APPLICATION HEIGHT IN HERBICIDES EFFICIENCY IN BEAN CROPS

ABSTRACTInadequate herbicide application can result in failures in weed control and/or poisoning of the crops, resulting in yield losses. In this research were assessed the effects of the sprayer nozzle boom height in the distribution of the spray solution for weed control, influencing intoxication of beans and crop yield. Experiments were conducted in laboratory and field conditions. In laboratory, the performance of flat spray tip TT 11002 was assessed at heights 0.20, 0.30, 0.40 and 0.50 meters with respect to the target surface. In the field the same heights were assessed in applications of herbicides fomesafen, fluazifop-P-butyl and fomesafen + fluazifop-P-butyl. There was an inverse relationship between the height of the spray boom and the coefficients of variation of the patterns. The mixture better efficiency in a tank of fluazifop-P-butyl + fomesafen was obtained with the height of 0.50 m from the target. This treatment resulted in better weed control, lower poisoning of the bean plants and better crop yield rates.

WATER USE EFFICIENCY, GROWTH AND YIELD OF WHEAT CULTIVATED UNDER COMPETITION WITH Setaria

ABSTRACT Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.

SULFENTRAZONE SELECTIVITY AND EFFICIENCY IN CASSAVA CROPS IN SANDY AND CLAYEY SOILS

ABSTRACT Weeds have the potential to dramatically interfere in cassava cultivation, reducing its productive potential; however, there are few studies on the selective herbicides in this crop. Therefore, the objective was to evaluate in this work the selectivity and efficiency of sulfentrazone in cassava crops grown in sandy and clayey soils. Two experiments were carried out: The first one was carried out in sandy soil conditions in the conventional system; and the second one was carried out in clayey soil conditions in the no-tillage system. The experimental design was a randomized block with four replications. The treatments consisted in doses of 250, 500, 750 and 1,000 g ha-1 of sulfentrazone, and weeded and non-weeded controls. Sulfentrazone application in cassava crops has linearly reduced the production of roots in a proportion of 0.0153 and 0.0107 t ha-1 at each increment in grams of the active ingredient, respectively. It was concluded that sulfentrazone was not selective for cassava crops grown both in sandy and in clayey soil; however, it was highly effective in weed control in both soils.

Application Volumes and Sizes of Droplets for the Application of Diquat Herbicide in the Control of Eichhornia crassipes

The objective of this study was to evaluate the efficiency of application and the efficacy of control of water hyacinth (Eichhornia crassipes) with the use of the diquat herbicide done with two application volumes associated to three droplets classes. Three experiments were conducted; in the first, the application efficiency was evaluated; in the second, the control efficiency and; in the third, the droplet spectrum. They were conducted in a completely randomized design with five, four and six replicates, respectively. The treatments were arranged in a 2 x 3 factorial design, with two application volumes (100 and 200 L ha-1) and three droplets classes (fine, extremely coarse and ultra-coarse) to the first and second experiment and the third comprised two diquat concentrations in spray solution (2 and 4 g i.a. L-1) and three droplets classes (fine, extremely coarse and ultra-coarse). The application efficiency was determined by the coverage by droplets, spray deposition and active ingredient of the herbicide (diquat). The efficacy was measured by the control and the percentage of plants with regrowth at 50 days after application. The spectrum of droplets produced per each nozzle model used to obtain the droplets classes were analyzed. According to the parameters analyzed, using the droplets classes extremely thick and ultra thick can provide greater certainty in the application of diquat in the aquatic environment associated with the deposition of the active and sufficient coverage to control Eichhornia crassipes with both application volumes

Treatment of Fe-containing Acid Mine Waters in Fixed Bed Adsorption Column with Calcite Side-Stone

