Dry Ice Research Articles

Quality of frozen equine semen stored in different shipping containers

The use of cryopreserved semen in horses requires sophisticated equipment, including containers maintaining the temperature of liquid nitrogen (LN). Simpler and less expensive devices for transport of frozen semen may help breeding programs in developing countries and reduce the costly return of empty containers. Veterinarians sometimes question the quality of frozen-thawed shipped semen because of potential fluctuations in shipping temperatures. This study aimed to investigate the effects of shipping duration and temperature on post-thaw quality of frozen semen stored either in a dry shipper (≤ -150°C) or on dry ice (≤ -78°C) for 14 days. Straws (n=165) containing cryopreserved semen from five stallions stored in liquid nitrogen were transferred (D0) to a dry shipper (DS) and to a styrofoam box with dry ice (DI). Straws from DS and DI were returned to LN on D1, D3, D7, D10, and D14. All semen doses were evaluated at each time point by CASA for total (TMot) and progressive motility (PMot), and kinematic parameters such as average path velocity (VAP), curve-linear velocity (VCL) and straight-line velocity (VSL), by fluorescence microscopy for the percentage of membrane-intact spermatozoa (SYBR14/PI stain), and high mitochondrial membrane potential (HMMP; JC-1 stain). Data were analyzed by repeated measures ANOVA with both storage time and storage device as within subject factors. Thetemperature inside the DS and DI containers was monitored continuously with a Tempod 200XB data logger. There were no temperature fluctuations during the 14-day storage in both containers. Until D7 of storage, no changes were observed in TMot, PMot, and membrane-intact spermatozoa (%). Thereafter all three parameters decreased in semen stored in DI but not in DS (storage device at least p<0.05, time p<0.01, time x storage device p<0.001; e.g., TMot D7 on DI and in the DS both 59±14 versus 34±10 and 60±13%, respectively, on D14; membrane-intact spermatozoa D7 on DI 50±13 and in the DS 52±12 versus 28±7 and 53±19% on D14). The HMMP percent decreased continuously during storage in both containers (p<0.001) and this decrease was more pronounced for DI compared to DS (time x storage device p<0.05; DI from 43±4 on D1 to 26±3% on D14, DS from 43±5 on D1 to 30±4% on D14). All velocity parameters remained constant with storage in both devices. In conclusion, cryopreserved frozen stallion semen can be stored for up to 7 days on dry ice without negative effects on post-thaw characteristics. Dry ice may thus be an alternative to liquid nitrogen containers for the short-term transport of frozen stallion semen. Controlled insemination trials to confirm the fertility of frozen stallion semen shipped on dry ice are justified.

COMPARING THE EFFICIENCY OF DIFFERENT CARBON DIOXIDE SOURCES IN COLLECTING MOSQUITO VECTOR SPECIES ON THE TEMPE CAMPUS OF ARIZONA STATE UNIVERSITY.

We compared the effectiveness of 4 different carbon dioxide (CO2) sources (sugar-fermented BG-CO2, sugar-fermented Fleischmann yeast, dry ice, and compressed gas cylinders) in attracting different mosquito species in 2 separate 4 × 4 Latin square trials. The CO2 generated by dry ice and the gas cylinders collected more Culex quinquefasciatus than the sugar-fermented BG-CO2 and Fleischmann yeasts during the 1st trial (16-h surveillance periods), but there was no significant difference in Aedes aegypti numbers. There were no significant differences between the different CO2 sources in collecting Cx. quinquefasciatus and Ae. aegypti mosquitoes in the 2nd trial (24-h surveillance periods). Catches for Culiseta inornata and Cx. tarsalis were too low in both experiments for formal statistical analysis. Data can be used to inform local mosquito surveillance programs, but the selection of a CO2 source will also depend on financial and logistical constraints.

