scholarly journals Thin shell aerogel fabrication for FIREX-I targets using high viscosity (phloroglucinol carboxylic acid)/formaldehyde solution

2008 ◽  
Vol 26 (3) ◽  
pp. 449-453 ◽  
Author(s):  
H. Yang ◽  
K. Nagai ◽  
M. Nakai ◽  
T. Norimatsu
Keyword(s):  
Carboxylic Acid ◽  
Thin Shell ◽  
Shell Thickness ◽  
High Viscosity ◽  
Formaldehyde Solution ◽  
Resorcinol Formaldehyde ◽  
Foam Structure ◽  
Final Density ◽  
Emulsion Process ◽  
High Level

AbstractCapsules with a thin aerogel shell were prepared by the OO/W/OIemulsion process. (Phloroglucinol carboxylic acid)/formaldehyde (PF) was used as the water phase (W) solution to form the shell of the capsule. PF is a linear polymer prepared from phloroglucinol carboxylic acid. The viscosity of the PF solution can reach a high level of 9×10−5m2/s without gelation while resorcinol/formaldehyde (RF) gelates at ~3–4×10−5m2/s. Using the viscous PF solution, capsule with a 17 µm gel shell was fabricated. This thickness satisfies the specification of the first phase of Fast Ignition Realization Experiment (FIREX-I) at Osaka University. When PF gel was extracted to remove the organic solvent, shrinkage of 9% occurred. The final density of the PF aerogel was 145 mg/cm3. Both the shell thickness and density can satisfy the specification of FIREX-I. The pore size of the PF aerogel was less than 100 nm while that of RF was 200–500 nm. The SEM showed that PF had particle-like foam structure while RF had fibrous-like foam structure.

Interpretation of structure formation during the sol-gel transition of a resorcinol-formaldehyde solution by population balance

2003 ◽  
Vol 264 (2) ◽  
pp. 532-537 ◽  
Author(s):  
Takuji Yamamoto ◽  
Shin R. Mukai ◽  
Akira Endo ◽  
Masaru Nakaiwa ◽  
Hajime Tamon
Keyword(s):  
Structure Formation ◽  
Sol Gel ◽  
Population Balance ◽  
Formaldehyde Solution ◽  
Resorcinol Formaldehyde ◽  
Sol Gel Transition ◽  
Gel Transition

Overview of Performance and Analytical Modeling Techniques for Electromagnetic Heating and Applications to Steam-Assisted-Gravity-Drainage Process Startup

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 311-333 ◽  
Author(s):  
Sahar Ghannadi ◽  
Mazda Irani ◽  
Rick Chalaturnyk
Keyword(s):  
High Viscosity ◽  
Gravity Drainage ◽  
Induction Medium ◽  
Oil Sand ◽  
Steam Assisted Gravity Drainage ◽  
Production Wells ◽  
Reservoir Conditions ◽  
Startup Time ◽  
Industry Practice ◽  
High Level

Summary Steam-assisted gravity drainage is the method of choice to extract bitumen from Athabasca oil-sand reservoirs in Western Canada. Under reservoir conditions, bitumen is immobile because of high viscosity, and its typically high level of saturation limits the injectivity of steam. In current industry practice, steam is circulated within injection and production wells. Operators keep the steam circulating until mobile bitumen breaks through the producer and communication is established between the injector and the producer. The “startup” phase is a time-consuming process taking three or more months with no oil production. A variety of processes could be used to minimize the length of the startup phase, such as electromagnetic (EM) heating in either the induction (medium frequency) or radio-frequency ranges. Knowledge of the size of the hot zone formed by steam circulation and of the benefits of simultaneous EM-heating techniques increases understanding of the startup process and helps to minimize startup duration. The aim of the present work is to introduce an analytical model to predict startup duration for steam circulation with and without EM heating. Results reveal that resistive (electrothermal) heating with/without brine injection cannot be a preferable method for mobilizing the bitumen in startup phase. Induction slightly decreases startup time at frequencies smaller than 10 kHz, and at 100 kHz it can reduce startup time to less than two months.

