Thermophysical properties of granular-fibrous material on the temperature interval from 175 to 450 K

Several thermophysical properties of liquid and supercooled ruthenium were measured using electrostatic levitation. Over the 2225–2775 K temperature interval, the density can be expressed as ρ(T) = 10.75 × 103 – 0.56(T – Tm)(kg ⋅ m−3) with Tm = 2607 K. In addition, the surface tension can be expressed as σ(T) = 2.26 × 103 – 0.24(T – Tm)(mN ⋅ m−1) and the viscosity as η(T) = 0.60 exp[4.98 × 104/(RT)] (mPa ⋅ s) over the 2450–2725 K range. The isobaric heat capacity was estimated as CP(T) = 35.9 + 1.1 × 10−3(T – Tm)[(J/(mol K)] over the 2200–2750 K span by assuming a constant emissivity. The volume expansion coefficient, the enthalpy, and the entropy of fusion were also calculated as 5.2 × 10−5 K−1, 29.2 kJ ⋅ mol−1, and 11.2 J/(mol K).

Download Full-text

STUDY OF INFLUENCE OF FREEZING-DEFROSTING ON THERMOPHYSICAL PROPERTIES OF MEAT SYSTEMS

EUREKA Life Sciences ◽

10.21303/2504-5695.2018.00537 ◽

2018 ◽

Vol 1 ◽

pp. 32-38 ◽

Cited By ~ 1

Author(s):

Marina Yancheva ◽

Olena Dromenko ◽

Vladimir Potapov ◽

Olga Grinchenko ◽

Tetiana Zhelieva

Keyword(s):

Chemical Composition ◽

Temperature Interval ◽

Thermophysical Properties ◽

Phase Transfer ◽

Raw Material ◽

Chemical Compositions ◽

Colloid Stability ◽

Aggregate State ◽

Maximal Speed ◽

Meat Proteins

There were studied thermophysical properties of meat systems, based on comminuted beef with different chemical compositions in the process of freezing-defrosting. It was demonstrated, that the morphological base of meat (the ratio of muscular, connective and fatty tissues) and its chemical composition essentially influence thermophysical properties in the process of freezing-defrosting. It was revealed, that under conditions of realization of freezing-defrosting cycle with the fat mass share increase, the temperature increase of the maximal speed of crystal creation, decrease of the cryoscopic temperature interval, increase of the share of moisture that changes its aggregate state in the cryoscopic temperature interval, increase of specific heat of the phase transfer in the cryoscopic temperature interval are observed in a meat system. The type of changes of the cryoscopic temperature interval allows to detect that fat essentially influences the process of freezing-defrosting. The realized studies of comparison of thermodynamic changes in meat systems at refrigerator processing allowed to determine the strategy of saving meat systems’ stability that is in providing meat proteins’ colloid stability and renewing initial properties of the meat raw material after storage and defrosting.

Download Full-text

MEASUREMENT OF THERMOPHYSICAL PROPERTIES OF FLEXIBLE THERMAL INSULATION

Aviation Materials and Technologies ◽

10.18577/2713-0193-2021-0-1-119-126 ◽

2021 ◽

pp. 119-126

Author(s):

A.V. Zuev ◽

◽

Yu.P. Zarichnyak ◽

D.Ya. Barinov ◽

L.L. Krasnov ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Heat Capacity ◽

Thermal Insulation ◽

Thermophysical Properties ◽

Fibrous Material ◽

Sewing Thread ◽

Silica Fibers ◽

Porous Fibrous Material ◽

Highly Porous

The paper presents the results of measuring thermal conductivity and heat capacity of a flexible thermal insulation. Flexible thermal insulation is a highly porous fibrous material, a construction that includes felt, covered on all sides with fabric. The whole structure is stitched with a thread. The fibrous core, fabric and sewing thread are composed of silica fibers. Thermal conductivity was measured by the stationary method on flat samples. The heat capacity was determined using a NT-1000 calorimeter. The calculation of heat transfer was carried out for the conditions characteristic of those in effect when the spacecraft entered the orbit.

Download Full-text