Fibers

The present study aimed to assess the potentiality of water soluble fungal pigments for dyeing on cotton yarn. Five different shades of pigments were extracted from Monascus purpureus, Isaria farinosa, Emericella nidulans, Fusarium verticillioides, and Penicillium purpurogenum using ethanol. Maximum concentration of pigment was obtained from Monascus purpureus (red, 25.02±1.6 UA) followed by Penicillium purpurogenum (yellow, 23.05±0.3 UA). The optimum dyeing condition was observed at a pigment concentration of 1 gram, pH 5, temperature 80 °C, time duration 90 min, and a liquor ratio of 1:30 was found to be the optimal for dyeing. Maximum uptake of 80 % was achieved with Monascus purpureus red pigment. Moreover, the effect of mordant in dyeing was evaluated by different mordanting methods. A strong variation in shade and color depth could be achieved by using pre-mordanting method with alum and ferrous sulfate giving better wash fastness properties when compared with post-mordanting or without a mordant.

Plant fibers find wide application in various fields that demand specific parameters of fiber quality. To develop approaches for the improvement of yield and quality of bast fibers, the knowledge of the fiber developmental stages and of the key molecular players that are responsible for a certain parameter, are vitally important. In the present review the key stages of fiber development, such as initiation, intrusive growth, and formation of thickened cell wall layers (secondary and tertiary cell walls) are considered, as well as the impact of each of these stages on the final parameters of fiber yield and quality. The problems and perspectives of crop quality regulation are discussed.

In this study, erbia (Er2O3)-doped Bi2O3 ceramics were prepared from sol–gel derived nanocrystalline powders. The morphological properties were investigated by scanning electron microscopy. X-ray diffraction (XRD) analysis was carried out in order to characterize the phase and crystal structure of the powder samples. Temperature dependent electrical properties were determined by thermogravimetry/differential thermal analyzer (TG/DTA) and 4-point probe techniques. The stable fluorite face centered cubic δ-type phase was observed at room temperature from the XRD result, which was supported by the DTA and temperature dependent electrical conductivity measurements. Electrical conductivity results indicate that there is a transition approximately at 650 °C, which can be attributed to an order–disorder transition (ODT). The activation energy values obtained from the Arrhenius approach for heating and cooling process were presented. Two regimes, corresponding to high temperature region (HTR) and low temperature region (LTR), were observed. As a result of morphological changes during the ODT, the electrical conductivity modifies and the activation energies are different for studied sample at HTR and LTR.

Environmentally benign layer-by-layer (LbL) deposition was used to obtain flame-retardant and antimicrobial cotton. Cotton was coated with 8, 10, and 12 phytic acid (PA) and chitosan (CH)-urea bilayers (BL) and then immersed into copper (II) sulfate (CuSO4) solution. Our findings were that 12 BL of PA/CH-urea + Cu2+ were able to stop flame on cotton during vertical flammability testing (VFT) with a limiting oxygen index (LOI) value of 26%. Microscale combustion calorimeter (MCC) data showed a reduction of peak heat release rates (pHRR) of more than 61%, while the reduction of total heat release (THR) was more than 54%, relative to untreated cotton. TG-IR analysis of 12 BL-treated cotton showed the release of water, methane, carbon dioxide, carbon monoxide, and aldehydes, while by adding Cu2+ ions, the treated cotton produces a lower amount of methane. Treated cotton also showed no levoglucosan. The intumescent behavior of the treatment was indicated by the bubbled structure of the p...

La mobilisation des matières premières « terre » et « fibre végétale » dans la construction, utilisées séparément ou ensemble, relève de longues traditions à  travers tous les continents. De multiples techniques utilisant ces ressources  ont  été  développées  en  fonction  de particularités  qui  dépendent  de  contextes  géologiques, géographiques, climatiques et culturels, mais aussi de la nécessité de faire avec les moyens disponibles sur place.

Aujourd’hui, le recours aux énergies fossiles doit être réduit drastiquement en raison des émissions de gaz à effet de  serre  (GES)  et  du  réchauffement  climatique  qu’il  induit.  Devant  l’urgence  actuelle  de  réduire  l’impact environnemental  du  secteur  du  bâtiment,  on  assiste  à  un  intérêt  mondial  croissant  pour  des  matériaux  peu consommateurs de ressources non-renouvelables, à la fois pour leur fabrication et pour leur mise en œuvre.

