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Technology for the transformation of waste feathers to quality regenerated filaments has been developed. Regardless of superior properties of natural keratin materials, previously developed regenerated materials from keratin had tensile properties much lower than their natural counterparts due to backbone hydrolysis and inefficient reconstruction of disulfide crosslinkages. In this work, tough keratin filaments have been regenerated from white duck feathers via efficient restoration of disulfide crosslinkages using a dithiol reducing agent. Dithiol substantially reserves free thiol groups in the extraction and formed lengthy intermolecular crosslinkages in regenerated keratin filaments. Due to the high degree of intermolecular reconstruction of disulfide bonds and formation of lengthy crosslinkages via dithiol chain-extension, the keratin filaments exhibited considerable improvements in mechanical properties, especially for ductility and water stability. The tenacity and elongation at break were 160.7 MPa and 14%, respectively. The filaments retained about 80% of the tenacity of natural feathers at either dry or wet conditions and demonstrated stretchability 150% higher than natural feathers. The fiber regeneration technology makes it possible to substitute primary fiber sources by renewable poultry feathers. Successful filament substitution or addition can bring more than 88-billion-dollar revenue. The technology not only contributes to a sustainable fiber and poultry industry but adds substantial values to poultry feathers.

Breeding philopatry is well known in the Black-headed Gull (Chroicocephalus ridibundus). Using a capture-mark-recapture method, we studied if Black-headed Gulls show nest site tenacity and mate fidelity as well, and investigated if there are differences between a stable, and a newly established and fast-growing colony, as well as for differences between the center and edges of these colonies located in north-eastern Germany. We found a high level of nest site tenacity in the center of the stable colony on Böhmke Island, and lower degrees of nest site tenacity at the edge of the same colony and in the newly established and fast-growing colony on Riether Werder. Mate fidelity was very strong in all individuals which returned to their previous breeding place, regardless of the nest site location.

Perseverance in foraging is a high-risk/high-gain strategy. In this issue of Neuron, Sayin et al. (2019) decipher the neuronal circuit that arbitrates this choice in Drosophila. The fly's remarkable tenacity illuminates the interaction between working memory and decision making.

High strength and low alloy steels are commonly used in the manufacture of tubes, which are standardized by the API standard for oil and gas transport systems. The high yielding limits, high tenacity at low temperatures and the smaller thicknesses, allow the use of ducts with larger diameters and subjected to higher internal pressures, thus increasing their efficiency in the transport of fluids. This paper deals with the identification of the best temperatures applicable to stress relief and quenching and tempering treatments that optimize mechanical properties in circumferential welded joints, through Vickers traction and Charpy impact tests with V-notch “. In addition, the specimens will be characterized metallographically to correlate the mechanical and microstructural properties found in the different regions of the welded joint.

Polyimide fibers (PI) combine high thermal stability, good chemical and UV resistance. However, most commercial PI fibers including P84®, Kermel®, Yilun® and Suplon® do not exhibit sufficiently high mechanical properties. Finding an appropriate method that is commercially available to prepare PI fibers with a high tenacity and modulus is required urgently for making large scale manufacturing attractive. Herein, we describe an approach to preparing high-performance PI fibers by introducing the heterocyclic pyrimidine and benzimidazole units into PI backbones. PI fibers prepared by this way exhibited a higher tenacity and modulus compared to those previously reported PIs and even Kevlar 49® fibers due to the high molecular weight, strong hydrogen bonding interaction and highly oriented crystalline structure. In addition, the detailed structural analysis based on WAXD and SAXS has revealed that the stress-induced crystallization and more compact morphology formed in PI fibers by the post hot-drawing process. Accordingly, as the drawing ratio was set to 3.8, an optimum tenacity and modulus of the PI fiber reached to 2.3N/tex and 71.8N/tex, respectively, indicating that the resultant fibers have a great potential application as the reinforcing fiber in advanced composites.

An environmentally sustainable variation of Engineered Cementitious Composites (ECC) with non-processed rice husk ash (RHA) at the amount of 30% of cement (by volume) replacement and high tenacity polypropylene (PP) fiber was evaluated in terms of durability properties (pore structure and shrinkage). Conventional concretes were also used as baseline materials to compare with ECC mixtures (with and without RHA). The incorporation of RHA on ECC mixture showed an improvement in the durability by increasing the capillary resistance and enhancing the tortuosity of capillary pores. In addition, the incorporation of RHA reduced both free and restrained shrinkage of ECC.

Current production of ramie fiber (the “queen” of nature fiber) requires the oxidation degumming process which suffers from the presence of metal elements due to the well-known Fenton reaction. In this study, the metal species/contents in current major degumming systems along Yangtze valley and their effects on the final ramie fiber properties (e.g. degree of polymerization (DP), tenacity, elongation) were assessed. The potential of employing our recently developed spherical bacterial cellulose (SBC) as recyclable metal adsorbent was also evaluated. Results showed that excessive amounts of metal elements (e.g. Ca, Mg, Fe, Mn, Cu, Pb) existed in the degumming systems which were detrimental to the final fiber properties. The application of 2,2,6,6-tetramethylpy-peridine-1-oxy radical (TEMPO)-oxidized spherical bacterial cellulose efficiently removed these metal elements and improved the degree of polymerization and tenacity of ramie fiber products. Our results could also open the door for the potential application of spherical bacterial cellulose as super absorbance in different types of waste water treatment.

