Grass Fiber Research Articles

Use of a by-product of peat excavation, cotton grass fibre, as a sorbent for oil-spills

The sorbents used to collect oil in case of oil-spills are mostly synthetic, which limits the possibilities of their disposal. We studied the absorption capacities and rates of cotton grass fibre, a by-product of peat excavation, and cotton grass mats for several oil types and compared them with a synthetic, commercially available oil sorbent. We found cotton grass fibre to have superior absorption properties: Cotton grass sorbent absorbed oil approximately two to three times as much, and two to three times as fast as the synthetic one. Cotton grass fibre absorbed no measurable amount of water in the conditions used in the tests making it ideal for absorbing oil from the surface of water. In removing diesel oil from the surface of water, the efficiency was over 99% up to an absorbing factor of 20 times its own weight. The biodegradable cotton grass fibre proved to be an effective oil sorbent with low raw-material costs.

Effects of alkali treatment on the structure, morphology and thermal properties of native grass fibers as reinforcements for polymer matrix composites

Effects of alkali treatment on the structure, morphology and thermal properties of native grass fibers as reinforcements for polymer matrix composites

AMS 14C Dating Using Black Pottery and Fiber Pottery

A technique of accelerator mass spectrometry (AMS) has made it possible to directly measure radiocarbon ages of pottery by isolating organic materials sealed in the pottery when the pottery was formed. We analyzed the carbon contents and 14C ages for “black pottery” from the Philippines and “fiber pottery” from Japan using the relevant carbonaceous materials extracted from the pottery samples, i.e., adhered chaff or grass fibers that were incorporated in the pottery matrix, respectively. The carbon yield of the pottery sample varied largely depending on the pottery types, the preservation conditions, as well as the chemical pretreatment methods to purify carbonaceous materials for 14C dating. We will discuss criteria for sample selection of well-preserved pottery, and a modified method, instead of the standard alkali treatment, to obtain sufficient material for precise 14C dating.

Estimation of Mechanical Properties by Vibration Characteristics of Short-Fiber Composite Material

The purpose of this work is to develop the procedure and mathematic model to estimate mechanical properties of short grass fiber filled PA6. First, vibration tests were carried out to study vibration characteristics of composite material. Then various micro-mechanics models for short fiber composites are evaluated using vibration and tensile test varying in-plane tensile angle. Along the evaluation, a combination of micro-mechanics model is proposed to get appropriate results. Also, procedure to identify young's modulus of matrix and dumping factor of composite by comparison of vibration test results and FEM considering in-plane distributions of fiber orientation is demonstrated. Through evaluation, the FEM analysis using mechanical properties of composite material determined by proposed procedures considering fiber orientation and distribution of fiber orientation angle gives good estimation

Molar progression and tooth wear in tammar (Macropus eugenii) and parma (Macropus parma) wallabies

We investigated the functional significance of molar progression and the influence of diet on the usefulness of molar progression as an index of age in two macropodid marsupials, the tammar wallaby (Macropus eugenii), a grazing species, and the parma wallaby (Macropus parma), a browser/grazer, by exploring the relationships between the index of molar progression and several skull and tooth parameters. We also tested allometric models that related molar progression and aspects of tooth morphology to body mass. Results support the notion that molar progression in these closely related macropods results from 'mesial shift'(forward movement resulting from growth of the bones of the skull bearing the dentary, the anterior viscerocranium) rather than from 'mesial drift' (forward movement of molars relative to the anterior viscerocranium).There were no significant differences between the two species in the rate of molar progression despite differences in diet. Instead, the greater reliance of tammar wallabies on grasses was reflected in differences in their tooth morphology from that of parma wallabies. The sum of the breadths of erupted molariform teeth of tammars increased significantly faster with body mass and with length of the anterior viscerocranium than in parma wallabies and approximated a theoretical model for compensation with metabolic body mass more closely than models based on other morphological parameters.The total mesiodistal length of dentition, the mesiodistal lengths of the component teeth of the proximal molar row, and the distance between the mesial and distal lophs were all significantly lower in tammar wallabies than in parma wallabies. These differences result in tammar wallabies having greater numbers of transverse cutting edges per unit of molar tooth length, which maximises the efficiency of comminution of long grass fibres.