Cette  attention  particulière  pour  les  matériaux  «  bas  carbone  »  croise  celle  d’une  meilleure  efficience énergétique pendant la phase d’utilisation du bâti, notamment par une isolation thermique adaptée. Dans de telles perspectives, il a été prouvé que l’utilisation de matériaux biosourcés peut impacter très efficacement la consommation  énergétique  des  bâtiments  (C&B,  2012).  Par  ailleurs,  un  retour  à  la  construction  de  murs régulateurs  du  confort thermique  et peu  énergivores  est également  primordial,  car  il  constituerait  l’une  des réponses  à  adopter  face  à  l’évolution  actuelle  des  exigences  en  termes  de  confort  thermique  et,  de  façon générale, pour un environnement bâti sain.

Au Sénégal, le roseau Typha australis est devenu envahissant, notamment dans les fleuves et lacs du nord du pays. Jusqu’à présent, il était considéré à juste titre comme nuisible. L’exploitation raisonnée de cette plante, transformée en ressource-matière, constitue ainsi une opportunité en vue de contribuer à un développement local durable au Sénégal. C’est dans ce cadre qu’a été lancé le Projet PNEEB / TYPHA :
« Transfert de technologie : Projet de production de matériaux d’isolation thermique à base de Typha ». Afin de le mettre en œuvre, le projet a  engagé  CRAterre  pour  des  services  de  Recherche  et  Développement  qui  concernent  la  production  et l’utilisation, au Sénégal, de matériaux de construction à base de Typha et de terre.

Qu’il s’agisse de maçonnerie en terre avec des matériaux denses et monolithiques, ou d’éléments légers et de petites dimensions, ou encore d’isolants  thermiques en doublage de parois existantes, ces stratégies doivent être pensées de manière globale à l’échelle de l’habitat (elles doivent par exemple inclure une réflexion sur la gestion des protections solaires, de la ventilation et de l’humidité).

La réflexion menée sur la production des éléments de construction en terre et en Typha a donc été menée dans ce sens :
•      rechercher de modes de construction économiques,
•      utiliser de matériaux moins dépendants des énergies fossiles,
•      redécouvrir des qualités urbaines et architecturales du patrimoine et des savoirs y afférents,
•      mettre à profit des propriétés thermomécaniques inhérentes aux matières premières naturelles.

Ce  rapport  constitue  donc  tout  d’abord  une  capitalisation  des  recherches  bibliographiques  et  des expérimentations  menées  sur  les  matières  premières  «  Terre  »  et  «  Typha  »,  ainsi  que  sur  les  éléments constructifs qui ont été produits dans le cadre du projet. Il propose ainsi :
•      un aperçu de l’état actuel des connaissances sur  les propriétés mécaniques et hygrothermiques du Typha australis, ainsi qu’un panorama d’applications sur le Typha et les mélanges de Typha et de terre, réalisées dans plusieurs pays et dans différents laboratoires de recherche,
•      un compte-rendu du travail effectué et des activités organisées durant les deux années du projet.

La synthèse globale des résultats atteints est présentée en trois parties et huit chapitres :
•    La première partie constitue la dimension « recherche en amont » sur les matières et les matériaux Typha et Terre-Typha
  o  dans le chapitre 1 nous présenterons le cadre de la recherche, les antécédents à la phase actuelle de R&D, les livrables rendus en accord avec les termes de références,
  o  le chapitre 2 nous permettra d’exposer quelques prérequis et définitions préalables sur les propriétés que nous recherchons dans les éléments de construction que nous avons développés  et,  à  cet  égard,  pourquoi  les  matériaux  à  base  de  «  Typha  »  sont particulièrement intéressants,
  o  le chapitre 3 constituera un aperçu des méthodes suivies pour initier et développer la démarche de recherche-développement ancrée à la fois sur une prospection théorique et pratique ainsi que sur une recherche participative.
•    La deuxième partie présente les résultats de la R&D, tant sur la mise au point de méthodes spécifiques que sur les objectifs atteints. Elle suit la logique de « Recherche et Développement », à savoir une démarche qui débute avec l’analyse des « matières premières »  et qui va jusqu’à la proposition de « systèmes constructifs » :
  o  le chapitre 4 dresse un bilan des activités ainsi qu’une synthèse des livrables exigés pour la R&D,
  o  le chapitre 5 restitue les résultats du volet d’identification des
« matières premières » afin de les transformer en « matériaux »,
  o  le chapitre 6 présente la mise au point des « éléments de construction » ainsi que le développement  des  «équipements  »  et
« outils  »  spécifiques  nécessaires  à  leur production.
  o  le chapitre 7 décrit les modalités de mise-en-œuvre des éléments de construction et comment  ils  s’intègrent  aux  « systèmes  constructifs »  existants  et/ou  comment  ils permettent d’en constituer de nouveaux,
•    La troisième partie est consacrée à l’évaluation des performances des matériaux produits (Typha et Terre-Typha). Cette partie est d’abord basée sur une synthèse de la littérature, puis sur les premiers résultats actuels de la caractérisation des matériaux réalisés :
  o  le  chapitre  8  présente  les  premiers  résultats  des  essais  de  caractérisation hygrothermiques et mécaniques réalisés en laboratoire,
  o  une discussion sur l’ensemble des résultats obtenus est ensuite proposée, permettant de mettre en lumière les résultats probants, les pistes de recherche à poursuivre, ainsi que les compléments d’action nécessaires.
Tous les éléments présentés dans ce rapport constituent des
« propositions » pour le contexte Sénégalais. Les résultats de R&D testés lors des différents essais de mise-en-œuvre ont été sélectionnés et validés par l’équipe PNEEB-Typha. Si ce travail donne déjà des résultats permettant de passer à une phase opérationnelle, il est bien entendu que d’autres équipements de production et d’autres matériaux pourraient être développés par la suite.

