Further Insight into the Reaction FeO+ + H2 → Fe+ + H2O: Temperature Dependent Kinetics, Isotope Effects, and Statistical Modeling

2014 ◽  
Vol 118 (34) ◽  
pp. 6789-6797 ◽  
Author(s):  
Shaun G. Ard ◽  
Joshua J. Melko ◽  
Oscar Martinez ◽  
Vladimir G. Ushakov ◽  
Anyang Li ◽  
...  
Keyword(s):  
Statistical Modeling ◽  
Isotope Effects ◽  
Temperature Dependent ◽  
Insight Into

Mechanistic insight into the influence of O2 on N2O formation in the selective catalytic reduction of NO with NH3 over Pd/CeO2 catalyst

2021 ◽  
Author(s):  
Liping Sheng ◽  
Songda Li ◽  
Zhaoxia Ma ◽  
Fei Wang ◽  
Hu He ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
No Reduction ◽  
Catalytic Reduction ◽  
Temperature Dependent ◽  
N2o Formation ◽  
Reduction Of No ◽  
Mechanistic Insight ◽  
Insight Into

O2 greatly affected the pathway for NO reduction over the Pd/CeO2 catalyst and resulted in a temperature-dependent NH3-SCR performance and formation of N2O.

scholarly journals 4-hydroxyphenylpyruvate dioxygenase thermolability is responsible for temperature-dependent melanogenesis inAeromonas salmonicidasubsp.salmonicida

2018 ◽  
Author(s):  
Yunqian Qiao ◽  
Jiao Wang ◽  
He Wang ◽  
Baozhong Chai ◽  
Chufeng Rao ◽  
...  
Keyword(s):  
Cold Water ◽  
Biological Significance ◽  
Adaptive Strategy ◽  
Aeromonas Salmonicida ◽  
Temperature Dependent ◽  
Ideal Model ◽  
Melanin Production ◽  
Water Fish ◽  
Insight Into

AbstractAeromonas salmonicidasubsp.salmonicida(A.s.s) is a major pathogen affecting fisheries worldwide. It is a well-known member of the pigmentedAeromonasspecies, which produces melanin at ≤ 22 °C. However, melanogenesis decreases as the culture temperature increases and is completely suppressed at 30-35 °C while bacterial growth is not affected. The mechanism and biological significance of this temperature-dependent melanogenesis are not clear. Heterologous expression of anA.s.s.4-hydroxyphenylpyruvate dioxygenase (HppD), the most crucial enzyme in the HGA-melanin synthesis pathway, results in thermosensitive pigmentation inEscherichia coli, suggesting that HppD plays a key role in this process. In the current study, we demonstrated that the extreme thermolability of HppD is responsible for the temperature-dependent melanization ofA.s.s.Substitutions in three residues, Ser18, Pro103, or Leu119 of HppD fromA.s.sincreases the thermolability of this enzyme and results in temperature-independent melanogenesis. Moreover, replacing the corresponding residues of HppD fromAeromonasmedia strain WS, which forms pigment independent of temperature, with those ofA.s.sHppD leads to thermosensitive melanogenesis. Structural analysis suggested that mutations at these sites, especially at position P103, can strengthen the secondary structure of HppD and greatly improve its thermal stability. In addition, we found that HppD sequences of allA.s.sisolates are identical and that two of the three residues are completely conserved withinA.s.sisolates, which clearly distinguishes these from otherAeromonasstrains. We suggest that this property represents an adaptive strategy to the psychrophilic lifestyle ofA.s.s.ImportanceAeromonas salmonicidasubsp.salmonicida(A.s.s) is the causative agent of furunculosis, a bacterial septicemia of cold water fish of theSalmonidaefamily. As it has a well-defined host range,A.s.shas become an ideal model to investigate the co-evolution of host and pathogen. For many pathogens, melanin production is associated with virulence. Although other species ofAeromonascan produce melanin,A.s.sis the only member of this genus that has been reported to exhibit temperature-dependent melanization. Here we demonstrate that thermosensitive melanogenesis inA.s.sstrains is due to the thermolability of 4-hydroxyphenylpyruvate dioxygenase (HppD). The strictly conservedhppDsequences amongA.s.sand the exclusive thermosensitive pigmentation of these strains might provide insight into the role of melanin in the adaptation to a particular host, and offer a novel molecular marker to readily differentiateA.s.sstrains from otherA. salmonicidasubspecies andAeromonasspecies.

