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Materials (Basel, Switzerland) Nov 2022How to reduce consumption of energy in manufacturing has become a topical issue nowadays. Certain manufacturing processes are known for being highly energy-intensive and...
How to reduce consumption of energy in manufacturing has become a topical issue nowadays. Certain manufacturing processes are known for being highly energy-intensive and compression of materials belongs to this group. This article presents the simulation of the process of compression of dry ice snow with the use of the Mohr-Coulomb model. Two simulation variants were considered in this research. In the first one, constant input parameters were used and in the second one, the input parameters were variable, depending on the changing density of the compressed material. The experimental data were compared with the predicted values to find that the model using constant input parameters was inferior as regards to the goodness of fit. On the other hand, the model with variable input parameters was less accurate in predicting the maximum compression force acting in the process. The last section of this article deals with simulations performed with the Drucker-Prager Cap and modified Cam-Clay models. Finally, it was concluded that the Mohr-Coulomb model yields a more accurate representation of the compression process while requiring less information on the variation of the material parameters.
PubMed: 36431420
DOI: 10.3390/ma15227932 -
Journal of Vascular Surgery Nov 1985Amputation done on an emergency basis of severely ischemic or infected limbs in critically ill patients frequently results in increased morbidity and mortality. To...
Amputation done on an emergency basis of severely ischemic or infected limbs in critically ill patients frequently results in increased morbidity and mortality. To evaluate the effect of delaying an inevitable operative amputation by a simplified method of freezing the involved extremity, the records of 56 patients who underwent preoperative cryoamputation during a 12-year period were reviewed. Data concerning risk factors, associated medical conditions, local or systemic signs of sepsis, level of amputation, morbidity, and mortality were analyzed. Following cryoamputation of 57 limbs, 16 above-knee amputations (AKA) and 41 below-knee amputations (BKA) were performed. The overall mortality rate associated with cryoamputation was 14% (8 of 57); four postoperative deaths occurred in both the AKA and BKA groups. The mortality rate for 1021 primary operative major amputations during the same period was 7% (p less than 0.04). The only factor identified that significantly affected survival following cryoamputation was diabetes mellitus, which was present in 68% of surviving patients and in 12% of those who died (p less than 0.001). This experience suggests that cryoamputation is a valuable, simple technique that allows for deliberate stabilization and preparation of seriously ill, septic patients prior to surgical procedures, which, when performed on an emergency basis have been associated with mortality rates exceeding 40%.
Topics: Adult; Aged; Amputation, Surgical; Cryosurgery; Dry Ice; Female; Humans; Leg; Male; Middle Aged; Retrospective Studies
PubMed: 4057438
DOI: 10.1067/mva.1985.avs0020812 -
Materials (Basel, Switzerland) Feb 2022In the processing of waste materials, attention must be given to the efficient use of energy. The pelletization of dry ice is a good example of such processes. A...
In the processing of waste materials, attention must be given to the efficient use of energy. The pelletization of dry ice is a good example of such processes. A literature review shows that in the pelletizers available on the market, the force applied in the process is excessive. As a result, the efficiency of the utilization of inputs, including electricity and carbon dioxide, is at a very low level. This article presents the results of experimental research on the effect of the degree of dry ice compression on the value of the Poisson ratio. The first part of this article presents the research methodology and a description of the test stand, developed specifically for this research, bearing in mind the unique properties of carbon dioxide in the solid state. The results presented show the behavior of dry ice during compression in a rectangular chamber for different final densities of the finished product. As a result, it is possible to determine the values of the Poisson ratio as a function of density, using for this purpose four mathematical models. The findings of this research may be useful for research work focused on the further development of this process, such as by using the Drucker-Prager/Cap numerical model to optimize the geometric parameters of the parts and components of the main unit of the machine used in the extrusion process of dry ice.
PubMed: 35208095
DOI: 10.3390/ma15041555 -
QJM : Monthly Journal of the... Nov 2017
Topics: Asphyxia; Automobiles; Confined Spaces; Dry Ice; Female; Humans; Middle Aged
PubMed: 29025068
DOI: 10.1093/qjmed/hcx146 -
Translational Animal Science Apr 2020Artificial insemination (AI) is widely used in livestock industries to breed for desirable characteristics and increase yields. The standard practice of storing and...
