scholarly journals The use of the hot-ball method for observing the transport of moisture in porous stones

2012 ◽  
Vol 20 (3) ◽  
pp. 9-14 ◽  
Author(s):  
Danica Fidríková ◽  
Ľudovít Kubičár
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Water Content ◽  
Water Transport ◽  
Water Diffusion ◽  
Porous Structures ◽  
Conductivity Sensor ◽  
Set Up ◽  
Physical And Chemical ◽  
Local Moisture

AbstractThe effect of moisture on materials leads to changes in their physical and chemicalproperties. Materials with different porosities are saturated by various mechanisms. Thispaper is focused on water transport or diffusion in various porous structures. The Hot-BallMethod is used for determining the water content in certain parts of a specimen. Theprocess of water transport or water diffusion is closely related to a porous structure.Porosity affects the transport properties of a material; therefore, knowledge of themechanisms distributing the water in materials with different porosities is very important.The measurements were carried out by thermal conductivity sensors (hot-ball sensor)located in different positions along the path of the water’s movement. The principle of thehot-ball sensor (thermal conductivity sensor) is based on the Hot-Ball Method formeasuring thermal conductivity. The local moisture content and local temperature ofa porous stone is inspected using the Hot-Ball Method, where the measured values of thethermal conductivity are correlated with the water content. The experimental set up for theinvestigation of the water diffusion in stones is described.

Simultaneous use of newly adopted simple sensors for continuous measurements of soil moisture and salinity

Soil Research ◽  
2003 ◽  
Vol 41 (2) ◽  
pp. 309 ◽  
Author(s):  
F. Konukcu ◽  
A. Istanbulluoglu ◽  
I. Kocaman
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Water Content ◽  
Water Table ◽  
Arid Regions ◽  
Sandy Loam ◽  
Clay Loam ◽  
Evaporation Chamber ◽  
Wide Range ◽  
Semi Arid

Methods available to measure salinity and moisture content in arid and semi-arid regions are limited because of the high salinities and very wide range of water contents (i.e. from saturation near the water table to air dry in the evaporation front). This paper is focused on the instrumentation employed in monitoring salt and moisture profiles in a column study which has wide applicability in salinity research. Experiments were conducted in a specially designed evaporation chamber which provided high evaporative demand as experienced in arid and semi-arid regions. Intensively instrumented soil columns with a constant shallow saline water table were used. Moisture content was measured by thermal conductivity and salinity by 4-electrode probe. In each case, instruments were manufactured specifically for the purpose in order to provide the desired degree of spatial resolution. Two soil types, sandy loam and clay loam, were used. Results indicated that thermal-conductivity probes measured water content over a wide range from saturation to 0.16 m3/m3 for clay loam and to 0.09 m3/m3 for sandy loam soil with great sensitivity (R2 > 0.95) and were unaffected by salt accumulation. The 4-electrode probes provided reliable measurements (R2 > 0.95) of the salinity of the soil solution for the range relevant to agricultural application. However, the accuracy of the probe decreased with the decreases in the water content after permanent wilting point.

Calibration of thermal conductivity sensors with consideration of hysteresis

2003 ◽  
Vol 40 (5) ◽  
pp. 1048-1055 ◽  
Author(s):  
Man Feng ◽  
Delwyn G Fredlund
Keyword(s):  
Thermal Conductivity ◽  
Water Content ◽  
Laboratory Testing ◽  
Calibration Procedure ◽  
Sensor Calibration ◽  
Sensor Output ◽  
Direct Function ◽  
Voltage Versus ◽  
Capillary Hysteresis ◽  
Conductivity Sensor

A thermal conductivity sensor monitors soil suction by measuring the changes in thermal conductivity of the porous tip. The thermal conductivity of the porous tip is a direct function of its water content. It has long been recognized that the suction versus water content relationship of a porous material exhibits hysteresis of various magnitudes between wetting and drying processes. The sensor output may correspond to various suction values of the sensor porous tip, depending on the wetting or drying state of the porous tip. The current calibration procedure, however, represents only one of the drying processes of the sensor porous tip. A laboratory testing program was carried out to better understand the hysteretic properties of the sensor output voltage versus the suction and to further improve the calibration procedure. The output of the sensor was monitored as the sensor porous tip was subjected to various drying and wetting processes. The test results indicate an error of 30%–70% for suctions higher than 100 kPa if the hysteretic effects of the porous tip are not considered in data interpretation. Based on the laboratory testing results, a revised calibration procedure was proposed that takes into consideration the capillary hysteretic effects.Key words: thermal conductivity sensor, calibration, matric suction, capillary hysteresis.

