scholarly journals Accuracy Examination in the RCS Computation of a Leaf Using the Resistive Sheet Technique with Various Thicknesses and Moisture Contents

Author(s):  
Minseo Park ◽  
Han-Joong Kim ◽  
Kwiseob Um ◽  
Sin-Myong Park ◽  
Soon-Koo Kweon ◽  
...  
Author(s):  
F. Seehofer ◽  
W. Schulz

AbstractThe phenomenon of the smoulder stream flowing through the cigarette during smouldering and during the puff intervals is demonstrated for the first time and its dependence upon physical conditions is examined. The volume of the smoulder stream can amount up to 180 ml per cigarette. Increasing draw resistance of the cigarette and augmenting moisture content of the tobacco as well as perforation of the cigarette paper have a decreasing effect on volume and velocity of the smoulder stream. The porosity of the cigarette paper has no perceptible influence. The spatial position of the cigarette affects volume and velocity of the smoulder stream. The influence exercised by the smoulder stream on the yields of total condensate, nicotine, phenols, aldehydes, and acroleine when the cigarette tip is open during the puff intervals is determined. When the moisture contents of the tobacco were extremely high, yield decreases reaching 50 % could be observed.


2012 ◽  
Vol 2 (2) ◽  
pp. 79-86 ◽  
Author(s):  
James W. McKinley ◽  
Rebecca E. Parzen ◽  
Álvaro Mercado Guzmán

Urine-diversion dehydration toilets (UDDT) are common throughout the developing world, and the toilet product is widely used as compost. There is no comprehensive research to date that characterizes the compost to determine its quality, extent of pathogen inactivation, and the effects of climate and bulking materials on the compost. Compost was collected from 45 UDDT in Bolivia and analyzed for physical, chemical, and biological parameters. Eighty percent and 56% of samples did not meet acceptable compost guidelines for moisture content and pH, respectively, indicating desiccation was the dominant process in UDDT. Bulking materials significantly impacted compost characteristics in terms of pH, carbon, carbon-to-nitrogen ratio, and carbon stability (P < 0.05). Composts with ash exhibited, on average, low carbon concentrations (4.9%) and high pH values (9.7), which can be harmful to plants and composting microorganisms. Composts with sawdust exhibited, on average, high carbon concentrations (40.0%) and carbon-to-nitrogen ratios (31.0). Climate had no significant impact on chemical characteristics, however composts from humid regions had significantly higher moisture contents (34.4%) than those from arid climates (24.8%) (P < 0.05). Viable Ascaris lumbricoides ova were identified in 31% of samples, including samples with high pH, low moisture contents, and long storage times.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4667
Author(s):  
Sunyong Park ◽  
Hui-Rim Jeong ◽  
Yun-A Shin ◽  
Seok-Jun Kim ◽  
Young-Min Ju ◽  
...  

Agricultural by-products have several disadvantages as fuel, such as low calorific values and high ash contents. To address these disadvantages, this study examined the mixing of agricultural by-products and spent coffee grounds, for use as a solid fuel, and the improvement of fuel characteristics through torrefaction. Pepper stems and spent coffee grounds were first dried to moisture contents of <15% and then combined, with mixing ratios varying from 9:1 to 6:4. Fuel pellets were produced from these mixtures using a commercial pelletiser, evaluated against various standards, and classified as grade A, B, or Bio-SRF. The optimal ratio of pepper stems to spent coffee grounds was determined to be 8:2. The pellets were torrefied to improve their fuel characteristics. Different torrefaction temperatures improved the mass yields of the pellets to between 50.87% and 88.27%. The calorific value increased from 19.9% to 26.8% at 290 °C. The optimal torrefaction temperature for coffee ground pellets was 230 °C, while for other pellets, it was 250 °C. This study provides basic information on the potential enhancement of agricultural by-products for fuel applications.


2021 ◽  
pp. 174425912198938
Author(s):  
Michael Gutland ◽  
Scott Bucking ◽  
Mario Santana Quintero

Hygrothermal models are important tools for assessing the risk of moisture-related decay mechanisms which can compromise structural integrity, loss of architectural features and material. There are several sources of uncertainty when modelling masonry, related to material properties, boundary conditions, quality of construction and two-dimensional interactions between mortar and unit. This paper examines the uncertainty at the mortar-unit interface with imperfections such as hairline cracks or imperfect contact conditions. These imperfections will alter the rate of liquid transport into and out of the wall and impede the liquid transport between mortar and masonry unit. This means that the effective liquid transport of the wall system will be different then if only properties of the bulk material were modelled. A detailed methodology for modelling this interface as a fracture is presented including definition of material properties for the fracture. The modelling methodology considers the combined effect of both the interface resistance across the mortar-unit interface and increase liquid transport in parallel to the interface, and is generalisable to various combinations of materials, geometries and fracture apertures. Two-dimensional DELPHIN models of a clay brick/cement-mortar masonry wall were created to simulate this interaction. The models were exposed to different boundary conditions to simulate wetting, drying and natural cyclic weather conditions. The results of these simulations were compared to a baseline model where the fracture model was not included. The presence of fractures increased the rate of absorption in the wetting phase and an increased rate of desorption in the drying phase. Under cyclic conditions, the result was higher peak moisture contents after rain events compared to baseline and lower moisture contents after long periods of drying. This demonstrated that detailed modelling of imperfections at the mortar-unit interface can have a definitive influence on results and conclusions from hygrothermal simulations.


2021 ◽  
Vol 12 (1) ◽  
pp. 1370-1384
Author(s):  
Yiju Tang ◽  
Jing Liu ◽  
Tianxuan Hao ◽  
Fan Li ◽  
Lizhen Zhao

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Jae W. Park ◽  
Won B. Yoon

AbstractNovel algorithm to determine the least cost formulation of a surimi blend was developed using linear programming (LP). Texture properties and the unit cost of surimi blend at the target moisture content were used as constraint functions and the objective function, respectively. The mathematical models to describe the moisture content dependence of the ring tensile properties were developed using critical moisture content, and the model parameters were used for the least cost LP (LCLP) model. The LCLP model successfully predicted the quality of surimi blend. Sensitivity analysis was used to obtain an additional information when the perturbations of design variables are provided. A standard procedure to determine the least cost formulation for blending surimi with varied moisture contents was systematically developed.


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