Subzero Temperature Conditions Research Articles

Probing the interaction between biomolecules under sub-zero temperature conditions by electrophoresis in ice grain boundaries

BackgroundPsychrophiles can survive under cryogenic conditions because of various biomolecules. These molecules interact with cells, ice crystals, and lipid bilayers to enhance their functionality. Previous studies typically measured these interactions by thawing frozen samples and conducting biological assays at room temperature; however, studying these interactions under cryogenic conditions is crucial. This is because these biomolecules can function at lower temperatures. Therefore, a platform for measuring chemical interactions under sub-zero temperature conditions must be established. ResultsThe chemical interactions between biomolecules under sub-zero temperature conditions were evaluated within ice grain boundaries with a channel-like structure, which circumvents the need for thawing. An aqueous solution of sucrose was frozen within a microfluidic channel, facilitating the formation of freeze-concentrated solutions (FCSs) that functioned as size-tunable electrophoretic fields. Avidin proteins or single-stranded DNA (ssDNA) were introduced into the FCS in advance. Probe micro/nanospheres whose surfaces were modified with molecules complementary to the target analytes were introduced into the FCS. If the targets have functionalities under sub-zero temperature conditions, they interact with complementary molecules. The chemical interactions between the target molecules and nanospheres led to the aggregation of the particles. The size tunability of the diameter of the FCS channels enabled the recognition of aggregation levels, which is indicative of interaction reactivity. The avidin–biotin interaction and ssDNA hybridization served as models for chemical interactions, demonstrating interactivity under sub-zero temperature conditions. The results presented herein suggest the potential for in situ measurement of biochemical assays in the frozen state, elucidating the functionality of bio-related macromolecules at or slightly below 0 °C. SignificanceThis is the first methodology to evaluate chemical interactions under sub-zero temperature conditions without employing the freeze-and-thaw process. This method has the advantage of revealing the chemical interactions only at low temperatures. Therefore, it can be used to screen and evaluate the functionality of cryo-related biomolecules, including cold-shock and antifreeze proteins.

Numerical studies of pull-through failures in cold-formed steel battens at sub-zero temperatures

Cold-formed steel (CFS) roof and wall cladding systems comprising thin, high strength steel battens and claddings are popularly used in the building industry worldwide. These cladding systems have been observed to encounter failures under combined snow and strong wind actions during blizzards. Significant damage is caused by the disengagement of the entire roof/wall cladding when localised pull-through failures occur in thin-walled steel battens at the batten to truss/rafter screw connections due to a splitting mechanism around the screw head. This study uses detailed finite element analyses of the pull-through failures of a range of batten configurations under combined wind and sub-zero temperature conditions. Suitable finite element models capable of simulating the pull-through failures of battens were developed and validated using experimental results, followed by detailed numerical parametric studies. The main outcomes of this study are accurate design equations and capacity reduction factors essential for predicting the pull-through capacities of CFS battens at sub-zero temperatures.

Low-temperature tensile properties of meta-stable β titanium Ti-5Al-5V-5Mo-3Cr alloy fabricated by pulsed laser powder bed fusion

Ti-5Al-5V-5Mo-3Cr (Ti-5553) alloy is increasingly used in structural airplane components, such as landing gear and fuselage, thanks to its high strength, good ductility, and low density. These components are consistently subjected to sub-zero temperatures during the flight. In this study, pulsed laser powder bed fusion (L-PBF) parameters were firstly optimized to fabricate highly dense (>99%) parts, and their effect on microstructure and microhardness was analyzed. Finally, tensile properties were evaluated under sub-zero temperature conditions and compared to the standard room ones to validate the feasibility of using Ti5553 under low-temperature environments.

