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Showing papers by "Colorado State University published in 1969"


Journal ArticleDOI
TL;DR: In this article, the concept of "aging" is discussed in terms of the entity's survival time distribution, and a set of seven criteria for aging is established, based on these quantities, and the chain of implications among the criteria is developed.
Abstract: The concept of “aging,” or progressive shortening of an entity's residual lifetime, is discussed in terms of the entity's survival time distribution. Quantities defined to describe the aging phenomenon include the “specific aging factor,” “hazard rate,” “hazard rate average,” and “mean residual lifetime.” A set of seven criteria for aging is established, based on these quantities, and a chain of implications among the criteria is developed. The hazard rate average and mean residual lifetime are noted as being particularly useful for empirical studies. An application of these two quantities is illustrated for a set of empirical survival time data.

341 citations


Journal ArticleDOI
TL;DR: In this article, the authors considered local scour caused by the horseshoe vortex system which forms at the base of the piers and proposed design criteria for blunt-nosed piers under the conditions of clear-water scour and scour with continuous sediment motion.
Abstract: Local scour caused by the horseshoe vortex system which forms at the base of the piers is considered. Piers which induce a pressure field strong enough to cause the formulation of the horseshoe vortex system are termed blunt nosed; all others being classed as sharp-nosed piers. The condition of the sediment transported into and out of the scour hole forms the basis for the further classification of the scour process into clear-water scour and scour with continuous sediment motion. The pier Reynolds number is shown to be an important variable describing the strength of the horseshoe vortex system. Further, the equilibrium scour depth depends on the initial sediment transport condition for a steady uniform flow with fully developed bed material transport. Design criteria are proposed for blunt-nosed piers under the conditions of clear-water scour and scour with continuous sediment motion. Several deviations from the above ideal design conditions are discussed; methods for design in these cases are suggested.

291 citations


Journal ArticleDOI
TL;DR: An extensive dust devil census taken near Tucson, Ariz., has provided, from two independent areas, quantitative information on the relation of environmental conditions to the spatial distribution, frequency and duration of a particular type of dry atmospheric thermal as mentioned in this paper.
Abstract: An extensive dust devil census taken near Tucson, Ariz., has provided, from two independent areas, quantitative information on the relation of environmental conditions to the spatial distribution, frequency and duration of a particular type of dry atmospheric thermal. The observations indicate that for these two areas, each approximately 100 mi2 in area, dust devils are initially sighted most frequently in the vicinity of dry river beds which lie in the lee of small hills. Once initiated, the visible lifetime of the observed dust devils ranged from a few seconds to approximately 20 rain. These data show that dust devil duration increases with dust devil size. The results indicate that the energy for the dust devil is the warm boundary layer air which is continually being fed into the visible vortex as it moves along with essentially the same speed and direction as the environmental wind. The highest dust devil frequency occurs with the lowest atmospheric stability and not necessarily with the hig...

202 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical development of the Navier-Stokes equation through analysis of the dimensionless form of Navier Stokes equation is presented, which shows that energy losses at high-flow velocities in porous medium are a result of convective acceleration effects not turbulent effects.
Abstract: Many investigators are concerned about the validity of the Forchheimer equation which represents the relationship between the velocity of flow and pressure gradient in porous media. A theoretical development of this equation through analysis of the dimensionless form of the Navier-Stokes equation is presented. It shows that energy losses at high-flow velocities in porous medium are a result of convective acceleration effects not turbulent effects. In addition, two dimensionless terms representing the flow behavior are defined and evaluated. It is shown that a constant could be used to represent the geometric properties of the medium and that a characteristic length representative of the flow exist. Both of these quantities are easily evaluated through hydraulic measurements of gradients and flow velocities. Experimental data from many sources were used to evaluate the theoretical results.

157 citations


Journal ArticleDOI
TL;DR: The Suinn Test Anxiety Behavior Scale (STABS) was devised and data gathered to provide an anxiety scale with the aforementioned characteristics, particularly desirable for research studies reporting on improvements in clients by different treatment innovations where a control group is lacking.

