Letteratura scientifica selezionata sul tema "Underwater Research and Recovery Unit"
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Articoli di riviste sul tema "Underwater Research and Recovery Unit"
1
Carton, Geoffrey, J. C. King e R. Josh Bowers. "Munitions-Related Technology Demonstrations at Ordnance Reef (HI-06), Hawaii". Marine Technology Society Journal 46, n. 1 (1 gennaio 2012): 63–82. http://dx.doi.org/10.4031/mtsj.46.1.9.
Testo completoAbstract (sommario):
AbstractDevelopment of methods and technologies to characterize sites with underwater military munitions (UWMM) and respond to UWMM where the risks posed to human health or the environment or explosive hazards are unacceptable is underway. Department of Defense Military Munitions Sea Disposal Site Hawaii (HI-06), referred to locally as Ordnance Reef, is off Oahu’s leeward coast. This site has become the focal point for research on UWMM. Past studies found that the site presents no immediate danger to public safety. The location and water depth at this site present advantages for UWMM research and development.Promising technologies demonstrated at Ordnance Reef (HI-06) include those for munitions recovery, at-sea demilitarization, nondestructive testing, and explosives detection. Studies on fate and transport of munitions-related compounds and corrosion are ongoing.Among these technologies are the Remotely Operated Underwater Munitions Recovery System (ROUMRS) and the Explosive Hazard Demilitarization System (EHDS). Both are assemblages of commercial off-the-shelf components, and each is housed in a standard 6-m International Organization for Standardization (ISO) shipping container and can be operated on a barge.ROUMRS consists of a remotely operated vehicle, manipulators, an interface between a precision GPS, and underwater navigation equipment used during recovery of UWMM. The system also transports recovered UWMM for treatment. The EHDS consists of a portable X-ray unit to allow positive identification of recovered munitions, remotely operated wet band saws to cut recovered munitions to expose their explosive fill, and low-temperature ovens to treat the exposed explosives, making the remaining material safe for recycling.
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O, Tărăbuță. "A Study of the Feasibility of Autonomous Underwater Vehicles and Remotely Operated Vehicles in Black Sea". Scientific Bulletin of Naval Academy XIX, n. 1 (15 luglio 2018): 440–47. http://dx.doi.org/10.21279/1454-864x-18-i1-067.
Testo completoAbstract (sommario):
An underwater vehicle designed for industrial use in the Black Sea has to tackle two specific characteristics of it, given by its enclosed nature: the strong vertical stratification and the high content of hydrogen sulfide at greater depths. These particular environmental conditions impose also new approaches of design and technology for construction. The innovation foreseen of our study is the very concept of a universal underwater vehicle, based on modular design. Currently, unmanned underwater vehicles are controlled in two main ways, either autonomously (AUV) or by data transfer through an umbilical cable (ROV). Despite the fact AUV and ROV have many common characteristics they are used separately and are disjoint throughout their life cycle. To increase the technical performances and economic efficiency of such vehicles, we planned to design a universal carrier platform able to support different modules. Based on the common carrier sub-system, DCUV (Dual Controlled Underwater Vehicles) can be assembled as an AUV, controlled autonomously and by radio when surfaced. After its recovery and transfer of the sea data recorded during its evolution as an AUV, the specific modules (sensors and battery) are replaced with functional modules needed to change it into an ROV, which can be then remotely controlled towards the contacts of interest. The concept of providing DCUV with a common propulsion unit will be eased by designing of an innovative multi-control system that will integrate data from sensors and human operator with the propulsion motors and end effectors, based on state-of- the-art microcontrollers and their appropriate programming.
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Chen, Le, Zhipeng Lin, Taiju Yin, Zhongchao Li, Chunsheng Shen e Bobo Luo. "Analysis of Reservoir Architecture of Shallow-water Delta Front Based on Process—A Case of S2L410 in Southern 79 Block in Wennan Oilfield". Studies in Engineering and Technology 4, n. 1 (30 luglio 2017): 96. http://dx.doi.org/10.11114/set.v4i1.2530.
Testo completoAbstract (sommario):
The sand body distribution is relatively limited in this block, the lens-shaped sandbodies are more developed, the change of intergranular sandbody is fast and the internal architecture of the sand body is complex, which results in the difficulties of the arrangement of horizontal wells in the study area and the tapping of remaining oil in high water reservoirs. In this paper, taking an example of S2L410 sandbodies in Wen 79 Southern Block, rich drilling data, core data, logging data and geological research results accumulated over many years in Wennan Oilfield were applied to discuss the anatomical method of the reservoir architecture unit in the underwater distributary channel in the shallow delta front, the hierarchy of the internal architecture of the reservoir and the anatomy of the single sand body. On the basis of this, the sequence of the underwater distributary channel in the composite channel is determined by the cross section and the source profile. Under the guidance of the sedimentology principle, the formation process of the underwater distributary channel is restored and the evolution process of underwater distributary channel is recovered.
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Popov, Vladimir Vladimirovich, Aleksandra Vitalievna Ivanovskaya, Valentin Leonidovich Erofeev e Elena Vladimirovna Bogatyreva. "Specific features of methodology for conducting experimental studies of adaptive control system of ship lifting devices". Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2022, n. 3 (23 agosto 2022): 40–49. http://dx.doi.org/10.24143/2073-1574-2022-3-40-49.
Testo completoAbstract (sommario):
Lowering and recovery operations, as well as towing underwater and surface objects are carried out with the help of a ship winch. As a result of the impact of any external disturbances, longitudinal oscillations appear in the towing rope, whose resonant maxima may fall into the vessel’s frequency range. The longer the cable, the greater the number of resonant frequencies in the operating range. Such operating conditions of the ship’s lifting equipment have a negative impact on the operation of the ship’s power plant as a whole. In order to increase the reliability of deck lifting equipment it is proposed to use an adaptive control system that would respond in a timely manner to changes in loading. Lifting equipment of a fishing vessel with non-stationarity of dynamic processes in operation is considered as an application of such a system. There is considered a principle of operation of the adaptive hydraulic drive of a trawl winch. The important scientific and technical problem of developing a complex mathematical model of the above control system has been solved. The directions of experimental research are determined. There is proposed a laboratory unit to evaluate the influence of the parameters of a mechanical system on the dynamics of a hydraulic drive of a load-lifting device adaptive to load variability. The unit operates due to changing the number and weight of the load discs installed on the driving and driven pulleys and simulating a change in the inertial coefficient, which is typical for a trawl winch. The second direction of experimental research is the verification of the adequacy of the obtained mathematical models. There are presented the results of the verification in the form of calculated and averaged experimental dynamometer cards, which are well correlated, with deviation up to 8%.
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Wang, Zhenfei, Meixin Hu e Ketao Zhang. "Underwater Turbid Media Stokes-Based Polarimetric Recovery". Sensors 24, n. 5 (20 febbraio 2024): 1367. http://dx.doi.org/10.3390/s24051367.
