WorldWideScience

Sample records for waterwheels

  1. Thermodynamics, entropy and waterwheels

    CERN Document Server

    Bagnoli, Franco

    2016-01-01

    In textbooks, it is often repeated that Carnot arrived to the formulation of the second law of thermodynamics without knowing the first, using the caloric theory. In fact, in his book, R\\'eflexions sur la puissance motrice du feu, he often repeats that the "fall" of the caloric through a heat engine is equivalent to the fall of the water through a water wheel. Actually, one can play the analogy between thermal and hydraulic machines all the way down, and discover, with the help of the first principle and introducing the concept of the absolute height, what really "falls" through a waterwheel, i.e., the entropy. Adding a bit of relativity it is possible to extend the analogy to real machines and also to introduce the analogous of third law of thermodynamics.

  2. Experimental study of the chaotic waterwheel

    Science.gov (United States)

    Rutherford, George; Erxleben, Amy; Rosa, Epaminondas, Jr.

    2007-03-01

    The chaotic waterwheel is often given as an example of a mechanical system that can exhibit chaotic behavior. Its early demonstration by Malkus and the realization that it can be modeled by the Lorenz equations has secured it a prominent place in almost every general presentation of chaos. It seems quite surprising, then, that no experimental investigations of this textbook system have ever been published. To fill this historic gap, and to initiate an experimental study of this incredibly rich dynamic system, our lab has constructed a research-grade waterwheel consisting of a vacuum-formed polycarbonate frame in which 36 cylindrical cells are mounted on an 18 inch diameter. The wheel and its axis can be tilted, and water is fed into the top of the wheel and drains out through thin tubes at the bottom of each cell. An aluminum skirt at the wheel's periphery passes through a variable gap magnet to provide magnetic braking. Angular time series data are collected with an absolute rotary encoder. The data are smoothed and angular velocity and acceleration are calculated via fast fourier transforms. The data show quasi-uniform rotation as well as periodic and chaotic motion and agree fairly well with computer simulations of the idealized wheel equations. We will discuss differences between the experimental data and the simulation predictions as well as plans for future studies.

  3. Windmills and waterwheels explained what they do and how they work

    CERN Document Server

    Yorke, Stan

    2013-01-01

    Stan Yorke, using easy to follow text, diagrams and photographs, describes the various styles of mill and waterwheel and how they work. The book includes a list of restored mills which are open to the public.

  4. An Experiment of the Malkus-Lorenz Waterwheel and Its Measurement by Image Processing

    Science.gov (United States)

    Kim, Heewon; Seo, Jiwon; Jeong, Bora; Min, Chohong

    We introduce a simple and efficient experimental setup for the Malkus-Lorenz waterwheel. Through a series of image processing techniques, our work is listed as one of the few experiments that measure not only the angular velocity but also the mass distribution. Our experiment is to observe qualitative changes on the waterwheel as the leakage rate changes, while the other physical parameters are fixed. We perform a bifurcation analysis for the qualitative changes, and the phase portraits from experiments are validated by the bifurcation analysis.

  5. Las azudas de Larmahue: una singular manifestación del ingenio humano para regar cultivos en tierras de secano. / The norias or waterwheels of Larmahue, Chile: an unusual manifestation of the human struggle to irrigate crops in dry lands.

    Directory of Open Access Journals (Sweden)

    Carolina Quilodrán Rubio

    2011-12-01

    Full Text Available Puesto a prueba desde tiempos inmemoriales, el ingenio humano ha creado verdaderas obras de arte para dar respuesta a condiciones adversas. Una prueba de ello son las azudas o ruedas de agua, fruto de la necesidad de conseguir un eficiente riego de los campos destinados al cultivo. Los babilonios ya supieron de sus beneficios. Otras culturas han enriquecido su diseño y perfeccionado su funcionamiento. Y en pleno valle central chileno se puede admirar, hoy en día, las azudas de Larmahue./ Put to test since the dawn of time, human ingenuity has created real works of art in response to adverse conditions. An example of that are the azudas or waterwheels, born from a necessity to obtain efficient irrigation of field crops. The Babylonians knew of their benefits. Other cultures enriched its design and perfected it and, nowadays, in the heart of the Chilean Central Valley you can admire the waterwheels of Larmahue.