Tenacity and fracture toughness of a novel β/α″ Ti-22Nb-10Zr (wt.%) coating processed by magnetron sputtering were modified as a result of the martensitic transformation (β → α″) activated by the presence of compressive residual stresses when the coating deposition is performed at high bias voltage values. Mechanical properties, such as hardness, H, and Young’s modulus, E, values, and therefore elastoplastic response of the coating were characterized through H/E, and H3/E2 ratios as a function of the extent of the martensitic transformation. These ratios were correlated to the elastic response and to the resistance to plastic deformation of a surface subjected to sliding mechanical contact, respectively. The usefulness of both ratios to design “hard and tough” coatings, suitable for enhancing of its wear resistance, is compared with the tenacity, G, the semi-quantitative, FT, and the quantitative, KI, fracture toughness values obtained from nano-scratch characterization. Results show that Ti-22Nb-10Zr (wt.%) coating with the highest and lowest hardness and Young’s modulus values, and therefore the highest H/E and H3/E2, has the highest cracking resistance and fracture toughness. Under linearly ramped loading from 0.1 to 5 and 100 mN it was impossible to produce fracture of the coating when it was deposited with a bias voltage of −63 V. In return, the coating deposited with a bias voltage of −148 V shows an almost complete elastic recovery until the moment of its fracture and delamination, which is an evidence of its high tenacity and superior fracture toughness. The KI value is ∼21 MPa∗m1/2, which is higher than typical values of bio-ceramics (Al2O3 and ZrO2) used in medical applications, demonstrating that this coating could be used in components subjected to high wear and cyclic impacts, e.g. on femoral heads in artificial hip joints.

A functionalized zirconium phosphate (FZrP) nanosheet was synthesized and introduced to PA46/PPO alloy as a solid lubricant. FZrP showed a high efficiency in improving the tribological performances, mechanical properties and moisture resistance of PA46/PPO. With the incorporation of 2.0% FZrP, the wear loss and friction coefficient of PA/PPO were decreased by 94.48% and 56.60%, respectively. Moreover, the friction and wear mechanism of FZrP was intensively studied and revealed: FZrP nanosheet retained and accumulated on the wear surface because of its strong interfacial binding force with the matrix, which resulted in the formation of a protective layer with good strength, tenacity and lubricity to resist severe wear damage.

Five different poly (ethylene terephthalate) (PET) materials (two recycled and three virgin ones) were melt-spun into fibres using a capillary rheometer and aerodynamic stretching. In order to cover a wide range of processing parameters, two temperatures in combination with six different take-up pressures were used during the melt spinning process. The surface smoothness, diameter and mechanical properties of the PET fibres were investigated. Compared with other studies, this study provides comprehensive research on melt-spun PET fibres. One recycled PET and one virgin PET in this study showed acceptable tenacity, outstanding elongation at break and desirable fibre fineness in denier. The molecular and rheological properties of these materials were studied further and presented minor differences in weight-average molar mass and molar mass distribution as well as in their viscosity, which resulted in their similar processing behaviour. This study proved the possibility to make a fibre from bottle-grade recycled co-polymer PET with similar properties to the fibre-grade virgin homo-polymer PET.

The dislodging effect of breaking waves is among the critically important factors structuring rocky intertidal communities . Because behavior is so difficult to study in the field, the interaction of wave force with behavior of intertidal organisms is poorly understood. Here, we present a field study of the interaction of breaking waves with the natural behavior of individuals of Lottia gigantea , an intertidal limpet with a complex territorial behavioral ecology . We hypothesized that limpets engaging in fast-moving territorial chase in response to intraspecific contact are more vulnerable to wash-off by a passing wave than are slowly foraging limpets that do not take part in such chase. We measured the lift force required to dislodge limpets while they were engaged in three natural behavioral responses to intraspecific contact in the field: 1.) continued foraging, 2.) retreat, and 3.) territorial pursuit. We divided the measured force-to-remove by aperture area to estimate resistance to wave-induced lift force, or tenacity. Tenacity (Newtons·cm −2) in slowly foraging limpets was 2–4 times stronger than previously reported for moving limpets (retreating at high speed from sea stars). Small foraging limpets showed stronger tenacity than did large limpets. Tenacity was significantly reduced by high-speed territorial and retreat responses, especially in small limpets. We compounded the wash-off probabilities of tenacity during the expected number of high-speed chases in the face of an entire year of reported waves at a nearby ocean buoy, and estimated that limpets should suffer substantially greater mortality (11.5%) than do limpets that refrain from all territorial chase (2.9%). Overall, these data support our hypothesis that dislodgement by breaking waves comprises a significant risk attendant to territorial chase. The fact that limpets nevertheless engage in these chases suggests that the resources gained by this behavior are substantial.

Pliable and water-resistant protein fibers from feathers were developed via continuous one-step spinning and crosslinking using sucrose-tetra-aldehydes. Though flexible protein fibers from feathers were developed, poor wet stability and low tenacity still limit the large and high-end applications of feather-derived fibers. Despite that saccharide aldehydes are considered as an efficient and sustainable crosslinker, substantial concerns such as generation of formaldehyde, high consumption of modifiers, loss of mechanical properties, yellowing, and decline in dyeability of fibers, exist after crosslinking. In this work, we controlled structures of crosslinkers and incorporated disaccharide-tetra-aldehydes into a continuous wet-spinning line. No formaldehyde was generated in the whole process. Protein fibers with controlled aldimine crosslinkages had not only a 92% tenacity retention after immersed in water for 1 week but also a substantial increase in mechanical properties. The dry and wet tenacity of feather-derived fibers was 120% and 90% of wool, respectively. Moreover, crosslinking from disaccharide-tetra-aldehydes retained the color of fibers and minimized the consumption of amine groups, the dyeing sites, on keratin. No toxicity was introduced by crosslinking. This work promotes resource recovery from poultry wastes, decreases the reliance of fiber industry on petroleum-based products, and diminishes environmental impact of fiber industries.