Formation of resorcinol-formaldehyde hollow nanoshells through a dissolution–regrowth process

Nanoscale ◽  
2020 ◽  
Vol 12 (28) ◽  
pp. 15460-15465
Author(s):  
Shuai Zhou ◽  
Yaocai Bai ◽  
Wenjing Xu ◽  
Ji Feng ◽  
Xiaojing Wang ◽  
...  
Keyword(s):  
Shell Thickness ◽  
Colloidal Particles ◽  
Resorcinol Formaldehyde ◽  
Hollow Nanostructures

Dissolution and regrowth of resorcinol formaldehyde (RF) colloidal particles can occur spontaneously when they are subjected to etching in solvents such as ethanol and tetrahydrofuran, resulting in the formation of hollow nanostructures with controllable shell thickness.

scholarly journals Use of Carboxylic Acid Ester as Lubricant Component

2021 ◽  
Vol 135 (4) ◽  
pp. 7-9
Author(s):  
V. A. Zavorotny ◽  
◽  
I. V. Podkovyrova ◽  
Keyword(s):  
Molecular Structure ◽  
Carboxylic Acid ◽  
Viscosity Index ◽  
Dicarboxylic Acids ◽  
Caproic Acid ◽  
High Viscosity ◽  
Mineral Oil ◽  
Effect Of Temperature ◽  
Esterification Reaction ◽  
Theoretical Foundations

This paper discusses the use of esters of dicarboxylic acids as components of lubricants. Influence of molecular structure on the properties of ester compositions and the course of the esterification reaction. The theoretical foundations for the production of esters, the synthesis of the ester of caproic acid and butyldiglycol are considered, and the effect of temperature on the esterification process is reflected. Samples of a semi-synthetic oil were prepared, consisting of mineral oil and an ester of various concentrations. The viscosity and density were determined, the viscosity index of the samples under study was calculated. An oil with an optimal concentration of an ester and a high viscosity index was selected.

Thin-Shell Thickness of Two-Dimensional Materials

2015 ◽  
Vol 82 (12) ◽  
Author(s):  
Enlai Gao ◽  
Zhiping Xu
Keyword(s):  
Thin Shell ◽  
Shell Thickness ◽  
2D Materials ◽  
Wide Spectrum ◽  
Elastic Shell ◽  
Bending Stiffness ◽  
Interlayer Distance ◽  
Structural Deformation ◽  
Two Dimensional ◽  
Number Of Layers

In applying the elastic shell models to monolayer or few-layer two-dimensional (2D) materials, an effective thickness has to be defined to capture their tensile and out-of-plane mechanical behaviors. This thin-shell thickness differs from the interlayer distance of their layer-by-layer assembly in the bulk and is directly related to the Föppl–von Karman number that characterizes the mechanism of nonlinear structural deformation. In this work, we assess such a definition for a wide spectrum of 2D crystals of current interest. Based on first-principles calculations, we report that the discrepancy between the thin-shell thickness and interlayer distance is weakened for 2D materials with lower tensile stiffness, higher bending stiffness, or more number of atomic layers. For multilayer assembly of 2D materials, the tensile and bending stiffness have different scaling relations with the number of layers, and the thin-shell thickness per layer approaches the interlayer distance as the number of layers increases. These findings lay the ground for constructing continuum models of 2D materials with both tensile and bending deformation.

scholarly journals Influence of shell thickness on the refractive index sensitivity of localized surface plasmon resonance inflection points in silver-coated gold nanorods

RSC Advances ◽  
2020 ◽  
Vol 10 (29) ◽  
pp. 16827-16831 ◽  
Author(s):  
Kyeong Rim Ryu ◽  
Ji Won Ha
Keyword(s):  
Refractive Index ◽  
Gold Nanorods ◽  
Localized Surface Plasmon Resonance ◽  
Thin Shell ◽  
Shell Thickness ◽  
Localized Surface Plasmon ◽  
Thick Shell ◽  
Refractive Index Sensitivity ◽  
Inflection Points ◽  
Index Sensitivity

Single Ag@AuNRs with thick shell thickness show higher RI sensitivity than single Ag@AuNRs with thin shell thickness.

Effect of high pressure on growth of colloidal particles during sol–gel phase transition of resorcinol–formaldehyde solution

Adsorption ◽  
2019 ◽  
Vol 25 (6) ◽  
pp. 1115-1120 ◽  
Author(s):  
T. Yamamoto ◽  
M. Tayakout-Fayolle ◽  
K. Iimura ◽  
H. Satone ◽  
T. Kakibe ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Colloidal Particles ◽  
Sol Gel ◽  
Formaldehyde Solution ◽  
Resorcinol Formaldehyde ◽  
Gel Phase

scholarly journals Inactivation of the lys7 Gene, Encoding Saccharopine Reductase in Penicillium chrysogenum, Leads to Accumulation of the Secondary Metabolite Precursors Piperideine-6-Carboxylic Acid and Pipecolic Acid from α-Aminoadipic Acid