  6. Comment on "Most computational hydrology is not reproducible, so is it really science?" by Christopher Hutton et al.: Let hydrologists learn the latest computer science by working with Research Software Engineers (RSEs) and not reinvent the waterwheel ourselves

    Science.gov (United States)

    Hut, R. W.; van de Giesen, N. C.; Drost, N.

    2017-05-01

    The suggestions by Hutton et al. might not be enough to guarantee reproducible computational hydrology. Archiving software code and research data alone will not be enough. We add to the suggestion of Hutton et al. that hydrologists not only document their (computer) work, but that hydrologists use the latest best practices in designing research software, most notably the use of containers and open interfaces. To make sure hydrologists know of these best practices, we urge close collaboration with Research Software Engineers (RSEs).

  7. What Carnot's Father Taught His Son about Thermodynamics

    Science.gov (United States)

    Muller, Erich A.

    2012-01-01

    The historical development of the classical postulates of the second law of Thermodynamics can be traced back to the book by Sadi Carnot, "Reflections on the motive power of fire." While unique in its own right and in some sense revolutionary, the book starts with an analogy between heat engines and waterwheels. Waterwheels were common engines of…

  8. Designs and applications for floating-hydro power systems in small streams

    Energy Technology Data Exchange (ETDEWEB)

    Rehder, J.B.

    1983-01-01

    The project focuses on an appropriate technology for small-scale hydro power: floating waterwheels and turbines. For background, relic and existing systems such as early floating mills, traditional Amish waterwheels, and micro-hydro systems are examined. In the design phase of the project, new designs for Floating Hydro Power Systems include: an analysis of floatation materials and systems; a floating undershot waterwheel design; a floating cylinder (fiberglass storage tank) design; a submerged tube design; and a design for a floating platform with submerged propellers. Finally, in the applications phase, stream flow data from East Tennessee streams are used in a discussion of the potential applications of floating hydro power systems in small streams.

  9. A brief history of the Coriolis force

    NARCIS (Netherlands)

    Gerkema, T.; Gostiaux, L.

    2012-01-01

    In 1835, Gustave Coriolis derived the expression of a force acting in rotating systems, now known as the Coriolis force. His work was inspired by rotating devices such as waterwheels. However, the onerotating device that has always been with us is the Earth itself. Indeed, the earliest studies on ho

  10. Pico Hydropower Application on Tidal Irrigation CanalSupporting The Indonesian Agricultural Activities Case Study: Telang II – Banyuasin

    Directory of Open Access Journals (Sweden)

    Darmawi Darmawi

    2013-01-01

    Full Text Available A review of waterwheel history has conducted to evaluate the possibility and thetechnology development in its relation to harvest the energy from the flowing water inand out of irrigation canal regarding the tidal movement. The study has conducted atthe east shore of South Sumatra. Hydro energy became a promising renewable energyin order to achieve at least 5% of total Indonesian national energy mix consumption in 2025. Tidal turbine energy is technologically potential for Indonesian futureregarding the beach of 81,000 kilometers long and 20 millions hectares of tidalswamp area out of 33 millions hectares available. Mechanical torque of 30 Nm isproduced by a waterwheel of 0.38 meter radius. An estimation of 60 watt at the peakof rain season could harvested from each tidal irrigation canal in Telang II. Thismechanical energy is applicable to generate small quantity water pump, water aerationinjector and small electric energy energy appliances.

  11. Business development. Outdoor leisure facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This case study describes three UK examples where renewable energy sources have been used to produce small amounts of power at leisure facilities (eg warden's offices, toilet blocks, visitor centres, mountain huts, youth hostels, etc) in areas away from the electricity network. The first application describes the use of two wind generators and a refurbished waterwheel to provide power for a new water sports centre on the shores of Lough Neagh in County Armagh, Northern Ireland. The wind generators provide power for the lighting and computers within the centre, while the waterwheel reduces the risk of power failure by the batteries. The second application features the use of a wind generator and four solar photovoltaic (PV) modules to provide electricity to the warden's office and workshop at the Farlington Marshes Nature Reserve in Hampshire. The third application involves the use of 2.5 kW wind generators to provide power supplies for the Loch Osslan and Glen Affric youth hostels in Inverness-shire, Scotland, and thus raise the standard of accommodation. The technology used, operating experience, costs and benefits are outlined for each application.

