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Effect of Bicarbonate Ion and Root Aeration on Lime-Induced ChlorosisLindsay, Willard L. 01 May 1953 (has links)
Chlorosis in plants has been recognized as a devastating disease for over one-hundred and fifty years. It is easily recognized by a yellowing of the plant foilage and is associated with a reduced chlorophyll synthesis.
Chlorosis is found so frequently on calcareous soils that its cause is attributed at least in part to this soil factor. It is therefore referred to as lime-induced chlorosis. This type of chlorosis has become a serious problem, especially in many of the fruit-growing regions of Europe and the Western United States where the soils are calcareous. In Utah the disease is more destructive than any other nutritional disease that affect horticultural crops. The exact cause of lime-induced chlorosis is not known, nor has a satisfactory control been developed as yet.
Many conditions found in high-lime soils have been studied with regard to chlorosis, yet the problem is not so simple as it may appear. Green and chlorotic plants are frequently found growing in the same field, and yet a chemical analysis of the two soils fails to indicate a significant difference between them. It is common in chlorotic orchards to see trees where some of the major branches produce chlorotic foilage while the remainder of the tree is healthy and green. The severity of chlorosis varies from tree to tree as well as from season to season.
It has been found that the heavier textured soils which are poorly drained are more conductive to chlorosis than are the lighter textured soils. If the soil moisture is held near field capacity, chlorosis is much more severe than if the soil is allowed to approach the wilting point before irrigation. Recent studies have also shown that the bicarbonate ion in solution cultures can induce chlorosis and retard the uptake of iron by plants. Since these factors--high moisture, soil aeration, and bicarbonate ion concentration--are all interrelated, it seems that their relationship to chlorosis should be investigated more thoroughly. Workers in the past have failed to show a consistent correlation between either the oxygen or the carbon dioxide can be measured at the soil-root interface. this is after all the only place in the soil that is of great importance as far as the living plant is concerned.
Since the severity of chlorosis increases under poorly aerated conditions on calcareous soils, this hypothesis has been advanced: The respired carbon dioxide is given off at the plant root as carbonic acid which in a calcareous soil reacts with calcium and magnesium carbonate to give an increased bicarbonate ion concentration in the root environment. The resulting increased concentration of bicarbonate may reduce the effective oxygen at the root and thereby disturb the normal respiration and active-ion absorption of the roots or the increased concentration of bicarbonate may affect the roots absorption and plant metabolism in some other manner.
The purpose of this investigation was to study the effect of the bicarbonate ion and different aeration mixtures on chlorosis. A preliminary study was made to relate the composition of the soil solution taken from the field with different conditions associated with chlorosis.
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The Mineral Content of Various Sections of Some Plants as Influenced by Conditions Associated with Lime-Induced ChlorosisVar Petersen, Hyrum Del 01 May 1961 (has links)
The so-called "lime-induced" chlorosis has been recognized for many years as a problem where plants are grown on calcareous soils. The characteristics associated with lime-induced chlorosis are the same as those associated with iron deficiency chlorosis--interveinal yellowing of the leaves at the meristemic region combined with reduced vigor of the plant as a whole. Lime-induced chlorosis is unique in that the iron content of both chlorotic plant and the soil do not always show a deficiency in iron when chemically analyzed. This leads to the theory that iron is inactivated in both the soil and plant.
Although no single factor has been found to adequately explain this physiological disease, many factors have been associated with it. Thorne, Wann, and Robinson (1950) observed that calcareous soils characterized by fine texture, high moisture content, poor aeration, and cool temperatures intensify the development of chlorosis in plants. In general increased chlorosis has also been noted under conditions of high pH. The pH and phosphorus effects appear to involve reduced iron solubility in the soil and within the plant while the exact effects of the bicarbonate ion on chlorosis have not been established.
