Correlation of Surface Characteristics and Thermal Conductivity of High Silica Glass Fibre Materials

2008 ◽  
Vol 39-40 ◽  
pp. 193-196 ◽  
Author(s):  
Janina Setina ◽  
V. Akishins ◽  
L. Petersone
Keyword(s):  
Thermal Conductivity ◽  
Surface Roughness ◽  
Glass Fibre ◽  
Silica Glass ◽  
Surface Characteristics ◽  
Woven Fabrics ◽  
X Ray ◽  
Wide Range ◽  
High Silica

The new generation of high silica materials with high thermal resistance was created by leaching of chopped glass fibre. These materials with low thermal conductivity are inert to the majority of chemical reagents, resistant to organic and mineral acids, weak alkali, water and highpressure steam. High silica chopped strand mats are non-woven fabrics designed for using in a wide range of insulation and protection applications at temperature till 11000C. The technology and quality of leaching process of initial Si-Al-Na glass widely depends on quality of fibre surface characteristics, i.e., roughness of surface of glass filaments. The surface roughness of the fibre before leaching is a function of chemical durability, therefore it depend on content of Al2O3. The thermal conductivity (within 20…10000C) of chopped strand mats directly depends on the surface roughness. The morphology and compositional profiles of surface of glass fibre before and after leaching were investigated using AFM, SEM, X-ray microanalysis and X-ray powder diffractometer. The different defects for fibre with content of Al2O3 <2.5% and high roughness namely cracking and crystalline deposits of Na2SO4 on top and into pores of fiber after leaching have been identified. The presence of sodium ions on surface of fibre decreases the heat insulation properties of mats. The structure of glass filaments surface was investigated in order to clarify the influence of surface characteristics on thermal conductivity of high silica glass fibre non-woven fabrics.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

scholarly journals Surface Characteristics of Seersucker Woven Fabrics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Malgorzata Matusiak ◽  
Vladimir Bajzik
Keyword(s):  
Surface Roughness ◽  
Evaluation System ◽  
Surface Friction ◽  
Surface Characteristics ◽  
Measurement Procedure ◽  
Woven Fabrics ◽  
Point Of View ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Surface Parameters

AbstractThe surface characteristics of fabrics are important from the point of view of the sensorial comfort of clothing users. Surface friction and surface roughness are the most important surface parameters of fabrics. These parameters can be measured using different methods, the most important and well-accepted method being that using the Kawabata evaluation system (KES)-FB4 testing instrument. In this work, the surface roughness and surface friction of the seersucker woven fabric have been determined using the KES-FB4. However, the measurement procedure needs modification. On the basis of the results, the influence of the repeat of the seersucker effect and the linear density of the weft yarn on the surface parameters has been determined.

scholarly journals Obtaining human hair keratin-based films and their characteristics

2021 ◽  
Vol 15 (1) ◽  
pp. 27-36
Author(s):  
V. V. Mykhaliuk ◽  
◽  
V. V. Havryliak ◽  
Keyword(s):  
Molecular Weight ◽  
Disulfide Bonds ◽  
Protein Concentration ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Surface Characteristics ◽  
Film Structure ◽  
X Ray ◽  
Wide Range ◽  
Scanning Electron

Background. Keratins are natural biopolymers with a wide range of applications in the field of biotechnology. Materials and Methods. Extraction of keratins was performed by a modified Nakamura method using 250 mM DTT. The protein concentration in the supernatant was determined by Bradford method. The protein composition was studied by their electro­phoretic separation in a polyacrylamide gel in the presence of sodium dodecyl sulfate. The films were made by casting. The surface characteristics of the films were determined using a scanning electron microscope REMMA-102. The elemental composition of the films was determined using an X-ray microanalyzer. Results. The protein concentration in the supernatant was 3.75 mg/mL. After using dithiothreitol in the extraction mixture, we obtained proteins of intermediate filaments with a molecular weight of 40–60 kDa and a low Sulfur content. In the low molecular weight region, we obtained keratin-associated proteins with a molecular weight of 10–30 kDa and a high content of Sulfur. These proteins belong to fibrillar proteins, which can be used as a matrix for the creation of new keratin-containing biocomposites with a wide range of applications in reparative medicine and tissue engineering. Based on the obtained keratin extract, polymer films with and without the addition of glycerol were made. Scanning electron microscopy revealed that glycerol provided the film structure with homogeneity and plasticity due to the accumulation of moisture after the fixation by water vapor. The X-ray microanalysis of films revealed such elements as Sodium, Silicon, Sulfur, Potassium. Among the detected elements, Sulfur has the largest share that is due to the large number of disulfide bonds in the keratin molecule. Conclusions. The polymer keratin films with the addition of glycerol demonstrated better mechanical properties and can be used in biomedicine.