  12. Trap diversity and evolution in the family Droseraceae.

    Science.gov (United States)

    Poppinga, Simon; Hartmeyer, Siegfried R H; Masselter, Tom; Hartmeyer, Irmgard; Speck, Thomas

    2013-07-01

    We review trapping mechanisms in the carnivorous flowering plant family Droseraceae (order Caryophyllales). Its members are generally known to attract, capture, retain and digest prey animals (mainly arthropods) with active snap-traps (Aldrovanda, Dionaea) or with active sticky flypaper traps (Drosera) and to absorb the resulting nutrients. Recent investigations revealed how the snap-traps of Aldrovanda vesiculosa (waterwheel plant) and Dionaea muscipula (Venus' flytrap) work mechanically and how these apparently similar devices differ as to their functional morphology and shutting mechanics. The Sundews (Drosera spp.) are generally known to possess leaves covered with glue-tentacles that both can bend toward and around stuck prey. Recently, it was shown that there exists in this genus a higher diversity of different tentacle types and trap configurations than previously known which presumably reflect adaptations to different prey spectra. Based on these recent findings, we finally comment on possible ways for intrafamiliar trap evolution.

  13. Nano watermill driven by the revolving charge

    CERN Document Server

    Zhou, Xiaoyan; Nie, Xuechuan; Wu, Fengmin; Liu, Yang; Lu, Hangjun

    2015-01-01

    Using molecular dynamics simulations, we propose a novel nanoscale watermill for unidirectional transport of water molecules through a curved single-walled carbon nanotube (SWNT). In this nanoscale system, a revolving charge is introduced to drive water chain confined inside the SWNT, which is served as nano waterwheel and nano engine. A resonance-like phenomenon is found that the revolving frequency of the charge plays a key role in pumping water chain. The water flux across the SWNT increases with respect to the revolving frequency of the external charge and reaches the maximum when the frequency is 4 THz. Correspondingly, the number of the hydrogen bonds of water chain inside the SWNT decreases dramatically with the frequency ranging from 4 THz to 25 THz. The mechanism behind the resonant phenomenon has been investigated systematically. Our findings are helpful for designing nanoscale fluidic devices and energy converters.

  14. Project considerations and design of systems for wheeling cogenerated power

    Energy Technology Data Exchange (ETDEWEB)

    Tessmer, R.G. Jr.; Boyle, J.R.; Fish, J.H. III; Martin, W.A.

    1994-08-01

    Wheeling electric power, the transmission of electricity not owned by an electric utility over its transmission lines, is a term not generally recognized outside the electric utility industry. Investigation of the term`s origin is intriguing. For centuries, wheel has been used to describe an entire machine, not just individual wheels within a machine. Thus we have waterwheel, spinning wheel, potter`s wheel and, for an automobile, wheels. Wheel as a verb connotes transmission or modification of forces and motion in machinery. With the advent of an understanding of electricity, use of the word wheel was extended to be transmission of electric power as well as mechanical power. Today, use of the term wheeling electric power is restricted to utility transmission of power that it doesn`t own. Cogeneration refers to simultaneous production of electric and thermal power from an energy source. This is more efficient than separate production of electricity and thermal power and, in many instances, less expensive.

  15. Design and development of an ultra-compact drum-shaped chamber for combinatorial pulsed laser deposition

    Science.gov (United States)

    Katayama, M.; Itaka, K.; Matsumoto, Y.; Koinuma, H.

    2006-01-01

    We have designed a compact combinatorial pulsed laser deposition (PLD) chamber as a building block of a desktop laboratory for advanced materials research. Development of small-size systems for the growth and characterization of films would greatly help in interconnecting a variety of analytical tools for rapid screening of advanced materials. This PLD chamber has four special features: (1) a drum-shaped growth chamber, (2) a waterwheel-like combinatorial masking system, (3) a multi-target system having one feedthrough, and (4) a small reflection high-energy electron diffraction (RHEED) system. The performance of this system is demonstrated by the RHEED intensity oscillation during homoepitaxial growth of SrTiO 3 as well as by simultaneous fabrication of a ternary phase diagram of rare earth-doped Y 2O 3 phosphors.

