WorldWideScience

Sample records for aqueducts

  1. Aqueduct stenosis and schizophrenia

    OpenAIRE

    Dewan, M J; Bick, P

    1983-01-01

    Three patients with hydrocephalus and aqueduct stenosis are described, who also have schizophrenia defined according to strict diagnostic criteria. There are no previous reports of such an association.

  2. Enlarged Vestibular Aqueducts and Childhood Hearing Loss

    Science.gov (United States)

    ... Health Info » Hearing, Ear Infections, and Deafness Enlarged Vestibular Aqueducts and Childhood Hearing Loss On this page: ... more information about enlarged vestibular aqueducts? What are vestibular aqueducts? The inner ear Credit: NIH Medical Arts ...

  3. Enlarged Vestibular Aqueduct Syndrome (EVAS)

    Science.gov (United States)

    ... referred to as EVA syndrome (EVA). CAUSES During fetal development, the vestibular aqueduct starts out as a wide ... in early gestation, or EVA results from aberrant development later in fetal and postnatal life. It is believed that an ...

  4. Impounding Experimental Research of Large Span Aqueduct

    Directory of Open Access Journals (Sweden)

    Huafeng Deng

    2013-04-01

    Full Text Available In this study, we have a research of the impounding experimental research of large span aqueduct. Caohe aqueduct is the mark building of the middle line of the South-to-North Water Diversion Project, of which the span is 30m. For this aqueduct, the structure is relatively complicated with great technical difficulties, what’s more there's no engineering experience or theoretical method to provide reference in domestic and abroad. It can be seen clear that whether the actual stressing state, deformation conditions and prestressed tension effect etc. meet the design requirements will directly affect the safe operation of aqueduct, so the impounding experiment of the aqueduct was carried out before formal operation. At the meanwhile, the deformation characteristics and stress characteristics of the aqueduct under various impounding conditions were analyzed in detail. The experiment results analysis shows that, the aqueduct structure is under a good elastic working condition with only 0.98mm maximum deflection deformation at mid-span, which meets the design and specification requirements. At the same time, all of the measure point’s stress is in the range of designed material, which means the structure form is safe and reliable and can meet the requirements of the later operation good.

  5. Impounding Experimental Research of Large Span Aqueduct

    OpenAIRE

    Huafeng Deng; Min Zhu; Xianfan Yuan; Qian Luo

    2013-01-01

    In this study, we have a research of the impounding experimental research of large span aqueduct. Caohe aqueduct is the mark building of the middle line of the South-to-North Water Diversion Project, of which the span is 30m. For this aqueduct, the structure is relatively complicated with great technical difficulties, what’s more there's no engineering experience or theoretical method to provide reference in domestic and abroad. It can be seen clear that whether the actual stressing state, de...

  6. Investigation of the vestibular aqueduct and the cochlear aqueduct by temboral bone CT scan

    International Nuclear Information System (INIS)

    The visualization of the vestibular aqueduct and the cochlear aqueduct was investigated by temporal bone CT scan. The vestibular aqueduct was visualized in horizontal CT sections of 70.0% of normal ears, 61.5% of ears with chronic otitis media, 58.3% of ears with combined hearing impairment, 66.7% of ears in cases of sudden deafness, 70.8% of ears of patients with sensorineural hearing impairment without sudden deafness, 71.4% of cases of vertigo without hearing impairment and 12.5% of both diseased and contralateral ears of patients with Meniere's disease. Only in Meniere's disease was the vestibular aqueduct less visible in the diseased than in the normal ear (P<0.01). The cochlear aqueduct was visible in coronal sections of 50.0% of normal ears, 76.9% of those with chronic otitis media, 58.3% of those with combined hearing impairment, 66.7% of those with sudden deafness 41.7% of those with sensorineural hearing impairment without sudden deafness, 50.0% of the diseased ears of patients with Meniere's disease, 37.5% of the contralateral ears of those with Meniere's disease and 64.3% of those with vertigo without hearing impairment. Although the cochlear aqueduct was thus highly demonstrable in patients with chronic otitis media or sudden deafness, the difference between the percentage of visualization in these diseased and in normal ears was not statistically significant. (author)

  7. Innovative approach to replace concrete aqueducts at Kakabeka Falls GS

    Energy Technology Data Exchange (ETDEWEB)

    Chidiac, M. [Stone and Webster Canada, Toronto, ON (Canada); Dunphy, J. [Aker Maritime Kiewit Contractors, St. John' s, NF (Canada); Young, L. [Exebridge Project Services, Toronto, ON (Canada)

    2004-09-01

    The original facilities of the Kakabeka Falls generating station on the Kaministikwia River west of Thunder Bay, Ontario were constructed between 1906 and 1914. They included 3 low pressure, reinforced concrete aqueducts that measured 3.1 meter in diameter and 1980 meters long to carry water to a powerhouse containing 4 generators. In 1994, the aqueducts were deemed to be at the end of their service life and required replacement to avoid a failure which would potentially cause serious environmental damage, pose a threat to public safety and result in a severe loss of generation production. Several alternative water transport systems were considered to replace the aqueducts. One single 5 meter diameter aqueduct made of cast-in-place reinforced concrete was chosen to replace the 3 aging aqueducts. Replacement of the aqueduct began in May 1997 and work was completed on schedule 7 months later. The generating station returned to service in early 1998. The new aqueduct has performed excellently during its 6 years in service and does not show any evidence of concrete deficiencies such as cracks or erosions. Some minor repairs were made to the elastomeric seal membrane at a few joints where some delamination occurred but with no leakage path developing. The new aqueduct is expected to last nearly 100 years. 12 figs.

  8. Vestibular tributaries to the vein of the vestibular aqueduct

    DEFF Research Database (Denmark)

    Hansen, Jesper Marsner; Qvortrup, Klaus; Friis, Morten

    2010-01-01

    CONCLUSION: The vein of the vestibular aqueduct drains blood from areas extensively lined by vestibular dark cells (VDCs). A possible involvement in the pathogenesis of an impaired endolymphatic homeostasis can be envisioned at the level of the dark cells area. OBJECTIVES: The aim of this study...... was to investigate the vascular relationship between the vein of the vestibular aqueduct and the vestibular apparatus, with focus on the VDCs. METHODS: Sixteen male Wistar rats were divided into groups of 6 and 10. In the first group, 2 µm thick sections including the vein of the vestibular aqueduct, utricle...... relation to the VDCs in the utricle and the crista ampullaris of the lateral semicircular canal in the vestibular apparatus. One major vein emanated from these networks, which emptied into the vein of the vestibular aqueduct. Veins draining the saccule and the common crus of the superior and posterior...

  9. Morphological analysis of the vestibular aqueduct by computerized tomography images

    International Nuclear Information System (INIS)

    Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm2 of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm2, 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant

  10. Morphological analysis of the vestibular aqueduct by computerized tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Sergio Ricardo [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil)]. E-mail: sergioanat.morf@epm.br; Smith, Ricardo Luiz [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Isotani, Sadao [Institute of Physics, University of Sao Paulo, Sao Paulo (Brazil); Alonso, Luis Garcia [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Anadao, Carlos Augusto [Otorhinolaryngology Department, Sao Paulo Federal University-Paulista Medical School, Sao Paulo (Brazil); Prates, Jose Carlos [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Lederman, Henrique Manoel [Image Diagnosis Department, Sao Paulo Federal University-Paulista Medical School, Sao Paulo (Brazil)

    2007-01-15

    Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm{sup 2} of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm{sup 2}, 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant.

  11. Relations of aqueduct with some structures of mesencephalon

    Directory of Open Access Journals (Sweden)

    Stanković Gordana

    2009-01-01

    Full Text Available Introduction. Aqueductus mesencephali is the biggest part of the ventricular system and that is why it is the most common place of intraventricular obstruction of cerebrospinal fluid. This study was done in order to study topographic characteristics of aqueduct more thoroughly. Materials and methods. Transversal sections of mesencephalon were made in three levels. The first section was made caudally immediately from the posterior commissure. The second section was made in the middle part of the superior colliculi, and the third section was made in the rostral parts of the caudal sections of the superior colliculi. Distances of the aqueduct from structures of mesencephalon, obtained on the second section, are: 1. The distance of the aqueduct from the superior colliculi - 6.96 mm; 2. The distance of the aqueduct from the red nucleus - 6.02 mm; 3. The distance of the aqueduct from the substantia nigra - 12.29 mm; 4. The distance of the aqueduct from the interpeduncular fossa - 10.22 mm. Conclusion. Knowledge of the anatomy of the aqueductus mesencephali is very important because of interpretation of patogenesis of hidrocefalus as well as of other syndromes that occure in some pathological processes in the system of ventricles.

  12. A possible third window for bone conducted hearing: Cochlear aqueduct vs. vestibular aqueduct

    Science.gov (United States)

    Kim, Namkeun; Stenfelt, Stefan

    2015-12-01

    A third window, which is another cochlear fluid pathway different from the oval window and round window, is considered to be a significant factor in bone-conducted hearing. A three-dimensional finite element model of the human ear consisting of the middle ear and cochlea was used to investigate the effect of the third windows on bone-conducted heraing. This study is aimed to find the third window which causes the consistent cochlear responses with previous studies in air-conducted hearing, and causes the asymmetry of the volume velocity ratio between the oval window and round window in bone-conducted hearing. The preliminary result shows that the cochlear aqueduct and the vestibular aqueduct with high impedance do not affect the basilar membrane velocity in air-conducted hearing. On the contrary, in bone-conducted hearing, the direction of the shaking structure for the bone-conducted stimulation as well as the third window can be a significant factor causing the asymmetry of the volume velocity ratio found by Stenfelt et al.

  13. Aqueduct: a methodology to measure and communicate global water risks

    Science.gov (United States)

    Gassert, Francis; Reig, Paul

    2013-04-01

    The Aqueduct Water Risk Atlas (Aqueduct) is a publicly available, global database and interactive tool that maps indicators of water related risks for decision makers worldwide. Aqueduct makes use of the latest geo-statistical modeling techniques to compute a composite index and translate the most recently available hydrological data into practical information on water related risks for companies, investors, and governments alike. Twelve global indicators are grouped into a Water Risk Framework designed in response to the growing concerns from private sector actors around water scarcity, water quality, climate change, and increasing demand for freshwater. The Aqueduct framework organizes indicators into three categories of risk that bring together multiple dimensions of water related risk into comprehensive aggregated scores and includes indicators of water stress, variability in supply, storage, flood, drought, groundwater, water quality and social conflict, addressing both spatial and temporal variation in water hazards. Indicators are selected based on relevance to water users, availability and robustness of global data sources, and expert consultation, and are collected from existing datasets or derived from a Global Land Data Assimilation System (GLDAS) based integrated water balance model. Indicators are normalized using a threshold approach, and composite scores are computed using a linear aggregation scheme that allows for dynamic weighting to capture users' unique exposure to water hazards. By providing consistent scores across the globe, the Aqueduct Water Risk Atlas enables rapid comparison across diverse aspects of water risk. Companies can use this information to prioritize actions, investors to leverage financial interest to improve water management, and governments to engage with the private sector to seek solutions for more equitable and sustainable water governance. The Aqueduct Water Risk Atlas enables practical applications of scientific data

  14. Leak and condition evaluation of a buried aqueduct

    Science.gov (United States)

    Maser, Kenneth R.; Zarghamee, Medhi S.

    1998-03-01

    A leak survey of a major metropolitan area aqueduct was carried out using a combination of infrared thermography, ground penetrating radar (GPR), and ultrasonic techniques. The objective of the infrared survey was to investigate the entire length of the aqueduct in order to reveal possible leak conditions which would not be observable by other means. The objective of the GPR survey was to focus attention more locally on key areas such as known leak locations, proposed test pit locations, and areas which were identified from the infrared survey. The ultrasonic tests were carried out on the concrete wall of the aqueduct when it was exposed for detailed evaluation. The infrared survey was carried out from a helicopter, and covered the entire 16 mile length of the aqueduct. The GPR survey was carried longitudinally on 20665 linear feet of the aqueduct (26% of the total near surface length), and transversely at 89 different stations. The ultrasonic tests were carried out in 8 excavated test pits. The analysis of the infrared and GPR survey results revealed that: (1) of the 25 documented leaks surveyed, 13 were confirmed, 9 show no evidence of leakage, and 3 could not be evaluated; (2) 35 additional sites have indications of possible leakage; (3) the soil cover in one area far exceeds the anticipated design conditions; (4) the soil conductivity is high (i.e., corrosion is likely) in 9 areas, 6 of which surround or are close to documented leak sites; and (5) there is a major leakage channel along the side of the pipe caused by one of the leaks. The results of the ultrasonic testing revealed occasional delamination between the structural wall of the aqueduct and the inner steel lining.

  15. Direct measurement flow resistance of cochlear aqueduct in guinea pigs

    NARCIS (Netherlands)

    Laurens-Thalen, EO; Wit, HP; Segenhout, JM; Albers, FWJ

    2004-01-01

    Objective - The cochlear aqueduct connects the scala tympani to the subarachnoid space and is the main pressure equalization canal for the inner ear. Increases in inner ear volume and pressure are thought to cause clinical symptoms such as vertigo, tinnitus and fluctuating hearing loss. In this stud

  16. Hydrogeological Characteristics of Hellenic Aqueducts-Like Qanats

    Directory of Open Access Journals (Sweden)

    Andreas N. Angelakis

    2013-09-01

    Full Text Available In ancient Hellas, water management began in the early Minoan Era (ca. 3200–1100 BC and was related to the geomorphology, the geology, the topography, and the local climatic, hydrological, and socio-political conditions. Historical and archaeological evidences show that ancient Greeks had developed even qanat-related technologies since the Classical times. During democratic periods, the focus of water management was on sustainable small scale, safe, and cost effective management practices, and institutional arrangements, whereas in oligarchic periods, emphasis was on the construction of large-scale hydraulic projects, including aqueducts and/or qanats, mostly related to the public sectors. Aqueducts-like qanats are gently sloping, artificially constructed underground galleries, which bring groundwater from the mountainous area to the lowlands, where water is used, sometimes several kilometers away. It is worth noticing that no large-scale lifting techniques were available, and water was transferred from the source (usually a spring by aqueducts (qanats from a higher elevation to a lower level by gravity. Historically, the aqueduct-like qanat technology was developed by Persians in the middle of 1st Millennium BC, and spread towards the Arabian Peninsula and Egypt. The expansion of Islam led to diffusion of qanats in Mediterranean countries (e.g., Spain, Italy, and Cyprus. Much of the population of Iran and other arid countries in North Africa and in Asia depend on water supply by aqueducts-like qanats, even today. This technology is characterized by its durability and sustainability, although an aqueduct-like qanat is expensive, both in construction and maintenance. It is pointed out that, the technique of tunneling was used during the Classical period in ancient Hellas. Since the well known tunnel at the island of Samos, Hellas, was designed and constructed by Eupalinos (ca. 530 BC, several underground tunnels (with and without well

  17. Rhombencephalosynapsis as a cause of aqueductal stenosis: an under-recognized association in hydrocephalic children

    International Nuclear Information System (INIS)

    Rhombencephalosynapsis is a rare genetic aberration characterized by variable vermian hypoplasia/aplasia in conjunction with united cerebellar hemispheres. Genetic defects in the isthmic organizer at the mesencephalic-metencephalic junction are presumably responsible for the associated aqueductal stenosis. We performed a retrospective review of 20 children with rhombencephalosynapsis to evaluate for and emphasize the association of aqueductal stenosis and hydrocephalus. We retrospectively reviewed the MR and CT images of 20 children (0-11 years old) with rhombencephalosynapsis encountered at two academic children's hospitals. Rhombencephalosynapsis spectrum severity was graded based on pre-existing literature. We analyzed examinations for ventriculomegaly and degree of aqueductal stenosis. The collicular distances were measured from the collicular apices. Imaging studies were also analyzed for malformations of cortical and cerebellar development. Thirteen of the 20 children (65%) with rhombencephalosynapsis presented with clinical or imaging evidence of hydrocephalus and aqueductal stenosis, principally involving the caudal cerebral aqueduct. All children with aqueductal stenosis had collicular fusion. All six children with complete rhombencephalosynapsis had aqueductal stenosis. The cerebral aqueduct varied from normal to stenotic in children with incomplete rhombencephalosynapsis. Corpus callosum dysgenesis was present in four children. Aqueductal stenosis in the setting of rhombencephalosynapsis is an under-recognized cause of noncommunicating hydrocephalus. Our findings support the hypothesis that a defect involving the common gene(s) responsible for the differentiation and development of both the roof plate and midline cerebellar primordium at the mesencephalon/first rhombomere junction may be responsible for the association of aqueductal stenosis and rhombencephalosynapsis. (orig.)