Manufacturing carbon nanotube (CNT) fibres on a large scale with properties that are a significant fraction of those measured for individual tubes or smaller bundles is crucial to achieving greater impact in industrial applications. We describe three macrostructured morphologies produced on a laboratory scale: CNT ribbons, ropes and tows, wherein tows are the most suitable for industrial scale-up, comprising a bundled structure of thousands of individual micro-fibres. For each morphology, we present the tensile failure mechanisms and mechanical performance observed over six orders of magnitude of strain rate. The tests were conducted on a conventional Hounsfield tensile tester (10─4 to 10─1 s─1 strain rate) and a modified split-Hopkinson tensile bar tester (30–150 s─1 strain rate). To avoid the problem of clamp failure, we present a novel method of testing loops, rather than uniaxial samples, as-produced from our chemical vapour deposition reactor. For material benchmarking and validation, we also tested unsized carbon fibre (Hexcel AS4) and Dyneema tows (SK25). All materials were used ‘dry’, i.e. not as a composite, for raw material and structure comparison. We show here that CNT tows exhibit both a mechanical performance and fracture behaviour which combines the ductility of Dyneema with the tenacity of carbon fibre.

In the present study, an attempt is made to improve the ballistic performance of unidirectional (UD) ultra-high molecular weight polyethylene (UHMWP) fabrics through shear thickening fluid (STF) impregnation. Impact tests in the range of 250-700 m/s were conducted using an aero-ballistic range. It was observed that the ballistic limit ( V50) and the energy absorption of STF treated UD-UHMWP fabrics can be improved up to 5% and 13% respectively, corresponding to their neat ones. Increased energy absorption of STF treated fabric is attributed to the enhancement in the friction between layers of the STF-UHMWP fabric and the shear thickening effect. The effect of sample thickness of STF treated panels on the energy absorption, failure mechanism, and back face signature (BFS) is evaluated and compared with their neat counterparts. The damage was localised in the thinner panels (5 and 10 layers), and the layers were perforated through shear plugging near the impact region. The failure mode of thicker panels (20 and 30 layers) is accompanied by the tensile fracture of high tenacity fibres. It is concluded that the STF impregnation improves the ballistic resistance of UD-UHMWP fabric without affecting the flexibility and adding weight penalty.

In this study the influence of matrix type on plasma-treated high tenacity polypropylene fiber reinforced cementitious composites were investigated. The fibers were subjected to low frequency cold plasma of oxygen gas. Power rate of the generator was 50, 100 and 200 W, and duration was 0.5, 2 and 20 min. 25 × 60 × 300 mm prismatic samples were prepared with two type of matrices, and plasma-treated/untreated fibers. Scanning electron microscope was used to determine physical modifications on the fibre surface. Four point bending tests were conducted on prismatic samples. Matrices with treated and untreated fiber reinforcement were compared by means of flexural properties. Analysis of variences was applied to the plasma treated fiber reinforced groups. Test results showed that the flexural behaviour of composites was affected by plasma power and duration. There was physical modification for each plasma power and duration. The influence of plasma treatment on fiber-matrix bond properties was mainly affected by matrix type: weak matrix showed better flexural properties with low power and short duration plasma-treated fibers, whereas comparatively stronger matrix expressed greater flexural properties at higher power and longer durations when compared to untreated fiber reinforced composites.

Inter-yarn friction plays a pivotal role in determining the impact resistance of woven fabric based soft armour panels (SAPs). The current study presents a comparison of ballistic response of SAPs made from para-aramid, ultra-high molecular weight polyethylene (UHMWPE) and poly para-phenylene-2,6-benzobisoxazole (PBO) woven fabrics and demonstrates the importance of inter-yarn friction. Plain woven fabrics were prepared using para-aramid, UHMWPE and PBO yarns and SAPs of constant areal density was produced using multiple layers of these fabrics. It is found that despite lower tenacity and modulus of para-aramid fibres, in comparison to those of UHMWPE and PBO fibres, para-aramid SAP exhibits the lowest back face signature (BFS) owing to the highest inter-yarn friction. On comparing UHMWPE based SAPs made from fabrics with yarns of different fineness, fine UHMWPE yarn based fabric exhibits higher inter-yarn friction owing to more crossovers per unit length, which further translates into lower BFS of respective SAP. Therefore, while selecting fibres for soft body armour applications, inter-yarn friction should be considered along with the tensile properties.

Decommissioning offshore Floating Production, Storage and Offloading (FPSO) platforms requires extensive technical knowledge, since it generates different post-consumer materials, including mooring lines. These ropes are made from polyester high tenacity yarn, based on polyethylene terephthalate (PET), and their high added value means they should not be discarded as scrap. This paper aims to present a review and technical opportunities, from an economic standpoint, of recycling the mooring lines recovered from decommissioned FPSOs. Studies conducted over the last two years have researched and developed different potential applications for the fibers. These studies include collaborative project initiatives involving technical and management professionals, universities and private enterprises, with a view to achieving a more sustainable destination for these fibers.