  16. Different mechanics of snap-trapping in the two closely related carnivorous plants Dionaea muscipula and Aldrovanda vesiculosa

    CERN Document Server

    Poppinga, Simon

    2011-01-01

    The carnivorous aquatic Waterwheel Plant (Aldrovanda vesiculosa L.) and the closely related terrestrial Venus Flytrap (Dionaea muscipula SOL. EX J. ELLIS) both feature elaborate snap-traps, which shut after reception of an external mechanical stimulus by prey animals. Traditionally, Aldrovanda is considered as a miniature, aquatic Dionaea, an assumption which was already established by Charles Darwin. However, videos of snapping traps from both species suggest completely different closure mechanisms. Indeed, the well-described snapping mechanism in Dionaea comprises abrupt curvature inversion of the two trap lobes, while the closing movement in Aldrovanda involves deformation of the trap midrib but not of the lobes, which do not change curvature. In this paper, we present the first detailed mechanical models for these plants, which are based on the theory of thin solid membranes and explain this difference by showing that the fast snapping of Aldrovanda is due to kinematic amplification of the bending deforma...

  17. Another view of China's population policy.

    Science.gov (United States)

    1996-11-01

    This article describes a new videotape developed by JOICFP on China's population policy and its implementation. The 43-minute documentary video entitled "The Ever Turning Waterwheel" documents the actual lives of city and rural people. It was produced by a joint Japanese-Chinese production team of 30 people with the cooperation of the State Family Planning Commission in China, JOICFP, the Shanghai International Center for Population Communication, and Sony PCL. It is available in English, Chinese, and Japanese. The video covers a train ride to small rural villages in central China and the heart of ancient traditions and culture. Its title refers to the number of waterwheels that were used for agricultural irrigation throughout the centuries. The emphasis on the rural heartland allows for the expression of the traditional rural view of respect for others and commitment to community. Men and women are seen working together for the benefit of the whole, even though the area is impoverished. The video depicts the powerful and cohesive community spirit and the role of family planning in improving the health of women. Exceptions to the one-child family are also revealed. Scenes show the progression from a peasant's fear of family planning promoters to parasite control among the children and acceptance of family planning. Other scenes depict the community working together to build latrines and secure safe drinking water. Family planning promoters are depicted explaining issues to women who are seeking advice and counsel. The video shows community traditions remaining intact while attitudes change. The message at the end reinforces the value placed on women and their equality with men.

  18. An Applied Local Wisdom to Manage Water for Developing Riverside Community: A Case Study of the Lam Ta Kong River Basin

    Directory of Open Access Journals (Sweden)

    Surapong Kongsat

    2009-01-01

    Full Text Available Problem statement: An integrated water resource management is accepted technique to solve the water resource problems both water shortage and flood plane in order to improve human life. The combination between local wisdom and modern technology by farmer participation is a main part of integrated management. The mentioned techniques had been being applied for human life in the northeast region of Thailand. Approach: This study investigated the local wisdom of water resource management and an application of the local wisdom to manage water resource for developing the economic, society and culture of Lam Ta Kong’s community, Nakhorn Ratchasima province, Thailand. Information was investigated from relevant document and field survey including questionnaire and interview. Results: The result founded that there were two types of the local wisdoms including an original local wisdom on water management and a combination of original and modern science local wisdom to manage available water. For original wisdom, there were earth dam, rock dam, rocks dyke, wooden weir, waterwheel and shallow well that were found in source and midst of the river basin. They constructed the dams and weirs barrier flow river along the Lam Ta Kong River in order to storage water for using purposes in dry season and to mitigate flood plane during rainy season as an early age of the local wisdom. The waterwheel was used to bail water from river to their community. For the combination of original and modern science, there were concrete dam, Watergate, irrigating tube, irrigation channel, water pump, water pump dynamo and underground water drilling that were found at the source, midst and tide tail of the river basin. These combined local wisdoms are considered as a current apparatus in water resource management of the area. The stored water was managed with annual rainfall for cultivation, industrial, family activity and residences for the necessaries of life. Conclusion

  19. Elastic models of the fast traps of carnivorous Dionaea and Aldrovanda

    Science.gov (United States)