Testo completoAbstract (sommario):
Underwater optical imaging for information acquisition has always been an innovative and crucial research direction. Unlike imaging in the air medium, the underwater optical environment is more intricate. From an optical perspective, natural factors such as turbulence and suspended particles in the water cause issues like light scattering and attenuation, leading to color distortion, loss of details, decreased contrast, and overall blurriness. These challenges significantly impact the acquisition of underwater image information, rendering subsequent algorithms reliant on such data unable to function properly. Therefore, this paper proposes a method for underwater image restoration using Stokes linearly polarized light, specifically tailored to the challenges of underwater complex optical imaging environments. This method effectively utilizes linear polarization information and designs a system that uses the information of the first few frames to calculate the enhanced images of the later frames. By doing so, it achieves real-time underwater Stokes linear polarized imaging while minimizing human interference during the imaging process. Furthermore, the paper provides a comprehensive analysis of the deficiencies observed during the testing of the method and proposes improvement perspectives, along with offering insights into potential future research directions.
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Xue, Teng, Tianchi Zhang e Jing Zhang. "Research on Underwater Image Restoration Technology Based on Multi-Domain Translation". Journal of Marine Science and Engineering 11, n. 3 (22 marzo 2023): 674. http://dx.doi.org/10.3390/jmse11030674.
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Underwater images are crucial in various underwater applications, including marine engineering, underwater robotics, and subsea coral farming. However, obtaining paired data for these images is challenging due to factors such as light absorption and scattering, suspended particles in the water, and camera angles. Underwater image recovery algorithms typically use real unpaired dataset or synthetic paired dataset. However, they often encounter image quality issues and noise labeling problems that can affect algorithm performance. To address these challenges and further improve the quality of underwater image restoration, this work proposes a multi-domain translation method based on domain partitioning. Firstly, this paper proposes an improved confidence estimation algorithm, which uses the number of times a sample is correctly predicted in a continuous period as a confidence estimate. The confidence value estimates are sorted and compared with the real probability to continuously optimize the confidence estimation and improve the classification performance of the algorithm. Secondly, a U-net structure is used to construct the underwater image restoration network, which can learn the relationship between the two domains. The discriminator uses full convolution to improve the performance of the discriminator by outputting the true and false images along with the category to which the true image belongs. Finally, the improved confidence estimation algorithm is combined with the discriminator in the image restoration network to invert the labels for images with low confidence values in the clean domain as images in the degraded domain. The next step of image restoration is then performed based on the new dataset that is divided. In this way, the multi-domain conversion of underwater images is achieved, which helps in the recovery of underwater images. Experimental results show that the proposed method effectively improves the quality and quantity of the images.
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Zhao, Jie, Yilin Liang, Yudi Fang, Yixuan Weng, Weizhe Ma, Huaixun Zhang e Yiyang Zhang. "Research on the Unit Black-Start Strategy Considering Recovery Path and Start Sequence". Sustainability 14, n. 20 (12 ottobre 2022): 13057. http://dx.doi.org/10.3390/su142013057.
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Large-scale power outage events bring serious economic losses to national and social development and cause bad impacts, and the reasonable formulation of a unit black-start strategy is the basis of power outage recovery. Firstly, the Dijkstra shortest path algorithm is used to search for the optimal recovery path of the unit to be started after a major blackout occurs, and secondly, a comprehensive index of the unit start sequence considering the unit characteristics and unit distance is defined to guide the unit start sequence formulation by combining the unit capacity, climbing rate, start power, and other characteristics with the recovery time and capacitance value of the recovery path. Finally, based on the unit start sequence and optimal recovery path, and taking into account the unit start constraints, a complete unit black-start strategy is proposed, and the effectiveness of this strategy is verified by IEEE30 node system simulation. The results show that the proposed unit black-start strategy can reduce the unit recovery time and improve the recovery success rate.
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KOPER, Piotr, Agnieszka PALMOWSKA e Agnieszka MYSZKOWSKA. "RESEARCH OF SINGLE ROOM DECENTRALIZED HEAT RECOVERY UNIT". Architecture, Civil Engineering, Environment 12, n. 4 (2020): 109–14. http://dx.doi.org/10.21307/acee-2019-056.
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Zhang, Wei, Haitian Chen, Tao Chen, Zheping Yan e Hongliang Ren. "Research on Coordinated Robotic Motion Control Based on Fuzzy Decoupling Method in Fluidic Environments". Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/820258.
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The underwater recovery of autonomous underwater vehicles (AUV) is a process of 6-DOF motion control, which is related to characteristics with strong nonlinearity and coupling. In the recovery mission, the vehicle requires high level control accuracy. Considering an AUV called BSAV, this paper established a kinetic model to describe the motion of AUV in the horizontal plane, which consisted of nonlinear equations. On the basis of this model, the main coupling variables were analyzed during recovery. Aiming at the strong coupling problem between the heading control and sway motion, we designed a decoupling compensator based on the fuzzy theory and the decoupling theory. We analyzed to the rules of fuzzy compensation, the input and output membership functions of fuzzy compensator, through compose operation and clear operation of fuzzy reasoning, and obtained decoupling compensation quantity. Simulation results show that the fuzzy decoupling controller effectively reduces the overshoot of the system, and improves the control precision. Through the water tank experiments and analysis of experimental data, the effectiveness and feasibility of AUV recovery movement coordinated control based on fuzzy decoupling method are validated successful, and show that the fuzzy decoupling control method has a high practical value in the recovery mission.
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Niemeyer, Frank, Christopher Karberg, Kathrin Baumgarten, Henrich Preuß, Jan Witte, Patrick Bethke, Johann Wollstadt, Konrad Chwelatiuk, Jana Brinkmann e Eileen Trunczik. "MiniLab - Agile underwater platform with integrated sensors for environmental and visual applications". International Hydrographic Review 28 (1 novembre 2022): 212–20. http://dx.doi.org/10.58440/ihr-28-n15.
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The Fraunhofer “Smart Ocean Technologies” (SOT) research team extends its range of services towards underwater technology by developing new internal infrastructure. To test sensor technology and materials, empirical underwater data is required to evaluate new technology within realistic conditions. Various external factors like swell, wind, and the underwater environment itself complicate stable framework conditions during the measurements. For this purpose, a test platform called MiniLab was developed which can be extended by modules with respect to common interfaces. It serves as a base frame for internal as well as external projects. The MiniLab consists of an underwater unit and an on-ground unit. Both are connected via a hybrid underwater cable. In addition to the environmental conditions, camera live streams can be transmitted. The MiniLab service platform is currently being used in the Warnow River and in the Digital Ocean Lab (DOL) in the Baltic Sea. However, it is available for observations in other waters (Fraunhofer, 2021a).