scholarly journals Thermophysiological comfort of zinc oxide nanoparticles coated woven fabrics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Muhammad Tayyab Noman ◽  
Michal Petru ◽  
Nesrine Amor ◽  
Petr Louda
Keyword(s):  
Surface Roughness ◽  
Zinc Oxide ◽  
Surface Topography ◽  
Zinc Oxide Nanoparticles ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Oxide Nanoparticles ◽  
Zno Nps ◽  
X Ray ◽  
Moisture Management

AbstractThis study investigates physicochemical impact of ultrasonic irradiations on surface topography of woven fabrics. In a simultaneous in-situ sonochemical method, the synthesis and coating of zinc oxide nanoparticles (ZnO NPs) on woven textiles were successfully achieved. Different instruments i.e. Alambeta, moisture management tester, air permeability tester and permetester were utilised during experimentation for thermal evaluation, moisture transportation and air permeation. The results regarding thermophysiological comfort of ZnO coated fabrics were evaluated on the basis of thickness and ZnO NPs coated amount on fabrics. In addition, the achieved results depict the impact of sonication (pressure gradient) on surface roughness of cotton and polyester. The coating of ZnO NPs on fabrics, crystal phase identification, surface topography and fluctuations in surface roughness were estimated by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray Diffractometry (XRD), ultrahigh-resolution scanning electron microscopy (UHR-SEM) and energy dispersive X-ray (EDX). Moreover, thermophysiological properties i.e. thermal conductivity, absolute evaporative resistance, thermal absorptivity, air permeability, overall moisture management capacity and relative water vapour permeability of untreated and ZnO treated samples were evaluated by standard test methods.

Identification of Surface Quality of Plastic Electrodes after Blasting

2013 ◽  
Vol 334-335 ◽  
pp. 71-76
Author(s):  
B. Haluzíková ◽  
Jan Valíček ◽  
P. Škubala ◽  
Marta Harničárová ◽  
D. Bražina ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Roughness ◽  
Surface Characteristics ◽  
Injection Molding Process ◽  
Maximum Height ◽  
Molding Process ◽  
Arithmetic Average ◽  
Average Maximum ◽  
Wide Range

Nowadays, plastics have become one of the most demanded materials, replacing the traditional ones such as metals. Therefore, many companies are concerned with the production of plastics, with their distribution and innovation development. Plastics have found utility in a wide range of applications, we use them every day. Measurement of surface roughness of plastic moldings produced by the injection molding process was carried out by a contact profilometer Mitutoyo Surftest SJ401. A reason for this measurement is to obtain information about surface roughness. For further technical adjustment is required to have higher surface roughness what helps to increase electrical conductivity of plastic moldings. This involves determination of a ratio between Ra/Rz (the ratio between the arithmetic average of the roughness profile Ra and the average maximum height of the profile Rz) in order to satisfy customer demand for achieving better surface characteristics leading to an increase in electrical conductivity.

scholarly journals Portable X-ray fluorescence (pXRF) calibration for analysis of nutrient concentrations and trace element contaminants in fertilisers

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262460
Author(s):  
Gifty E. Acquah ◽  
Javier Hernandez-Allica ◽  
Cathy L. Thomas ◽  
Sarah J. Dunham ◽  
Erick K. Towett ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Nutrient Concentrations ◽  
Good Prediction ◽  
X Ray ◽  
Accuracy And Precision ◽  
Wide Range ◽  
High Throughput Detection ◽  
Characterisation Methods

