Showing papers by "North Carolina State University published in 1981"
TL;DR: In this article, the Fourier flexible form and its derived expenditure system are introduced, subject to smoothness conditions on the consumer's true indirect utility function, and a finite parameter approximation of the true expenditure system is obtained by dropping all high-order terms of Fourier expenditure system past an appropriate truncation point.
975 citations
TL;DR: A method is proposed for estimating effective population size from data on linkage disequilibrium among neutral genes at several polymorphic loci or restriction sites, but for very tightly linked genes estimates of N are more dependent on long-term than on recent population history.
Abstract: A method is proposed for estimating effective population size (N) from data on linkage disequilibrium among neutral genes at several polymorphic loci or restriction sites. The efficiency of the method increases with larger sample size and more tightly linked genes; but for very tightly linked genes estimates of N are more dependent on long-term than on recent population history. Two sets of data are analysed as examples.
770 citations
TL;DR: In this paper, the authors bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols.
Abstract: Publisher Summary The purpose of this chapter is to bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols. Soil taxonomy terminology, including soil moisture regimes, is used. The outcome of the race between world food production and population is determined in the tropics, where most of the world's undernourished people live. The applicability of high-input soil management technologies, however, diminishes in marginal lands where soil and water constraints are not easily overcome at low cost. The rising price spiral of petroleum-related products since has limited the economic feasibility of soil management technologies based on the intensive use of purchased inputs, particularly for farmers with limited resources in the tropics. The term ‘‘low’’ is used in relation to “high”-input technology where the application of fertilizers and amendments largely eliminate chemical soil constraints. The identification of plant species and ecotypes tolerant to the main acid soil stresses allows the development of low-input soil management systems for Oxisol and Ultisol regions where socioeconomic constraints prevent the widespread application of large quantities of lime and fertilizers. The basic approach is to use plants adapted to acid soil constraints, to maximize the use of fertilizers and lime needed to produce about 80% of their maximum yield, and to take advantage of favorable attributes of acid, infertile Oxisols and Ultisols.
527 citations
TL;DR: In this paper, a two-dimensional airfoil embedded in a uniform low Mach number flow is examined by applying several TE noise theories to the measured data, and the TE noise spectra and directivity are quantitatively determined for the case of a high Reynolds number and a fully turbulent boundary layer.
491 citations
TL;DR: In this paper, the Equal Area Criterion (EACC) was used to optimize the net savings associated with reduction of power and energy losses through shunt capacitor placement on primary distribution feeders.
Abstract: New generalized procedures are developed for optimizing the net savings associated with reduction of power and energy losses through shunt capacitor placement on primary distribution feeders. These procedures are applied to realistic problems to facilitate their immediate use by the electric utility distribution system designer. It is shown that a basic principle, called here "The Equal Area Criterion", offers significant computational and physical insight into numerous problems outside the bounds of studies previously reported and widely accepted in industry
377 citations
TL;DR: An improved method for estimation of DNA fragment lengths from mobility on agarose gels is introduced, and the lengths of pBR322 fragments of known sequence were predicted with better than 1% accuracy.
295 citations
TL;DR: Nittrouer et al. as discussed by the authors used boxcoring of the upper 1/2 m of sediment to predict the formation of sedimentary strata in an allochthonous shelf environment: the Washington continental shelf.
241 citations
TL;DR: In this article, a model which explains reported complex effects of feed composition and pressure on component permeabilities in high-pressure gas separators based on glassy polymer membranes is discussed, and potential deviations from the theory are discussed in terms of separable solubility and mobility-related effects.
Abstract: A model is discussed which explains reported complex effects of feed composition and pressure on component permeabilities in high-pressure gas separators based on glassy polymer membranes. A special form of Fick's law which accounts for the fact that penetrants in glassy polymers sorb into and diffuse through two different molecular environments provides the basis for the analysis of gas mixture permeation. Potential deviations from the theory are discussed in terms of separable solubility-and mobility-related effects.
219 citations
TL;DR: This method by virtue of its simplicity and sensitivity can be used for routine nutritional analyses for available lysine and can be adapted to analysis of unknown protein samples if conditions are used to eliminate from analyses those samples for which the contribution of N-terminal amino groups to the total fluorescence is not insignificant.