Influence of anionic polyacrylamide on the freeze–thaw resistance of silty clay

Freeze–thaw (FT) alternation can severely affect the properties of fine–grained soils, often leading to the failure of foundation backfill projects, such as open canals and roads in cold regions. To address these problems, a water–soluble anionic polyacrylamide (APAM) was used to improve the properties of fine–grained soils, particularly silty clay. This study aims to analyze the effects of the APAM polymer on the physico–mechanical and microstructural properties of silty clay under both unfrozen and FT cycles. For this purpose, different addition dosages and FT cycle numbers were determined, and then a series of zeta potential, thermal conductivity, permeability, triaxial compression, and scanning electron microscopy (SEM) tests were conducted on the soil samples. Additionally, a unidirectional freezing test was constructed to investigate the coupled thermo–hydro–mechanical processes of APAM–treated soil samples under subzero temperature conditions. The results showed that the addition of the APAM polymer significantly enhanced the macroscopic engineering properties and microstructural characteristics of silty clay. This improvement was attributed to the charge neutralization, adsorption bridging effect, and hydrophobic interaction provided by the APAM polymer. However, all the soil samples showed a significant deterioration in their engineering properties during FT cycles, especially after the third FT cycle. It was notable that APAM–treated soil samples were superior to the untreated sample in terms of FT resistance. During the unidirectional freezing process, the pore water migrated from the unfrozen zone towards the freezing front due to the temperature gradient. The treated sample's pore water migration volume was considerably lower than that of the untreated sample, resulting in a 55.25% reduction in total frost heave when the APAM dosage was 0.30%. The findings of this paper may be utilized to mitigate the risk of frost damage to foundation backfill projects in cold regions, as well as to get a better understanding of the stabilization mechanism of the eco–friendly APAM polymer.

Pull-out failure capacities of cold-formed steel batten screw connections at sub-zero temperatures

Cold-formed steel (CFS) roof and wall cladding systems are used worldwide, and are constructed using high-strength, thin steel battens and claddings. In North American countries, which are frequently subjected to blizzards (winter storms), these cladding systems are particularly vulnerable to pull-out failures during combined windstorm and snowy conditions. Despite extensive research studies investigating the pull-out failure mechanism and the critical parameters of screw connections between cladding and battens at ambient temperature, the behaviour of these connections under blizzard conditions has not been experimentally investigated. To fill this knowledge gap, an experimental study was undertaken that included 144 laboratory tests of screw connections in battens of varying grades and thicknesses, and three distinct types of screws. The pull-out failure capacities of screw connections in battens were evaluated under wind suction loading at four different temperatures, including ambient and sub-zero temperatures. The results of the study provided insights into the pull-out failure mechanisms of screw connections in battens and enabled the development of suitable design rules for combined wind action and sub-zero temperature conditions. The findings of this study are expected to be of significant value to engineers and building designers who are involved in the construction of lightweight cold-formed steel buildings.

Localised pull-through failures of cold-formed steel batten screw connections under combined wind and sub-zero temperature conditions

The utilisation of thin cold-formed steel (CFS) elements is widespread in contemporary lightweight building construction. Roof and wall cladding systems are predominantly made of thin, high-strength steel claddings and battens. Blizzards are predominantly observed in North American countries, resulting in significant roof damage. A localized pull-through failure mechanism, occurring at the batten to rafter/truss screw connections, has been extensively investigated at ambient temperature to comprehend the critical factors that influence the pull-through failure capacities of CFS battens. Nonetheless, the pull-through capacity of CFS battens at sub-zero temperatures has not been examined, and as a result, the performance of the steel cladding systems during blizzards under the combined action of strong winds and sub-zero temperatures remains unknown. To investigate the pull-through failure behaviour and capacities of batten screw connections, an experimental study comprising 96 tests was conducted involving two steel grades and three thicknesses of steel battens and two screw fasteners at sub-zero temperatures. The study was conducted at both ambient and sub-zero temperatures to understand the pull-through failure behaviour and capacities of batten screw connections. Appropriate pull-through capacity equations and associated increment factors were developed to predict the pull-through capacities of batten screw connections that are subjected to the combined effects of high wind uplift loads and sub-zero temperatures.