With the increasing popularity of local blending of fertilisers, the fertiliser industry faces issues regarding quality control and fertiliser adulteration. Another problem is the contamination of fertilisers with trace elements that have been shown to subsequently accumulate in the soil and be taken up by plants, posing a danger to the environment and human health. Conventional characterisation methods necessary to ensure the quality of fertilisers and to comply with local regulations are costly, time consuming and sometimes not even accessible. Alternatively, using a wide range of unamended and intentionally amended fertilisers this study developed empirical calibrations for a portable handheld X-ray fluorescence (pXRF) spectrometer, determined the reliability for estimating the macro and micro nutrients and evaluated the use of the pXRF for the high-throughput detection of trace element contaminants in fertilisers. The models developed using pXRF for Mg, P, S, K, Ca, Mn, Fe, Zn and Mo had R2 values greater or equal to 0.97. These models also performed well on validation, with R2 values greater or equal to 0.97 (except for Fe, R2val = 0.55) and slope values ranging from 0.81 to 1.44. A second set of models were developed with a focus on trace elements in amended fertilisers. The R2 values of calibration for Co, Ni, As, Se, Cd and Pb were greater than or equal to 0.80. At concentrations up to 1000 mg kg-1, good validation statistics were also obtained; R2 values ranged from 0.97–0.99, except in one instance. The regression coefficients of the validation also had good prediction in the range of 0–100 mg kg-1 (R2 values were from 0.78–0.99), but not as well at lower concentrations up to 20 mg kg-1 (R2 values ranged from 0.10–0.99), especially for Cd. This study has demonstrated that pXRF can measure several major (P, Ca) and micro (Mn, Fe, Cu) nutrients, as well as trace elements and potential contaminants (Cr, Ni, As) in fertilisers with high accuracy and precision. The results obtained in this study is good, especially considering that loose powders were scanned for a maximum of 90 seconds without the use of a vacuum pump.

scholarly journals A Study of Laser Micromachining of PM Processed Ti Compact for Dental Implants Applications

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2246 ◽  
Author(s):  
Peter Šugár ◽  
Jaroslav Kováčik ◽  
Jana Šugárová ◽  
Barbora Ludrovcová
Keyword(s):  
Surface Roughness ◽  
Laser Energy ◽  
Surface Characteristics ◽  
Xrd Analysis ◽  
Point Of View ◽  
Nanosecond Laser ◽  
Machined Surface ◽  
X Ray ◽  
Industrial Grade ◽  
Different Characteristics

The paper deals with the experimental study of laser beam micromachining of the powder metallurgy processed Ti compacts applying the industrial grade fibre nanosecond laser operating at the wavelength of 1064 nm. The influence of the laser energy density on the surface roughness, surface morphology and surface elements composition was investigated and evaluated by means of surface roughness measurement, scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The different laser treatment parameters resulted in the surfaces of very different characteristics of the newly developed biocompatible material prepared by advanced low temperature technology of hydride dehydride (HDH) titanium powder compactation. The results indicate that the laser pulse energy has remarkable effects on the machined surface characteristics which are discussed from the point of view of application in dental implantology.

Line Profile Analysis (LPA) Methods: Systematic Ranking of the Quality of their Basic Assumptions

2004 ◽  
Vol 443-444 ◽  
pp. 127-130
Author(s):  
Arnold C. Vermeulen ◽  
Rob Delhez
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Line Profiles ◽  
Qualitative Comparison ◽  
New Developments ◽  
X Ray ◽  
Basic Assumptions ◽  
Wide Range

All methods of analyzing the broadening of XRD line profiles have to take into account two basic effects: broadening by the instrument - including the X-ray spectrum - and the characteristics of broadening by size effects and by lattice defects - including their interaction. These effects are handled in practice by a wide range of auxiliary assumptions. In this paper these assumptions and their quality with respect to "appropriateness of purpose" are listed and compared. By systematic ranking of these assumptions in accordance with their quality, a 2-dimensional map can be constructed that visualizes the differences in the quality of the assumptions. This 2-dimensional map brings a new viewpoint to the various methods for line profile analysis, because it enables a qualitative comparison of the assumptions of existing methods and new developments.