Adding dry ice into ultra-high-performance concrete to enhance engineering performances and lower CO2 emissions

Developing low-carbon cement-based materials is crucial to address the pressing sustainability concerns the construction industry faces. This study elucidates the effect of adding dry ice on the micro-meso-macro properties of ultra-high-performance concrete (UHPC). The main original points of the method were summarized as follows: simple operation, low technical difficulty, no specific equipment required, and solving the problem that the carbonation curing method is difficult to use in low water-cement ratio concrete. The results show that adding dry ice generates microscopic CO2 bubbles that react with the carbonation of Ca(OH)2 and improve the later-stage strength and electrical resistivity. And adding dry ice reduces the heat of hydration and promotes ettringite formation. The results of microscopic analyses confirmed that increasing the dry ice content results in a decrease in Ca(OH)2; hence more calcium carbonate is formed. It was also observed that the carbon conversion effect became more apparent when the curing period was 28 days. And optical micrograph analysis showed that adding dry ice increased the total bubble content of the matrix and decreased the average bubble diameter, thus affecting the change in macroscopic properties. Moreover, as the addition of dry ice increased from 0 to 15%, the CO2 emission per unit strength decreased from 6.5 to 4.5 kg·CO2·m−3·MPa−1 (30% reduction in CO2 emission). Therefore, adding dry ice to UHPC is an effective way to utilize carbon and is crucial to achieving carbon neutrality in the concrete industry.

Effect of post-process and in-process cooling on wide-area stir zone processed via friction stir processing with pin overlapping

In the current investigation, the influence of post-process and in-process cooling on microstructural, mechanical and electrochemical behavior of wide-area stir zone (WSZ) processed with overlapping friction stir processing (OL-FSP) was studied. The WSZ was successfully prepared in Al5083 aluminum alloy using multi-pass friction stir processing (FSP) with 50% pin overlapping under both cooling conditions. The post-process cooling FSP (PP-FSP) used solid CO2 as cooling media, whereas the in-process cooling FSP (IP-FSP) used water as cooling media. The microstructural investigations revealed that grain refinement is uniform in each overlapping pass for both cooling conditions. The IP-FSP resulted in better grain refinement than PP-FSP. Three different types of intermetallic particles (needle-shaped Fe-containing, rod-shaped Mg-containing, and very small Mg-containing grain boundary intermetallic particles) were identified in the base alloy and OL-FSP samples. The hardness was observed to be constant across the WSZ due to the uniform grain refinement, and the IP-FSP sample has better hardness and strength than the PP-FSP sample due to the better cooling effect. The elongation followed a similar trend of hardness. The electrochemical findings revealed that the IP-FSP sample has better corrosion resistance than the PP-FSP sample due to the better grain refinement and fine intermetallics.

Large‐scale quantitative neuropathological analysis across the spectrum of Alzheimer’s disease neuropathologic change

AbstractBackgroundWhile traditional histologic neuropathological assessment of neurodegenerative disease has tremendous diagnostic value, insights into neurodegeneration’s pathophysiological underpinnings can be significantly enhanced with large‐scale quantitative analyses. As part of the Seattle Alzheimer’s Disease Brain Cell Atlas (SEA‐AD), we present a neuropathology dataset across 84 brains spanning the spectrum of AD neuropathologic change donated by UW Alzheimer’s Disease Research Center and Adult Changes in Thought study participants.MethodHuman brain tissue was collected at rapid autopsy (postmortem interval &lt;12 hours). One hemisphere (randomly selected) was embedded in alginate for uniform coronal slicing (4mm), with alternating slabs fixed in 10% neutral buffered formalin or frozen in a dry ice isopentane slurry. Superior and Middle Temporal Gyrus (MTG) was sampled from fixed slabs and subjected to standard processing, embedding, sectioning (5µm), histochemical (H&amp;E/Luxol fast blue), and immunohistochemical (duplex pTau and pTDP‐43, Aβ and Iba1, and monoplex GFAP, a‐synuclein, and NeuN) labeling. HALO image analysis software (Indica Labs, Albuquerque NM) was used to define and quantify relevant cellular and pathological features within each cortical layer (Figures 1‐3).Result84 individuals were included in these analyses (Table 1).While quantitative metrics of pTau and Aβ aligned with traditional neuropathological measures, they showed substantial variability within discrete diagnostic stages (Figure 4). These findings were robust to quantification (discrete count vs. total area stained) and normalization (total nuclei vs. total area analyzed) methods, and highlight the importance of deploying highly quantitative, continuous measures of pathology in the study of neurodegeneration. This unique resource provides spatially preserved measures of pathologic burden across the spectrum of AD with potential for correlative analysis across pathologies, clinical and biomarker parameters, and omics applications to better support the identification of vulnerable cell types in early stages of AD progression, the principal goal of SEA‐AD.ConclusionHere we present a large‐scale quantitative neuropathology dataset, which enables analysis of pathological proteins and cell types at unprecedented scale and accuracy. Little is known about the interactions of AD‐relevant cell types with pathologic peptides across disease progression. The presented analyses exemplify the potential of this unique publicly‐accessible resource to identify and quantify novel disease‐relevant relationships.