  18. A New Palaeo-environmental Proxy from Roman Aqueducts: What Can We Learn from Calcareous Sinter?

    Science.gov (United States)

    Surmelihindi, G.; Passchier, C. W.

    2014-12-01

    Roman aqueducts belong to the greatest engineering structures of the ancient world. Recently, carbonate deposits in the remains of aqueduct bridges and channels were recognized as a new proxy for palaeo-environmental changes. These deposits show similar fabric and lamination characteristics as other types of terrestrial carbonates from caves and rivers such as freshwater tufa, and hot spring deposits like travertine.We present a multi-disciplinary study on calcium carbonate deposits from aqueduct sites in Southern France and Turkey, assisted by monitoring studies at aqueduct water sources in Italy of water composition and recent carbonate growth. The microstructure of the deposits shows considerable variation, even along a single aqueduct, mainly due to different climatic regimes, variations in channel type, aqueduct gradient and water velocity. However, downstream samples of several aqueducts show regular laminations associated with a strong δ18O cyclicity that can be interpreted as an effect of seasonal warming and cooling of water in the aqueduct channel. δ13C isotope curves are more complicated but commonly show antithetic cyclicity to δ18O. Deposits from aqueducts in the eastern Mediterranean, at Aspendos and Patara (Southern Turkey), typically show a regular layering of alternating sparite and micrite, which coincides with δ18O cyclicity. This reflects extreme seasonal cyclicity in temperature and rainfall in southern Turkey. However, deposits from the aqueduct of Cahors (Southern France), have cyclicity in δ18O that shows poor correlation with the microstructure and δ13C. This is probably due to the more variable, less seasonal rainfall patterns in southern France.Carbonate deposits from ancient aqueducts can serve as a high-resolution data source of palaeoclimate, and to determine the number of years the aqueducts functioned. Besides a regular lamination, most deposits also show single, distinct layers that can be a proxy for extreme weather events or

  19. MR imaging features and clinical value of vestibular aqueduct and endolymphatic sac in patients with large vestibular aqueduct syndrome

    International Nuclear Information System (INIS)

    Objective: To investigate MR imaging features of endolymphatic sac and vestibular aqueduct in patients with large vestibular aqueduct syndrome (LVAS) and its correlation with hearing loss. Methods: MR imaging findings of LVAS were analyzed in 31 cases (62 ears) retrospectively. MR imaging features were grouped into 4 types. In the first type, the signals of endolymphatic and vestibular aqueduct were hypointense without any hyperintense area. In the second type, the signals of endolymphatic sac and vestibular were hyperintense which were confined within vestibular fissure. In the third type, the area from vestibular aqueduct backward out of the edge of the petrous bone was hyperintense, but its lower boundary was above posterior semicircular. In the fourth type the area which was hyperintense was below the posterior semicircular. To avoid errors in visual inspection, the hyperintense and hypointense area of endolymphatic and the signal intensity of vestibular aqueduct and cerebrospinal fluid (CSF) were measured. The differences of signal intensity among the vestibular endolymphatic sac between the high-signal areas and low signal areas were compared with paired t-test. The correlation of the endolymphatic sac MRI classification and degree of hearing loss was analyzed by corrected Chi-square test and Spearman correlation analysis. Result: Ten ears belonged to type Ⅰ (moderate hearing loss in 1 ear,severe in 4 ears,profound in 5 ears), 17 ears belonged to type Ⅱ (moderate hearing loss in 1 ear; severe in 5 ears,profound in 11 ears), 23 ears to type Ⅲ (moderate hearing loss in 3 ear, severe in 5 ears, profound in 15 ears) and 12 ears belonged to Ⅳ (mild hearing loss in 1 ear, moderate in 1 ear, severe 3 ear, profound in 7 ears). The boundary between hyperintense and hypointense area was clear, and the signal intensity ratios was 2.02 ± 0.06. The signal ratios of hyperintense and hypointense area to vestibular and CSF were 0.95 ±0.12, 0.49 ±0.10, 0.99 ± 0

  20. The vein of the vestibular aqueduct with potential pathologic perspectives

    DEFF Research Database (Denmark)

    Friis, Morten; Sørensen, Mads Sølvsten; Qvortrup, Klaus

    2008-01-01

    HYPOTHESIS: Pathologic changes around the vein of the vestibular aqueduct (VVA) may cause obstruction to the flow of blood toward the sigmoid sinus. Furthermore, a distal obstruction of this vessel may be responsible for a development of a retrograde flow of blood with concomitant drainage...... of endolymphatic sac (ES) substances to the inner ear. BACKGROUND: The VVA is responsible for the venous drainage of the vestibular apparatus and endolymphatic duct and ES. Previous studies have linked the VVA to Ménière's disease. The aim of the present article was a 3-dimensional perspective study of the VVA...... with its adjacent anatomic structures. METHODS: In 14 rats, the VVA was examined by 3-dimensional reconstruction of 2-microm serial sections, corrosion cast technique, and scanning electron microscopy. RESULTS: From the external aperture of the vestibular aqueduct, the VVA is interposed between the ES...

  1. Seismic Protection of an Ancient Aqueduct Using SMA Devices

    International Nuclear Information System (INIS)

    The effectiveness of the use of Cu-based shape memory alloy (SMA) prestressing devices on an ancient aqueduct is examined in this paper. The dynamic characteristics of the aqueduct were measured within the span of three years and computational models were developed that matched very closely its dynamic behaviour. Using this as a bench mark, SMA prestressing devices were applied on the structure and the effects on its dynamic characteristics were assessed. It was noted that the SMA prestressing devices have a significant effect on the dynamic response of the structure. This is attributed to the stiffening of the structure due to the increase in contact between the masonry units and hence the increase of its stiffness through the increase of the modulus of elasticity of the masonry matrix. It can be concluded that the SMA prestressing devices can provide an inconspicuous means of stiffening masonry structures and increase their resistance to earthquake loads

  2. Prestressed Concrete Pipe Failure Jordan Aqueduct, Reach 3

    OpenAIRE

    United States Bureau of Reclamation

    1994-01-01

    The Bureau of Reclamation conducted failure investigations to identify the cause(s) of a catastrophic rupture of prestressed concrete pipe under impressed current cathodic protection, which occurred on Reach 3 of the Jordan Aqueduct near Salt Lake City, Utah, on August 7, 1984. The multidisciplinary analyses included corrosion, design, petrographic, structural, and metallurgical investigations. From the onset of the failure, the issue was one of reconciling cathodic overprotection and defec...

  3. Aqueduct: an interactive tool to empower global water risk assessment

    Science.gov (United States)

    Reig, Paul; Gassert, Francis

    2013-04-01

    The Aqueduct Water Risk Atlas (Aqueduct) is a publicly available, global database and interactive tool that maps indicators of water related risks for decision makers worldwide. Aqueduct makes use of the latest geo-statistical modeling techniques to compute a composite index and translate the most recently available hydrological data into practical information on water related risks for companies, investors, and governments alike. Twelve global indicators are grouped into a Water Risk Framework designed in response to the growing concerns from private sector actors around water scarcity, water quality, climate change, and increasing demand for freshwater. The Aqueduct framework includes indicators of water stress, variability in supply, storage, flood, drought, groundwater, water quality and social conflict, addressing both spatial and temporal variation in water hazards. It organizes indicators into three categories of risk that bring together multiple dimensions of water related risk into comprehensive aggregated scores, which allow for dynamic weighting to capture users' unique exposure to water hazards. All information is compiled into an online, open access platform, from which decision-makers can view indicators, scores, and maps, conduct global risk assessments, and export data and shape files for further analysis. Companies can use this tool to evaluate their exposure to water risks across operations and supply chains, investors to assess water-related risks in their portfolio, and public-sector actors to better understand water security. Additionally, the open nature of the data and maps allow other organizations to build off of this effort with new research, for example in the areas of water-energy or water-food relationships. This presentation will showcase the Aqueduct Water Risk Atlas online tool and the features and functionalities it offers, as well as explain how it can be used for both private and public sector applications. The session will

  4. Do as the Romans: Construct an Aqueduct! Grades 6-8.

    Science.gov (United States)

    Rushton, Erik; Ryan, Emily; Swift, Charles

    In this activity, students work with specified materials to create aqueduct components to transport two liters of water across a short distance in the classroom. The goal is to build an aqueduct that will supply Aqueductis, a Roman city, with clean water for private homes, public baths, and glorious fountains. By introducing various ideas and…

  5. Rhombencephalosynapsis as a cause of aqueductal stenosis: an under-recognized association in hydrocephalic children

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, Matthew T. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Children' s National Medical Center, Washington, DC (United States); Choudhri, Asim F. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); Grimm, John; Nelson, Marvin D. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States)

    2014-07-15

    Rhombencephalosynapsis is a rare genetic aberration characterized by variable vermian hypoplasia/aplasia in conjunction with united cerebellar hemispheres. Genetic defects in the isthmic organizer at the mesencephalic-metencephalic junction are presumably responsible for the associated aqueductal stenosis. We performed a retrospective review of 20 children with rhombencephalosynapsis to evaluate for and emphasize the association of aqueductal stenosis and hydrocephalus. We retrospectively reviewed the MR and CT images of 20 children (0-11 years old) with rhombencephalosynapsis encountered at two academic children's hospitals. Rhombencephalosynapsis spectrum severity was graded based on pre-existing literature. We analyzed examinations for ventriculomegaly and degree of aqueductal stenosis. The collicular distances were measured from the collicular apices. Imaging studies were also analyzed for malformations of cortical and cerebellar development. Thirteen of the 20 children (65%) with rhombencephalosynapsis presented with clinical or imaging evidence of hydrocephalus and aqueductal stenosis, principally involving the caudal cerebral aqueduct. All children with aqueductal stenosis had collicular fusion. All six children with complete rhombencephalosynapsis had aqueductal stenosis. The cerebral aqueduct varied from normal to stenotic in children with incomplete rhombencephalosynapsis. Corpus callosum dysgenesis was present in four children. Aqueductal stenosis in the setting of rhombencephalosynapsis is an under-recognized cause of noncommunicating hydrocephalus. Our findings support the hypothesis that a defect involving the common gene(s) responsible for the differentiation and development of both the roof plate and midline cerebellar primordium at the mesencephalon/first rhombomere junction may be responsible for the association of aqueductal stenosis and rhombencephalosynapsis. (orig.)

  6. Can a fixed measure serve as a pertinent diagnostic criterion for large vestibular aqueduct in children?

    International Nuclear Information System (INIS)

    A vestibular aqueduct midpoint width greater than 1.50 mm is currently considered to be pathognomonic for a large vestibular aqueduct syndrome. To analyse the diameter of the vestibular aqueduct in children as a function of age and consequently to determine if a fixed measure could serve as a pertinent diagnostic criterion. This was a retrospective study of 200 high-resolution CT scans of the ear in 100 patients aged 0-16 years and from various paediatric medical departments. On each CT scan, the lateral semicircular canal diameter, the vestibular aqueduct midpoint width between the external aperture and common crus, and the vestibular aqueduct external aperture diameter were measured. Spearman's rank test and the Mann-Whitney correlation test were used for an integrated statistical analysis. There was no statistically significant variability in vestibular aqueduct diameter as a function of age or sex of patients. A CT scan threshold value, fixed and independent of age and sex, is thus legitimate for the diagnosis of vestibular aqueduct dilatation. (orig.)

  7. Papillary Ependymoma WHO Grade II of the Aqueduct Treated by Endoscopic Tumor Resection

    Directory of Open Access Journals (Sweden)

    Andreas M. Stark

    2009-01-01

    Full Text Available Papillary ependymoma is a rare tumor that may be located along the ventricular walls or within the spinal cord. We report the case of a 54-year-old patient with a papillary ependymoma WHO grade II arising at the entrance of the aqueduct. The tumor caused hydrocephalus. The tumor was completely removed via a right-sided endoscopic approach with restoration of the aqueduct. The free cerebrospinal fluid passage through the aqueduct was not only visualized by endoscopy but also controlled by intraoperative high-field magnetic resonance imaging. Therefore, an additional endoscopic third ventriculostomy was unneccessary.

  8. An Approximate Analytical Solution of Sloshing Frequencies for a Liquid in Various Shape Aqueducts

    Directory of Open Access Journals (Sweden)

    Yuchun Li

    2014-01-01

    Full Text Available An approximate analytical solution of sloshing frequencies for a liquid in the various shape aqueducts is formulated by using the Ritz method. The present approximate method is, respectively, applied to find the sloshing frequencies of the liquid in rectangular, trapezoid, oval, circular, U-shaped tanks (aqueducts, and various shape tuned liquid dampers (TLD. The first three antisymmetric and symmetric frequencies by the present approach are within 5% accuracy compared to the other analytical, numerical, and experimental values. The approximate solutions of this paper for the various shape aqueducts are acceptable to the engineering applications.

  9. Cine-MR imaging aqueductal CSF flow in normal pressure hydrocephalus syndrome before and after CSF shunt

    Energy Technology Data Exchange (ETDEWEB)

    Mascalchi, M. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Arnetoli, G. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Inzitari, D. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Dal Pozzo, G. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Lolli, F. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Caramella, D. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy)); Bartolozzi, C. (Sezione di Radiodiagnostica, Dipt. di Fisiopatologia Clinica, and Dipt. di Scienze Neurologiche, Florence Univ. (Italy))

    1993-11-01

    Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction. (orig.).

  10. Cine-MR imaging aqueductal CSF flow in normal pressure hydrocephalus syndrome before and after CSF shunt

    International Nuclear Information System (INIS)

    Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction. (orig.)

