Photocatalytic Effect of Fe(III) on Oxidation of Two-Carbon Substrates Related to Natural Waters

1994 ◽  
Vol 59 (5) ◽  
pp. 1066-1076 ◽  
Author(s):  
Šárka Klementová ◽  
Dana M. Wagnerová
Keyword(s):  
Mathematical Model ◽  
Natural Waters ◽  
Substrate Oxidation ◽  
Quantum Yields ◽  
Ferric Ions ◽  
Photochemical Reduction ◽  
Photocatalytic Effect ◽  
Carbon Substrates ◽  
Glyoxalic Acid ◽  
The Common

The influence of ferric ions on photoinitiated reaction of dioxygen with two carbon organic acids, aldehydes and alcohols related to natural waters was demonstrated. Photocatalytic effect of ferric ions, i.e. photochemical reduction of Fe(III) as the catalyst generating step, has been found to be the common principal of these reactions. The overall quantum yields of the reactions are in the range from 0.3 to 1.2. A mathematical model designed for the mechanism of cyclic generation of catalyst in the singlet substrate oxidation by O2 was applied to the system glyoxalic acid + Fe(III); a fair agreement between the simulated and experimental kinetic curves was obtained. The experimental rate constant is 4.4 .10-4 s -1.

scholarly journals A Mathematical Model and Numerical Solution of a Boundary Value Problem for a Multi-Structure Plate

Mathematics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 244 ◽  
Author(s):  
Vildan Yazıcı ◽  
Zahir Muradoğlu
Keyword(s):  
Mathematical Model ◽  
Boundary Value Problem ◽  
Numerical Solution ◽  
Transmission Conditions ◽  
Numerical Examples ◽  
Deformation Problem ◽  
The Common ◽  
Plate System ◽  
Structure Plate ◽  
Numerical Approaches

This study examined the deformation problem of a plate system (formed side-by-side) composed of multi-structure plates. It obtained numerical approaches of the transmission conditions on the common border of plates that composed the system. Numerical examples were solved in different boundary and transmission conditions.

DYNAMICS OF A2 FINGER PULLEY RUPTURE

2007 ◽  
Vol 07 (01) ◽  
pp. 75-87 ◽  
Author(s):  
MING A. TAN ◽  
FRANZ K. FUSS ◽  
GÜNTHER NIEGL
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Initial Rate ◽  
Constant Force ◽  
Common Occurrence ◽  
Pulley System ◽  
Convergence Test ◽  
A2 Pulley ◽  
The Common ◽  
Rupture Mechanism

A mathematical model of the A2 pulley system will enable us to have a better understanding of the mechanics of the pulley-tendon system and provide us with insights of the pulley rupture mechanism. The A2 pulley was modeled based on parallel pulley fibers attached to a phalanx with a tendon passing them. Mechanical properties of the pulleys such as stiffness, strength and friction were included in the model. A convergence test was done to ensure the accuracy of the test. The model managed to show high loads on flexed finger may lead to pulley ruptures. Further studies on the rupture mechanism showed that pulley ruptures are self-propagating when a constant force is applied and the rate of rupture increases, as fewer intact fibers are present to support the load. The initial rate of propagation is much slower and this accelerates as more fibers are ruptured. This explains the common occurrence of partial pulley ruptures.

Design of the Conjugate Cam Induction Hardening Mechanism and Establishment of the Motion Controlling Mathematical Model

2012 ◽  
Vol 155-156 ◽  
pp. 726-730
Author(s):  
Zhong Hua Li ◽  
Qian Tang ◽  
Di Yan ◽  
Jie Wu
Keyword(s):  
Mathematical Model ◽  
Induction Hardening ◽  
Uniform Motion ◽  
Hardening Mechanism ◽  
Kinematic Relationship ◽  
Nc Machine ◽  
The Common ◽  
Relationship Of ◽  
The Mathematical Model ◽  
Basic Motion

The common methods of cam induction hardening are discussed at present. By analyzing the basic motion law of conjugate cam, a new induction hardening mechanism is designed. The motion controlling mathematical model is built on the basis of the kinematic relationship of the transmission of the induction hardening mechanism. Through the mathematical model calculation, we can get angular velocity of the workbench, then realize that single axis on NC machine controls the inductor to make isometric uniform motion relative to the cam surface, so that the cam hardening depth distribution is uniform.

