Impact of cross-lapping angle and needling parameters on mechanical and functional properties of nonwoven air filter fabric

2021 ◽  
pp. 152808372110481
Author(s):  
Wondwossen Mamuye ◽  
SM Ishtiaque ◽  
Rupayan Roy ◽  
Priyal Dixit
Keyword(s):  
Fibre Orientation ◽  
Structural Characteristics ◽  
Research Work ◽  
Areal Density ◽  
Nonwoven Fabric ◽  
Mean Flow ◽  
Stroke Frequency ◽  
Air Filter ◽  
Box Behnken Design ◽  
The Cross

This research work investigated the influence of the cross-lapping angle in combination with punch density and stroke frequency on structural characteristics and properties of nonwoven fabric. An attempt has been made to change the cross-lapping angle by keeping the number of layers constant to maintain the same areal density of fabrics. The fibre orientation in the carded web was measured by using Lindsley and image analysis methods. Three variables, that is, cross-lapping angle, punch density and stroke frequency, were considered for the sampling plan to create a three-factor three-level Box–Behnken design. The properties such as mean flow pore size, bursting strength, filtration efficiency and pressure drop were evaluated and analysed in the light of fibre orientation in the carded web. It was concluded that the cross-lapping angle influenced the fibre orientation to a large extent; accordingly, the properties of nonwoven fabric were highly influenced by the fibre orientation.

Customization of hierarchical air filter media by tailoring the structural parameters of needle punched nonwoven

2021 ◽  
pp. 152808372110290
Author(s):  
Rupayan Roy ◽  
SM Ishtiaque
Keyword(s):  
Layered Structure ◽  
Fibre Orientation ◽  
Structural Parameters ◽  
Gradient Structure ◽  
Mean Flow ◽  
Filter Media ◽  
Sem Images ◽  
Air Filter ◽  
Wide Range ◽  
Different Order

An attempt has been made to investigate the filtration behaviour of filter media with gradient structure created through layers of needle punched nonwoven. Batts of different fibre orientation influenced by carding parameters were prepared. Carding parameters i.e. feeder, cylinder and doffer speed were optimized by using response surface methodology to achieve the batts of different fibre orientation. Three batts with a wide range of fibre orientation were selected to create the gradient structures by placing them in a different position in the layered structure. The physical, mechanical and functional properties of nonwoven were evaluated. The different order of fibre orientation of batts was also analysed with the help of SEM images. The fabric with inverse gradient structure having batts in increasing order of fibre orientation in the layered structure provided very high (close to the highest) filter efficiency and very low (close to lowest) pressure drop instead of having higher (close to highest) mean flow pore size.

scholarly journals Eco-Friendly Poly(Vinyl Alcohol) Nanofiber-Based Air Filter for Effectively Capturing Particulate Matter

2021 ◽  
Vol 11 (9) ◽  
pp. 3831
Author(s):  
Han-Jung Kim ◽  
Dong-In Choi ◽  
Sang-Keun Sung ◽  
Su-Han Lee ◽  
Sang-Jin Kim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Quality Factor ◽  
Vinyl Alcohol ◽  
Nonwoven Fabric ◽  
Poly Vinyl Alcohol ◽  
Contamination Level ◽  
Plastic Pollution ◽  
Air Filters ◽  
Air Filter ◽  
Filter Surface

Due to the increasing use of polypropylene-based nonwoven dust masks and air filters, environmental problems that occur due to the plastic pollution resulting from the disposal of these materials have also increased. Hence, an eco-friendly air filter based on PVA nanofibers (NFs) was fabricated by electrospinning on a nonwoven fabric, and its performance was evaluated as a filter capable of blocking or capturing particulate matter. The quality factor of the optimized PVA NF-based air filter was found to be 0.010606 Pa−1, which is lower than that of a HEPA filter (0.015394 Pa−1), but higher than that of a cabin air filter (0.010517 Pa−1) and a dust mask (0.009102 Pa−1). The contamination level of the PVA NF-based filter was analyzed by optical and structural analyses of the filter surface. Finally, the filter was soaked in water to selectively remove the contaminated PVA NF layer, and the remaining nonwoven fabric was able to be reused to make the filter.

