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The theory-led prediction of LaBeH8, which has a high superconducting critical temperature (Tc) above liquid nitrogen under a pressure level below 1 Mbar, has been experimentally confirmed. YBeH8, which has a structural configuration similar to that of LaBeH8, has also been predicted to be a high-temperature superconductor at high pressure. In this study, we focus on the structural phase transition and superconductivity of YBeH8 under pressure by using first-principles calculations. Except for the known face-centered cubic phase of Fm 3 ̄ m, we found a monoclinic phase with P 1 ̄ symmetry. Moreover, the P 1 ̄ phase transforms to the Fm 3 ̄ m phase at ∼200 GPa with zero-point energy corrections. Interestingly, the P 1 ̄ phase undergoes a complex electronic phase transition from semiconductor to metal and then to superconducting states with a low Tc of 40 K at 200 GPa. The Fm 3 ̄ m phase exhibits a high Tc of 201 K at 200 GPa, and its Tc does not change significantly with pressure. When we combine the method using two coupling constants, λopt and λac, with first-principles calculations, λopt is mainly supplied by the Be–H alloy backbone, which accounts for about 85% of total λ and makes the greatest contribution to the high Tc. These insights not only contribute to a deeper understanding of the superconducting behavior of this ternary hydride but may also guide the experimental synthesis of hydrogen-rich compounds. [ABSTRACT FROM AUTHOR]

The theory-led prediction of LaBeH8, which has a high superconducting critical temperature (Tc) above liquid nitrogen under a pressure level below 1 Mbar, has been experimentally confirmed. YBeH8, which has a structural configuration similar to that of LaBeH8, has also been predicted to be a high-temperature superconductor at high pressure. In this study, we focus on the structural phase transition and superconductivity of YBeH8 under pressure by using first-principles calculations. Except for the known face-centered cubic phase of Fm 3 ̄ m, we found a monoclinic phase with P 1 ̄ symmetry. Moreover, the P 1 ̄ phase transforms to the Fm 3 ̄ m phase at ∼200 GPa with zero-point energy corrections. Interestingly, the P 1 ̄ phase undergoes a complex electronic phase transition from semiconductor to metal and then to superconducting states with a low Tc of 40 K at 200 GPa. The Fm 3 ̄ m phase exhibits a high Tc of 201 K at 200 GPa, and its Tc does not change significantly with pressure. When we combine the method using two coupling constants, λopt and λac, with first-principles calculations, λopt is mainly supplied by the Be–H alloy backbone, which accounts for about 85% of total λ and makes the greatest contribution to the high Tc. These insights not only contribute to a deeper understanding of the superconducting behavior of this ternary hydride but may also guide the experimental synthesis of hydrogen-rich compounds. [ABSTRACT FROM AUTHOR]

Egg (oocyte) vitrification is the dominant method for preserving fertility for women of reproductive age. However, the method is typically performed by hand, requiring precise (∼0.1 to 10 μL) and time-sensitive (∼1 s) liquid exchange of cryoprotectants (CPA) around eggs as well as fine handling of eggs (∼100 μm) for immersion into liquid nitrogen (LN2). Here, we developed a microfluidic platform for programmable vitrification. Our platform is based on a millimeter-sized hanging droplet inside which a given egg is suspended and subjected to liquid exchanges within seconds. After programmable exposures to CPA, the egg is extracted from the liquid–air interface of the droplet using a motorized fine-tip instrument and immersed into LN2 for vitrification. To benchmark our platform with the manual method, we vitrified over a hundred mouse eggs and found comparable percentages (∼95%) for post-vitrification survivability. In addition, our platform performs real-time microscopy of the egg thereby enabling future studies where its morphology may be linked to functional outcomes. Our study contributes to the ongoing efforts to enhance the automation of embryology techniques towards broader applications in reproductive medicine both for clinical and research purposes. [ABSTRACT FROM AUTHOR]

Liquid nitrogen is a widely utilized effective low-temperature cooling medium, also employed in the ATR-GG (Gas Generator cycle Air Turbo rocket) engine to cool high-temperature components. Due to the high-temperature work environment and the ease with which liquid nitrogen evaporates and boils, liquid nitrogen would experience a flash boiling process. In order to study the influence of flash boiling on spray characteristics, experiments and simulations were conducted with two types of hollow-cone nozzles and two types of solid-cone nozzles under subcooled water at normal temperature which is not affect by flash boiling and superheat liquid nitrogen inflow conditions. The research found that flashing already begins inside the nozzle, significantly reducing the discharge coefficient of the solid-cone nozzle. The nitrogen gas-liquid mixture fills the air core of the hollow-cone spray, resulting in a comparatively smaller impact on the discharge coefficient. The liquid nitrogen spray exhibit spray collapse, unable to achieve the spray cone angels as the water spray. The major reason is that during the flashing process, nitrogen vapor expansion enhances the axial velocity, reducing the spray cone angle. The study recommends using hollow-cone nozzles to mitigate the impact of flash boiling on the spray characteristics. [ABSTRACT FROM AUTHOR]

Heterostructured ferritic steels with bimodal-grained lamellar (BG-L) and ultrafine-grained lamellar (UFG-L) microstructure were prepared through a warm deformation process. The BG-L steel exhibits enhanced mechanical properties compared to conventional quenched and tempered (QT) steel. While the UFG-L steel demonstrates an outstanding combination of strength, ductility, and toughness. Furthermore, the UFG-L steels exhibit no ductile-to-brittle transition (DBT) from room temperature (RT) to liquid nitrogen temperature (LNT) and the Charpy impact energy remains as high as 314 J at LNT. The enhanced toughness at LNT can be attributed to the crack-arrester mechanism caused by grain-boundary delamination. [ABSTRACT FROM AUTHOR]

Sperm cryopreservation is a rather complex process that needs to be adapted to wild and domestic bird species to ensure adequate efficiency. This study aimed to determine the usability of different cryoprotectants in the cryopreservation of Gloster canary sperm. For this purpose, sperm samples were collected from 12 2‐year‐old male Gloster canaries three times a week using cloacal massage for 4 weeks. After individual evaluation, sperm samples from the canaries were combined. Mixed sperm were divided into two groups in the study. Overall, 8% dimethyl sulfoxide (DMSO) and ethylene glycol (EG) were used as cryoprotectants. Sperm samples were drawn into straws after adding Dulbecco's Modified Eagle Medium (DMEM) extender with high glucose ratio and two different cryoprotectants in a 1:1 ratio and frozen to −80°C with liquid nitrogen vapour and then stored in liquid nitrogen at −196°C. Frozen‐thawed semen samples were evaluated regarding motility, vitality, plasma membrane integrity (hypoosmotic swelling test [HOST]), density and abnormal spermatozoa rate. The highest motility value after freezing and thawing was determined in the EG group with 31.667% ± 4.773%. In addition, vitality, plasma membrane integrity and normal sperm morphology were statistically significantly higher in the EG‐frozen group, whereas head and tail abnormality was low (p < 0.05). This study determined that a DMEM extender containing 8% EG was more advantageous than a DMEM containing DMSO regarding spermatological parameters and could be used for long‐term storage of canary sperm. [ABSTRACT FROM AUTHOR]