125 citations


Journal ArticleDOI
TL;DR: Planarian neoblasts were studied during the course of regeneration by electron microscopy and showed polysomal aggregations of ribosomes, prominent supernumerary nucleoli, endoplasmic reticulum forming at the nuclear membrane, and a curious kind of dense lump in close proximity to thenuclear membrane on the cytoplasmic side.

110 citations


Journal ArticleDOI
TL;DR: In this article, a generalized computer model for fish population simulation and maximum yield determination is described, which utilizes age-specific natural mortality rates, growth rates, relative fecundities, and any desired stock-recruitment relationship.
Abstract: A generalized computer model for fish population simulation and maximum yield determination is described. The model utilizes age-specific natural mortality rates, growth rates, relative fecundities, and any desired stock-recruitment relationship. Best harvest strategies are found by treating long-term yield as a response surface on the set of age- and year-specific fishing rates. The model is illustrated using data on arctic cod, stream brook trout, and on a hypothetical population with strong age-class dominance. Best predicted management strategies include periodic harvest when age at entry to the fishery cannot be controlled, but maximum yield is usually obtained with constant fishing rate.

82 citations


Journal ArticleDOI
TL;DR: Chinese hamster cells were synchronized by selecting mitotic cells from an asynchronous population, either with or without a 2-h pretreatment with Colcemid, which increased the total aberration frequency by a factor of 2–3 due to an increase in the frequency of deletions and the appearance of chromatid type exchanges.

72 citations


Journal ArticleDOI
TL;DR: In this article, hot-film anemometry was used to measure the characteristics of turbulence in hydrodynamically smooth and hydroynamically rough open-channel flow and showed that the relative turbulent intensity of the vertical velocity component was about 60% of the longitudinal, and spectral energy distribution was not significantly affected by the type of flow.
Abstract: Measurements of the characteristics of turbulence in hydrodynamically smooth and hydrodynamically rough open-channel flow using hot-film anemometry technics showed: (a) that the relative turbulent intensity of the vertical velocity component was about 60% of the longitudinal, (b) that the spectral energy distribution was not significantly affected by the type of flow, (c) that most of the turbulent energy is contained in frequencies less than 5 hertz, (d) the macroscale of the turbulence as determined from the autocorrelation function was on the same order as the depth and (e) the ratio of the microscale to depth ranged from 0.1 to 0.2. The measurements were used to verify experimentally the longitudinal direction momentum terms in the Navier-Stokes equation and to determine qualitatively the magnitude of the production, diffusion, and dissipation terms in the energy equation.

70 citations


Journal ArticleDOI
02 May 1969-Science
TL;DR: Experiments are presented which show a system of population feedback control in planarians in the presence of other planarians, where the brain exerts an influence (probably neurohormonal) to suppress fissioning.
Abstract: Reduced population densities lead to increased rates of fissioning in planarians whereas higher population densities suppress fissioning. This effect is not primarily due to mucus deposition or substances secreted into the water. Experiments are presented which show a system of population feedback control. In the presence of other planarians, the brain exerts an influence (probably neurohormonal) to suppress fissioning. This influence becomes attenuated with axial distance from the brain.

65 citations


Journal ArticleDOI
TL;DR: In this paper, the authors studied nonlinear longitudinal instabilities with shock waves in combustion chambers of liquid rocket motors with concentrated combustion, and showed that these instabilities can be caused by a nonlinear linear longitudinal instability.
Abstract: Liquid rocket motors with concentrated combustion, studying nonlinear longitudinal instabilities with shock waves in combustion chambers

Journal ArticleDOI
TL;DR: In this paper, the similarity between the stably stratified atmospheric boundary layer and a wind tunnelboundary layer developing over a cold plate is illustrated, showing that mean flow and turbulence characteristics in the near wall region of the stratified boundary layer are well described by Monin and Obukhov similarity theory.
Abstract: The similarity which exists between the stably stratified atmospheric boundary layer and a wind tunnelboundary layer developing over a cold plate is illustrated. It is shown that mean flow and turbulence characteristics in the near wall region of the stratified boundary layer are well described by Monin and Obukhovssimilarity theory, and that this theory provides a good basis for modeling in the laboratory of similar characteristics of the atmospheric surface layer. Various forms of stability parameters are shown to be universallyrelated.


