Maize (Zea mays L.) is an important cereal crop not only in the world but more specifically in South Africa. Therefore, understanding maizeâs nutrient requirement becomes an importance factor especially during the vegetative growth period. Nitrogen (N) and phosphorus (P) are reported to be two essential nutrients for both accelerated vegetative growth and maximum yield. Addition of these two plant nutrients should include consideration of both form and total nutrient concentration, since these two factors determine availability and accessibility. In order to evaluate the response of maize to P sources and P application rates as well as N sources a glasshouse experiment was conducted in 40.5 L pots filled with a dark brown sandy-loam topsoil pertaining a medium soil pH of 5.5. Treatments consisted of three main factor treatments viz. N source (urea and limestone ammonium nitrate - LAN), P source (monoammonium phosphate - MAP, nitrophosphate - NP and ammonium polyphosphate - APP) and P application rate (0, 10, 20, 30 and 40 kg P ha-1). Treatments combinations were replicated three times and independently subjected to a randomized complete block design with a factorial combination. The experiment was repeated on two planting dates. Treatments and treatment combinations were band applied to dry soil in a single 0.34 m line, 50 mm below and 50 mm away from the maize seeds; which were planted with a between row spacing of 0.91 m, 50 mm below the soil surface. After planting the soil was watered and maintained at field capacity for a duration of five weeks after emergence. The aerial parameters of three plants per pot were measured on a weekly basis following emergence while the subsoil parameters were taken at the end of the five week vegetative growing period. Both aerial and subsoil parameters showed responses to nitrogen source; which was strongly reflected during both plantings. Plants treated with LAN yielded both greater aerial and subsoil measurements compared to urea, primarily ascribed to immediate availability after application in addition to ease in uptake. Both aerial and subsoil parameter response to phosphorus source and P application rate, though apparent throughout both plantings, was more prominent during the first planting. Monoammonium phosphate and NP (orthophosphate sources) yielded greater aerial measurements compared to that of the APP (polyphosphate source). Subsoil parameter results comparing phosphorus sources were inconsistent. Subsoil parameters of the fertilized zone were significantly greater with the use of MAP (orthophosphate), while APP (polyphosphate) yielded significant greater subsoil parameters within the unfertilized zone. Both aerial and subsoil parameter measurements taken either throughout or at the end of the vegetative growth period were overall significantly greater when P was applied at 40 kg P ha-1. Subsoil parameter response in and away from the fertilizer band was however inconsistent. The aerial dry plant material was analyzed (Omnia Nutriology®) to evaluate the effect of the three main treatments on the quantitative nutrient concentration as well as the uptake thereof. Nutrient concentration and uptake was used to determine the synergistic or antagonistic effect of treatments or treatment combinations. Nutrient concentration measurements were inconsistent for N source, however total uptake proved to be more efficient with the application of LAN compared to urea. Both nutrient concentration and uptake was greater with the application of both the orthophosphate sources (MAP and NP) compared to the polyphosphate source (APP). The 40 kg P ha-1 application yielded a synergistic response to the total uptake of S, N, P, Ca and B, while a synergistic nutrient concentration response was found with the control treatment for N, Mg, Cu and Zn nutrients. Nutrient uptake was also stimulated by an increasing rate of P.

<p> Enhanced warming and increasingly ice-free Arctic seas affect Arctic precipitation. We investigate increased Arctic precipitation due to declining sea ice by relating variations in moisture sources to stable isotope compositions of precipitation. We develop a novel method for deriving moisture sources using condensation profiles derived from cloud radar measurements to formulate initial heights for air mass back trajectories. This method was used to locate the moisture sources of seventy Barrow, AK storm events between 2009 and 2013. Trajectories were calculated by NOAA's HYSPLIT, using GDAS reanalysis wind fields. We demonstrate that the moisture source migrates with season, from distal in winter to proximal in summer. Moisture source dew point exhibits a semiannual cycle, with summer and winter maxima. The spring minimum reflects the reintroduction of the Arctic source. The autumn dew point minimum reflects pre-ice ocean cooling locally. 36% of isotopic variation is statistically explained by a combination of the moisture source dew point and trajectory cooling. Transport distance and path both influence the best descriptor of isotopic composition. For local events, dew point is the stronger influence on isotopic composition, explaining 21% of variance. For distal events, the effects of trajectory cooling supersedes the moisture source signal. The orographic effect of the Alaskan and Brooks ranges account for the influence of trajectory path on isotopic composition. Local moisture events during transition seasons were slightly enriched relative to distal events. If we measure further isotopic enrichment during future transition seasons, it may reflect increased contributions from the Arctic source and thus precipitation increase. Deuterium excess reflects various combinations of latitude, sea surface temperature and relative humidity. Moisture source dew point significantly but weakly predicts storm-specific d-excess. Similar analyses can be performed across the Arctic if reanalysis data can generate reliable condensation profiles. To evaluate the efficacy of condensation profiles produced by reanalysis data, we compared the condensation profiles derived from cloud radar to those from reanalysis. On average, reanalysis produced condensation profiles with mean cloud height 1.4 times higher than those from cloud radar. The greater elevation bias translated into a more distal, and thus warmer and drier, moisture source.</p>

