scholarly journals Evaluation of Properties of Composite Panels Fabricated from Waste Newspaper and Wood Dust for Structural Application

2020 ◽  
pp. 8-15
Author(s):  
Ekong Ufot Nathaniel ◽  
Ubong Williams Robert ◽  
Mercy Effiong Asuquo
Keyword(s):  
Heat Capacity ◽  
Flexural Strength ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Treated Wood ◽  
Untreated Wood ◽  
Wood Dust ◽  
Mean Values ◽  
The Mean

In this work, dry forms of waste newspaper pulp, untreated wood dust and treated wood dust were used at varying weight proportions to fabricate composite panels which thenafter served as test samples. With increase in the content of either the untreated wood dust or the treated wood dust in the developed panels, the results showed increase in the mean values of bulk density, thermal conductivity, thermal diffusivity, flexural strength but decrease in the mean values of specific heat capacity and percentage water absorption. Also, at p < 0.05, significant differences were revealed in the mean values of bulk density and specific heat capacity between the results obtained for samples with untreated wood dust content and those associated with samples containing the treated wood dust. Again, samples containing the untreated wood dust were found to be better thermal insulators but with lower flexural strength than those of same proportions of the treated wood dust component. From application viewpoint, the findings in this work indicated that the fabricated samples could compete favorably with conventional materials commonly used for thermal insulation in buildings. It is, therefore, obvious that recycling waste newspaper and wood dust into such panels can help to reduce the adverse effect of the waste materials on environment also improve economy by providing building sector with low-cost and environmentally-friendly insulation materials suitable for internal building design.

scholarly journals Proposal for determining changes in entropy of semi ideal gas using mean values of temperature functions

2014 ◽  
Vol 68 (5) ◽  
pp. 615-628 ◽  
Author(s):  
Branko Pejovic ◽  
Vladan Micic ◽  
Mitar Perusic ◽  
Goran Tadic ◽  
Ljubica Vasiljevic ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Internal Energy ◽  
Temperature Interval ◽  
Specific Heat Capacity ◽  
Mean Value ◽  
Ideal Gas ◽  
Mean Values ◽  
Arbitrary Temperature ◽  
The Mean

In a semi-ideal gas, entropy changes cannot be determined through the medium specific heat capacity in a manner as determined by the change of internal energy and enthalpy, i.e. the amount of heat exchanged. Taking this into account, the authors conducted two models through which it is possible to determine the change in the specific entropy of a semi-ideal gas for arbitrary temperature interval using the spread sheet method, using the mean values of the appropriate functions. The idea is to replace integration, which occurs here in evitably, with mean values of the previous functions. The models are derived based on the functional dependence of the actual specific heat capacity on the temperature. The theorem used is that of the mean value of a function as well as the mathematical properties of the definite integral. The mean value of a fractional function is determined via its integrand while the logarithmic functions were performed by applying a suitable transformation of the differential calculus. The relations derived relation, using the computer program, have enabled the design of appropriate thermodynamic tables through which it is possible to determine the change in entropy of arbitrary state changes in an efficient and rational manner, without the use of calculus or finished forms. In this way, the change in the entropy of a semi-ideal gas is determined for an arbitrary temperature interval using the method which is analogous to that applied in determining the change of internal energy and enthalpy or the amount of heat exchanged, which was the goal of the work. Verification of the proposed method for both the above functions was performed for a a few characteristic semi-ideal gases where change c(T) is significant, for the three adopted temperature intervals, for the characteristic change of state. This was compared to the results of the classical integral and the proposed method through the prepared tables. In certain or special cases, it is possible to apply the presented method also in determining the change in entropy of the real gas. Apart from that, the paper shows that the change in entropy for the observed characteristic case can be represented or graphically determined using the planimetric method of diagrams with suitably selected coordinates.

INDIRECT MEASUREMENT OF Zn-DOPED In2S3 NANOFILMS' SPECIFIC HEAT CAPACITY

2008 ◽  
Vol 07 (04n05) ◽  
pp. 229-233 ◽  
Author(s):  
S. LAZZEZ ◽  
K. BOUBAKER BEN MAHMOUD ◽  
M. AMLOUK
Keyword(s):  
Heat Capacity ◽  
Electron Microscope ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Thermal Analyses ◽  
Indirect Measurement ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Mean

ZnIn 2 S 4 nanofilms were grown on In 2 S 3 substrates. The band gap of ZnIn 2 S 4 barriers was approximately 2.8 eV at room temperature. The morphology and structure of the obtained nanofilms were already investigated via transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction analyses.1,2 In this paper, thermal analyses are performed via a photothermal technique, which has been used to indirectly evaluate the specific heat capacity of the obtained Zn -doped nanofilms. The yielded value for an optimal zinc-to-indium ratio, x (0.33), at the mean room temperature (T∞ = 301 K ), was Cs ≈ 411.5 J K -1 kg -1.

