Готові списки джерел за темами / ZONE PROTECTION SYSTEM

Зміст

  1. Статті в журналах
  2. Дисертації
  3. Книги
  4. Частини книг
  5. Тези доповідей конференцій
  6. Звіти організацій

Добірка наукової літератури з теми "ZONE PROTECTION SYSTEM"

Автор: Grafiati
Опубліковано: 11 вересня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "ZONE PROTECTION SYSTEM".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "ZONE PROTECTION SYSTEM"

1

Zhang, Zhan Long, Li Yao, and Qun Wang. "Reliability Evaluation for Distribution System Including Protection System Failures." Advanced Materials Research 989-994 (July 2014): 1181–84. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.1181.

Повний текст джерела
Анотація:
A new model and method for incorporating the effect of protection system failures into distribution system reliability evaluation are developed this paper. Firstly, the distribution system is partitioned into zones with the auto (or non-auto) switch being the boundary; through the network equivalent approach, for each load point, three component groups are respectively formed by two types of zone-elements. Then two types of protection failures and their impacts on reliability modeling are discussed. Finally, the reliability Markov model of load point with protection failures has been developed. The test results of the samples demonstrate the practicability and validness of the method.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Steiakakis, Emmanouil, Dionysios Vavadakis, and Ourania Mourkakou. "Groundwater Vulnerability and Delineation of Protection Zones in the Discharge Area of a Karstic Aquifer—Application in Agyia’s Karst System (Crete, Greece)." Water 15, no. 2 (January 5, 2023): 231. http://dx.doi.org/10.3390/w15020231.

Повний текст джерела
Анотація:
This work represents a contribution to the protection techniques of karst aquifers against groundwater pollution. The paper sets out the methodology being introduced for the protection of the karstic system that gives rise to five (5) major groups of springs and supplies fourteen (14) pumping wells near Agyia Chania (Crete, Greece). Starting from a geological and hydrogeological survey of the area, the work presents a vulnerability assessment of the karstic aquifer based on the application of three index-based methods (EPIK, PRESK and DRISTPI). The protection zones for the discharge area of the aquifer were delineated through an integrated geomorphological approach and groundwater flow modeling. At first, the risk of polluting substances migration from ground surface to groundwater was considered based on the spatial distribution of vulnerability. Following this, the vulnerability was evaluated in the saturated zone, where the attenuation mechanisms of contaminants were reducing due to the raised flow velocity. The groundwater flow and contaminant transport processes was considered using the MODFLOW code. Next, the data from the vulnerability mapping and the groundwater flow simulation were merged into an integrated assessment to delimit the protection zones for the water abstraction points. The vulnerability assessment outlines zones of high vulnerability in the SE part of the area, far away from the discharge zone of the aquifer and the water abstraction points. These zones are associated with an intensive infiltration process via carbonate formations. Protection Zone I was delineated 20 m around the water abstraction points, and it should be excluded from any anthropogenic activity. Protection Zone II coves part of the very high and high vulnerability zones defined by the DRISTPI method (located upwards of the water abstraction points), as well as an area downwards of springs and wells, where the flow path lines which demonstrate the subsurface travelling time of 50 days are projected to the ground surface. Protection Zone III extends outside Zone Ι and Zone ΙΙ, up to the limits of the hydrogeological or hydrological basin, whichever is larger. It includes the entire capture zone (i.e., the surface and underground catchment area) that feeds the water abstraction points. In this manner the protection zones include the entire contributing area to water abstraction points, not just the ground surface recharge zone.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Rusina, N., V. Lyulʹchyk, P. Bida, O. Kachanovsʹkyy, S. Bulakevych, and O. Petrova. "Problems of installation water protective zones and coastal protective stripes." Zemleustrìj, kadastr ì monìtorìng zemelʹ, no. 3 (August 28, 2021): 6. http://dx.doi.org/10.31548/zemleustriy2021.03.06.

Повний текст джерела
Анотація:
The issue of establishing the boundaries of water protection and coastal stripes in Ukraine were examined in the article. The purpose of the study is to present the practical results of the formation the boundary delimiter of coastal protection stripes, based on scientific and methodological approaches to the development of land management projects for the establishment of coastal protection stripes and modern technologies in the area of geographic information system. Theoretical principles of establishing the boundaries of water protective zones and coastal protective stripes on water resources are analyzed. Regulatory basic documents on the subject of use in the establishment of water protection zones and coastal protection stripes have been explored. It is noted that the size of water protective zones and coastal protective stripes can be set in accordance with the provisions of the Land Code of Ukraine, and according to the especial projects in land management. It is suggested the procedure for establishing coastal and water protective zones is based on determining the hydrographic characteristics of water sites and morphological parameters of coastal areas using remote sensing data and geoinformation system and includes six steps: 1. Determination of morphometric parameters of water sites. 2. Obtaining relief data and its application 3.Determining the steepness of the slopes. 4. Construction of catchment areas and determination of surface effluent directions. 5. Creation of a buffer zone around water sites (construction of a protective stripe and a water protective zone). 6. Combining layers of informative maps for the final definition of boundaries. The use of the methodology is presented on a specific example, namely the pond in the village Gremyache, Rivne region. Methodology will provide a technical background for establishing and decision-making on the size of water protective zones and coastal protection stripes around water objects. One more aspect of the problem, solved by the methodology proposed in the article, involves informative supporting of decisions in a sphere of controlling water fund lands at the regional level as part of the planning measures for sustainable regions development and protection of water objects. Keywords: water protective zone, coastal protection belt, land management project, Earth remote sensing data of the Earth and geographic information system data, boundaries of the water protective zone and coastal protective stripe
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Chen, Wei Gang, Feng Du, Yue Zhuo, and Michael Anheuser. "Zone Selective Protection System with Multiple Power Sources." Applied Mechanics and Materials 538 (April 2014): 251–55. http://dx.doi.org/10.4028/www.scientific.net/amm.538.251.

Повний текст джерела
Анотація:
In the power system with multiple power sources, the fault current direction is not fixed. Therefore, the conventional ZSI protection is not suitable. Furthermore, the ZSI protection with fault current direction judgment function is required. In this paper, the R, L property based fault current direction judgment method is proposed. This method is verified based on the simulation and test result. The validation shows this method can correctly judge the fault current direction within shorter time than state of art method.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Xu, Qiang Ye, Jin Lian, and Hao Lian. "An Adaptive Protection Method for Power System under Wide Area Networks." Advanced Materials Research 403-408 (November 2011): 4189–93. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.4189.

Повний текст джерела
Анотація:
The grid structure and its operation mood are becoming more complicated with the expansion of China Power Network which have higher requirement for security protection for relay protection network. This article proposes adaptive setting of switch positioner and line fault under wide area networks. Adaptive setting of switch positioner in system operation mode can effectively extend the protection scope of zone 2 impedance relay on the premise of protecting the cooperative relationship which has a better sensibility than traditional setting value of zone 2 impedance relay. Adaptive setting of line fault has high level of adaptation in system operation mode and sensitivity in each adjacent line which has lager protection scope than that of the traditional setting value and switch positioner.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Park, Sung Yoon, Chien-Lun Lan, Ranteg S. Rao, and Gang-Len Chang. "Field Evaluation of the Dilemma Zone Protection System at Suburban Intersections." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 21 (June 11, 2018): 51–62. http://dx.doi.org/10.1177/0361198118774235.

Повний текст джерела
Анотація:
Despite the fact that both traffic researchers and highway agencies have devoted considerable efforts over the past few decades to improving intersection safety, development of effective strategies to contend with this vital issue remains a challenging task. This research presents the field evaluation results of a Dilemma Zone Protection System (DZPS) implemented at two hazardous intersections in Maryland, U.S.A. The deployed DZPS can offer both proactive and reactive protections to drivers approaching a signalized intersection during a yellow phase. Field evaluations conducted at two intersections with DZPS deployed confirmed a 100% detection rate for red-light-running vehicles, timely activation of the all-red extension to prevent right-angle crashes, and effectively discouraging drivers from taking aggressive “pass” decisions during the yellow or all-red phases. The potential extension of the DZPS for speed harmonization on arterial traffic flows is also discussed.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Amirrul, H. G., H. Hendrayana, and D. P. E. Putra. "Delineation of Mrutu Spring Protection Zone: An Attempt to Maintain the Sustainability of Groundwater Resources." IOP Conference Series: Earth and Environmental Science 1039, no. 1 (September 1, 2022): 012046. http://dx.doi.org/10.1088/1755-1315/1039/1/012046.

Повний текст джерела
Анотація:
Abstract Lumajang Regency government plans to optimize water resources using Mrutu Spring groundwater as a water source for the Drinking Water Supply System (SPAM). The maintenance of the groundwater quality and quantity sustainability is necessary to delineate the protection zone of Mrutu Spring. Geological, hydrogeological, and land use parameters assessed the spring protection zone. The Mrutu Spring protection zone determination was conducted using manual and analytical solutions and combination hydrogeological methods. This study finds that the protection zone of Mrutu Spring is around Mrutu Spring up to Mrutu Spring groundwater recharge in the northwest. Mrutu Spring protection zone is divided into protection zone I, II, III, and groundwater recharge for the spring protection zone. The geometry of protection zone I is a circle with a radius of 1.64 km and 314 m2. Protection zone II is in the fifth circle with a 1.64 km and 2.87 km2. Protection zone II has an ellipsoidal shape with a radius of 16.74 km and 67.28 km2. The groundwater recharge for the spring protection zone is oval, with a radius of ± 12 km and 57,85 km2.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Jeong, Jin A., and Chung Kuk Jin. "The Experimental Measurement on the Throwing Power of Sacrificial Anode Cathodic Protection for Concrete Piles in Natural Sea Water." Advanced Materials Research 1125 (October 2015): 350–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1125.350.

Повний текст джерела
Анотація:
This paper represents the experimental studies on the throwing power of sacrificial anode cathodic protection system applied to reinforced concrete piles in salt water condition by means of zinc anodes. Many previous studies show the effectiveness of sacrificial anode cathodic protection system, however, the major problem of sacrificial anode cathodic protection system is limited a distance to the point reaching protection current from the anode in high resistivity environments such as concrete, etc. In case of concrete pile in sea water condition, it should be combined submerged zone, tidal zone, splash zone, and atmospheric zone. In this study, the cathodic protection current by zinc sacrificial anodes was limited to scores of centimeters above the water line with tidal, depending on the concrete resistivity. Experimental tests were carried out on pile type reinforced concrete specimens with the change of water level. The test factors were corrosion and protection potential, current, and 4 hour depolarization potential. As a result of tests, cathodic protection current by zinc sacrificial anode was influenced up to about 10cm above the water line, and high resistivity areas such as atmospheric zone could not be protected with this system.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Zha, Liteng, Yunlong Zhang, Praprut Songchitruksa, and Danny R. Middleton. "An Integrated Dilemma Zone Protection System Using Connected Vehicle Technology." IEEE Transactions on Intelligent Transportation Systems 17, no. 6 (June 2016): 1714–23. http://dx.doi.org/10.1109/tits.2015.2490222.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Jose, Thara, Monalisa Biswal, K. Venkatanagaraju, and O. P. Malik. "Integrated approach based third zone protection during stressed system conditions." Electric Power Systems Research 161 (August 2018): 199–211. http://dx.doi.org/10.1016/j.epsr.2018.04.011.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Дисертації з теми "ZONE PROTECTION SYSTEM"

1

Caton, Brian. "The conservation of scenic coasts : an examination of the English heritage system and its possible use in South Australia /." Title page, contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09ENV/09envc366.pdf.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Marzec, Denise Pivatto. "Relé de distância tipo-fase compensado para sistemas de transmissão." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/60986.

Повний текст джерела
Анотація:
Relés de distância são muito utilizados para proteger linhas de transmissão. Porém, há baixa precisão dos limites de sua zona de proteção devido a fenômenos de subalcance e sobrealcance. Assim, nesta dissertação de mestrado é proposto um algoritmo com compensação da resistência de falta, baseado em coordenadas de fase, objetivando aumentar a precisão dos limites da zona de proteção. A formulação proposta utiliza uma estimativa da corrente de falta para estimar a resistência de falta e compensar a impedância aparente calculada. Foram realizados o equacionamento e desenvolvimento do algoritmo para faltas tipo fase. Simulações e testes numéricos comparativos com formulações estado-da-arte verificaram a eficiência do método proposto.
Distance Relays are widely used to protect transmission lines. However, due to underreaching and overreaching phenomena, there is a low precision in protection zone limits of distance relays. Thus, in this dissertation, a new algorithm based in phase coordinates is proposed to increase the precision in zone protection limits. The proposed method uses the fault corrent to estimate the fault resistance and compensate the apparent impedance calculated. The equation development was done for phase type faults. Comparative tests with state-of-the-art formulations verified the efficiency of the proposed method.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Твердохлєбова, Наталя Євгеніївна, та С. Д. Євтушенко. "Забезпечення безпеки учасників спортивних змагань". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/38886.

Повний текст джерела
Анотація:
Сучасні стадіони повинні відповідати суворим вимогам, що пред'являються до безпеки під час спортивних змагань. Головна вимога, яка має бути виконана, – створення об'єкта, безпечного для всіх, хто ним користується, будь-то глядачі, учасники матчу, офіційні особи, представники ЗМІ, обслуговуючий персонал.
Modern stadiums must match the strict requirements for safety during sports competitions. The main requirement that must be met is the creation of an object that is safe for all participants, be it spectators, match participants, officials, media representatives, service personnel.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Твердохлєбова, Наталя Євгеніївна, та Степан Дмитрович Євтушенко. "Організація системи безпеки на стадіонах". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/47827.

Повний текст джерела
Анотація:
Сучасні стадіони повинні відповідати суворим вимогам, що пред'являються до безпеки всіх учасників під час спортивних змагань. Головна вимога, яка має бути виконана, – створення об'єкта, безпечного для всіх, хто ним користується, будь-то глядачі, учасники матчу, офіційні особи, представники ЗМІ, обслуговуючий персонал.
Modern stadiums must match the strict requirements for safety during sports competitions. The main requirement that must be met is the creation of an object that is safe for all participants, be it spectators, match participants, officials, media representatives, service personnel.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Sinnott, Dennis. "The development of a hydrological buffer zone strategy for designating the mesotope protection zone of raised mire systems." Thesis, University of Central Lancashire, 2004. http://clok.uclan.ac.uk/22523/.

