Twenty-four equations for estimating evaporation and/or evapotranspiration were compared with measured Piche evaporation. At least 1728 months of records from 12 Peruvian stations were analyzed in this study. Computer programs were developed to work this study and the results were compared by plotting. It has been found that the equation that best fits the Piche evaporation in the low elevation stations in Peru is Christiansen's formula (ET2) which was used as a base for his formula for Class A pan evaporation (EVC).

With population, industry, and irrigation ever increasing in the arid west, there arises new and greater demands for water. Much of the water now urgently needed is lost as seepage from the many miles of canals in the western states. Rohwer and Stout have estimated that in the western states from one-third to one-half of the water diverted for irrigation is lost before it reaches the farmers' fields. Of these losses, seepage probably accounts for the greatest loss. It is reported by the Bureau of Reclamation that, of the 14,600,000 acre feet of water diverted on 36 projects in 1946, twenty-three percent was lost by seepage from canals and laterals. The loss of water by canal seepage not only is a waste of one of the greatest, most urgently needed natural resources, but in many areas may cause high water tables which necessitate drainage for continued use of the land for agriculture. In the early days of irrigation little thought was given to conservation of water, especially through prevention of canal seepage. Though today the problem of seepage is much more recognized, very little-as compared with expansion of irrigation-has been done toward prevention of canal seepage losses. The Lewiston Area, bound on the east, west and south by Cub and Bear Rivers and on the north by the Utah-Idaho State line has been confronted with a high water table and inadequate drainage for many years. Because of the peculiar geologic formation of the area, natural drainage is poor. williams, Maughan, and Israelsen state that the water table is not only fed by irrigation water, but also by excessive seepage from canals. Since the water table is within three feet of the surface in many areas, the influence of seepage from canals has been of great concern. The major objective of investigations made was to obtain information as to the extent of canal seepage losses in the Lewiston Area, Utah.

Widgeongrass (Ruppia maritima), muskgrass (Chara Sp.), and midge larvae (family Chironomidae) were grown under controlled greenhouse conditions using a solution of Logan tap water, 3000 ppm. sodium chloride, and an algicide-fungicide inhibiter. Soil, vegetation, and invertebrates came from a spring-fed marsh in western Utah. Ammonium sulfate, treble superphosphate, and sewage sludge fertilizers were applied to the plants at 5, 10, 20, 25, 50, 75, 100, and 300 pounds per acre equivalents of ammonium sulfate; 5, 25, 50, 75, 100, and 300 pounds per acre equivalents of treble superphsophate; and 5, 25, 100, 200, 300, 400, 500,700, and 1000 pounds per acre equivalents of sewage sludge. Widgeongrass plants had weights below the control at all fertilizer levels. Plant lengths at treatment levels of 10 pounds per acre equivalents ammonium sulfate and 5 pounds per acre equivalents sewage sludge were greater than the control length, but the differences were not significant. Muskgrass plants had weights which were neither significantly above or below the control weight. Muskgrass plants at the 75 pounds per acre rate of treble superphosphate had significantly greater lengths than did the control. The highest chironom.id survival rate, 12. 6 percent, occurred in the control treatm.ent. B1uegreen algae, Oscilatoria sp., was present in all fertilized treatments.

In the present research, nicotine alkaloid production by Nicotiana tabacum (tobacco) hairy roots and tropane alkaloid production by Hyoscyamus niger hairy roots were investigated. The first objective of this research was to improve the oxygen mass transfer in hairy root cultures with microbubbles. Oxygen was shown as a critical nutrient for the growth of tobacco and H. niger hairy roots. In a 1-liter fermentor, microbubble dispersion improved the oxygen mass transfer, tobacco hairy root growth, and nicotine production in the medium. In a novel ground-joint column bioreactor, microbubbles enhanced the oxygen mass transfer and the growth of H. niger hairy roots. The second objective of this research was to enhance the release of alkaloids from the hairy roots into the culture medium. In a l-liter fermentor, nicotine concentration in medium was improved by adjusting the medium pH to 6. Unlike the nicotine alkaloid, hyoscyamine concentration in medium was not detectable at medium pH 6, whereas hyoscyamine in medium increased to 42 mg l-1 at medium pH 3. Similar to the hyoscyamine, scopolamine in medium increased from 0.1 to 11 mg l-1 when the medium pH was adjusted from 6 to 3. The release of alkaloids into culture medium provides opportunities to isolate a high-value alkaloid directly from the culture fluid, and reduces the cost of product recovery.

Equations and tables for estimating Fuess evaporation from climatological data were developed. Ten years of average records from 22 stations in Venezuela were analyzed in order to develop the equations. Mathematical regression analysis, and plotting and computer programs were used to work out the equations. The form of the final expression for estimating Fuess evaporation is as follows:Ev = K CRCTCWCHCDTCSCM Pan evaporation was computed using the Christiansen, Mathison, Blaney-Criddle, Hargreaves, Penman, and Kohler formulas. The computed pan evaporation from these formulas, measured Fuess evaporation, and computed Fuess evaporation were compared. The equation best suited for estimating Fuess evaporation in Venezuela was selected by statistical analysis. Coefficients were determined for the new Fuess evaporation formula. An example showing ease of application of the equation is given.

