Atmospheric lidar research applying to H2O, O2 and aerosols

Experimental research on a near infrared tunable dye laser was reported, and theoretical simulations were presented for various lidar configurations. The visible and nearinfrared wavelengths considered were suitable for observations of aerosols, water vapor, molecular oxygen pressure and temperature in the troposphere and above. The first phase of development work was described on a ruby pumped, tunable dye laser for the wavelength region 715 to 740 nanometers. Lidar simulations were summarized for measurements of H2O and for two color lidar observations of aerosols in the atmosphere

Absorption of Nutrient Ions by the Tomato Plant at Various Stages of Development

In studies with herbaceous annuals, it has often been observed that characteristic changes in metabolism and rate of growth are closely associated with certain stages in the development cycle (Loehwing, 1942, 1948, 1951; Murneek, 1937; Wittwer, 1943). Of particular interest have been changes accompanying synapsis and syngamy. One of the changes following these stages appears to be a marked acceleration in the rate of inorganic ion uptake from the substrate. Such accelerations have been shown to follow floral initiation and formation of the embryo in several plants including barley (Burd, 1919), corn (Hornberger, 1882; Jones and Huston, 1914), cotton (Olson and Bledsoe, 1942) and tobacco (Vladescu, 1934). Al though it has been reported that the largest increment in nutrient absorption by the tomato plant occurs during flowering and fruiting (Hester, 1938; Hester et al., 1951), this plant has apparently not been examined critically to determine whether two maxima are present within this period of stimulated uptake. This investigation was initiated to determine whether the rate of ion absorption by the tomato plant was correlated with particular stages in development

The Adaptability of Several Histological Techniques to the Preparation of P32 Radioautographs from Plant Tissues

With the increased use of radioactive isotopes in plant research, there has been a corresponding increase in the application of radioautographic techniques. Through the use of such radioautographs, tissue localization of the radioactive elements has been accomplished thereby giving additional insight into the accumulation and role of various elements in specific tissues. One of the radioactive elements that has found widespread application in physiological research is P 32. Although a number of workers have prepared P32 autographs from unsectioned plant tissues, very few have been made using histological sections (McIlrath, 1948). Because of the widespread use of this radioactive element in plant research and the very few histological radioautographs found in the literature, this problem was undertaken to determine which of several histological techniques might be adaptable to the preparation of such radioautographs

Tunable lasers for water vapor measurements and other lidar applications

A tunable dye laser suitable for differential absorption (DIAL) measurements of water vapor in the troposphere was constructed. A multi-pass absorption cell for calibration was also constructed for use in atmospheric DIAL measurements of water vapor

Molecular Precursors in Aqueous Solution for CIGSe Solar Cells

Thin film solar cells are one of the most promising alternatives to traditional silicon based solar cells. Copper, indium, gallium, and sufur/selenium (CIGS) act as the absorber layer in one type of thin films. CIGS films are preferable to silicon because they can have wider applications, such as flexible solar cells. The highest efficiency CIGS solar cells have been made using either expensive vacuum equipment or highly toxic chemicals. This study investigates non-toxic molecular precursor solutions deposited by spray coating. Stoichiometric amounts of CIGS are dissolved in ammonium thioglycolate and ammonium hydroxide to create the molecular precursor solution. This solution is then spray coated onto a molybdenum coated glass substrate. The CIGS coated substrate is then selenized to encourage crystal growth. The selenized substrate is then made into a full solar device. The research concluded that one can successfully dissolve molecular precursors in water-based solvents and deposit the solution onto a substrate. With some improvements in deposition and the solution’s ability to wet the molybdenum, CIGS solar cells could be made using nontoxic, water-based solvents

The Nutrient Substrate in Relation to Temperature and Photoperiodic Responses of Spinach

Plant physiologists throughout the years have used various substrates in an attempt to secure one which would give plant responses comparable to those of soil. Plants grown in water culture method, as practiced by the physiologist of the nineteenth century, showed little correlation with those grown in solid substrates or soil. Plants grown in chemically inert sand give results closer to those in soil but serious limitations are still encountered. In recent years gravel and other coarse mineral materials have been employed and the plant growth responses obtained correlate quite closely with those found when soil is used. Certain disadvantages have been found with many mineral media which are not totally inert, physically or chemically. Often the physical phenomena of adsorption and ionic replacement have been found to seriously alter the composition of the nutrient solution when mineral substrate is used. The bringing of the mineral into soluble form by the root acid has also been a definite drawback

Nitrate Adsorbed on Pumice as a Nitrogen Source for Plant Growth

In recent years it has been shown, through the use of commercial ion-exchange material, that plants are able to utilize nitrate ions incorporated in soil or nutrient culture in an adsorbed state (Schlenkler, 1940, 1942; Converse, Gammon and Sayre, 1943; Graham and Albrecht, 1943; Jenny, 1946; Arnon and Grossenbacher, 1947; Hunter, 1948). In view of the apparent adsorptive power of pumice (Veller and Arutyunyan, 1933), it was of interest to determine whether this material could be utilized in plant nutrition studies to supply nitrogen as adsorbed nitrate. Although preliminary experimentation showed that the nitrate fixing capacity of pumice was very low, it did not indicate what portion of this nitrate was available for plant absorption. It was for this reason that this investigation was undertaken