Thesis (M.S.)--University of Wisconsin -- La Crosse, 1984. / Includes bibliographical references (leaves 54-59).

The saltwater mosquito larva, Aedes dorsal is, is one of the only organisms capable of inhabiting hypersaline lakes composed almost entirely of high concentrations of NaHC03 and Na2C03 salts. Under laboratory conditions larvae survived and developed normally in saline media with pH values up to 10.5, HC0₃⁻ concentrations up to 250 mM, or C0₃²- concentrations up to 100 mM. Despite ingestion of these alkaline media at rates equivalent to 130% of larval body weight per day, these insects regulated hemolymph pH (7.55-7.70) and HCO₃⁻ concentrations (8.0 - 18.5 mM) within narrow physiological limits. Micropuncture and microcannulation studies on the rectal salt gland demonstrated that this organ was an important site of pH and HC0₃⁻ regulation. Microcannulated salt glands secreted a strongly hyperosmotic fluid containing 402 mM HCO₃⁻ and 41 mM C0₃²⁻ at a rate of 38 nl-h⁻¹. Lumen-to-bath HC0₃⁻ and C0₃²⁻ gradients of 21:1 and 241:1, respectively, were generated by the salt gland epithelium against a transepithelial potential of -25 mV (lumen negative) demonstrating clearly the active nature of HCO₃⁻ secretion. To study the mechanisms of HCO₃⁻ transport, an in vitro microperfused rectal salt gland preparation was developed. Net total CO₂ transport (J[sup=JCo₂; sub=net]) as measured by microcalorimetry in perfused salt glands was unaffected by bilateral Na⁺ or K⁺ and serosal Cl⁻ substitutions, or by serosal addition of 1.0 mM ouabain, 2.0 mM amiloride or 0.5 mM SITS. Removal of luminal Cl⁻ inhibited (J[sup=JCo₂; sub=net] by 80%, while serosal addition of 1.0 mM acetazolamide or 0.5 mM DIDS inhibited by (J[sup=JCo₂; sub=net] 80% and 40%, respectively. Perfusion of the anterior and posterior rectal segments demonstrated clearly that the anterior rectum was the site of CO₂ secretion in the microperfused salt gland. Net Cl⁻ reabsorption in the anterior segment was measured by electron microprobe analysis and was equivalent to the rate of CO₂ secretion. In addition, Cl⁻ reabsorption in the anterior segment was completely inhibited by bilaterally replacing C0₂ and HC0₃⁻ with a phosphate or HEPES buffered saline. These data provide strong quantitative evidence for the presence of a 1:1 Cl⁻/HCO₃⁻ exchange mechanism located in the anterior rectal salt gland segment. Microcannulation studies on the individual salt gland segments demonstrated that both rectal segments are capable of secreting a hyperosmotic fluid containing Na⁻, Cl⁻ and HCO₃⁻. Based on these results and the results of studies in which the effects of serosal ion substitutions on salt gland fluid secretion were examined, it has been suggested tentatively that both segments secrete a NaCl-rich fluid and that fluid secretion is driven by coupled NaCl transport. It is further suggested that once this fluid enters the salt gland lumen its composition is modified by ion exchange and reabsorptive processes which are dependent upon the ionic regulatory needs of the animal. In larvae inhabiting low Cl⁻, NaHCO₃-CO₃ lakes, this modification involves a 1:1 exchange of luminal Cl⁻ for serosal HCO₃⁻. The cellular mechanisms of anterior salt gland HCO₃⁻ and Cl⁻ transport were examined using ion and voltage-selective microelectrodes in conjunction with a microperfused anterior segment preparation which allowed complete changes in serosal and mucosal saline composition to be made in <5-10 seconds. Addition of DIDS or acetazolamide to or removal of CO₂ and HCO₃⁻ from the serosal bath caused large, 20-50 mV hyperpolarizations of Va and had little effect on . Rapid changes in luminal Cl⁻ concentration altered Va in a rapid, step-wise manner. The slope of the relationship between Va and luminal Cl⁻ activity was 42.2 mV/decalog a[sup=l; sub=Cl⁻ (r = 0.992). Intracellular Cl⁻ activity was 23.5 mM and was approximately 10 mM lower than that predicted for a passive distribution at the apical membrane. Changes in serosal Cl⁻ concentration had no effect on indicating an electrically silent basolateral Cl⁻ exit step. Intracellular pH in anterior rectal cells was 7.67 and the calculated a[sup=C;sub=HCO₃] - was 14.4 mM. These results show that under control conditions HC0₃⁻ enters the anterior rectal cell by an active mechanism against an electrochemical gradient of 77.1 mV and exits the cell at the apical membrane down a favorable electrochemical gradient of 27.6 mV. Based on these results, a tentative cellular model has been proposed in which Cl⁻ enters the apical membrane of the anterior rectal cells by passive, electrodiffusive movement through a Cl⁻-selective channel, and HCO₃⁻ exits the cell by an active or passive electrogenic transport mechanism. The electrically silent nature of basolateral Cl⁻ exit and HC0₃⁻ entry, and the effects of serosal addition of Cl⁻/HCO₃⁻ exchange inhibitor DIDS on (J[sup=JCo₂; sub=net] and V[sub=te] suggest strongly that the basolateral membrane is the site of a direct coupling between Cl⁻ and HCO₃⁻ movements via a Cl⁻/HC0₃⁻ exchange mechanism. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.