An agroclimatic risk assessment for agricultural production across the Canadian prairie provinces has been assembled to address challenges related to frost, heat units, and moisture. Based on 30 years of daily climate data from 1971 though 2000 from 230 climate stations, the assessment provides a series of risk maps depicting the likelihood to achieve certain thresholds of frost dates or durations, heat unit accumulations, growing season rainfall, crop water demand (CWD), and crop water deficits. Maps for each parameter provide a spatial representation of 50%, 25%, and 10% risks and the coefficient of variation.

Climatic change has been observed in many locations and has been seen to have dramatic impact on a wide range of ecosystems. The traditional method to analyse trends in climatic series is regression analysis. Koenker and Bassett (1978) developed a regression-type model for estimating the functional relationship between predictor variables and any quantile in the distribution of the response variable. Quantile regression has received considerable attention in the statistical literature, but less so in the water resources literature. This study aims to apply quantile regression to problems in water resources and climate change studies. The core of the thesis is made up of three papers of which two have been published and one has been submitted. One paper presents a novel application of quantile regression to analyze the distribution of sea ice extent. Another paper investigates changes in temperature and precipitation extremes over the Canadian Prairies using quantile regression. The third paper presents a Bayesian model averaging method for variable selection adapted to quantile regression and analyzes the relationship of extreme precipitation with large-scale atmospheric variables. This last paper also develops a novel statistical downscaling model based on quantile regression. The various applications of quantile regression support the conclusion that the method is useful in climate change studies.

Global climate models predict changes in precipitation patterns in many areas of the world. Extreme precipitation in particular is poorly represented in climate models and there are significant difficulties involved in assessing the frequency and severity of future extreme precipitation events. In this study, several methods have been reviewed and compared for estimating projected changes in Intensity-Duration-Frequency (IDF) curves, commonly used in urban hydrology. A theoretical approach based on geostatistical considerations is employed to derive reasonable areal-reduction factors that make it possible to compare gridded model data with observations. The mean value method and QQ-mapping have been used to remove biases from modeled data. A simple scaling model has been developed to construct IDF curves using the bias-corrected modeled data for the control and future climate. To investigate uncertainties in predicted changes, different simulations from the North American Regional Climate Change Assessment Program (NARCCAP) have been analyzed.

Knowledge of past chmate variability is vital if the causes of observed chmate changes since instrumental records began are to be fully understood, particularly those, post-1850 AD, possibly due to anthropogenic activity. The past two millennia provide a long enough background with which to compare post-r850 AD change, whilst errors on proxy records remain relatively small. In the Eastem Mediterranean changes in water balance are of particular interest as water is an important resource. Oxygen isotope records from lakes in the region record changes in water balance and are therefore an important archive for observing natural, and anthropogenicaly forced, variabiUty in hydrology. Full understanding of cUmate proxies requires high-resolution analysis through the instramental time period for comparison with measured climate variability. Varved lake sediments provide the possibility for obtaining annually-resolvedarchives of climate proxies, andstrong chronological control through time. In this study gebchemical-climate proxies including oxygen and stable carbon isotope ratios were measured from two lakes in central Turkey with varved sediment archives. Lake Burdur's complex carbonate mineralogy and large catchment led to stable isotope data that is controlled by a variety of mischariisms and highlights the complex nature of some lake-isotope systems. A 1725 year long record was obtained from Nar GolU, with the top 900 years analysed at an annual resolution. Calibration of the top of this record with instmmental cHmate records suggests stable isotope variability at Nar is controlled by changes in evaporation, driven by changes in sunmier temperature and relative humidity. The proxy record from Nar shows sununer evaporation at Nar to be enhanced at times of increased Indian and African monsoon rainfall, and reduced during drier monsoon periods. Major shifts in the chmate system occur c. 500 and c. 1400 AD associated with times of change between relatively warm and cold periods of Northern Hemisphere temperatures. Cycles, with a frequency of 64 years, observed in the Nar isotope record and proxy records of solar activity suggest a solar forcing mechanism for decadal variability in the Eastem Mediterranean-Indian- African sununer climate system.