Temperature Dependent Anti-Icing Performance of the Microstructure Surface: Wettability Change and Ice Nucleation

Icing has caused much inconvenience to daily production and life. A microstructure surface possessing a hydrophobic property is an effective countermeasure to impede or delay ice formation for anti-icing purposes. However, surface wettability is sensitive to environmental conditions such as temperature and humidity. In the worst-case scenario, a Wenzel state drop forms and causes degradation of surface anti-icing performance. In this study, a copper alloy was used as the testing sample, and the surface was fabricated using mechanical polishing, micro-milling machining and ultrafast laser etching to form the desired topology and microstructures. The hydrophobicity and icephobicity of four types of surfaces including smooth flat, rough flat, rough microstructure and smooth microstructure were tested by depositing droplets from room temperature to an ultralow subzero temperature condition (below −30 °C). At −10 °C, the icephobicity of the surface was consistent with the surface wettability at room temperature. However, the hydrophobicity of the surface slightly decreased, and a Wenzel state drop formed on the microstructure surface. At −30 °C, the apparent contact angle and the ice–substrate contact area were mainly affected by ice nucleation rather than surface wettability. The bottom layer of the droplet froze after immediate contact with the substrate due to a higher degree of supercooling. The formation of a Cassie state drop reduced the ice–substrate contact area and created more air cushions, which facilitated the extension of the icing process of the drop. The enhancement in the anti-icing performance of the microstructure surface was analyzed from a theoretical basis.

Self-Transformation Strategy Toward Vanadium Dioxide Cathode For Advanced Aqueous Zinc Batteries.

In the lithium-dominated era, rechargeable Zn batteries are emerging as a competitive alternative. However, the sluggish kinetics of ion diffusion and structural destruction of cathode materials have thus far hampered the realization of future large-scale energy storage. Herein, an in situ self-transformation approach is reported to electrochemically boost the activity of a high-temperature, argon-treated VO2 (AVO) microsphere foreffectiveZn ion storage. The presynthesized AVO with hierarchical structure and high crystallinity allows efficient electrochemical oxidation and water insertion to induce self-phase transformation into V2 O5 ·nH2 O within the first charging process, which leads to rich active sites and fast electrochemical kinetics. Using AVO cathode, an outstanding discharge capacity of 446 mAh g-1 at 0.1 A g-1 , high rate capability of 323 mAh g-1 at 10 A g-1 and excellent cycling stabilityfor 4000 cycles at 20 A g-1 with high capacity retention are demonstrated. Importantly, such zinc-ion batteries with phase self-transition can also perform well at high-loading, sub-zero temperature, or pouch cell conditions for practical application. This work not only paves a new route to design in situ self-transformation in energy storage devices, but also broadens the horizons of aqueous zinc-supplied cathodes.

Repair efficiency evaluation for cracked asphalt mixture pavement in different ambient temperatures using bitumen and polymer concrete as repair materials

This paper studies the effect of crack repairing process on the behavior of pavement at four ambient low and medium temperatures ranging from −20 °C to 30 °C. Asphalt mixture samples in the shape of semi-circular bend (SCB) were tested in intact, cracked, and repaired conditions under tensile or opening mode of loading. Two adhesive types: namely pure bitumen and polymer concrete were used to repair the crack. To investigate the efficiency of the repair process, some indexes such as failure load, initial and post-failure energies, and failure patterns were evaluated using the intact and cracked SCB specimens. Failure patterns showed that in the repaired specimens with pure bitumen, the failure initiates from the mid-section (i.e., from the repaired zone), while in polymer concrete repaired specimens, the failure initiates far from the repaired zone. Experimental results also revealed that the temperature has a noticeable effect on the repair efficiency using bitumen adhesive. Indeed, for sub-zero temperature conditions, such repairing material partially provided acceptable integrity for the pavement compared to the intact asphalt mixture. But, for service temperatures greater than + 10 °C, repair with bitumen was inefficient. However, repair with polymer concrete was efficient in all temperatures, and the strength of specimens repaired by the polymer concrete was even higher than the intact specimen. Similar trends and results were also obtained for the work of failure indexes.

Subzero-temperature homogeneous liquid-liquid extraction for the stereoselective determination of chiral triadimefon and its metabolite in water, fruit juice, vinegar, and fermented liquor by HPLC.

