نتایج جستجو برای: r12
تعداد نتایج: 486 فیلتر نتایج به سال:
This study aimed to explore the dynamic variations of rumen fermentation characteristics and bacterial community composition during a 24 h in vitro fermentation. A total twenty-three samples were collected from original fluid (ORF, n = 3), at 12 (R12, 10), (R24, 10). Results showed that gas production, concentrations microbial crude protein, ammonia nitrogen, individual volatile fatty acids (VF...
Discharge gas temperature value is an indicator of compressor safe operating conditions, particularly on R12 and R502 commercial applications. These refrigerants will be replaced very soon by R134a and R22 respectively, also if R22 is not considered a final solution. High discharge temperatures are typical in LBP-R22 hermetic compressors operating at low evaporating temperature as low as -40"C;...
A quadratic polynomial differential system can be identified with a single point of R12 through the coefficients. Using the algebraic invariant theory we classify all the quadratic polynomial differential systems of R12 having an integrable saddle. We show that there are only 47 topologically different phase portraits in the Poincaré disc associated to this family of quadratic systems up to a r...
To approach the complete basis set limit of the "gold-standard" coupled-cluster singles and doubles plus perturbative triples [CCSD(T)] method, we extend the recently proposed perturbative explicitly correlated coupled-cluster singles and doubles method, CCSD(2)(R12) [E. F. Valeev, Phys. Chem. Chem. Phys. 8, 106 (2008)], to account for the effect of connected three-electron correlations. The na...
In this paper, the performance of an ejector cooling system and the effect of the following different working fluids such as water, ammonia, R134a, R141b, R12, R600 and R245fa are described and the effects of cycle parameters on the consumed heat and work and COP are studied. This cycle with the working fluid R141b has the least COP while the working fluid R₁₂ in comparison with the other worki...
Series production of R134a compressors started in 1990. 200 compressors, from the very first series, were built into cabinets placed in an apartment house in Denmark. Cabinets with R12 compressors were placed in the same apartment house as well. The cabinets have two separate cooling systems; one for a cold cabinet and one for a freezer. 10 running cabinets were called back for analysis; 7 cabi...
Conservative subtheories of R 2 and S 1 2 are presented. For S 1 2 , a slight tightening of Jeřábek’s result [18] that T 0 2 ∀Σ1 S 1 2 is presented: It is shown that T 0 2 can be axiomatised as BASIC together with induction on sharply bounded formulas of one alternation. Within this ∀Σ1-theory, we define a ∀Σ0-theory, T−1 2 , for the ∀Σ0-consequences of S 1 2 . We show T −1 2 is weak by showing...
در این مقاله بررسی عملکرد سیالات مختلف در سیکل ترکیبی توان و تبرید مورد مطالعه قرار گرفته است . اگزرژی را می توان برای ارزیابی و بهبود سیستم های انرژی با ارائه اطلاعات مفید تر و معنی دار تر از تجزیه و تحلیل انرژی استفاده کرد . در واقع، تجزیه و تحلیل اگزرژی شامل استفاده از قوانین اول و دوم ترمودینامیک میباشدکه برای تحلیل انرژی و اگزرژی برای سیکل ترکیبی توان وتبرید با سیالات مختلف در این مقاله از...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید