Floodgates were constructed in 1971 on the main creek draining Hexham Swamp, a large wetland on the floodplain of the lower Hunter River, New South Wales. Substantial changes in vegetation have occurred in Hexham Swamp subsequent to the construction of the floodgates. Previous areas of mangroves and saltmarsh have been reduced (180ha to 11ha, and 681ha to 58ha, respectively), and Phragmites australis has expanded (170ha to 1005ha). Much of the mangrove loss (ca. 130ha) was a result of clearing, and the remainder has gradually died off. The factors contributing to the dieback are likely to be a combination of drying of the soil, root competition and, at times, waterlogging. Field sampling as well as microcosm and reciprocal transplant experiments involving key species, Sarcocornia quinqueflora, Sporobolus virginicus, Paspalum vaginatum and Phragmites australis, suggest that a reduction in soil salinity has been an important factor in initiating successional change from saltmarsh to Phragmites reedswamp. The data also suggest that increased waterlogging has been an important factor in initiating vegetation change. This apparently paradoxical result (floodgates and associated drainage generally result in drying of wetlands) is likely to have resulted from occlusion of drainage lines (by sediment and reeds) and is, therefore, likely to be a condition that developed gradually. That is, the initial effect of the floodgates is expected to have been a drying of the swamp, followed over time by an increasing wetness. An examination of vegetation changes after removal of cattle from part of Hexham Swamp, suggests that grazing had little effect on species composition of vegetation or rate of expansion of Phragmites australis. However, grazing does affect vegetation structure (height and density), possibly favours some coloniser species (e.g. Sarcocornia quinqueflora) in particular environmental conditions, and possibly inhibits establishment of Phragmites australis.

Os vertedores são estruturas hidráulicas construídas para controlar o nível d’água do reservatório, permitindo a passagem das vazões escoadas com a máxima eficiência possível sem provocar problemas à estrutura. Para atingir este objetivo, as condições de aproximação do escoamento à estrutura e a forma geométrica do perfil vertente são muito importantes. O controle da soleira por comportas provoca uma mudança significativa nas condições de escoamento sobre o perfil vertente. O posicionamento e a forma da comporta tem forte influência no comportamento do coeficiente de vazão e nas pressões sobre a soleira. A formação de vórtice é um fenômeno indesejável que pode ocorrer quando a operação da comporta é parcial, prejudicando a capacidade de vazão e provocando vibrações na estrutura. Este trabalho apresenta uma abordagem teórica sobre o assunto vertedor de superfície e escoamento sob comportas, apresentando resultados de diferentes estudos para melhor compreensão do funcionamento do vertedor. / Spillways are hydraulic structures constructed to control the water level of the reservoir, allowing the overflows with the maximum possible efficiency without provoking problems to the structure. The approach flow pattern to the structure and the geometric form of the spillway profile are basic importance. The control of the spillway by the floodgates modifies the draining conditions. The positioning and the form of the gate have strong influence in the behavior of the discharge coefficient and the pressures on the surface profile. A vortex formation is an undesirable phenomenon that it can occur when the operation of the floodgate is partial, reducing the discharge coefficient and produce vibrations in structure. This work presents a theoretical approach about flow over spillway and under of the partial opening of the floodgate, presenting results of different studies for better understanding the function of the spillway.