No description available.

No description available.

La société Solvay est le plus grand producteur de bicarbonate de sodium raffiné au monde. Le NaHCO3 est un des produits parmi les plus connus et utilisés. Sa production a lieu dans des colonnes à bulles de volumes très importants. La production du bicarbonate de sodium raffiné dans ces réacteurs peut se résumer par la réaction entre une solution saturée de carbonate de sodium (Na2CO3) et le CO2(gaz) Cette production implique la connaissance et le contrôle des réacteurs de type triphasique. En effet dans ce procédé on met en jeu deux types de transferts entre un gaz et un liquide le CO2 et la solution de Na2CO3 et entre un liquide et un solide, NaHCO3 (liq) et NaHCO3 (solide) Le but de ce travail est d’acquérir des informations concernant la cristallisation du NaHCO3 dans une colonne à bulles. L’étude de la cristallisation de ce produit se fait au travers des modèles des cinétiques de cristallisation : la vitesse de croissance G (m•s-1) et la vitesse de nucléation J (#.m-3•s-1). Nous avons utilisé pour cette étude deux réacteurs différents; un réacteur parfaitement mélangé ou MSMPR (Mixed Suspension Mixed Product Removal) et un réacteur de type colonne à bulles à l’échelle laboratoire. Le premier réacteur nous a permis d’étudier le transfert liquide solide et les différents paramètres qui peuvent intervenir dans la cristallisation comme par exemple : La sursaturation, la température, l’agitation, la densité du solide et les impuretés. Dans la colonne à bulles nous avons étudié les principaux paramètres opératoires comme par exemple : le débit de gaz injecté, la température, la composition la présence d’impureté dans la solution. Grâce à l’étude des différents paramètres du procédé de cristallisation dans les deux réacteurs, nous avons pu établir clairement les relations entre les paramètres opératoires d’une colonne à bulles et les paramètres de cristallisation. Une évaluation paramétrique de la vitesse de croissance et de la vitesse de germination du NaHCO3 a été réalisée dans les deux réacteurs. Nous avons comparé les résultats obtenus dans nos différents réacteurs aux résultats obtenus dans des colonnes industrielles afin d’observer en premier lieu, l’effet des paramètres étudiés à une grande échelle et en deuxième lieu afin de savoir si notre étude peut être corrélée à une échelle industrielle. Ainsi l’information obtenue concernant chaque paramètre étudié sera utilisée pour l’amélioration d’un modèle global décrivant le procédé de cristallisation du NaHCO3 dans les colonnes de production industrielle Solvay.

With additional research on species characteristics and continued work towards cost effective production methods, algae are viewed as a possible alternative biofuel crop to current feedstocks such as corn. Current open pond production methods involve bubbling carbon dioxide (CO_(2)) gas into the media to provide a carbon source for photosynthesis, but this can be very inefficient releasing most CO_(2) back into the atmosphere. This research began by investigating the effect of sodium bicarbonate (NaHCO_(3)) in the growth media as an alternative carbon source to bubbling CO_(2) into the cultures. The second part examined if NaHCO_(3) could act as a lipid trigger in higher (10.0 g/L) concentrations. The microalgae species Dunaliella tertiolecta (Chlorophyta), Mayamaea spp. (Baciallariophyta) and Synechoccocus sp. (Cyanophyta) were grown with 0.0 g/L, 0.5g/L, 1.0 g/L, 2.0 g/L and 5.0 g/L dissolved NaHCO_(3) in modified seawater (f/2) media. To investigate effects of NaHCO_(3) on lipid accumulation, growth media cultures were divided into two ―lipid phase‖ medias containing either 0.0g/L (non-boosted) or 10.0 g/L (boosted) NaHCO_(3) treatments. Culture densities were determined using spectrophotometry, which showed both all three species are able to successfully grow in media ameliorated with these high NaHCO_(3) concentrations. Highest growth phase culture densities occurred in NaHCO_(3) concentrations of 2.0 g/L for D. tertiolecta and Mayamaea spp., and the 5.0 g/L treatment for Synechoccocus sp. Highest growth rates occurred in the 5.0 g/L NaHCO_(3) concentration treatments for D. tertiolecta, Mayamaea spp., and Synechoccocus sp. (0.205 d-1 ±0.010, 0.119 d-1 ±0.004, and 0.372 d-1 ±0.003 respectively). As a lipid accumulation trigger two of the three species (D. tertiolecta and Mayamaea spp) had their highest end day oil indices in a 10.0 g/L treatment. Highest oil indices occurred in boosted 5.0 g/L Dunaliella tertiolecta and 2.0 g/L Mayamaea spp. (13136 ± 895 and 62844 ± 8080 respectively (relative units)). The results obtained indicate NaHCO3 could be used as a photosynthetic carbon source for growth in all three species and a lipid trigger for D. tertiolecta and Mayamaea spp.

Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.

Tomato (Lycopersicon esculentum Mill.) is an important commercial crop. High quality tomatoes for the local and export markets are grown hydroponically. In this study, the effect of electrically activated sodium bicarbonate and non-ionized sodium bicarbonate solutions on productivity and postharvest quality of hydroponically grown tomatoes was tested. Sodium bicarbonate is a ready source of bicarbonate. By using a novel technique obtained from Radical Waters (Pty) Ltd., ionized bicarbonate (anolyte) can be produced from sodium bicarbonate and applied to plants to stimulate photosynthesis, and improve yield and postharvest quality. The effect of ionized and non-ionized bicarbonate solutions on productivity and postharvest quality was studied by measuring the following: (1) Preharvest growth rate (leaf length, stem height and diameter); total yield; starch concentration in leaves; fruit count; leaf chlorophyll content; CO2-uptake; soluble solids and concentration of K+, Na+ and NO3¯ in leaves. (2) Postharvest rate of respiration and transpiration; ethylene production; total soluble solids content; ascorbic acid content; pH; fruit firmness; fruit mass; fruit diameter; longevity; concentration of K+, Na+ and NO3¯ at one-third towards maturity, two-thirds towards maturity, at maturity and during ripening, and rate of ripening at 12 and 23°C. During the preharvest period, plants treated with anolyte showed increased growth rate, starch concentration, chlorophyll content, soluble solids content and improved yield. During the growth period, the concentration of K+ and NO3¯ was higher in plants treated with anolyte than in plants treated with non-ionized sodium bicarbonate. The concentration of Na+ during the preharvest period was higher in plants treated with non-ionized sodium bicarbonate than in plants treated with anolyte. After harvest, fruits from plants treated with anolyte had a reduced rate of ethylene production, rate of respiration and transpiration, total increased soluble solids and ascorbic acid content than fruits from plants treated with non-ionized sodium bicarbonate. Fruits from plants treated with anolyte had reduced rate of ripening and were larger and heavier than fruits from plants treated with non-ionized sodium bicarbonate. Anatomical and ultrastructural studies revealed that treatment with anolyte stimulated cell growth and photosynthesis. These results were confirmed by comparing the CO2-uptake of treated and untreated plants. Application of anolyte stimulated photosynthesis, thus improving yield and fruit quality. Treatment with non-ionized sodium bicarbonate resulted in salt- stress and calcium deficiency. Some of the fruits on plants treated with non-ionized sodium bicarbonate suffered from blossom-end rot due to salt-stress. / Prof. C.S. Whitehead

The cultivation of chrysanthemums originated in China more than 2000 years ago. Today this flower is regarded as one of the most popular cut flowers in the world. It is, therefore, important to ensure that high quality flowers are produced consistently for the local and export markets. Chrysanthemum morifolium cv. ‘Sunny Reagan’ flowers were grown in a greenhouse sprayed with an electro-activated sodium bicarbonate solution (anolyte) in an attempt to improve productivity and postharvest quality. A non-activated sodium bicarbonate solution was also used to determine the overall effect of sodium bicarbonate on chrysanthemum plants. Sodium bicarbonate acts to enrich the environment of the plant with CO₂ thereby increasing its photosynthetic activity. Anolyte showed a positive preharvest effect on the chrysanthemum plant by increasing the leaf size and overall quality. On the other hand, sodium bicarbonate produced low quality plants with fewer flowers than the control. These plants also exhibited necrotic leaf edges, which is a sign of salt stress. Anolyte-treated plants exhibited no significant increase in postharvest longevity. Anolyte treated plants showed an increase in leaf cell size and density and a decrease in the size of intercellular air spaces, indicating an improved ability for photosynthesis, whereas, treatment with sodium bicarbonate resulted in thinner leaves with a smaller midrib and a less developed vascular system when compared to the control. The chloroplasts in anolyte-treated plants exhibited an increase in starch grains, also an indication of enhanced photosynthesis. Anolyte-treated plants also showed an increase in chlorophyll concentration and an improved CO₂ uptake. It is clear from this study that anolyte stimulated photosynthesis in chrysanthemum plants, thus resulting in longer stems with more and larger flowers and leaves. / Prof. C.S. Whitehead