Marine ecosystems are experiencing substantial disturbances due to climate change and overfishing, and plastic pollution is an additional growing threat. Microfibres are among the most pervasive pollutants in the marine environment, including in the Southern Ocean. However, evidence for microfibre contamination in the diet of top predators in the Southern Ocean is rare. King Penguins (Aptenodytes patagonicus) feed on mesopelagic fish, which undergo diel vertical migrations towards the surface at night. Microfibres are concentrated in surface waters and sediments but can also be concentrated in fish, therefore acting as contamination vectors for diving predators feeding at depth. In this study, we investigate microfibre contamination of King Penguin faecal samples collected in February and March 2017 at South Georgia across three groups: incubating, chick-rearing and non-breeding birds. After a KOH digestion to dissolve the organic matter and a density separation step using a NaCl solution, the samples were filtered to collect microfibres. A total of 77% of the penguin faecal samples (36 of 47) contained microfibres. Fibres were measured and characterized using Fourier-Transform Infrared spectroscopy to determine their polymeric identity. Most fibres (88%) were made of natural cellulosic materials (e.g. cotton, linen), with only 12% synthetic (e.g. polyester, nylon) or semi-synthetic (e.g. rayon). An average of 21.9 ± 5.8 microfibres g −1 of faeces (lab dried mass) was found, with concentrations more than twice as high in incubating penguins than in penguins rearing chicks. Incubating birds forage further north at the Antarctic Polar Front and travel longer distances from South Georgia than chick-rearing birds. This suggests that long-distance travelling penguins are probably more exposed to the risk of ingesting microfibres when feeding north of the Antarctic Polar Front, which might act as a semi-permeable barrier for microfibres. Microfibres could therefore provide a signature for foraging location in King Penguins.

The aim of this work is to review a possible correlation of composition, thermal processing, and recent alternative stabilization technologies to the mechanical properties. The chemical microstructure of polyacrylonitrile (PAN) is discussed in detail to understand the influence in thermomechanical properties during stabilization by observing transformation from thermoplastic to ladder polymer. In addition, relevant literature data are used to understand the comonomer composition effect on mechanical properties. Technologies of direct fiber heating by irradiation have been recently involved and hold promise to enhance performance, reduce processing time and energy consumption. Carbon fiber manufacturing can provide benefits by using higher comonomer ratios, similar to textile grade or melt-spun PAN, in order to cut costs derived from an acrylonitrile precursor, without suffering in regard to mechanical properties. Energy intensive processes of stabilization and carbonization remain a...

By showing how geometric overshot coverlets can be understood in relationship to the global economy and within politicized cultural movements, Falls and Smith demonstrate how these erstwhile domestic, utilitarian objects explode the art/craft dichotomy, belong to a rich narrative of historical art forms, and tell us far more about American culture today than simply representing a nostalgic past, particularly with regard to ideas about race, class, nationalism, women’s labor, and the separation of private versus public spaces.