Vad händer om de ständiga förbättringarna tar slut? Förmågan att ständigt utvecklas och förändras har i vårt samhälle och inom den svenska industrin blivit en allt viktigare konkurrensfördel för att skapa framgångsrika organisationer. Marknadsförändringar förekommer numera i en alltmer progressiv takt och det framstår att organisationer med ett gott kreativt klimat förmår att skapa goda förutsättningar för att hantera omvärldens föränderlighet. Kärnan för industriella organisationer är ytterst att upprätthålla en accepterad produktionstakt och samtidigt skapa ett kreativt klimat som ger goda förutsättningar för att utveckling kan frodas. Det råder en enighet om att organisationer med ett gott kreativt klimat som ger medarbetare stöd, möjlighet och utrymme att omsätta idéer till verklig nytta, skapar goda förutsättningar för organisationers utvecklingsförmåga. Lösningen blir således organisationers interna kreativa klimat och hur förutsättningar för att förhålla sig utvecklingsorienterad skapas, i en alltmer föränderlig miljö, med en tro på den enskilda medarbetares förmåga att ständigt utvecklas. Organisationer har således mycket att vinna på att förstå och kontinuerligt mäta skillnaden mellan det rådande kreativa klimatet och det eftertraktade klimatet. Syftet med den här fallstudien är att mäta en svensk industris kreativa klimat och undersöka vilka hinder och möjligheter organisationens ledare och medarbetare upplever i utvecklingsarbetet.  Ett sekundärt syfte är att bidra till en ökad förståelse av förutsättningarna för en utvecklingsorienterad organisation i en industriell kontext genom att undersöka, utvärdera och analysera komplexiteten av utvecklingsarbetet. Studien visar en diskrepans i det kreativa klimatet mellan organisationens befintliga avdelningar och uppmuntrar till ytterligare forskning för att åskådliggöra de kausala relationerna.

No description available.

In the warm humid tropical climate of Bali, Indonesia, overheating and high humidity influence occupants' comfort, indoor climate and the comfort of their homes, both directly and indirectly. The traditional way to deal with these problems, using natural ventilation, was ecologically sound and acceptable. However, development of tourism in Bali has had a positive impact on people's earning, causing cultural pressure, migration and a rapid rise in the urban population, as well as increasing housing demand. In urban areas, the methods of climate modification have moved away from natural ventilation, and comfort is now more often achieved by installing air conditioning. This has caused increasing energy use and had economic impact. As world-wide energy consumption will continue to increase, the use of more energy will have more impact on global warming. In these circumstances, energy efficiency is paramount, particularly in the dwelling designs for new housing development in Indonesia. The study focuses on the design of a thermally comfortable dwelling in the warm humid climate of Bali, Indonesia, with emphasis on the energy efficiency of the naturally ventilated and air-conditioned dwelling. Using a computer program and energy conservation strategies, a dwelling design was simulated. A model dwelling was adopted from a standard house type for people on a middle class income, based on the family size of a couple with two children. Such units are built by the National Housing Authority of Indonesia. A comprehensive study of the computer-simulation outcomes, survey research, previous works undertaken and literature reviews were carried out, to develop a thermally comfortable dwelling design. This new thermally efficient dwelling design was simulated to draw the final conclusions of the research. The research discovered that the combination of both natural ventilation and air conditioning, integrated with the combined design of a compound-compact dwelling, are an intelligent response to the thermal comfort performance problems of a dwelling in the warm humid climate and architecturally adaptable to the culture of Bali. The study found that a combination of natural ventilation with air conditioning which is only used when necessary, coupled with insulation and shading devices, can significantly reduce energy consumption and achieve adequate thermal comfort. In this respect, however, architectural design should come first, and be considered before an engineering solution. The reasons are that architectural solutions are more robust, and has a long duration of applicability, while the technology is perhaps the opposite, being prone to mechanical failure. When a less compact dwelling is designed, increased use of natural ventilation can be achieved. The use of airtight construction, insulation in the building envelope and shading devices are effective ways of reducing the air-conditioning load.

The intent of this study was to investigate the efficient use of energy by developing an energy efficient grocery store combined with cogeneration. This study demonstrated the potential to reduce the energy use in buildings, by implementing a decentralized source of energy generation that allowed for the use of a portion of the energy generated to be shared across building boundaries. This study considered a high energy use building such as a grocery store to be a part of a residential community, which could potentially participate in the sharing of energy across building boundaries. To better utilize energy resources the study proposed the implementation of a cogeneration facility to supply energy primarily to the store. Surplus energy generated by this cogeneration system was then shared with the requirements of the surrounding residential community. Finally, in order to better account for energy consumption of these buildings both site and source energy was considered. The study focused on hot and humid climates. This study was presented in two parts: Analyzing conventional grocery store systems to determine the maximum savings possible; and examining the option of co-generation systems to provide power to grocery stores and a portion of the community in order to reduce source energy use for the grocery store and a portion of the surrounding community. Source energy savings were in the range of 47% to 54% depending on the energy efficiency measures selected and the cogeneration configuration determined in the grocery store. Economic payback periods in the range of 4 to 7 years (time until zero net present value) were observed. The selection of appropriate options was narrowed down to two options that utilized more thermal energy within the boundaries of the store and generated more amount of surplus energy to be absorbed by the neighboring residential buildings.