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Sample records for tubular steel towers

  1. 78 FR 14361 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    Science.gov (United States)

    2013-03-05

    ... Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, PA; Notice of Initiation of Investigation To Terminate Certification of Eligibility Pursuant to... Tubular Products, McKeesport Tubular Operations Division, Subsidiary of United States Steel Corporation...

  2. Optimization of steel monopod offshore-towers under probabilistic constraints

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2008-01-01

    In this work, economical design implementation of a circular steel monopod-offshore-tower, which is subjected to the extreme wave loading, is presented. The mass of the tower is considered as the objective function. The thickness and radius of the cross-section of the tower are adopted as design

  3. 78 FR 37584 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    Science.gov (United States)

    2013-06-21

    ... make the following certification: All workers of U.S. Steel Tubular Products, McKeesport Tubular... Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, Pennsylvania; Notice of Amended Certification Pursuant to Section 221 of the Trade Act of 1974...

  4. Fatigue Life of High-Strength Steel Offshore Tubular Joints

    DEFF Research Database (Denmark)

    Petersen, Rasmus Ingomar; Agerskov, Henning; Lopez Martinez, Luis

    1996-01-01

    In the present investigation, the fatigue life of tubular joints in offshore steel structures is studied. Two test series on full-scale tubular joints have been carried through. One series was on joints in conventional offshore structural steel, and the other series was on joints in high-strength......In the present investigation, the fatigue life of tubular joints in offshore steel structures is studied. Two test series on full-scale tubular joints have been carried through. One series was on joints in conventional offshore structural steel, and the other series was on joints in high......-strength steel with a yield stress of 820-830 MPa and with high weldability and toughness properties. The test specimens of both series had the same geometry. The present report concentrates on the results obtained in the investigation on the high-strength steel tubular joints.The test specimens were fabricated...... from Ø 324-610 mm tubes, and the joints were loaded in in-plane bending. Both fatigue tests under constant amplitude loading and tests with a stochastic loading that is realistic in relation to offshore structures, are included in the investigation.A comparison between constant amplitude and variable...

  5. Reality based optimization of steel monopod offshore-towers

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2008-01-01

    In this work, the implementation of reliability-based optimization (RBO) of a circular steel monopod-offshore-tower with constant and variable diameters (represented by segmentations) and thicknesses is presented. The tower is subjected to the extreme wave loading. For this purpose, the

  6. The role of duplex stainless steels for downhole tubulars

    International Nuclear Information System (INIS)

    Francis, R.

    1993-01-01

    In sour conditions there is an increasing trend to turn to corrosion resistant alloys for downhole tubulars. The most commonly used CRA tubular is 13Cr, and there are thousands of feet in service. However, there are limits to the use of 13Cr, ie., the risk of sulphide stress corrosion cracking at high H 2 S levels, and the possibility of pitting or high corrosion rates in waters with high chloride contents. Where the service conditions are felt to be too severe for 13Cr alloys it has been traditional to switch to nickel base alloys such as alloys 825 and C-276 (UNS N08825 and N10276). The alloys are much more expensive than 13Cr, and in recent years the duplex stainless steels have been selected as alloys with superior corrosion and SSCC resistance compared with 13Cr, and having lower cost than nickel alloys. Originally the 22Cr duplex alloy (UNS 31803) was used, but more recently the 25Cr super duplex alloys (UNS S32760 and S32750) have become more available. The present paper reviews the data available for 13Cr and the limits of applicability. Data is also presented for laboratory tests for both the 22Cr and 25Cr super duplex alloys. There is extensive service experience with both 22Cr and 25Cr super duplex in the North Sea, covering both downhole tubulars, manifold and post wellhead equipment. Data is presented showing some of the sour condition being experienced in the North Sea by super duplex alloys. These results show that there is a substantial gap between the limits of use for 13Cr and the 25Cr super duplex stainless steel alloys. This means that in many sour environments super duplex stainless steel provides a cost effective alternative to nickel-base alloys

  7. Steel-reinforced concrete-filled steel tubular columns under axial and lateral cyclic loading

    Science.gov (United States)

    Farajpourbonab, Ebrahim; Kute, Sunil Y.; Inamdar, Vilas M.

    2018-03-01

    SRCFT columns are formed by inserting a steel section into a concrete-filled steel tube. These types of columns are named steel-reinforced concrete-filled steel tubular (SRCFT) columns. The current study aims at investigating the various types of reinforcing steel section to improve the strength and hysteresis behavior of SRCFT columns under axial and lateral cyclic loading. To attain this objective, a numerical study has been conducted on a series of composite columns. First, FEM procedure has been verified by the use of available experimental studies. Next, eight composite columns having different types of cross sections were analyzed. For comparison purpose, the base model was a CFT column used as a benchmark specimen. Nevertheless, the other specimens were SRCFT types. The results indicate that reinforcement of a CFT column through this method leads to enhancement in load-carrying capacity, enhancement in lateral drift ratio, ductility, preventing of local buckling in steel shell, and enhancement in energy absorption capacity. Under cyclic displacement history, it was observed that the use of cross-shaped reinforcing steel section causes a higher level of energy dissipation and the moment of inertia of the reinforcing steel sections was found to be the most significant parameter affecting the hysteresis behavior of SRCFT columns.

  8. A methodology for replacement of conventional steel by microalloyed steel in bus tubular structures

    International Nuclear Information System (INIS)

    Cruz, Magnus G.H.; Viecelli, Alexandre

    2008-01-01

    The aim of this article is to show the use of a methodology that allows, in a trustful way and without the need to build up a complete physical model, the replacement of conventional steel by structural microalloyed steel (HSLA) in tubular structure, concerning passengers transport in vehicles with capacity of more than 20 people. The validation of the methodology is based on the ECE R66-00 regulation and on the Brazilian CONTRAN 811/96 resolution, which regulate minimal conditions of safety for this kind of vehicle. The methodology has four sequential and dependent stages, where the main focus is related to the experimental tests through the models that are simplified initially for later calibration using finite element method. Modular structures made of two different materials were tested and analyzed to confirm the present methodology, first the structure made of steel that is used by the bus industry in Brazil was tested and then it was compared with the new microalloyed steel. Experimental values are compared with calculated ones, foreseeing parametric optimisation and keeping the security levels according to legislation

  9. A methodology for replacement of conventional steel by microalloyed steel in bus tubular structures

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Magnus G.H. [Marcopolo S.A., Unidade Ana Rech, Av. Rio Branco, 4889, Ana Rach, 95060-650 Caxias do Sul (Brazil)], E-mail: magnus@verbonet.com.br; Viecelli, Alexandre [Mechanical Engineering Department, Universidade de Caxias do Sul, Rua Francisco Getulio Vargas, 1130, 95070-560 Caxias do Sul, RS (Brazil)], E-mail: avieceli@ucs.br

    2008-07-01

    The aim of this article is to show the use of a methodology that allows, in a trustful way and without the need to build up a complete physical model, the replacement of conventional steel by structural microalloyed steel (HSLA) in tubular structure, concerning passengers transport in vehicles with capacity of more than 20 people. The validation of the methodology is based on the ECE R66-00 regulation and on the Brazilian CONTRAN 811/96 resolution, which regulate minimal conditions of safety for this kind of vehicle. The methodology has four sequential and dependent stages, where the main focus is related to the experimental tests through the models that are simplified initially for later calibration using finite element method. Modular structures made of two different materials were tested and analyzed to confirm the present methodology, first the structure made of steel that is used by the bus industry in Brazil was tested and then it was compared with the new microalloyed steel. Experimental values are compared with calculated ones, foreseeing parametric optimisation and keeping the security levels according to legislation.

  10. Wind turbine tower for storing hydrogen and energy

    Science.gov (United States)

    Fingersh, Lee Jay [Westminster, CO

    2008-12-30

    A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

  11. Easy steel tower elevation. Development of a steel tower elevating aiding device; Tetto shoko wo rakuraku to. Tetto shoko hojo sochi no kaihatsu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tobe, Y. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1999-02-10

    Elevation of a transmission line steel tower is performed by an operator`s own force upon fixing a safety device to prevent a fall on a safety wire (SW) previously installed on a specified tower leg. It is a considerable burden for the operator to move the tower having a height of 80 to 100 m up and down several times a day. In order to reduce the fatigue, a portable, small and light-weight steel tower elevation aiding device was developed. The existing SW is used to fix the device, requiring no additional facility to be fixed on the tower. Safety assurance depends on the safety device on the SW as currently used. The device has pulling force of 50 kgf (the device operates in a range of 4 to 50 kgf to assure workability in elevation and stopping), and elevation speed of 15 to 20 m/minute (equivalent to the present work. The braking force can be adjusted in three steps at descent according to the ability of the operator). An Ni-hydrogen battery is used, capable of two returns on a tower per charge. Considering the device to be transported in mountainous area, the shape is such that a single unit can be put into a backpack. The device can also be used in general construction sites. (NEDO)

  12. Evaluation of seismic behavior of a braced tubular steel structure by pseudodynamic testing

    International Nuclear Information System (INIS)

    Shiny, P.B.; Javadian-Gilani, A.S.; Mahin, S.A.

    1984-01-01

    The inelastic seismic behavior of an X-braced, tubular steel frame is studied experimentally by means of pseudodynamic testing. The pseudodynamic method, which utilizes a numerical algorithm in the on-line computer control of a test specimen, can realistically simulate the seismic response of a structural model. This paper presents a brief outline of the experimental procedure and the results of the tubular frame tests, including the global responses, the inelastic energy-dissipation capabilities, and the failure mechanism of the frame at various excitation levels. Correlation of these results with previous experimental studies illustrates the feasibility and accuracy of the new test method

  13. Evaluation of selected martensitic stainless steels for use in downhole tubular expansion - Results of a laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Robert [Shell International E and P, b.v. Kessler Park 1, Postbus 60, 2280 AB Rijswijk (Netherlands)

    2004-07-01

    A laboratory program was performed to evaluate the potential of selected martensitic stainless steels for downhole cladding applications. The evaluation of the effects of tubular expansion on mechanical properties, defects, and resistance to environmentally assisted cracking demonstrated that some steels were acceptable for the intended application. The results were used to qualify and select the stainless steel for the intended sweet cladding applications. (authors)

  14. Influence of stainless steel Internals on Corrosion of tower wall materials

    Science.gov (United States)

    Chen, Bing; Ren, Ke

    2017-12-01

    In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

  15. Composite wind turbine towers

    Energy Technology Data Exchange (ETDEWEB)

    Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2008-07-01

    This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

  16. High strength H2S resistant steels and alloys for oil field tubular products

    International Nuclear Information System (INIS)

    Straatmann, J.A.; Grobner, P.J.

    1976-01-01

    New sources of oil and natural gas are more frequently occurring at greater depths in hostile surface and underground environments. The materials utilized in drilling and completing the wells require higher strength along with improved resistance to corrosive/embrittling attack by contaminants present in the deep, high pressure-high temperature formations. Higher strength steels having yield strengths in excess of 690 MPa and possessing improved resistance to sulfide stress corrosion cracking (SSC) have been developed and are currently being evaluated by the oil industry. The research to develop these new steels combined modifications of chemical compositions, heat treatment and processing variables. For most severe SSC environments and deep wells, it was necessary to provide even better alloys for tubular materials. The successful solution to the problem was found with the utilization of nickel-base alloys. These materials are being evaluated in commercial applications

  17. Hysteretic Behavior of Tubular Steel Braces Having Carbon Fiber Reinforced Polymer Reinforcement Around End Net Sections

    Directory of Open Access Journals (Sweden)

    Cem Haydaroğlu

    2015-12-01

    Full Text Available This study presents an experimental investigation into the seismic retrofit of tubular steel braces using carbon fiber reinforced polymer (CFRP members. CFRP retrofitting of net sections for compact tubes are proposed for delaying potential local net section failure. A total of almost full-scale three (TB-1, TB-2, and TB-3 compact steel tubular specimens were designed per AISC specifications, constructed, and cyclically tested to fracture. Retrofitted braces, when compared to the reference specimen, developed fuller hysteretic curves. Increase in cumulative hysteretic energy dissipation and the elongation in fracture life in the specimen retrofitted with CFRP plates and CFRP sheet wraps at net sections are observed during testing. This resulted in a maximum of 82.5% more dissipated energy for compact tube specimens. Also, this retrofit provided a longer experimental fracture life (maximum 59% more. Due to fracture initiation during the last cycles, significant reductions in strength and stiffness have been obtained. No significant change (maximum 10% in the brace stiffness was observed, which could be desirable in seismic retrofit applications. Pushover analysis per FEMA 356 for the bare specimen shows that FEMA does not represent actual brace behavior in the compression side although pushover and experimental results are in good agreement in the tension side.

  18. Comparison of the performance of concrete-filled steel tubular and hollow steel diagrid buildings

    Science.gov (United States)

    Peter, Minu Ann; S, Sajith A.; Nagarajan, Praveen

    2018-03-01

    In the recent construction scenario, diagrid structures are becoming a popular high-rise building structural system. Diagrid structures consist of diagonals in the perimeter and an interior core. The corner and interior vertical columns are not required due to the structural efficiency of diagrid structural systems. Steel and concrete are commonly used material for diagrid. An alternate material for diagrid is concrete-filled steel tube (CFST). CFST incorporates the advantages of both steel and concrete. In CFST, the inward buckling of the steel tube is effectively prevented by the filled concrete. The compressive strength of concrete increases due to the tri-axial state of stress in concrete induced by the steel tube. The longitudinal as well as lateral reinforcement to the concrete core is also provided by the steel tube. This paper compares the performance of CFST and steel diagrid buildings using linear static analysis. For this purpose, a 12 storey and 36 storey building are analysed using finite element method and CFST diagrid building is found to perform better.

  19. Empirical Approach for Determining Axial Strength of Circular Concrete Filled Steel Tubular Columns

    Science.gov (United States)

    Jayalekshmi, S.; Jegadesh, J. S. Sankar; Goel, Abhishek

    2018-03-01

    The concrete filled steel tubular (CFST) columns are highly regarded in recent years as an interesting option in the construction field by designers and structural engineers, due to their exquisite structural performance, with enhanced load bearing capacity and energy absorption capacity. This study presents a new approach to simulate the capacity of circular CFST columns under axial loading condition, using a large database of experimental results by applying artificial neural network (ANN). A well trained network is established and is used to simulate the axial capacity of CFST columns. The validation and testing of the ANN is carried out. The current study is focused on proposing a simplified equation that can predict the ultimate strength of the axially loaded columns with high level of accuracy. The predicted results are compared with five existing analytical models which estimate the strength of the CFST column. The ANN-based equation has good prediction with experimental data, when compared with the analytical models.

  20. Empirical Approach for Determining Axial Strength of Circular Concrete Filled Steel Tubular Columns

    Science.gov (United States)

    Jayalekshmi, S.; Jegadesh, J. S. Sankar; Goel, Abhishek

    2018-06-01

    The concrete filled steel tubular (CFST) columns are highly regarded in recent years as an interesting option in the construction field by designers and structural engineers, due to their exquisite structural performance, with enhanced load bearing capacity and energy absorption capacity. This study presents a new approach to simulate the capacity of circular CFST columns under axial loading condition, using a large database of experimental results by applying artificial neural network (ANN). A well trained network is established and is used to simulate the axial capacity of CFST columns. The validation and testing of the ANN is carried out. The current study is focused on proposing a simplified equation that can predict the ultimate strength of the axially loaded columns with high level of accuracy. The predicted results are compared with five existing analytical models which estimate the strength of the CFST column. The ANN-based equation has good prediction with experimental data, when compared with the analytical models.

  1. Numerical analysis on seismic behavior of reinforced concrete beam to concrete filled steel tubular column connections with ring-beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yi., E-mail: zhaoyi091218@163.com [School of Civil and Architectural Engineering, Zhongyuan University of Technology,Zhengzhou 450000 (China); Xu, Li. Hua. [School of Civil Engineering, Wuhan University, No.8, Donghu Road, WuHan 430072 (China)

    2016-06-08

    This paper presents numerical study of the seismic behavior of reinforced concrete beam to concrete filled steel tube column connections with ring-beam. The material stress-strain relations, element type and boundary condition are selected, which are consistent with actual situation. Then the seismic behavior of this type of joint are researched by ABAQUS, and finite element analyses are conducted under cyclic loading. Its parameters are discussed including thickness of steel tubular column wall, sectional dimension of the ring-beam and strength of the core concrete. The results show that the ultimate capacity of the connections is improved with sectional dimension of the ring-beam increased. In the meanwhile, the influence on skeleton curve of the joints is slight of which included thickness of steel tubular column wall and strength of the core concrete.

  2. Welding simulation and fatigue assessment of tubular K-joints in high-strength steel

    International Nuclear Information System (INIS)

    Zamiri Akhlaghi, F.

    2014-01-01

    Application of newly developed high strength steel hollow sections is increasing in construction industry – especially for bridge structures – due to their satisfactory material properties and fabrication advantages. These sections allow for longer spans, more slender structures. Savings in weight and volume of material compared to traditional steel grades increase sustainability of construction and compensate for part of higher unit cost of material. Nevertheless, use of high strength steels cannot be promoted unless potential fatigue issues are properly addressed. Two fabrication methods are currently available for the planar Warren trusses made of circular hollow sections (CHS): welding the tubes together, or using cast steel nodes and connecting truss members to them by girth welds. Previous research on tubular bridge trusses indicates that the problematic fatigue cracking sites for the first fabrication method are located at weld toes in the gap region of the truss joints. For the second method, cracking occurs at the root of CHS–cast butt welds. Fatigue performance of these two methods were investigated by constant amplitude fatigue testing of two full scale trusses made of steel grade S690QH and with a geometry similar to previous S355J2H investigation. Fatigue lives of K-joints were in agreement with current recommended code values. For CHS–cast welded connections, no visible cracking was observed up to 2£10"6 cycles. Due to the effect of residual stresses, fatigue cracking was observed in compressive joints as well as tensile joints. Indeed, tensile welding residual stresses keep the crack open during all or part of the compressive load cycle. Their distribution and impact on fatigue life of tubular joints has not been fully investigated before for a complex detail such as Tubular K-joint made of high strength steel. Experimental and numerical methods were utilized for assessment of welding residual stresses. Neutron diffraction experiments were

  3. ANALISIS KINERJA COOLING TOWER 8330 CT01 PADA WATER TREATMENT PLANT-2 PT KRAKATAU STEEL (PERSERO. TBK

    Directory of Open Access Journals (Sweden)

    Hutriadi Pratama Siallagan

    2017-11-01

    Full Text Available Pada proses produksi baja sangat erat kaitannya dengan pendinginan baik untuk proses pendinginan baja maupun pendinginan mesin-mesin produksi supaya terhindar dari over heat sehingga dapat bekerja dengan optimal. Pada PT Krakatau Steel menggunakan beberapa sistem pendingin salah satunya adalah sistem pendingin cooling tower 8330 CT 01. Sistem pendingin tersebut digunakan untuk menunjang proses produksi dan juga pendinginanan mesin produksi khusunya pada Slab Steel Plant (SSP, dengan peran yang sangat besar maka cooling tower 8330 CT 01 harus diketahui bagaimana kinerjanya. Skripsi ini membahas tentang analisis kinerja Cooling tower 8330 CT 01 dengan membandingkan data teori dengan data aktual berdasarkan perhitungan-perhitungan sehingga dapat diketahui bagaimana kinerja dari Cooling tower 8330 CT 01 tersebut. Dari hasil analisis diperoleh penurunan efisiensi sebesar 22,353%, kapasitas pendinginan 7.033,35 Kj/s, Hal tersebut diakibatkan oleh temperatur air yang masuk Cooling tower 8330 CT 01 tidak terlalu tinggi, karena SSP sedang dalam pengerjaan revitatalisi, agar lebih efektif dan efisien Cooling tower 8330 CT 01 sebaiknya lebih dimamfaatkan lagi untuk pendingin objek lainnya sehingga temperatur air yang masuk tidak terlalu rendah.

  4. Analisis Kinerja Cooling Tower 8330 Ct01 Pada Water Treatment Plant-2 PT Krakatau Steel (Persero). Tbk

    OpenAIRE

    Siallagan, Hutriadi Pratama

    2017-01-01

    Pada proses produksi baja sangat erat kaitannya dengan pendinginan baik untuk proses pendinginan baja maupun pendinginan mesin-mesin produksi supaya terhindar dari over heat sehingga dapat bekerja dengan optimal. Pada PT Krakatau Steel menggunakan beberapa sistem pendingin salah satunya adalah sistem pendingin cooling tower 8330 CT 01. Sistem pendingin tersebut digunakan untuk menunjang proses produksi dan juga pendinginanan mesin produksi khusunya pada Slab Steel Plant (SSP), dengan peran ya...

  5. Arch-Axis Coefficient Optimization of Long-Span Deck-Type Concrete-Filled Steel Tubular Arch Bridge

    Science.gov (United States)

    Liu, Q. J.; Wan, S.; Liu, H. C.

    2017-11-01

    This paper is based on Nanpuxi super major bridge which is under construction and starts from Wencheng Zhejiang province to Taishun highway. A finite element model of the whole bridge is constructed using Midas Civil finite element software. The most adverse load combination in the specification is taken into consideration to determine the method of calculating the arch-axis coefficient of long-span deck-type concrete-filled steel tubular arch bridge. By doing this, this paper aims at providing references for similar engineering projects.

  6. Experimental Research on Seismic Performance of Four-Element Variable Cross-Sectional Concrete Filled Steel Tubular Laced Columns

    Science.gov (United States)

    Ou, Zhijing; Lin, Jianmao; Chen, Shengfu; Lin, Wen

    2017-10-01

    A total of 7 experimental tests were conducted to investigate seismic performance of four element variable cross-sectional Concrete Filled Steel Tubular (CFST) laced columns. The experimental parameters are longitudinal slope and arrangement type of lacing tubes. The rules on hysteresis loop, ductility, energy expenditure, and stiffness degradation of specimens are researched. Test results indicate that all specimens have good seismic performance; their hysteresis loops are full without obvious shrinkage. With the increase of longitudinal slope, the horizontal carrying capacity increases, energy dissipation capacity improve, and there is slightly increase in stiffness degradation. The influence of arrangement type of lacing tubes on displacement ductility of specimens is big.

  7. Evaluating a steel beam’s rigid connection to a concrete filled tubular column when submitted to dynamic load

    Directory of Open Access Journals (Sweden)

    Maritza Uribe Vallejo

    2009-01-01

    Full Text Available Using prequalified connections during the structural design stage becomes increasingly necessary when developing structural en-gineering projects which include steel elements; this is so that the steel elements’ appropriate behavior can be ensured according to the structural system and seismic demand. Unfortunately, the international entities providing this type of information (i.e. FEMA only have a limit series of prequalified connections and such series do not include rigid connections between steel beams and concrete filled tubular (CFT columns having an extended end plate, which has become a very widespread building practice in Colombia. This paper describes the most important aspects of a study at the Universidad Nacional de Colombia concerning the behavior of a steel beam rigidly connected to a CFT-column, using six physical models having different width-thickness ratio (b/t columns. ANSYS v.10 software was used for studying theoretical models (finite elements analysis for comparative analysis of cyclic test theoretical and experimental results for each specimen presented for the qualification phase. The six tested specimens’ hysteretic curves are presented. Several conclusions are drawn concerning finite element validation for this type of connection and the influence of width-thickness ratio (b/t variation and design recommendations for suitable behavior under dynamic loads when this type of connection was used.

  8. The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

    Science.gov (United States)

    Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

    2013-01-01

    The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).

  9. H2S cracking resistance of type 420 stainless steel tubulars

    International Nuclear Information System (INIS)

    Klein, L.J.

    1984-01-01

    Type 420 stainless steel (13Cr) production tubing is being used successfully in deep sour gas wells in the Tuscaloosa Trend. Despite their reputation for poor H 2 S cracking resistance in laboratory tests, 12-13% Cr steels continue to perform well in sour environments. NACE Tensile Test and Shell bent beam test results indicate Type 420 is more resistant to H 2 S cracking than Type 410, but is not as resistant as carbon steel, at to 586-690 MPa (85-100 ksi) yield strength level. In addition to evaluating Type 420 stainless steel in the standard NACE Tensile and Shell bent beam tests, the effects on cracking tendency of chloride concentration, pH, and H 2 S gas concentration in the NACE Test solution were also examined. Type 420 appears to be more resistant to H 2 S cracking than is indicated by standard laboratory tests, at least in low H 2 S level sour environments

  10. Optimum design of large span concrete filled steel tubular arch bridge based on static, stability and modal analysis

    Institute of Scientific and Technical Information of China (English)

    赵长军; 胡隽; 徐兴

    2002-01-01

    A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.

  11. Mechanical Behavior of Recycled Aggregate Concrete-Filled Steel Tubular Columns before and after Fire

    Directory of Open Access Journals (Sweden)

    Wenchao Liu

    2017-03-01

    Full Text Available Recycled aggregate concrete (RAC is an environmentally friendly building material. This paper investigates the mechanical behavior of recycled aggregate concrete filled steel tube (RACFST columns exposed to fire. Two groups of 12 columns were designed and tested, under axial compression, before and after fire, to evaluate the degradation of bearing capacity due to fire exposure. Six specimens were subjected to axial compression tests at room temperature and the other six specimens were subjected to axial compression tests after a fire exposure. The main parameters of the specimens include the wall thickness of the steel tube (steel content and the type of concrete materials. Several parameters as obtained from the experimental results were compared and analyzed, including the load-bearing capacity, deformation capacity, and failure characteristics of the specimens. Meanwhile, rate of loss of bearing capacity of specimens exposed to fire were calculated based on the standards EC4 and CECS28:90. The results show that concrete material has a large influence on the rate of loss of bearing capacity in the case of a relatively lower steel ratio. While steel content has little effect on the rate of loss of bearing capacity of concrete-filled steel tube (CFST columns after fire, it has a relatively large influence on the loss rate of bearing capacity of the RACFST columns. The loss of bearing capacity of the specimens from the experiment is more serious than that from the calculation. As the calculated values are less conservative, particular attention should be given to the application of recycled aggregate concrete in actual structures.

  12. Mechanical Behavior of Recycled Aggregate Concrete-Filled Steel Tubular Columns before and after Fire.

    Science.gov (United States)

    Liu, Wenchao; Cao, Wanlin; Zhang, Jianwei; Wang, Ruwei; Ren, Lele

    2017-03-09

    Recycled aggregate concrete (RAC) is an environmentally friendly building material. This paper investigates the mechanical behavior of recycled aggregate concrete filled steel tube (RACFST) columns exposed to fire. Two groups of 12 columns were designed and tested, under axial compression, before and after fire, to evaluate the degradation of bearing capacity due to fire exposure. Six specimens were subjected to axial compression tests at room temperature and the other six specimens were subjected to axial compression tests after a fire exposure. The main parameters of the specimens include the wall thickness of the steel tube (steel content) and the type of concrete materials. Several parameters as obtained from the experimental results were compared and analyzed, including the load-bearing capacity, deformation capacity, and failure characteristics of the specimens. Meanwhile, rate of loss of bearing capacity of specimens exposed to fire were calculated based on the standards EC4 and CECS28:90. The results show that concrete material has a large influence on the rate of loss of bearing capacity in the case of a relatively lower steel ratio. While steel content has little effect on the rate of loss of bearing capacity of concrete-filled steel tube (CFST) columns after fire, it has a relatively large influence on the loss rate of bearing capacity of the RACFST columns. The loss of bearing capacity of the specimens from the experiment is more serious than that from the calculation. As the calculated values are less conservative, particular attention should be given to the application of recycled aggregate concrete in actual structures.

  13. Experiment on interface separation detection of concrete-filled steel tubular arch bridge using accelerometer array

    Science.gov (United States)

    Pan, Shengshan; Zhao, Xuefeng; Zhao, Hailiang; Mao, Jian

    2015-04-01

    Based on the vibration testing principle, and taking the local vibration of steel tube at the interface separation area as the study object, a real-time monitoring and the damage detection method of the interface separation of concrete-filled steel tube by accelerometer array through quantitative transient self-excitation is proposed. The accelerometers are arranged on the steel tube area with or without void respectively, and the signals of accelerometers are collected at the same time and compared under different transient excitation points. The results show that compared with the signal of compact area, the peak value of accelerometer signal at void area increases and attenuation speed slows down obviously, and the spectrum peaks of the void area are much more and disordered and the amplitude increases obviously. whether the input point of transient excitation is on void area or not is irrelevant with qualitative identification results. So the qualitative identification of the interface separation of concrete-filled steel tube based on the signal of acceleration transducer is feasible and valid.

  14. Study on the blasting demolition of steel construction. Part 2. Demolition work of steel tower; Tekkotsu kozobutsu no bakuha kaitai ni kansuru kenkyu. 2. Koro yagura happa kaitai koji

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Y.; Wada, Y.; Katsuyama, K. [National Institute for Resources and Environment, Tsukuba (Japan); Nishida, T.; Hoshino, M.; Nagano, M. [Kacoh Co. Ltd., Tokyo (Japan)

    1997-06-30

    This paper describes the blasting demolition of steel tower of iron works. The steel tower had four columns, and its dimension was 17 mtimes17 m in cross section and 77.6 m height. The total weight was about 1,724 t. The 18.4 kg V-type linear shaped charge was fixed around columns with box weld structures, and initiated using 16 seismograph electric detonators. Vibration and noise were measured during blasting and collapse of the tower. In the both case, the vibration levels were between 67 and 71 dB, which were low and under 75 dB, the standard level during specific construction works of the regulation act of vibration. The noise level was 120 dB(A) at the point 200 m away from the blasting source, which was over 85 dB(A), the standard level. The collapse process of steel tower was simulated using discontinuous deformation analysis. The results agreed well with those from the actual collapse. The steel tower landed about 6 seconds after the initiation, and it took about 15 seconds to complete the collapse. Before the demolition, the 6 t parts of forefeet of two columns in the collapse direction were cut and removed by blasting. Thus, the collapse was controlled in the given direction. 5 refs., 13 figs., 2 tabs.

  15. Electron beam welding of flanges with tubular shafts of steel 40KhNMA

    International Nuclear Information System (INIS)

    Leskov, G.I.; Zhivaga, L.I.; Shipitsyn, B.N.; Savichev, R.V.

    1975-01-01

    The results are presented of elaborating the technological process for the electron beam welding of flanges with a tube of the 40KhNMA steel and of investigation into the quality of the welded joints. A welded piece has been fabricated conforming to the technology suggested observing the parameters worked-out in the following sequence: assembling the piece; pre-welding of the edges in some points; welding; high tempering; welds quality control; removal of the seam reinforcement inside of the tube and the weld root to the depth of 2 mm; quenching; tempering; welds quality control; finishing. The welds quality control consists in visual inspection, ultrasonic testing, magnetic flaw detection, as well as X-ray and metallographic analyses. The mechanical properties are studied on notched samples cut out of the welded joints. The test results have shown that the mechanical properties of the welded joints meet the requirements on the same level with the base metal

  16. Surface transformation hardening on steels treated with solar energy in central tower and heliostats field

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, G.P.; Lopez, V.; de Damborenea, J.J.; Vazquez, A.J. [Centro Nacional de Investigaciones Metalurgicas CENIM/CSIC, Madrid (Spain)

    1995-04-28

    The possibility of surface hardening on AISI 4140 steel treated with concentrated solar energy in solar installations for electricity production has been studied. The samples were slides from a 35 mm diameter steel bar and their height was 35 mm. The quenching was made in water but also was considered the possibility of self-quenching by cooling in air. The amount of the surface hardness and the different structures obtained in both cases are presented, and some discussion is made with reference to the surface hardness, the hardness profiles and the structures obtained. The heating of steel with concentrated solar energy may produce similar hardening to that obtained with more conventional techniques of surface hardening

  17. A PVDF-Based Sensor for Internal Stress Monitoring of a Concrete-Filled Steel Tubular (CFST) Column Subject to Impact Loads.

    Science.gov (United States)

    Du, Guofeng; Li, Zhao; Song, Gangbing

    2018-05-23

    Impact loads can have major adverse effects on the safety of civil engineering structures, such as concrete-filled steel tubular (CFST) columns. The study of mechanical behavior and stress analysis of CFST columns under impact loads is very important to ensure their safety against such loads. At present, the internal stress monitoring of the concrete cores CFST columns under impact loads is still a very challenging subject. In this paper, a PVDF (Polyvinylidene Fluoride) piezoelectric smart sensor was developed and successfully applied to the monitoring of the internal stress of the concrete core of a CFST column under impact loads. The smart sensor consists of a PVDF piezoelectric film sandwiched between two thin steel plates through epoxy. The protection not only prevents the PVDF film from impact damages but also ensures insulation and waterproofing. The smart sensors were embedded into the circular concrete-filled steel tube specimen during concrete pouring. The specimen was tested against impact loads, and testing data were collected. The time history of the stress obtained from the PVDF smart sensor revealed the evolution of core concrete internal stress under impact loads when compared with the impact force⁻time curve of the hammer. Nonlinear finite element simulations of the impact process were also carried out. The results of FEM simulations had good agreement with the test results. The results showed that the proposed PVDF piezoelectric smart sensors can effectively monitor the internal stress of concrete-filled steel tubular columns under impact loads.

  18. Trends, Opportunities, and Challenges for Tall Wind Turbine and Tower Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, Eric; Roberts, Owen; Dykes, Katherine

    2017-06-28

    This presentation summarizes recent analysis focused on characterizing the opportunity for Tall Wind technologies generally and for tall tower technologies specifically. It seeks to illuminate and explain the concept of Tall Wind, its impact on the wind industry to date, and the potential value of Tall Wind in the future. It also explores the conditions and locations under which the impacts of Tall Wind offer the most significant potential to increase wind technology performance. In addition, it seeks to examine the status of tall tower technology as a key sub-component of Tall Wind, focusing on the potential for continued innovation in tubular steel wind turbine towers and the status and potential for a select set of alternative tall tower technologies.

  19. Biocorrosion of mild steel and copper used in cooling tower water and its control.

    Science.gov (United States)

    Li, Xiao Lei; Narenkumar, Jayaraman; Rajasekar, Aruliah; Ting, Yen-Peng

    2018-03-01

    The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653-10 ppm) with biocide (F5100-5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.

  20. Effect of Elemental Sulfur and Sulfide on the Corrosion Behavior of Cr-Mo Low Alloy Steel for Tubing and Tubular Components in Oil and Gas Industry.

    Science.gov (United States)

    Khaksar, Ladan; Shirokoff, John

    2017-04-20

    The chemical degradation of alloy components in sulfur-containing environments is a major concern in oil and gas production. This paper discusses the effect of elemental sulfur and its simplest anion, sulfide, on the corrosion of Cr-Mo alloy steel at pH 2 and 5 during 10, 20 and 30 h immersion in two different solutions. 4130 Cr-Mo alloy steel is widely used as tubing and tubular components in sour services. According to the previous research in aqueous conditions, contact of solid sulfur with alloy steel can initiate catastrophic corrosion problems. The corrosion behavior was monitored by the potentiodynamic polarization technique during the experiments. Energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) have been applied to characterize the corrosion product layers after each experiment. The results show that under the same experimental conditions, the corrosion resistance of Cr-Mo alloy in the presence of elemental sulfur is significantly lower than its resistance in the presence of sulfide ions.

  1. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  2. Water tower

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    The water tower, being built on the highest point of the site, 460.5 m above the sea level. The tank will hold 750 m3 of water, and the tower will be topped by a knob which can serve as a geological survey reference mark.

  3. Summary of tower designs for large horizontal axis wind turbines

    Science.gov (United States)

    Frederick, G. R.; Savino, J. M.

    1986-01-01

    Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

  4. Tower counts

    Science.gov (United States)

    Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

    2007-01-01

    Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers. 

  5. Cooling tower

    Energy Technology Data Exchange (ETDEWEB)

    Norbaeck, P; Heneby, H

    1976-01-22

    Cooling towers to be transported on road vehicles as a unit are not allowed to exceed certain dimensions. In order to improve the efficiency of such a cooling tower (of cross-flow design and box-type body) with given dimensions, it is proposed to arrange at least one of the scrubbing bodies displaceable within a module or box. Then it can be moved out of the casing into working position, thereby increasing the front surface available for the inlet of air (and with it the efficiency) by nearly a factor of two.

  6. Cooling towers

    International Nuclear Information System (INIS)

    Boernke, F.

    1975-01-01

    The need for the use of cooling systems in power plant engineering is dealt with from the point of view of a non-polluting form of energy production. The various cooling system concepts up to the modern natural-draught cooling towers are illustrated by examples. (TK/AK) [de

  7. Virtual Tower

    International Nuclear Information System (INIS)

    Wayne, R.A.

    1997-01-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems

  8. Cooling towers

    International Nuclear Information System (INIS)

    Korik, L.; Burger, R.

    1992-01-01

    What is the effect of 0.6C (1F) temperature rise across turbines, compressors, or evaporators? Enthalpy charts indicate for every 0.6C (1F) hotter water off the cooling tower will require an additional 2 1/2% more energy cost. Therefore, running 2.2C (4F) warmer due to substandard cooling towers could result in a 10% penalty for overcoming high heads and temperatures. If it costs $1,250,000.00 a year to operate the system, $125,000.00 is the energy penalty for hotter water. This paper investigates extra fuel costs involved in maintaining design electric production with cooling water 0.6C (1F) to 3C (5.5F) hotter than design. If design KWH cannot be maintained, paper will calculate dollar loss of saleable electricity. The presentation will conclude with examining the main causes of deficient cold water production. State-of-the-art upgrading and methodology available to retrofit existing cooling towers to optimize lower cooling water temperatures will be discussed

  9. Steel Towers for Wind Turbines

    OpenAIRE

    Matos, Rui Manuel Maia Pinto de

    2017-01-01

    Tese de doutoramento em Construção Metálica e Mista, apresentada ao Departamento de Engenharia Civil da Faculdade de Ciências e Tecnologia da Universidade de Coimbra In the last few years it was registered an increase in the exploitation of renewable energies, namely wind energy, due to the increasing concern about the environmental problems related with the global warming. The forecast of the official entities is to increase the exploitation of the wind energy of around 61% in the Europe...

  10. Distal renal tubular acidosis

    Science.gov (United States)

    ... this disorder. Alternative Names Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA Images Kidney anatomy Kidney - blood and urine flow References Bose A, Monk RD, Bushinsky DA. Kidney ...

  11. Structural problems in the construction of natural draught cooling towers

    International Nuclear Information System (INIS)

    Zerna, W.

    1977-01-01

    The paper deals with the structural requirements and development possibilities for large cooling towers, and in particular discusses parameter investigations into the reinforcement of cooling tower shells and problems of optimisation. In conclusion proposals are made as to how concrete cooling towers of very large dimensions reinforced with steel, as for example are required in dry cooling for large capacity plant, can be developed economically. (orig.) [de

  12. Steel

    International Nuclear Information System (INIS)

    Zorev, N.N.; Astafiev, A.A.; Loboda, A.S.; Savukov, V.P.; Runov, A.E.; Belov, V.A.; Sobolev, J.V.; Sobolev, V.V.; Pavlov, N.M.; Paton, B.E.

    1977-01-01

    Steels also containing Al, N and arsenic, are suitable for the construction of large components for high-power nuclear reactors due to their good mechanical properties such as good through-hardening, sufficiently low brittleness conversion temperature and slight displacement of the latter with neutron irradiation. Defined steels and their properties are described. (IHOE) [de

  13. Transition piece for joining together tubular pieces

    International Nuclear Information System (INIS)

    Holko, K.H.

    1981-01-01

    A transition piece for joining together tubular pieces formed respectively from a low alloy or carbon steel and a high temperature alloy containing at least 16% chromium includes a plurality of tubular parts welded together and formed from materials of selected composition with a maximum chromium content difference of 5% between adjacent parts when the chromium content of each part is below 10% and a maximum chromium difference of 7% between adjacent parts when the chromium content of either part is above 10%. The transition parts are also graded as to such characteristics as thermal expansion coefficient. The transition parts at opposite ends of the transition joint have chromium percentages similar to the tubular pieces to which they are to be joined. The parts may be joined by fusion and/or friction welding and parts may be formed by fusion weld deposition. (author)

  14. Influence of structure and properties of tubular billets of the 12 Kh 18N10T steel on deformability of tubes at cold-rolling mills

    International Nuclear Information System (INIS)

    Vil'yams, O.S.; Bol'shova, N.M.; Olejnik, O.V.; Velikotnaya, E.S.

    1979-01-01

    Metallographic analysis of the defects of the ''oblique cracks'' type on the surface of hot-rolled tubes of the 12Kh18N10T steel has been carried out. Recommended is the complex of mechanical properties and the structure factors (grain size) of conversion hot-rolled tubes, providing the combination of ductility and high rapture strength during rolling at pilger mills. At a grain size not coarser than number 5, a billet must have σsub(T) 5 >=40 %. Hot-rolled coarse-grained billet is not recommended for warm rolng because of high strain hardening

  15. A study of the life expectancy of cooling towers

    International Nuclear Information System (INIS)

    Bolvin, M.; Chauvel, D.

    1993-01-01

    The paper describes the following different tasks of the study whose aim was to extend the life time of cooling towers for French Nuclear Power plants to 40 years. The aging factors specific to cooling towers were measured and analysed with regard to the external surface, the internal surface and inside the concrete. The safety coefficient for buckling was calculated and then the stress analysis of the materials (concrete and steel) was done. A special computer program written for cooling towers was used with a model including the soil stiffness and the supports of the tower. (author)

  16. Impact of the surface roughness of AISI 316L stainless steel on biofilm adhesion in a seawater-cooled tubular heat exchanger-condenser.

    Science.gov (United States)

    García, Sergio; Trueba, Alfredo; Vega, Luis M; Madariaga, Ernesto

    2016-11-01

    The present study evaluated biofilm growth in AISI 316L stainless steel tubes for seawater-cooled exchanger-condensers that had four different arithmetic mean surface roughness values ranging from 0.14 μm to 1.2 μm. The results of fluid frictional resistance and heat transfer resistance regarding biofilm formation in the roughest surface showed increases of 28.2% and 19.1% respectively, compared with the smoothest surface. The biofilm thickness taken at the end of the experiment showed variations of up to 74% between the smoothest and roughest surfaces. The thermal efficiency of the heat transfer process in the tube with the roughest surface was 17.4% greater than that in the tube with the smoothest surface. The results suggest that the finish of the inner surfaces of the tubes in heat exchanger-condensers is critical for improving energy efficiency and avoiding biofilm adhesion. This may be utilised to reduce biofilm adhesion and growth in the design of heat exchanger-condensers.

  17. Reliability of Tubular Joints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    In this paper the preliminary results obtained by tests on tubular joints are presented. The joints are T-joints and the loading is static. It is the intention in continuation of these tests to perform tests on other types of joints (e.g. Y-joints) and also with dynamic loading. The purpose...... of the test is partly to obtain empirical data for the ultimate load-carrying capacity of tubular T-joints and partly to obtain some experience in performing tests with tubular joints. It is well known that tubular joints are usually designed in offshore engineering on the basis of empirical formulas obtained...... by experimental test results. Therefore, there is a need for performing experimental tests in this area....

  18. Structure of natural draft cooling towers, 1. Study on cooling tower shells

    Energy Technology Data Exchange (ETDEWEB)

    Ishioka, H; Sakamoto, Y; Tsurusaki, M; Koshizawa, K; Chiba, T [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1976-09-01

    Recently in Japan, demands for cooling tower systems have been increasing remarkably with the construction of large power plants and the legislation of environmental regulations. In view of the severe natural conditions in Japan such as strong wind and seismic loadings, etc., the establishment of the optimum design and construction method is essential for the building of safe and economical towers. In order to establish a comprehensive plan of a power plant cooling system of the appropriate structural type, the authors have made researches and experiments on design conditions, static and dynamic analyses, and comparative studies of various structural types such as reinforced concrete thin-shell structures, steel framed structures and composite shell segment structures, based on the investigation results of towers in Europe and America. These results are presented in three reports, the 1st of which concerns cooling tower shells as are herein described.

  19. Cooling tower calculations

    International Nuclear Information System (INIS)

    Simonkova, J.

    1988-01-01

    The problems are summed up of the dynamic calculation of cooling towers with forced and natural air draft. The quantities and relations are given characterizing the simultaneous exchange of momentum, heat and mass in evaporative water cooling by atmospheric air in the packings of cooling towers. The method of solution is clarified in the calculation of evaporation criteria and thermal characteristics of countercurrent and cross current cooling systems. The procedure is demonstrated of the calculation of cooling towers, and correction curves and the effect assessed of the operating mode at constant air number or constant outlet air volume flow on their course in ventilator cooling towers. In cooling towers with the natural air draft the flow unevenness is assessed of water and air relative to its effect on the resulting cooling efficiency of the towers. The calculation is demonstrated of thermal and resistance response curves and cooling curves of hydraulically unevenly loaded towers owing to the water flow rate parameter graded radially by 20% along the cross-section of the packing. Flow rate unevenness of air due to wind impact on the outlet air flow from the tower significantly affects the temperatures of cooled water in natural air draft cooling towers of a design with lower demands on aerodynamics, as early as at wind velocity of 2 m.s -1 as was demonstrated on a concrete example. (author). 11 figs., 10 refs

  20. Drop Tower Physics

    Science.gov (United States)

    Dittrich, William A.

