scispace - formally typeset
Search or ask a question

Answers from top 14 papers

More filters
Papers (14)Insight
In this paper, the authors propose a phase-field model that describes the crystallization in an ice template and the evolution of particles during anisotropic solidification.
An early indicator for inhomogeneous crystallization is provided by the uncharacteristically high Pt 4f photoelectron peak for crystalline ice compared with the corresponding uniformly thick amorphous case.
This suggests that annealing led to crystallization of ice and subsequently the system became maximally freeze-concentrated.
On the other hand, if the dust-to-ice ratio is high (larger than 1) and/or the thermal inertia is high (larger than 100), the crystallization front evolves in a continuous and smooth manner, even for pure, exothermic crystallization.
That CH formation completely overrides ice nucleation and crystallization is indicative of the rapidity of the process under the new set of extreme conditions.
Ice may form in an instant, a moment of crystallization that can even be heard as clearly as a shotgun sometimes, but its life cycle is full of inbuilt slowness.
A model based on the heat transfer balance allows to predict the rate of ice crystallization.
Electron diffraction results on vapor deposited amorphous ice indicate that the temperature of the nucleation of the cubic phase depends upon the amount of time between the deposition and the onset of crystallization, suggesting that freshly deposited ice layers reconstruct on times of the order of hours.
an increase in the local ordering of the interfacial water which is expected to facilitate the crystallization of ice at the surface.
Results showed that the quality of the ice layer is the key factor for the control of the crystallization process.
The crystallization kinetics are consistent with a "classical" nucleation and growth mechanism indicating that there is an energetic barrier for deeply supercooled water to convert to ice.
Further study suggests that the grain size and the associated ice crystallization fraction are dependent on the field strength as well as frequency.
We expect that the combination of state-of-the-art simulation methods here employed to study ice nucleation from solution will be of much use in forthcoming numerical investigations of crystallization in mixtures.
These modeling approaches can then be considered as a promising tool for the understanding and the prediction of the ice crystallization process in SSHEs so as to identify new ways to improve the performance of the process.

Related Questions

What is the temperature range that forms the ice crystal during cryopreservation?5 answersIce crystal formation during cryopreservation occurs at high subzero temperatures. Specifically, ice seeding at temperatures above -10 °C can induce ice formation. Another study mentions that the temperature of the cooling fluid used for cryopreservation is between -20 °C and -30 °C, which is warm enough to minimize the formation of stress fractures in cell membranes due to thermal changes.
What is devitrification ice?4 answersDevitrification ice refers to the process by which a metastable glass or supercooled liquid transitions into a stable crystalline phase. It involves the nucleation and growth of ice particles in glass-forming solutions, particularly in compositions near the water-rich edge of the concentration range. Devitrification can occur during the warming phase of cryopreservation, such as in cell and tissue preservation, cryosurgery, and food manufacturing. The presence of nanoparticles, such as hydroxyapatite (HA) nanoparticles, in cryoprotective solutions can significantly affect the devitrification and recrystallization events upon warming. Successful cryopreservation requires not only fast cooling but also controlled rewarming processes to avoid devitrification. The kinetics of ice crystal growth in nanoparticle-containing dispersions are still not well understood. Devitrification can be influenced by factors such as cell dehydration during warming, which affects intracellular ice formation and critical warming rates.
How do ice crystal dimensions pose challenges to the stability of proteins?4 answersIce crystal dimensions pose challenges to the stability of proteins by affecting their structure and activity. Large ice crystals have been found to have a greater impact on protein stability compared to small ice crystals. The presence of large ice crystals can lead to a reduction in water-holding capacity and protein stability. Additionally, large ice crystals can cause changes in protein secondary and tertiary structure, as well as protein thermal stability. On the other hand, small ice crystals have been shown to have beneficial effects on water properties and protein stability. The size of ice crystals is an important factor to consider in preserving the stability of proteins during freezing.