See research exhibition catalog (Fold/Unfold) here: https://www.amazon.com/gp/product/1548165727/ref=dbs_a_def_rwt_bibl_vppi_i3

This review paper examines the current state-of-the-art in fabrication of aligned fibers via electrospinning techniques and the effects of these techniques on the mechanical and dielectric properties of electrospun fibers. Molecular orientation, system configuration to align fibers, and post-drawing treatment, like hot/cold drawing process, contribute to better specific strength and specific stiffness properties of nanofibers. The authors suggest that these improved, aligned nanofibers, when applied in composites, have better mechanical and dielectric properties for many structural and multifunctional applications, including advanced aerospace applications and energy storage devices. For these applications, most fiber alignment electrospinning research has focused on either mechanical property improvement or dielectric property improvement alone, but not both simultaneously. Relative to many other nanofiber formation techniques, the electrospinning technique exhibits superior nanofi...

Use of smart cementitious materials is becoming increasingly critical for enhanced serviceability of structures. Addition of carbon fibers, carbon nanotubes and various nanopowders such as nano-silica, carbon black and graphite giving cementitious materials electrical properties that can be used for self-sensing has been known for almost two decades. Many sensing principle and techniques using smart materials have been successfully developed and applied mostly in laboratory testing over the last few decades. The strong capacity of Fiber Reinforced Cementitious Composites for autogenous healing in addition to crack control (especially in the case of Strain-Hardening Cementitious Composites, SHCC) has been reported by many researchers. Similarly, the applications of different mineral and bio-additive materials to achieve self-healing of cracks have been noted with great interests. Designing for serviceability based on the durability of the materials used in concrete structures is often neglected. With durability performance testing becoming more sophisticated, detailed service life design is being demanded in most important infrastructure projects. The present review is focused on identifying field applications and highlighting the Performance-Driven Design Approach (PDDA) for tailoring material solutions for the problems likely to be faced by the civil infrastructures in the future. A real-life case study is presented to illustrate the minimal cost implications of adopting the latest smart material for an eco-friendly, durable, reliable and resilient infrastructure. Identifying critical challenges faced by the industry and developing solutions for the same is going to help bridge the current gaps between research and adoption.

This thesis work concerns the study of particular types of carbon fiber composites. The properties of these materials are applied in aerospace, in which carbon fiber composites  play an important role in the design of the Space Shuttle's Thermal  Protection System.

Abstract: In this work the effect on hair of two types of keratin samples obtained from wool, was investigated. Fiber surface changes were evaluated by contact angle measurements. The effectiveness of these keratin ingredients to restore the mechan-ical properties and the moisture ...

This paper presents a review on dip-coating for fibrous materials, mainly concentrated on the mechanism, recently developed dip-coating methods and novel functional applications. The emphasis has been made here, to present theoretical basis of dip-coating-induced film deposition, especially, the reported works to predict the thickness based on various processing parameters. Different modified dip-coating techniques to fabricate deposited films for fibrous substrate have also been gathered. The scope of reviewed dip-coating methods are not only conventional solution and sol–gel-based dip-coating, but also recently developed vacuum-assisted, spin-assisted, photo-assisted and multi-layered dip-coating methods. An overview of reported and potential applications for coated fibrous materials has also been given, which mainly including self-cleaning, oil–water separation, conductive textiles, fibrous-based energy storage devices, and photonic crystals, etc. This review is intended to give readers a good horizon for the present status concerning variety of studies and applications related to dip-coating. An effort has been made here to report the important contributions in the area of dip-coating for fibrous substrate, and critical points regarding future research directions are outlined in the summary.

The use of FRP as reinforcement for concrete structures has been growing rapidly in recent years. This state-of-the-art report summarizes the current state of knowledge on these materials. In addition to the material properties of the constituents, i.e. resins and fibers, design philosophies for reinforced and prestressed elements are discussed. When the available data warrants, flexure, shear and bond behavior, and serviceability of the members has been examined. Strengthening of existing structures with FRPs and field applications of these materials are also presented.

In this review paper some recent advances on optical fiber sensors are reported. In particular, fiber Bragg grating (FBG), long period gratings (LPGs), evanescent field and hollow core optical fiber sensors are mentioned. Examples of recent optical fiber sensors for the measurement of strain, temperature, displacement, air flow, pressure, liquid-level, magnetic field, and the determination of methadone, hydrocarbons, ethanol, and sucrose are briefly described.