A novel method based on homogeneous liquid-liquid extraction with deep eutectic solvents (DES) under subzero-temperature conditions in combination with high performance liquid chromatography (HPLC) for the determination of chiral fungicide triadimefon (TF) and its metabolite triadimenol (TN) in water, fruit juice, vinegar, and fermented liquor was developed in this study. The method involved using deep eutectic solvents (DES) under subzero-temperature conditions in combination with high performance liquid chromatography (HPLC). This novel technique, known as subzero-temperature homogeneous liquid-liquid extraction (STHLLE), offers several advantages, including high efficiency, time-saving, low-cost, and eco-friendliness. The enantiomers of chiral TF and TN were simultaneously separated and quantified using HPLC coupled with a Daicel Chiralpak OD-RH column. Various experimental parameters such as DES composition and volume, freezing condition, salt concentration, and pH were optimized to enhance the recoveries of the target analytes. Under the optimized conditions, spiked recoveries of six enantiomers (i.e., S-TF, R-TF, SR-TN, RS-TN, SS-TN, and RR-TN) in the water, fruit juice, vinegar, and fermented liquor samples were 82.2-100.1% with relative standard deviations of 0.4-10.1%. The current method demonstrated a detection range of 0.03-0.06 mg L-1 in the target analytes. This established technique exhibits potential for efficient and precise extraction and quantification of the enantiomers of TF and TN in water phase samples.

Development of elastomeric intumescent fire-retardant coating for protection of structures at sub-zero temperature condition

The aim of this work is to develop an elastomeric intumescent fire retardant (IFR) coating which can protect the substrates against fire after application and remain stable without any phase separation during storage at sub-zero temperatures. Initially, an elastomeric polymer solution (15 wt%) was prepared using a combination of solvents such as xylene, ethyl acetate and butanol. Thereafter, fire retardant materials along with some fillers such as TiO2 and kaolin were added to the prepared polymeric solution to make an IFR paint. Three different paint compositions were prepared by varying percentages of kaolin and TiO2 using a fixed PVC, and named as TK10, TK73 and TK11. The unpigmented polymeric solution was used as a control during the performance evaluation of the pigmented compositions. The effect of TiO2 and kaolin percentage on the prepared coatings was evaluated in terms of mechanical properties, thermal stability, fire retardancy and char stability characteristics using various analytical instruments. To simulate real conditions, the prepared coatings were also applied over the cotton cloth and fire protection ability was studied in detail. Results revealed that the kaolin and TiO2 combination increased the strength of the char and fire-resistant properties when used in the ratio of 7:3 i.e. TK73.

Spray characteristics of fouled gasoline direct injectors under flash boiling and sub-zero temperature conditions

This study investigated the spray characteristics of a fouled injector under different ambient pressures, fuel temperatures, and flashing ratios. Four fouled injectors and a clean injector were used to analyze the effects of deposits on spray characteristics. A fouled injector, showing the greatest difference in spray characteristics compared to a clean injector, was selected as a representative fouled injector and analyzed. The near-field and far-field spray visualization were performed by using the Mie-scattering imaging technique. Quantitative indices, such as the spray angle, penetration length, and sharpness intensity, were defined to compare the spray characteristics of the fouled and clean injectors. These quantitative indices were calculated using the MATLAB image processing tool. Deposits formed differently even under the same engine operating condition, such that the spray structure was different depending on the fouled injector. In the near-field spray visualization, there were relatively large droplets and long ligaments in the fouled injector compared to the clean injector due to the low atomization performance.

