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Hydrogen isotopes are the main fuel in the fusion reactor, and the separation of hydrogen isotope gas mixture is the key process for the operation of fusion reactor. Cryogenic gas chromatography is an effective method which can be used for both separation and analysis of hydrogen isotopes. The chromatographic stationary phase determines the hydrogen isotopes separation performance. In this study, a series of pillared-layer MOFs Ni2(L)2 (dabco) (H2L: 1,4-benzenedicarboxylic acid (H2bdc), 1,4-naphthalenedicarboxylic acid (H2ndc), 9,10-anthracenedicarboxylic acid (H2adc); dabco: 1,4-diazabicyclo-[2.2.2]octane) were synthesized by changing the bridging dicarboxylate ligands with different steric hindrance. The effect of MOFs structure on hydrogen isotope interaction strength was studied by isothermal adsorption experiments of pure H2 and D2 at 77 K and 87 K, and programmed temperature desorption experiments of H2-D2 mixture from 25 K to 120 K. The enrichment factor for D2 over H2 up to 6.8 was obtained for Ni2(adc)2 (dabco) by static adsorption experiment of H2-D2 mixture. Finally, the MOFs composites Ni2(L)2 (dabco)@γ-Al2O3 were obtained by in situ solvothermal reaction loading MOFs on γ-Al2O3, and cryogenic gas chromatographic separation performance of H2-D2 and H2-HD-D2 mixtures using three composites-packed columns at liquid nitrogen temperature was investigated. The optimum separation was achieved when Ni2(adc)2 (dabco)@γ-Al2O3 was used as stationary phase due to strongest interaction strength with hydrogen isotope. The separation resolution R (H2/HD) and R (HD/D2) is up to 1.31 and 3.26 respectively.

A sustainable, easy to operate, scalable, and chemically pre-treatments free method has been explored for rice straw (RS) biomass conversion to furfural, 5-hydroxymethylfurfural (5-HMF), lignin and bio-char production. Initially, the RS was dipped into liquid nitrogen in a thermos flask and grinded easily to fine powder for better handling of biomass under reaction conditions in a reactor. The process also reduces the volume of biomass and enhances the surface area of RS biomass which was further analysed by SEM, TEM, IR, TGA and DSC, and further validated by its fruitful conversion to furfural, 5-HMF, lignin and bio-char synthesis in satisfied yields. The developed acidic process was performed at 130 °C for 6 hrs under a closed reaction system in reflux conditions. The ultra-performance liquid chromatography (UPLC) purity of furfural and 5-HMF was measured to >90% without additional purification technique. Moreover, the method was also examined in 250-gram scale and found to perform well.

Two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets are widely used in photocatalysis, energy storage and membrane separation owing to their high specific surface area, rapid photogenic carrier migration rate and numerous active sites. In this study, high performance g-C3N4 nanosheets with a particle size of about 290 nm were prepared by gas exfoliation. It was observed that the structure and properties of g-C3N4 nanosheets prepared at 500 °C were superior as compared to 300 °C and 400 °C. The state of g-C3N4 layers at different temperatures was also studied by molecular dynamics simulation. It was revealed that the liquid nitrogen (L-N2) molecules could only penetrate the edge space between g-C3N4 layers at 500 °C, however, no penetration took place in the layers. The traditional gas exfoliation mechanisms were observed to be incapable in explaining this phenomenon. Combining the experimental studies and molecular dynamics simulations, a novel gas exfoliation mechanism was proposed in this study so as to prepare few-layered g-C3N4 nanosheets. Based on this, the L-N2 molecules entered the edge space in g-C3N4 layers and subsequently pushed deeper to exfoliate the nanosheets.

Bismuth telluride based photosensitive elements were obtained and their properties were studied. Liquid exfoliation was used for bismuth telluride 2D material suspensions preparation in organic solvent only with no additional surfactants. 2D sheets in suspension had average size of 200–300 nm and thickness of 2–2.5 nm. Resistive photosensitive elements were obtained by the drop-casting method. The photoresponses of sensitive elements studied at room temperature and liquid nitrogen temperature.

LiNi0.8Co0.15Al0.05O2 has attracted attention due to its high capacity and low cost. Herein, we report a method for the rapid and efficient preparation of NCA cathode materials using oxalic acid with freeze-drying techniques, and compare the differences of electrochemical properties for different metal concentrations. The solvent volatilization by liquid nitrogen freezing and freeze-drying techniques resulted in a more uniform mixing of metal ions while reducing the reaction time and energy consumption. The results characterized using X-ray diffraction revealed that the layered structure of the material was better and the cation mixing was lower when the metal ion concentration in the solution reached 0.15 mol L−1. The electrochemical data revealed an initial charge–discharge capacity of 195 mAh g−1 at 0.1 C, capacity retention of 88.75% for 100 cycles at 1 C, and a discharge capacity of 139.7 mAh g−1 at 5 C. In addition, the cyclic voltammetry and electrochemical impedance spectroscopy reflect the material has low electrode polarization and excellent lithium-ion diffusion coefficient. The initial material diffusion coefficient is $$2.673 \times 10^{-15}\text{ cm}^{2} \mathrm{S}^{-1}$$ ; after 50 and 100 cycles, it is $$6.040 \times 10^{-16} \text{cm}^{2}\mathrm{S}^{-1}$$ 10−16 cm2S−1 and $$1.704 \times 10^{-16} \text{cm}^{2}\mathrm{S}^{-1}$$ respectively. The results provide a new idea for the energy-efficient synthesis of LiNi0.8Co0.15Al0.05O2.

The performance degradation of High Temperature Superconducting (HTS) tape, which may be influenced by various heat exchange conditions due to different cooling methods, is of significant for HTS devices under repeated overcurrent. In this article, considering different heat exchange conditions, a series of repeated overcurrent experiments were carried on YBCO tapes under 50Hz sinusoidal alternating current. The degradation of critical current of YBCO tapes after repeated overcurrent was recorded. the resistance characteristics of YBCO tapes under different cooling conditions were analyzed. Through finite element simulation, the temperature and current distribution of YBCO tape under different heat exchange conditions were simulated. The experimental results show that the overcurrent capability of the conductor under conduction cooling is far inferior to the liquid nitrogen immersion method.