scholarly journals Compositional study of the lost temples in instructional design

2021 ◽  
pp. 150-157
Author(s):  
Galina Kozlova ◽  
Lyudmila Kozlova
Keyword(s):  
Instructional Design ◽  
Structural Characteristics ◽  
Research Work ◽  
First Year ◽  
Volumetric Models ◽  
Technical University ◽  
The Temple ◽  
Compositional Study ◽  
Illustrative Material ◽  
Sample Board

The article presents the design and research work of the authors and first-year architecture students of Irkutsk National Research Technical University concerning compositional study of lost temples of Irkutsk with the reconstruction of their architectural appearance. The illustrative material was prepared using the students’ works. The complex of Siberian Baroque temples in Irkutsk in the mid-18th – late 19th centuries and various types of church buildings were studied. The work uses modeling as a tool for predicting the architectural appearance of the temple. Sketch drawings and models of the Miracle-Working, Tikhvinsky and Annunciation temples were completed, and the model of the evolution of Siberian Baroque temples was recreated. The main stages of the term project, from building functional, planning and volumetric models to designing image and structural characteristics of the object on the sample board, were presented.

scholarly journals Порівняння бокового та медіанного доступу за оваріогістеректомії у кішок

2017 ◽  
Vol 19 (77) ◽  
pp. 179-184
Author(s):  
A.D. Stepanov
Keyword(s):  
Mammary Gland ◽  
Abdominal Wall ◽  
Research Work ◽  
Surgical Access ◽  
Median Laparotomy ◽  
The Cross ◽  
The Right ◽  
Upper Third ◽  
Sexually Mature ◽  
Ventral Wall

In the article results of examinations got in case of surgical accesses through the flank and ventral wall of the stomach’s implementation on purpose to the cats’ ovariohysterectomy are given. The research work was carried out on healthy sexually-mature cats. Surgeries were done in the upper third of the right flank abdominal wall and in the behind the umbilical zone. The cross-cut on the boundary of groin and illium area in the direction from the hook-bone’s front border to the fourth nipple of the mammary gland of the appropriate side was applied on the side abdominal wall. It is established that in case of the accomplishment of cat’s ovariohysterectomy with the use of suggested surgical access through the side abdominal wall a duration of an operation and a period of healing are in line with those which are in case of application of median laparotomy. It is proved that the surgical access with the cross-cut done in the upper third of the right flank abdominal wall and on the boundary of groin and illium area in case of cat’s ovariohysterectomy secure better opportunities for the fulfillment of the surgical method than the median one. It is also noted that in case of cat’s ovariohysterectomy the surgical access through the upper third of the right flank abdominal wall with the cut in the direction from the hook-bone’s front border to the fourth nipple of the mammary gland of the appropriate side could be recommended as an alternative of an access through the middle line of the stomach.

scholarly journals The Fabrics Design Influence in Real and Simulated Drape of Clothing

2020 ◽  
Author(s):  
Rui Miguel ◽  
José Lucas ◽  
Sónia Melo ◽  
Madalena Pereira ◽  
Clara Fernandes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Comparative Analysis ◽  
Experimental Work ◽  
Structural Characteristics ◽  
Research Work ◽  
Wear Performance ◽  
The Real ◽  
Fashion Products ◽  
Technology And Design

