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Climate warming accelerates permafrost thawing, causing warming‐driven disasters like ground collapse and retrogressive thaw slump (RTS). These phenomena, involving intricate multiphysics interactions, phase transitions, nonlinear mechanical responses, and fluid‐like deformations, and pose increasing risks to geo‐infrastructures in cold regions. This study develops a thermo‐hydro‐mechanical (THM) coupled single‐point three‐phase material point method (MPM) to simulate the time‐dependent phase transition and large deformation behavior arising from the thawing or freezing of ice/water in porous media. The mathematical framework is established based on the multiphase mixture theory in which the ice phase is treated as a solid constituent playing the role of skeleton together with soil grains. The additional strength due to ice cementation is characterized via an ice saturation‐dependent Mohr–Coulomb model. The coupled formulations are solved using a fractional‐step‐based semi‐implicit integration algorithm, which can offer both satisfactory numerical stability and computational efficiency when dealing with nearly incompressible fluids and extremely low permeability conditions in frozen porous media. Two hydro‐thermal coupling cases, that is, frozen inclusion thaw and Talik closure/opening, are first benchmarked to show the method can correctly simulate both conduction‐ and convection‐dominated thermal regimes in frozen porous systems. The fully THM responses are further validated by simulating a 1D thaw consolidation and a 2D rock freezing example. Good agreements with experimental results are achieved, and the impact of hydro‐thermal variations on the mechanical responses, including thaw settlement and frost heave, are successfully captured. Finally, the predictive capability of the multiphysics MPM framework in simulating thawing‐triggered large deformation and failure is demonstrated by modeling an RTS and the settlement of a strip footing on thawing ground. [ABSTRACT FROM AUTHOR]

Frozen and thawed meat plays an important role in stabilizing the meat supply chain and extending the shelf life of meat. However, traditional methods of research and development (R&D) struggle to meet rising demands for quality, nutritional value, innovation, safety, production efficiency, and sustainability. Frozen and thawed meat faces specific challenges, including quality degradation during thawing. Artificial intelligence (AI) has emerged as a promising solution to tackle these challenges in R&D of frozen and thawed meat. AI's capabilities in perception, judgment, and execution demonstrate significant potential in problem‐solving and task execution. This review outlines the architecture of applying AI technology to the R&D of frozen and thawed meat, aiming to make AI better implement and deliver solutions. In comparison to traditional R&D methods, the current research progress and promising application prospects of AI in this field are comprehensively summarized, focusing on its role in addressing key challenges such as rapid optimization of thawing process. AI has already demonstrated success in areas such as product development, production optimization, risk management, and quality control for frozen and thawed meat. In the future, AI‐based R&D for frozen and thawed meat will also play an important role in promoting personalization, intelligent production, and sustainable development. However, challenges remain, including the need for high‐quality data, complex implementation, volatile processes, and environmental considerations. To realize the full potential of AI that can be integrated into R&D of frozen and thawed meat, further research is needed to develop more robust and reliable AI solutions, such as general AI, explainable AI, and green AI. [ABSTRACT FROM AUTHOR]

Numerous applications in civil and transportation engineering require concrete with high early strength and good durability properties. Limited studies have revised the performance of high early-strength concrete prepared with calcium sulfoaluminate (CSA) cement and internal curing technology. This study evaluates the strength and durability properties of four concrete mixtures designed with low and high cement contents, incorporated with and without internal curing. Compressive and split tensile strength, autogenous and drying shrinkage, and freezing and thawing resistance were evaluated. High early-strength concrete mixtures with internal curing achieved lower strength and improved durability (shrinkage and freezing and thawing resistance) in comparison with their analogous control mixtures. All concrete mixtures obtained compressive strength higher than 17 MPa (2,500 psi) within the first 4 h. Concrete mixtures with high cement content showed less contraction (<200 με) than their analogous control mixtures. The internally cured concrete mixture with low cement content exhibited slight expansion instead of shrinkage. Finally, the freezing and thawing resistance showed great improvement because no or little damage was observed in the internally cured concrete mixtures. The internally cured concrete specimens overcame 300 cycles, whereas the control mixtures reached maximum 164 cycles. The internally cured mixtures with low and high cement contents showed a final relative dynamic of elasticity of 79.7% and 99%, respectively. Based on these results, using CSA concrete for repair works could be feasible with internal curing technique. Practical Applications: Extensive damage is observed in concrete pavements due to several factors, primarily due to freeze–thaw action and shrinkage. Given that replacing the damaged pavement is expensive and time-consuming, several transportation agencies prefer to restore/repair the degraded portion of pavement using high early-strength concrete. Using high early-strength concrete ensures the pavement achieves its design strength at an early age, which ultimately allows opening the roadway to oncoming traffic in a shorter duration. The use of calcium sulfoaluminate cement instead of ordinary portland cement in high early-strength concrete helps to reduce the overall carbon footprint due to lower energy consumed during calcium sulfoaluminate's clinkering process, along with relatively faster strength development. Previously, researchers have demonstrated the effectiveness of internal curing to improve durability of high early-strength concrete by better freeze–thaw and shrinkage resistance. Overall, the given study focuses on understanding the benefits of internal curing in high early-strength concrete mixtures prepared with a low and high calcium sulfoaluminate cement content. Irrespective of the cement content, high early-strength concrete mixtures with internal curing had superior freeze–thaw and shrinkage resistance, proving that internal curing effectively improves the durability properties without compromising on its design strength. [ABSTRACT FROM AUTHOR]

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other mixes with 0.05%, 0.1%, 0.15%, and 0.2% basalt fibers. Slump flow and V-funnel flow tests were employed to assess the influence of basalt fibers on the rheological properties of fresh self-compacting concrete (SCC). Additionally, mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were analyzed. Furthermore, the mechanical properties were assessed following exposure to elevated temperatures (400 °C and 600 °C) as well as 100 and 200 freeze-thaw (F/T) cycles. Additionally, water absorption and ultrasonic pulse velocity tests were conducted on the SCC mixes after 28 days of curing. The results revealed that the addition of fiber has a significant effect on the rheological properties of fresh SCC mixtures. As the volume of fibers increases, the reduction in rheological properties increases. Basalt fiber had no effect on the compressive strength, while the splitting and flexural strength were significantly enhanced by 33% using basalt fiber. As temperatures and freezing-thawing cycles escalated, the mechanical properties of SCC exhibited a decline. Experimental findings indicated that elevating the temperature to 600 °C resulted in a decrease of over 20% in both the tensile and compressive strengths of SCC. Moreover, the results demonstrated that the incorporation of basalt fibers substantially enhanced the mechanical properties of SCC when subjected to high temperatures and freezing-thawing cycles. In addition, water absorption increased slightly by the incorporation of basalt fiber. [ABSTRACT FROM AUTHOR]