    2014-01-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

  1. Wind tower service lift

    Science.gov (United States)

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  2. Structure of natural draft cooling towers, 1

    International Nuclear Information System (INIS)

    Ishioka, Hitoshi; Sakamoto, Yukichi; Tsurusaki, Mamoru; Koshizawa, Koichi; Chiba, Toshio

    1976-01-01

    Thousands of natural draft cooling towers have been utilized, in Europe and America, as cooling systems of power plants or as countermeasures against thermal polution. Recently in Japan, demands for cooling tower systems have been increasing remarkably with the construction of large power plants and the legislation of environmental regulations. In view of the severe natural conditions in Japan such as strong wind and seismic loadings, etc., the establishment of the optimum design and construction method is essential for the building of safe and economical towers. In order to establish a comprehensive plan of a power plant cooling system of the appropriate structural type, the authors have made researches and experiments on design conditions, static and dynamic analyses, and comparative studies of various structural types such as reinforced concrete thin-shell structures, steel framed structures and composite shell segment structures, based on the investigation results of towers in Europe and America. These results are presented in three reports, the 1st of which concerns cooling tower shells as are hereinafter described. (auth.)

  3. Tubular closure device

    International Nuclear Information System (INIS)

    Klahn, F.C.; Nolan, J.H.; Wills, C.

    1982-01-01

    This invention relates to a closure mechanism for closing openings such as the bore of a conduit and for releasably securing members within the bore. More particularly, this invention relates to a closure mechanism for tubular irradiation surveillance specimen assembly holders used in nuclear reactors

  4. Tall towers for large wind turbines. Report from Vindforsk project V-342

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Staffan; Lyrner, Tomas; Hassanzadeh, Manouchehr; Stalin, Thomas; Johansson, John

    2010-07-15

    The general rule of thumb has been to furnish a wind turbine with a tower as tall as the turbine diameter, with deviations downwards for high wind speed sites. In this report the statement is questioned, with special emphasis for wind turbines sited in forests. The aim of this project was to propose and calculate candidate types of tall towers for on-shore wind turbines in the 3 - 5 MW range, with special reference to siting in forests with a representative wind shear. During the project this scope has been more precisely defined to study 3 and 5 MW wind turbines with hub heights of 80 - 175 meters featuring the following tower solutions: 1. Steel shell tower designed in a conventional way with flanges and both longitudinal and transverse welds. 2. Steel shell tower with bolted friction joints only. 3. Concrete tower with pretensioned steel tendons. 4. Hybrid tower with a lower concrete part and an upper part built as a conventional steel shell. 5. Lattice tower. 6. Wooden tower. During the execution of the project the design of a total of 42 towers was outlined and calculated. Today the welded steel shell tower dominates the wind turbine market. Larger turbines and higher hub heights result in larger optimal tower base diameters. For the road transportation there are limitations due to bridges and other obstacles. In Sweden the limit for transports with special permits in general maximizes the diameter to 4,5 metres. To some extent it is still technically possible to build towers with a less than optimal diameter, but due to the high mass and the large wall thickness they tend to be uneconomical in comparison with other alternatives above a hub height of roughly 100 metres. In this report welded steel shell towers were outlined for 3 MW turbines up to a hub height of 150 metres whereas the limit for the 5 MW towers was 100 metres. When diameter restrictions tend to make welded towers uneconomical, the next logical choice is steel shell towers with bolted friction

  5. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

  6. Ejection Tower Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Ejection Tower Facility's mission is to test and evaluate new ejection seat technology being researched and developed for future defense forces. The captive and...

  7. Tubular closure mechanism

    International Nuclear Information System (INIS)

    Kalen, D.D.; Mitchem, J.W.

    1982-01-01

    This invention relates to a closure mechanism for tubular irradiation surveillance specimen assembly holder used in nuclear reactors. The closure mechanism is composed of a latching member which includes a generally circular chamber with a plurality of elongated latches depending therefrom. The latching member circumscribes part of an actuator member which is disposed within the latching member so as to be axially movable. The axial movement of the actuator actuates positioning of the latches between positions in which the latches are locked and secured within the actuator member. Means, capable of being remotely manipulated, are provided to move the actuator in order to position the latches and load the articles within the tube

  8. Transporting method for adsorbing tower and the adsorbing tower

    International Nuclear Information System (INIS)

    Shimokawa, Nobuhiro.

    1996-01-01

    A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)

  9. Cooling towers: a bibliography

    International Nuclear Information System (INIS)

    Whitson, M.O.

    1981-02-01

    This bibliography cites 300 selected references containing information on various aspects of large cooling tower technology, including design, construction, operation, performance, economics, and environmental effects. The towers considered include natural-draft and mechanical-draft types employing wet, dry, or combination wet-dry cooling. A few references deal with alternative cooling methods, principally ponds or spray canals. The citations were compiled for the DOE Energy Information Data Base (EDB) covering the period January to December 1980. The references are to reports from the Department of Energy and its contractors, reports from other government or private organizations, and journal articles, books, conference papers, and monographs from US originators

  10. TacTower

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Jürgensen, Christine

    2009-01-01

    Learning from the multiplayer interaction in sports, we describe our project TacTower; a flexible system for professional elite handball players to train game perception and kinesthetic em- pathy. The design is founded in ideas of Collective Interaction and qualities that is inherent in sport...

  11. Cell Towers and Songbirds

    Science.gov (United States)

    Klosterman, Michelle; Mesa, Jennifer; Milton, Katie

    2009-01-01

    This article describes how our common addiction to cell phones was used to launch a discussion about their use, impacts on the environment, and connections to issues of civic concern. By encouraging middle school science students to adopt the perspectives of special-interest groups debating communication tower restrictions designed to protect…

  12. Talking Towers, Making Withs.

    Science.gov (United States)

    Lemke, J. L.

    The notion of a linguistic "register" is useful in posing questions about how the ways language is used differ from one kind of human activity to another. This paper analyzes a videotaped segment of male grade 4/5 students (n=3) who are talking as they work to build a tower from plastic drinking straws and pins. Discussion of the…

  13. A drilling rig tower

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, A.A.; Barashkov, V.A.; Bulgakov, E.S.; Kuldoshin, I.P.; Lebedev, A.I.; Papin, N.M.; Rebrik, B.M.; Sirotkin, N.V.

    1981-05-23

    Presentation is made of a drilling rig tower, comprising a gantry, a support shaft with a bracing strut and drawings out, and turn buckles. In order to increase the reliability of the tower in operation, to decrease the over all dimensions in a transport position, and to decrease the amount of time taken to transfer the tower from an operational position into a transportable one, and vice versa, the tower is equipped with a rotary frame made in the form of a triangular prism, whose lateral edges are connected by hinges: the first one with the lower part of the support shaft, the second with the gantry, and the third one to the upper part of the support shaft by means of the drawings out. The large boundary of the rotary frame is connected by a hinge to the support shaft by means of a bracing strut, which is equipped with a slide block connected to it by a hinge, and the rotary frame has a guide for the slide block reinforced to it on the large boundary. Besides this, the lateral edge of the rotary frame is connected to the gantry by means of turn buckles.

  14. TacTower

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Jürgensen, Christine

    2009-01-01

    Learning from the multiplayer interaction in sports, we describe our project TacTower; a flexible system for professional elite handball players to train game perception and kinesthetic em- pathy. The design is founded in ideas of Collective Interaction and qualities that is inherent in sport...... and is based on consid- erations about paralanguage, kinesthetic emphatic interaction, physical positioning of players and collaborative interaction....

  15. Expandable tubulars for use in geologic structures

    Science.gov (United States)

    Spray, Jeffery A.; Svedeman, Steven; Walter, David; Mckeighan, Peter; Siebanaler, Shane; Dewhurst, Peter; Hobson, Steven; Foss, Doug; Wirz, Holger; Sharpe, Aaron; Apostal, Michael

    2014-08-12

    An expandable tubular includes a plurality of leaves formed from sheet material that have curved surfaces. The leaves extend around a portion or fully around the diameter of the tubular structure. Some of the adjacent leaves of the tubular are coupled together. The tubular is compressed to a smaller diameter so that it can be inserted through previously deployed tubular assemblies. Once the tubular is properly positioned, it is deployed and coupled or not coupled to a previously deployed tubular assembly. The tubular is useful for all types of wells and boreholes.

  16. Tubular closure mechanism

    International Nuclear Information System (INIS)

    Kalen, D.D.; Mitchem, J.W.

    1981-01-01

    An apparatus is provided for closing the bore of a tube and releasably securing articles within the tube under longitudinal load. A latching member has a cylindrical section and several circumferentially-spaced elongated latches hanging down from one end of the cylinder. An elongated actuator has integral cam and spline and is partly located within the latch with the cam radially contacting the latches and the spline projecting into the circumferential spaces between the latches. The actuator is axially movable between a position in which the latches are locked to the tube walls and a position in which the latches are secured from contact with the tube walls. Means are provided for axially moving the actuator such that the cam positions the latches; and means are also provided for engaging the articles within the tube. The closure is particularly applicable to tubular irradiation surveillance specimen assembly holders used in reactors

  17. Dynamic testing of NOVA laser switchyard tower

    International Nuclear Information System (INIS)

    Weaver, H.J.; Pastrnak, J.W.; Fields, D.E.

    1984-01-01

    NOVA is the latest in a series of powerful laser systems designed to study the feasibility of initiating a controlled fusion reaction by concentrating several laser beams on a small fuel target. The laser components, turning mirrors and target chamber are all mounted on large steel frame structures. These structures were first analyzed via finite element models to access their seismic integrity as well as their overall vibrational stability. When construction was completed, a modal analysis was performed on the structures to verify and improve the finite element models. This report discusses the linking of the analytical and experimental studies for the NOVA switchyard tower structure

  18. Solar tower enhanced natural draft dry cooling tower

    Science.gov (United States)

    Yang, Huiqiang; Xu, Yan; Acosta-Iborra, Alberto; Santana, Domingo

    2017-06-01

    Concentrating Solar Power (CSP) plants are located in desert areas where the Direct Normal Irradiance (DNI) value is very high. Since water resource is scarcely available, mechanical draft cooing technology is commonly used, with power consumption of mechanical fans being approximately 2% of the total power generated. Today, there is only one solar power plant (Khi Solar One in South Africa) uses a condenser installed in a Natural Draft Cooling (NDC) tower that avoids the windage loss of water occurring in wet cooling towers. Although, Khi Solar One is a cavity receiver power tower, the receivers can be hung onto the NDC tower. This paper looks at a novel integration of a NDC tower into an external molten salt receiver of a solar power plant, which is one of a largest commercial molten salt tower in China, with 100MWe power capacity. In this configuration study, the NDC tower surrounds the concrete tower of the receiver concentrically. In this way, the receiver concrete tower is the central support of the NDC tower, which consists of cable networks that are fixed to the concrete tower and suspended at a certain height over the floor. The cable networks support the shell of the NDC tower. To perform a preliminary analysis of the behavior of this novel configuration, two cases of numerical simulation in three dimensional (3D) models have been solved using the commercial Computational Fluid Dynamics (CFD) code, ANSYS Fluent 6.3. The results show that the integration of the NDC tower into an external central receiver tower is feasible. Additionally, the total heat transfer rate is not reduced but slightly increases when the molten salt receiver is in operation because of the additional natural draft induced by the high temperature of the receiver.

  19. Good Towers of Function Fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Nguyen, Nhut

    2014-01-01

    In this paper, we will give an overview of known and new techniques on how one can obtain explicit equations for candidates of good towers of function fields. The techniques are founded in modular theory (both the classical modular theory and the Drinfeld modular theory). In the classical modular...... setup, optimal towers can be obtained, while in the Drinfeld modular setup, good towers over any non-prime field may be found. We illustrate the theory with several examples, thus explaining some known towers as well as giving new examples of good explicitly defined towers of function fields....

  20. Improve crossflow cooling tower operation

    International Nuclear Information System (INIS)

    Burger, R.

    1989-01-01

    This paper reports how various crossflow cooling tower elements can be upgraded. A typical retrofit example is presented. In the past decade, cooling tower technology has progressed. If a cooling tower is over ten years old, chances are the heat transfer media and mechanical equipment were designed over 30 to 40 years ago. When a chemical plant expansion is projected or a facility desires to upgrade its equipment for greater output and energy efficiency, the cooling tower is usually neglected until someone discovers that the limiting factor of production is the quality of cold water returning from the cooling tower

  1. Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

    Science.gov (United States)

    Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

    2018-02-01

    Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

  2. Experimental Investigation on Strengthening of Bolted Connections in Transmission/Communication Towers

    Science.gov (United States)

    Balagopal, R.; Prasad Rao, N.; Rokade, R. P.; Umesha, P. K.

    2018-06-01

    Due to increase in demand for power supply and increase in bandwidth for communication industry, the existing transmission line (TL) and communication towers needs to be strengthened. The strengthening of existing tower is economical rather than installation of new towers due to constraints in acquisition of land. The size of conductors have to be increased or additional number of antenna needs to be installed in existing TL/communication tower respectively. The compression and tension capacity of members in the existing towers have to be increased to sustain the additional loads due to wind and self-weight of these components. The tension capacity enhancement of existing angle sections in live line condition without power shut-down is a challenging task. In the present study, the use of Glass Fiber Reinforced Plastic (GFRP) plate/angle sections is explored to strengthen existing bolted connections in TL/communication towers. Experimental investigation conducted at component level on strengthening of existing two types of single cover steel butt joint, one made of steel plate and another joint made of steel angle sections respectively. First series of experiment conducted on strengthening the connection using GFRP plate/cleat angle sections. The second series of strengthening experiment is conducted using steel plate/angle sections to replace GFRP sections. The load sharing behaviour of strengthened GFRP and steel section is compared and suitable recommendations are given.

  3. Wind turbine generator application places unique demands on tower design and materials

    Science.gov (United States)

    Kita, J. P.

    1978-01-01

    The most relevant contractual tower design requirements and goal for the Mod-1 tower are related to steel truss tower construction, cost-effective state-of-the-art design, a design life of 30 years, and maximum wind conditions of 120 mph at 30 feet elevation. The Mod-1 tower design approach was an iterative process. Static design loads were calculated and member sizes and overall geometry chosen with the use of finite element computer techniques. Initial tower dynamic characteristics were then combined with the dynamic properties of the other wind turbine components, and a series of complex dynamic computer programs were run to establish a dynamic load set and then a second tower design.

  4. TacTowers

    DEFF Research Database (Denmark)

    Ludvigsen, Martin; Fogtmann, Maiken Hillerup; Grønbæk, Kaj

    2010-01-01

    The interactive training equipment, TacTower, is aimed at supporting multiple elite athletes, such as handball players in training their micro-tactical skills in close-contact situations. It focuses on psychomotor abilities and trains the skills involved in reading the opponents’ actions and anti...... for the elite athletic community, as this domain holds interesting challenges while also inspiring relevant, new forms of interaction design for other domains....

  5. Cooling tower and environment

    International Nuclear Information System (INIS)

    Becker, J.; Ederhof, A.; Gosdowski, J.; Harms, A.; Ide, G.; Klotz, B.; Kowalczyk, R.; Necker, P.; Tesche, W.

    The influence of a cooling tower on the environment, or rather the influence of the environment on the cooling tower stands presently -along with the cooling water supply - in the middle of much discussion. The literature on these questions can hardly be overlooked by the experts concerned, especially not by the power station designers and operators. The document 'Cooling Tower and Environment' is intented to give a general idea of the important publications in this field, and to inform of the present state of technology. In this, the explanations on every section make it easier to get to know the specific subject area. In addition to older standard literature, this publication contains the best-known literature of recent years up to spring 1975, including some articles written in English. Further English literature has been collected by the ZAED (KFK) and is available at the VGB-Geschaefsstelle. Furthermore, The Bundesumweltamt compiles the literature on the subject of 'Environmental protection'. On top of that, further documentation centres are listed at the end of this text. (orig.) [de

  6. Tubular nanostructured materials for bioapplications

    Science.gov (United States)

    Xie, Jining; Chen, Linfeng; Srivatsan, Malathi; Varadan, Vijay K.

    2009-03-01

    Tubular nanomaterials possess hollow structures as well as high aspect ratios. In addition to their unique physical and chemical properties induced by their nanoscale dimensions, their inner voids and outer surfaces make them ideal candidates for a number of biomedical applications. In this work, three types of tubular nanomaterials including carbon nanotubes, hematite nanotubes, and maghemite nanotubes, were synthesized by different chemical techniques. Their structural and crystalline properties were characterized. For potential bioapplications of tubular nanomaterials, experimental investigations were carried out to demonstrate the feasibility of using carbon nanotubes, hematite nanotubes, and maghemite nanotubes in glucose sensing, neuronal growth, and drug delivery, respectively. Preliminary results show the promise of tubular nanomaterials in future biomedical applications.

  7. Influence of building and supply conditions on coolant pumps and the various coolant pump designs for cooling towers

    International Nuclear Information System (INIS)

    Holzhueter, E.; Migod, A.; Siekmann, H.

    1977-01-01

    This contribution tries to present the various factors influencing the design of cooling tower pumps. As cooling tower pumps are very often designed as concrete speral casing pumps, the suction bend construction often offers itself. The running wheel of cooling tower pumps is usually of semi-axial design, whereby one has to differ between rigid, adjustable, and resetable running wheels. Finally, the type of cooling system and the nominal width are decisive for either the construction type of the spiral casing pump or the tubular type pump. Both methods are compared in a critical way. (orig.) [de

  8. Induced draught circular cooling tower

    International Nuclear Information System (INIS)

    Blanquet, J.C.

    1980-01-01

    Induced draught atmospheric cooling towers are described, to wit those in which the circulation is by power fans. This technique with fans grouped together in the centre enables a single tower to be used and provides an excellent integration of the steam wreath into the atmosphere. This type of cooling tower has been chosen for fitting out two 900 MW units of the Chinon power station in France [fr

  9. Cooling Tower Losses in Industry

    OpenAIRE

    Barhm Mohamad

    2017-01-01

    Cooling towers are a very important part of many chemical plants. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling.

  10. Towers of hybrid mesons

    International Nuclear Information System (INIS)

    Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

    2009-01-01

    A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

  11. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  12. 77 FR 34013 - Certain Oil Country Tubular Goods From the People's Republic of China: Preliminary Results of the...

    Science.gov (United States)

    2012-06-08

    ...\\ Moreover, U.S. Steel contends that financial statements will show that that surrogate financial ratios can... financial ratios.\\26\\ \\24\\ See Letter from U.S. Steel, ``Oil Country Tubular Goods from the People's... whether financial ratios reflect labor expenses that are included in other elements of the respondent's...

  13. Mechanical properties of API X80 steel pipe joints welded by Flux Core Arc Weld Process; Propriedades mecanicas de juntas de tubos de aco API X80 soldadas com arame tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, Robert E. Cooper; Silva, Jose Hilton F.; Trevisan, Roseana E. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Fabricacao

    2003-07-01

    Flux Core Arc Welding processes (FCAW) are beginning to be applied in pipeline welds, however, very limited experimental data regarding mechanical properties of pipeline weld joints with these processes are available in the literature. In this paper, the effects of preheat temperature and type of FCAW on mechanical properties (microhardness and tensile strength) of API X80 weld joint steel are presented. FCAW processes with gas protection and self-shielded were used. Multipasses welding were applied in 30'' diameter and 0,625'' thickness tubes. Influence factors were: FCAW type and preheat temperature. Acceptance criteria of welded joints were evaluated by API 1104 standard for tensile strength test and ASTM E384-99 for microhardness test. The results obtained showed that FCAW type and preheat temperature have no influence on mechanical properties of API X80 joint steel. (author)

  14. Modification of the colony tower for the Rio Blanco detonation

    International Nuclear Information System (INIS)

    Blume, J.A.; Freeman, S.A.; Honda, K.K.; Lee, L.A.

    1975-01-01

    Supplemental structural bracing was designed and installed for the 180-ft-tall Colony Tower, an experimental oil shale processing retort structure, in anticipation of its lateral response to the Rio Blanco detonation. The tower is a steel structure with both horizontal and vertical diagonal bracing. Data obtained from the earlier Project Rulison detonation indicated that an evaluation study was necessary. Design criteria that would provide an adequate margin of safety were developed based on predicted Rio Blanco ground motion. The evaluation of the unmodified structure showed that several bracing members would be subjected to forces exceeding their yield strength, and some would reach a level at which failure could occur. Further analyses were made with assumed modified bracing members. A final scheme for modified vertical bracing was established and installed. After modification, the response of the tower during the Rio Blanco detonation was measured by instruments on the ground and at various locations on the tower, and no evidence of damage was discovered. The modification of the Colony Tower and the procedures used to determine these modifications show the usefulness of current ground motion and structural response prediction technology for forecasting dynamic behavior of important structures subjected to ground motion from underground nuclear explosions. (auth)

  15. EDF's ageing management program for cooling towers

    International Nuclear Information System (INIS)

    Roure, T.; Crolet, Y.

    2015-01-01

    EDF operates a large fleet of cooling towers for its thermal and nuclear plants. Proactive maintenance strategies require ranking the towers according to the risk of failure and the observed damage. The ranking includes monitoring data such as: foundation settlements, material properties, quantified crack patterns, shell deformation, meteorological data, and corrosion. The numerical tool suite includes a finite element analysis of each tower under thermal and mechanical loadings and a corrosion predicting tool, based on carbonation. The first module computes the behavior of cooling towers under five types of loading: soil differential settlement, self-weight, moisture transport, temperature and wind. By comparison with the ultimate resisting capacity of the reinforced concrete cross section, a risk index map is produced for each tower. This risk index is used to rank the cooling towers and then to identify which structures should be monitored more closely or reinforced - if needed - first in the case of an extended operating life. The second module aims to anticipate the corrosion depth of reinforcement steel of the towers in the future. Examination of the existing carbonation is currently done for each structure and evolution of the carbonation depth is computed so as to predict with reasonable assurance when carbonation reaches the rebars. A prediction of the eventual cross-section loss of rebars is then made for long term analysis (i.e. up to 60 years of operating life). When corrosion is predicted the first module takes into account this loss and computes the behavior of the predicted corrosion damaged structure under the same loadings. (authors)

  16. Cooling towers principles and practice

    CERN Document Server

    Hill, G B; Osborn, Peter D

    1990-01-01

    Cooling Towers: Principles and Practice, Third Edition, aims to provide the reader with a better understanding of the theory and practice, so that installations are correctly designed and operated. As with all branches of engineering, new technology calls for a level of technical knowledge which becomes progressively higher; this new edition seeks to ensure that the principles and practice of cooling towers are set against a background of up-to-date technology. The book is organized into three sections. Section A on cooling tower practice covers topics such as the design and operation of c

  17. You're a What?: Tower Technician

    Science.gov (United States)

    Vilorio, Dennis

    2012-01-01

    In this article, the author talks about the role and functions of a tower technician. A tower technician climbs up the face of telecommunications towers to remove, install, test, maintain, and repair a variety of equipment--from antennas to light bulbs. Tower technicians also build shelters and radiofrequency shields for electronic equipment, lay…

  18. 45-FOOT HIGH DROP TOWER

    Data.gov (United States)

    Federal Laboratory Consortium — The Drop Tower is used to simulate and measure the impact shocks that are exerted on parachute loads when they hit the ground. It is also used for HSL static lift to...

  19. The Design of Akhmat Tower

    Science.gov (United States)

    Beardsley, Sara; Stochetti, Alejandro; Cerone, Marc

    2018-03-01

    Akhmat Tower is a 435m supertall building designed by Adrian Smith + Gordon Gill Architecture. It is currently under construction in the city of Grozny, in the Chechen Republic, in the North Caucasus region of Russia. The design of the tower was done during a collaborative process by a multi-disciplinary architectural and engineering team, based primarily in the United States and Russia. During this process, the designers considered many factors including, most primarily, the cultural and historical context, the structural requirements given the high seismicity of the region, and the client's programmatic needs. The resulting crystalline-shaped tower is both an aesthetic statement and a performative architectural solution which will be a new landmark for Chechnya. "The Design of Akhmat Tower" describes in detail the design process including structural considerations, exterior wall design, building program, interior design, the tuned mass damper, and the use of building information modeling.

  20. Allegheny County Cell Tower Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset portrays cell tower locations as points in Allegheny County. The dataset is based on outbuilding codes in the Property Assessment Parcel Database used...

  1. Evaluation of performance of AISI 444 steel for application in distillation towers; Avaliacao do desempenho do aco AISI 444 para aplicacao como 'lining' em torres de destilacao

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, R.F.; Miranda, H.C. de; Farias, J.P. [Universidade Federal do Ceara (DEMM/UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Metalurgica e de Materiais. Lab. de Caracterizacao de Materiais], e-mail: rf.guimaraes@yahoo.com.br

    2008-07-01

    In this work, the behavior of the AISI 444 ferritic stainless steel submitted to thermal fatigue test and their corrosion resistance in heavy crude oil was evaluated. The AWS E309MoL-16 and E316L-17 weld metal was employed as filler metal. Plates of the AISI 444 were welded on ASTM A-516 Gr. 60 plates and submitted to fatigue thermal cycle. Samples were extracted from plates welded and heat treated immersed in heavy crude oil at 300 deg C. Optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive of X-ray analysis (EDX) were used to characterize the microstructure and the corroded surface. The results show that the AISI 444 stainless steels did not present cracks after the thermal fatigue cycle and the heat treated immerse in heavy crude oil. The electrode AWS E309MoL-16 show better corrosion resistance than the AWS E316L-17. (author)

  2. Studies of column supported towers

    International Nuclear Information System (INIS)

    Chauvel, D.; Costaz, J.-L.

    1991-01-01

    As a result of a research and development programme into the civil engineering of cooling towers launched in 1978 by Electricite de France, very high cooling towers were built at Golfech and Chooz, in France, using column supports. This paper discusses the evolution of this new type of support from classical diagonal supports, presents some of the results of design calculations and survey measurements taken during construction of the shell and analyses the behaviour of the structure. (author)

  3. Research Based on the Acoustic Emission of Wind Power Tower Drum Dynamic Monitoring Technology

    Science.gov (United States)

    Zhang, Penglin; Sang, Yuan; Xu, Yaxing; Zhao, Zhiqiang

    Wind power tower drum is one of the key components of the wind power equipment. Whether the wind tower drum performs safety directly affects the efficiency, life, and performance of wind power equipment. Wind power tower drum in the process of manufacture, installation, and operation may lead to injury, and the wind load and gravity load and long-term factors such as poor working environment under the action of crack initiation or distortion, which eventually result in the instability or crack of the wind power tower drum and cause huge economic losses. Thus detecting the wind power tower drum crack damage and instability is especially important. In this chapter, acoustic emission is used to monitor the whole process of wind power tower drum material Q345E steel tensile test at first, and processing and analysis tensile failure signal of the material. And then based on the acoustic emission testing technology to the dynamic monitoring of wind power tower drum, the overall detection and evaluation of the existence of active defects in the whole structure, and the acoustic emission signals collected for processing and analysis, we could preliminarily master the wind tower drum mechanism of acoustic emission source. The acoustic emission is a kind of online, efficient, and economic method, which has very broad prospects for work. The editorial committee of nondestructive testing qualification and certification of personnel teaching material of science and technology industry of national defense, "Acoustic emission testing" (China Machine Press, 2005.1).

  4. Push-Pull Ventilation in a Painting Shop for Large Steel Constructions

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per

    This paper describes the analysis of a push-pull ventilation system for a painting shop that is used for painting steel chimneys and windmill towers.......This paper describes the analysis of a push-pull ventilation system for a painting shop that is used for painting steel chimneys and windmill towers....

  5. The Design of Akhmat Tower

    Directory of Open Access Journals (Sweden)

    Beardsley Sara

    2018-01-01

    Full Text Available Akhmat Tower is a 435m supertall building designed by Adrian Smith + Gordon Gill Architecture. It is currently under construction in the city of Grozny, in the Chechen Republic, in the North Caucasus region of Russia. The design of the tower was done during a collaborative process by a multi-disciplinary architectural and engineering team, based primarily in the United States and Russia. During this process, the designers considered many factors including, most primarily, the cultural and historical context, the structural requirements given the high seismicity of the region, and the client’s programmatic needs. The resulting crystalline-shaped tower is both an aesthetic statement and a performative architectural solution which will be a new landmark for Chechnya. “The Design of Akhmat Tower” describes in detail the design process including structural considerations, exterior wall design, building program, interior design, the tuned mass damper, and the use of building information modeling.

  6. Assessment of cooling tower impact

    International Nuclear Information System (INIS)

    1986-01-01

    This guideline describes the state of the art of the meteorological impact of wet cooling towers that are about 80 m to 170 m high, and have a waste heat power in the range of 1000 MW and 2500 MW. The physical processes occurring in the lowest layer of the atmosphere and their impact in the dispersion of cooling tower emissions are represented. On the basis of these facts, the impact on weather or climate in the vicinity of a high wet cooling tower is estimated. Thereby the results of the latest investigations (observations, measurements, and modeling) on the different locations of plants as well as their different power and construction types are taken into consideration. (orig.) [de

  7. Round Earthen Towers in Zhangzhou

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The round earthen towers inZhangzhou,Fujifan Province,have long been famous a-round the world.Built of rammedearth,each tower consists uf four tofive stories and Is nearly 100 metersin diameter and 17 to 18meters high.Scatteredaround the mountains,valleys and plains insouthwestern Fujian,thetowers look very muchlike round castles.SomeChinese and foreign ar-chitercts,historians andfolk-custom researcherscall them“flyng sau-cers”from outer spaceor“mushrooms”fromearth.They represent,indeed,a unique archi-tectural style in theworld.

  8. Cooling towers in the landscape

    International Nuclear Information System (INIS)

    Boernke, F.

    1977-01-01

    The cooling tower as a large technical construction is one of the most original industrial buildings. It sticks out as an outlandish element in our building landscape, a giant which cannot be compared with the traditional forms of technical buildings. If it is constructed as a reinforced-concrete hyperboloid, its shape goes beyond all limits of building construction. Judgment of these highly individual constructions is only possible by applying a novel standard breaking completely with tradition. This new scale of height and dimension in industrial construction, and in particular the modern cooling tower, requires painstaking care and design and adaptation to the landscape around it. (orig.) [de

  9. Windfarms and telecommunications towers (Scotland)

    International Nuclear Information System (INIS)

    Munro, Hector; Kellett-Bowman, Elaine; Harris, David

    1996-01-01

    A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

  10. Dynamic analysis of cooling towers

    International Nuclear Information System (INIS)

    Bittnar, Z.

    1987-01-01

    Natural draught cooling towers are shell structures subjected to random vibrations due to wind turbulence and earthquake. The need of big power plant units has initiated the design of very large cooling towers. The random response of such structures may be analysed using a spectral approach and assuming a linear behaviour of the structure. As the modal superposition method is the most suitable procedure for this purpose it is necessary to determine the natural frequencies and mode shapes with adequate accuracy. (orig./GL)

  11. Windfarms and telecommunications towers (Scotland)

    Energy Technology Data Exchange (ETDEWEB)

    Munro, Hector; Kellett-Bowman, Elaine; Harris, David [and others

    1996-10-30

    A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

  12. A construction method of reinforced-concrete very high stacks and natural draft cooling towers

    International Nuclear Information System (INIS)

    Miyamoto, Takao; Hosokawa, Osamu

    1978-01-01

    The new Shimizu flex-lip system was developed by the Shimizu Construction Co., Ltd. for constructing very high (about 200 m) towers made of reinforced concrete. Utilizing this system, towers of any shape, circular, triangular, square and polygonal, can be constructed. The wall thickness can be varied from 200 mm to 1 m. The diameter of towers can be enlarged from 3 m to any valve and the inclination of tower walls can be designed in any way between +1/5 and -1/5. The advantage of this system is to use the jack down mechanism, to test concrete strength without sampling, to reduce the connections of reinforcing steel bars and to adopt the continuous, and to use automatic measuring system using laser for checking up positional error. The design and analysis of high tower structures were systemized and automated with the development of the flex-lip construction method. The several past records of having applied this method to industrial areas are shown. As for natural draft cooling towers, the Shimizu jump-up system has been studied for the cooling water capacity of 60,000 m 3 /h. The towers are 120 m high, 110 m in diameter at the bottom and 65 m in diameter at the top. The advantage of this construction method, the plan of concrete jump-up and the construction test are explained. (Nakai, Y.)

  13. Modified tubularized incised plate urethroplasty

    Directory of Open Access Journals (Sweden)

    Shivaji Mane

    2013-01-01

    Full Text Available Aim: To share our experience of doing tubularized incised plate urethroplasty with modifications. Materials and Methods: This is a single surgeon personal series from 2004 to 2009. One hundred patients of distal hypospadias were subjected for Snodgrass urethroplasty with preputioplasty. The age range was 1 to 5 year with mean age of 2.7 years. Selection criteria were good urethral plate, without chordee and torsion needing complete degloving. Main technical modification from original Snodgrass procedure was spongioplasty, preputioplasty, and dorsal slit when inability to retract prepuce during surgery. Results: Average follow-up period is 23 months. Seven (7% patients developed fistula and one patient had complete preputial dehiscence. Phimosis developed in three (3% patients and required circumcision. Dorsal slit was required in seven patients. One patient developed meatal stenosis in postoperative period. All other patients are passing single urinary stream and have cosmesis that is acceptable. Conclusions: Modified tubularized incised plate urethroplasty with preputioplasty effectively gives cosmetically normal looking penis with low complications.

  14. A modular interpretation of various cubic towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Bassa, Alp; Beelen, Peter

    2017-01-01

    In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound.......In this article we give a Drinfeld modular interpretation for various towers of function fields meeting Zink's bound....

  15. Cooling towers for thermal power plants

    International Nuclear Information System (INIS)

    Chaboseau, J.

    1987-01-01

    After a brief recall on cooling towers testing and construction, this paper presents four examples of very large French nuclear power plant cooling towers, and one of an Australian thermal power plant [fr

  16. Dynamic interaction effects in cooling tower groups

    International Nuclear Information System (INIS)

    Riera, J.D.

    1984-01-01

    A theoretical and experimental determination of the dynamic response of reinforced concrete cooling towers, taking into consideration group effects, are described. The results for an individual tower are thoroughly examined. A complete analysis is then performed for the critical wind orientations, for each tower in a six towers group. It's shown that ignoring group effects in the analysis may lead to a significant underestimation of the structural response. (E.G.) [pt

  17. Dwelling towers of Czech castles

    Czech Academy of Sciences Publication Activity Database

    Durdík, Tomáš

    2009-01-01

    Roč. 63, - (2009), s. 139-150 ISSN 1875-2896. [Meeting of Europa Nostra Scientific Council /44./. Kilkenny, 27.09.2008-02.10.2008] Institutional research plan: CEZ:AV0Z80020508 Keywords : castle * castellology * dwelling tower * donjon * keep * medieval archaeology * architecture * Bohemia * Middle Ages Subject RIV: AC - Archeology, Anthropology, Ethnology

  18. Mobile Tower Radiation Protection System

    Directory of Open Access Journals (Sweden)

    Jabbar Slman Hussein

    2017-12-01

    Full Text Available Clean environment is one of the most necessarily needs for Human life. So what about mobile effect and its towers pollution? It's effect on public health? Effect of huge groan of mobile networks. In counting of these dangers that will harm us from mobile towers in the far run, was the reasons for writing this research, came this study to look at the mobile towers and mobile effects possible health harm for the purpose of diagnosis of these effects and to suggest ways that can be used to avoid or minimize the risks.  Faraday Cage, is the solution suggested here, also there are many other solutions for this problem, a Faraday cage is a metallic enclosure that stops the entry or escape of an EM field. Also, two experiments are accomplished, first one showing the effect of Faraday cage on preventing the EMR from mobile cellphone, and the second  experiment gives the effect of Faraday cage on preventing the EMR from mobile tower EMR on human health listed in the research, that have been done by using conducting shell (grid design according the EM wavelength used by three company's mobile working in Iraq, the result show good isolations.

  19. Tubular lining material for pipelines having bends

    Energy Technology Data Exchange (ETDEWEB)

    Moringa, A.; Sakaguchi, Y.; Hyodo, M.; Yagi, I.

    1987-03-24

    A tubular lining material for pipelines having bends or curved portions comprises a tubular textile jacket made of warps and wefts woven in a tubular form overlaid with a coating of a flexible synthetic resin. It is applicable onto the inner surface of a pipeline having bends or curved portions in such manner that the tubular lining material with a binder onto the inner surface thereof is inserted into the pipeline and allowed to advance within the pipeline, with or without the aid of a leading rope-like elongated element, while turning the tubular lining material inside out under fluid pressure. In this manner the tubular lining material is applied onto the inner surface of the pipeline with the binder being interposed between the pipeline and the tubular lining material. The lining material is characterized in that a part of all of the warps are comprised of an elastic yarn around which, over the full length thereof, a synthetic fiber yarn or yarns have been left-and/or right-handedly coiled. This tubular lining material is particularly suitable for lining a pipeline having an inner diameter of 25-200 mm and a plurality of bends, such as gas service pipelines or house pipelines, without occurrence of wrinkles in the lining material in a bend.

  20. Atmospheric emissions from power plant cooling towers

    International Nuclear Information System (INIS)

    Micheletti, W.

    2006-01-01

    Power plant recirculated cooling systems (cooling towers) are not typically thought of as potential sources of air pollution. However, atmospheric emissions can be important considerations that may influence cooling tower design and operation. This paper discusses relevant U.S. environmental regulations for potential atmospheric pollutants from power plant cooling towers, and various methods for estimating and controlling these emissions. (orig.)

  1. Cooling tower modification for intermittent operation

    International Nuclear Information System (INIS)

    Midkiff, W.S.

    1975-03-01

    One of the cooling towers at Los Alamos Scientific Laboratory is being operated intermittently. The cooling tower has been modified to restrict air flow and to keep the tower from drying out. The modifications are relatively inexpensive, simple to operate, and have proved effective. (U.S.)

  2. Dry cross-flow cooling tower

    Energy Technology Data Exchange (ETDEWEB)

    Fordyce, H E

    1975-01-23

    The invention deals with dry cooling towers in particular a circular cooling tower of the mechanical-draught construction whose operating characteristics should be independent of the wind direction. The recycling of the hot air should be as low as possible without necessitating high fan or natural-draught shafts, so that the costs of the tower can be brought down to a minimum.

  3. Tubular inverse opal scaffolds for biomimetic vessels

    Science.gov (United States)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  4. Plant Vogtle cooling tower studies

    International Nuclear Information System (INIS)

    O'Steen, L.

    2000-01-01

    Intensive ground-based field studies of plumes from two large, natural-draft cooling towers were conducted in support of the MTI modeling effort. Panchromatic imagery, IR imagery, meteorological data, internal tower temperatures and plant power data were collected during the field studies. These data were used to evaluate plume simulations, plume radioactive transfer calculations and plume volume estimation algorithms used for power estimation. Results from six field studies indicate that a 3-D atmospheric model at sufficient spatial resolution can effectively simulate a cooling tower plume if the plume is of sufficient size and the ambient meteorology is known and steady. Small plumes and gusty wind conditions degrade the agreement between the simulated and observed plumes. Thermal radiance calculations based on the simulated plumes produced maximum IR temperatures (near tower exit) which were in good agreement with measured IR temperatures for the larger plumes. For the smaller plumes, the calculated IR temperature was lower than the measured temperature by several degrees. Variations in maximum IR plume temperature with decreasing power (one reactor was undergoing a shutdown process), were clearly observed in the IR imagery and seen in the simulations. These temperature changes agreed with those calculated from an overall tower energy and momentum balance. Plume volume estimates based on camcorder images at three look angles were typically 20--30 percent larger than the plume volumes derived from the simulations, although one estimate was twice the simulated volume. Volume overestimation is expected and will have to be accounted for to some degree if plume volume is to be a useful diagnostic quantity in power estimation. Volume estimation with MTI imagery will require a large, stable plume and two looks in the visible bands (5m GSD) along with a solar shadow

  5. Origin and prevention of infection with Legionella pneumophila through cooling towers and evaporative cooling towers

    International Nuclear Information System (INIS)

    Schulze-Roebbecke, R.

    1994-01-01

    Evaporative cooling towers and industrial ventilator cooling towers have repeatedly been described as the origin of Legionnaires' disease. This article describes the design and function of cooling towers and evaporative cooling towers, sums up knowledge on the colonization of such systems with Legionella pneumophila, and describes conditions permitting the transmission of Legionella. Furthermore, design, maintenance, cleaning and disinfection measures are indicated which are believed to reduce the risk of infection through industrial and evaporative cooling towers. (orig.) [de

  6. Development of small-size transmission tower erection method; Kogata tetto kumitate koho no kaihatsu kenkyu (gaibushiki crane ni yoru kogata tetto kumitate koho no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Matsuishi, S.; Asano, J.; Koji, Y. [Kansai Electric Power Co. Inc., Osaka (Japan); Tsujimura, I.; Teramoto, A. [The Kanden Kogyo Incorporated, Osaka (Japan); Sasaki, T.; Mito, K. [AG Ajikawa Corp., Osaka (Japan); Tsuji, M.; Fukumoto, T.; Yamaguchi, N.

    1997-09-30

    To reduce the construction period and cost and to enhance the safety during 77 kV-class transmission tower election, a new method of small steel transmission tower erection using an external type crane has been developed. For the selection of cranes, a commercially available self-climbing crane was employed which has an operating radius of 11 m, a lifting load capacity of 1.5 t, and a lift of up to 60 m. For the space analysis using a model tower, various supporting methods with horizontal supporting members, stress analysis for each tower stub, and apparatuses were examined. For the demonstration tests of election using the model tower, strain gages were attached at each point of steel tower, crane and horizontal supporting members, to measure the stress of members at each stage of the election. It was confirmed that there were no problems. For the election of actual steel tower, the practicality of this method was compared with that of conventional methods. The construction period was reduced in 20%, and the cost was reduced in 4%. The safety of this method was drastically enhanced due to the lack of moving on the tower and less manual operation. 9 figs., 1 tab.

  7. Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

    2011-04-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

  8. Hybrid Tower, Designing Soft Structures

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin; Holden Deleuran, Anders

    2015-01-01

    and constraint solvers and more rigorous Finite Element methods supporting respectively design analysis and form finding and performance evaluation and verification. The second investigation describes the inter-scalar feedback loops between design at the macro scale (overall structural behaviour), meso scale...... (membrane reinforcement strategy) and micro scale (design of bespoke textile membrane). The paper concludes with a post construction analysis. Comparing structural and environmental data, the predicted and the actual performance of tower are evaluated and discussed....

  9. Tubular bioreactor and its application; Tubular bioreactor to sono tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, I.; Nagamune, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yuki, K. [Nikka Whisky Distilling Co. Ltd. Tokyo (Japan); Inaba, H. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1994-09-05

    The loop type tubular bioreactor (TBR) was developed where biocatalysts are trapped in the reactor by membrane module. A UF membrane or MF membrane and crossflow filtration were adopted for the membrane module, and the reactor loop was composed of four membrane modules. The reactor was operated at 2-4 m/s in membrane surface velocity and 300-400 kPa in filtration pressure. As the result of the high-density culture of lactic acid bacteria and yeast, a biomass concentration was more than 10 times that in batch culture, suggesting the remarkable enhancement of a production efficiency. As the result of the continuous fermentation of cider, the fast fermentation more than 60 times that in conventional ones was obtained together with the same quality as conventional ones. Such a fast fermentation was probably achieved by yeast suspended in the fermenter of TBR, by yeast hardly affected physico-chemically as compared with immobilized reactors, and by small effect of mass transfer on reaction systems. 4 refs., 6 figs.

  10. Sicilian Castles and Coastal Towers

    Directory of Open Access Journals (Sweden)

    Kirk Scott

    2017-11-01

    Full Text Available While much attention has been paid to the development of castles as the hallmark architectural symbol of the Middle Ages, less attention has been given to the changes in European defensive strategies that occurred between the 15th and 17th centuries. It was at this time when the modern nations of Europe began to take form, as sea-based trade between distant nations took precedence over land-based trade routes. This paper examines how this transformation manifested in the defensive structures of Sicily, Italy, where the hilltop castles of the Middle Ages gradually gave way to a more cohesive network of coastal towers around the island. Putting this transition in its historical context, presenting an anthropological model from which to view this transition, and using geospatial methods to track these changes, the results of this study indicate that as defensive towers began to dominate the Sicilian coast around the 16th century, their command over the environment was no greater than that of the feudal castles which were still in use. Yet, unlike the castles of feudal lords, these towers represented an island-wide system of defense and the beginning of an adherence to a more centralized power structure then seen previously.

  11. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    International Nuclear Information System (INIS)

    Satake, Norimoto; Sugaya, Yoshinobu; Sugimoto, Tadao

    1976-01-01

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works. (Wakatsuki, Y.)

