Bark Fiber Research Articles

Simplified Scale Modeling Of Turbulent Flame Spread With Implication To Wildland Fires

Scale-model experiments were performed to measure rates of horizontal and up-slope flame spread for models of stem fires (fires of the tree crowns and the fibrous bark on the tree boles) and grass fires and radiant heat flux to the environments. This work was motivated by previous studies of stationary fires in which two different types of scaling laws were proposed, both of which were applicable for turbulent flame spread. Data obtained include radiant heat fluxes, flame heights and depths, and pyrolysis front locations. Comparisons of the measurements with the scaling laws aid understanding of scaling effects on turbulent flame spread; scaling laws for the flame spread in the wildland are suggested.

Otomi bark paper in Mexico: Commercialization of a pre-hispanic technology

The Otomi village of San Pablito in northern Puebla has preserved the tradition of making bark paper for over 400 yr, and today is the only papermaking center in all of Mexico. In the past 20 yr, bark paper has become highly commercialized and severalaspects of the Otomi papermaking process have changed. Unprecedented production levels have caused the total depletion of traditional sources of raw material. In response to this situation, the Otomi have been forced to change the types of bark that are utilized, the logistics of bark collection, and the treatment of the bark fiber prior to use. The majority of the paper currently produced in San Pablito is made from the bark ofTrema micrantha imported from the state of Veracruz. A plantation of this species is being established near San Pablito to reduce the Otomi dependence on outside sources of raw material.

牛, とくに肥育牛における木材樹皮給与上の衛生的諸問題

Fattening cattle were fed more than 1 kg of bark of needle-leaved trees, as a substitute for ricestraw, for a long time. As a result, many clumps and balls of bark fibers were formed with villi as nuclei in the rumen. They often induced pyloric obstruction, tympanites, and anorexia. In cattle fed raw bark of needle-leaved trees, chronic eosinophilic abomasitis and enteritis prevailed and there were a decrease in the number of protozoa (especially, large ones) harbored and the synthesis in the rumen and a fall in the rate of milk fat.When bark feeding was suspended, clumps of bark fibers disappeared, but balls did not and villi remained in injured condition. The bark and the balls of bark fibers were particularly rich in ADF and ADF lignin. No marked changes were found in the color, odor, or quality of meat produced from the cattle involved.

A Synopsis of the Old World Species of Trichospermum Blume (Tiliaceae)

Summary The genus Trichospermum Blume as accepted here includes not only the groups formerly separated as Belotia and Halconia, but also Althoffia K. Schum. It is predominantly a Malesian genus, distributed from the Malay Peninsula to the Solomon Islands, the Santa Cruz Islands, Fiji and Samoa, the number of species being greatest in New Guinea and adjacent islands; there are at least three species in tropical America. The thick fibrous bark is much used for making rope and cord. The Old World species of Trichospermum, sensu lato, number thirty-six, of which sixteen (T. arachnoideum, buruensis, fauroensis, fletcheri, fosbergii, gracile, graciliflorum, grewioides, helotrichum, incaniopsis, ovatum, rhamnifolius, smithii, stellato-pilosum, subdehiscens and talaudensis) are described here for the first time; Althoffia ledermannii is renamed T. burretii; the species T. kajewskii is reduced to synonymy of T. psilocladum. Two new combinations are proposed: T. pleiostigma (F.v.M.) and T. tripyxis (K. Schum.). Burret's sub-division of Trichospermum is neither accepted nor replaced as the species show a reticulate relationship. The key and the main specific differences are based on the trichomes of the lower surface of the leaf.

Fiber Surface Modification. Pt. II Modification of Ligniferous Wood and Bark Fibers Using a Dichloro-s-triazine

Article Fiber Surface Modification. Pt. II Modification of Ligniferous Wood and Bark Fibers Using a Dichloro-s-triazine was published on January 1, 1969 in the journal Holzforschung (volume 23, issue 6).