  11. The Miracle of Water: Prolegomena to the Early Renaissance Aqueduct of Dubrovnik

    OpenAIRE

    Seferović, Relja; Stojan, Mara

    2007-01-01

    Inadequate water supply prompted the Ragusan authorities in the first half of the fifteenth century to consider the construction of an aqueduct. The latter owes its design to Italian master Onofrio della Cava, bearing witness to his engineering skill but also to the far-sighted politics of the Ragusan commune. Based on archival material and field research, the authors trace the construction of the aqueduct from the spring in ©umet to the City fountains and industrial facilities.

  12. Characterization of building materials from the aqueduct of Antioch-on-the-Orontes (Turkey)

    OpenAIRE

    Benjelloun, Yacine; De Sigoyer, Julia; Carlut, Julia; Hubert, Aurelia; Dessales, Hélène; Pamir, Hatice; Karabacak, Volkan

    2015-01-01

    The Roman aqueduct of Antioch-on-the-Orontes (Turkey), a city located near the junction between the active Dead Sea fault and the East Anatolian fault, has been damaged several times due to historical earthquakes, as mentioned in ancient texts. The traces of repairs are studied in order to identify their potential seismic origin. The deformations of the structure were characterised thanks to a LIDAR scan. Several bricks were sampled on different parts of the city’s aqueducts, on the original ...

  13. An Approximate Analytical Solution of Sloshing Frequencies for a Liquid in Various Shape Aqueducts

    OpenAIRE

    Yuchun Li; Zhuang Wang

    2014-01-01

    An approximate analytical solution of sloshing frequencies for a liquid in the various shape aqueducts is formulated by using the Ritz method. The present approximate method is, respectively, applied to find the sloshing frequencies of the liquid in rectangular, trapezoid, oval, circular, U-shaped tanks (aqueducts), and various shape tuned liquid dampers (TLD). The first three antisymmetric and symmetric frequencies by the present approach are within 5% accuracy compared to the other analytic...

  14. Following Roman waterways from a computer screen: GIS-based approaches to the analysis of Barcino’s aqueducts

    OpenAIRE

    Orengo, Hèctor A.; Miró, Carme

    2011-01-01

    From the 1950's until today the Roman colony of Barcino (modern Barcelona) has been believed to posses two aqueducts. One was transporting water from the Montcada mountains and the other one from the Collserola range. In this article, GIS-based least-cost route analysis (LCR) in combination with more traditional archaeological techniques is applied to analyse these aqueduct’s routes. The results obtained suggest Barcino had only one aqueduct: the one carrying water from Montcada. The aqueduct...

  15. Monitoring invasive quagga mussels, Dreissena rostriformis bugensis (Bivalvia: Dreissenidae, and other benthic organisms in a western US aqueduct

    Directory of Open Access Journals (Sweden)

    S. Mark Nelson

    2013-01-01

    Full Text Available A quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 invasion of an aqueduct in Arizona was monitored from 2007 – 2011using colonization substrates. As numbers increased, a filtering-collector caddisfly (Smicridea fasciatella McLachlan, 1871 declinedsignificantly in abundance. After two years of colonization, freshwater sponges were detected and associated with a decline in D. r. bugensisnumbers. Periphyton biomass increased considerably on substrates; perhaps partially, the result of decreased turbidity. Aqueduct biofoulerscould have major impacts on costs associated with aqueduct maintenance. From an operations viewpoint, mussels are undesirable due to flowrestriction associated with increased friction. Augmented sponge and periphyton biomass may also influence aqueduct operations andefficiencies.

  16. Phase-contrast magnetic resonance imaging reveals net retrograde aqueductal flow in idiopathic normal pressure hydrocephalus.

    Science.gov (United States)

    Ringstad, Geir; Emblem, Kyrre Eeg; Eide, Per Kristian

    2016-06-01

    OBJECT The objective of this study was to assess the net aqueductal stroke volume (ASV) and CSF aqueductal flow rate derived from phase-contrast MRI (PC-MRI) in patients with probable idiopathic normal pressure hydrocephalus (iNPH) before and after ventriculoperitoneal shunt surgery, and to compare observations with intracranial pressure (ICP) scores. METHODS PC-MRI at the level of the sylvian aqueduct was undertaken in patients undergoing assessment for probable iNPH. Aqueductal flow in the craniocaudal direction was defined as positive, or antegrade flow, and net ASV was calculated by subtracting retrograde from antegrade aqueductal flow. Aqueductal flow rate per minute was calculated by multiplying net ASV by heart rate. During the same hospital admission, clinical examination was performed using NPH score and overnight continuous ICP monitoring. Twelve patients were followed prospectively 12 months after shunt placement with clinical assessment and a second PC-MRI. The study also included 2 healthy controls. RESULTS Among 21 patients examined for iNPH, 17 (81%) received a shunt (shunt group), and 4 were treated conservatively (conservative group). Among the patients with shunts, a clinical improvement was observed in 16 (94%) of the 17. Net ASV was negative in 16 (76%) of 21 patients before shunt placement and in 5 (42%) of 12 patients after shunt placement, and increased from a median of -5 μl (range -175 to 27 μl) to a median of 1 μl (range -61 to 30 μl; p = 0.04). Among the 12 patients with PC-MRI after shunt placement, 11 were shunt responders, and in 9 of these 11 either a reduced magnitude of retrograde aqueductal flow, or a complete reversal from retrograde to antegrade flow, occurred. Net ASV was significantly lower in the shunt group than in the conservative group (p = 0.01). The aqueductal flow rate increased from -0.56 ml/min (range -12.78 to 0.58 ml/min) to 0.06 ml/min (range -4.51 to 1.93 ml/min; p = 0.04) after shunt placement. CONCLUSIONS In

  17. Long lasting near-obstruction stenosis of mesencephalic aqueduct without development of hydrocephalus--case report.

    Science.gov (United States)

    Radoš, Milan; Orešković, Darko; Radoš, Marko; Jurjević, Ivana; Klarica, Marijan

    2014-08-28

    The aim of this study is to present the five-year longitudinal magnetic resonance imaging (MRI) follow up of a patient with incidental finding of near-obstruction stenosis of the aqueduct of Sylvius due to a large pineal cyst. The patient was scanned 3 times on a 3T MR device using a set of standard structural sequences supplemented with high-resolution constructive interference of steady state (CISS) T2 sequence for precise delineation of the aqueduct of Sylvius and cardiac-gated phase-contrast sequences for the analysis of cerebrospinal fluid (CSF) movement. On all MR scans, the size of the pineal cyst and severity of near-obstruction aqueductal stenosis did not show any morphological changes. There was no significant ventricular enlargement although structural CISS sequence showed a near-obstruction stenosis and cardiac-gated phase-contrast sequences did not detect CSF movement through the aqueduct of Sylvius. Our findings are contradictory to the classic hypothesis of CSF physiology based on secretion, circulation, and absorption of CSF, which states that the impairment of CSF circulation through the aqueduct of Sylvius inevitably leads to a hypertensive hydrocephalus development involving the third and the lateral ventricle. Our research group previously proposed a new hypothesis of CSF physiology, which offers more suitable explanation for such clinical cases. PMID:25165053

  18. Fast multiphase MR imaging of aqueductal CSF flow: 2. Study in patients with hydrocephalus.

    Science.gov (United States)

    Mascalchi, M; Ciraolo, L; Bucciolini, M; Inzitari, D; Arnetoli, G; Dal Pozzo, G

    1990-05-01

    The signal intensity in the region corresponding to the cerebral aqueduct was evaluated in three patients with noncommunicating tension hydrocephalus (caused by aqueductal obstruction in two and type I Arnold-Chiari malformation in the other), seven patients with suspected normal-pressure hydrocephalus (three of whom subsequently underwent successful shunting), and 10 patients with ex vacuo (atrophic) hydrocephalus. A gradient-echo MR sequence, called fast multiphase imaging, was used. Serial images corresponding to different phases of the cardiac cycle were acquired. No flow-related enhancement was observed over the entire cardiac cycle in the patients with noncommunicating hydrocephalus. Patients with normal-pressure hydrocephalus showed a higher aqueductal CSF signal intensity, consistent with increased systolic flow rates, than patients with ex vacuo hydrocephalus. When comparing the above two groups of patients with a control group of healthy volunteers, significantly higher and lower values of the (mean) maximum aqueductal signal intensity were found in the normal-pressure hydrocephalus patients and the ex vacuo hydrocephalus patients, respectively. Fast multiphase MR evaluation of aqueductal CSF flow may help to differentiate patients with different types of hydrocephalus. PMID:2112327

  19. Decompressive craniectomy arrests pulsatile aqueductal CSF flux: An in vivo demonstration using phase-contrast MRI. Case report.

    Science.gov (United States)

    Scollato, Antonio; Gallina, Pasquale; Bahl, Gautam; Di Lorenzo, Nicola

    2015-06-01

    We give a case study demonstration, using aqueductal cerebrospinal fluid (CSF) stroke volume quantification with phase-contrast magnetic resonance imaging, of a large opening in the rigid cranium by a decompressive craniectomy and its subsequent closure by bone flap repositioning resulted in the arrest and subsequent restoration of aqueductal CSF flow. PMID:25958958

  20. Aqueduct Concrete Temperature Control Technology%渡槽砼温控技术

    Institute of Scientific and Technical Information of China (English)

    郭红军

    2014-01-01

    The Aqueduct project much larger scale cross-sections of the building canals for. Carried out in the construction inspection and control, can prevent common aqueduct cracks, improve temperature control quality. Clear concrete thermostat unique technology, the associated control program that can prevent frame cracks, ensure construction standards Aqueduct.%规模偏大的渡槽工程多为河渠交叉地段的建筑物。在施工中进行查验和管控,能预防常见的渡槽裂痕,提升温控质量。明晰砼温控特有的技术、关联的管控程序,可以防止构架裂缝,保证渡槽的施工水准。

  1. Historical and Technical Notes on Aqueducts from Prehistoric to Medieval Times

    Directory of Open Access Journals (Sweden)

    Giovanni De Feo

    2013-11-01

    Full Text Available The aim of this paper is to present the evolution of aqueduct technologies through the millennia, from prehistoric to medieval times. These hydraulic works were used by several civilizations to collect water from springs and to transport it to settlements, sanctuaries and other targets. Several civilizations, in China and the Americas, developed water transport systems independently, and brought these to high levels of sophistication. For the Mediterranean civilizations, one of the salient characteristics of cultural development, since the Minoan Era (ca. 3200–1100 BC, is the architectural and hydraulic function of aqueducts used for the water supply in palaces and other settlements. The Minoan hydrologists and engineers were aware of some of the basic principles of water sciences and the construction and operation of aqueducts. These technologies were further developed by subsequent civilizations. Advanced aqueducts were constructed by the Hellenes and, especially, by the Romans, who dramatically increased the application scale of these structures, in order to provide the extended quantities of water necessary for the Roman lifestyle of frequent bathing. The ancient practices and techniques were not improved but survived through Byzantine and early medieval times. Later, the Ottomans adapted older techniques, reintroducing large-scale aqueducts to supply their emerging towns with adequate water for religious and social needs. The scientific approach to engineering matters during the Renaissance further improved aqueduct technology. Some of these improvements were apparently also implemented in Ottoman waterworks. Finally the industrial revolution established mechanized techniques in water acquisition. Water is a common need of mankind, and several ancient civilizations developed simple but practical techniques from which we can still learn. Their experience and knowledge could still play an important role for sustainable water supply

  2. 大型渡槽结构模态分析%Modal analysis of large aqueducts

    Institute of Scientific and Technical Information of China (English)

    王博; 李杰

    2000-01-01

    Large aqueduct plays an important role in water conservancy works transportingwater from the South to the North, In this paper, based on structural characteristic of largeaqueduct, considering the influence of aqueduct traversal bending-twisting vibration, restrainttwisting deformation, brace deformation and the rubber supports with basin shape on dynamicaction, modes of a large aqueduct are analyzed by shell beam element method. Influence of de-signed water level, brace height, brace section size and stiffness of the rubber supports with ba-sin shape on the mode of large aqueduct is investigated. Variation scopes of modes of thelarge aqueducts in four cases mentioned above are studied. The computation results lay thefoundation for seismic design of large aqueduct.%大型渡槽在南水北调水利工程中起着重要作用。本文根据大型渡槽的结构特点,考虑渡槽横向弯扭耦合振动、约束扭转变形、渡槽支架变形和盆式橡胶支座等对渡槽动力作用的影响,应用梁段有限元方法,对某大型渡槽的模态进行分析,研究了该渡槽设计水位、渡槽支架高度、渡槽支架截面尺寸、渡槽盆式橡胶支座刚度变化等对大型渡槽模态的影响,探讨了该大型渡槽在上述4种工况下的模态变化范围,所得结果可为大型渡槽的抗震设计提供依据。

  3. Climate Change and Adaptation Planning on the Los Angeles Aqueduct

    Science.gov (United States)

    Roy, S. B.; Bales, R. C.; Costa-Cabral, M. C.; Chen, L.; Maurer, E. P.; Miller, N. L.; Mills, W. B.

    2009-12-01

    This study provides an assessment of the potential impacts of climate change on the Eastern Sierra Nevada snowpack and snowmelt timing, using a combination of empirical (i.e., data-based) models, and computer simulation models forced by GCM-projected 21st century climatology (IPCC 2007 AR4 projections). Precipitation from the Eastern Sierra Nevada is one of the main water sources for Los Angeles' more than 4 million people - a source whose future availability is critical to the city's growing population and large economy. Precipitation in the region falls mostly in winter and is stored in the large natural reservoir that is the snowpack. Meltwater from the Eastern Sierra is delivered to the city by the 340-mile long Los Angeles Aqueducts. The analysis is focused on the nature of the impact to the LAA water supplies over the 21st century due to potential climate change, including volume of precipitation, the mix of snowfall and rainfall, shifts in the timing of runoff, interannual variability and multi-year droughts. These impacts further affect the adequacy of seasonal and annual carryover water storage, and potentially water treatment. Most of the snow in the 10,000 km^2 Mono-Owens basins that feed the LAA occurs in a relatively narrow, 10-20 km wide, high-elevation band on the steep slopes of 20 smaller basins whose streams drain into the Owens River and thence LAA. Extending over 240 km in the north-south direction, these basins present special challenges for estimating snowpack amounts and downscaling climate-model data. In addition, there are few meteorological stations and snow measurements in the snow-producing parts of the basins to drive physically based hydrologic modeling.