  12. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sataki, N; Sugaya, Y; Sugimoto, T [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1976-01-01

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works.

  13. Rhabdomyolysis with acute tubular necrosis following occupational inhalation of thinners.

    Science.gov (United States)

    Ngajilo, D; Ehrlich, R

    2017-07-01

    Thinners are mixtures of organic solvents commonly containing toluene, xylene, acetone, hexane, benzene and methyl isobutyl ketone. This report describes a case of rhabdomyolysis with acute tubular necrosis and renal failure, most likely attributable to toluene, following occupational exposure to thinners while cleaning a steel water tank. These adverse health effects have previously been reported following acute poisoning or intentional inhalation by drug abusers, but rarely in the occupational setting. Poor working conditions, lack of health and safety training and delayed treatment contributed to the onset and severity of the patient's complications. This case emphasizes the need for strict control measures, including adequate ventilation, training on working in confined spaces, appropriate personal protective equipment and emergency rescue procedures in such settings. In addition, rhabdomyolysis, acute tubular necrosis and renal failure should be added to safety data material as possible complications of excessive inhalation of thinners. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The concrete technology of post pouring zone of raft foundation of Hongyun Building B tower

    Science.gov (United States)

    Yin, Suhua; Yu, Liu; Wu, Yanli; Zhao, Ying

    2017-08-01

    The foundation of Hongyun building B tower is made of raft board foundation which is 3300mm in the thickness concreted pouring amount of large and the late poured band in the pouring settlement formed. The temperature of the pouring settlement was controlled in order to prevent the crack of the construction of the late poured band. The steel of post pouring band was designed and monitorred. The quality of post pouring band quality is guaranteed in the raft concrete foundation of Hongyun Building B tower.

  15. Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

    Directory of Open Access Journals (Sweden)

    Ana Tobar

    Full Text Available BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03. Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001, a 94% higher Bowman's space volume (P=0.003, a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02 and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01. The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity

  16. Modified corrosion protection coatings for Concrete tower of Transmission line

    Science.gov (United States)

    Guo, Kai; Jing, Xiangyang; Wang, Hongli; Yue, Zengwu; Wu, Yaping; Mi, Xuchun; Li, Xingeng; Chen, Suhong; Fan, Zhibin

    2017-12-01

    By adding nano SiO2 particles, an enhanced K-PRTV anti-pollution flashover coating had been prepared. Optical profile meter (GT-K), atomic force microscopy (AFM) and infrared spectrometer (FT-IR) characterization were carried out on the coating surface analysis. With the use of modified epoxy resin as the base material, the supplemented by phosphate as a corrosion stabilizer, to achieve a corrosion of steel and galvanized steel with rust coating. Paint with excellent adhesion, more than 10MPa (1), resistant to neutral salt spray 1000h does not appear rust point. At the same time coating a large amount of ultra-fine zinc powder can be added for the tower galvanized layer zinc repair function, while the paint in the zinc powder for the tower to provide sacrificial anode protection, to achieve self-repair function of the coating. Compared to the market with a significant reduction in the cost of rust paint, enhance the anti-corrosion properties.

  17. Iatrogenic Digital Compromise with Tubular Dressings

    Directory of Open Access Journals (Sweden)

    Corre, Kenneth A

    2009-08-01

    Full Text Available Objective: This case report describes a digit amputation resulting from an improperly applied tubular dressing. The safe application of digital tubular dressings, and the rationale behind it, is detailed to raise emergency physician (EP awareness.Methods: We present a case report of a recent iatrogenic-induced digit ischemia caused by improperly applied tube gauze. We review the literature on the subject and the likely sources of poor outcomes presented. The proper application of tubular gauze dressings is then outlined.Conclusion: EPs and emergency department personnel must be educated on the safe application of tubular gauze dressings to avoid dire outcomes associated with improper applications.[WestJEM. 2009;10:190-192.

  18. Renal Tubular Function in Systemic Lupus Erythematosus*

    African Journals Online (AJOL)

    immune' diseases such as. Sjogren's syndrome,'" systemic lupus erythematosus. (SLE),3 alveolitis' and chronic active hepatitis.' The reported abnormalities of renal tubular function include impairment of acid excretion and urinary concentration.

  19. A neglected case of Renal Tubular Acidosis

    International Nuclear Information System (INIS)

    Derakhshan, A.; Basiratnia, M.; Fallahzadeh, M.H.; Al-Hashemi, G.H.

    2007-01-01

    In this report, we present a case of a child with distal renal tubular acidosis, severe failure to thrive and profound rickets, who was only 7.8 Kg when presented at 6 years of age. His response to treatment and his follow up for four years is discussed. Although failure to thrive is a common finding in renal tubular acidosis but the physical and x-ray findings in our case were unique. (author)

  20. Cooling tower drift: comprehensive case study

    International Nuclear Information System (INIS)

    Laulainen, N.S.; Ulanski, S.L.

    1979-01-01

    A comprehensive experiment to study drift from mechanical drift cooling towers was conducted during June 1978 at the PG and E Pittsburg Power Plant. The data from this study will be used for validation of drift deposition models. Preliminary results show the effects of tower geometry and orientation with respect to the wind and to single- or two-tower operation. The effect of decreasing relative humidity during a test run can also be seen

  1. The future cooling tower; Fremtidens koeletaarn

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, C.H. (Vestas Aircoil A/S, Lem St. (Denmark)); Schneider, P. (Teknologisk Institut, AArhus (Denmark)); Haaning, N. (Ramboell A/S, Copenhagen (Denmark)); Lund, K. (Nyrup Plast A/S, Nyrup (Denmark)); Soerensen, Ole (MultiWing A/S, Vedbaek (Denmark)); Dalsgaard, T. (Silhorko A/S, Skanderborg (Denmark)); Pedersen, Michael (Skive Kommune, Skive (Denmark))

    2011-03-15

    This project has designed and built a pilot-scale cooling tower with an output of up to 100 kW for which good correlation has been ascertained between measured and calculated values for output and pressure loss. The new cooling tower will save approximately 15% of electricity consumption compared with the widespread dry coolers. The pilot tower uses rainwater so that both water consumption and electricity consumption are saved in softening plants. On the basis of this cooling tower, models have been made and these have been implemented in PackCalc II in order to calculate electricity and other operating savings. (Energy 11)

  2. Atmospheric cooling tower with reduced plume

    International Nuclear Information System (INIS)

    Gautier, D.M.; Lagoutte, A.

    1985-01-01

    The cooling tower, usable in thermal-electric power plants, has a vertical chimney having a central water tower fed with water to be cooled, a pipe network distributing water coming from the water tower and dispersing it in flows streaming down on a packing, and a basin to receive the water cooled by contact with an air flow passing through apertures at the lower part of the chimney and flowing up through the chimney. The cooling tower has inlet air pipes for the said apertures to a zone of the chimney situated beyond the streaming zone, the said pipes being arranged such their surface is swept by water to be cooled [fr

  3. Cooling towers of nuclear power plants

    International Nuclear Information System (INIS)

    Mikyska, L.

    1986-01-01

    The specifications are given of cooling towers of foreign nuclear power plants and a comparison is made with specifications of cooling towers with natural draught in Czechoslovak nuclear power plants. Shortcomings are pointed out in the design of cooling towers of Czechoslovak nuclear power plants which have been derived from conventional power plant design. The main differences are in the adjustment of the towers for winter operation and in the designed spray intensity. The comparison of selected parameters is expressed graphically. (J.B.)

  4. Mechanical Properties of UHPFRC Joint for FORIDA Wind Turbine Tower

    DEFF Research Database (Denmark)

    Sørensen, Eigil Verner

    FORIDA Development, Vestas and Aalborg University are currently undertaking the project “FORIDA Hybrid Towers – The towers for next generation of wind turbines”, aiming to develop a new wind turbine tower structure (The FORIDA Tower) for very tall turbines. The tower is going to be a hybrid of ma...

  5. Thermal CFD Analysis of Tubular Light Guides

    Directory of Open Access Journals (Sweden)

    Ondřej Šikula

    2013-12-01

    Full Text Available Tubular light guides are applicable for daylighting of windowless areas in buildings. Despite their many positive indoor climate aspects they can also present some problems with heat losses and condensation. A computer CFD model focused on the evaluation of temperature distribution and air flow inside tubular light guides of different dimensions was studied. The physical model of the tested light guides of lengths more than 0.60 m proves shows that Rayleigh numbers are adequate for a turbulent air flow. The turbulent model was applied despite the small heat flux differences between the turbulent and laminar model. The CFD simulations resulted into conclusions that the growing ratio of length/diameter increases the heat transmission loss/linear transmittance as much as by 50 percent. Tubular light guides of smaller diameters have lower heat transmission losses compared to the wider ones of the same lengths with the same outdoor temperature being taken into account. The simulation results confirmed the thermal bridge effect of the tubular light guide tube inside the insulated flat roof details. The thermal transmittance of the studied light guides in the whole roof area was substituted with the point thermal bridges. This substitution gives possibility for simple thermal evaluation of the tubular light pipes in roof constructions.

  6. On the prospects for dry cooling tower building in FRG

    International Nuclear Information System (INIS)

    Dzhurinskij, M.B.; Zlotin, A.A.

    1982-01-01

    Advantages and disadvantages of dry cooling towers for NPPs are considered. Construction of a number of cooling towers in FRY are described. The advisability of building cooling towers of a combined type - with wet aud dry sections is noted

  7. Fire ants perpetually rebuild sinking towers

    Science.gov (United States)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  8. 77 FR 75984 - Utility Scale Wind Towers From the Socialist Republic of Vietnam: Final Determination of Sales at...

    Science.gov (United States)

    2012-12-26

    ... Determination 1. Steel Plate 2. Surrogate Financial Statements 3. Financial Ratio Adjustments 4. Packed Weight... financial statements for Ganges International Pvt Ltd. for purposes of calculating the surrogate financial ratios. Scope of the Investigation The merchandise covered by this investigation are certain wind towers...

  9. A Virtual Tool for Minimum Cost Design of a Wind Turbine Tower with Ring Stiffeners

    Directory of Open Access Journals (Sweden)

    Fatih Karpat

    2013-07-01

    Full Text Available Currently, renewable energy resources are becoming more important to reduce greenhouse gas emissions and increase energy efficiency. Researchers have focused on all components of wind turbines to increase reliability and minimize cost. In this paper, a procedure including a cost analysis method and a particle swarm optimization algorithm has been presented to efficiently design low cost steel wind turbine towers. A virtual tool is developed in MATLAB for the cost optimization of wind turbine steel towers with ring stiffeners using a particle swarm optimization algorithm. A wind turbine tower optimization problem in the literature is solved using the developed computer program. In the optimization procedure the optimization results match very well with the optimization results obtained previously. The wall thickness of the shell segments and the dimensions of the ring stiffeners are selected as the design variables, and the limits of the local buckling for the flat ring stiffeners, the local shell buckling limit, the panel ring buckling limit and the limitation of the frequency are considered the design constraints. Numerical examples are presented to understand the impacts of the design variables on the total cost of the wind turbine tower.

  10. Experiences with the first dry cooling tower for the THTR power plant at Schmehausen, FRG

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, W [Vereinigte Elektrizitaetswerke Westfalen AG (VEW), Dortmund (Germany, F.R.)

    1990-07-01

    The cable net cooling tower at Schmehausen was completed 12 years ago. Annual inspections are required by law. This paper reports on the following topics brought to light by these inspections: repair of damaged concrete on the pylon head; the search for a durable means of protecting the steel cables between the lifter ring and the thrust ring from corrosion; renewal of the attachment of the aluminium lining; cracks in the ring foundation; and weakening of the foundation anchors. (author).

  11. Augmented Reality Tower Technology Assessment

    Science.gov (United States)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  12. Cooling towers - terms and definitions

    International Nuclear Information System (INIS)

    1991-02-01

    In the field of cooling tower construction and operation, the use of publications has shown that a systematic glossary has not yet been developed. Therefore a dictionary of the terms used in this field, together with their clear definitions, is urgently required. This work has been started by the V.I.K. (Association for the Industrial Power Economy) in Essen and completed by the VDI-Group 'Energy Engineering'. Because of the strong international links and the increasing overseas trade in this field also the corresponding terms in other languages, English, French and Spanish are included. As to make it possible to find the German terms and definitions when starting from a foreign language, alphabetical lists are included for the various languages giving the number of the corresponding German term. In such cases where the technical term used in the United States is not identical with the corresponding term used in the United Kingdom, both terms are included. (orig./HP) [de

  13. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here.

  14. Reuse of refinery's tertiary-treated wastewater in cooling towers: microbiological monitoring.

    Science.gov (United States)

    Dos Santos, Vera Lúcia; Veiga, Andréa Azevedo; Mendonça, Rafael Silva; Alves, Andrea Lima; Pagnin, Sérgio; Santiago, Vânia M J

    2015-02-01

    The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources.

  15. Ranitidine has no influence on tubular creatinine secretion

    NARCIS (Netherlands)

    van den Berg, J. G.; Koopman, M. G.; Arisz, L.

    1996-01-01

    Oral cimetidine competitively inhibits tubular secretion of creatinine. We investigated the potential of oral ranitidine, a comparable H2-receptor antagonist, to block tubular creatinine secretion. In 10 healthy subjects, clearances of inulin and endogenous creatinine were simultaneously measured

  16. Performance characteristics of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan; Li Dandan

    2007-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In contrast to conventional cooling towers, the cooling tower analyzed in this study is void of fill. By means of efficient atomization nozzles, a shower cooling tower (SCT) is possible to be applied in industry, which, in terms of water cooling, energy saving and equipment investing, is better than conventional packed cooling towers. However, no systematic thermodynamic numerical method could be found in the literature up to now. Based on the kinetic model and mass and heat transfer model, this paper has developed a one dimensional model for studying the motional process and evaporative cooling process occurring at the water droplet level in the SCT. The finite difference approach is used for three motional processes to obtain relative parameters in each different stage, and the possibility of the droplets being entrained outside the tower is fully analyzed. The accuracy of this model is checked by practical operational results from a full scale prototype in real conditions, and some exclusive factors that affect the cooling characteristics for the SCT are analyzed in detail. This study provides the theoretical foundation for practical application of the SCT in industry

  17. Statistics Analysis Measures Painting of Cooling Tower

    Directory of Open Access Journals (Sweden)

    A. Zacharopoulou

    2013-01-01

    Full Text Available This study refers to the cooling tower of Megalopolis (construction 1975 and protection from corrosive environment. The maintenance of the cooling tower took place in 2008. The cooling tower was badly damaged from corrosion of reinforcement. The parabolic cooling towers (factory of electrical power are a typical example of construction, which has a special aggressive environment. The protection of cooling towers is usually achieved through organic coatings. Because of the different environmental impacts on the internal and external side of the cooling tower, a different system of paint application is required. The present study refers to the damages caused by corrosion process. The corrosive environments, the application of this painting, the quality control process, the measures and statistics analysis, and the results were discussed in this study. In the process of quality control the following measurements were taken into consideration: (1 examination of the adhesion with the cross-cut test, (2 examination of the film thickness, and (3 controlling of the pull-off resistance for concrete substrates and paintings. Finally, this study refers to the correlations of measurements, analysis of failures in relation to the quality of repair, and rehabilitation of the cooling tower. Also this study made a first attempt to apply the specific corrosion inhibitors in such a large structure.

  18. Drill pipes and casings utilizing multi-conduit tubulars

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1989-01-24

    A seal adapted for use with a multi-conduit well tubular, or the like, is described which consists of: a plate with fluid passages, each passage corresponding to an opening of a conduit of the multiconduit tubular, and a groove on the plate around each passage; and elastomer means partially embeddable into each groove for sealing each conduit of a tubular to a corresponding conduit of another similar tubular.

  19. Development of Partial Tubular Flat Knitting Fabric Composite Preform

    Directory of Open Access Journals (Sweden)

    Jiang Wei Qing

    2016-01-01

    Full Text Available After building some structures of partial tubular flat knitting fabric composite preform, the influencing factor on tubular section was analyzed and the fabric was knitted selectively. The partial tubular flat knitting fabric composite preform were Knitted by changing different yarn, row number and two-sided partial tubular flat knitting fabric. Multilayer sheet would be got after hot pressing and it has big market prospects and good application value.

  20. Tubular permanent magnet actuators: cogging forces characterization

    NARCIS (Netherlands)

    Paulides, J.J.H.; Janssen, J.L.G.; Encica, L.; Lomonova, E.A.

    2009-01-01

    Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper

  1. Work tool in a tubular element

    International Nuclear Information System (INIS)

    Griffaton, J.

    1991-01-01

    The stand, which is positioned in relation with the tubular element, has clutch disengagement means for a working rod in rotation, with at least two positioning regions on the rod. Application for laser welding a sleeve into PWR steam generator tubes [fr

  2. Boron--epoxy tubular structure members

    Science.gov (United States)

    Shakespeare, W. B. J.; Nelson, P. T.; Lindkvist, E. C.

    1973-01-01

    Composite materials fabricate thin-walled tubular members which have same load-carrying capabilities as aluminum, titanium, or other metals, but are lighter. Interface between stepped end fitting and tube lends itself to attachments by primary as well as secondary bonding. Interlaminar shear and hoop stress buildup in attachment at end fitting is avoided.

  3. Pointlike Inclusion Interactions in Tubular Membranes

    NARCIS (Netherlands)

    Vahid Belarghou, A.; Idema, T.

    2016-01-01

    Membrane tubes and tubular networks are ubiquitous in living cells. Inclusions like proteins are vital for both the stability and the dynamics of such networks. These inclusions interact via the curvature deformations they impose on the membrane. We analytically study the resulting membrane

  4. Noise from cooling towers of power parks

    International Nuclear Information System (INIS)

    Zakaria, J.; Moore, F.K.

    1975-01-01

    A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A-weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed

  5. The Schmehausen cable net cooling tower

    International Nuclear Information System (INIS)

    Schlaich, J.; Mayr, G.; Weber, P.; Jasch, E.

    1976-01-01

    The prototype of a large cable net shell as a natural-draught cooling tower for the THTR-300 is presented. Results of wind tunnel tests and calculations are given, and the capacity is discussed. Design features of the main components are presented in illustrations and are described with regard to the construction process of the cooling tower. Finally, it is shown that the cable net cooling tower is a suitable construction for large dimensions and caving-in or seismic areas. (orig./HP) [de

  6. Reliability Analysis of Tubular Joints in Offshore Structures

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1987-01-01

    Reliability analysis of single tubular joints and offshore platforms with tubular joints is" presented. The failure modes considered are yielding, punching, buckling and fatigue failure. Element reliability as well as systems reliability approaches are used and illustrated by several examples....... Finally, optimal design of tubular.joints with reliability constraints is discussed and illustrated by an example....

  7. Diffraction patterns from 7-Angstroms tubular halloysite

    International Nuclear Information System (INIS)

    Eggleton, T.

    1998-01-01

    Full text: The diffraction patterns from 7-Angstroms tubular halloysite are superficially like those from kaolinite. Diffraction from a tubular aggregate of atoms, however, differs from that from a crystal because there is no linear repetition in two of the three conventional crystallographic directions. In tubular halloysite, the tube axis is [010] or [110] and in this direction the unit cell repeats in the normal linear fashion. The x-axis, by contrast, changes direction tangentially around the tube circumference, and there can be no true z-axis, because unit cells in the radial direction do not superimpose, since each successive tubular layer has a larger radius than its predecessor and therefore must contain more unit cells than its predecessor. Because tubular 'crystals' do not have a lattice repeat, use of Bragg 'hkl' indices is not appropriate. In the xy plane, a small area of the structure approximates a flat layer silicate, and hk indices may been used to label diffraction maxima. Similarly, successive 1:1 layers tangential to the tube walls yield a series of apparent 001 diffraction maxima. Measurement of these shows that the d-spacings do not form an exact integral series. The reason for this lies in the curvature of the structure. Calculated electron and powder X-ray diffraction patterns, based on a model of concentric 1:1 layers with no regular relation between them other than the 7.2 Angstroms spacing, closely simulate the observed data. Evidence for the 2-layer structure that is generally accepted may need to be reassessed in the light of these results

  8. 76 FR 48143 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2011-08-08

    ..., 75 FR 81565 (December 28, 2010). \\3\\ Certain Oil Country Tubular Goods from the People's Republic of..., from Steven Hampton, International Trade Analyst, ``Certain Hot-Rolled Carbon Steel Flat Products from...

  9. Optimum design of steel structures

    CERN Document Server

    Farkas, József

    2013-01-01

    This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...

  10. Design and operation of hybrid cooling towers

    International Nuclear Information System (INIS)

    Alt, W.

    1987-01-01

    The first hybrid cooling tower at a coal-fired power station with a waste heat output of 550 MW has been in operation since the middle of 1985. Experience during the construction stage and the initial period of operation has confirmed the correctness of the design standards and of the design itself and, of course, also offers a wealth of knowledge to be observed on future construction projects. A second cooling tower of similar design is being erected at the present time. This cooling tower serves a power station unit with 2500 MW of waste heat output. The programme for this cooling tower offers the possibility for all the accumulated and evaluated experience to be of influence both on the design and also on the method of operation. This paper reports on the details. (orig.) [de

  11. Dry cooling towers - the Schmehausen example

    International Nuclear Information System (INIS)

    Weber, P.

    1977-01-01

    In a prototype, there are often problems which require special static, constructive, and assembling measures for their solution. In the case of the Schmehausen dry cooling tower, the demands on the assembling technology are particularly high. (orig.) [de

  12. Cooling tower water circuits with raceways

    International Nuclear Information System (INIS)

    Nicollet, G.

    1981-02-01

    Two physical models built at the National Hydraulics Laboratory in Chatou have led to the determination of the design of the works. This new design economizes 4 to 5 MW on pumping power for each cooling tower [fr

  13. LaGuardia air traffic control tower.

    Science.gov (United States)

    2011-01-01

    To celebrate FAA and its LaGuardia Airport employees past, : present, and future this booklet outlines the airports history and accomplishments and includes copies of some of the photographs in the : air traffic control towers history g...

  14. Damping of wind turbine tower vibrations

    DEFF Research Database (Denmark)

    Brodersen, Mark Laier; Pedersen, Mikkel Melters

    Damping of wind turbine vibrations by supplemental dampers is a key ingredient for the continuous use of monopiles as support for offshore wind turbines. The present thesis consists of an extended summary with four parts and appended papers [P1-P4] concerning novel strategies for damping of tower...... dominated vibrations.The first part of the thesis presents the theoretical framework for implementation of supplemental dampers in wind turbines. It is demonstrated that the feasibility of installing dampers at the bottom of the tower is significantly increased when placing passive or semiactive dampers...... in a stroke amplifying brace, which amplifies the displacement across the damper and thus reduces the desired level of damper force. For optimal damping of the two lowest tower modes, a novel toggle-brace concept for amplifying the bending deformation of the tower is presented. Numerical examples illustrate...

  15. Wind towers architecture, climate and sustainability

    CERN Document Server

    Bahadori, Mehdi N; Sayigh, Ali

    2014-01-01

    This book offers a holistic treatment of wind towers, from their underlying scientific principles to design and operation. Includes suggestions for optimization based on the authors' own research findings from recent analytical studies.

  16. Good towers of function Fields

    DEFF Research Database (Denmark)

    Nguyen, Nhut

    Algebraic curves are used in many different areas, including error-correcting codes. In such applications, it is important that the algebraic curve C meets some requirements. The curve must be defined over a finite field GF(q) with q elements, and then the curve also should have many points over...... this field. There are limits on how many points N(C) an algebraic curve C defined over a finite field can have. An invariant of the curve which is important in this context is the curve’s genus g(C). Hasse and Weil proved that N(C)≤q+1+2g(C) √q and this bound can in general not be improved. However...... of q. In this thesis, we study a construction using Drinfeld modules that produces explicitly defined families of algebraic curves that asymptotically achieve Ihara’s constant. Such families of curves can also be described using towers of function fields. Restated in this language the aim...

  17. Wind tower with vertical rotors

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, A

    1978-08-03

    The invention concerns a wind tower with vertical rotors. A characteristic is that the useful output of the rotors is increased by the wind pressure, which is guided to the rotors at the central opening and over the whole height of the structure by duct slots in the inner cells. These duct slots start behind the front nose of the inner cell and lead via the transverse axis of the pillar at an angle into the space between the inner cells and the cell body. This measure appreciably increases the useful output of the rotors, as the rotors do not have to provide any displacement work from their output, but receive additional thrust. The wind pressure pressing from inside the rotor and accelerating from the outside produces a better outflow of the wind from the power plant pillar with only small tendency to turbulence, which appreciably improves the effect of the adjustable turbulence smoothers, which are situated below the rotors over the whole height.

  18. Corrosion of steels in sour gas environments

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1984-03-01

    This report presents a study on the effects of sour gas environments on steels. Emphasis is placed on alloys commonly used in the heavy water, sour gas and refining industries. In addition, 'high strength, low alloy' steels, known as 'oil country tubular goods', are included. Reference is made to the effects of hydrogen sulphide environments on austenitic steels and on certain specialty steels. Theories of hydrogen-related cracking mechanisms are outlined with emphasis placed on sulphide stress cracking and hydrogen induced cracking in carbon and low alloy steels. Methods of controlling sulphide stress cracking and hydrogen induced cracking are addressed separately. Case histories from the heavy water, refining, and sour gas industries are used to illustrate operating experience and failure mechanisms. Finally, recommendations, based largely on the author's industrial experience, are made with respect to quality assurance and inspection requirements for sour service components. Only published literature was surveyed. Abstracts were made of all references, reviewing the major sources in detail

  19. Cooling tower water ozonation at Southern University

    International Nuclear Information System (INIS)

    Chen, C.C.; Knecht, A.T.; Trahan, D.B.; Yaghi, H.M.; Jackson, G.H.; Coppenger, G.D.

    1990-01-01

    Cooling-tower water is a critical utility for many industries. In the past, inexpensive water coupled with moderate regulation of discharge water led to the neglect of the cooling tower as an energy resource. Now, with the increased cost of chemical treatment and tough EPA rules and regulations, this situation is rapidly changing. The operator of the DOE Y-12 Plant in Oak Ridge as well as many other industries are forced to develop an alternate method of water treatment. The cooling tower is one of the major elements in large energy systems. The savings accrued from a well engineered cooling tower can be a significant part of the overall energy conservation plan. During a short-term ozonation study between 1987-1988, the Y-12 Plant has been successful in eliminating the need for cooling tower treatment chemicals. However, the long-term impact was not available. Since April 1988, the ozone cooling water treatment study at the Y-12 Plant has been moved to the site at Southern University in Baton Rouge, Louisiana. The purpose of this continued study is to determine whether the use of ozonation on cooling towers is practical from an economic, technical and environmental standpoint. This paper discusses system design, operating parameter and performance testing of the ozonation system at Southern University

  20. Component for articulated offshore loading towers

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, H.

    1980-09-01

    The construction of offshore natural gas liquefaction plants must be regarded as technically feasible and the marketing prospects for LNG - a source of clean burning energy - appear excellent. Nevertheless, the optimum loading procedure for LNG tankers in the - sometimes adverse - offshore environment is still a matter under discussion by the experts - with a tendency to adopt and adapt well-proven components from the offshore crude oil sector. Here, articulated towers are in use for tankerloading and the crude oil is pumped at ambient temperature through the cardan joint of the tower itself. In the case of the cryogenic liquid LNG, this method would entail intolerable risks. Leaks and subsequent LNG spills within the tower joint will cause low temperature-embrittlement and most likely damage the cardan connection at the tower's base plate on the sea bed. The described submarine joint for ultra-cold liquids, which has the same cardanic properties as the cardan joint of the tower is completely separated from the latter. Thus a cryogenic leakage in this submarine joint will under no circumstance reach and affect the tower cardan.

  1. Stray current induced corrosion in lightning rod cables of 525 kV power lines towers: a case study

    International Nuclear Information System (INIS)

    Wojcicki, F. R.; Negrisoli, M. E. M.; Franco, C. V.

    2003-01-01

    With the growth of several areas in modern society, the necessity to generate and carry electrical energy to big cities has greatly increased. Cables supported by power towers with galvanized steel foundation usually carry energy. As the foundations are underground they may cause high rates of corrosion. These are usually detected by a conventional potential measurement using a Cu/CuSO 4 reference electrode. It is believed that corrosion results from stray currents that flow through the ground to close the loop between neighboring towers. Stray currents originate in the lightning rod cables of the power line towers, induced by the strong electromagnetic and electric fields of the energized power lines. The intensity and direction of those currents were measured, indicating substantial values of both their AC and DC components. The potential of the tower ground system, measured in the perpendicular direction of the main axis of the power line, was plotted as a function of the distance to the tower base. The results clearly indicated the tendency to corrosive attack in the anodic towers as reflected by the slope of the plot, whereas no signs of corrosion could be found in the reverse slope, confirming the visual inspection of the foundation. The profile of the potential plots could be changed providing the electric insulation of the lightning rod cable. (Author) 8 refs

  2. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Albloushi, Mohammed

    2017-11-01

    The use of seawater in cooling towers for industrial applications has much merit in the Gulf Cooperation Council countries due to the scarcity and availability of fresh water. Seawater make-up in cooling towers is deemed the most feasible because of its unlimited supply in coastal areas. Such latent-heat removal with seawater in cooling towers is several folds more efficient than sensible heat extraction via heat exchangers. Operational challenges such as scaling, corrosion, and biofouling are a major challenge in conventional cooling towers, where the latter is also a major issue in seawater cooling towers. Biofouling can significantly hamper the efficiency of cooling towers. The most popular methods used in cooling treatment to control biofouling are disinfection by chlorination. However, the disadvantages of chlorination are formation of harmful disinfection byproducts in the presence of high organic loading and safety concerns in the storage of chlorine gas. In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities

  3. Design basis for the copper/steel canister

    International Nuclear Information System (INIS)

    Bowyer, W.H.

    1996-02-01

    The development of the copper/iron canister which has been proposed by SKB for the containment of high level nuclear waste has been studied from the point of view of choice of materials, manufacturing technology and quality assurance. This report describes the observations on progress which have been made between March 1995 and Feb 1996 and the result of further literature studies. A first trial canister has been produced using a fabricated steel liner and an extruded copper tubular, a second one using a fabricated tubular is at an advanced stage. A change from a fabricated steel inner canister to a proposed cast canister has been justified by a criticality argument but the technology for producing a cast canister is at present untried. The microstructure achieved in the extruded copper tubular for the first canister is unacceptable. Similar problems exist with plate used for the fabricated tubular, but some more favourable structures have been achieved already by this route. Seam welding of the first tubular failed through a suspected material problem. The second fabricated tubular welded without difficulty. Welding of lids and bottoms to the copper canister is problematical.There is as yet no satisfactory non destructive test procedures for the parent metal or the welds in the copper canister material, partly due to the coarse grain size which arise in the proposed material processed by the proposed routes. Further studies are also required on crevice corrosion, galvanic attack and stress corrosion cracking in the copper 50 ppm phosphorus alloy. 28 refs

  4. SOFC mini-tubulares basadas en YSZ

    Directory of Open Access Journals (Sweden)

    Campana, R.

    2008-08-01

    Full Text Available Tubular SOFC have the advantage over planar SOFC of the low temperature sealing and more resistance to thermal shock. On the other hand the volumetric power density of tubular Fuel Cells goes with the inverse of the tube diameter which added to the faster warm-up kinetics makes low diameter tubular SOFC favorable for low power applications. Anode supported tubular SOFC of 3mm diameter and 150 mm length with YSZ electrolyte were fabricated and tested by V-I measurements using H2-Ar (5, 10, 100 vol% as fuel and air for the cathode. The NiO-YSZ tubes of about 400 μm thickness were produced by hydrostatic pressure and then coated with an YSZ film of 15-20 μm. The electrolyte was deposited using a manual aerograph. After sintering either Pt paste or LSF (with YSZ or SDC coatings of about 20-50 μm thickness were deposited for the cathode. The OCV of the cells were excellent, very close to the expected Nernst law prediction indicating that there were not gas leaks. The maximun electrical power of the cell was near to 500mW/cm2 at 850ºC operation temperature. Complex impedance measurements of the cells were performed in order to determine the resistance of the different cell components.

    La principal ventaja de las SOFC tubulares frente a las planares es el sellado de la cámara anódica y catódica a bajas temperaturas. Además la densidad de energía volumétrica de las pilas tubulares es inversamente proporcional al diámetro del tubo, que añadido a los tiempos cortos de encendido y apagado hacen que las mini-tubulares sean interesantes para usos de baja potencia. Se han fabricado y caracterizado SOFC tubulares soportadas en ánodo de 3mm de diámetro y de 150 mm de longitud, 400μm de espesor, con electrolito de YSZ depositado por spray de 15-20 μm. Los tubos de NiO-YSZ son producidos por prensado isostático. La caracterización eléctrica se ha realizado empleando H2-Ar como combustible an

  5. Tower Based Load Measurements for Individual Pitch Control and Tower Damping of Wind Turbines

    International Nuclear Information System (INIS)

    Kumar, A A; Hugues-Salas, O; Savini, B; Keogh, W

    2016-01-01

    The cost of IPC has hindered adoption outside of Europe despite significant loading advantages for large wind turbines. In this work we presented a method for applying individual pitch control (including for higher-harmonics) using tower-top strain gauge feedback instead of blade-root strain gauge feedback. Tower-top strain gauges offer hardware savings of approximately 50% in addition to the possibility of easier access for maintenance and installation and requiring a less specialised skill-set than that required for applying strain gauges to composite blade roots. A further advantage is the possibility of using the same tower-top sensor array for tower damping control. This method is made possible by including a second order IPC loop in addition to the tower damping loop to reduce the typically dominating 3P content in tower-top load measurements. High-fidelity Bladed simulations show that the resulting turbine spectral characteristics from tower-top feedback IPC and from the combination of tower-top IPC and damping loops largely match those of blade-root feedback IPC and nacelle- velocity feedback damping. Lifetime weighted fatigue analysis shows that the methods allows load reductions within 2.5% of traditional methods. (paper)

  6. Adiabatic Rearrangement of Hollow PV Towers

    Directory of Open Access Journals (Sweden)

    Eric A Hendricks

    2010-10-01

    Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

  7. Aerodynamical errors on tower mounted wind speed measurements due to the presence of the tower

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, H. [Uppsala Univ. (Sweden). Dept. of Meteorology; Dahlberg, J.Aa. [Aeronautical Research Inst. of Sweden, Bromma (Sweden)

    1996-12-01

    Field measurements of wind speed from two lattice towers showed large differences for wind directions where the anemometers of both towers should be unaffected by any upstream obstacle. The wind speed was measured by cup anemometers mounted on booms along the side of the tower. A simple wind tunnel test indicates that the boom, for the studied conditions, could cause minor flow disturbances. A theoretical study, by means of simple 2D flow modelling of the flow around the mast, demonstrates that the tower itself could cause large wind flow disturbances. A theoretical study, based on simple treatment of the physics of motion of a cup anemometer, demonstrates that a cup anemometer is sensitive to velocity gradients across the cups and responds clearly to velocity gradients in the vicinity of the tower. Comparison of the results from the theoretical study and field tests show promising agreement. 2 refs, 8 figs

  8. Tower Mesonetwork Climatology and Interactive Display Tool

    Science.gov (United States)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

  9. Mycobacteria in Finnish cooling tower waters.

    Science.gov (United States)

    Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

    2014-04-01

    Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. © 2013 APMIS. Published by John Wiley & Sons Ltd.

  10. The shape of natural draft cooling towers

    International Nuclear Information System (INIS)

    Grange, J.L.

    1992-07-01

    The shape of cooling towers is more often designed empirically. There, it is considered from a theoretical point of view. The analysis of dynamic of natural draft and of the air flow in a cooling tower shell is presented. It is shown, that although it is convergent, a tower works like a diffuser for pressure recovery. And it is turbulence that produces a transfer of kinetic energy and allows a good operation of the diffusor. The equations permit to define a shell profile which depends upon the operating conditions of the cooling tower. In the same way, a stability criteria for natural draft depending upon operating conditions is established. A heating model of one meter diameter has been built in a thermal similitude. The turbulence rate has been measured with a hot wire anemometer at the tower exit and visualizations have also been made. Natural draft stability has been studied by these means for four different shell shapes and a wide range of operating conditions. Experimental and theoretical results agree satisfactorily and experiments can be considered as a validation of theory

  11. Aircraft Steels

    Science.gov (United States)

    2009-02-19

    component usage. PH 13-8Mo is a precipitation-hardenable martensitic stainless steel combining excellent corrosion resistance with strength. Custom 465 is...a martensitic , age-hardenable stainless steel capable of about 1,724 MPa (250 ksi) UTS when peak-aged (H900 condition). Especially, this steel can...NOTES 14. ABSTRACT Five high strength steels (4340, 300M, AerMet 100, Ferrium S53, and Hy-Tuf) and four stainless steels (High Nitrogen, 13

  12. Cooling tower water conditioning study. [using ozone

    Science.gov (United States)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  13. Operating manual for the Tower Shielding Facility

    International Nuclear Information System (INIS)

    1985-12-01

    This manual provides information necessary to operate and perform maintenance on the reactor systems and all equipment or systems which can affect their operation or the safety of personnel at the Tower Shielding Facility. The first four chapters consist of introductory and descriptive material of benefit to personnel in training, the qualifications required for training, the responsibilities of the personnel in the organization, and the procedures for reviewing proposed experiments. Chapter 8, Emergency Procedures, is also a necessary part of the indoctrination of personnel. The procedures for operation of the Tower Shielding Reactor (TSR-II), its water cooling system, and the main tower hoists are outlined in Chapters 5, 6, and 7. The Technical Specification surveillance requirements for the TSR-II are summarized in Chapter 9. The maintenance and calibration schedule is spelled out in Chapter 10. The procedures for assembly and disassembly of the TSR-II are outlined in Chapter 11

  14. Towers of the new 380 kV high-voltage overhead line across the Elbe

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, F; Sperl, H D; Wagemann, F

    1979-11-01

    As part of the European power transmission line between North Sweden and Southern Italy, a 380 kV rotary-current overhead line crosses the Elbe river south of Hamburg. To achieve the overhead clearance of 80 m required for navigation and the maximum line sag of 85 m, two steel trelliswork towers were constructed about 1200 m apart, each of them 227 m high. The 12 phases (cables) of the line are suspended each on three horizontal beams at a horizontal distance of 16 m. Exceptional loads far beyond the standards set in VDE 0210/5.69 have been assumed for the layout. In the case of the wind loads the frequent gales had to be considered; for ice loads, class I of the IEC/TC 11 Draft on Ice loading on Overhead Lines . Amsterdam 1977, was assumed. Some further loads are described as well as the tender procedure, supply and assembly of the towers.

  15. The raft foundation reinforcement construction technology of Hongyun Building B tower

    Science.gov (United States)

    Liu, Yu; Yin, Suhua; Wu, Yanli; Zhao, Ying

    2017-08-01

    The foundation of Hongyun building B tower is made of raft board foundation which is 3300mm in the thickness include four kinds of reinforcement Φ32, Φ28, Φ12 and 12 steel grade two, in respective. It is researched that the raft foundation mass concrete construction technology is expatiated from temperature and cracks of the raft foundation and the temperature control and monitoring of the concrete base slab construction and concrete curing. According to the characteristics with large volume and thickness of the engineering of raft foundation, the construction of the reinforced force was calculated and the quality control measures were used to the reinforcement binding and connection, so it is success that Hongyun Building B tower raft foundation reinforced construction.

  16. Update on the Purdue University 2-second Drop Tower

    Science.gov (United States)

    Collicott, Steven

    an update on progress for the micro-gravity community. The most noticeable current activity is testing of the air-bag decelerator. The tower is one that will use a free-falling experiment inside of a drag shield to avoid most aerodynamic drag. The airbag is designed from experiences of others yet the small, triangular room in which the tower terminates imposes challenges. The airbag is approximately 1.5m diameter and 1.5m tall. Initial testing led to a desire to increase vent area, and just this week the bag has returned from the shop that was modifying it. On-board computer, battery packs, lighting, and cameras have been acquired. Thanks to Lockheed Martin, one camera is 500 frames per second with 1.3 million 12-bit gray scale pixels per frame. The Spincraft company donated steel hemisphere-cylinders to serve as the nose of the drag shield. Wind tunnel and CFD modeling of the drag shield has been performed by Purdue undergraduate aerospace students. Currently the drag shield structure and experiment package structure are being design and analyzed. The experiment volume is approximately a cylinder 0.45m diameter and 0.6m tall. Tower operation is intended to commence in fall 2010 with inert package drops at full mass and full height. Developing the operations procedures, especially operational safety, are the goals of this work. First science is then expected in the winter. References 1. Y. Chen, "A Study of Capillary Flow in a Vane-wall Gap in Zero Gravity," Ph.D. thesis, School of Aeronautics and Astronautics, Purdue University. August 2003. 2. Y. Chen and S. H. Collicott, "Investigation of the Symmetric Wetting of a Vane-Wall Gap in Propellant Tanks," AIAA Journal, 42, No. 2, pp. 305-314, February 2004. 3. Y. Chen, and S. H. Collicott, "Experimental Study on the Capillary Flow in a Vane-Wall Gap Geometry," AIAA Journal, 43, No. 11, pp. 2395-2403, November, 2005. 4. Y. Chen and S. H. Collicott, "Study of Wetting in an Asymmetrical Vane-Wall Gap in Propellant Tanks

  17. Engineering photochemical smog through convection towers

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, S.; Prueitt, M.L.; Bossert, J.E.; Mroz, E.J.; Krakowski, R.A.; Miller, R.L. [Los Alamos National Lab., NM (United States); Jacobson, M.Z.; Turco, R.P. [Los Alamos National Lab., NM (United States)]|[Univ. of California, Los Angeles, CA (United States). Atmospheric Sciences Dept.

    1995-02-01

    Reverse convection towers have attracted attention as a medium for cleansing modern cities. Evaporation of an aqueous mist injected at the tower opening could generate electrical power by creating descent, and simultaneously scavenge unsightly and unhealthful particulates. The study offered here assesses the influence to tower water droplets on the photochemical component of Los Angeles type smog. The primary radical chain initiator OH is likely removed into aqueous phases well within the residence time of air in the tower, and then reacts away rapidly. Organics do not dissolve, but nighttime hydrolysis of N{sub 2}O{sub 5} depletes the nitrogen oxides. A lack of HOx would slow hydrocarbon oxidation and so also ozone production. Lowering of NOx would also alter ozone production rates, but the direction is uncertain. SO{sub 2} is available in sufficient quantities in some urban areas to react with stable oxidants, and if seawater were the source of the mist, the high pH would lead to fast sulfur oxidation kinetics. With an accommodation coefficient of 10{sup {minus}3}, however, ozone may not enter the aqueous phase efficiently. Even if ozone is destroyed or its production suppressed, photochemical recovery times are on the order of hours, so that tower processing must be centered on a narrow midday time window. The cost of building the number of structures necessary for this brief turnover could be prohibitive. The increase in humidity accompanying mist evaporation could be controlled with condensers, but might otherwise counteract visibility enhancements by recreating aqueous aerosols. Quantification of the divergent forcings convection towers must exert upon the cityscape would call for coupled three dimensional modeling of transport, microphysics, and photochemistry. 112 refs.

  18. Corrosion behavior of the tube - tubular plate joint zone in the presence of sediments

    International Nuclear Information System (INIS)

    Lucan, D.; Fulger, M.; Pirvan, I.; Cotolan, V.

    1997-01-01

    The corrosion is a very important problem which concerns the safe operation of steam generators. The predominant part of corrosion problems is related to the local concentration of aggressive species and/or to the impurities from the slow-flow regions, like those created by cracks in tube - tubular plate joint zones. The consequences of such local concentrations are very important and as such entail interest in the design and utilization of steam generators. This study presents the results of the corrosion tests performed under specific operation conditions of the secondary circuit in NPP (temperature, 260 o C; pressure, 5.1 MPa) on a crack simulating device made of carbon steel SA 508 cl.2 (forming the tubular plate) and Incoloy-800 (forming the tubes). The chemical medium of these tests was the following: solution of NaCl, 25g/l (pH=10.5); solution of NaCl, 50 g/l (pH=10.5); solution of NaCl, 75g/l (pH=10.5); solution of NaCl, 75g/l + solution of Na 2 SO 4 , 10 g/l (pH=10.5). The behavior of these two materials to corrosion was studied by metallographic investigations. The results are presented as microphotographs evidencing the occurrence of pitting corrosion first on material of the tubular plate, in the presence of medium particularly aggressive and on the material of the tubes. The aim of this study is to establish the corrosion mechanism as well as the formation of the oxide layer on the carbon steel in crack simulating devices. (authors)

  19. The new Drop Tower catapult system

    Science.gov (United States)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  20. Distal renal tubular acidosis and hepatic lipidosis in a cat.