The soil freezing characteristic curve (SFCC) plays a crucial role in investigating the soil freezing‐thawing process. Due to the challenges associated with measuring the SFCC, there is a shortage of high‐quality or rigorous test results with sufficient metadata to be effectively used for applications. Current researchers typically conduct freezing tests to measure the SFCC and assume a singular SFCC when studying the freezing‐thawing process of soils, although limited studies indicated that there is a hysteresis during the freezing and thawing process. In this paper, a series of freezing‐thawing tests were performed to assess the SFCC, utilizing a precise nuclear magnetic resonance apparatus. The test results reveal a hysteresis between the SFCC obtained from the freezing process and that from the thawing process. Through analyzing the test results, the hysteresis mechanism of the SFCC is attributed to supercooling. Supercooling inhibits initial pore ice formation during freezing, causing a drastic liquid water‐ice phase change once supercooling ends. Despite being considered closely related, the hysteresis of the SFCC differs from the soil water characteristic curve (SWCC), and the models used to simulate the hysteresis of SWCC cannot directly be used. To address the impact of supercooling on soil freezing‐thawing hysteresis, a novel theoretical model is proposed. Comparisons between the measured and predicted results affirm the validity of the proposed model. Plain Language Summary: Understanding the freezing and thawing behavior of soils is critical for construction in cold regions. The soil freezing characteristic curve (SFCC), which describes the relationship between temperature and unfrozen water content, is essential for characterizing soil behavior during freeze‐thaw cycles. However, measuring SFCCs for both freezing and thawing presents significant challenges, often resulting in simplifications and incomplete data in many studies. In this research, we conducted freezing‐thawing tests using precise technology called nuclear magnetic resonance to examine the SFCC. We found a hysteresis between the SFCC during freezing and thawing, primarily attributed to supercooling, where the soil remains liquid below the freezing temperature. Supercooling delays initial ice formation, causing a rapid transition from liquid water to ice once it ceases. Importantly, the SFCC hysteresis differs significantly from the drying‐wetting hysteresis in the soil water characteristic curve. To address this, we propose a novel model considering the impact of supercooling on soil freezing‐thawing hysteresis. The proposed model fits well with the measured data and outperforms existing models. This study introduces a new understanding and a reliable model for soil freezing‐thawing process, contributing to better comprehension of frozen soil phase changes. Key Points: Supercooling is the primary cause of freezing‐thawing hysteresisThe hysteresis of the soil freezing characteristic curve differs substantively from that of the soil water characteristic curveThe proposed model can address the impact of supercooling on soil freezing‐thawing hysteresis [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The swelling properties of polyacrylonitrile gel prepared by the repeating cycle of freezing and thawing were examined, as its transient response toward the equilibrium swollen states varies with the variation of mixing ratio (r) of the immersion solvent which consisted of N, N–dimethylacetamide and benzene. Two experimental protocols were used; successive solvent exchanges were conducted in Protocol 1, and no solvent exchange but the varying of the volume of immersion solvent was conducted in Protocol 2. Also, the aging time was set between the end of the freezing and thawing cycle and the start of the swelling experiment. As a result, the equilibrium swelling ratio decreased with the increase in the aging time. Significant discrepancies for the transient responses were found for the immersion solvents between r ≤ 0.74 and r ≥ 0.78 both in Protocol 1 and 2, in which the elution of polyacrylonitrile molecules was related to the responses. A characteristic overshoot curve was observed in the swelling with r ≥ 0.78 in Protocol 2, which was also attributed to the polyacrylonitrile elution. The polymer solvent interaction parameter was calculated on the basis of the osmotic pressure equilibrium, which was associated with the interpretation of the transient response data. [ABSTRACT FROM AUTHOR]

Concrete is one of the most commonly used construction materials; however, its durability plays a pivotal role in areas where the concrete is exposed to severe environmental conditions, which initiate cracks inside and disintegrate it. Randomly distributed short fibers arrest the initiation and propagation of micro-cracks in the concrete and maintain its integrity. Traditional polypropylene fibers are thin and encounter the problem of balling effects during concrete mixing, leading to uneven fiber distribution. Thus, a new polypropylene fiber is developed by gluing thin ones together, forming macro-polypropylene fibers. Thus, different amounts of fibers, 0–1.5% v/f with an increment of 0.5% v/f, are used in different grades of concrete to study their impact on durability properties, including resistance to freezing and thawing cycles, sulfate, and acid attacks. A total of 432 cube samples were tested at 28, 56, and 92 days. The results reveal that the maximum durability, in terms of compressive strength loss, is noted with a fiber content of 1% with improved resistance of 72%, 54%, and 24% against freeze–thaw cycles, sulfate attack, and hydrochloric acid attack, respectively, at 92 days. Thus, the resulting fiber-reinforced concrete may be effective in areas where these extreme exposure conditions are expected. [ABSTRACT FROM AUTHOR]

The causes of cracks in concrete are varied, and regardless of their origin, these cracks invariably have a detrimental impact on the durability of concrete structures and escalate their maintenance costs. This paper presents a comprehensive review of current knowledge regarding the methods of self-healing in concrete, ranging from autogenic and improved autogenic self-healing to the autonomous self-healing of concrete. Particular emphasis is placed on the methods of autonomous concrete self-healing: the bacterial healing method, the crystalline hydrophilic additives healing method, and the capsule-based self-healing method. The hypothesis is that applying these self-healing methods could potentially prevent damages or cracks in concrete caused by freeze–thaw cycles, thereby extending the lifespan of concrete structures. The mechanism of action and current achievements in the field are provided for each method. [ABSTRACT FROM AUTHOR]

Utilizing waste materials to produce sustainable concrete has substantial environmental implications. Furthermore, understanding the exceptional durability performance of ultra-high-performance concrete can minimize environmental impacts and retrofitting costs associated with structures. This study presents a systematic experimental investigation of eco-friendly ultra-high-performance self-compacting basalt fiber (BF)-reinforced concrete by incorporating waste nanomaterials, namely nano-wheat straw ash (NWSA), nano-sesame stalk ash (NSSA), and nano-cotton stalk ash (NCSA), as partial substitutes for Portland cement. The research evaluates the effects of varying dosages of nanomaterials (ranging from 5 to 15% as cement replacements) in the presence of BFs. Rheological properties were analyzed, including flow diameter, L-box, and V-funnel tests. Additionally, the study investigated compressive, splitting tensile, and flexural strengths, load-displacement behavior, ultrasonic pulse velocity, and durability performance of the ultra-high-performance self-compacting basalt fiber (BF)-reinforced concrete (UHPSCFRC) samples subjected to sulfate attack, freeze-thaw cycles, autogenous shrinkage, and exposure to temperatures of 150, 300, 450, and 600°C. Microstructural characteristics of the mixtures were examined using X-ray diffraction (XRD) analysis. The findings reveal that self-compacting properties can be achieved in the UHPSCFRC by incorporating NWSA, NSSA, and NCSA. The presence of 10% NWSA significantly improved the mechanical properties of the UHPSCFRC, exhibiting more than 27.55% increase in compressive strength, 17.36% increase in splitting tensile strength, and 21.5% increase in flexural strength compared to the control sample. The UHPSCFRC sample with 10% NWSA demonstrated superior performance across all extreme durability tests, surpassing both the control and other modified samples. XRD analysis revealed the development of microcracking at temperatures of 450 and 600°C due to the evaporation of absorbed and capillary water and the decomposition of ettringites.