リサイクル性を考慮したプラスチックアロイ材料の強度特性に関する研究

Nowadays, more than 13 million-ton plastics are produced in Japan that are used in various industrial fields. There are three main well-known methods for plastic recycling. The purpose of each method includes material recycling, chemical recycling or thermal recycling (energy recovery) of plastics waste. However, new processes are continuously being developed for recycling of plastics waste. Especially, material recycling is considered a simple process, whereas, re-pellet process for wasted plastics is too difficult and unable to reproduce plastics that have the strength and the durability characteristics similar to virgin plastic materials.Recently, plastic alloy process, especially those that employ a mixture of liquid crystal polymer as dispersant phase for fibril phenomena, has been focused on as a new plastic producing technology in order to have better characteristics such as strength, durability and ability to be recycled.In this study, the strength and recyclable characteristics of plastic alloy materials are investigated using polycarbonate and polypropylene as the matrix plastics, as well as three kinds of liquid crystal polymer as fibril dispersant.The experimental results of measurement of tensile strength, charpy impact and recycle times of various plastic alloys are summarized as follows,(1) The plastic alloy that is used with polycarbonate as matrix plastic and novaccurate as a liquid crystal polymer has a higher tensile strength compared to other alloy materials. This is due to the fact that a fibril phenomenon was observed in this plastic alloy.(2) In case of a mixture of polycarbonate and novaccurate, the recycled plastic alloy processed by single-shaft extruding machine exhibited a higher strength and recyclables property than the one processed by double-shaft extruding machine.(3) Strength characteristics of plastic alloy materials by polycarbonate and novaccurate decreased with recycling times, as the reagent of the solubility phase was mixed with alloys.(4) If the injection-molding machine is directly employed for the plastic alloy without extruding machine, a higher strength of plastic alloy could be expected similar to the one of grass fiber plastic (FRP).

1310 FBG センサと SMA 繊維を用いた組物 GFRP の損傷検知および制御

Damage detection and control of braided grass fiber reinforced plastics (GFRP) were conducted by using embedded Fiber Bragg Grating (FBG) fiber optic sensors and Shape Memory Alloy (SMA) wire actuators during tensile and fatigue tests. The sensors and actuators were embedded warpwise in braided composites. Reflected optical spectrum from FBG sensors were used for evaluation of damages during by calculating the maximum correlation coefficient with the initial spectrum. The experimental results showed that the sensors could detect damage initiation and actuators could suppress development of the damages.

Neumonitis por hipersensibilidad en los yeseros de la construcción (espartosis): estudio de 20 casos

Background and objectiveEspartosis is a type of hypersensitivity pneumonitis which frequently affects construction workers handling esparto fibres used as support material inside gypsum plaster. Exactly which agents produce this disease remains under discussion. The aims of this study were: a) to assess the possible etiologic role of the fungi colonizing esparto grass fibres and esparto itself in the genesis of this disease, and b) to describe the clinical characteristics of this disease in a large series of patients. Patients and methodTwenty patients diagnosed of hypersensitivity pneumonitis due to esparto grass exposure were studied. Mycologic cultures of the esparto grass fibre samples provided by each patient were performed. Fungi and/or esparto were used for determination of specific IgG antibodies, specific skin tests and specific bronchial challenge tests. ResultsMost frequently isolated fungi in causal esparto samples were Aspergillus sp. (60%) and Mucor sp. (47%). Specific IgG antibody determinations and/or specific bronchial challenge tests showed antigenicity not only for Aspergillus sp. but also for non-fungi-contaminated esparto grass and other fungi such as Penicillium sp. or Mucor sp. These results were helpful for establishing a new etiologic approach to the diagnosis of this disease. ConclusionsAspergillus fumigatus is recognized as a causal agent in hypersensitivity pneumonitis due to esparto grass exposure; however, other antigenic sources such as Penicillium frequentans and other fungi, as well as esparto grass fibres, also appear to play a role in the genesis of this disease.

