Optimization of a two-step process comprising lipase catalysis and thermal cyclization improves the efficiency of synthesis of six-membered cyclic carbonate from trimethylolpropane and dimethylcarbonate

2012 ◽  
Vol 29 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Amin Bornadel ◽  
Rajni Hatti-Kaul ◽  
Kent Sörensen ◽  
Stefan Lundmark ◽  
Sang-Hyun Pyo
Keyword(s):  
Cyclic Carbonate ◽  
Thermal Cyclization ◽  
Step Process ◽  
Lipase Catalysis

Mechanisms of ethylene biosynthesis and response in plants

2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Ethylene Biosynthesis ◽  
Unsaturated Hydrocarbon ◽  
Flower Senescence ◽  
Detailed Knowledge ◽  
Plant Growth And Development ◽  
Step Process ◽  
Ethylene Response ◽  
Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

Making Repeated Choices: A Dual-Step Process

2008 ◽  
Author(s):  
Shenghua Luan ◽  
Shuli Yu
Keyword(s):  
Step Process

Platelet Adhesion to Native Collagens Involves Proteoglycans and May Be a Two-Step Process

1987 ◽  
Vol 58 (02) ◽  
pp. 786-789 ◽  
Author(s):  
O Behnke
Keyword(s):  
Electron Microscope ◽  
Platelet Adhesion ◽  
Close Contact ◽  
Blood Platelets ◽  
Collagen Fibrils ◽  
Platelet Membrane ◽  
Step Process ◽  
Rat Blood ◽  
Wide Gap ◽  
Rat Tail

SummaryAdhesion of rat blood platelets to native rat tail collagen fibrils was studied in the electron microscope under conditions that preserved collagen-associated proteoglycans (CAPG). The CAPG molecules were aligned in chain-like configurations that encircled the fibrils with a 65 nm period; they appeared to coat the fibrils completely and extended 60-100 nm away from the fibril. The initial platelet-fibril contact occurred between the platelet glycocalyx and the CAPG of the fibrils i.e. between two surfaces with net-negative charges. When close contact was established between the fibril surface proper and the platelet membrane, CAPG were not identified in the area of contact, and the collagen-platelet distance was reduced to a ~10-12 nm wide gap traversed by delicate links in register with fibril periodicities.

Preferential Orientation of Photochromic Gadolinium Oxyhydrides

2020 ◽  
Author(s):  
Elbruz Murat Baba ◽  
Jose Montero ◽  
Dmitrii Moldarev ◽  
Marcos V. Moro ◽  
Max Wolff ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Rare Earth ◽  
Preferential Orientation ◽  
Reactive Magnetron ◽  
Flow Ratio ◽  
Deposition Pressure ◽  
Step Process ◽  
Oxidation In Air ◽  
Key Parameter

<p>We report preferential orientation control in photochromic gadolinium oxyhydride (GdHO) thin films deposited by a two-step process. Gadolinium hydride (GdH<sub>2-x</sub>) films were grown by reactive magnetron sputtering, followed by oxidation in air. The preferential orientation, grain size, anion concentrations, and photochromic response of the films are strongly dependent on the deposition pressure. GdHO films show preferential orientation along the [100] direction and exhibit photochromism when synthesized at deposition pressures up to 5.8 Pa and. The photochromic contrast is larger than 20 % when the films are deposited below 2.8 Pa with 0.22 H<sub>2</sub>/Ar flow ratio. We argue that the degree of preferential orientation defines the oxygen concentration which is known to be a key parameter for photochromism in rare-earth oxyhydride thin films. The experimental observations described above are explained by the oxidation-induced decrease of the grain size as a result of the increase of the deposition pressure of the sputtering gas. </p>

Fostering Information Literacy in the Management Education at the U.S. Coast Guard Academy

2019 ◽  
Vol 2 (3) ◽  
pp. 1-17
Author(s):  
Alina M. Zapalska ◽  
Ben Wroblewski
Keyword(s):  
Learning Environment ◽  
Information Literacy ◽  
Management Education ◽  
Management Program ◽  
Coast Guard ◽  
Sequential Approach ◽  
Step Process ◽  
New Knowledge ◽  
The U.S

This paper illustrates the information literacy (IL) strategy in an undergraduate Management program at U.S. Coast Guard Academy. The paper exemplifies a sequential approach that improves students’ capabilities to evaluate and apply information in a specifically designed learning environment while generating new knowledge in undergraduate business coursework. The paper also emphasizes how IL can be developed within management coursework through a six-step process, including defining, locating, selecting, organizing, presenting, and assessing.  This specially designed framework of IL learning can be applied across all relevant courses using specially designed assignments in the Management major.

An improved small sewage treatment plant for biological purification of wastewater

1994 ◽  
Vol 29 (12) ◽  
pp. 23-29 ◽  
Author(s):  
G. Voigtländer ◽  
E.-P. Kulle
Keyword(s):  
Energy Supply ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Septic Tank ◽  
Additional Energy ◽  
Anaerobic Reactor ◽  
Step Process ◽  
Operational Costs ◽  
Aerobic Reactor

The paper presents a small sewage treatment plant (package plant) operating without additional energy. Purification of sewage is achieved in a three-step process: sedimentation tank, anaerobic reactor and wastewater pond or aerobic reactor. The efficiency of the anaerobic reactor - in contrast to the efficiency of a common septic tank - is significantly increased by using fixed biomass systems. Further degradation of sewage compounds by adhering microorganisms occurs in pond or aerobic reactor. The bed for the aerobic biomass is made of a semipermeable plastic film and arranged in order to ensure simultaneous supply of oxygen. The three pilot plants are showing different results. The main aims of research i.e. lowering of operational costs, energy supply, minimizing of maintenance expenditure and cleaning work, reliability of degradation efficiency have been achieved so far for the anaerobic reactor.

Sustainable Solid Catalysts for Cyclic Carbonate Synthesis from CO2 and Epoxide

2015 ◽  
Vol 19 (8) ◽  
pp. 681-694 ◽  
Author(s):  
Xian-Dong Lang ◽  
Xiao-Fang Liu ◽  
Liang-Nian He
Keyword(s):  
Cyclic Carbonate ◽  
Solid Catalysts
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