A large-scale demonstration test of a triaxial high-temperature superconducting (HTS) cable for a practical cable system was performed in a chemical plant of a private company. The 200 m-long HTS (REBCO: REBa2Cu3O7-δ) triaxial cable, which was manufactured by connecting 3 cables using 2 joints via a snake-shaped layout, was laid approximately 5 m higher than ground level, and the cable was cryocooled by circulating liquid nitrogen. For the preverification test, the rise-up test of the liquid nitrogen and the development of technology for bending the cable, joining it, as well as laying and installing it, were conducted. No leakage of liquid nitrogen at the terminal due to damage caused by heat shock or liquid nitrogen drop impact was observed. The pressure required for the liquid nitrogen to achieve a 5 m height was from 27.5 to 33 kPa, which is in good agreement with the calculated pressure of 33.6 kPa. The cooling rate was well controlled, and the desired level of 4 K/h was achieved. The economic challenges and methods of achieving market penetration were also discussed. The goal was to realize a superconducting cable for practical applications, and it was thought that the energy and costs necessary for cryocooling could be drastically reduced by using the existing cold system in the plant. In this way, it is expected HTS cables can achieve low costs and high energy-saving effects and penetrate markets in the future.

Two immobilization methods (i.e., ice water-soaked using a digital temperature controller vs. freeze-dried using liquid nitrogen) were applied for mass production techniques of TiO2-embedded expanded polystyrene (TiEPS) balls with nanoscale TiO2 particles embedded on EPS balls. No significant changes in crystalline structure of TiO2 nanoparticles embedded on the TiEPS balls were observed during the mass production of TiEPS balls. Greater residuals of freeze-dried TiEPS balls suggested the improved immobilization methods for mass production procedures of TiEPS balls. Although similar growth inhibition between TiEPS balls using two immobilization methods was observed within 10 hrs, both growth and reproduction of M. aeruginosa can be more significantly inhibited by applying the freeze-dried TiEPS balls after 10 hrs. These results were mainly attributed to the difference in exposed surface area of embedded TiO2 nanoparticles which generated various reactive oxygen species peroxidizing and leading to the inactivation and degradation of M. aeruginosa. Relatively greater k value (0.207 day-1) was estimated from freeze-dried TiEPS balls than that (0.089 day-1) from ice water-soaked TiEPS balls, suggesting that both growth and reproduction of M. aeruginosa were effectively inhibited with greater amounts of reactive oxygen species generated from freeze-dried TiEPS balls. Consequently, self-floating freeze-dried TiEPS balls can be readily applied to inhibit the excessive growth of harmful algae in the stagnant water body without the recovery process for long time.

The protocol of aseptic cryoprotectant-free vitrification on human spermatozoa is well documented. However, data about the effect of permeable cryoprotectants at this procedure is limited. Presented study aimed to test the aseptic capillary vitrification technologies using permeable cryoprotectant-included or cryoprotectant-free media. Thirty-two normal samples were included and analyzed after vitrification in three different media and thawing. Three treatment groups were formed: Group 1, basic medium; Group 2, basic medium with 0.25 M sucrose; Group 3, basic medium with glycerol. Before plunging into liquid nitrogen, capillaries were filled by 10 μl of spermatozoa suspension and isolated from liquid nitrogen by location in hermetically closed 0.25 ml straws. Progressive motility, plasma membrane integrity, total motility/viability after 24, 48 and 72 h in vitro culture, apoptosis and mitochondrial membrane potential (ΔΨm) were determined after thawing at 42 °C. Progressive motility of spermatozoa in groups 1, 2, 3 was 24.9 ± 1.7%, 34.5 ± 2.8% and 34.0 ± 1.4%, respectively (P1-2,3 0.1). In conclusion, supplementation of medium for aseptic capillary technology for cryoprotectant-free vitrification of human spermatozoa by permeable cryoprotectant does not improve the quality of spermatozoa after warming.

Cryoprotective properties of combined media of permeable (dimethyl sulfoxide) and impermeable (polyethylene glycol with m. w. 1500) cryoprotective agents during rapid cooling in liquid nitrogen of canine erythrocytes using saline and sucrose-saline media have been investigated. It was found that the use of combined solutions of cryoprotective agents based on polyethylene glycol with m.w. 1500 (15%) and dimethyl sulfoxide (2.5–10%) in saline was not quite effective for cryopreservation of canine erythrocytes. Reducing the salt concentration and adding cell-impermeable sucrose to the cryopreservation medium increase the preservation of erythrocytes after warming. The best cryoprotective properties for canine erythrocytes were demonstrated by 10% dimethyl sulfoxide based on sucrose-saline medium, with high preservation of cells after freeze-warming, mechanical and osmotic stability of warmed erythrocytes. This indicates the possibility of a long-term storage and use of cryopreserved canine erythrocytes for transfusions. Probl Cryobiol Cryomed 2021; 31(1): 038–050

Maintaining enough flexibility and satisfied electrochemical performance simultaneously at subzero temperatures is still challengeable for flexible solid supercapacitors. In the present work, by adopting an organohydrogel electrolyte and reduced graphene oxide (rGO) films with microvoids serving as electrodes, a supercapacitor, which could be steadily operated down to -60 °C, has been obtained and has shown excellent low-temperature tolerance. The organohydrogel electrolyte consists of LiCl in glycerol/water solution containing polyvinyl alcohol, exhibiting excellent flexibility at -60 °C. Due to the introduction of micropores between rGO sheets, the porous membrane can be folded even in liquid nitrogen. Combining the rGO electrodes with the organohydrogel electrolyte, the maximum voltage of the present supercapacitor could be extended to 2.0 V, and a capacitance of 7.73 F·g-1 at -60 °C could be achieved. After 5000 charge/discharge cycles at -20 °C, the capacitance retention rate is 87.5%. The excellent flexibility and low-temperature resistance of the current supercapacitor pave a novel way for developing compression-resistant electronic samples compatible with a low-temperature environment.

Respective detection of microplastics (MPs) and nanoplastics (NPs) is of great importance for their different environmental behaviors and toxicities. Using spherical polystyrene (PS) and poly(methyl methacrylate) (PMMA) plastics as models, the efficiency for sequential isolation of MPs and NPs by membrane filtration and cloud-point extraction was evaluated. After filtering through a glass membrane (1 μm pore size), over 90.7% of MPs were trapped on the membrane, whereas above 93.0% of NPs remained in the filtrate. The collected MPs together with the glass membrane were frozen in liquid nitrogen, ground, and suspended in water (1 mL) and subjected to pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) determination. The NPs in the filtrate were concentrated by cloud-point extraction, heated at 190 °C to degrade the extractant, and then determined by Py-GC/MS. For MPs and NPs spiked in pure water, the method detection limits are in the range of 0.05-1.9 μg/L. The proposed method is applied to analyze four real water samples, with the detection of 1.6-7.6 μg/L PS MPs and 0.6 μg/L PMMA MPs in three samples, and spiked recoveries of 75.0-102% for MPs and 67.8-87.2% for NPs. Our method offers a novel sample pretreatment approach for the respective determination of MPs and NPs.