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the generation and growth of small water waves by a turbulent wind in a laboratory channel and traced the evolution of these oscillations with fetch from their inception with amplitudes in the micron range under conditions of steady air flow.
Abstract: The generation and growth of small water waves by a turbulent wind has been investigated in a laboratory channel. The evolution of these oscillations with fetch was traced from their inception with amplitudes in the micron range under conditions of steady air flow. The experiments revealed that the waves are generated at all air velocities in small bursts consisting of groups of waves of nearly constant frequency. After travelling for some distance downstream, these wavelets attain sufficient amplitude to become visible. For this condition, a wind speed critical to raise waves is well defined. After the first wavelets appear, two new stages of growth are identified at longer fetches if the air speed remains unchanged. In the first of these, the wave component associated with the spectral peak grows faster with fetch than any other part of the wave spectrum of the initial waves until its amplitude attains an upper limit consistent with Phillips's equilibrium range, which appears to be universal for wind waves on any body of water. If the air flow is not changed, then the frequency of this dominant wave remains constant with fetch up to equilibrium. This frequency tends to decrease, however, with increasing wind shear on the water. In the second stage of growth, only the energy of wave components with spectral densities lower than the equilibrium limit tend to increase with fetch so that the wave spectrum is maintained near equilibrium in the high-frequency range of the spectrum.The origin of the first waves and the rate of their subsequent growth was examined in the light of possible generating mechanisms. There was no indication that they were produced by direct interaction of the water surface with the air turbulence. Neither could any significant feedback of the waves into the turbulence structure be detected. The growth of the waves was found to be in better agreement with theoretical predictions. Under the shearing action of the wind, the first waves were found to grow exponentially. The growth rates agreed with the estimates from the viscous shearing mechanism of Miles (1962a) to a fractional error of 61% or less. A slight improvement was obtained with the viscous theory of Drake (1967) in which Miles’ model is extended to include the effect of the drift current induced by the wind in the water. Since the magnitude of the water currents observed in the tunnel is very small, this improvement is not significant.

Journal ArticleDOI
30 May 1969-Science
TL;DR: On the basis of products obtained, quantum yields, scavenger experiments, and other chemical tests, a nonchain, free-radical mode of degradation is proposed.
Abstract: Both as a pure solid and in hexane solution, DDT readily decomposed when irradiated with ultraviolet light (2537 angstroms). Principal products identified by gas-liquid and thin-layer chromatography from irradiations of the solid phase were 1,1-dichloro-2,2-bis (p-chlorophenyl) ethane, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene, and 4,4'-dichlorobenzophenone. 1,1-Dichloro-2,2-bis(p-chlorophenyl) ethane and hydrochloric acid were identified from irradiated solutions of DDT in hexane. On the basis of products obtained, quantum yields, scavenger experiments, and other chemical tests, a nonchain, free-radical mode of degradation is proposed.

