scholarly journals Anodization Parameters Influencing the Growth of Titania Nanotubes and Their Photoelectrochemical Response

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ying-Chin Lim ◽  
Zulkarnain Zainal ◽  
Wee-Tee Tan ◽  
Mohd Zobir Hussein
Keyword(s):  
Dimensional Change ◽  
Bath Temperature ◽  
Tube Length ◽  
Complexing Agent ◽  
Dimensional Changes ◽  
Photoelectrochemical Response ◽  
Voltage Ramp ◽  
Wide Range ◽  
Electrode Cell ◽  
Nanotube Growth

TiO2nanotubes (TNTs) were fabricated by electrochemical oxidation of Ti foil in a standard two-electrode cell-containing NH4F. The effects of bath temperature, voltage ramp prior to constant voltage held during anodization and present of complexing agent on the crystalline phase, nanotube growth, and dimensional change of TNT were investigated using XRD and FESEM. The results show that tube length decreases with bath temperature attributed to faster chemical dissolution rate at high temperature. However, nanotubes growth rate was enhanced by ~260% with the addition of EDTA as the complexing agent. Meanwhile, the nanotubes diameter was found to be proportionally dependent on bath temperature but independent of the voltage ramp and addition of EDTA. Photoelectrochemical response under illumination was enhanced by using the calcined TNT and is strongly affected by its dimensional changes. Thus, desired properties of TNT can be obtained by tuning the electrochemical condition for a wide-range application.

A Simple Numerical Method for Determining the Sensitivity of Bending Deflections of Stepped Shafts to Dimensional Changes

1985 ◽  
Vol 107 (1) ◽  
pp. 141-146
Author(s):  
G. Umasankar ◽  
C. R. Mischke
Keyword(s):  
Dimensional Change ◽  
Element Model ◽  
Neutral Axis ◽  
Computationally Efficient ◽  
Simple Method ◽  
Dimensional Changes ◽  
Stepped Shaft ◽  
Dimension Change ◽  
Deflection Analysis ◽  
Uniform Diameter

A simple method of computing the effect of a dimensional change at a particular element of a stepped shaft on two bearings, on bending deflections, and on slopes of the neutral axis at any of the nodes of interest is presented. The changes in deflection and slope of the neutral axis are derived as incremental quantities and as functions of the dimension change and the prior deflections and slopes of the neutral axis of the shaft. For shaft synthesis, the implications are that one can begin with a uniform diameter bar subjected to the loading and make a complete deflection analysis with superposed closed-form relations. Then the geometry can be modified element by element and the deflectional changes easily updated. This is computationally efficient. Further, deflections and deflection changes computed using the proposed method are identical to those obtained using a finite beam element model of the shaft.

scholarly journals Glucosylceramide Plays a Role in Fungal Germination, Lipid Raft Organization and Biofilm Adhesion of the Pathogenic Fungus Scedosporium aurantiacum

2020 ◽  
Vol 6 (4) ◽  
pp. 345
Author(s):  
Victor Pereira Rochetti ◽  
Rodrigo Rollin-Pinheiro ◽  
Evely Bertulino de Oliveira ◽  
Mariana Ingrid Dutra da Silva Xisto ◽  
Eliana Barreto-Bergter
Keyword(s):  
Cell Surface ◽  
Pathogenic Fungus ◽  
Clinical Manifestations ◽  
Tube Length ◽  
Total Biomass ◽  
Fungal Cell ◽  
Germ Tube Length ◽  
Wide Range ◽  
Fluorescent Stain ◽  
Altered Lipid