178 citations
TL;DR: In this article, a state-of-the-art report is presented on a graphical method for scheduling construction projects such as highways, runways, railways, tunnels and pipelines.
Abstract: A state-of-the-art report is presented on a graphical method for scheduling construction projects. Sometimes called the linear balance method or linear scheduling method, the method is particularly applicable to linear projects such as highways, runways, railways, tunnels and pipelines. A critical review and assessment is made of the method, including its possibilities for use in United States highway construction and maintenance projects.
162 citations
TL;DR: In this article, the authors developed new generalized procedures for optimizing the net monetary savings associated with the reduction of power and energy losses through placement of fixed and switched shunt capacitors on primary distribution feeders.
Abstract: New generalized procedures are developed for optimizing the net monetary savings associated with the reduction of power and energy losses through placement of fixed and switched shunt capacitors on primary distribution feeders. The computer-based optimization techniques are structured around three subproblems which encompass a wide range of design problems of interest to the distribution engineer. Realistic reactive load distributions on nonuniform feeders of commonly encountered wire sizes are accommodated within the modeling. A wide range of numerical examples is presented to reflect net dollar savings for typical applications
TL;DR: Turbidity, caused by suspended clay particles, significantly reduced feeding rates but not size selectivity of bluegills preying on two size classes of Daphnia pulex, covering the range of turbidities found in North Carolina lakes.
Abstract: Turbidity, caused by suspended clay particles, significantly reduced feeding rates but not size selectivity of bluegills (Lepomis macrochirus) preying on two size classes of Daphnia pulex. Bluegill feedling rates in a 3-minute period declined from approximately 14 prey per minute in clear water to 11, 10, and 7 per minute in pools of 60, 120, and 190 NTU (nephelometric turbidity units), respectively. Size selectivity was independent of turbidity level; the proportion of large daphnia consumed was approximately 0.70 in all treatments and the control. These turbidity levels covered the range of turbidities found in North Carolina lakes.
TL;DR: In this article, the authors discuss the effects of single ring muItiple emission, distinct orbital multiple emission, and other related phenomena on the FSR spectra of reduced species.
TL;DR: The experimental evidence concerning the existence and importance of maternal effects in beef cattle, dairy cattle and swine is reviewed and some suggestions are given for altering management programs to increase production and selection efficiency.
TL;DR: Both LH and FSH were higher during the last 2 weeks of lactation than during the first 3 weeks, and serum prolactin concentrations in selected samples collected on Days 10 and 20 were not significantly different between treatment groups, intact sows had consistently higher concentrations compared with ovex sows.
Abstract: Concentrations of LH, FSH, prolactin, estrogen, and progesterone were measured in blood samples collected at various intervals during and immediately following lactation to determine the role of the ovary in controlling gonadotropin and prolactin secretion and initiation of estrous cycles in the pig. Ten primiparous sows were ovariectomized (ovex, n = 5) or left intact (n 5) 2 to 4 days after farrowing. Serum progesterone and estrogens in samples collected daily during lactation were not different between intact and ovex sows. Serum FSH increased immediately after ovariectomy and remained elevatedduring lactation,but LH concentrations were similar between ovex and intact sows. Both LH and FSH were higher during the last 2 weeks of lactation than during the first 3 weeks. On Days 10 and 20 of lactation, all sows received (i.v.) two challenges of gonadotropin releasing hormone (GnRH; 400 �g each) at 135 mm intervals. Peak change (maximum value minus baseline) in FSH after GnRH was higher in ovex than in intact sows on both Days 10 and 20. Peak change in FSH in ovex rows was higher on Day 20 than on Da� 10, but peak change in FSH in intact rows was similar between Days 10 and 20. Peak change in LH after GnRFI was similar between ovex and intact sows. Peak change in LH after the second GnRH challenge on Day 10 was higher than that after each of the other three challenges. Although serum prolactin concentrations in selected samples collected on Days 10 and 20 were not significantly different between treatment groups, intact sows had consistently higher concentrations compared with ovex sows. Separation of four sows from their litters for 4 h during the last week of lactation resulted in a decline in serum prolactin, but prolactin increased fivefold within 15 mm and tenfold during the second hour after piglets were replaced. In contrast, LH did not change prior to or after piglets were allowed to nurse. After weaning, concentrations of estrogens peaked during 24 h around onset of estrus prior to
TL;DR: In this article, it was shown that very low levels of surfactant not only displace adsorbed soluble polymer from the latex particle surface, but simultaneously reduce the concentration of soluble polymer required to effect flocculation.