Cryopreservation allows for the long-term storage of biological materials, ensuring their viability for future use and preserving biodiversity. This study aimed to develop an efficient protocol for the long-term in vitro conservation of fegra fig. In vitro precultured shoot tips of fegra fig with 0.3 M sucrose showed the highest regrowth percentage (100%) before plunging into liquid nitrogen. After plunging into liquid nitrogen, the regrowth percentage was 43.33%. Following cryopreservation, the recovered shoots were rooted and acclimatized to ex vitro conditions. The genetic fidelity of the acclimatized 8-week-old fegra fig plantlets after cryopreservation with their mother plant was tested using randomly amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), and start codon targeted (SCoT) molecular markers. Genetic similarity between the stored plantlets with their mother plant was 100% ensuring uniformity and true-to-type regenerated plants following cryopreservation. This study presents, for the first time, an efficient protocol for the genetic conservation of fegra fig. [ABSTRACT FROM AUTHOR]

A clean and effective unconventional fossil fuel is coalbed methane (CBM). The development of CBM is essential to reducing the lack of oil and gas resources, preventing coal mine gas mishaps, and safeguarding the atmosphere. After the coal samples prepared in this study were frozen and thawed by liquid nitrogen, the change rules of coal surface and internal pores were investigated by metallurgical microscopy and carbon dioxide adsorption. The results showed that: 1) The values of specific surface area, characteristic adsorption energy, and total SF microvolume of coal samples increased after freeze-thawing of liquid nitrogen, but the CO2 adsorption experiments showed that the pore width decreased, which indicated that the mechanism of freeze-thawing fracture effect coal by liquid nitrogen mainly increased the number of micropores in coal. 2) The water saturation of coal samples rose with the degree of surface cracking, but when the water content reached a specific level, the rise in surface porosity of coal reduced with the water saturation. 3) The increase in the number of cycles has a greater effect on the extent of expansion of pores on the coal surface than on the expansion of pores in the coal. [ABSTRACT FROM AUTHOR]

The article discusses the use of cryoinflation with liquid nitrogen as an alternative treatment for fistulas in hidradenitis suppurativa (HS). The study evaluated the efficacy and tolerability of cryoinflation in HS tunnels, showing promising results in terms of clinical improvement and ultrasound parameters. The procedure was well-tolerated by patients and demonstrated potential as a non-invasive therapy for HS tunnels, warranting further research to confirm its effectiveness. [Extracted from the article]

Objective: This study aimed to assess the complication rate during and 24 hours after cryoablation in lung, bone, and soft tissue tumors. Methods: We reviewed complications in a total of 85 consecutive patients who underwent cryoablation using a liquid nitrogen-based system in various lesions between April 2017 and October 2022. There were no liver and renal lesions. Complications were categorized using the Society of Interventional Radiology classification. Results: Eighty-five patients were treated for 96 lesions in the bone (36.4%; 35 of 96), lung (18.8%; 18 of 96), and soft tissue (44.8%; 43 of 96). The primary technical success rate was 97.7% (83 of 85). The total grade 2 and 1 complication rates were 5.2% (5/96) and 20.8% (20/96), respectively. Two patients had asymptomatic pulmonary embolisms incidentally noted at the 24-hour follow-up computed tomography (grade 2). The most frequent complications were simple and hemorrhagic pleural effusions (18.7%; 18 of 96). Lung procedures had the highest complication rate, where 13 patients (72.2%; 13 of 18) reported complications, including 2 cases of symptomatic hydropneumothorax requiring drainage (grade 2) and an additional 2 days of hospital stay. Eight patients (24.2%; 8 of 33) with bone lesions and 4 (9.3%; 4 of 43) with soft tissue lesions experienced complications. Conclusion: Cryoablation using a liquid nitrogen-based system is safe, with only minor complications observed. Advances in knowledge: This study provides data on the safety of liquid nitrogen-based percutaneous cryoablation in tumors located in lung, in bones and in soft tissues. Despite using larger diameter cryoprobes than those typically reported with argon-based system, our experience shows that complications are mostly low and comparable in frequency and severity. [ABSTRACT FROM AUTHOR]

Existing empirical relations used to predict the porosity of gravel beds are mainly derived from laboratory-generated sediment beds with random grain packing. However, such relations could not adequately describe beds with non-random grain arrangements that occur widely in fluvial deposits. In this work, the effect of grain imbrication on gravel-bed porosity has been quantified using beds with variable strengths of imbrication generated by flume experiments. Mono-sized ellipsoids with specific shapes were used in experiments to remove particle size and sorting effects on porosity. Random bed packings were generated by settling of ellipsoids in still water whilst imbricated beds generated under flowing water. Beds were frozen using liquid nitrogen before extraction. A new relatively simple and time-saving workflow was developed to measure the orientation of particles and quantify the degree of grain imbrication in frozen beds from X-ray Computed Tomography images. Beds with the strongest grain fabric display a ca. 0.03 absolute reduction of porosity value on average (8–10% relative reduction) compared to that of random packing for undisturbed beds. Further, results were obtained for beds deposited under still-water conditions subject to disturbance by shaking, to mimic the potential effect of vibrations from currents, waves or other sources in the environment. A reduction in bed porosity of ca. 0.014–0.018 (ca. 5% relative reduction) is observed between beds with the strongest grain fabric and those with random packing that had undergone shaking after deposition. Hence, a significant proportion (> 50%) of the porosity loss observed for imbricated beds may be attributable to tighter packing due to turbulence-related vibrations from the flow. The small decrease in porosity value despite the formation of strong imbrication is considered to be due to the limited improvement in grain organization, as the results show that the flat shape of the ellipsoids and the uniformity of their size promote the formation of a stacking structure under gravity, leading to a similarly highly ordered grain organization in random packings compared to the imbricated packings. [ABSTRACT FROM AUTHOR]