Tropical fibre sources for pigs—digestibility, digesta retention and estimation of fibre digestibility in vitro

The digestibility of high-fibre diets and digesta passage was measured in growing pigs and attempts were made to predict the in vivo digestibility from in vitro data. In Experiment 1, six diets were formulated to measure digestibility using low-fibre cassava starch, fish meal and soya bean meal in combination with six locally available fibre sources. Four green plants: banana sheaths ( Musa paradisiaca), duckweed ( Lemna minor), sweet potato vines ( Ipomoea batatas) and water spinach ( Ipomoea aquatica) were used for the BS, DW, SPV and WS diets, respectively. In addition two by-products, copra meal (CM) and tofu residues (TR), were used for the CM and TR diets, respectively. Digesta retention of solids was measured using chromium mordanted Para grass ( Brachiaria mutica) fibre and Co–EDTA was used for the retention of liquid. In Experiment 2, the digestibility of diets based on the fibre sources: brewer’s grains (BG), copra meal, cassava residues (CR), whole ground rice (WGR), coarse rice bran (RB) and tofu residues was measured in growing crossbred Baxuyen pigs. These fibre sources replaced 30% of a basal diet consisting of mainly maize, rice bran, soya bean meal and fish meal. The diets from Experiments 1 and 2 were also used to measure in vitro neutral detergent fibre (NDF) degradation, using faecal inocula taken from pigs fed on the same diets. In Experiment 1, the coefficient of total tract apparent digestibility (CTTAD) organic matter (OM), crude protein (CP), and neutral detergent fibre values of all, except for the BS diet, were similar and ranged from 0.82 to 0.84, 0.65 to 0.76 and 0.69 to 0.72, respectively. CTTAD for OM, CP and NDF of the BS diet were, however, significantly lower and 0.72, 0.60 and 0.32, respectively. Solids and liquid mean retention times (MRT) for the BS diet were 22.2 and 22.6 h and for the other diets, MRT ranges were 32.9–38.9 and 29.5–36.9 h, respectively, and were similar for the two markers ( P=0.31). In Experiment 2, CTTAD for OM of the WGR and RB diets were 0.73–0.77 and for NDF 0.57–0.64. These data were lower than those for the other diets ( P=0.01), which were similar and were 0.82–0.90 and 0.70–0.79, respectively. Crude protein CTTAD for the BAS diet (0.87) was significantly higher than that of the TR (0.73) and WGR (0.75) diets ( P<0.01). There was a high correlation between the NDF digestibility in vitro at 36 h and in vivo in Experiment 1 ( r 2=0.92, R.S.D.=0.035). The results indicate that the green plants and high-fibre by-products had relatively high CTTAD of OM, CP and NDF and could be reasonable feed resources for pigs, even though intake will restrict the levels of inclusion from 200 to 350 g kg −1 of the diet. However, lignin and silica limited the utilisation of coarse rice bran, and a short retention time and the high-fibre and tannin contents reduced the digestibility of the banana sheaths. In vitro NDF degradation seemed to be a reliable predictor of in vivo NDF digestibility.

A Study on Poly Butylene Terephthalate Gears Filled with Glass Fibers.

We tested poly butylene telephthalate (PBT) as a gear material in our previous study and found that it had larger fatigue strength and lower coefficient of friction than those of polyacetal used as a gear material currently. In the present study, since plastic gears that can transmit high power have been strongly demanded by the industrial world, we reinforced PBT by compounding grass fibers for higher power transmission than normal PBT and conducted operation tests on gears made of reinforced PBT. Wear behavior was particularly investigated under a relatively larger torque since plastic gears filled with grass fibers were expected to be worn significantly due to a fall of grass fibers from the mother material. Availability of PBT filled with grass fibers for a gear material was discussed by comparing basic operational characteristics with those of normal PBT gears.