TL;DR: Based on theoretical analysis and laboratory data, the authors proposed a unified two-parameter wave spectral model as is the mean squared surface elevation, and λ 0, n0 are the wavelength and frequency of the waves at the spectral peak.
Abstract: Based on theoretical analysis and laboratory data, we proposed a unified two-parameter wave spectral model as is the mean squared surface elevation, and λ0, n0 are the wavelength and frequency of the waves at the spectral peak This spectral model is independent of local wind Because the spectral model depends only on internal parameters, it contains information about fluid-dynamical processes For example, it maintains a variable bandwidth as a function of the significant slope which measures the nonlinearity of the wave field And it also contains the exact total energy of the true spectrum Comparisons of this spectral model with the JONSWAP model and field data show excellent agreements Thus we established an alternative approach for spectral models Future research efforts should concentrate on relating the internal parameters to the external environmental variables
TL;DR: Simultaneous iteration methods are extensions of the power method whereby iteration is carried out with a number of trial vectors that converge onto the eigenvectors corresponding to the dominant eigenvalues.
Abstract: Simultaneous iteration methods are extensions of the power method whereby iteration is carried out with a number of trial vectors tha t converge onto the eigenvectors corresponding to the dominant eigenvalues. T h e y are particularly suitable where the matrix requiring eigensolution is large and sparse, or where approximations to the required dominant eigenvectors are already available. The first s imultaneous iteration methods are due to Bauer [1] and have been discussed by Wilkinson [10]. Subsequent methods are related to Bauer ' s bi-iteration technique but improve the convergence rate by including an interaction analysis into the iteration cycle. These methods have been most highly developed for the real syrmnetric eigenvalue problem where the left and right eigenvectors coincide. A previous paper by the authors [4] describes two possible pro~cedures for real unsymmetr ic eigenvalue problems. One procedure is a bi-iteration technique in which left and right eigenvector sets are simultaneously predicted, while the
TL;DR: The self-diffusion of 30Si in high purity and N-doped α-SiC single crystals has been measured in the temperature range 2273 to 2573 K as mentioned in this paper.
Abstract: The self-diffusion of30Si in high purity and N-doped α-SiC single crystals has been measured in the temperature range 2273 to 2573 K. The diffusion (DSi*) in N-doped crystals exceeds that in the pure crystals because of the increase in the concentration of the charged acceptor-type Si vacancies in the presence of the N species. A comparison ofDC* andDSi* shows that the former exceeds the latter by approximately 102, primarily because of the greater entropy of migration of C. Possible crystallographic paths of transport for both species are also discussed.
TL;DR: An algorithm is presented for calculating an osculatory quadratm sphne that preserves the monotonicity and convexity of the data when consmtent with the given derivatives at the data points and a discussion of pathologms that can occur when these algorithms are maplemented.
Abstract: An algorithm is presented for calculating an osculatory quadratm sphne that preserves the monotonmlty and convexity of the data when consmtent with the given derivatives at the data points A method is also presented for calculatmn of an mterpolatory quadratm sphne with monotonicity and convexity consistent with that of the data Included is a discussion of pathologms that can occur when these algorithms are maplemented. Examples are given that illustrate the dependence of the method on only local informatmn and its usefulness m geometrm design.
01 Apr 1981
TL;DR: Gulf Stream Water intrudes across the bottom during summer to replace the upwelled water, and accounts for the colder and more stratified water over the northern Florida and the North Carolina shelves as mentioned in this paper.
Abstract: Summer bottom temperatures along the continental shelf between Cape Hatteras and Cape Canaveral are abnormally low in regions where isobaths diverge. The regions are north of capes and shoals, which force the flow of shelf water to change vorticity and induce upwelling. Gulf Stream Water intrudes across the bottom during summer to replace the upwelled water, and accounts for the colder and more stratified water over the northern Florida and the North Carolina shelves.
TL;DR: In this article, a greenhouse experiment was conducted to examine the effects of salinity, nitrogen, and aeration on the growth of Spartina alterniflora Loisel in a factorial arrangement of treatments with salt marsh substrate at three salinity levels (15, 30, 45) at two nitrogen levels (0 and 168 kg/ha) and at two aeration levels (zero and oxygen saturation).