P14: Degradation of High Molecular Weight Multimers of von Willebrand Factor under Whole Blood Conditions in High Turbulent Flow: Implications for Continuous Flow Left Ventricular Assist Devices

Background: High turbulent flow often found in continuous flow left ventricular assist devices (cf-LVADs) is believed to cause acquired von Willebrand Syndrome (AvWS). Our group recently published a study on the kinetic and dynamic effects of various flows on the loss of high molecular weight multimers (HMWMs) of von Willebrand factor (vWF). In the study, we applied high shear to citrated human platelet-poor plasma (PPP) and characterized the flow by Reynolds number (Re). The present study aims to extend upon our previous findings by investigating the degradation of HMWM under whole blood conditions at higher flow conditions to be characterized by energy dissipation rate and clinically relevant exposure times previously employed. Methods: Diluted ovine blood with a hematocrit of 25%, dynamic viscosity of 3.0 cP and density of 1030 kg/m3 was flowed through a custom high shear rotary device. The device is designed to provide a fully controlled exposure time, texp and flow regime. The flow rate was set at 1.75 ml/sec, 0.76 ml/sec, or 0.38 ml/sec, resulting in an exposure time of 22 ms, 50 ms, or 100 ms, respectively. The dynamic flow condition was controlled by the speed of the rotor, ω, and characterized by the energy dissipation rate per unit mass, ε. The ω of 10k, 12k, 15k, 18k, 20k, and 22k RPM were applied, and the corresponding ε were estimated by running a series of large eddy simulations (LES). After each run, a 0.5 ml sample solution was collected, frozen in dry ice immediately, and shipped to the Blood Center of Wisconsin for multimer analysis. The amount of multimer degradation at each testing condition was assessed with respect to the mean of the initial concentration of HMWM of vWF in the controls. Results: The results show that the loss of HMWM at all given exposure times increases in a logarithmic manner within the extended flow conditions (Fig. 1A). The loss of HMWM versus energy dissipation rate at given texp is shown in Fig. 1B. It is noted that as the flow becomes more chaotic, the loss of HMWM appears to be primarily dominated by the energy dissipation rate while the exposure time to chaotic flow becomes less significant. It is not clear if the less significant effect of kinetics at relatively high flow conditions (>18k RPM) is because there are no more HMWM left to be cleaved by ADAMTS13, an enzyme that cleaves vWF. The results are consistent with our previous observations using human PPP, in that both flow conditions and exposure time play crucial roles in the destruction of HMWM. Conclusion: This study demonstrated the relative roles of flow and exposure time using whole blood to characterize the loss of HMWM in terms of energy dissipation rate and exposure time. The findings have the potential to assist in the design and optimization of blood pumps, ultimately leading to improved clinical outcomes for patients with AvWS.

Recent Progress in Cold Utilization of Liquefied Natural Gas

AbstractLiquefaction of natural gas occurs at –162 °C and atmospheric pressure for transporting it over long distances. In the customer's segment, the liquefied natural gas is regasified before distribution. Around 830 kJ kg−1 energy is required for the production of liquefied natural gas and is often saved as cold energy, which can be reused by regasification terminals. Hence, for the past few years, cold energy utilization has been an important topic of research in the energy sector. The different techniques to utilize cold energy for power generation, air fractionation, extraction of natural gas liquids, refrigeration systems, desalination, and dry ice manufacturing are reviewed and discussed. Applying the cold utilization of LNG technique in these systems can help to improve efficiency and decrease operating costs effectively.