    Joyeux, Marc

    2013-09-01

    The carnivorous aquatic waterwheel plant (Aldrovanda vesiculosa L.) and the closely related terrestrial Venus flytrap (Dionaea muscipula Sol. ex J. Ellis) both feature elaborate snap-traps, which shut after reception of an external mechanical stimulus by prey animals. Although Aldrovanda is usually considered a miniature aquatic Dionaea, the shutting mechanisms of the two plants differ quite markedly. The fast shutting of Aldrovanda is indeed based on a simple swelling or shrinking mechanism, while the movement of Dionaea's traps is accelerated by the snap-buckling of the lobes. The purpose of this Brief Report is to describe several key improvements to the elastic models that have recently been introduced to elucidate these movements [Poppinga and Joyeux, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.84.041928 84, 041928 (2011)]. In particular, a precise mechanism for the action of the motor cells of Aldrovanda is proposed, the facts that the opening of the leaves of Dionaea is an irreversible mechanism based on growth and that the strain field is anisotropic and much smaller on the inner than on the outer surface of the leaves during shutting are taken properly into account, and a more accurate formula for calculating mean curvatures is used. The improvements brought to the model are described in detail and the physical consequences of these improvements are discussed.

  20. Different mechanics of snap-trapping in the two closely related carnivorous plants Dionaea muscipula and Aldrovanda vesiculosa

    Science.gov (United States)

    Poppinga, Simon; Joyeux, Marc

    2011-10-01

    The carnivorous aquatic waterwheel plant (Aldrovanda vesiculosa L.) and the closely related terrestrial venus flytrap (Dionaea muscipula Sol. ex J. Ellis) both feature elaborate snap-traps, which shut after reception of an external mechanical stimulus by prey animals. Traditionally, Aldrovanda is considered as a miniature, aquatic Dionaea, an assumption which was already established by Charles Darwin. However, videos of snapping traps from both species suggest completely different closure mechanisms. Indeed, the well-described snapping mechanism in Dionaea comprises abrupt curvature inversion of the two trap lobes, while the closing movement in Aldrovanda involves deformation of the trap midrib but not of the lobes, which do not change curvature. In this paper, we present detailed mechanical models for these plants, which are based on the theory of thin solid membranes and explain this difference by showing that the fast snapping of Aldrovanda is due to kinematic amplification of the bending deformation of the midrib, while that of Dionaea unambiguously relies on the buckling instability that affects the two lobes.

  1. Dethridge wheel for pico-scale hydropower generation: An experimental and numerical study

    Science.gov (United States)

    Paudel, Shakun; Saenger, Nicole

    2016-11-01

    This study aims to assess the potential of the Dethridge wheel for developing power from very low head sites in open channel flow. The Dethridge wheel has been in use since early 20th century for measuring flow in irrigation canals. Being robust and simple in design, this technology served as a reliable flow metering solution for more than a century. Working in a similar principle to the conventional waterwheel, this wheel could be a viable option of power generation for decentralized application in remote areas. Two different methods, experimental and numerical, are used for investigating the potential of the wheel. An experimental approach in which a physical model of the Dethridge wheel is built and tested at the hydraulics laboratory of Darmstadt University of Applied Sciences. Whereas a three dimensional numerical model of the Dethridge wheel is simulated using a commercial Computational Fluid Dynamics (CFD) code Flow-3D. Efficiency of around 60% is achieved in the model tests. Computed results are also in good agreement with the physical model results. The results from the physical and the numerical model are presented in this paper.

  2. Elastic models of the fast traps of carnivorous Dionaea and Aldrovanda

    CERN Document Server

    Joyeux, Marc

    2013-01-01

    The carnivorous aquatic Waterwheel Plant (Aldrovanda vesiculosa L.) and the closely related terrestrial Venus Flytrap (Dionaea muscipula SOL. EX J. ELLIS) both feature elaborate snap-traps, which shut after reception of an external mechanical stimulus by prey animals. Although Aldrovanda is usually considered as a miniature aquatic Dionaea, the shutting mechanisms of the two plants are actually quite different. The fast shutting of Aldrovanda is indeed based on a simple swelling/shrinking mechanism, while the movement of Dionaea's traps is accelerated by the snap-buckling of the lobes. The purpose of this Report is to describe several key improvements to the elastic models that have recently been introduced to elucidate these movements [Poppinga and Joyeux, Phys. Rev. E 84, 041928 (2011)]. In particular, a precise mechanism for the action of the motor cells of Aldrovanda is proposed, the facts that the opening of the leaves of Dionaea is an irreversible mechanism based on growth and that the strain field is a...

