Non-linear mechanical behaviour and bio-composite modelling of oil palm mesocarp fibres

Understanding the non-linear mechanical behaviour of oil palm mesocarp fibres (OPMF) is important for bio-composite application. The mechanical characterisation of this fibre is challenging due to the microstructure of the fibres consisting of silica bodies on the surface and cellular structures within the cross section. In this work, we proposed a constitutive material model for OPMF by including a stress-softening function into the large strain viscoelastic model. The model shows agreement with loading–unloading and stress relaxation tensile tests. The model was then used for micro-scale finite element modelling of the fibre–silica body–matrix (resin) interface to simulate sliding of a bio-composite material. A multi-particles model was also developed to check the effect of the constitutive model towards the mechanics of a bio-composite system. Modelling results suggested that under the micro-scale level (~50 μm), silica body plays a major role in improving the mechanical behaviour of the bio-composite system. On the other hand, under the macro-scale level (~0.18 mm), a single fibre model is sufficient to simulate a bio-composite multi-fibres material

Synthesis and Characterization of Bio-Composite

Eco-friendly biodegradable bio-composites were prepared using sisal fiber and starch using handmade mould. XRD patterns confirm that degree of crystallinity decrease with the increase in reinforcing material.SEM image says roughness surface structure of composites. FTIR study confirms that the composites are dewaxed and H2O content is decreased. DSC scan confirms that the glass transition temperature of bio-composites is decreased with the increasing in concentration of reinforcing material

PENGARUH BENTONIT KOMERSIAL DAN SERAT DAUN NANAS PADA SIFAT MEKANIK DAN KECEPATAN PEMBAKARAN DARI KOMPOSIT LIMBAH POLIPROPILENA

ABSTRAK Geokomposit (GeCo) dan geobiokomposit (GeBiCo) telah disintesis secara reaktif dengan inisiator benzoil peroksida (BPO) dan pelarut ksilena. Limbah polipropilena (LPP) dipergunakan sebagai matriks polimer. Bentonit komersial (commercial Bentonite, comBen) sebagai penghambat bakar, sedangkan seng borat (Zinc Borate, ZB) dipergunakan sebagai aditif penghambat bakar. Serat daun nanas (Pineapple Leaf Fiber, PaF) dipergunakan sebagai penguat. Asam akrilat yang telah dicangkokkan pada LPP (LPP-g-AA) dipergunakan sebagai senyawa penggandeng multifungsional, sedangkan divinil benzena (DVB) dipergunakan sebagai senyawa penyambung silang. Spektrofotometer FTIR dan XRD dipergunakan untuk karakterisasi terjadinya interaksi antara bahan-bahan penyusun komposit. Hasil uji sifat mekanik energi serap (Absorption Energy, AE) dan ketangguhan impak (Impact Toughness, IT) menunjukkan bahwa geokomposit dan geobiokomposit mempunyai sifat yang lebih baik dari pada LPP. Geokomposit dan geobiokomposit juga mempunyai sifat ketahanan bakar lebih baik dari pada LPP hal ini ditunjukkan dari hasil uji waktu pembentukan nyala (Time To Ignition, TTI) dan kecepatan bakar (Burning Rate, BR). Hasil uji kalor pembakaran mendukung hasil uji ketahanan bakar yakni geokomposit dan geobiokomposit mempunyai kalor pembakaran lebih kecil dari pada LPP. Kata Kunci: bentonit, geobiokomposit, geokomposit, ketahanan bakar, polipropilena, serat daun nanas ABTRACT Geo-composite (GeCo) and geo-bio-composite (GeBiCo) have been reactively synthesized by initiator benzoyl peroxide (BPO) using solvent xylene. Recycled polypropylene (rPP) was used as the matrix polymer. Commercial bentonite (comBen) was used as a fire retardant, while zinc borate (ZB) was used as an additive. Pineapple leaf fiber (PaF) was used as a reinforcement. Acrylic acid was grafted on rPP (rPP-g-AA) used as multifunctional coupling compound, whereas divinyl benzene (DVB) was used as a crosslinker compound. XRD and FTIR spectrophotometer were used to characterize the interaction between constituent composite materials. Results of testing the mechanical properties of energy absorption (EA) and impact toughness (IT) showed that geo-composite and geo-bio-composite have better mechanical properties than the LPP. Geo-composite and geo-bio-composite also have better fire resistance properties than LPP as indicated from results of the time to ignition (TTI) and burning rate (BR). Results of heat of combustion supported of testing the fire resistance, geo-composite and geo-bio-composite have heat of combustion less than the LPP. Keywords: bentonite, fire resistence, geocomposite, geobiocomposite, pineapple fiber, polypropylen

Investigation of Mechanical properties on Vinylester based bio composite with Gelatin as randomly distributed filler material)

