An Empirical Test for Steward's Model of Great Basin Settlement Patterns

1973 ◽  
Vol 38 (2) ◽  
pp. 155-176 ◽  
Author(s):  
David Hurst Thomas

AbstractJulian Steward's theory of Great Basin cultural ecology and settlement patterns has been subjected to empirical validation. Since the only data available to test this hypothesis are archaeological, it was first necessary to determine the artifactual correlates for the posited ethnographic system. These deductive propositions were determined by the BASIN I computer simulation model. On the basis of data obtained in a regional random sampling project in the Reese Valley of central Nevada, over 75% of the nearly 130 deductive predictions were statistically verified. The rejected propositions probably reflect failure of the computer model rather than shortcomings in Steward's theory. The archaeological manifestation of the Shoshonean pattern is defined as the Reese River Subsistence-Settlement System which operated in the central Great Basin from about 2500 B.C. to historic times.


2010 ◽  
Vol 21 (15) ◽  
pp. 2674-2684 ◽  
Author(s):  
Ezgi Can Eren ◽  
Ram Dixit ◽  
Natarajan Gautam

The noncentrosomal cortical microtubules (CMTs) of plant cells self-organize into a parallel three-dimensional (3D) array that is oriented transverse to the cell elongation axis in wild-type plants and is oblique in some of the mutants that show twisted growth. To study the mechanisms of CMT array organization, we developed a 3D computer simulation model based on experimentally observed properties of CMTs. Our computer model accurately mimics transverse array organization and other fundamental properties of CMTs observed in rapidly elongating wild-type cells as well as the defective CMT phenotypes observed in the Arabidopsis mor1-1 and fra2 mutants. We found that CMT interactions, boundary conditions, and the bundling cutoff angle impact the rate and extent of CMT organization, whereas branch-form CMT nucleation did not significantly impact the rate of CMT organization but was necessary to generate polarity during CMT organization. We also found that the dynamic instability parameters from twisted growth mutants were not sufficient to generate oblique CMT arrays. Instead, we found that parameters regulating branch-form CMT nucleation and boundary conditions at the end walls are important for forming oblique CMT arrays. Together, our computer model provides new mechanistic insights into how plant CMTs self-organize into specific 3D arrangements.



Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6324
Author(s):  
Tudur Wyn David ◽  
Noel Bristow ◽  
Vasil Stoichkov ◽  
Han Huang ◽  
Grazia Todeschini ◽  
...  

The outdoor performance of large area Organic Photovoltaics (OPVs) is investigated in this work. Initially, the diurnal performance of the three modules is determined and found to be similar. Subsequently module degradation is monitored, and it is found that the larger area module displays a significantly greater stability as compared to the smallest area module; in fact the larger module displays a T50% (time to fall to 50% of its original value) of 191 days whilst the smallest module displays a T50% of 57 days. This is attributed to an increased level of water infiltration due to a larger perimeter-to-area ratio. These findings are then used to verify a computer simulation model which allows the model parameters, series and shunt resistances, to be calculated. It is determined that the series resistance is not an obvious obstruction at these module sizes. The findings of this work provide great promise for the application of OPV technology on a larger scale.



1982 ◽  
Vol 104 (3) ◽  
pp. 182-186 ◽  
Author(s):  
W. A. Helmer ◽  
P. Y. S. Chen ◽  
M. B. Vaidya

A computer simulation model was developed for a solar lumber drier and a solar-dehumidification drier. Experimental data taken on an existing solar and solar-dehumidification drier compared well with the computer prediction. The solar-dehumidification lumber drier is able to dry wood about as fast as a conventional drier and yet use less than 50 percent of the fossel fuel energy at the site.



1994 ◽  
Vol 30 (11) ◽  
pp. 143-146
Author(s):  
Ronald D. Neufeld ◽  
Christopher A. Badali ◽  
Dennis Powers ◽  
Christopher Carson

A two step operation is proposed for the biodegradation of low concentrations (< 10 mg/L) of BETX substances in an up flow submerged biotower configuration. Step 1 involves growth of a lush biofilm using benzoic acid in a batch mode. Step 2 involves a longer term biological transformation of BETX. Kinetics of biotransformations are modeled using first order assumptions, with rate constants being a function of benzoic acid dosages used in Step 1. A calibrated computer model is developed and presented to predict the degree of transformation and biomass level throughout the tower under a variety of inlet and design operational conditions.



1977 ◽  
Vol 8 (3) ◽  
pp. 7-14
Author(s):  
Robert Austin Milch ◽  
Narain D. Bhatia


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