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other mixes with 0.05%, 0.1%, 0.15%, and 0.2% basalt fibers. Slump flow and V-funnel flow tests were employed to assess the influence of basalt fibers on the rheological properties of fresh self-compacting concrete (SCC). Additionally, mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were analyzed. Furthermore, the mechanical properties were assessed following exposure to elevated temperatures (400 °C and 600 °C) as well as 100 and 200 freeze-thaw (F/T) cycles. Additionally, water absorption and ultrasonic pulse velocity tests were conducted on the SCC mixes after 28 days of curing. The results revealed that the addition of fiber has a significant effect on the rheological properties of fresh SCC mixtures. As the volume of fibers increases, the reduction in rheological properties increases. Basalt fiber had no effect on the compressive strength, while the splitting and flexural strength were significantly enhanced by 33% using basalt fiber. As temperatures and freezing-thawing cycles escalated, the mechanical properties of SCC exhibited a decline. Experimental findings indicated that elevating the temperature to 600 °C resulted in a decrease of over 20% in both the tensile and compressive strengths of SCC. Moreover, the results demonstrated that the incorporation of basalt fibers substantially enhanced the mechanical properties of SCC when subjected to high temperatures and freezing-thawing cycles. In addition, water absorption increased slightly by the incorporation of basalt fiber.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to reveal the weathering rate of arsenic sandstone and the main influence factors of the area with abundant and coarse sediment in the middle reaches of the Yellow River, the paper selected 3 original rock samples (test blocks) for each red and grayishwhite arsenic sandstone from Erlaohugou small watershed in Jungar Banner in Inner Mongolia Autonomous Region. It conducted continuous observation of the morphological changes and weathering erosion amount of each sample for nearly 3 years by using the 3 treatment methods of completely exposed, rainproof and windproof. It calculated the weathering rate based on the proportion of weathering denudation amount to the initial mass of the sample and analyzed the main influence factors of the arsenic sandstone weathering rate and its contribution rate. The results show that the bare in natural state, the grayishwhite arsenic sandstone weathering rate is greater than the red arsenic sandstone weathering rate, average annual weathering rate calculated according to the specimen quality are 32.61% and 21.88% respectively. The contribution rates of precipitation, wind power and freeze-thaw to the weathering of grayishwhite Pisha sandstone are 80.96%, 10.24% and 8.80% respectively, while the contributions to the weathering of red Pisha sandstone are 88.53%, 4.89% and 6.58% respectively. The influence of precipitation to the weathering rate of Pisha sandstone is significantly greater than that of wind power and freeze-thaw. The alternately or superimposed weathering forces of precipitation, wind and freeze-thaw accelerate the weathering of feldspathic sandstone. [ABSTRACT FROM AUTHOR]

Inland saline-alkaline wetlands distributed in the mid-high latitude have repeatedly experienced freezing and thawing. However, the response of greenhouse gas (GHG) emission and microbially-mediated carbon and nitrogen cycle to freezing and thawing remains unclear. We monitored the GHG flux in an inland saline-alkaline wetland and found that, compared with the growth period, the average CO2 flux decreased from 171.99 to 76.61–80.71 mg/(m2‧h), the average CH4 flux decreased from 10.72 to 1.96–3.94 mg/(m2‧h), and the average N2O flux decreased from 56.17 to − 27.14 to − 20.70 μg/(m2‧h). Freezing and thawing significantly decreased the relative abundance of functional genes involved in carbon and nitrogen cycles. The aceticlastic methanogenic pathway was the main methanogenic pathway, whereas the Candidatus Methylomirabilis oxyfera was the most abundant methane oxidizer in the wetland. Ammonia-oxidizing archaea and denitrifier belonging to proteobacteria was the major microbial N2O source, while bacteria within clade II nosZ was the major microbial N2O sink. Freezing and thawing reduced the relative abundance of these genes, leading to a decrease in GHG flux. [ABSTRACT FROM AUTHOR]

Freezing has been widely used to preserve meat and aquatic products. However, environmental fluctuations in freezing/thawing would bring inevitable damage to the structure and characteristics of myofibrillar proteins. The gelation of myofibrillar proteins during thermal processing significantly impacts the quality of gel-type muscle foods. Therefore, it is of critical importance to understand role of freezing-induced damage to myofibrillar proteins in heat-induced gelation. This review covers recent developments on quality changes of myofibrillar protein gels in relation to freezing/thawing and presents the mechanisms and the control technologies available for improving gelling properties of frozen-thawed myofibrillar proteins. The mechanisms are based on the denaturation and oxidation of myofibrillar proteins occurring in freezing/thawing and the relationship with molecular aggregation during gelation. The emerging technologies discussed herein focus on freezing/thawing technologies and applications of cryoprotectants. The degree of myofibrillar protein cross-linking in relation to denaturation and oxidation plays a crucial role in further molecular aggregation during gelation. We here propose that freezing-induced over-aggregation of myofibrillar proteins in relation to denaturation and oxidation would spatially hinder salt dissolution and further intermolecular assembling of myosin during gelation, thus producing an amorphous gel network. Recent novel technologies preserve myofibrillar protein characteristics from freezing-induced denaturation and oxidation by accelerating freezing/thawing rate and inhibiting ice crystal growth and therefore modify gelling properties of frozen-thawed myofibrillar proteins. This review could be helpful for the development of gel-type muscle foods processed from frozen-thawed meat and aquatic products as raw materials. • Degree of myosin aggregation related to denaturation/oxidation affects gelation. • Frozen-thawed myofibrillar proteins form a cracked gel during heating. • Protein denaturation/oxidation in freeze/thaw induces molecular over-aggregation. • A model is proposed linking denaturation/oxidation in freeze/thaw for the impaired gels. • Novel anti-freeze techniques improve freeze/thaw myofibrillar protein gelation. [ABSTRACT FROM AUTHOR]