Analytical Determination of Soil Thermal Conductivity and Diffusivity

1988 ◽  
Vol 110 (4) ◽  
pp. 306-312 ◽  
Author(s):  
J. G. Ingersoll
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Porosity ◽  
Analytical Determination ◽  
Seasonal Temperature ◽  
Soil Thermal Conductivity ◽  
Dry Soil

A simple model has been developed that can be used to calculate the soil thermal conductivity and diffusivity on the basis of the following factors: soil porosity; soil water content; conductivity, specific heat, and density of the constituents of soil, i.e., solid matter, water, and air. The model assumes that the void space in soil can be presented by a combination of plane fissures, whose direction is either parallel to the heat flow or perpendicular to it. A coefficient introduced to account for this combination in the two directions can be estimated from measured data as a function of the soil water content. Moreover, it is assumed that air and moisture conduct heat across the fissures in parallel. It is found that soil conductivity and diffusivity increase relatively rapidly with a few percent addition of moisture to entirely dry soil. For instance, assuming a typical soil porosity of 40 percent we conclude that the ratio of soil diffusivities of saturated to dry soil is about four, while that of soild with 2.5 percent moisture content to dry soil is a little over two. That is to say, a small moisture addition to dry soil brings the diffusivity half way to its saturation value. Since soil always contains small amounts of moisture, this finding explains the fact that measured seasonal temperature damping factors in extreme humid and extreme arid climates differ by less than a factor of two even though the moisture content of the respective soils may differ by more than an order of magnitude.

PENGARUH VIRGIN COCONUT OIL (VCO) TERHADAP KARAKTERISTIK DAN UMUR SIMPAN ROTI MANIS

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Aulia Alfi
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Coconut Oil ◽  
Temperature Treatment ◽  
Ash Content ◽  
Virgin Coconut Oil ◽  
Food Ingredients ◽  
Life Analysis ◽  
Antibacterial And Antifungal ◽  
Physical And Chemical

Virgin Coconut Oil (VCO) adalah bahan alami yang memiliki sifat antimikroba (antivirus, antibakteri, dan antijamur). Sehingga VCO dapat memberikan efek pengawet pada bahan makanan, salah satunya adalah roti manis. Penelitian ini dilakukan untuk mengevaluasi pengaruh VCO terhadap karakteristik (fisik dan kimia) dan umur simpan roti manis. Roti manis dianalisis secara fisik (tekstur dan porositas) dan kimia (kadar air, kadar abu, kadar lemak, kadar protein, dan kandungan karbohidrat), dan analisis umur simpan dengan FFA, uji organoleptik dan jamur setiap dua hari selama delapan hari penyimpanan di suhu ruang. Variasi perlakuan roti manis adalah dari rasio konsentrasi VCO: margarin: mentega, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). Hasil penelitian menunjukkan bahwa VCO tidak memiliki pengaruh yang signifikan terhadap karakteristik fisik dan karakteristik kimia roti manis. Namun, VCO berpengaruh signifikan terhadap kadar air roti manis yang dihasilkan, roti manis K memiliki kadar air tertinggi (22,36%) dan berbeda dengan sampel roti manis lainnya. VCO secara efektif menghambat pertumbuhan jamur di roti manis pada konsentrasi 8%, 12%, dan 16%. Roti manis K dan A memiliki masa simpan 4 hari, sedangkan roti manis B, C, dan D memiliki masa simpan 6 hari.Kata kunci: VCO, roti manis, karakteristik, umur simpanABSTRACTVirgin Coconut Oil (VCO) is a natural ingredient that has antimicrobial (antiviral, antibacterial, and antifungal) properties. So that VCO can provide a preservative effect on food ingredients, one of which is sweet bread. This research was conducted to evaluate the effect of VCO on characteristics (physical and chemical) and shelf life of sweet bread. Sweet bread was analyzed physically (texture and porosity) and chemistry (moisture content, ash content, fat content, protein content, and carbohydrate content), and shelf life analysis with FFA, organoleptic and mold tests every two days for eight days of storage at ambient temperature. Treatment variations of sweet breads is from the ratio of the concentration of VCO: margarine: butter, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). The results showed that VCO did not have a significant effect on the physical characteristics and chemical characteristics of sweet bread. However, the VCO has a significant effect on the water content of the sweet bread produced, sweet bread K has the highest moisture content (22,36%) and it is different from other sweet bread samples. VCO effectively inhibits the growth of sweet bread mold at concentrations of 8%, 12%, and 16%. K and A sweet bread has a shelf life of 4 days, while sweet breads B, C, and D have a shelf life of 6 days.Keywords: VCO, sweet bread, characteristics, shelf life