A mini-review on cryogenic carbon capture technology by desublimation: theoretical and modeling aspects

Carbon capture, utilization, and storage (CCUS) technologies are the most effective methods to reduce CO2 emissions from fossil fuel power plants. Of the different CCUS technologies, cryogenic carbon capture (CCC) methods are the most mature technology as they can obtain remarkably high CO2 recovery and purity (99.99%). The significant advantage of the CCC process is that it can be easily retrofitted to existing systems and can handle the gas stream’s impurities. Different desublimation-based CCC technologies like Cryogenic packed bed, Anti sublimation, External cooling loop, CryoCell process and Novel low-cost CO2 capture technology (NLCCT) are reported in the literature. The significant limitations of these processes are the continuous removal of the dry ice into storage tanks. For the efficient design of CCC systems, accurate prediction of the phase equilibria data and modeling of the frost formation is called for. This paper reviews the recently reported cryogenic desublimation technologies and analyses the various challenges in making them economically viable. The article also examines the different heat and mass transfer models employed to model CO2 frost formation.

A Comparative Study of the Performance and Electrode Processes of Solid Oxide H2O Electrolysis and CO2 Electrolysis

Solid oxide CO2 electrolysis was less studied compared with H2O electrolysis and the relevant reaction mechanism and electrode processes were poorly understood. This paper investigated the performance and electrode processes differences between CO2 electrolysis and H2O electrolysis. The shape of j-V curves, electrochemical impedance spectroscopy data and calculated distribution relaxation time results were analyzed. It was found that the performance of CO2 electrolysis degraded the most compared with that in SOFC mode and for H2O electrolysis after a 65 h’ operation. Meanwhile, j-V curve of CO2 electrolysis changed a lot and finally showed a convex total resistance pattern with applied current. It was also found that the characteristic frequency of charge transfer reaction and diffusion process for CO2 electrolysis was much lower than that of H2O electrolysis. A thermal activated peak at 10-100 Hz which was not noted for H2O electrolysis was considered to be CO2 adsorption and dissociation process in fuel electrode. Besides, diffusion process for H2O-H2 and CO2-CO mixture also differed. Finally, it was indicated that the different performance degradation may be due to different suppressed degree of charge transfer reaction in fuel electrode for H2O electrolysis and CO2 electrolysis and additional suppressed adsorption or dissociation process of CO2 for CO2 electrolysis.

Poly(allylamine)–based amine blends for separation of carbon dioxide in the indoor environment

Amine and polyamine-based materials have been widely cited as solid CO2 sorbents and as catalyst modifiers for CO2 electrochemical reduction, however, lab-scale research into a pilot or industrial-scale application is challenging, beginning with the identification of an effective adsorbent. In this investigation, a membrane with a strong affinity for the adsorption and absorption of carbon dioxide is made by blending small molecular amines and a poly(allylamine) (PAA) solution. The membrane was characterized using Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM). The results show that Ethylenediamine (EDA)/Methyldiethanolamine (MDEA) is cross-linked with PAA via hydrogen bonds. We change the proportion of EDA/MDEA with PAA to determine the carbon dioxide separation and selectivity of membranes in ambient air. Results from the separation effectiveness deterioration test for MDEA and PAA, with the same ratio 7 wt% at 200 mbar pressure, show decreased CO2 concentrations of 98 and 35 ppm, respectively.

The Effect of Annealing Temperature and Quenching Media Variations On Heat Treatment Process of Cu-Zn-Al Shape Memory Alloys For Shape Memory Effect and Microstructure

Shape Memory Alloys (SMA) is a material that can return to its original shape after undergoing mechanical deformation. The most commonly SMA material used is the Ni-Ti alloy. However, it is high cost. So that it is necessary to have alternative materials, for instance Cu-Zn-Al. Several studies related to Cu-Zn-Al Shape Memory Alloys have poor mechanical properties. So there further research required in order to determine the heat treatment process of Cu-Zn-Al Shape Memory Alloys. In this study Cu-21Zn-5Al alloys were given heat treatment with annealing temperature variations (425;550;600°C) and cooling media (brine, dry ice). Annealing process affects the mechanical properties and microstructure of the test material. Cooling media results the cooling rate during solution treatment. Tests in this study include hardness test, metallographic test, XRD test, DSC test, and SME test. From the test results, it was found that all the test variables have the Shape Memory Effect. The variable that had the greatest recovery (38.3%) was annealing temperature of 450°C with the cooling solution media using brine. In addition, the most rapid cooling occurs in the brine cooling media.