We previously developed a new vitrification method (equilibrium vitrification) by which two-cell mouse embryos can be vitrified in liquid nitrogen in a highly dehydrated/concentrated state using low concentrations of cryoprotectants. In the present study, we examined whether this method is effective for mouse embryos at multiple developmental stages. Four-cell embryos, eight-cell embryos, morulae, and blastocysts were vitrified with EDFS10/10a, 10% (v/v) ethylene glycol and 10% (v/v) DMSO in FSa solution. The FSa solution was PB1 medium containing 30% (w/v) Ficoll PM-70 plus 0.5 M sucrose. The state of dehydration/concentration was assessed by examining the survival of vitrified embryos after storage at -80°C. When four-cell embryos and eight-cell embryos were vitrified with EDFS10/10a in liquid nitrogen and then stored at -80°C, the survival rate was high, even after 28 days, with relatively high developmental ability. On the other hand, the survival of morulae and blastocysts vitrified in liquid nitrogen and stored at -80°C for four days was low. Therefore, morulae and blastocysts cannot be vitrified in a highly dehydrated/concentrated state using the same method as with two-cell embryos. However, when blastocysts were shrunken artificially before vitrification, survival was high after storage at -80°C for four days with high developmental ability. In conclusion, the equilibrium vitrification method using low concentrations of cryoprotectants, which is effective for two-cell mouse embryos, is also useful for embryos at multiple stages. This method enables the convenient transportation of vitrified embryos using dry ice.

Studying the law of coal adsorption capacity under the action of liquid nitrogen is very important for the extraction of coalbed methane. For this study, the lignite’s ability to adsorb methane was...

Objective: To investigate whether a metal chamber is an appropriate system for vitrification of ovarian tissue under clinical grade. Methods: Experimental study, control versus treatment. Bovine ovarian cortices cut in 1x1x1 mm fragments were vitrified using ethylene glycol and dimethyl sulfoxide inside steel cryovials, whose bases were in touch with Liquid Nitrogen (LN2). Screw caps closed the cryovials before plunging into LN2. Primordial (n=356) and primary (n=327) follicles and the stroma were analyzed after histological preparation using light microscopy. Results: High rate of primordial (93%) and primary (80%) follicles presented normal morphology in the rewarmed fragments. There was not a significant difference between controls and primordial follicles morphology (P=0.1519). Significant difference was observed for the primary follicles (P=0.0097). Important to point out that stromal cells and collagen fibers presented a remarkable integrity, without major alterations in the cryopreserved tissues. Conclusions: The steel cryovial seems to be a safe means of vitrification under clinical grade conditions, with very fast cooling rates and no direct contact of the biological material with the liquid nitrogen (LN2). Ovarian reserve represented by primordial and primary follicles and stroma are very well preserved in this vitrification system.

The article provides a comparative assessment of the main technological characteristics of consortia of lactic acid microorganisms used to make starter cultures for cottage cheese products, before and after freezing in liquid nitrogen, during storage for 6 months. It was found that when stored for 6 months with a temperature regime of minus (40 ± 2) ºС and below, the main technologically significant characteristics of consortia of lactic acid microorganisms for the manufacture of starter cultures used in the dairy industry are preserved.

Mesenchymal stromal cells (MSCs) have been demonstrated to possess anti-inflammatory and antimicrobial properties and are of interest in biotechnologies that will require cryopreservation. Recently, MSC-like cells were isolated from colostrum and milk. We used an interrupted slow freezing procedure to examine cryoinjury incurred during slow cooling and rapid cooling of MSC-like cells from swine colostrum. Cells were loaded with either dimethyl sulfoxide (Me2SO) or glycerol, cooled to a nucleation temperature, ice-nucleated, and further cooled at 1 °C/min. At several temperatures along the cooling path, cells were either thawed directly, or plunged into liquid nitrogen for storage and later thawed. The pattern of direct-thaw and plunge-thaw responses was used to guide optimization of cryopreservation protocol parameters. We found that both 5% Me2SO (0.65 M, loaded for 15 min on ice) or 5% glycerol (0.55 M, loaded for 1 h at room temperature) yielded cells with high post-thaw membrane integrity when cells were cooled to at least −30 °C before being plunged into, and stored in, liquid nitrogen. Cells cultured post-thaw exhibited osteogenic differentiation similar to fresh unfrozen control. Fresh and cryopreserved MSC-like cells demonstrated antimicrobial activity against S. aureus. Also, the antimicrobial activity of cell-conditioned media was higher when both fresh and cryopreserved MSC-like cells were pre-exposed to S. aureus. Thus, we were able to demonstrate cryopreservation of colostrum-derived MSC-like cells using Me2SO or glycerol, and show that both cryoprotectants yield highly viable cells with osteogenic potential, but that cells cryopreserved with glycerol retain higher antimicrobial activity post-thaw.

—The purpose of this work was to study the possibility of obtaining nanocellulose (NS) by ultrasonic (US) processing of powdered cellulose in a medium of liquid nitrogen (LN). To achieve this goal, it was necessary to determine the effect of the time of ultrasonic treatment in the medium of LN on the dispersed composition, crystallinity index and degree of polymerization (DP) of cellulose samples. Studies were performed using a powder X-ray diffractometer, a laser particle analyzer, and a scanning and transmission electron microscope. The DP of cellulose was determined by the viscosity of its solution in cadoxene by the standard method. It has been found that cryogenic grinding of flax cellulose samples does not lead to significant changes in its structural modification and degree of crystallinity, which indicates the high resistance of this material to such effects. However, ultrasonic exposure in the medium of LN with the subsequent treatment with 25, 45, 65% H2SO4 allows us to obtain cellulose nanospheres with a diameter of 48 to 437 nm and a yield of up to 40%. Unlike other types of nanoparticles (nanofibrillar, nanocrystalline cellulose), cellulose nanospheres have a larger surface area, which opens up the possibility of their effective use for the modification of composite materials.