  4. Misdiagnosis of otosclerosis in a patient with enlarged vestibular aqueduct syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Távora-Vieira Dayse

    2012-07-01

    Full Text Available Abstract Introduction In the present case we report on the mismanagement of a patient misdiagnosed with otosclerosis, who was subsequently found to have enlarged vestibular aqueduct syndrome bilaterally. This highlights the need to not only be vigilant in pre-operative assessment of otosclerosis but also in post-operative investigations of stapedectomy failures. Case presentation Our patient, a 56-year-old Caucasian Australian woman, lost the hearing in her right ear following a stapedectomy approximately 25 years ago. It is thought that preoperative imaging was not conducted, while an inadequate (unmasked audiogram was used to formulate the initial diagnosis of otosclerosis. The hearing in her left ear deteriorated to the point that a cochlear implant was now being considered for her right ear. Imaging performed as part of our pre-cochlear implant battery revealed bilateral enlarged vestibular aqueducts and thus the decision to proceed with a right cochlear implant was made following discussion with our patient and her family in regard to not only general surgical risks but specifically the remote risk that the surgical drilling required during the procedure could risk a deterioration of the hearing in her left ear because of the enlarged vestibular aqueduct on that side. Conclusions This report illustrates a case of misdiagnosis and mismanagement of bilateral enlarged vestibular aqueduct resulting in profound hearing loss. Fortunately our patient has been successfully implanted with a right cochlear implant with remarkable outcomes.

  5. STUDY ON THE EROSION RATE OF POWDERED ACTIVATED CARBON IN RAW WATER AQUEDUCT

    Institute of Scientific and Technical Information of China (English)

    YIN Hai-long; YANG Yang; XU Zu-xin

    2012-01-01

    Growing interest in using Powdered Activated Carbon (PAC) in raw water aqueduct,as a method of polluted surface water treatment,raises the question of transport of PAC in the aqueduct,which is related to the potential PAC erosion along the aqueduct.By means of a recently developed re-circulating flume,erosion rates of PAC with the grain size of 230 meshes (less than 62 μm)depending on shear stress and bulk density were the discussed with real-time measurement of suspended PAC conccntration.Lateral cross sectional averaging shear stress was decided by the actual value in the raw water conveying aqueduct of upstream Huangpu River,Shanghai,China,smaller than 1.8 N·m 2.As for the bulk density,it was measured with compacting times varying from 1 d to 15 d,equivalent to 1 550 kg/m3-1 800 kg/m3.Experiments were conducted for the shear stress and bulk density separately,so as to isolate and quantify the effects of one of the parameters.The results demonstrate that,for a particular PAC particle,the erosion rate increases with shear stress and decreases with bulk density as a function of power form.A product of powers of the lateral cross sectional averaging shear stress and bulk density to estimate PAC erosion rate is presented by approximating experimental data sets.

  6. Endovascular treatment of symptomatic vestibular aqueduct dehiscence as a result of jugular bulb abnormalities.

    Science.gov (United States)

    Thénint, Marie-Aude; Barbier, Charlotte; Hitier, Martin; Patron, Vincent; Saleme, Suzana; Courthéoux, Patrick

    2014-11-01

    A new endovascular treatment consisting of stent-assisted coil implantation is described for jugular bulb abnormalities causing symptomatic vestibular aqueduct dehiscence. Three patients presenting with vertigo associated with pulsatile tinnitus or hearing loss were treated. This technique cured the vertigo and pulsatile tinnitus in all patients and preserved normal cerebral venous drainage with no side effects. PMID:25442142

  7. Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

    International Nuclear Information System (INIS)

    There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

  8. Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T.; Naganawa, S.; Fukatsu, H.; Sakurai, Y.; Ishigaki, T. [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, 466-8550, Shouwa-ku, Nagoya (Japan); Aoki, I.; Ninomiya, A. [Medical Systems Company, Toshiba Corporation, Nasu Operations, Otawara-shi, Tochigi (Japan); Nakashima, T. [Department of Otorhinolaryngology, Nagoya University School of Medicine, Shouwa-ku, Nagoya (Japan)

    2003-09-01

    There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

  9. Global Map: 1:1,000,000-Scale Canals and Aqueducts of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer includes Global Map data showing the canals, aqueducts, and the Intracoastal Waterway in the United States, Puerto Rico, and the U.S. Virgin Islands....

  10. Summary of Running and Operation of Aqueduct Building Machine for U-shaped Aqueduct with Large Span and Thin Wall%大跨度薄壁 U形渡槽造槽机运行操作综述

    Institute of Scientific and Technical Information of China (English)

    周继红

    2014-01-01

    南水北调中线湍河渡槽大跨度薄壁 U型渡槽通过现场实践验证和不断优化,工程运用DZ40/1600型渡槽造槽机操作工艺合理、简便,满足工程设计要求;浇筑完成的槽身,经检测其结构尺寸和施工质量均满足设计要求,为大型渡槽造槽机施工积累了宝贵的经验。%the operational technology on the aqueduct building machine (model:DZ40/1600) for construction of the u-shaped aqueduct with large span and thin wall on the aqueduct over the Tuan River on the middle route of the south-to-north water diversion project is proved reasonable and simple through the site practice and continuous optimization of the machine, satisfying the engineering design re-quirements.The aqueduct body after being constructed and measured meets the design requirements in terms of structural sizes and con-struction quality.Therefore, application of this aqueduct building machine accumulates experience for the construction of the large aque-ducts.

  11. Community Knowledge Sharing and Co-Production of Water Services: Two Cases of Community Aqueduct Associations in Colombia

    OpenAIRE

    Valeria Llano-Arias

    2015-01-01

    Local-level participatory communication practices have enabled the opening of new democratic spaces in which decisions on water policies are taken. Through their resistance to water privatisation policies, many Colombian community aqueducts have made use of a transformed political and social role. Citizens from community aqueduct associations are generating new forms of political participation and citizenship, capable of challenging the widespread political apathy in the country. This arti...

  12. 大型多纵梁斜交渡槽结构受力特性%FINITE ELEMENT ANALYSIS OF LARGESCALE SKEW AQUEDUCT BRIDGE

    Institute of Scientific and Technical Information of China (English)

    赵平; 唐克东; 刘祚秋; 陈文义; 李树瑶

    2001-01-01

    本文采用空间杆系有限元方法,旨在对同跨度斜交渡槽与正交渡槽进行计算对比,使对斜交渡槽受力特性有一个较为清晰的认识,从计算结果对比来看,斜交渡槽的内力较为复杂,是典型的组合受力构件。%This paper presents a spatial frame element analysis of large scale skew aqueduct bridge. Comparison is made between skew aqueduct bridges and straight aqueduct bridges. It is found that the internal force distribution of a skew aqueduct bridge is complicated compared with that of a straight aqueduct bridge. A skew aqueduct bridge is characterized by the internal forces of a composite structure.

  13. Calcareous sinter from ancient aqueducts as a source of data in paleoclimate, tectonics and hydrology

    Science.gov (United States)

    Surmelihindi, G.; Passchier, C. W.

    2010-12-01

    During the lifetime the Roman Empire (300BC-400AD), about 1200 major aqueducts were built to supply cities in the Mediterranean with drinking water. The ruins of many of these channels contain sinter (calcium carbonate), which was deposited at a rate of 0.5-5 mm/year over the life of the aqueduct, usually 50-200 but up to 1000 years. Calcareous sinter inside the ancient aqueduct channels can give important insight into paleoclimatology in the form of temperature and rainfall, reflect palaeohydrology of water, water chemistry, flow rate, bacterial activity and source area of the water. This type of data is important to build climate models and to understand earthquake and flood patterns in the Mediterranean, and can be a new, additional source of information besides speleothems, travertine and tufa deposits. In our study we focus on Mediterranean climate patterns, and selected four aqueduct sites from Southern Turkey, Greece and Italy. The calcareous sinter deposits may reflect annual or subannual lamination characterized by alternating light, dense, coarse-grained and dark, porous, microcrystalline layers which are thought to represent winter and summer conditions respectively. Moreover, abrupt changes in the sequence of lamination can be a signal of natural hazards such as earthquakes or flood events. Deposits from the aqueduct of Patara (Southern Turkey) show 40-50 laminae couples, which may be annual layers. δ18O and δ 13C stable isotope data indicate high cyclicity within the sinter samples from Patara during the Roman period. Higher δ18O values correspond with dark, porous layers and lower values with light, dense layers. Major geochemical analyses show similar seasonal changes. Electron microprobe study shows that within dark laminae, detrital Fe, Mg, K, Al and Si are enriched whereas the light layers have high Ca content. Trace element analyses by LA-ICP-MS also indicate higher Mg/Ca and Sr/Ca values in the dark layers, which can be interpreted in terms

  14. Characterization of building materials from the aqueduct of Antioch-on-the-Orontes (Turkey)

    Science.gov (United States)

    Benjelloun, Yacine; de Sigoyer, Julia; Carlut, Julie; Hubert-Ferrari, Aurélia; Dessales, Hélène; Pamir, Hatice; Karabacak, Volkan

    2015-07-01

    The Roman aqueduct of Antioch-on-the-Orontes (Turkey), a city located near the junction between the active Dead Sea fault and the East Anatolian fault, has been damaged several times due to historical earthquakes, as mentioned in ancient texts. The traces of repairs are studied in order to identify their potential seismic origin. The deformations of the structure were characterised thanks to a LIDAR scan. Several bricks were sampled on different parts of the city's aqueducts, on the original structure and on repaired parts. The bricks were characterized through a petrological approach. 14C and archaeomagnetism were tested on the bricks in order to constrain the age of their production. The synthesis of all the data showed a local origin for the bricks, and led to the identification of several manufacturing techniques and several types of production, thus, confirming the potentiality of this approach to date and characterise post-seismic repairs.

  15. "Flow comp off": An easy technique to confirm CSF flow within syrinx and aqueduct

    Directory of Open Access Journals (Sweden)

    Anitha Sen

    2013-01-01

    Full Text Available Flow compensation, a gradient pulse used for artifact reduction, often used to suppress cerebrospinal fluid (CSF flow artifacts in spinal magnetic resonance imaging (MRI, can be switched off to make the CSF flow voids within syrinx (syringomyelia and within aqueduct [normal pressure hydrocephalus (NPH] more obvious (thus confirming CSF flow. It is a simple method which does not require much time or expertise.

  16. Seismic response of an elevated aqueduct considering hydrodynamic and soil-structure interactions

    Science.gov (United States)

    Valeti, Bhavana; Ray-Chaudhuri, Samit; Raychowdhury, Prishati

    2016-03-01

    In conventional design of an elevated aqueduct, apart from considering the weight of water inside the channels, hydrodynamic forces are generally neglected. In a few special cases involving high seismic zones, hydrodynamic forces have been modeled considering equivalent lumped-mass type idealization or other models. For support conditions, either the base is considered as fixed or in a few cases, equivalent spring-dashpot system is considered. However, during an intense seismic event, nonlinear soil-structure interactions (SSI) may alter the response of the aqueduct significantly. This paper investigates the effect of hydrodynamic forces and SSI on seismic response of a representative elevated aqueduct model. Different modeling concepts of SSI has been adopted and the responses are compared. Frequency domain stochastic response analysis as well as time-history analysis with a series of ground motions of varying hazard levels have been performed. Demand parameters such as base shear and drift ratio are studied for varying heights of water in channels and different site conditions. From the frequency domain analysis, the effect of convective masses is found to be significant. From the time history analysis, the overall effect of increase in height of water is found to be negligible for nonlinear base case unlike the fixed and elastic base cases. For the nonlinear base condition, the base shear demand is found to decrease and the drift ratio is found to increase when compared to the results of linear base condition. The results of this study provide a better understanding of seismic behavior of an elevated aqueduct under various modeling assumptions and input excitations.

  17. Misdiagnosis of otosclerosis in a patient with enlarged vestibular aqueduct syndrome: a case report

    OpenAIRE

    Távora-Vieira Dayse; Miller Stuart

    2012-01-01

    Abstract Introduction In the present case we report on the mismanagement of a patient misdiagnosed with otosclerosis, who was subsequently found to have enlarged vestibular aqueduct syndrome bilaterally. This highlights the need to not only be vigilant in pre-operative assessment of otosclerosis but also in post-operative investigations of stapedectomy failures. Case presentation Our patient, a 56-year-old Caucasian Australian woman, lost the hearing in her right ear following a stapedectomy ...

  18. 大前庭水管综合征的相关研究进展%The research progress of large vestibular aqueduct syndrome

    Institute of Scientific and Technical Information of China (English)

    阿布利克木·依明; 唐亮

    2012-01-01

    Large vestibuiar aqueduc syndrome (LVAS) is one of common non-syndromic hearing disorders. With the rapid development of medical imaging, audiology, molecular biology , genetics, cochlear implant surgery, we have made remarkable achievements in the diagnosis and treatment of large vestibular aqueduct syndrome. This article reviewed related researches of the large vestibular aqueduct syndrome.

  19. Relationship between the external aperture and hearing loss in large vestibular aqueduct syndrome

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Backgroud Large vestibular aqueduct syndrome (LVAS) is a major cause of hearing loss in childhood. This study aimed at measuring external aperture of enlargement of the vestibular aqueduct (EVA) and analyzing relationship between the size of external aperture and hearing loss.Methods Diagnostic criteria of LVAS were based on hearing loss and CT images. CT images of temporal bone of 100 LVAS patients were collected and 60 control subjects were reviewed retrospectively in the past 10 years. A battery of audiometric and vestibular function tests were performed. The width of the vestibular aqueduct (VA) was measured on axial CT images of the temporal bone.Results One hundred patients (65 men, 35 women) were diagnosed as having the isolated EVA. Hearing loss mostly occurred in early childhood. The diagnosis age of LVAS was 7.7 years on average. The causes of hearing loss could not be confirmed by initial consult. Typically, audiometric curve is the high-frequency down-sloping configuration. 92% of the cases had severe or profound sonsorineural hearing loss (SNHL). The mean size of the external aperture was (7.5±1.2) mm in present LVAS. Statistical analysis showed that the degree of hearing loss is unrelated to the width of VA. Conclusions LVAS is a distinct clinical entity characterized by fluctuating, progressive SNHL. The degree of hearing loss is unrelated to the size of external aperture of VA. The protective management and hearing aid have become the main therapies. The cochlear implantation might be performed if the hearing loss affected learning at school.