Tesi sul tema "Underwater Research and Recovery Unit"
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Orire, Endurance. "The techno-economics of bitumen recovery from oil and tar sands as a complement to oil exploration in Nigeria / E. Orire". Thesis, North-West University, 2009. http://hdl.handle.net/10394/5704.
Testo completoAbstract (sommario):
The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in
the country since 1903 and has remained untapped over the years. The need for the country to
complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to
improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is
classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110
and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be
derived.
This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with
that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during
hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes
contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation.
Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research.
The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum
technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria
bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ
combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14
Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00
and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada.
A trade off is thereafter done using life cycle costing so as to select the best process technology for the
Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for
steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in
situ combustion. Though in situ combustion returned the highest net present value and internal rate of
return, it proved not to be the best option for Nigeria due to environmental concern and response time to
production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity
drainage.
An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify
the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in
Nigeria is a wise economic decision.Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.
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WEN, CHANG YA, e 張雅雯. "Research on the Learning Effect of Combining the Issue of Biodiversity with Science and Technology DomainTake the Unit of “Underwater Species” for Example". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/65663973739300728966.
Testo completoAbstract (sommario):
碩士國立臺北教育大學
自然科學教育學系碩士班
94
The goal of this research is to discuss the influence of teaching the unit of “Underwater Species” combining the issue of biodiversity with Science and Technology Domain on the students’ concept of underwater species, the students’ attitude toward the protection of biodiversity, and the students’ capacity of the identification of biodiversity. Additionally, to understand thoughts and feedback from students after receiving the combined curriculum is another end. This research uses Quasi-experiment and, mainly, quantitative statistic analysis. The research objects are two 4th-grade classes in an elementary school at Xizhi City, Taipei County, within which one is the experimental group receiving the teaching approach of combining the issue of biodiversity with Science and Technology Domain while the other is the control group receiving the general science course. These two groups need to take pre-tests and post-tests of “The Concept of Underwater Species Test,” “The Attitude toward the Protection Biodiversity Scale,” and “The Identification of Biodiversity Test;” still, students of the experimental group fill in “The Feedback Questionnaire of Students’ Learning” after receiving the combined curriculum. The data analyzed methods include analysis of variance (ANOVA) and covariance (ANCOVA). The followings are the main results of this research: 1. The score of “The Concept of Underwater Species Test” from the students receiving the curriculum combining teaching with the issue of biodiversity is much more excellent than the students receiving the general teaching (F= 17.119，p﹤.05), which suggests that the curriculum combining teaching with the issue of biodiversity can efficiently improve the students’ learning achievement of the concept of underwater species. 2. The score of “The Attitude toward the Protection Biodiversity Scale” from the students receiving the curriculum combining teaching with the issue of biodiversity is much more excellent than the students receiving the general teaching (F=12.329，p﹤.05), which suggests that the curriculum combining teaching with the issue of biodiversity can efficiently improve the students’ attitude toward the protection of biodiversity. 3. The score of “The Identification of Biodiversity Test” from the students receiving the curriculum combining teaching with the issue of biodiversity is much more excellent than the students receiving the general teaching (F=36.617，p﹤.001), which suggests that the curriculum combining teaching with the issue of biodiversity can efficiently improve the students’ capacity of the identification of biodiversity. 4. After practicing the teaching approach combining with the issue of biodiversity, the experimental group is positively affirmed in the aspects of the learning attitude of the curriculum, the learning motivation, and the learning strategy. Still, in the process of the teaching activity, the most favorite teaching activity students like is the interactive teaching activity such as outdoor teaching and playing games, which implies that the teaching activities, such as outdoor observation and survey by students themselves, proceeding in the vivacious and interesting way could efficiently enhance the students’ learning interest.
Libri sul tema "Underwater Research and Recovery Unit"
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Reid, Gary R. Standard operating guidelines for San Diego County Sheriff Department's Underwater Research and Recovery Unit. 2004.
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Barnhard, Megan, e Jade Rivera. Could You Live Underwater?: A Design Thinking and STEM Curriculum Unit for Curious Learners. Taylor & Francis Group, 2021.
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Barnhard, Megan, e Jade Rivera. Could You Live Underwater?: A Design Thinking and STEM Curriculum Unit for Curious Learners. Prufrock Press, 2018.
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Barnhard, Megan, e Jade Rivera. Could You Live Underwater?: A Design Thinking and STEM Curriculum Unit for Curious Learners. Prufrock Press, 2018.
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Barnhard, Megan, e Jade Rivera. Could You Live Underwater?: A Design Thinking and STEM Curriculum Unit for Curious Learners. Taylor & Francis Group, 2021.
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Could You Live Underwater?: A Design Thinking and STEM Curriculum Unit for Curious Learners. Taylor & Francis Group, 2021.
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Hoff, Scott, e Nancy A. Collop. Sleep Disorders and Recovery from Critical Illness. Oxford University Press, 2014. http://dx.doi.org/10.1093/med/9780199653461.003.0022.
Testo completoAbstract (sommario):
Many factors contribute to sleep disruption in critically ill patients. Sleep is a complex process, with broad effects on diverse physiologic systems. Environmental factors, such as light exposure, noise from diverse sources, and sleep interruptions related to patient care, have all received considerable investigational attention. Critical illness can affect elements involved in sleep initiation and maintenance. The various modes of mechanical ventilation may have different effects on sleep fragmentation and on the propensity to cause central apnoeas, thereby potentially prolonging the time on the ventilator. Pharmacologic agents, especially sedatives, can directly affect sleep architecture and may contribute to the incidence of intensive care unit delirium. Additional research is needed on the biological effects of critical illness on sleep, how sleep disruption affects systemic physiology and outcomes, and how these interactions can be modulated for therapeutic purposes.
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Laurent, Julien, Randal Samstag, Jim Wicks e Ingmar Nopens, a cura di. CFD Modelling for Wastewater Treatment Processes. IWA Publishing, 2022. http://dx.doi.org/10.2166/9781780409030.
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Abstract This Scientific and Technical Report (STR) provides in-depth fundamentals and guidelines regarding Computational Fluid Dynamics (CFD) simulations of Water Resources Recovery Facilities (WRRFs) unit processes (e.g. headworks, aerobic and anaerobic biological reactors, settling tanks, disinfection). Each unit process is described with respect to: Literature review and process descriptionRelevant CFD concepts and modelling approachCase studiesFuture research needs CFD Modelling for Wastewater Treatment Processes also opens the discussion on two fundamental topics: experimental validation of CFD simulations, and the complementarity between CFD and Chemical Reaction Engineering approaches. This book is intended for undergraduate and graduate students majoring in fields related to wastewater treatment and/or fluid mechanics, as well as researchers and engineers who conduct research and practices in modelling such unit processes. Water resource recovery modelling is not just about lab-scale processes. Now and in the future it is about improving our understanding of (and designing better) full-scale facilities!
