This study used electrospinning to fabricate a polyvinylidene fluoride (PVDF) piezoelectric nanofiber harvesting device with interdigitated electrode to capture ambient energy. According to d33 mechanical-electric energy conversion mode, the energy harvesting device can be applied on the low frequency ambient vibration and impact abilities for the transformation mechanical energy into electrical energy effectively. First, the PVDF powder was mixed in acetone solution uniformly and the dimethyl sulfoxide (DMSO) was mixed with multi-walled carbon nanotube (MWCNT) to prepare PVDF macromolecular solution. The mixed solution was filled in a metals needle injector and contacted hundreds of voltage. After the PVDF drop in the needle was subjected to high electric field, the drop overcame surface tension of the solution itself, then extremely fine PVDF fiber was formed and spun out. The electrospun was collected orderly using X-Y digital control stage and the linear diameter of electrospun can be controlled easily by adjusting the travelling speed of the stage. In the spinning process, as affected by stretching strain and electric field at the same time, the PVDF piezoelectric fiber resulted in electric polarization and transformed £] piezoelectric crystal phase, in which the dipoles are oriented in the same direction. Furthermore, MWCNT was added to improve the mechanical properties of fiber and increase £] phase, to enhance the tensile strength and piezoelectric property of PVDF fiber effectively. Finally, the photolithography was used to fabricate interdigitated electrodes with 100£gm gap on the flexible PI substrate. The PVDF fibers, with a length and diameter of approximately 1cm and 700-1000nm, were aligned on interdigitated electrodes and packaged with the PI film. In order to increase the conversion efficiency of piezoelectric fiber in d33 mode, the PVDF fibers were repolarized in a high electric field. The results showed that the PVDF fiber energy harvesting device can generate 15mV open-circuit voltage under low frequency vibration of 4Hz and generate above 30mV open-circuit voltage under 6Hz vibrations. As compared with the piezoelectric fiber not repolarized by interdigitated electrode, its output voltage was increased by1- 2 times.

The health maintaining properties of citrus consumption are attributed to the wide assortment of bioactive compounds. Consumption of grapefruit along with certain medications, however, is posing a risk of drug toxicity and side reactions. The first study involved isolation of bioactive furocoumarins with a combination of chromatographic techniques and synthesis. Five furocoumarins namely, dihydroxybergamottin, paradisin A, bergamottin, bergaptol and geranylcoumarin were isolated from grapefruit and series of furocoumarin monomers and paradisin A were synthesized. The second study involved influence of pre- and post-harvest factors on the levels of furocoumarins in grapefruit juice. Considerable differences were observed in the levels of these compounds in different grapefruit cultivars. Ray Red showed the lowest levels of all three furocoumarins and Duncan contains the highest amount of DHB and bergamottin, where as the highest levels of paradisin A was observed in Star Ruby. The highest levels of DHB and bergamottin were found in Flame cultivar grown in California. The changes in the levels of these furocoumarins during the season in Rio Red and Marsh White grapefruit cultivars were evaluated. The third study investigated biological activities of grapefruit juices and furocoumarins. Grapefruit and Pummelo juices were found to be potent inhibitors of cytochrome CYP3A4 and CYP2C9 isoenzymes at 5% concentration while CYP2D6 was less affected. Among the five furocoumarins tested, the inhibitory potency was in the order of paradisin A>dihydroxybergamottin>bergamottin>bergaptol>geranylcoumarin at 0.1 µM to 0.1 mM concentrations. A fourth study investigated the effect of furocoumarins on bacterial auto-inducer signaling, and found that furocoumarins are potent inhibitors of AI-1 and AI-2 activities at 0.01% concentration. In a fifth study, involving synthesized furocoumarin monomers and dimer on anti-proliferative activities on normal and cancer cell lines, furocoumarins found to be non-toxic to normal cells. However, bergamottin showed a significant anti-proliferative activity in HT-29 and MCF-7 cell lines. This dissertation indicates that furocoumarins are bioactive compounds from grapefruit juice with potent inhibitory property of major drug metabolizing cytochrome P450 isoenzymes. Furocoumarins show a considerable variation between varieties, location and season. These results corroborate the involvement of furocoumarins in grapefruit drug interaction.

Der Klimawandel wird künftig die landwirtschaftlichen Erträge beeinflussen. Die Studie schätzt die Auswirkungen der projizierten Klimaänderungen auf die Entwicklung der Erträge von Winterweizen, Winterroggen, Wintergerste, Winterraps und Silomais ab. Die Auswertungen erfolgten mit den statistisch orientierten Modell YIELDSTAT für den Zeitraum bis 2050 auf der Grundlage des Klimaszenarios WEREX IV A1B. Unter pessimistischen Annahmen sind durchgängig leichte Ertragseinbußen bis 2050 zu erwarten. Allerdings sind weder CO2-Düngungseffekte noch der wissenschaftlich-technischen Fortschritt hierbei berücksichtigt worden. Dagegen kann bei optimistischen Betrachtungen von einer weiteren Ertragssteigerung vor allem bei Wintergetreide und Winterraps gerechnet werden. Das Regionalmodell WEREX IV projiziert eine vergleichsweise moderate Klimaänderung bis 2050. Mit einer stärkeren Ertragsbeeinflussung, insbesondere auf den leichten, diluvialen Standorten, ist dann zu rechnen, wenn sich das künftige Klima schneller und extremer verändert als gegenwärtig mit WEREX IV berechnet wurde. Infolge zunehmender Extremereignisse wird die Ertragsstabilität künftig abnehmen.

