scholarly journals Development of an Elastic, Electrically Conductive Coating for TPU Filaments

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7158
Author(s):  
Henriette Grellmann ◽  
Mathis Bruns ◽  
Felix Michael Lohse ◽  
Iris Kruppke ◽  
Andreas Nocke ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Mechanical Strain ◽  
Special Focus ◽  
Electrically Conductive ◽  
Mechanical And Electrical Properties ◽  
Elastic Filaments ◽  
Wide Range ◽  
Conductive Fibers ◽  
Multifilament Yarns ◽  
Conductive Particles

Electrically conductive filaments are used in a wide variety of applications, for example, in smart textiles and soft robotics. Filaments that conduct electricity are required for the transmission of energy and information, but up until now, most electrically conductive fibers, filaments and wires offer low mechanical elongation. Therefore, they are not well suited for the implementation into elastomeric composites and textiles that are worn close to the human body and have to follow a wide range of movements. In order to overcome this issue, the presented study aims at the development of electrically conductive and elastic filaments based on a coating process suited for multifilament yarns made of thermoplastic polyurethane (TPU). The coating solution contains TPU, carbon nanotubes (CNT) and N-Methyl-2-pyrrolidone (NMP) with varied concentrations of solids and electrically conductive particles. After applying the coating to TPU multifilament yarns, the mechanical and electrical properties are analyzed. A special focus is given to the electromechanical behavior of the coated yarns under mechanical strain loading. It is determined that the electrical conductivity is maintained even at elongations of up to 100%.

scholarly journals Melt Spinning of Highly Stretchable, Electrically Conductive Filament Yarns

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 590
Author(s):  
Henriette Probst ◽  
Konrad Katzer ◽  
Andreas Nocke ◽  
Rico Hickmann ◽  
Martina Zimmermann ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Fiber Composite ◽  
Thermoplastic Polyurethane ◽  
Smart Textiles ◽  
Electrically Conductive ◽  
Textile Technology ◽  
Highly Stretchable ◽  
Elastomer Composites ◽  
Conductive Fibers ◽  
Fine Copper

Electrically conductive fibers are required for various applications in modern textile technology, e.g., the manufacturing of smart textiles and fiber composite systems with textile-based sensor and actuator systems. According to the state of the art, fine copper wires, carbon rovings, or metallized filament yarns, which offer very good electrical conductivity but low mechanical elongation capabilities, are primarily used for this purpose. However, for applications requiring highly flexible textile structures, as, for example, in the case of wearable smart textiles and fiber elastomer composites, the development of electrically conductive, elastic yarns is of great importance. Therefore, highly stretchable thermoplastic polyurethane (TPU) was compounded with electrically conductive carbon nanotubes (CNTs) and subsequently melt spun. The melt spinning technology had to be modified for the processing of highly viscous TPU–CNT compounds with fill levels of up to 6 wt.% CNT. The optimal configuration was achieved at a CNT content of 5 wt.%, providing an electrical resistance of 110 Ωcm and an elongation at break of 400%.

Occupational hazard in Malaysian traffic police: special focus on air pollutants

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Putri Anis Syahira Mohamad Jamil ◽  
Karmegam Karuppiah ◽  
Irniza Rasdi ◽  
Vivien How ◽  
Shamsul Bahri Mohd Tamrin ◽  
...  
Keyword(s):  
Occupational Injuries ◽  
Indicator System ◽  
Control Measures ◽  
Special Focus ◽  
Safety Measures ◽  
Traffic Police ◽  
Wide Range ◽  
And Control ◽  
Risk Occupation ◽  
High Risk Occupation