2004 ◽  
Vol 70 (2) ◽  
pp. 1031-1039 ◽  
Author(s):  
Leopoldo Naranjo ◽  
Eva Martín de Valmaseda ◽  
Javier Casqueiro ◽  
Ricardo V. Ullán ◽  
Mónica Lamas-Maceiras ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Penicillium Chrysogenum ◽  
Reductase Activity ◽  
Antitumor Agent ◽  
Pipecolic Acid ◽  
Gene Encoding ◽  
Double Recombination ◽  
Acid Pathway ◽  
High Level ◽  
Saccharopine Reductase

ABSTRACT Pipecolic acid serves as a precursor of the biosynthesis of the alkaloids slaframine and swainsonine (an antitumor agent) in some fungi. It is not known whether other fungi are able to synthesize pipecolic acid. Penicillium chrysogenum has a very active α-aminoadipic acid pathway that is used for the synthesis of this precursor of penicillin. The lys7 gene, encoding saccharopine reductase in P. chrysogenum, was target inactivated by the double-recombination method. Analysis of a disrupted strain (named P. chrysogenum SR1−) showed the presence of a mutant lys7 gene lacking about 1,000 bp in the 3′-end region. P. chrysogenum SR1− lacked saccharopine reductase activity, which was recovered after transformation of this mutant with the intact lys7 gene in an autonomously replicating plasmid. P. chrysogenum SR1− was a lysine auxotroph and accumulated piperideine-6-carboxylic acid. When mutant P. chrysogenum SR1− was grown with l-lysine as the sole nitrogen source and supplemented with dl-α-aminoadipic acid, a high level of pipecolic acid accumulated intracellularly. A comparison of strain SR1− with a lys2-defective mutant provided evidence showing that P. chrysogenum synthesizes pipecolic acid from α-aminoadipic acid and not from l-lysine catabolism.

scholarly journals Subsea Processing Equipment: A Strategy for Effective Assessment and Selection

2015 ◽  
Vol 773-774 ◽  
pp. 1335-1339
Author(s):  
Kafayat Oluwatoyin Shobowale ◽  
Fakhruldin Mohd Hashim ◽  
Hilmi bin Hussien
Keyword(s):  
Domain Knowledge ◽  
Oil And Gas ◽  
Transient Flow ◽  
High Viscosity ◽  
Base System ◽  
Step Process ◽  
Failure Data ◽  
Reservoir Conditions ◽  
High Level ◽  
Unfavorable Condition

Subsea processing equipment’s are deployed in Deepwater / subsea marginal field, fields having challenging reservoir characteristics (which includes: high viscosity, high GVF) in order to economically recover oil and gas. They includes: multiphase booster pump, subsea separation and compression equipment’s. These equipment’s faces a high level of uncertainty as regards well and reservoir conditions, putting the equipment in an unfavorable condition covering a wide and variable range of processes including transient Flow, variable oil flow, fluid pressures, temperature and gas compression effects. More so, knowledge engineers in different areas are assessing this domain in different ways making the performance parameters and relations to be defined differently when utilizing computer based tools for assessment and selection. A four step process is proposed which are: domain knowledge acquisition, failure data analysis, knowledge model and a knowledge base system will reveal the key components and parameters that are needed to make an optimum decision. The applicability of these four step process is demonstrated in the assessment and selection of subsea multiphase booster pumps.

scholarly journals Extraction of consistent shell theory equations from 3D theory of elasticity

2019 ◽  
Vol 15 (2) ◽  
pp. 135-148
Author(s):  
Evgeny M Zveryaev
Keyword(s):  
Thin Shell ◽  
Shell Thickness ◽  
Shell Theory ◽  
Three Dimensional ◽  
Initial Approximation ◽  
Theory Of Elasticity ◽  
Curvilinear Coordinates ◽  
System Of Equations ◽  
Dimensional Problem ◽  
Output Data

Aims of research. Derivation of consistent equations of the theory of thin elastic shells without hypotheses and stress averaging over the shell thickness. Methods. Using the iterative method of Saint-Venant - Picard - Banach, the three-dimensional problem of the theory of elasticity is solved without any hypotheses. By the principle of compressed mappings, the solution converges asymptotically, regardless of the choice of the values of the initial approximation. Results. A method has been developed for integrating the spatial equations of the theory of elasticity in curvilinear coordinates for a thin shell. The presence of a small parameter allows the integration of the system of equations in such a way that the output data of the first operator is input to the next operator, etc., dividing the original complex operator into a sequence of simple integrable Picard type operators. Each equation contains terms of only one asymptotic order.

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