Повний текст джерела
Анотація:
The overall aim of this thesis has been to develop a pragmatic strategy to aid decisionmaking concerning the management of raised bogs for future sustainability, and specifically to provide a tool to identify the extents and locations of those areas around the bog margins within which water tables need to be managed. Undesirable water losses resulting from damage to peripheral lagg fens that would once have surrounded intact mire systems will be associated with a steepening change in hydraulic gradient. Although steep hydraulic gradients are frequently cited as a problematic threat to a raised bog there has been a lack of previous attempts to quantify a suite of indicative gradients to form a predictive model. This thesis has considered the possibility of identifying key areas of threatened lagg fen from analysis of topographic and hydraulic gradient data across the mire surface of surviving peat domes and their adjacent landscapes. These marginal lagg areas are important to the overall sustainable hydrology of raised bogs, but the identification of land judged necessary to the hydrological integrity of these habitats has received little attention in the scientific literature. Acquisition of the necessary indicative data, carried out at the landscape scale at a range of raised mires, was made feasible by the use of differential Global Positioning Systems (dGPS) for accurate and rapid surveying of transects across a suite of UK raised mires. It may be that developments in dGPS and remote sensing methods such as LiDAR will offer opportunities for future development of this approach. An early product of the strategy was the development of a methodology for carrying out rapid assessments of the condition or "health" of the sites. Profiles of the raised bogs were computed and a database of gradient results was generated for each profile. This involved the identification of generic slope features within the profile of the bogs. An attempt to identify characteristic values associated with generic profiles was then made. A simple data model has been derived, which is indicative of gradient thresholds between characteristic groups. Significant values for hydraulic gradient of between 0.0063-0.0082 across the raised bog dome, and 0.02 for the Rand or steeper shoulders of the bog are suggested for thresholds between relatively intact and damaged systems. These results may be used to compute target water levels at the edges of a mire, and to predict where in the surrounding land this needs to be achieved in order to help sustain the raised water table of the core peat dome. Following a verification process the indicative model was used to predict a preferred hydrological boundary at a further raised bog site (Swarth Moor in North Yorkshire; SD806695). Whilst the results relate to raised n-iires within the UK, and it would be useful therefore to now carry out a comparative study elsewhere, the results of this thesis strongly suggest that quantified gradient data provide a surrogate for judging where the hydrology of peripheral land may influence the condition of the core site. This may offer advantages to conservation agencies in their attempts to maximise the potential for sustainable restoration of this rare and valued habitat.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

ZaheriSarabi, Donia. "New Dilemma Zone Mitigation Strategies." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/64975.

Повний текст джерела
Анотація:
Drivers' mistakes in making immediate decision facing yellow signal interval to stop or go through the intersection is one of main factors contributing to intersection's safety. Incorrect decision might lead to a red light running and a right -angle Collison when passing through the intersection or a rear-end collision when failing to stop safely.Improperly timed traffic signal intervals result in the inability of the drivers to make the right decision and can place them in the dilemma zone. Advance warning systems (AWS) have been used to provide information about the downstream traffic signal change prior to approaching the intersection. On the other hand, advance warning systems increase drivers approach speed according to the literature. However, effect of AWS on dilemma zone has not been studied before. The goal of this thesis is to minimize the number of vehicles caught in dilemma zone by determining more precise boundaries for dilemma zone and to reduce the number of red light violations by predicting the red light runners before arriving to the intersection. Here, dilemma zone boundaries at the presence of AWS has been reexamined with the aid of a large dataset (more than 1870 hours of data for two different intersections). Upper dilemma zone boundaries found to be higher for the intersections with AWS. This is due to vehicles' increasing the speed at the flashing yellow sings to escape the dilemma zone.Moreover, an algorithm for predicting red light runners and distinguishing them from right turners is presented.
Master of Science
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Zaremski, Brian Zachary. "The Advancement of Adaptive Relaying in Power Systems Protection." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32121.

Повний текст джерела
Анотація:
The electrical distribution system in the United States is considered one of the most complicated machines in existence. Electrical phenomena in such a complex system can inflict serious self-harm. This requires damage prevention from protection schemes. Until recently, there was a safe gap between capacity to deliver power and the demand. Therefore, these protection schemes focused on dependability allowing the disconnection of lines, transformers, or other devices with the purpose of isolating the faulted element. On some occasions, the disconnections made were not necessary. The other extreme of reliability calls for security. This aspect of reliability calls for the operation of the protective devices only for faults within the intended area of protection. There is a tradeoff here; where a dependable protection scheme will assuredly prevent damage, it is prone to unnecessary operation which can lead to cascading outages. Where a secure scheme will not operate unnecessarily, it is prone to pieces of the system becoming damaged when relays fail to operate properly. With microprocessor based relaying schemes, a hybrid reliability focus is attainable through adaptive relaying. Adaptive relaying describes protection schemes that adjust settings and/or logic of operations based on the prevailing conditions of the system. These adjustments can help to avoid relay miss-operation. Adjustments could include, but are not limited to, the logging of data for post-mortem analysis, communication throughout the system, as well changing relay parameters. Several concepts will be discussed, one of which will be implemented to prove the value of the new tools available.
Master of Science
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Lami, Falah Khairullah Abbood. "A new improved method to damp inter-area oscillations in power systems with SSR mitigation and zone protection compensation." Thesis, University of Leicester, 2013. http://hdl.handle.net/2381/27812.

Повний текст джерела
Анотація:
The objective of this work is to design a damping controller for a thyristor controlled series capacitor (TCSC) to damp robustly inter-area oscillations in power systems with an immunity against sub-synchronous resonance (SSR) oscillations which may lead to torsional oscillations. The new control strategy has two main loops; an SSR mitigation loop and a bang-bang loop, the latter is designed with the aim of damping inter-area oscillations with a settling time 8-10 sec. The appropriate selection of the bang-bang series compensation component, ∆KC, is addressed by considering the Eigen analysis of the generators’ shafts and an impedance scan of the series compensated line for different compensation levels. The SSR mitigation loop is designed with the aim of providing a fine tune control signal to be added to the main value of the inserted series compensation (KC), to damp SSR oscillations and related torsional mode of oscillations. To address this issue, a new observer-based multiple model adaptive control algorithm is designed to control a multi-stage TCSC. The SSR modelling challenges associated with the load dynamics and with the insertion of the series compensation into the transmission system are overcome by a fine tuning control loop, which adjusts the resultant series compensation (KC). Considering the integration and coordination of oscillation damping and distance protection in the transmission system, a new adaptive technique must be designed to control the distance relay (DR) to prevent its mal operation (during the damping process). The new strategy is illustrated through an 11-bus 4-machine 2-area benchmark power system. The performance and advantages of the new algorithm are validated using time domain simulation via PSCAD software.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Arguence, Olivier. "Modélisation des ilots non-intentionnels et caractérisation des méthodes passives de détection d’ilotage." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT045/document.

