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2021 ◽  
Author(s):  
Dmitry Smirnov ◽  
Henni Ouerdane

The experimental analysis of cryogenic chambers coupled with Stirling cryocoolers has received scant attention in the research literature. This work provides a novel contribution by developing and experimentally validating an analytical model of the coupling to predict temperatures in the system. The paper unifies the Stirling cryocooler equation previously derived by Otaka et al. and the thermal-electrical analogy for the chamber. The analytical formula predicts steady-state temperatures in the chamber as a function of the system's controllable design and operational parameters. The model was validated with experimental data from 15 tests of an alpha-type Stirling cryocooler coupled with a thermal chamber. The resulting model showed an accurate prediction of temperatures with an average coefficient of variance of 5%, mean biased error of 2%, and R² value of 0.95. The findings are relevant because of the urgent need to learn how to control cryogenic spaces using electricity-based systems. Such spaces will be of high significance in the future because advanced solutions and products in biomedicine, electronics, computing and other fields use cryogenic spaces.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1142
Author(s):  
Davide Papurello ◽  
Davide Bertino ◽  
Massimo Santarelli

The sustainable transition towards renewable energy sources has become increasingly important nowadays. In this work, a microgeneration energy system was investigated. The system is composed of a solar concentrator system coupled with an alpha-type Stirling engine. The aim was to maximize the production of electrical energy. By imposing a mean value of the direct irradiance on the system, the model developed can obtain the temperature of the fluid contained inside the Stirling engine. The heat exchanger of the microgenerator system was analyzed, focusing on the solar coupling with the engine, with a multiphysical approach (COMSOL v5.3). A real Stirling cycle was implemented using two methods for comparison: the first-order empirical Beale equation and the Schmidt isothermal method. Results demonstrated that a concentrator of 2.4 m in diameter can generate, starting from 800 W/m2 of mean irradiance, a value of electrical energy equal to 0.99 kWe.


2021 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Dhimas Satria ◽  
Rina Lusiani ◽  
Erny Listijorini ◽  
Aswata

This research is a development of previous research, where in the previous research, a design innovation was carried out on an alpha-type stirling engine by making the phase angle to 180o, with the aim of reducing the effect when the cold cylinder is compressed, because the phase angle currently used is (90o) with disadvantages, namely the cold cylinder is perpendicular to the top, so that the compression process against gravity. But in previous studies, the generator pipe was too long, causing a lot of energy or heat loss (heat loss) so that the compression speed was small. So that in the research, innovated and analyzed the pipe insulation of alpha-type stirling engine generators, alpha-type stirling engines, 180o phase angle. The research method used is to use the thermodynamic approach with Schmidt theory and the theory of the ideal cycle stirling engine. while the simulation is done using the Ideal Stirling Cycle Calculator. Results investigated shows that providing insulation on the generator pipes of an alpha-type stirling engine for an alpha-type stirling engine with a 180o phase angle is proven to reduce a lot of energy or heat loss (heat loss) due to too long generator pipes, with a heat loss value ratio of 226.66 W for the pipe. generator that uses insulation whose value is smaller than the value of the heat loss when the generator pipe without using isocation is 1,584.12 W.


Author(s):  
Mr. Pratik Prakash Chavan

From the nineteenth century, the mechanical transformation needs an incredible nuclear power creation. The pre-owned advances have a few specialized issues making hurt people and harming materials. There are numerous ways by which altering existing methods will assist with diminishing the uses. The work proposes the best approach to assemble and use the minimal expense Stirling motor for the efficient power energy application. A protected outside burning motor was the creation proposed by Robert Stirling to save human existence and materials. This motor is imagined for working with various temperatures without start inside by squander heat recuperation. It is worked by cyclic pressure and extension measure. The plan interaction includes the plan of chambers, heat expansion, dismissal, proficiency, power yield and some more. This motor is agreeable for individuals since it is very, less loud and minimized in size and alpha motor has more noteworthy proportion contrasted with different sorts. It is elective fuel hotspot for other fuel. This is efficient power energy application. This present’s development and execution trial of an alpha-type Stirling motor.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 752
Author(s):  
Zhengqing Yu ◽  
Wenxi Ding ◽  
Muhammad Tahir Aleem ◽  
Junzhi Su ◽  
Junlong Liu ◽  
...  

As an important zoonotic protozoan, Toxoplasma gondii (T. gondii) has spread around the world, leading to infections in one-third of the population. There is still no effective vaccine or medicine against T. gondii, and recombinant antigens entrapped within nanospheres have benefits over traditional vaccines. In the present study, we first expressed and purified T. gondii proteasome subunit alpha type 1 (TgPSA1), then encapsulated the recombinant TgPSA1 (rTgPSA1) in chitosan nanospheres (CS nanospheres, rTgPSA1/CS nanospheres) and incomplete Freund’s adjuvant (IFA, rTgPSA1/IFA emulsion). Antigens entrapped in CS nanospheres reached an encapsulation efficiency of 67.39%, and rTgPSA1/CS nanospheres showed a more stable release profile compared to rTgPSA1/IFA emulsion in vitro. In vivo, Th1-biased cellular and humoral immune responses were induced in mice and chickens immunized with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion, accompanied by promoted production of antibodies, IFN-γ, IL-4, and IL-17, and modulated production of IL-10. Immunization with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion conferred significant protection, with prolonged survival time in mice and significantly decreased parasite burden in chickens. Furthermore, our results also indicate that rTgPSA1/CS nanospheres could be used as a substitute for rTgPSA1/IFA emulsion, with the optimal administration route being intramuscular in mass vaccination. Collectively, the results of this study indicate that rTgPSA1/CS nanospheres represent a promising vaccine to protect animals against acute toxoplasmosis.


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