EFFECT OF DRYING RATE AND MOISTURE REMOVAL ON THE DRYING PROPERTIES OF GROUND AND FERMENTED CASSAVA MASH ("GARI")

2021 ◽  
Vol 15 (1) ◽  
pp. 66-74
Author(s):  
A. S. Oyerinde
Keyword(s):  
Heat Capacity ◽  
Moisture Content ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Initial Moisture Content ◽  
Drying Rate ◽  
Moisture Removal ◽  
Steady State Temperature ◽  
Drying Properties

Drying characteristics of ground and fermented cassava mash called "gari" (a carbohydrate and staple food in Nigeria) were studied. Several properties such as drying rate, thermal conductivity, thermal diffusivity, specific heat capacity, and bulk density were investigated during the roasting of the mash. These properties were discovered to be influenced by the removal of moisture as the mash dries. The optimum initial moisture content was 46 % wb at 60 % Rh. The roasting chamber reaches a steady state temperature of 160 oC in 12 minutes before roasting while 5 kg of the wet cassava mash dried to a final moisture content of 9.8 % wb in 21 minutes. It was observed that as the moisture content reduces from 46 % to 9.8 %, the bulk density increased from 441.32 kg/m3 to 507.91 kg/m3, drying rate reduces from 2.64 to 0.54 kg/min and specific heat capacity reduces from 4.14 to 2.01 kJ/(kgK). The effects of the moisture removal on the studied parameters were thus discussed as the mash dries along the length of the dryer.

scholarly journals Thermal Properties of New Developed Nigerian Illa and Ekpoma Rice Flour Varieties as Effected with Moisture Content

2021 ◽  
Vol 2 (2) ◽  
pp. 460-471
Author(s):  
Ide PATRICK EJIKE ◽  
Ikoko OMENAOGOR
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Rice Flour ◽  
Thermal Parameters

Thermal parameters of food flour moisture content and temperature give an insight in the development and prediction of models that meet the needs of process design models, it also determine the thermal load of a particular product during handling. The bulk density (ρ), thermal conductivity (k), specific-heat capacity (Cp) and diffusivity (α) of Illa and Ekpoma rice flour were studied at varied (MC) moisture content (%) level. The results showed significance in thermal properties values at the different MC levels. The MC increased from 10.56 to 18.50%, increased the specific heat capacity (Cp) from 5.72 to 48.61kJ kg-1 °C-1 and 6.84 to 29.41 kJ kg-1 °C-1 for Illa and Ekpoma rice variety respectively and thermal conductivity(k) from 0.03 to 1.56 W/m0C and 0.03 to 0.38 W m-1 °C-1 for Illa and Ekpoma rice flour samples. Thermal diffusivity(α) and bulk density (ρ) of the processed Illa and Ekpoma rice flour samples decreased across the MC range of 10.56 to 18.50% (d.b). Thermal diffusivity(α) decreased from 4.38 to 1.25 x 10-4 m2 s-1 and 3.42 to 1.30 x 10-4 m2 s-1 for Illa and Ekpoma rice flour respectively while the values of bulk density (ρ) decreased from 697.72 to 676.34 kg m-3 and 687.49 to 664.26 kg m-3 for Illa and Ekpoma rice flour respectively.The developed model equations can be applied in estimation of thermal parameters of rice flour. Finally, Ekpoma and Illa rice flour sample displayed good thermal characteristics and it can be used as an alternative to imported wheat flour.

scholarly journals Effect of Germination Period on Some Functional and Engineering Properties of Sorghum Flour

2021 ◽  
pp. 12-22
Author(s):  
G. O. Ogunlakin ◽  
E. H. Onibokun ◽  
B. Fashogbon
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Absorption Capacity ◽  
Engineering Properties ◽  
Germination Period ◽  
Sorghum Flour ◽  
Two Samples

Sorghum (red and white) were germinated for 24, 48, 72, and 96 h to determine the effect of germination on some functional and engineering properties of sorghum flour. The bulk density results for the red and white germinated sorghum are 0.620-0.673 g/cm3 and 0.477-0.620 g/cm3, respectively. Water absorption capacity values for the two samples are 116.630-125.970% and 81.643-98.293% while the oil absorption capacity ranged from 62.917 to 85.750% and 44.933 to 61.980%, respectively for the two samples. The dispersibility test for the two samples gave 85.67-87.33% and 83.00-84.67%. The swelling power at 55 °C are 2.54-2.67 and 2.70-3.26, at 75 °C, 3.62-4.68 and 3.85-4.56, and at 90 °C, 2.98-4.79 and 6.29-7.23, respectively for the two samples. For the engineering properties, the specific heat capacity ranged from 0.14 to 0.45 kJ/kg K and 0.12 to 0.14 kJ/kg K, thermal conductivity, from 0.55 to 1.67 W/mK and 1.01 to 1.24 W/mK and thermal diffusivity from 0.13 to 0.82 m2/s and 0.11 to 0.12 m2/s, respectively for red and white germinated sorghum flours. It can be concluded from this study that increased the values of bulk density, WAC, OAC, and dispersibility test of the two samples with the increase in germination period with the optimum germination period of 72 h. Engineering properties results indicated that germination had a beneficial effect on the thermal conductivity of the germinated red sorghum and the thermal conductivity and specific heat capacity of the white germinated sorghum with 96 h having the best result for both samples.