The adsorption of petroleum hydrocarbons by soils in the unsaturated zone determines the amount that goes into the groundwater. However, the intricate behavior of petroleum hydrocarbon adsorption in soil media under the influence of freeze–thaw conditions in globally prevalent seasonally frozen regions remains unclear. Alkanes as a non-polar compound are an important part of petroleum hydrocarbons. We conducted field-scale seasonal freeze-thaw experiments using n-dodecane to quantify the dynamic patterns and influencing factors of the physicochemical properties of soil media and their adsorption capacity for petroleum hydrocarbons during different freeze–thaw cycles. Our findings demonstrated that, as the number of natural freeze–thaw cycles increased, the proportion of soil micro-agglomerates rose rapidly, thereby expanding the available adsorption sites and enhancing the adsorption capacity for non-polar organic pollutants. The rise in sorption capacity for the outdoor freeze–thaw experimental group surpassed that of the indoor room-temperature control group by an impressive 75.57%, showing the enhancement of the adsorption capacity for non-polar organic pollutants. Conversely, the decline in soil organic matter content during the later stages of the freeze–thaw process hampered its adsorption performance for non-polar organic pollutants. The decrease in sorption capacity for the outdoor freeze–thaw experimental group surpassed that of the indoor room temperature control group by 77.97%. By shedding light on the adsorption mechanisms of non-polar organic pollutants in soils subjected to freeze–thaw conditions, our research facilitated a comprehensive understanding and predictive modeling of this process. Furthermore, our study provided a scientific foundation for exploring the convergence and migration transformation patterns of other organic compounds in petroleum-contaminated areas within seasonally frozen regions. [ABSTRACT FROM AUTHOR]

The destructive effects of global warming have attracted attention to the optimal using of resources and recycling. Therefore, slag has been considered as a solution in various industrial sectors including the road construction. Also, among the new materials, cement carbon nanostructures which can improve the concrete mechanical properties and resistance are used. These nanostructures are produced through Chemical Vapor Deposition method during the cement production process on the type II cement. In this study, it is aimed to improve the mechanical properties and resistance of concrete pavements with slag and cement carbon nanostructures. The results showed that using 66% slag and 5% cement carbon nanostructures (SC66N5) have been shown the best performance in concrete pavements. Increasing the amount of slag and carbon nanostructures enhance the compressive strength, flexural strength, tensile strength, chlorine passing current and durability against freezing and thawing cycles, and decrease permeability and water absorption percentage. The results showed that in SC66N5 28-day sample, the compressive strength (52%), flexural strength (32%), tensile strength (53%), chlorine passing current (88%) and passing ultrasonic pulse velocity after freezing and thawing (7%) are increased with respect to the cement concrete sample. Furthermore, the permeability (46%), water absorption percentage (45%), weight loss after freezing and thawing cycles (78%) are reduced in comparison to the cement concrete sample. The results revealed that using slag and cement carbon nanostructures improve the durability of concrete pavements.

The unfrozen water content of rock during freezing and thawing has an important influence on its physical and mechanical properties. This study presented a model for calculating the unfrozen water content of rock during freezing and thawing process, considering the influence of unfrozen water film and rock pore structure, which can reflect the hysteresis and super-cooling effects. The pore size distribution curves of red sandstone and its unfrozen water content under different temperatures during the freezing and thawing process were measured using nuclear magnetic resonance (NMR) to validate the proposed model. Comparison between the experimental and calculated results indicated that the theoretical model accurately reflected the water content change law of red sandstone during the freezing and thawing process. Furthermore, the influences of Hamaker constant and surface relaxation parameter on the model results were examined. The results showed that the appropriate magnitude order of Hamaker constant for the red sandstone was 10−19 J to 10−18 J; and when the relaxation parameter of the rock surface was within 25–30 μm/ms, the calculated unfrozen water content using the proposed model was consistent with the experimental value.

Freezing is an effective technique to prolong the storage life of food. However, the freeze‐thaw process also brings challenges to the quality of food, such as mechanical damage and freeze cracks. Increasingly, physical fields have been preferred as a means of assisting the freezing and thawing (F/T) processes to improve the quality of frozen food because of their high efficiency and simplicity of application. This article systematically reviews the application of high‐efficiency physical field techniques in the F/T of food. These include ultrasound, microwave, radio frequency, electric fields, magnetic fields, and high pressure. The mechanisms, application effects, advantages and disadvantages of these physical fields are discussed. To better understand the role of various physical fields, the damage to food caused by the F/T process and traditional freezing is discussed. The evidence shows that the physical fields of ultrasound, electric field and high pressure have positive effects on the F/T of food. Proper application can control the size and distribution of ice crystals effectively, shorten the freezing time, and maintain the quality of food. Microwave and radio frequency exhibit positive effects on the thawing of food. Dipole rotation and ion oscillation caused by electromagnetic waves can generate heat inside the product and accelerate thawing. The effects of magnetic field on F/T are controversial. Although some physical field techniques are effective in assisting F/T of food, negative phenomena such as uneven temperature distribution and local overheating often occur at the same time. The generation of hotspots during thawing can damage the product and limit application of these techniques in industry. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Headwater streams are highly heterogenous and characterized by a sequence of riffles and pools, which are identified as distinct habitats. That higher species richness and density in riffles than in pools is considered a general pattern for macroinvertebrates. As temperate winters can last long up to half a year, however, macroinvertebrate communities of riffles and pools may assemble differently under ices or snows. Particularly, defoliation concentrating in autumn can largely change habitats in both riffles and pools by litter patching. According to the absence or presence of litter patches, there exist four types of subhabitats, i.e., riffle stones, riffle litters, and pool sediments, pool litters, which are selectively colonized by macroinvertebrates. To study the spatial pattern and temporal dynamics of colonization, macroinvertebrates were surveyed in a warmer temperate forest headwater stream in Northeast China during four periods: autumn, pre-freezing, freezing, and thawing periods. Our study focused on functional trait composition, functional diversity and functional redundancy of macroinvertebrate communities. The colonization of macroinvertebrates was found to be significantly different in these subhabitats. Riffle stones supported higher taxonomic and functional diversities than pool sediments; litter patches supported higher total macroinvertebrate abundance and higher functional redundancy than riffle stones or pool sediments. The functional trait composition changed significantly with seasonal freeze-thaw in both riffle stones and pool sediments, but not in litter patches. Macroinvertebrate community in litter patches showed seasonal stability in taxonomic and functional diversities and functional redundancy. Thus, this study strongly highlights that litter patches play an important role structuring macroinvertebrate community over winter, supporting high abundance and maintaining functional stability. [ABSTRACT FROM AUTHOR]

Concrete is one of the most commonly used construction materials; however, its durability plays a pivotal role in areas where the concrete is exposed to severe environmental conditions, which initiate cracks inside and disintegrate it. Randomly distributed short fibers arrest the initiation and propagation of micro-cracks in the concrete and maintain its integrity. Traditional polypropylene fibers are thin and encounter the problem of balling effects during concrete mixing, leading to uneven fiber distribution. Thus, a new polypropylene fiber is developed by gluing thin ones together, forming macro-polypropylene fibers. Thus, different amounts of fibers, 0–1.5% v/f with an increment of 0.5% v/f, are used in different grades of concrete to study their impact on durability properties, including resistance to freezing and thawing cycles, sulfate, and acid attacks. A total of 432 cube samples were tested at 28, 56, and 92 days. The results reveal that the maximum durability, in terms of compressive strength loss, is noted with a fiber content of 1% with improved resistance of 72%, 54%, and 24% against freeze–thaw cycles, sulfate attack, and hydrochloric acid attack, respectively, at 92 days. Thus, the resulting fiber-reinforced concrete may be effective in areas where these extreme exposure conditions are expected.