Butyrivibriospp. and Other Xylanolytic Microorganisms From the Rumen have Cinnamoyl Esterase Activity

High concentrations of hydroxycinnamic acids in the hemicellulosic fraction of dry season tropical grasses may influence the rate of microbial degradation of arabinoxylans by ruminant animals. The ability of 22 strains ofButyrivibrio fibrisolvens, other ruminal bacteria (Ruminococcus albusSY3,Ruminococcus flavefaciensRF1,Prevotella ruminicolaAR20) and the ruminal phycomyceteNeocallimastix patriciarumCX to digest the tropical grassHeteropogon contortus(spear grass) and hydrolyse esterified ferulic and p-coumaric acid was examined. Significant digestion (8–36%) of spear grass occurred with theB. fibrisolvensstrains H17c, A38, LP92-1-1, 49,R. albusSY3 andN. patriciarum. Hydrolysis of ester-linked ferulic and p-coumaric acid occurred with all organisms exceptB. fibrisolvensstrains GS113, OB156 and LP1028 andP. ruminicolaAR20. The ratio of ferulic to p-coumaric acid hydrolysed by different strains ofButyrivibriospp. varied markedly from 0.96 for AR 51 to 0.16 for A38. Butyrivibrios which were fibrolytic (H17c and A38) had higher extracellular cinnamoyl esterase activity than bacteria that did not digest spear grass fibre (LP 91-4-1 and AR 20) which had low activities or only produced cell associated enzyme. Cell associated and extracellular esterase activity were induced whenButyrivibriospp. strains H17c, A38 and E14 and theRuminococcusspp. were grown on birchwood xylan but induction did not occur to the same extent withN. patriciarum. This is the first reported observation of cinnamoyl esterase activity in the genusRuminococcus. The fungusN. patriciarumhad significantly higher digestibility of spear grass and solubilisation of phenolic acids than the bacteria. The study shows that high levels of extracellular cinnamoyl esterases are characteristic of a selection of fibre-degrading ruminal bacteria and fungi which probably indicates that these enzymes are common amongst xylanolytic ruminal microorganisms.

Plant Limitations to Fiber Digestion and Utilization

Energy availability from forages is limited by fiber concentration because fiber is slowly and incompletely digested, whereas cell solubles are almost completely digested. Thus, the proportion of fiber to cell solubles is a major determinant of energy availability in forages. Grasses normally have more fiber than legumes, especially in leaves. Grass fiber is more digestible than that of legumes, but that of legumes digests at a faster rate. Ruminants digest 40–50% of legume fiber and 60–70% of grass fiber. Some fiber cannot be digested no matter how long it remains in the rumen. Lignin is thought to interfere with microbial degradation of fiber polysaccharides by acting as a physical barrier and by being cross-linked to polysaccharides by ferulate bridges. In addition to the effects of lignin, physical and structural barriers may limit fiber digestibility. Because the middle lamella and primary wall of thick-walled cells are so highly lignified, many cells can be digested only from the interior of the cell. For many cells, access to cell interiors is limited because of large particle sizes. Forage digestibility could be improved by reducing the amount of lignified cells or by developing improved cultivars so that lignified cells are more digestible.

Forage quality and patch choice by wapiti (Cervus elaphus)

Recent models suggest that herbivores might optimize energy gain by selecting patches of intermediate vegetation biomass. We tested this hypothesis in wapiti (Cervus elaphus) by estimating daily rates of energy gain in relation to grass biomass and by measuring patch choice in experimental pastures in which grass biomass was manipulated by mowing. The digestible energy content of grasses declined with increasing biomass due to maturational changes in fiber and lignin content. Daily rates of dry matter intake by wapiti increased with grass biomass at a decelerating rate, implying a Type II functional response. Linking these values to published ad libitum energy intake and energy expenditure parameters, Fryxell's (1991) model predicted that the daily rate of energy gain should be highest when wapiti feed in grasslands with 1000–1100 kg/ha. In trials in which grass biomass within a mosaic of patches was manipulated experimentally between 800–2900 kg/ha, wapiti preferred patches of 1200 kg/ha, close to the value predicted by the energy gain model. Our results suggest that the rate of energy gain by wapiti is constrained by both grass biomass and grass fiber content, the latter of which varies inversely with grass biomass. Behavioral preference for grass patches of intermediate biomass and fiber content could help explain patterns of aggregation and seasonal migration reported previously for wapiti.