Self-cleaning surface is potentially a very useful addition for many commercial products due to economic, aesthetic, and environmental reasons. Super-hydrophobic selfcleaning, also called Lotus effect, utilizes right combination of surface chemistry and roughness to force water droplets to form high contact angle on a surface, easily roll off a surface and pick up dirt particles on its way. Electrospinning is a promising technique for creation of superhydrophobic self-cleaning surfaces owing to a wide set of parameters that allow effectively controlling roughness of resulted webs. This article gives a brief introduction to the theory of super-hydrophobic selfcleaning and basic principles of the electrospinning process and reviews the scientific literature where electrospinning was used to create superhydrophobic surfaces. The article reviewed are categorized into several groups and their results are compared in terms of superhydrophobic properties. Several issues with current state of the art and highlights of important areas for future research are discussed in the conclusion. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: 824-845, 2012

In order to reduce costs of experimental research, new methods of forecasting material properties are being developed. The current intensive increase in computing power motivates to develop the computer simulations for material properties prediction. This is due to the possibility of using analytical and numerical methods of homogenization. In this work calculations for predicting the properties of WPC composites using analytical homogenization methods, i.e. Mori-Tanaka (first and second order) models, Nemat-Nasser and Hori models and numerical homogenization methods were performed.

Macrosynthetic fiber–reinforced concrete (MSFRC) has reached maturity as an engineering material and is widely being used in some civil engineering applications. However, design approaches for MSFRC are not as well developed as for steel fibers, and there is a need for further research on this new material in order to further help the development of guidelines and increase the practical applications. The main objective of this study is to critically review the present state of knowledge and applications of MSFRC and to study the effect of these fibers on fresh-and hardened-state performance of different concrete mixtures. Seven groups of concrete mixtures were produced with different volume fractions of steel fibers, fly ash, macrosynthetic fibers, and chemical admixture. Mini slump, compression, and flexural tests were conducted on the specimens for evaluating their mechanical performance, and water absorption and sorptivity tests were also conducted for measuring the permeability of these different concrete mix groups. Therefore, with this comprehensive study, a detailed understanding is gained about the present state of applications of macrosynthetic fibers and their potential for being used as a fiber-reinforcement mechanism in concrete elements.

In this study, boron doped and undoped poly(vinyl) alcohol/zirconium-barium acetate (PVA/Zr-Ba) nanofibers were prepared using an electrospinning technique then calcinated at three different temperatures; 250 oC, 500 oC, 800 oC for 2 h. The
originality of this study is the addition of boron to metal acetates. The fibers were characterized by FT-IR, DSC, XRD and SEM. The addition of boron did not only increase the thermal stability of the fibers, but also increased their diameters, which gave stronger fibers. The FT-IR spectra of the fibers were in good accordance with literature data. The DSC results indicate that the glass transition (Tg) and melting temperatures (Tm) showed a change with the addition of boron. Also, boron doped fibers were observed to degrade at higher temperatures. XRD analyses showed that after further heat treatment at 800 oC, zirconia exists in two phases of tetragonal and monoclinic modifications. The systematic evolution of morphological features in the spun and the processed fibers were studied by scanning electron microscopy. The SEM appearance of the fibers showed
that the addition of boron resulted in the formation of cross linked bright surfaced fibers.

En este artículo de revisión se presentan las diferentes formas de fabricación de nanofibras de polímeros haciendo énfasis tanto en la técnica de electrospinning, la cual es un proceso sencillo, versátil y adecuado para la fabricación de materiales unidimensionales (1D), como en los parámetros que se deben considerar al utilizar este método; además, se señala la importancia de los parámetros de procesamiento (voltaje, distancia y flujo), de solución (concentración, viscosidad y tensión superficial) y ambientales (temperatura y humedad). Finalmente, se mencionan las distintas aplicaciones que involucran nanofibras en campos de acción como energía, ingeniería de tejidos, medio ambiente y alimentos.

Fibers derived from processing of biological materials have long been implemented for commercial use as they are widely
available from a diverse range of renewable materials. Moreover, their natural mechanical and functional properties
continue to provide newfound sources of technological advancement in areas including medicine and filtration among
other more traditional fields. While not only providing inspiration, the study of biological fiber formation in organisms
such as spiders and silk worms has facilitated fundamental knowledge; however, this review concentrates instead on
more recent artificial fabrication techniques that have been adapted for the formation of 1D (one dimensional) fibers from
biological materials. In addition, we provide an extensive look at the various biological materials from the standpoint of
their applications and fabrication methods. Areas encompassing the latest advancements in fiber processing techniques
with respect to compositional and geometric control are discussed and provide a promising outlook of future growth in this
continually growing field.