scholarly journals Uncertainty estimation of the mean specific heat capacity for the major gases contained in biogas

2020 ◽  
Vol 66 (No. 2) ◽  
pp. 52-59
Author(s):  
Petr Travnicek ◽  
Ivan Vitázek
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Scientific Work ◽  
Uncertainty Estimation ◽  
Simple Arithmetic ◽  
Capacity Calculation ◽  
The Mean ◽  
Specific Heat Capacities ◽  
The Individual

The paper is focused on the uncertainty estimation of the mean isobaric and isochoric specific heat capacity calculation. The differences in the data among the individual sources for the technical calculation are presented in the first part of the paper. These differences are discussed in this paper. Research of scientific work with listed values of measurement uncertainties has been carried out in the second part of the paper. Furthermore, mathematical models were calculated which describe the dependence of the specific heat capacities and temperature. The maximal error models were carried out. Two approaches were used for the calculation of the mean specific heat capacity. The first approach is the calculation with help of integration of the function which describes the dependence of the specific heat capacity and temperature. The second approach is the calculation of a simple arithmetic mean of the specific heat capacity related to the maximal and minimal value of the temperature interval. The conclusion of the work shows that the time-effective second way is applicable in the case of a narrow temperature range. A value of 5.5% (Δ<sub>t</sub> = 200 K) was reached for the relative uncertainty. This is a similar value to that in the case of using the first way.

scholarly journals EVALUATION OF THERMAL STORAGE CAPACITIES OF SOME SELECTED MATERIALS FOR SOLAR DRYING APPLICATIONS

2020 ◽  
Vol 4 (3) ◽  
pp. 192-196
Author(s):  
Umar Hassan ◽  
Adeleke Waliyi Adekola ◽  
Mohammed Mohammed ◽  
Adamu Muhammad Auwal ◽  
Sanusi Abdulganiyu
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Thermal Storage ◽  
Solar Drying ◽  
Storage Facility ◽  
Storage Material ◽  
British Standard

This work aimed at evaluating the thermal storage capacities of granite grits, laterite rock, sand, laterite, and Clay for solar drying applications. The sample materials were ground and sieved through 0.425mm British Standard sieve. The thermal conductivity, specific heat capacity, bulk density and melting point of the materials were determined. The results showed that Clay displayed better potentiality as thermal storage material with the highest thermal conductivity and specific heat capacity of 2.16 W/m oC and 1.398 kJ/kg K respectively. Laterite was observed to be the least with 1.07 W/moC, and 0.499 kJ/kg K respectively. The Sand was observed to have higher bulk density compared with other sample materials while Laterite exhibited the lowest. The analysis of the result indicates that clay could be used as material for thermal energy storage facility in solar drying applications.

scholarly journals SOME MOISTURE DEPENDENT THERMAL PROPERTIES AND BULK DENSITY OF Prosopis Africana SEEDS (OKPEYE)

2017 ◽  
Vol 36 (3) ◽  
pp. 936-943
Author(s):  
FU Asoiro ◽  
CJ Ohagwu
Keyword(s):  
Heat Capacity ◽  
Thermal Properties ◽  
Moisture Content ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Heat Conductivity ◽  
Hot Plate ◽  
Heat Diffusivity ◽  
Prosopis Africana

The thermal heat conductivity, specific heat capacity, thermal heat diffusivity and bulk density of Prosopis africana seeds were determined as a function of moisture content. Specific heat capacity was measured by the method of mixture while the thermal heat conductivity was measured by the guarded hot plate method. Thermal heat diffusivity was calculated from the experimental results obtained from specific heat capacity, thermal heat conductivity and bulk density. The bulk density for Prosopis africana (PA) seeds decreased from 890kg m-3 to 590kg m-3 as moisture content increased from 4 to 20% wet basis (w.b). Specific heat capacity increased from 2760J kg-1 ºC-1 to 2960J kg-1 ºC-1with increasing moisture content. The thermal heat conductivity ranged between 0.70 and 0.90W m-1oC-1 when moisture content rose from 4% to 20% (w.b). Thermal heat diffusivity increased from 2.7 10-7 to 4.2 10-7m2 s-1 as moisture content increased from 4 to 20% (w.b). The values obtained for these thermal properties and bulk density could be useful for design of systems for heat treatment of Prosopis africana seeds.  http://dx.doi.org/10.4314/njt.v36i3.38

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

Development of the room temperature protocol based on room temperature ionic liquids and surfactant ionic liquids for the synthesis of derivatives of 2-amino-thiazoles and thermo-physical analysis of the synthesized derivatives using TGA-DSC.

2020 ◽  
Vol 10 ◽  
Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Heat Capacity Data ◽  
General Strategy ◽  
Capacity Data ◽  
Derivatives Of

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.

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