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Elliott, Doug, e Linda Denehy. Post-ICU Rehabilitation. Oxford University Press, 2014. http://dx.doi.org/10.1093/med/9780199653461.003.0051.
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More than three-quarters of patients who experience a critical illness and intensive care unit admission survive their initial physiological insult and are subsequently discharged from hospital. Some of these survivors have physical, psychological, or cognitive deficits that persist and delay optimal recovery in the following months and, in some instances, years. A range of generic screening and functional assessment strategies has been used with post-ICU cohorts, but methodological limitations were evident. Further research is therefore required, possibly using a battery of instruments to cover a broad range of function across the recovery period, to explore optimal screening times. Commencing or continuing rehabilitation strategies for patients after ICU discharge in both hospital and post-hospital environments have their own set of challenges. A key step is to improve awareness and understanding of the sequelae of critical illness among rehabilitation specialists, primary care practitioners, and the broader health community. Coordination and optimal use of scarce resources in hospital and community settings is required. Evidence supporting post-ICU rehabilitation interventions is mixed. Studies are needed to discern which patients likely to respond and the optimal amount, type, and timing of interventions. Innovative use of wearable technologies and smartphone or tablet applications may offer some solutions for monitoring, motivation, compliance, and optimal recovery for survivors of a critical illness who have identified functional deficits.
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Xu, Kui, Joseph C. LaManna e Michelle A. Puchowicz. Ketogenic Diet, Aging, and Neurodegeneration. A cura di Detlev Boison. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190497996.003.0024.
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The brain is normally completely dependent on glucose, but is capable of using ketones as an alternate energy source, as occurs with prolonged starvation or chronic feeding of a ketogenic diet. Research has shown that ketosis is neuroprotective against ischemic insults in rodents. This review focuses on investigating the mechanistic links to neuroprotection by ketosis in the aged. Recovery from stroke and other pathophysiological conditions in the aged is challenging. Cerebral metabolic rate for glucose, cerebral blood flow, and the defenses against oxidative stress are known to decline with age, suggesting dysfunction of the neurovascular unit. One mechanism of neuroprotection by ketosis involves succinate-induced stabilization of hypoxic inducible factor-1alpha (HIF1α) and its downstream effects on intermediary metabolism. The chapter hypothesizes that ketone bodies play a role in the restoration of energy balance (stabilization of ATP supply) and act as signaling molecules through the up-regulation of salvation pathways targeted by HIF1α.
Capitoli di libri sul tema "Underwater Research and Recovery Unit"
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Ni, Tian, Lindan Zhang, Can Sima, Jia Guo e Haibo Wu. "Research on Autonomous Docking Control for Underwater Recovery of Unmanned Submersible Vehicles". In Lecture Notes in Electrical Engineering, 187–200. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-1095-9_18.
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Muthucumarana, Rasika. "The Development of the Maritime Archaeology Unit, MUCH Management and Current Research Projects in Sri Lanka". In Maritime and Underwater Cultural Heritage Management on the Historic and Arabian Trade Routes, 29–48. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-55837-6_2.
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Garipağaoğlu-Uğur, Nihan, e Orhan Akova. "The Use of Virtual Reality and Augmented Reality in Cultural Heritage and Deep-Diving Destinations". In Handbook of Research on Digital Communications, Internet of Things, and the Future of Cultural Tourism, 138–60. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8528-3.ch008.
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Underwater cultural heritage and deep diving are important attractions for tourism. Using cutting-edge technology tools for cultural heritage became more important for tourism destinations. The purpose of this chapter is to evaluate the use of virtual reality (VR) and augmented reality (AR) in tourism from the perspective of cultural heritage and deep diving. This chapter will contribute to the literature to show a new way of sustainable tourism. Commercial diving to an underwater heritage site a is popular touristic activity. Sometimes shipwreck recovery can be hazardous for cultural heritage. The review results indicate that these underwater cultural heritage sites need to be protected for sustainable tourism development. Virtual tours contribute to the sustainability of cultural heritage. On the other hand, treasure hunting trips and recreational diving may cause damage to the archaeological sites. Underwater cultural heritage sites should be protected for sustainable tourism. VR and AR applications can be used to promote a touristic destination by tourism marketers for experimental marketing.
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Akah, A. "The Role of Rare Earths in Fluid Catalytic Cracking (FCC) Catalyst". In Materials Research Foundations, 298–342. Materials Research Forum LLC, 2024. http://dx.doi.org/10.21741/9781644903056-9.
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Rare earth oxides enhance catalyst activity and prevent the loss of acid sites during the FCC unit operation, especially when feed with high metal content is used. This chapter reviews the effects of rare earth elements on the structure, activity, and stability of FCC catalysts. It also looks into the mechanism of catalyst deactivation by vanadium and how rare earths are used to combat this. The objective is to elucidate the interaction of vanadium species with the zeolite component of the FCC catalysts and to show the role of rare earth elements in countering the deleterious effects of vanadium. The recycle of spent FCC catalyst with a focus on rare earth element recovery is also outlined.
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Leal, Wanessa Oliveira, e Pâmela Andressa Freitas Franco. "Family-centered nursing care in the neonatal intensive care unit". In Challenges and Research in Health Sciences: A Multidisciplinary Approach. Seven Editora, 2024. http://dx.doi.org/10.56238/sevened2024.012-032.
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Family-centered nursing care in the Neonatal Intensive Care Unit is a holistic approach that recognizes the importance of the family in the care and development of the newborn and involves them as an integral part of the healthcare team, valuing their needs, concerns and experiences during the newborn's hospitalization. The aim of this study was to discuss family-centered nursing care in the Neonatal Intensive Care Unit. This is an integrative review and its guiding question was: "What is family-centered nursing care in the Neonatal Intensive Care Unit?". The databases used were BDENF, MEDLINE and PUBMED. The study sample consisted of nine original articles. To extract the data, the type of study and the year of publication were analyzed. The results were presented and discussed in terms of the nurse's role and the importance of humanization in interventions and the family's participation and perception of nursing care. It was concluded that family-centered nursing care in the Neonatal Intensive Care Unit aims to promote a humanized and integrated approach to caring for the newborn and the family, valuing the partnership and collaboration between the health team and the parents, contributing to the healthy development, well-being and recovery of the newborn, as well as strengthening family ties and emotional support for the parents during their stay in the Neonatal Intensive Care Unit.
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Mpala, Tshepiso, Indira Chimanlal, Heidi Richards, Anita Etale e Lebea N. Nthunya. "Hybrid membrane processes equipped with crystallization unit for a simultaneous recovery of freshwater and minerals from saline wastewater". In Development in Wastewater Treatment Research and Processes, 71–91. Elsevier, 2024. http://dx.doi.org/10.1016/b978-0-323-99278-7.00010-9.