Investigation of Quality of Drilled Holes by Guiding the Drill Bit Using Permanent Magnet on a Glass Fibre Reinforced Polymer Composite Material

2016 ◽  
Vol 860 ◽  
pp. 64-69
Author(s):  
Md Anayet Ullah Patwari ◽  
Suleiman Mohammed Yusuf ◽  
Mohammad Ahsan Habib ◽  
Shahrair Ragib ◽  
Ferdous Azam
Keyword(s):  
Surface Roughness ◽  
Composite Materials ◽  
Permanent Magnet ◽  
Glass Fibre ◽  
Drill Bit ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

The use of glass fibre reinforced polymer composite materials (GFRP) increases due to its superior properties that draw the attention of the other researches focusing on relevant aspects concerning the machining of such materials. In conventional machining for hole creation, drilling is the most frequently employed machining process for hole generation in fibre reinforced materials. Due to the laminated structure of the composite materials, several types of damages and other surface irregularities are introduced during drilling processes. These defects in the holes lead to about 60% of the rejections in assembly plant. Surface roughness has been identified to be the main contribution for defects in holes machined in composites. These defects would create reduction in structural stiffness, which may lead to variation of dynamic performance of the whole structure. Hence, achieving the desired hole quality is of great importance for the functional behaviour of the mechanical parts. In the present work, the effect of permanent magnet on the quality of drilled holes on GFRP composite is presented. Experiments are performed under different magnetic drilling conditions of spindle speed, feed rate and drill diameter on CNC drilling machine using three levels of factors. A procedure has been adopted to assess and optimize the chosen factors by the use of Box Behnken design to analyse the effects of different parameters. From the experimental results, it has been observed that the technique used is convenient to predict the main effects and their interaction effects of different influential combinations of machining parameters on surface roughness. It has been found that effect of permanent magnetic on the guiding mechanism of the drill bit which lead to get improved surface roughness with better circularity compared to normal drilling processes. A mathematical model has been developed for the prediction of surface roughness using permanent magnet and normal drilling processes.

scholarly journals Improving surface representation and consequences in NWP forecast

2021 ◽  
Author(s):  
Martina Tudor ◽  
Stjepan Ivatek-Šahdan
Keyword(s):  
Surface Roughness ◽  
Surface Wind ◽  
Surface Characteristics ◽  
Model Forecast ◽  
Grid Spacing ◽  
Substantial Impact ◽  
Wind Speeds ◽  
Nwp Model ◽  
Surface Fields

&lt;p&gt;The fields that describe surface properties, from terrain height to vegetation types can have substantial impact on NWP model forecast, especially on the model variables close to the surface. These fields can be computed from different databases. Higher resolution of the terrain height database and higher quality of input data leads to a better representation of the terrain height and other surface fields, especially as NWP models move to a higher resolution. Here we use ALARO configuration of the ALADIN System with TOUCANS turbulence scheme (prognostic TKE) with nonhydrostatic dynamics in 2km resolution over Croatia. The model domain contains Dinaric Alps mountains and Adriatic sea.&amp;#160; The existing operational NWP application uses fields from an old database that is insufficient to properly describe the surface in 2km grid spacing. The fields describing topography, such as terrain height, land sea mask, subgrid terrain variability including surface roughness are computed from a new database in substantially higher resolution. The new fields describing the surface characteristics are more realistic, but also substantially different from the fields used before.&amp;#160; However, the model, including the turbulence parametrisation, was tuned using the old database. Therefore, the subsequent model forecast was not automatically improved when the fields from the new database were used. Tuning only one parameter in a scheme is substantial work, but tuning the whole model with a large number of tuning parametres is daunting. Therefore, the computation of surface roughness and other parameters was tuned in order to improve the 10m wind forecast. Decreased surface roughness does not always lead to higher surface wind speeds and vice versa.&lt;/p&gt;

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