scholarly journals Flow Map for Hydrodynamics and Suspension Behavior in a Continuous Archimedes Tube Crystallizer

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1466
Author(s):  
Jana Sonnenschein ◽  
Pascal Friedrich ◽  
Moloud Aghayarzadeh ◽  
Otto Mierka ◽  
Stefan Turek ◽  
...  
Keyword(s):  
Crystallization Process ◽  
Small Scale ◽  
Operating Parameters ◽  
Material System ◽  
Growth Phases ◽  
Dimensionless Numbers ◽  
Cfd Simulations ◽  
High Quality ◽  
New Material ◽  
Flow Map

The Archimedes Tube Crystallizer (ATC) is a small-scale coiled tubular crystallizer operated with air-segmented flow. As individual liquid segments are moved through the apparatus by rotation, the ATC operates as a pump. Thus, the ATC overcomes pressure drop limitations of other continuous crystallizers, allowing for longer residence times and crystal growth phases. Understanding continuous crystallizer phenomena is the basis for a well-designed crystallization process, especially for small-scale applications in the pharmaceutical and fine chemical industry. Hydrodynamics and suspension behavior, for example, affect agglomeration, breakage, attrition, and ultimately crystallizer blockage. In practice, however, it is time-consuming to investigate these phenomena experimentally for each new material system. In this contribution, a flow map is developed in five steps through a combination of experiments, CFD simulations, and dimensionless numbers. Accordingly, operating parameters can be specified depending on ATC design and material system used, where suspension behavior is suitable for high-quality crystalline products.

Cross-sectional TEM specimen preparation from magneto-optical disk by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 236-237
Author(s):  
F. Shaapur ◽  
M.J. Kim ◽  
Seh Kwang Lee ◽  
Soon Gwang Kim
Keyword(s):  
System Development ◽  
Thin Foil ◽  
Specimen Preparation ◽  
Material System ◽  
Cross Sectional ◽  
Protective Layers ◽  
New Material ◽  
Diamond Saw ◽  
Original Production ◽  
Thick Medium

TEM characterization and microanalysis of the recording media is crucial and complementary to new material system development as well as quality control applications. Due to the type of material generally used for supporting the medium, i.e., a polymer, conventional macro- and microthinning procedures for thin foil preparation are not applicable. Ultramicrotorny (UM) is a viable option and has been employed in previous similar studies. In this work UM has been used for preparation of XTEM samples from a magneto-optical (MO) recording medium in its original production format.The as-received material system consisted of a 4-layer, 2100 Å thick medium including a 300 Å TbFeCo layer enveloped by silicon nitride protective layers supported on a 1.2 mm thick × 135 mm (5.25 in.) diameter polycarbonate disk. Recording tracks had an approximate pitch of 1.6 μm separated by 800 Å deep peripheral grooves. Using a Buehler Isomet low-speed diamond saw, 1 mm wide and 20 mm long strips were cut out of the disk along the recording tracks.

Attribute Based Selection of Thermoplastic Resin for Vacuum Infusion Process

2011 ◽  
Vol 1 (3) ◽  
pp. 31-52 ◽  
Author(s):  
R. T. Durai Prabhakaran ◽  
Aage Lystrup ◽  
Tom Løgstrup Andersen
Keyword(s):  
Material System ◽  
Mathematical Tool ◽  
Thermoplastic Resin ◽  
Thermoplastic Polymers ◽  
Vacuum Infusion ◽  
Thermosetting Polymers ◽  
Current Scenario ◽  
New Material ◽  
Selection Of ◽  
Vacuum Infusion Process

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection for vacuum infused of a wind turbine blade—is shown to demonstrate the intricacies involved in the proposed methodology for resin selection.

scholarly journals A Study on the Techniques of Composite Mold Structure for Hovercraft Using New Material System

2008 ◽  
Vol 32 (9) ◽  
pp. 699-703
Author(s):  
Yun-Hae Kim ◽  
Chang-Won Bae ◽  
Keun-Sil Park ◽  
Sung-Youl Bae ◽  
Kyung-Man Moon ◽  
...  
Keyword(s):  
Material System ◽  
New Material

scholarly journals Numerical CFD simulations on a small-scale ORC expander using a customized grid generation methodology

2017 ◽  
Vol 129 ◽  
pp. 843-850 ◽  
Author(s):  
Giuseppe Bianchi ◽  
Sham Rane ◽  
Ahmed Kovacevic ◽  
Roberto Cipollone ◽  
Stefano Murgia ◽  
...  
Keyword(s):  
Grid Generation ◽  
Small Scale ◽  
Cfd Simulations

Attribute Based Selection of Thermoplastic Resin for Vacuum Infusion Process

2012 ◽  
pp. 267-288
Author(s):  
R. T. Durai Prabhakaran ◽  
Aage Lystrup ◽  
Tom Løgstrup Andersen
Keyword(s):  
Material System ◽  
Mathematical Tool ◽  
Thermoplastic Resin ◽  
Thermoplastic Polymers ◽  
Vacuum Infusion ◽  
Thermosetting Polymers ◽  
Current Scenario ◽  
New Material ◽  
Selection Of ◽  
Vacuum Infusion Process

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection for vacuum infused of a wind turbine blade—is shown to demonstrate the intricacies involved in the proposed methodology for resin selection.