<p>Community interactions based on various parameters in defined niches have been studied to understand their influence on bacterial life. Yet there currently are no models that can depict how spatial interactions control the complex combinatorics of different microbial communities. Biodiversity influences the ecosystem properties of bacterial communities, but the relationship between bacterial biodiversity and function remains to be understood entirely. Here, the focus is on developing a simple and effective platform to study neighborhood interactions between different species of lactic acid bacteria by controlling two metrics – distance and composition. Using this simple platform, I explore 1) how spatial and temporal arrangement between different bacteria affect their interaction in a high throughput manner, 2) how biodiversity can be manipulated in terms of its starting population, the number of species, and species identity. </p>

Thesis: S.M., Massachusetts Institute of Technology, Department of Biological Engineering, February, 2021 / Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, February, 2021 / Cataloged from the official PDF version of thesis. / Includes bibliographical references (pages 49-51). / This thesis studies the problem of learning causal directed acyclic graphs (DAGs) in the setting where both observational and interventional data is available. This setting is common in biology, where gene regulatory networks can be intervened on using chemical reagents or gene deletions. The identifiability of causal DAGs under perfect interventions, which eliminate dependencies between targeted variables and their direct causes, has previously been studied. This thesis first extends these identifiability results to general interventions, which may modify the dependencies between targeted variables and their causes without eliminating them, by defining and characterizing the interventional Markov equivalence class that can be identified from general interventions. Subsequently, this thesis proposes the first provably consistent algorithm for learning DAGs in this setting. Finally, this algorithm as well as related work is applied to analyze biological datasets. / by Karren Dai Yang. / S.M. / S.M. / S.M. Massachusetts Institute of Technology, Department of Biological Engineering / S.M. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Extraction of oil and gas in Utah’s Uintah Basin results in large quantities of wastewater, or produced water, with nutrients and residual organic chemical that represent a significant resource for producing energy-related and value-added products. Produced water was obtained as a biomass producing nutrient source from industries operating in Utah’s Uintah Basin. Within the Uintah Basin (defined as Uintah and Duchesne Counties within Utah) approximately 93 million barrels of water were produced in 2013 while only 11% of the water was disposed of through evaporation, with the national average at 2%. The rest is reinjected into the subsurface. The goal of this project was to design a system that utilizes produced water as a nutrient source for growing microalgae biomass in a biofilm form using a Rotating Algal Biofilm Reactor (RABR). The biomass would then be harvested and converted into biocrude oil using hydrothermal liquefaction (HTL). The objectives were to (1) cultivate biomass on produced water, (2) optimize the reactor to reduce energy costs to operate while increasing biomass productivity, and (3) increase feedstock quality for HTL. The RABR was constructed out of polystyrene disks, and experimentation was carried out to optimize rotational speed of the reactor. Two strains of algal biomass were identified as biofilm formers and grown using produced water as the nutrient source. The biomass was then utilized as a HTL feedstock that gave an average yield of 34.5% ash free dry weight.

This research focused on development of nanoparticle- based therapeutics against amyloid fibrils. Amyloid fibrils are associated with various diseases such as Parkinson’s, Huntington’s, mad cow disease, Alzheimer’s, and cataracts. Amyloid fibrils develop when proteins change their shape from a native form to a pathogenic “misfolded” form. The misfolded proteins have the ability to recruit more native proteins into the pathogenic forms, which self-assemble into amyloid fibrils that are hallmarks of the various protein-misfolding diseases listed above. Amyloid fibrils are highly resistant to degradation, which may contribute to the symptoms of amyloid diseases. Synthetic drugs, natural compounds, and antibodies are widely explored for potential to stop pathogenic protein assembly or to promote fibril degradation and clearance, but to date have had little success in relieving symptoms in clinical trials. In this research, I have synthesized fluorine-containing silica nanoparticles (NPs), and tested their fibril-inhibiting activity against amyloid fibrils formed by a non-pathogenic protein, β-lactoglobulin (BLG). These fluoro-silica NPs prevented BLG amyloid formation, whereas non-fluorinated nanoparticle analogs did not inhibit fibrillation under the same reaction conditions. The fluoro-silica NPs interacted with the BLG protein in a manner that prevented the protein from adopting a form that could self-assemble into fibrils. Additional applications of the NPs were explored as small-molecule drug-delivery systems; such that multiple functionalities could be introduced into a single nano- therapeutic.

Spider silk has the potential to be a useful biomaterial due to its high tensile strength and elasticity. It is also biocompatible and biodegradable, making it useful for wound dressings and sutures, tissue and bone scaffolds, vessels for drug delivery, and ligament and tendon replacements. In some studies where spider silk has been used to grow cells, the silk has promoted more cell growth than the control. However, it is difficult to obtain the high volume of silk needed for these undertakings on a large scale. Spiders are territorial and cannibalistic, so they cannot be easily farmed. Therefore, spider silk proteins are frequently produced in other organisms. E. coli is often used for spider silk production due to the relative ease of gene manipulation and the cost effectiveness of large-scale fermentation. However, due to the large protein size of the spider silk and the repeating amino acid motifs, there are some challenges with production in E. coli. Metabolic modeling is a way to model the metabolism of an organism and can help overcome some of the difficulties of spider silk production in E. coli by predicting metabolic engineering strategies. In this study, a metabolic modeling tool known as dynamic FBA predicted that ammonium is depleted during cell growth. Laboratory results confirmed that by adding additional ammonium to the medium, the E. coli cells experienced more cell growth and were able to produce more spider silk protein