The acid mining drainage is considered the most significant environmental pollution problem around the world for the extensive formation acidic leachates containing heavy metals. Adsorption is widely used methods in water treatment due to it easy operation and the availability of a wide variety of commercial adsorbent (low cost). The primary goal of this thesis was to investigate the efficiency of neutralizing agents, CaCO3 and CaSiO3, and metal adsorption materials with unmodified limestone from Company Nordkalk Oy. In addition to this, the side materials of limestone mining were tested for iron adsorption from acidic model solution. This study was executed at Lappeenranta University of Technology, Finland. The work utilised fixed-bed adsorption column as the main equipment and large fluidized column. Atomic absorption spectroscopy (AAS) and x-ray diffraction (XRD) was used to determine ferric removal and the composition of material respectively. The results suggest a high potential for the studied materials to be used a low cost adsorbents in acid mine drainage treatment. From the two studied adsorbents, the FS material was more suitable than the Gotland material. Based on the findings, it is recommended that further studies might include detailed analysis of Gotland materials.

Belt conveyor energy efficiency analysis and energy model development

An energy model of a belt conveyor was designed. Operation of a belt conveyor was researched. Operational indexes were calculated. Energy optimization process and recommendations were presented.

A comparative analysis of preprocessing techniques of cardiac event series for the study of heart rhythm variability using simulated signals

In the present study, using noise-free simulated signals, we performed a comparative examination of several preprocessing techniques that are used to transform the cardiac event series in a regularly sampled time series, appropriate for spectral analysis of heart rhythm variability (HRV). First, a group of noise-free simulated point event series, which represents a time series of heartbeats, was generated by an integral pulse frequency modulation model. In order to evaluate the performance of the preprocessing methods, the differences between the spectra of the preprocessed simulated signals and the true spectrum (spectrum of the model input modulating signals) were surveyed by visual analysis and by contrasting merit indices. It is desired that estimated spectra match the true spectrum as close as possible, showing a minimum of harmonic components and other artifacts. The merit indices proposed to quantify these mismatches were the leakage rate, defined as a measure of leakage components (located outside some narrow windows centered at frequencies of model input modulating signals) with respect to the whole spectral components, and the numbers of leakage components with amplitudes greater than 1%, 5% and 10% of the total spectral components. Our data, obtained from a noise-free simulation, indicate that the utilization of heart rate values instead of heart period values in the derivation of signals representative of heart rhythm results in more accurate spectra. Furthermore, our data support the efficiency of the widely used preprocessing technique based on the convolution of inverse interval function values with a rectangular window, and suggest the preprocessing technique based on a cubic polynomial interpolation of inverse interval function values and succeeding spectral analysis as another efficient and fast method for the analysis of HRV signals

Minimizing Conducted RF-Emissions in Switch Mode Power Supplies Using Spread-Spectrum Techniques

Switching power supplies are usually implemented with a control circuitry that uses constant clock frequency turning the power semiconductor switches on and off. A drawback of this customary operating principle is that the switching frequency and harmonic frequencies are present in both the conducted and radiated EMI spectrum of the power converter. Various variable-frequency techniques have been introduced during the last decade to overcome the EMC problem. The main objective of this study was to compare the EMI and steady-state performance of a switch mode power supply with different spread-spectrum/variable-frequency methods. Another goal was to find out suitable tools for the variable-frequency EMI analysis. This thesis can be divided into three main parts: Firstly, some aspects of spectral estimation and measurement are presented. Secondly, selected spread spectrum generation techniques are presented with simulations and background information. Finally, simulations and prototype measurements from the EMC and the steady-state performance are carried out in the last part of this work. Combination of the autocorrelation function, the Welch spectrum estimate and the spectrogram were used as a substitute for ordinary Fourier methods in the EMC analysis. It was also shown that the switching function can be used in preliminary EMC analysis of a SMPS and the spectrum and autocorrelation sequence of a switching function correlates with the final EMI spectrum. This work is based on numerous simulations and measurements made with the prototype. All these simulations and measurements are made with the boost DC/DC converter. Four different variable-frequency modulation techniques in six different configurations were analyzed and the EMI performance was compared to the constant frequency operation. Output voltage and input current waveforms were also analyzed in time domain to see the effect of the spread spectrum operation on these quantities. According to the results presented in this work, spread spectrum modulation can be utilized in power converter for EMI mitigation. The results from steady-state voltage measurements show, that the variable-frequency operation of the SMPS has effect on the voltage ripple, but the ripple measured from the prototype is still acceptable in some applications. Both current and voltage ripple can be controlled with proper main circuit and controller design.