The cryopreservation of Anthurium andraeanum germplasm resources is extremely important for the production and selection of new varieties. At present, the cryopreservation procedure for the callus of A. andraeanum has not been established. In this study, the leaves of A. andraeanum were used as explants to culture the callus. The cryopreservation procedure of the callus by vitrification was initially established by using the orthogonal experimental method of four factors and three levels in the preculture, loading, and dehydration steps. Furthermore, the vitrification-based cryopreservation was optimized by changing the preculture temperature and loading solution and adding exogenous substances to the plant vitrification solution (PVS2). In this procedure, the callus was precultured at 25 °C for 2 d, and loaded in 50% PVS2 at 25 °C for 60 min. The callus was dehydrated with PVS2 containing 0.08 mM reduced glutathione (GSH) at 0 °C for 60 min. After rapid-cooling in liquid nitrogen for 1 h, it was rapid-warming in a water bath at 40 °C for 90 s and unloaded for 30 min. After 1 d of recovery, the cell relative survival rate of the cryopreserved callus was 64.60%. The results provide a valuable basic and effective method for the long-term conservation of A. andraeanum germplasm resources. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ammonia removal from wastewater by electrooxidation (EO) is an interesting approach because of its efficiency and easy maintenance and operation. In this process, ammonia is oxidized to nitrate or nitrogen gas. Ammonia conversion to the latter is desirable to remove nitrogen from the liquid; however, the influence of several operating parameters on nitrate generation has not been systematically evaluated. Therefore, this work aimed to investigate the effect of current density (200–800 A m−2), chloride concentration (0–10 000 mg L) and initial pH (5–9) on the electrooxidation of an ammonia‐containing solution and the associated generation of nitrate. For this purpose, a laboratory‐scale electrochemical reactor containing two Ti/RuO2 electrodes was used. RESULTS: The results indicated high ammonia removal efficiency – 98% within 150 min at 800 A m−2 and 97% within 240 min at 500 A m−2 – generating around 70 and 102 mg NO3−‐N L−1 under these conditions, respectively. Increasing the chloride concentration from 5000 to 7500 mg L−1 reduces the electrolysis time needed to remove all ammonia from 180 to 150 min. However, with increasing initial chloride concentration, the amount of nitrate generated rose from 69.5 to 135.9 mg N L−1. On the other hand, in the test without chloride, nitrate generation was considerably lower (0–0.61 mg L−1). CONCLUSION: The higher the current density applied, the greater the ammonia removal by EO. Although current density influenced the ammonia oxidation rates, it did not directly affect nitrate formation. The lower the concentration of ammonia in the solution, the more significant was the fraction of nitrate generated. Most of the inlet ammonia was oxidized to nitrogen gas, nitrite was rapidly oxidized to nitrate and higher chloride concentrations enhanced ammonia oxidation. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

We report the synthesis of the polycrystalline Cu 3 N phase via a diffusion reaction between copper and nitrogen under extreme conditions. Herein, the solid-state diffusion mechanism for the synthesis of the Cu 3 N phase was analyzed. Structural indexing of the new phase was confirmed using the X-ray diffraction technique. Synthesis of the above Cu 3 N phase applying this novel technique is an inexpensive method for the industrial production of the material. The microstructure of the above solid was investigated under a high-resolution scanning electron microscope. [ABSTRACT FROM AUTHOR]

Cryogenic liquids such as liquid oxygen and liquid hydrogen are extensively used in many processes and manufacturing industries. In these industries, transferring cryogens via pipelines is a routine phenomenon. As the boiling points and latent heat of cryogens are low, excessive vaporization of these cryogens is innate. Therefore, ensuring that the cryogen reaches the utility in its liquid form is challenging. In the case of liquid hydrogen and liquid helium, the pipelines are jacketed with a high boiling cryogen like nitrogen. The idea is to dump most of the heat into cheap nitrogen to limit the loss of precious hydrogen or helium. From a heat inleak point, maximizing the amount of nitrogen in the jacket is advantageous by choosing large cross‐sectional areas. Also, larger flow cross sections would lower pressure drops and, therefore, lower pumping costs. However, such a choice would add to the mass of the pipeline. An increase in the mass of the pipeline increases the need for better structural support of the pipeline assembly. Therefore, the design of cryogen jackets for limiting heat inleak is a multi‐objective optimization problem. In this work, we model the heat leak into the hydrogen via the nitrogen jacket and the pressure drop of liquid nitrogen, and we find the mass of the pipeline assembly. Then, we optimize the design of nitrogen jackets fitted over hydrogen pipelines. We employ the evolutionary optimization technique, genetic algorithm (GA), to perform this optimization.cryogen; genetic algorithm; heat inleak; liquid hydrogen; optimization. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are a type of cell capable of regulating the immune system, as well as exhibiting self-renewal and multi-lineage differentiation potential. Mesenchymal stem cells have emerged as an essential source of seed cells for therapeutic cell therapy. It is crucial to cryopreserve MSCs in liquid nitrogen prior to clinical application while preserving their functionality. Furthermore, efficient cryopreservation greatly enhances MSCs' potential in a range of biological domains. Nevertheless, there are several limits on the MSC cryopreservation methods now in use, necessitating thorough biosafety assessments before utilizing cryopreserved MSCs. Therefore, in order to improve the effectiveness of cryopreserved MSCs in clinical stem cell treatment procedures, new technological techniques must be developed immediately. The study offers an exhaustive analysis of the state-of-the-art MSC cryopreservation techniques, their effects on MSCs, and the difficulties encountered when using cryopreserved MSCs in clinical applications. [ABSTRACT FROM AUTHOR]

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Combining cholesterol‐loaded methyl‐β‐cyclodextrin (CD‐CHL) with vitamin E‐loaded methyl‐β‐cyclodextrin (CD‐Vit E) to combat cold shock and oxidative stress during sperm cryopreservation in soybean lecithin extenders remains unexplored. Thus, the current study aimed to investigate the effect of treating bull sperm with CD‐CHL and CD‐Vit E prior to cryopreservation in a soybean lecithin extender. Sperm collected from eight fertile bulls were pooled and split into six aliquots. Five aliquots were treated, in a Tris‐based extender, with CD‐CHL (2 mg/120 × 106 cells/mL) and either 0, 0.5, 1.0, 1.5 or 2 mg CD‐Vit E/120 × 106 cells/mL. The control aliquot was diluted in a Tris‐based extender without further supplementation. After incubation at 22°C for 15 min and addition of a soybean lecithin extender, all aliquots were equilibrated for 2 h at 4°C and then cryopreserved in liquid nitrogen. Computer‐assisted sperm analysis (CASA) was used to explore the different sperm motility parameters, hypo‐osmotic swelling test to determine membrane functionality and fluorescein isothiocyanate‐conjugated Aeachis hypogaea (peanut) agglutinin (FITC‐PNA) to quantify acrosome integrity. The effect of oxidative stress on the sperm membrane was assessed through lipid peroxidation measurement. Compared to control, CD‐CHL alone improved significantly (p < 0.05) all CASA motility parameters, membrane functionality and acrosome integrity of thawed sperm. The membrane functionality was more significantly (p < 0.05) improved when 0.5 mg CD‐Vit E was combined with CD‐CHL. Concerning lipid peroxidation, no significant differences (p > 0.05) in malondialdehyde (MDA) levels were registered between groups. In conclusion, the combination of CD‐CHL and CD‐Vit E demonstrated a significant positive effect on the cryopreservation of bull sperm in a soybean lecithin extender. [ABSTRACT FROM AUTHOR]