  3. Automation of hydroelectric power plants

    Energy Technology Data Exchange (ETDEWEB)

    Grasser, H.S. (Consolidated Papers, Inc., Wisconsin Rapids, WI (US))

    1990-03-01

    This paper describes how the author's company has been automating its hydroelectric generating plants. The early automations were achieved with a relay-type supervisory control system, relay logic, dc tachometer, and a pneumatic gate-position controller. While this system allowed the units to be started and stopped from a remote location, they were operated at an output that was preset by the pneumatic control at the generating site. The supervisory control system at the site provided such information as unit status, generator breaker status, and a binary coded decimal (BCD) value of the pond level. The generating units are started by energizing an on-site relay that sets the pneumatic gate controller to a preset value above the synchronous speed of the hydroelectric generator. The pneumatic controller then opens the water-wheel wicket gates to the preset startup position. As the hydroelectric generator starts to turn, the machine-mounted dc tachometer produces a voltage. At a dc voltage equivalent to synchronous speed, the generator main breaker closes, and a contact from the main breaker starts a field-delay timer. Within a few seconds, the field breaker closes. Once the cycle is complete, a relay changes the pneumatic setpoint to a preset operating point of about 8/10 wicket gate opening.

  4. Chaotic gas turbine subject to augmented Lorenz equations.

    Science.gov (United States)

    Cho, Kenichiro; Miyano, Takaya; Toriyama, Toshiyuki

    2012-09-01

    Inspired by the chaotic waterwheel invented by Malkus and Howard about 40 years ago, we have developed a gas turbine that randomly switches the sense of rotation between clockwise and counterclockwise. The nondimensionalized expressions for the equations of motion of our turbine are represented as a starlike network of many Lorenz subsystems sharing the angular velocity of the turbine rotor as the central node, referred to as augmented Lorenz equations. We show qualitative similarities between the statistical properties of the angular velocity of the turbine rotor and the velocity field of large-scale wind in turbulent Rayleigh-Bénard convection reported by Sreenivasan et al. [Phys. Rev. E 65, 056306 (2002)]. Our equations of motion achieve the random reversal of the turbine rotor through the stochastic resonance of the angular velocity in a double-well potential and the force applied by rapidly oscillating fields. These results suggest that the augmented Lorenz model is applicable as a dynamical model for the random reversal of turbulent large-scale wind through cessation.

  5. Los molinos hidráulicos de la cuenca del Guadalquivir a fines de la Edad Media. Instrumental y equipamiento técnico

    Directory of Open Access Journals (Sweden)

    Córdoba De La Llave, Ricardo

    2003-06-01

    Full Text Available This study is dedicated to analyse the tools and technical equipment of the hydraulic mills that worked in the main rivers of the Guadalquivir valley at the end of the Middle Ages. Using as basical references the information given by seven notarial contracts written about the tools of these industrial buildings (documents dated between the years 1497 and 1528 and referred to hydraulic mills powered by vertical wheels and horizontal waterwheels from the Guadaira and Guadajoz rivers, it exposes the main components of the hydraulic system and the tools emplaced in the mill' room that were used in order to milling the wheat.

    Este trabajo está dedicado al análisis del instrumental y equipamiento técnicos de los molinos hidráulicos que funcionaron en los grandes ríos de la cuenca del Guadalquivir a fines de la Edad Media. Tomando como base los testimonios proporcionados por siete escrituras notariales de aprecio de los útiles contenidos en dichas instalaciones (datadas entre 1497 y 1528 y referidas tanto a molinos como a aceñas situadas en los ríos Guadaira y Guadajoz, aborda el conocimiento de las principales piezas de la maquinaria hidráulica y de los elementos que integraban el equipamiento situado en la sala de molino, mediante los cuales se llevaba a cabo el proceso de molturación del cereal.

  6. Rancang Bangun Pompa Sistem Wheel Spiral untuk Skala Kecil

    Directory of Open Access Journals (Sweden)

    Feri Arlius

    2017-04-01

    about one hour with 3 times repeatation RPM 6,917 ± 7,83, angle velocity 0,72 ± 0,77, axis power 0,25 ± 0,27 Watt, accomodated rate of flow 0,0001533 ± 0,0001732 m3/s, kinetic energy 0,36 ± 0,42 Watt, and rate of pump efficiency 67,85%. The maximum high of output can reached by the pump is 1.52 m. This pump can rise water higher than the highest goosebeak on waterwheel and the efficiency is highest than the waterwheel. So, it can be used to irrigate the lands that position is above the water.