Os vertedores são estruturas hidráulicas construídas para controlar o nível d’água do reservatório, permitindo a passagem das vazões escoadas com a máxima eficiência possível sem provocar problemas à estrutura. Para atingir este objetivo, as condições de aproximação do escoamento à estrutura e a forma geométrica do perfil vertente são muito importantes. O controle da soleira por comportas provoca uma mudança significativa nas condições de escoamento sobre o perfil vertente. O posicionamento e a forma da comporta tem forte influência no comportamento do coeficiente de vazão e nas pressões sobre a soleira. A formação de vórtice é um fenômeno indesejável que pode ocorrer quando a operação da comporta é parcial, prejudicando a capacidade de vazão e provocando vibrações na estrutura. Este trabalho apresenta uma abordagem teórica sobre o assunto vertedor de superfície e escoamento sob comportas, apresentando resultados de diferentes estudos para melhor compreensão do funcionamento do vertedor. / Spillways are hydraulic structures constructed to control the water level of the reservoir, allowing the overflows with the maximum possible efficiency without provoking problems to the structure. The approach flow pattern to the structure and the geometric form of the spillway profile are basic importance. The control of the spillway by the floodgates modifies the draining conditions. The positioning and the form of the gate have strong influence in the behavior of the discharge coefficient and the pressures on the surface profile. A vortex formation is an undesirable phenomenon that it can occur when the operation of the floodgate is partial, reducing the discharge coefficient and produce vibrations in structure. This work presents a theoretical approach about flow over spillway and under of the partial opening of the floodgate, presenting results of different studies for better understanding the function of the spillway.

Šiame magistro darbe analizuojama grynai turtinių nuostolių atlyginimo problema. Grynai turtiniai nuostoliai daugumoje valstybių suvokiami kaip trečiųjų asmenų ekonominio pobūdžio nuostoliai, kurie patiriami įvykus deliktui tarp kitų asmenų. Žvelgiant lyginamuoju aspektu, valstybių teisės sistemose yra suformuotos dvi pozicijos šių nuostolių atžvilgiu: liberalioji ir griežtoji. Pirmoji pozicija, leidžianti grynai turtinių nuostolių atlyginimą, vyrauja Prancūzijoje. Tuo tarpu JAV, Anglijoje, Vokietijoje ir Austrijoje yra taikoma grynai ekonominių nuostolių atlyginimo ribojimo taisyklė. Magistro darbo autorė atlikdama lyginamąjį tyrimą, stengėsi išsiaiškinti, kokios priežastys skatina riboti grynai turinių nuostolių atlyginimą, taip pat įvertinti, kurios valstybės pozicija yra racionaliausia ir teisiškai labiausiai pagrįsta. Tiesa, pažymėtina yra tai, kad nors valstybėje vyrauja viena ar kita pozicija, tam tikrais atvejais neapsieinama be pagrindinės taisyklės išimčių. Lietuvoje šiuo klausimu kol kas dar nėra nei teismų praktikos, nei mokslinių diskusijų. Tad autorė, išanalizavusi įstatyminę bazę, pateikia išvadą, kad Lietuvai artimiausia galėtų būti Prancūzijos pozicija. Be lyginamosios valstybių teisės sistemų analizės, magistro darbe pateikiamas ir istorinis ekonominių asmens interesų apsaugos tendencijų tyrimas, siekiant išsiaiškinti, kada atsirado grynai turtinių nuostolių ribojimo taisyklė ir dėl kokių priežasčių. Taip pat paskutinėje magistro darbo dalyje lyginamuoju... [toliau žr. visą tekstą] / The thesis ‘Recovery of Pure Economic Loss: Comparative Aspects’ provides a comparative analysis of recovery possibilities of pure economic loss in six different countries, namely the USA, England, Germany, Austria, France and Lithuania, that belong to different legal families and inherit distinct tort law traditions. In most of the countries pure economic loss define economic nature loss of third parties that are experienced in the case of the tort of other persons. The objective of investigation is to evaluate legal rationality of each regulatory system and to estimate which one of them causes least practical problems. In addition, as the position of Lithuania has not yet been settled, the author of the thesis proposes possible directions of the regulation of recovery of pure economic loss by analyzing legal basis of Lithuanian laws. The research consists of three parts each of them dealing with different aspects of the problem. First of all, the concept of pure economic loss is analyzed by trying to define the archetypical features of the mentioned loss and to expose the summarized topics that are discussed in doctrine and courts. The second part of the thesis covers historical investigation of the protection of economic interests and comparative analysis of legal regulation and jurisprudence of recovery of pure economic loss in six mentioned countries. Additionally, at the end of this part the author discusses the possibilities of harmonization of the countries positions... [to full text]