Ramie provides the longest and strongest natural fiber in textile industry, but its traditional degumming process is costly and requires a large amount of alkali, which causes serious environmental concerns. In the current work, a steam explosion (STEX) treatment followed by sodium percarbonate (SP) soak degumming process was investigated. Microstructure, chemical composition and mechanical properties of the refined ramie fibers were comprehensively characterized. The residual gum content was below 5%, the fineness was higher than 1600 Nm (6.25 dtex), the breaking tenacity was 5.4 cN/dex, and the whiteness was above 50%. All of the properties met the requirements of Chinese national standard, and the breaking tenacity and whiteness were notably better than those of the fibers degummed traditionally. In addition, environmental impacts of the new degumming process were evaluated. Only 50% chemicals were needed for the new process, and chemical oxygen demand (COD) of the waste reduced to 35% of the traditional method. Therefore, the new method was more environment-friendly and economically feasible. It has great potential for industry applications.

This paper evaluates the relationship between the rheological properties of doughs and the constituents of flours made from ancient grain. It also examines the effect of water on the rheological properties of doughs obtained with three types of flour (refined white flour, type 2 flour, and whole wheat flour) and the associated chemical and physical phenomena. A Chopin alveograph was used to take rheological measurements. Significant differences were found between doughs made with refined and unrefined flours. Tenacity, deformation energy, and the curve configuration ratio decreased as total water content increased, while the inverse trend was found for extensibility and the index of swelling. The analysis made it possible to develop a model to predict the rheological properties of doughs produced with refined and unrefined flours, if the starch, insoluble fiber, protein, and gluten content is known. Although, ancient grains are notorious for their poor technological properties, even a minimum improvement in rheological performances would contribute to satisfying the increasing demand for these products and facilitate their production, with positive returns for economies and biodiversity. Finally, level curves diagrams made it possible to identify the optimum water content of doughs corresponding to the technological properties of the required finished product.

There are several measures or graph parameters of the vulnerability and reliability of a communication network, such as connectivity, toughness, scattering number, integrity, tenacity, rupture degree and edge-analogues of some of them. Among these parameters, the scattering number, integrity, tenacity are the better ones to measure the stability of a network. When designing stable networks, it is often required to know the structure of networks attaining the maximum and minimum values of given stability parameters with prescribed number of communications stations and links. In this paper, we present some new bounds for the scattering number, integrity, tenacity of regular graphs in terms of the spectrum.

Sunnhemp fibre is an under-exploited natural fibre. In this study, an attempt has been made to explore the possibility of production of unspinnable sunnhemp based unconventional fabric (needle punched nonwoven) for value addition and diversified uses. Mechanical processing for preparation of all sunnhemp, sunnhemp-jute (1:1) and sunnhemp-polypropylene (1:1) blended needle punched nonwoven has been optimised and processing parameters have been suggested. Softening treatment of sunnhemp fibre has been done successfully for better processing. Boiling in water with 1% nonionic detergent for 15 min has been suggested as pre-processing for softening. Tenacity, elongation-at-break, initial modulus, breaking energy, stress relaxation, creep, compressibility, recovery-from-compression, bending load, electrical insulation, thermal insulation, sound insulation, air permeability and frictional force have been evaluated and analysed for all the above-mentioned samples. Based on those properties the probable use has been suggested.

We investigated a major fiber spinning process parameter, the coagulation bath concentration, which has a critical effect on the porosity of the polyacrylonitrile (PAN) fibers. Utilizing thermoporosimetry, a calorimetric method based on the Gibbs–Thomson effect, this work details the correlation between coagulation bath concentration, porosity and pore size distribution. Pore size, as well as the pore size distribution, of the fibers throughout the wet spinning process were determined in detail. Moreover, the changes in the number of porous zones, pore size and fiber morphology during the wet spinning process were also examined by changing the coagulation bath composition. Two coagulation bath compositions, 77.5 wt% and 80 wt% DMAc/deionized water were considered. The fibers spun at 80 wt% coagulation bath solvent concentration displayed skinless rough surfaces with high porosity values compared to the fibers spun at 77.5 wt%. Attempts to spin into slightly more concentrated DMAc baths were unstable due to reduced tow tenacity, leading to fiber failure. The study showed that even minor changes in the coagulation bath composition can have a pronounced effect on the fiber properties such as cross-sectional shape, the integrity of the external skin, and the number and size of pores.

Carol Kuhlthau's (2004) work shows that affect is a vital part of information seeking for high school students and undergraduates. This article explores the influence of affect on research university faculty. Like beginning information users, advanced information users are influenced by their confidence, ambition, and interest in their work. This study employed phenomenological interviews to explore how scholars' willingness to tackle new areas of research, submit manuscripts to prestigious publications, approach colleagues for collaboration, and conduct literature searches with tenacity is impacted by their emotions and dispositions.

The objective of the present work is improving compressed concrete filled steel tube elements of square section by means of helical reinforcement of a concrete core. Conducted experimental studies of centrically and eccentrically compressed laboratory samples of such elements have shown that in comparison with similar samples without helical reinforcement their durability ha increased by 31÷42%. Values of longitudinal sample deformation fixed at maximum with helical reinforcement made of C25 concrete class have increased almost 3 times. Maximum longitudinal sample deformation made of C50 concrete class were inferior by 20%. Increase in durability and deformability of improved samples is explained by increase in performance of placing of shear reinforcement that is ensured by helical reinforcement. Confining element ration at central compression was equal to 1.36÷1.9, at eccentrical compression with eccentricity ratio of 0.107 it was 1.28÷1.35, and at eccentricity ratio of 0.214 -1.15÷1.26. High durability and deformability ensure greater tenacity of such structure that makes them attractive for usage in buildings and constructions in areas with increased seismic activity. The revealed features of strength resistance of concrete filled steel tube elements with square section will be used when developing an algorithm and a computer program for the automated calculation of their bearing capacity.