  7. Is it restoration or reconciliation? California's experience restoring the Sacramento - San Joaquin River Delta provides lessons learned and pathways forward to sustain critical ecosystem functions and services in a highly managed riverine delta.

    Science.gov (United States)

    Viers, J. H.; Kelsey, R.

    2014-12-01

    Reconciling the needs of nature and people in California's Sacramento - San Joaquin River Delta represents one of the most critical ecosystem management imperatives in western North America. Over 150 years the Delta has been managed for near-term human benefits and in the process 95% of riverine and deltaic wetlands have been lost throughout the region. Despite extensive land conversion and alteration of hydrological and physical processes, the Delta remains important habitat for migratory birds and is home to over 60% of California's native fish species. It is also the waterwheel for the state's vast water distribution network and is maintained by a system of constructed levees that are at risk from catastrophic failure due to sea level rise, floods, and/or seismic activity. Such a collapse would have dire consequences for > 25M humans and world's 10th largest economy that depend on its freshwater. Thus, the ultimate cost of this ecosystem alteration and simplification is a riverscape that is no longer reliable for nature or people. For 30 years, attempts to 'restore' Delta ecosystems and improve reliability have met with mixed results. For example, reconnection of floodplains to floodwaters has resulted in improved ecological health for native fishes and recharge to localized aquifers. Uncoordinated releases of discharges below dams, however, have resulted in diminished water quality and populations of indicator species. Attempts to create wildlife friendly farms have been countered by an increase in perennial agriculture and commensurate increases in irrigation water demand. From these lessons learned, we demonstrate three key components of a reconciled Delta that will be necessary in the future: 1) full restoration of critical habitats, reconnecting land and water to rebuild ecosystem function; 2) landscape redesign, incorporating natural and engineered infrastructure to create a biologically diverse, resilient landscape to support both agriculture and natural

  8. Effects of “submerged aeration systems” on water quality and phytoplankton community structure in Portunus trituberculatus culture ponds%“底充式增氧”技术对梭子蟹养殖池塘水质环境及浮游植物群落结构的影响

    Institute of Scientific and Technical Information of China (English)

    傅彩萍; 郑忠明; 金忠文; 郝锵; 陆开宏

    2012-01-01

    于2009年6-9月在浙江省宁海县三门湾海域养殖场,选取2口水文环境相似的梭子蟹Portunus trituberculatus养殖池塘,分别采用“底充式增氧”(实验塘)和传统水车式增氧(对照塘)方式,比较研究了池塘水质环境及其浮游植物群落结构的变化.结果显示:(1)实验塘水质的溶解氧和氨氮指标均优于对照塘,其中实验塘底部溶解氧质量浓度维持在5 mg/L以上,而对照塘则维持在4.28~6.45mg/L;养殖末期,实验塘的氨氮质量浓度为0.140mg/L,低于对照塘(1.360mg/L).(2)实验塘内主要藻类细胞丰度值(3 980×105个/L)远远高于对照塘(234×105个/L).经MDS标序、ANOSIM检验、SIMPER和Bio-Env分析可知,2口池塘浮游植物群落结构存在明显差异,养殖中后期实验塘浮游植物群落结构稳定,而对照塘的浮游植物群落结构较不稳定.实验塘优势种为卵囊藻Oocystis sp.和席藻Phormidiumsp.,对照塘以蓝藻和硅藻为优势种,2口池塘浮游植物群落结构不相似性高达84.44%.浮游植物细胞丰度与含有溶解氧的环境变量组合相关性最强.(3)与水车式增氧方式相比,“底充式增氧”技术对梭子蟹养殖塘的增氧效果明显,且能改善池塘水质,同时对于改善和稳定养殖池塘内的藻相结构起到重要作用.%Two adjacent Portunus trituberculatus culture ponds with similar hydrological environment in Sanmen Bay, Ninghai County, Zhejiang Province were selected to compare the effects of "submerged aeration system" (experimental pond) and traditional waterwheel aeration system (control pond) on water quality and phytoplankton community structure of the aquaculture pond from June to September 2009. The results show that (1) the indices of dissolved oxygen and ammonia nitrogen of the experimental pond with "submerged aeration system" are better than those of the control pond; the mass concentration of dissolved oxygen at the bottom of the experimental pond is kept at above