The application of soil bracing systems through the artificial ground freezing (AGF) method is developing in the field of geotechnical engineering. Retaining structures cannot be stabilized if the strength of the material used at the construction stage is not sufficient. For this reason, this study aims to investigate the usability of an innovative composite material named pykrete, which contains sustainable sawdust obtained with natural pinewood after a recycling process. The mechanical properties are inferred from different types of pine sawdust (fine, medium and coarse) with various densities (dense, medium dense and loose) at two freezing temperatures (− 20 and − 10 °C) as an advanced temporary retaining structure against lateral earth pressure. Unconfined compression tests (UCC) are applied on 60 types of pykrete samples after a freezing application in a CDF/CIF freezing–thawing machine. In addition, the micro-textural structures of the samples were examined by a light microscope in terms of freezing and thawing performance. The strain ratio's mean values of the samples increased from 3.10 and 4.81 to 4.95% at − 20 °C, and from 5.45 and 6.04 to 6.65% at − 10 °C, according to the fine, medium and coarse sawdust types, respectively. The innovative pykrete material with a fine pinewood sawdust type and a density of 18% by weight can be used as a high-strength composite material with 4.83 MPa compressive strength within retaining structures in civil engineering applications, according to the experimental results. [ABSTRACT FROM AUTHOR]

To explore the influence of freezing and thawing on drainage behaviour for porous asphalt pavement (PA), molecular dynamics simulation was applied to study the interaction between asphalt and water. Based on the establishment and verification of micro models for asphalt (virgin and aged) and water (ice, ice–water mixture and water), the micro behaviour of interfacial transition zone was intuitively observed. Combined with the multi-gradient experiment results, the micro influence mechanism of freezing and thawing on drainage behaviour of porous asphalt pavement was revealed. The results show that the interaction energy of asphalt–water changes with the occurrence of freeze–thaw. The interaction energy (attraction) between aged asphalt and water is enhanced, which leads to water-induced distress more easily. In addition, with the occurrence of freeze–thaw, the relative concentration of hydrogen atoms at the interfacial transition zone gradually increases, while the fluctuation of carbon atoms increases. The results provide a micro-mechanism for the study of drainage behaviour of porous asphalt pavement under freezing and thawing, which has certain theoretical significance and practical value. [ABSTRACT FROM AUTHOR]

RCC remains a widely used construction material over the last decade. RCC is placed in a manner similar to paving; the material is delivered by dump trucks or conveyors, spread by small bulldozers or specially modified asphalt pavers, and then compacted by vibratory rollers. By definition, Roller Compacted Concrete (RCC) is the concrete compacted by a roller in a hardened state. RCC is a special type of concrete that has essentially the same ingredients as concrete. However, at different ratios, partial substitution of fly ash is increased for Portland cement. This type of concrete has facilitated constructing many new dam and pavement projects and reducing costs by shortening the time duration of implementation. Rolled concrete materials are generally applied instead of the soil-cement mixtures in projects. Soil-cement and rolled concrete are both completely compacted mixtures of cement, aggregate, and water, while their main differences are the type and size of aggregates. Using this kind of concrete has provided a chance for the construction of many dams and new pavements with economic advantages, leading to the quick construction management. Since these structures are exposed to climatic factors, their durability, especially against alternate thawing-freezing cycles, is of paramount importance. In the current research, silica nanoparticles were added to the RCC mix of three different diameters (10, 15, and 30 nm) and three different ratios (1, 3, and 5% by cement weight) in 50, 100, and 300 cycles to investigate their effects on compressive strength, dimensions, and weights of RCC samples. The experimental results illustrated that mixtures containing nano-silica had a better durability and strength than non-additive mixtures.

[Display omitted] Biological drug substance (DS) is typically stored frozen to increase stability. However, freezing and thawing (F/T) of DS can impact product quality and therefore F/T processes need to be controlled. Because active F/T systems for DS bottles are lacking, freezing is often performed uncontrolled in conventional freezers, and thawing at ambient temperature or using water baths. In this study, we evaluated a novel device for F/T of DS in bottles, which can be operated in conventional freezers, generating a directed air stream around bottles. We characterized the F/T geometry and process performance in comparison to passive F/T using temperature mapping and analysis of concentration gradients. The device was able to better control the F/T process by inducing directional bottom-up F/T. As a result, it reduced cryo-concentration during freezing as well as ice mound formation. However, freezing with the device was dependent on freezer performance, i.e. prolonged process times in a highly loaded freezer were accompanied by increased cryo-concentrations. Thawing was faster compared to without the device, but had no impact on concentration gradients and was slower compared to thawing in a water bath. High-performance freezers might be required to fully exploit the potential of directional freezing with this device and allow F/T process harmonization and scaling across sites. [ABSTRACT FROM AUTHOR]

A hybrid chitosan monolithic hydrogel (CS) was modified by incorporating with HKUST-1 and fabricated using an in-situ growth method. The resulting hydrogel CS/HKUST-1 was further modified to enhance the porous structure, in which the porous converted from close pores to interconnected porous structures. The chemical and physical characteristics of the modified hydrogel were examined using various characterization techniques like BET, SEM, EDX, FTIR, XRD, Zeta potential, and compression test to understand the effect of the modification. The outcomes displayed that this method provided homogeneous dispersing of HKUST-1 crystals within the chitosan hydrogel matrix, which can improve the material's specific surface area and adsorption capacity. The CS/HKUST-1 monolithic hybrid hydrogel's permeability is further enhanced by the freezing and thawing process and the produced hydrogel is called FCS/HKUST-1, which helps to open the hydrogel's pores and significantly increases its surface area. FCS/HKUST-1 hydrogels display higher mechanical properties without fracture after compression with elastic properties, whereas the CS/HKUST-1 hydrogel crashed at around 47 % compression strain. Consequently, the obtaining dual modified chitosan/ HKUST-1 hydrogel (FCS/HKUST-1) was evaluated as an adsorbent to eliminate Eosin Y (EY) dye from its aqueous solution and the adsorption mechanism was proposed as multilayer adsorption depending on the Freundlich isotherm model. The modified monolithic hydrogel displayed an excellent maximum adsorption capacity with EY dye about 625 mg·g−1. The FCS/HKUST-1 hydrogel showed extremely selective removal for anionic dye higher than cationic dye, which allows facile separation of the dyes with different charges in a mixture solution. The outcomes also demonstrate that the modified hydrogel would be an eco-friendly material, which shows excellent recyclability, indicating that this material considerable promising adsorbent in water treatment. [Display omitted] • Dual modification of cross-linked chitosan hydrogel to produce interconnected porous chitosan hydrogel. • Chitosan hydrogel incorporating with MOF material using an in-situ growth method. • The permeability of produced hydrogel is further enhanced by the freezing and thawing process. • The modified chitosan hydrogel provides a high surface area and good mechanical properties. • FCS/HKUST-1 hydrogel exhibited excellent adsorption capacity, good reusability and selective removal towards anionic dyes. [ABSTRACT FROM AUTHOR]