Concentration of hydrogen peroxide and improving its energy efficiency

Distillation is a unit operation of process industry, which is used to separate a liquid mixture into two or more products and to concentrate liquid mixtures. A drawback of the distillation is its high energy consumption. An increase in energy and raw material prices has led to seeking ways to improve the energy efficiency of distillation. In this Master's Thesis, these ways are studied in connection with the concentration of hydrogen peroxide at the Solvay Voikkaa Plant. The aim of this thesis is to improve the energy efficiency of the concentration of the Voikkaa Plant. The work includes a review of hydrogen peroxide and its manufacturing. In addition, the fundamentals of distillation and its energy efficiency are reviewed. An energy analysis of the concentration unit of Solvay Voikkaa Plant is presented in the process development study part. It consists of the current and past information of energy and utility consumptions, balances, and costs. After that, the potential ways to improve the energy efficiency of the distillation unit at the factory are considered and their feasibility is evaluated technically and economically. Finally, proposals to improve the energy efficiency are suggested. Advanced process control, heat integration and energy efficient equipment are the most potential ways to carry out the energy efficient improvements of the concentration at the Solvay Voikkaa factory. Optimization of the reflux flow and the temperatures of the overhead condensers can offer immediate savings in the energy and utility costs without investments. Replacing the steam ejector system with a vacuum pump would result in savings of tens of thousands of euros per year. The heat pump solutions, such as utilizing a mechanical vapor recompression or thermal vapor recompression, are not feasible due to the high investment costs and long pay back times.

NIR-Vis Up-Conversion Luminescence in the Yb3+,Er3+ Doped Y2O2S, ZrO2, and NaYF4 Nanomaterials

Since the discovery of the up-conversion phenomenon, there has been an ever increasing interest in up-converting phosphors in which the absorption of two or more low energy photons is followed by emission of a higher energy photon. Most up-conversion luminescence materials operate by using a combination of a trivalent rare earth (lanthanide) sensitizer (e.g. Yb or Er) and an activator (e.g. Er, Ho, Tm or Pr) ion in a crystal lattice. Up-converting phosphors have a variety of potential applications as lasers and displays as well as inks for security printing (e.g. bank notes and bonds). One of the most sophisticated applications of lanthanide up-conversion luminescence is probably in medical diagnostics. However, there are some major problems in the use of photoluminescence based on the direct UV excitation in immunoassays. Human blood absorbs strongly UV radiation as well as the emission of the phosphor in the visible. A promising way to overcome the problems arising from the blood absorption is to use a long wavelength excitation and benefit from the up-conversion luminescence. Since there is practically no absorption by the whole-blood in the near IR region, it has no capability for up-conversion in the excitation wavelength region of the conventional up-converting phosphor based on the Yb3+ (sensitizer) and Er3+ (activator) combination. The aim of this work was to prepare nanocrystalline materials with high red (and green) up-conversion luminescence efficiency for use in quantitative whole-blood immunoassays. For coupling to biological compounds, nanometer-sized (crystallite size below 50 nm) up-converting phosphor particles are required. The nanocrystalline ZrO2:Yb3+,Er3+, Y2O2S:Yb3+,Er3+, NaYF4:Yb3+,Er3+ and NaRF4-NaR’F4 (R: Y, Yb, Er) materials, prepared with the combustion, sol-gel, flux, co-precipitation and solvothermal synthesis, were studied using the thermal analysis, FT-IR spectroscopy, transmission electron microscopy, EDX spectroscopy, XANES/EXAFS measurements, absorption spectroscopy, X-ray powder diffraction, as well as up-conversion and thermoluminescence spectroscopies. The effect of the impurities of the phosphors, crystallite size, as well as the crystal structure on the up-conversion luminescence intensity was analyzed. Finally, a new phenomenon, persistent up-conversion luminescence was introduced and discussed. For efficient use in bioassays, more work is needed to yield nanomaterials with smaller and more uniform crystallite sizes. Surface modifications need to be studied to improve the dispersion in water. On the other hand, further work must be carried out to optimize the persistent up-conversion luminescence of the nanomaterials to allow for their use as efficient immunoassay nanomaterials combining the advantages of both up-conversion and persistent luminescence.