Infections caused by Scedosporium species present a wide range of clinical manifestations, from superficial to disseminated, especially in immunocompromised patients. Glucosylceramides (GlcCer) are glycosphingolipids found on the fungal cell surface and play an important role in growth and pathogenicity processes in different fungi. The present study aimed to evaluate the structure of GlcCer and its role during growth in two S. aurantiacum isolates. Purified GlcCer from both isolates were obtained and its chemical structure identified by mass spectrometry. Using ELISA and immunofluorescence techniques it was observed that germination and NaOH-treatment of conidia favor GlcCer exposure. Monoclonal anti-GlcCer antibody reduced germination when cultivated with the inhibitor of melanin synthesis tricyclazole and also reduced germ tube length of conidia, both cultivated or not with tricyclazole. It was also demonstrated that anti-GlcCer altered lipid rafts organization, as shown by using the fluorescent stain filipin, but did not affect the susceptibility of the cell surface to damaging agents. Anti-GlcCer reduced total biomass and viability in biofilms formed on polystyrene plates. In the presence of anti-GlcCer, germinated S. aurantiacum conidia and biofilms could not adhere to polystyrene with the same efficacy as control cells. These results highlight the relevance of GlcCer in growth processes of S. aurantiacum.

scholarly journals Comparison of Photoelectrochemical Current in Amorphous and Crystalline Anodized TiO2 Nanotube Electrodes

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Candy C. Mercado ◽  
Michael Eric L. Lubrin ◽  
Hazel Anne J. Hernandez ◽  
Reynaldo A. Carubio
Keyword(s):  
Low Temperature ◽  
Annealing Temperature ◽  
Pore Diameter ◽  
Low Voltage ◽  
Tube Length ◽  
Photoelectrochemical Performance ◽  
Amorphous Titania ◽  
Photoelectrochemical Response ◽  
And Performance ◽  
Photocatalytic Applications

The interest in TiO2 nanotubes has resulted in a lot of studies including the effects of various parameters on the properties and performance for different applications. This study investigated the effect of anodization at a low temperature on the properties and photoelectrochemical performance. The effects of varied anodization settings on morphology, crystallinity, and PEC response were studied. Low-temperature anodization resulted in smaller pore diameter and shorter tube length. Annealing temperature affected the presence of varied phases of TiO2 such as the prominence of anatase and amounts of rutile and amorphous TiO2 at 125°C. To observe photoelectrochemical response, annealing at 450°C is necessary. However, a cathodic response was observed for TiO2 nanotubes synthesized with low voltage at low temperature. Hence, amorphous titania nanotubes annealed at 125°C with thickness achieved in the anodization can be a potential material used for photocatalytic applications due to its determined cathodic photoelectrochemical response.

Dynamic moisture sorption and dimensional stability of furfurylated wood with low lignin content

Holzforschung ◽  
2019 ◽  
Vol 74 (1) ◽  
pp. 68-76
Author(s):  
Tiantian Yang ◽  
Erni Ma ◽  
Jinzhen Cao
Keyword(s):  
Relative Humidity ◽  
Dimensional Stability ◽  
Furfuryl Alcohol ◽  
Lignin Content ◽  
Moisture Sorption ◽  
Dimensional Change ◽  
Poplar Wood ◽  
Sorption Coefficient ◽  
Dimensional Changes ◽  
Sinusoidal Shape

AbstractDegradation of lignin occurs naturally in wood due to the influence of microorganisms or photic radiation. To improve the properties of wood with low lignin content, furfuryl alcohol (FA) at the concentration of 25% was used to modify poplar wood (Populus euramericana Cv.) after partial delignification. Moisture sorption and dimensional stability of the samples were investigated under dynamic conditions where the relative humidity (RH) was changed sinusoidally between 45% and 75% at 25°C. Both the moisture content (MC) and the tangential dimensional change varied with a sinusoidal shape similar to the RH. Hygroscopicity and hygroexpansion increased after delignification, while furfurylation led to an inverse impact by reducing MC, dimensional changes, amplitudes of MC and dimensional changes, moisture sorption coefficient (MSC), and humidity expansion coefficient (HEC). After delignification and further furfurylation, the MC and the dimensional changes were reduced by about 20%, and the maximum drop in amplitudes of MC and dimensional changes was about 30%, while the MSC and the HEC decreased by over 15%. In addition, the furfurylated wood with low lignin content exhibited lower sorption hysteresis and swelling hysteresis.