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Osa, Edosa, e Daniel Chinemelem Samuels. "Design of a Control System for an Autonomous Underwater Vehicle EDYSYS1". In Advances in Transdisciplinary Engineering. IOS Press, 2023. http://dx.doi.org/10.3233/atde230504.
Testo completoAbstract (sommario):
This paper describes the design of a control system for an autonomous underwater vehicle EDYSYS 1. An autonomous underwater vehicle is an unmanned and self-propelled underwater vessel that can operate independently underwater and carry out several missions as assigned to it compared to a Remotely Operated Vehicle (ROV) which is usually tethered to a ship or some other moored water vehicle. Intelligent design of control systems for autonomous underwater vehicles is an active area of research giving the demands for autonomy and the capacity for intelligent systems to satisfy such demands. A control system has been designed with the Raspberry Pi 4 computer as the main control unit. Various subsystems and sensors for data acquisition by the vehicle are controlled by the Raspberry Pi 4 which has the Robot Operating System (ROS) configured in it. The necessary intelligence for controlling each sensor is configured using Python programming language. The relevant Python scripts are thereafter implemented as nodes within the ROS framework. By calling the relevant nodes in ROS, various values of sensory data were obtained by the designed system in the ROS environment. Successful communication via LoRa was also achieved.
8
Du, Jianwei, Hui Li, Miaochen Zhang e Hongtao Liu. "Operation Strategy of Single Unit Tripping in Multi-Units IGCC Power Plant". In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220398.
Testo completoAbstract (sommario):
Integrated Gasification Combined Cycle power generation technology is recognized as one of the important future development directions of clean power generation. Taking a large-scale IGCC power plant as the research object, the operating strategy of single unit tripping in multi-units was discussed in this paper. Gasification unit and air separation unit shall ramp down and balance with various gas demand in 1–2 minutes after one-unit trips. Duct burners of heat recovery steam generator can be used to produce more steam and increase steam turbines output subsequently. New stabilized power output can be reached within 20 minutes after the tripping.
9
Hermawan, Marko S., e Ubaidillah Nugraha. "The Development of Small-Medium Enterprises (SMEs) and the Role of Digital Ecosystems During the COVID-19 Pandemic". In Handbook of Research on Current Trends in Asian Economics, Business, and Administration, 123–47. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8486-6.ch007.
Testo completoAbstract (sommario):
Small and medium enterprises (SMEs) have been the backbone of Indonesia's economy for over 100 years. There is nearly 64-million-unit business, with 98% of the market share belonging to the micro-business and 52% categorized as informal. Despite the uncertainty created by the prolonged crisis, a path of recovery is happening in the SME sector. Continuous effort to support SMEs has been planned include mapping out a cluster program. This chapter illustrates challenges and types of resilience and cluster issues facing SMEs that need to be resolved to prepare SMEs for recovery, and one of them is information technology. For many businesses, including SMEs, participation in the digital economy is the key to greater resiliency. The development of SMEs in Indonesia is an interesting topic with an actual illustration of the recent trends of Asian countries' economies and businesses in the current COVID-19 pandemic.
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Al-Saadoon, Ghossoon M. Waleed, e Ebrahim Al Naemi. "Virtualization Technology and Security Challenges". In Handbook of Research on Threat Detection and Countermeasures in Network Security, 254–75. IGI Global, 2015. http://dx.doi.org/10.4018/978-1-4666-6583-5.ch014.
Testo completoAbstract (sommario):
The aim of server virtualization is to eliminate the Hardware equipment in the Datacenter and maximize the utilization of the existing resources. This helps companies in achieving the business goals and objectives in cost effective manner and better support and integration. Virtualization technology changes the protection way of security, as most of hardware and software become after virtualization such as servers, switches, Logical Unit Numbers (LUNs) etc. and it's no longer trying to protect a physical hardware, (Hurwitz & et al, 2013). The overall objective of this chapter is to find out the solution for reducing the keep regular increasing recurring cost and risk involved in information technology management and maintenance. The chapter is about finding out the solution from which it's possible to ultimately lower the cost, speed deployment, provide additional disaster recovery options, and ease testing and developing, and provide unprecedented mobility, flexibility and reliability.
Atti di convegni sul tema "Underwater Research and Recovery Unit"
1
Gerber, Hans W., e Gu¨nther F. Clauss. "Space Shuttle MODUS: Key System for the Installation of Networks of Benthic Stations". In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2005. http://dx.doi.org/10.1115/omae2005-67107.
Testo completoAbstract (sommario):
In the last decade within several European and bi-national (German-Italian) projects a set of equipment and technology for benthic stations, and their deployment and recovery has been developed. Starting with a single prototype station which operated autonomously for several months in the Mediterranean Sea (GEOSTAR2 – Geophysical and Oceanographic Station for Abyssal Research – Deep Sea Mission, 1999–2001, /1/) with a near-real-time-communication-system including a acoustic link from station to buoy and a shore radio link. This concept has been extended to realize a sub-sea network of several benthic stations (ORION- Ocean Research by Integrated Observation Networks, 2002–2005, /1/). This includes an extended version of the GEOSTAR acoustic underwater communication system between the stations and the buoy unit for direct shore communication. For the deployment and recovery of these benthic stations the deep-sea shuttle MODUS (Mobile Docker for Underwater Sciences) has been developed and used (operation depth 4000 m). All operations up to now were successfully conducted. The ORION-network is under operation at a water depth of 3700 m North of Sicily/Italy since December 2003. In addition to this MODUS has been used to install the first long-term benthic station directly cable connected to shore. Thus, the first European long term benthic station has been established, with the aim to demonstrate a technology for the ongoing plans for a European deep-sea shore network (ESONET – European Seafloor Observatory Network, /1/). The deployment took place east of Sicily using MODUS and a ROV for the realization of the cable connection between the station and the cable termination in January 2005.
2
Malinda, H. A. N., M. M. T. M. Marasingha, S. C. D. Senarath, P. C. Dassanayake e A. L. Kulasekara. "Experimental bending performance characterization of sHAMs used underwater growing robot". In Engineering Research Unit Symposium 2023. Engineering Research Unit, 2023. http://dx.doi.org/10.31705/eru.2023.7.
Testo completoAbstract (sommario):
Soft-growing robots represent an emerging field characterized by their ability to extend at the tip while the base remains stationary. These robots offer a unique advantage in navigating through confined spaces inaccessible to humans. Specifically, in underwater exploration tasks, their flexible bodies render them particularly efficient. Moreover, these robots exhibit the capability to steer even while growing. There exist several steering methods including sHAMs (soft Hydraulic Artificial Muscles), sPAMs (soft Pneumatic Artificial Muscles), tendon-driven techniques, and predefined bending mechanisms, applicable both in air and underwater [1],[2]. This paper specifically delves into the study of sHAMs (soft Hydraulic Artificial Muscles) and their inherent characteristics. Various critical factors influence the bending behavior of sHAMs, including pressure, the diameter ratio between the robot body and the sHAM, the length of the robot body, and the number of sHAMs employed. In this study, we concentrate on varying the diameter ratio between the body and sHAM, while keeping other parameters constant. To achieve this, we fabricated robot bodies with varying diameters while maintaining a constant diameter for the sHAM. By systematically analyzing the results obtained from this experimental setup, we aim to provide insights into how the bending angle varies in relation to the diameter ratio.