Artificial insemination (AI) is widely used in livestock industries to breed for desirable characteristics and increase yields. The standard practice of storing and transporting bovine semen uses liquid nitrogen (LN), a scarce commodity in many regions of the world. This study explored the feasibility of using dry ice, a more readily available alternative. We developed equipment that dispenses dry ice from widely available liquid carbon dioxide (LCO) tanks into an easily transportable device. In vivo fertility results with a dry ice cold chain showed no statistical difference to the conventional LN method. In vitro bovine semen analyses also showed that storage under these conditions minimally affects characteristics associated with fertility. A dry ice cold chain system could leverage the global availability of LCO to expand the reach of AI and other cold storage applications of biological materials in low-resource settings.
PubMed: 32705012
DOI: 10.1093/tas/txaa012 -
Chemical & Pharmaceutical Bulletin 2018Ultra cryo-milling using liquid nitrogen (LN2) and dry ice beads has been proposed as a contamination-free milling technique. The morphological change of dry ice beads...
Ultra cryo-milling using liquid nitrogen (LN2) and dry ice beads has been proposed as a contamination-free milling technique. The morphological change of dry ice beads was visually monitored in LN2 to clarify their production process and cryo-milling process. We found that dry ice pellets, which are starting material of beads and available on the market, immediately disintegrate in LN2, resulting in the spontaneous production of dry ice beads. In addition, the resultant beads maintain their size and shape even under vigorous agitation in LN2, demonstrating that they could play a role of milling media in the milling process. The driving conditions of this cryogenic milling process including beads size were optimized to enhance the milling efficiency. Dry ice beads provided superior milling efficiency compared to original pellets. The milling efficiency increased as the size of the dry ice beads decreased; furthermore, the larger the amount of beads used, the finer the milled particles. Any crystals of three drug compounds were effectively pulverized to the sub- or single-micron range. Cryo-milling with dry ice beads is valuable on pharmaceutical field because it does not contaminate the product with fractured and/or eroded beads.
Topics: Chemistry, Pharmaceutical; Cold Temperature; Crystallization; Drug Compounding; Dry Ice; Light; Microspheres; Nitrogen; Particle Size; Solubility; Water
PubMed: 30068799
DOI: 10.1248/cpb.c18-00161 -
Journal of the Advanced Practitioner in... Mar 2019Ms. X is a 23-year-old female who presented to clinic with stage 2A endometrial cancer of the ovary. At her first visit, Ms. X was prescribed paclitaxel and carboplatin... (Review)
Review
Ms. X is a 23-year-old female who presented to clinic with stage 2A endometrial cancer of the ovary. At her first visit, Ms. X was prescribed paclitaxel and carboplatin on day 1 for 6 cycles. During the visit, the nurse noted Ms. X could not keep her hands out of her hair; she continually played with it. The nurse, judging by Ms. X's body language, suspected she valued her hair. Ms. X revealed she had been doing some research and wanted to use a cold cap to try and prevent alopecia during her treatment. On the first day of chemotherapy, Ms. X came to the clinic with her mother. They brought a manual cap for scalp cooling and a cooler of dry ice. Her mother was to serve as a "capper" and change the cap at 20- to 30-minute intervals during treatment to keep her scalp cool. Ms. X was made comfortable in an infusion bed, and the cap was applied 30 minutes prior to the start of therapy. Ms. X's mother changed the dry ice caps every 20 minutes throughout the infusion. Ms. X then left it on for 90 minutes following her chemotherapy. After 6 cycles of chemotherapy, Ms. X still had all her hair. She appeared to have retained 100% of her hair, although she estimates that she lost about 5% of her hair. During therapy, she followed the instructions outlined in Table 1. Ms. X reported that she rented the cap for $500 per month and paid $45 per week for the dry ice. Her mother also had to miss work to be the "capper," and this added to the out-of-pocket costs of scalp cooling.