This research work aims to study the influence of the fabrics in the wear performance of clothing. For this, an experimental work was developed with two fabric samples having the same weight/m2, one single and another double, and a jacket prototype. Through a comparative analysis of the mechanical properties, very interesting results was obtained in the evaluation and characterization of the two fabrics performance in designing the same jacket, namely the drape and the corresponded aesthetic fabrics behaviours during wear. The structural characteristics and mechanical properties of each fabric were introduced into Marvelous Designer Version 8 software to simulate the virtual draping of fabrics in a skirt. The analysis of the drape profile of each fabric given by the software and the drape of the real fabrics evaluated in laboratory indicates, coherently, that the double fabric falls less than the single, but in a more harmonious way, what evidence the close links between technology and design of fashion products. Keywords: Fabrics design, Fabrics mechanical properties, Clothing drape, Real and simulated drape

scholarly journals Relation Between the Interannual Variability in the Stratospheric Rossby Wave Forcing and Zonal Mean Fields Suggesting an Interhemispheric Link in the Stratosphere

2019 ◽  
Author(s):  
Yuki Matsushita ◽  
Daiki Kado ◽  
Masashi Kohma ◽  
Kaoru Sato
Keyword(s):  
Interannual Variability ◽  
Rossby Wave ◽  
Reanalysis Data ◽  
Mean Flow ◽  
Flux Divergence ◽  
Wave Forcing ◽  
Mean Fields ◽  
Meridional Cross Section ◽  
The Cross ◽  
Modern Era

Abstract. Focusing on the interannual variabilities in the zonal mean fields and Rossby wave forcing in austral winter, an interhemispheric coupling in the stratosphere is examined using reanalysis data: the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). In the present study, the Eliassen-Palm (EP) flux divergence averaged over the latitude and height regions of 50°–30° S and 0.3–1 hPa, respectively, are used as a proxy of the Rossby wave forcing, where the absolute value of the EP flux divergence is maximized in the winter in the Southern Hemisphere (SH). The interannual variabilities in the zonal mean temperature and zonal wind are significantly correlated with the SH Rossby wave forcing in the stratosphere in both the SH and Northern Hemisphere (NH). The interannual variability in the strength of the poleward residual mean flow in the SH stratosphere is also correlated with the strength of the wave forcing. This correlation is significant even around the equator at an altitude of 40 km and at NH low latitudes of 20–40 km. The temperature anomaly is consistent with this residual mean flow anomaly. The relationship between the cross-equatorial flow and the zonal mean absolute angular momentum gradient (My) is examined in the meridional cross section. The My around the equator at the altitude of 40 km is small when the wave forcing is strong, which provides a pathway for the cross-equatorial residual mean flow. These results indicate that an interhemispheric coupling is present in the stratosphere through the meridional circulation modulated by the Rossby wave forcing.

scholarly journals Fiberglass Vs. Synthetic Air Filtration Media

2002 ◽  
Vol os-11 (3) ◽  
pp. 1558925002OS-01 ◽  
Author(s):  
Edward Vaughn ◽  
Gayetri Ramachandran
Keyword(s):  
Research Work ◽  
Test Methods ◽  
Air Filtration ◽  
Filter Media ◽  
Air Filter ◽  
Filter Performance ◽  
And Performance ◽  
Synthetic Media

This paper deals with ASHRAE filters used in air filtration applications and summarizes, on the basis of current research work, some of the reasons for the disagreement that exists among filter manufacturers concerning the properties and performance of various types of air filter media in general, glass and synthetic media in particular. Attention is also drawn to some important items that need to be incorporated in test methods and to some factors that could be affecting filter performance

Turbulent Wall-Pressure Fluctuations: A New Model for Off-Axis Cross-Spectral Density

1997 ◽  
Vol 119 (2) ◽  
pp. 277-280 ◽  
Author(s):  
B. A. Singer
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Spectral Density ◽  
Flow Direction ◽  
Wall Pressure ◽  
Mean Flow ◽  
New Approach ◽  
Cross Spectral Density ◽  
The Mean ◽  
The Cross