3
Navasardian, A. A. "Underwater hydro unit with the combined energy extraction". In 2014 International Conference on Renewable Energy Research and Application (ICRERA). IEEE, 2014. http://dx.doi.org/10.1109/icrera.2014.7016549.
Testo completo
4
Sun, Yushan, Lifeng Wang, Xiangrui Ran e Guocheng Zhang. "Research on Recovery Strategy and Motion Control for Autonomous Underwater Vehicle". In 2018 International Conference on Advanced Control, Automation and Artificial Intelligence (ACAAI 2018). Paris, France: Atlantis Press, 2018. http://dx.doi.org/10.2991/acaai-18.2018.4.
Testo completo
5
Perera, K. L. M., T. I. Hettiarachchi, J. A. A. S. Kumara, R. M. M. Ruwanthika e P. S. S. D. Arunya. "Bimanual tele rehabilitation robot". In Engineering Research Unit Symposium 2023. Engineering Research Unit, 2023. http://dx.doi.org/10.31705/eru.2023.14.
Testo completoAbstract (sommario):
Post-stroke patients lose their interlimb coordination and ability to do bimanual activities. This is common for arms, and usually, patients get one arm paretic. This is a heavy burden since everyday activities need both hands to do. For recovery, they need intensive bimanual therapy. The robotic approach is more effective than traditional rehabilitation for this kind of therapy. A bimanual master-slave robotic system can be used to do simultaneous exercises for patients’ both hands. Our focus is to implement the two most basic and critical movements into this robot. One is Flexion and Extension, and the other is Internal and external rotation. Stroke is one of the conditions that causes long-term disabilities. This causes a lot of struggles for patients to recover. To overcome that and speed up the recovery we propose a robotic approach, with reduced dependency on a therapist and increased repeatability and robustness. When doing these exercises, the patient’s shoulder must be in a relaxed position. Otherwise, the generated torques will depend on the shoulder position. Hence there must be adjustments for varying arm lengths as it changes the position of the elbow joint. Also, we are going to implement two exercises which are done in perpendicular planes into one 1 DOF (Degrees of Freedom), robot. And we need to provide methods to change the motor orientation for that.
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Elsharafi, Mahmoud, Ali Elmozughi, Kelton Vidal, Rumelia Thomas, Saleh Almutairi, Thilanka Senevirathne e Joshua Lambright. "Energy Recovery Unit Using Phase Change Materials". In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23020.
Testo completoAbstract (sommario):
Abstract Energy recovery can benefit from phase change materials. A phase change material is a substance with a high heat of fusion, melting, and solidifying at a certain temperature, which is capable of storing and releasing large amounts of energy. The objective of this research is to enhance the efficiency of a system by performing experiments with corrugated plates within the recovery unit and paraffin as the PCM (Phase Change Material). This research focuses on understanding Thermal Energy Storage (TES) at melting temperature for heating. This research used corrugated plates as an advanced material and channels of media which carry the thermal fluid (water) to the back plate of the unit which was occupied with the PCM or in this case paraffin. The experiment measured the temperature in and out from the unit to estimate how much kWh (power) that unit can save in the molten wax and also, monitor the temperature inside the PCM using implanted thermocouples. The approach of this work is to collect temperature as a function of time to find how much energy units are used to reach the charging point and reverse the flow to retrieve energy from the unit.
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Solak, Fulya, Haluk Gozde, M. Akif Senol e M. Cengiz Taplamacioglu. "Design of power control unit for heat recovery device used in renewable energy system". In 2015 4th International Conference on Renewable Energy Research and Applications (ICRERA). IEEE, 2015. http://dx.doi.org/10.1109/icrera.2015.7418596.
Testo completo
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Huang, Weigang, Donglei Zhang, Jiawei Yu, Tao He e Xianzhou Wang. "Numerical Simulation Study on the Recovery Process of Autonomous Underwater Vehicle". In ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/omae2021-64000.
Testo completoAbstract (sommario):
Abstract AUV (Autonomous Underwater Vehicle) recovery is considerably influenced by the nearby flow field and simulations of AUV in different motion paths in the wake of a submarine with a propeller are presented in this paper. A commercial CFD solver STAR CCM+ has been used to research the motion and flow characteristics of AUV, which using the advanced computational continuum mechanics algorithms. The DARPA (Defense Advanced Research Projects Agency) SUBOFF Submarine (L1 = 4.356m) propelled with INSEAN (Italian Ship Model Basin) E1619 propeller is used in this study, and the self-propulsion characteristics of the propeller at an incoming flow velocity of 2.75m/s are obtained through numerical simulation and results are compared with the available experimental data to prove the accuracy of the chosen investigation methodology. A grid/time-step convergence test is performed for verification study. AUV (L2 = 0.4356m) is a smaller-scale SUBOFF without a sail, which approaches the submarine in different motion paths in the submarine wake at a relative speed combined with the dynamic overlapping grid technology. The hydrodynamic performance of the AUV when approaching the submarine and the velocity distribution of the surrounding flow field are analyzed, which provides a useful reference for underwater recovery of the AUV.
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Jalab, Rem, Abdelrahman M. Awad, Mustafa S. Nasser, Joel Minier-Matar e Samer Adham. "Pilot Scale Osmotic Concentration Process for Reducing Wastewater Volumes from Gas Processing Facilities in Qatar". In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0080.
Testo completoAbstract (sommario):
Over the past 10-15 years, there has been increasing attention in the development of forward osmosis (FO) technology as a low-energy technical solution to wastewater treatment through the exploitation of the natural osmosis phenomenon across semi-permeable membrane. The significant energy benefit arises in applications where direct recovery of the permeate product from the draw solution (DS) is obviated such as in osmotic concentration (OC) process. In the current research, an OC FO-based pilot-scale unit was applied for wastewater volume reduction from oil and gas processing facilities in Qatar. The pilot unit uses seawater of 40 g/L salinity as a DS and wastewater generated during oil and gas operations as a feed. This feed water is of comparatively low conductivity (2 g/L salinity), making it unusually suited to treatment by OC. Based on FO technology principles, the feed gets concentrated at lower volume with the water permeation through the membrane, meanwhile the water transfer to DS side dilutes it. The diluted DS could be directly discharged into the ocean; so the energy intensive step of DS recovery is entirely eliminated. Two FO membranes (Toyobo and NTU) of hollow fiber configuration were tested to assess their performance and fouling propensity on both synthetic and real wastewaters. Results demonstrated that the membrane-based process can achieve feed water recoveries up to 90% without any scaling issues. Achieved water flux ranges between 1.5 to 12 LMH for feed recoveries between 60 and 90% using a constant dilution rate of the draw solution. Above all, the pilot unit maintained stable water flux of 1.62 and 6 LMH using at 75% feed recovery for over 48 hours of continuous operation Toyobo and NTU membranes respectively.
