"Fuel beds of ponderosa pine needles and white pine needles were burned under controlled environmental conditions to determine the effects of fuel moisture and windspeed upon the rate of fire spread. Empirical formulas are presented to show the effect of these parameters. A discussion of rate of spread and some simple experiments show how fuel may be preheated before the fire reaches the fuel. The interrelationship between unit energy release rate and rate of spread produces a fire characteristics curve. Diffusion flame analysis shows good agreement when working with 1/2-inch stick fires."

ENGLISH: The anchoveta is the major constituent of the important bait and reduction fisheries of the Gulf of Panama. It is a short-lived species, the great majority of the catch consisting of fish in their first year of life. Fish for reduction are caught chiefly in the Isla Verde area, between Punta Chame and the entrance of the Panama Canal. In 1960 and 1961 anchovetas were tagged with metal internal tags and released in the major areas of occurrence of this species. The tags were recovered from the meal in the reduction plants with magnets. From the 53,380 fish tagged in 1960, 745 tags were returned during the 1960 season, 246 during the 1961 season, and 8 during the 1962 season. From the 113,202 tagged in 1961, 373 tags were returned during the 1961 season and 48 during the 1962 season. Complete catch statistics are available, and length-frequency and length-weight data were used to convert these from pounds to numbers of fish of each year class. The annual survival rate for the fish of the 1959 year class in the Isla Verde area was estimated to be 0.086 by the Chapman-Robson method, 0.102 by the year-class method, and 0.088 by the Jackson positive method. The first method is considered to give the best estimate. Six estimates of the population of fish of the 1959 year class in the Isla Verde area were obtained from the sample tag ratios of six experiments conducted in that area in 1960. The estimates differed due to the temporal decrease in the population, but the downward trend corresponded fairly well to what was expected from the total annual mortality rate. It was estimated that the population of 1959-year class fish was about 818 million on March 8, 1960, and about 70 million on March 8, 1961. As the population of anchovetas decreases during the season the effort increases sufficiently that the catch remains roughly constant. This is described as the "constant absolute catch" type fishery. Of the original population of fish in the Isla Verde area at the beginning of the 1960 season, about 11 per cent were caught and 81 per cent died of natural causes. Evaluation of growth and mortality data demonstrated that beginning the fishery for the youngest age group later than March 8 (the date it began in 1960) would reduce the yield per recruit, while increasing the fishing effort would greatly increase it. Further, it is believed unlikely that increases in the catch in the Isla Verde area alone would noticeably decrease the number of recruits to that area. Therefore there is no foreseeable need for regulation of the fishery. SPANISH: El principal constituyente de la importante pesquería para carnada y para reducción en el Golfo de Panamá es la anchoveta. Es una especie de vida corta cuya pesca, en su mayor parte, está constituida por peces que se encuentran en su primer año de vida. Para la industria de reducción los peces son capturados principalmente en el área de Isla Verde, entre Punta Chame y la entrada del Canal de Panamá. En 1960 y 1961 las anchovetas fueron marcadas con marcas metálicas internas y liberadas en las áreas más importantes en que se encuentra esta especie. Las marcas fueron recobradas de la harina en las plantas de reducción por medio de magnetos. De los 53,380 peces marcados en 1960, fueron devueltas 745 marcas durante la temporada pesquera de 1960, 246 durante la de 1961, y 8 durante la de 1962. De los 113,202 marcados en 1961, 373 marcas fueron devueltas durante la temporada pesquera de 1961 y 48 durante la de 1962. Se dispone de estadísticas completas de captura, y los datos de frecuencia-longitud y de longitud-peso fueron usados para convertir éstos de libras a números de peces de cada clase anual. La tasa anual de supervivencia correspondiente a la clase anual de 1959 en el área de Isla Verde estimó en 0.086 por medio del método Chapman-Robson; en 0.102 por método de la clase anual; y en 0.088 por el método positivo de Jackson. Se considera que el primer método dé la mejor estimación. Seis estimaciones de la población de peces de la clase anual 1959 en el área de Isla Verde fueron obtenidas según la proporción de marcas halladas en las muestras correspondientes a seis experimentos efectuados en aquella área en 1960. Las estimaciones variaron debido a la disminución temporal de la población, pero esta tendencia descendente correspondió bastante bien a lo que se esperaba según la tasa total de mortalidad anual. Se estimó que la población de peces de la clase anual de 1959 era de unos 818 millones el 8 de marzo de 1960, y aproximadamente de unos 70 millones el 8 de marzo de 1961. Conforme a que la población de anchovetas disminuye durante la temporada pesquera, el esfuerzo aumenta lo suficientemente como para que la pesca se mantenga más o menos constante. Este es el tipo de pesquería descrito como de "captura absoluta constante". De lapoblación original de peces en el área de Isla Verde al comienzo de la temporada pesquera de 1960, cerca del 11 por ciento fue capturada y el 81 por ciento murió por causas naturales. La evaluación de los datos del crecimiento mortalidad demostraron que al comenzar la pesquería a explotar grupo de edad más joven en una fecha posterior al 8 de marzo (la fecha en que comenzó en 1960) se reduciría el rendimiento por recluta, mientras que al aumentar el esfuerzo de pesca lo aumentaría considerablemente. Más aún, se cree improbable que el aumento en la pesca en el área de Isla Verde de por sí disminuyera perceptiblemente el número de reclutas en esa área. En consecuencia no se prevé la necesidad de una reglamentación de la pesquería.(PDF contains 172 pages.) | This article is bilingual and contains both Spanish and English translations.