Models for the distribution of the wall-pressure under a turbulent boundary layer often estimate the coherence of the cross-spectral density in terms of a product of two coherence functions. One such function describes the coherence as a function of separation distance in the mean-flow direction, the other function describes the coherence in the cross-stream direction. Analysis of data from a large-eddy simulation of a turbulent boundary layer reveals that this approximation dramatically underpredicts the coherence for separation directions that are neither aligned with nor perpendicular to the mean-flow direction. These models fail even when the coherence functions in the directions parallel and perpendicular to the mean flow are known exactly. A new approach for combining the parallel and perpendicular coherence functions is presented. The new approach results in vastly improved approximations for the coherence.

scholarly journals Discharge Estimation Using Tsallis and Shannon Entropy Theory in Natural Channels

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1786
Author(s):  
Jitendra Kumar Vyas ◽  
Muthiah Perumal ◽  
Tommaso Moramarco
Keyword(s):  
Flow Velocity ◽  
Surface Flow ◽  
Tsallis Entropy ◽  
Accurate Estimation ◽  
Mean Flow ◽  
Flow Area ◽  
Cross Sectional ◽  
The Cross ◽  
Discharge Estimation ◽  
Mean Flow Velocity

Streamflow measurements during high floods is a challenge for which the World Meteorological Organization fosters the development of innovative technologies for achieving an accurate estimation of the discharge. The use of non-contact sensors for monitoring surface flow velocities is of interest to turn these observed values into a cross-sectional mean flow velocity, and subsequently, into discharge if bathymetry is given. In this context, several techniques are available for the estimation of mean flow velocity, starting from observed surface velocities. Among them, the entropy-based methodology for river discharge assessment is often applied by leveraging the theoretical entropic principles of Shannon and Tsallis, both of which link the maximum flow velocity measured at a vertical of the flow area, named the y-axis, and the cross-sectional mean flow velocity at a river site. This study investigates the performance of the two different entropic approaches in estimating the mean flow velocity, starting from the maximum surface flow velocity sampled at the y-axis. A velocity dataset consisting of 70 events of measurements collected at two gauged stations with different geometric and hydraulic characteristics on the Po and Tiber Rivers in Italy was used for the analysis. The comparative evaluation of the velocity distribution observed at the y-axis of all 70 events of measurement was closely reproduced using both the Shannon and Tsallis entropy approaches. Accurate values in terms of the cross-sectional mean flow velocity and discharge were obtained with average errors not exceeding 10%, demonstrating that the Shannon and Tsallis entropy concepts were equally efficient for discharge estimation in any flow conditions.

scholarly journals Investigation about the Effect of Manufacturing Parameters on the Mechanical Behaviour of Natural Fibre Nonwovens Reinforced Thermoplastic Composites

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2560 ◽  
Author(s):  
Imen Gnaba ◽  
Peng Wang ◽  
Damien Soulat ◽  
Fatma Omrani ◽  
Manuela Ferreira ◽  
...  
Keyword(s):  
Mechanical Behaviour ◽  
Areal Density ◽  
Nonwoven Fabric ◽  
Natural Fibre ◽  
Thermoplastic Composites ◽  
Reinforced Composites ◽  
Nonwoven Fabrics ◽  
Composite Scale ◽  
Needle Punching ◽  
Manufacturing Parameters

To date, nonwoven fabrics made with natural fibres and thermoplastic commingled fibres have been extensively used in the composite industry for a wide variety of applications. This paper presents an innovative study about the effect of the manufacturing parameters on the mechanical behaviour of flax/PP nonwoven reinforced composites. The mechanical properties of nonwoven fabric reinforced composites are related directly to the ones of dry nonwoven reinforcements, which depend strongly on the nonwoven manufacturing parameters, such as the needle-punching and areal densities. Consequently, the influence of these manufacturing parameters will be analysed through the tensile and flexural properties. The results demonstrated that the more areal density the nonwoven fabric has, the more the mechanical behaviour can be tested for composites. By contrast, it has a complex influence on needle-punching density on the load-strain and bending behaviours at the composite scale.

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