In the present work an attempt has been made to develop Bio-composite Material using raw dupion silk fiber reinforced vinylester matrix in addition with gelatin as filler material with varying percentage using hand lay-up method. The experiments namely tensile, flexural and hardness test were conducted on the standard samples prepared. An appreciable improvement was found in the mechanical properties of the Bio-composite, which can be used for variety of applications in the human bone replacement. The biocomposites were prepared in varying percentage of filler addition (0%, 10%, 20%, and 30%) and different mechanical tests (tensile, flexure and ardness) were conducted on the samples prepared as per ASTM standards. According to literature survey the human femur bone with tensile strength for female is 30.08±7.96MPa. In this work it was found that tensile strength of 30% gelatin filled with Dupion silk fiber reinforced vinylester bio-composite material is 26.86 MPa

Properties of bio-composite products from acacia strand and coconut veneer / Siti Nadrah M. Omar

Properties of bio-composite product from Acacia strand and coconut veneer were ascertained. The effects of strand size and layer arrangement were determined. Different strand sizes (10 mm, 15 mm and 20 mm) were used to create different combinations of layer arrangement; strand-veneer-strand (SVS) and veneer-strand-veneer (VSV). Comply is a bio-composite product, was assessed for the mechanical properties (bending and internal bonding) and physical properties (thickness swelling and water absorption) in accordance with the European Standard. The value of MOR and MOE were found to be not significant when comparing SVS (10 mm and 15 mm) with 100% strand. Meanwhile, it was found that SVS (10 mm) and 100% strand had the highest value of IB and TS respectively. Both layer arrangements were then being compared with plywood made by coconut veneer. The result showed that plywood had the highest value of MOR (51.54 MPa) and IB (0.66 MPa), VSV had the highest value of MOE (8037.79 MPa), and plywood had the best value of TS (12.19%)

The multi-functional foot in athletic movement: Extraordinary feats by our extraordinary feet

The unique architecture of the foot system provides a sensitive, multi-tensional method of communicating with the surrounding environment. Within the premise of the paper, we discuss three themes: complexity, degeneracy and bio-tensegrity. Complex structures within the foot allow the human movement system to negotiate strategies for dynamic movement during athletic endeavours. We discuss such complex structures with particular attention to properties of a bio-tensegrity system. Degeneracy within the foot structure offers a distinctive solution to the problems posed by differing terrains and uneven surfaces allowing lower extremity structures to overcome perturbation as and when it occurs. This extraordinary structure offers a significant contribution to bipedalism through presenting a robust base of support and as such, should be given more consideration when designing athletic development programmes

Synthesis and characterization of bio-composite material

An eco-friendly biodegradable bio-composite were prepared using sisal fiber and cassava starch by using handmade mould.Bio-composites are finding applications in many fields ranging from construction industry to automotive industry,so we have synthesized and characterized such composites.Surface morphology,glass transition temperatures were investigated by SEM and TGA/DTA study respectively.XRD patterns confirm crystallite size and degree of crystallinity is found to be maximum for S1.5 composite as compared to other two composites and that may be due to properly wetting the fiber by matrix.SEM image shows roughness surface structure of composites.TGA/DTA analysis shows with increases in starch concentration in the composite glass transition temperature increases.So higher the percentage of starch in composite increases the free volume and molecular mobility, which results in increasing of Tg

Uniqueness of human running coordination: The integration of modern and ancient evolutionary innovations

Running is a pervasive activity across human cultures and a cornerstone of contemporary health, fitness and sporting activities. Yet for the overwhelming predominance of human existence running was an essential prerequisite for survival. A means to hunt, and a means to escape when hunted. In a very real sense humans have evolved to run. Yet curiously, perhaps due to running’s cultural ubiquity and the natural ease with which we learn to run, we rarely consider the uniqueness of human bipedal running within the animal kingdom. Our unique upright, single stance, bouncing running gait imposes a unique set of coordinative difficulties. Challenges demanding we precariously balance our fragile brains in the very position where they are most vulnerable to falling injury while simultaneously retaining stability, steering direction of travel, and powering the upcoming stride: all within the abbreviated time-frames afforded by short, violent ground contacts separated by long flight times. These running coordination challenges are solved through the tightly-integrated blending of primitive evolutionary legacies, conserved from reptilian and vertebrate lineages, and comparatively modern, more exclusively human, innovations. The integrated unification of these top-down and bottom-up control processes bestows humans with an agile control system, enabling us to readily modulate speeds, change direction, negotiate varied terrains and to instantaneously adapt to changing surface conditions. The seamless integration of these evolutionary processes is facilitated by pervasive, neural and biological, activity-dependent adaptive plasticity. Over time, and with progressive exposure, this adaptive plasticity shapes neural and biological structures to best cope with regularly imposed movement challenges. This pervasive plasticity enables the gradual construction of a robust system of distributed coordinated control, comprised of processes that are so deeply collectively entwined that describing their functionality in isolation obscures their true irrevocably entangled nature. Although other species rely on a similar set of coordinated processes to run, the bouncing bipedal nature of human running presents a specific set of coordination challenges, solved using a customized blend of evolved solutions. A deeper appreciation of the foundations of the running coordination phenomenon promotes conceptual clarity, potentially informing future advances in running training and running-injury rehabilitation interventions