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Greenalgae as a substrate for biogas production - cultivation and biogas potentialsLiu, Yang January 2010 (has links)
<p>Algae is regarded as a good potential substrate for biogas production, due to high cells productivity, low cellulose and zero lignin content. Two parts were included in this study: first, cultivations of micro-algae (<em>Chlorella sorokiniana</em> and <em>Tetraselmis suecica</em>) at two different nitrate concentrations, also the effect of addition of CO<sub>2</sub> on algae grow was investigated in this first part. Second, batch fermentations of the cultivated micro-algae as well as a powder <em>Chlorella</em> (obtained from Raw Food Shop) and a dry mix filamentous algae (collected in the pounds in the park at the back of the Tema-building and then dried) were performed. In this part also effects of thermo-lime pretreatment (room temperature, 80<sup>o</sup>C, 105<sup>o</sup>C and 120<sup>o</sup>C) on the algae biogas potentials was investigated.</p><p> </p><p>Both strains of micro-algae cultured at low nitrate gave more CH<sub>4</sub> yield: 319 (±26) mL and 258 (±12) mL CH<sub>4 </sub>per added gVS was obtained during the degradation of <em>Chlorella sorokiniana </em>grown at 0.4mM-N and 2mM-N level, respectively. For<em> Tetraselmis suecica</em> 337 (±37) mL and 236 (±20) mL CH<sub>4</sub> per added gVS was obtained at 2.4mM-N and 12mM-N level, respectively. Powder <em>Chlorella</em> gave the highest biogas production (719 ±53 mL/added gVS) and CH<sub>4</sub> yields (392 ±14 mL/added gVS), followed by the dry filamentou<em>s</em> algae (661 ±20 mL biogas and 295 ±9 mL CH<sub>4</sub> per added gVS) and <em>Tetraselmis suecica</em> (12 mM-N; 584 ±7 mL biogas and 295 ±9 mL CH<sub>4</sub> per added gVS).</p><p> </p><p>A negative effect of lime treatment at room temperature on CH<sub>4</sub> yield of algal biomass was obtained. Lime treatment at 120<sup>o</sup>C showed the fastest degradation rate for <em>Tetraselmis</em> <em>suecica </em>and powder <em>Chlorella</em> during the initial 5 days of incubation. </p><p> </p><p><em>Chlorella sorokiniana</em> and <em>Tetraselmis suecica</em> cultures flushed with biogas containing 70% and also CO<sub>2</sub> enriched air (5% CO<sub>2</sub>) did not increase cells growth (measured as OD<sub>600</sub>) if compared to references grown under air. On the contrary, a clearly inhibition effect on the algal cells growth was observed in some cultures.</p>
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The lime industry, a potential business area for Kanthal / Kalkindustrin, en möjlig marknad för KanthalEjenstam, Jesper January 2010 (has links)
<p>The subject of this M.Sc. thesis is to find out whether the lime industry is a possible business area for Kanthal AB. The lime industry is one of the biggest chemical industries in the world and it is very energy demanding. In the process of making quicklime, calcium oxide, a lot of energy is needed as the dissociation of limestone, which consists mainly of calcium carbonate, takes place in the temperature span between 900°C and 1300°C. The total production of quicklime was in 2009 about 280 million tonnes, and the selling price was about $100 per ton. Today, all limekilns are driven by fossil fuels, i.e. oil, coal and gas. The increasing demand on lowering the emissions of carbon dioxide strongly affects the industry, as it is responsible for about 2 % of the total emissions of carbon dioxide. The industry itself claims that the emissions may only be reduced about 10 %, although at very high costs. Kanthal AB produces electric heating solutions that may be suitable for lime production. However, the lime industry is conservative and the use of electricity for lime production is not economically feasible today. Most of the electricity comes from coal power plants and therefore the use of electricity would not be more environmentally friendly in most countries. New limekilns, which are more environmentally friendly, are on the way. These kilns do not necessarily have to use fossil fuels, provides a purer end product and the emission of carbon dioxide is minimized. The size of the production is also much lower, but the end products might be used in more demanding areas, e.g. the pharmaceutical industry, and be sold at a higher price. It is this area Kanthal has to focus on if going to enter the lime industry at this point.</p>
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The lime industry, a potential business area for Kanthal / Kalkindustrin, en möjlig marknad för KanthalEjenstam, Jesper January 2010 (has links)
The subject of this M.Sc. thesis is to find out whether the lime industry is a possible business area for Kanthal AB. The lime industry is one of the biggest chemical industries in the world and it is very energy demanding. In the process of making quicklime, calcium oxide, a lot of energy is needed as the dissociation of limestone, which consists mainly of calcium carbonate, takes place in the temperature span between 900°C and 1300°C. The total production of quicklime was in 2009 about 280 million tonnes, and the selling price was about $100 per ton. Today, all limekilns are driven by fossil fuels, i.e. oil, coal and gas. The increasing demand on lowering the emissions of carbon dioxide strongly affects the industry, as it is responsible for about 2 % of the total emissions of carbon dioxide. The industry itself claims that the emissions may only be reduced about 10 %, although at very high costs. Kanthal AB produces electric heating solutions that may be suitable for lime production. However, the lime industry is conservative and the use of electricity for lime production is not economically feasible today. Most of the electricity comes from coal power plants and therefore the use of electricity would not be more environmentally friendly in most countries. New limekilns, which are more environmentally friendly, are on the way. These kilns do not necessarily have to use fossil fuels, provides a purer end product and the emission of carbon dioxide is minimized. The size of the production is also much lower, but the end products might be used in more demanding areas, e.g. the pharmaceutical industry, and be sold at a higher price. It is this area Kanthal has to focus on if going to enter the lime industry at this point.