High performance lightweight foamed concrete (HPLWFC) have a structural strength with low density and high flowability. HPLWFC is used in modern concrete technology and extensively in the construction applications of high-rise buildings, long-span concrete structures and road sub-bases among others. This present work investigated the effect of size and shape specimen on the compressive strength of HPLWFC reinforced with glass fibres. Foam agent (organic material) was used to obtain lightweight concrete. The volume fractions of the glass fibres used were: 0.0%, 0.06%, 0.2%, 0.4%, and 0.6% by total volume of concrete. The fresh properties of HPLWFC were measured by flowability and fresh density tests. In this study, the size and shape of specimens used for compressive strength were cubes by size (150 Â 150 Â 150, 100 Â 100 Â 100 and 50 Â 50 Â 50 mm) and cylinders by size (150 Â 300 and 100 Â 200 mm). The results of HPLWFC mixes showed the increase in the compressive strength for all sizes of specimens with glass fibre content. The small size of specimens gave higher compressive strength in comparison with other sizes. The disparity in the compressive strength for two sizes and shapes (cubes and cylinders) were reduced with a rise in the volume fraction of the glass fibres.

Over the last few years, the risk to human health related to asbestos fiber exposure has been widely demonstrated by many studies. Serpentinites are the main rocks associated with naturally occurring asbestos (NOA). In order to investigate the presence of NOA, a mineralogical study was conducted on eleven serpentinite samples collected nearby the village of Episcopia (Lucania, Southern Italy). Various analytical techniques such as X-ray powder diffraction (XRPD), scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS) and derivative thermogravimetry (DTG) were used to determine the occurrence of asbestos minerals and to make morphological observations. Results pointed out that all of the samples contain asbestos minerals (e.g., tremolite, actinolite and chrysotile). Moreover, it was observed that both natural processes and human activity may disturb NOA-bearing outcrops and provoke the formation of potentially inhalable airborne dust causing the release o...

Indus Civilization economic strategies have traditionally been reconstructed from a land-based focus. However, marine, estuarine and river fishing was, and remains, an important aspect of South Asian food procurement and foodways. While great strides have been taken in understanding the types of fish exploited and the methods used to catch these fish, the initial stages in creating a fishing strategy, the choice of materials used to create fishing technologies, remain abstracted due to preservation problems. Through careful analogy with modern plant remains this paper explores the types of fiber that may have been exploited by Indus fisherfolk. Comparisons between the range of plants exploited by Indus peoples and the functionality of these taxa suggest that there was a diversity of materials available. Bast fibers would likely have been most suited to net production, and numerous taxa can be seen in the Indus archaeobotanical and athracological assemblages. Combined with textiles, fiber impressions, artefactual and motif evidence, both within and contemporary to the Indus Civilization it can be suggested that Indus fisherfolks were familiar with bast fiber creation technologies, net and line making.

Materials based on highly porous fibers are now becoming increasingly popular as thermal insulators to fight severely increasing temperatures due to climate change. In this study, fibers from solid waste materials like coconut husk and absorbent pads of used disposable diapers were evaluated for their synergistic effect as thermal insulating material. Dried coconut husk fibers and cleaned used disposable diapers were heated at 150 0 C-300 0 C for 2 hours and then molded to make pads. Scanning Electron Microscopy and HD digital microscope were used in the analytical imaging of the fibers. Fiber pads from coconut husk fibers, used disposable diapers and their combination, and polyethylene foam (+control) were evaluated for their burning rate based on ASTM D 1992 while thermal conductivity, and thermal resistance were obtained using the testing hot box. The morphology of the coconut husk fibers with used disposable diapers showed thicker and rougher surface with foamy coatings which confirmed porous fiber structure. One-Factor ANOVA showed significant difference among the different setups for burning rate (F=926.506; p=0.000), thermal conductivity (F=203.993; p=0.000), and thermal resistance (F=197.820; p=0.000) wherein the setup for the combination of the coconut husk fibers and used disposable diapers exhibits satisfactory burning rate (M=3.268), lowest thermal conductivity (M=0.037) and highest thermal resistance (M=0.273). The results affirm that the natural coconut husk fibers and used disposable diapers have synergistic effect for better thermal properties, thus, producing a more effective and safer thermal insulating material.