Basic Study on Effects of Water Content on Printing Paper on Equivalent Thermal Conductivity

2018 ◽  
Vol 2018 (1) ◽  
pp. 41-43
Author(s):  
Takashi Fukue ◽  
Hirotoshi Terao ◽  
Koichi Hirose ◽  
Tomoko Wauke ◽  
Hisashi Hoshino ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Water Content ◽  
Basic Study ◽  
Equivalent Thermal Conductivity ◽  
Printing Paper

INVESTIGATION OF EROSION RESISTANCE OF GRAY-BROWN SOILS IN THE SOUTHEASTERN SLOPES OF THE GREATER CAUCASUS

2020 ◽  
pp. 47-49
Author(s):  
Aliyev Z.H.
Keyword(s):  
Erosion Resistance ◽  
Preventive Measures ◽  
Chemical Properties ◽  
Anthropogenic Factors ◽  
Erosion Process ◽  
Greater Caucasus ◽  
Sloping Lands ◽  
Set Up ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, sharp changes have occurred in the state of sloping lands of Azerbaijan. There was tension from the influence of the anthropogenic factors on the mountain slopes. The fact that the erosion process is rein-forced in the research site. Due to lack of agrotechnical measures on the slopes erosion process has been strength-ened, soil flooded with soil, physical and chemical properties of the soil have deteriorated, nutritional elements are reduced, vegetation is reduced and destruction limit. For some reason, the purpose of the research was Aqsu, two land cuts were set up to determine the degree of actual erosion in the Qizmeydan village. prevent erosion intensity, take preventive measures to take and implement appropriate measures.

scholarly journals Influence of Temperature and Moisture Content on Thermal Performance of Green Roof Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2421
Author(s):  
Bohan Shao ◽  
Caterina Valeo ◽  
Phalguni Mukhopadhyaya ◽  
Jianxun He
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Green Roof ◽  
Green Roofs ◽  
Power Functions ◽  
Thick Substrate ◽  
Different Temperatures ◽  
Test Cells ◽  
Substrate Moisture ◽  
Phase Transition Zone

The influence of moisture content on substrate thermal conductivity at different temperatures was investigated for four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 and −10 °C, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature. Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature’s amplitude for the green roof with 150 mm thick substrate. When a sedum mat was added, there was a 20% reduction in the amplitude of the inner temperature as compared with the cell without a sedum mat.

scholarly journals KARAKTERISTIK DAN SKRINING FITOKIMIA EKSTRAK ETANOL 70% BATANG KEPUH (Sterculia foetida L.)

Jurnal Kimia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
N. P. S. E. Cahyani ◽  
J. Susiarni ◽  
K. C.S. Dewi ◽  
N. L.P. Melyandari ◽  
K. W.A. Putra ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Ethanol Extract ◽  
Phytochemical Screening ◽  
Residual Solvent ◽  
Solvent Content ◽  
Residual Content ◽  
Ethanol Level ◽  
Anti Inflammatory

Kepuh (Sterculia foetida L) is a type of kapok plant that has been scientifically proven to have activity as an anti-inflammatory and analgesic. 70% ethanol extract of stem stem is obtained by maceration using 70% ethanol. Examination of the characteristics of 70% ethanol extract of kepuh stem included organoleptic, of moisture content and determination of residual solvent content. Phytochemical screening of 70% ethanol extract of kepuh bark includes: alkaloid, flavonoid, saponin, tannin , polyphenol, and examination of glycosides. The results of the examination of the characteristics of 70% ethanol extract of kepuh stem obtained water content of 8.66 ± 0.748%, the residual content of the solvent had a 0 (zero) ethanol level. The results of phytochemical screening showed 70% ethanol extract of stem stem containing steroid compounds, triterpenoids, flavonoids, saponins, tannins and polyphenols. The identification using UV-Vis spectrophotometry produced ? 212, the absorbance was 1.8601 and ? 284, the absorbance was 0.42186.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

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