How long does dry ice last?3 answersDry ice can last for appreciable periods of time, but it sublimes during storage. It has been common practice to allow the sublimed carbon dioxide (CO2) to escape into the atmosphere to prevent pressure build-up. However, there are methods to prolong the lifespan of dry ice. One method involves humidifying dry ice particles prepared by compressing snow dry ice. The humidification process involves spraying the dry ice with about 0.1-5% water and maintaining a temperature of about 18°C for approximately 15 minutes. Another method is to encase dry ice in a porous pouch, which allows for safe handling and can help keep frozen foodstuffs frozen for longer periods of time. Additionally, dry ice can be used as a heat sink in sludge freeze/thaw treatment, indicating that it can be effective in conditioning sludges. Finally, the quality of dry ice can be improved by passing liquefied gaseous CO2 through a humidifying vessel packed with ice, resulting in hard and dense dry ice.
How is the formation of gas bubles during freezing affected by by the velocity of the ice-water interface?3 answersThe velocity of the ice-water interface affects the formation of gas bubbles during freezing. The width of the gas tubes formed on the ampoule wall was found to be nearly independent of the freezing rate and ampoule diameter. The freezing interface strain gradually increased with lower ambient temperatures or an increase in the volume of water, leading to an increase in the interface strain. Water molecules were found to get exchanged between the ice-like and water-like domains of the interface with a time scale of ~10 ps. Visual experiments showed that the advancing ice-liquid interface interacted with sludge agglomerates, pushing them to move at lower advancing speeds, while forming needle-like ice crystals at faster freezing processes. The formation of gas bubbles during freezing is affected by the velocity of the ice-water interface, which influences the width of gas tubes, the freezing interface strain, and the interaction with other substances.
How long does it take a stone to fall from a height of 10 m?2 answersThe abstracts provided do not contain any information about the time it takes for a stone to fall from a height of 10 m.

See what other people are reading

What is scientific machine learning?
5 answers
Scientific machine learning (SciML) is an emerging field that combines scientific computing, model order reduction, and machine learning techniques to develop advanced models for various applications. It integrates traditional modeling methods based on first principles with data-driven machine learning approaches to create robust and fast models that can be easily integrated with data while maintaining a high level of detail. SciML algorithms have been applied in diverse areas such as urban drainage systems, electronic chips, and nanomaterial formation processes, showcasing their ability to handle complex multiphysics coupling effects, predict behaviors in real-time, and generalize well in predictive modeling. Despite being in early stages, SciML has demonstrated promising capabilities in enhancing computational efficiency and understanding intricate systems through a combination of traditional scientific methods and modern machine learning techniques.
What is the role of technical aspects in film?
5 answers
Technical aspects in film play a crucial role in various stages of film production and presentation. From the manufacturing of film equipment for clamping, tensioning, and cleaning films, to the utilization of contemporary digital media for colorimetry and cinematography, technical elements significantly impact the quality and visual appeal of films. Quality control processes in screen-film radiography and film processing ensure consistent high-quality radiographs. Moreover, the analysis of technical imagery in western sci-fi films demonstrates how technical images are used to convey emotions, stimulate thinking, and shape the director's vision. Thin film science and technology contribute to the development of future devices by engineering properties like porosity and crystallite size. Overall, technical aspects in film production enhance storytelling, visual aesthetics, and audience engagement.
Does dicalcium phosphate dihydrate's crystalline structure support osteoconduction by promoting the adhesion and proliferation of bone cells?
5 answers
Dicalcium phosphate dihydrate (DCPD) has been recognized for its potential in promoting osteoconduction by supporting the adhesion and proliferation of bone cells. Studies have shown that DCPD, a crystalline calcium orthophosphate phase, exhibits higher metastability compared to other phases. Furthermore, the morphology of calcium orthophosphate crystals, such as octacalcium phosphate (OCP), has been found to influence the attachment, spreading, and growth of bone cells. Additionally, surface modifications involving calcium phosphate coatings have been shown to enhance cell adhesion, proliferation, and osteogenic functionality on various substrates, indicating the positive impact of calcium phosphate structures on bone cell behavior. Therefore, the crystalline structure of DCPD and related calcium phosphate coatings indeed support osteoconduction by facilitating bone cell adhesion and proliferation.