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Effekter av luftföroreningar på lavar och grönalger på lind i Norrköpings kommunSonelin, Sarah January 2012 (has links)
Syftet med denna studie var att undersöka vilka effekter luftföroreringar har på lavar och grönalger som växer på lindar, genom att jämföra lavfloran i urban miljö och i landsbygdsmiljö. Mer specifikt var syftet att utreda hur avstånd till närmaste väg, trafikintensitet och trädets exponerade respektive icke-exponerade sida gentemot en väg påverkar lavfloran i urban miljö. 18 utvalda lavarter samt grönalger eftersöktes på 86 lindar i urban miljö och 37 i landsbygdsmiljö inom Norrköpings kommun. Resultaten visade att artantalet, samt förekomsten och täckningsgraden för flertalet lavar var större i landsbygdsmiljö jämfört med urban miljö. Kortare avstånd till närmaste väg och hög trafikintensitet hade negativ effekt på flertalet lavar. I båda fallen visades det motsatta för grönalger. Det fanns ingen skillnad i förekomster av lavar om de exponerades utåt mot vägen eller bort från vägen. / The aim of this study was to investigate which effects air pollution has on epiphytic lichens and green algae in urban and rural environment, respectively. More specifically, the aim was to investigate the effects on the lichen flora of distance to the nearest road, traffic volume and to compare the effect of tree sides exposed and not exposed to roads in the urban environment. 18 selected lichen selected species and green algae as a taxonomic group where searched on 86 lime trees in urban and 37 in rural environments in the Norrköping municipality. The species number was higher and the majority of the lichens occurred more often and showed a higher cover on trees in rural areas compared to trees in the urban environment. Shorter distance to the nearest road and high traffic volume had a negative impact on the majority of lichens. In both cases the opposite was shown for the green algal group. The lichens occurred equally often on the sides of the trees that were exposed to the road as on the sides that were not exposed to the road.
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Development of Oxidative Lime Pretreatment and Shock Treatment to Produce Highly Digestible Lignocellulose for Biofuel and Ruminant Feed ApplicationsFalls, Matthew David 2011 August 1900 (has links)
At present, the United States generates biofuels (ethanol) from corn grain. Unfortunately, low crop yields and limited growth regions result in limited availability. Furthermore, the use of staple food crops for ethanol production has generated a highly controversial food vs. fuel debate. Because of its high abundance and relatively low cost, lignocellulosic biomass is a promising alternative feedstock for biofuel production; however, structural features of lignocellulose limit accessibility of enzymes or microorganisms. These structural barriers include high lignin content, acetyl groups on hemicellulose, high cellulose crystallinity, cellulose degree of polymerization, and small pore volume. To overcome these barriers, a variety of pretreatment processes (chemical and mechanical) have been developed.
Oxidative-lime pretreatment (OLP) is highly effective at reducing lignin content and removing acetyl groups from hemicellulose. Combining OLP with a mechanical treatment process greatly enhances the enzymatic digestibility of lignocellulose.
Recommended OLP conditions were determined for Dacotah (120 °C, 6.89-bar O2, 240 min) and Alamo (110 °C, 6-89-bar O2, 240 min) switchgrass. Using recommended conditions, 72-h glucan digestibilities (g glucan hydrolyzed/100 g glucan in raw biomass; 15 filter paper units/g raw glucan) of 85.2 and 88.5 were achieved for Dacotah and Alamo, respectively. Adding ball milling to OLP further enhanced glucan digestibility to 91.1 (Dacotah) and 90.0 (Alamo).