Changes in the dimensions of the venae cavae

1959 ◽  
Vol 196 (4) ◽  
pp. 741-744 ◽  
Author(s):  
Hiroshi Irisawa ◽  
Alexander P. Greer ◽  
Robert F. Rushmer
Keyword(s):  
Venous Pressure ◽  
Dimensional Change ◽  
Venous Flow ◽  
Dimensional Changes ◽  
Cyclic Patterns ◽  
Venae Cavae ◽  
Surgical Conditions ◽  
Two Phases ◽  
Pressure Changes ◽  
Clockwise Hysteresis

In 11 dogs a variable resistance gauge, a bonded strain gauge, or mutual inductance coils were installed on the venae cavae under aseptic surgical conditions so that dimensional changes in unexposed veins could be measured directly. The cyclic patterns of dimensional change resembled inverted images of venous flow records obtained by others. Since some changes in the venous dimensions apparently were not related to pressure, active contraction of the walls may have been responsible. Studies involving infusion and hemorrhage confirmed the existence of two phases in the pressure-diameter relationship correlated with the level of venous pressure. The pattern of diameter and venous pressure changes during transfusion and withdrawal of blood tended to be a clockwise hysteresis loop.

An Experimental Investigation of Pressure Drop During Partial Condensation of Low Pressure Steam

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Jacques du Plessis ◽  
Michael Owen
Keyword(s):  
Pressure Drop ◽  
Cooling System ◽  
Thermal Power ◽  
Steam Pressure ◽  
Tube Length ◽  
Condenser Tube ◽  
Cooling Systems ◽  
Frictional Pressure Drop ◽  
Wide Range ◽  
Experimental Apparatus

Abstract As direct dry-cooling systems are becoming more popular for thermal power plants, there is a demand to increase the flexibility of the application and performance of these cooling systems. A novel hybrid (dry/wet) dephlegmator (HDWD) cooling system is being developed, and at this stage in the development of the HDWD, the performance analysis and optimization of the HDWD is currently subject to uncertainties in a number of parameters. One of the parameters is the confidence in the correlations to predict the steam-side pressure drop over the wide range of full to partial condensation conditions expected in the system as a result of the design. This study makes use of an experimental apparatus to measure steam pressure drop over a range of partial to full condensation inside a circular horizontal tube. The experiment is conducted by measuring the steam flow and steam pressure drop in a horizontal primary condenser tube with the presence of a secondary condenser tube. The primary condenser has a tube length of 2.5 m and an inside tube diameter of 19.3 mm similar to the proposed HDWD design. Existing correlations for pressure drop in condensing flow are compared with the results to assess the applicability of the correlations for the HDWD case. It was found that the correlation of Lockhart and Martinelli’s with the Chisholm parameter fits the experimental data the best with a mean error of ±15.6%. A parametric study also indicated that there is a prominent increase in the frictional pressure drop at low partial condensation ratios (i.e., high steam through flow) as expected with wave drag at the vapor and condensate interface due to the difference in velocity.

Poiseuille Number Correlations of Gas Flow in Concentric Micro Annular Tubes

2008 ◽  
Author(s):  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Koichi Suzuki
Keyword(s):  
Boundary Conditions ◽  
Gas Flow ◽  
Slip Flow ◽  
Tube Length ◽  
Slip Boundary Conditions ◽  
Slip Boundary ◽  
Rarefaction Effect ◽  
Wide Range ◽  
Poiseuille Number ◽  
Fast Flow

Poiseuille number, the product of friction factor and Reynolds number (f · Re) for quasi-fully developed concentric micro annular tube flow was obtained for both no-slip and slip boundary conditions. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The compressible momentum and energy equations were solved for a wide range of Reynolds and Mach numbers for both isothermal flow and no heat conduction flow conditions. The detail of the incompressible slip Poiseuille number is kindly documented and its value defined as a function of r* and Kn is represented. The outer tube radius ranges from 50 to 150μm with the radius ratios of 0.2, 0.5 and 0.8 and selected tube length is 0.02m. The stagnation pressure, pstg is chosen in such away that the exit Mach number ranges from 0.1 to 0.7. The outlet pressure is fixed at the atmospheric pressure. In the case of fast flow, the value of f · Re is higher than that of incompressible slip flow theory due to the compressibility effect. However in the case of slow flow the value of f · Re is slightly lower than that of incompressible slip flow due to the rarefaction effect, even the flow is accelerated. The value of f · Re obtained for no-slip boundary conditions is compared with that of obtained for slip boundary conditions. The values of f · Re obtained for slip boundary conditions are predicted by f · Re correlations obtained for no-slip boundary conditions since rarefaction effect is relatively small for the fast flow.

