Thermophysical Properties of Mate Leaves: Experimental Determination and Theoretical Effect of Moisture Content

Zanoelo, Éverton Fernando; Benincá, Cristina; Ribeiro, E.

doi:10.1111/j.1745-4530.2009.00385.x

Cited by 13 publications

(15 citation statements)

References 12 publications

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“…Thermal diffusivity (a, m 2 /s) was determined by a transient heat transfer method (Zanoelo et al 2011). An infinite copper cylinder (32 mm interior diameter by 350 mm height and 0.7 mm thickness) filled with the murtilla purée was heated in a constant temperature water bath (JEIO Tech, Seoul, South Korea).…”

Section: Thermal Diffusivity and Conductivitymentioning

confidence: 99%

Effect of high hydrostatic pressure on rheological and thermophysical properties of murtilla (Ugni molinae Turcz) berries

et al. 2016

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Effects of high hydrostatic pressure (HHP) on rheological and thermophysical properties of murtilla berries were evaluated after pressure treatments for 5 min between 100 and 500 MPa. Differential scanning calorimetry was employed to measure specific heat capacity. HHP caused a significant decrease in specific heat and density, while thermal diffusivity did not changed significantly. Thermal conductivity showed a slight increase upon HHP treatment. Apparent viscosity increased significantly above 200 MPa HHP treatment. Apparent viscosity of treated samples between 200 and 400 MPa did not differ significantly and the increase was significant at 500 MPa. Herschel-Bulkley, Bingham and Ostwald de Waele models were used to describe the rheological behaviour of murtilla purée, and Ostwald de Waele model gave the best fit for the experimental data.

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Section: Thermal Diffusivity and Conductivitymentioning

confidence: 99%

Effect of high hydrostatic pressure on rheological and thermophysical properties of murtilla (Ugni molinae Turcz) berries

et al. 2016

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“…; Zanoelo et al . ). In essence, the procedure employs a quasi‐adiabatic vacuum‐jacketed calorimeter, with a previously determined apparent heat capacity, where a known mass of heated distilled water (known specific heat) and the amount of solution with unknown specific heat are mixed.…”

Section: Methodsmentioning

confidence: 97%

“…; Zanoelo et al . ):

C p_{m} = \frac{m_{w} C p_{w} (T_{w} - T_{e}) - Q (T_{e} - T_{\infty})}{m_{m} (T_{e} - T_{i})}

where m w is the mass of water, m m is the mass of molasses solution, Cp w is the specific heat of water, T w and T i are the initial temperatures of water and sample of soy molasses, respectively, T e is the temperature of the mixture at equilibrium and Q is the apparent heat capacity of the calorimeter. It is assumed that all heat from pure water is exchanged with the solution and partially lost throughout the surrounding.…”

Section: Methodsmentioning

confidence: 99%

Boiling Point, Specific Heat and Density Measurements and Modeling of Soybean Molasses and Its Aqueous Solutions

Guedes

Corazza

Zanoelo

2015

J Food Process Engineering

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This work reports a new set of experimental data of boiling point elevation (BPE), specific heat and density for soybean molasses and its aqueous solutions at different total solids concentration and temperatures. BPEs up to 8.2C were measured with an ebulliometer at pressure range of 7.6-86.9 kPa and mass fraction of total solids up to 0.6. The method of mixtures in a quasi-adiabatic calorimeter was used to determine specific heats from 3,394 to 3,948 J/kg/C as a function of mass fraction of total solids between 0.1 and 0.4. Densities of the same product measured by applying the oscillating U-tube method were close to 995-1,104 kg/m 3 at 40-60C in the mass fraction range of total solids from 0.05 to 0.4. Different reliable empirical models (Capriste-Lozano, based on Dühring's and mixing rules) were suggested to estimate the examined properties in a temperature and a solid mass fraction range wider than those experimentally investigated. Transient data of mass fraction of total solids were also obtained in a single-effect evaporator at two different pressure (32.5 and 85.2 kPa). In order to highlight the importance of the measured thermophysical properties, a valid model based on conservative equations of mass and energy was used to simulate the process of concentration of aqueous solution of soy molasses. PRACTICAL APPLICATIONSSoybean molasses is a carbohydrate-rich by-product from soybean meal processing for production of protein concentrate. This product is normally concentrated by evaporation and further used as raw material for animal feed, industrial boiler fuel, production of isoflavones and as a substrate in fermentation processes, especially for the production of alcohols. Despite the large volume generation of this agro-industrial residue and its growing commercial applications, its thermophysical properties, such as boiling point, specific heat and density, are not available in the literature. These properties are fundamental to design, simulate and optimize process operations involving such a by-product. In this context, this study aims to cover this lack, providing the experimental determination and modeling of the properties mentioned earlier.

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“…The well‐known method of mixtures (Mohsenin 1980; Sasseron 1984; Valentas et al . 1997; Zanoelo et al . 2011) was applied to determine the specific heat of the hydrolyzed by‐products.…”

Section: Methodsmentioning

confidence: 99%

Thermophysical Properties of Hydrolyzed By‐products From the Meat Industry

Oliveira¹,

Zanoelo²

2011

J Food Process Engineering

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The method of mixtures, a pycnometric technique and a procedure based on an unsteady‐state condition of heat transfer were applied to obtain the specific heat, apparent density and thermal conductivity of processed by‐products from residuals of poultry slaughterhouses, respectively. Physical‐chemical analyses revealed that the investigated material presented 3.7% of water, 10.2% of ash, 8 to 25% of lipid and 37 to 60% of protein. The effect of moisture content and mass fraction of lipids on the aforementioned thermophysical properties was experimentally investigated at approximately 25C. Semiempirical models based on theoretical considerations and on the content of water, lipid and matter free of these components were suggested. A group of model parameters tuned on the experimental results revealed a specific heat, apparent density and thermal conductivity of dry processed by‐product without lipid close to 366 J/kg/C, 396 kg/m and 0.038 W/m/C, respectively. PRACTICAL APPLICATIONS A growing availability of residuals from poultry slaughterhouses is an important consequence of the large expansion of the poultry meat industry in Brazil. Excessive consumption of energy and large emission of non‐toxic odorous pollutants are the major current problems in the rendering industry. The determined thermophysical properties are essential for modeling and design calculations of cheaper and cleaner continuous industrial digesters that could replace the traditional technology of thermal hydrolysis of poultry by‐products.

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Thermophysical Properties of Mate Leaves: Experimental Determination and Theoretical Effect of Moisture Content

Cited by 13 publications

References 12 publications

Effect of high hydrostatic pressure on rheological and thermophysical properties of murtilla (Ugni molinae Turcz) berries

Effect of high hydrostatic pressure on rheological and thermophysical properties of murtilla (Ugni molinae Turcz) berries

Boiling Point, Specific Heat and Density Measurements and Modeling of Soybean Molasses and Its Aqueous Solutions

Thermophysical Properties of Hydrolyzed By‐products From the Meat Industry

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