In previous studies, shock treatment achieved promising results, but was often inconsistent. This work refined shock treatment with a focus on using consistent procedures and performance analysis. The combination of OLP and shock treatment enhanced the 72-h glucan digestibility of several promising biomass feedstocks: bagasse (74.0), corn stover (92.0), poplar wood (94.0), sorghum (71.8), and switchgrass (89.0). Highly digestible lignocellulose can also be used as ruminant animal feed. Shock treatment plus OLP increased the total digestible nutrients (TDNN; g nutrients digested/100 g organic matter) of corn stover from 51.9 (untreated) to 72.6. Adding in pre-washed corn stover solubles to produce a combined feed (17.8 percent corn stover solubles and 82.2 percent shock OLP corn stover) increased TDNN to 74.9. Mixing in enough solubilized protein to match the crude protein content of corn grain further improved TDNN to 75.5, only 12.6 less than corn grain.
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Identifying soils with potential of expanding sulfate mineral formation using electromagnetic inductionFox, Miranda Lynn 15 November 2004 (has links)
Sulfate-bearing soils are a problem in highway construction as they combine with materials used for lime stabilization to form minerals, particularly ettringite, that expand and induce heave in the stabilized soil. This research involves quantifying sulfate in soils that may be potentially used in highway construction using electromagnetic induction. The objectives are to: 1) document electrical conductivity (EC) variability within selected sites that contain sulfate-bearing materials, and 2) determine if electromagnetic induction has potential for locating hazardous levels of sulfate-bearing materials.
The 0.43 ha study area is located in the Blackland Prairies and is a Vertisol known to contain gypsum at the time of site selection. Apparent EC using a model EM38 electromagnetic induction instrument was measured at 200 locations in July and November 2003, using a sampling grid with 5-m spacings. Representative rows and columns were selected from the map of apparent electrical conductivity, and soil cores taken to a depth of 1.5 m at 29 points. Soil samples were obtained by dividing cores into depth increments of 0 to 25 cm, 25 to 75 cm, and 75 to 150 cm. Laboratory analyses were run for each sample and included moisture content, EC and soluble cations and anions of the saturated paste extract, and percent gypsum. Elevation measurements were made to determine if changes in elevation related to EC measurements.
Apparent EC proved to be more successful at detecting soluble salts during the dry sampling period (July) when the effect of soil moisture content was less. For July data, EC and gypsum were significantly correlated in the deepest samples (r2 = 0.51 and 0.15, respectively) to apparent EC. Further, soluble sulfate was significantly correlated to apparent EC (r2 = 0.30) at a depth of 25 to 75 cm. Results suggest that the EM38 can be used successfully to map variability of soil salinity across a field, but although correlation exists between apparent EC and sulfate-bearing materials, it is not sufficiently strong to serve as a good predictor for conditions surrounding lime-induced heave in soil.
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Chemical usage and savings at the Austin Water Utility drinking water treatment plantsDobbertien, Matthew Francis, 1988- 18 June 2012 (has links)
The goal of this research was to maintain excellent water quality at reduced chemical operations cost. Chemical usage data at the Austin water treatment plants were examined by identifying trends and investigating suspected inefficiencies. The investigation consisted in jar test experiments, plant-scale experiments, and equilibrium modeling. Lime and ferric sulfate were suspected to be added inefficiently with respect to cost while the other treatment chemicals were assessed to be added efficiently. Lime was investigated in greater depth than ferric sulfate because ferric sulfate was better characterized in its effect on finished water quality within the range of interest. The goal of lime addition is to remove hardness from the water by a process called lime softening. Hardness removal decreases corrosion in transmission lines and prevents deposition of unwanted solids in household appliances. Additionally, lime softening aids in particle removal and disinfection-by-product precursor reduction. The efficiency of lime addition was evaluated based on settled water pH and causticity goals, which serve as the operating parameters for the water treatment plants. The most efficient lime softening occurs when multiple softening goals are simultaneously achieved. First, the dissolved calcium concentration must achieve a minimum. Second, the dissolved magnesium concentration must be reduced by at least 10 mg/L as CaCO₃. Third, total alkalinity must be preserved at its maximum concentration while also achieving excellent hardness removal. Fourth, natural organic matter (NOM), which serves as a precursor for disinfection-by-products, must be removed sufficiently to achieve DBP reduction goals. Finally, the turbidity in the effluent from the settling basin must be below 2.0 NTU. Through the chemical investigation of lime based on existing scientific literature, computer modeling, jar test experiments, and full-scale testing, it was determined that the optimal condition operating condition for lime softening was a settled water pH range from 10.0 - 10.1. / text
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The Iron Content of Some Plants as Influenced by Conditions Associated with Lime-Induced ChlorosisWarnock, Robert E. 01 January 1952 (has links)
No description available.
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