PubMed: 31538026
DOI: No ID Found -
Biotechnology and Bioengineering Nov 2022As opposed to remarkable advances in the cell therapy industry, research reveal inexplicable difficulties associated with preserving and post-thawing cell death. Post... (Review)
Review
As opposed to remarkable advances in the cell therapy industry, research reveal inexplicable difficulties associated with preserving and post-thawing cell death. Post cryopreservation apoptosis is a common occurrence that has attracted the attention of scientists to use apoptosis inhibitors. Transporting cells without compromising their survival and function is crucial for any experimental cell-based therapy. Preservation of cells allows the safe transportation of cells between distances and improves quality control testing in clinical and research applications. The vitality of transported cells is used to evaluate the efficacy of transportation strategies. For many decades, the conventional global methods of cell transfer were not only expensive but also challenging and had adverse effects. The first determination of some projects is optimizing cell survival after cryopreservation. The new generation of cryopreservation science wishes to find appropriate and alternative methods for cell transportation to ship viable cells at an ambient temperature without dry ice or in media-filled flasks. The diversity of cell therapies demands new cell shipping methodologies and cryoprotectants. In this review, we tried to summarize novel improved cryopreservation methods and alternatives to cryopreservation with safe and viable cell shipping at ambient temperature, including dry preservation, hypothermic preservation, gel-based methods, encapsulation methods, fibrin microbeads, and osmolyte solution compositions.
Topics: Cell Survival; Cryopreservation; Cryoprotective Agents; Dry Ice; Fibrin; Postal Service
PubMed: 35898166
DOI: 10.1002/bit.28197 -
Journal of the Mechanical Behavior of... Jul 2017To obtain hydroxyapatite (HA) coatings with high crystallinity which have long-term stability in clinical applications, coarse powders were usually injected to less...
To obtain hydroxyapatite (HA) coatings with high crystallinity which have long-term stability in clinical applications, coarse powders were usually injected to less energetic plasma. However, the HA coatings accumulated by partly melted particles usually have high porosity and poor mechanical properties, especially poor bonding strength. In this work, by profiting its quenching and mechanical impact, dry-ice blasting was in-situ employed during plasma spray process to improve the microstructure characterization and bonding strength of HA coatings. In addition, the influence of in-situ dry-ice blasting on the phase composition and crystallinity of plasma-sprayed HA coatings was investigated. The results show that a significant reduction of porosity and an apparent increase in bonding strength are revealed in plasma-sprayed HA coatings due to the cleaning effect of dry-ice blasting on the convex unmelted particles and splashing fragments. HA coatings prepared by the combination process of plasma spraying and dry-ice blasting have a compromise structure with minimum globular pores but with pronounced microcracks. The disappearance of CaO phase and the increase in crystallinity also derive from the application of dry-ice blasting.
Topics: Coated Materials, Biocompatible; Dry Ice; Durapatite; Materials Testing; Surface Properties
PubMed: 28292707
DOI: 10.1016/j.jmbbm.2017.03.003 -
PDA Journal of Pharmaceutical Science... 2020The internal temperature of a passive thermal shipper employing dry ice as the coolant often decreases to less than the equilibrium sublimation point (-78.5°C) during...
The internal temperature of a passive thermal shipper employing dry ice as the coolant often decreases to less than the equilibrium sublimation point (-78.5°C) during shipment. In this paper, we demonstrate that in many cases, this unexpected phenomenon is due to excessive sublimation cooling by the dry ice. We performed a series of experiments and determined the dry ice temperature with the change in dry ice sublimation rates under various external conditions. The results show that the sublimation temperature decreases to less than -80°C and decreases further when the dry ice sublimation rate is artificially increased. The lowest temperature observed in the experiments was -100.6°C, which occurred when the dry ice nuggets were subjected to a forced-air cooling condition, which is an extreme situation that is not expected to happen in actual shipping environments. Several types of shippers were also tested to investigate the impact of shipper material and shipper design. The lowest temperature observed in these shippers was -93.2°C when the shipper was placed on its side instead of upright. Based on the results from these controlled experiments, we conclude that the temperature inside a shipper cooled by dry ice will decrease because of excessive sublimation cooling effect but will not reach less than -100°C in normal shipping environments.
Topics: Cold Temperature; Drug Packaging; Dry Ice
PubMed: 31209165
DOI: 10.5731/pdajpst.2018.009589