Potential use, mechanical and thermal studies of sabai grass fibre

Low-cost panels, corrugated sheets, etc., require cheap fibres such as agroforest-based materials which could be used for making composites. Sabai grass, a main construction material for thatches, walls, roofs and ropes, is inexpensive and is grown in large quantities in Raigarh, Ambikapur, Hoshangabad, Narsinghpur and Jagdalpur in Madhya Pradesh, India [1, 2]. It is used where high strength is not required [3-10]. It can also be used as a filler material in plastics and in mud matrix [10] after suitable pretreatment to the surface. The chemical composition is listed in Table I (based on dry weight). Standard methods [7] were used for the above analysis reported in TAPPI (Technical Association Pulp and Paper Industry, USA). The chemical constituents such as cellulose, lignin and ash are different in different sabai grass samples. Understanding the structure, mechanical and thermal behaviour of this grass fibre will open up new avenues for the utilization of this grass fibre. Therefore, it is necessary to know its structure, mechanical and thermal behaviour. In this study the structure, cell length in the fibre and cell wall thickness were measured. The strength and thermal degradation were determined. Sabai grass was obtained from Madhya Pradesh, India. Fibre was obtained by beating leaves with a hammer and was separated by pulling apart. The structure of this fibre was determined by observing silver-coated longitudinal sections (LS) and fractured cross-sections by scanning electron microscopy (SEM; Jeo135 CF). Samples for tensile testing were prepared by cutting a window of 5 cm in cardboard and fixing the fibre across it. An average of 20 ultimate tensile stress (UTS) values were taken as determined on a 1185 model Instron. Samples for thermal studies were prepared by chopping the fibres to a length of 1-2 mm. Thermogravimetric (TG) and differential thermogravimetric (DTG) runs were carried out on a Stanton model 730/750 thermal analyser in the temperature range 0-520 °C at a heating rate of 20 °Cmin -t in static air. Differential scanning calorimetry (DSC) runs were carried out on a Perkin-Elmer DSC-2C using aluminium pans in the temperature range 50-500 °C at a heating rate of 20 °Cmin -1. An inert atmosphere was maintained by flowing dry argon gas. The sample weight for all runs was about 5 rag. Fig. 1 shows sabai grass which is used for making rope and paper. Fig. 2 shows a longitudinal section having a large number of cells. The cell size varies from 3 to 20/zm. The cell width is 1.6-3.2/zm and the length 30-50/zm. Fig. 3 shows the stress-strain curve of sabai grass fibre tested at a crosshead speed of 0.005 mmin -1 . The UTS of sabai grass is 76 MPa. Fig. 4 shows cells fractured at a speed of testing of 0.005 m rain -a . Plant fibres of different age, source and place have different chemical compositions and hence different properties. Factors that mainly contribute to the tensile strength of a plant fibre are the cellulosic content and the microfibril angle of the fibre with cells arranged regularly bonded to each other by lignin. This type of structure can be assumed to be parallel to the fringed fibril structure, while crystalline regions (long imperfect crystals about 100 molecules in cross-section) are embedded in non-crystalline regions.