    Science.gov (United States)

    Brown, S A; Spyridakis, L K; Crowell, W A

    1986-11-15

    Clinical and laboratory evidence of hepatic failure was found in a chronically anorectic cat. Simultaneous blood and urine pH determinations established a diagnosis of distal renal tubular acidosis. The cat did not respond to treatment. Necropsy revealed distal tubular nephrosis and hepatic lipidosis. The finding of distal renal tubular acidosis in a cat with hepatic lipidosis emphasizes the importance of complete evaluation of acid-base disorders in patients.

  1. Control Towers in Supply Chain Management - Past and Future

    Directory of Open Access Journals (Sweden)

    Anna Trzuskawska-Grzesińska

    2017-02-01

    Full Text Available The global economy requires global supply chain management which relies on visibility and responsiveness. Determinants such as: information technology tools, process knowledge, sales and operations planning experiences, etc., enable the formation of theory and practice for the supply chain control tower concept. The goal of the research paper is to identify business examples of different approaches to the supply chain control tower in the past and initiate a discussion on their future. This paper synthesizes past control tower practices and identifies possible future trends. The author performed: literature analysis, three selected companies' case studies and comparative analyses. As the control towers evolve, while supply chains are transforming continuous, update from the market is needed. The research findings showed the selected companies, in the future, perceived control tower's activities as a potential source of revenue not just solely a source of cost and time optimization as well as a source of value added to customer. The researched control towers were built and still they are developed. The business frequently changes and requires control towers to be adjusted, reengineered and adaptive. The researched control towers are needed to keep control over supply chain while it is transforming. There is a differentiation between the supply chain control towers, logistic services control towers and reverse supply chain control towers. An integration mechanism between the control towers would be necessary to assure entire supply chain visibility and orchestration. The research also shows the knowledge gap regarding the control towers in supply chain, specially their possible configurations and future.

  2. TUBULAR DISORDERS WITH RICKETS-LIKE SYNDROME

    Directory of Open Access Journals (Sweden)

    N.N. Kartamysheva

    2011-01-01

    Full Text Available Often under the guise of «ordinary» Rickets are more severe kidney diseases, developing as a result of inherited or acquired, primary or secondary defects in the renal tubules. Incorrect diagnosis leads to an inadequate therapy, rapid progression of disease and renal failure. The article describes the main approaches to the diagnosis and treatment of disorders of tubular rachitis similar syndrome, presents a number of clinical cases in author's practice.Key words: tubulopathy, acidosis, electrolyte disorders, rickets, rickets-like syndrome, diagnostics, treatment, children.

  3. Fractal solutions of recirculation tubular chemical reactors

    International Nuclear Information System (INIS)

    Berezowski, Marek

    2003-01-01

    Three kinds of fractal solutions of model of recirculation non-adiabatic tubular chemical reactors are presented. The first kind concerns the structure of Feigenbaum's diagram on the limit of chaos. The second kind and the third one concern the effect of initial conditions on the dynamic solutions of models. In the course of computations two types of recirculation were considered, viz. the recirculation of mass (return of a part of products' stream) and recirculation of heat (heat exchange in the external heat exchanger)

  4. Tubular solid oxide fuel cell development program

    Energy Technology Data Exchange (ETDEWEB)

    Ray, E.R.; Cracraft, C.

    1995-12-31

    This paper presents an overview of the Westinghouse Solid Oxide Fuel Cell (SOFC) development activities and current program status. The Westinghouse goal is to develop a cost effective cell that can operate for 50,000 to 100,000 hours. Progress toward this goal will be discussed and test results presented for multiple single cell tests which have now successfully exceeded 56,000 hours of continuous power operation at temperature. Results of development efforts to reduce cost and increase power output of tubular SOFCs are described.

  5. Corrosion of Galvanized Steel Under Different Soil Moisture Contents

    OpenAIRE

    Pereira,Roseana Florentino da Costa; Oliveira,Edkarlla Sousa Dantas de; Lima,Maria Alice Gomes de Andrade; Brasil,Simone Louise Delarue Cezar

    2015-01-01

    Galvanized steel has been widely applied in different applications and the industry significantly increased its production in recent years. Some galvanized structures can be completely or partially buried, such as transmission tower footings. The corrosion of these metallic structures is related to the soil chemical and physicochemical properties, which define the aggressiveness of the environment. To assess the effect of the soil moisture on galvanized steel corrosion, a comparative study wa...

  6. Lifting system and apparatus for constructing wind turbine towers

    Science.gov (United States)

    Livingston, Tracy; Schrader, Terry; Goldhardt, James; Lott, James

    2011-02-01

    The disclosed invention is utilized for mounting a wind turbine and blade assembly on the upper end of a wind turbine tower. The invention generally includes a frame or truss that is pivotally secured to the top bay assembly of the tower. A transverse beam is connected to the frame or truss and extends fore of the tower when the frame or truss is in a first position and generally above the tower when in a second position. When in the first position, a wind turbine or blade assembly can be hoisted to the top of the tower. The wind turbine or blade assembly is then moved into position for mounting to the tower as the frame or truss is pivoted to a second position. When the turbine and blade assembly are secured to the tower, the frame or truss is disconnected from the tower and lowered to the ground.

  7. Piers cooling towers. From first idess to realizations

    International Nuclear Information System (INIS)

    Bozetto, P.; Tzincoca, A.

    1988-01-01

    After a first part consecrated at the historical aspect of vertical piers cooling towers the second part indicates the experience pulled of the Chooz and Golfech cooling towers conception and realization [fr

  8. Stray current induced corrosion in lightning rod cables of 525 kV power lines towers: a case study

    OpenAIRE

    Wojcicki, F. R.; Negrisoli, M. E. M.; Franco, C. V.

    2003-01-01

    With the growth of several areas in modem society, the necessity to generate and carry electrical energy to big cities has greatly increased. Cables supported by power towers with galvanized steel foundation usually carry energy. As the foundations are underground they may cause high rates of corrosion. These are usually detected by a conventional potential measurement using a Cu/CuSO4 reference electrode. It is believed that corrosion results from stray currents that f...

  9. The Tower and Glass Marbles Problem

    Science.gov (United States)

    Denman, Richard T.; Hailey, David; Rothenberg, Michael

    2010-01-01

    The Catseye Marble company tests the strength of its marbles by dropping them from various levels of their office tower, to find the highest floor from which a marble will not break. We find the smallest number of drops required and from which floor each drop should be made. We also find out how these answers change if a restriction is placed on…

  10. The Tower of Hanoi and Inductive Logic

    Science.gov (United States)

    Merrotsy, Peter

    2015-01-01

    In the "Australian Curriculum," the concept of mathematical induction is first met in the senior secondary subject Specialist Mathematics. This article details an example, the Tower of Hanoi problem, which provides an enactive introduction to the inductive process before moving to more abstract and cognitively demanding representations.…

  11. Legionella confirmation in cooling tower water

    Science.gov (United States)

    Farhat, Maha; Shaheed, Raja A.; Al-Ali, Haidar H.; Al-Ghamdi, Abdullah S.; Al-Hamaqi, Ghadeer M.; Maan, Hawraa S.; Al-Mahfoodh, Zainab A.; Al-Seba, Hussain Z.

    2018-01-01

    Objectives: To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires’ disease. Methods: Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. Results: All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Conclusion: Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods. PMID:29436561

  12. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Al-Bloushi, Mohammed

    2017-01-01

    In this study, the research focuses on biofouling control in seawater cooling towers by investigating two different approaches. The first strategy addresses the use of alternative oxidants (i.e. ozone micro-bubbles and chlorine dioxide) in treatment of cooling towers. The second strategy investigates removing nutrients in seawater using granular activated carbon filter column and ultrafiltration to prevent the growth of microorganisms. Laboratory bench-scale tests in terms of temperature, cycle of concentration, dosage, etc. indicated that, at lower oxidant dosages (total residual oxidant (TRO) equivalent = 0.1 mg/l Cl2), chlorine dioxide had a better disinfection effect than chlorine and ozone. The performance of oxidizing biocides at pilot scale, operating at assorted conditions, showed that for the disinfectants tested, ozone could remove 95 % bioactivity of total number of bacteria and algae followed by chlorine dioxide at 85%, while conventional chlorine dosing only gave 60% reduction in bioactivities. Test results of GAC bio-filter showed that around 70 % removal of total organic carbon in the seawater feed was achieved and was effective in keeping the microbial growth to a minimum. The measured results from this study enable designers of seawater cooling towers to manage the biofouling problems when such cooling towers are extrapolated to a pilot scale.

  13. X-ray Observations at Gaisberg Tower

    Directory of Open Access Journals (Sweden)

    Pasan Hettiarachchi

    2018-01-01

    Full Text Available We report the occurrence of X-rays at ground level due to cloud-to-ground flashes of upward-initiated lightning from Gaisberg Tower, in Austria, which is located at an altitude of 1300 m. This is the first observation of X-ray emissions from upward lightning from a tower top located at high altitude. Measurements were carried out using scintillation detectors installed close to the tower top in two phases from 2011 to 2015. X-rays were recorded in three subsequent strokes of three flashes out of the total of 108 flashes recorded in the system during both phases. In contrast to the observations from downward natural or triggered lightning, X-rays were observed only within 10 µs before the subsequent return stroke. This shows that X-rays were emitted when the dart leader was in the vicinity of the tower top, hence during the most intense phase of the dart leader. Both the detected energy and the fluence of X-rays are far lower compared to X-rays from downward natural or rocket-triggered lightning. In addition to the above 108 flashes, an interesting observation of X-rays produced by a nearby downward flash is also presented. The shorter length of dart-leader channels in Gaisberg is suggested as a possible cause of this apparently weaker X-ray production.

  14. Frost protection for atmospheric cooling tower

    International Nuclear Information System (INIS)

    Legrand, G.

    1987-01-01

    When the atmospheric temperature is near or lower than zero it is necessary to reduce the air flow entering in a cooling tower. A wire netting mounted on the air inlet is sprinkled with cold water. The level of the ice curtain and consequently the air flow is regulated by aspersion by hot water [fr

  15. The Exact Limit of Some Cubic Towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Beelen, Peter; Nguyen, Nhut

    2017-01-01

    Recently, a new explicit tower of function fields was introduced by Bassa, Beelen, Garcia and Stichtenoth (BBGS). This resulted in currently the best known lower bound for Ihara’s constant in the case of non-prime finite fields. In particular over cubic fields, the tower’s limit is at least as go...

  16. Technical specifications: Tower Shielding Reactor II

    International Nuclear Information System (INIS)

    1979-02-01

    The technical specifications define the key limitations that must be observed for safe operation of the Tower Shielding Reactor II (TSR-II) and an envelope of operation within which there is reasonable assurance that these limits cannot be exceeded. The specifications were written to satisfy the requirements of the Department of Energy (DOE) Manual Chapter 0540, September 1, 1972

  17. Tubular fluoropolymer arrays with high piezoelectric response

    Science.gov (United States)

    Zhukov, Sergey; Eder-Goy, Dagmar; Biethan, Corinna; Fedosov, Sergey; Xu, Bai-Xiang; von Seggern, Heinz

    2018-01-01

    Polymers with electrically charged internal air cavities called ferroelectrets exhibit a pronounced piezoelectric effect and are regarded as soft functional materials suitable for sensor and actuator applications. In this work, a simple method for fabricating piezoelectret arrays with open-tubular channels is introduced. A set of individual fluoroethylenepropylene (FEP) tubes is compressed between two heated metal plates. The squeezed FEP tubes are melted together at +270 °C. The resulting structure is a uniform, multi-tubular, flat array that reveals a strong piezoelectric response after a poling step. The fabricated arrays have a high ratio between piezoelectrically active and non-active areas. The optimal charging voltage and stability of the piezoelectric coefficients with pressures and frequency were experimentally investigated for two specific array structures with wall thickness of 50 and 120 μm. The array fabricated from 50 μm thick FEP tubes reveals a stable and high piezoelectric coefficient of {d}33 = 120-160 pC N-1 with a flat frequency response between 0.1 Hz and 10 kHz for pressures between 1 and 100 kPa. An increase of wall thickness to 120 μm is accompanied by a more than twofold decrease in the piezoelectric coefficient as a result of a simultaneously higher effective array stiffness and lower remanent polarization. The obtained experimental results can be used to optimize the array design with regard to the electromechanical performance.

  18. Repair procedure used in removing corroded pits in the distillation towers of the Getulio Vargas Refinery Unit 2100

    Energy Technology Data Exchange (ETDEWEB)

    Lordelos, H.M.; Santin, J.L.

    1977-07-01

    A description is given of the corrosion pits on ASTM A240, Type 405 steel cladded to carbon steel plates used in Petroleo Brasileiro S.A.'s Getulio Vargas Refinery Unit 2100 distillation towers; the repair procedure used, including sand blasting of the corroded surfaces, grinding of the pits, and welding of those pits whose depth was above a maximum limit, and the use of liquid penetrant to check the repairs made; and hydrostatic testing of the T2201 catalytic cracking unit, which used also cladded metals and on which the pits were much smaller in size and number than those on the distillation units.

  19. Steel making

    CERN Document Server

    Chakrabarti, A K

    2014-01-01

    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  20. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process contact cooling towers... Process contact cooling towers provisions. (a) The owner or operator of each new affected source that... end finisher process that utilizes a process contact cooling tower shall comply with paragraph (c) of...

  1. Occupational exposure to radiofrequency fields in antenna towers

    International Nuclear Information System (INIS)

    Alanko, T.; Hietanen, M.

    2007-01-01

    Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

  2. Rectosigmoid tubular duplication presenting as perineal sepsis in a neonate.

    Science.gov (United States)

    Zhang, Zhibo; Huang, Ying; Wang, Dajia; Su, Pengjun

    2010-03-01

    Tubular rectal duplication is a very rare congenital anomaly. We report a case of tubular rectal duplication in a newborn baby who presented with perianal sepsis. The diagnosis was confirmed by barium enema, magnetic resonance imaging, and at operation. We performed total mucosectomy through a posterior sagittal incision combined with laparotomy. The patient was doing quite well at 17-month follow-up examination.

  3. Cyclosporine A induces senescence in renal tubular epithelial cells

    NARCIS (Netherlands)

    Jennings, Paul; Koppelstaetter, Christian; Aydin, Sonia; Abberger, Thomas; Wolf, Anna Maria; Mayer, Gert; Pfaller, Walter

    The nephrotoxic potential of the widely used immunosuppressive agent cyclosporine A (CsA) is well recognized. However, the mechanism of renal tubular toxicity is not yet fully elucidated. Chronic CsA nephropathy and renal organ aging share some clinical features, such as renal fibrosis and tubular

  4. Intrarenal purinergic signaling in the control of renal tubular transport

    DEFF Research Database (Denmark)

    Prætorius, Helle; Leipziger, Jens Georg

    2010-01-01

    -reaching advances indicate that ATP is often used as a local transmitter for classical sensory transduction. This transmission apparently also applies to sensory functions in the kidney. Locally released ATP is involved in sensing of renal tubular flow or in detecting the distal tubular load of NaCl at the macula...

  5. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  6. Cellular Phone Towers, Tower locations and attributes generated from FCC anntenna registration database. Tower data was cross referenced with county zoning special use permits., Published in 2008, 1:600 (1in=50ft) scale, Waupaca County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2008. Tower locations and attributes generated from FCC anntenna registration database. Tower data was cross referenced...

  7. Radio Transmitters and Tower Locations, Layer includes all towers identified visually and include cellular and other communication towers., Published in 2008, 1:1200 (1in=100ft) scale, Noble County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Radio Transmitters and Tower Locations dataset current as of 2008. Layer includes all towers identified visually and include cellular and other communication towers..

  8. Cancer in proximity to TV towers

    International Nuclear Information System (INIS)

    Hocking, B.; Gordon, I.; Hatfield, G.

    1996-01-01

    Full text: The effects of low level electro-magnetic fields on cancer development are controversial. There have been few epidemiological studies on the effects of radio-frequency radiation (RFR) and differing conclusions on possible detrimental health effects in humans (Goldsmith, Int. J Occ. and Env. Hlth, 1:47-57, 1995) (WHO, Env. Health Criteria 137). An unusual opportunity to assess possible risks further arose as cancer data (1972-1990) became available covering an area of North Sydney where three TV towers are located in a populated locality. An analysis of data was undertaken comparing cancer incidence and mortality in the three municipalities which immediately surround the TV towers compared to the adjacent three surrounding municipalities. Methods Data for the RFR sources on the towers was obtained (Dept. of Communications, Radio and TV Stations, 1994). The combined field strengths of the video and audio from the three towers and four channels at increasing distances were calculated (NCRP Report 119). Data from the NSW Cancer Registry on incidence, mortality and residence for 1972-1990 available via Healthwiz were extracted by municipality and for sex and age bands 0-14, 15-69 and 70+. Privacy reasons limit the availability of more refined data. The data were examined using a Poisson regression model (Frome EL, Biometrics, 39:665-74, 1983) with the numbers of cases or deaths regarded as Poisson random variables, whose mean is a product of the person years for the observation, and functions of the variables. The variables used were age categories, sex, calendar period (1972-78, 1979-84 and 1985-90), and area (inner 0-4 km and outer 4-12 km). To compare with the whole of NSW standardised incidence ratios and standardised mortality ratios were calculated. Confidence intervals were calculated using the 'exact' method (Liddell FDK, J. Epid. and Comm. Health, 38:85-88, 1984). Calculated field strengths are well below the limits prescribed in the Australian

  9. Study on Tower Models for EHV Transmission Line

    Directory of Open Access Journals (Sweden)

    Xu Bao-Qing

    2016-01-01

    Full Text Available Lightning outage accident is one of the main factors that threat seriously the safe and reliable operation of power system. So it is very important to establish reasonable transmission tower model and evaluate the impulse response characteristic of lightning wave traveling on the transmission tower properly for determining reliable lightning protection performance. With the help of Electromagnetic Transient Program (EMTP, six 500kV tower models are built. Aiming at one line to one transformer operating mode of 500kV substation, the intruding wave overvoltage under different tower models is calculated. The effect of tower model on intruding overvoltage has been studied. The results show that different tower models can result in great differences to the calculation results. Hence, reasonable selection of the tower model in the calculation of back- strike intruding wave is very important.

  10. Modality analysis of anchored ion exchange tower using Ansys

    International Nuclear Information System (INIS)

    Li Liang; Lei Zeyong

    2008-01-01

    Ion exchange towers are exposed to serious damage in the event of earthquakes. It is very necessary to study the seismic resistance of ion exchange tower. A finite element model of anchored ion exchange tower was made by Ansys. The first 10 ranks of inherent frequencies were made out, and three-dimensional main vibratory model figures were drawn out. The maximal stress along x-axis and y-axis and the main displacement were found at the bottom part of the wall of tower junction with the pillars. It is concluded that the breakage of tower wall easily occurs at the bottom part of the wall of tower junction with the pillars. Therefore, it is very important to reinforce the junction of the tower body, and the strengthening plate should lie near the bottom of wall. (authors)

  11. Forming of Polymeric Tubular Micro-components

    DEFF Research Database (Denmark)

    Qin, Yi; Zhao, Jie; Anyasodor, Gerald

    2015-01-01

    platform for the production of functional polymeric tubular micro-components. The chapter gives background on the current market and process development trends, followed by description of materials, process configuration, tool design and machine development for each processing technology as well......This chapter is intended to provide an overview of three nontraditional shaping technologies for the forming of polymeric micro-tubes, which are hot embossing, blow molding, and cross rolling, as well as realization of a process chain and the integration of a modular machine-based manufacturing...... as strategy for integration of the technologies and equipment into a common platform. Finally, potential applications of the technologies and facilities developed are highlighted....

  12. Sunscope natural light systems : tubular skylights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This brochure described a tubular skylight designed by Sunscope Natural Light Systems. The Sunscope is a super-reflective light system in which daylight is reflected down a cylinder to a translucent ceiling fixture that diffuses natural light throughout the room in which it is placed. The Sunscope requires no structure changes, is installed in less than 3 hours, and requires no drywall repairs or repainting. The system eliminates the need for daytime electric lighting, and causes no winter heat losses or summer heat gains. Available in 3 sizes, the Sunscope has no moving parts and is fully maintenance-free. The system was designed for use in commercial and residential applications. 7 figs.

  13. Inherited renal tubular defects with hypokalemia

    Directory of Open Access Journals (Sweden)

    Muthukrishnan J

    2009-01-01

    Full Text Available Bartter′s and Gitelman′s syndrome are two ends of a spectrum of inherited renal tubular disorders that present with hypokalemic metabolic alkalosis of varying severity. Clinical features and associated calcium and magnesium ion abnormalities are used to diagnose these cases after excluding other commoner causes. We report on two cases, the first being a young boy, born of pregnancy complicated by polyhydramnios, who had classical dysmorphic features, polyuria, hypokalemia and hypercalciuria and was diagnosed as having Bartter′s syndrome. The second patient is a lady who had recurrent tetany as the only manifestation of Gitelman′s syndrome, which is an unusual presentation. Potassium replacement with supplementation of other deficient ions led to satisfactory clinical and biochemical response.

  14. An ultrasonic inspection tool for production tubulars

    Energy Technology Data Exchange (ETDEWEB)

    Newton, K; Martin, R; Ravenscroft, F [AEA Technology, Harwell (United Kingdom)

    1994-06-01

    Advances in ultrasonic technology, high temperature techniques and remote processing power are enabling a new generation of inspection tools to be developed. This paper describes a particular new ultrasonic caliper system, developed by AEA Technology, with the aim of providing improved information about the condition of production tubulars of oil and gas wells. The system is designed to provide enhanced surface area coverage compared to the current devices, which are typically mechanical 'finger' calipers. It also provides a non-contacting measure of corrosion and wear together with direct on-line output and automated data analysis. The new tool is designed to operate in oil and gas, vertical or deviated wells and has the potential for modification to inspect small diameter pipes in topside or other plant. (author)

  15. Cytocompatibility of a silk fibroin tubular scaffold

    International Nuclear Information System (INIS)

    Wang, Jiannan; Wei, Yali; Yi, Honggen; Liu, Zhiwu; Sun, Dan; Zhao, Huanrong

    2014-01-01

    Regenerated silk fibroin (SF) materials are increasingly used for tissue engineering applications. In order to explore the feasibility of a novel biomimetic silk fibroin tubular scaffold (SFTS) crosslinked by poly(ethylene glycol) diglycidyl ether (PEG-DE), biocompatibility with cells was evaluated. The novel biomimetic design of the SFTS consisted of three distinct layers: a regenerated SF intima, a silk braided media and a regenerated SF adventitia. The SFTS exhibited even silk fibroin penetration throughout the braid, forming a porous layered tube with superior mechanical, permeable and cell adhesion properties that are beneficial to vascular regeneration. Cytotoxicity and cell compatibility were tested on L929 cells and human umbilical vein endothelial cells (EA.hy926). DNA content analysis, scanning electron and confocal microscopies and MTT assay showed no inhibitory effects on DNA replication. Cell morphology, viability and proliferation were good for L929 cells, and satisfactory for EA.hy926 cells. Furthermore, the suture retention strength of the SFTS was about 23 N and the Young's modulus was 0.2–0.3 MPa. Collectively, these data demonstrate that PEG-DE crosslinked SFTS possesses the appropriate cytocompatibility and mechanical properties for use as vascular scaffolds as an alternative to vascular autografts. - Highlights: • A PEG-DE cross-linked small caliber porous silk fibroin tubular scaffold (SFTS) • PEG-DE cross-linked SF film had no inhibitory effect on DNA replication of cells. • Cells cultured on the SFTS showed good morphology, cell viability and proliferative activity. • SFTS would be beneficial to endothelialization. • SFTS had good suture retention strength and flexibility

  16. Optical study of solar tower power plants

    International Nuclear Information System (INIS)

    Eddhibi, F; Amara, M Ben; Balghouthi, M; Guizani, A

    2015-01-01

    The central receiver technology for electricity generation consists of concentrating solar radiation coming from the solar tracker field into a central receiver surface located on the top of the tower. The heliostat field is constituted of a big number of reflective mirrors; each heliostat tracks the sun individually and reflects the sunlight to a focal point. Therefore, the heliostat should be positioned with high precision in order to minimize optical losses. In the current work, a mathematical model for the analysis of the optical efficiency of solar tower field power plant is proposed. The impact of the different factors which influence the optical efficiency is analyzed. These parameters are mainly, the shading and blocking losses, the cosine effect, the atmospheric attenuation and the spillage losses. A new method for the calculation of blocking and shadowing efficiency is introduced and validated by open literature

  17. Restoration of the Serranos Towers in Valencia.

    Directory of Open Access Journals (Sweden)

    Camilla Mileto

    2003-12-01

    Full Text Available The recent restoration of the emblematic Serranos Towers carried out by an interdisciplinary team of specialists was an excuse to delve into the history and masonry of the towers, from their initial building and use as a prison to the restorations works practised in the 19th century and subsequent repairs. The cleaning of the walls permitted a direct study of the masonry, which provided a great deal of information that complemented the rigorous historical investigation. The maintenance scheme planned for the future is an interesting proposal, where good sense prevails over improvisation, so often a reality in the restoration of monuments today.

  18. Wind-induced response analysis of a wind turbine tower including the blade-tower coupling effect

    Institute of Scientific and Technical Information of China (English)

    Xiao-bo CHEN; Jing LI; Jian-yun CHEN

    2009-01-01

    To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects,and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.

  19. Side Stream Filtration for Cooling Towers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  20. The solar two power tower project

    International Nuclear Information System (INIS)

    Chavez, J.M.; Klimas, P.C.; Laquil, P. de III; Skowronski, M.

    1993-01-01

    A consortium of United States utility concerns led by Southern California Edison Company (SCE) has begun a cooperative project with the U.S. Department of Energy (DOE) and industry to convert the 10-MWe Solar One Tower Pilot Plant to molten nitrate salt technology. Successful operation of the convert plant to be called Solar Two, will reduce the economic risks in building the initial commercial power tower projects and accelerate the commercial acceptance of this promising renewable energy technology. In a molten salt power tower plant, sunlight is concentrated by a field of sun-tracking mirrors, called heliostats, onto a centrally located receiver, atop a tower. Molten salt is heated in the receiver and stored until it is needed to generate steam to power a conventional turbine generator. Joining the SCE and DOE in sponsoring in sponsoring this project are the following organizations: Los Alamos department of Water Power, Idaho Power Company, PacifiCorp, Pacific Gas and Electric Company, Sacramento Municipal Utility District, Arizona Public Service Company, Salt River Project, City of Pasadena, California Energy Commission, Electric Power Research Institute, South Coast Air Quality Commission, Electric Power research Institute, South Coast Air Quality Management District, and Bechtel Corporation. The Solar Two project will convert the Solar One heat transfer system from a water/steam type to molten nitrate salt by replacing the water/steam receiver and oil/rock thermal storage system with a nitrate salt receiver, salt thermal storage, and steam generator. The estimate cost of Solar Two, including 3-year test period, is 48.5 millions. The plant will be on line in early 1995. (authors)

  1. INTEGRATED TWIN TOWERS DAN ISLAMISASI ILMU

    Directory of Open Access Journals (Sweden)

    Syaifuddin Syaifuddin

    2013-05-01

    Full Text Available This paper shows some idea as follows: First, integrated design of the Twin Towers as the changing action from IAIN to UIN Sunan Ampel. The religion and general knowledge’s position of Twin Towers’ integrated design is not mixed into one, but it works individually, and at the certain time are united in mutual dialogue. Second, Islamize design is done in order to criticize the general knowledge which has western sources and are secular, materialistic, and individualistic. In the process to Islamize the knowledge, Islamic knowledge tries to intervene the general knowledge in order to filter it so the knowledge will be Islamized. Consequently, to Islamize knowledge is to give an Islamic concept into general knowledge. Third, there are the similarities and differences between integrated design knowledge based on Islamic knowledge and integrated Twin Towers. The difference is in its epistemology process. The similarity is in the curriculum (ontology and objective (axiology. In the curriculum, the examined knowledge is religion and general knowledge. While the objective, Islamize knowledge and integrated Twin Towers aims to integrate religion and general knowledge, to dialogue, to communicate, and to synergy, so it can be a knowledge which is intact-integral-integrative.

  2. Subring Depth, Frobenius Extensions, and Towers

    Directory of Open Access Journals (Sweden)

    Lars Kadison

    2012-01-01

    Full Text Available The minimum depth d(B,A of a subring B⊆A introduced in the work of Boltje, Danz and Külshammer (2011 is studied and compared with the tower depth of a Frobenius extension. We show that d(B,A < ∞ if A is a finite-dimensional algebra and Be has finite representation type. Some conditions in terms of depth and QF property are given that ensure that the modular function of a Hopf algebra restricts to the modular function of a Hopf subalgebra. If A⊇B is a QF extension, minimum left and right even subring depths are shown to coincide. If A⊇B is a Frobenius extension with surjective Frobenius, homomorphism, its subring depth is shown to coincide with its tower depth. Formulas for the ring, module, Frobenius and Temperley-Lieb structures are noted for the tower over a Frobenius extension in its realization as tensor powers. A depth 3 QF extension is embedded in a depth 2 QF extension; in turn certain depth n extensions embed in depth 3 extensions if they are Frobenius extensions or other special ring extensions with ring structures on their relative Hochschild bar resolution groups.

  3. Testing methods of steel wi re ropes at the anchor

    Directory of Open Access Journals (Sweden)

    Stanislav Kropuch

    2012-12-01

    Full Text Available The present paper introduces an application of the acoustic andthermographic method in the defectoscopic testing of immobilesteel wire ropes at the most critical point, the anchor. Firstmeasurements and their results by these new defectoscopic methodsare shown. In defectoscopic tests at the anchor, the widelyused magnetic method gives unreliable results, and therefore presentsa problem for steel wire defectoscopy. Application of the two new methods in the steel wire defectoscopy at the anchor point will enableincreased safety measures at the anchor of steel wire ropes in bridge, roof, tower and aerial cable lift constructions.

  4. Development of a new method of measurement of the polarization resistance to estimate the level of corrosion of the reinforced concrete of cooling towers

    International Nuclear Information System (INIS)

    Mitzithra, M.E.; Deby, F.; Laurens, S.; Balayssac, J.P.; Salin, J.

    2014-01-01

    This paper summarises the results obtained from the numerical simulations of an operative measurement mode of polarization resistance adapted for evaluating the corrosion of reinforced concrete on cooling towers. A simple operative measurement mode of R p is proposed, adapted for cooling towers submitted to corrosion due to carbonation. By means of numerical experimentations, abacuses and correction laws are built involving the different influencing parameters: steel reinforcement's concrete cover, concrete resistivity and current intensity injected from the counter electrode. Finally, a first application of the proposed procedure for calculating the real value of R p in laboratory conditions is presented. (authors)

  5. Measurements on cooling tower plumes. Pt. 3

    International Nuclear Information System (INIS)

    Fortak, H.

    1975-11-01

    In this paper an extended field experiment is described in which cooling tower plumes were investigated by means of three-dimensional in situ measurements. The goal of this program was to obtain input data for numerical models of cooling tower plumes. Data for testing or developing assumptions for sub-grid parametrizations were of special interest. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station at Neurath and also two (1975) at the single cooling tower of the RWE power station at Meppen. Because of the broad spectrum of weather situations, it can be assumed that the results are representative with regard to the interrelationship between the structure of cooling tower plumes and the large-scale meteorological situation. A large number of flights with a powered glider ASK 16 (more than 100 flight hours) crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapour pressure. Therefore a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the plumes boundaries, which could be defined by the mentioned jumps of temperature and vapour pressure, a maximum of downward vertical motion was observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. The discontinuities of temperature and vapour pressure show that the plume fills the space below the visible plume down to the ground. However, all effects decrease rapidly towards the ground. It turned out that high

  6. Modeling of Direct Contact Wet Cooling Tower in ETRR-2

    International Nuclear Information System (INIS)

    El Khatib, H.H.; Ismail, A.L.; ElRefaie, M.E.

    2008-01-01

    The Egyptian Testing and Research Reactor no.2 (ETRR-2) was commissioned at 1997 with maximum power 22 MW for research purposes; an induced draft wet cooling tower (counter flow type) was putted in operation in 2003 instead of the first one. Investigations are achieved to evaluate cooling tower performance to guarantee that the cooling tower capable to dissipate heat generated in reactor core. Merkel and Poppe analysis was applied to simulate this cooling tower packing. Merkel analysis was applied to predict water outlet temperature from cooling tower and also to show the effect of ambient conditions on this temperature. Poppe analysis was applied to predict Merkel number which evaluate cooling tower. The Runge-Kutta numerical method was applied to solve the differential equations in this model and an engineering equation solver (EES) is the language used to model the cooling tower. This research illustrates that the cooling tower achieves good performance in various sever ambient condition at maximum operating condition of reactor power. The results show that at severe summer condition of wet bulb temperature equals 24 degree c and tower inlet temperature equals 37 degree c, the outlet water temperature equals 30.4 degree c from cooling tower, while the Merkel number is be found 1.253

  7. Intrarenal purinergic signaling in the control of renal tubular transport

    DEFF Research Database (Denmark)

    Prætorius, Helle; Leipziger, Jens Georg

    2010-01-01

    Renal tubular epithelial cells receive hormonal input that regulates volume and electrolyte homeostasis. In addition, numerous intrarenal, local signaling agonists have appeared on the stage of renal physiology. One such system is that of intrarenal purinergic signaling. This system involves all......-reaching advances indicate that ATP is often used as a local transmitter for classical sensory transduction. This transmission apparently also applies to sensory functions in the kidney. Locally released ATP is involved in sensing of renal tubular flow or in detecting the distal tubular load of NaCl at the macula...

  8. Perfis tubulares : aspectos arquitetônicos e estruturais.

    OpenAIRE

    Gerken, Fernanda de Sousa

    2003-01-01

    Programa de Pós Graduação em Engenharia Civil. Departamento de Engenharia Civil, Escola de Minas, Universidade Federal de Ouro Preto. O presente trabalho tem como objetivo apresentar uma visão geral da utilização das estruturas tubulares no contexto da evolução das estruturas metálicas em geral, com destaque para o estudo de obras que mostram o estado da arte da construção tubular no Brasil. A utilização dos perfis tubulares estruturais é abordada tanto do ponto de vista da ...

  9. Fatigue in Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    1999-01-01

    types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel with a yield stress of ~ 360-410 MPa or high-strength steel with a yield stress of ~ 810-1010 MPa. The fatigue tests and the fracture mechanics analyses......Fatigue damage accumulation in steel structures under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series have been carried through on various...... have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude and variable amplitude fatigue...

  10. HIGH FREQUENCY INDUCTION WELDING OF HIGH SILICON STEEL TUBES

    Directory of Open Access Journals (Sweden)

    Ricardo Miranda Alé

    2012-06-01

    Full Text Available High-Si steel is a low cost alternative for the fabrication of tubular structures resistant to atmospheric corrosion. However, the literature has often pointed out that steels presenting a higher Si content and/or a lower Mn/Si ratio have higher susceptibility to defects at the weld bond line during HFIW (High Frequency Induction Welding process, which has been widely used for manufacturing small diameter tubes. In this study the effect of the HFIW conditions on the quality of steel tubes with high-Si content and low Mn/Si ratio is investigated. The quality of welded tubes was determined by flare test and the defects in the bond line were identified by SEM. It has been found that higher welding speeds, V-convergence angles and power input should be applied in welding of high-Si steel, when compared to similar strength C-Mn steel.

  11. Analysis of Ideal Towers for Tall Wind Applications

    Energy Technology Data Exchange (ETDEWEB)

    Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Joseph O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lantz, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-12

    Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hub heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.

  12. ''Novel'' types of cooling towers for the power industry

    International Nuclear Information System (INIS)

    Mikyska, L.

    1991-01-01

    New types of cooling towers are beginning to be used abroad for the cooling circuits of nuclear power plants employing power generation units rated at 1,300 to 1,400 MW. These so-called water recovery cooling towers make use of natural draught without a droplet section. They are actually upgraded designs which were built in Europe as far back as 70 years ago. Because of the unsuitable materials then employed, these cooling towers fell into oblivion. Today, however, they are undergoing a renaissance. An upgraded design of these towers is described and compared with existing cooling towers with a droplet section. The feasibility of using these towers in Czechoslovak conditions is considered. (author)

  13. Analysis of Ideal Towers for Tall Wind Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Damiani, Rick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Joseph O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lantz, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-27

    Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hub heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.

  14. Scenario analysis of large scale algae production in tubular photobioreactors

    NARCIS (Netherlands)

    Slegers, P.M.; Beveren, van P.J.M.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    Microalgae productivity in tubular photobioreactors depends on algae species, location, tube diameter, biomass concentration, distance between tubes and for vertically stacked systems, the number of horizontal tubes per stack. A simulation model for horizontal and vertically stacked horizontal

  15. Hot Firing of a Full Scale Copper Tubular Combustion Chamber

    National Research Council Canada - National Science Library

    Cooley, C

    2002-01-01

    This paper describes the chamber design and hot firing test results for a full-scale copper tubular combustion chamber that has future application in a high-thrust, upper-stage expander cycle engine...

  16. Genetics Home Reference: renal tubular acidosis with deafness

    Science.gov (United States)

    ... adults with renal tubular acidosis with deafness have short stature, and many develop kidney stones. The metabolic acidosis ... enlarged vestibular aqueduct, can be seen with medical imaging. The vestibular aqueduct is a bony canal that ...

  17. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

    Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

  18. Tubular forms of papova viruses in human laryngeal papilloma.

    Science.gov (United States)

    Arnold, W

    1979-01-01

    In two cases of recurrent laryngeal papillomatosis tubular forms of papova viruses could be observed. The same material revealed the close relation between nuclear chromatine and the release of particles, as well as a capsomere like substructure of the virions.

  19. The Fourier transform of tubular densities

    KAUST Repository

    Prior, C B

    2012-05-18

    We consider the Fourier transform of tubular volume densities, with arbitrary axial geometry and (possibly) twisted internal structure. This density can be used to represent, among others, magnetic flux or the electron density of biopolymer molecules. We consider tubes of both finite radii and unrestricted radius. When there is overlap of the tube structure the net density is calculated using the super-position principle. The Fourier transform of this density is composed of two expressions, one for which the radius of the tube is less than the curvature of the axis and one for which the radius is greater (which must have density overlap). This expression can accommodate an asymmetric density distribution and a tube structure which has non-uniform twisting. In addition we give several simpler expressions for isotropic densities, densities of finite radius, densities which decay at a rate sufficient to minimize local overlap and finally individual surfaces of the tube manifold. These simplified cases can often be expressed as arclength integrals and can be evaluated using a system of first-order ODEs. © 2012 IOP Publishing Ltd.

  20. A tubular electrode for radiofrequency ablation therapy

    KAUST Repository

    Antunes, Carlos Lemos Lemos Lemos

    2012-07-06

    Purpose – Due to its good mechanical and biocompatibility characteristics, nitinol SEMS is a popular endoprothesis used for relieving stricture problems in hollow organs due to carcinomas. Besides its mechanical application, SEMS can be regarded as well as potential electrode for performing RF ablation therapy on the tumor. The purpose of this work is to perform numerical and experimental analyses in order to characterize the lesion volume induced in biological tissue using this kind of tubular electrode. Design/methodology/approach – Data concerning electrical conductivity and dimension of the damaged tissue after RF ablation procedure were obtained from ex vivo samples. Next, numerical models using 3D finite element method were obtained reassembling the conditions considered at experimentation setup and results were compared. Findings – Numerical and experimental results show that a regular volume of damaged tissue can be obtained considering this type of electrode. Also, results obtained from numerical simulation are close to those obtained by experimentation. Originality/value – SEMSs, commonly used as devices to minimize obstruction problems due to the growth of tumors, may still be considered as an active electrode for RF ablation procedures. A method considering this observation is presented in this paper. Also, numerical simulation can be regarded in this case as a tool for determining the lesion volume.

  1. The Fourier transform of tubular densities

    International Nuclear Information System (INIS)

    Prior, C B; Goriely, A

    2012-01-01

    We consider the Fourier transform of tubular volume densities, with arbitrary axial geometry and (possibly) twisted internal structure. This density can be used to represent, among others, magnetic flux or the electron density of biopolymer molecules. We consider tubes of both finite radii and unrestricted radius. When there is overlap of the tube structure the net density is calculated using the super-position principle. The Fourier transform of this density is composed of two expressions, one for which the radius of the tube is less than the curvature of the axis and one for which the radius is greater (which must have density overlap). This expression can accommodate an asymmetric density distribution and a tube structure which has non-uniform twisting. In addition we give several simpler expressions for isotropic densities, densities of finite radius, densities which decay at a rate sufficient to minimize local overlap and finally individual surfaces of the tube manifold. These simplified cases can often be expressed as arclength integrals and can be evaluated using a system of first-order ODEs. (paper)

  2. Inflatable Tubular Structures Rigidized with Foams

    Science.gov (United States)

    Tinker, Michael L.; Schnell, Andrew R.

    2010-01-01

    Inflatable tubular structures that have annular cross sections rigidized with foams, and the means of erecting such structures in the field, are undergoing development. Although the development effort has focused on lightweight structural booms to be transported in compact form and deployed in outer space, the principles of design and fabrication are also potentially applicable to terrestrial structures, including components of ultralightweight aircraft, lightweight storage buildings and shelters, lightweight insulation, and sales displays. The use of foams to deploy and harden inflatable structures was first proposed as early as the 1960s, and has been investigated in recent years by NASA, the U.S. Air Force Research Laboratory, industry, and academia. In cases of deployable booms, most of the investigation in recent years has focused on solid cross sections, because they can be constructed relatively easily. However, solid-section foam-filled booms can be much too heavy for some applications. In contrast, booms with annular cross sections according to the present innovation can be tailored to obtain desired combinations of stiffness and weight through choice of diameters, wall thicknesses, and foam densities. By far the most compelling advantage afforded by this innovation is the possibility of drastically reducing weights while retaining or increasing the stiffnesses, relative to comparable booms that have solid foamfilled cross sections. A typical boom according to this innovation includes inner and outer polyimide film sleeves to contain foam that is injected between them during deployment.

  3. Tubular Initial Conditions and Ridge Formation

    Directory of Open Access Journals (Sweden)

    M. S. Borysova

    2013-01-01

    Full Text Available The 2D azimuth and rapidity structure of the two-particle correlations in relativistic A+A collisions is altered significantly by the presence of sharp inhomogeneities in superdense matter formed in such processes. The causality constraints enforce one to associate the long-range longitudinal correlations observed in a narrow angular interval, the so-called (soft ridge, with peculiarities of the initial conditions of collision process. This study's objective is to analyze whether multiform initial tubular structures, undergoing the subsequent hydrodynamic evolution and gradual decoupling, can form the soft ridges. Motivated by the flux-tube scenarios, the initial energy density distribution contains the different numbers of high density tube-like boost-invariant inclusions that form a bumpy structure in the transverse plane. The influence of various structures of such initial conditions in the most central A+A events on the collective evolution of matter, resulting spectra, angular particle correlations and vn-coefficients is studied in the framework of the hydrokinetic model (HKM.

  4. Hereditary Hypokalemic salt-losing tubular disorders

    International Nuclear Information System (INIS)

    Peters, M.; Konard, M.; Seyberth, H.W.

    2003-01-01

    The inherited hypokalemic tubular disorders are frequently summarized under the heading Bartter Syndrome since they share several clinical and biochemical findings such as renal salt wasting, hypokalemic metabolic alkalosis, normal blood pressure despite hypereninemic hyperaldosteronism and hyperplasia of the juxtaglomerular apparatus. However, careful characterization of the clinical phenotype and correlation with the clinical phenotype and the correlation with the underlying molecular basis justifies the differentiation into at least four distinct disease entities: (i) the hyperprostaglandin E syndrome or antenatal variant of Bartter syndrome (HPS/aBS), which is caused by mutations in either the Na-K-2Cl cotransporter or the potassium channel of the medullary thick ascending limb of Henle's loop; (ii) the HPS/aBS with sensorineural deafness which results from inactivating mutation in the Barttin beta-subunit of the renal chloride channels; (iii) the classic Bartter syndrome caused by mutations in the chloride channel of the distal nephron; and (iv)Gitelman's variant of Bartter syndrome which is caused by mutations of the Na-Cl cotransporter of the distal convoluted tubule. This review will summarize the clinical characteristics of these diseases and progress recently made in the identification of the underlying molecular defects that will hopefully add to the current knowledge of the pathogenesis of these diseases. (author)

  5. Cooling tower wood sampling and analyses: A case study

    International Nuclear Information System (INIS)

    Haymore, J.L.

    1985-01-01

    Extensive wood sampling and analyses programs were initiated on crossflow and counterflow cooling towers that have been in service since 1951 and 1955, respectively. Wood samples were taken from all areas of the towers and were subjected to biological, chemical and physical tests. The tests and results for the analyses are discussed. The results indicate the degree of wood deterioration, and areas of the towers which experience the most advanced degree of degradation

  6. Radiation scanning aids tower diagnosis at Arun LNG plant

    International Nuclear Information System (INIS)

    Naklie, M.M.; Pless, L.; Gurning, T.P.; Hyasak, M.