This study focuses on the fabrication of poly(vinyl alcohol)/ poly(vinyl pyrrolidone)-Iodine nanofibers via electrospinning. Electrospun fibers were characterized by FT-IR, DSC and SEM techniques. DSC results indicated that the thermal stability of nanofibers were improved after the addition of chitosan and poloxamer 188. SEM images showed that the spongiform structure is much more compact and fibrous in the case of added chitosan, with an average fiber diameter of 374nm, whereas the addition of poloxamer 188 resulted in a more porous and beaded composition, with average fiber diameter of 489nm.

The effectiveness of externally applied fiber-reinforced polymer (FRP) ropes made of carbon fibers in X-shape formation and in both sides of the joint area of reinforced concrete (RC) beam–column connections is experimentally investigated. Six full-scale exterior RC beam–column joint specimens are tested under reverse cyclic deformation. Three of them have been strengthened using carbon FRP (CFRP) ropes that have been placed diagonally in the joint as additional, near surface-mounted reinforcements against shear. Full hysteretic curves, maximum applied load capacity, damage modes, stiffness and energy dissipation values per each loading step are presented and compared. Test results indicated that joint sub assemblages with X-shaped CFRP ropes exhibited improved hysteretic behavior and ameliorated performance with respect to the reference specimens. The effectiveness and the easy-to-apply character of the presented strengthening technique is also discussed.

In this review paper some recent advances on optical fiber sensors are reported. In particular, fiber Bragg grating (FBG), long period gratings (LPGs), evanescent field and hollow core optical fiber sensors are mentioned. Examples of recent optical fiber sensors for the measurement of strain, temperature, displacement, air flow, pressure, liquid-level, magnetic field, and the determination of methadone, hydrocarbons, ethanol, and sucrose are briefly described.

Raw earth is one of the oldest building materials, which is suitable for various uses: from the construction of load-bearing walls to use for plasters and finishes. The presence of straw fibers can give different behavior to this material. The present paper illustrates preliminary sensory and qualitative analyses, and subsequent laboratory tests that allow the characterization of the raw earth material with straw fibers for rammed earth constructions through mechanized compaction and the identification of a compatible earth mortar. The raw material considered in this study is mainly clayey; for this reason, a mix design usable with the pise (or clay) technique has been developed. Cylindrical samples have been made through a press and subject to unconfined compression and indirect tensile tests. The results of the tests showed consistent tensile and compressive strength values in the context of earth materials. At the same time, a study for the realization of a mortar with the same b...

High performance lightweight foamed concrete has the same mechanical properties of normal weight concrete (conventional concrete). The main applications are void filling, bridge abutments, bridge decks, marine structures, frame buildings, roads, sewer systems, roofing, walls, and floors. However, concrete is extensive brittleness and considered weak material in tension. Glass fibers are used as additive to the lightweight foamed concrete to increase the energy absorption capacity. The work was prepared to investigate the effect of glass fibers on tensile properties of lightweight foamed concrete with different volume fraction of glass fibers (0.06, 0.2, 0.4 and 0.6%) by the testing fresh density, dry density, flowability, compressive strength, direct tensile strength and splitting tensile strength. The results showed that a reduction in flowability was obtained with increased glass fibers content. Besides, the fresh and dry densities increased with the addition of glass fibers. Also, significant enhancements in compressive strength, direct tensile strength and splitting tensile strength were got by glass fibers inclusion. Thus, the increase of compressive strength, direct tensile strength and splitting tensile strength were up to the 56.6%, 50% and 46%, respectively, due to 0.6% glass fibers. 1. Introduction Aerated concrete is known as lightweight foamed concrete (LWFC). LWFC is lighter than normal weight concrete by mixing foams into cement slurry, LWFC has been a very recognized material with its noticeable characteristics particularly in thermal insulation with a low thermal conductivity between 0.10 W/mK to 0.66 W/mK [1,2]. Density of foam concrete about (400 to 1600 kg/m 3) depending on proportion of foam agent and water, foam concrete can be using for structural application, partition, insulation and filling grades [2]. The structural lightweight concrete having bulk density lower than 1950 Kg/m 3 and compressive strength more than 17 MPa. The structural lightweight concrete is 25% lighter than normal-weight concrete with a compressive strength up to 60 MPa [3]. The main reason of using lightweight concrete for structural purposes is to reduce the self-weight of concrete structures. Reducing the dead load of the structure is very important in earthquake regions, for tall buildings, and special concrete structures [4]. The Concrete is substantial brittleness, and which results in poor fracture toughness, poor resistance to crack propagation, and low impact strength. This inherent brittleness has limited their application in fields requiring high impact, vibration and fracture strengths. Concrete with fibers have wide range of usage due to their obvious advantages over ordinary concrete. The function of the use fibers in concrete to enhance the mechanical properties of concrete. Fibers are used to modify the tensile and flexural strengths, toughness, impact resistance, fracture energy, arrest crack formation and propagation, and thus improve strength and ductility. The concrete with fiber as additive are used widely in highways, tunnel linings, concrete pipes, reinforced concrete frames, reinforced concrete beam members, shell roof systems, skyscrapers and pre-stressed concrete, light shell constructions, domes and folded plates in recent years [5-9]. (Ghorpade, 2010) [10] investigated the effect of glass fiber on high performance concrete with silica fume as admixture. The length of fiber is 12mm and the specific gravity of the fiber is 2.68. Glass fibers by 0, 0.5, 1.0, and 1.5 % to produce high performance concrete. The maximum percentage increase in compressive strength is observed at 1% fiber and 10% silica fume. The flexural strength is increased up to 1% of fiber volume then the strength is decreased. It is also observed that the use of glass fiber up to 1.0% percentage increases the splitting tensile strength. (Murthy et al., 2012) [11] studied the performance of glass fiber reinforced concrete. The results shows the increase in compressive strength is nominal while the flexural strength increased significantly as expected with the increase in percentage of glass fiber. Also, significant reduction in the slump value of the glass fiber reinforced concrete was observed with increase in glass fiber content. (Chandramouli et al., 2010) [12] founded the addition of glass fibers to concrete enhance the mechanical properties of the concrete. Significance improved in the compressive strength, flexural strength and splitting tensile strength due addition 0.03% glass fibers.