A State of the Art Review of Isochoric Cryopreservation and Cryoprotectants

There is a developing enthusiasm for discovering new methods, cryoprotectants, systems and devices for cells, tissues, and organ preservation in medicine, in sub-zero temperature conditions and a growing interest in developing more efficient and economical methods for long-term preservation of food in a frozen state. Most of the preservation protocols currently used in medicine and food preservation involve the use of atmospheric pressure, and temperatures lower than normal body temperature in medicine, or lower than room temperature in the food industry. In this state of the art review, we analyzed the results of a new preservation method that uses an isochoric system. We aimed to offer a clear overview of the potential of this new technology. Firstly, to study the origins of isochoric preservation, we searched using the WoS Database. A search with the world "isochoric" returned 488 results. A more specific search of the term "isochoric freezing" returned 94 results. From these searches, we selected the 12 most relevant articles and discuss them here in detail. We present an overall characterization and criticism of the current use and potential of this new preservation method that can be used in the medicine and food industry. The main findings indicate encouraging results for the tested biological matter, including for the preservation of food products (e.g.cherries, spinach, potatoes), biological organisms (e. g. Caenorhabditis elegans, Escherichia coli, Listeria, Salmonella typhimurium), organs (e.g. rat hearts), tissues (e. g., tilapia fish filets) or cells (e. g., mammalian cells, pancreatic cells). Accordingly, we conclude that the isochoric system holds huge potential as a new technique in the field of preservation.

Spray Characteristics of Bioethanol-Blended Fuel under Various Temperature Conditions Using Laser Mie Scattering and Optical Illumination

Bioethanol has great potential to reduce emissions from transportation while improving energy security and developing the economy. Bioethanol has a higher octane-number and a higher enthalpy of vaporisation than gasoline (resulting in charge cooling)—properties that have been used to extend knocking limits. Therefore, bioethanol can be used to substitute gasoline in automotive engine applications. The characteristics of bioethanol spray, such as hydrous bioethanol fuel which consists of 93% bioethanol and 7% water, were investigated under various temperature conditions from sub-zero (−15 °C) to room temperature (17 °C) by means of high-speed direct photography and laser Mie scattering techniques without any seeding materials. The experimental results show that the spray patterns are not significantly changed. In the case of the sub-zero temperature condition, the spray tip penetration decreases while the spray angle keeps almost constant once the spray becomes fully developed. The results show that scaling of the spray tip penetration rate achieves a reasonable collapse of the experimental results. The normalised droplet diameter was also obtained and shows that larger droplets are formed at the sub-zero temperature condition.

Changes in friction of zinc flake coated threaded fasteners due to humidity, temperature and storage duration

The friction coefficient of a specific material combination is often assumed to be invariant in manufacturing processes such as during the tightening of threaded fastener joints. This paper considers the impact of storage conditions on threaded fastener friction. Fasteners were stored in hot humid and sub-zero temperature conditions to study friction in the thread and under-head contacts. Four Zn-flake coatings, commonly used in the automotive industry were considered. Consequent tightening of these fasteners at room temperature revealed that storage history had a significant impact on their friction coefficients, halving under-head friction in some cases. This varied behavior was considered to be a response to coating nano-hardness and structure and differences in adsorption/absorption of water and zinc-oxide formation during storage.

Antifreeze Proteins: A Tale of Evolution From Origin to Energy Applications.

Icing and formation of ice crystals is a major obstacle against applications ranging from energy systems to transportation and aviation. Icing not only introduces excess thermal resistance, but it also reduces the safety in operating systems. Many organisms living under harsh climate and subzero temperature conditions have developed extraordinary survival strategies to avoid or delay ice crystal formation. There are several types of antifreeze glycoproteins with ice-binding ability to hamper ice growth, ice nucleation, and recrystallization. Scientists adopted similar approaches to utilize a new generation of engineered antifreeze and ice-binding proteins as bio cryoprotective agents for preservation and industrial applications. There are numerous types of antifreeze proteins (AFPs) categorized according to their structures and functions. The main challenge in employing such biomolecules on industrial surfaces is the stabilization/coating with high efficiency. In this review, we discuss various classes of antifreeze proteins. Our particular focus is on the elaboration of potential industrial applications of anti-freeze polypeptides.

Recent progress in lithium-ion battery thermal management for a wide range of temperature and abuse conditions

Lithium-ion batteries are important power sources for electric vehicles and energy storage devices in recent decades. Operating temperature, reliability, safety, and life cycle of batteries are key issues in battery thermal management, and therefore, there is a need for an effective thermal-management system. This review summarises the latest research progress on lithium-ion battery thermal management under high temperature, sub-zero temperature, and abuse conditions. Heat generation mechanisms are characterised under both normal and abuse conditions. Different cooling methods, which include air cooling, liquid cooling, phase change cooling, heat pipe cooling, and their combinations are reviewed and discussed. Thereafter, features of different battery heating methods such as air/liquid heating, alternate current heating, and internal self-heating are discussed. An improvement in battery safety under abuse conditions is discussed from the perspective of battery material modification and thermal management design. The research progress in recent investigations is summarised, and the prospects are proposed. • The investigations on the lithium ion battery thermal management is reviewed. • The air, liquid, PCM and combined cooling methods are discussed. • The external, alternating current and self-heating methods are analyzed. • The thermal runaway mechanism and prevention methods are discussed. • Research challenges and directions for future studies are provided.