Abstract This paper provides a specific deliberation on occupational hazards confronted daily by Malaysian Traffic Police. Traffic police is a high-risk occupation that involves a wide range of tasks and, indirectly, faced with an equally wide variety of hazards at work namely, physical, biological, psychosocial, chemical, and ergonomic hazards. Thereupon, occupational injuries, diseases, and even death are common in the field. The objective of this paper is to collate and explain the major hazards of working as Malaysian traffic police especially in Point Duty Unit, their health effects, and control measures. There are many ways in which these hazards can be minimised by ensuring that sufficient safety measures are taken such as a wireless outdoor individual exposure indicator system for the traffic police. By having this system, air monitoring among traffic police may potentially be easier and accurate. Other methods of mitigating these unfortunate events are incorporated and addressed in this paper according to the duty and needs of traffic police.

scholarly journals Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline O’Keeffe ◽  
Laura Rhian Pickard ◽  
Juan Cao ◽  
Giuliano Allegri ◽  
Ivana K. Partridge ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Fibre ◽  
Electromagnetic Interference ◽  
Design Tool ◽  
Electrically Conductive ◽  
Current Collection ◽  
Wide Range ◽  
Predictive Design ◽  
The Right ◽  
Metal Wires

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.

scholarly journals Diet and general cognitive ability in the UK Biobank dataset

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piril Hepsomali ◽  
John A. Groeger
Keyword(s):  
Cognitive Ability ◽  
Dietary Patterns ◽  
Red Meat ◽  
Milk Intake ◽  
Special Focus ◽  
General Cognitive Ability ◽  
Food Groups ◽  
Uk Biobank ◽  
Wide Range ◽  
The Uk

AbstractAccumulating evidence suggests that dietary interventions might have potential to be used as a strategy to protect against age-related cognitive decline and neurodegeneration, as there are associations between some nutrients, food groups, dietary patterns, and some domains of cognition. In this study, we aimed to conduct the largest investigation of diet and cognition to date, through systematically examining the UK Biobank (UKB) data to find out whether dietary quality and food groups play a role on general cognitive ability. This cross-sectional population-based study involved 48,749 participants. UKB data on food frequency questionnaire and cognitive function were used. Also, healthy diet, partial fibre intake, and milk intake scores were calculated. Adjusted models included age, sex, and BMI. We observed associations between better general cognitive ability and higher intakes of fish, and unprocessed red meat; and moderate intakes of fibre, and milk. Surprisingly, we found that diet quality, vegetable intake, high and low fibre and milk intake were inversely associated with general cognitive ability. Our results suggest that fish and unprocessed red meat and/or nutrients that are found in fish and unprocessed red meat might be beneficial for general cognitive ability. However, results should be interpreted in caution as the same food groups may affect other domains of cognition or mental health differently. These discrepancies in the current state of evidence invites further research to examine domain-specific effects of dietary patterns/food groups on a wide range of cognitive and affective outcomes with a special focus on potential covariates that may have an impact on diet and cognition relationship.

scholarly journals Two-Side Laser Processing Method for Producing High Aspect Ratio Microholes

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
Vahid Nasrollahi ◽  
Pavel Penchev ◽  
Stefan Dimov ◽  
Lars Korner ◽  
Richard Leach ◽  
...  
Keyword(s):  
Cross Sections ◽  
Laser Processing ◽  
Industrial Applications ◽  
Laser Drilling ◽  
Special Focus ◽  
Geometrical Accuracy ◽  
Aspect Ratios ◽  
Wide Range ◽  
High Flexibility ◽  
Accuracy And Repeatability

Laser microprocessing is a very attractive option for a growing number of industrial applications due to its intrinsic characteristics, such as high flexibility and process control and also capabilities for noncontact processing of a wide range of materials. However, there are some constrains that limit the applications of this technology, i.e., taper angles on sidewalls, edge quality, geometrical accuracy, and achievable aspect ratios of produced structures. To address these process limitations, a new method for two-side laser processing is proposed in this research. The method is described with a special focus on key enabling technologies for achieving high accuracy and repeatability in two-side laser drilling. The pilot implementation of the proposed processing configuration and technologies is discussed together with an in situ, on-machine inspection procedure to verify the achievable positional and geometrical accuracy. It is demonstrated that alignment accuracy better than 10 μm is achievable using this pilot two-side laser processing platform. In addition, the morphology of holes with circular and square cross sections produced with one-side laser drilling and the proposed method was compared in regard to achievable aspect ratios and holes' dimensional and geometrical accuracy and thus to make conclusions about its capabilities.