Trans content is simbol of cristalinity in polymers ?
4 answers
The trans content in polymers is indeed a symbol of crystallinity. The higher the trans content, the greater the crystallinity observed in the polymer. For instance, in polyethylene terephthalate (PET), the transformation from gauche to trans conformation during stretching increases the trans content, which correlates well with the crystallinity observed through techniques like DSC measurement. Additionally, in polybutadienes, isomerizations to increase trans content led to more crystalline or semicrystalline structures, with a decrease in crystallinity as trans content reduced. This relationship between trans content and crystallinity is crucial in understanding the structural effects on physical properties and the overall crystallization kinetics of polymers.
How does chemical vapor growth of graphene work?
5 answers
Chemical vapor deposition (CVD) for graphene growth involves complex gas-phase surface reactions, mass, momentum, and energy transfer processes. Factors like temperature, pressure, and reactor design play crucial roles in optimizing graphene synthesis. Electric fields applied during CVD can significantly impact graphene growth, enabling selective or rapid growth of clean films. Direct CVD of graphene on specific substrates like 3C-SiC can be challenging due to low carbon atom diffusion, necessitating alternative methods like PECVD for successful growth. A modified CVD method utilizing ceramic plates and defect-rich vertical graphene accelerates graphene growth without increasing nucleation density, enabling rapid millimeter-sized graphene grain production in minutes. Overall, CVD processes involve intricate mechanisms combining chemical reactions, transport phenomena, and reactor optimization to achieve efficient graphene synthesis.
Amorphous sillicon photodiode'
5 answers
An amorphous silicon photodiode is a key component in various optoelectronic devices. It typically consists of a photodiode structure with an amorphous silicon layer, electrodes, and sometimes additional layers for improved performance. The use of amorphous silicon in photodiodes offers advantages such as ease of fabrication and compatibility with large-scale production processes. To enhance the efficiency and reduce dark current in amorphous silicon devices, techniques like incorporating nitrogen-doped indium tin oxide films or barrier metal films made of high-melting point metals have been proposed. These innovations aim to improve the overall performance and reliability of amorphous silicon photodiodes for various applications in light detection and energy conversion technologies.
What temperatures Molding glass can go?
5 answers
Molding glass can be processed at temperatures ranging from 400 to 700 °C, above the glass forming temperature, with high press forces of 1-20kN imposed simultaneously. The crystallization temperature for CaO-SiO2 based flux ranges from 813 to 874 °C, while for CaO-Al2O3 based flux, it ranges from 932 to 972 °C. Precision glass molding involves heating the glass above the transition temperature Tg, pressing it into shape, and then cooling it down to approximately 200 °C, leading to uneven cooling speeds and stress distribution on the glass lens. The preferred mold temperature range for molding glass containers like bottles and jars is 480–550°C, impacting the strength of the final products. Smart-phone curved glass forming conditions were tested at temperatures of 620°C and 650°C using a glass molding system.
What is the quantum confinement effect?