The low efficiency of dendritic cells and macrophages from mice susceptible to Paracoccidioides brasiliensis in inducing a Th1 response

In the present study we evaluated T cell proliferation and Th lymphokine patterns in response to gp43 from Paracoccidioides brasiliensis presented by isolated dendritic cells from susceptible and resistant mice. T cell proliferation assays showed that dendritic cells from susceptible mice were less efficient than those from resistant mice. The pattern of T cell lymphokines stimulated by dendritic cells was always Th1, although the levels of IL-2 and IFN-gamma were lower in T cell cultures from susceptible mice. To determie whether different antigen-presenting cells such as macrophages and dendritic cells stimulated different concentrations of Th1 lymphokines, the production of IFN-gamma and IL-2 was measured. It was observed that dendritic cells were more efficient than macrophages in stimulating lymphoproliferation in resistant mice. However, no significant difference was observed for IFN-gamma or IL-2 production. When cells from susceptible mice were used, macrophages were more efficient in stimulating lymphoproliferation than dendritic cells, but no difference was observed in the production of Th1 cytokine. Taken together, these results suggest the lower efficiency of dendritic cells and macrophages from B10.A mice in stimulating T cells that secrete Th1 lymphokines in vitro, an effect that may be involved in the progression of the disease in vivo.

Plasma and testicular testosterone levels, volume density and number of Leydig cells and spermatogenic efficiency of rabbits

Plasma and tissue testosterone concentrations were determined by radioimmunoassay in 12 eight-month-old sexually mature New Zealand White rabbits and evaluated for possible associations with spermatogenic efficiency as well as with volume density and number of Leydig cells. Testicular tissue was processed histologically and histometry was performed in order to quantify germ cells, Sertoli cells and Leydig cells. Spermatogenic efficiency, reported as the ratios among germ cells (spermatogonia, primary spermatocytes and round spermatids) and by the ratio of germ cells to Sertoli cells, was not associated with testosterone levels. However, Leydig cell parameters such as number of Leydig cells per gram of testis, total number of Leydig cells per testis and percent cell volume of Leydig cell nuclei were correlated significantly with testosterone levels. The statistically significant correlation (r = 0.82, P<0.05) observed between testosterone levels and the number of Leydig cells per gram of testis suggests that, in the rabbit, the latter parameter can serve as a criterion for monitoring testosterone levels in this species under normal conditions.

Comparative performance of two air samplers for monitoring airborne fungal propagules

Many studies have attempted to evaluate the importance of airborne fungi in the development of invasive fungal infection, especially for immunocompromised hosts. Several kinds of instruments are available to quantitate fungal propagule levels in air. We compared the performance of the most frequently used air sampler, the Andersen sampler with six stages, with a portable one, the Reuter centrifugal sampler (RCS). A total of 84 samples were analyzed, 42 with each sampler. Twenty-eight different fungal genera were identified in samples analyzed with the Andersen instrument. In samples obtained with the RCS only seven different fungal genera were identified. The three most frequently isolated genera in samples analyzed with both devices were Penicillium, Aspergillus and Cladophialophora. In areas supplied with a high efficiency particulate air filter, fungal spore levels were usually lower when compared to areas without these filters. There was a significant correlation between total fungal propagule measurements taken with both devices on each sampling occasion (Pearson coefficient = 0.50). However, the Andersen device recovered a broader spectrum of fungi. We conclude that the RCS can be used for quantitative estimates of airborne microbiological concentrations. For qualitative studies, however, this device cannot be recommended.