    1990-01-01

    Radiation scanning has been used effectively to troubleshoot the treating towers of the Arun LNG plant in Sumatra, Indonesia. The plant is one of the world's largest such facilities. The analysis was part of an investigation aimed at increasing the capacity of the treater section of the plant. Radiation scanning is a tool which, in addition to tower differential pressure and product purity, can aid in diagnosing tower performance

  7. Modeling constrained sintering of bi-layered tubular structures

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Kothanda Ramachandran, Dhavanesan; Ni, De Wei

    2015-01-01

    Constrained sintering of tubular bi-layered structures is being used in the development of various technologies. Densification mismatch between the layers making the tubular bi-layer can generate stresses, which may create processing defects. An analytical model is presented to describe the densi...... and thermo-mechanical analysis. Results from the analytical model are found to agree well with finite element simulations as well as measurements from sintering experiment....

  8. Electrolyte composition of renal tubular cells in gentamicin nephrotoxicity

    International Nuclear Information System (INIS)

    Matsuda, O.; Beck, F.X.; Doerge, A.T.; Thurau, K.

    1988-01-01

    The effect of long-term gentamicin administration on sodium, potassium, chloride and phosphorus concentrations was studied in individual rat renal tubular cells using electron microprobe analysis. Histological damage was apparent only in proximal tubular cells. The extent of damage was only mild after 7 days of gentamicin administration (60 mg/kg body wt/day) but much more pronounced after 10 days. GFR showed a progressive decline during gentamicin treatment. In non-necrotic proximal tubular cells, sodium was increased from 14.6 +/- 0.3 (mean +/- SEM) in controls to 20.6 +/- 0.4 after 7 and 22.0 +/- 0.8 mmol/kg wet wt after 10 days of gentamicin administration. Chloride concentration was higher only after 10 days (20.6 +/- 0.6 vs. 17.3 +/- 0.2 mmol/kg wet wt). Both cell potassium and phosphorus concentrations were diminished by 6 and 15, and by 8 and 25 mmol/kg wet wt after 7 and 10 days of treatment, respectively. In contrast, no major alterations in distal tubular cell electrolyte concentrations could be observed after either 7 or 10 days of gentamicin administration. As in proximal tubular cells, distal tubular cell phosphorus concentrations were, however, lowered by gentamicin treatment. These results clearly indicate that gentamicin exerts its main effect on proximal tubular cells. Decreased potassium and increased sodium and chloride concentrations were observed in proximal tubular cells exhibiting only mild histological damage prior to the onset of advanced tissue injury. Necrotic cells, on the other hand, showed widely variable intracellular electrolyte concentration patterns

  9. A tall tower study of Missouri winds

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Neil I. [Department of Soil, Environmental and Atmospheric Sciences, 332 ABNR Building, University of Missouri, Columbia, MO 65211 (United States)

    2011-01-15

    This paper summarizes the results of a study of wind speeds observed at heights up to 150 m above ground level around Missouri. This is an amalgamation of four projects that allowed a total of eleven tall communication towers to be instrumented with wind observation equipment across the State of Missouri. This provided an assessment of the wind resource and the characteristics of the seasonal and diurnal cycles of wind in different areas of Missouri at the heights of utility scale wind turbines. Comparisons were also made to wind speeds predicted at these levels from a previously published wind map. The main finding was that the observed winds at each tower were smaller than those presented in the wind map. The discrepancy is most likely to be due to underestimation of the surface roughness and turbulence leading to an overestimation of near-surface wind shear. However, the wind shear, as expressed by the shear parameter was consistently greater than the 'standard' value of 1.4. The reconciliation of these two apparently contradictory findings is that the shear varies with the height at which it is measured. In wind resource assessment, wind shear is usually observed below 50 m and is tacitly assumed to be constant with height when used to extrapolate winds to higher levels. The author advocates the use of the friction velocity as a measure of shear in wind power applications in preference to the shear parameter that is usually used. This is because the shear parameter has a velocity bias that can also manifest as a bias with height or season. As wind power resource assessment is starting to use taller towers than the standard 50 m, intercomparison of site resources and extrapolation to turbine heights can be compromised if the shear parameter is used. (author)

  10. GPM GROUND VALIDATION METEOROLOGICAL TOWER ENVIRONMENT CANADA GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Meteorological Tower Environment Canada GCPEx dataset provides temperature, relative humidity, 10 m winds, pressure and solar radiation...

  11. Improving performance and reducing costs of cooling towers

    International Nuclear Information System (INIS)

    Bartz, J.A.

    1992-01-01

    Cooling towers represent a significant capital investment at a steam electric power station. In addition, deficiencies in thermal performance can result in major operating penalties of fuel cost, replacement energy, and capacity addition. This paper summarizes two recent EPRI research projects aimed at reducing thermal performance deficiencies and decreasing installed costs of evaporative cooling towers. First, EPRI Research Project 2113, Cooling Tower Performance Prediction and Improvement, is summarized. This project has resulted in published data sets on the measured thermal performance characteristics of a variety of cooling tower packings, computer codes to predict tower performance, and computer code validation through large-scale tower performance measurements. Principal results are contained in an EPRIGEMS software module, Cooling Tower Advisor. This PC- based software contains a tutorial plus codes to predict tower thermal performance, arranged in a user-friendly format. The second EPRI effort, Research Project 2819-10/11, Fabric Structures for Power Plant Applications, has resulted in designs and costs of large structures with shells constructed of recently-developed fabrics. Primary power plant applications for such structures are the shells of natural draft cooling towers and coal-pile covers. Fabric structures offer low initial cost, acceptable life, and seismic superiority, among other advantages. Detailed conceptual designs and installed cost data are reviewed. 8 refs., 9 figs., 3 tabs

  12. The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

    International Nuclear Information System (INIS)

    Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

    2008-01-01

    Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered

  13. Luminal nucleotides are tonic inhibitors of renal tubular transport

    DEFF Research Database (Denmark)

    Leipziger, Jens Georg

    2011-01-01

    PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are express...... discovered as an important signaling compartment in which local purinergic signaling determines an inhibitory tone for renal tubular transport. Blocking components of this system leads to tubular hyper-absorption, volume retention and elevated blood pressure.......PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are expressed...... in all renal tubular segments and their stimulation generally leads to transport inhibition. Recent evidence has identified the tubular lumen as a restricted space for purinergic signaling. The concentrations of ATP in the luminal fluids are sufficiently high to inflict a tonic inhibition of renal...

  14. Measurements at cooling tower plumes. Pt. 1

    International Nuclear Information System (INIS)

    Gassmann, F.; Haschke, D.; Solfrian, W.

    1976-04-01

    Referring to the present status of knowledge model conceptions, assumptions and approaches are summarized, which can lead to mathematical models for the simulation of dry or wet cooling tower plumes. By developing a one-dimensional plume model (FOG) the most important problems are considered in detail. It is shown that for the calibration of the necessary parameters as well as for the development of models full scale measurements are of decisive importance. After a discussion of different possibilities of measurement the organisation of a campaign of measurement is described. (orig.) [de

  15. Transmission Tower Environment Monitoring Using UAV

    International Nuclear Information System (INIS)

    Redzuwan, Redia Mohd; Din, Norashidah Md; Baharuddin, Mohd Zafri; Mustafa, Intan Shafinaz; Omar, Rohayu Che'

    2013-01-01

    Power utility engineers used to conduct ground survey to collect topographic data. Therefore, they can get detailed and accurate information, but these techniques take a lot of labors and expenses, and spending times for the surveying. An attractive solution to the ground survey is using images taken using Unmanned Aerial Vehicle (UAV). Images captured from UAV can be collected quickly and efficiently over the same area covered in the land survey, in a fraction of the time. The purpose of this research is to mosaic the large numbers of spectral images together into a region wide panoramic image which allows experts to analyze the data for transmission tower monitoring purposes.

  16. Girassol, Riser Towers for ultra deep water

    Energy Technology Data Exchange (ETDEWEB)

    Rougier, Regis

    1999-07-01

    This is a brief presentation of the technical concept developed by ALTO MAR GIRASSOL (AMG) for the Girassol umbilical and flowlines system. In 1998 AMG was awarded a contract by Elf Exploration Angola for the engineering, procurement, construction and installation (EPCI) of the umbilical and flowline system. The technical concept is based around the use of sealine bundles and self-supporting hybrid riser towers which carry the production, water injection, gas injection, gas lift and service lines. The items discussed are: (1) selected field layout, (2) seabed flowlines, hybrid riser system, umbilicals, export lines, installation plan and overall project schedule.

  17. ASTRID© - Advanced Solar Tubular ReceIver Design: A powerful tool for receiver design and optimization

    Science.gov (United States)

    Frantz, Cathy; Fritsch, Andreas; Uhlig, Ralf

    2017-06-01

    In solar tower power plants the receiver is one of the critical components. It converts the solar radiation into heat and must withstand high heat flux densities and high daily or even hourly gradients (due to passage of clouds). For this reason, the challenge during receiver design is to find a reasonable compromise between receiver efficiency, reliability, lifetime and cost. There is a strong interaction between the heliostat field, the receiver and the heat transfer fluid. Therefore, a proper receiver design needs to consider these components within the receiver optimization. There are several design and optimization tools for receivers, but most of them focus only on the receiver, ignoring the heliostat field and other parts of the plant. During the last years DLR developed the ASTRIDcode for tubular receiver concept simulation. The code comprises both a high and a low-detail model. The low-detail model utilizes a number of simplifications which allow the user to screen a high number of receiver concepts for optimization purposes. The high-detail model uses a FE model and is able to compute local absorber and salt temperatures with high accuracy. One key strength of the ASTRIDcode is its interface to a ray tracing software which simulates a realistic heat flux distributions on the receiver surface. The results generated by the ASTRIDcode have been validated by CFD simulations and measurement data.

  18. Measurements at cooling tower plumes. Part 3. Three-dimensional measurements at cooling tower plumes

    International Nuclear Information System (INIS)

    Fortak, H.

    An extended field experiment is described in which cooling tower plumes were studied by means of three-dimensional in situ measurements. The goal was to obtain input data for numerical models of cooling tower plumes. Of special interest were data for testing or developing assumptions for sub-grid parametrizations. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station Neurath and also two (1975) at the single cooling tower of the RWE power station Meppen. Because of the broad spectrum of weather situations it can be assumed that the results are representative with regard to the interrelationship between structure of cooling tower plume and large-scale meteorological situation. A large number of flights with a powered glider crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapor pressure. Therefore, a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the boundary, which could be defined by the mentioned jumps of temperature and vapor pressure, a maximum of downward vertical motion could be observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. High-resolution aerology is necessary in order to explain the structure and behavior of such plumes. This is especially the case in investigations regarding the dynamic break-through of temperature inversions. Such cases were observed frequently under various meteorological conditions and are described

  19. The tower of Hanoi myths and maths

    CERN Document Server

    Hinz, Andreas M; Petr, Ciril

    2018-01-01

    The solitaire game “The Tower of Hanoi" was invented in the 19th century by the French number theorist Édouard Lucas. The book presents its mathematical theory and offers a survey of the historical development from predecessors up to recent research. In addition to long-standing myths, it provides a detailed overview of the essential mathematical facts with complete proofs, and also includes unpublished material, e.g., on some captivating integer sequences. The main objects of research today are the so-called Hanoi graphs and the related Sierpiński graphs. Acknowledging the great popularity of the topic in computer science, algorithms, together with their correctness proofs, form an essential part of the book. In view of the most important practical applications, namely in physics, network theory and cognitive (neuro)psychology, the book also addresses other structures related to the Tower of Hanoi and its variants. The updated second edition includes, for the first time in English, the breakthrough reach...

  20. The anchors of steel wire ropes, testing methods and their results

    Directory of Open Access Journals (Sweden)

    J. Krešák

    2012-10-01

    Full Text Available The present paper introduces an application of the acoustic and thermographic method in the defectoscopic testing of immobile steel wire ropes at the most critical point, the anchor. First measurements and their results by these new defectoscopic methods are shown. In defectoscopic tests at the anchor, the widely used magnetic method gives unreliable results, and therefore presents a problem for steel wire defectoscopy. Application of the two new methods in the steel wire defectoscopy at the anchor point will enable increased safety measures at the anchor of steel wire ropes in bridge, roof, tower and aerial cable lift constructions.

  1. Performance characteristics of counter flow wet cooling towers

    International Nuclear Information System (INIS)

    Khan, Jameel-Ur-Rehman; Yaqub, M.; Zubair, Syed M.

    2003-01-01

    Cooling towers are one of the biggest heat and mass transfer devices that are in widespread use. In this paper, we use a detailed model of counter flow wet cooling towers in investigating the performance characteristics. The validity of the model is checked by experimental data reported in the literature. The thermal performance of the cooling towers is clearly explained in terms of varying air and water temperatures, as well as the driving potential for convection and evaporation heat transfer, along the height of the tower. The relative contribution of each mode of heat transfer rate to the total heat transfer rate in the cooling tower is established. It is demonstrated with an example problem that the predominant mode of heat transfer is evaporation. For example, evaporation contributes about 62.5% of the total rate of heat transfer at the bottom of the tower and almost 90% at the top of the tower. The variation of air and water temperatures along the height of the tower (process line) is explained on psychometric charts

  2. Wind-induced Vibrations in the European Court Towers

    DEFF Research Database (Denmark)

    Hansen, Jannick B.; Brincker, Rune; Andersen, Ken G.

    2012-01-01

    Issues regarding occupancy comfort in vibration-sensitive structures are the motivation of this study concerning windinduced vibrations in the European Court Towers in Luxembourg. In one of the two identical towers tuned liquid dampers (TLD) have been installed. Recent studies investigate the cha...

  3. Main photoautotrophic components of biofilms in natural draft cooling towers.

    Science.gov (United States)

    Hauer, Tomáš; Čapek, Petr; Böhmová, Petra

    2016-05-01

    While photoautotrophic organisms are an important component of biofilms that live in certain regions of natural draft cooling towers, little is known about these communities. We therefore examined 18 towers at nine sites to identify the general patterns of community assembly in three distinct tower parts, and we examined how community structures differ depending on geography. We also compared the newly acquired data with previously published data. The bottom sections of draft cooling towers are mainly settled by large filamentous algae, primarily Cladophora glomerata. The central portions of towers host a small amount of planktic algae biomass originating in the cooling water. The upper fourths of towers are colonized by biofilms primarily dominated by cyanobacteria, e.g., members of the genera Gloeocapsa and Scytonema. A total of 41 taxa of phototrophic microorganisms were identified. Species composition of the upper fourth of all towers was significantly affected by cardinal position. There was different species composition at positions facing north compared to positions facing south. West- and east-facing positions were transitory and highly similar to each other in terms of species composition. Biofilms contribute to the degradation of paint coatings inside towers.

  4. Proceedings: Cooling tower and advanced cooling systems conference

    International Nuclear Information System (INIS)

    1995-02-01

    This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  5. 78 FR 17183 - Information Collection: Grey Towers Visitor Comment Card

    Science.gov (United States)

    2013-03-20

    ... DEPARTMENT OF AGRICULTURE Forest Service Information Collection: Grey Towers Visitor Comment Card... request: (1) An extension from the Office of Management and Budget; and (2) to merge the currently approved information collection 0596- 0222, ``Grey Towers Visitor Comment Card'' with 0596-0226, ``Forest...

  6. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  7. Adaptive Backstepping Control of Lightweight Tower Wind Turbine

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Borup, Kasper Trolle; Niemann, Hans Henrik

    2015-01-01

    the angular deflection of the tower with respect to the vertical axis in response to variations in wind speed. The controller is shown to guarantee asymptotic tracking of the reference trajectory. The performance of the control system is evaluated through deterministic and stochastic simulations including......This paper investigates the feasibility of operating a wind turbine with lightweight tower in the full load region exploiting an adaptive nonlinear controller that allows the turbine to dynamically lean against the wind while maintaining nominal power output. The use of lightweight structures...... for towers and foundations would greatly reduce the construction cost of the wind turbine, however extra features ought be included in the control system architecture to avoid tower collapse. An adaptive backstepping collective pitch controller is proposed for tower point tracking control, i.e. to modify...

  8. The design and stability determination of wind turbine tower

    International Nuclear Information System (INIS)

    Abas Abd Wahab; Khairul Barriyah

    2001-01-01

    In wind turbine tower design, two load categories (static and wind load) were considered. The static load for this structure is the tower self-weight, which can be calculated from its density and area of the material, whereas the wind load was calculated based on CP3: Chapter V: Part 2: 1972, using the maximum wind speed of 30 m/s. The stability of this tower under the action of these two loads has been determined using RISA-3D program. The program were subjected to two joint types, i.e pinned and fixed joints. The tower using fixed joint members has established the necessary tower stability. The simulation, calculation and results are being discussed in detail in this paper. (Author)

  9. Frequency analysis of a tower-cable coupled system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Moo Yeol [Young Sin Precision Engineering Ltd., Gyungju (Korea, Republic of); Kim, Seock Hyun; Park, In Su [Kangwon National University, Chuncheon (Korea, Republic of); Cui, Chengxun [Yanbian University, Yangji (China)

    2013-06-15

    This study considers the prediction of natural frequency to avoid resonance in a wind turbine tower- cable coupled system. An analytical model based on the Rayleigh-Ritz method is proposed to predict the resonance frequency of a wind turbine tower structure supported by four guy cables. To verify the validity of the analytical model, a small tower-cable model is manufactured and tested. The frequency and mode data of the tower model are obtained by modal testing and finite element analysis. The validity of the proposed method is verified through the comparison of the frequency analysis results. Finally, using a parametric study with the analytical model, we identified how the cable tension and cable angle affect the resonance frequency of the wind turbine tower structure. From the analysis results, the tension limit and optimal angle of the cable are identified.

  10. Mathematical rationalization for the renal tubular transport: revised concepts.

    Science.gov (United States)

    Mioni, Roberto; Marega, Alessandra; Romano, Giulio; Montanaro, Domenico

    2017-09-01

    The current emphasis on kinetics and in situ control of molecular exchanges, across the tubular membrane, has not been paralleled by corresponding improvements in our understanding of tubular behaviour at the macroscopic level of classical physiology. In this paper, we propose a mathematical rationalization of macroscopic tubular transport by means of a principal transport equation, originating from the law of mass action between substrate and carrier. The other equations, derived from the main one, demonstrate the possibility of distinguishing between transporters with low affinity and high capacity and transporters with high affinity and low capacity. Moreover, our model formalizes both tubular reabsorption and tubular secretion. Regarding the renal calcium handling, our model confirms the two-compartment system proposed by Mioni in 1971, with some important variants, which are in agreement with the fractional reabsorptions of this cation along the tubule, as verified by micro-puncture technique. To obtain the frequency distribution of saturated tubules, we have utilized the infinitesimal analysis method, starting from the equations proposed by Smith in 1943, concluding that all titration curves result from the combined effect of enzymatic approach and anatomical heterogeneity of the nephrons. The theoretical equations included in our manuscript reflect substantial and palpable physiological mechanisms able to suggest diagnosis and therapy of some electrolyte and hormonal disorders. At the end of this paper, we highlight advantages and disadvantages detectable by comparing our mathematical approach with Marshall's and Bijvoet's methods, proposed, respectively, in 1976 and 1984.

  11. Proximal tubular dysfunction as an indicator of chronic graft dysfunction

    Directory of Open Access Journals (Sweden)

    N.O.S. Câmara

    2009-03-01

    Full Text Available New strategies are being devised to limit the impact of renal sclerosis on graft function. Individualization of immunosuppression, specifically the interruption of calcineurin-inhibitors has been tried in order to promote better graft survival once chronic graft dysfunction has been established. However, the long-term impact of these approaches is still not totally clear. Nevertheless, patients at higher risk for tubular atrophy and interstitial fibrosis (TA/IF development should be carefully monitored for tubular function as well as glomerular performance. Since tubular-interstitial impairment is an early event in TA/IF pathogenesis and associated with graft function, it seems reasonable that strategies directed at assessing tubular structural integrity and function would yield important functional and prognostic data. The measurement of small proteins in urine such as α-1-microglobulin, N-acetyl-beta-D-glucosaminidase, alpha/pi S-glutathione transferases, β-2 microglobulin, and retinol binding protein is associated with proximal tubular cell dysfunction. Therefore, its straightforward assessment could provide a powerful tool in patient monitoring and ongoing clinical assessment of graft function, ultimately helping to facilitate longer patient and graft survival associated with good graft function.

  12. PORFIDO on the NEMO Phase 2 tower

    Energy Technology Data Exchange (ETDEWEB)

    Ciaffoni, Orlando; Cordelli, Marco; Habel, Roberto; Martini, Agnese; Trasatti, Luciano [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (RM) (Italy)

    2014-11-18

    We have designed and built an underwater measurement system, PORFIDO (Physical Oceanography by RFID Outreach) to gather oceanographic data from the Optical Modules of a neutrino telescope with a minimum of disturbance to the main installation. PORFIDO is composed of a sensor glued to the outside of an Optical Module, in contact with seawater, and of a reader placed inside the sphere, facing the sensor. Data are transmitted to the reader through the glass by RFID and to shore in real time for periods of years. The sensor gathers power from the radio frequency, thus eliminating the need for batteries or connectors through the glass. We have deployed four PORFIDO probes measuring temperatures with the NEMO-KM3Net-Italy Phase 2 tower in april 2013. The four probes are operative and are transmitting temperature data from 3500 m depth.

  13. PORFIDO on the NEMO Phase 2 tower

    International Nuclear Information System (INIS)

    Ciaffoni, Orlando; Cordelli, Marco; Habel, Roberto; Martini, Agnese; Trasatti, Luciano

    2014-01-01

    We have designed and built an underwater measurement system, PORFIDO (Physical Oceanography by RFID Outreach) to gather oceanographic data from the Optical Modules of a neutrino telescope with a minimum of disturbance to the main installation. PORFIDO is composed of a sensor glued to the outside of an Optical Module, in contact with seawater, and of a reader placed inside the sphere, facing the sensor. Data are transmitted to the reader through the glass by RFID and to shore in real time for periods of years. The sensor gathers power from the radio frequency, thus eliminating the need for batteries or connectors through the glass. We have deployed four PORFIDO probes measuring temperatures with the NEMO-KM3Net-Italy Phase 2 tower in april 2013. The four probes are operative and are transmitting temperature data from 3500 m depth

  14. Emergent patterns of collective cell migration under tubular confinement.

    Science.gov (United States)

    Xi, Wang; Sonam, Surabhi; Beng Saw, Thuan; Ladoux, Benoit; Teck Lim, Chwee

    2017-11-15

    Collective epithelial behaviors are essential for the development of lumens in organs. However, conventional assays of planar systems fail to replicate cell cohorts of tubular structures that advance in concerted ways on out-of-plane curved and confined surfaces, such as ductal elongation in vivo. Here, we mimic such coordinated tissue migration by forming lumens of epithelial cell sheets inside microtubes of 1-10 cell lengths in diameter. We show that these cell tubes reproduce the physiological apical-basal polarity, and have actin alignment, cell orientation, tissue organization, and migration modes that depend on the extent of tubular confinement and/or curvature. In contrast to flat constraint, the cell sheets in a highly constricted smaller microtube demonstrate slow motion with periodic relaxation, but fast overall movement in large microtubes. Altogether, our findings provide insights into the emerging migratory modes for epithelial migration and growth under tubular confinement, which are reminiscent of the in vivo scenario.

  15. Power generation characteristics of tubular type SOFC by wet process

    Energy Technology Data Exchange (ETDEWEB)

    Tajiri, H.; Nakayama, T. [Kyushu Electric Power Company, Inc., Fukuoka (Japan); Kuroishi, M. [TOTO Ltd., Kanagawa (Japan)] [and others

    1996-12-31

    The development of a practical solid oxide fuel cell requires improvement of a cell performance and a cell manufacturing technology suitable for the mass production. In particular tubular type SOFC is thought to be superior in its reliability because its configuration can avoid the high temperature sealing and reduce the thermal stress resulting from the contact between cells. The authors have fabricated a tubular cell with an air electrode support by a wet processing technique, which is suitable for mass production in improving a power density. To enhance the power output of the module, the Integrated Tubular-Type (ITT) cell has been developed. This paper reports the performance of the single cells with various active anode areas and the bundle with series-connected 9-ITT cells with an active anode area of 840 cm{sup 2}.

  16. Effect of corrosion on the buckling capacity of tubular members

    Science.gov (United States)

    Øyasæter, F. H.; Aeran, A.; Siriwardane, S. C.; Mikkelsen, O.

    2017-12-01

    Offshore installations are subjected to harsh marine environment and often have damages from corrosion. Several experimental and numerical studies were performed in the past to estimate buckling capacity of corroded tubular members. However, these studies were either based on limited experimental tests or numerical analyses of few cases resulting in semi-empirical relations. Also, there are no guidelines and recommendations in the currently available design standards. To fulfil this research gap, a new formula is proposed to estimate the residual strength of tubular members considering corrosion and initial geometrical imperfections. The proposed formula is verified with results from finite element analyses performed on several members and for varying corrosion patch parameters. The members are selected to represent the most relevant Eurocode buckling curve for tubular members. It is concluded that corrosion reduces the buckling capacity significantly and the proposed formula can be easily applied by practicing engineers without performing detailed numerical analyses.

  17. HER-2 amplification in tubular carcinoma of the breast.

    Science.gov (United States)

    Oakley, Gerard J; Tubbs, Raymond R; Crowe, Joseph; Sebek, Bruce; Budd, G Thomas; Patrick, Rebecca J; Procop, Gary W

    2006-07-01

    The prognostic and therapeutic implications of HER-2 gene amplification and estrogen and progesterone receptor status in breast cancer are well described. To address the relative paucity of information concerning HER-2 amplification for tubular carcinomas, we assessed the frequency of gene amplification in 55 tubular carcinomas of the breast from 54 patients, 5 of which had axillary node metastases. The HER-2 gene copy number was assessed by fluorescence in situ hybridization for the majority of tumors analyzed, whereas estrogen and progesterone receptor status was achieved by immunohistochemical analysis. HER-2 gene amplification was not observed in any of the tumors examined, and most were estrogen receptor-positive. This HER-2 gene amplification frequency was significantly lower than the frequency of gene amplification previously reported for all invasive ductal carcinoma of no special type (P < .01). HER-2 gene amplification likely occurs infrequently, or not at all, in tubular carcinomas of the breast, whereas most express estrogen receptors.

  18. MODELING OF TUBULAR ELECTROCHEMICAL REACTOR FOR DYE REMOVAL

    Directory of Open Access Journals (Sweden)

    V. VIJAYAKUMAR

    2017-06-01

    Full Text Available The aim of the present investigation is to model a tubular electrochemical reactor for the treatment of synthetic dye wastewater. The tubular reactor was modeled and solved by finite difference method. For the model solution, the column was divided into 11 nodes in the axial direction and the variation in the radial direction has been neglected. An initial dye concentration of 200 mg L-1was taken in the reservoir. The reactor was operated in a batch with recirculation operation. Based on preliminary experiments all parameters have been optimized. The model simulation is compared with the experimental value and it is observed that the model fairly matches well with the experiment. The modeling of tubular electrochemical reactors for dye waste water treatment could be useful in the design and scale up of electrochemical process.

  19. Performance of water distribution systems in a pilot cooling tower

    International Nuclear Information System (INIS)

    Tognotti, L.; Giacomelli, A.; Zanelli, S.; Bellagamba, B.; Lotti, G.; Mattachini, F.

    1990-01-01

    An experimental study has been carried out on the water distribution system of a Pilot cooling tower of 160 m 3 /hr The performances of different industrial water distributors have been evaluated by changing the operative conditions of the pilot tower. In particular, the efficiency and the uniformity of the water distribution have been investigated and compared with the results obtained in a small-scale loop, in which the single nozzles were tested. Measurements in both systems, pilot tower and small scale loop, included the geometric characteristics of the jet umbrella by ensemble photography, the wetted zone by measuring the specific flowrate, the drop-size distribution and liquid concentration by high-speed photography. The results show that correlations exist between the nozzle behaviour in single and pilot tower configuration. The uniformity of water distribution in the pilot tower is strongly related to the nozzle installation pattern and to the operative conditions. Coalescence plays an important role on the drop size distribution in the pilot-tower. Comments upon the influence of these parameters on tower behaviour are also included

  20. Improving the efficiency of natural draft cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Smrekar, J. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia); Oman, J. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia)]. E-mail: janez.oman@fs.uni-lj.si; Sirok, B. [Faculty of Mechanical Engineering, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2006-06-15

    This study shows how the efficiency of a natural draft cooling tower can be improved by optimising the heat transfer along the cooling tower (CT) packing using a suitable water distribution across the plane area of the cooling tower. On the basis of cooling air measurements, it is possible to distribute the water in such a way that it approaches the optimal local water/air mass flow ratio and ensures the homogeneity of the heat transfer and a reduction of entropy generation, thus minimising the amount of exergy lost. The velocity and temperature fields of the air flow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements at an arbitrary point above the spray zone over the entire plane area of the cooling tower. The topological structures of the moist air velocity profiles and the temperature profiles above the spray zone were used as input data for calculation of the local entropy generation in the tower. On the basis of the measured boundary conditions, a numerical analysis of the influence of the water distribution across the cooling tower's plane area on entropy generation and exergy destruction in the cooling tower was conducted.

  1. Asbestos in cooling-tower waters. Final report

    International Nuclear Information System (INIS)

    Lewis, B.A.G.

    1979-03-01

    Water discharges from cooling towers constructed with asbestos fill were found to contain chrysotile--asbestos fibers at concentrations as high as 10 8 fibers/liter. The major source of these fibers, appears to be the components of the towers rather than the air drawn through the towers or the makeup water taken into the towers. Suggested mechanisms for the release of chrysotile fibers from cooling-tower fill include freeze-thaw cycles and dissolution of the cement due to acidic components of the circulating water. Ash- or other material-settling ponds were found to reduce asbestos-fiber concentrations in cooling-tower effluent. The literature reviewed did not support the case for a causal relationship between adverse human health effects and drinking water containing on the order of 10 6 chrysotile--asbestos fibers/liter; for this and other reasons, it is not presently suggested that the use of asbestos fill be discontinued. However, caution and surveillance are dictated by the uncertainties in the epidemiological studies, the absence of evidence for a safe threshold concentration in water, and the conclusive evidence for adverse effects from occupational exposure. It is recommended that monitoring programs be carried out at sites where asbestos fill is used; data from such programs can be used to determine whether any mitigative measures should be taken. On the basis of estimates made in this study, monitoring for asbestos in drift from cooling towers does not appear to be warranted

  2. Improving the efficiency of natural draft cooling towers

    International Nuclear Information System (INIS)

    Smrekar, J.; Oman, J.; Sirok, B.

    2006-01-01

    This study shows how the efficiency of a natural draft cooling tower can be improved by optimising the heat transfer along the cooling tower (CT) packing using a suitable water distribution across the plane area of the cooling tower. On the basis of cooling air measurements, it is possible to distribute the water in such a way that it approaches the optimal local water/air mass flow ratio and ensures the homogeneity of the heat transfer and a reduction of entropy generation, thus minimising the amount of exergy lost. The velocity and temperature fields of the air flow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements at an arbitrary point above the spray zone over the entire plane area of the cooling tower. The topological structures of the moist air velocity profiles and the temperature profiles above the spray zone were used as input data for calculation of the local entropy generation in the tower. On the basis of the measured boundary conditions, a numerical analysis of the influence of the water distribution across the cooling tower's plane area on entropy generation and exergy destruction in the cooling tower was conducted

  3. Numerical Simulation of Tower Rotor Interaction for Downwind Wind Turbine

    Directory of Open Access Journals (Sweden)

    Isam Janajreh

    2010-01-01

    Full Text Available Downwind wind turbines have lower upwind rotor misalignment, and thus lower turning moment and self-steered advantage over the upwind configuration. In this paper, numerical simulation to the downwind turbine is conducted to investigate the interaction between the tower and the blade during the intrinsic passage of the rotor in the wake of the tower. The moving rotor has been accounted for via ALE formulation of the incompressible, unsteady, turbulent Navier-Stokes equations. The localized CP, CL, and CD are computed and compared to undisturbed flow evaluated by Panel method. The time history of the CP, aerodynamic forces (CL and CD, as well as moments were evaluated for three cross-sectional tower; asymmetrical airfoil (NACA0012 having four times the rotor's chord length, and two circular cross-sections having four and two chords lengths of the rotor's chord. 5%, 17%, and 57% reductions of the aerodynamic lift forces during the blade passage in the wake of the symmetrical airfoil tower, small circular cross-section tower and large circular cross-section tower were observed, respectively. The pronounced reduction, however, is confined to a short time/distance of three rotor chords. A net forward impulsive force is also observed on the tower due to the high speed rotor motion.

  4. Thermal performance of a transpired solar collector updraft tower

    International Nuclear Information System (INIS)

    Eryener, Dogan; Hollick, John; Kuscu, Hilmi

    2017-01-01

    Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

  5. Dynamic behavior and identification of failure modes of cooling towers

    International Nuclear Information System (INIS)

    Serhan, S.J.

    1994-01-01

    The major thrust of this paper is to provide an engineering assessment of two hyperboloidal 540-foot high reinforced concrete cooling towers at a nuclear power plant relative to the proposed construction of a new safety-related facility in the shadow of these cooling towers. A three-dimensional full 360-degree finite-element model that is capable of realistically representing the response of the two cooling towers subjected to the plant design-basis safe shutdown earthquake, 90 mph wind, and 300 mph tornado is used to create a data pool which supports the proposed construction of the new facility. Dynamic time history analyses are performed to represent the complex interplay of the dynamic characteristics of the cooling towers and the input wind-pressure excitation in terms of gust factors. This study resulted in the confirmation and enhancement of many of the important aspects in the design/analysis methodologies for cooling towers reported in literature. In summary, this study provides a high confidence that no significant damage will be caused to the two cooling towers when subjected to the plant design-basis safe shutdown earthquake and the 90 mph basic wind velocity. However, the two cooling towers are expected to collapse if subjected in a direct hit to a 300 mph tornado. The nonlinear finite element analyses including base uplift performed for this study and the literature research on past failures of cooling towers due to severe wind storms confirm that the mode of failure will not be the overturning cantilever tree-type and the towers will collapse inwardly with the exception of few isolated debris

  6. Research into spectra transformation of cooling tower droplet drift

    International Nuclear Information System (INIS)

    Mandrykin, G.P.

    1990-01-01

    Empirical droplet-diameter distributions in a cooling tower and outside are well approximated by the Rosin-Rammler-Bennet two-parameter function. Fractional efficiency of eliminators is also approximated by the above function fairly well. The design formulas proposed are universal and allow evaluation of droplet spectra transformation as well as the efficiency of measures for preventing droplet emissions from cooling towers both at the design and operation stages. Estimates of cooling tower droplet emissions calculated by the formulas suggested may be recommended as input data applied to the solution of environmental pollution problems and their assessment

  7. Fire behaviour of cooling tower packing; Brandverhalten von Kuehlturmeinbauten

    Energy Technology Data Exchange (ETDEWEB)

    Mattausch, Tim [DMT GmbH und Co. KG, Dortmund (Germany). Fachstelle fuer Brandschutz

    2013-10-01

    The rapid burning down of the cooling tower of the shutdown power plant in Schwandorf revealed the potential of a total loss of a cooling tower in case of fire. VGB ordered a research project in order to obtain more knowledge about the fire risk of cooling tower packing currently applied. Depending on kind and age of the plastics used, the results of these tests manifest a big variation of the fire behaviour. For the applications of plastics, it is essential to determine and to adhere to organisational fire protection measures. (orig.)

  8. Virtual and remote control tower research, design, development and validation

    CERN Document Server

    2016-01-01

    The interdisciplinary research and development work carried out in the last ten years which is presented in this book aimed at replacing the conventional airport control tower by a new “remote tower operation” work environment (RTO) which should enhance work efficiency and safety and reduce costs. This revolutionary human–system interface allows for remote aerodrome traffic control without a physical tower building and enables the establishment of remote airport traffic control centers (RTC) of which each may serve several airports from a central location.

  9. Kaiseraugst nuclear power station: meteorological effects of the cooling towers

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Considerations of water conservation persuaded the German Government in 1971 not to allow the use of the Aar and Rhine for direct cooling of nuclear power stations. The criticism is often made that the Kaiseraugst cooling towers were built without full consideration of the resulting meteorological effects. The criticism is considered unjustified because the Federal Cooling Tower Commission considered all the relevant aspects before making its recommendations in 1972. Test results and other considerations show that the effect of the kaiseraugst cooling towers on meteorological and climatic conditions is indeed minimal and details are given. (P.G.R.)

  10. Steel alloys

    International Nuclear Information System (INIS)

    Bloom, E.E.; Stiegler, J.O.; Rowcliffe, A.F.; Leitnaker, J.M.

    1977-01-01

    The invention deals with a fuel element for fast breeder reactors. It consits essentially of a uranium oxide, nitride, or carbide or a mixture of these fuels with a plutonium or thorium oxide, nitride, or carbide. The fuel elements are coated with an austenitic stainless steel alloy. Inside the fuel elements, vacancies or small cavities are produced by neutron effects which causes the steel coating to swell. According to the invention, swelling is prevented by a modification of type 304, 316, 321, or 12 K 72HV commercial steels. They consist mainly of Fe, Cr, and Ni in a ratio determined by a temary diagram. They may also contain 1.8 to 2.3% by weight of Mo and a fraction of Si (0.7 to 2% by weight) and Ti(0.10 to 0.5% by weight) to prevent cavity formation. They are structurally modified by cold working. (IHOE) [de

  11. Cultivation of micro-algae in closed tubular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gudin, C.; Bernard, A.; Chaumont, D.

    1983-11-01

    A description is presented of the three culture pilot utilities in activity under natural light, including glass tubular solar collector (30 mm diameter) in which the microalgae culture circulates. The utility is controled automatically (thermal regulation, gaseous transfers, continuous culture organization). The tests were conducted for the production of polysaccharides (Porphyridium cruentum, chlamydomonas mexicana) or hydrocarbons (Botriococcus braunii).

  12. Modeling of heat transfer in wall-cooled tubular reactors

    NARCIS (Netherlands)

    Koning, G.W.; Westerterp, K.R.

    1999-01-01

    In a pilot scale wall-cooled tubular reactor, temperature profiles have been measured with and without reaction. As a model reaction oxidation of carbon monoxide in air over a copper chromite catalyst has been used. The kinetics of this reaction have been determined separately in two kinetic

  13. The H^{-1}-norm of tubular neighbourhoods of curves

    NARCIS (Netherlands)

    Gennip, van Y.; Peletier, M.A.

    2011-01-01

    We study the H^{-1}-norm of the function 1 on tubular neighbourhoods of curves in R^2. We take the limit of small thickness epsilon, and we prove two different asymptotic results. The first is an asymptotic development for a fixed curve in the limit epsilon to 0, containing contributions from the

  14. Hemodynamic and tubular changes induced by contrast media.

    Science.gov (United States)

    Caiazza, Antonella; Russo, Luigi; Sabbatini, Massimo; Russo, Domenico

    2014-01-01

    The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI.

  15. Elevated oxidized glutathione in cystinotic proximal tubular epithelial cells.

    Science.gov (United States)

    Wilmer, Martijn J G; de Graaf-Hess, Adriana; Blom, Henk J; Dijkman, Henry B P M; Monnens, Leo A; van den Heuvel, Lambertus P; Levtchenko, Elena N

    2005-11-18

    Cystinosis, the most frequent cause of inborn Fanconi syndrome, is characterized by the lysosomal cystine accumulation, caused by mutations in the CTNS gene. To elucidate the pathogenesis of cystinosis, we cultured proximal tubular cells from urine of cystinotic patients (n = 9) and healthy controls (n = 9), followed by immortalization with human papilloma virus (HPV E6/E7). Obtained cell lines displayed basolateral polarization, alkaline phosphatase activity, and presence of aminopeptidase N (CD-13) and megalin, confirming their proximal tubular origin. Cystinotic cell lines exhibited elevated cystine levels (0.86 +/- 0.95 nmol/mg versus 0.09 +/- 0.01 nmol/mg protein in controls, p = 0.03). Oxidized glutathione was elevated in cystinotic cells (1.16 +/- 0.83 nmol/mg versus 0.29 +/- 0.18 nmol/mg protein, p = 0.04), while total glutathione, free cysteine, and ATP contents were normal in these cells. In conclusion, elevated oxidized glutathione in cystinotic proximal tubular epithelial cell lines suggests increased oxidative stress, which may contribute to tubular dysfunction in cystinosis.

  16. Tubularized incised plate technique for recurrent hypospadias: a ...

    African Journals Online (AJOL)

    management of recurrent hypospadias. Summary background ... The potential advantages of tubularized incised plate .... after a mean duration of 4.9 ± 3.1 years from the previous repair (Table 2). .... erection and the risk of infection, especially in patients older than 15 .... However, previous surgery often limits the availability ...

  17. Modeling of Unidirectional-Overloaded Transition in Catalytic Tubular Microjets

    NARCIS (Netherlands)

    Klingner, Anke; Khalil, Islam S. M.; Magdanz, Veronika; Fomin, Vladimir M.; Schmidt, Oliver G.; Misra, Sarthak

    2017-01-01

    A numerical time-resolved model is presented for predicting the transition between unidirectional and overloaded motion of catalytic tubular microjets (Ti/Fe/Pt rolled-up microtubes) in an aqueous solution of hydrogen peroxide. Unidirectional movement is achieved by periodic ejection of gas bubbles

  18. Characterization of Foam Catalysts as Packing for Tubular Reactors.

    Czech Academy of Sciences Publication Activity Database

    Lali, Farzad

    2016-01-01

    Roč. 105, JUL 2016 (2016), s. 1-9 ISSN 0255-2701 Institutional support: RVO:67985858 Keywords : overall mass transfer * foam catalyst * tubular reactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.234, year: 2016

  19. Importance of early audiologic assessment in distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Elizabeth Norgett

    2010-12-01

    Full Text Available Anand P Swayamprakasam1, Elizabeth Stover1, Elizabeth Norgett1, Katherine G Blake-Palmer1, Michael J Cunningham2, Fiona E Karet11Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK; 2Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USAAbstract: Autosomal recessive distal renal tubular acidosis is usually a severe disease of childhood, often presenting as failure to thrive in infancy. It is often, but not always, accompanied by sensorineural hearing loss, the clinical severity and age of onset of which may be different from the other clinical features. Mutations in either ATP6V1B1 or ATP6V0A4 are the chief causes of primary distal renal tubular acidosis with or without hearing loss, although the loss is often milder in the latter. We describe a kindred with compound heterozygous alterations in ATP6V0A4, where hearing loss was formally diagnosed late in both siblings such that they missed early opportunities for hearing support. This kindred highlights the importance of routine audiologic assessments of all children with distal renal tubular acidosis, irrespective either of age at diagnosis or of which gene is mutated. In addition, when diagnostic genetic testing is undertaken, both genes should be screened irrespective of current hearing status. A strategy for this is outlined.Keywords: sensorineural hearing loss, renal tubular acidosis, recessive, genetics, mutation

  20. Finite element analysis of tubular joints in offshore structures ...

    African Journals Online (AJOL)

    ... representing a 2-D model of the joint between the brace and the chord walls. This was subsequently followed but finite element analysis of six tubular joints. A global analysis was initially undertaken, then the submodel analysis carried in the areas of stress concentration. Journal of Civil Engineering, JKUAT (2001) Vol 6, ...

  1. New methods for the geometrical analysis of tubular organs.

    Science.gov (United States)

    Grélard, Florent; Baldacci, Fabien; Vialard, Anne; Domenger, Jean-Philippe

    2017-12-01

    This paper presents new methods to study the shape of tubular organs. Determining precise cross-sections is of major importance to perform geometrical measurements, such as diameter, wall-thickness estimation or area measurement. Our first contribution is a robust method to estimate orthogonal planes based on the Voronoi Covariance Measure. Our method is not relying on a curve-skeleton computation beforehand. This means our orthogonal plane estimator can be used either on the skeleton or on the volume. Another important step towards tubular organ characterization is achieved through curve-skeletonization, as skeletons allow to compare two tubular organs, and to perform virtual endoscopy. Our second contribution is dedicated to correcting common defects of the skeleton by new pruning and recentering methods. Finally, we propose a new method for curve-skeleton extraction. Various results are shown on different types of segmented tubular organs, such as neurons, airway-tree and blood vessels. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Expansion of Tubular with Elastomers in Multilateral Wells

    Directory of Open Access Journals (Sweden)

    Md Velden

    2013-06-01

    Full Text Available The use of solid expandable tubular technology during the last decade has focused on solving many challenges in well drilling and delivery including zonal isolation, deep drilling, conservation of hole sizes, etc. not only as pioneered solution but also providing cost effective and long lasting solutions. Concurrently, the technology was extended for construction of multilateral in typical wells. The process of horizontal tubular expansion is similar to the vertical expansion of expandable tubular in down-hole environment with the addition of uniformly distributed force due to its weight. The expansion is targeted to increase its diameter such that post expansion characteristics remain within allowable limits. In this study a typical expandable tubular of 57.15 mm outer diameter and 6.35 mm wall thickness was used with two different elastomer seals of 5 and 7 mm thickness placed at equal spacing of 200 mm. The developed stress contours during expansion process clearly showed the high stress areas in the vicinity of expansion region which lies around the mandrel. These high stresses may result in excessive wear of the mandrel. It was also found out that the drawing force increases as the mandrel angle, expansion ratio, and friction coefficient increases. A mandrel angle of 20o  requires minimum expansion force and can be considered as an optimum geometrical parameter to lower the power required for expansion.