The effect of chain extender Pyromellitic dianhydride (PMDA) on the comprehensive properties of the virgin (vPET) and recycled Polyethylene terephthalate (rPET) fibers was investigated. Five different weight fractions of PMDA were melt mixed with PETs to create long-chain branched (LCB) structures. The modified LCB-PET granules were melt spun into fibers using a capillary rheometer at 270 and 280 °C, and then aerodynamically stretched by an aspirator at seven take-up pressures. The different shear viscosity, thermal properties and spinnability of LCB-vPET and LCB-rPET, and the surface morphology, draw ratios, tenacity, elongation at break of PET fibers, as well as the performance-reliability plots using Weibull distribution were well discussed. A semi-empirical mathematical model further confirmed the exponential relationship between the tenacity and elongation at break of the PET fibers. This research depicts a visible window for academic and industrial researchers to produce PMDA modified PET fibers with desirable comprehensive properties.

Gummy components in raw ramie are required to be removed to extract cellulose fibers. However, current common degumming techniques are largely limited because of long procedures, heavy environmental pollution, high energy consumption, and insufficient efficiency. Here, deep eutectic solvent (DES) was explored to ramie cellulose fiber degumming without combining any further treatment. Three DESs, namely, choline chloride-urea (CU), choline chloride-imidazole (CI), and ethylamine hydrochloride-ethylene glycol (EE), were demonstrated to be capable of removing non-cellulose impurities in 2 h in one-step boiling process without damaging cellulose structure. The purified fibers were systematically characterized in terms of mechanical properties and chemical constitutions. Results showed that the DES can effectively remove most non-cellulosic materials from raw ramie. The CU treated fibers exhibited a higher tenacity (6.51 cN/dtex) and lower residual gum content (3.76 %), which was nearly in the same level of traditional alkaline (TAL) treated fibers. The fibers degummed with CI showed the highest break elongation (3.30 %) and relatively good tenacity (5.50 cN/dtex). Comparatively, the EE treated fibers exhibited the poorest tenacity (3.05 cN/dtex) despite of the lowest residual gum content (3.15 %). Besides, the DES was reusable and recyclable, which can be repeatedly used for many times. The cellulose fibers achieved high tenacity and low residual gum content after the fifth cycles’ treatment with DES, which still met the requirement of downstream applications. Finally, the lignin in degumming waste solution was further fractionated, and the purity of the extracted lignin was proved to be 9.54 %. Featured with high efficiency, short process, less chemical and energy usage, high quality fibers as well as easy reutilization of solvent, this approach is of great potential for cellulose fiber isolation.

This work aims to study the effect of reactive molding on polyamide-6 (PA6) based micro composites with either glass or high tenacity viscose as fibre reinforcements. For this purpose, microdroplet pullout test was found to be well suited to determine the interfacial shear strength. For pull-out testing, samples are prepared with a common method implying melting polyamide-6 and an innovative method which allows the microdroplets formation by direct wetting in the reactive mixture. Conditions to obtain microdroplet in this new method are close to those of real size composite molding. First, this work focus on the verification of the new sample preparation method using 1 H and 13 C NMR to determine conversion rate and verify the presence of polyamide-6 on wetted fibres bundles. Contact angle are calculated to confirm the NMR analysis conclusions. Both of these analyses confirm that PA6 is effectively formed on fibres when wetting with the reactive mixture. Finally, interfacial shear strength is compared for both glass and high tenacity viscose with these two types of preparation procedures. Obtained values for glass fibres are τ = 25 ± 6 MPa with PA6-melting and τ = 20 ± 3 MPa with reactive mixture wetting. Reactive mixture wetting also allows to avoid high tenacity viscose degradation during PA6 formation, leading to the determination of the interfacial shear strength τ = 12 ± 3 MPa.

This paper presents the microstratigraphic analysis of the protohistoric site El Calvari del Molar, dated to the 8th century and the first quarter of 6th century BCE. It focuses specifically on Room 8, located in the northern part. The sedimentary record covers different stratigraphic units, including several floors with their layers of preparation and domestic structures. The study of these floors, mainly through micromorphology, allows us to determine the composition, the processing and the technical treatment as well as the possible origin of the lithological materials used in their manufacture. We highlight that the floors are composed of earth construction, made of local carbonated materials, mainly clayey fine sands. Mixing this material with water would cause a precipitation of CaCO favoured by the impermeability of their preparation layers, mostly silty clay aggregates, leading to the semi-cementation of the floor, which appears to have been the aim of the builders of El Calvari. This type of earth floor brings together a series of characteristics at the construction level such as cohesion among particles and tenacity, similar features to lime mortars. In short, we have the opinion that the micromorphological analysis is an essential tool for the study and interpretation of domestic architectural elements. In this case, it has allowed us to identify and characterize the techniques and construction strategies of this type of floor by these first protohistoric builders of the NE Iberia., This paper is part of the HUM2004-04861-C03-01 and HUM2007-65725-C03 research projects funded by the Ministry of Science and Innovation and the HAR2010-1105-C02 research project funded by the Ministry of Economy and Competitiveness. The research has also been funded by the grants awarded to the “El jaciment protohistòric del Calvari del Molar i l'àrea minerometal·lúrgica Molar-Bellmunt-Falset” research programme by the Culture Department of the Regional Government of Catalonia, the Tarragona Provincial Government and the Municipality of El Molar (in order to carry out the excavation of the El Calvari archaeological site).