Liquid nitrogen is the most common refrigerant adopted in the artificial ground freezing (AGF) method for the rapid freezing of soil. However, the relatively high price of liquid nitrogen demands the reuse of liquid nitrogen in AGF, which utilizes partially gasified liquid nitrogen after an initial injection. This study investigated the reusability of liquid nitrogen in AGF by performing a field experiment. Temperatures of the ground were monitored near the sub-freezing pipes installed 1 m away from the main freezing pipes, where liquid nitrogen was initially injected. A frozen wall having a thickness of 1 m was formed between two sub-freezing pipes after 5 days of injecting liquid nitrogen into the main freezing pipes. Furthermore, the lowest temperature of − 12 °C measured in the sub-freezing pipe implied that the temperature of nitrogen after circulating through the main freezing pipe was sufficiently low to freeze the surrounding soil formation. The freezing rate, elapsed time for freezing, and freezing duration evaluated from the monitored temperature data also demonstrated the promising potential of reusing liquid nitrogen in AGF for saturated silty deposits. [ABSTRACT FROM AUTHOR]

Persistent luminescence (PersL) phosphors have garnered significant attention for their extensive applications in various fields. It is regrettable that these PersL phosphors typically possess deep traps. At low temperatures (LT), energy stored in the trap cannot be released to the luminescent centers through thermal de‐trapping, thereby causing these PersL phosphors to lose their PersL characteristics in LT. Currently, there is little research on LT PersL phosphors, and multicolor LT PersL in a single host material has not been reported. In this work, multicolor LT PersL is achieved in a single host material by modifying the emission center. Remarkably, an ultra‐shallow trap with a depth of 0.23 eV is discovered in the Cs2NaLuCl6:5%Ln3+ phosphors, which is essential for achieving PersL at 77 K. First‐principles calculations indicate that the ultra‐shallow trap in Cs2NaLuCl6:5%Ln3+ is caused by the distortion of [NaCl6] octahedron in the phosphors. These findings provide new perspectives into X‐ray‐induced trap generation and offer valuable insights for designing multicolor PersL phosphors for LT applications. [ABSTRACT FROM AUTHOR]

In this manuscript, we report on the synthesis of a polynitrogen material from a potassium azide precursor using nanosecond-pulsed spark discharge plasma in liquid nitrogen. The polynitrogen material was characterized using Raman and Fourier transform infrared (FTIR) spectroscopy and identified as K2N6, with planar N6 rings and K- ions that have P6/mmm symmetry. An analysis of the mechanism behind such a transformation shows the importance of direct plasma–chemical effects in polymerization, while the crystal structure changes are believed to be due to plasma-emitted radiation in the ultraviolet range. [ABSTRACT FROM AUTHOR]

Surface quality, machining efficiency, and tool life are all significantly impacted by tool wear in metal cutting machining. Research priorities and areas of focus in tool wear are shifting as intelligent machining becomes the norm. Unfortunately, there are currently no acknowledged most effective ways for analyzing tool based on the energy signals specially in the machining of titanium and its alloys. In the present work, the titanium machining was performed under different lubrication conditions such as dry, minimum quantity lubrication (MQL), liquid nitrogen and hybrid, etc. Then, the spectrograms are used to transform the acquired energy data into time–frequency features. Starting with a set of randomly generated hyper parameters (HPs), the long short-term memory (LSTM) model is fine-tuned using sine cosine algorithm (SCA) with loss serving as the fitness function. The confusion matrix provides additional validation of the 98.08% classification accuracy. Additional evaluations of the suggested method's superiority include its specificity, sensitivity, F1-score, and area under the curve (AUC). [ABSTRACT FROM AUTHOR]

Autophagosome biogenesis is a complex process orchestrated by dynamic interactions between Atg (autophagy-related) proteins and characterized by the turnover of specific cargoes, which can differ over time and depending on how autophagy is stimulated. Proteomic analyses are central to uncover protein-protein interaction networks and when combined with proximity-dependent biotinylation or proximity labeling (PL) approaches, they also permit to detect transient and weak interactions. However, current PL procedures for yeast Saccharomyces cerevisiae, one of the leading models for the study of autophagy, do not allow to keep temporal specificity and thus identify interactions and cargoes at a precise time point upon autophagy induction. Here, we present a new ascorbate peroxidase 2 (APEX2)-based PL protocol adapted to yeast that preserves temporal specificity and allows uncovering neighbor proteins by either western blot or proteomics. As a proof of concept, we applied this new method to identify Atg8 and Atg9 interactors and detected known binding partners as well as potential uncharacterized ones in rich and nitrogen starvation conditions. Also, as a proof of concept, we confirmed the spatial proximity interaction between Atg8 and Faa1. We believe that this protocol will be a new important experimental tool for all those researchers studying the mechanism and roles of autophagy in yeast, but also other cellular pathways in this model organism. Abbreviations: APEX2, ascorbate peroxidase 2, Atg, autophagy-related; BP, biotin phenol; Cvt, cytoplasm-to-vacuole targeting; ER, endoplasmic reticulum; LN2, liquid nitrogen; MS, mass spectrometry; PAS, phagophore assembly site; PL, proximity labeling; PE, phosphatidylethanolamine; PPINs, protein-protein interaction networks; PPIs, protein-protein interactions; RT, room temperature; SARs, selective autophagy receptors; WT, wild-type. [ABSTRACT FROM AUTHOR]

To improve the efficiency of coalbed methane and recoverability of reservoirs, enhanced fracturing technology is usually required to improve the low porosity and permeability status of coal reservoirs. As a feasible method for strengthening permeability, microwave–LN2 freeze–thaw (MLFT) cycles modify the microscopic pore structure of coal through the coupled effect of temperature stress changes, phase change expansion, and fatigue damage. 1H nuclear magnetic resonance combined with fractal dimension theory was used to characterize quantitatively the pore system and geometric features of coal. The geometric fractal model constructed using the T2 spectrum indicates that the fractal dimensions Dp and De have high fitting accuracy, demonstrating that percolation and effective pores exhibit good fractal characteristics. Dp and De are correlated negatively and positively, respectively, with the cyclic parameters. The relevance analysis shows that the NMR fractal method can reflect the pore–fracture heterogeneity of coal, which has a significant effect on the percentage of fluid migration space. This study reveals that MLFT cycles have significant enhancement effects on promoting the extension of multi-type pores structures within the coal matrix, as well as the connectivity and permeability of cracks. [ABSTRACT FROM AUTHOR]

