27 research outputs found
A Control Program for Hydropower Operation Based on Minimizing the Principal Stress Values on the Dam Body: Mosul Dam Case Study
This study examines the vibrations produced by hydropower operations to improve embankment dam safety. This study consists of two parts: In the first part, ANSYS-CFX was used to generate a three-dimensional (3-D) finite volume (FV) model to simulate a vertical Francis turbine unit in the Mosul hydropower plant. The pressure pattern result of the turbine model was transformed into the dam body to show how the turbine unit's operation affects the dam's stability. The upstream reservoir conditions, various flow rates, and fully open inlet gates were considered. In the second part of this study, a 3-D FE Mosul dam model was simulated using an ANSYS program. The operational turbine model's water pressure pattern is conveyed to the dam's turbine-shared zone. The maximal and minimal upstream reservoir water levels were investigated. A control program was created depending on the principle stress model results collected from the operation of the hydropower plant with the minimum principal stress on the dam body. This research suggests an enhanced turbine operating system, reducing stress on the dam body and increasing dam operation life.
Possibilities of Investing Urban Heritage
لقد كرست الدراسات التي تعنى بالتراث ولسنوات عديدة إهتمامها بالقيم الثقافية المجردة، إلاّ إنَّ معرفة القيمة الأقتصادية للتراث التي تبنى عليها القرارات الإستثمارية لمشروعات الحفاظ أصبح متاحاً خصوصاً مع تطور أقتصاديات الحفاظ الذي يعد من المجالات الجديدة التي تستفيد من لغة. تمثلت المشكلة البحثية: "نقص الأدبيات، سيما العربية التي تناقش الإستثمار وامكانيته في مشروعات الحفاظ على التراث العمراني". وقد بني البحث على فرضية مؤداها: "ان الإستثمار الموجه في مشروعات الحفاظ على التراث العمراني يمكن أن يسهم في توفير التمويل الذي تتطلبه هذه المشاريع، فضلا عن إسهامه في تنمية المجتمعات المحلية". يهدف البحث إلى: "بناء القاعدة النظرية لمفاهيم الإستثمار في مشروعات الحفاظ على التراث العمراني، وبيان إمكانيات الإستثمار التي يوفرها التراث العمراني، ومن ثم بيان دور الإستثمارفي الحفاظ على التراث واحداث التنمية على المستويين العمراني والاجتماعي". لغرض تحقيق هدف البحث واختبار فرضيته فقد اشتمل البحث على مبحثين رئيسيين، الاول: امكانات استثمار التراث العمراني، والثاني: تجربة مؤسسة الاغاخان في مشروع متنزه الازهر بوصفه حالة دراسية. توصل البحث إلى جملة إستنتاجات وتوصيات، تمثل الإستنتاج الرئيس فيه: أن اعادة الاستخدام والسياحة (الداخلية منها والخارجية)، تمثل إمكانات الإستثمار الأساسية في مشروعات الحفاظ.For many years, heritage studies have devoted their attention to abstract cultural values. However, knowledge of the economic value of the heritage on which investment decisions are based on preservation projects has become available, especially with the development of conservation economics, which is one of the new fields that benefit from the language of the economy as one of the basic concepts in our lives. In general, and its development in the field of preservation, especially. The research problem was: "Lack of literature, especially Arabic, which discusses investment and its potential in projects to preserve urban heritage". The research is based on the hypothesis that "investment directed at urban heritage conservation projects can contribute to the financing required by these projects, as well as contribute to the development of local communities." The research aims at: "Building the theoretical base of the concepts of investment in projects to preserve urban heritage, and indicating the potential of investment provided by the urban heritage, and then the role of investment in preserving the heritage and development activities on the urban and social levels."