Purpose of the study:to investigate the impact of hydroxyethyl starch (HES) and polyethylene oxide (PEO) on the indicators of preservation of murine testis interstitial cells (IC) under cryopreservation. Materials and methods.To isolate IC the enzymes were used: 0.2 mg/ml collagenase and 0.1 mg/ml DNase. The obtained cell suspension was cryopreserved in the solutions that contained 0; 0,7; 1,4; 2,1; 2,8 M of dimethyl sulfoxide (DMSO) and/or 10%, 20% fetal cow serum, 10 mg/ml PEO or HES. The samples (1 ml) were cooled at a rate of 1 °C/min to -80 °C then stored in liquid nitrogen (-196 °C). They were warmed at 37 °C in the water bath. Cryopreservation solution was removed. The number of cells and their preservation were assessed before and after with the assistance of Goryaev’s camera. Viability of IC, Leydig cell preservation and preservation of metabolic activity were measured with trypan blue dye, histochemical staining for 3β-hydroxysteroid dehydrogenase activity. Results.It was shown that 1,4 M DMSO without supplements favored IC preservation. Addition to the cryopreservation solution 10% and 20% of fetal cow serum or 10 mg/ml HES increased total preservation of IC by more than 10% and Leydig cell cryopreservation by an average 15%. HES 10 mg/ml may decrease DMSO concentration to 0,7 M. This combination had the best indicators of total preservation of IC, preservation of viable cells and Leydig cells: 75,8 (53,3; 93,3), 55,6 (45,1; 69,4), 57,1 (40,2;70,3) %, respectively. PEO was ineffective. Conclusion.High-molecular weight synthetic polymers such as HES can substitute protective properties of blood serum under cryopreservation and allow decreasing effective concentration of permeable cryoprotective such as DMSO.

In this paper, we report here the hydrogen storage capacity of activated carbon aerogel synthesized by ambient pressure drying using a new catalyst. The carbon aerogel (CA) has been synthesized by the sol-gel method using resorcinol (R) and formaldehyde (F). For drying of RF wet gel instead of expensive and unsafe supercritical process, we have used ambient pressure drying. To avoid shrinkage which may occur due to this mode of drying, instead of usual catalyst (C): Na2CO3, organic catalyst triethylamine (TEA), which is known to be a condensing agent has been used. In order to find out the effect of change of R/C ratio on hydrogen sorption, three different R/C namely CA 1000, CA 2000, and CA 3000 were taken. Structural and microstructural details have been studied employing XRD, SEM, TEM, nitrogen adsorption, FTIR, and Raman spectroscopy. TEM and nitrogen adsorption studies have revealed that aerogel with R/C 1000 exhibits a higher degree of micropore density. The hydrogen storage capacities for all R/C ratios have been determined. It has been found that carbon aerogel (CA) with R/C = 1000, exhibits the highest hydrogen adsorption capacity out of the three aerogels. At liquid nitrogen temperature, the hydrogen storage capacity of aerogel with R/C = 1000 for the as-synthesized and activated carbons have been found to be 4.00 wt % and 4.80 wt %. A viable reason for the occurrence of high hydrogen storage capacity at liquid nitrogen temperature for aerogel with R/C = 1000 has been put forward.

D cryo-plate method was successfully adapted for storage at – 80 °C and – 196 °C of Allium shoot tips. The optimal D cryo-plate method using garlic shoot tips for the storage at – 80 °C and – 196 °C includes preculture of shoot tips for 2 days at 25 °C on solidified 1/2 MS medium containing 0.3 M sucrose, then placing them in wells on an aluminum cryo-plate, embedded in calcium alginate gel. Osmoprotection was performed by immersing the cryo-plates with shoot tips for 30 min at 25 °C in 2.0 M glycerol and 1.0 M sucrose. The optimal dehydration time of shoot tips was for 30 to 180 min at 25 °C. Cooling was performed by transferring the samples on the cryo-plate into 2 ml cryotubes, then cooling into a deep freezer at – 80 °C for 14 days or directly plunging into liquid nitrogen (− 196 °C) for 60 min. The regrowth rate of shoot tips stored both at – 80 °C and – 196 °C was almost 100%. This optimized procedure was applied to seven Allium spp. The average regrowth rates after cooling at – 80 °C and – 196 °C were 95.3 and 94.0%, respectively. Thus, the storage of shoot tips at – 80 °C using D cryo-plate method is considered to be efficiently applicable for practical genebank storage. D cryo-plate method was successfully adapted for storage at – 80 °C of Allium shoot tips. Grass transition temperature of shoot tips after air desiccation were − 39.4 °C.

The application of the V cryo-plate method using either PVS2 or PVS3 and the D cryo-plate method to Platycodon grandiflorum in vitro axillary buds was investigated. Precultured buds (1 mm) were attached to cryo-plates using calcium alginate gel. Then, osmoprotection treatment (2 M glycerol and 1 M sucrose) was performed by immersing the cryo-plates for 30 min at 25°C. The procedures for each cryogenic method were as follows: in the V cryo-plate method, the buds on cryo-plates were exposed to PVS2 for 40 min (highest regrowth 71.1%) or PVS3 for 50 min (highest regrowth 82.2%). In the D cryo-plate method, the buds on the cryo-plates were dehydrated under the air current of a laminar air flow cabinet for 60 min (highest regrowth 80.0%) at 25°C. Then, the cryo-plates were plunged directly into liquid nitrogen. After cryopreservation, buds on the cryo-plates were rewarmed and unloaded by immersion in 1 M sucrose solution for 15 min at 25°C for subsequent plant regeneration. The average regrowth seen on the V cryo-plates exposed to PVS3 and in the D cryo-plate method was higher than that of the V cryo-plates exposed to PVS2. The regrowth after cryopreservation in the V cryo-plate method with PVS2 was not stable. Thus, the V cryo-plate method with PVS3 and the D cryo-plate method are considered to be practical cryopreservation methods for P. grandiflorum germplasm.

A comparative analysis of the survival rate of the human gut microbiota after low-temperature preservation under the protection of penetrating (dimethylsulfoxide and glycerol), nonpenetrating (gelatin) and gas (helium) protectors was performed. Increased resistance of intestinal bacteria to the effect of low temperatures was revealed. A significant portion of the bacteria (50.0 ± 3.0%) remained viable after freezing in liquid nitrogen without the cryoprotector(s). The greatest survival was achieved under the protection of 5% dimethylsulfoxide (86.0 ± 4.0%), 5% glycerol (82.0 ± 5.2%), and 10% gelatin (75.0 ± 5.0%). The combination of cell-penetrating (dimethylsulfoxide and glycerol) and nonpenetrating (gelatin) protectors did not lead to a synergistic effect. The use of atmospheric helium for cryoprotection of heterogeneous human gut microbiota did not increase its survival, even in combination with such powerful protectors as dimethylsulfoxide and glycerol, which indicates the need to optimize cryoprotection media, in particular, for strict anaerobes.