Liquid nitrogen (LN2) fracturing has various advantages, such as low reservoir damage, minimal environmental impact, and excellent permeability. In this study, the cracking pattern and damage evolution characteristics of bedded coal subjected to LN2 fracturing were investigated. The deterioration features of the mechanical parameters and failure mechanisms were examined in a comparable manner using Brazilian splitting tests. Additionally, the damage characteristics of bedded coal during LN2 fracturing were explored. The results indicated that LN2 cooling promoted the development of thermal cracks, consequently reducing the effective bearing capacity of the coal. Randomly distributed thermal cracks actively contributed to macroscopic crack propagation, increasing the proportion of shear cracks and the complexity of the fracture surface. Different bedding angles led to distinct failure modes, significantly impacting the proportion of shear cracks and the fracture surface complexity. Moreover, the bedding planes constantly influenced the propagation direction of the fracturing cracks, resulting in a macroscopic damage zone that expanded preferentially at the weak bedding planes with the borehole at the center. With increasing bedding angles, both the degree and rate of damage of coal decreased sequentially. Consequently, it was feasible to employ LN2 fracturing in low-permeability reservoirs along the bedding planes, facilitating swift and efficient reservoir fracturing. [ABSTRACT FROM AUTHOR]

Tetrataenite is a promising candidate for rare earth-free permanent magnets due to its low cost and intrinsic magnetic properties. This work investigates the effect of combined milling at liquid nitrogen temperatures (cryomilling) and the addition of carbon as an interstitial element for promoting the formation of tetrataenite. Crystal structure, microstructure, and magnetic properties are investigated to understand the influence of mechanical processing and compositional modifications. No unambiguous evidence of the ordered phase of tetrataenite is found in the structural characterization. However, using Scanning Transmission Electron Microscopy (STEM) and powder X-ray diffraction (PXD) analyses, the occurrence of both twinning and stacking faults resulting from the high-energy milling process is observed, which is a relevant factor for identifying tetrataenite in FeNi alloys. The probability of a stacking fault and twinning occurring for a carbon-free FeNi sample before annealing is found to be 2% and 1.4%, respectively. After annealing, the stacking fault probability decreased to 1.2%, while that of twinning was 1.4%. By increasing the carbon concentration to 5 at.%, the stacking faults and twinning probabilities decrease slightly to 1.2% and 1.3%, respectively. The occurrence of stacking faults combined with small crystallite sizes was a hindering factor in identifying the presence of tetrataenite. [ABSTRACT FROM AUTHOR]

Evolution of nitrogen under shock compression up to 100 GPa is revisited via molecular dynamics simulations using a machine-learned interatomic potential. The model is shown to be capable of recovering the structure, dynamics, speciation, and kinetics in hot compressed liquid nitrogen predicted by first-principles molecular dynamics, as well as the measured principal shock Hugoniot and double shock experimental data, albeit without shock cooling. Our results indicate that a purely molecular dissociation description of nitrogen chemistry under shock compression provides an incomplete picture and that short oligomers form in non-negligible quantities. This suggests that classical models representing the shock dissociation of nitrogen as a transition to an atomic fluid need to be revised to include reversible polymerization effects. [ABSTRACT FROM AUTHOR]

We study properties of nitrogen at high pressure and temperature (100–120 GPa, 2000–3000 K) where molecular and polymeric phases compete both in solid and liquid phase. We employ ab initio MD simulations with the SCAN functional and study the pressure-induced polymerization in liquid nitrogen for system sizes up to 288 atoms in order to reduce finite-size effects. The transition is studied upon both compression and decompression, and at 3000 K, it is found to take place between 110 and 115 GPa, coming close to experimental data. We also simulate the molecular crystalline phase close to the melting line and analyze its structure. We show that the molecular crystal in this regime is highly disordered, in particular, due to pronounced orientational and also translational disorder of the molecules. Its short-range order and vibrational density of states are very close to those of the molecular liquid revealing that the system likely represents a plastic crystal with high entropy. [ABSTRACT FROM AUTHOR]

Aspergillus species are known to be very important in human and domestic animal health. Aspergillus species commonly cause severe systemic and skin infections, as well as allergic lung diseases. With the development of PCR techniques, these methods are used to identify and diagnose fungi. DNA extraction from Aspergillus species is difficult because the fungal cell wall structure is very durable and complex. Fungal DNA extraction methods containing proteinase K and liquid nitrogen are widely used to break down the cell wall. However, these methods cause DNA loss during the extraction in Aspergillus species. In this study, on the contrary, the commonly used DNA extraction by means of ammonium hydroxide, which is generally used to break down chitin in DNA extraction of ticks and plants, is used. The efficiency of the cell wall lysis method from A. flavus with ammonium hydroxide was compared with methods containing proteinase K and liquid nitrogen. For this purpose, DNA extraction of A. flavus was tried using three different methods. As a result, the cell wall of A. flavus was lysed using ammonium hydroxide in this study. The obtained DNA’s quality, concentration, and PCR performance were sufficient. This method has been evaluated as a faster, more straightforward, and more economical alternative.

Phyllostachys praecox shoots were frozen using liquid nitrogen at –60, –90 or –120 ℃ to an internal temperature of –18 ℃, or frozen at –90 ℃ to an internal temperature of –6, –12 or –18 ℃, vacuum-packed and stored in a freezer at –18 ℃ for 24 weeks. In order to analyze the effect of liquid nitrogen freezing on physiological and biochemical characteristics of P. praecox shoots during frozen storage, L-phenylalanine ammonialyase (PAL) and peroxidase (POD) activities, total phenolic content, relative electrical conductivity, and water state were measured and ice crystal structure and cell morphology were observed. The results showed that with increasing freezing time, the PAL and POD activities, total phenolic content, and peak area of free water in all six groups decreased significantly (P 0.05). The PAL and POD activities and relative conductivity of P. praecox shoots frozen at –6 ℃ were higher than those frozen at –12 and –18 ℃, and the size of ice crystals was smaller and the degree of cell damage was greater in P. praecox shoots frozen at –6 ℃ than at –12 and –18 ℃. The difference between P. praecox shoots frozen at –12 and –18 ℃ was not significant (P > 0.05). Collectively, these findings indicated that the most suitable liquid nitrogen freezing conditions of P. praecox shoots are –90 and –12 ℃ for freezing and internal temperature, respectively.