10 answers
The quantum confinement effect is a phenomenon observed in semiconductor materials, where the electronic and optical properties of the material are significantly altered due to the spatial confinement of charge carriers (electrons and holes) within dimensions that are comparable to the de Broglie wavelength of the carriers. This confinement leads to the discretization of energy levels, a departure from the continuous energy bands found in bulk materials. In practical terms, quantum confinement can manifest in various forms depending on the dimensionality of the confinement: in one dimension as quantum wells, in two dimensions as quantum wires, and in three dimensions as quantum dots (QDs). Each form of confinement restricts the motion of charge carriers in one or more dimensions, leading to distinct changes in the material's physical properties. For instance, quantum dots, which exhibit three-dimensional confinement, show size-dependent optical and electronic properties because the energy levels of the dots can be tuned by changing their size. This tunability is crucial for applications in near-field thermal radiation, light-emitting diodes (LEDs), and thin-film transistors. Quantum confinement effects are not only limited to altering electronic and optical properties but also influence the thermodynamic behavior of materials. For example, specific heat can exhibit unique features under spatial confinement, indicating phase transitions at certain temperatures. Moreover, the effect plays a significant role in enhancing the performance of semiconductors by tuning defect levels through strategies like hydrogen doping in nanostructures, thereby optimizing their electronic applications. Furthermore, quantum confinement can lead to the observation of quantum confinement effects in disordered materials, such as amorphous thin-film transistors, where it affects the field-effect mobility and device characteristics. It also impacts the linewidth broadening in metal halide perovskites, suggesting that quantum confinement is not a limiting factor in achieving ultrahigh color purity in next-generation LEDs. Additionally, the effect is evident in the blue shift of energy gaps in thin films, confirming its presence through spectroscopy experiments. In summary, the quantum confinement effect is a fundamental phenomenon that significantly influences the physical properties of nanostructured materials, with wide-ranging implications for electronic, optical, and thermodynamic applications.
What are the physical and chemical properties that contribute to the durability and strength of paper?
4 answers
The durability and strength of paper are influenced by various physical and chemical properties. Physical properties such as tear resistance, breaking length, and mechanical strength are crucial factors in determining the durability of paper. Chemical properties like the presence of hydrogen bonds between fibers, crosslinking agents, and crystallization play a significant role in enhancing the strength of paper. Additionally, the composition of the pulp, including cellulose, hemicellulose, and lignin contents, affects the mechanical properties of the paper sheets. Moreover, the addition of specific components during the papermaking process, such as modified chitosan and plant poly-gum, can further improve the strength and waterproof properties of paper. Overall, a combination of physical attributes like tear resistance and mechanical strength, along with chemical factors like crosslinking and pulp composition, collectively contribute to the durability and strength of paper.
How many zeolitic imidazolate frameworks have been synthesized so far?
4 answers
A variety of zeolitic imidazolate frameworks (ZIFs) have been synthesized, showcasing their versatility and potential applications. The synthesis of meltable iron-based ZIF, denoted as MUV-24, has been described, highlighting its unique properties and transformation upon heating. Additionally, a pyrithione-loading ZIF-8 has been developed to target biofilms and enhance bacterial sensitivity to pyrithione, showcasing its potential in combating infections caused by multidrug-resistant bacteria. Studies on the nucleation of ZIFs have provided insights into the initial cluster formations and the transition to various crystal structures, shedding light on the nucleation and growth processes of these frameworks. Furthermore, the functionality-induced locking of ZIFs has been reported, leading to exceptional framework rigidity and improved gas separation performance. Overall, these studies demonstrate the diverse range of ZIFs synthesized and their promising applications in various fields.
What is the typical storage time limit for silicon epitaxy wafers in various applications?
5 answers
The storage time limit for silicon epitaxy wafers can vary depending on the specific application and storage conditions. For mirror-polished wafers, storing silicon wafers in an immersed state with hydrogen peroxide at concentrations of 0.05wt%-1wt% and temperatures of 10-30°C can prevent surface staining for up to 120 hours. Additionally, the efficiency limits of epitaxially grown silicon wafers can be optimized by quantifying losses from defects like decorated stacking faults and inhomogeneous processing, allowing for systematic material improvement. Nucleation annealing at 750°C followed by growth annealing at 1050°C can significantly enhance the generation lifetime of epitaxial layers, although it may not affect recombination lifetime, potentially due to defects from metallic impurities and boron complexes in heavily doped substrate regions.