  3. Transient acute tubular dysfunction in the newborn: CT findings

    International Nuclear Information System (INIS)

    McLaughlin, M.G.; Schwartz, J.R.; Swayne, L.C.; Columbia Univ., New York; Rubenstein, J.B.; University of Medicine and Dentistry of New Jersey, Newark, NJ; Block, D.C.

    1990-01-01

    We report the CT and sonographic findings of transient acute tubular disease in a newborn infant, who was dehydrated at birth. The initial CT scan demonstrated focal areas of increased attenuation within the central portions of both kidneys, and sonography showed echogenic medullary pyramids. After adequate hydration, a follow-up examination demonstrated complete spontaneous resolution. (orig.)

  4. Renal pathophysiologic role of cortical tubular inclusion bodies.

    Science.gov (United States)

    Radi, Zaher A; Stewart, Zachary S; Grzemski, Felicity A; Bobrowski, Walter F

    2013-01-01

    Renal tubular inclusion bodies are rarely associated with drug administration. The authors describe the finding of renal cortical tubular intranuclear and intracytoplasmic inclusion bodies associated with the oral administration of a norepinephrine/serotonin reuptake inhibitor (NSRI) test article in Sprague-Dawley (SD) rats. Rats were given an NSRI daily for 4 weeks, and kidney histopathologic, ultrastructural pathology, and immunohistochemical examinations were performed. Round eosinophilic intranuclear inclusion bodies were observed histologically in the tubular epithelial cells of the renal cortex in male and female SD rats given the NSRI compound. No evidence of degeneration or necrosis was noted in the inclusion-containing renal cells. By ultrastructural pathology, inclusion bodies consisted of finely granular, amorphous, and uniformly stained nonmembrane-bound material. By immunohistochemistry, inclusion bodies stained positive for d-amino acid oxidase (DAO) protein. In addition, similar inclusion bodies were noted in the cytoplasmic tubular epithelial compartment by ultrastructural and immunohistochemical examination.  This is the first description of these renal inclusion bodies after an NSRI test article administration in SD rats. Such drug-induced renal inclusion bodies are rat-specific, do not represent an expression of nephrotoxicity, represent altered metabolism of d-amino acids, and are not relevant to human safety risk assessment.

  5. Urinary Markers of Tubular Injury in Early Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Temesgen Fiseha

    2016-01-01

    Full Text Available Diabetic nephropathy (DN is a common and serious complication of diabetes associated with adverse outcomes of renal failure, cardiovascular disease, and premature mortality. Early and accurate identification of DN is therefore of critical importance to improve patient outcomes. Albuminuria, a marker of glomerular involvement in early renal damage, cannot always detect early DN. Thus, more sensitive and specific markers in addition to albuminuria are needed to predict the early onset and progression of DN. Tubular injury, as shown by the detection of tubular injury markers in the urine, is a critical component of the early course of DN. These urinary tubular markers may increase in diabetic patients, even before diagnosis of microalbuminuria representing early markers of normoalbuminuric DN. In this review we summarized some new and important urinary markers of tubular injury, such as neutrophil gelatinase associated lipocalin (NGAL, kidney injury molecule-1 (KIM-1, liver-type fatty acid binding protein (L-FABP, N-acetyl-beta-glucosaminidase (NAG, alpha-1 microglobulin (A1M, beta 2-microglobulin (B2-M, and retinol binding protein (RBP associated with early DN.

  6. Some asymptotic properties of functions holomorphic in tubular domains

    International Nuclear Information System (INIS)

    Zavialov, B.I.

    1988-10-01

    For the function holomorphic in curved tubular domain the connection between asymptotic behaviour of real part of its boundary value at a given point of base manifold and asymptotic behaviour of the whole function from the inside of this domain is studied. (author). 3 refs

  7. Torsional stresses in the transverse fillet weld tubular joints

    NARCIS (Netherlands)

    Gunay, D.; Aydemir, A.; Özer, H.

    1996-01-01

    Torsional stresses, 'tre and tel , in tbe transverse fillet tubular weld joint subjected to torsional load have been analyzed by the finite element method using triangular and quadrilateral izoparametric axisymmetric fourier type torus finite elements. There is an axisymmetry with respect to

  8. Experiments in MARIUS on HTR tubular fuel with loose particles

    Energy Technology Data Exchange (ETDEWEB)

    Bosser, R; Langlet, G

    1972-06-15

    The work described on HTR tubular fuel with loose particles is the first part of a program in three points. The cell is the same in the three experiments, only particles in the fuel container are changed. The aim of the experiment is to achieve the buckling in a critical facility. A description of the techniques of measurements, calculations, and results are presented.

  9. 75 FR 63802 - Action Affecting Export Privileges; Parto Abgardan Cooling Towers Co.

    Science.gov (United States)

    2010-10-18

    ... Abgardan Cooling Towers Co. Parto Abgardan Cooling Towers Co., P.O. Box 966, Folsom, CA 95763; and P.O. Box... Making Denial of Export Privileges of Aqua-Loop Cooling Towers, Co. Applicable to Parto Abgardan Cooling...-Loop Cooling Towers, Co. (``Aqua-Loop'') on March 25, 2010 (``Denial Order''), applicable to the...

  10. Evaluation of Tower Shadowing on Anemometer Measurements at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    The objective of this study is to evaluate the effect of tower shadowing from the meteorology towers at LANL during 2014. This study is in response to the Department of Energy Meteorological Coordinating Council visit in 2015 that recommended an evaluation of any biases in the wind data introduced by the tower and boom alignment at all meteorology towers.

  11. Demo-application of shape memory alloy devices: the rehabilitation of the S. Giorgio Church bell tower

    Science.gov (United States)

    Indirli, Maurizio; Castellano, Maria G.; Clemente, Paolo; Martelli, Alessandro

    2001-07-01

    This paper describes the rehabilitation of the S. Giorgio Church Bell-Tower (Trignano, Municipality of S. Martino in Rio, Reggio Emilia, Italy), completed in September 1999. This masonry building, seriously damaged by the earthquake of October 15th 1996 which struck the Reggio Emilia and Modena Districts, Italy), was investigated by the authors immediately after the seismic event, as other ancient Cultural Heritage Structures (CUHESs) in the same area. In the past, seismic events have visited substantial destruction that translates into a significant loss of architectural heritage. The most common solution traditionally used to enhance the CUHESs seismic behaviour is the introduction of localized reinforcements, usually Traditional Steel Ties (TSTs), increasing stability and ductility. Anyway, in many cases said reinforcement techniques, often too invasive, proved to be inadequate to prevent collapse. For these reasons, the Bell-Tower intervention applies Innovative Antiseismic Techniques (IATs) by the use of superelastic Shape Memory Alloy (SMA) Devices (SMADs), a technology developed after a large amount of theoretical studies, numerical analyses and test campaigns. The SMADs, which can be considered a powerful tool with respect to the traditional methods, provide acceleration reduction, force limitation and energy dissipation. Furthermore, they are characterized by low invasivity and complete reversibility. When another earthquake occurred on June 18th 2000, with the same epicenter and a comparable Richter Magnitudo, the Bell-Tower, subjected to a new investigation, showed no damage of any type. Thus, the new seismic event has been the best verification of the retrofit intervention.

  12. Nerve regeneration using tubular scaffolds from biodegradable polyurethane.

    Science.gov (United States)

    Hausner, T; Schmidhammer, R; Zandieh, S; Hopf, R; Schultz, A; Gogolewski, S; Hertz, H; Redl, H

    2007-01-01

    In severe nerve lesion, nerve defects and in brachial plexus reconstruction, autologous nerve grafting is the golden standard. Although, nerve grafting technique is the best available approach a major disadvantages exists: there is a limited source of autologous nerve grafts. This study presents data on the use of tubular scaffolds with uniaxial pore orientation from experimental biodegradable polyurethanes coated with fibrin sealant to regenerate a 8 mm resected segment of rat sciatic nerve. Tubular scaffolds: prepared by extrusion of the polymer solution in DMF into water coagulation bath. The polymer used for the preparation of tubular scaffolds was a biodegradable polyurethane based on hexamethylene diisocyanate, poly(epsilon-caprolactone) and dianhydro-D-sorbitol. EXPERIMENTAL MODEL: Eighteen Sprague Dawley rats underwent mid-thigh sciatic nerve transection and were randomly assigned to two experimental groups with immediate repair: (1) tubular scaffold, (2) 180 degrees rotated sciatic nerve segment (control). Serial functional measurements (toe spread test, placing tests) were performed weekly from 3rd to 12th week after nerve repair. On week 12, electrophysiological assessment was performed. Sciatic nerve and scaffold/nerve grafts were harvested for histomorphometric analysis. Collagenic connective tissue, Schwann cells and axons were evaluated in the proximal nerve stump, the scaffold/nerve graft and the distal nerve stump. The implants have uniaxially-oriented pore structure with a pore size in the range of 2 micorm (the pore wall) and 75 x 700 microm (elongated pores in the implant lumen). The skin of the tubular implants was nonporous. Animals which underwent repair with tubular scaffolds of biodegradable polyurethanes coated with diluted fibrin sealant had no significant functional differences compared with the nerve graft group. Control group resulted in a trend-wise better electrophysiological recovery but did not show statistically significant

  13. A software architecture for a transportation control tower

    NARCIS (Netherlands)

    Baumgrass, A.; Dijkman, R.M.; Grefen, P.W.P.J.; Pourmirza, S.; Völzer, H.; Weske, M.H.

    2014-01-01

    A Transportation Control Tower is a software application that facilitates transportation planners with easily monitoring and dispatching transportation resources. This paper presents a software architecture for such an application. It focuses in particular on the novel aspects of the software

  14. Newton slopes for Artin-Schreier-Witt towers

    DEFF Research Database (Denmark)

    Davis, Christopher; Wan, Daqing; Xiao, Liang

    2016-01-01

    We fix a monic polynomial f(x)∈Fq[x] over a finite field and consider the Artin-Schreier-Witt tower defined by f(x); this is a tower of curves ⋯→Cm→Cm−1→⋯→C0=A1, with total Galois group Zp. We study the Newton slopes of zeta functions of this tower of curves. This reduces to the study of the Newton...... slopes of L-functions associated to characters of the Galois group of this tower. We prove that, when the conductor of the character is large enough, the Newton slopes of the L-function form arithmetic progressions which are independent of the conductor of the character. As a corollary, we obtain...

  15. Transient Simulation of Wind Turbine Towers under Lightning Stroke

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2013-01-01

    Full Text Available A simulation algorithm is proposed in this paper for lightning transient analysis of the wind turbine (WT towers. In the proposed algorithm, the tower body is first subdivided into a discrete multiconductor system. A set of formulas are given to calculate the electrical parameters of the branches in the multiconductor system. By means of the electrical parameters, each branch unit in the multiconductor system is replaced as a coupled π-type circuit and the multiconductor system is converted into a circuit model. Then, the lightning transient responses can be obtained in different parts on the tower body by solving the circuit equations of the equivalent discretization network. The laboratory measurement is also made by a reduced-scale tower for checking the validity of the proposed algorithm.

  16. Hadron calorimeter towers with a high space resolution

    International Nuclear Information System (INIS)

    Bellettini, G.; Bertani, R.; Bradaschia, C.; Del Fabbro, R.; Scribano, A.; Terreni, G.

    1982-01-01

    The performances of a set of hadron calorimeter towers for measuring the hadron impact point are described. It is shown that an accuracy of 1-2 cm can be achieved with a proper treatment of the data. (orig.)

  17. Lower parts of Temelin nuclear power plant cooling towers

    International Nuclear Information System (INIS)

    Sebek, J.

    1988-01-01

    The progress of work is described in detail on the foundations and lower parts of the cooling towers of the Temelin nuclear power plant. The cooling tower is placed on a reinforced concrete footing of a circular layout. Support pillars are erected on the reinforced concrete continuous footing. They consists of oblique shell stanchions. Inside, the footing joins up to monolithic wall and slab structures of the cooling tower tub. The tub bottom forms a foundation plate supporting prefab structures of the cooling tower inner structural systems. The framed support of the chimney shell consists of 56 pairs of prefabricated oblique stanchions. Following their erection into the final position and anchoring in the continuous footing, the concreting of the casing can start of the reinforced conrete chimney. (Z.M.). 3 figs

  18. Optimization of cooling tower performance analysis using Taguchi method

    Directory of Open Access Journals (Sweden)

    Ramkumar Ramakrishnan

    2013-01-01

    Full Text Available This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N analysis, analysis of variance (ANOVA and regression were carried out in order to determine the effects of process parameters on cooling tower effectiveness and to identity optimal factor settings. Finally confirmation tests verified this reliability of Taguchi method for optimization of counter flow cooling tower performance with sufficient accuracy.

  19. Use of cooling tower blow down in ethanol fermentation.

    Science.gov (United States)

    Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

    2010-01-01

    Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible.

  20. Final Rule for Industrial Process Cooling Towers: Fact Sheet

    Science.gov (United States)

    Fact sheet concerning a final rule to reduce air toxics emissions from industrial process cooling towers. Air toxics are those pollutants known or suspected of causing cancer or other serious health effects.

  1. A Dimensioning Methodology for a Natural Draft Wet Cooling Tower

    Directory of Open Access Journals (Sweden)

    Ioana Opriș

    2017-05-01

    Full Text Available The paper proposes a methodology for the dimensioning of a natural draft wet cooling tower. The main geometrical dimensions depend on the packing type, the cooling and the weather conditions. The study is based on splitting the tower in three main zones: the spray and packing zone, the rain zone and the natural draft zone. The methodology is developed on modular bases, by using block-modules both for the three main zones of the cooling tower and for the inlet/outlet air properties. It is useful in explaining to the students the complex physical phenomena within the cooling tower but also for the development of a computer program to be used in engineering, management and education.

  2. Parametric study of closed wet cooling tower thermal performance

    Science.gov (United States)

    Qasim, S. M.; Hayder, M. J.

    2017-08-01

    The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

  3. Noise emissions of cooling towers; Geraeuschemissionen von Kuehltuermen

    Energy Technology Data Exchange (ETDEWEB)

    Hinkelmann, Dirk [Mueller-BBM GmbH, Gelsenkirchen (Germany)

    2013-09-01

    Cooling towers are often large structures with high sound emission. The impact of water drops on the water surface in the collecting basin leads to the generation of middle- and high-frequency noise that is emitted via the air intake opening and the outlet. In forced-draft cooling towers, additional noise is generated by drives and fans. The sound emissions can be predicted by means of empirical calculation models. In this way, noise control measures can be taken into account already at an early phase of planning. Different, proven measures for reduction of sound emissions are taken depending on cooling tower design. Regulations on noise acceptance testing for cooling towers are given in various standards. (orig.)

  4. Natural-draught cooling tower of the Philippsburg-1 reactor

    International Nuclear Information System (INIS)

    Ernst, G.; Wurz, D.

    1983-01-01

    In spring 1980 a comprehensive research programm was carried out on the natural-draught cooling tower of the Philippsburg-1 reactor. The study was meant to synchronously acquire all parameters necessary for the evaluation of plant operation and cooling tower emissions. The study is subdivided into 8 sub-projects. Parts 1 to 7 that are included in this progress-of-work report describe experimental work and discuss the results. A critical analysis of measuring results proves that the values for operational behaviour and cooling tower emissions were duly anticipated. Even a very critical judgment of the results can exclude direct or indirect hazards for humans, animals and plants owing to cooling tower emissions. Sub-project 8 compares results from diffusion calculations (24 models) to results gained from experiments. The results of sub-project 8 will be published in a progress report to come. (orig.) [de

  5. Natural-draught cooling towers made of reinforced concrete

    International Nuclear Information System (INIS)

    Kraetzig, W.B.; Peters, H.L.; Zerna, W.

    1978-01-01

    Large power plant units and dry cooling tower technology require larger dimensions for natural-draught cooling towers. The main curvation radii in latitudinal and meridian direction are thus increased, which results in a lower three-dimensional support strength. This development is an incentive for constant re-consideration of calculation methods, safety philosophy, and dimensioning criteria. In this context, wind effects have been re-formulated and given a scientific foundation. Constructional measures to improve the static and dynamic behaviour of the structure have been presented and critically assessed. A cost analysis, finally, gave the most rational applications of the new shell construction with reinforcing elements. A cooling tower now under construction gave a realistic example. Fundamental aspects concerning the foundations of cooling tower shells and two special types of foundation are further points to clarify the subject. (orig./HP) [de

  6. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    Even in our globalized world the notion of national economies remain incredibly strong, just as a considerable part of the literature on transnational governance and globalization continue to rely on a zero-sum perspective concerning the relationship between the national and the transnational. De...... of the European steel industry....

  7. Towers of generalized divisible quantum codes

    Science.gov (United States)

    Haah, Jeongwan

    2018-04-01

    A divisible binary classical code is one in which every code word has weight divisible by a fixed integer. If the divisor is 2ν for a positive integer ν , then one can construct a Calderbank-Shor-Steane (CSS) code, where X -stabilizer space is the divisible classical code, that admits a transversal gate in the ν th level of Clifford hierarchy. We consider a generalization of the divisibility by allowing a coefficient vector of odd integers with which every code word has zero dot product modulo the divisor. In this generalized sense, we construct a CSS code with divisor 2ν +1 and code distance d from any CSS code of code distance d and divisor 2ν where the transversal X is a nontrivial logical operator. The encoding rate of the new code is approximately d times smaller than that of the old code. In particular, for large d and ν ≥2 , our construction yields a CSS code of parameters [[O (dν -1) ,Ω (d ) ,d ] ] admitting a transversal gate at the ν th level of Clifford hierarchy. For our construction we introduce a conversion from magic state distillation protocols based on Clifford measurements to those based on codes with transversal T gates. Our tower contains, as a subclass, generalized triply even CSS codes that have appeared in so-called gauge fixing or code switching methods.

  8. The Tower Shielding Facility: Its glorious past

    International Nuclear Information System (INIS)

    Muckenthaler, F.J.

    1997-01-01

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports

  9. Christchurch Bay Tower data archive. Principal report

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, J.R.

    1998-05-01

    Wave force experiments at the Christchurch Bay Tower yielded valuable data on wave forces on cylinders under the complex flows experienced in real sea conditions. The last experiments were conducted in 1987, but the data remain an important source of information on the wave forces on cylinders, together with the measured wave particle kinematics. The use of two columns with different diameters enabled the studies to extend over a large range of Keulegan Carpenter numbers and Reynolds numbers. The experiments included clean vertical and horizontal cylinders, cylinders with real kelp fouling, with simulated hard roughness and a flexible cylinder. Considerable effort was devoted to quality control of the measured data. The experiments were funded mainly by the UK Department of Energy, and ownership of the results has now been transferred to the Offshore Safety Division of the Health and Safety Executive. They have now commissioned the archiving of a set of important records from the experiments, covering clean cylinders, kelp fouling, hard roughness and a horizontal cylinder. The purpose is to make the data available for future work on wave loadings and the related wave particle kinematics. The raw measured data are not usable without specialist decoding, calibration and certain pre-processing tasks. So, in this archiving work, the data have been processed into parameters such as 2 axis forces and 3 axis wave kinematics. As a result of this archiving project the data are available on CD ROM. (author)

  10. The Tower Shielding Facility: Its glorious past

    Energy Technology Data Exchange (ETDEWEB)

    Muckenthaler, F.J.

    1997-05-07

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  11. Assessment of requirements for dry towers

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D E; Sonnichsen, J C

    1976-09-01

    The regional limitations of surface water supplies in the U.S. were assessed with respect to the consumptive use requirements of wet cooling towers. The study simulated unit consumptive use factors by region, assessed regional water supplies, and examined electric load projections through 2000 A.D. to ascertain where and when water limitations may occur and, therefore, where dry cooling may be required. It was concluded that the cooling water supply situation in the United States through the year 2000 is adequate in most areas, but is uncertain over much of the Southwest. The uncertainty is related to increasing competition for the available supplies and to potential Federal and/or State policy decisions that may have a significant effect on power plant cooling. Limitations on coastal siting, seismic zone constraints, and state constraints on the purchase and transfer of water rights from other uses to cooling supply have the potential of bringing wet/dry or dry cooling into relatively common use in the 1990's. (LCL)

  12. Factor H and Properdin Recognize Different Epitopes on Renal Tubular Epithelial Heparan Sulfate

    NARCIS (Netherlands)

    Zaferani, Azadeh; Vives, Romain R.; van der Pol, Pieter; Navis, Gerjan J.; Daha, Mohamed R.; van Kooten, Cees; Lortat-Jacob, Hugues; Seelen, Marc A.; van den Born, Jacob

    2012-01-01

    During proteinuria, renal tubular epithelial cells become exposed to ultrafiltrate-derived serum proteins, including complement factors. Recently, we showed that properdin binds to tubular heparan sulfates (HS). We now document that factor H also binds to tubular HS, although to a different epitope

  13. Evaluation of dynamic response for monopole and hybrid wind mill tower

    Science.gov (United States)

    Shah, Hemal J.; Desai, Atul K.

    2017-07-01

    The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovative tower is studied for different operating frequencies of wind turbine. From study it is concluded that the innovative tower will reduce resonance condition considering soil structure interaction.

  14. DEVELOPMENT OF METHODS FOR STABILITY ANALYSIS OF TOWER CRANES

    Directory of Open Access Journals (Sweden)

    Sinel'shchikov Aleksey Vladimirovich

    2018-01-01

    Full Text Available Tower cranes are one of the main tools for execution of reloading works during construction. Design of tower cranes is carried out in accordance with RD 22-166-86 “Construction of tower cranes. Rules of analysis”, according to which to ensure stability it is required not to exceed the overturning moment upper limit. The calculation of these moments is carried out with the use of empirical coefficients and quite time-consuming. Moreover, normative methodology only considers the static position of the crane and does not take into account the presence of dynamic transients due to crane functioning (lifting and swinging of the load, boom turning and the presence of the dynamic external load (e.g. from wind for different orientations of the crane. This paper proposes a method of determining the stability coefficient of the crane based on acting reaction forces at the support points - the points of contact of wheels with the crane rail track, which allows us, at the design stage, to investigate stability of tower crane under variable external loads and operating conditions. Subject: the safety of tower cranes operation with regard to compliance with regulatory requirements of ensuring their stability both at the design stage and at the operational stage. Research objectives: increasing the safety of operation of tower cranes on the basis of improving methodology of their design to ensure static and dynamic stability. Materials and methods: analysis and synthesis of the regulatory framework and modern research works on provision of safe operation of tower cranes, the method of numerical simulation. Results: we proposed the formula for analysis of stability of tower cranes using the resulting reaction forces at the supports of the crane at the point of contact of the wheel with the rail track.

  15. Influence of detergents on water drift in cooling towers

    Science.gov (United States)

    Vitkovicova, Rut

    An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  16. Optimization of cooling tower performance analysis using Taguchi method

    OpenAIRE

    Ramkumar Ramakrishnan; Ragupathy Arumugam

    2013-01-01

    This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression were carried out in order to determine the effects of process...

  17. Influence of detergents on water drift in cooling towers

    Directory of Open Access Journals (Sweden)

    Vitkovicova Rut

    2017-01-01

    Full Text Available An influence of detergents on the water drift from the cooling tower was experimentally investigated. For this experimental measurements was used a model cooling tower, especially an experimental aerodynamic line, which is specially designed for the measurement and monitoring of processes taking place around the eliminators of the liquid phase. The effect of different concentrations of detergent in the cooling water on the drift of water droplets from a commonly used type eliminator was observed with visualization methods.

  18. Acoustic results of the Boeing model 360 whirl tower test

    Science.gov (United States)

    Watts, Michael E.; Jordan, David

    1990-09-01

    An evaluation is presented for whirl tower test results of the Model 360 helicopter's advanced, high-performance four-bladed composite rotor system intended to facilitate over-200-knot flight. During these performance measurements, acoustic data were acquired by seven microphones. A comparison of whirl-tower tests with theory indicate that theoretical prediction accuracies vary with both microphone position and the inclusion of ground reflection. Prediction errors varied from 0 to 40 percent of the measured signal-to-peak amplitude.

  19. 99mTc renal tubular function agents: Current status

    International Nuclear Information System (INIS)

    Eshima, D.; Fritzberg, A.R.; Taylor, A. Jr.

    1990-01-01

    Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3. 61 references

  20. Exergy analysis of a distillation tower for crude oil fractionation

    International Nuclear Information System (INIS)

    Rivero, R.

    1990-01-01

    In this paper the application of the exergy method to a crude oil atmospheric distillation tower is presented. The fundamentals and procedures are presented as well as the main parameters used to describe the thermodynamic performance of the system, such as Exergy Losses, Effectiveness and Improvement Potential. A parametric analysis of the influence on the effectiveness of the tower is then performed as a function of the number of trays, the amount of stripping steam, the use of reboilers and the operation pressure. The results obtained are discussed. As expected, the effectiveness of the tower increases with the overall number of trays in the tower and in the stripping columns for a constant operation pressure and a constant amount of stripping steam but there is a limit at which the pressure drop across the trays and the stripping steam requirements make the effectiveness decrease. The use of reboilers in the stripping columns adjacent to the main tower allows an increase in the effectiveness basically due to a greater heat integration. Finally, the increase in the operation pressure of the tower produces an increase of the effectiveness but also an increase in the stripping steam requirements

  1. FLUXNET: A Global Network of Eddy-Covariance Flux Towers

    Science.gov (United States)

    Cook, R. B.; Holladay, S. K.; Margle, S. M.; Olsen, L. M.; Gu, L.; Heinsch, F.; Baldocchi, D.

    2003-12-01

    The FLUXNET global network was established to aid in understanding the mechanisms controlling the exchanges of carbon dioxide, water vapor, and energy across a variety of terrestrial ecosystems. Flux tower data are also being used to validate ecosystem model outputs and to provide information for validating remote sensing based products, including surface temperature, reflectance, albedo, vegetation indices, leaf area index, photosynthetically active radiation, and photosynthesis derived from MODIS sensors on the Terra and Aqua satellites. The global FLUXNET database provides consistent and complete flux data to support global carbon cycle science. Currently FLUXNET consists of over 210 sites, with most flux towers operating continuously for 4 years or longer. Gap-filled data are available for 53 sites. The FLUXNET database contains carbon, water vapor, sensible heat, momentum, and radiation flux measurements with associated ancillary and value-added data products. Towers are located in temperate conifer and broadleaf forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra on five continents. Selected MODIS Land products in the immediate vicinity of the flux tower are subsetted and posted on the FLUXNET Web site for 169 flux-towers. The MODIS subsets are prepared in ASCII format for 8-day periods for an area 7 x 7 km around the tower.

  2. Carbon steel protection in G.S. (Girlder sulfide) plants. CITROSOLV process influence. Pt. 6

    International Nuclear Information System (INIS)

    Lires, O.A.; Burkart, A.L.; Delfino, C.A.; Rojo, E.A.

    1988-01-01

    In order to protect carbon steel towers and piping of Girlder sulfide (G.S.) experimental heavy water plants against corrosion produced by the action of aqueous solutions of hydrogen sulfides, a method, previously published, was developed. Carbon steel, exposed to saturated aqueous solutions of hydrogen sulfide, forms iron sulfide scales. In oxygen free solutions evolution of corrosion follows the sequence: mackinawite → cubic ferrous sulfide → troilite → pyrrotite → pyrite. Scales formed by pyrrotite-pyrite or pyrite are the most protective layers (these are obtained at 130 deg C, 2 MPa, for periods of 14 days). CITROSOLV Process (Pfizer) is used to descaling and passivating stainless steel plant's components. This process must be used in mixed (carbon steel - stainless steel) circuits and may cause the formation of magnetite scales over the carbon steel. The influence of magnetite in the pyrrotite-pyrite scales formation is studied in this work. (Author) [es

  3. Engineering and economic evaluation of wet/dry cooling towers for water conservation

    International Nuclear Information System (INIS)

    Hu, M.C.

    1976-11-01

    The results are presented of a design and cost study for wet/dry tower systems used in conjunction with 1000 MWe nuclear power plants to reject waste heat while conserving water. Design and cost information for wet/dry tower systems are presented, and these cooling system alternatives are compared with wet and dry tower systems to determine whether the wet/dry tower concept is an economically viable alternative. The wet/dry cooling tower concept investigated is one which combines physically separated wet towers and dry towers into an operational unit. In designing the wet/dry tower, a dry cooling tower is sized to carry the plant heat load at low ambient temperatures, and a separate wet tower is added to augment the heat rejection of the dry tower at higher ambient temperatures. These wet/dry towers are designed to operate with a conventional low back pressure turbine commercially available today. The component wet and dry towers are state-of-the-art designs. From this study it was concluded that: wet/dry cooling systems can be designed to provide a significant economic advantage over dry cooling yet closely matching the dry tower's ability to conserve water, a wet/dry system which saves as much as 99 percent of the make-up water required by a wet tower can maintain that economic advantage, and therefore, for power plant sites where water is in short supply, wet/dry cooling is the economic choice over dry cooling

  4. Heat transfer and thermal storage performance of an open thermosyphon type thermal storage unit with tubular phase change material canisters

    International Nuclear Information System (INIS)

    Wang, Ping-Yang; Hu, Bo-Wen; Liu, Zhen-Hua

    2015-01-01

    Highlights: • A novel open heat pipe thermal storage unit is design to improve its performance. • Mechanism of its operation is phase-change heat transfer. • Tubular canisters with phase change material were placed in thermal storage unit. • Experiment and analysis are carried out to investigate its operation properties. - Abstract: A novel open thermosyphon-type thermal storage unit is presented to improve design and performance of heat pipe type thermal storage unit. In the present study, tubular canisters filled with a solid–liquid phase change material are vertically placed in the middle of the thermal storage unit. The phase change material melts at 100 °C. Water is presented as the phase-change heat transfer medium of the thermal storage unit. The tubular canister is wrapped tightly with a layer of stainless steel mesh to increase the surface wettability. The heat transfer mechanism of charging/discharging is similar to that of the thermosyphon. Heat transfer between the heat resource or cold resource and the phase change material in this device occurs in the form of a cyclic phase change of the heat-transfer medium, which occurs on the surface of the copper tubes and has an extremely high heat-transfer coefficient. A series of experiments and theoretical analyses are carried out to investigate the properties of the thermal storage unit, including power distribution, start-up performance, and temperature difference between the phase change material and the surrounding vapor. The results show that the whole system has excellent heat-storage/heat-release performance

  5. Probabilistic Capacity Assessment of Lattice Transmission Towers under Strong Wind

    Directory of Open Access Journals (Sweden)

    Wei eZhang

    2015-10-01

    Full Text Available Serving as one key component of the most important lifeline infrastructure system, transmission towers are vulnerable to multiple nature hazards including strong wind and could pose severe threats to the power system security with possible blackouts under extreme weather conditions, such as hurricanes, derechoes, or winter storms. For the security and resiliency of the power system, it is important to ensure the structural safety with enough capacity for all possible failure modes, such as structural stability. The study is to develop a probabilistic capacity assessment approach for transmission towers under strong wind loads. Due to the complicated structural details of lattice transmission towers, wind tunnel experiments are carried out to understand the complex interactions of wind and the lattice sections of transmission tower and drag coefficients and the dynamic amplification factor for different panels of the transmission tower are obtained. The wind profile is generated and the wind time histories are simulated as a summation of time-varying mean and fluctuating components. The capacity curve for the transmission towers is obtained from the incremental dynamic analysis (IDA method. To consider the stochastic nature of wind field, probabilistic capacity curves are generated by implementing IDA analysis for different wind yaw angles and different randomly generated wind speed time histories. After building the limit state functions based on the maximum allowable drift to height ratio, the probabilities of failure are obtained based on the meteorological data at a given site. As the transmission tower serves as the key nodes for the power network, the probabilistic capacity curves can be incorporated into the performance based design of the power transmission network.

  6. The Fatigue Behavior of Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    2009-01-01

    of the investigation, fatigue test series with a total of 540 fatigue tests have been carried through on various types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel or high-strength steel. The fatigue tests......Fatigue damage accumulation in steel structures under random loading has been studied in a number of investigations at the Technical University of Denmark. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part...... and the fracture mechanics analyses have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude...

  7. Evacuated, displacement compression mold. [of tubular bodies from thermosetting plastics

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A process of molding long thin-wall tubular bodies from thermosetting plastic molding compounds is described wherein the tubular body lengths may be several times the diameters. The process is accomplished by loading a predetermined quantity of molding compound into a female mold cavity closed at one end by a force mandrel. After closing the other end of the female mold with a balance mandrel, the loaded cavity is evacuated by applying a vacuum of from one-to-five mm pressure for a period of fifteen-to-thirty minutes. The mold temperature is raised to the minimum temperature at which the resin constituent of the compound will soften or plasticize and a pressure of 2500 psi is applied.

  8. Luminous effectiveness of tubular light-guides in tropics

    Energy Technology Data Exchange (ETDEWEB)

    Darula, Stanislav; Kittler, Richard; Kocifaj, Miroslav [ICA, Slovak Academy of Sciences, 9, Dubravska Road, 845 03 Bratislava (Slovakia)

    2010-11-15

    Novel tubular light-guides with a transparent hemispherical cupola placed on an unobstructed flat roof collect all sunlight and skylight available at ground level year round. This advantage is heightened in the dry and sunny tropical regions where the sun rises to very high altitudes and often the hours of sunshine last throughout the whole day. Hollow light-guides with very high inner specular reflectances can transport sunbeams downward into the windowless building core very effectively. Due to the tube's diameter and length and multiple reflections, complex illuminance patterns are produced on the underside of the tube, i.e. on top of the glazed ceiling aperture that illuminates the interior space or its working plane. This paper discusses several daylight conditions in tropical interiors illuminated by tubular light-guides. The recently published HOLIGILM calculation program and the user-friendly tool HOLIGILM 4.2 have facilitated the production of this paper. (author)

  9. Acute tubular necrosis in a patient with paroxysmal nocturnal hemoglobinuria

    Directory of Open Access Journals (Sweden)

    Eranga S Wijewickrama

    2013-01-01

    Full Text Available Acute renal failure (ARF is a well-recognized complication of paroxysmal nocturnal hemoglobinuria (PNH. The predominant mechanism is intravascular hemolysis resulting in massive hemoglobinuria ARF. We report a case of acute tubular necrosis (ATN developed in the absence of overwhelming evidence of intravascular hemolysis in a 21-year-old man with anemia, who was eventually diagnosed to have PNH. The patient presented with rapidly deteriorating renal functions in the background of iron deficiency anemia, which was attributed to reflux esophagitis. There was no clinical or laboratory evidence of intravascular hemolysis. Renal biopsy revealed ATN with deposition of hemosiderin in the proximal tubular epithelial cells. Diagnosis of PNH was confirmed with a positive Ham′s test and flow cytometry. Our case emphasizes the need to consider ATN as a possible cause for ARF in patients suspected to have PNH even in the absence of overwhelming evidence of intravascular hemolysis.

  10. Calculation and design of steel bearing structure for wind turbine

    Directory of Open Access Journals (Sweden)

    Bešević Miroslav

    2014-01-01

    Full Text Available Wind represents directed movement of the air and is caused by differences in atmospheric pressure which are caused by uneven heating of air masses. Global and local winds can be distinguished. Global winds have high altitude, while local winds occur in the ground layer of the atmosphere. Given that the global wings have high altitude they cannot be used as propellant for wind generators, but they should be known for their effects on the winds in the lower atmosphere. Modern wind turbines are made with a horizontal axle that has a system for the swiveling axis in the horizontal plane for tracking wind direction changes. They can have different number of blades, but for larger forces three blades are commonly used because they provide the greatest efficiency. Rotor diameter of these turbines depends on the strength and it ranges from 30 m for the power of 300 kW to 115 m for the power of 5 MW. Wind turbines are mounted on vertical steel tower which can be high even more than 100 m. Depending on the diameter of the turbine rotor, column is usually built as steel conical and less often as a steel-frame. This study includes analysis and design of steel tower for wind generator made by manufacturer Vestas, type V112 3MW HH 119 (power 3.2 MW for the construction of wind farm 'Kovačica'.

  11. Renal tubular acidosis complicated with hyponatremia due to cortisol insufficiency

    OpenAIRE

    Izumi, Yuichiro; Nakayama, Yushi; Onoue, Tomoaki; Inoue, Hideki; Mukoyama, Masashi

    2015-01-01

    Adrenocortical insufficiency such as occurs in Addison's disease causes hyponatremia and renal tubular acidosis (RTA). Hyponatremia results from both aldosterone and cortisol insufficiency. RTA is due to aldosterone insufficiency. The involvement of cortisol in RTA is unclear. Here, we report a woman in her 70s who was admitted to our hospital with severe hyponatremia (106 mEq/l) and RTA. The patient exhibited low plasma cortisol levels with little response to rapid adrenocorticotropic hormon...

  12. Oscillations of manometric tubular springs with rigid end

    Science.gov (United States)

    Cherentsov, D. A.; Pirogov, S. P.; Dorofeev, S. M.; Ryabova, Y. S.

    2018-05-01

    The paper presents a mathematical model of attenuating oscillations of manometric tubular springs (MTS) taking into account the rigid tip. The dynamic MTS model is presented in the form of a thin-walled curved rod oscillating in the plane of curvature of the central axis. Equations for MTS oscillations are obtained in accordance with the d’Alembert principle in projections onto the normal and tangential. The Bubnov-Galerkin method is used to solve the equations obtained.

  13. CT diagnosis of intramedulear lesions of the tubular bone

    International Nuclear Information System (INIS)

    Wagner-Manslau, C.; Feuerbach, S.; Biehl, T.

    1985-01-01

    Three cases are used to demonstrate that intramedullary masses of the tubular bones can be discovered using computered tomography even when changes in the plain film are lacking or discrete. However, it was not possible to differentiate between osteomyelitis, chondrosarcoma and enchondroma owing to the identical morphology of these three diseases. Consequently, CT does not allow any statement on type and dignity and histological clarification is indispensable. (orig./WU) [de

  14. A tubular flux-switching permanent magnet machine

    Science.gov (United States)

    Wang, J.; Wang, W.; Clark, R.; Atallah, K.; Howe, D.

    2008-04-01

    The paper describes a novel tubular, three-phase permanent magnet brushless machine, which combines salient features from both switched reluctance and permanent magnet machine technologies. It has no end windings and zero net radial force and offers a high power density and peak force capability, as well as the potential for low manufacturing cost. It is, therefore, eminently suitable for a variety of applications, ranging from free-piston energy converters to active vehicle suspensions.

  15. CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR

    OpenAIRE

    Gao-Jin Lv; Shu-Bin Wu; Rui Lou

    2010-01-01

    Pyrolysis characteristics of corn stalk hemicellulose were investigated in a tubular reactor at different temperatures, with focus mainly on the releasing profiles and forming behaviors of pyrolysis products (gas, char, and tar). The products obtained were further identified using various approaches (including GC, SEM, and GC-MS) to understand the influence of temperature on product properties and compositions. It was found that the devolatilization of hemicellulose mainly occurred at low tem...

  16. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    Renal acidification ability was examined in 90 recurrent renal stone formers, using fasting morning urinary pH levels followed by a short ammonium chloride loading test in subjects with pH levels above 6.0. Fifteen patients (16.6%) revealed a distal renal tubular acidification defect: one patient......, this has important therapeutic implications. The pathological sequence in renal stone formers with dRTA is discussed....

  17. Tubular transport and metabolism of cimetidine in chicken kidneys

    International Nuclear Information System (INIS)

    Rennick, B.; Ziemniak, J.; Smith, I.; Taylor, M.; Acara, M.

    1984-01-01

    Renal tubular transport and renal metabolism of [ 14 C]cimetidine (CIM) were investigated by unilateral infusion into the renal portal circulation in chickens (Sperber technique). [ 14 C]CIM was actively transported at a rate 88% that of simultaneously infused p-aminohippuric acid, and its transport was saturable. The following organic cations competitively inhibited the tubular transport of [ 14 C]CIM with decreasing potency: CIM, ranitidine, thiamine, procainamide, guanidine and choline. CIM inhibited the transport of [ 14 C]thiamine, [ 14 C]amiloride and [ 14 C]tetraethylammonium. During CIM infusion, two renal metabolites, CIM sulfoxide and hydroxymethylcimetidine, were found in urine. When CIM sulfoxide was infused, its transport efficiency was 32% and not saturable. CIM sulfoxide did ot inhibit the simultaneous renal tubular transport of p-aminohippuric acid or tetraethylammonium. CIM is transported by the organic cation transport system and the kidney metabolizes CIM. Transport of CIM and other cationic drugs could produce a drug interaction to alter drug excretion

  18. Mechanical testing of adherence of stacked layers in tubular geometry

    Energy Technology Data Exchange (ETDEWEB)

    Correia, L.A.; Schuring, E.W.; Van Delft, Y.C. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

    2007-09-15

    For the development of new molecular separation technologies strong robust tubular membrane systems are required. The fragile membranes, however, need a strong defect free support such as a porous asymmetric ceramic tube. Mechanical failure of these ceramic membrane systems during manufacturing and operation is mainly caused by delamination of the stacked layers. Therefore development is focused on improving the adherence. As no standard mechanical test for tubular samples is available yet, a new tensile test was developed to facilitate the current research. The most important components in the new equipment is a test tool with a curvature matching that of the test sample and a sample casing that align and guide the test tool during the tensile test. With this tensile test the manufacturing procedure for the ECN standard tubular {alpha}-alumina support was optimized. Firing the asymmetric support at 1300C resulted in the highest mechanical strength for the support system with cohesive fracture in the support tube. With the test developed the process condition could be identified where the material of the support tube is the weakest link in the support system.

  19. Flow analysis of tubular fuel assembly using CFD code

    International Nuclear Information System (INIS)

    Park, J. H.; Park, C.; Chae, H. T.

    2004-01-01

    Based on the experiences of HANARO, a new research reactor is under conceptual design preparing for future needs of research reactor. Considering various aspects such as nuclear physics, thermal-hydraulics, mechanical structure and the applicability of HANARO technology, a tubular type fuel has been considered as that of a new research reactor. Tubular type fuel has several circular fuel layers, and each layer consists of 3 curved fuel plates arranged with constant small gap to build up cooling channels. In the thermal-hydraulic point, it is very important to maintain each channel flow velocity be equal as much as possible, because the small gaps between curved thin fuel plates independently forms separate coolant channels, which may cause a thermal-hydraulic problem in certain conditions. In this study, commercial CFD(Computational Fluid Dynamics) code, Fluent, has been used to investigate flow characteristics of tubular type fuel assembly. According to the computation results for the preliminary conceptual design, there is a serious lack of uniformity of average velocity on the each coolant channel. Some changes for initial conceptual design were done to improve the balance of velocity distribution, and analysis was done again, too. The results for the revised design showed that the uniformity of each channel velocity was improved significantly. The influence of outermost channel gap width on the velocity distribution was also examined

  20. A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio.

    Directory of Open Access Journals (Sweden)

    Jin Woo Lee

    Full Text Available Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR. NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts.

  1. Plastic deformation of tubular crystals by dislocation glide.

    Science.gov (United States)

    Beller, Daniel A; Nelson, David R

    2016-09-01

    Tubular crystals, two-dimensional lattices wrapped into cylindrical topologies, arise in many contexts, including botany and biofilaments, and in physical systems such as carbon nanotubes. The geometrical principles of botanical phyllotaxis, describing the spiral packings on cylinders commonly found in nature, have found application in all these systems. Several recent studies have examined defects in tubular crystals associated with crystalline packings that must accommodate a fixed tube radius. Here we study the mechanics of tubular crystals with variable tube radius, with dislocations interposed between regions of different phyllotactic packings. Unbinding and separation of dislocation pairs with equal and opposite Burgers vectors allow the growth of one phyllotactic domain at the expense of another. In particular, glide separation of dislocations offers a low-energy mode for plastic deformations of solid tubes in response to external stresses, reconfiguring the lattice step by step. Through theory and simulation, we examine how the tube's radius and helicity affects, and is in turn altered by, the mechanics of dislocation glide. We also discuss how a sufficiently strong bending rigidity can alter or arrest the deformations of tubes with small radii.

  2. Filament winding technique, experiment and simulation analysis on tubular structure

    Science.gov (United States)

    Quanjin, Ma; Rejab, M. R. M.; Kaige, Jiang; Idris, M. S.; Harith, M. N.