In this work knitted wool fabrics were coated by a Si:O x :C y :H z thin film with the aim to promote pilling resistance. The wool samples were plasma coated in a radio frequency (RF) glow discharge using hexamethyldisiloxane (HMDSO) as the precursor, in mixture with argon and oxygen gases, for different deposition times and reaction pressures, at constant discharge power. Deposited films were characterized by means of Fourier transform infrared (FTIR) spectroscopy and surface morphology by means of scanning electron microscopy; moreover, propensity to pilling of treated samples was investigated, showing that treated fabrics had a better pilling performance respect to untreated ones.

In this article, a novel and simple method to produce both boron doped and undoped holmia stabilized bismuth oxide nanoceramic materials has been put forward. Boron doped and undoped poly ( vinyl alcohol)/bismuth-holmia acetate nanofibers were produced using the electrospinning technique and were calcined at 850 degrees C afterward in order to obtain nanopowder. The characteristics of the nanofibers were investigated with FT-IR, XRD, and SEM. XRD analyses showed that boron undoped holmia stabilized bismuth oxide nanopowders have the face-centered cubic structure (delta-phase), and that the incorporation of boron atoms into the composite prevents the nucleus formation and turns the structure into a more amorphous glassy form. The SEM micrographs of the fibers showed that the addition of boron results in the formation of cross-linked bright-surfaced fibers. The average fiber diameters for electrospun boron doped and undoped PVA/Bi-Ho acetate nanofibers were calculated using the ImageJ software as 102 nm and 171 nm, respectively.

Cellulose, the most abundant natural polymer on earth, is used in numerous applications in our daytoday life. However, the discovery that cellulose-based systems could lead to the formation of liquid crystalline phases only dates to the 1970s. Compared with all known applications of cellulose, the liquid crystalline behavior has been less considered. Associated with this are the low solubility of cellulose and the existence of a chiral nematic precursor solution and its processing under the action of a shear field, which is used to produce fibers and films. In this review, we first conduct a short review of the main features of cellulosic liquid crystalline phases including the main textures observed by polarizing optical microscopy and the cholesteric phase characteristics of thermotropic and lyotropic systems observed for cellulose and cellulose derivatives. Then,wefocus on the rheological properties of liquid crystalline solutions and special attention is given to the formation of striations developed during shear and the formation of the band texture, which appears during the relaxation process.
Among the different techniques used, special emphasis is given to the results obtained by coupling rheology with optical microscopy (Rheo-optics) and nuclear magnetic resonance (Rheo-NMR) techniques. Some examples described in the literature, related to the use of cellulose and cellulose derivatives liquid crystals to the production of structural color scaffolds, stimuli-responsive films and fibers, are addressed. In these systems, the initial cholesteric phase determines the unique properties exhibited by the films and the fibers produced from cellulosic liquid crystalline systems.