  20. COMPUTATIONAL INVESTIGATION ON CSF FLOW ANALYSIS IN THE THIRD VENTRICLE AND AQUEDUCT OF SYLVIUS

    Directory of Open Access Journals (Sweden)

    Edi Azali Hadzri

    2011-12-01

    Full Text Available In this study, a three dimensional (3D model of the third ventricle and aqueduct of Sylvius derived from MRI scans was constructed by using Computational Fluid Dynamics (CFD modeling. Cerebrospinal fluid(CSF can be modeled as a Newtonian Fluid and its flow through the region of interest (ROI was visualized using Engineering Fluid Dynamics (EFD.The constructed ROI was regarded as rigid walled and only steady state flow was able to be defined due to the limitations of current software. Different flow rate was simulated at the Foramen of Monro and a small stenosis was modeled at the middle of the aqueduct of Sylvius at a fixed location. This was made corresponding to normal patients with variation of CSF flow rate physiologically and abnormal patients with tumor causing obstruction to or within the aqueduct of Sylvius, respectively. Due to the small dimensions of the ROI geometry, gravity and complex external gravity that acted upon it was considered to be neglected. The results show as the flow rate increase, the pressure drop of CSF in the ROI proportionally increased. For normal CSF flow rate, the presence of stenosis in the aqueduct demonstrates a significant increased pressure drop.ABSTRAK-Dalam kajian ini, model tiga dimensi (3D untuk ventrikel ketiga dan akueduk Sylvius, yang terhasil daripada pengimejan resonans magnetik telah dikonstruksi menggunakan Permodelan Perkomputeran Dinamik Bendalir (Computational Fluid Dynamics (CFD. Cecair serebrospinal (Cerebrospinal fluid (CSF dimodelkan sebagai bendalir Newtonan dan alirannya melalui kawasan kepentingan (region of interest (ROI digambarkan menggunakan Dinamik Bendalir Kejuruteraan (Engineering Fluid Dynamics (EFD. Kawasan kepentingan yang dikonstruksi dianggap sebagai dinding tegar dan hanya aliran keadaan tunak yang dapat ditakrifkan berdasarkan pengehadan perisian komputer terkini. Kadar aliran yang berbeza disimulasikan di foramen monro dan laluan stenosis yang kecil dimodelkan di tengah

  1. SLC26A4 mutation testing for hearing loss associated with enlargement of the vestibular aqueduct

    OpenAIRE

    Ito, Taku; Muskett, Julie; Chattaraj, Parna; Choi, Byung Yoon; Lee, Kyu Yup; Zalewski, Christopher K.; King, Kelly A.; Li, Xiangming; Wangemann, Philine; Shawker, Thomas; Brewer, Carmen C.; Alper, Seth L.; Griffith, Andrew J

    2013-01-01

    Pendred syndrome (PS) is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct (EVA), and mutations of the SLC26A4 gene. However, not all EVA patients have PS or SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in ¼ of North American or European EVA populations, one mutant allele is detected in another ¼ of patient populations, and no mutations are detected in the other ½....

  2. Remote sensing for monitoring a water transportation project - The California Aqueduct

    Science.gov (United States)

    Estes, J. E.; Senger, L. W.

    1973-01-01

    Land use changes were investigated on the west side of the San Joaquin Valley, California, an arid region presently importing water via the California Aqueduct, utilizing airphoto mosaics (1957), high-altitude photography (1971), and Earth Resources Technology Satellite (ERTS-1) data (1972). Attention was focused on land use characteristics for the three dates, changes which had occurred, and the sequence of land use category change. Research indicated that water importation was contributing to an overall pattern of regional change trending from an oil-producing and grazing area into a cropping region. Furthermore, the general pattern of specific category change was trending in the direction of higher economic intensity land use succession.

  3. Efficient Molecular Genetic Diagnosis of Enlarged Vestibular Aqueducts in East Asians

    OpenAIRE

    Choi, Byung Yoon; Stewart, Andrew K.; Nishimura, Katherine K.; Cha, Won Jae; Seong, Moon-Woo; Park, Sung Sup; Kim, Seung Won; Chun, Yang Sook; Chung, Jong Woo; Park, Shi-Nae; Chang, Sun O; Kim, Chong-Sun; Alper, Seth L; Griffith, Andrew J.; Oh, Seung-Ha

    2009-01-01

    Context: Enlargement of the vestibular aqueduct (EVA) is a commonly detected inner ear anomaly related to hearing loss and often associated with mutations of SLC26A4 encoding pendrin, a transmembrane exchanger of Cl−, I−, and HCO3−. Here we describe the phenotypes of 27 Korean EVA subjects and their SLC26A4 genotypes determined by bidirectional nucleotide sequencing. Results: The detected variants include two novel missense substitutions (p.V138L and p.P542R). We characterized the ability of ...

  4. [Case Report of Cerebellar Vermis Arteriovenous Malformation Presenting with Hydrocephalus due to Aqueductal Stenosis].

    Science.gov (United States)

    Ono, Kenichiro; Oishi, Hidenori; Suga, Yasuo; Yamamoto, Munetaka; Nonaka, Senshu; Nakajima, Madoka; Miyajima, Masakazu; Arai, Hajime

    2015-09-01

    A 56-year-old man complained of gait disturbance and confused thinking. Magnetic resonance imaging(MRI)revealed an arteriovenous malformation(AVM)of the cerebellar vermis(Spetzler-Martin grade IV)causing hydrocephalus. One dilated precentral cerebellar vein was compressing the aqueduct. After feeder embolization over 3 sessions using N-butyl cyanoacrylate(NBCA), the nidus was reduced to one-third in size. However, symptoms remained unimproved, and endoscopic third ventriculostomy(ETV)was performed. The third ventricle showed thinning of the floor, with a fenestration in part of the floor. Radiological findings and clinical symptoms improved, and the patient returned home after rehabilitation. The condition of the patient remained stable as of six months later. On angiography, the draining vein showed a pressure of 20 mmHg with no change in the residual AVM. Embolization alone achieved a reduction in nidus volume, but could not reduce venous pressure, and combination therapy including ETV proved necessary. Cases with hydrocephalus due to aqueductal stenosis by AVM are extremely rare. This pathology is discussed with reference to the literature. PMID:26321699

  5. How Roebling did it: Building the world's first wire-rope suspension aqueduct in 1840s Pittsburgh

    Science.gov (United States)

    Gibbon, Donald L.

    2006-05-01

    The noted bridge designed John Roebling introduced his wire-rope suspension concept in Pittsburgh on a wooden aqueduct. His design was later implemented in bridges in Pittsburgh and elsewhere, including New York's Brooklyn Bridge. This article describes Roebling's work based on reviews of his notes and other historical documents.

  6. There were giants in the Earth in those days: the ancient catchment and aqueduct of 'Triglio' near Taranto (Italy)

    Science.gov (United States)

    Spilotro, Giuseppe; Fidelibus, Maria Dolores; Canora, Filomena; Pellicani, Roberta

    2014-05-01

    In the area between the towns of Crispiano, Statte and Taranto, partly along the Gravina (canyon) of the Triglio, a huge aqueduct, which presently reaches Taranto, develops. The water intake apparatus, which is constituted by small underground tunnels some kilometers long and with regularly spaced pits for the digging and for the aeration of the conduct, is very notable. As a matter of fact, the water intake works deep inside very permeable calcareous rocks testify the capability of withdrawal water even from an unfriendly environment like a karst vadose zone in a semi-arid region. The first part of the work is attributed at Roman age and more precisely in the interval between the 1st century BC and AC. In 950 A.D., after the fall of the Roman Empire, Nicephorus II Phocas, Emperor of the East, rebuilds Taranto after the wars and restructures the Triglio Aqueduct that remains outside the city walls. In 1334, Catherine II of Valois, Princess of Taranto, completes the aqueduct bringing it into the city. In the nineteenth century, the aqueduct becomes the "Public Source" and the Apulian Aqueduct Authority uses the structure to provide water until 1922, when the city began to be served by the Sele. The aqueduct presently extends for about 12 km and can be divided into three parts: (1) water intake apparatus, hypogeum stretch for water interception, formed by branches of tunnels converging in a single pipe; (2) hypogeum conductor apparatus, which is a unique underground pipeline entirely excavated in the rock; (3) epigeum conductor apparatus, the final stretch of the aqueduct where it emerges from the ground level. The trend of the tunnels of the water intake apparatus has been reconstructed through studies carried out by Speleo Group Statte and other researchers. The water intake apparatus is composed by tunnels and pits excavated into a calcareous mass, draining the karst vadose zone and the alluvial deposits, where the tunnel is parallel to the water course of the

  7. USGS Small-scale Dataset - Global Map: 1:1,000,000-Scale Canals and Aqueducts of the United States 201406 Shapefile

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer includes Global Map data showing the canals, aqueducts, and the Intracoastal Waterway in the United States, Puerto Rico, and the U.S. Virgin Islands....

  8. MR imaging of the vestibular aqueduct in normal volunteers and patients with Meniere's disease

    International Nuclear Information System (INIS)

    In this paper we attempted MR visualization of the vestibular aqueduct (VA) with a surface coil. Sagittal plane was most preferable from the result of preliminary study using a dry temporal bone. In all of ten normal volunteers, VAs were visualized well. In none of them, proton-density weighted spin-echo (SE) images were inferior to both T1- and T2-weighted SE images. In four of eight patients with Meniere's disease, VAs were not visualized due to obstruction of VA, although in all of ten non-Meniere's disease patients with hearing loss or vertigo, VAs were well visualized. Although further investigation is needed, MR imaging of VA including both its content and surrounding bony structure would give important information to manage the patients with either Meniere's disease or other disorders of internal ears. (author)

  9. Operation Aqueduct: Onsite radiological safety report for announced nuclear tests, October 1989--September 1990

    International Nuclear Information System (INIS)

    Aqueduct was the name assigned to the series of underground nuclear weapons tests conducted at the Nevada Test Site (NTS) from October 1, 1989, through September 30, 1990. This report includes those experiments publicly announced. Remote radiation measurements were taken during and after each nuclear event by a telemetry system. Reynolds Electrical ampersand Engineering Co., Inc. (REECO) Health Protection Department (HPD) Radiation Protection Technicians (RPTS) with portable radiation detection instruments surveyed reentry routes into ground zeros (GZ) before other planned entries were made. Continuous surveillance was provided while personnel were in radiation areas and appropriate precautions were taken to protect persons from unnecessary exposure to radiation and toxic gases. Protective clothing and equipment were issued as needed. Complete radiological safety and industrial hygiene (IH) coverage was provided during drilling and mineback operations. Telemetered and portable radiation detector measurements are listed. Detection instrumentation used is described and specific operational procedures are defined

  10. A novel low-profile ventriculoamniotic shunt for foetal aqueductal stenosis.

    Science.gov (United States)

    Chen, Yanfei; Emery, Stephen P; Maxey, Antonina P; Gu, Xinzhu; Wagner, William R; Chun, Youngjae

    2016-01-01

    This study proposed a novel ventriculoamniotic shunt device for foetal aqueductal stenosis treatment fabricated with 3Fr or 4Fr size catheters that have a longitudinal bending stiffness with kink resistance, sufficient luminal area for cerebrospinal fluid drainage and capacity for valve integration. Computational flow dynamics studies were carried out to optimise the device design, including size of the lumen and length of the device. An in vitro pressure and flow rate measurement test circuit was constructed to assess the high pressure relieving functionality of draining cerebrospinal fluid from foetal brain. Additionally, a resistance force measurement test platform was built to quantitatively evaluate the anchor performance of various geometric designs. The valve functionality was qualitatively evaluated through the visualisation of the flow patterns in the amniotic sac with injected red coloured fluid under stereomicroscopy. These in vitro results demonstrate the feasibility of the ventriculoamniotic shunt device designed for placement in the foetal brain. PMID:27004923

  11. 大前庭导水管综合征%The large vestibular aqueduct syndrome

    Institute of Scientific and Technical Information of China (English)

    李原; 王忠植

    2004-01-01

    大前庭导水管综合征(large vestibular aqueduct syndrome,LVAS)是以前庭导水管扩大伴有感音神经性耳聋为特征的一种临床独立病症.由Valvassori等于1978年首先描述并正式命名。是先天性内耳畸形的一种.Okurnara等进一步将其分为合并耳蜗畸形(如Mondini畸形)与不合并耳蜗畸形两个亚型.但前者不列入LVAS的范畴。其临床发

  12. Comprehensive monitoring of meteorology, hydraulics, and thermal regime of the San Diego Aqueduct, California

    Science.gov (United States)

    Jobson, Harvey E.; Sturrock, Alex M.

    1976-01-01

    Water temperature, as well as meteorologic and hydraulic variables which influence the energy budget of the San Diego Aqueduct in southern California, were continuously monitored for a 1-year period beginning July 24, 1973. Incoming solar and atmospheric radiation, windspeed and direction, water temperature, and wet- and dry-bulb air temperatures were recorded at 10-minute intervals at each end of the 26-km concrete-lined canal, while flow rates and stages were determined at hourly intervals for five locations. Although only daily averaged values are presented in this report, all information necessary for the use and interpretation of these data are presented. Windspeeds were minimum during the early morning hours and maximum during the late afternoon; however, they were variable spatially. On the other hand, incoming radiation and absolute vapor pressure varied little from point to point. (Woodard-USGS)

  13. Goldenhar syndrome, anterior encephalocele, and aqueductal stenosis following fetal primidone exposure.

    Science.gov (United States)

    Gustavson, E E; Chen, H

    1985-08-01

    Fetal exposure to primidone was associated with Goldenhar syndrome, hemifacial microsomia, tetralogy of Fallot, aqueductal stenosis, and anterior encephalocele in this male infant. No similar cases in anticonvulsant-exposed pregnancies were found on literature review, despite the increased incidence of other anomalies following such exposure. Goldenhar syndrome, especially related to rare central nervous system anomalies, is reviewed. Experimental production of hemifacial microsomia by a folic acid antagonist, triaxene, is mediated via hemorrhage in the fetus. Intraventricular hemorrhage was noted in this infant as were dilated lateral and third ventricles. The hemorrhagic diathesis and/or the folic acid depletion of newborns following fetal anticonvulsant exposure may have been the underlying mechanism. PMID:4035586

  14. Modal analysis of large-scale double cell aqueducts%大型双槽渡槽结构振动特性分析

    Institute of Scientific and Technical Information of China (English)

    陈淮; 祁冰; 杜晓伟

    2001-01-01

    根据大型双槽渡槽的结构特点,应用薄壁梁段有限元法,考虑了渡槽横向弯扭耦合振动、约束扭转变形和盆式橡胶支座等对渡槽结构动力作用的影响;对实际工程中某大型渡槽进行了振动特性分析,研究了该渡槽设计水位变化对大型渡槽模态的影响,探讨了该大型渡槽在几种工况下的模态变化范围,所得结果可为该大型渡槽的抗震设计提供依据。%Based on structural characteristics of large-scale double cell aqueduct, this paper considers the influences of aqueduct transversal bending-twisting vibration, restraint twisting deformation, rubber supports of basin shape on structural dynamic action with use of shell-beam element method. Vibration characteristics analysis is conducted for some large-scale double cell aqueduct. Influence of designed water level on the mode of the aqueduct is investigated. Variation scopes of mode of the aqueducts in a few cases are studied. The computation results lay the foundation of seismic design of the large-scale aqueduct.

  15. Research on aqueduct design based on VB%基于VB下的渡槽设计研究

    Institute of Scientific and Technical Information of China (English)

    邢旭光; 史文娟

    2011-01-01

    渡槽是一种重要的水工结构.将渡槽设计与Visual Basic编程理论结合,通过应用计算机编程可实现对渡槽结构进行各部位验算与校核.文章阐述了该软件系统的开发思想和实现过程,同时对总体框架的设计、模块的划分、具体环节的实现作了详细论述.依据各部位的关键技术参数,对渡槽设计相关的水力计算、槽身、刚架和基础结构计算作了论述,并给出了计算机软件设计的流程图,以期为工程设计人员采用计算机程序设计提供参考.%Aqueduct is an important hydraulic structure. This paper combined the design of aqueduct with the theory of Visual Basic programming and went on application of computer program to realize check of every parts of aqueduct structure. It expounded the development and the process of realization for this software system, and discussed the design of overall framework, the partition of module and the realization of specific links at the same time. It also discussed the hydraulic calculation which the design concerned , some calculations of the aqueduct body structure, rigid frame structure and foundation structure based on the key technical parameters of related parts. Meanwhile, some flow chats were established to provide references for engineering staff to design computer program.