An Experimental-Theoretical study on heat transfer aspects of indirect Sublimation, for application in CO2-based refrigeration systems

Recent advances in CO2-based refrigeration systems have made it necessary to derive heat transfer correlations for the design of the corresponding industrial equipment. The current study focuses on the derivation of such correlation for indirect sublimation, whereby a material is sublimated on a hot surface by transferring energy to it via a conduction mechanism. We took an experimental-theoretical approach to investigate the subject in the case of constant wall temperature. An apparatus with real-time temperature and weight display was built to sublimate the dry ice blocks of different sizes, with circular and rectangular geometries. When the temperature of the hotplate was changed from −30 to 200 °C, the heat transfer coefficient “hsub” decreased from 126 to 70 W/m2K. Such coefficients are about one-fourth of the corresponding values in flow (direct) sublimation. Weight and area of the block had positive/negative effects on heat transfer, respectively. In the theoretical part, two “linear-gradient” and “semi-analytical” models were developed. The more accurate semi-analytical model could estimate “hsub” with 6.4 and 21.3 % average error in circular and rectangular geometries. Linear-gradient was analytic, with respective errors of 17.3 and 25.9%.

Lessons Learned: Asphyxiation Hazard Associated with Dry Ice.

Dry ice is widely used in the chemistry research settings as an excellent coolant. Herein, we report a case study of a graduate student researcher who lost consciousness while retrieving 180 lbs of dry ice from a deep dry ice container. We share the details of the incident and the lessons learned from it to promote safer handling of dry ice in these situations.

Dynamics of cupcake baking: Coupled multiphase heat and mass transport in a deformable porous material

This study presents a coupled multiphase porous media transport model with evaporation, large deformation, and material transformation (phase change from starch gelatinization) for cupcake baking in a conventional oven. The governing equations for transport and deformation are energy, mass, and momentum conservation of the solid cupcake batter matrix, water, water vapor, and carbon dioxide produced during baking. They are solved numerically to predict the evolution of the cupcake batter's temperature, moisture, dimensional change, and color during baking. Cupcake-baking experiments are used to validate the model against measured temperature, moisture, color, and cupcake height during baking. The rate of carbon dioxide production, vapor generation, and the cupcake batter's mechanical properties determine the cupcake's final shape. The novelty of the numerical model is the coupling of the massive change in mechanical and thermophysical properties with multiphase transport and expansion due to pressure and moisture loss from shrinkage.

39 An in-Vitro Model of the Equine Fecal Microbiome to Assess How Horse Population Affects Fermentation Following a Starch Challenge

Abstract The use of an in-vitro model of the equine microbiome is beneficial to assess how fermentation patterns differ based on a horse populations’ habitual diet. The purpose of this study was to determine the in-vitro fermentation patterns of the microbial community within different horse populations before and following a starch challenge. Fecal samples were taken from three different populations of horses: horses from the Shackleford Banks, a North Carolina feral horse population living on native grasses; horses from the NCSU Equine Educational Unit that are predominantly kept on cool season mixed pastures, though may be supplemented with hay and concentrates when warranted; and privately owned horses that were fed mixed diets consisting of grass hay, concentrates and some pasture. Horses were monitored and fecal samples were collected immediately following a void and were stored on dry ice and frozen until analysis. Fecal samples from individual horses were pooled to form a representative sample for each population and mixed with an anaerobic medium to prepare an inoculum. The inoculum was placed into bottles containing either a treatment substrate of alfalfa (A) or of alfalfa and starch (AS). Bottles were capped, purged with CO2 and placed in a water bath at 39°C to incubate for 0, 2, 4 or 24 hours. Culture samples were processed to measure methane and short chain fatty acids (SCFAs; acetate, propionate, butyrate and other isoacids) using gas chromatography. Results were analyzed using the Proc Mixed procedure in SAS to compare the effects of horse population, time and treatment. Methane was significantly greater after 24 hours within all populations with AS, as the inoculum compared with A alone (P = 0.03). Propionate was greater for AS (molar percentage, mean ± standard deviation; 2.21 ± 4.97%) versus the A treatment (11.95 ± 4.97%, P = 0.02). Acetate concentrations were significantly (P &amp;lt; 0.001) greater within the A treatment in the Shackleford and NCSU horses (60.31 ± 10.3% and 62.18 ± 11.47%, respectively) compared with the AS treatment (59.09 ± 11.21% and 59.77 ± 8.85%, respectively). Privately owned horses showed similar values of acetate concentration when comparing the treatment of A (63.42 ± 10.13%) versus AS (63.55 ± 10.77%). Butyrate concentrations were greater in the Shackleford Banks and NCSU horses (13.16 ± 1.92% and 2.64 ± 4.22%, respectively) compared with the privately owned horses (10.96 ± 2%). Isoacids were greater in the Shackleford Banks horses (10.19 ± 4.15%) than the NCSU horses (9.87 ± 3.98%) and the privately owned horses (9.52 ± 3.53%; P&amp;lt; 0.0001). It appears that fermentation of starch differs between these horse populations, likely due to their habitual diet.