  9. 能量效率与可更新能源%Energy Efficiency and Renewable Energy Resources

    Institute of Scientific and Technical Information of China (English)

    陈盖; 蓝盛芳

    2001-01-01

    一些可更新能源可减少甚至消除我们对化石能和核能的依赖,其中很多虽然已为人类使用数百年,但因为化石能的普遍使用,一直都为起人类的注意。人类已发明了新技术来利用这些可更新能源。其利用有赖于一定的技术是既定的事实,目前有成功建立这样的能源工业还是十分昂贵的。如果人类生产经济和市场允许的话,这些新技术经进一步改进和简化后,就可以降低成本,并且应用起来也很可靠。相对于开发应用核能,水能和化石能数以百万计的投资耗费来讲,用于可更新资源的资金可谓微乎其微。虽然传统能源和替代能源各具优点,但保护能源往往还是解决能源短缺最便宜,最容易的途径。%Exciting new technologies have been invented to use renewable energy sources.Ocean thermal electric conversion,tidal and wave power stations and geothermal steam source can produce useful amounts of energy in some localities.One of the most promising technologies is direct electricity generation by Photovoltaic cells.Since solar energy is available everywhere,Photovoltaic collectors could provide clean,inexpensive,non-polluting,renewable energy,independent of central power grids or fuel-supply systems.Biomass also may have some modern applications.In addition to direct combustion,biomass can be converted into Methane or Ethanol,which are lean-burning,easily storable and transportable fuels.These alternative uses of biomass also allow nutrients to be returned to the soil and help reduce our reliance on expensive,energy-consuming artificial fertilizers.Fuel wood,windmills and waterwheels,for instance,once supplied a major part of the external energy for human activities.More major conservation methods,such as home insulation and energy-efficient appliances and transportation,can drastically reduce energy consumption and similarty reduces energy expenses.Our natural resources

  10. Motherland Image Evolution in Chinese Free Verse of the 20th Century%20世纪中国新诗中"祖国"意象的演变

    Institute of Scientific and Technical Information of China (English)

    刘永睿; 张向东

    2011-01-01

    In Chinese free werse of the 20th century, "the motherland" (or"China")is a common image, as a result of China's destiny ups and downs in 20th century, "mother land's" image connotation in free poetry also changes. By the end of Qing Dynasty, motherland was the mountains and rivers broken as well as Chinese territory overrun and occupied by the enemy; During May Forth Movement, motherlan is"the nirvana phoenix", "youth China", "motherland like flower's"; During 1920's and 1930's China is" the nightmare hanging from cliff","a ditch despairs stagnant water"; During Sino-Japanese War, motherland is"coldly blocking China", covers entirely by" the blood and the muds"; After the liberation, great motherland is grand"Tian'an men",the bright"Five-Starred Red Flag"and the great leader; Since the new time,motherland's connotation has been richly colorful, not only"riverside worn-out old waterwheel"but also"the crimson daybreak", prosperous" scaffold"and" railway line"" the language and the quarry stone throw build" the spiritual home;In overseas Chinese eyes, motherland is"specially anchors of Chinese local accent" "the Chinatown" ,several millennium bright cultures"sad kind nurses with hardship""the Baiyu balsam pear".%"祖国"(或"中国")是二十世纪中国诗歌中常见的一个意象,由于二十世纪中国命运的坎坷多变,诗歌中"祖国"意象的内涵也与时俱变.清末诗歌中的祖国是山河破碎、神州陆沉;五四的祖国是"涅槃的凤凰"、"少年中国"、"如花的祖国";二、三十年代的中国是"噩梦挂着悬崖"的"一沟绝望的死水";抗战期间的祖国是被"寒冷封锁着的中国"、布满"血和泥"的中国;解放后的伟大祖国,是雄伟的"天安门"、鲜艳的"五星红旗"和伟大领袖;新时期以来的祖国,其内涵丰富多彩,既是"河边破旧的老水车",也是"绯红的黎明",欣欣向荣的"脚手架"和"铁道线",又是"语言和乱石投筑"的精神家园;在海外华人眼中,祖国则