This thesis analyzes the feasibility of having an integrated wind and solar farm to optimize the use of land resources and capital investment by evaluating the effect that wind turbine shadows have on the area surrounding them. Two methods are used to predict shadow impact. The first method is based on the traditional textbook “Clear Sky” equations, which have maximum sensitivity to shadows because the method considers every day to be a perfect day. The second method uses measured global-horizontal and diffuse-horizontal solar radiation in units of W/m2, which take into account the true variations of daily conditions. The calculations are performed for 1 square meter surfaces, over different assumed areas of a wind power plant, for every second of the day. For purposes of shadow calculations, the tip-top height (i.e., tower height plus blade length) is used. All calculations are performed with the specifications of a GE 1.5 MW wind turbine, which is the most commonly used wind turbine in USA. / text

Biofuel is a renewable and sustainable energy source with near-neutral carbon footprint. Algae are an ideal feedstock for biofuel production because they reproduce quickly and have high oil. Algae can be cultivated in non-arable land, and would not impact the food supply. Unfortunately, processing algae into biofuel is more expensive than land crops due to the large volumes of dilute algal suspension that must be harvested and concentrated. In order to improve algae-based biofuel economics, resins were developed that reduce costs associated with water pumping and transport. Hydrophobic resins were developed for binding oil out of an algal suspension so that the residual biomass could be recovered without solvent contamination. Binding behavior displayed lipid species specificity, and binding capacity was improved by ethanol treatment of the biomass. Algae was harvested by binding to anion exchange resin and directly converted into biodiesel. One-step, room temperature in situ transesterification of algae yielded nearly as much biodiesel as two-step, heated transesterification of dried biomass. Elution with transesterification reagent also regenerated the resin for subsequent algal binding. Functionalized resins were developed with high algal binding capacity at neutral pH. Binding was easily reversed, as treatment with buffer with pH higher than pKa of the resin functional group removed the algae and regenerated the resin for subsequent use. The resin bound 10% of its weight in algae and released it as a 100-fold concentrated suspension. The polymers developed can be scaled up for commercial processes and reduce algal harvesting and concentration costs. / text

3 pp. / “Summer slump” is a decline in growth of alfalfa usually beginning in July in areas where maximum daily temperature exceeds 100 °F, such as the low elevation deserts of Southwestern U.S (Fig. 1). In more temperate regions, there is a gradual decrease in alfalfa yield in successive harvests throughout the year, but the yield decline in the summer is not as sharp as in hot summer regions. The term summer slump has also been applied to reduction in growth of perennial cool season grasses such as tall fescue during the summer.

Darbo objektas – bulvės, užaugintos chemizuotame ir ekologiniame fonuose Marijampolės apskrityje, Vilkaviškio rajone, Bambinių kaime. Darbo tikslas - Palyginti bulvių veisles, išaugintas chemizuotame(tręštame mineralinėmis trašomis) ir ekologiniame (tręštame organinėmis trąšomis) fonuose derliaus dydį ir juslines savybes. Darbo metodas. Tyrimai buvo atlikti 2006 m. balandžio - rugsėjo mėnesiais. Sėkla buvo apie 20 d. padaiginta šviesioje bei šiltoje patalpoje. Fonas paruoštas lauko bandymams. Įdirbtus laukus pavasarį ekologiniame fone tręšta tik mėšlu, o chemizuotame fone patręšta specialomis subalansuotomis bulvėms skirtomis trąšomis. Stebėtas bulvių vystymasis ir augimas visą vegetaciją. Tyrimai buvo vykdomi lauko bandymų metodu..Baigus vegetacijai, bulvės buvo kasamos ir sveriamos. Nustatyta 1 bulvių kero masė g, bei suskaičiuotas gumbų skaičius vnt. Iškasta kiekvienos veislės po 10 bulvių kerų. Gumbų masė nustatyta svėrimo metodu. 2007m. vasario mėn. visoms bulvių veislėms buvo atlikta juslinė analizė. Ekologiškai ir chemizuotai augintų bulvių gumbai virti vienodomis sąlygomis: kiekviena bulvių veislė atskiruose puoduose, su lupyna, be druskos. Virimo trukmė apie 30 min. Degustacijos metodas aprobuotas ir taikomas LŽI selekcininkų, išvedant veisles. Tyrimo rezultatai parodė, kad tręšiant mineralinėmis trąšomis bulves, derlingiausia buvo ‘Vinetos‘ veislė, o tręšiant tik mėšlu bulves, derlingiausia buvo ‘Vitaros‘, Quartos‘ veislės. Geriausiu skoniu pasižymėjo... [toliau žr. visą tekstą] / The object of labour- the potatoes which has been raise up in chemistry and ecology setting in Marijampole District of Vilkaviskis in Bambinys village. The objective of labour- to compare the harvest size and quality of taste of the potatoes breeds which has been raised up in intense and chemistry setting. Method of work-the Research has been done in April-September of 2007. The seed. was germinate about 20 days at light and worm premises. The set was prepared for field experiment. In a spring the cultivate fields has been fertiled ecology set just by dung and in chemistry set just by special fertile which was balanced to potatoes. Has been observe the potatoes evolution and vegetation. The research has been done by the outdoor experiment. At the end of vegetation the potatoes been mined and weight. Was maked the weigth of one potatoes scrub (g) and counted unite of scrubs. From every breed was mined 10 unit of scrubs. The tubers weight determined by the weight method. In February of 2007 to every potatoes strains has been done savour. The tubers which has been raised up in ecology and intense setting been boiled on the same conditions: the each potatoes breed had boiled in separate pots with skin and without salt. The boil duration was about half an hour. The method of savour been created and apllyed by the LZI Selectors to do selections of breeds. The results of experiment showed that when potatoes been raised up intense the mostly harvest been ‘Vinetos’ Strain... [to full text]