FIELD EVALUATION OF AUTOCIDAL GRAVID OVITRAP AND SIRENIX TRAP AGAINST CONTAINER INHABITING MOSQUITOES IN SAINT AUGUSTINE, NORTHEASTERN FLORIDA

Mosquito control programs are utilizing cost-effective long-term autocidal traps targeting the gravid population of container-inhabiting and other mosquito species, with the aim of reducing vector populations and disease transmission risk. In this field study we directly compared the efficacy of two autocidal trap types-the Autocidal Gravid Ovitrap (AGO) and SIRENIX mosquito trap in reducing mosquito abundances in St. Augustine, Florida to a control only site that had no autocidal traps deployed. Pre-treatment (wk1-4) and post-treatment (wk 5-14) adult mosquitoes were captured in all three sites using BG traps baited with BG lure and dry ice. Pre- and post-treatment trap counts of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and total mosquitoes (three species together) were compared to determine significant changes in abundance. Percent reduction in abundance of each species/group at the two trap sites were calculated to evaluate the trap efficacy at controlling Aedes and Culex container mosquitoes. Aedes albopictus populations were significantly reduced (86.6%) at the SIRENIX site compared to the populations at the AGO site (67.7% reduction). Ae. aegypti populations were reduced by 72.4% at the SIRENIX site compared to 25% at the AGO site. Culex quinquefasciatus population reduction at the SIRENIX site was 59.6% compared to 11.8% at the AGO site. The total mosquito group had only 45.1% and 10.3% reduction at the SIRENIX and AGO sites, respectively. Furthers studies conducted across the entire mosquito season would be required for full understanding of the effectiveness of these traps.

141 Preliminary investigation of kisspeptin gene expression and concentration in stallion semen

The objective of this study was to determine if the reproductive hormone kisspeptin (Kiss1) is present within stallion spermatozoa and seminal plasma. Semen samples (n = 19) were collected between March and August from 12 mature (ages 5–25) light horse-type stallions using an artificial vagina. Immediately following collection, raw semen samples were aliquoted for 2 different experiments. For experiment one, 10 mL of raw semen (n = 19) were centrifuged, and the seminal plasma was decanted and stored at −20°C for later analysis of Kiss1 concentrations using a competitive equine ELISA kit (MyBioSource) at a sample dilution ratio of 1:50,000. For experiment 2, 5 mL of raw semen (n = 10) were layered on top of 5 mL of EquiPure and centrifuged. The EquiPure was removed and the purified sperm pellet was rinsed with phosphate buffered solution (PBS). The PBS was decanted, and the purified sperm pellet was flash frozen in dry ice and stored at −80°C for later analysis of Kiss1 gene expression via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Total RNA was isolated from thawed sperm samples using phenol-chloroform extraction, treated with DNase, and RNA quantity assessedbefore reverse transcription and qRT-PCR using primers validated on equine tissues. Preliminary results revealed the presence of the Kiss1 protein in seminal plasma and Kiss1 transcript in spermatozoa. Mean concentration of Kiss1 in seminal plasma was 1,262 ng/mL. Analysis by one-way ANOVA revealed no significant difference (P = 0.425) in Kiss1 concentrations between stallions. Spearman's correlation analysis was performed, but no significant correlation between stallion age and concentration of Kiss1 in seminal plasma was detected (r = −0.345; P = 0.270). Amplification of the Kiss1 transcript in spermatozoa was observed at a mean cycle threshold of 32 in both Kiss1 and the housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Our findings of the expression of Kiss1 in stallion semen agrees with published results in the human, mouse, rat, dog, and goat. Further investigation and understanding of the role of kisspeptin in semen production and testicular function could improve the management of stallion fertility.