For the purpose of achieving the objective of the research and test hypothesis, the research included two main approaches. The first: the potential investment of urban heritage, and the second: the experiment of the Aga Khan Foundation in the Azhar Park project as a case study. The research concludes with number of conclusions and recommendations, the main conclusion being: Reuse and tourism (internal and external) represent the main investment potential in conservation projects
The Impact of Urban Development of Buffer Zone on Universal Heritage
برزت أهمية المنطقة الفاصلة (Buffer Zone)، التي تحيط بالمباني والمواقع التأريخية، لتمثل ضمانة عدم أضرار مشاريع التطوير للمدن بالمواقع التاريخية. أهتمت أغلب الدراسات المعمارية، لاسيما العربية منها، التي تناولت تطوير المدن التأريخية على دور العمارة في صيانة وترميم المباني والمواقع، مما ولد نقصا معرفياً في دور العمارة في التطوير الحضري لمحيط المدن التاريخية وأهميتها في الحفاظ عليها. تتضمن الدراسة مبحثين رئيسين الأول: الطروحات النظرية الخاصة بالمناطق الفاصلة، ومعايير المناطق الفاصلة من أجل أن تكون فاعلة، ليتم أستخلاص مؤشرات الأطار النظري، والثاني: الحالة الدراسية المتمثلة في اكروبولس أثينا.World heritage cities and sites have been under increasing pressure over the ages due to population growth and development projects of the cities to which they belong, leading to damage to their outstanding universal value, and may lead not to be inscribed on the list of heritage, or exposed to inscription on the list of threatened sites, The World Heritage List that was included in it. The study includes two main topics, the first: theoretical propositions of the buffer zone, and the related criteria to be effective, to extract the indicators of the theoretical framework, and the second: case study, represented by the Acropolis of Athens
The development of GPS navigation systems in civil aircraft
The industry of civil aviation is developing in a fast manner to occupy the increasing needs for a fast, safe and comfortable transportation. To achieve these needs, some effective programs, plans, and systems designs are required. The current reliable aircraft navigation and landing systems have relatively a low level of accuracy especially in aircraft landing stage. The best landing category could be achieved requires a runway visual range up to 50 meters and automatic landing system is not in operation yet all over the world. Aircraft navigates using Radar, Radio and Satellite navigation systems. The Federal Aviation Administration (FAA) plans to replace legacy navigation systems with satellite based navigation technology. Currently, the Global Positioning System (GPS) and its augmentations is the main satellite navigation system used all over the world for air navigation applications. The development of aircraft navigation has been performed with the enhancement of GPS augmentation systems. In this paper, aircraft navigation systems and techniques will be presented in this paper to evaluate the integrity and reliability of each system, and to make a comparison among these systems according to accuracy, integrity and availability
Baltische Flora, enthaltend die in Est-, Liv-, und Kurland wilddwachsenden Samenpflanzen und höheren Sporenpflanzen : eine zur Erlangung der Magister-Würde verfasste und mit Bewilligung der Hochverordneten physico-mathematischen Facultät der Kaiserl. Universität zu Dorpat zur öffentlichen Vertheidigung bestimmte Abhandlung
http://tartu.ester.ee/record=b1868533~S1*es
Palm Oil Clinker as a Waste by-Product: Utilization and Circular Economy Potential
Conservation of natural resources to create ecological balance could be significantly improved by substituting them with waste by-products. Palm oil industry operations increases annually, thereby generating huge quantity of waste to be dumped into the landfill. Palm oil clinker (POC) is a solid waste by-product produced in one of the oil palm processing phases. This chapter is designed to highlight the generation, disposal problems, properties and composition of POC. The waste to resource potentials of POC would be greatly discussed in the chapter starting with the application of POC in conventional and geopolymer structural elements such as beams, slabs, columns made of either concrete, mortar or paste for coarse aggregates, sand and cement replacement. Aspects such as performance of POC in wastewater treatment processes, fine aggregate and cement replacement in asphaltic and bituminous mixtures during highway construction, a bio-filler in coatings for steel manufacturing processes and a catalyst during energy generation would also be discussed. Circular economy potentials, risk assessment and leaching behavior during POC utilization would be evaluated. The chapter also discusses the effectiveness of POC in soil stabilization and the effect of POC pretreatment for performance enhancement. Towards an efficient utilization, it is important to carry out technical and economic studies, as well as life cycle assessments, in order to compare all the POC areas of application described in the present review article. POC powder has proven to be pozzolanic with maximum values of 17, 53.7, 0.92, 3.87, 1.46, for CaO, SiO2, SO3, Fe2O3 and Al2O3. Therefore, the present chapter would inspire researchers to find research gaps that will aid the sustainable use of agroindustry wastes. The fundamental knowledge contained in the chapter could also serve as a wake-up call for researchers that will motivate them to explore the high potential of utilizing POC for greater environmental benefits associated with less cost when compared with conventional materials