Повний текст джерела
Анотація:
Un ilot non-intentionnel peut se former lorsque d’une petite partie du réseau est déconnectée du reste du système électrique, et continue pourtant de fonctionner à l’insu du gestionnaire de réseau en raison de la présence de générateurs locaux. Cet événement n’est pas voulu : le comportement des ilots n’est pas maitrisé, ce qui entraîne des risques potentiels pour les personnes et équipements électriques. L’ilotage non-intentionnel est un phénomène complexe et mal connu, aujourd’hui considéré comme rare, mais dont la probabilité d’apparition tend actuellement, a priori, à s’accroître progressivement. Cet accroissement est dû à l’effet conjugué de plusieurs phénomènes : premièrement, le développement des installations de production de petite et moyenne puissance, raccordées directement au réseau de distribution ; deuxièmement, l’élargissement des seuils de détection qui sont utilisés dans leurs protections de découplage ; et troisièmement, l’implémentation dans ces installations d’automatismes de régulation de puissance active et réactive. Dans ce contexte, la chaire industrielle Smartgrid d’Enedis a financé ces travaux de thèse afin de mieux caractériser ces phénomènes d’ilotage et d’améliorer leur détection.Afin d’atteindre ces objectifs, une première priorité de la thèse a été d’améliorer la compréhension des ilots non-intentionnels au travers d’une approche analytique. Celle-ci a notamment permis la résolution formelle d’un modèle simple capable d’expliquer le comportement en fréquence d’un îlot. Ces résolutions ont été enrichies par de nombreuses expérimentations en laboratoire et par des simulations numériques. Les modèles ont fait l’objet d’une étude bibliographique approfondie, notamment pour le choix des modèles de charge.Une seconde priorité de la thèse a été d’estimer l’efficacité des méthodes passives de détection d’ilotage au travers du calcul de la zone de non-détection (ZND). L'influence de plusieurs charges sur la ZND a été analysé, ce qui a permis d’améliorer la compréhension du phénomène complexe que sont les ilots non-intentionnels. L’efficacité des nouvelles protections anti-ilotage utilisant des seuils sur la dérivée en fréquence (ROCOF) a aussi fait l’objet d’évaluations approfondies. Enfin, les méthodes de calcul de ZND ont été améliorés par rapport aux méthodes préexistantes, ce qui a permis de radicalement améliorer l’estimation faite de l'impact des nouvelles régulations de puissance P(f) et Q(U)
Unintentional islands might appear when a subpart of the grid is disconnected from the power system and keeps working because of local generation. These events are unwanted: their behavior is not controlled and leads to potential risks for people and for electric equipment. Unintentional islanding is a complex phenomenon and badly understood. Nowadays it is considered to be rare, but a priori its occurrence probability is currently steadily increasing. This rising is the consequence of several phenomena: firstly, the development of distributed generation of small and average size directly connected to the distribution grid; secondly, the enlargement of frequency thresholds used by isolating protections; and thirdly, the implementation of power regulations of active and reactive power in the generation unit. Within this context, the Smart Grid chair of Enedis financed this PhD thesis in order to better characterize these islanding phenomena and to improve their detection.To achieve these targets, a first priority of the PhD was to improve the comprehension of unintentional islanding through symbolic calculation. This approach makes it possible to solve a simple model and to explain the evolution of the frequency during an island. These results are completed with several laboratory experiments and by numeric simulations. Models are designed based on a thorough bibliography, in particular for load modeling.A second priority of the PhD was to estimate the efficiency of anti-islanding protections through the computation of non-detection zone (NDZ). The impact of several loads on the NDZ is analyzed to improve the understanding of unintentional islanding, which is a complex phenomenon. The efficiency of new anti-islanding protections using thresholds on the rate of change of frequency (ROCOF) is also thoroughly evaluated. It is shown that the computation method used by the protection plays a key role. At last, the calculation methods of the NDZ is improved regarding previous methods. Among other things, it allows to radically change the estimations of the impact of new power regulations P(f) and Q(U)
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Scarfe, Bradley Edward. "Oceanographic Considerations for the Management and Protection of Surfing Breaks." The University of Waikato, 2008. http://hdl.handle.net/10289/2668.

Повний текст джерела
Анотація:
Although the physical characteristics of surfing breaks are well described in the literature, there is little specific research on surfing and coastal management. Such research is required because coastal engineering has had significant impacts to surfing breaks, both positive and negative. Strategic planning and environmental impact assessment methods, a central tenet of integrated coastal zone management (ICZM), are recommended by this thesis to maximise surfing amenities. The research reported here identifies key oceanographic considerations required for ICZM around surfing breaks including: surfing wave parameters; surfing break components; relationship between surfer skill, surfing manoeuvre type and wave parameters; wind effects on waves; currents; geomorphic surfing break categorisation; beach-state and morphology; and offshore wave transformations. Key coastal activities that can have impacts to surfing breaks are identified. Environmental data types to consider during coastal studies around surfing breaks are presented and geographic information systems (GIS) are used to manage and interpret such information. To monitor surfing breaks, a shallow water multibeam echo sounding system was utilised and a RTK GPS water level correction and hydrographic GIS methodology developed. Including surfing in coastal management requires coastal engineering solutions that incorporate surfing. As an example, the efficacy of the artificial surfing reef (ASR) at Mount Maunganui, New Zealand, was evaluated. GIS, multibeam echo soundings, oceanographic measurements, photography, and wave modelling were all applied to monitor sea floor morphology around the reef. Results showed that the beach-state has more cellular circulation since the reef was installed, and a groin effect on the offshore bar was caused by the structure within the monitoring period, trapping sediment updrift and eroding sediment downdrift. No identifiable shoreline salient was observed. Landward of the reef, a scour hole ~3 times the surface area of the reef has formed. The current literature on ASRs has primarily focused on reef shape and its role in creating surfing waves. However, this study suggests that impacts to the offshore bar, beach-state, scour hole and surf zone hydrodynamics should all be included in future surfing reef designs. More real world reef studies, including ongoing monitoring of existing surfing reefs are required to validate theoretical concepts in the published literature.
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Книги з теми "ZONE PROTECTION SYSTEM"

1

Group, United States National Park Service Coastal Barriers Study. Report to Congress, Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

United States. National Park Service. Coastal Barriers Study Group. Report to Congress, Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

United States. National Park Service. Coastal Barriers Study Group. Report to Congress, Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

United States. National Park Service. Coastal Barriers Study Group. Report to Congress, Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

United States. National Park Service. Coastal Barriers Study Group. Report to Congress, Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Report to Congress, Coastal Barrier Resources System: Georgia, recommendations for additions to or deletions from the Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Report to Congress, Coastal Barrier Resources System: Connecticut, recommendations for additions to or deletions from the Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Report to Congress, Coastal Barrier Resources System: Virginia, recommendations for additions to or deletions from the Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Report to Congress, Coastal Barrier Resources System: Alabama, recommendations for additions to or deletions from the Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Report to Congress, Coastal Barrier Resources System: Delaware, recommendations for additions to or deletions from the Coastal Barrier Resources System. [Washington, D.C.?]: The Group, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Частини книг з теми "ZONE PROTECTION SYSTEM"

1

Joga, S. Ramana Kumar, Pampa Sinha, and Manoj Kumar Maharana. "Genetic Algorithm and Graph Theory Approach to Select Protection Zone in Distribution System." In Lecture Notes in Electrical Engineering, 165–74. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-7241-8_13.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Abd-Elaty, Ismail, and Salvatore Straface. "Mathematical Models Ensuring Freshwater of Coastal Zones in Arid and Semiarid Regions." In Earth Systems Protection and Sustainability, 55–83. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-98584-4_3.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Ruiz, Vannia, Katherine Hermosilla, Carolina Martínez, and Francisco de la Barrera. "Socio-ecological Transformations in Coastal Wetlands: An Approach from the South-Central Zone of Chile." In Human-Nature Interactions, 405–16. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-01980-7_31.