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Cao, Jianwei, Linyi Gu, Feng Wang e Ying Chen. "Research on Electro-Hydraulic Control of Propellers of the Underwater Vehicles With Switch-Mode Hydraulic Power Supply". In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13525.
Testo completoAbstract (sommario):
Switch-mode hydraulic power supply is a hydraulic pressure converting unit made of some distributed hydraulic components, which can boost or buck hydraulic pressure continuously with low power loss (about 20%)and continuous flow-rate. There are two types of switch-mode hydraulic power supply, pressure boost and pressure buck. (see "Switch-mode Hydraulic Power Supply Theory", 2005 ASME, IMECE-FPST No.79019)[1]. This paper introduces a new propeller driving system using the motor of the switch-mode hydraulic power supply for the underwater vehicle. And PFM (Pulse Frequency Modulation) control of high-speed switch-valves is applied to adjust the rotation speed of the propeller. The system has advantages over the widely used servo-valve valve-control system and pump-control system on the energy-weight ratio, anti-contamination performance and energy-saving capacity.
Rapporti di organizzazioni sul tema "Underwater Research and Recovery Unit"
1
O'Connell, Kelly, David Burdick, Melissa Vaccarino, Colin Lock, Greg Zimmerman e Yakuta Bhagat. Coral species inventory at War in the Pacific National Historical Park: Final report. National Park Service, 2024. http://dx.doi.org/10.36967/2302040.
Testo completoAbstract (sommario):
The War in the Pacific National Historical Park (WAPA), a protected area managed by the National Park Service (NPS), was established "to commemorate the bravery and sacrifice of those participating in the campaigns of the Pacific Theater of World War II and to conserve and interpret outstanding natural, scenic, and historic values on the island of Guam." Coral reef systems present in the park represent a vital element of Guam?s cultural, traditional, and economical heritage, and as such, are precious and in need of conservation. To facilitate the management of these resources, NPS determined that a scleractinian (stony coral) species survey was necessary to establish a baseline for existing coral communities and other important factors for conservation. EnviroScience, Inc. performed a survey of stony coral species, coral habitat, and current evidence of stressors at WAPA?s H?gat and Asan Units in 2022. This report summarizes these findings from a management perspective and compares its findings to previous survey data from 1977 and 1999 (Eldridge et al. 1977; Amesbury et al. 1999). WAPA is located on the tropical island of Guam, located on the west-central coast of the island, and encompasses 2,037 acres. Underwater resources are a significant component of the park, as 1,002 acres consists of water acres. The park is comprised of seven units, of which two of these, the H?gat and Asan Beach Units, include all the oceanic water acres for the park. The H?gat Beach Unit (local spelling, formerly known as ?Agat?) is located at the south-west portion of the park and consists of 38 land acres and 557 water acres (NPS 2003). The Asan Beach Unit consists of 109 acres of land and 445 water acres (NPS 2003). A current baseline for existing coral communities and other important factors for conservation necessitates the need for up-to-date data on the location, presence, relative abundance, and present health of corals. Park managers need this updated data to determine where and how to best focus conservation priorities and identify restoration opportunities. Management actions in park reef areas informed by this inventory included identifying locations where there were: high rates of sedimentation; high coral biomass; rare or threatened species, with a priority given to species endemic to Guam and listed as ?threatened? under the U.S. Endangered Species Act (ESA; Acropora globiceps, A. retusa, A. speciosa, and Seriatopora aculeata); coral persistence and decline, disease and/or nuisance species, including the crown-of-thorns starfish (Acanthaster cf. solaris, ?COTS?) and the sponge Terpios hoshinota; and bleached areas. All work carried out was in accordance with the NPS statement of work (SOW) requirements, which involved a quantitative inventory using both new and pre-existing transects. The resulting transects totaled 61 (including the four from the 1999 study), each measuring 50 meters in length and distributed across depths of up to 50 feet. Divers took photo-quadrat samples covering an area of approximately 9 m?, encompassing 50 photo-quadrats of dimensions 0.50 m x 0.36 m (n=50). The collective area surveyed across all 61 transects amounted to ~549 m?. Additionally, a qualitative search was conducted to enhance documentation of coral species that have limited distribution and might not be captured by transects, along with identifying harmful species and stressors. Timed roving diver coral diversity surveys were carried out at a total of 20 sites occurring within the waters of WAPA, including eight sites at the H?gat unit and 12 sites at the Asan unit. The findings from this report reveal significant disparities in benthic cover compositions between H?gat and Asan units. The H?gat unit exhibits high abundances of turf algae and unconsolidated sediment while the Asan beach unit presents a different scenario, with hard coral as the dominant benthic cover, followed closely by crustose coralline algae (CCA). The Asan unit is also more difficult to access from shore or boat relative to H?gat which provides that unit some protection from human influences. The Asan beach unit's prevalence of hard coral, CCA, and colonizable substrate suggests a more favorable environment for reef growth and the potential benefits of maintaining robust coral cover in the area. These distinct differences in benthic communities highlight the contrasting ecological dynamics and habitats of the two study areas. Across both H?gat and Asan beach unit transects, a total of 56 hard coral species were recorded from 27 genera, with 44 species recorded from the H?gat unit and 48 species recorded from the Asan unit. Of the four historical transects surveyed in the Asan unit from 1999, three experienced declines in percent coral cover (17.38-78.72%), while the fourth had an increase (10.98%). During the timed roving diver coral diversity surveys, a total of 245 hard coral species, including 241 scleractinian coral species representing 49 genera and 4 non-scleractinian coral species representing 4 genera were recorded. Uncertainties related to coral identification, unresolved boundaries between morphospecies, differences in taxonomists' perspectives, and the rapidly evolving state of coral taxonomy have significant implications for species determinations during coral diversity surveys. While the recent surveys have provided valuable insights into coral diversity in WAPA waters, ongoing taxonomic research and collaboration among experts will be essential to obtain a more comprehensive and accurate understanding of coral biodiversity in the region. Of the several ESA coral species that were searched for among the H?gat and Asan beach units, Acropora retusa was the only coral species found among quantitative transects (n=2) and A. globiceps was observed during coral diversity surveys. Acropora speciosa, which was dominant in the upper seaward slopes in 1977, is now conspicuously absent from all the surveys conducted in 2022 (Eldredge et al., 1977). The disappearance and reduction of these once-dominant species underscores the urgency of implementing conservation measures to safeguard the delicate balance of Guam's coral reefs and preserve the diversity and ecological integrity of these invaluable marine ecosystems. Other formerly common or locally abundant species were infrequently encountered during the diversity surveys, including Acropora monticulosa, A. sp. ?obtusicaulis?, A. palmerae, Stylophora sp. ?mordax?, Montipora sp. ?pagoensis?, and Millepora dichotoma. Significant bleaching-associated mortality was recorded for these species, most of which are restricted to reef front/margin zones exposed to