Despite its success in the mechanical characterization of biological tissues, magnetic resonance elastography (MRE) uses ill-posed wave inversions to estimate tissue stiffness. 1-Norm has been recently introduced as a mathematical measure for the scattering of mechanical waves due to inhomogeneities based on an analysis of the delineated contours of wave displacement. To investigate 1-Norm as an MRE-based quantitative biomarker of mechanical inhomogeneities arising from microscopic structural tissue alterations caused by the freeze-thaw cycle (FTC) or Alzheimer's disease (AD). In this proof-of-concept study, we prospectively investigated excised porcine kidney (n = 6), liver (n = 6), and muscle (n = 6) before vs. after the FTC at 500–2000 Hz and excised murine brain of healthy controls (n = 3) vs. 5xFAD species with AD (n = 3) at 1200–1800 Hz using 0.5 T tabletop MRE. 1-Norm analysis was compared with conventional wave inversion. While the FTC reduced both stiffness and inhomogeneity in kidney, liver, and muscle tissue, AD led to lower brain stiffness but more pronounced mechanical inhomogeneity. Our preliminary results show that 1-Norm is sensitive to tissue mechanical inhomogeneity due to FTC and AD without relying on ill-posed wave inversion techniques. 1-Norm has the potential to be used as an MRE-based diagnostic biomarker independent of stiffness to characterize abnormal conditions that involve changes in tissue mechanical inhomogeneity. [Display omitted] • The freeze-thaw cycle and Alzheimer's disease change tissue inhomogeneity. • The freeze-thaw cycle reduced kidney, liver and muscle stiffness and inhomogeneity. • Alzheimer's disease reduced brain stiffness but increased mechanical inhomogeneity. • 1-Norm can measure inhomogeneities due to the scattering of mechanical waves. [ABSTRACT FROM AUTHOR]

The causes of cracks in concrete are varied, and regardless of their origin, these cracks invariably have a detrimental impact on the durability of concrete structures and escalate their maintenance costs. This paper presents a comprehensive review of current knowledge regarding the methods of self-healing in concrete, ranging from autogenic and improved autogenic self-healing to the autonomous self-healing of concrete. Particular emphasis is placed on the methods of autonomous concrete self-healing: the bacterial healing method, the crystalline hydrophilic additives healing method, and the capsule-based self-healing method. The hypothesis is that applying these self-healing methods could potentially prevent damages or cracks in concrete caused by freeze–thaw cycles, thereby extending the lifespan of concrete structures. The mechanism of action and current achievements in the field are provided for each method.

In the 1960s, sperm cryopreservation was developed as a method to preserve fertility. Currently, techniques for the cryopreservation of human spermatozoa have been widely used in assisted reproduction. However, although sperm cryobiology has made notable achievements, the optimal method for the recovery of viable spermatozoa after cryopreservation remains elusive. Postthawing sperm quality can be affected by cryoprotectants, ice formation, storage conditions, and osmotic stress during the freezing process. This review discusses recent advances in different cryopreservation techniques, cryoprotectants, and freezing and thawing methods during cryopreservation and new indications for the use of cryopreserved spermatozoa.

Several studies indicate that the temperature distribution in concrete may affect the extent of frost scaling. This study presents a numerical model that describes the thermal response of freezing mortars in the presence of an external liquid reservoir, where the external liquid is either pure water or 3% sodium chloride solution. The phase transformation of supercooled external liquid is modelled in two stages: quick freezing, when the supercooled liquid starts to form crystals and slow freezing. The model is developed in two parts. In part I, the focus is the modelling of external liquid, and therefore a non-porous body with an external liquid reservoir is modelled and validated. In part II, the model developed in part I is developed further for a porous body containing different phases, i.e., unfrozen liquid and ice, in the pores. A comparison of simulated and experimentally measured temperature distributions shows a good agreement.

Thermal effects in concrete are associated with a heat release from the exothermic cement hydration reactions during concrete curing under normal conditions or under severe cold conditions, or when it is subjected to cycles of freezing and thawing. These thermal effects may cause cracking, impact concrete porosity and affects its thermal, mass and hydraulic conductivities, and hence create major durability problems. This paper presets an experimental study of the thermal management ability of an aqueous waterproofing solution (the Multi-Crystallization Enhancer (MCE)) that is intermixed with water at the time of batching. The experiments were performed according to the applicable ASTM procedures for measuring the rate of heat release, temperature profiles, compressive and flexural strengths, temperature-time factor and thermal and electrical conductivities. Additionally, the impact of cycles of freezing and thawing on the percentages of mass change, length change and relative dynamic modulus were investigated. The findings indicate that the addition of the MCE at a dosage of 2% of cement weight has the potential to mitigate the thermal effects during cement hydration and during curing concrete under freezing conditions providing a solution for thermal problems of mass concrete. The findings demonstrate that the MCE can delay the exothermic heat release and can reduce its rate at the initial stage. It can also increase the resistance of concrete against cycles of freezing and thawing by achieving 92% reduction in the percentage mass change, 15% reduction in the percentage length change and 17% enhancement in the relative dynamic modulus, after 300 cycles. These thermal impacts of the MCE are also associated with 16% reduction in the thermal conductivity and 90.7% reduction in the total charge passage through concrete.

The main objective of this work was to study the adsorption characteristics of Cd by adding corn stover biochar and saline-alkali soil after freezing and thawing, and the saline-alkali land in Lesheng Town, Da'an City, Jilin Province was selected as the model/representative area. The artificially simulated freezing and thawing environments was conducted in the experiments. After the soil is incubated, adsorption experiments were carried out. FTIR spectra analysis indicated that biochar amendment increased the aromatic contents of the soil. Moreover, the results showed that regardless of biochar amendment, the freezing-thawing could increase hydroxyl, carboxyl, and aromatic hydrocarbon contents. In contrast, freezing-thawing reduced the soil pH, cation exchange capacity, conductivity, and exchangeable sodium (regardless of biochar amendment). In all cases, Cd adsorption isotherms and kinetic curves were best fit by the Langmuir equation and quasi-second-order kinetic equation, respectively, and the thermodynamic parameters of Cd adsorption (ΔG < 0, ΔH > 0, and ΔS > 0) suggested that the process was consistently spontaneous, endothermic, and disordered. A significant increase in soil Cd adsorption capacity was observed in the with increasing pH. [ABSTRACT FROM AUTHOR]