Dimensional Changes of Graphite Flakes and Fracture in Tensile Tests of Gray Cast Iron

2018 ◽  
Author(s):  
Naoya Tada ◽  
Takeshi Uemori
Keyword(s):  
Cast Iron ◽  
Tensile Test ◽  
Internal Combustion Engines ◽  
Gray Cast Iron ◽  
Early Stage ◽  
Dimensional Change ◽  
Tensile Tests ◽  
High Ratio ◽  
Gray Cast ◽  
Dimensional Changes

Gray cast iron has been used as a component in various mechanical parts, such as the blocks and heads of automobile and marine engines, cylinder liners for internal combustion engines, and machine tool bases. It is desirable because of its good castability and machinability, damping characteristics, and high ratio of performance to cost. On the other hand, the weak graphite flakes present in gray cast iron act as stress concentrators and negatively affect the strength of this material. It is therefore important to know the relationship between the distribution of graphite flakes and the strength or fracture of gray cast iron. In this study, a tensile test of gray cast iron was carried out using a plate specimen in a scanning electron microscope, and the microscopic deformation was observed on the surface of specimen. Particularly, the change in the size of graphite flakes during the tensile test was examined, and the observed trend was discussed. We found from the experimental results that the dimensional changes in the graphite flakes varied in the observed area, and that the final fracture occurred in an area where a relatively large dimensional change was observed. This suggests that the fracture location or the critical parts of gray cast iron, can be predictable from the dimensional changes of the graphite flakes at an early stage of deformation.

Dimensional Changes by Heat Treatment of Helical Gear

2013 ◽  
Vol 535-536 ◽  
pp. 271-274
Author(s):  
Jeongsuk Lim ◽  
Sunghoon Kang ◽  
Young Seon Lee
Keyword(s):  
Heat Treatment ◽  
Elastic Deformation ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Dimensional Change ◽  
Helical Gear ◽  
Tooth Profile ◽  
Dimensional Changes ◽  
Gear Teeth ◽  
Experimental Works

The dimensional change of tooth profile by heat treatment of helical gear was investigated by experimental and numerical approaches. Especially, the three-dimensional elasto-plastic finite element (FE) simulation was adopted to analyze the elastic deformation during load, unloading, ejecting of workpiece. Quenching simulation was also carried out to investigate the change of tooth profile on the forged gear. In experiments, the amount of elastic deformation of the forged gear was quantitatively determined by comparing the tooth profiles on the forged gear and die. The dimensional change of the forged gear tooth after quenching was also evaluated from the comparision of the cold forged and quenched gear teeth. From experimental works, it was found that the amounts of dimensional changes after forging and quenching of helical gear are 10 and 10 μm, respectively.

Study on Orthogonal Experiment of Electrochemical Formation of Zinc Selenide from Acidic Aqueous Solutions

2011 ◽  
Vol 233-235 ◽  
pp. 2739-2742
Author(s):  
C.G. Zhang ◽  
Zheng Fang Shi ◽  
J. Miao
Keyword(s):  
Zinc Selenide ◽  
Zinc Sulfate ◽  
Sodium Citrate ◽  
Orthogonal Experiment ◽  
Bath Temperature ◽  
Molar Ratio ◽  
Complexing Agent ◽  
Deposition Parameters ◽  
Znse Thin Films ◽  
Citrate Bath

There were carried on experiment in zinc sulfate and selenite sodium electrolyte solution. To further studying the influence of the ZnSe films ingredient and the appearance influence of electrochemical formation ZnSe thin films, the deposition parameters, which are the pH, Zn2+/SeO32- molar ratio, complexing agent sodium citrate, bath temperature and current density, are studied by the orthogonal experiment, the influence on Zn of the parameters from strong to weak are attained.

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