moderate-to-high levels of wave energy. Sedimentation was present in both H?gat and the Asan units, though it was more commonly encountered in H?gat transects. While significant portions of the reef area within the WAPA H?gat unit are in poor condition due to a variety of stressors, some areas still hosted notable coral communities, which should be a potential focus for park management to prevent further degradation. There is a need for more effective management of point source pollution concerns, particularly when subpar wastewater treatment or runoff from areas with potential pollution or sediment-laden water is flowing from nearby terrestrial environments. Future monitoring efforts should aim to establish a framework that facilitates a deeper understanding of potential point source pollution incidents. This would empower park managers to collaborate with adjacent communities, both within and outside of park boundaries, to mitigate the localized impacts of pollution (McCutcheon and McKenna, 2021). COTS were encountered during transect surveys as well as in coral diversity surveys. including along the upper reef front/reef margin at site Agat-CS-2. The frequency of these observations, particularly in the WAPA H?gat unit and where stress-susceptible corals are already uncommonly encountered, raise concern about the ability of the populations of these coral species to recover following acute disturbance events, and calls in to question the ability of some of these species to persist in WAPA waters, and in Guam?s waters more broadly. More frequent crown-of-thorns control efforts, even if only a handful of sea stars are removed during a single effort, may be required to prevent further loss to vulnerable species. There were several documented incidents of Terpios hoshinota covering large sections of branching coral in the reef flat along transects, but it is still unclear how detrimental this sponge is to the overall reef system. There is a concern that elevated levels of organic matter and nutrients in the water, such as those resulting from sewage discharge or stormwater runoff, could lead to increased Terpios populations (De Voogd et al. 2013). Consequently, it is important to track populations in known areas of sedimentation and poor water quality. The presence of unique species at single survey sites within the study areas underscores the ecological importance of certain locations. Some species are known to occur in other locations in Guam, while a few may be limited to specific sites within WAPA waters. These differences are likely influenced by environmental and biological factors such as poor water quality, severe heat stress events, chronic predation by crown-of-thorns sea stars, disease, and reduced herbivore populations. These factors collectively shape the condition of the benthic community, leading to variations in species distribution and abundance across the study sites. Documenting coral stress and identifying potentially harmful species allows for proactive management strategies to prevent the establishment of nuisance or detrimental species while populations are still manageable. Updated data on the location, presence, relative abundance, and health of corals is essential for park managers to prioritize conservation efforts and identify restoration opportunities effectively. Observations from this report raise concerns about the health and resilience of coral ecosystems in the H?gat unit and emphasize the need for knowledge of local factors that shape benthic community structure. Understanding the drivers responsible for these variations is crucial for effective conservation and management strategies to preserve the ecological balance and overall health of coral reefs in both units. Continued monitoring efforts will be critical in assessing long-term trends and changes in benthic cover and enabling adaptive management approaches to safeguard these valuable marine ecosystems in the face of ongoing environmental challenges.
2
Schuurman, Gregor, Christopher Hoving, Anna Hess, Lainey Bristow, Philip Delphey, Jessica Hellmann, Heather Keough, Randy Knutson e Annie Kellner. Blue snowflakes in a warming world: Karner blue butterfly climate change vulnerability synthesis and best practices for adaptation. National Park Service, 2023. http://dx.doi.org/10.36967/2301333.
Testo completoAbstract (sommario):
This report?developed at the request of the United States Fish and Wildlife Service-led Karner Blue Butterfly Recovery Team by Recovery Team members and partners?provides a Karner blue butterfly climate change vulnerability synthesis, explores a range of potential responses, and presents best practices for climate change-informed conservation of the species. The three decades since the Karner blue butterfly?s (Lycaeides [Plebejus] melissa samuelis Nabokov) listing as federally endangered in the United States have seen a diverse and dedicated research and management community coalesce around the species? recovery. This geographically expansive conservation collaboration has broken new ground for threatened and endangered species recovery. Many Karner blue recovery areas are making steady progress towards recovery goals, but some are not. An extremely hot and dry 2012, perhaps aided by adverse longer-term climate trends such as declining snow cover, extirpated the Karner blue from Indiana Dunes National Park and the surrounding Indiana Dunes Karner Blue Butterfly Recovery Unit?the southernmost recovery unit and once host to one of the species? largest populations?as well as from northwest Ohio. Because of the fundamental challenge that climate change represents to Karner blue butterfly recovery and of the general need for endangered species conservation plans to better address climate change, the United States Fish and Wildlife Service-led Karner Blue Butterfly Recovery Team tasked a subset of the team to: Explore the species? climate change sensitivity and adaptive capacity, review ongoing and projected climate change across the Karner blue range and associated uncertainties, and develop and suggest best practices concerning long-term adaptation strategies. Consistent with that mandate, this report synthesizes what is known about Karner blue climate change vulnerability and applies current thinking in climate change adaptation to help foster strategic, long-term, climate change-informed Karner blue recovery and conservation. It develops and explores a range of potential climate change-informed butterfly- and habitat-stewardship responses, using the resist-accept-direct (RAD) framework to foster a broad range of approaches, and provides guidance regarding how they may be pursued. The report also provides suggestions for improving the climate change-exposure component of Karner blue vulnerability assessment.
3
Herbert, Sian. Approaches to Stabilisation. Institute of Development Studies, aprile 2022. http://dx.doi.org/10.19088/k4d.2022.068.
Testo completoAbstract (sommario):
This rapid literature review explores how approaches to stabilisation have varied by the donor, local context, and over time. While this paper was framed around a research question on the “Area Based Stabilisation” (ABS) approach, this term is barely used in the literature. Therefore, it is not possible to define an ABS approach or compare it to other approaches. However, there is considerable literature on approaches to stabilisation more generally, with some comparative analysis of approaches by donors and how these are evolving according to the context and some illustrative lessons from their application. As per the question from FCDO, this query also draws on analyses of the following case examples: Regional Strategy for the Stabilization, Recovery and Resilience (RSS) of the Boko Haram-affected areas of the Lake Chad Basin Region; Helmand Provincial Reconstruction Team (PRT) in Afghanistan; Area Based Recovery Approach (ABRA) in Iraq; and the Stabilisation Facility for Libya (SFL). As the Stabilisation Unit (2019) emphasises, as the purpose of engaging in stabilisation activities, and the political and conflict contexts, vary so much, it is only possible to draw out some generic/illustrative lessons across cases.