Influence of processing conditions of atmospheric freeze-drying/low-temperature drying on the drying kinetics of sliced fruits and their vitamin C retention

Sliced fruits (apple and kiwi) were dried under atmospheric freeze-drying (AFD) and/or low-temperature drying (LTD) conditions, and the drying kinetics, resultant degree of shrinkage, and vitamin C retention were evaluated. The air temperature programs were set in the range of −20 to 10 °C, and the impact of the sub-zero temperature setting was investigated. As expected, shortening the sub-zero temperature time and increasing the air temperature led to a shorter total drying time. Notably, the application of freezing had an effect to reduce the drying time. The application of the LTD condition without freezing significantly increased the total drying time compared with that of the drying condition with freezing. When the temperature was increased stepwise from −20 to 10 °C, the total drying time was effectively reduced when the sub-zero temperature was maintained for a relatively long time. This was the most practical drying program for maintaining product quality. It was found that drying at sub-zero temperatures has advantages in reducing product shrinkage; however, the impact was not remarkable. The application of sub-zero temperature conditions was advantageous for vitamin C retention for both apple and kiwi drying. However, if the negative effect of freezing on quality is significant, simple LTD conditions may be a good compromise for balancing total drying time and product quality. • Sliced apple and kiwi were dried under atmospheric freeze-drying conditions. • Drying kinetics, degree of shrinkage, and vitamin C retention were evaluated. • The application of freezing was found to be advantageous in reducing the drying time. • The application of sub-zero temperature was advantageous for vitamin C retention. • In some conditions, freezing was negative to the retention of product quality.

The Effects of In-Process Cooling during Friction Stir Welding of 7475 Aluminium Alloy

Certain age hardenable alloys such as AA7475 cannot be joined with perfection using fusion welding techniques. This requires non-conventional welding technique such as friction stir welding process to join these ‘difficult to weld’ alloys. In this study, three different cooling conditions i.e. cryogenic, sub-zero, and zero-degree Celsius temperature conditions have been analyzed to understand its impact on the welding process. In-process cooling was found to behave effectively and also enhanced the mechanical properties of the welded joints. A stable microstructure was clearly seen in the images observed under the metallurgical microscope. The weld efficiencies were found to be good in each of the samples which are indicative of a strong metallic joint. The effective cooling conditions employed had an overall positive impact on the joint.

Experimental investigation of fuel temperature effects on transient needle motion and injection velocity of solenoid type diesel injector

Real driving emission (RDE) test conducted in sub-zero temperature conditions has been acting as a severe emission regulation over the existing test methods for diesel engines. In order to cope with this tightened regulation, many studies have been conducted to interpret the factors causing the deteriorated diesel engine combustion in cold operation conditions. The deteriorated fuel injection performance has been regarded as one of the key contributing factors but the governing mechanisms are not thoroughly understood so far. This study aims to provide a comprehensive understanding of the effects of fuel temperature including sub-zero conditions on fuel injection performance by measuring the transient needle motion and injection velocity of a diesel injector using synchrotron X-ray imaging techniques. The factors causing the deteriorated injector performance and their contributions are discussed thoroughly based on the results. The results showed that the injection duration was shortened as the fuel temperature decreased as a result of decreased needle opening speed and increased needle closing speed. The increase of fuel viscosity and bulk modulus was discussed as the main factors associated with these results. The total injection mass was reduced by lowering the fuel temperature not only by the shortened injection duration but also by the decreased injection velocity. These factors exerted near equivalent contribution to the reduced injection mass at low fuel temperatures.