    2018-04-01

    Filament winding process has emerged as one of the potential composite fabrication processes with lower costs. Filament wound products involve classic axisymmetric parts (pipes, rings, driveshafts, high-pressure vessels and storage tanks), non-axisymmetric parts (prismatic nonround sections and pipe fittings). Based on the 3-axis filament winding machine has been designed with the inexpensive control system, it is completely necessary to make a relative comparison between experiment and simulation on tubular structure. In this technical paper, the aim of this paper is to perform a dry winding experiment using the 3-axis filament winding machine and simulate winding process on the tubular structure using CADWIND software with 30°, 45°, 60° winding angle. The main result indicates that the 3-axis filament winding machine can produce tubular structure with high winding pattern performance with different winding angle. This developed 3-axis winding machine still has weakness compared to CAWIND software simulation results with high axes winding machine about winding pattern, turnaround impact, process error, thickness, friction impact etc. In conclusion, the 3-axis filament winding machine improvements and recommendations come up with its comparison results, which can intuitively understand its limitations and characteristics.

  3. A Role for Tubular Necroptosis in Cisplatin-Induced AKI

    Science.gov (United States)

    Xu, Yanfang; Ma, Huabin; Shao, Jing; Wu, Jianfeng; Zhou, Linying; Zhang, Zhirong; Wang, Yuze; Huang, Zhe; Ren, Junming; Liu, Suhuan; Chen, Xiangmei

    2015-01-01

    Cell death and inflammation in the proximal tubules are the hallmarks of cisplatin-induced AKI, but the mechanisms underlying these effects have not been fully elucidated. Here, we investigated whether necroptosis, a type of programmed necrosis, has a role in cisplatin-induced AKI. We found that inhibition of any of the core components of the necroptotic pathway—receptor-interacting protein 1 (RIP1), RIP3, or mixed lineage kinase domain-like protein (MLKL)—by gene knockout or a chemical inhibitor diminished cisplatin-induced proximal tubule damage in mice. Similar results were obtained in cultured proximal tubular cells. Furthermore, necroptosis of cultured cells could be induced by cisplatin or by a combination of cytokines (TNF-α, TNF-related weak inducer of apoptosis, and IFN-γ) that were upregulated in proximal tubules of cisplatin-treated mice. However, cisplatin induced an increase in RIP1 and RIP3 expression in cultured tubular cells in the absence of cytokine release. Correspondingly, overexpression of RIP1 or RIP3 enhanced cisplatin-induced necroptosis in vitro. Notably, inflammatory cytokine upregulation in cisplatin-treated mice was partially diminished in RIP3- or MLKL-deficient mice, suggesting a positive feedback loop involving these genes and inflammatory cytokines that promotes necroptosis progression. Thus, our data demonstrate that necroptosis is a major mechanism of proximal tubular cell death in cisplatin-induced nephrotoxic AKI. PMID:25788533

  4. Thermodynamic model and parametric analysis of a tubular SOFC module

    Science.gov (United States)

    Campanari, Stefano

    Solid oxide fuel cells (SOFCs) have been considered in the last years as one of the most promising technologies for very high-efficiency electric energy generation from natural gas, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. Among the SOFC technologies, tubular SOFC stacks with internal reforming have emerged as one of the most mature technology, with a serious potential for a future commercialization. In this paper, a thermodynamic model of a tubular SOFC stack, with natural gas feeding, internal reforming of hydrocarbons and internal air preheating is proposed. In the first section of the paper, the model is discussed in detail, analyzing its calculating equations and tracing its logical steps; the model is then calibrated on the available data for a recently demonstrated tubular SOFC prototype plant. In the second section of the paper, it is carried out a detailed parametric analysis of the stack working conditions, as a function of the main operating parameters. The discussion of the results of the thermodynamic and parametric analysis yields interesting considerations about partial load SOFC operation and load regulation, and about system design and integration with gas turbine cycles.

  5. Legionella safety in cooling towers; Legionellaveiligheid in koeltorens

    Energy Technology Data Exchange (ETDEWEB)

    Kordes, B. [Kordes Advies, (Netherlands); De Bok, F. [KBBL Wijhe, (Netherlands); De Zeeuw, L. [Holland Environment Group, (Netherlands); Settels, P. [Safety, Health Services and Ergonomics, ING, (Netherlands); Oesterholt, F.; Wullings, B. [KWR Watercycle Research Institute, (Netherlands); Guiot, P. [Tevan, Gorinchem (Netherlands); Brands, R. [Cumulus Nederland, Cuijk (Netherlands); Nuijten, O. [Kennisinstituut ISSO, Rotterdam (Netherlands); Wijne, R. [Beer advocaten, Amsterdam (Netherlands)

    2010-04-15

    In 9 articles attention is paid to several aspects with regard to Legionella in cooling towers: representative sampling, the use of copper and silver ionization or hydrogen peroxide to prevent Legionella growth and biofilms, the use of a zero-tolerance model to control a cooling tower installation, detection of DNA of Legionella Pneumophila, legionella safety in air conditioners, the model Legionella risk analysis and control of cooling tower installations, legislation and regulations for the control of cooling tower installations with regard to the Dutch Occupational Health and Safety Act ('Arbo-wet'), and an article about a lawsuit for victims of a Legionella outbreak, caused by careless owners of a cooling tower in Amsterdam, Netherlands. [Dutch] In 9 artikelen wordt in deze aflevering aandacht besteed aan verschillende aspecten m.b.t. Legionella in koeltorens: representatieve monstername, de toepassing van koper en zilver-ionisatie of waterstofperoxide om de groei van Legionella en biofilms te voorkomen, het gebruik van een zero-tolerance model om een koeltoren installatie te controleren, detectie van DNA van Legionella Pneumophila, Legionella veiligheid in luchtbehandelingsinstallaties, het model Legionella risicoanalyse en beheersplan voor koeltoreninstallaties, de rol van de Arbo-wet, en een artikel over een rechtszaak voor slachtoffers van Legionella door onzorgvuldig beheer van een koeltoren in Amsterdam.

  6. Numerical Simulation of Wind Turbine Blade-Tower Interaction

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; Hu Zhou; Decheng Wan

    2012-01-01

    Numerical simulations of wind turbine blade-tower interaction by using the open source OpenFOAM tools coupled with arbitrary mesh interface (AMI) method were presented.The governing equations were the unsteady Reynolds-averaged Navier-Stokes (PANS) which were solved by the pimpleDyMFoam solver,and the AMI method was employed to handle mesh movements.The National Renewable Energy Laboratory (NREL) phase Ⅵ wind turbine in upwind configuration was selected for numerical tests with different incoming wind speeds (5,10,15,and 25 m/s) at a fixed blade pitch and constant rotational speed.Detailed numerical results of vortex structure,time histories of thrust,and pressure distribution on the blade and tower were presented.The findings show that the wind turbine tower has little effect on the whole aerodynamic performance of an upwind wind turbine,while the rotating rotor will induce an obvious cyclic drop in the front pressure of the tower.Also,strong interaction of blade tip vortices with separation from the tower was observed.

  7. Sensor Placement For Structural Monitoring of Transmission Line Towers

    Directory of Open Access Journals (Sweden)

    Benny eRaphael

    2015-11-01

    Full Text Available Transmission line towers are usually analyzed using linear elastic idealized truss models. Due to the assumptions used in the analysis, there are discrepancies between the actual results obtained from full scale prototype testing and the analytical results. Therefore, design engineers are interested in assessing the actual stress levels in transmission line towers. Since it is costly to place sensors on every member of a tower structure, the best locations for sensors need to be carefully selected. This study evaluates a methodology for sensor placement in transmission line towers. The objective is to find optimal locations for sensors such that the real behavior of the structure can be explained from measurements. The methodology is based on the concepts of entropy and model falsification. Sensor locations are selected based on maximum entropy such that there is maximum separation between model instances that represent different possible combinations of parameter values which have uncertainties. The performance of the proposed algorithm is compared to that of an intuitive method in which sensor locations are selected where the forces are maximum. A typical 220 kV transmission tower is taken as case study in this paper. It is shown that the intuitive method results in much higher number of non-separable models compared to the optimal sensor placement algorithm. Thus the intuitive method results in poor identification of the system.

  8. Improvement of coal focus and cooling towers of COFRENTES NPP

    International Nuclear Information System (INIS)

    Martinez, I.; Bogh, P.

    1998-01-01

    Cofrentes Nuclear Power Plant is performing a improving program of its cooling towers based on the filling revamping and cooling water circuit improvement. Furthermore, and as consequence of the acquired experience on cooling towers due to the mentioned program, Cofrentes NPP has decided to follow up with this project from a different point of view based on the thermal-hydraulic optimization of the cooling process inside the towers. This program, which is going to be carried out by Cofrentes NPP, Iberinco and Energy Planning and Power Generation (EPPG) provides an improvement on the thermal profile and of the draught inside the cooling towers by improving the water distribution in the towers active area. In order to perform such a program is needed to fulfill a test program to assure a guaranteed performance gain. In this way, Iberinco is developing a test procedure which improves the results which are obtained with the present standards used commonly by the industry. As a consequence of this program, Cofrentes is expecting to obtain a gain of 5 to 8 MWe with a revenue period of 4 to 5 months, results validated in another foreigner Plant which have developed a similar program. (Author)

  9. Study of technological features of tubular compressed concrete members in concreting

    Directory of Open Access Journals (Sweden)

    Voskobiinyk Olena

    2017-01-01

    Full Text Available The technological features of core concreting were analyzed as the main factor in ensuring of strength and reliability of compressed concrete-filled steel tubular (CFST members. We have conducted the analysis of existing concreting methods of CFST members. In this respect, the most dangerous types of possible technological defects of concrete core of CFST members are inhomogeneity along the height, voids, caverns, and concrete “weak spots”. The authors considered the influence of such technological factors of concreting: placeability, time, concrete mixture compaction method, concreting height on the concrete core strength of CFST members. Based on the experimental studies conducted we suggested the regression correlations for determining the concrete strength of CFST members of different length depending on the movability of concrete mixture and a time for its compaction. The authors performed the correlation analysis of technological factors of concreting on the strength of the concrete core. We carried out the comparison of data on the concrete core strength of CFST members, that were determined by non-destructive methods (sclerometer test results, ultrasonic method and direct compression strength tests. We experimentally proved that using movable mixtures with the slump of about 4 – 9 cm the overall variation coefficient of concrete core strength of CFST members along the height reaches nearly 13%. Based on the experimental studies conducted we suggested the guidelines on optimal regimes of concrete compaction during manufacturing CFST members at a construction site environment.

  10. Determination of the replacement cooling tower capability at the ETRR-2 research reactor

    International Nuclear Information System (INIS)

    El-Din El-Morshdy, S.

    2004-01-01

    The ETRR-2 replacement cooling tower capability has been evaluated by the thermal acceptance test performed in June 2003. All instruments used were calibrated prior to the test. The measured data are collected at regular intervals in accordance with the acceptance test code for water cooling towers of the cooling tower institute recommendations. Both the characteristic curve and the performance curve methods were used to evaluate the tower capability. The test results yield a tower capability of about 105% and so the tower is thermally accepted. (orig.)

  11. One-year dynamic monitoring of a masonry tower

    Directory of Open Access Journals (Sweden)

    Guidobaldi Marco

    2015-01-01

    Full Text Available The paper presents some results of the continuous dynamic monitoring program carried out on the tallest historic tower in Mantua, Italy. This project follows an extensive diagnostic investigation aimed at assessing the structural condition of the tower after the Italian earthquakes of May 2012. A simple dynamic monitoring system was permanently installed in the upper part of the building and automatic modal identification was performed. The results allow to evaluate the effects of changing temperature on automatically identified natural frequencies, to verify the practical feasibility of damage detection methods based on natural frequencies shifts and provide clear evidence of the possible key role of continuous dynamic monitoring in the preventive conservation of historic towers.

  12. An integrated reliability-based design optimization of offshore towers

    International Nuclear Information System (INIS)

    Karadeniz, Halil; Togan, Vedat; Vrouwenvelder, Ton

    2009-01-01

    After recognizing the uncertainty in the parameters such as material, loading, geometry and so on in contrast with the conventional optimization, the reliability-based design optimization (RBDO) concept has become more meaningful to perform an economical design implementation, which includes a reliability analysis and an optimization algorithm. RBDO procedures include structural analysis, reliability analysis and sensitivity analysis both for optimization and for reliability. The efficiency of the RBDO system depends on the mentioned numerical algorithms. In this work, an integrated algorithms system is proposed to implement the RBDO of the offshore towers, which are subjected to the extreme wave loading. The numerical strategies interacting with each other to fulfill the RBDO of towers are as follows: (a) a structural analysis program, SAPOS, (b) an optimization program, SQP and (c) a reliability analysis program based on FORM. A demonstration of an example tripod tower under the reliability constraints based on limit states of the critical stress, buckling and the natural frequency is presented.

  13. New student-designed research and demonstration drop tower

    Science.gov (United States)

    Bell, Donald; Weislogel, Mark

    A new drop tower has been designed and constructed at Portland State University. The ap-proach incorporates innovative features to increase throughput and microgravity quality in a highly public facility. Push button operation with full wireless CCTV coverage and passive magnetic deceleration provides quiet, safe operation from a single control station with low re-cycle time. A two-stage coaxial release mechanism decouples the payload from the drag shield to minimize disturbances to the experiment during release. This is especially important for fluids experiments that are highly sensitive to initial conditions. Performance of the new tower is presented including release, free fall, and deceleration accelerometer data. The two second tower is used for research and educational outreach. The research efforts focus on capillary flows and phenomena relevant to spacecraft fluid systems. The outreach efforts utilize partnerships with local primary, secondary and post-secondary institutions to promote the fields of science, technology, engineering and mathematics.

  14. Induced flocculation of Pachysolen tannophilus using the tower fermentor

    Energy Technology Data Exchange (ETDEWEB)

    Deverell, K.F.; Clark, T.A.

    1985-12-01

    This article reports the induction of flocculation with Pachysolen tannophilus by the use of controlled aeration in a tower fermentor. The observed environmental and physiological conditions for flocculent growth are described. Although most studies with P. tannophilus have used oxylose as substrate, a synthetic glucose medium was chosen for this study as the faster growth rate of the organism on glucose was considered to favor more rapid selection of a flocculent strain. Due to flocculation, the concentration of yeast cells retained in the tower was up to 16 times greater than in the overflow. Ethanol yields approaching theoretical were achieved at low specific oxygen uptake rates, conditions which also favored maximum flocculation. Future work will involve continuous tower fermentation of sugar mixtures representative of the composition of wood hydrolysates.

  15. Membrane distillation of industrial cooling tower blowdown water

    Directory of Open Access Journals (Sweden)

    N.E. Koeman-Stein

    2016-06-01

    Full Text Available The potential of membrane distillation for desalination of cooling tower blowdown water (CTBD is investigated. Technical feasibility is tested on laboratory and pilot scale using real cooling tower blowdown water from Dow Benelux in Terneuzen (Netherlands. Two types of membranes, polytetrafluorethylene and polyethylene showed good performance regarding distillate quality and fouling behavior. Concentrating CTBD by a factor 4.5 while maintaining a flux of around 2 l/m2*h was possible with a water recovery of 78% available for reuse. Higher concentration factors lead to severe decrease in flux which was caused by scaling. Membrane distillation could use the thermal energy that would otherwise be discharged of in a cooling tower and function as a heat exchanger. This reduces the need for cooling capacity and could lead to a total reduction of 37% water intake for make-up water, as well as reduced energy and chemicals demands and greenhouse gas emissions.

  16. Cooling Tower Overhaul of Secondary Cooling System in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Chul; Lee, Young Sub; Jung, Hoan Sung; Lim, In Chul [KAERI, Daejeon (Korea, Republic of)

    2007-07-01

    HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power.

  17. An integrated reliability-based design optimization of offshore towers

    Energy Technology Data Exchange (ETDEWEB)

    Karadeniz, Halil [Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft (Netherlands)], E-mail: h.karadeniz@tudelft.nl; Togan, Vedat [Department of Civil Engineering, Karadeniz Technical University, Trabzon (Turkey); Vrouwenvelder, Ton [Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft (Netherlands)

    2009-10-15

    After recognizing the uncertainty in the parameters such as material, loading, geometry and so on in contrast with the conventional optimization, the reliability-based design optimization (RBDO) concept has become more meaningful to perform an economical design implementation, which includes a reliability analysis and an optimization algorithm. RBDO procedures include structural analysis, reliability analysis and sensitivity analysis both for optimization and for reliability. The efficiency of the RBDO system depends on the mentioned numerical algorithms. In this work, an integrated algorithms system is proposed to implement the RBDO of the offshore towers, which are subjected to the extreme wave loading. The numerical strategies interacting with each other to fulfill the RBDO of towers are as follows: (a) a structural analysis program, SAPOS, (b) an optimization program, SQP and (c) a reliability analysis program based on FORM. A demonstration of an example tripod tower under the reliability constraints based on limit states of the critical stress, buckling and the natural frequency is presented.

  18. A modular restoration tower for electric power line transmission

    Energy Technology Data Exchange (ETDEWEB)

    Nicolazzi, L.C.; Pereira, J.C.; Leonel, C.E.L.; Rocha, G.B.; Bianchezzi, V.; Mendes, F. [Universidade Federal Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], Emails: lauro@grante.ufsc.br, jcarlos@grante.ufsc.br; Luz, R.L. [ELETROSUL Centrais Eletricas S.A., Florianopolis, SC (Brazil)], Email: rluz@eletrosul.gov.br

    2009-07-01

    The main target of this R and D project is to develop an restoration tower for electric energy lines transmission. Whereas these towers should present the main features like transport facility, easiest assembling associated with a low cost of manufacture, it was applied the single-column tower concepts supported by stays, modularized, framed and articulated at the base. The concepts used for this development was a design methodology. From the different definition situations of load, numerical models have been developed focusing the design to the best of structural element arrangements of its modules. Then, tests were performed in laboratory to determine the module structural performance for different work load situations. These tests served to identify inconsistencies in the numerical models and proposed adjustments in its design to improve its performance on the strength and stability. (author)

  19. Mathematical modeling of methyl ester concentration distribution in a continuous membrane tubular reactor and comparison with conventional tubular reactor

    Science.gov (United States)

    Talaghat, M. R.; Jokar, S. M.; Modarres, E.

    2017-10-01

    The reduction of fossil fuel resources and environmental issues made researchers find alternative fuels include biodiesels. One of the most widely used methods for production of biodiesel on a commercial scale is transesterification method. In this work, the biodiesel production by a transesterification method was modeled. Sodium hydroxide was considered as a catalyst to produce biodiesel from canola oil and methanol in a continuous tubular ceramic membranes reactor. As the Biodiesel production reaction from triglycerides is an equilibrium reaction, the reaction rate constants depend on temperature and related linearly to catalyst concentration. By using the mass balance for a membrane tubular reactor and considering the variation of raw materials and products concentration with time, the set of governing equations were solved by numerical methods. The results clearly show the superiority of membrane reactor than conventional tubular reactors. Afterward, the influences of molar ratio of alcohol to oil, weight percentage of the catalyst, and residence time on the performance of biodiesel production reactor were investigated.

  20. The influence of the static wind load concept on the material requirements for reinforced-concrete natural-draught cooling towers

    International Nuclear Information System (INIS)

    Harnach, R.

    1977-01-01

    The natural wind is the decisive risk factor in natural-draught cooling towers; therefore, the establishment of an assumed velocity is indispensable for the safety and reliability of the construction. In the framework of a statistical wind concept, static substitution loads for the assumed dynamic wind pressure have been determined, also including dynamic wind effects and the resonance response of the structure. On this basis, it has been studied how wind loads with different periodicity affect the material requirements of reinforced-concrete natural-draught cooling towers. It is found that the additional steel requirements, related to the total building cost, remain within acceptable limits even for extreme wind loads. (orig.) [de

  1. Integration of Small Solar tower Systems into Distributed Power Islands

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S. [Ciemat, Madrid (Spain)

    2000-07-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-paks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leadings to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begum. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostat configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs.

  2. Integration of Small Solar Tower Systems Into Distributed Power Islands

    International Nuclear Information System (INIS)

    Romero, M.; Marcos, M. J.; Tellez, F. M.; Blanco, M.; Fernandez, V.; Baonza, F.; Berger, S.

    1999-01-01

    One of the short-term priorities for renewable energies in Europe is their integration for local power supply into communities and energy islands (blocks of buildings, new neighborhoods in residential areas, shopping centers, hospitals, recreational areas, eco-parks, small rural areas or isolated ones such as islands or mountain communities). Following this strategy, the integration of small tower fields into so-called MIUS (Modular Integrated Utility Systems) is proposed. This application strongly influences field concepts leading to modular multi-tower systems able to more closely track demand, meet reliability requirements with fewer megawatts of installed power and spread construction costs over time after output has begun. In addition, integration into single-cycle high-efficiency gas turbines plus waste-heat applications clearly increments the solar share. The chief questions are whether solar towers can be redesigned for such distributed markets and the keys to their feasibility. This paper includes the design and performance analysis of a 1.36-MW plant and integration in the MIUS system, as well as the expected cost of electricity and a sensitivity analysis of the small tower plant's performance with design parameters like heliostats configuration and tower height. A practical application is analyzed for a shopping center with 85% power demand during day-time by using a hybrid solar tower and a gas turbine producing electricity and waste heat for hot water and heating and cooling of spaces. The operation mode proposed is covering night demand with power from the grid and solar-gas power island mode during 14 hours daytime with a maximum power production of 1.36 MW. (Author) 26 refs

  3. De Reus van Schimmert: from water tower to data center

    Directory of Open Access Journals (Sweden)

    Konstantinos Tzanakakis

    2017-12-01

    Full Text Available The water tower of Schimmert was built in 1926 to cover the needs of water of Schimmert and the surrounding areas as well. This imposing 38 meters high tower dwarfs any nearby buildings, providing a 360° view of the surrounding area and deserves its pseudonym de Reus van Schimmert (the Giant of Schimmert. In the attempt to find a sustainable business model for the iconic building the concept of installing a data center in its core is investigated. The waste heat from the servers will be transferred to the reservoir on the top and from there used to power a district heating system in Schimmert.

  4. Two upward lightning at the Eagle Nest tower

    OpenAIRE

    Montañá Puig, Juan; Van der Velde, Oscar Arnoud; Romero Durán, David; March Nomen, Víctor; Solà de Las Fuentes, Gloria; Pineda Ruegg, Nicolau; Soula, Serge; Hermoso Alameda, Blas

    2012-01-01

    A new instrument composed by a high speed camera, two high energy detectors, a E-field antenna and a VHF antenna were installed at the Eagle Nest tower (northeast of Spain) during summer 2011. With this equipment several lightning flashes to the tower and its vicinity have been observed. This paper presents two examples: the first was an upward negative leader triggered by a close c1oud-to-ground flash and the second was an upward negative flash not associated with previous lightning activity...

  5. Energy and exergy analysis of counter flow wet cooling towers

    Directory of Open Access Journals (Sweden)

    Saravanan Mani

    2008-01-01

    Full Text Available Cooling tower is an open system direct contact heat exchanger, where it cools water by both convection and evaporation. In this paper, a mathematical model based on heat and mass transfer principle is developed to find the outlet condition of water and air. The model is solved using iterative method. Energy and exergy analysis infers that inlet air wet bulb temperature is found to be the most important parameter than inlet water temperature and also variation in dead state properties does not affect the performance of wet cooling tower. .

  6. Towards Cooling Tower Efficiency-An Energy Audit Approach

    Directory of Open Access Journals (Sweden)

    Long Su Weng Alwin

    2017-01-01

    Full Text Available This research studied the power generation trends from national grid and gas for a period of 4 years. Energy audit of critical systems like this is needful for optimal energy utilization. An energy audit was carried outon 6 industrial cooloing towers and their annual operating cost calculated. Variable speed drive suggested was installed and corresponding annual energy savings of 114,900 kWh/year cost saving of RM30,000 was achieved at a case study plant located in Malaysia. Cooling towers with smart systems was recommended for higher energy savings.

  7. Dry cooling tower operating experience in the LOFT reactor

    International Nuclear Information System (INIS)

    Hunter, J.A.

    1980-01-01

    A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features

  8. Calculation of cooling tower plumes for high pressure wintry situations

    International Nuclear Information System (INIS)

    Gassmann, F.; Tinguely, M.; Haschke, D.

    1982-12-01

    The diffusion of the plumes of the projected nuclear power plants at Kaiseraugst and Schwoerstadt, during high pressure wintry conditions, has been examined using a mathematical model to simulate the plumes. For these calculations, microaerological measurements were made in the proximity of Kaiseraugst and Schwoerstadt. These give a typical image of the weather during high pressure wintry conditions, which is normally associated with an inversion, sometimes strong, at a low height. Dry cooling towers with natural draught, which offer an alternative solution to the wet cooling towers proposed for Kasieraugst, are examined equally. (Auth./G.T.H.)

  9. Environmental Tests of the Flight GLAST LAT Tracker Towers

    Energy Technology Data Exchange (ETDEWEB)

    Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; Angelis, A.De; Drell, P.; Favuzzi, C.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Goodman, J.; Himel, T.

    2008-03-12

    The Gamma-ray Large Area Space telescope (GLAST) is a gamma-ray satellite scheduled for launch in 2008. Before the assembly of the Tracker subsystem of the Large Area Telescope (LAT) science instrument of GLAST, every component (tray) and module (tower) has been subjected to extensive ground testing required to ensure successful launch and on-orbit operation. This paper describes the sequence and results of the environmental tests performed on an engineering model and all the flight hardware of the GLAST LAT Tracker. Environmental tests include vibration testing, thermal cycles and thermal-vacuum cycles of every tray and tower as well as the verification of their electrical performance.

  10. Cooling tower drift: experiment design for comprehensive case study

    International Nuclear Information System (INIS)

    Laulainen, N.S.

    1978-01-01

    A drift experiment program to develop a data base which can be used for validation of drift deposition models has been formulated. The first field effort is designed for a suitable mechanical-draft cooling tower to be selected after site visits have been conducted. The discussion here demonstrates the importance of characterizing the droplet size spectrum emitted from the tower and to accurately account for droplet evaporation, because the downwind droplet deposition patterns and near-surface airborne concentrations are extremely sensitive to these parameters

  11. Desalination using spray tower and vapour compression refrigeration system

    International Nuclear Information System (INIS)

    Sathish Kumar, S.; Mani, A.

    2006-01-01

    A desalination system using a spray tower and Vapour Compression Refrigeration (VCR) system is proposed for obtaining fresh water from brackish water. In the spray tower, simultaneous heat and mass transfer take place between the brackish water and air, which results in the evaporation of the brackish water and humidification of the air. Fresh water is obtained from the humidified air by condensing the water vapour using a VCR system. Parametric studies were carried out to study the effect of various operational parameters on the fresh water production rate. (author)

  12. Cooling tower practice in Germany: state of the art

    International Nuclear Information System (INIS)

    Zerna, W.; Kraetzig, W.B.; Mungan, I.

    1982-01-01

    Development in design and construction of natural draught cooling towers that has taken place in Germany is discussed. Research has been concentrated on theory and analysis of shells, on acting forces, especially on wind effects, on buckling behavior and constructional problems. An approximate earthquake analysis allows a quick estimation of seismic response. The earthquake analysis is carried out by the response-spectrum-method. All design methods develop construction methods minimizing the imperfections and their control and correction during the erection process. It is shown how by arranging stiffening rings the buckling resistance and the lowest natural frequency of this new generation of cooling towers can be improved. 13 refs

  13. Design considerations and construction of an experimental prototype of concentrating solar power tower system in Saudi Arabia

    International Nuclear Information System (INIS)

    Abu-Hamdeh, Nidal H.; Alnefaie, Khaled A.

    2016-01-01

    Highlights: • Article is about designing and building a small scale prototype solar power tower system. • Calculations revealed that 10 heliostats are required to direct incident solar rays. • Design requirements showed that a solar tower of 7 m height should be used. • Storage tanks are cylindrical vessels with height of 1 m and a diameter of 1.5 m each. • The percentage error in the thermal power obtained from this system is about 5.3%. - Abstract: A prototype of a solar power tower system was designed and constructed to produce electricity from solar energy. This prototype of a solar power tower system was constructed and installed at King Abdulaziz University in Saudi Arabia where solar intensity is excessive. Heliostats were implemented to capture the solar rays during daylight. These mirrors are used to direct the solar energy to a solar receiver that is made of alloy steel so that thermal energy is conveyed to a thermal fluid inside the receiver. Based on a detailed selection procedure presented in this article, a final number of ten heliostats were chosen to direct the solar energy to the solar receiver. In addition; two motors were used to control the heliostat rotational and elevation movements. The thermal fluid is a molten salt mixture (which consists of 60% NaNO_3 and 40% KNO_3). Cold and hot storage tanks were manufactured from steel and they were insulated with calcium silicate from all sides. A one-meter high and one and a half-meter cylindrical vessel was adopted for each of the cold and hot tanks. In this article, a detailed design analysis of each component is presented. The thermal power transferred to the water in the heat exchanger as it is heated by the molten salt was measured and found to be 11.26 kW. The thermal power given by the molten salt in the heat exchanger was also measured and found to be 12.31 kW. The design thermal power was 13 kW. The percentage error in the thermal power obtained is about 5.3%.

  14. Design basis for the copper/steel canister. Stage three. Final report

    International Nuclear Information System (INIS)

    Bowyer, W.H.

    1997-02-01

    The development of the copper/iron canister proposed for the containment of high-level waste in the Swedish disposal programme has been studied from the points of view of choice of materials, manufacturing technology and Q A. This report describes the observations on progress which has been made between March 1995 and February 1996 and the results of further literature studies. A first trial canister has been produced by SKB using a fabricated steel liner and an extruded copper tubular, a second one using a fabricated tubular is at an advanced stage. A change from a fabricated steel inner canister to a proposed cast canister has been justified by a criticality argument but the technology for producing a cast canister is at present untried. It is considered that such a change will require a significant development programme. The microstructure achieved in the extruded copper tubular for the first canister is unacceptable. An improved microstructure may be achieved by extruding at a lower temperature but this remains to be demonstrated. Similar problems exist with plate used for the fabricated tubular but some more favourable structures have been achieved already by this route. Seam welding of the first tubular failed through a suspected material problem. The second fabricated tubular welded without difficulty. However it was necessary to constrain it during welding and it subsequently distorted during machining. There was some evidence of hot tearing close to the weld. The distortion problem may be overcome by a stress relieving anneal but this could cause further grain size problems. 19 refs

  15. Measurements of greenhouse gases at Beromünster tall-tower station in Switzerland

    Science.gov (United States)

    Ayalneh Berhanu, Tesfaye; Satar, Ece; Schanda, Rudiger; Nyfeler, Peter; Moret, Hanspeter; Brunner, Dominik; Oney, Brian; Leuenberger, Markus

    2016-06-01

    In order to constrain the regional flux of greenhouse gases, an automated measurement system was built on an old radio tower at Beromünster, Switzerland. The measurement system has been running since November 2012 as part of the Swiss greenhouse gases monitoring network (CarboCount-CH), which is composed of four measurement sites across the country. The Beromünster tall tower has five sampling lines with inlets at 12.5, 44.6, 71.5, 131.6, and 212.5 m above ground level, and it is equipped with a Picarro cavity ring-down spectrometer (CRDS) analyzer (G-2401), which continuously measures CO, CO2, CH4, and H2O. Sensors for detection of wind speed and direction, air temperature, barometric pressure, and humidity have also been installed at each height level. We have observed a non-negligible temperature effect in the calibration measurements, which was found to be dependent on the type of cylinder (steel or aluminum) as well as trace gas species (strongest for CO). From a target gas of known mixing ratio that has been measured once a day, we have calculated a long-term reproducibility of 2.79 ppb, 0.05 ppm, and 0.29 ppb for CO, CO2, and CH4, respectively, over 19 months of measurements. The values obtained for CO2 and CH4 are compliant with the WMO recommendations, while the value calculated for CO is higher than the recommendation. Since the installation of an air-conditioning system recently at the measurement cabin, we have acquired better temperature stability of the measurement system, but no significant improvement was observed in the measurement precision inferred from the target gas measurements. Therefore, it seems that the observed higher variation in CO measurements is associated with the instrumental noise, compatible with the precision provided by the manufacturer.

  16. Bioinspired coupled helical coils for soft tissue engineering of tubular structures - Improved mechanical behavior of tubular collagen type I templates.

    Science.gov (United States)

    Janke, H P; Bohlin, J; Lomme, R M L M; Mihaila, S M; Hilborn, J; Feitz, W F J; Oosterwijk, E

    2017-09-01

    The design of constructs for tubular tissue engineering is challenging. Most biomaterials need to be reinforced with supporting structures such as knittings, meshes or electrospun material to comply with the mechanical demands of native tissues. In this study, coupled helical coils (CHCs) were manufactured to mimic collagen fiber orientation as found in nature. Monofilaments of different commercially available biodegradable polymers were wound and subsequently fused, resulting in right-handed and left-handed polymer helices fused together in joints where the filaments cross. CHCs of different polymer composition were tested to determine the tensile strength, strain recovery, hysteresis, compressive strength and degradation of CHCs of different composition. Subsequently, seamless and stable hybrid constructs consisting of PDSII® USP 2-0 CHCs embedded in porous collagen type I were produced. Compared to collagen alone, this hybrid showed superior strain recovery (93.5±0.9% vs 71.1±12.6% in longitudinal direction; 87.1±6.6% vs 57.2±4.6% in circumferential direction) and hysteresis (18.9±2.7% vs 51.1±12.0% in longitudinal direction; 11.5±4.6% vs 46.3±6.3% in circumferential direction). Furthermore, this hybrid construct showed an improved Young's modulus in both longitudinal (0.5±0.1MPavs 0.2±0.1MPa; 2.5-fold) and circumferential (1.65±0.07MPavs (2.9±0.3)×10 -2 MPa; 57-fold) direction, respectively, compared to templates created from collagen alone. Moreover, hybrid template characteristics could be modified by changing the CHC composition and CHCs were produced showing a mechanical behavior similar to the native ureter. CHC-enforced templates, which are easily tunable to meet different demands may be promising for tubular tissue engineering. Most tubular constructs lack sufficient strength and tunability to comply with the mechanical demands of native tissues. Therefore, we embedded coupled helical coils (CHCs) produced from biodegradable polymers - to

  17. A young woman with recurrent kidney stones: questions on hypokalaemic tubular acidosis

    Directory of Open Access Journals (Sweden)

    Jill Vanmassenhove

    2017-04-01

    Full Text Available This paper discusses the diagnostic and therapeutic approach to the problem of a young woman presenting with recurrent kidney stones. In the clinical work-up, a hypokalaemic normal anion gap metabolic acidosis was found. The diagnostic tests to solve this common clinical problem and some therapeutic recommendations are discussed. Question on hypokalaemic tubular acidosis: 1. What is the significance of the plasma anion gap (PAG? 2. How does one appreciate the respiratory component of the acid base status? 3. How does one perform tests for tubular acidification disturbances? 4. What is the pathogenesis of distal tubular acidification ­disturbances? 5. What is the explanation of the hypokalaemia in distal ­tubular acidosis? 6. What is the pathogenesis of nephrolithiasis in distal tubular acidosis? 7. How does one treat a patient with distal tubular acidosis and recurrent nephrolithiasis?

  18. LBA-ECO CD-04 Leaf Litter Data, km 83 Tower Site, Tapajos National Forest, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — Above-ground litter productivity was measured in a 18 ha plot adjacent to the eddy flux tower at the logged forest tower site, km 83, Tapajos National Forest, Para,...

  19. LBA-ECO CD-04 Leaf Litter Data, km 83 Tower Site, Tapajos National Forest, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Above-ground litter productivity was measured in a 18 ha plot adjacent to the eddy flux tower at the logged forest tower site, km 83, Tapajos National...

  20. Cellular Phone Towers, Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected to orthophotography. Probably includes towers other than cell towers (uncertain). Not published., Published in 2003, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2003. Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected...

  1. Potential weather modification caused by waste heat release from large dry cooling towers

    International Nuclear Information System (INIS)

    Lee, J.

    1979-01-01

    A numerical model of a cooling tower plume is employed to study the possible atmospheric effects of thermal plumes from natural draft dry cooling towers. Calculations are performed for both single and multiple towers, each of which can dissipate the waste heat from a nominal 1000 MWe power generating unit, and the results are compared with those for wet cooling towers associated with plants of the same generating capacity. Dry cooling tower plumes are found to have a higher potential for inducing convective clouds than wet cooling tower plumes, under most summertime meteorological conditions. This is due to the fact that both the sensible heat and momentum fluxes from a dry tower in summer are approximately one order of magnitude larger than those from a wet cooling tower

  2. Corrosion resistant steel

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Borisov, V.P.; Latyshev, V.B.

    1980-01-01

    Corrosion resistant steel for production of sheets and tubes containing C, Mn, Cr, Si, Fe is suggested. It is alloyed with vanadium and cerium for improving tensile properties and ductility. The steel can be melted by a conventional method in electric-arc or induction furnaces. The mentioned steel is intended to be used as a substitute for nickel-bearing austenitic steels

  3. Drill pipes and casings utilizing multi-conduit tubular; Flerkanals roerstreng

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1997-04-23

    The invention relates to a multi-conduit tubular having fluid conduits and electrical conduits, with associated surface fluid and electrical commutators, and downhole sensors for providing surface monitors with instantaneous formation data. Each tubular includes a plurality of uniform linear conduits there through, with a gasket seal plate interposed between joined tubular for assuring a high pressure seal between joined conduits. the seal plate includes an intermediate electrical connector for connecting electrical conduit connectors of one tubular to another. A coupling collar with uniform diameter internal coarse and fine threads joins the tubular ends having similar threads by differential thread action without respective tubular rotation. Each tubular end includes an inter-engaging index recess and index lug, and drive recesses and lugs for maintaining angular registry of the tubular string and for driving one drill tubular with another. A fluid commutator includes a rotating shaft with passages connected to the tubular conduits, and rotating in a manifold having annular grooves in communication with the shaft passages and external fluid sources. An adaptor couples each commutator shaft passage to one or more tubular conduits. Slip rings on a quill shaft and stationary brush means provide electrical continuity from the electrical conduit wires to surface equipment. A cross-over sub includes formation parameter sensors and telemetry equipment in a blocked off portion of a fluid conduit. An annular accumulator connected with the well bore annulus applies a pressure thereto in response to downhole sensors to change the effective density of the drill mud. The multi-conduit tubular is further adapted for use as a well casing to provide downhole access of a plurality of fluids and electrical parameter sensors. 28 figs.

  4. Generation of Urinary Albumin Fragments Does Not Require Proximal Tubular Uptake

    OpenAIRE

    Weyer, K.; Nielsen, R.; Christensen, E. I.; Birn, H.

    2012-01-01

    Urinary albumin excretion is an important diagnostic and prognostic marker of renal function. Both animal and human urine contain large amounts of albumin fragments, but whether these fragments originate from renal tubular degradation of filtered albumin is unknown. Here, we used mice with kidneys lacking megalin and cubilin, the coreceptors that mediate proximal tubular endocytosis of albumin, to determine whether proximal tubular degradation of albumin forms the detectable urinary albumin f...

  5. Evaluation of protective effect of deposits formed by naphthenic corrosion and sulfidation on carbon steel and steel 5Cr-0.5Mo exposed in atmospheric distillation fractions

    Directory of Open Access Journals (Sweden)

    Gloria Duarte

    2017-05-01

    Full Text Available Refining of so-called opportunity crude oils with a high level of naphthenic acids and sulfur compounds has been increasing interest due to limited availability of light crude oils, however, considerable corrosive effects in the processing to high temperature on pipes and distillation towers mainly by the attack of naphthenic acids and sulfur compounds; sulfur compounds could be corrosive or can reduce the attack of naphthenic acids due to the formation of sulfides layers on the metal surface. In this work was evaluated the performance of deposits formed on the surface of carbon steel AISI SAE 1020 and 5% Cr-0.5% Mo steel exposed in crude oil fractions obtained from atmospheric distillation tower. For this, gravimetric tests were performed in dynamic autoclave using metal samples pre-treated in a crude oil fraction obtained from the atmospheric distillation tower of the Crude Distillation Unit (CDU # 1 in order to form layers of sulfides on the surface of the two materials and subsequently to expose pre-treated and non-pretreated samples in two different crude oil fractions obtained from atmospheric distillation tower of Crude Distillation Unit (CDU # 2. The evaluation showed that the samples pretreated decreased tendency to corrosion by naphthenic acids and sulfidation compared to untreated samples.

  6. Industrial cooling tower design and operation in the moderate-continental climate conditions

    OpenAIRE

    Laković Mirjana S.; Banjac Miloš J.; Laković Slobodan V.; Jović Milica M.

    2016-01-01

    A large number of producers offer a wide choice of various types of industrial cooling towers. Usually, a proper choice of pre-fabricated cooling tower satisfies end-user needs. However, if there are specific end-user requirements, it is necessary to design cooling tower according to those requirements. For the adhesive factory located in southern region of Serbia, 350 kW mechanical draught wet cooling tower was designed and built. Dimensioning of the cooli...

  7. Tubular overexpression of gremlin induces renal damage susceptibility in mice.

    Directory of Open Access Journals (Sweden)

    Alejandra Droguett

    Full Text Available A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-β. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1 specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2- to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-β and αSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage

  8. The rebirth of interest in renal tubular function.

    Science.gov (United States)

    Lowenstein, Jerome; Grantham, Jared J

    2016-06-01

    The measurement of glomerular filtration rate by the clearance of inulin or creatinine has evolved over the past 50 years into an estimated value based solely on plasma creatinine concentration. We have examined some of the misconceptions and misunderstandings of the classification of renal disease and its course, which have followed this evolution. Furthermore, renal plasma flow and tubular function, which in the past were estimated by the clearance of the exogenous aryl amine, para-aminohippurate, are no longer measured. Over the past decade, studies in experimental animals with reduced nephron mass and in patients with reduced renal function have identified small gut-derived, protein-bound uremic retention solutes ("uremic toxins") that are poorly filtered but are secreted into the lumen by organic anion transporters (OATs) in the proximal renal tubule. These are not effectively removed by conventional hemodialysis or peritoneal dialysis. Residual renal function, urine produced in patients with advanced renal failure or undergoing dialysis treatment, may represent, at least in part, secretion of fluid and uremic toxins, such as indoxyl sulfate, mediated by proximal tubule OATs and might serve as a useful survival function. In light of this new evidence of the physiological role of proximal tubule OATs, we suggest that measurement of renal tubular function and renal plasma flow may be of considerable value in understanding and managing chronic kidney disease. Data obtained in normal subjects indicate that renal plasma flow and renal tubular function might be measured by the clearance of the endogenous aryl amine, hippurate. Copyright © 2016 the American Physiological Society.

  9. Stem cell factor expression after renal ischemia promotes tubular epithelial survival.

    Directory of Open Access Journals (Sweden)

    Geurt Stokman

    Full Text Available BACKGROUND: Renal ischemia leads to apoptosis of tubular epithelial cells and results in decreased renal function. Tissue repair involves re-epithelialization of the tubular basement membrane. Survival of the tubular epithelium following ischemia is therefore important in the successful regeneration of renal tissue. The cytokine stem cell factor (SCF has been shown to protect the tubular epithelium against apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: In a mouse model for renal ischemia/reperfusion injury, we studied how expression of c-KIT on tubular epithelium and its ligand SCF protect cells against apoptosis. Administration of SCF specific antisense oligonucleotides significantly decreased specific staining of SCF following ischemia. Reduced SCF expression resulted in impaired renal function, increased tubular damage and increased tubular epithelial apoptosis, independent of inflammation. In an in vitro hypoxia model, stimulation of tubular epithelial cells with SCF activated survival signaling and decreased apoptosis. CONCLUSIONS/SIGNIFICANCE: Our data indicate an important role for c-KIT and SCF in mediating tubular epithelial cell survival via an autocrine pathway.

  10. Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

    Science.gov (United States)

    Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

    2006-12-01

    A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

  11. Solar tracking control tower; Steuerungstechnik folgt der Sonne

    Energy Technology Data Exchange (ETDEWEB)

    Leu, Andreas [Jetter AG, Ludwigsburg (Germany). Bereich technisches Marketing und Seminare

    2010-11-15

    The ''Gemue-Dome'' building at Waldzimmern is a unique industrial building. The research, development and innovation center has a rotary control tower equipped with solar cells which automatically tracks the sun. This automation task was a challenge for the control and power supply sections. (orig.)

  12. Further investigation on the performance of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan

    2008-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In the previous model we presented [Qi Xiaoni, Liu Zhenyan, Li Dandan. Performance characteristics of a shower cooling tower. Energy Convers Manage 2007;48(1):193-203.], three critical assumptions were made to reduce the complexity and computational time, which can also reduce the models' accuracy. Accurate modelling of the operating process is a determining factor both for designing the shower cooling tower (SCT) and for optimising its operation. In this paper, we derive a new model without applying the three assumptions. According to the condition of the outlet air, the governing equations consider two cases, including the supersaturated and unsaturated states. This model is used to predict the performance of a full scale SCT located in China with different conditions for validation. The differences in the heat and mass transfer analyses of the two models are described at different atmospheric conditions

  13. Continuous measurements of methane from a tower network over Siberia

    International Nuclear Information System (INIS)

    Sasakawa, M.; Machida, T.; Saeki, T.; Koyama, Y.; Maksyutov, S.; Shimoyama, K.; Tsuda, N.; Suto, H.; Arshinov, M.; Davydov, D.; Fofonov, A.; Krasnov, O.