Integrated Photonic Circuits in Gallium Nitride and Aluminum Nitride

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1450001 ◽  
Author(s):  
Chi Xiong ◽  
Wolfram Pernice ◽  
Carsten Schuck ◽  
Hong X. Tang
Keyword(s):  
High Speed ◽  
Optical Signal ◽  
Silicon Substrates ◽  
Material System ◽  
Group Iii ◽  
Electro Optic ◽  
New Material ◽  
Nanophotonic Circuits ◽  
Group Iii Nitride ◽  
On Chip

Integrated optics is a promising optical platform both for its enabling role in optical interconnects and applications in on-chip optical signal processing. In this paper, we discuss the use of group III-nitride (GaN, AlN) as a new material system for integrated photonics compatible with silicon substrates. Exploiting their inherent second-order nonlinearity we demonstrate and second, third harmonic generation in GaN nanophotonic circuits and high-speed electro-optic modulation in AlN nanophotonic circuits.

Fully-Coupled Turbojet Engine CFD Simulations and Cycle Analyses Along the Equilibrium Running Line

2020 ◽  
Author(s):  
Alejandro Briones ◽  
Andrew W Caswell ◽  
Brent Rankin
Keyword(s):  
Flow Rate ◽  
Fluid Dynamic ◽  
Thermodynamic Cycle ◽  
Angular Speed ◽  
Small Scale ◽  
Cfd Simulations ◽  
Fuel Flow ◽  
Turbojet Engine ◽  
Design Cycle ◽  
Fully Coupled

Abstract This work presents fully-coupled computational fluid dynamic (CFD) simulations and thermodynamic cycle analyses of a small-scale turbojet engine at several conditions along the equilibrium running line. The CFD simulations use a single mesh for the entire engine, from the intake to the exhaust, allowing information to travel in all directions. The CFD simulations are performed along the equilibrium running line by using the iterative Secant method to compute the fuel flow rate required to match the compressor and turbine power. The freestream pressure and temperature and shaft angular speed are the only inputs needed for the CFD simulations. To evaluate the consistency of the CFD results with thermodynamic cycle results, outputs from the CFD simulations are prescribed as inputs to the cycle model. This approach enables on-design and off-design cycle calculations to be performed without requiring turbomachinery performance maps. In contrast, traditional off-design cycle analyses require either scaling, calculating, or measuring compressor and turbine maps with boundary condition assumptions. In addition, the CFD simulations and the cycle analyses are compared with measurements of the turbojet engine. The CFD simulations, thermodynamic cycle analyses, and measurements agree in terms of total temperature and pressure at the diffuser-combustor interface, air and fuel mass flow rate, equivalence ratio, and thrust. The developed methods to perform CFD simulations from the intake to the exhaust of the turbojet engine are expected to be useful for guiding the design and development of future small-scale gas turbine engines.

scholarly journals From Coffee to Biodiesel—Deep Eutectic Solvents for Feedstock and Biodiesel Purification

Separations ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 22 ◽  
Author(s):  
Aleksandra Sander ◽  
Ana Petračić ◽  
Jelena Parlov Vuković ◽  
Lana Husinec
Keyword(s):  
Potassium Carbonate ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Acid Number ◽  
Biodiesel Production ◽  
Small Scale ◽  
Total Acid ◽  
High Quality ◽  
Purification Method ◽  
Coffee Grounds

Over three billion cups of coffee are consumed daily, making waste coffee grounds readily available throughout the world. Containing approximately 10–15 wt% of oil, they have great potential for biodiesel production. The goal of this work was to produce high quality biodiesel from waste coffee grounds. One fresh and four different types of waste coffee grounds were collected. Oil was extracted by the Soxhlet method with n-hexane and then purified via extractive deacidification with a potassium carbonate-based deep eutectic solvent. Biodiesels were synthesized by means of alkali catalyzed transesterification at different catalyst:methanol:oil mass ratios and reaction times. Impurities present in crude biodiesels were extracted with a choline chloride-based deep eutectic solvent. All batch extraction experiments were performed at room conditions in a small scale extractor. Optimal conditions for synthesis and purification were defined in order to assure high quality of the produced biodiesel. Additionally, continuous column extraction with the choline chloride-based solvent was tested as a purification method for crude biodiesel. Stabilization time and optimal biodiesel to solvent mass ratio were determined. The potassium carbonate-based solvent efficiently reduced the total acid number of the feedstock (deacidification efficiency ranged from 86.18 to 94.15%), while the one based on choline chloride removed free glycerol and glycerides from crude biodiesels. After continuous purification, the purified biodiesel was of excellent quality with glycerol and glyceride contents below the EN 14214 limit.

Sign in / Sign up

Export Citation Format

Share Document