Повний текст джерела
Анотація:
Significance StatementThe increase in the world population has generated high pressures on the different ecosystems, mainly due to the expansion of urban areas and productive activities such as agriculture. Coastal wetlands are among the most affected ecosystems, which due to their geographical location are highly fragile and susceptible to changes and pressures. The aims of this research are focus on (1) Making a comparison regarding to the changes experienced in two similar coastal wetlands with actual protection measures (one Ramsar site and national reserve since 1996 and another declared a nature sanctuary in 2017). (2) evaluating the main transformations in both wetlands, as socio-ecological systems, from human activity and the extent of public policies that can be generated that go around the protection of these ecosystems.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Strager, Michael P. "Protecting Surface Water Drinking Supplies in WV With Zones of Critical Concern." In Geospatial Information System Use in Public Organizations, 112–20. Abingdon, Oxon ; New York, NY : Routledge, 2019.: Routledge, 2019. http://dx.doi.org/10.4324/9780429272851-8.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Yin, Chengqing, Ming Zhao, Weigen Jin, and Zhiwen Lan. "A multi-pond system as a protective zone for the management of lakes in China." In Nutrient Dynamics and Retention in Land/Water Ecotones of Lowland, Temperate Lakes and Rivers, 321–29. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1602-2_34.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

von Schorlemer, Sabine. "Fighting Terrorist Attacks Against World Heritage – An Integrated Approach." In 50 Years World Heritage Convention: Shared Responsibility – Conflict & Reconciliation, 201–13. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-05660-4_16.

Повний текст джерела
Анотація:
AbstractThis contribution will examine intentional acts of terrorist groups and organised networks directed against cultural heritage as a challenge for international law, e.g., by creating grey zones. In particular, it will be asked to what extent criminal law enforcement can be identified as a missing link in the system of the legal protection of cultural property, including World Heritage. It is seen as necessary to strengthen criminal sanctions for possession and sale of illegally trafficked cultural objects. In that respect, it will be argued, the Nicosia Convention on Offences Relating to Cultural Property, adopted by the Council of Europe in 2017, may give new impetus to criminal law as a tool in the fight against offences against cultural property, helping to reduce lawless areas. Cultural heritage protection, it is emphasised, requires a robust, legally integrated approach, including criminal prosecution for plundering, smuggling, and destruction.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Walker, Therez B., and Natalya Lawrence. "Advocacy for protected areas in the Caribbean: a collaborated approach to ecotourism in Antigua and Barbuda." In Tourism transformations in protected area gateway communities, 52–65. Wallingford: CABI, 2022. http://dx.doi.org/10.1079/9781789249033.0005.

Повний текст джерела
Анотація:
Abstract The Caribbean is unique for its diverse marine and terrestrial environment that provides shoreline protection, food security and livelihoods, as well as facilitating tourism and other economic activities, for its residents and visitors alike. The role of Protected Areas (PAs) for conservation has been realized, and consideration must be given to the intricate linkages between social, economic and biological systems on small islands. The North East Marine Management Area (NEMMA) plays a significant role in the island of Antigua and Barbuda, for its importance to biodiversity conservation, as it connects many marine PAs in one continuous zone over the commercially important east coast of the island. This chapter highlights the advocacy work of those in gateway communities, and the importance of stakeholder collaboration in developing ecotourism. Practical implications emerge, as this case provides a framework for governance to collaborate for a more inclusive form of sustainable ecotourism in PAs.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Kantoush, Sameh A., Mohamed Saber, Mohammed Abdel-Fattah, and Tetsuya Sumi. "Integrated Strategies for the Management of Wadi Flash Floods in the Middle East and North Africa (MENA) Arid Zones: The ISFF Project." In Natural Disaster Science and Mitigation Engineering: DPRI reports, 3–34. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-2904-4_1.

Повний текст джерела
Анотація:
AbstractSustainable management of wadi flash flood (WFF) risks is desperately needed to secure development in wadi systems. Due to rapid flow generation with sudden high flood peaks, spatiotemporal variability of rainfall occurrence, and poorly sited rapid development, most Middle East and North Africa (MENA) region have no comprehensive proper protection from WFFs. In arid regions, single mitigation measures, including storage dams, recharge dams, artificial lakes and embankments, are implemented, although soft mitigation measures are not dominant, such as early warning systems. The single management strategy under climate change impacts is not adequate to reduce flash flood risks; an integrated strategy is required. The objective of the international symposium on flash floods (ISFF) project has been to develop scientific understanding of WFFs in wadi systems; monitor, model, and mitigate; issue warnings; and plan urban development by discussing and networking the strategies in the MENA region. To achieve this goal, the project defines priorities for future research challenges and potential projects for WFFs. This chapter provides a state-of-the-art scientific basis in terms of integrated flash flood management. Further, priorities are defined for the main research gaps, and the emerging research methodologies can contribute to guide the management of WFFs in such regions.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Venkatanagaraju, Kasimala, and Monalisa Biswal. "Synchrophasor-Based Wide Area Protection Scheme for System Stressed Conditions to Avoid Power System Blackout." In Handbook of Research on Smart Power System Operation and Control, 1–34. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8030-0.ch001.

Повний текст джерела
Анотація:
Protection of transmission system is crucial for the secured and stable operation of power system. Under stress conditions, the operating parameters of power system violate their limits. From the past anatomy reports of several blackouts, it is clear that equipment, control, and protective relay failures are the major causes behind large power system failure. From study, it is also revealed that failure of back-up protection is more prone during system stressed conditions. In transmission system, third-zone of distance relay is highly affected by system stressed events such as voltage instability and load encroachment. As third-zone protection is a delayed protection scheme, with the help of wide area measurement system better protection function can be provided to reduce future percentage of blackout. In this chapter, a detailed discussion about the existing solutions is provided to mitigate the issue of system stressed conditions and a synchrophasor technology-based approach is provided. Results for different cases are provided to show the efficacy of the proposed method.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Restás, Ágoston, Miguel Almeida, Saeid Lotfi, László Bodnár, and Domingos Xavier Viegas. "Basic rules for developing fire sprinkler system in the forest." In Advances in Forest Fire Research 2022, 539–43. Imprensa da Universidade de Coimbra, 2022. http://dx.doi.org/10.14195/978-989-26-2298-9_84.

