific science mission, with an optical particle counter for aerosol distribution profiles, a cloud sensor to measure cloud extinction, or a 5-hole probe for 3D wind vectors. UAV cloud measurements are rare and have only become possible in recent years through the miniaturization of instrumentation. These are the first UAV measurements at Mace Head. ACPM simulations are compared to in-situ cloud extinction measurements from UAVs to quantify closure in terms of cloud radiative flux. Two out of seven cases exhibit sub-adiabatic vertical temperature profiles within the cloud, which suggests that entrainment processes affect cloud microphysical properties and lead to an overestimate of simulated cloud radiative flux. Including an entrainment parameterization and explicitly calculating the entrainment fraction in the ACPM simulations both improved cloud-top radiative closure. Entrainment reduced the difference between simulated and observation-derived cloud-top radiative flux (δRF) by between 30 W m−2 and 40 W m−2. After accounting for entrainment, satellite-derived cloud droplet number concentrations (CDNC) were within 30 % of simulated CDNC. In cases with a well-mixed boundary layer, δRF is less than 25 W m−2 after accounting for cloud-top entrainment, compared to less than 50 W m−2 when entrainment is not taken into account. In cases with a decoupled boundary layer, cloud microphysical properties are inconsistent with ground-based aerosol measurements, as expected, and δRF is as high as 88 W m−2, even after accounting for cloud-top entrainment. This work demonstrates the need to take in-situ measurements of aerosol properties for cases where the boundary layer is decoupled as well as consider cloud-top entrainment to accurately model stratocumulus cloud radiative flux.

scholarly journals A new global anthropogenic SO<sub>2</sub> emission inventory for the last decade: a mosaic of satellite-derived and bottom-up emissions

2018 ◽  
Vol 18 (22) ◽  
pp. 16571-16586 ◽  
Author(s):  
Fei Liu ◽  
Sungyeon Choi ◽  
Can Li ◽  
Vitali E. Fioletov ◽  
Chris A. McLinden ◽  
...  
Keyword(s):  
Emission Inventory ◽  
Correlation Coefficients ◽  
In Situ Measurements ◽  
Point Sources ◽  
Ozone Monitoring Instrument ◽  
So2 Emissions ◽  
Bottom Up ◽  
Earth Observing System ◽  
The Us

Abstract. Sulfur dioxide (SO2) measurements from the Ozone Monitoring Instrument (OMI) satellite sensor have been used to detect emissions from large point sources. Emissions from over 400 sources have been quantified individually based on OMI observations, accounting for about a half of total reported anthropogenic SO2 emissions. Here we report a newly developed emission inventory, OMI-HTAP, by combining these OMI-based emission estimates and the conventional bottom-up inventory, HTAP, for smaller sources that OMI is not able to detect. OMI-HTAP includes emissions from OMI-detected sources that are not captured in previous leading bottom-up inventories, enabling more accurate emission estimates for regions with such missing sources. In addition, our approach offers the possibility of rapid updates to emissions from large point sources that can be detected by satellites. Our methodology applied to OMI-HTAP can also be used to merge improved satellite-derived estimates with other multi-year bottom-up inventories, which may further improve the accuracy of the emission trends. OMI-HTAP SO2 emissions estimates for Persian Gulf, Mexico, and Russia are 59 %, 65 %, and 56 % larger than HTAP estimates in 2010, respectively. We have evaluated the OMI-HTAP inventory by performing simulations with the Goddard Earth Observing System version 5 (GEOS-5) model. The GEOS-5 simulated SO2 concentrations driven by both HTAP and OMI-HTAP were compared against in situ measurements. We focus for the validation on 2010 for which HTAP is most valid and for which a relatively large number of in situ measurements are available. Results show that the OMI-HTAP inventory improves the agreement between the model and observations, in particular over the US, with the normalized mean bias decreasing from 0.41 (HTAP) to −0.03 (OMI-HTAP) for 2010. Simulations with the OMI-HTAP inventory capture the worldwide major trends of large anthropogenic SO2 emissions that are observed with OMI. Correlation coefficients of the observed and modeled surface SO2 in 2014 increase from 0.16 (HTAP) to 0.59 (OMI-HTAP) and the normalized mean bias dropped from 0.29 (HTAP) to 0.05 (OMI-HTAP), when we updated 2010 HTAP emissions with 2014 OMI-HTAP emissions in the model.

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