Extant research affirms that angel investors seek passionate entrepreneurs but questions surround whether there is value in passion itself, or if it is instead used as a marker for other important characteristics like tenacity and inspirational leadership. Employing both a qualitative and quantitative study, we find that angels value passion in addition to tenacity, as well as both together, when evaluating entrepreneurs for investment. We also find that the entrepreneurial experience of angels positively moderates the value provided by passion and tenacity.

The study proves the feasibility of manufacturing injection moulded polypropylene composites reinforced with short rayon cellulose fibres of two selectively tailored fibre–matrix interfaces. The originally developed method relies on selective chemical grafting of two different polymer waxes onto the surface of cellulose fibres in order to obtain two different strengths of fibre–matrix interfaces in one composite. This selective tailoring of a dual-interface is meant to improve the notched impact strength without deteriorating of its flexural strength. Compatibilised fibres have a strong interphase, which conditions the transfer of strain from the matrix to fibres during deformation. Fibres tailored for a weak interface more efficiently hinder the crack propagation at crash. A 32% improvement of composite notched impact strength was achieved with merely a 5% deterioration of its flexural strength. Its specific properties are on the level or better than those of polypropylene counterpart reinforced with the same content of glass fibres.

Effect of intensification of cellulose dissolution process on the spinning of lyocell fibers and their physical properties was systematically investigated. The cellulose dissolution process was intensified by pre-swelling of the pulps that benefited in bringing down the conventional process temperature of 75 °C to 50 °C as well as by assisting in good dissolution and formation of homogeneous dope. Further, effect of dopes prepared from pre-swelled and un-swelled pulps at a lower temperature (i.e. 50 °C) on spinnability and fiber properties, was thoroughly investigated and compared with dopes prepared at 75 °C. The resultant fibers were morphologically and structurally analyzed using SEM and XRD and correlated with their physical properties. It was observed that fibers regenerated from pre-swelled dope, showed increased overall molecular orientation (measured by birefringence) as well as high amorphous orientation that resulted in improved tenacity of the fibers. Finally, it has been observed that cellulose dissolution using pre-swelled method is an energy-efficient technique over un-swelled method (almost 35% at 50 °C and ∼20% at 75 °C of energy saving). Present work makes lyocell process more sustainable and simultaneously enhance fiber properties.

Although traditional alkaline (TAL) process for ramie degumming is commonly used in the industry, it causes severe environmental concerns. In this work, an emerging organic solvent degumming process utilizing FeCl3 catalyst (FeCl3-OS) was developed in one step. The influences of FeCl3-OS system on fiber properties (e.g. residual gum content, tenacity, degree of polymerization (DP), etc.) were evaluated, and the recyclability of degumming solution was also studied. The results indicated that ramie fiber could be isolated with FeCl3-OS treatment (FeCl3 1.0 %, 200 ℃, 121 min), and the tenacity and residual gum content of refined fibers were 7.9 cN/dtex and 3.88 %, respectively. Fibers treated in FeCl3-OS system were endowed better moisture sorption (9.2 %) and higher yield (75.2 %) compared with that in TAL system. Moreover, fibers with five cycles’ treatment possessed outstanding performances, that was 4.44 cN/dtex of tenacity and 4.33 % of residual gum content, which fulfilled the requirements of the spinning process.

This monograph is dedicated to the memory of Dr. Jared James Grantham (1936-2016), a wonderful man, a compassionate physician, a passionate researcher, and an exceptional scientist. Without his vision, achievements and impact on countless collaborators and disciples, the field of Polycystic Kidney Disease would not be where it is today. His intellect, tenacity, modesty and kindness continue to be an inspiration to all.

Carbon nanotube (CNT) yarns were evaluated for sensor applications by measuring electrical properties during uniaxial tension loading. Mechanical properties (tenacity and failure strain) and electrical properties (resistivity and gauge factor) were investigated and statistical distributions for these properties were obtained. Cyclic loading test results showed that permanent strain after unloading exists and that the resistance at zero load increases linearly with permanent strain. Furthermore, the relative resistance change during loading was found to be linear with strain. Although mechanical properties of CNT yarns exhibited a significant statistical variation, the resistance was found to have much less statistical variation making them good candidates as sensors for structural health monitoring in composites.

In this work, the crystalline morphologies and mechanical properties of olefin multiblock copolymer (OBC) were regulated by blending with polymers possessing architecture similar to the constituent blocks. In order to understand the influence of multiblock architecture on the interaction between OBC and blended substances, ethylene-octene random copolymer (ORC) with similar crystallinity was blended with corresponding substances for comparison. We found that polyethylene (PE) chains, which possessed architecture resembling hard blocks, were inclined to cocrystallize with OBC and form remarkable lamellar structure in their blends. On the contrary, they aggregated together in ORC matrix and developed crystals similar to pure PE. The distinct crystalline properties were closely correlated to their state in the melt as revealed by Time–Temperature superposition examinations. The results of tensile tests exhibited that the strength of OBC samples could be improved without great depression of tenacity when appropriate amount of PE was blended. This might be ascribed to the good compatibility between added PE and OBC hard blocks considering their similar chain architecture. The findings contribute to understanding the relationship between morphologies and apparent properties of multi-block copolymer-based blends, which can be significant to achieve target mechanical properties for multiblock copolymers by a simply blending approach.