Complications in drilling operations in basalt for CO2 sequestration: An overview

The review article addresses the functional impediments of drilling in basaltic formation for CO2 storage. The rising temperature of earth due to increased emission of CO2 is an alarming situation for 8 billion people residing on the planet. Government of the Arab Republic of Egypt hosted the 27th Conference of the Parties of the united nation Framework Convention on Climate Change (COP 27-UNFCCC) where leaders from more than 100 nations gathered to discuss the solution that car bring back the temperature of earth to its optimum range. Out of several solutions like hydrogen economy, clean fuels, smart utilization of hydrocarbon and etc. carbon capture, utilization and storage (CCUS) remain one of the crucial technologies that can help in tackling the situation of global warming by capturing CO2 directly from atmosphere. The captured CO2 can be utilized for generation of several products with CO2 as raw material or can be injected into geological formations. For gigatons scale of removal of CO2 from atmosphere storage into geological formation is the most economical and feasible option available. Geological formation like petroleum reservoirs, coal seams, basaltic sequences are the prospective sites for injection where CO2 can be stored and out of these available sites basaltic sequence storage is the most safe as it stores the CO2 as solid part of the formation (gaseous CO2 converts to solid CO2 in form pf carbonates) itself and is an fast process as almost all of the injected CO2 is reported to be stored permanently within two to three years as compared to other formations where it can takes thousands of years for phase change of CO2. Basaltic sequences are also advantageous due to their non-commercial value with a drawback of its hardness and abrasivity. The minerals that constitute the basalt attain the value of 6–7 on Mohr’s scale of hardness making it one of the hardest rocks on earth. This hardness and abrasivity of basalt are a major concern that impacts the drilling process and makes it complicated as well as uneconomical. Thus, this review article emphasizes on geology of basalt that generates complication while drilling procedures.

Research on cleaning technology and damage assessment of single-stage compressor rotating blades with dry ice as agent

Numerical investigations based on the Euler-Lagrange approach were carried out first to verify the efficiency of the on-wing cleaning of the compressor blades of aero engines by taking dry ice instead of aqueous solvents as agent. The coupling between particles and the gas phase as well as the interaction between particles and blades were considered by means of comprehensive simulations of the movement of dry ice in the blasting device and the rotating blade channel of the single-stage compressor. Then, the factors that influence dry ice cleaning efficiency were verified and analyzed through dry ice cleaning test on single-stage compressor rotating blades. Finally, the damage assessment of the blade surface and coating under low temperature and impact force was completed. According to the results, the erosion rate cloud map obtained by simulation calculations and the cleaning effect image obtained by the test both showed that the interaction between particles and blades was mainly in the area near the leading edge of the blade. The main variables that affected the cleaning efficiency were the blade rotating speed, the dry ice mass flow rate and the cleaning angle. Furthermore, the highest cleaning efficiency was acquired when the blade rotational speed was 2500 r/min, the dry ice mass flow rate was 6 kg/min and the cleaning angle was 90°. Under these conditions, the blade surface and the coating are not damaged. Dry ice cleaning is a feasible technology in terms of on-wing aero engines, which has broad prospects of applications.

Simulations of Halos Produced by Carbon Dioxide Ice Crystals in the Martian Atmosphere

AbstractIt has been known for decades that carbon dioxide (CO2) ice clouds exist in the Martian atmosphere. According to remote sensing observations and previous modeling studies, the Martian CO2 ice crystals may be sufficiently large to generate halos. However, observations of CO2 ice crystal halos have not been reported so far. This study simulates the scattering and polarized phase functions at a wavelength of 0.48 μm based on state‐of‐the‐art light‐scattering computational capabilities. The specific CO2 ice crystal habits considered in the simulations include cubes, octahedrons, cubo‐octahedrons, and truncated octahedrons of various sizes. The halos produced by CO2 ice crystals peak at approximately 29° and 42°. Moreover, large CO2 ice crystals may cause strong scattering peaks at 155° and 180°. An ensemble of water (H2O) ice crystals and CO2 ice crystals with appropriate mixing fractions might be responsible for a halo occurrence recently observed on Mars.