Modeling of Liquid-Liquid Demixing Curve in Lead-Zinc Binary System

2018 ◽  
Vol 18 ◽  
pp. 49-54
Author(s):  
Naceur Amel ◽  
Adjadj Fouzia
Keyword(s):  
Mathematical Model ◽  
Free Energy ◽  
Phase Separation ◽  
Binary System ◽  
Free Energies ◽  
Common Tangent ◽  
Different Temperatures ◽  
Lead Zinc ◽  
The Common ◽  
Zn Alloys

In this work we discussed the modeling of the demixing curve in the liquid state in the Lead – Zinc binary system. We are interested to recalculate the free energies relating on Pb-Zn alloys for several temperatures based on the thermodynamic data collected in the bibliography. This calculation allows us to trace the curve of phase separation from a program after obtaining the mole fractions corresponding to the common tangent to the curve of the free energy with two minima at different temperatures. To do this, we used the Matlab 7.1 as the programming language and the Redlich-Kister polynomial as a mathematical model of development. The results obtained are very satisfactory by comparing them with those of the bibliography.

Study on Dynamic Fuzzy Classification of Design Proposal Based on Design Style

2010 ◽  
Vol 136 ◽  
pp. 207-211
Author(s):  
Zhu Gao ◽  
Xiao Min Ji
Keyword(s):  
Mathematical Model ◽  
Fuzzy Classification ◽  
Innovative Design ◽  
Refinement Method ◽  
Form Design ◽  
The Common ◽  
Product Customization ◽  
Design Proposal ◽  
Design Style

Based on the common background of product prototype form, Under the support of the shape split library and product design libraries and library, this paper proposes the product customization parameters, and the refinement method of design between designers and clients, builds the shape split libaray based on eigenvalue of Mathematical model of shape prototype, discussed the dynamic fuzzy classification method based on graphic-based design to determine the shape innovative design process. It will give a basis for the development of CAID system combining the parameterization form design with personalization.

scholarly journals Carbon monoxide apparent quantum yields and photoproduction in the Tyne estuary

2011 ◽  
Vol 8 (3) ◽  
pp. 703-713 ◽  
Author(s):  
A. Stubbins ◽  
C. S. Law ◽  
G. Uher ◽  
R. C. Upstill-Goddard
Keyword(s):  
Carbon Monoxide ◽  
Natural Waters ◽  
Sea Water ◽  
River Estuary ◽  
Quantum Yields ◽  
Absorption Data ◽  
Coastal Sea ◽  
Order Of Magnitude ◽  
Good Proxy ◽  
Minimum Estimate

Abstract. Carbon monoxide (CO) apparent quantum yields (AQYs) are reported for a suite of riverine, estuarine and sea water samples, spanning a range of coloured dissolved organic matter (CDOM) sources, diagenetic histories, and concentrations (absorption coefficients). CO AQYs were highest for high CDOM riverine samples and almost an order of magnitude lower for low CDOM coastal seawater samples. CO AQYs were between 47 and 80% lower at the mouth of the estuary than at its head. Whereas, a conservative mixing model predicted only 8 to 14% decreases in CO AQYs between the head and mouth of the estuary, indicating that a highly photoreactive pool of terrestrial CDOM is lost during estuarine transit. The CDOM absorption coefficient (a) at 412 nm was identified as a good proxy for CO AQYs (linear regression r2 > 0.8; n = 12) at all CO AQY wavelengths studied (285, 295, 305, 325, 345, 365, and 423 nm) and across environments (high CDOM river, low CDOM river, estuary and coastal sea). These regressions are presented as empirical proxies suitable for the remote sensing of CO AQYs in natural waters, including open ocean water, and were used to estimate CO AQY spectra and CO photoproduction in the Tyne estuary based upon annually averaged estuarine CDOM absorption data. A minimum estimate of annual CO production was determined assuming that only light absorbed by CDOM leads to the formation of CO and a maximum limit was estimated assuming that all light entering the water column is absorbed by CO producing photoreactants (i.e. that particles are also photoreactive). In this way, annual CO photoproduction in the Tyne was estimated to be between 0.99 and 3.57 metric tons of carbon per year, or 0.004 to 0.014% of riverine dissolved organic carbon (DOC) inputs to the estuary. Extrapolation of CO photoproduction rates to estimate total DOC photomineralisation indicate that less than 1% of DOC inputs are removed via photochemical processes during transit through the Tyne estuary.