Four hyperbranched polysiloxanes (HPSis) with different molecular weights and concentration ratios of double bonds to epoxy groups (1:6.5–1:0.7) were synthesized and characterized. Each HPSi was facilely grafted onto surfaces of Kevlar fibers (KFs) to develop novel modified fibers (HPSi-g-KFs). The structures and integrated properties of HPSi-g-KFs as well as the origin behind were systematically investigated. Results show that HPSi-g-KFs have much rougher surface morphologies, and their surface free energies are as high as about 1.7 times that of KFs, showing greatly improved wettability. Besides, HPSi-g-KFs have excellent UV resistance after 168 h UV irradiation, the retentions of tenacity, energy to break, modulus and break extension are as high as 92, 86, 95 and 96%, respectively, while those of KFs are 66–85%. In addition, compared with KFs, HPSi-g-KFs have higher tensile tenacity and energy to break with similar modulus and break extension, much better thermal stability and flame retardancy. The nature of HPSi has different influence on different property of fibers, the HPSi with smaller molecular weight and more epoxy groups is beneficial to prepare HPSi-g-KFs with better wettability, while that with larger molecular weight and more double bonds tends to prepare HPSi-g-KF with better flame retardancy and UV resistance.

Phase change materials are used for thermal management solution in textiles because of the automatic acclimatising properties of textiles. Most of the phase change materials used in textiles is usually found in the range of 28–32 °C of their melting point. This paper reports a type of smart monofilament fibre development incorporated with microencapsulated phase change material through melt spinning process. Up to 12% microcapsules are successfully incorporated into the polypropylene monofilament showing 9.2 J/g of latent heat. Some of the mechanical properties of the developed fibre are also studied together with the surface morphology of monofilament. A statistical model is developed for latent heat, tenacity and modulus of monofilament fibre and is validated by experimental values. The fibre properties predicted by the developed models are agreed very well to the experiments results.

It is well-known that in order to train a gymnast capable to take part into high level competitions, hard training for years, perseverance, tenacity, seriousness in training, material conditions and state-of-the-art equipment as well as highly-skilled experts are required. The training approach also requires a forecast of the evolution of gymnastics in the future, especially nowadays when the free- style exercises remained the only ones in the programme of major competitions.

A range of polyacrylonitrile (PAN) and pitch based carbon fibre types (high, standard and intermediate modulus fibres) have been characterised using both physical and chemical techniques, the results highlighting the heterogeneity of the fibre. Nano-indentation showed variation in stiffness between different fibres of the same type as well as variation along a 20 μm length of a single fibre. Tensile tests showed variance of approximately 25% in tenacity for three different carbon fibre types but less variability in modulus with values from 8% to 19%. Raman spectroscopy showed variation in the graphitic content both between fibres of different origin as well as variation, with 0.5 μm spatial resolution, along the length of a single fibre. Inverse gas chromatography surface energy measurements of larger samples of fibres were carried out using the novel approach of incremental surface coverage by varying the probe molecule concentration and revealed different levels of energetic heterogeneity for PAN based fibres collected at different stages of carbon fibre production. The heterogeneity of the unoxidised fibres (collected after carbonisation) was restricted to about 15% of the fibre surface whereas the surface oxidised fibre sample (collected after the electrolytic oxidation bath) was heterogeneous over more than 30% and the sized fibres were shown to be quite homogeneous.

A binary ionic liquid system was confirmed to be a promising solvent to dissolve chitosan, and the regenerated chitosan fibers were prepared by wet and dry-wet spinning technique respectively. The SEM results show that the chitosan fibers prepared by wet spinning technique present striated surface and round cross section, and the chitosan fibers prepared by dry-wet spinning technique present smooth surface and irregular cross section. The mechanical testing results show that the regenerated chitosan fibers present relatively high tenacity, especially, these prepared by dry-wet spinning process present excellent strength and initial modulus, i.e. 2.1 cN/dtex and 83.5 cN/dtex, which is stronger than that of most reported chitosan fibers. The FT-IR results show that the dissolution of chitosan in the binary ionic liquid system is due to the protonation of NH 2 groups in the chitosan chains. Furthermore, a possible reaction during the dissolution and regeneration process is proposed.

In this study, breads varying in yeast content and therefore leading to distinct cellular structures are investigated. Firstly, X-ray microtomography is used to characterize not only the final cellular structure, but also the process of development of microstructure during the fermentation stage. With μCT, image analysis of the full 3-D microstructure, measuring the size, shape, networking/connectivity and distribution of various phases was possible. These measurements represent the full 3-D microstructure, which is not always possible by 2-D image analysis using statistical techniques. Secondly, the textural properties of the baked bread were obtained by compression tests and finally, the sensorial quality of the final product is also evaluated and correlated with the above properties. Results showed that an increase of the yeast content increased the percentage volume of pores and decreased the force required for compression of the bread sample and the tenacity. Moreover, a larger quantity of smaller sized pores led to a firmer bread structure. Regarding the sensorial properties, none of the investigated microstructural parameters were significantly correlated with the overall quality of the bread. In fact, the overall quality was more strongly affected from other parameters such as odor and appearance attributes.