In this study, it was aimed to determine the usability of different diluents and cry protectants in cryopreservation of Peking duck semen. Semen samples were collected from five male ducks, twice a week for four weeks, using the abdominal massage method. In the study, 40 semen samples were used. Semen samples from ducks were combined (mixed) after being evaluated individually. Mix semen volume (ml), density (×109 / mL), pH, motility (%) and vitality (%) values were determined as 1.84±0.04, 1.72±0.8, 6.88±0.29, 71.55±3.28 and 74.27±4.67 respectively. In the study, as cry protectant, Glucose I (Gâ… ) containing 6%DMF (dimethylformamide), Tris-Glucose I (TI), Lactated Ringer's-Glucose I (LGI), Lactated Ringer's I (LI) and Glucose II (Gâ… I) containing 5% DMSO, Tris-Glucose II (TII), Lactated Ringer's-Glucose II (LGII), Lactated Ringer's II (LII) were used as diluents. The mixed semen was divided into eight equal parts and 1:3 ratio diluent was added and equilibrated in straws for 90 minutes at + 4°C. The straws were first frozen to -80°C with liquid nitrogen vapour, and then stored in liquid nitrogen at -196°C. After freezing and thawing, the highest motility value was determined in diluent LGI with 41.91%. In other diluents used, the mortality values were determined as LII (33.10%), LGII (32.80%), LI (29.00%), GI (23.66%), TI (12.91%), GII (11.22%) and TII (6.90%). Vitality (%) values were determined as LGI (44.08%), LII (38.50%), LGII (35.10%), LI (33.58), GI (30.91%), GII (23.10%), TI (20.66%) and TII (14.80%) respectively. In this study, it has been determined that the lactated Ringer's-Glucose diluent containing 6% DMF is more advantageous in terms of semen vitality and mortality values when compared to other diluents and that it can be used for long-term storage of duck sperm.

Molecular investigations are crucial for further developments in precision medicine. RNA sequencing, alone or in combination with further omic-analyses, resulted in new therapeutic strategies. In this context, biobanks represent infrastructures to store tissue samples and body fluids in combination with clinical data to promote research for new predictive and prognostic biomarkers as well as therapeutic candidate molecules. Until today, the optimal storage conditions are a matter of debate especially with view to the storage temperature. In this unique approach we compared parallel samples from the same tumour, one half stored at − 80 °C and one half in the vapor phase of liquid nitrogen, with almost identical pre-analytical conditions. We demonstrated that RNA isolated from breast cancer samples revealed significantly higher RINe-values after 10 years of storage in the vapor phase of liquid nitrogen compared to storage at − 80 °C. In contrast, no significant difference was found regarding the DIN-values after DNA isolation. Morphological changes of the nucleus and cytoplasm, especially in the samples stored at − 80 °C, gave insights to degenerative effects, most possibly due to the storage protocol and its respective peculiarities. In addition, our results indicate that exact point-to point documentation beginning at the sample preparation is mandatory.

Introduction: Measurements from frozen sample collections are important key indicators in clinical studies. It is a prime concern of biobanks and laboratories to minimize preanalytical bias and variance through standardization. In this study, we aimed at assessing the effects of different freezing and thawing conditions on the reproducibility of medical routine parameters from frozen samples. Materials and Methods: In total, 12 pooled samples were generated from leftover lithium heparinized plasma samples from clinical routine testing. Aliquots of the pools were frozen using three freezing methods (in carton box at -80°C, flash freezing in liquid nitrogen, and controlled-rate freezing [CRF]) and stored at -80°C. After 3 days, samples were thawed using two methods (30 minutes at room temperature or water bath at 25°C for 3 minutes). Ten clinical chemistry laboratory parameters were measured before (baseline) and after freeze-thaw treatment: total calcium, potassium, sodium, alanine aminotransferase, lactate dehydrogenase (LDH), lipase, uric acid, albumin, c-reactive protein (CRP), and total protein. We evaluated the influence of the different preanalytical treatments on the test results and compared each condition with nonfrozen baseline measurements. Results: We found no significant differences between freezing methods for all tested parameters. Only LDH was significantly affected by thawing with fast-rate thawing being closer to baseline than slow-rate thawing. Potassium, LDH, lipase, uric acid, albumin, and CRP values were significantly changed after freezing and thawing compared with unfrozen samples. The least prominent changes compared with unfrozen baseline measurements were obtained when a CRF protocol of the local biobank and fast thawing was applied. However, the observed changes between baseline and frozen samples were smaller than the measurement uncertainty for 9 of the 10 parameters. Discussion: Changes introduced through freezing-thawing were small and not of clinical importance. A slight statistically based preference toward results from slow CRF and fast thawing of plasma being closest to unfrozen samples could be supported.

Geopolymer beads, conceived as alternative low cost adsorbents for wastewater treatment, were shaped by a dripping technique in liquid nitrogen, through an ice-templating process. PEG600 was added as a binder to ease the process, standardizing the beads dimension. The beads were investigated in terms of morphology, microstructure and mechanical strength, following compressive tests by ISO 18591. Functional tests, to verify the adsorption capacity, were conducted using methylene blue (MB) with different concentrations and for different contact time. The removal efficiency was mainly related to the morphology and porosity of the beads, which in turn was directly related to the water content added to the geopolymer slurry. In general, all beads reached an average removal efficiency of 98% after 24 h. However, the best performing beads were able to uptake MB very quickly, attaining a removal efficiency of 76% after only 30 min. (C) 2020 Elsevier Inc. All rights reserved.

In 1758, Benjamin Franklin froze water by means of the evaporation of diethyl ether. Diethyl ether became the coolant in early mechanical refrigerators and ice makers. Refrigeration advances by Carl von Linde and others provide medical oxygen from the air, liquid nitrogen for cryopreservation and cryoablation, xenon for inhaled anesthesia, and liquid helium for supercooling of magnetic resonance image scanners.

Carbon materials have been extensively researched as solar absorbers in the field of solar steam generation (SSG) for their full spectrum absorption, non-biotoxicity, and excellent photothermal properties. In this work, we provide a general ice-templating method for obtaining multidimensional carbon materials controlled by regulating the surface tension during the phase separation of phenolic resin solution. Through spraying the atomized droplets into liquid nitrogen, freeze drying, and carbonization, a type of spherical carbon material assembled with carbon nanosheets with a thickness of about 3 nm can be obtained. With the enhancement of the surface tension by spray and the adjustment of the concentration of phenolic resin, a series of morphologies of carbon materials can be obtained from nanowires to nanosheets and further to spherical assemblies. In addition, an efficient SSG system was designed by combining the carbon material with polyurethane foam as matrix, notably showing good evaporation efficiency of 81.7% with a solar flux of 500 W/m2. This work provides a new idea for the morphology control of assembled carbon materials and has achieved excellent performance in the field of photothermal conversion.