Surface studies of limestones and dolostones : characterisation using various techniques and batch dissolution experiments with hydrochloric acid solutions

In this thesis, stepwise titration with hydrochloric acid was used to obtain chemical reactivities and dissolution rates of ground limestones and dolostones of varying geological backgrounds (sedimentary, metamorphic or magmatic). Two different ways of conducting the calculations were used: 1) a first order mathematical model was used to calculate extrapolated initial reactivities (and dissolution rates) at pH 4, and 2) a second order mathematical model was used to acquire integrated mean specific chemical reaction constants (and dissolution rates) at pH 5. The calculations of the reactivities and dissolution rates were based on rate of change of pH and particle size distributions of the sample powders obtained by laser diffraction. The initial dissolution rates at pH 4 were repeatedly higher than previously reported literature values, whereas the dissolution rates at pH 5 were consistent with former observations. Reactivities and dissolution rates varied substantially for dolostones, whereas for limestones and calcareous rocks, the variation can be primarily explained by relatively large sample standard deviations. A list of the dolostone samples in a decreasing order of initial reactivity at pH 4 is: 1) metamorphic dolostones with calcite/dolomite ratio higher than about 6% 2) sedimentary dolostones without calcite 3) metamorphic dolostones with calcite/dolomite ratio lower than about 6% The reactivities and dissolution rates were accompanied by a wide range of experimental techniques to characterise the samples, to reveal how different rocks changed during the dissolution process, and to find out which factors had an influence on their chemical reactivities. An emphasis was put on chemical and morphological changes taking place at the surfaces of the particles via X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). Supporting chemical information was obtained with X-Ray Fluorescence (XRF) measurements of the samples, and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) measurements of the solutions used in the reactivity experiments. Information on mineral (modal) compositions and their occurrence was provided by X-Ray Diffraction (XRD), Energy Dispersive X-ray analysis (EDX) and studying thin sections with a petrographic microscope. BET (Brunauer, Emmet, Teller) surface areas were determined from nitrogen physisorption data. Factors increasing chemical reactivity of dolostones and calcareous rocks were found to be sedimentary origin, higher calcite concentration and smaller quartz concentration. Also, it is assumed that finer grain size and larger BET surface areas increase the reactivity although no certain correlation was found in this thesis. Atomic concentrations did not correlate with the reactivities. Sedimentary dolostones, unlike metamorphic ones, were found to have porous surface structures after dissolution. In addition, conventional (XPS) and synchrotron based (HRXPS) X-ray Photoelectron Spectroscopy were used to study bonding environments on calcite and dolomite surfaces. Both samples are insulators, which is why neutralisation measures such as electron flood gun and a conductive mask were used. Surface core level shifts of 0.7 ± 0.1 eV for Ca 2p spectrum of calcite and 0.75 ± 0.05 eV for Mg 2p and Ca 3s spectra of dolomite were obtained. Some satellite features of Ca 2p, C 1s and O 1s spectra have been suggested to be bulk plasmons. The origin of carbide bonds was suggested to be beam assisted interaction with hydrocarbons found on the surface. The results presented in this thesis are of particular importance for choosing raw materials for wet Flue Gas Desulphurisation (FGD) and construction industry. Wet FGD benefits from high reactivity, whereas construction industry can take advantage of slow reactivity of carbonate rocks often used in the facades of fine buildings. Information on chemical bonding environments may help to create more accurate models for water-rock interactions of carbonates.

Forecasting financial weather - can we foresee market sentiment? Spectrum of stock price behavior - NYSE case study

The desire to create a statistical or mathematical model, which would allow predicting the future changes in stock prices, was born many years ago. Economists and mathematicians are trying to solve this task by applying statistical analysis and physical laws, but there are still no satisfactory results. The main reason for this is that a stock exchange is a non-stationary, unstable and complex system, which is influenced by many factors. In this thesis the New York Stock Exchange was considered as the system to be explored. A topological analysis, basic statistical tools and singular value decomposition were conducted for understanding the behavior of the market. Two methods for normalization of initial daily closure prices by Dow Jones and S&P500 were introduced and applied for further analysis. As a result, some unexpected features were identified, such as a shape of distribution of correlation matrix, a bulk of which is shifted to the right hand side with respect to zero. Also non-ergodicity of NYSE was confirmed graphically. It was shown, that singular vectors differ from each other by a constant factor. There are for certain results no clear conclusions from this work, but it creates a good basis for the further analysis of market topology.