Glass formation and the nature of the chemical interaction in the As2Se3–Tl2Te3 system were studied by differential-thermal (DTA), X-ray phase (XRD), microstructural (MSA) analysis. Based on the performed experiments T-x phase diagram is constructed. It is established that the phase diagram of the system is a partially quasi-binary section of the quaternary system Tl,As//Se,Te. Eutectic equilibrium and peritectic transformation process occur in the system. When the ratio of As2Se3 and Tl2Te3 components is 1:1, a new quaternary compound Tl2As2Se3Te3 is formed. It has been established that the Tl2As2Se3Te3 compound melts with an open maximum at 568 K and crystallizes in a hexagonal symmetry. In the system, under normal cooling, the glass formation area reaches −80 mol.% Tl2Te3, and in the mode of quenching in liquid nitrogen up to −100 mol.% T12Te3. The photoelectric properties of glassy alloys (As2Se 3 ) 1 − x (Tl2Te 3 ) x (x = 0. 0 1 ; 0.3; 0.05) have been studied. Depending on the Tl2Te3 concentration of the system, the observed changes in the photoelectric properties and calculated parameters are presented. [ABSTRACT FROM AUTHOR]

Nuclear energy, as an important component of the power system, has become a key focus of future energy development research. Various equipment and pipelines in nuclear power plants require regular inspection, maintenance, and repair. The pipelines in nuclear power plants are typically large, necessitating a device that can locally isolate sections of the pipeline during maintenance operations. Ice plug freezing technology, an economical and efficient method for maintaining and replacing equipment without shutdown, has been widely applied in nuclear power plants. The structure of the ice plug jacket, a type of low-temperature jacket heat exchanger, affects the flow path of the working fluid within the jacket and consequently impacts heat transfer. This study utilizes Computational Fluid Dynamics (CFD) to establish five types of jacket structures: standard, center-offset (center-in, side-out), helical, helical fin, and labyrinth. The effects of different structures on the freezing characteristics of ice plugs are analyzed and compared. The research indicates that the labyrinth jacket enhances the heat transfer performance between liquid nitrogen and the liquid inside the pipe, forming a larger ice layer at the same liquid nitrogen flow rate. Additionally, the standard jacket has the shortest sealing time at high liquid nitrogen flow rates. [ABSTRACT FROM AUTHOR]

This study examines the impact of high-pressure torsion (HPT) processing at various temperatures on the precipitation behavior of Cu-Cr alloys. The introduction of defects through HPT is observed to promote the precipitation of Cr atoms. Unlike the traditional large-scale precipitation that typically occurs around 400 °C, HPT can induce the precipitation of solute atoms even at room temperature. Furthermore, the temperature at which HPT is performed significantly influences the behavior of the precipitated phase during subsequent aging, ultimately affecting the alloy's overall properties. At elevated temperatures (ETs) and room temperature (RT), Cr atoms tend to aggregate, forming Guinier–Preston (GP) zones or precipitates, which coarsen into incoherent precipitates after annealing. In contrast, when HPT is conducted at liquid nitrogen temperature (LNT), Cr atoms are retained in their original positions, leading to the formation of uniformly distributed, high-density small precipitates post-annealing. This phenomenon results in superior properties for HPT-LNT-treated samples, evidenced by a microhardness of 191.8 ± 3.2 HV and an electrical conductivity of 84.6 ± 1.8% IACS. [ABSTRACT FROM AUTHOR]

Fungi occupy important environmental, cultural, and socioeconomic roles. However, biological research of this diverse kingdom has lagged behind that of other phylogenetic groups. This is partially the result of the notorious difficulty in culturing a diverse array of filamentous fungal species due to their (i) often unpredictable growth, (ii) unknown preferences for culturing conditions, and (iii) long incubation times compared with other microorganisms such as bacteria and yeasts. Given the complexity associated with concurrently culturing diverse fungal species, developing practical methods for preserving as many species as possible for future research is vital. The widely accepted best practice for preserving fungal tissue is the use of cryogenic biobanking at −165 C, allowing for the preservation and documentation of stable genetic lineages, thus enabling long-term diversity-centered research. Despite the extensive literature on fungal cryopreservation, substantial barriers remain for implementation of cryogenic biobanks in smaller mycological laboratories. In this work, we present practical considerations for the establishment of a fungal culture biobank, as well as provide evidence for the viability of 61 fungal genera in cryogenic storage. By providing a pragmatic methodology for cryogenically preserving and managing many filamentous fungi, we show that creating a biobank can be economical for independently owned and operated mycology laboratories, which can serve as a long-term resource for biodiversity, conservation, and strain maintenance. [ABSTRACT FROM AUTHOR]

• LNF exhibited a high freezing rate and contributed to small ice crystal forming. • LNF maintained WHC and shear force of Monopterus albus. • LNF alleviated myofibrillar protein denaturation of Monopterus albus. • LNF at −110 °C is more suitable for Monopterus albus than LNF at −50 °C and −80 °C. Monopterus albus is highly susceptible to spoilage due to high protein and moisture contents while frozen storage can effectively prolong the shelf-life. To study the effect of liquid nitrogen freezing (LNF) on quality, microstructure of ice crystal and muscle fiber, and physicochemical properties of proteins, Monopterus albus was frozen at -20 °C by refrigerator (RF, control), -50 °C, -80 °C, and -110 °C by LNF, respectively. The -110 °C LNF exhibited the highest freezing rate among four groups, contributing to the formation of small ice crystals with more uniform distribution and alleviating the damage to muscle fiber. In -110 °C LNF group, protein secondary structure changed relatively subtle, resulting in high protein solubility, Ca2+-ATPase activity, and total sulfhydryl content, as well as low surface hydrophobicity and disulfide bond content. LNF retarded the rise of TVB-N value, prevented the loss of immobilized and free water, and maintained water holding capacity and shear force. In conclusion, -110 °C LNF was recommended a promising freezing process for frozen Monopterus albus due to less alteration of quality and alleviation of protein denaturation. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: In contrast to traditional impact-based testing, the Dynamic Tensile Tear Test (DT3) has shown great potential to characterise high-grade pipeline steels as it mimics the in-field pipeline conditions. However, material characterisation using the DT3 method has only been performed at room temperature and lower-shelf characterisation has not yet been investigated. Objective: This study investigates a solution to perform low-temperature characterisation and analyse dynamic brittle fracture behaviour using the DT3 setup. Methods: A large-surface spray cooling system using liquid nitrogen was constructed and implemented onto the DT3 system. Cooling performance and temperature uniformity were assessed using thermocouples across a large surface area up to 412 cm2 (2 × 206 cm2). Numerical validation was performed through Finite Element (FE) analysis using the Modified Bai-Wierzbicki (MBW) material model. A combined stress–strain criterion was used to take into account cleavage failure. Results: Temperatures down to -125 °C were reached using the spray cooling system and a fracture tests was performed at -80 °C. The obtained data and resulting fracture surface indicated clear brittle fracture behaviour. An average crack velocity of 152 m/s was measured, which is in the same order of magnitude associated with crack velocities observed in large-scale testing. Conclusions: The constructed spray cooling system proved to be capable of cooling a large volume down to cryogenic temperatures while achieving acceptable temperature uniformity. Lower-shelf characterisation of X70 grade pipeline steel was achieved using the DT3 method and a good correlation was obtained between numerical data and experimental observations. [ABSTRACT FROM AUTHOR]