Current polymeric transfer methods of 2D materials often bring about the presence of wrinkles, cracks, and polymer residue, limiting the quality of the transferred materials and performance of devices. Herein, we report a transfer approach combining pretreatment by liquid nitrogen and lithium ion intercalation with polymer composite of small molecules and polystyrene to achieve high-fidelity transfer of 2D transition metal dichalcogenides (TMDs) grown by chemical vapor deposition. In this method, the as-grown samples were pretreated by liquid nitrogen and lithium ion intercalation to weaken the bonding between the TMD and the substrate. A polymer composite incorporating small molecules, namely camphor or naphthalene, was used to increase the dissolution of the polymer film. These two processes work synergistically to enable nearly 100% transfer of monolayer TMDs virtually free of wrinkles, cracks, or organic residue with retained optical properties. Our technique can be generalized for the efficient and high quality transfer of other 2D materials.

The sustainable, cleaner and eco-friendly cryogenic coolants, namely, carbon dioxide (CO2) and liquid nitrogen (LN2) were compared with conventional wet coolant in this investigation. The performance and the influence of these coolants about cutting zone temperature (Tc), feed (Fx), normal (Fy) and thrust (Fz) forces, tool wear, chip morphology, surface morphology and roughness (Ra) in the machining of die steel were examined. The use of CO2 and LN2 caused a reduction of 50.49% and 53.97% respectively in Tc in comparison with the wet coolant. Similarly, the application of cryogens during the end milling operations reduced the tool wear, chip width and produced lower cutting forces. The Ra value obtained was in the range of 0.17 μm to 0.22 μm by CO2 cooling. Likewise, it was about 0.22 μm to 0.39 μm in LN2 cooling. The substantial improvement in surface topography and morphology was seen through the use of the cryogenic CO2 environment. Also, the 55NiCrMoV7 steel surface finish was better in cryogenic environments.

In ice cream production, the dispersal of ice crystals ‒ an important organoleptic indicator ‒ depends on the number of water crystallization centers at the first stage of freezing (nucleation). At the subsequent freezing, the remaining water crystallizes at existing centers. This paper reports the results of studying the substantiation of nucleation intensification by increasing the rate of freezing in nitrogen and by employing a germ-forming effect, predetermined by the presence of particles. The nucleation initiators considered are suspended particles of the fat phase and a partially soluble stabilizer (microcrystalline cellulose) and coagulated protein. It has been established that the largest dispersal of ice crystals was achieved when the freezing rate increased while using nitrogen. At a fraction of the frozen water of 40‒50% under immersion freezing and subsequent aerial pre-freezing the size of ice crystals over 6-month-storage did not exceed 37µm. It has been shown that the fatty particles were an additional factor in initiating the nucleation at immersion and contact-free freezing in a freezer. We have established a positive effect of the suspended particles of microcrystalline cellulose and coagulated protein on the dispersal of ice crystals in the process of ice cream production and over a 6-month-storage. The average diameter of ice crystals during storage when using microcrystalline cellulose in the creamy ice cream was 39µm, in fermented milk ice cream containing yogurt – 32‒34µm. The study results make it possible to define new directions in the intensification of nucleation, based on the principles of the increased rate of freezing and the intensification of nucleation using additional crystallization centers

Cryopreservation of human spermatozoa with low concentration while maintaining adequate post-thawing motility remains a major challenge for male fertility preservation. A convenient and efficient ultra-rapid freezing method for small amounts of human spermatozoa in a closed Hemi-Straw carrier system (CHS) was developed. Spermatozoa from 60 healthy men were involved in a parameter refining test and another 15 extreme oligozoospermic specimens were assigned to a verification test. A commercialized sperm freezing medium, Quinn's Advantage® Sperm Freeze medium (glycerol and sucrose as the cryoprotective agent) was used in the study. The results showed that the highest recovery rates would be obtained via the method of 2 μl single droplet sequential interval loading, by placing the straw at 1 cm above the liquid nitrogen (LN2) surface for 60 s during freezing and 2 cm above the LN2 for 2 min during thawing. This method was applied in cryopreservation for the normozoospermic specimens and compared with a conventional slow freezing method. The results were better than those in the control group in the total motility recovery rate (77.8 ± 11.2% vs 56.6 ± 11.9%, P

Even though conventionally prepared octacalcium phosphate and collagen composite (OCP/Col) has exhibited excellent bone regeneration and has recently been commercialized for treating bone defects, reproducible appositional bone formation with OCP/Col has never been achieved. The present study investigated whether appositional bone formation could be achieved by altering the density of OCP/Col and applying liquid nitrogen during the preparation of OCP/Col. The prepared OCP/Col disks had eight variations and were divided into categories according to four different type of densities (1.0, 1.3, 1.7, and 2.0) of OCP/Col and two different pre‐freezing conditions of gas phase (G group: −80°C) and liquid phase (L group: −196°C). These disks were implanted into subperiosteal pockets in rodent calvaria, five samples per each eight variations. Radiomorphometric analysis was conducted at 4 and 12 weeks after implantation, and histological analysis was conducted at 12 weeks after implantation. OCP/Col samples in the L group tended to retain their height and shape and had enhanced appositional bone formation, whereas OCP/Col samples in the G group tended to lose their height and shape and had limited appositional bone formation. The appositional bone formation increased along with growing density of OCP/Col, and L2.0 demonstrated higher appositional bone formation than other samples. These results suggest that the pre‐freezing conditions and densities of OCP/Col affect the appositional bone formation.

In this study, a simple and rapid sample preparation method named liquid-nitrogen-induced homogeneous liquid–liquid microextraction has been developed for the extraction and pre-concentration of Co(II) and Ni(II) ions before their analysis by flame atomic absorption spectrometry. For this purpose, first, acetonitrile containing 8-hydroxyquinoline is added into a sample solution and the mixture is vortexed. As a result, a homogeneous solution is formed. Subsequently, the solution is cooled using liquid nitrogen for a few seconds. By this process, due to difference in the freezing point of acetonitrile and water, the homogeneous state is broken and the analytes (as oxinate complexes) are extracted into liquid acetonitrile phase collected on top of the frozen aqueous phase. The linear dynamic ranges obtained for Ni(II) and Co(II) were 1.0–30 and 0.50–20 μg L−1, respectively. The obtained limits of detection were 0.36 and 0.20 μg L−1 for Ni(II) and Co(II), respectively.