The mechanical behavior of four carbon nanotube (CNT) wires, comprised of 1-yarn, 30-yarn, 60-yarn, and 100-yarn, was investigated under constant tension at two loading rates of 0.02 mm/s and 2 mm/s. Tests were conducted with both as-fabricated and pre-stressed wires. The ultimate tenacity or apparent ultimate tensile strength of all four wires was found to be independent of loading rate, with those for the single-yarn wire about twice those of the multiple-yarn wires. Strain at a given stress level and failure strain of the multiple-yarn wires before pre-stressing were almost an order of magnitude larger than those for the single-yarn wire, and this difference was reduced considerably after pre-stressing. The failure mechanisms of 1-yarn wire or twisted individual yarns in multiple-strand wires involved ductile (necking) deformation and fibrillar breakage. Inner yarns in multiple-yarn wires initially failed at the same location, followed by outer yarns failing at different locations. Additionally, sliding occurred between individual yarns, and twisting of the yarns accompanied by surface wear took place in the multiple-yarn wires, which contributed to their failure at a lower load compared to the single-yarn wire.

Purified konjac glucomannan(KGM) was blended with Xanthan gum to prepared gel, which was valued by its viscosity and tenacity. The konjac micro-balls(KMBs) were prepared in drying and wetting method respectively. The diameter of the KMBs was analyzed with laser particle size analyzer. To a carrier of drug deliver, the delivery characteristics of the NMP, which embedded in KMB, was discussed. The results showed that KMB was well dispersed in DMSO, and its diameter was 4.08 μm. In paraffin, KMB was homogeneous disperse with diameter(2.23 μm). In the behavior of drug delivery, the characteristics of drug sustained-release were obvious, and the delivery time was more than 24 h.

This work uses high tenacity expanded polytetrafluoroethylene (ePTFE) filaments as both a fiber reinforcement and a reservoir for solid lubricants. The goal is to reduce the wear of the composites by regulating the PTFE transfer. Expanded PTFE films are a porous network of PTFE nodes and fibrils, while highly oriented ePTFE filaments are aligned crystalline fibers that are regarded as high-tenacity fibers that can be woven into threads or yarns. Reported yield strength of these filaments can exceed 500 MPa. The best performing composites were those that had filaments of ePTFE aligned normal to the counterface. The wear rates obtained from the inclusion of expanded PTFE filaments were better than conventional powder filled PTFE–PEEK composites reaching values as low as K = 7 × 10−8 mm3/N m and showed stable friction coefficients below μ = 0.125 for over 2 million cycles.

The limpet, Nacella concinna, collected from the Antarctic Peninsula (67 S), was incubated at -0.3 degrees C and 2.9 degrees C for 9 months to test if the previously reported absence of acclimation capacity in Antarctic marine ectotherms could be due to the extended time it takes for them to adjust their physiology to a new stable state. Acclimation was tested through acute measurements of upper lethal limit and a modified measure of tenacity, that tested muscle capacity by measuring the length of time that N. concinna were able to remain attached to the substratum at different temperatures. Both measures acclimated in response to incubation to the higher temperature. Lethal limits were elevated in N. concinna incubated at 2.9 degrees C (8.1 +/- 0.3 degrees C) compared to those incubated at -0.3 degrees C (6.9 +/- 0.4 degrees C). 2.9 degrees C incubated N. concinna also had a maximum tenacity at 2.1 degrees C. a higher temperature than the maximum tenacity of those incubated at -0.3 degrees C, which occurred at -1.0 degrees C. This study is the first to show that the Antarctic limpet can acclimate its physiology, but that it requires a greater period of time for acclimation to occur than previous studies have allowed for.

It is well-known that network intrinsic distortions or introduction of impurities, into this last, modifies the nature of the traps energy present in material, affecting in an important way material toughness. In this work, we were interested to the effect of both structural defects effect introduced by a lowering in temperature and doping on the alumina toughness, measured by Vickers indentation. The obtained results reveal the importance of these defects which behave, in this case, like trapping electric sites and modify, in a more or less strong way, material toughness. We show that the dopants are generally unfavorable to toughness. However, we underlined an interesting case of increase in the tenacity of the single crystal alumina doped with chromium.

The effect of twist and solvent densification on the internal structure of carbon nanotube yarns was revealed using focused ion beam milling and related to yarn strength through tensile testing. Denser carbon nanotube yarns with smaller diameters were produced either through solvent densification or with increasing twist densities from 5 to ∼15 turns/mm, but led to only minor improvement in yarn tenacity. At twist densities greater than ∼15 turns/mm, a core-sheath structure developed and was correlated with a decline in strength. The implications of bonding between the nanotubes in the twisted yarn are briefly considered. These results have implications for the future development of high strength carbon nanotube yarn.

A poly[(butylene succinate)-co-adipate] (PBSA) nanocomposite containing 3 wt% organically modified montmorillonite exhibited an improvement in tenacity (elongation at break) as compared to the neat PBSA. The nanocomposite also showed moderate improvement in tensile modulus and strength. The small-angle X-ray scattering and transmission electron microscopy were used to investigate the exact tenacity improvement mechanism in the nanocomposite.

The effects of pretreatment and mechanical modification on characteristics of jute fibre were evaluated in this paper. The experimental results show that pretreatments and mechanical modifications both have obvious effects on the characteristics of jute fibre. The blended agent used for pretreatment can form a thin film on the surface of jute fibre to make it smoother, so the fibre can be refined by further mechanical modification. Regarding the four process routes used for mechanical modification discussed in this study, the process of draft-cutting and speedily carding can produce jute fibre with finer diameter, lower average length, higher percentage of short fibre, and lower tenacity. The jute fibre pretreated with blended agent and mechanically modified by Process I has linear density of 16.1 dtex, average length of 35.2 mm, and tenacity of 3.4 cN/dtex, indicating that it is available for high value textile end uses.