コーテッド平織物の観察と１軸伸張実験

Coated plain-weave fabrics are used as a membrane material of membrane structures including architectural membrane structures such as clear span air-supported membrane structure, flexible containers and airships. Uni/biaxial extension properties of coated fabrics are vary important for the design of membrane structures. In the present paper, the authors first presented SEM photographs of the surface and cut section to understand the structure of this material. Then unidirectional tensile tests were done up to failure. The stress-strain curves showed nonlineality and anisotropy. Some discussion was done on these properties. Poisson's ratio showed extreme nonlinearity at the stress region up to 20% of the failure stress which is the design stress. Specimens used here were a PTFE-coated grass fiber fabric and a PVC-coated polyester fabric which are widely used in the field of architectural membrane structure.

Effects of Grass Contaminated Cotton on Yarn Manufacturing

ABSTRACT COTTONS contaminated with grass and control cottons were processed into yarn. These cottons were carded with and without the use of crush rolls. The grass was not pulverized by the crush rolls as other foreign matter often is. The grass tends to fibrillate and behave as coarse fibers. These **grass fiber appears to interfere with the drafting process and the ring travelers during yarn formation resulting in increased end breaks. They are also thought to obstruct the intimate association between fibers in the yarn thus lowering the strength of contaminated yarns.

Degradation of Bermuda and Orchard Grass by Species of Ruminal Bacteria

Fiber degradation in Bermuda grass and orchard grass was evaluated gravimetrically and by scanning and transmission electron microscopy after incubation with pure cultures of rumen bacteria. Lachnospira multiparus D-32 was unable to degrade plant cell wall components. Butyrivibrio fibrisolvens 49 degraded 6 and 14.9% of the fiber components in Bermuda grass and orchard grass, respectively, and Ruminococcus albus 7 degraded 11.4% orchard grass fiber but none in Bermuda grass. Both B. fibrisolvens and R. albus lacked capsules, did not adhere to fiber, and degraded only portions of the more easily available plant cell walls. R. flavefaciens FD-1 was the most active fiber digester, degrading 8.2 and 55.3% of Bermuda and orchard grass fiber, respectively. The microbe had a distinct capsule and adhered to fiber, especially that which is slowly degraded, but was able to cause erosion and disorganization of the more easily digested cell walls, apparently by extracellular enzymes. Results indicated that more digestible cell walls could be partially degraded by enzymes disassociated from cellulolytic and noncellulolytic bacteria, and data were consistent with the hypothesis that the more slowly degraded plant walls required attachment. Microbial species as well as the cell wall architecture influenced the physical association with and digestion of plant fiber.

Natural vegetable fibres as reinforcement in cement sheets

Synopsis Some relevant physical and mechanical properties of the fibres from water reed, elephant grass, plantain and musamba are discussed. The effect of elephant grass fibres upon the strength of reinforced cement sheets and the consistence of the mortar is shown to be beneficial.

A low-cost roofing material for developing countries

A comparison is made between cement roofing sheets reinforced with asbestos fibres, elephant grass and sugar cane residue on the basis of some physical and mechanical properties and derived costs. The grass fibre sheets are shown to be the most attractive choice.

Studies on rumen metabolism. VII. Effect of lipids (in vitro) on the digestion of grass fibre and cellulose.

AbstractProduction of propionate from grass fibre, by rumen micro‐organisms, in closed systems increased and acetate decreased over 48–72 h incubation periods when lipid was added. Similar effects of lipid on [14C] propionate and [14] Cacetate production were obtained when [14C] cellulose was added to the substrate as a marker. Total volatile fatty acid (VFA) or total [14C] VFA production from grass fibre was not affected significantly by lipid. Cod liver oil was more effective than either linseed oil or peanut oil in producing these effects. Glycerol liberated from lipid by lipolytic activity would seem to favour acetate formation, rather than propionate formation.When grass fibre was fermented in an artificial micro‐rumen for 24 h, addition of oil stimulated the production of total VFA's largely due to significant increases in acetate. Relative rates of formation of the individual short chain fatty acids did not change over a 24 h period. On the other hand, less total [14C] VFA was produced from [14C] cellulose in the dialysate of the artificial micro‐rumen when oil was added. The specific activities of the individual VFA's were higher without oil but maximum specific activities were obtained slightly earlier when oil was added.