We have studied carbyne as a promising hydrogen storage material. Density functional theory simulations with vdW corrections have been used to investigate lithium sorption on carbyne and the interaction of pristine and Li-functionalized carbon chains with molecular hydrogen. We showed that Li adatoms at small concentrations stay atomically dispersed on carbyne, donating 0.9e to the chain. Moreover, in the presence of Li, hydrogen adsorption energy increases by more than 5 times in comparison with pristine carbyne. Overall, up to three hydrogen molecules per Li adatom have an adsorption energy close to the range of 200–600 meV per H2, which is necessary for effective sorption/desorption cycles. The resulting theoretical uptake (7.1 wt%) is higher than the U.S. Department of Energy's ultimate goal (6.5 wt%). The calculated van't Hoff desorption temperatures exceed considerably the boiling point of liquid nitrogen. Our results confirm the potential of Li-decorated carbyne for hydrogen storage.

The objective of this study was to develop a successful freezing protocol for cryopreservation of Danube barbel sperm, and to identify the presence of different spermatozoa subpopulations. By testing different concentrations of different cryoprotectants, we determined that the use of 5% dimethyl sulfoxide (DMSO) yielded the highest total motility of ~25%. Cooling rates influenced by frame height and cooling time in liquid nitrogen vapor showed that a frame height of 3 cm and cooling time of 2 min yielded the highest post-thaw motility. Supplementation of cryomedia with 0.1 M of sugars led to an increase in the total post-thaw motility by ~50%, while protein supplementation lowered post-thaw motility. Motile spermatozoa hierarchically clustered according to their motility parameters, displaying a four-subpopulation (SP1-SP4) structure. SP1 was defined by low values of velocity but high overall linearity; SP2 was comprised of fast non-linear spermatozoa, that had high velocity values but low linearity; SP3 was characterized by fast linear spermatozoa, and SP4 by slow non-linear spermatozoa. Protocols developed in this study will lead to the creation of new and enhanced conservation strategies for this species.

Cryogenic coolants as cutting fluids are gaining significance as they are eco-friendly, recyclable and moreover they do no longer produce any dangerous effect on the operators. Cryogenic liquid nitrogen at −196 °C has commonly used coolant in cryogenic machining industries. This experimental work was performed by milling action of AISI D2 tool steel tool wherein the lubrication effect caused due to cryogenic coolant (LN2) sprayed as a cutting fluid in comparison to the less moist (Dry) and moist (wet) metal removing operations based on tear and wear of tool and roughness of the surface on the machined component. Experiments have accomplished the usage of TiN coated tungsten carbide tool which has different speed combinations and feed rate combinations. The workpiece roughness of the surface was minimized up to 15–28% for dry metal removing as well as 26–38% over moist metal removing. This is because of LN2 machining offers higher lubrication and cooling effect was the minimization in the temperature behind cutting.

Cannabis sativa L. seeds are rich in essential polyunsaturated fatty acids and highly digestible proteins, with a good nutritional value. Proteomics studies on hempseed reported so far have mainly been conducted on processed seeds and, to our knowledge, no optimization of protein extraction from hemp seeds has been performed. This study investigates the SDS-PAGE profile of hempseed proteins comparing different methods of extraction, (Osborne sequential extraction, TCA/acetone, MTBE/methanol, direct protein solubilization of defatted hempseed flour), two conditions to keep low temperature during seed grinding (liquid nitrogen or ice) and two solubilization buffers (urea-based or Laemmli buffer). Among the tested conditions, the combination of liquid nitrogen + TCA/acetone + Laemmli buffer was not compatible with SDS-PAGE of proteins. On the other hand, urea-based buffer achieved more reproducible results if combined with all the other conditions. TCA/acetone, MTBE/methanol, and direct protein solubilization of defatted hempseed flour demonstrated a good overview of protein content, but less abundant proteins were poorly represented. The Osborne sequential separation was helpful in diluting abundant proteins thus enhancing the method sensitivity.

In X-ray macromolecular crystallography, cryoprotection of crystals mounted on harvesting loops is achieved when the water in the sample solvent transitions to vitreous ice before crystalline ice forms. This is achieved by rapid cooling in liquid nitrogen or propane. Protocols for protein crystal cryoprotection are based on either increasing environmental pressure or reducing the water fraction in the solvent. This study presents a new protocol for cryoprotecting crystals. It is based on vapour diffusion dehydration of the crystal drop to reduce the water fraction in the solvent by adding a highly concentrated salt solution, 13 M potassium formate (KF13), directly to the reservoir. Cryoprotection by the KF13 protocol is non-invasive to the crystal, high throughput, not labour intensive, can benefit diffraction resolution and ligand binding, and is very useful in cases with high redundancy such as drug discovery projects which utilize very large compound or fragment libraries. Moreover, an application of KF13 to discover new crystal hits from clear drops of equilibrated crystallization screening plates is also shown.

In this work, DC and low frequency noise measurements are performed on n-channel gate all around (GAA) vertically stacked silicon nanosheets (NS) at room and liquid nitrogen temperature. Principal static (DC) parameters such as low field mobility, access resistance and subthreshold swing are estimated. Preliminary low frequency noise studies reveal that the 1/f noise may be explained by the carrier number fluctuations mechanism at room and liquid nitrogen temperature operation.

A simple process to synthesize metal nitride particles was proposed using submerged arc discharge plasma in liquid nitrogen. Gibbs standard free energy was considered for the selection of the nitride-forming materials. In this study, titanium (Ti) and aluminum (Al) electrodes were used as raw materials for nitride particle preparation. Liquid nitrogen acted as a dielectric medium as well as a nitridation source in this process. A copper electrode was also used as a non-reactive material for comparison with the reactive Ti and Al electrodes. As the operating conditions of the experiments, the arc discharge current was varied from 5 A (low-power mode) to 30 A (high-power mode). The formation of titanium nitride (TiN) and aluminum nitride (AlN) was confirmed in the particles prepared in all experimental conditions by X-ray powder diffraction (XRD). The observation using a field emission scanning electron microscope (FE-SEM) and a field emission transmission electron microscope (FE-TEM) indicated that the synthesized TiN particles showed a cubic morphology, whereas AlN particles containing unreacted Al showed a spherical morphology. The experiments using different metal electrode configurations showed that the anode generated most of the particles in this process. Based on the obtained results, a particle formation mechanism was proposed.

Isolation of heat-sensitive reaction products in post-synthesis workup procedures often requires ambient-or low-temperature solvent removal. In the method demonstrated here, solvent evaporation is driven by the pressure gradient between a distillation flask and a chilled receiver in an evacuated closed system containing a minimal amount of residual noncondensable gas. Using an all-glass apparatus, the method is exemplified by evaporation of solvent samples from a distillation flask containing 50 mL of either dimethylformamide, dimethyl sulfoxide (DMSO), or N-methylpyrrolidone (NMP). The distillation flask is suspended in a water bath at temperatures of 18−28 °C, the evaporated solvent is collected in a receiver chilled with liquid nitrogen, and the entire process is completed in 90−140 min. The practicality of this method is further illustrated on a bench-chemistry scale by DMSO and NMP solvent removal from solutions of benzophenone, monitored by gravimetric and (1)H NMR methods. Modification of the demonstrated method to mimic freeze-drying conditions (by reducing heat flow to the distillation flask) can be used for recovery of water-soluble compounds including polymers and biopolymers. We propose the name “cryovap” for this solvent removal method.