Research on Safety Accidents in Bridge Construction Based on Safety Rheology and Mutation

2012 ◽  
Vol 204-208 ◽  
pp. 2162-2166
Author(s):  
Peng Wang ◽  
Wei Jun Yang
Keyword(s):  
Mathematical Model ◽  
Bridge Construction ◽  
The Common ◽  
Physics Model

The common safety accidents in bridge construction were according to safety rheology and mutation.The paper got the physics model and mathematical model of some common safety accidents that sky diving ,object striking and collapsing by safety rheology and mutation. It can be used to analyse safety accidents in bridge well.

Modelling the behaviour of oil spills in natural waters

1993 ◽  
Vol 20 (2) ◽  
pp. 210-219 ◽  
Author(s):  
G. K. Luk ◽  
H. F. Kuan
Keyword(s):  
Mathematical Model ◽  
Natural Waters ◽  
Oil Spills ◽  
State Of The Art ◽  
Oil Composition ◽  
Weathering Processes ◽  
Transport And Mixing ◽  
Spilled Oil ◽  
Initial Results ◽  
Petroleum Oil

This paper is a state-of-the-art review of the formulations for the different processes responsible for the transport and mixing of petroleum oil spilled in natural waters. Processes accounting for the transfer and loss of the surface oil, such as initial spreading, evaporation, dissolution, emulsification, dispersion, photo-oxidation, and sedimentation, are included. Based on the findings, a dynamic mathematical model describing the fate of spilled oil was developed. To reflect field observations, the surface oil composition in the model is allowed to vary with time as a result of weathering. Initial results for model testing are presented. Key words: oil spill, mathematical model, fate model, weathering processes.

Optimal Design of Basic Parameter of Disconnected Steering Trapezoid

2012 ◽  
Vol 424-425 ◽  
pp. 334-337
Author(s):  
Cui Xia Guo ◽  
Kang Liu ◽  
Wen Ling Xie
Keyword(s):  
Mathematical Model ◽  
Deflection Angle ◽  
Steering Wheel ◽  
Optimized Design ◽  
Pure Rolling ◽  
Tire Wear ◽  
Optimization Parameters ◽  
Basic Parameters ◽  
The Common ◽  
The Ideal

In the design of disconnected steering trapezoid, the Fmincon function of MATLAB optimization toolbox is used to optimize its basic parameters. First, establish the optimal mathematical model. Second, obtain wheel angle curve of inside and outside steering by least-squares fitting. Finally, compare the curve with the ideal Ackerman geometric curve to get the optimization parameters of disconnected steering trapezoid. The example of optimized design validated that the actual curve of deflection angle of the both sides of steering wheel was almost close to perfect Ackerman geometry curve, it ensures the steering of wheel do pure rolling in the common conditions, which reduce tire wear

scholarly journals Photo degradation kinetics of insensitive munitions constituents nitroguanidine, nitrotriazolone, and dinitroanisole in natural waters

2021 ◽  
Author(s):  
Lee Moores ◽  
Stacy Jones ◽  
Garrett George ◽  
David Henderson ◽  
Timothy Schutt
Keyword(s):  
Laboratory Experiments ◽  
Natural Waters ◽  
Matrix Effects ◽  
Degradation Kinetics ◽  
Relative Rate ◽  
Ph Dependence ◽  
Degradation Pathway ◽  
Quantum Yields ◽  
The Individual ◽  
Kinetics Of

Herein the matrix effects on the kinetics of aqueous photolysis for the individual munitions constituents of IMX-101: nitroguanidine (NQ), dinitroanisole (DNAN), and nitrotriazolone (NTO) are reported along with the environmentally relevant kinetics and quantum yields. Photolysis potentially represents a major degradation pathway for these munitions in the environment and further understanding the complex matrices effects on photolytic kinetics was needed. Aqueous systems are of particular interest due to the high solubility of NQ (3,800 ppm) and NTO (16,642 ppm) compared to the traditional munitions trinitrotoluene (TNT, 100.5 ppm) and 1,3,5-trinitro-1,3,5-triazine (RDX, 59.9 ppm). Environmental half-lives (and quantum yields) were found to be 0.44 days, 0.83 days, and 4.4 days for NQ, DNAN, and NTO, respectively, under natural sunlight. In laboratory experiments using nominally 300 nm bulbs in a merry-go-round style reactor in DI water the relative rate of photolysis for the three munitions constituents followed the same order NQ > DNAN > NTO, where DNAN and NTO reacted 57 and 115 times more slowly, respectively, than NQ. In the various environmentally relevant matrices tested in the laboratory experiments NQ was not significantly affected, DNAN showed a faster degradation with increasing ionic strength, and NTO showed a modest salinity and pH dependence on its rate of photolysis.

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