Structural retention harvesting represents one of the most important recent silvicultural innovations and is widely practiced in the harvesting of mature boreal stands. Following structural retention harvests, mortality of retained trees is often dramatically elevated compared to pre-harvest stands. I examined tree mortality following structural retention harvests in the southeastern Yukon Territory, using dendrochronological techniques to quantify annual mortality. I estimated integrated losses in the first five years to be at least 17.3% of retained stems. Analysis of mortality type showed that windthrow was the most important post-harvest mortality mechanism. This study represents the first analysis of mortality responses following structural retention harvests in the northern extent of operational forestry in Canada. Rates of post-harvest tree mortality observed in this study are among the highest reported to date from managed Canadian boreal forests, indicating that greater attention must be given to post-harvest stand responses if sustainable forestry practices are desired.

Structural retention harvesting represents one of the most important recent silvicultural innovations and is widely practiced in the harvesting of mature boreal stands. Following structural retention harvests, mortality of retained trees is often dramatically elevated compared to pre-harvest stands. I examined tree mortality following structural retention harvests in the southeastern Yukon Territory, using dendrochronological techniques to quantify annual mortality. I estimated integrated losses in the first five years to be at least 17.3% of retained stems. Analysis of mortality type showed that windthrow was the most important post-harvest mortality mechanism. This study represents the first analysis of mortality responses following structural retention harvests in the northern extent of operational forestry in Canada. Rates of post-harvest tree mortality observed in this study are among the highest reported to date from managed Canadian boreal forests, indicating that greater attention must be given to post-harvest stand responses if sustainable forestry practices are desired.

Interspecific competition is comprised of both resource dependant and resource independent processes. While many studies have focused on the role that resource dependant competition plays in reducing crop yields, few have investigated whether resource independent effects, such as light or hormonal signaling, may contribute to these yield losses. The focus of this thesis was to investigate the role of the shade avoidance response in determining the onset and outcome of crop-weed competition in maize (Zea mays L.). The results of greenhouse and field trials demonstrate that shade avoidance in maize can be induced shortly after seedling emergence and that the effects of this early response can be detected throughout the entire life cycle of the crop. Seedlings exposed to a weedy or low red to far-red light (R/FR) environment at emergence displayed an initial increase in plant height and a reduction in the root-to-shoot ratio. These effects were followed by a reduction in the rate of leaf appearance (RLA) and a linear decline in biomass and leaf area (LA) as the duration of time spent in a weedy environment increased. Conversely, seedlings emerging in a weed-free or ambient R/FR environment were unaffected regardless the duration of time spent in the weedy environment. These effects of early crop-weed competition are distinct from those of plant population density (i.e., intraspecific competition). Results of a field trial demonstrated that intraspecific competition at a conventional density of 8 plants m-2 did not negatively impact RLA or biomass accumulation until well after the defined critical period for weed control. Moreover, intraspecific competition at 16 plants m-2 was not detected until the 12th leaf tip stage, suggesting that the effects of crop density are more closely associated with canopy closure than an early shade avoidance response. At maturity, seedlings that expressed shade avoidance at early stages of development set fewer kernels and partitioned less biomass to the developing ear. Shade avoidance also doubled the plant-to-plant variability in yield parameters without affecting the mean or frequency distribution of shoot biomass at maturity. When taken together, the results of these studies indicate that shade avoidance destabilizes stand productivity by increasing plant-to-plant variability in reproductive effort prior to intra- or interspecific competition for resources.