Cutting fluids pollute the environment and harm human health. Cryogenic grinding with liquid nitrogen and carbon dioxide gas is a new method that is used to create a cleaner environment and maintain human health. In order to investigate the effect of the cooling method in the grinding process, surface roughness and hardness were compared in the presence of lubricating fluid and cryogenic cooling with three speeds and three grinding depths. The results of this study showed that except for high depths of cut and cutting velocities, the obtained surface quality with liquid nitrogen and carbon dioxide gas was better in comparing to lubricating fluid. In addition, in high depths of cut and cutting velocities, the obtained hardness from liquid nitrogen and carbon dioxide gas is higher in comparing to lubricating fluid. Then, by using ANOVA, that is concluded the depth of cut is the most effective parameter on surface roughness and hardness. Keywords: Grinding, Coolant, Cryogenic, Surface roughness, Hardness

Introducción: Laelia autumnalis es una orquídea nativa de México amenazada por la pérdida de su hábitat. Para la conservación de esta especie es necesario evaluar la efectividad de métodos de desinfección y secado para aplicar técnicas de crioconservación y cultivo in vitro.Método: En un primer experimento, se consideró la técnica de inmersión directa en nitrógeno líquido para optimizar el almacenamiento a largo plazo. Sin embargo, la germinación asimbiótica fue afectada por el hongo Alternaria sp., motivo por el cual se realizó un segundo experimento con dos ensayos para evaluar la viabilidad y germinación asimbiótica de las semillas en función de los desinfectantes hipoclorito de calcio al 1% e hipoclorito de sodio comercial al 15% y los métodos de secado con aire en la campana de flujo laminar, gel de sílice y bomba de vacío, antes y después de la inmersión en nitrógeno líquido.Resultados: Los desinfectantes hipoclorito de calcio e hipoclorito de sodio disminuyeron la viabilidad en 49 y 37%, respectivamente, así como los métodos de secado con aire en la campana de flujo laminar y bomba de vacío con 36 y 28%, respectivamente. La pérdida de viabilidad fue menor cuando se desinfectó después de la inmersión en nitrógeno líquido; la germinación se estimuló con hipoclorito de sodio (100%).Conclusión: Las semillas de L. autumnalis deben desinfectarse con hipoclorito de sodio y secarse con aire de la campana de flujo laminar después de la crioconservación por inmersión directa en nitrógeno líquido para evitar daños en los tejidos.

Disposing of liquid crystal display (LCD) waste has significant effects on the environment, human and animal health, and metal resources by extension if inappropriately treated. In this study, we have developed a process for the separation of indium–tin oxide (ITO) glass from the LCD panel and evaluated the best digestion process for the analysis of In and Sn from ITO glass. The digestion process of scrap LCD in this work involves the separation of the polarizing film from ITO glass by environmentally friendly cold thermal shock method with liquid nitrogen, the removal of liquid crystals between the ITO glass substrates by ultrasonic cleaning, and the analysis of In and Sn from ITO glass by acid digestion method with a suitable reagent. Various brands of scrap LCDs were treated with six different digestion methods to determine In and Sn concentrations. The result of this study indicates that aqua-regia digestion procedure was the best method for the analysis of In and Sn. The concentrations of In and Sn in various brands of LCDs were in the range of 233–332 mg/kg and 43–421.5 mg/kg, respectively. Further, the analysis of In and Sn metals at different locations of the same scrap LCD was also carried out and it was observed that the concentrations of these metals (In—0.0278–0.0369% and Sn—0.0033–0.0078%) were significantly similar, with slight variations in their percentages.

Rare earth barium copper oxide (REBCO) type materials are widely used in second-generation high-temperature superconductor tapes to carry high current volumes. These tapes can provide high critical currents along with good tolerance to perpendicular magnetic fields. However, REBCO tapes generally use a laminate structure that suffers from low peeling strength among its inner interfaces. Previously, we proposed a bending-peeling (BP) method and applied it to measurement of the interfacial strength of REBCO tapes at room temperature. All samples failed at the REBCO layer at room temperature. In this paper, we used the BP method to perform low-temperature interfacial strength measurements at liquid-nitrogen temperatures. There are two types of failure, where one involves peeling of the REBCO layer and the other involves peeling at the interface between the tape and the epoxy resin. The errors in the BP method were discussed in detail. The superconducting current was monitored during the BP experiment and showed that the effect of out-of-plane tensile stress on the superconducting current was not significant before the breaking of the tape. The degradation in the superconductivity is mainly caused by the structural failure of the REBCO layer.

A key problem in the conversion of cellulose into chemicals and fuels is the low product yield from cellulose due to its robust structure. In this work, for the first time, cellulose was pretreated with coupling of liquid nitrogen and ball milling (LN–BM) for cellulose hydrolysis. After the LN–BM treatment, the glucose yield from cellulose by HCl in water increased by almost 2 times and yield of formic acid catalyzed by H2SO4–NaVO3 was more than 3-fold that obtained from untreated cellulose. The yields were also much higher than that from the individually ball-milled cellulose. The structure variation of cellulose indicated that reduction of both crystallinity index and molecular weight contributed to improving the conversion efficiency, but the former was the dominant factor. The combination of liquid nitrogen and ball milling developed in this work is an effective and environment-friendly approach for cellulose pretreatment.

Material disintegration is the primary step in β-glucan determination in cereal grains. This study investigated the effect of disintegration approach on β-glucan content, determined by an enzymatic method in mature kernels of barley and oat. Milling with a coffee grinder was found to be relevant only for pre-disintegration and homogenization of the grain (4.6% and 3.2% β-glucan content was found in barley and oats, respectively). Ball milling appeared to be the most efficient approach for reducing material particle size, but resulted in samples with underestimated β-glucan content (4.6% and 3.3% in barley and oats, respectively). Grinding with mortar and pestle in liquid nitrogen and repeated centrifugal milling were found to be the optimal disintegration methods for barley kernels (5.2% and 4.7–4.8% β-glucan content, respectively). Grinding with mortar and pestle (either in dry state or in liquid nitrogen) and single centrifugal milling were the optimal disintegration methods for oat kernels (3.6–3.9% and 3.3–3.4% β-glucan content, respectively).