Penetrating sealers are one means to reduce moisture and chemical transport into concrete. However, a large variety of products are available, possessing different functional modes of action. This study investigated representative families of penetrating sealers applied to vertical, sawn faces of properly air-entrained concrete (approximately 6%) to represent field application of sealers to concrete joints. Concrete was characterized for water transport, chloride diffusion, gas permeability, frost resistance in the presence of deicing salts, and potential for oxychloride formation. The results showed that some sealers effectively reduced water absorption, prolonged time to saturation, and reduced chloride penetration. However, delayed time to critical saturation did not always result in improved frost resistance. All sealers significantly reduced the potential of oxychloride formation. The tests used for this study are broadly applicable and provide enhanced characterization for selection and application of new types of sealers and modes of action. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The repeating cycle of freezing and thawing brings about a physical gelation for the solutions of polyacrylonitrile (PAN) in N, N-dimethylacetamide (DMA) for appropriate concentrations. It was revealed from wide-angle-X-ray diffraction that the PAN molecules were cross-linked by the crystallization to form a network through the freezing and thawing steps. The profiles of small-angle-X-ray scattering for the gels showed the excess scattering from the network structure formed through gelation, which could not be observed for the pure PAN solution. A reversible swelling and shrinking were observable for the PAN gel as a function of the relative content of DMA and benzene by varying the mixing ratio. The degree of swelling measured by weight, for the swollen and shrunk gels, was in a range from 0.7 to 8. A scaling relation appeared for the gel swelling between the PAN volume fraction (ϕ) and the shear moduli (G) which was measured by tensile and indentation tests, as G = Gs ×(ϕ)s; Gs= 1200 kPa and s = 2.26 ± 0.23. A discussion is given on the value of the scaling exponent, s, on the basis of the conformation of flexible chain molecules in solution and the analogy in the microscopic and macroscopic properties between semidilute polymer solutions and gels. [ABSTRACT FROM AUTHOR]

We investigated the proteome variations in Trachurus murphyi with different cycles of freezing and thawing (FT) under frozen storage. A total of 2,482 proteins were assessed quantitatively, of which 269 proteins were recognized as differential abundance proteins during the second FT cycle until the eighth FT cycle. Bioinformatics analysis on gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway analyses of Differential Analysis of Proteins (DAPs) indicated multiple DAPs engaged with the protein structure, metabolic enzymes, and protein turnover. In addition, some of the observed proteins were probably the underlying markers of protein oxidation (PO). The analysis of PO sites revealed the sites of PO, such as amino adipic semialdehydes, γ‐glutamic semialdehydes, and Schiff bases. Bioinformatics analyses demonstrated the involvement of differentially expressed proteins in the Hippo signaling pathway (Ko04390), indicating strong protein degradation with greater numbers of FT cycles under frozen storage. It provides an insight into quality stability from a proteomics quality perspective at the molecular level. The results obtained have deepened our current understandings of the mechanisms that reveal variations in proteomes and quality, as well as help promote quality control of T. murphyi across the cold transportation chain. Practical Application: Temperature fluctuation is one of the core issues during frozen food storage and distribution faced by the frozen food industry. Fluctuation may result in microstructural changes, ice recrystallization, and protein change in frozen food products. Tandem mass tag–based methods were adopted to study proteome variations in Trachurus murphyi muscles under different cycles of freezing and thawing under frozen storage conditions in this paper. The results obtained have deepened our current understandings of the mechanisms that reveal variations in proteomes and quality, as well as help promote quality control of T. murphyi across the cold transportation chain. [ABSTRACT FROM AUTHOR]

In this study, we have developed a simple technique to prepare cationic chitosan hydrogel with interconnected porous structure using freeze–thaw process and the obtained hydrogel was named FCS hydrogel. Scanning electron microscopy (SEM) imaging discovered that the synthesized hydrogel demonstrated interconnected porous structure in the scope of 5–20 μm. We also showed that the FCS hydrogel exhibits pH responsiveness behavior, and demonstrated reversible swelling and de-swelling behaviors maintaining their mechanical stability. We demonstrate that the FCS hydrogel swelling capacity decreased at alkaline pH and rose with a decline in pH value. Besides, the FCS hydrogel presented specific surface area of 78.25 ± 8.75 m2 g−1, due to the cryogenic treatment of glutaraldehyde cross-linked chitosan hydrogel could increase the surface area and permeability of composite hydrogel and then strongly increasing the adsorption capacity. Subsequently, the FCS monolithic hydrogel tested dyes removal, which provides a high removal efficiency towards anionic dyes including congo red (CR) and sodium fluorescein (SFL) dyes. Significantly, we show that the FCS hydrogel could be regenerated and reused as an adsorbent for wastewater treatment without significant loss of pollutants removal efficiency over a number of adsorption and washing cycles. This study offers a promising environmental friendly and sustainable interconnected porous hydrogel for anionic dye removal from wastewater. [ABSTRACT FROM AUTHOR]

The effects of osmotic dehydration pretreatments on freezing-thawing qualities of blueberries were studied. Ordinary frozen at -18 °C and super low temperature quick freezing at -80 °C were set as the control groups, and static osmotic dehydration freezing and ultrasonic assisted osmotic dehydration freezing were set as experimental groups, then the freezing curves, drip loss, hardness, color, soluble solids contents, anthocyanins contents, peroxidase and polyphenol oxidase activities of blueberries were determined. The results showed that the freezing time of blueberries after static osmotic dehydration was shortened by 9.41% compared with ordinary slow freezing, and the soluble solid contents and hardness were significantly higher than those of other treatment groups (P<0.05), which could keep good color and appearance qualities, and effectively inhibit enzymes activities. Ultrasonic assisted osmotic dehydration pretreatment although improved the blackberries freezing rates compared with static osmotic dehydration freezing pretreatment, and presented similar effects on anthocyanins retention of blackberries with super low temperature quick freezing, other indicators were significantly lower than that of normal osmosis pretreatment group (P<0.05). The results showed that the two kinds of osmotic dehydration pretreatments presented superior effects than freezing storage at -18 °C, the static osmotic dehydration for freezing blueberries were more suitable for preserving the processing and edible qualities of materials, and ultrasonic osmotic dehydration pretreatment could effectively retain the anthocyanins of freeze-thawed blueberries. [ABSTRACT FROM AUTHOR]

The adsorption of petroleum hydrocarbons by soils in the unsaturated zone determines the amount that goes into the groundwater. However, the intricate behavior of petroleum hydrocarbon adsorption in soil media under the influence of freeze–thaw conditions in globally prevalent seasonally frozen regions remains unclear. Alkanes as a non-polar compound are an important part of petroleum hydrocarbons. We conducted field-scale seasonal freeze-thaw experiments using n-dodecane to quantify the dynamic patterns and influencing factors of the physicochemical properties of soil media and their adsorption capacity for petroleum hydrocarbons during different freeze–thaw cycles. Our findings demonstrated that, as the number of natural freeze–thaw cycles increased, the proportion of soil micro-agglomerates rose rapidly, thereby expanding the available adsorption sites and enhancing the adsorption capacity for non-polar organic pollutants. The rise in sorption capacity for the outdoor freeze–thaw experimental group surpassed that of the indoor room-temperature control group by an impressive 75.57%, showing the enhancement of the adsorption capacity for non-polar organic pollutants. Conversely, the decline in soil organic matter content during the later stages of the freeze–thaw process hampered its adsorption performance for non-polar organic pollutants. The decrease in sorption capacity for the outdoor freeze–thaw experimental group surpassed that of the indoor room temperature control group by 77.97%. By shedding light on the adsorption mechanisms of non-polar organic pollutants in soils subjected to freeze–thaw conditions, our research facilitated a comprehensive understanding and predictive modeling of this process. Furthermore, our study provided a scientific foundation for exploring the convergence and migration transformation patterns of other organic compounds in petroleum-contaminated areas within seasonally frozen regions.