Повний текст джерела
Анотація:
It is a well-observed phenomenon in developed societies that, in order to return to nature, a part of the society seeks to settle near forests or in the forest creating wildland – urban interface (WUI) areas. It has special features and generates significant risk of fire on the experts try to find responds. In the present study, the authors intend to explore the theoretical foundations of the application of the sprinkler system in forest protecting built environment from fires. Understanding and finding basic rules for the effective sprinkler system application can contribute to reduce the impacts caused by fire. Authors found geometry of circle overlapping generates always problems regarding the effectiveness of sprinkler systems. 50% overlapping in longitudinal axis seems to be acceptable solution. In this case overlapping rate is 78% per circle with 1.6 kg.m-2 water coverage levels and 22% of the circles have 0.8 kg.m-2 water coverage level. Sequentially used system seems good solution for replacing the evaporated water, where 75% of the coverage level is accepted as lowest threshold of the effective rate. As an example, 300 m long protection zone requires 120 sprinkler heads. Building up this zone it requires 1,920 kg of water for wetting up, and then keeping it in service, it requires 7,200 kg.h-1 water. 39% of the service water is lost because it is above the upper limit of effectiveness.
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "ZONE PROTECTION SYSTEM"

1

Drabkin, M. M. "Protection zone of the Charge Transfer System." In 11th International Symposium on High-Voltage Engineering (ISH 99). IEE, 1999. http://dx.doi.org/10.1049/cp:19990682.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Wiboonrat, Montri. "Zone protection approach of data center system reliability." In 2017 International Conference on Information and Communications (ICIC). IEEE, 2017. http://dx.doi.org/10.1109/infoc.2017.8001689.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Kangvansaichol, K. "Multi-zone differential protection for transmission networks." In Eighth IEE International Conference on Developments in Power System Protection. IEE, 2004. http://dx.doi.org/10.1049/cp:20040153.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Rajalwal, Nilesh Kumar, and Debomita Ghosh. "Adaptive Zone-III Relay Characteristic using System Integrity Protection Scheme." In 2019 IEEE International Conference on Intelligent Systems and Green Technology (ICISGT). IEEE, 2019. http://dx.doi.org/10.1109/icisgt44072.2019.00029.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Moore, P. J. "Improved zone 2 acceleration scheme using sound phase seen impedance." In Eighth IEE International Conference on Developments in Power System Protection. IEE, 2004. http://dx.doi.org/10.1049/cp:20040160.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Wiboonrat, Montri. "Zone protection approach of data center system reliability and power quality." In 2017 International Conference on Advanced Robotics and Intelligent Systems (ARIS). IEEE, 2017. http://dx.doi.org/10.1109/aris.2017.8297187.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Xu, Peng, Meirong Chen, Lifang Feng, Fangli Ma, Guanfeng Wu, and Yang Xu. "Protection zone designation of railway radio environment based on TD-LTE system." In Conference on Data Science and Knowledge Engineering for Sensing Decision Support (FLINS 2018). WORLD SCIENTIFIC, 2018. http://dx.doi.org/10.1142/9789813273238_0107.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Ferdous, Farhana, and Ruma. "Zone Protection System of Transmission Line by Distance Relay using Matlab/Simulink." In 2018 International Conference on Advancement in Electrical and Electronic Engineering (ICAEEE). IEEE, 2018. http://dx.doi.org/10.1109/icaeee.2018.8642978.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Nikolaidis, V. C., and A. M. Chliara. "Emergency Zone 3 Modification to Prevent Cascaded Outages: Local vs. Centralized Approach." In 13th International Conference on Development in Power System Protection 2016 (DPSP). Institution of Engineering and Technology, 2016. http://dx.doi.org/10.1049/cp.2016.0100.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Nikolaidis, V. C., G. Michaloudis, A. M. Tsimtsios, D. Tzelepis, and C. D. Booth. "A multi-zone differential protection scheme for MV distribution systems with distributed generation." In 15th International Conference on Developments in Power System Protection (DPSP 2020). Institution of Engineering and Technology, 2020. http://dx.doi.org/10.1049/cp.2020.0071.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "ZONE PROTECTION SYSTEM"

1

Hopper. L30500 Analysis of the Effects of High-Voltage Direct-Current Transmission Systems on Buried Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2008. http://dx.doi.org/10.55274/r0010196.

Повний текст джерела
Анотація:
The economics of high voltage direct current for long-distance transmission of electrical energy have been reported as very attractive, to the extent that several projects are in the making. Several reasons other than the savings in transmission costs, for example the exchange of peak power between time zones and seasonal zones, would permit utilities to save on plant investment for generating capacity while maintaining a high level of service. This report summarizes work on the initial phase of a study to determine the effects of high-voltage direct-current (H.V.D.C.) electric transmission lines on buried pipeline systems. Pipeline Research Council International, Inc. initiated this work in response to an anticipated threat posed by the Pacific Northwest-Southwest Intertie H.V.D.C. system now being designed (and other possible H.V.D.C. lines in the future) because of the announced plans to pass direct current through the earth. The objectives of the overall program are:(1) To determine the nature and magnitude of problems that will be created by the earth current from H.V.D.C. systems, and(2) To devise means of protecting pipelines from the effects of such currents. A computer program was written based on a mathematical model of a buried pipeline in the environment created by an H.V.D.C. system. Excellent agreement was obtained between computed soil potential gradients and measurements obtained during a field test of H.V.D.C. in Oregon. Reasonably good agreement was also obtained between measured pipe-to-soil potentials on the Pacific Lighting Gas Supply Company pipeline near Camino, California, and computed values during a field test of H.V.D.C. power transmission.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Acosta, Felipe, and Guillermo Riveros. Repair of corroded steel girders of hydraulic steel structures (HSS) using fiber-reinforced polymers (FRP). Engineer Research and Development Center (U.S.), August 2023. http://dx.doi.org/10.21079/11681/47404.

Повний текст джерела
Анотація:
Although steel hydraulic structures have a protective system to prevent corrosion, this type of deterioration will eventually occur due to the constant exposure to harsh environmental conditions. There are several techniques that can be implemented to repair corroded steel structural elements. This report presents a numerical study to evaluate the mechanical behavior of corroded steel girders used in hydraulic steel structures and to evaluate several carbon fiber–reinforced polymers (CFRP) layups to repair them. The girders were modeled as simply supported with four-point loading boundary conditions. The corrosion deterioration was modeled as loss in section as 10%, 25%, and 40%. The effectiveness of the deterioration was established based on the level of stresses at the steel compared with the undamaged condition after it is strengthened with CFRP. It was found that CFRP repair is more practical for reducing the stresses at the steel in the shear dominated zone if deterioration is below 25%. At the tensile dominated zone, CFRP is effective for reducing the stresses for deterioration below 40%.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Russo, David, Daniel M. Tartakovsky, and Shlomo P. Neuman. Development of Predictive Tools for Contaminant Transport through Variably-Saturated Heterogeneous Composite Porous Formations. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7592658.bard.