Journal ArticleDOI
20 Dec 1969-Nature
TL;DR: Raptors in Britain, including the peregrine, sparrow hawk and golden eagle, have reproduced less successfully with the increased use of chlorinated hydrocarbons, especially DDT, and egg breakage in the nest seems to be a major part of the phenomenon.
Abstract: CHLORINATED hydrocarbons may cause reproductive failure in several vertebrate species, and their presence seems to be related to the eggshell quality of birds Raptors in Britain, including the peregrine (Falco peregrinus), sparrow hawk (Accipiter nisus) and golden eagle (Aquila chrysaetos), have reproduced less successfully with the increased use of chlorinated hydrocarbons, especially DDT1–3, and egg breakage in the nest seems to be a major part of the phenomenon Increased egg breakage in raptors and herring gulls (Larus argentatus) has also been correlated with DDT residues in the eggs4,5

Journal ArticleDOI
01 May 1969-Ecology
TL;DR: The upstream distribution of brown trout (Salmo trutta) in the Little South Poudre River drainage stops between the elevations of 2,590 and 2,750 m in five tributaries as discussed by the authors.
Abstract: Upstream distribution of brown trout (Salmo trutta) in the Little South Poudre River drainage stops between the elevations of 2,590 and 2,750 m in five tributaries. As no geomorphic barriers limit distribution, trout distribution may be related to water temperature. Brook trout (Salvelinus fontinalis) is present at higher altitudes in all headwaters. Maximum 5—day water temperature is approximately 13°C at the upper altitudinal distribution of brown trout. Distribution of other species is discussed briefly.

Journal ArticleDOI
01 Nov 1969-Blood
TL;DR: In a continuing study of the toxicity of 90Sr in beagles exposed continuously from mid-gestation to 1.5 years of age, a myeloproliferative disorder has arisen in dogs fed the two highest dose levels, 12 and 4 µCi 90SR/day, respectively, and the relationship between granulocytic leukemia and MMM is clarified.

Journal ArticleDOI
TL;DR: In this article, the radial flow jump involves a force not found in the rectangular jump, and it is shown that the depth and energy loss for a radial jump are less and greater respectively than that for a rectangular jump.
Abstract: Hydraulic jumps involving radial flow, as in diverging stilling basins, have not been properly analyzed. Dynamical considerations disclose that the radial flow jump involves a force not found in the rectangular jump. As a consequence, the sequent depth and energy loss for a radial jump are less and greater respectively than that for a rectangular jump. In addition, experimental findings indicate that the length of the radial jump is less than that of the rectangular jump.

Journal ArticleDOI
01 Feb 1969-Toxicon
TL;DR: Histolysis, thrombosis and proteolysis produced by venoms of vipers from Asia, Europe and Africa were investigated, and hemorrhagic activity had a good correlation with proteolytic activity, especially with hemoglobin as a substrate.

Journal ArticleDOI
TL;DR: Ion-exchange chromatographic procedures have been described which permit the separate elution of selenocystine, selenomethionine, Se -methylselenocysteine and selenohomocystines from their sulfur analogs and from other amino acids in a mixture.

Journal ArticleDOI
TL;DR: Camallanus marinus sp.nov. as discussed by the authors was described from two males and one female found in a scombrid fish and is characterized by having 12-17 rings of 60-65 spines, a spicule ratio of 5:1, and ten pairs of caudal papillae.
Abstract: Camallanus marinus sp.nov. is described from eleven specimens recovered from a variety of marine fishes. It is the only species in Camallanus s.s. with a single spicule. Spinitectus palawanensis sp.nov. is described from two males and one female found in a scombrid fish. It is characterized by having 12–17 rings of 60–65 spines, a spicule ratio of 5:1, and ten pairs of caudal papillae. Cucullanus lutjani, sp.nov. is described from two specimens from lutjanid fishes. It is distinct in lacking a preanal sucker, in possessing a gubernaculum and eight pairs of cloacal papillae.Oceanicucullanus padfica gen. et sp.nov. is described from two specimens found in cyprinid fish. It is most similar to Indocucullanus, differing from it in the absence of a gubernaculum, and in possessing three pairs of teeth in the radii of the oesophagus. Philometra (Philometra) lateolabracis Yamaguti, 1935; Terranova sp.; and Procamallanus spp. are reported for the first time in the Philippines.We wish to thank Dr D. S. Rabor, Silliman University, Damageute, Negros Oriental, Republic of the Philippines, for general support in field activities, and Dr Loren Wood, Curator of Fishes, and Dr Robert F. Inger, Curator of Reptiles, Chicago Museum of Natural History, for identification of hosts. Acknowledgement is also made to Dr Betty June Myers for technical assistance and advice in handling materials.