The butt joints of AA2099-T86 alloy were prepared by friction stir welding process under four different environments, i.e. conventional (C-FSW), liquid nitrogen (LN-FSW), ultrasonic vibration welding (U-FSW), and ultrasonic vibration with liquid nitrogen (ULN-FSW). The welding tool rotational speed of 650 rpm and tool traverse speed of 80 mm/min were fixed for all experiments. The microstructural characterization of the welded samples is examined with optical microscopy, SEM, and XRD. Higher tensile strength and microhardness were obtained in the ULW-FSW welded samples. The ultrasonic vibrations promote plastic deformation and material mixing, increasing the dislocation density and improving the weld strength. In addition, liquid nitrogen restricts the grain size and dissolution of strengthening precipitates due to the rapid welding cooling rate, resulting in higher hardness. Comparative analysis of weld joint efficiencies revealed that the ULN-FSW welded sample achieved an impressive efficiency of 87.12%. In contrast, U-FSW, LN-FSW, and C-FSW displayed efficiencies of about 86.17%, 83.01%, and 74%, respectively. [ABSTRACT FROM AUTHOR]

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Fish swim bladder (FSB) is a type of traditional nutraceutical, but the lack of high-quality drying methods limits its premium market development. In order to obtain optimal-quality dried FSBs from Chinese longsnout catfish, the effects of liquid nitrogen pre-freezing (LNF) and drying on the physical properties and flavor of FSB were evaluated. Four methods were used for FSB drying, including natural air-drying (ND), hot-air-drying (HD), LNF combined with freeze-drying (LN-FD), and LNF combined with HD (LN-HD). Color, collagen content, rehydration ratio, textural properties, and flavor characteristics (by GC-IMS, E-nose, and E-tongue) were measured to clarify the differences among four dried FSBs. The results showed that ND cannot effectively remove moisture from FSB as the final product showed a stronger sourness in taste. HD led to a decrease in the collagen content and the collapse of the fiber structure in FSB. Compared to HD, LN-HD showed a higher collagen content (0.56 g/g) and a different flavor fingerprint. FSB treated by LN-FD had better physical qualities in terms of an attractive color, a high collagen content (0.79 g/g), low shrinkage, a higher rehydration ratio (2.85), and a soft texture, while also possessing richer characteristic flavors. The application of LN-FD may help the optimization of the nutrition level, rehydration ability, mouthfeel, and flavor of dried FSB. [ABSTRACT FROM AUTHOR]

This study examines a rare case of frostbite on the hands caused by liquid nitrogen, focusing on the scar maturation process. Frostbite is typically less prone to abnormal scarring compared to burns, and this report contrasts the differences in scar maturation between the two. A 31-year-old male hospital employee sustained first- to second-degree frostbite on his gloved hands from a 20-s exposure to liquid nitrogen while changing a cylinder. Conservative treatment was applied, and the patient was monitored for 9 months. The deeply affected area took 50 days to epithelialize but healed without hypertrophic scarring. A mild extension contracture was noted in the distal interphalangeal joint of the right index finger, but the skin remained supple and soft. Incidents of liquid nitrogen-induced frostbite are uncommon, with only 14 cases reported in PubMed previously. In frostbite, the wound healing involves a slow replacement of damaged connective tissue, which acts as an internal splint, reducing wound contraction. This contrasts with burns, where rapid connective tissue replacement occurs, often leading to significant wound contraction due to the presence of myofibroblasts in granulation tissue. In the presented case, the slow healing process and minimal wound contraction led to mature scarring without abnormalities, underlining a distinctive healing trajectory in frostbite injuries compared to burns. [ABSTRACT FROM AUTHOR]

Though CsPbBr3 single crystals (SCs) possess intriguing photoelectronic properties for x/γ-ray detection, the serious ion migration and high thermally activated carrier concentration at room temperature (RT), typically associated with defect states in CsPbBr3 crystals, result in a high dark current and drift of baseline, hindering their potential applications. In this investigation, liquid nitrogen cooling is proposed to freeze deep-level defects in CsPbBr3 SCs, thereby suppressing the ion migrations and decreasing the thermally excited carrier concentration. Utilizing photoluminescence (PL) and time-resolved PL spectra, coupled with theoretical models for photoexcitation and photoemission processes, the freezing of deep-level defects at liquid nitrogen temperature (LNT) is confirmed, which is conducive to decreasing non-radiative recombination. At LNT, the CsPbBr3 SC exhibits a higher resistivity of 4.95 × 1011 Ω cm and a higher mobility–lifetime product of 9.54 × 10−3 cm2 V−1, in contrast to the RT values of 3.86 × 109 Ω cm and 3.67 × 10−3 cm2 V−1, respectively. Furthermore, the x-ray detector at LNT exhibits a high sensitivity of 9309 μC Gyair−1 cm−2 and an impressively low detection limit of 0.054 nGy s−1, which offers a route for obtaining highly sensitive x-ray detectors for applications including ultra-low dose radiation imaging. [ABSTRACT FROM AUTHOR]

Liquid hydrogen leaks can lead to the formation of solid-air deposition near the leakage source, and oxygen enrichment may exacerbate the risk of ignition of liquid hydrogen and combustible clouds. This study, based on NASA's large-scale liquid hydrogen leakage experiments, constructed a three-dimensional model to dissect the evaporation/condensation and melting/solidification processes of air components (water, oxygen, and nitrogen), aiming to analyze the phase transitions of each air component and study the concentration and extent changes of condensed air components and solid-air deposition over time. The findings indicated that after the leakage stopped, the concentrations of liquid nitrogen and oxygen initially increased and then decreased below the leakage source, related to the heat absorption from liquid hydrogen evaporation and ground heat exchange, while the range of solid-air deposition gradually diminished. This model provides a reliable prediction of solid-air deposition formation, offering a reference for further research. [Display omitted] • Condensation and solidification processes of nitrogen and oxygen are considered separately. • The concentration and range of liquid nitrogen and liquid oxygen continue to increase after the leakage is stopped. • The solidification range of nitrogen and oxygen decreases after the liquid hydrogen evaporates completely. • Thermal conductivity of ground conditions affects the duration of solid-air deposition. [ABSTRACT FROM AUTHOR]

A super-lightweight, bidirectionally ordered, three-dimensional porous hybrid graphene aerogel (HGA) was prepared and evaluated. The preparing parameters involved obtaining a uniform suspension through mechanical stirring for 3 h, followed by ultrasonic dispersion for 30 min, maintaining pH at 9. The suspension then underwent liquid nitrogen pre-freezing, vacuum freeze-drying for 48 h and hydrazine hydrate vapor reduction at 90 ℃ for 24 h. Furthermore, the microstructure, the adsorption and reusability properties of HGA were evaluated. The results demonstrated that HGA could adsorb organic solvents up to 159 times its own weight and effectively separate oil from water. The HGA exhibited excellent mechanical properties, releasing 98% of its shape with a 30% compression ratio under a stress 2653 times its own weight. Additionally, after 10 adsorption-combustion cycles, the adsorption capacity decreased by only 3.67%, and the mass retention rate exceeded 90%, indicating good reusability and flame-retardant properties. [ABSTRACT FROM AUTHOR]