Повний текст джерела
Анотація:
The vadose (unsaturated) zone forms a major hydrologic link between the ground surface and underlying aquifers. To understand properly its role in protecting groundwater from near surface sources of contamination, one must be able to analyze quantitatively water flow and contaminant transport in variably saturated subsurface environments that are highly heterogeneous, often consisting of multiple geologic units and/or high and/or low permeability inclusions. The specific objectives of this research were: (i) to develop efficient and accurate tools for probabilistic delineation of dominant geologic features comprising the vadose zone; (ii) to develop a complementary set of data analysis tools for discerning the fractal properties of hydraulic and transport parameters of highly heterogeneous vadose zone; (iii) to develop and test the associated computational methods for probabilistic analysis of flow and transport in highly heterogeneous subsurface environments; and (iv) to apply the computational framework to design an “optimal” observation network for monitoring and forecasting the fate and migration of contaminant plumes originating from agricultural activities. During the course of the project, we modified the third objective to include additional computational method, based on the notion that the heterogeneous formation can be considered as a mixture of populations of differing spatial structures. Regarding uncertainly analysis, going beyond approaches based on mean and variance of system states, we succeeded to develop probability density function (PDF) solutions enabling one to evaluate probabilities of rare events, required for probabilistic risk assessment. In addition, we developed reduced complexity models for the probabilistic forecasting of infiltration rates in heterogeneous soils during surface runoff and/or flooding events Regarding flow and transport in variably saturated, spatially heterogeneous formations associated with fine- and coarse-textured embedded soils (FTES- and CTES-formations, respectively).We succeeded to develop first-order and numerical frameworks for flow and transport in three-dimensional (3-D), variably saturated, bimodal, heterogeneous formations, with single and dual porosity, respectively. Regarding the sampling problem defined as, how many sampling points are needed, and where to locate them spatially in the horizontal x₂x₃ plane of the field. Based on our computational framework, we succeeded to develop and demonstrate a methdology that might improve considerably our ability to describe quntitaively the response of complicated 3-D flow systems. The results of the project are of theoretical and practical importance; they provided a rigorous framework to modeling water flow and solute transport in a realistic, highly heterogeneous, composite flow system with uncertain properties under-specified by data. Specifically, they: (i) enhanced fundamental understanding of the basic mechanisms of field-scale flow and transport in near-surface geological formations under realistic flow scenarios, (ii) provided a means to assess the ability of existing flow and transport models to handle realistic flow conditions, and (iii) provided a means to assess quantitatively the threats posed to groundwater by contamination from agricultural sources.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Price, Roz. Socio-economic Factors Impacting Marine Protected Areas in the Eastern Tropical Pacific Marine Corridor (CMAR) Region. Institute of Development Studies, June 2022. http://dx.doi.org/10.19088/k4d.2022.107.

Повний текст джерела
Анотація:
This rapid review explores socio-economic and political issues that may affect the effectiveness of the Eastern Tropical Pacific Marine Corridor (CMAR). It specifically focuses on key socioeconomic and governance issues around marine protected areas (MPAs) and exclusive economic zones (EEZs) of Colombia, Costa Rica, Ecuador and Panama based in the Eastern Tropical Pacific ocean. Research highlights the importance of understanding perceptions and context in environmental governance analyses and practice (Partelow, Jäger & Schlüter, 2021); and MPAs are increasingly recognised as being embedded in social-ecological systems, where human dimensions (e.g., social, economic, cultural, political, and institutional) interact with ecological characteristics (Burbano & Meredith, 2020, p.2). How do you define the effectiveness of an MPA is another key question to consider (but not explored in detail in this review). Bearing in mind that most MPAs have multiple objectives, including non-biological, which highlights the need for the development and adoption of standardised effectiveness metrics beyond biological considerations to measure factors contributing to their success or failure (Giakoumi et al., 2018). For example, there are growing calls for marine conservation success to move beyond area coverage to include a broader set of metrics related to the effective and equitable management of the marine environment (see Bennett et al., 2021). Hence, the more information the better when establishing integrated, well-designed and connected MPAs – for example, the more information on a sea area, the coastal populations and their socio-ecological relationships, the better stressors, systemic impacts and inter-annual variabilities can be identified, and the more effective protection can be developed (Relano, Palomares & Pauly, 2021, p.13).
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Weissinger, Rebecca. Trends in water quality at Bryce Canyon National Park, water years 2006–2021. Edited by Alice Wondrak Biel. National Park Service, November 2022. http://dx.doi.org/10.36967/2294946.

Повний текст джерела
Анотація:
The National Park Service collects water-quality samples on a rotating basis at three fixed water-quality stations in Bryce Canyon National Park (NP): Sheep Creek, Yellow Creek, and Mossy Cave Spring. Data collection began at Sheep Creek and Yellow Creek in November 2005 and at Mossy Cave in July 2008. Data on in-situ parameters, fecal-coliform samples, major ions, and nutrients are collected monthly, while trace elements are sampled quarterly. This report analyzes data from the beginning of the period of record for each station through water year 2021 to test for trends over time. Concentrations are also compared to relevant water-quality standards for the State of Utah. Overall, water quality at the park’s monitoring stations continues to be excellent, and park managers have been successful in their goal of maintaining these systems in unimpaired condition. Infrequent but continued Escherichia coli exceedances from trespass livestock at Sheep and Yellow creeks support the need for regular fence maintenance along the park boundary. High-quality conditions may qualify all three sites as Category 1 waters, the highest level of anti-degradation protection provided by the State of Utah. Minimum and maximum air temperatures at the park have increased, while precipitation remains highly variable. Increasing air temperatures have led to increasing water temperatures in Sheep and Yellow creeks. Sheep Creek also had a decrease in flow across several quantiles from 2006 to 2021, while higher flows decreased at Yellow Creek in the same period. Surface flows in these two creeks are likely to be increasingly affected by higher evapotranspiration due to warming air temperatures and possibly decreasing snowmelt runoff as the climate changes. The influx of ancient groundwater in both creek drainages helps sustain base flows at the sites. Mossy Cave Spring, which is sampled close to the spring emergence point, showed less of a climate signal than Sheep and Yellow creeks. In our record, the spring shows a modest increase in discharge, including higher flows at higher air temperatures. An uptick in visitation to Water Canyon and the Mossy Cave Trail has so far not been reflected by changes in water quality. There are additional statistical trends in water-quality parameters at all three sites. However, most of these trends are quite small and are likely ecologically negligible. Some statistical trends may be the result of instrument changes and improvements in quality assurance and quality control over time in both the field sampling effort and the laboratory analyses. Long-term monitoring of water-quality stations at Bryce Canyon NP suggests relatively stable aquatic systems that benefit from protection within the park. To maintain these unimpaired conditions into the future, park managers could consider: Regular fence checks and maintenance along active grazing allotments at the park boundary to protect riparian areas and aquatic systems from trespass livestock. Developing a springs-monitoring program to track changes in springflow at spring emergences to better understand bedrock-aquifer water supplies. These data would also help quantify springflow for use in water-rights hearings. Supporting hydrogeologic investigations to map the extent and flow paths of groundwater aquifers. Working with the State of Utah to develop groundwater-protection zones to protect groundwater aquifers from developments that would affect springs in the park. Prioritizing watershed management with proactive fire risk-reduction practices. Explicitly including watershed protection as a goal in plans for fire management and suppression. Using additional data and analyses to better understand the drivers of trends in water quality and their ecological significance. These could include higher-frequency data to better understand relationships between groundwater, precipitation, and surface flows at the sites. These could also include watershed metrics...
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Meir, Shimon, Michael S. Reid, Cai-Zhong Jiang, Amnon Lers, and Sonia Philosoph-Hadas. Molecular Studies of Postharvest Leaf and Flower Senescence. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592657.bard.

