scholarly journals Fabrication of Cellulose Sponge: Effects of Drying Process and Cellulose Nanofiber Deposition on the Physical Strength

2020 ◽  
Vol 20 (1) ◽  
pp. 1
Author(s):  
Abdul Halim ◽  
Yinchao Xu ◽  
Toshiharu Enomae
Keyword(s):  
Mass Transfer ◽  
Sodium Phosphate ◽  
Cellulose Nanofiber ◽  
Regenerated Cellulose ◽  
Cellulose Ii ◽  
Drying Process ◽  
Exponential Factor ◽  
Physical Strength ◽  
Cellulose Sponge ◽  
Drying Conditions

Cellulose sponge was fabricated by regenerating cellulose from a xanthate solution. The solution, which contained sodium phosphate particles as a template to create sponge porosity, was dried at 55, 65, 75 and 85 °C for 2, 4, 6, and 8 h. Mass transfer during the initial and last stages of drying was controlled in terms of temperature and concentration differences, respectively. The activation energy and pre-exponential factor of the mass transfer coefficient were -51,841.947 kJ mol-1 and 7.26×109 m-2 h-1, respectively. Regenerated cellulose contained a crystalline type of cellulose II, and the crystallinity was independent of drying conditions. At a low drying temperature (T≤55 °C) and short drying period (t≤2h), the cellulose was unregenerated. At higher temperatures and longer drying periods, no relationship between temperature and physical strength was observed. Cellulose nanofiber (CNF) was added to the xanthate solution at a ratio of 1:100 of CNF to linter cellulose for xanthation; however, this did not affect the physical strength of the cellulose sponge for both mechanically and chemically fabricated CNF.

scholarly journals Modeling and simulation of heat and mass transfer in an Ethiopian fresh injera drying process

Heliyon ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. e06201
Author(s):  
Alamrew B. Solomon ◽  
Solomon W. Fanta ◽  
Mulugeta A. Delele ◽  
Maarten Vanierschot
Keyword(s):  
Mass Transfer ◽  
Modeling And Simulation ◽  
Heat And Mass Transfer ◽  
Drying Process

scholarly journals Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Drying Process ◽  
Drying Time ◽  
Oven Drying ◽  
Sun Drying ◽  
Different Temperatures ◽  
Final Water Content ◽  
Drying Curves ◽  
Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

Method of Ginkgo biloba Drying and Drying Machine Design

2014 ◽  
Vol 541-542 ◽  
pp. 722-726
Author(s):  
Jun Ming Hou ◽  
De Xu Yang ◽  
Ke Jia Wu
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Ginkgo Biloba ◽  
Medical Industry ◽  
Combined Effect ◽  
Machine Design ◽  
Drying Process ◽  
Heat Transmission ◽  
Electrically Conducting

In this paper the drying process of ginkgo biloba is discussed. The process combined effect of convective Heat and mass transfer on hydromagnetic electrically conducting viscous, how to improve the ability of drying is an important problem. The heat transmission for drying process is discussed. The parameter of drying process is determined. The ginkgo biloba drying machine is developed and the key part of drying machine is designed. The whole drying machine is developed, which can enhance the ability of medical industry. The study can help the Optimization of drying process and the level of the ginkgo biloba drying.

An Experimental Study of Heat and Mass Transfer During Drying of Packed Beds

1992 ◽  
Vol 114 (3) ◽  
pp. 727-734 ◽  
Author(s):  
W. C. Lee ◽  
O. A. Plumb ◽  
L. Gong
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Glass Beads ◽  
Drying Rate ◽  
Packed Beds ◽  
Transfer Coefficients ◽  
Model Predictions ◽  
Drying Models ◽  
Surface Saturation ◽  
Drying Conditions

An experimental study has been conducted to provide a data base for drying packed beds of granular, nonhygroscopic materials. Experimental results for drying rate, saturation distribution, temperature distribution, and surface saturation are reported for drying glass beads under carefully documented drying conditions. Capillary pressure for both imbibition and drainage was measured for the glass beads, whose size ranged from 65 μm to 450 μm. The drying results demonstrate that, contrary to available model predictions, porous materials do not necessarily exhibit saturation gradients that always increase with distance from the drying surface. Under certain conditions the capillary potential is sufficient to create an internal drying front. The measurements of surface saturation are the first to be reported. They are utilized to speculate on the reasons for the failure of drying models to compare well with experiment without adjusting the convective heat or mass transfer coefficients.

scholarly journals EXPERIMENTAL INVESTIGATION OF CLAY-STRAW BUILDING FINISHING LAYER UNDER DIFFERENT DRYING CONDITIONS

2016 ◽  
Vol 8 (2) ◽  
pp. 65-70
Author(s):  
Tadas Tamošiūnas ◽  
Romas Girkontas ◽  
Andrius Savickas ◽  
Šarūnas Skuodis ◽  
Lumir Mica
Keyword(s):  
Main Idea ◽  
Life Time ◽  
Analysis Program ◽  
Drying Process ◽  
Environmental Friendly ◽  
Bright Yellow ◽  
Before And After ◽  
Yellow Clay ◽  
Drying Conditions ◽  
Clay Tiles

This manuscript represents investigation of six different clay mixtures under variable drying conditions, namely: bright yellow clay (typical for Lithuania), brown clay (Lithuania Sergėnai district), mixture of different clays, white Spanish clay, clay mass which is resistant for thermal coldness (with synthetic cardigan) and Lithuanian coarse clay with granite additives. Drying process was provided imitating natural drying process and fast drying in drying oven at 110 C°. The main idea of this study – imitate clay and clay-straw buildings drying process and to determine which of used clay types had smallest volumetric and linear deformations. Volumetric and linear deformations for clay-straw buildings is one of the most important factors evaluating cracking in this type of buildings. To reach this purpose six tiles of different clay types were used. Before drying stage water content, plasticity, and liquid limits index, respectively was determined for all types of clay. All clay tiles volumetric and linear deformations before and after drying process were measured with specialized view analysis program in order not to damage samples’ form. According to the obtained results a clay type whith the smallest deforamations (volumetric and linear) was found. With the smallest volumetric and linear deformations clay-straw building is not only environmental friendly, sustainable and green, but it does not require a lot of maintenance during building life time.

Effects of drying conditions on density and mechanical properties of cellulose nanofiber shieets

2020 ◽  
Vol 2020.28 (0) ◽  
pp. 155
Author(s):  
Hiroki TAKAHASHI ◽  
Morimasa NAKAMURA ◽  
Takashi MATSUOKA ◽  
Shinichiro IWAMOTO ◽  
Takashi ENDO
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofiber ◽  
Drying Conditions

Electrospun regenerated cellulose nanofiber based metal-chelating affinity membranes for protein adsorption

2018 ◽  
Vol 10 ◽  
pp. 168-174 ◽  
Author(s):  
Cheng Duan ◽  
Qiuxia Fu ◽  
Yang Si ◽  
Lifang Liu ◽  
Xia Yin ◽  
...  
Keyword(s):  
Protein Adsorption ◽  
Cellulose Nanofiber ◽  
Regenerated Cellulose ◽  
Metal Chelating ◽  
Affinity Membranes

scholarly journals Cortex Effect on Vacuum Drying Process of Porous Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Zhijun Zhang ◽  
Shiwei Zhang ◽  
Tianyi Su ◽  
Shuangshuang Zhao
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Fruits And Vegetables ◽  
Water Saturation ◽  
Coupled Model ◽  
Water Evaporation ◽  
Vacuum Drying ◽  
Vapor Pressures ◽  
Drying Process ◽  
Medium Vacuum

Corns, fruits, and vegetables are usually used as porous medium in drying process. But in fact, it must be considered as the cortex effect on mass transfer because the mass transfer of cortex is very difficult than inner medium. Based on the theory of heat and mass transfer, a coupled model for the porous medium vacuum drying process with cortex effect is constructed. The model is implemented and solved using COMSOL software. The water evaporation rate is determined using a nonequilibrium method with the rate constant parameterKrthat has been studied. The effects of different vapor pressures (1000, 5000, and 9000 Pa), initial moisture contents (0.3, 0.4, and 0.5 water saturation), drying temperatures (323, 333, and 343 K), and intrinsic permeability for cortex part (10−13, 10−14, 10−15 m2) on vacuum drying process were studied. The results facilitate a better understanding of the porous medium vacuum drying process that nearer to the reality.

scholarly journals High-Strength Regenerated Cellulose Fiber Reinforced with Cellulose Nanofibril and Nanosilica

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2664
Author(s):  
Yu Xue ◽  
Letian Qi ◽  
Zhaoyun Lin ◽  
Guihua Yang ◽  
Ming He ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Cellulose Fiber ◽  
High Strength ◽  
Composite Fiber ◽  
Regenerated Cellulose ◽  
Fiber Reinforced ◽  
Physical Strength ◽  
Nano Sio2 ◽  
Shear Thinning Fluids ◽  
Regenerated Fibers

In this study, a novel type of high-strength regenerated cellulose composite fiber reinforced with cellulose nanofibrils (CNFs) and nanosilica (nano-SiO2) was prepared. Adding 1% CNF and 1% nano-SiO2 to pulp/AMIMCl improved the tensile strength of the composite cellulose by 47.46%. The surface of the regenerated fiber exhibited a scaly structure with pores, which could be reduced by adding CNF and nano-SiO2, resulting in the enhancement of physical strength of regenerated fibers. The cellulose/AMIMCl mixture with or without the addition of nanomaterials performed as shear thinning fluids, also known as “pseudoplastic” fluids. Increasing the temperature lowered the viscosity. The yield stress and viscosity sequences were as follows: RCF-CNF2 > RCF-CNF2-SiO22 > RCF-SiO22 > RCF > RCF-CNF1-SiO21. Under the same oscillation frequency, G’ and G” decreased with the increase of temperature, which indicated a reduction in viscoelasticity. A preferred cellulose/AMIMCl mixture was obtained with the addition of 1% CNF and 1% nano-SiO2, by which the viscosity and shear stress of the adhesive were significantly reduced at 80 °C.

scholarly journals Processes of heat and mass transfer during drying of red beetroot

2020 ◽  
Vol 6 (2) ◽  
pp. 81-87
Author(s):  
Zhanna Petrova ◽  
◽  
Kateryna Samoilenko ◽  
Vitaly Vishnevsky
Keyword(s):  
Mass Transfer ◽  
Energy Consumption ◽  
Heat And Mass Transfer ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Calculation Model ◽  
Experimental Results ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Process

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.

Sign in / Sign up

Export Citation Format

Share Document