Biobanks have become an integral part of health and bioscience research. However, the ultra-low temperature (ULT) storage methods that biobanks employ [ULT freezers and liquid nitrogen (LN2)] are associated with carbon emissions that contribute to anthropogenic climate change. This paper aims to provide a 'Roadmap' for reducing carbon emissions associated with ULT storage in biobanking. The Roadmap offers recommendations associated with nine areas of ULT storage practice: four relating to ULT freezers, three associated with LN2 storage, and two generalised discussions regarding biosample management and centralisation. For each practice, we describe (a) the best approaches to mitigate carbon emissions, (b) explore barriers associated with hindering their implementation, and (c) make a series of recommendations that can help biobank stakeholders overcome these barriers. The recommendations were the output of a one year, UK-based, multidisciplinary research project that involved a quantitative Carbon Footprinting Assessment of the emissions associated with 1 year of ULT storage (for both freezers and LN2) at four different case study sites; as well as two follow up stakeholder workshops to qualitatively explore UK biobank stakeholder perceptions, views, and experiences on how to consider such assessments within the broader social, political, financial, technical, and cultural contexts of biobanking. [ABSTRACT FROM AUTHOR]

Objective: This paper investigates the critical role of material thickness in freeze-dried pellets for enhancing the storage stability of encapsulated bacteria. Freeze dried material of varying thicknesses obtained from different annealing durations is quantified using Scanning Electron Microscopy (SEM) and X-ray microtomography (μCT), the material thickness is then correlated to the storage stability of the encapsulated cells. Methods: A formulation comprising of sucrose, maltodextrin, and probiotic cells is quenched in liquid nitrogen to form pellets. The pellets undergo different durations of annealing before undergoing freeze-drying. The material thickness is quantified using SEM and μCT. Storage stability in both oxygen-rich and oxygen-poor environments is evaluated by measuring CFU counts and correlated with the pellet structure. Results: The varying annealing protocols produce a range of material thicknesses, with more extensive annealing resulting in thicker materials. Storage stability exhibits a positive correlation with material thickness, indicating improved stability with thicker materials. Non-annealed pellets exhibit structural irregularities and inconsistent storage stability, highlighting the impracticality of avoiding annealing in the freeze-drying process. Conclusions: Extensive annealing not only enhances the storage stability of probiotic products but also provides greater control over the freeze-drying process, ensuring homogeneous and reproducible products. This study underscores the importance of material thickness in freeze-dried pellets for optimizing storage stability for probiotic formulations, and emphasize the necessity of annealing as a critical step in freeze-drying quenched pellets to achieve desired structural and stability outcomes. [ABSTRACT FROM AUTHOR]

Due to the significant pollution caused by the current extraction technology for deep coalbed methane (CBM), we propose the application of anhydrous cracking technology—liquid nitrogen cyclic freeze–thaw technology—to crack deep coal seams to achieve the release and extraction of coal bed methane. The self-made system for applying confining pressure is employed to simulate the deep coal seam in coal sample testing. Subsequently, the effect of joint structure with different angles of coal surface and bedding on the liquid nitrogen cyclic freeze–thaw process is evaluated. The investigation study identifies the damage patterns of the coal sample against the sole factor and coupling effect of confining pressure and joint angle. The findings reveal a clear impact of the cyclic freeze–thaw of liquid nitrogen on the expansion of deep coal seams. The application of appropriate inclined joints, combined with confining pressure, significantly minimizes the crushing time of coal samples, with the maximum expansion rate occurring at joints with a bedding angle of 45°±5°. This study provides vital theoretical support for the green and efficient exploitation of deep CBM. Practical Applications: The results of this study indicate that the waterless hydraulic fracturing technology—liquid nitrogen cyclic freeze–thaw technology—is highly suitable for coalbed methane extraction in deep, low-permeability coal seams, leading to increased gas recovery. The deeper the coal seam, the more pronounced the effects. Moreover, this technology does not cause environmental pollution. It specifically targets the pores, fractures, and joint structures within the coal, preserving the overall framework of the coal and preventing tunnel instability, thereby enhancing coal mining safety. Additionally, under the influence of liquid nitrogen cyclic freeze–thaw, joints at different angles exhibit varying rates of expansion. Joints extending at a 45° angle to the coal's bedding planes show the most rapid expansion, indicating that this orientation stores the maximum amount of coalbed methane postliquid nitrogen freeze–thaw. This pattern can be scientifically applied in the actual engineering design of extraction wells. The experimental results can provide a theoretical basis for guiding the on-site application of deep coal seam permeability enhancement and green coalbed methane extraction technology, thereby reducing environmental pollution. [ABSTRACT FROM AUTHOR]

Liquid nitrogen (LN2) can be utilized in the development of enhanced geothermal systems, as well as for deep/ultra-deep hydrocarbon reservoir stimulation, fire suppression, and other high-temperature geological projects. It is a crucial issue in the utilization of LN2 to investigate the pore structure evolution, permeability, and damage characteristics of high-temperature rocks under the influence of LN2 cooling shock. These rocks were first slowly heated to 150∼600°C and held for 2 h, followed by LN2 or natural cooling. The evolution of pore volume in high-temperature rocks affected by liquid nitrogen cooling was quantified. T 2 cutoff values were determined through centrifugal tests, while the contents of irreducible and mobile fluids were estimated. Based on the aforementioned analysis as well as changes in irreducible fluid saturation, pore throat, tortuosity, and permeability, this study examines the closure and development of pores along with permeability behavior. The findings suggest that, despite a more pronounced decrease in porosity at lower heating temperatures, LN2 cooling specimens exhibit superior pore connectivity and permeability compared to those cooled naturally. LN2 stimulation not only induces crack initiation and propagation but also results in further cooling induced densification based on heating densification. 225°C is considered to be the optimal temperature for cooling contraction induced densification in this study. At higher heating temperatures, the damage to rock cooled with LN2 is more severe than that of naturally cooled. This results in a greater increase in porosity, movable fluid content and proportion, and permeability of LN2 cooled specimens compared to naturally cooled specimens. The damage mechanism can be better understood by the constructed damage model that coordinates the pore increase/decrease and mutual pore transformation from the perspective of pore evolution. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of the distribution of γ-hexachlorocyclohexane in turnips and beets between their bulbs, tops, and skin. The sample preparation procedure recommended by GOST is supplemented by the use of liquid nitrogen for the deeper crushing and destruction of plant cells. It was found that the use of liquid nitrogen, with other experimental parameters being constant, leads to a 2–3-fold increase in the amount of the pesticide being determined. It was found that the distribution of γ-HCCH in plants is uneven: the highest concentration of the pesticide is found in the skin, while the amount of γ-HCCH in the tops was the lowest. It was shown that the pesticide is better accumulated in beet skin than in turnip skin; for the tops the pattern is reversed, and the accumulation of γ-HCCH in the bulbs of these root crops is similar in magnitude. The obtained data can be useful for analytical quality control services of agricultural products. [ABSTRACT FROM AUTHOR]