Investigation of Structure-Property Relationships in Thermoplastic Polyurethane/Multiwalled Carbon Nanotube Composites

2017 ◽  
Author(s):  
Felicia Stan ◽  
Catalin Fetecau ◽  
Nicoleta V. Stanciu ◽  
Razvan T. Rosculet ◽  
Laurentiu I. Sandu
Keyword(s):  
Electrical Properties ◽  
Shear Viscosity ◽  
Thermoplastic Polyurethane ◽  
Structure Property ◽  
Multiwalled Carbon ◽  
Structure Property Relationships ◽  
Mechanical And Electrical Properties ◽  
High Shear Rates ◽  
Nanotube Composites ◽  
Multi Walled Carbon Nanotubes

In this study, the structure-property relationships in thermoplastic polyurethane (TPU) filled with multi-walled carbon nanotubes (MWCNTs) were investigated. Firstly, the contribution of MWCNTs to the melt shear viscosity and the pressure-volume-temperature (pVT) behavior was investigated. Secondly, injection-molded samples and 2 mm diameter filaments of TPU/MWCNT composites were fabricated and their mechanical and electrical properties analyzed. It was found that the melt processability of TPU/MWCNT composites is not affected by the addition of a small amount (1–5 wt.%) of MWCNTs, all composites displaying shear-thinning at high shear rates. The mechanical and electrical properties of the TPU/MWCNT composites were substantially enhanced with the addition of MWCNTs. However, the conductivity values of composites processed by injection molding were two and three orders of magnitude lower than those of composites processed by extrusion, highlighting the role of melt shear viscosity on the dispersion and agglomeration of nanotubes.

scholarly journals Insights into Clinical, Genetic, and Pathological Aspects of Hereditary Spastic Paraplegias: A Comprehensive Overview

2021 ◽  
Vol 8 ◽  
Author(s):  
Liena E. O. Elsayed ◽  
Isra Zuhair Eltazi ◽  
Ammar E. Ahmed ◽  
Giovanni Stevanin
Keyword(s):  
Clinical Symptoms ◽  
Disease Onset ◽  
Lower Limbs ◽  
Special Focus ◽  
Clinical Genetic ◽  
Comprehensive Overview ◽  
Functional Studies ◽  
Hereditary Spastic Paraplegias ◽  
Wide Range ◽  
Complex Forms

Hereditary spastic paraplegias (HSP) are a heterogeneous group of motor neurodegenerative disorders that have the core clinical presentation of pyramidal syndrome which starts typically in the lower limbs. They can present as pure or complex forms with all classical modes of monogenic inheritance reported. To date, there are more than 100 loci/88 spastic paraplegia genes (SPG) involved in the pathogenesis of HSP. New patterns of inheritance are being increasingly identified in this era of huge advances in genetic and functional studies. A wide range of clinical symptoms and signs are now reported to complicate HSP with increasing overall complexity of the clinical presentations considered as HSP. This is especially true with the emergence of multiple HSP phenotypes that are situated in the borderline zone with other neurogenetic disorders. The genetic diagnostic approaches and the utilized techniques leave a diagnostic gap of 25% in the best studies. In this review, we summarize the known types of HSP with special focus on those in which spasticity is the principal clinical phenotype (“SPGn” designation). We discuss their modes of inheritance, clinical phenotypes, underlying genetics, and molecular pathways, providing some observations about therapeutic opportunities gained from animal models and functional studies. This review may pave the way for more analytic approaches that take into consideration the overall picture of HSP. It will shed light on subtle associations that can explain the occurrence of the disease and allow a better understanding of its observed variations. This should help in the identification of future biomarkers, predictors of disease onset and progression, and treatments for both better functional outcomes and quality of life.

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