Повний текст джерела
Анотація:
Original objectives: To understand the regulation of abscission by exploring the nature of changes of auxin-related gene expression in tomato (Lycopersicon esculatumMill) abscission zones (AZs) following organ removal, and by analyzing the function of these genes. Our specific goals were: 1) To complete the microarray analyses in tomato flower and leaf AZs, for identifying genes whose expression changes early in response to auxin depletion; 2) To examine, using virus-induced gene silencing (VIGS), the effect of silencing target genes on ethylene sensitivity and abscission competence of the leaf and flower AZs; 3) To isolate and characterize promoters from AZ-specific genes to be used in functional analysis; 4) To generate stable transgenic tomato plants with selected genes silenced with RNAi, under the control of an AZ-specific promoter, for further characterization of their abscission phenotypes. Background: Abscission, the separation of organs from the parent plant, results in postharvest quality loss in many ornamentals and other fresh produce. The process is initiated by changes in the auxin gradient across the AZ, and is triggered by ethylene. Although changes in gene expression have been correlated with the ethylene-mediated execution of abscission, there is almost no information on the initiation of the abscission process, as the AZ becomes sensitized to ethylene. The present project was focused on elucidating these early molecular regulatory events, in order to gain a better control of the abscission process for agricultural manipulations. Major conclusions, solutions, achievements: Microarray analyses, using the Affymetrix Tomato GeneChip®, revealed changes in expression, occurring early in abscission, of many genes with possible regulatory functions. These included a range of auxin- and ethylene-related transcription factors (TFs), other TFs that are transiently induced just after flower removal, and a set of novel AZ-specific genes. We also identified four different defense-related genes, including: Cysteine-type endopeptidase, α- DOX1, WIN2, and SDF2, that are newly-associated with the late stage of the abscission process. This supports the activation of different defense responses and strategies at the late abscission stages, which may enable efficient protection of the exposed tissue toward different environmental stresses. To facilitate functional studies we implemented an efficient VIGS system in tomato, and isolated two abscission-specific promoters (pTAPG1 and pTAPG4) for gene silencing in stable transformation. Using the VIGS system we could demonstrate the importance of TAPGs in abscission of tomato leaf petioles, and evaluated the importance of more than 45 genes in abscission. Among them we identified few critical genes involved in leaf and flower abscission. These included: PTRP-F1, PRP, TKN4, KNOTTED-like homeobox TF, KD1, and KNOX-like homeodomain protein genes, the silencing of which caused a striking retardation of pedicel abscission, and ERF1, ERF4, Clavata-like3 protein, Sucrose transporter protein, and IAA10 genes, the silencing of which delayed petiole abscission. The importance of PRPand KD1 genes in abscission was confirmed also by antisense–silencing using pTAPG4. Experiments testing the effects of RNAi silencing of few other genes are still in progress, The analysis of the microarray results of flower and leaf AZs allowed us to establish a clear sequence of events occurring during acquisition of tissue sensitivity to ethylene, and to confirm our hypothesis that acquisition of ethylene sensitivity in the AZ is associated with altered expression of auxin-regulated genes in both AZs. Implication, both scientific and agricultural: Our studies had provided new insights into the regulation of the abscission process, and shaded light on the molecular mechanisms that drive the acquisition of abscission competence in the AZ. We pointed out some critical genes involved in regulation of abscission, and further expanded our knowledge of auxin-ethylene cross talk during the abscission process. This permits the development of novel techniques for manipulating abscission, and thereby improving the postharvest performance of ornamentals and other crops.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Shani, Uri, Lynn Dudley, Alon Ben-Gal, Menachem Moshelion, and Yajun Wu. Root Conductance, Root-soil Interface Water Potential, Water and Ion Channel Function, and Tissue Expression Profile as Affected by Environmental Conditions. United States Department of Agriculture, October 2007. http://dx.doi.org/10.32747/2007.7592119.bard.

Повний текст джерела
Анотація:
Constraints on water resources and the environment necessitate more efficient use of water. The key to efficient management is an understanding of the physical and physiological processes occurring in the soil-root hydraulic continuum.While both soil and plant leaf water potentials are well understood, modeled and measured, the root-soil interface where actual uptake processes occur has not been sufficiently studied. The water potential at the root-soil interface (yᵣₒₒₜ), determined by environmental conditions and by soil and plant hydraulic properties, serves as a boundary value in soil and plant uptake equations. In this work, we propose to 1) refine and implement a method for measuring yᵣₒₒₜ; 2) measure yᵣₒₒₜ, water uptake and root hydraulic conductivity for wild type tomato and Arabidopsis under varied q, K⁺, Na⁺ and Cl⁻ levels in the root zone; 3) verify the role of MIPs and ion channels response to q, K⁺ and Na⁺ levels in Arabidopsis and tomato; 4) study the relationships between yᵣₒₒₜ and root hydraulic conductivity for various crops representing important botanical and agricultural species, under conditions of varying soil types, water contents and salinity; and 5) integrate the above to water uptake term(s) to be implemented in models. We have made significant progress toward establishing the efficacy of the emittensiometer and on the molecular biology studies. We have added an additional method for measuring ψᵣₒₒₜ. High-frequency water application through the water source while the plant emerges and becomes established encourages roots to develop towards and into the water source itself. The yᵣₒₒₜ and yₛₒᵢₗ values reflected wetting and drying processes in the rhizosphere and in the bulk soil. Thus, yᵣₒₒₜ can be manipulated by changing irrigation level and frequency. An important and surprising finding resulting from the current research is the obtained yᵣₒₒₜ value. The yᵣₒₒₜ measured using the three different methods: emittensiometer, micro-tensiometer and MRI imaging in both sunflower, tomato and corn plants fell in the same range and were higher by one to three orders of magnitude from the values of -600 to -15,000 cm suggested in the literature. We have added additional information on the regulation of aquaporins and transporters at the transcript and protein levels, particularly under stress. Our preliminary results show that overexpression of one aquaporin gene in tomato dramatically increases its transpiration level (unpublished results). Based on this information, we started screening mutants for other aquaporin genes. During the feasibility testing year, we identified homozygous mutants for eight aquaporin genes, including six mutants for five of the PIP2 genes. Including the homozygous mutants directly available at the ABRC seed stock center, we now have mutants for 11 of the 19 aquaporin genes of interest. Currently, we are screening mutants for other aquaporin genes and ion transporter genes. Understanding plant water uptake under stress is essential for the further advancement of molecular plant stress tolerance work as well as for efficient use of water in agriculture. Virtually all of Israel’s agriculture and about 40% of US agriculture is made possible by irrigation. Both countries face increasing risk of water shortages as urban requirements grow. Both countries will have to find methods of protecting the soil resource while conserving water resources—goals that appear to be in direct conflict. The climate-plant-soil-water system is nonlinear with many feedback mechanisms. Conceptual plant uptake and growth models and mechanism-based computer-simulation models will be valuable tools in developing irrigation regimes and methods that maximize the efficiency of agricultural water. This proposal will contribute to the development of these models by providing critical information on water extraction by the plant that will result in improved predictions of both water requirements and crop yields. Plant water use and plant response to environmental conditions cannot possibly be understood by using the tools and language of a single scientific discipline. This proposal links the disciplines of soil physics and soil physical chemistry with plant physiology and molecular biology in order to correctly treat and understand the soil-plant interface in terms of integrated comprehension. Results from the project will contribute to a mechanistic understanding of the SPAC and will inspire continued multidisciplinary research.
Стилі APA, Harvard, Vancouver, ISO та ін.
Також вас можуть зацікавити розширені добірки на тему "ZONE PROTECTION SYSTEM" для конкретних типів джерел:
Статті в журналах Дисертації Книги
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії