scholarly journals Preparation of Breathable Cellulose Based Polymeric Membranes with Enhanced Water Resistance for the Building Industry

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4310
Author(s):  
Atif Hussain ◽  
Pierre Blanchet
Keyword(s):  
Cellulose Fiber ◽  
Composite Membranes ◽  
Physical Structure ◽  
Building Industry ◽  
Morphological Examination ◽  
Vapour Permeability ◽  
Surfactant Treatment ◽  
Hygroscopic Properties ◽  
Phosphoric Acid Ester ◽  
Pass Through

This study focuses on the development of advanced water-resistant bio-based membranes with enhanced vapour permeability for use within building envelopes. Building walls are vulnerable to moisture damage and mold growth due to water penetration, built-in moisture, and interstitial condensation. In this work, breathable composite membranes were prepared using micro-fibrillated cellulose fiber (CF) and polylactic acid (PLA). The chemical composition and physical structure of CF is responsible for its hydrophilic nature, which affects its compatibility with polymers and consequently its performance in the presence of excessive moisture conditions. To enhance the dispersibility of CF in the PLA polymer, the fibers were treated with an organic phosphoric acid ester-based surfactant. The hygroscopic properties of the PLA-CF composites were improved after surfactant treatment and the membranes were resistant to water yet permeable to vapor. Morphological examination of the surface showed better interfacial adhesion and enhanced dispersion of CF in the PLA matrix. Thermal analysis revealed that the surfactant treatment of CF enhanced the glass transition temperature and thermal stability of the composite samples. These bio-based membranes have immense potential as durable, eco-friendly, weather resistant barriers for the building industry as they can adapt to varying humidity conditions, thus allowing entrapped water vapor to pass through and escape the building, eventually prolonging the building life.

scholarly journals Numerical and experimental investigation of heat and mass transfer within bio-based material

2019 ◽  
Vol 23 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Mounir Asli ◽  
Frank Brachelet ◽  
Alexis Chauchois ◽  
Emmanuel Antczak ◽  
Didier Defer
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Water Vapour ◽  
Test Facility ◽  
Good Prediction ◽  
Vapour Permeability ◽  
Hygroscopic Properties ◽  
Good Concordance ◽  
The Mathematical Model

In this paper, the coupled heat and mass transfer within porous media has been studies. First, the studied materials have been characterized experimentally and than evaluated their thermal properties, namely thermal conductivity and specific heat in different states (dry-wet). The hygroscopic properties, namely water vapour permeability, water vapour sorption. At second time, we present and validate the mathematical model describing heat and mass transfer within bio-based materials, by the confrontation with the experimental results. The materials properties obtained from the characterisation part are used as model?s input parameters. Moreover, a test facility is mounted in the laboratory in order to compare the numerical and experimental data. The founded results show a good concordance between the simulated and measured data. According to this results the mathematical model of Philip and de Vries gives a good prediction of hygrothermal behaviour of bio-based material. This model will allow us to save money and time of the experimental part in the future.

scholarly journals Resilient hemp shiv aggregates with engineered hygroscopic properties for the building industry

2019 ◽  
Vol 212 ◽  
pp. 247-253 ◽  
Author(s):  
Atif Hussain ◽  
Juliana Calabria-Holley ◽  
Mike Lawrence ◽  
Yunhong Jiang
Keyword(s):  
Building Industry ◽  
Hygroscopic Properties ◽  
Hemp Shiv

Buckling Behavior of Through-Plates under Gravity Loads

2011 ◽  
Vol 105-107 ◽  
pp. 2183-2187
Author(s):  
Razieh Samimi ◽  
Seyed Rasoul Mirghaderi
Keyword(s):  
Building Industry ◽  
Load Path ◽  
Hollow Section ◽  
Panel Zone ◽  
Economical Design ◽  
Buckling Behavior ◽  
Bending Capacity ◽  
Pass Through ◽  
The Moment ◽  
Hollow Structural Sections

Due to the development in the construction and building industry in recent years, numerous methods for safer, easier and more economical design of structures have been studied.Because of the high bi-axial bending capacity and high compressive strength of hollow structural sections, these sections are considered as a popular alternative by designers. Supporting the panel zone demands in the columns and occurring the moment hinge at the ends of beam are too available in column with hollow section. One of the major problems in the way of using these sections is lack of appropriate load path to connect beams to them, which ends up using through-plates. Through-plates are plates that pass through column and beams connect to them at their webs. Consequently these plates should have sufficient stiffness in order to provide enough strength. This paper proceeds to study the buckling behavior of through-plates in moment beam to column connections under gravity loads.

Design and Development of Thermoplastic Polyurethane Based Composite Membranes

2010 ◽  
Author(s):  
R. Vasanthakumari
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Absorption ◽  
Thermoplastic Polyurethane ◽  
Composite Membranes ◽  
Design And Development ◽  
Good Thermal Stability ◽  
Electrolyte Membranes ◽  
Pass Through ◽  
High Flexibility