The role of bark type in relative tolerance to fire of three central Victorian Eucalypts

A laboratory approach to the study of fire resistance in trees is described and the method applied to three central Victorian eucalypts which possess different types of bark. For each species, bark thickness increases with the girth of the trunk or older branches. The fibrous bark of E. obliqua is thicker than the subfibrous bark of E. radiata, and this in turn is thicker than the decorticating bark of E. cypellocarpa for the same girth of trunk or branch. The rate of heat penetration to the cambium, however, is greatest in E. obliqua and least in E. cypellocarpa. This apparent anomaly is due to the greater inflammability of the fibrous bark. It is suggested that the fire tolerance of a species should be evaluated against fuel accumulation and the fire intensity of the site, as well as the extent of damage to various parts of the tree and the ability of these parts to recover.

The anatomy of bark. III. Enlarged fibres in the bloodwoods (Eucalyptus spp.)

Immensely enlarged fibres which are characteristic of certain bloodwoods separate them clearly from other species wlth which they are usually associated in the systematic classification of the genus Eucalyptus. Separation nf the two types of bloodwood herein described agrees closely with a regrouping recently suggested on morphological characteristics. Other eucalypts with large bark fibres are described briefly and their relationships considered.

Growth, Rubber Storage, and Seed Production by Guayule as Affected by Boron Supply

1. Plants of guayule were grown from early seedling stage in gravel culture for a period of 16 months, during which time they were supplied with nutrient solutions containing 0.0-10.0 p.p.m. of boron. In other experiments, somewhat older seedlings were transplanted from the field and grown in sand or gravel cultures to determine the effects of deficient or excessive amounts of boron (0.0-40.0 p.p.m.) when these were supplied by means of nutrient solutions. 2. The plants showed marked boron-deficiency symptoms when supplied with a boron-free nutrient, but they subsequently grew vigorously and produced seeds when supplied with a nutrient solution containing 4 p.p.m. 3. According to results based on vegetative growth in gravel cultures, guayule has a tolerance range of from 0.1 to 2.0 p.p.m. of nutrient solution, a range somewhat wider than that reported for most crop plants of a mesophytic type. 4. Data on percentage of rubber in gravel-culture plants show an optimum boron requirement of 0.1-2.0 p.p.m., a concentration range similar to that required for maximum vegetative growth and seed production. The concentration of rubber in the stems and roots of boron-deficient plants was lower than that of similar parts of plants grown with an adequate supply. 5. Since boron deficiency was associated with both reduced vegetative growth and lower percentage of rubber, the total rubber output of boron-deficient plants was relatively small. An excessive amount of boron (10 p.p.m. in the nutrient) was also associated with a decrease in rubber output. Over the range studied, the amount of boron supplied to the plants had only a very slight effect on the concentration of resins in their stems and roots. 6. The stem diameters of gravel-culture plants showed that cambial activity was somewhat reduced in the plants receiving nutrient containing 10.0 p.p.m. of boron, and also in the stems of plants that received a deficient amount. The proportions of pith, xylem, bark, and bark fiber in the basal region of the stem were not altered as the result of supplying the plants with nutrient containing various levels of boron (0.01-10.0 p.p.m.). In stems of plants grown with a limited supply (0.004 p.p.m.) the area of bark was greater, in proportion to the amount of wood produced, than in comparable segments of stem from plants grown with an adequate boron supply. 7. Boron-deficient plants produced fewer seeds than did plants supplied with an adequate amount. Seeds produced by boron-deficient plants were smaller and their germination was lower than those from plants grown with an adequate supply. With respect to size, number, and percentage germination, the quality of seeds produced by plants supplied with nutrient containing an excessive amount of boron (10 p.p.m.) was equal to that produced by plants grown with a moderate supply (0.1 p.p.m.). Boron accumulated in the seeds (and also leaves) of the plants grown with an adequate boron supply.