  16. Evidence of active tectonics on a Roman aqueduct system (II–III century A.D.) near Rome, Italy

    OpenAIRE

    Marra, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Montone, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Pirro, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Boschi, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia

    2004-01-01

    In this paper we describe evidence of strong tectonic deformation affecting two aqueducts of Roman age (II–III century A.D.). The channels are located approximately 20 km northeast of Rome along the ancient Via Tiburtina. Brittle and ductile deformation affects these two structures, including extensional joint systems, NE-oriented faults, and horizontal distortion. This deformation is consistent with rightlateral movement on major N-striking faults, and represents the first evidence ...

  17. Blockade of the cerebral aqueduct in rats provides evidence of antagonistic leptin responses in the forebrain and hindbrain.

    Science.gov (United States)

    Vaill, Michael I; Desai, Bhavna N; Harris, Ruth B S

    2014-02-15

    Previously, we reported that low-dose leptin infusions into the fourth ventricle produced a small but significant increase in body fat. These data contrast with reports that injections of higher doses of leptin into the fourth ventricle inhibit food intake and weight gain. In this study, we tested whether exogenous leptin in the fourth ventricle opposed or contributed to weight loss caused by third ventricle leptin infusion by blocking diffusion of CSF from the third to the fourth ventricle. Male Sprague-Dawley rats received third ventricle infusions of PBS or 0.3 μg leptin/24 h from miniosmotic pumps. After 4 days, rats received a 3-μl cerebral aqueduct injection of saline or of thermogelling nanoparticles (hydrogel) that solidified at body temperature. Third ventricle leptin infusion inhibited food intake and caused weight loss. Blocking the aqueduct exaggerated the effect of leptin on food intake and weight loss but had no effect on the weight of PBS-infused rats. Leptin reduced both body fat and lean body mass but did not change energy expenditure. Blocking the aqueduct decreased expenditure of rats infused with PBS or leptin. Infusion of leptin into the third ventricle increased phosphorylated STAT3 in the VMHDM of the hypothalamus and the medial NTS in the hindbrain. Blocking the aqueduct did not change hypothalamic p-STAT3 but decreased p-STAT3 in the medial NTS. These results support previous observations that low-level activation of hindbrain leptin receptors has the potential to blunt the catabolic effects of leptin in the third ventricle. PMID:24347057

  18. Diagnostic criteria for enlarged vestibular aqueduct (EVA) on CT of the temporal bones. Borderline cases of EVA

    International Nuclear Information System (INIS)

    The objective of this study was to examine measurements of the vestibular aqueduct on axial CT figures and to examine the cases with borderline EVA. The width of the vestibular aqueduct was measured in two places, the midpoint of the duct and the external aperture in the posterior cranial fossa. Criteria was as follow: Enlargement; ≥1.5 mm at the midpoint, ≥2 mm at the aperture, Borderline; 1-1.4 mm at the midpoint, 1.5-1.9 mm at the aperture. Three hundred forty-five cases with CT scans of the temporal bones taken during July 2003 to June 2004 in the secondary ENT referral center. Those patients include sensorinearal, mixed or conductive deafness, vertigo, ear infections and other ear diseases. Enlarged vestibular aqueduct was found in 10 ears with sensorineural deafness (SD) and 2 ears without SD. Borderline measurements were found in 19 ears with SD and 33 ears without SD. The enlarged midpoint measurement was not seen in the cases without SD. More than 1.5 mm of the definition for the enlargement at the midpoint of the vestibular aqueduct seemed to be appropriate in the clinical situation. The measurement at the midpoint of the duct is more reliable than at the external aperture. The conductive component in EVA Syndrome with mixed hearing loss is present only at the lower frequencies (250, 500 Hz), not at the middle and higer frequencies. Long-term follow-up of hearing should be done in the borderline cases with check-up of PDS gene anomaly if necessary. (author)

  19. 浅谈湍河渡槽结构形式比选%Comparison of Structure Form in Tuanhe Aqueduct

    Institute of Scientific and Technical Information of China (English)

    朱清帅; 马永征; 王玉岭; 张阳阳; 邹华

    2014-01-01

    湍河渡槽是南水北调中线一期工程的一种交叉渠系建筑物,针对其跨度大、流量大、结构复杂等特点,综合分析后提出采用双槽矩形断面形式。通过对比4种方案,从槽下净空、上游雍水、应力控制、施工、投资等5个方面分析计算,认为“U”型槽为最优方案,但也需要调整槽跨才能满足壅水高度标准。%Tuanhe aqueduct is one of the cross canal structures of the first phase of South-to-North Water Transfer Project .Due to its characteristics of large structure span ,great discharge ,and complex structure ,double chamfer rectangle section is selected for the aqueduct .Four schemes were compared from the five following aspects :net space below chamfer ,upstream backwater , stress control ,construction ,and investment ,and“U”-type aqueduct scheme was considered as the best .However ,the structure span has to be adjusted to meet the backwater height requirements .

  20. Optimizing CT for the evaluation of vestibular aqueduct enlargement:Inter-rater reproducibility and predictive value of reformatted CT measurements

    Institute of Scientific and Technical Information of China (English)

    Misun Hwang; Ryan Marovich; Samuel S. Shin; David Chi; Barton F. Branstetter IV

    2015-01-01

    Enlarged vestibular aqueduct (EVA), the most frequent identifiable cause of congenital hearing loss, is evaluated with high-definition multi-detector CT in the axial plane. Our purpose was to determine which reformatted CT measurements are most reproducible. Seven multiplanar reformatted images were created for each of the 64 temporal bones in patients with EVA. Intraclass correlation coefficients (ICC) were used to assess inter-observer variability, and both linear regression and ROC analyses were used to compare the measurements with severity of hearing loss, as assessed by pure tone audiometry. All seven measurements had excellent inter-observer variability, with average-measure ICC ranging from 0.92 to 0.98. There was no statistically significant correlation between the radiologic degree of aqueduct enlargement and severity of hearing loss using any of the seven measurements;ROC analyses revealed areas under the curves ranging from 0.57 to 0.73. Optimal accuracy was obtained with a threshold of 1.75 mm as measured at the aqueductal aperture in the P€oschl plane, with sensitivity of 0.75 and specificity of 0.63. Although the radiologic measurement may not serve as a reliable tool for assessing severity of EVA, P€oschl plane reformatting has proven to be better than conventional axial acquisition plane for identifying patients with clinically significant hearing loss.

  1. Research progress in structural dynamics of large scale aqueduct%大型渡槽结构动力学研究进展

    Institute of Scientific and Technical Information of China (English)

    张多新; 王清云; 白新理

    2011-01-01

    The large scaled aqueduct is the key construction in the lifeline engineering of irrigation area, whose safety issue has become the "botdeneck" in the construction of aqueduct,especially, in the circumstances of earthguake and wind, meanwhile, it is a hot spot of research at home and abroad. During the construction of largescale aqueduct, most important technical questions in earthquake resistance, seismic isolation, shock absorption and wind resistane techniques are structural dynamical problem. However, the aqueduct structural dynamics belongs to the category of fluid- solid interaction(FSI) system actually. The objective of this paper is to summarize and comment the results achieved in recent years based on the existing research in the FSI system of aqueduct. Firstly aqueduct model of FSI system was summarized and reviewed; then the dynamical properties and responses solution techniques for shock resistance and absorption and wind resistance of the aqueduct were briefly described ; finally, the research advances in the aqueduct structural dynamics were summarized and the further study contents and methods was put forward, which will give a reference to the progress of the aqueduct structural dynamics.%大型渡槽是灌区生命线工程中的关键性建筑物,其在地震及风载作用下的安全性已是渡槽建设的“瓶劲”,也是国内外研究的热点。渡槽结构的抗震、减震和抗风技术的核心是渡槽结构动力学的问题,而渡槽结构动力学系属流固耦合(FSI)系统的动力学范畴。在已有研究的基础上,首先对渡槽结构FSI系统模型的研究进行了总结和评述;然后简述了渡槽结构动力特性和响应的求解技术以及抗震、隔震、减震与抗风技术的研究概况;最后总结了渡槽结构动力学的研究进展,提出了该学科进一步研究的内容和方法。

  2. High resolution CT appearance of large vestibular aqueduct in infant%婴儿前庭导水管扩大的高分辨率CT表现

    Institute of Scientific and Technical Information of China (English)

    张保隆; 孙积宁; 曹福志; 于清霞; 赵巍

    2013-01-01

    Objective:To explore and study the high resolution CT ( HRCT) appearances of large vestibular aqueduct in infant. Methods; The HRCT appearances of 21 cases (42 ears) with large vestibular aqueduct were analyzed retrospectively. The axial images and multi - planar reconstruction were performed in all patients. Results: Twenty - one patients all were bilateral large vestibular aqueduct malformations. The number of large vestibular aqueduct malformations is 42 ears. The malformations were; ( 1 ) Isolated large vestibular aqueduct, without other malformations (10 ears), (2) Large vestibular aqueduct only with cochlear malformation (24 ears) , ( 3 ) Large vestibular aqueduct with vestibular or semicircular canals malformations (4 ears) , ( 4 ) Large vestibular aqueduct with cochlea and vestibular or semicircular canals malformations simultaneously (4 ears) . Conclusion: The HRCT has very important value in the diagnosis of the congenital large vestibular aqueduct malformations.%目的 探讨婴儿前庭导水管扩大畸形的高分辨率CT表现.方法 回顾性分析21例(42耳)婴儿(35天~5个月)先天性前庭导水管扩大畸形患者的CT表现,所有患者均做多层螺旋高分辨率CT横断面扫描及多平面重建.结果 21例先天性前庭导水管扩大畸形患者双侧畸形者21例,前庭导水管扩大畸形共计42耳.具体分布如下:(1)单纯性前庭导水管扩大,不伴其它畸形(10耳),(2)仅伴耳蜗畸形(24耳),(3)仅伴前庭或半规管畸形(4耳),(4)同时伴耳蜗及前庭或半规管畸形(4耳).结论 高分辨率CT对先天性前庭导水管扩大畸形具有重要的诊断价值,应提高对本病的影像学认识.

  3. Genetic basis of hearing loss associated with enlarged vestibular aqueducts in Koreans.

    Science.gov (United States)

    Park, H-J; Lee, S-J; Jin, H-S; Lee, J O; Go, S-H; Jang, H S; Moon, S-K; Lee, S-C; Chun, Y-M; Lee, H-K; Choi, J-Y; Jung, S-C; Griffith, A J; Koo, S K

    2005-02-01

    Sensorineural hearing loss associated with enlargement of the vestibular aqueduct (EVA) can be associated with mutations of the SLC26A4 gene. In western populations, less than one-half of the affected individuals with EVA have two mutant SLC26A4 alleles, and EVA is frequently caused by unknown genetic or environmental factors alone or in combination with a single SLC26A4 mutation as part of a complex trait. In this study, we ascertained 26 Korean probands with EVA and performed nucleotide sequence analysis to detect SLC26A4 mutations. All subjects had bilateral EVA, and 20 of 26 were sporadic (simplex) cases. Fourteen different mutations were identified, including nine novel mutations. Five mutations were recurrent and accounted for 80% of all mutant alleles, providing a basis for the design and interpretation of cost-efficient mutation detection algorithms. Two mutant alleles were identified in 21 (81%), one mutant allele was detected in three (11%), and zero mutant allele was detected in two (8%) of 26 probands. The high proportion of Korean probands with two SLC26A4 mutations may reflect a reduced frequency of other genetic or environmental factors causing EVA in comparison to western populations. PMID:15679828

  4. Establishment of a fish community in the hayden-rhodes and salt-gila aqueducts, Arizona

    Science.gov (United States)

    Mueller, G.

    1996-01-01

    Fish populations were studied in the Central Arizona Project's canal system during the first 4 years of aqueduct operation (1986-1989). Ichthyoplankton entering the canal from Lake Havasu averaged 1 larva/m3 during April-June 1987 and 1988. Larval fish densities increased significantly in downstream samples, substantiating diver observations that fish were spawning in the canal system. Of the 16 fish species collected, 14 were assumed to have originated from Lake Havasu and 2 were introduced by anglers from their bait buckets. Initially, the fish community was dominated numerically by threadfin shad Dorosoma petenense (>88%), centrarchids (< 10%), cyprinids (<2%), and striped bass Morone saxatilis (<1%). However, as annual water diversions increased from 13 x 108 m3 in 1986 to 9.4 x 108 m3 in 1989, community composition shifted from clupeids to centrarchids (70%). Fish densities dropped from an estimated 1,260 fish/ha in 1986 to 17 fish/ha in 1989, and biomass dropped from 116 to 73 kg/ha. Declines were attributed to higher operational velocities, associated scour, deprivation, and predation. Although initial populations adjusted downward to planned operational conditions, the fish community continued to represent a potentially valuable, but as yet unused, resource.

  5. 涵洞式渡槽结构理论分析研究%Analytical in estigation of reinforced concrete culvert aqueduct

    Institute of Scientific and Technical Information of China (English)

    陈爱玖; 解伟; 赵中极; 赵平

    2001-01-01

    利用三维有限元对涵洞式渡槽进行结构分析,根据结构特征、地质条件和结构材料的力学参数,对结构进行分析,得到应力和变形规律,为渡槽设计提供了可靠依据.%The structure of culvert aqueduct was analyzed in details by finite element. Based on structural characteristics,geological condition and mechanical paramenters of structure material, the equeduct is simplified to a three dimensional liner body. The ultimate bearing limit states of aqueduct structure is analyzed. The results obtained in this paper provied reliable basis for aqueduct design.