    2010-01-01

    We have been conducting continuous measurements of Methane (CH 4 ) concentration from an expanding network of towers (JR-STATION: Japan-Russia Siberian Tall Tower Inland Observation Network) located in taiga, steppe and wetland biomes of Siberia since 2004. High daytime means (>2000 ppb) observed simultaneously at several towers during winter, together with in situ weather data and NCEP/NCAR reanalysis data, indicate that high pressure systems caused CH 4 accumulation at subcontinental scale due to the widespread formation of an inversion layer. Daytime means sometimes exceeded 2000 ppb, particularly in the summer of 2007 when temperature and precipitation rates were anomalously high over West Siberia, which implies that CH 4 emission from wetlands were exceptionally high in 2007. Many hot spots detected by MODIS in the summer of 2007 illustrate that the contribution of biomass burning also cannot be neglected. Daytime mean CH 4 concentrations from the Siberian tower sites were generally higher than CH 4 values reported at NOAA coastal sites in the same latitudinal zone, and the difference in concentrations between two sets of sites was reproduced with a coupled Eulerian-Lagrangian transport model. Simulations of emissions from different CH 4 sources suggested that the major contributor to variation switched from wetlands during summer to fossil fuel during winter.

  14. Wind Shear Characteristics at Central Plains Tall Towers (presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.; Elliott, D.

    2006-06-05

    The objectives of this report are: (1) Analyze wind shear characteristics at tall tower sites for diverse areas in the central plains (Texas to North Dakota)--Turbines hub heights are now 70-100 m above ground and Wind measurements at 70-100+ m have been rare. (2) Present conclusions about wind shear characteristics for prime wind energy development regions.

  15. Galois towers over non-prime finite fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

    2014-01-01

    In this paper we construct Galois towers with good asymptotic properties over any non-prime finite field Fℓ; i.e., we construct sequences of function fields N=(N1⊂N2⊂⋯) over Fℓ of increasing genus, such that all the extensions Ni/N1 are Galois extensions and the number of rational places of these...

  16. Towers of Function Fields over Non-prime Finite Fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

    2015-01-01

    Over all non-prime finite fields, we construct some recursive towers of function fields with many rational places. Thus we obtain a substantial improvement on all known lower bounds for Ihara’s quantity A(ℓ), for ℓ = pn with p prime and n > 3 odd. We relate the explicit equations to Drinfeld modu...

  17. Continuous measurements of methane from a tower network over Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Sasakawa, M.; Machida, T.; Saeki, T.; Koyama, Y.; Maksyutov, S. (Center for Global Environmental Research, National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)); Shimoyama, K. (Inst. of Low Temperature Science, Hokkaido Univ., Hokkaido (Japan)); Tsuda, N. (Global Environmental Forum, Tokyo (Japan)); Suto, H. (Japan Aerospace Exploration Agency (Japan)); Arshinov, M.; Davydov, D.; Fofonov, A.; Krasnov, O. (Inst. of Atmospheric Optics, Russian Academy of Sciences, Siberian Branch (Russian Federation))

    2010-11-15

    We have been conducting continuous measurements of Methane (CH{sub 4}) concentration from an expanding network of towers (JR-STATION: Japan-Russia Siberian Tall Tower Inland Observation Network) located in taiga, steppe and wetland biomes of Siberia since 2004. High daytime means (>2000 ppb) observed simultaneously at several towers during winter, together with in situ weather data and NCEP/NCAR reanalysis data, indicate that high pressure systems caused CH{sub 4} accumulation at subcontinental scale due to the widespread formation of an inversion layer. Daytime means sometimes exceeded 2000 ppb, particularly in the summer of 2007 when temperature and precipitation rates were anomalously high over West Siberia, which implies that CH{sub 4} emission from wetlands were exceptionally high in 2007. Many hot spots detected by MODIS in the summer of 2007 illustrate that the contribution of biomass burning also cannot be neglected. Daytime mean CH{sub 4} concentrations from the Siberian tower sites were generally higher than CH{sub 4} values reported at NOAA coastal sites in the same latitudinal zone, and the difference in concentrations between two sets of sites was reproduced with a coupled Eulerian-Lagrangian transport model. Simulations of emissions from different CH{sub 4} sources suggested that the major contributor to variation switched from wetlands during summer to fossil fuel during winter.

  18. Design of cooling towers by the effectiveness-NTU method

    International Nuclear Information System (INIS)

    Jaber, H.; Webb, R.L.

    1989-01-01

    This paper develops the effectiveness-NTU, number of transfer units, design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat transfer design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A one-increment design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NYU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard Log-Mean Enthalpy Method (LMED) or effectiveness-NTU design methods to design cooling towers

  19. Indiana State University Graduates to Advanced Plastic Cooling Towers

    Science.gov (United States)

    Sullivan, Ed

    2012-01-01

    Perhaps more than many other industries, today's universities and colleges are beset by dramatically rising costs on every front. One of the areas where overhead can be contained or reduced is in the operation of the chilled water systems that support air conditioning throughout college campuses, specifically the cooling towers. Like many…

  20. Atmospheric wet-type cooling tower with antifreeze system

    International Nuclear Information System (INIS)

    Coic, P.

    1985-01-01

    The cooling tower has air inlets at its base, a network of pipes which distributes the air to be cooled above the packing, and valves to isolate a part of the network. It includes also a bypass circuit, provided with means to control the flow rate fraction which is by-passed [fr

  1. Hausdorff gaps and towers in P(\\omega)/Fin

    Czech Academy of Sciences Publication Activity Database

    Borodulin-Nadzieja, P.; Chodounský, David

    2015-01-01

    Roč. 229, č. 3 (2015), s. 197-229 ISSN 0016-2736 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : Hausdorff gaps * special gaps * towers Subject RIV: BA - General Mathematics Impact factor: 0.553, year: 2015 http://journals.impan.pl/cgi-bin/doi?fm229-3-1

  2. Simulation of control drives in a tower crane

    Directory of Open Access Journals (Sweden)

    Wojciech SOLARZ

    2011-01-01

    Full Text Available The design of a control system for a tower crane is investigated. Underlying the controller design is the theory of optimal linear control. Computer models of a crane and the control systems for the crane drives are developed. Simulation data reveals that the motion of the load can be effectively controlled so that it should follow a predetermined trajectory.

  3. Spectral fatigue analysis of a tensioned riser compliant tower

    NARCIS (Netherlands)

    Karadeniz, H.; Vrouwenvelder, A.C.W.M.; Shi, C.

    1998-01-01

    In this paper, the conceptual Tensioned Riser Compliant Tower (TRCT) structure of the Shell Oil, which is developed for a region of approximately 600 meter water depth of the West of Shetlands in the North Sea, is analyzed by using the SAPOS program of the Delft University of Technology. The fatigue

  4. Exergy optimization of cooling tower for HGSHP and HVAC applications

    International Nuclear Information System (INIS)

    Singh, Kuljeet; Das, Ranjan

    2017-01-01

    Highlights: • Development of new correlations for outlet parameters with all inlet parameters. • Simultaneous achievement of required heat load and minimum exergy destruction. • Multiple combinations of parameters found for same heat load at minimized exergy. • Study useful for optimum control of cooling tower under varying ambient conditions. • Generalized optimization study can be implemented for any mechanical cooling tower. - Abstract: In the present work, a constrained inverse optimization method for building cooling applications is proposed to control the mechanical draft wet cooling tower by minimizing the exergy destruction and satisfying an imposed heat load under varying environmental conditions. The optimization problem is formulated considering the cooling dominated heating, ventilation and air conditioning (HVAC) and hybrid ground source heat pump (HGSHP). As per the requirement, new second degree correlations for the tower outlet parameters (water temperature, air dry and wet-bulb temperatures) with five inlet parameters (dry-bulb temperature, relative humidity, water inlet temperature, water and air mass flow rates) are developed. The Box–Behnken design response surface method is implemented for developing the correlations. Subsequently, the constrained optimization problem is solved using augmented Lagrangian genetic algorithm. This work further developed optimum inlet parameters operating curves for the HGSHP and the HVAC systems under varying environmental conditions aimed at minimizing the exergy destruction along with the fulfillment of the required heat load.

  5. Interception and retention of simulated cooling tower drift by vegetation

    International Nuclear Information System (INIS)

    Taylor, F.G. Jr.; Parr, P.D.

    1978-01-01

    A key issue concerning environmental impacts from cooling tower operation is the interception of drift by vegetation and the efficiency of plants in retaining the residue scavenged from the atmosphere. Chromated drift water, typical of the cooling towers of the Department of Energy's uranium enrichment facilities at Oak Ridge, Tennessee, was prepared using radio-labelled chromium. A portable aerosol generator was used to produce a spectrum of droplets with diameters (100 to 1300 μ) characteristic of cooling towers using state-of-the-art drift eliminators. Efficiency of interception by foliage varied according to leaf morphology with yellow poplar seedlings intercepting 72% of the deposition mass in contrast to 45% by loblolly pine and 24% by fescue grass. Retention patterns of intercepted deposition consisted of a short-time component (0 to 3 days) and a long-time component (3 to 63 days). Retention times, estimated from the regression equation of the long component, indicated that drift contamination from any deposition event may persist from between 8 and 12 weeks. In field situations adjacent to cooling towers, the average annual concentration of drift on vegetation at any distance remains relatively constant, with losses from weathering being compensated by chronic deposition

  6. Walls, Towers, and Sphinxes: Multicultural Concept Construction and Group Inquiry

    Science.gov (United States)

    Bisland, Beverly Milner

    2005-01-01

    One can easily identify the United States of America by the Statue of Liberty, France by the Eiffel Tower, Egypt by its Great Sphinx, and China by its Great Wall. What do these landmarks tell people about these places? What are the characteristics of the place and culture that are symbolized by these landmarks? These questions can serve as the…

  7. Solar Power Tower Design Basis Document, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    ZAVOICO,ALEXIS B.

    2001-07-01

    This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

  8. Exposure level from selected base station tower around Kuala Nerus

    African Journals Online (AJOL)

    Health risk due to RF radiation exposure from base station tower (BST) has been debated for years leading to public concerns. Thus, this preliminary study aims to measure, evaluate and analyze the exposure level on three selected BST around Kuala Nerus. The measurement of exposure level in terms of voltage ...

  9. An improved AODV routing protocol based on tower structure

    Directory of Open Access Journals (Sweden)

    Li Yong Qiang

    2016-01-01

    Full Text Available The paper proposed a new routing protocol(IAODV based on tower structure in the Ad Hoc network for the problem which Location Routing Protocol need hardware and Complex algorithm. By the simulation, The complexity of the new routing protocol is reduced without reducing the performance of the network.

  10. Theoretical flow investigations of an all glass evacuated tubular collector

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    Heat transfer and flow structures inside all glass evacuated tubular collectors for different operating conditions are investigated by means of computational fluid dynamics. The investigations are based on a collector design with horizontal tubes connected to a vertical 14 manifold channel. Three...... the highest efficiency, the optimal inlet flow rate was around 0.4-1 kg/min, the flow structures in the glass tubes were relatively uninfluenced by the inlet flow rate, Generally, the results showed only small variations in the efficiencies. This indicates that the collector design is well working for most...

  11. Use of graphite layer open tubular (GLOT) in environmental analysis

    International Nuclear Information System (INIS)

    Bruner, F.; Lattanzi, L.; Borghesi, P.

    1996-01-01

    Recently it has been developed a series of new capillary columns characterised by the use of graphitized carbon black modified from different amount of liquid phase. The characteristics of these columns, called graphite layer open tubular (GLOT), are described together with their application to the environmental analysis. A specific application of GLOT columns is for the direct analysis of aqueous solutions avoiding solvent extraction procedure. A comparison between a GLOT column and a traditional capillary column, estimating their behaviour after repeated direct injections of aqueous solution sample is written. Some applications regarding the analysis of the atmosphere pollutants, as aliphatic and aromatic hydrocarbons, and their compounds are written too

  12. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association

    Directory of Open Access Journals (Sweden)

    P Ravi

    2013-01-01

    Full Text Available Renal tubular acidosis (RTA is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previously asymptomatic presented with the hypokalemic paralysis and on work-up found out to have type I RTA. The discoloration of teeth and enamel was diagnosed as AI.

  13. Screening renal stone formers for distal renal tubular acidosis

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use...

  14. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  15. A new tower with good p-rank meeting Zink’s bound

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Beelen, Peter; Nguyen, Nhut

    2017-01-01

    In this article we investigate the asymptotic p-rank of a new tower of function fields defined over cubic finite fields. Its limit meets Zink's bound, but the new feature of this tower is that its asymptotic p-rank for small cubic finite fields is much smaller than that of other cubic towers...

  16. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Science.gov (United States)

    2010-07-01

    ... coolers, and final-cooler cooling towers. 61.134 Section 61.134 Protection of Environment ENVIRONMENTAL... Standard: Naphthalene processing, final coolers, and final-cooler cooling towers. (a) No (“zero”) emissions are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

  17. De Reus van Schimmert : from a water tower to a green data center

    NARCIS (Netherlands)

    Tzanakakis, K.

    2017-01-01

    The water tower of Schimmert is an iconic tower that has served the local community for decades. In 2014 it was decommissioned and currently local companies and authorities are searching for a viable business model for this imposing tower. The present report examines the feasibility of transforming

  18. Cell-Phone Tower Power System Prototype Testing for Verizon Wireless |

    Science.gov (United States)

    Advanced Manufacturing Research | NREL Cell-Phone Tower Power System Prototype Testing for Verizon Wireless Cell-Phone Tower Power System Prototype Testing for Verizon Wireless For Verizon Wireless , NREL tested a new cell-phone tower power system prototype based on DC interconnection and photovoltaics

  19. 78 FR 10210 - Utility Scale Wind Towers From China and Vietnam

    Science.gov (United States)

    2013-02-13

    ... wind towers. Background The Commission instituted these investigations effective December 29, 2011...)] Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1\\ developed... with material injury by reason of imports of utility scale wind towers from China and Vietnam, provided...

  20. 78 FR 11146 - Utility Scale Wind Towers From the People's Republic of China: Antidumping Duty Order

    Science.gov (United States)

    2013-02-15

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-981] Utility Scale Wind Towers...''), the Department is issuing an antidumping duty order on utility scale wind towers (``wind towers...) 482-3936, or (202) 482-4852, respectively. SUPPLEMENTARY INFORMATION: Background In accordance with...

  1. Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

    Science.gov (United States)

    Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

    2010-01-01

    In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

  2. 75 FR 28551 - Certain Oil Country Tubular Goods From the People's Republic of China: Amended Final...

    Science.gov (United States)

    2010-05-21

    ... 32.07 Ltd. Co., Ltd. Wuxi Sp. Steel Tube Wuxi Precese Special 32.07 Manufacturing Co., Ltd. Steel Co., Ltd. Wuxi Zhenda Special Steel Tube Huai'an Zhenda Steel 32.07 Manufacturing Co., Ltd. Tube Manufacturing Co., Ltd. Xigang Seamless Steel Tube Xigang Seamless Steel 32.07 Co., Ltd. Tube Co., Ltd.;. Wuxi...

  3. Legionella in industrial cooling towers: monitoring and control strategies.

    Science.gov (United States)

    Carducci, A; Verani, M; Battistini, R

    2010-01-01

    Legionella contamination of industrial cooling towers has been identified as the cause of sporadic cases and outbreaks of legionellosis among people living nearby. To evaluate and control Legionella contamination in industrial cooling tower water, microbiological monitoring was carried out to determine the effectiveness of the following different disinfection treatments: (i) continuous chlorine concentration of 0.01 ppm and monthly chlorine shock dosing (5 ppm) on a single cooling tower; (ii) continuous chlorine concentration of 0.4 ppm and monthly shock of biocide P3 FERROCID 8580 (BKG Water Solution) on seven towers. Legionella spp. and total bacterial count (TBC) were determined 3 days before and after each shock dose. Both strategies demonstrated that when chlorine was maintained at low levels, the Legionella count grew to levels above 10(4) CFU l(-1) while TBC still remained above 10(8 )CFU l(-1). Chlorine shock dosing was able to eliminate bacterial contamination, but only for 10-15 days. Biocide shock dosing was also insufficient to control the problem when the disinfectant concentration was administered at only one point in the plant and at the concentration of 30 ppm. On the other hand, when at a biocide concentration of 30 or 50 ppm was distributed throughout a number of points, depending on the plant hydrodynamics, Legionella counts decreased significantly and often remained below the warning limit. Moreover, the contamination of water entering the plant and the presence of sediment were also important factors for Legionella growth. For effective decontamination of outdoor industrial cooling towers, disinfectants should be distributed in a targeted way, taking into account the possible sources of contamination. The data of the research permitted to modify the procedure of disinfection for better reduce the water and aerosol contamination and consequently the exposure risk.

  4. Emission of a natural-draught wet cooling tower and flow conditions at the brim of the cooling tower

    International Nuclear Information System (INIS)

    Baer, E.; Billet, W.; Dittrich, H.; Ernst, G.; Roller, W.; Wurz, D.

    1975-01-01

    Between July 1973 and September 1974, measurements were carried out around a natural-draught wet cooling tower during different weather conditions. The results of these measurements are to serve as basic material for the calculation of plume diffusion. (orig./TK) [de

  5. Nano-tubular cellulose for bioprocess technology development.

    Science.gov (United States)

    Koutinas, Athanasios A; Sypsas, Vasilios; Kandylis, Panagiotis; Michelis, Andreas; Bekatorou, Argyro; Kourkoutas, Yiannis; Kordulis, Christos; Lycourghiotis, Alexis; Banat, Ibrahim M; Nigam, Poonam; Marchant, Roger; Giannouli, Myrsini; Yianoulis, Panagiotis

    2012-01-01

    Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC) justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation). The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator). Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

  6. Advances in tubular solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, S.C. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

    1996-12-31

    The design, materials and fabrication processes for the earlier technology Westinghouse tubular geometry cell have been described in detail previously. In that design, the active cell components were deposited in the form of thin layers on a ceramic porous support tube (PST). The tubular design of these cells and the materials used therein have been validated by successful electrical testing for over 65,000 h (>7 years). In these early technology PST cells, the support tube, although sufficiently porous, presented an inherent impedance to air flow toward air electrode. In order to reduce such impedance to air flow, the wall thickness of the PST was first decreased from the original 2 mm (the thick-wall PST) to 1.2 mm (the thin-wall PST). The calcia-stabilized zirconia support tube has now been completely eliminated and replaced by a doped lanthanum manganite tube in state-of-the-art SOFCs. This doped lanthanum manganite tube is extruded and sintered to about 30 to 35 percent porosity, and serves as the air electrode onto which the other cell components are fabricated in thin layer form. These latest technology cells are designated as air electrode supported (AES) cells.

  7. Carbohydrates in Ankistrodesmus braunii biomass cultivated in tubular photobioreactors

    Directory of Open Access Journals (Sweden)

    Ana Lucía Morocho-Jácome

    2017-12-01

    Full Text Available The great need for microalgae biomass production in tubular photobioreactors has increased for use in biofuels, pharmaceuticals and even cosmetic applications. In order to better understand the potential applications of this material, it is imperative to know in detail its composition. Ankistrodesmus braunii was cultivated in 3.5 L tubular air-lift photobioreactors using 10 mM sodium nitrate as nitrogen source in batch mode at 60 µmol photons m-2 s-1. The maximum biomass concentration (Xm and the biomass productivity (PX reached at 6th day of cultivation was 1249 ± 72 mg L-1 and 165 ± 13 mg L-1 d-1, respectively. Carbohydrates productivity expressed in terms of glucose, galactose and glucose+galactose (1:1 were 2.57 ± 0.04, 4.12 ± 0.06 and 3.22 ± 0.05 mg L-1 d-1, respectively. Results show a statistical difference that was found between carbohydrate productivity values expressed as glucose, galactose and glucose+galactose (1:1.

  8. Understanding shape and morphology of unusual tubular starch nanocrystals.

    Science.gov (United States)

    Gong, Bei; Liu, Wenxia; Tan, Hua; Yu, Dehai; Song, Zhaoping; Lucia, Lucian A

    2016-10-20

    Starch nanocrystals (SNC) are aptly described as the insoluble degradation byproducts of starch granules that purportedly display morphologies that are platelet-like, round, square, and oval-like. In this work, we reported the preparation of SNC with unprecedented tubular structures through sulfuric acid hydrolysis of normal maize starch, subsequent exposure to ammonia and relaxation at 4°C. High-resolution transmission electron microscopy observation clearly proved that the SNCs possess tubular nanostructures with polygonal cross-section. After further reviewing the transformations of SNC by acid hydrolysis, ammonia treatment, and curing time at 4°C, a mechanism for T-SNC formation is suggested. It is conjectured that T-SNC gradually self-assembles by combination of smaller platelet-like/square nanocrystals likely loosely aggregated by starch molecular chains from residual amorphous regions. This work paves the way for the pursuit of new approaches for the preparation of starch-based nanomaterials possessing unique morphologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Dynamic modeling of temperature change in outdoor operated tubular photobioreactors.

    Science.gov (United States)

    Androga, Dominic Deo; Uyar, Basar; Koku, Harun; Eroglu, Inci

    2017-07-01

    In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values. The heat transferred to the reactor was mainly through radiation: the radiative heat absorbed by the reactor medium, ground radiation, air radiation, and solar (direct and diffuse) radiation, while heat loss was mainly through the heat transfer to the cooling water and forced convection. The amount of heat transferred by reflected radiation and metabolic activities of the bacteria and pump work was negligible. Counter-current cooling was more effective in controlling reactor temperature than co-current cooling. The model developed identifies major heat transfer mechanisms in outdoor operated tubular photobioreactors, and accurately predicts temperature changes in these systems. This is useful in determining cooling duty under transient conditions and scaling up photobioreactors. The photobioreactor design and the thermal modeling were carried out and experimental results obtained for the case study of photofermentative hydrogen production by Rhodobacter capsulatus, but the approach is applicable to photobiological systems that are to be operated under outdoor conditions with significant cooling demands.

  10. Additive manufacturing of patient-specific tubular continuum manipulators

    Science.gov (United States)

    Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

    2015-03-01

    Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

  11. Radiologic findings of tubular adenoma of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mi Gyoung; Oh, Ki Keun [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-10-01

    Tubular adenoma (TA) is known as a rare lesion of the breast which is difficult to diagnosis preoperatively because of its rarity and similarity to fibroadenoma. Hence, our purpose is to suggest the characteristic sonographic features for its correct diagnosis. We retrospectively analyzed the clinical data and mammographic and sonographic findings. of seven patients(mean age, 23) who during the previous five years had presented at our hospital with pathologically-proven tubular adenoma. TA was misdiagnosed as fibroadenoma, since on physical examination of these young females, the lesions presented a palpable, non-tender mass. Mammographically, they showed a well defined mass similar to fibroadenoma. However, sonographic findings were characteristic of TA and compared to fibroadenoma, showed a well demarcated and smooth bordered mass with transverse long axis, posterior enhancement and homogeneous lower internal echogenecity. No case showed lateral wall refractive shadowing. In young females, the clinical and mammographic findings of TA are similar to those of fibroadenoma. However, sonographic findings of TA can, be helpful in the differential diagnosis of this entity and fibroadenoma.

  12. Nano-tubular cellulose for bioprocess technology development.

    Directory of Open Access Journals (Sweden)

    Athanasios A Koutinas

    Full Text Available Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation. The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator. Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

  13. Radiologic findings of tubular adenoma of the breast

    International Nuclear Information System (INIS)

    Jeong, Mi Gyoung; Oh, Ki Keun

    1996-01-01

    Tubular adenoma (TA) is known as a rare lesion of the breast which is difficult to diagnosis preoperatively because of its rarity and similarity to fibroadenoma. Hence, our purpose is to suggest the characteristic sonographic features for its correct diagnosis. We retrospectively analyzed the clinical data and mammographic and sonographic findings. of seven patients(mean age, 23) who during the previous five years had presented at our hospital with pathologically-proven tubular adenoma. TA was misdiagnosed as fibroadenoma, since on physical examination of these young females, the lesions presented a palpable, non-tender mass. Mammographically, they showed a well defined mass similar to fibroadenoma. However, sonographic findings were characteristic of TA and compared to fibroadenoma, showed a well demarcated and smooth bordered mass with transverse long axis, posterior enhancement and homogeneous lower internal echogenecity. No case showed lateral wall refractive shadowing. In young females, the clinical and mammographic findings of TA are similar to those of fibroadenoma. However, sonographic findings of TA can, be helpful in the differential diagnosis of this entity and fibroadenoma

  14. Numerical research of a super-large cooling tower subjected to accidental loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Lin, Feng [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Gu, Xianglin, E-mail: gxl@tongji.edu.cn [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Lu, Xiaoqin [Guangdong Electric Power Design Institute, Guangzhou 510660 (China)

    2014-04-01

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion.

  15. Numerical research of a super-large cooling tower subjected to accidental loads

    International Nuclear Information System (INIS)

    Li, Yi; Lin, Feng; Gu, Xianglin; Lu, Xiaoqin

    2014-01-01

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion

  16. DEVELOPMENT OF TECHNICAL DECISIONS FOR HEAT SUPPLY WITH TUBULAR GAS HEATERS

    Directory of Open Access Journals (Sweden)

    IRODOV V. F.

    2017-05-01

    Full Text Available Annotation. Problems formulation. The problem that is solved is the development of autonomous heat supply systems that reduce the capital costs of construction and increase the efficiency of the use of energy resources. One of the ways to solve this problem is the use of tubular gas heaters. For this, it is necessary to develop new technical solutions for heat supply with tubular gas heaters, as well as scientific and methodological support for the development, construction and operation of heat supply systems with tubular gas heaters. Analysis of recent research. Preliminary studies of infrared tubular gas heaters are considered, which were used to heat industrial enterprises with sufficiently high premises. The task was to extend the principles of heat supply by means of tubular heaters for heating air, water and heating medium in relatively low rooms. Goal and tasks. To lay out the development of technical solutions for heat supply with tubular gas heaters, which increase the efficiency and reliability of heat supply systems and extend the use of tubular gas heaters in heat supply. Results. Technical solutions for heat supply with tubular gas heaters have made it possible to extend their applications for heating air, water and heating medium in relatively low rooms. Scientific novelty. New technical solutions for heat supply with tubular gas heaters increase the efficiency of using fuel and energy resources at low capital costs. Practical significance. Technical solutions for heat supply using tubular heaters have the potential for wide application in the heat supply of industrial, public and residential facilities. Conclusions. For two decades, new technical solutions for heat supply with tubular gas heaters have been developed, which increase the efficiency and reliability of heat supply systems and can be widely used for autonomous heating.

  17. Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

    Science.gov (United States)

    Wang, Miao; Wang, Jin; Wang, Jiajin; Shi, Cheng

    2018-02-01

    A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.

  18. Carbon steel protection in G.S. (Girlder sulfide) plants. Iron sulfide scales formation on surfaces covered by fabrication produced films. Pt. 4

    International Nuclear Information System (INIS)

    Burkart, A.L.

    1986-04-01

    This work describes the assays aimed to passivate the steel carbon of the process pipings. This steel is marked by the ASTM A 333 G6 and is chemically similar to those of isotopic exchange towers which corrode in contact with in-water hydrogen sulfide solutions forming iron sulfide protective layers. The differences between both materials lie in the surface characteristics to be passivated. The steel of towers has an internal side covered by paint which shall be removed prior to passivation. The steel's internal side shall be covered by a film formed during the fabrication process and constituted by calcinated wastes and iron oxides (magnetite, hematite and wustite). This film interferes in the formation process of passivating layers of pyrrhotite and pyrite. The possibility to passivate the pipes in their actual state was evaluated since it would result highly laborious and expensive to eliminate the film. (Author) [es

  19. Causes of Failure of High-Tensile Stud Bolts Used for Joining Metal Parts of Tower Crane

    Science.gov (United States)

    Tingaev, A. K.; Gubaydulin, R. G.; Shaburova, N. A.

    2017-11-01

    The causes of the failure of a high-tensile stud 2M48-6gx500 10.9 made from steel grade 30HGSA which led to a temporary inoperability of a tower crane were investigated. The bolts were used to assemble the tower sections and collapsed after 45 days from the moment the crane was commissioned. The cracks in the fracture are identified as fatigue with the characteristic sites of nucleation, sustainable development and static dolomite. To determine the possible causes of stud bolts destruction, metallographic, durometric and mechanical tests were carried out from which it follows that the stud bolt material in its original state corresponded to the delivery conditions. The destruction of the stud bolt appears to have resulted from a combination of several unfavorable factors: uncertainty about the actual tension of the stud bolt due to the lack of information about the magnitude of the twist factor; partial displacement of the centers of the brackets holes and rotation of the stud bolt axis during the sections’ assembly; no tight contact on the support surfaces of the section brackets. All this led to a discrepancy between the actual design of the stud bolt, the appearance of additional forces and the destruction of the stud bolt.

  20. The optimal operation of cooling tower systems with variable-frequency control

    Science.gov (United States)

    Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

    2018-02-01

    This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

  1. Solution and scope of utilization of the cross-stream cooling towers

    International Nuclear Information System (INIS)

    Zembaty, W.

    1995-01-01

    Technical solutions and operational properties of the cross-stream cooling towers as well as the scope of their utilization are presented. The differences within thermodynamic calculations of the cross-stream and counter-stream cooling towers due to the direction of the air flow as well as water flow in sprinkling system are discussed. The assessment of the capital and operational costs of the cross-stream cooling towers is given and compared with the cost of counter-stream cooling towers (utilizing as an example a calculation conducted for the cooling towers of the 720, 1100 and 1400 MW units). (author). 6 refs, 9 figs

  2. An investigation on fatigue in high-strength steel offshore structures

    DEFF Research Database (Denmark)

    Agerskov, Henning; Petersen, R.I.; Martinez, L. Lopez

    1998-01-01

    of the investigation, fatigue test series were carried out on both full scale tubular joints and smaller welded plate test specimens in high-strength steel as well as in conventional offshore structural steel. This paper gives a summary of the main results presented in two recent research reports [15, 16], from...... these investigations. A comparison between constant amplitude and variable amplitude fatigue test results shows shorter fatigue lives in variable amplitude loading than should be expected from the linear fatigue damage accumulation formula.Furthermore, in general longer fatigue lives were obtained for the test...... specimens in high-strength steel than those obtained in corresponding tests on joints in conventional offshore structural steel....

  3. An Investigation on Fatigue in High-Strength Steel Offshore Structures

    DEFF Research Database (Denmark)

    Agerskov, Henning; Petersen, R.I.; Lopez Martinez, L.

    1997-01-01

    . In the experimental part of the investigation, fatigue test series have been carried through on both full-scale tubular joints and smaller welded plate test specimens, in high-strength steel as well as in conventional offshore structural steel. The present document gives a summary of the main results presented in two...... recent research reports, Refs. 15 and 16, from these investigations.A comparison between constant amplitude and variable amplitude fatigue test results shows shorter fatigue lives in variable amplitude loading than should be expected from the linear fatigue damage accumulation formula. Furthermore......, in general longer fatigue lives were obtained for the test specimens in high-strength steel than those obtained in corresponding tests on joints in conventional offshore structural steel....

  4. Effect of the oxygen partial pressure on ferritic stainless steel AISI 441 at high temperatures

    International Nuclear Information System (INIS)

    Salgado, M.F.; Carvalho, I.S.; Santos, R.S.; Correa, O.V.; Ramanathan, L.V.

    2014-01-01

    Stainless steels can be exposed to aggressive gases at high temperatures. To understand the behavior of oxidation of the steel AISI 441 was made oxidation at temperatures between 850 ° C and 950 ° C, at two different atmospheres: synthetic air, using tubular furnace and Argon, containing 1ppm O_2, in thermobalance. The kinetics of oxidation of the films was established by measuring the mass gain per unit of area as a function of the oxidation time. The microstructure and chemical composition of the oxides were analyzed by SEM, EDS and XRD. Chemical analysis showed that films formed on steel AISI 441 had mostly chromium oxide and the following elements: Cr, Mn, Fe, Ti and Si. Regarding the kinetics of oxidation, it was observed that in synthetic air, the steel oxidation increased gradually with the temperature, but in argon, it showed the highest oxidation at 900 ° C and the lowest oxidation at 950 ° C. (author)

  5. Effect of section shape on frequencies of natural oscillations of tubular springs

    Science.gov (United States)

    Pirogov, S. P.; Chuba, A. Yu; Cherentsov, D. A.

    2018-05-01

    The necessity of determining the frequencies of natural oscillations of manometric tubular springs is substantiated. Based on the mathematical model and computer program, numerical experiments were performed that allowed us to reveal the effect of geometric parameters on the frequencies of free oscillations of manometric tubular springs.

  6. On Energy Balance and Production Costs in Tubular and Flat Panel Photobioreactors

    NARCIS (Netherlands)

    Norsker, N.H.; Barbosa, M.J.; Vermue, M.H.; Wijffels, R.H.

    2012-01-01

    Reducing mixing in both flat panel and tubular photobioreactors can result in a positive net energy balance with state-of-the-art technology and Dutch weather conditions. In the tubular photobioreactor, the net energy balance becomes positive at velocities <0.3 ms-1, at which point the biomass

  7. 78 FR 77421 - Certain Oil Country Tubular Goods From India: Preliminary Affirmative Countervailing Duty...

    Science.gov (United States)

    2013-12-23

    ..., Saudi Arabia, Taiwan, Thailand, the Republic of Turkey, Ukraine, and the Socialist Republic of Vietnam... DEPARTMENT OF COMMERCE International Trade Administration [C-533-858] Certain Oil Country Tubular... producers and exporters of certain oil tubular goods (OCTG) from India. The period of investigation is...

  8. 78 FR 77420 - Certain Oil Country Tubular Goods From the Republic of Turkey: Preliminary Negative...

    Science.gov (United States)

    2013-12-23

    ..., the Republic of the Philippines, Saudi Arabia, Taiwan, Thailand, the Republic of Turkey, Ukraine, and... DEPARTMENT OF COMMERCE International Trade Administration [C-489-817] Certain Oil Country Tubular... provided to producers and exporters of certain oil tubular goods (OCTG) from the Republic of Turkey (Turkey...

  9. Gamma flux responsive self-powered detector with a tubular emitter

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Todt, W.H.

    1982-01-01

    A gamma-sensitive flux detector comprises tubular emitter, an insulating core within the emitter and an insulating layer about the emitter, and a tubular conductive collector electrode about the insulating layer. The emitter material may be platinum, lead, bismuth, tantalum, tungsten; platinum preferred

  10. Tubular Carcinoma of the Breast: Advantages and Limitations of Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Filipa Vilaverde

    2016-01-01

    Full Text Available Tubular carcinoma of the breast is a rare variant of invasive ductal carcinoma. We report a case of 42-year-old asymptomatic female with a histopathological proven multifocal tubular carcinoma, studied by mammography, Tomosynthesis, Ultrasound, and Magnetic Resonance. Herein, we discuss the advantages and limitations of Tomosynthesis, an emerging imaging technique, in this particular case.

  11. Tubular lysosome morphology and distribution within macrophages depend on the integrity of cytoplasmic microtubules

    International Nuclear Information System (INIS)

    Swanson, J.; Bushnell, A.; Silverstein, S.C.

    1987-01-01

    Pinocytosis of the fluorescent dye lucifer yellow labels elongated, membrane-bound tubular organelles in several cell types, including cultured human monocytes, thioglycolate-elicited mouse peritoneal macrophages, and the macrophage-like cell line J774.2. These tubular structures can be identified as lysosomes by acid phosphatase histochemistry and immunofluorescence localization of cathepsin L. The abundance of tubular lysosomes is markedly increased by treatment with phorbol 12-myristate 13-acetate. When labeled by pinocytosis of microperoxidase and examined by electron microscopic histochemistry, the tubular lysosomes have an outside diameter of ≅ 75 nm and a length of several micrometers; they radiate from the cell's centrosphere in alignment with cytoplasmic microtubules and intermediate filaments. Incubation of phorbol myristate acetate-treated macrophages at 4 0 C or in medium containing 5 μM colchicine or nocodazole at 37 0 C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 37 0 C or removal of nocodazole from the medium leads to reassembly of microtubules and the reappearance of tubular lysosomes within 10-20 min. The authors conclude that microtubules are essential for the maintenance of tubular lysosome morphology and that, in macrophages, a significant proportion of the lysosomal compartment is contained within these tubular structures

  12. 76 FR 39071 - Certain Oil Country Tubular Goods From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2011-07-05

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-944] Certain Oil Country Tubular... administrative review of the countervailing duty order on certain oil country tubular goods (``OCTG'') from the... subject to administrative protective order (``APO'') of their responsibility concerning the disposition of...

  13. Tubular Carcinoma of the Breast: Advantages and Limitations of Breast Tomosynthesis

    Science.gov (United States)

    Rocha, Ana; Reis, Alcinda

    2016-01-01

    Tubular carcinoma of the breast is a rare variant of invasive ductal carcinoma. We report a case of 42-year-old asymptomatic female with a histopathological proven multifocal tubular carcinoma, studied by mammography, Tomosynthesis, Ultrasound, and Magnetic Resonance. Herein, we discuss the advantages and limitations of Tomosynthesis, an emerging imaging technique, in this particular case. PMID:28116205

  14. Compressibility effects in packed and open tubular gas and supercritical fluid chromatography

    NARCIS (Netherlands)

    Janssen, J.G.M.; Snijders, H.M.J.; Cramers, C.A.; Schoenmakers, P.J.

    1992-01-01

    The influence of the pressure drop on the efficiency and speed of anal. in packed and open tubular supercrit. fluid chromatog. (SFC) is described: methods previously developed to describe the effects of mobile phase compressibility on the performance of open tubular columns in SFC have been extended

  15. Vibration analysis of three guyed tower designs for intermediate size wind turbines

    Science.gov (United States)

    Christie, R. J.

    1982-01-01

    Three guyed tower designs were analyzed for intermediate size wind turbines. The four lowest natural frequencies of vibration of the three towers concepts were estimated. A parametric study was performed on each tower to determine the effect of varying such tower properties as the inertia and stiffness of the tower and guys, the inertia values of the nacelle and rotor, and the rotational speed of the rotor. Only the two lowest frequencies were in a range where they could be excited by the rotor blade passing frequencies. There two frequencies could be tuned by varying the guy stiffness, the guy attachment point on the tower, the tower and mass stiffness, and the nacelle/rotor/power train masses.

  16. PENGURANGAN KADAR CO2 MENGGUNAKAN SPIRULINA PLATENSIS DALAM TUBULAR BIOREACTOR

    Directory of Open Access Journals (Sweden)

    Zainal Syam Arifin

    2015-06-01

    Full Text Available Increasing the population impact on increasing energy demand. On the other hand, the energy generation industry has been blamed as one of the contributors of carbon dioxide about 25% of total CO2 emissions worldwide. Meanwhile, the production of biogas, which aims to address the increasing need of energy, produces carbon dioxide in the range of 25–50% by volume. To overcome this, a cheap method, optimum and efficient as well as environmentally friendly in reducing CO2 levels by using Spirulina platensis is needed. This research aims to created a mathematical models and found the optimum flow rate to reduced levels of CO2 by using Spirulina platensis. This study used a glass tubular bioreactor (D = 2.6 cm at a temperature of 30°C and irradiated with a fluorescent lamp Philips TL 36 Watt, color temperature: 6,200K cool daylight, light output: 2,600 lm, 72 lm/W. Tubular reactor was placed in a box lined with silver foil walls on three sides. With mathematical models of tubular reactor, the reaction rate constants could be predicted. Based on calculations of data and graphs, optimum volumetric velocity could also be predicted. Variation of flowrate to observed the reduction rate of CO2 was 0.25 mL/sec, 0.35 mL/sec, 0.5 mL/sec, 0.75 mL/sec, 1 mL/sec. Carbon source was 99.99% CO2.Observations of Spirulina growth was made on the flow rate of 0.25 mL/sec at the initial levels of dry weight 2.1208 g/L. The results of this study indicated that the low flowratewas a more effective way to reduced carbon dioxide levels using Spirulina platensis (= 2.82×10-4 sec-1. The highest conversion was obtained at a volumetric flow rate of 0.25 mL/sec and optimum speeds in the range of 0.3 to 0.4 mL/sec. The rate of incoming CO2 flux should be less than 0.047 mL/cm2.detik. Specific Growth Rate (µ of Spirulina platensis in this study was 2.56×10-2 minute-1.   Keywords: Spirulina platensis, a vertical tubular bioreactor, CO2 reduction     ABSTRAK

  17. Steel Plate Shear Walls: Efficient Structural Solution for Slender High-Rise in China

    International Nuclear Information System (INIS)

    Mathias, Neville; Long, Eric; Sarkisian, Mark; Huang Zhihui

    2008-01-01

    The 329.6 meter tall 74-story Jinta Tower in Tianjin, China, is expected, when complete, to be the tallest building in the world with slender steel plate shear walls used as the primary lateral load resisting system. The tower has an overall aspect ratio close to 1:8, and the main design challenge was to develop an efficient lateral system capable of resisting significant wind and seismic lateral loads, while simultaneously keeping wind induced oscillations under acceptable perception limits. This paper describes the process of selection of steel plate shear walls as the structural system, and presents the design philosophy, criteria and procedures that were arrived at by integrating the relevant requirements and recommendations of US and Chinese codes and standards, and current on-going research

  18. Third generation of Thyssen tailored tubes - a new category of tubular products

    Energy Technology Data Exchange (ETDEWEB)

    Flehmig, T.; Brueggenbrock, M.; Kibben, M.; Schwenecke, S. [ThyssenKrupp Stahl, Duisburg (Germany)

    2005-07-01

    Further weight saving goals have prompted the automotive industry to design lighter car body structures in order to reduce fuel consumption, while maintaining the high safety standards for occupants. Body structures developed with large portions of closed profiles have a so-called ''profile intensive design.'' Particularly in the case of large scale production, it is necessary to have cost effective manufacturing methods. Therefore, production and processing require short process chains as well as the latest techniques. New forming technologies, combined with laser-beam welding and hydroforming processes is one strategy to save costs. A further way to shorten the process chain is the joining and combining of process steps at first and then later fitting the tailored tubes with the new features. The result of these efforts led to a new category of tubular products the so called ''3{sup rd} generation Thyssen Tailored Tubes {sup registered} TTT {sup registered} ''. These nearly finished parts are manufactured by a new forming technology the so called ''Thyssen Tube Curling Process''. This technique permits the direct forming from flat blanks into welded longitudinal beams, for example from the NewSteelBody {sup registered} car, without a hydroforming step, all within a single machine. The paper points out a further forming method with similar results. Compared to processes like roll or roller forming in combination with hydroforming, these new methods cause only minimal plastic strains. The paper shows some parts, manufactured by these methods. The pre-bending of Thyssen Tailored Tubes {sup registered} is also a newly developed process. (orig.)

  19. Cracked reinforced concrete walls of chimneys, silos and cooling towers as result of using formworks

    Directory of Open Access Journals (Sweden)

    Maj Marek

    2018-01-01

    Full Text Available There are presented in this paper some problems connected with reinforced concrete shell objects operation in the aggressive environment and built in method of formworks. Reinforced concrete chimneys, cooling towers, silos and other shells were built for decades. Durability of cracked shells are one of the most important parameters during process of designing, construction and exploitation of shells. Some reasons of appearance of horizontal and vertical cracks as temperature, pressure of stored material, live loads e.g. dynamic character of wind, moisture, influence of construction joints, thermal insulation, chemistry active environmental etc. reduce the carrying capacity of the walls. Formworks, as is occurred recently, are the reason for technological joints with leaking connection, imperfections of flexible formworks slabs and as result can initiate cracks. Cracked surface of this constructions causes decreasing capacity and lower the state of reliability. Horizontal, vertical cracks can caused corrosion of concrete and steel bars, decreasing stiffness of contraction, increasing of deflection and carbonation of concrete cover. Local and global imperfactions of concrete shells are increasing according to greater number of cracks...

  20. Process for the fixing of a metallic end piece on a tubular component

    International Nuclear Information System (INIS)

    Charpin, Jean.

    1975-01-01

    Under this invention the process makes it possible to joint a tubular component and in particular a tubular filter and an end piece, with a connection of great mechanical strength, perfectly leak proof and with excellent corrosion resistance, particularly with respect to fluorinated by-products. This process is therefore of great worth in fixing to a bearer a thin ceramic compound tubular filter element, since such a filter can be used in particular for the separation of uranium isotopes by gaseous diffusion and for the separation of hydrocarbons in petrochemicals. To this end, the process under consideration is characterised in that it consists in depositing a layer of ceramic material, by hot projection, at the end of the tubular element and in sealing the end piece to the end of the tubular element by the hot projection of a ceramic or metallic substance [fr