Dynamic behaviour and hydraulic performance of reaction turbines in embankment dams / Ameen Mohammed Salih Ameen
Dam and powerhouse operation sustainability is the main concern from the hydraulic engineering perspective. Powerhouse operation represents one of the main sources of vibration on the dam’s structure and thus evaluating the turbine performance with different water level pressures is highly significant. Draft tube downstream turbines run under high pressure and suffer from connection problems such as vibrations and pressure fluctuation. Reducing the pressure fluctuation and minimizing the principal stress which is related to undesired rational components of water in the draft tube turbine is still ongoing and requires to be resolved. In this research, a 3-D numerical turbine model with the construction of a submerged weir at the outlet of the draft tubes is developed. Secondly, an investigation for the dynamic behavior of an embanked dam due to earthquake effects is conducted. (Finally, an optimization operating turbine system is generated to reduce the principal stress). To achieve this, two different cases of fully opened gates of reaction turbines are inspected including Haditha Dam in Iraq and Temenggor Dam in Malaysia. The finding of the first agreed aim in which initiating a 1.333 m and a 1 m submerged weir for Kaplan (Haditha Dam) and Francis turbines (Temenggor Dam) was a very excellent proposition to solve the problem of negative pressure pulsation in the draft tube. In addition, the results showed that the natural frequencies decrease with the increase of the upstream water level and foundation depth. Finally, with the combination of the dam models with turbine models, a control program is generated to run the turbines inside the powerhouse based on minimizing the principal stress values in the selected nodes of the dam body, which depends on the principal stress classification
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Image Authentication Based on Watermarking Approach: Review
Digital image authentication techniques have recently gained a lot of attention due to their importance to a large number of military and medical applications, banks, and institutions, which require a high level of security. Generally, digital images are transmitted over insecure media, such as the Internet and computer networks of various kinds. The Internet has become one of the basic pillars of life and a solution to many of the problems left by the coronavirus. As a result, images must be protected from attempts to alter their content that might affect important decision-making. An image authentication (IA) system is a solution to this difficult problem. In the previous literature, several methods have been proposed to protect the authenticity of an image. Digital image watermark is a strategy to ensure the reliability, resilience, intellectual property, and validity of multimedia documents. Digital media, such as images, audio, and video, can hide content. Watermarking of a digital image is a mechanism by which the watermark is embedded in multimedia and the image of the watermark is retrieved or identified in a multimedia entity. This paper reviews IA techniques, watermark embedding techniques, tamper detection methods and discusses the performance of the techniques, the pros and cons of each technique, and the proposed methods for improving the performance of watermark techniques
A Systematic Operation Program of a Hydropower Plant Based on Minimizing the Principal Stress : Haditha Dam Case Study
Dam operation and management have become more complex recently because of the need for considering hydraulic structure sustainability and environmental protect on. An Earthfill dam that includes a powerhouse system is considered as a significant multipurpose hydraulic structure. Understanding the effects of running hydropower plant turbines on the dam body is one of the major safety concerns for earthfill dams. In this research, dynamic analysis of earthfill dam, integrated with a hydropower plant system containing six vertical Kaplan turbines (i.e., Haditha dam), is investigated.In the first stage of the study, ANSYS-CFX was used to represent one vertical Kaplan turbine unit by designing a three-dimensional (3-D) finite element (FE) model. This model was used to differentiate between the effect of turbine units’ operation on dam stability in accordance to maximum and minimum reservoir upstream water levels, and the varying flowrates in a fully open gate condition. In the second stage of the analysis, an ANSYS-static modeling approach was used to develop a 3-D FE earthfill dam model. The water pressure pattern determined on the boundary of the running turbine model is transformed into the pressure at the common area of the dam body with turbines. The model is inspected for maximum and minimum upstream water levels. Findings indicate that the water stress fluctuations on the dam body are proportional to the inverse distance from the turbine region. Also, it was found that the cone and outlet of the hydropower turbine system are the most affected regions when turbine is running. Based on the attained results, a systematic operation program was proposed in order to control the running hydropower plant with minimized principal stress atselected nodes on the dam model and the six turbines.Validerad;2018;Nivå 2;2018-09-28 (marisr)</p