  6. A high-resolution palaeoenvironmental record from carbonate deposits in the Roman aqueduct of Patara, SW Turkey, from the time of Nero

    Science.gov (United States)

    Passchier, Cornelis; Sürmelihindi, Gül; Spötl, Christoph

    2016-01-01

    An inscription on the supporting wall of the inverted siphon of the aqueduct of the ancient Roman city of Patara, SW Turkey, explains how the wall collapsed during an earthquake and was subsequently restored. Carbonate deposits formed inside the aqueduct channel show cyclic stable isotope changes representing 17 years of deposition. This sequence, together with the text of the inscription, allows dating the earthquake to 68 AD and the original inauguration of the aqueduct to the winter of 51/52 AD. Thus, the carbonate deposits represent a high-resolution record of palaeotemperature and precipitation for SW Turkey covering the complete reign of the Emperor Nero. The period shows a cooling and drying trend after an initial warm and more humid period, interrupted by a few anomalous years. These 2 cm of calcite highlight the significance of carbonate deposits in ancient water supply systems as a high-resolution archive for palaeoclimate, palaeoseismology and archaeology. PMID:27357129

  7. 前庭导水管扩大畸形的CT诊断%CT Diagnosis of Large Vestibular Aqueduct

    Institute of Scientific and Technical Information of China (English)

    苏丹柯; 谢东; 李强

    2001-01-01

    Objective To study the diagnostic basis of large vestibular aqueduct (LVA) on axial HRCT, and to evaluate different CT scan technique in the diagnosis of LVA. Materials and Methods Findings on axial HRCT in 12 cases with LVA and in 80 healthy individuals were analyzed and compared. Results The normal vestibular aqueduct appeared as a tiny, shallow and ill-defined notch on the posterior surface of the petrous bone, or as a short, tubular, ill-defined low-density shadow parallel to the posterior semicircular canal. LVA displayed three features on CT: (1) Significant enlarged vestibular aqueduct demonstrated a large, deep and well-demarcated triangular bony defect on the posterior surface of the petrous bone. This sign was most commonly seen. (2) Bony defect was well-demarcated, usually its medial end was directly connected with the vestibule or common crus. (3) The maximum diameter of midsection of the aqueduct was larger than 1.5mm. Conclusion The three features on the axial HRCT described above should be regarded as the basis for the diagnosis of LVA. The diameter of the external aperture of vestibular aqueduct, which actually is the fissure of endolymphatic sac, exceeding 1.5mm should not be taken as the criterion for the diagnosis. The axial HRCT should be routinely used as an examination of choice.%目的探讨前庭导水管扩大畸形(large vestibular aqueduct,LVA)的轴位高分辨率CT(HRCT)诊断依据及不同CT扫描方式对LVA的诊断价值。材料与方法搜集12例LVA和80例正常人耳部轴位HRCT图像资料进行对照分析。结果正常人前庭导水管均表现为位于岩骨后缘的浅小模糊骨切迹或与后半规管基本平行、边缘模糊的略低密度细短管状影。LVA的CT特点:(1)表现为“岩骨后缘深大三角形明显骨缺损影”者最为多见; (2)“骨缺损影”边缘均清晰锐利,内端多与前庭或总脚呈“直接相通”表现; (3)前庭导水

  8. Mouse model of enlarged vestibular aqueducts defines temporal requirement of Slc26a4 expression for hearing acquisition

    OpenAIRE

    Choi, Byung Yoon; Kim, Hyoung-Mi; Ito, Taku; Lee, Kyu-yup; Li, Xiangming; Monahan, Kelly; Wen, Yaqing; Wilson, Elizabeth; Kurima, Kiyoto; Saunders, Thomas L.; Petralia, Ronald S; Wangemann, Philine; Friedman, Thomas B.; Griffith, Andrew J.

    2011-01-01

    Mutations in human SLC26A4 are a common cause of hearing loss associated with enlarged vestibular aqueducts (EVA). SLC26A4 encodes pendrin, an anion-base exchanger expressed in inner ear epithelial cells that secretes HCO3– into endolymph. Studies of Slc26a4-null mice indicate that pendrin is essential for inner ear development, but have not revealed whether pendrin is specifically necessary for homeostasis. Slc26a4-null mice are profoundly deaf, with severe inner ear malformations and degene...

  9. Using optical and microwave, modeled and airborne data to identify water leaks from rural aqueducts

    Science.gov (United States)

    Taylor, Frances M.; Malthus, Tim J.; Woodhouse, Iain H.; Hedger, Richard D.

    2003-03-01

    The development of techniques for the detection of water leaks from underground pipelines is seen as a high profile activity by water companies and regulators. This is due to increasing water demands and problems with current leak detection methods. In this paper optical reflectance and microwave backscatter models (SAIL + PROSPECT and RT2) were used to try and identify optimal indices for detecting water leaks amongst a variety of different land cover types at different growth stages. Results suggest that red/near infrared and red/middle infrared ratios show potential for leak detection. Given the sensitivity of L-band radar to moisture, and the ability to separate contributions from canopy and ground surface, it is possible to detect saturated soils through vegetation canopies. The results of both approaches are used to infer limits of detection in terms of season and meteorological conditions for a range of land covers. Preliminary findings suggest that leaks may be optimally detected when canopy height is low, surrounding soil is dry, and the leak has been present for more than 14 days. The modelled data is compared with L - band fully polarimetric E-SAR data, and 200 channel HYMAP hyperspectral airborne data which were acquired over an 8km section of the Vrynwy aqueduct (UK), which included a high concentration of leaks. Data was acquired as part of the British National Space Centre (BNSC) and Natural Environmental Research Council (NERC), SAR and Hyperspectral Airborne Campaign (SHAC) in June 2000. The results from this work suggest that remote sensing is both an effective and feasible tool for leak identification.

  10. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: I. Perennial shrubs and grasses

    Science.gov (United States)

    Berry, Kristin H.; Weigand, James F.; Gowan, Timothy A.; Mack, Jeremy S.

    2015-01-01

    We studied recovery of 21 perennial plant species along a severely disturbed aqueduct corridor in a Larrea tridentata-Ambrosia dumosa plant alliance in the Mojave Desert 36 years after construction. The 97-m wide corridor contained a central dirt road and buried aqueduct pipeline. We established transects at 0 m (road verge), 20 m and 40 m into the disturbance corridor, and at 100 m in undisturbed habitat (the control). Although total numbers of shrubs per transect did not vary significantly with distance from the verge, canopy cover of shrubs, species richness, and species diversity were higher in the control than at the verge and other distances. Canopy cover of common shrubs (Ericameria nauseosa, Ambrosia salsola, A. dumosa, L. tridentata, Grayia spinosa) and perennial grasses (Elymus elymoides, Poa secunda) also varied significantly by location. Discriminant analysis clearly separated the four distances based on plant composition. Patterns of recovery were bidirectional: secondary succession from the control into the disturbance corridor and inhibition from the verge in the direction of the control. Time estimated for species composition to resemble the control is dependent on location within the disturbance corridor and could be centuries at the road verge. Our findings have applications to other deserts.

  11. 100 km under ground. Longest well-known aqueduct tunnel of the antique in Jordan and Syria; 100 km unter Tage. Laengster bisher bekannter Aquaedukttunnel der Antike in Jordanien und Syrien

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Mathias [Technische Univ. Bergakademie Freiberg (Germany). IWTG

    2010-05-15

    Since 2004, the author of the contribution under consideration investigates an ancient tunnel system with unknown extents in the border area between Jordan and Syria. It is a part of a nearly 170 km long Roman aqueduct which supplies three cities with water. The nearly 106 km long, partly plastered tunneling system was built from approximately 2,900 building pits with stairs in open ends tunneling. Not only mallet and iron, but also half-mechanical propulsion equipment were used due to regular cut traces. The aqueduct might be one the most extensive aqueducts in the Roman antiquity. The tunnel might be the longest well-known tunnel from the antiquity.

  12. The pathophysiology of the aqueduct stroke volume in normal pressure hydrocephalus: can co-morbidity with other forms of dementia be excluded?

    International Nuclear Information System (INIS)

    Variable results are obtained from the treatment of normal pressure hydrocephalus (NPH) by shunt insertion. There is a high correlation between NPH and the pathology of Alzheimer's disease (AD) on brain biopsy. There is an overlap between AD and vascular dementia (VaD), suggesting that a correlation exists between NPH and other forms of dementia. This study seeks to (1) understand the physiological factors behind, and (2) define the ability of, the aqueduct stroke volume to exclude dementia co-morbidity. Twenty-four patients from a dementia clinic were classified as having either early AD or VaD on the basis of clinical features, Hachinski score and neuropsychological testing. They were compared with 16 subjects with classical clinical findings of NPH and 12 aged-matched non-cognitively impaired subjects. MRI flow quantification was used to measure aqueduct stroke volume and arterial pulse volume. An arterio-cerebral compliance ratio was calculated from the two volumes in each patient. The aqueduct stroke volume was elevated in all three forms of dementia, with no significant difference noted between the groups. The arterial pulse volume was elevated by 24% in VaD and reduced by 35% in NPH, compared to normal (P=0.05 and P=0.002, respectively), and was normal in AD. There was a spectrum of relative compliance with normal compliance in VaD and reduced compliance in AD and NPH. The aqueduct stroke volume depends on the arterial pulse volume and the relative compliance between the arterial tree and brain. The aqueduct stroke volume cannot exclude significant co-morbidity in NPH. (orig.)

  13. Aqueducts and geoglyphs : the response of Ancient Nasca to water shortages in the desert of Atacama (Peru)

    Science.gov (United States)

    Masini, Nicola; Lasaponara, Rosa

    2016-04-01

    The desert of Atacama is a plateau in South America, covering a 1,000-kilometre strip of land on the Pacific coast, west of the Andes mountains, between Chile and Peru. Due to the confluence of a cold ocean current (the Humboldt Current) along with other climatic factors, connected to the particular topography and geomorphology of the region, Atacama desert is one of the most arid areas of the world. In particular, in Nasca region (Southern Peru) the lack of water was (and still is) due to the following causes: (i) the scarce pluvial precipitations and the (ii) high infiltration capacity, and the consequent yearly significant reduction of the surface water (Schreiber & Lancho Rojas 2009). Over the millennia long periods of drought occurred and frequently the lack of water was persistent for several decades. Despite the arid and extreme nature of the environment, this region was populated by important civilizations, such as Paracas and Nasca, which flourished in the Early Intermediate period (200 BCE-500 AD) (Silvermann & Proulx 2002). In particular the Nasca civilization is well-known for its refined and colourful pottery, characterized by a rich icononographic repertory, and, above all, by the huge and mysterious geoglyphs drawn on the arid plateaus of the Rio Grande de Nasca Basin. In order to practice agriculture, the Nasca developed adequate strategies to cope with hostile environmental factors and water scarcity, building a very efficient aqueduct system. They were aided by the fact that underground water was likely enough close to the surface and accessible by constructing wells and underground aqueducts, known with quechua name of puquios (Schreiber & Lancho Rojas 2009; Lasaponara & Masini 2012a; 2012b) The effectiveness of the techniques of hydraulic engineering depended on the climate and the weather events that sometimes underwent drastic changes, as results of the cyclical phenomenon of El Niño Southern Oscillation (commonly called ENSO). Hence the

  14. Research on the Performance and Construction of Reinforce Concrete Aqueduct%钢筋混凝土渡槽性能及施工研究

    Institute of Scientific and Technical Information of China (English)

    姜博文; 高晶; 陈海山

    2012-01-01

    In order to improve the performance of reinforced concrete aqueduct, its influencing factors are analyzed in terms of its durability, mechanical behaviour, displacement control during earthquake, and fissure analysis. Measures are put forward in a bid to improve its performance in view of aqueduct, steel bar, concrete construction and reducing fissures.%为提高钢筋混凝土渡槽的性能,从耐久性能、受力性能、地震时位移控制及裂缝4方面,分析影响渡槽性能的内外因素,并从槽身、钢筋、混凝土施工及减少裂缝方面,探讨提高钢筋混凝土渡槽性能的工艺措施。

  15. 国内外渡槽发展现状及趋势%Current Development in Aqueduct at Home and Abroad and Its Trend

    Institute of Scientific and Technical Information of China (English)

    李小群; 张媛; 陈海山

    2011-01-01

    This article reviews the historic development of aqueduct at home and abroad and makes analysis on the major existent prob- lems in this respect. This author discusses the development trend of aqueduct in light of cross section structure, supporting patterns, materials, construction methods, and construction techniques.%在概述国内外渡槽修建和发展情况的基础上,详述渡槽研究过程中存在的主要问题,分析渡槽发展研究的总趋势是适应各种流量和跨度,并从横断面结构、支承型式、材料、施工方法、施工工艺5方面,探讨渡槽未来的发展方向和趋势。

  16. Aqueductal stenosis and mental retardation associated with O S odontoideum, "hypermobile" atlantoaxial dislocation and congenital stenosis of atlas leading to spastic quadriparesis

    OpenAIRE

    Rupant K Das; Sanjay Behari; Namit Singhal; Awadesh K Jaiswal; Mahapatra, Ashok K.

    2007-01-01

    Background: The authors report a unique concomitant occurrence of mental retardation, hydrocephalus due to aqueductal stenosis, a freely floating atlas (having anterior, posterior and transverse atlantoaxial dislocation [AAD]) consequent to an orthotopic os odontoideum and stenosis of atlantal ring. There were no features of coexisting chondroskeletal dysplasias or other systemic diseases. To the best of the authors′ knowledge, this is the first reported case of its type in the literature. Ca...

  17. 大型渡槽槽身的地震扭转效应研究%Study on seismic torsion effect of large-scale aqueduct body

    Institute of Scientific and Technical Information of China (English)

    高平; 魏德敏; 徐梦华

    2013-01-01

    通过多跨联合的横向地震激励的流固耦合计算分析,研究了横向地震激励下槽身的扭转效应.研究结果表明,在横向地震作用下,每跨两端支撑刚度的差异对槽身的扭矩影响不大,但是地震附加扭矩对槽身两端截面正应力的影响较大;对于简支槽身的渡槽,以跨中截面的弯曲内力作为控制条件来设计整个槽身是可以满足结构抗震安全要求的.%Torsion of a multi-span aqueduct body under lateral seismic excitation was studied by computational analysis of fluid structure interaction (FSI).The results show that under the condition of lateral earthquake waves,a difference in the stiffness at both ends of each aqueduct span has little influence on the torque of the aqueduct body,while the additional earthquake torque has a significant influence on the normal stresses of both end sections.For a simply supported beam aqueduct,the requirements of anti-seismic safety for its entire structure can still be met if the moment at the center section is adopted as the design threshold of its structure body.

  18. Trans aqueductal, third ventricle – Cervical subarachnoid stenting: An adjuvant cerebro spinal fluid diversion procedure in midline posterior fossa tumors with hydrocephalus: The technical note and case series

    Science.gov (United States)

    Teegala, Ramesh

    2016-01-01

    Background: Persistent or progressive hydrocephalus is one of the complex problems of posterior fossa tumors associated with hydrocephalus. The author evaluated the effectiveness of single-stage tumor decompression associated with a stent technique (trans aqueductal third ventricle – Cervical subarachnoid stenting) as an adjuvant cerebro spinal fluid (CSF) diversion procedure in controlling the midline posterior fossa tumors with hydrocephalus. Materials and Methods: Prospective clinical case series of 15 patients was evaluated from July 2006 to April 2012. Fifteen clinicoradiological diagnosed cases of midline posterior fossa tumors with hydrocephalus were included in this study. All the tumors were approached through the cerebello medullary (telo velo tonsilar) fissure technique. Following the excision of the posterior fossa tumor, a sizable stent was placed across the aqueduct from the third ventricle to the cervical subarachnoid space. Results: There were nine male and six female patients with an average age of 23 years. Complete tumor excision could be achieved in 12 patients and subtotal excision with clearance of aqueduct in remaining three patients. Hydrocephalus was controlled effectively in all the patients. There were no stent-related complications. Conclusions: This study showed the reliability of single-stage tumor excision followed by placement of aqueductal stent. The success rate of this technique is comparable to those of conventional CSF diversion procedures. This is a simple, safe, and effective procedure for the management of persistent and or progressive hydrocephalus. This technique may be very useful in situations where the patient's follow-up is compromised and the patients who are from a poor economic background. Long-term results need further evaluation to assess the overall functioning of this stent technique. PMID:27366254

  19. Lack of significant association between mutations of KCNJ10 or FOXI1 and SLC26A4 mutations in pendred syndrome/enlarged vestibular aqueducts

    OpenAIRE

    Landa, P. (Přemysl); Differ, A. M.; Rajput, K.; Jenkins, L; Bitner-Glindzicz, M

    2013-01-01

    Background Pendred syndrome is a common autosomal recessive disorder causing deafness. Features include sensorineural hearing impairment, goitre, enlarged vestibular aqueducts (EVA) and occasionally Mondini dysplasia. Hearing impairment and EVA may occur in the absence of goitre or thyroid dyshormonogensis in a condition known as non-syndromic EVA. A significant number of patients with Pendred syndrome and non-syndromic EVA show only one mutation in SLC26A4. Two genes, KCNJ10, encoding an inw...