Journal ArticleDOI
30 May 1969-Science
TL;DR: Closely adjacent cellular processes which contain polysomal ribosomes, unusual in the neuropil, suggest synaptic transmission-protein synthesis coupling and a possible role in memory.
Abstract: Complex synaptic configurations which appear to have especial evolutionary and functional significance are shown in the neuropil of the brain of the planarian Dugesia dorotocephala. Some of the endings in these synaptic attachments contain dense core vesicles, suggesting that nonadrenaline or serotonin or both are neurotransmitters at a more primitive phyletic level than reported hitherto. The spatial proximity and connectivity of the synapses suggest modes of action permitting greater functional complexity to the planarian brain than previously supposed. Closely adjacent cellular processes which contain polysomal ribosomes, unusual in the neuropil, suggest synaptic transmission-protein synthesis coupling and a possible role in memory.

Journal ArticleDOI
TL;DR: Pathologic findings indicated that the parasite and the vascular lesions which it caused resulted in impairment of cephalic arterial circulation and blindness of elk in Arizona, Colorado, and Wyoming.
Abstract: Elaeophora schneideri was identified as the cause of a specific neuro-ophthalmic disorder of elk (Cerrus canadensis) in Arizona, Colorado. New Mexico, and Wyoming. This intra-arterial nematode was found within the cephalic arterial system in 10 of 16 elk with visual disturbances. Pathologic findings indicated that the parasite and the vascular lesions which it caused resulted in impairment of cephalic arterial circulation. Blindness and death were attributed to ischemic damage in the brain, eyes, and optic nerves. Although E. schneideri is a relatively common parasite of deer and domestic sheep in certain mountainous regions of the western and southwestern United States, it had not been reported in elk prior to this study.

Journal ArticleDOI
TL;DR: The purpose of this study was to test the effectiveness of two innovations in method designed for more efficient use of therapist and client time: group desensitization, and massed trials.

Journal ArticleDOI
TL;DR: Thirty-three lizards from Costa Rica were examined for coccidia and Cryptosporidium ctenosauris sp.
Abstract: SYNOPSIS Thirty-three lizards from Costa Rica were examined for coccidia Cryptosporidium ctenosauris sp n is described from Ctenosaura similis, Eimeria basilisci sp n from Basiliscus basiliscus, and additional data are added to the description of Isosporacnemidophori Carini, 1942 Ellipsoidal oocysts of C ctenosauris averaged 217 by 115 μ They had no polar body or micropyle but had an oocyst residuum; the oocysts contained 4 elongate sporozoites with averaged 150 by 34 μ The oocysts of E basilisci were ellipsoidal and averaged 380 by 178 μ They had no oocyst residuum or polar body Their sporocysts were ovoid to ellipsoidal and averaged 127 by 70 μ A sporocyst residuum was present

Journal ArticleDOI
TL;DR: In this paper, the amount of stratospheric air intruding into the stable layer of the jet stream front in a case of cyclogenesis not accompanied by surface radioactive fallout is examined on a more general basis.
Abstract: In a previous studyReiter andMahlman [37]3) have estimated the amount of stratospheric air intruding into the stable layer of the jet stream front in a case of cyclogenesis not accompanied by surface radioactive fallout. In the present report the same case is examined on a more general basis. Outflow from, as well as inflow into, the stratosphere is estimated over the entire thickness of the ‘tropopause gap’.


Journal ArticleDOI
TL;DR: In this paper, the phonon dispersion relation has been measured for sodium chloride at room temperature for waves propagating along the symmetry directions [00ζ], [ζζ0], and [ζ�εζ] by slow neutron inelastic scattering using the Materials Testing Reactor three axis spectrometer.

Journal ArticleDOI
01 Sep 1969