Assessment of Shear Fracture Energy in Hybrid Composites with Natural and Synthetic Fibers.

Composite materials made with synthetic fibers are extensively employed across a diverse array of engineering structures. However, from an environmental point of view, synthetic fibers do not represent the best choice, since they are not renewable and are not biodegradable as natural fibers. This study investigates the application of adhesive joints with hybrid composites, which combine natural and synthetic fibers, as potential replacements for traditional composites made solely from synthetic fibers.

Mechanical and Thermal Characterization of Bamboo and Interlaminar Hybrid Bamboo/Synthetic Fibre-Reinforced Epoxy Composites.

The main objective of this study was to investigate the mechanical and thermal properties of bamboo, as well as interlaminar hybrid composites reinforced with both bamboo and synthetic fibres in an epoxy matrix. Bamboo and glass, aramid, and carbon bidirectional fabrics were used with a bi-component epoxy matrix to fabricate the composite materials using the vacuum bagging process. The synthetic fabrics were placed on the outer layers, while the bamboo fabrics were used as the core of the hybrid composites.

Natural Fibre Composites and Their Mechanical Behaviour.

At present, natural-fibre-reinforced-composites (NFRCs) are seen as realistic alternatives to synthetic- (e [...

Development and Mechanical Characterization of Short Curauá Fiber-Reinforced PLA Composites Made via Fused Deposition Modeling.

The increase in the use of additive manufacturing (AM) has led to the need for filaments with specific and functional properties in face of requirements of structural parts production. The use of eco-friendly reinforcements (i.e.

A Review on the Thermal Characterisation of Natural and Hybrid Fiber Composites.

The thermal stability of natural fiber composites is a relevant aspect to be considered since the processing temperature plays a critical role in the manufacturing process of composites. At higher temperatures, the natural fiber components (cellulose, hemicellulose, and lignin) start to degrade and their major properties (mechanical and thermal) change. Different methods are used in the literature to determine the thermal properties of natural fiber composites as well as to help to understand and determine their suitability for a certain applications (e.

A Review of Structural Adhesive Joints in Hybrid Joining Processes.

Hybrid joining (HJ) is the combination of two or more joining techniques to produce joints with enhanced properties in comparison to those obtained from their parent techniques. Their adoption is widespread (metal to metal joint, composite to composite and composite to metal) and is present in a vast range of applications including all industrial sectors, from automotive to aerospace, including naval, construction, mechanical and utilities. The objective of this literature review is to summarize the existing research on hybrid joining processes incorporating structural adhesives highlighting their field of application and to present the recent development in this field.

Mechanical and Thermal Characterization of Natural Intralaminar Hybrid Composites Based on Sisal.

The main objective of this work was to investigate the effect of hybridization on the mechanical and thermal properties of intralaminar natural fiber-reinforced hybrid composites based on sisal. Ramie, sisal and curauá fibers were selected as natural fiber reinforcements for the epoxy matrix based composites, which were produced by the hand lay-up technique. Tensile, flexural and impact tests were carried out according to American society for testing and materials (ASTM) standards to characterize the hybrid composites, while differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to evaluate the thermal properties.

Effect of Babassu Natural Filler on PBAT/PHB Biodegradable Blends: An Investigation of Thermal, Mechanical, and Morphological Behavior.

Blending of biodegradable polymers in combination with low-price organic fillers has proven to be a suitable approach to produce cost-effective composites in order to address pollution issues and develop products with superior mechanical properties. In the present research work PBAT/PHB/Babassu composites with 25, 50, and 75% of each polymer and 20% of Babassu were produced by melting extrusion. Their thermal, mechanical, and morphological behavior was investigated by differential scanning calorimetry (DSC), tensile testing, and scanning electron microscopy (SEM).

Cassava food toxins, konzo disease, and neurodegeneration in sub-Sahara Africans.

Endemoepidemic neurodegenerative diseases putatively caused by food toxins have been reported around the globe with no clear understanding of their pathogenetic mechanisms. These diseases include the amyotrophic lateral sclerosis/parkinsonism dementia complex among the Guamanians; neurolathyrism among Europeans, Indians, and populations of the Horn of Africa; and tropical ataxic neuropathy or konzo among sub-Sahara Africans. We focus on the molecular determinants of susceptibility to konzo, a poorly known self-limited and irreversible upper motor neuron disease (spastic paraparesis) highly prevalent in Congo-Kinshasa, Mozambique, Tanzania, Central African Republic, Angola, and Cameroon.

Evaluation of growth monitoring programme in children in Kinshasa.

A high dropout rate was noted at the under five clinic of the University of Kinshasa Teaching Hospital. A preliminary study carried out in March 1984 on 197 children indicated that none of them had completed the five year period of the growth monitoring programme. Five hundred mothers of children attending the under five year clinic were then randomly selected from the 1224 who registered between September 1983 and August 1984.

Dietary determinants of a non-progressive spastic paraparesis (Konzo): a case-referent study in a high incidence area of Zaire.

Background: Konzo is an upper motor neuron disease in Africa, characterized by an abrupt onset of a permanent but non-progressive spastic paraparesis. It is named after the local designation in the first report from Zaire. Konzo has been attributed to a metabolic insult from the combined effect of high cyanide and low sulphur intake from several weeks of exclusive consumption of insufficiently processed bitter cassava roots.

[High prevalence of konzo associated with a food shortage crisis in the Bandundu region of zaire].

Konzo is a form of spastic paraparesis reported from several rural areas in Sub-Saharan Africa. It has been attributed to cyanide exposure from exclusive consumption of insufficiently processed bitter cassava roots. We have tested this attribution in a community based epidemiological survey in an area of Bandundu region in Zaire composed of two agro-ecological zones: savanna and forest.

Cassava cyanogens and konzo, an upper motoneuron disease found in Africa.

Konzo is a distinct form of tropical myelopathy characterised by abrupt onset of spastic paraparesis. Epidemics in East Africa have been attributed to dietary cyanide exposure from insufficiently processed cassava but a study done in Zaire disputed such an aetiology. We investigated a konzo-affected population in rural Zaire and measured the cyanogen content of cassava flour, determined urinary thiocyanate as an indicator of cyanide intake, and compared blood cyanide concentrations in cases and controls.

Epidemiological evidence from Zaire for a dietary etiology of konzo, an upper motor neuron disease.

A clear association between seasonal outbreaks of a paralytic disease called konzo and toxic effects from consumption of insufficiently processed bitter cassava roots has been demonstrated in Bandundu region, Zaire. A community-based survey of 6764 inhabitants identified 110 live and 24 dead konzo-affected persons with a history of isolated non-progressive spastic paraparesis of abrupt onset. The start of these annual outbreaks of konzo in 1974 coincided with the completion of a new tarmac road to the capital, which facilitated the transport of cassava and made it the main cash crop.