Polymer electrolyte membranes used in fuel cells are proton selective and hence allows only protons to pass through it. The electrolyte composition, morphology and water absorption properties of the membrane greatly influence the performance of the fuel cell. For example the membranes used in fuel cells should meet following requirements. • Good thermal stability above 250°C. • Proton conductivity greater than 10^-2 S/cm. • Good water absorption and water retaining capacity. • mechanical strength and flexibility. The present paper is focused on design and development of a membrane suitable for fuel cell application. The base polymer chosen in this present work has been thermoplastic polyurethane because of its high flexibility, temperature resistance and solubility in organic solvent such as DMF. Fabrication of the coating machine was done and thermoplastic polyurethane (TPU) based Composite membranes with an average thickness of 40 microns were cast. Sulphonation of polystyrene was carried out to get SPS with assay 98%. TPU based composite membranes with conducting resins of 25% SPEEK, 4%SPS and 10% PANI were cast and characterized by FTIR, DSC, four probe conductivity and SEM. The composite membranes were studied for fuel cell suitability. The studies show that a current in the range of 0.5×10−4 A to 0.8344×10−4 A and about 0.5V can be drawn out of these membranes. The results were compared with that of NAFION membrane.

scholarly journals Hydrostatic Resistance and Mechanical Behaviours of Breathable Layered Waterproof Fabrics

2018 ◽  
Vol 26 (1(127)) ◽  
pp. 108-112 ◽  
Author(s):  
Iwona Frydrych ◽  
Pavla Tesinova ◽  
Lubos Hes ◽  
Veerakumar Arumugam
Keyword(s):  
Mechanical Properties ◽  
Water Vapour ◽  
Water Vapour Permeability ◽  
Cold Weather ◽  
Test Results ◽  
Vapour Permeability ◽  
Different Types ◽  
Mechanical Behaviours ◽  
Pass Through ◽  
Hydrophilic Membrane

Breathable layered waterproof fabrics have good applications in the fields of sportswear, protective clothing and construction industries. The properties of these fabrics in allowing water vapour to pass through while preventing liquid water from entering have made them unique. The mechanical properties of these fabrics are also very important for the satisfaction of the wearers. The layered constructions of these fabrics with different characteristic properties contribute to the influence on their hydrostatic resistance, mechanical properties and water vapour permeability. This study presents an experiment on eight different types of hydrophobic and hydrophilic membrane laminated layered fabrics used as sportswear during hot or cold weather. The hydrostatic resistance, tensile strength, stiffness and water vapour permeability of these fabrics were evaluated by varying different fabric parameters in the experiment. It was found from the test results that the fabric density, thickness and weight as well as types of membranes and layers have a significant effect on those properties of the layered fabrics.

Instrumentation for detecting channelling radiation in the high-voltage electron microscope

1983 ◽  
Vol 41 ◽  
pp. 318-319
Author(s):  
J. H. Butler ◽  
C. J. Humphreys
Keyword(s):  
Monochromatic Light ◽  
Incident Beam ◽  
Laboratory Frame ◽  
Relativistic Electrons ◽  
Voltage Electron ◽  
Dipole Emission ◽  
Sinusoidal Oscillations ◽  
Pass Through ◽  
Incident Beam Energy ◽  
Increasing Function

Electromagnetic radiation is emitted when fast (relativistic) electrons pass through crystal targets which are oriented in a preferential (channelling) direction with respect to the incident beam. In the classical sense, the electrons perform sinusoidal oscillations as they propagate through the crystal (as illustrated in Fig. 1 for the case of planar channelling). When viewed in the electron rest frame, this motion, a result of successive Bragg reflections, gives rise to familiar dipole emission. In the laboratory frame, the radiation is seen to be of a higher energy (because of the Doppler shift) and is also compressed into a narrower cone of emission (due to the relativistic “searchlight” effect). The energy and yield of this monochromatic light is a continuously increasing function of the incident beam energy and, for beam energies of 1 MeV and higher, it occurs in the x-ray and γ-ray regions of the spectrum. Consequently, much interest has been expressed in regard to the use of this phenomenon as the basis for fabricating a coherent, tunable radiation source.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Morphological Examination of a Herpes-type Virus Indigenous for Tree Shrews

1970 ◽  
Vol 28 ◽  
pp. 160-161
Author(s):  
J. P. Brunschwig ◽  
R. M. McCombs ◽  
R. Mirkovic ◽  
M. Benyesh-Melnick
Keyword(s):  
Electron Microscopy ◽  
Soft Tissue ◽  
Chick Embryo ◽  
Soft Tissue Sarcoma ◽  
Cell Cultures ◽  
Tree Shrew ◽  
Type Virus ◽  
Morphological Examination ◽  
Tree Shrews ◽  
Embryo Cells

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.

A New High Intensity Grid Cap for RCA-EMU-3 Electron Microscopes

1968 ◽  
Vol 26 ◽  
pp. 316-317
Author(s):  
George Christov ◽  
Bolivar J. Lloyd
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Voltage ◽  
High Intensity ◽  
Electron Gun ◽  
Tungsten Filament ◽  
Fluorescent Screen ◽  
Electron Microscopes ◽  
Pass Through ◽  
Ground Potential

A new high intensity grid cap has been designed for the RCA-EMU-3 electron microscope. Various parameters of the new grid cap were investigated to determine its characteristics. The increase in illumination produced provides ease of focusing on the fluorescent screen at magnifications from 1500 to 50,000 times using an accelerating voltage of 50 KV.The EMU-3 type electron gun assembly consists of a V-shaped tungsten filament for a cathode with a thin metal threaded cathode shield and an anode with a central aperture to permit the beam to course the length of the column. The cathode shield is negatively biased at a potential of several hundred volts with respect to the filament. The electron beam is formed by electrons emitted from the tip of the filament which pass through an aperture of 0.1 inch diameter in the cap and then it is accelerated by the negative high voltage through a 0.625 inch diameter aperture in the anode which is at ground potential.

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