Quick temperature-sweep pure-shift NMR: the case of solvent effects in atorvastatin

2019 ◽  
Vol 21 (35) ◽  
pp. 19209-19215 ◽  
Author(s):  
Małgorzata Rytel ◽  
Paweł Kasprzak ◽  
Piotr Setny ◽  
Krzysztof Kazimierczuk
Keyword(s):  
Solvent Effects ◽  
Temperature Dependent ◽  
Insight Into

Quick and sensitive serial pseudo-2D pure-shift NMR experiments provide novel insight into the temperature-dependent solvent distribution.

Conformational and aggregation properties of PffBT4T polymers: atomistic insight into the impact of alkyl-chain branching positions

2019 ◽  
Vol 7 (45) ◽  
pp. 14198-14204
Author(s):  
Lu Ning ◽  
Guangchao Han ◽  
Yuanping Yi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Alkyl Chain ◽  
Temperature Dependent ◽  
Chain Branching ◽  
Alkyl Chains ◽  
Dynamics Simulations ◽  
The Impact ◽  
Insight Into

The impact of the branching positions of alkyl chains on temperature dependent aggregation is rationalized by atomistic molecular dynamics simulations.

Thermal-Electric Finite Element Analysis of Electrosurgical Cautery Process

2007 ◽  
Author(s):  
Robert E. Dodde ◽  
Scott F. Miller ◽  
Albert J. Shih ◽  
James D. Geiger
Keyword(s):  
Heat Transfer ◽  
Electrical Conductivity ◽  
Finite Element ◽  
Biological Tissue ◽  
Tissue Temperature ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Temperature Dependent Thermal Conductivity ◽  
Insight Into ◽  
Good Agreement

Cautery is a process to coagulate tissues and seal blood vessels using the heat. In this study, finite element modeling (FEM) was performed to analyze temperature distribution in biological tissue subject to cautery electrosurgical technique. FEM can provide detailed insight into the heat transfer in biological tissue to reduce the collateral thermal damage and improve the safety of cautery surgical procedure. A coupled thermal-electric FEM module was applied with temperature-dependent electrical and thermal properties for the tissue. Tissue temperature was measured at different locations during the electrosurgical experiments and compared to FEM results with good agreement. The temperature-dependent electrical conductivity has demonstrated to be critical. In comparison, the temperature-dependent thermal conductivity does not impact heat transfer as much as the electrical conductivity. FEM results show that the thermal effects can be varied with the electrode geometry that focuses the current density at the midline of the instrument profile.

Vibration Response Studies of a Bi-Morph SMA Hybrid Composite Using 3D Laser Doppler Vibrometer

2020 ◽  
Author(s):  
Rupal Srivastava ◽  
Ranjeet Kumar ◽  
Bishakh Bhattacharya
Keyword(s):  
Laser Doppler Vibrometer ◽  
Smart Material ◽  
Laser Doppler ◽  
Operational Environment ◽  
Temperature Dependent ◽  
Reinforced Composite ◽  
Active Fiber Composites ◽  
Insight Into ◽  
Selection Of ◽  
Multiple Step

Abstract With the advancement in the field of morphing and adaptive structures, there has been a tremendous increase in the application of such systems in the civil and aerospace engineering, especially wherever space constraint and variable operational environment demand frequent changes in system configuration. The control of stiffness and hence dynamic response of such deployable structures can be achieved through smart material based actuation mechanisms such as shape memory alloys (SMA), and piezoelectric active fiber composites. Selection of appropriate smart material hinges on the requirements of the speed of actuation, actuator bandwidth, and force requirement. In this work, we study the vibration modes of a bi-morph SMA reinforced composite with controlled current input. The composite consists of two layers of SMA reinforcements with 0° and 90° orientation angles placed orthogonally in alternate plies. The temperatures of these layers are raised through Joule heating, first individually, and then followed by combined actuation, where the current supply is controlled using a programmable DC supply. As the material properties of SMA are temperature dependent, we observe thermal contraction and a resulting increase in laminate stiffness. The change of compliance at multiple step-input current contributes to variation in the natural frequency which is recorded using a 3D laser doppler vibrometer (LDV). This study gives us a deep insight into the application of SMA-based bimorph composites for active damping and vibration control subject to varying temperatures.

scholarly journals Mechanistic details of the MnO+ + H2/D2 reaction through temperature-dependent kinetics and statistical modeling

2019 ◽  
Vol 435 ◽  
pp. 26-33 ◽  
Author(s):  
Brendan C. Sweeny ◽  
Hanqing Pan ◽  
Shaun G. Ard ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
...  
Keyword(s):  
Statistical Modeling ◽  
Temperature Dependent
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