Modes of deformation involved in shearing of plain weave fabrics are analyzed in terms of the mechanical properties of yarn and the geometrical parameters of the fabric. The effective contact lengths at the intersecting points in the fabric are determined from , the initial modulus of shearing. The hysteresis produced during shearing is determined by the proposed mechanisms of deformation and is found to correlate well with experiments.

Relative amylose starch content of kernels was determined for three ear zones of inbred, F₁ and F₂ generations of high-amylose corn. Each ear was divided into three relatively equal zones, and the amylose content was determined for each. A significant linear decrease in amylose content was found progressing from the base to the tip of an ear. These results indicate that kernel sampling procedures should be standardized where precision is desired in investigations involving high-amylose starch synthesis. In addition, kernels from each of the three ear zones were degermed and the endosperm tissue was divided into tip, middle, and crown portions. The middle endosperm portion was consistently highest in amylose content within each ear zone.

The kineties of the reactions of cotton print cloth treated with 0.55 M solutions of 4.5-dihydroxy-1,3-bis(hydroxymethyl)-2-imidazolidinone (dimethyloldihydroxyethylene urea) in the presence of 0.03 M inorganic salt catalysts have been investigated. The present two-stage delayed-cure process for chemically modifying the performance of cellulosic fabrics depends on the significant differences in reactivities of cellu lose with methylol functional groups and with the hydroxyl groups of the urea derivatives. Specific reaction rate constants at 45, 55, 65, 75, and 85°C in the presence of ZnCl₂, Zn(NO₃)₂, MgCl ₂, and Mg(NO₃)₂ have been calculated by following the changes in nitrogen and formaldehyde contents and the changes in crease recovery properties of finished fabrics. These rates have been compared with those determined when cotton retets with an etherifying agent having ring hydroxyls only, as in the cellulose-dihydroxy ethyleneurea reactions, and with those determined when the etherifying agent has methylol hydroxyls only, as in the cellulose-dimethylolethyleneurea reactions. Enthalpies, entropies, and free energies of activation have been compared.

THE SUPPLY OF OXYGEN in the soil is one important factor restricting the parasitism of root rotting fungi on citrus. The relationships of oxygen (in two types of soil) to several citrus root parasites as well as germination and growth of three of the fungi in pure culture were determined in recent experimentation.

The fiber orientation and fiber breakage were studied in a felt, needled in a laboratory needling machine, and the relationship between degree of needle penetration and felt thickness, density, strength, and air permeability was determined.

It is postulated that the Australian angiosperm flora ins derived from a sample of a one—time world flora of about 180 families that entered Australia by a land bridge from Asia. Many of the genera that entered still persist. New genera evolved in all habitats, many from lineages which were adapted to soils of low fertility determined primarily by phosphate level. Soil parent materials with the highest phosphate content are derived mainly from the Tertiary basalts in the east and support rainforests (except in cold regions). Soil phosphate levels decrease from east to west across the continent. The number of rainforest genera in any community is usually correlated with soil P. The converse holds for xeromorphic genera. Some rainforest genera therefore are more readily adapted to aridity than to low fertility conditions. Expansion and contraction of the rainforest is determined partly by climate and partly by soil fertility levels. A sudden expansion of the rainforest in the Oligocene occurred when the basalt flows covered part of eastern Australia. Since that time the rainforests have contracted, partly as a result of the removal of basaltic material and partly because of the development of colder climates in the ranges. The absence of rainforest and the paucity of rainforest genera in southwest Western Australia are accounted for by low fertility levels rather than by a decimation of rainforest genera by a past dry climate. Xermorphy, a result of high lignification, heavy cutinization, silicification, or a combination of these may occur in rainforest species. Adaptation to low fertility accentuates xeromorphic characters through a reduction in leaf size. The low fertility xeromorphs are not xerophytes. Anatomical features have little significance in their survival, which is determined by the ability of the plants to withstand long periods of mineral starvation. Experimental work indicates that the degree of xeromorphy can be reduced in many taxa by the addition of phosphorus and nitrate; four different types of leaf response have been identified.

The distribution of fatty acids among the positions 1, 2, and 3 of triglycerides of seven vegetable fats has been determined. The fatty acid compositions in positions 1 and 3 are very similar in most cases, but in none of the fats is the distribution completely symmetrical.

Several commercial nonwoven fabrics have been stretched to varying extents, allowed to relax, and selected physical properties determined. In all cases, stretching beyond a threshold value of apprpximately 3 percent caused a decrease in initial modulus, shear modulus, bending length, and drape coefficient. The rupture stress showed a slight tendency to decrease,, while the breaking strain and the elastic recovery were sensibly unaffected. The relative change in initial modulus was found to be determined only by the amount of stretch applied, irrespective of the fabric construction. Shear modulus was approximately proportional to the initial modulus obtained from the stress-strain curve, which accords with the law of elastic distortion, although the derived value of Poisson's ratio was much higher than the measured value. It appears that bending length is the important factor in determining drape coefficient, since a unique relationship exists between these two parameters but not between shear modulus and drape coefficient. The improvement in drape obtained with the more extensible fabrics is significant but, for the majority of textile purposes, probably insufficient.