[Display omitted] Large-scale freezing and thawing experiments of monoclonal antibody (mAb) solutions are time and material consuming. Computational Fluid Dynamic (CFD) modeling of temperature, solute composition as well as the stress time, defined as the time between start of freezing and reaching T g ' at any point in the container, could be a promising approach to ease and speed up process development. Temperature profiles at six positions were recorded during freezing and thawing of a 2 L rectangular bottle and compared to CFD simulations via OpenFOAM. Furthermore, cryoconcentration upon freezing and concentration gradients upon thawing of a mAb solution were predicted and the stress time calculated. Temperature profiles during freezing were accurately matched by the CFD simulation. Thawing time was only 45 min to 60 min longer in the model. The macroscopic cryoconcentration of the mAb was also matched by the simulation; only a highly concentrated region in the top and a diluted core in the geometrical centre of the 2 L bottle were not well reflected in the simulation. The concentration gradient after thawing obtained by simulation as well agreed with the experimental result. In addition, CFD simulations allowed to extract the global temperature distribution, the formation of ice, and thus the distribution of stress in the freezing liquid. CFD simulations via OpenFOAM are a promising tool to describe large-scale freezing and thawing of mAb solutions and can help to generate a deeper understanding and to improve testing of the robustness of the processes. [ABSTRACT FROM AUTHOR]

In Japan, recycled concrete aggregate (RCA) and recycled-aggregate concrete (RAC) are standardized in the Japanese Industrial Standards (JIS) A 5021–5023. The differences between the specifications in JIS and those in foreign countries are explained. In Japan, the durability of RAC under severe conditions, particularly freezing and thawing with/without deicing salt is recently being studied to facilitate its use. In this paper, the test method for freezing and thawing durability of recycled concrete aggregate and the specification of precast concrete made with recycled aggregate, which can be used in freezing and thawing circumstance with deicing salt are described. [ABSTRACT FROM AUTHOR]

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This study highlights the influence of freezing-thawing processes on soil erosion in an alpine mine restoration area. Accordingly, a series of simulation experiments were conducted to investigate runoff, sediment, and nutrient losses, and potential influencing factors under freeze-thaw (FT) conditions. Three FT treatments (i.e., 0, 3, and 5 FT cycles), and two soil moisture contents (SMCs; i.e., 10% and 20% SMC on a gravimetric basis) were assessed. The runoff, sediment yield, ammonia nitrogen (AN), nitrate nitrogen (NN), total phosphorus (TP), and dissolved phosphorus (DP) losses from runoff were characterized under different rainfall durations. The fitting results indicated that the runoff rate and sediment rate, AN, NN, TP, and DP concentrations in runoff could be described by exponential functions. FT action increased the total runoff volume and sediment yield by 14.6%–26.0% and 8.8%–35.2%, respectively. The runoff rate and sediment rate increased rapidly with the increment of FT cycles before stabilizing. At 20% SMC, the total runoff volume and sediment yield were significantly higher than those at 10% SMC. The loss curves of AN and NN concentrations varied due to differences in their chemical properties. FT action and high SMC promoted AN and NN losses, whereas the FT cycles had little effect. FT action increased TP and DP losses by 60.2%–220.1% and 48.4%–129.8%, respectively, compared to cases with no FT action; the highest TP and DP losses were recorded at 20% SMC. This study provides a deep understanding of freezing-thawing mechanisms in the soils of alpine mine restoration areas and the influencing factors of these mechanisms on soil erosion, thereby supporting the development of erosion prevention and control measures in alpine mine restoration areas. [ABSTRACT FROM AUTHOR]

In this experimental study, physical, strength and durability properties of roller compacted concrete (RCC) containing metakaolin with or without steel fiber are investigated. For this purpose, seven different mixes were designed and tested in the lab. To assess properties of compressive strength, splitting tensile strength, water permeability and freezing and thawing resistance in terms of weight and compressive strength losses. There is an increasing compressive strength of RCC containing MK with or without steel fiber with increasing ages. 15% MK 45 kg/m3 steel fiber was found the best dosage for RCC at the age of 90 days. Also, there is a splitting tensile strength enhancement being increased with increasing MK and steel fiber in the mix. There is a continuous permeability reduction with increasing combined MK and steel fiber addition reaching 77.9% as maximum value for the mix of 20% metakaolin and 60 kg of steel fiber. Also, there is a reduction of weight and compressive strength losses of RCC subjected to freezing and thawing cycles up to 300 due to MK and steel fiber addition. It is concluded that using a combination of MK and steel fiber has a promised future to be used in more durable RCC for road construction.

Samples were collected from a 20‐year‐old concrete suffering alkali‐silica reaction for examination using scanning electron microscopy. The concrete was also exposed to cycles of freezing and thawing in service. The old concrete was processed and used as recycled concrete aggregate in new concrete tested under lab conditions. The study shows that backscattered electron imaging, energy dispersive x‐ray analysis and x‐ray mapping are helpful tools to identify the presence of alkali‐silica reaction products. X‐ray mapping was found helpful to confirm the presence of reaction products in cases where the products or the cracking are not very clear in the collected image. The study shows the presence of ettringite in the air voids of the concrete. The formed ettringite is believed to have no direct effect on the expansion due to the alkali‐silica reaction as they form in an empty space without causing swelling pressure on the concrete. The effect of the ettringite formed in the air voids on the resistance to freezing/thawing was not confirmed in this study. Recycling the old affected concrete as aggregate in new concrete was found to cause significant expansion under lab conditions. [ABSTRACT FROM AUTHOR]

The American Concrete Institute (ACI) provides guides, specifi- cations, and code documents related to concrete durability. The authors reviewed two code documents from ACI Committees 318 and 350, two guidance documents from ACI Committees 201 and 222, and a specification document from ACI Committee 350, and observed that several discrepancies exist in terms of providing uniform durability requirements for freezing and thawing and chemical sulfate attack of concrete, and allowable chloride limits for new construction. By analyzing existing concrete durability data from published literature, laboratory testing, and field exposure sites, recommendations on unified durability requirements and exposure class descriptions are made for potential adoption by ACI Committees 201, 222, 318, and 350. [ABSTRACT FROM AUTHOR]