Abstract: A greenhouse experiment was conducted to examine the effects of salinity, nitrogen, and aeration on the growth of Spartina alterniflora Loisel. The experiment was conducted in a factorial arrangement of treatments with salt marsh substrate at three salinity levels (15, 30, 45‰), at two nitrogen levels (0 and 168 kg/ha) and at two aeration levels (zero and oxygen saturation).
TL;DR: The mitochondrial isozyme, SOD-3, is unlike the cytosolic isozymes in every parameter studied and appears to be similar to the mitochondrial manganese-containing Superoxide dismutases purified from other eukaryotic organisms.
TL;DR: In this paper, a multivariate test for monotone trend based on Kendall's τ statistic was proposed as a way to test for change in blood constituents over the course of a drug experiment.
Abstract: During a drug trial, each subject may have many blood constituents measured at regular time intervals. The traditional method of evaluating such data using normal ranges has undergone much controversy in the clinical chemistry literature. We propose a new multivariate test for monotone trend based on Kendall's τ statistic as a way to test for change in blood constituents over the course of a drug experiment. The new test avoids the unrealistic assumptions and repeated testing problem of the normal range method. An example illustrates the new procedure.
TL;DR: Temporal relationships among the peripheral blood concentrations of corticosteroids, progesterone, LH1 and testosterone and stress-induced alterations in the secretion of these hormones were examined in bulls.
Abstract: Temporal relationships among the peripheral blood concentrations of corticosteroids, progesterone, LH1 and testosterone and stress-induced alterations in the secretion of these hormones were examined in bulls. Blood samples were obtained via jugular cannula from eight bulls at 30-min intervals over a 12-h period. A rectal electroejaculation probe was then inserted with (EE; n = 4) or without (NE; n = 4) electrical stimulation, and ejaculation and blood samples were collected (5-, 15-, and 30-min intervals) over a second 12-h period. Treatments were reversed at the conclusion of this second 12-h period, and blood samples were collected over a third 12-h period. A positive temporal relationship was observed between concentrations of LH and testosterone during the initial 12-h period. During this time, a positive temporal relationship was also observed between concentrations of corticosteroids and progesterone. In contrast, concentrations of corticosteroids and progesterone were negatively correlated with co...
TL;DR: In this paper, a weighted Cramer-von Mises distance between the empirical distribution function and the assumed model F0(x - θ) is minimized to produce estimators θ n that are asymptotically normal.
Abstract: A weighted Cramer-von Mises distance between the empirical distribution function and the assumed model F0(x - θ) is minimized to produce estimators θ n that are asymptotically normal. If the weight function is taken proportional to (- ln f 0)″/f 0 , then θ n is asymptotically efficient and the minimized distance has the appropriate loss of one degree of freedom. Special attention is focused on the limiting distribution of this latter goodness-of-fit statistic in both null and alternative situations.
TL;DR: In this paper, the authors investigated the relationship between the pressure drop and the volumetric heat transfer between the air and the rockbeds in low temperature storage applications and found that both the pressure and heat transfer coefficient depend upon the rock size and the air flow rate.
TL;DR: In this article, a critical assessment is made of the various diagnostic relations for the height of the nocturnal boundary layer, as well as of their past comparisons with experimental data The parametric relations involving the characteristics of the whole boundary layer are found to be less satisfactory than those involving only the surface layer variables The latter are tested against the Cubauw tower data for selected winter periods when the mixed-layer height h was measured directly with an acoustic sounder.
Abstract: A critical assessment is made of the various diagnostic relations for the height of the nocturnal boundary layer, as well as of their past comparisons with experimental data The parametric relations involving the characteristics of the whole boundary layer are found to be less satisfactory than those involving only the surface layer variables The latter are tested against the Cubauw tower data for the selected winter periods when the mixed-layer height h was measured directly with an acoustic sounder It is found that h has rather poor correlation with the height ho to which the effect of surface cooling extends Its correlation with hu, the height of the maximum in wind speed, is fair (r ≈ 05) during strong stability conditions, but poor in slight to moderate stability conditions Better correlations (r ≈ 07) are obtained with u*/f, (u*L/f)1/2 and Deardorff's (1972b) interpolation formula where u* is the friction velocity, L is the Obukhov length and f the Coriolis parameter The parametric