  20. Influence of Pile-soil Interaction on Dynamic Characteristic of Aqueduct Structure%桩土作用对渡槽动力特性影响分析

    Institute of Scientific and Technical Information of China (English)

    徐威; 刘亮; 谈政

    2012-01-01

    In existing numerical study of aqueduct, a simplified treatment of the boundary conditions of the bottom of the structure artificially increase the stiffness of the structure which is not consistent with the actual situation? This paper analyzed the effect to the dynamic characteristics of the aqueduct when considering pile-soil interaction by calculating an aqueduct model based on the potential fluid assumption. The activators under different conditions which can affect the performance of the pile-soil interaction were also investegated. The results show that: Both the coupling reaction between the aqueduct and water and the pile-soil interaction reduce free vibration frequency of the structure ,and also the influence of the former on the latter is indispensable.%现有的渡槽数值研究中,都将结构底部作刚接的简化处理,人为地增大了结构的刚度,与实际情况不相符合.本文基于势流体假设建立渡槽-水流固耦合二维联体式渡槽模型,分别计算比较刚性地基约束情况和考虑桩土作用的弹性地基约束情况下的渡槽结构在不同水深工况下的计算结果,分析各工况下土-结构相互作用的影响变化.结果表明,槽内水体作用和槽底桩土作用均使结构自振频率降低,并且前者对后者的影响不容忽视.

  1. Aqueducts and geoglyphs : the response of Ancient Nasca to water shortages in the desert of Atacama (Peru)

    Science.gov (United States)

    Masini, Nicola; Lasaponara, Rosa

    2016-04-01

    The desert of Atacama is a plateau in South America, covering a 1,000-kilometre strip of land on the Pacific coast, west of the Andes mountains, between Chile and Peru. Due to the confluence of a cold ocean current (the Humboldt Current) along with other climatic factors, connected to the particular topography and geomorphology of the region, Atacama desert is one of the most arid areas of the world. In particular, in Nasca region (Southern Peru) the lack of water was (and still is) due to the following causes: (i) the scarce pluvial precipitations and the (ii) high infiltration capacity, and the consequent yearly significant reduction of the surface water (Schreiber & Lancho Rojas 2009). Over the millennia long periods of drought occurred and frequently the lack of water was persistent for several decades. Despite the arid and extreme nature of the environment, this region was populated by important civilizations, such as Paracas and Nasca, which flourished in the Early Intermediate period (200 BCE-500 AD) (Silvermann & Proulx 2002). In particular the Nasca civilization is well-known for its refined and colourful pottery, characterized by a rich icononographic repertory, and, above all, by the huge and mysterious geoglyphs drawn on the arid plateaus of the Rio Grande de Nasca Basin. In order to practice agriculture, the Nasca developed adequate strategies to cope with hostile environmental factors and water scarcity, building a very efficient aqueduct system. They were aided by the fact that underground water was likely enough close to the surface and accessible by constructing wells and underground aqueducts, known with quechua name of puquios (Schreiber & Lancho Rojas 2009; Lasaponara & Masini 2012a; 2012b) The effectiveness of the techniques of hydraulic engineering depended on the climate and the weather events that sometimes underwent drastic changes, as results of the cyclical phenomenon of El Niño Southern Oscillation (commonly called ENSO). Hence the

  2. An Analysis of Single Span Simply-supported Aqueduct Bridges from the Perspective of Shear Lag Effect%单跨简支渡槽剪力滞效应分析

    Institute of Scientific and Technical Information of China (English)

    李遇春; 王立时; 袁纯强

    2012-01-01

    In this paper, several kinds of finite element models of aqueduct bodies have been created by using ANSYS Code. The nu- merical results indicate that the shell element can simulate the shear lag effect of the aqueduct bodies well in view of the accuracy of engineering requirements. This paper discusses the shear lag effects of the simply-supported single-box and multi-box aqueduct bridges in detail by means of the numerical method, which results in obtaining the longitudinal normal stress distribution of the bot- tom and upper flange of the aqueduct bodies. According to the results of calculations, the cross-section shape and width-span ratio of the aqueduct bodies are the main factors which have effect on the shear lag of the aqueduct bodies. The research results function as a reference to the structural design of aqueduct-bridges.%应用ANSYS程序建立了几种不同渡槽槽体结构的有限元模型,数值结果表明,采用板壳单元能很好地模拟槽体的剪力滞效应,计算精度满足工程要求。对单跨简支单箱、多箱槽体的剪力滞效应进行了较详细的数值研究,得到了槽体底板与上部翼缘的纵向正应力分布规律,研究了渡槽的截面形式、宽跨比等参数对渡槽剪力滞效应的影响。研究结果对渡槽结构设计具有参考价值。

  3. Application of 3DTSEDRIVE imaging in the detection of cerebral aqueduct obstruction%磁共振3D-TSE-DRIVE成像对中脑导水管梗阻的诊断

    Institute of Scientific and Technical Information of China (English)

    王茜; 陈腾; 王青; 郑金勇; 李传福

    2011-01-01

    目的 探讨磁共振3DTSEDRIVE成像对中脑导水管梗阻的诊断价值.方法 幕上脑积水患者31例,应用Philips Achieva (1.5T)超导型MRI扫描仪,SENSENV16线圈,行中脑导水管3DTSEDRIVE成像检查、相位对比法脑脊液电影成像及脑脊液流速分析.结果 3DTSEDRIVE序列检出中脑导水管部分狭窄、粘连22例,导水管闭塞3例,导水管通畅6例.结论 3DTSEDRIVE成像可清晰显示中脑导水管细节,能显著提高中脑导水管梗阻的诊断准确率,可作为常规MRI检查的重要补充.%Objective To investigate the diagnostic value of MR 3D-TSE-DRIVE imaging in the detection of cerebral aqueduct obstruction. Methods 31 patients with supra-tentorial hydrocephalus were enrolled in this study. 3D-TSE-DRIVE imaging, cerebrospinal fluid MR cine and flow analysis of cerebral aqueduct were performed with Philips Achieva (1. 5T) superconducting MRI scanner and SENSE-NV-16 coil in all cases. Results Using 3D-TSE-DRIVE sequence, 22 cases with partial aqueduct stenosis or adhesion and 3 cases with occluded aqueduct were detected, 6 cases were excluded of aqueduct obstruction. Conclusion 3D-TSE-DRIVE imaging has advantagcs in displaying the detail of cerebral aqueduct which may improve the diagnosis of aqueduct obstruction and is a valuable complement to routine MRI.

  4. 基于水体TLD效应的渡槽横向抗震研究%Research on Aqueduct Transverse Seismic Response Based on the TLD Effect of Water Body

    Institute of Scientific and Technical Information of China (English)

    徐家云; 胡学苏; 吴永昂; 徐国华

    2012-01-01

    为了解决大型渡槽的地震响应问题,从水体的TLD效应出发,通过对渡槽的横断面尺寸调整对比分析,找出水体TLD控制力规律,并在渡槽中沿纵向设全长的隔板,以进一步改善渡槽的横向抗震性能,利用ANSYS软件建立渡槽结构的空间三维动力分析模型.计算结果表明:水体的TLD效应对渡槽的横向地震响应有较大影响;沿槽中纵向增设隔板后,其地震响应进一步减小.%In order to solve the problem of the seismic response of large aqueducts, this article start with the TLD effects of water,adjust the size of cross-sectional dimensions of the aqueduct to contrast and analysis, and to identify the water body TLD control laws. Set the separator along the longitudinal length of the aqueduct to improve the transverse seismic performance of the aqueduct much more,using ANSYS to establish a spatial three-dimensional dynamic model of the aqueduct. The results show that: the water body TLD have a greater impact on transverse seismic effect on the aqueduct; after adding separator along the longitudinal of the aqueduct, its transverse seismic decrease further more.

  5. 临界性大前庭导水管的HRCT表现%HRCT appearances of the bordline large vestibular aqueduct

    Institute of Scientific and Technical Information of China (English)

    王林省; 张丽红; 陈月芹; 郭沐洁; 王玉红

    2015-01-01

    Objective To summarize the HRCT appearances of the bordline large vestibular aqueduct ,and to improve the knowledge of the disease and reduce missing .Methods 13 cases (15 ears) of the large vestibular aqueduct were found in 73 patients (143 ears) conformed by clinical documents and MRI ,their relevant HRCT documents were studied retro‐spectively .Standard axial and sagittal MPR images were done on Carestream10 .2 PACS .Results The morbidity is about 10 .5% (15/143) .11 are unilateral ,two cases are bilateral .The mid values of the vestibular aqueduct back limb are 0 .95~1 .30 mm (average:1 .21 mm) ,0 .97~1 .29 mm (average:1 .19 mm) .The vestibular aqueduct and endolymphatic sac were slightly dilated .The dilated vestibular aqueduct could also be identifed when it came into vestibule whether intraos‐sous or extraossous .on CISS Sequence of MRI ,one ear appeared high signal ,the others represented mixed signal in the all the enlarged endolymphatic sacs .Conclusion The bordline large vestibular aqueduct is not rare .On HRCT ,the vestibular aqueduct is slightly dilated .MRI could retrieve insufficience of CT ,and could reduce missing diagnosis .%目的:总结临界性大前庭导水管的 HRCT表现,提高对LVA的认识,减少CT漏诊率。方法回顾性分析经MRI确诊的73例(143耳)LVA HRCT资料,其中13例(15耳)为临界性LVA ,分析其 HR CT表现,并与其MRI对照。在Carestream10.2 PACS系统上行前庭导水管标准轴位、矢状位重建,测量前庭导水管中间径大小。结果临界性大前庭导水管占同期L V A的10.5%(15/143),其中双侧2例、单侧11例。在前庭导水管 H RC T轴位图像、矢状位图像上其后肢中段宽度位于0.95~1.30mm(均值1.21mm),0.97~1.29mm(1.19mm),其近段与前庭相通。在MRI积极干预稳态序列(CISS)序列上前庭导水管及骨内外内淋巴囊均有不同程度扩张,以骨外明显。其中1耳内淋巴囊

  6. 南水北调中线沙河渡槽施工方案研究及优选%Research and Optimization of Shahe Aqueduct Construction Scheme in the Middle Route of South-to-North Water Diversion Project

    Institute of Scientific and Technical Information of China (English)

    王玉华; 张利; 宋谦

    2011-01-01

    通过对3种典型的施工工法进行分析和论述,重点研究了30 m跨1 200t重U形渡槽的造槽机和架槽机两种机械化施工方案,通过建立仿真模型计算各种工况下的受力情况,分析设备的安全、可靠性,提出设备的主要性能指标,通过对架槽机、造槽机、满堂脚手架3种方案技术先进性、安全、进度等各方面优缺点综合分析,优选出能保证工程质量和工期的架槽机施工方案.%Shahe aqueduct is a main controlling project in the Middle Route of South-to-North Water Diversion Project. The aqueduct body is the structure of prestressed reinforced concrete beam with high flow, large span, long line and poor site conditions,so that the construction scheme is especially important. The analysis and discussion has been done with three typical construction methods of Shahe aqueduct in the Middle Route of South-to-North Water Diversion Project in this paper,and especially the two mechanical construction schemes by aqueduct-making machine and aqueduct-installing machine have been researched for 1,200t U-shaped aqueduct with span of 30rn. By simulation model, the forces have been calculated for different working conditions, the safety and reliability of the equipment has been analyzed, and the main performance index has been given. Aqueduct-in-stalling machine has finally been optimized for ensuring project quality and construction period according to the comprehensive analysis of merit and demerit for three schemes of aqueduct-making machine,aqueduct-installing machine,and full scaffold with the respects of technical achievement, safety, and schedule.

  7. 小型水库输水涵管加固技术方案关联因素分析%Relevant Factor Analysis of Reinforcing Solutions on Aqueducts in Small Reservoirs

    Institute of Scientific and Technical Information of China (English)

    刘锐

    2011-01-01

    Aqueducts are essential structures in reservoirs to irrigation, water supply, power generation, etc. In this paper we analyze the typical symptoms, reinforcing solutions and relevant factors of defective aqueducts in small reservoirs; summarize the main disease categories and reinforcing solutions of aqueducts; present the opinion that the critical relevant factors of reinforcing solutions for aqueducts are the size of cross section, the laying depth and the engineering geologic condition; thus provide ideas and approaches to select the appropriate aqueduct reinforcement solutions.%输水涵管是实现水库灌溉、供水、发电等运行功能的关键建筑物.通过分析研究小型水库输水涵管病害特征、加固技术方案及其主要的关联因素,归纳总结出输水涵管主要病害类别和主要加固技术方案,提出了输水涵管加固技术方案主要的关联因素为涵管断面尺寸、涵管埋设深度和工程地质条件,并结合工程实例,讨论了涵管加固方案比较选择的方法和思路.

  8. Seismic Response Analysis for Large-scale Aqueduct with Fluid Influence Based on Finite Strip Method%动水作用下大型渡槽结构有限条法地震反应分析

    Institute of Scientific and Technical Information of China (English)

    李起丛; 王云峰; 黄玉红

    2011-01-01

    Based on the theory of finite strip method, the aqueduct body is discretely meshed into some strips, and the explicit formulas for the element stiffness and mass matrix of the aqueduct body are derived. The braces of the aqueduct are simulated by using beam elements, and the rubber supports linking the aqueduct body and its braces are simulated by using spring elements. Then, the earthquake time history response of the large-scale aqueduct with fluid influence by added mass method is discussed under three cases and during respectively inputting three synchronous earthquake waves.%根据有限条法原理,把渡槽槽身划分为若干有限条,推导出渡槽槽身结构的单元刚度矩阵、质量矩阵的显示表达式.采用空间梁单元模拟渡槽支架,联接槽身和支架的支座采用弹性元件单元模拟;采用附加质量法考虑水体的动水作用;计算了大型渡槽结构在三种工况分别输入三种地震波作用下的时程响应.

  9. Utility of two types of MR cisternography for patency evaluation of aqueduct and third ventriculostomy site: Three dimentsional sagittal fast spin echo sequence and steady-state coherent fast gradient echo sequence

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Hyun; Kim, Eun Hee; Park, Jong Bin; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheol Kyu; Bae, Yun Jung; Lee, Kyung Mi [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-07-15

    We aimed to evaluate the utility of two types of MR cisternography [fast spin echo sequence and steady-state coherent gradient echo (GRE) sequence] in addition to phase contrast-cine imaging (PC-cine), for assessing patency at the aqueduct and third ventriculostomy site. 43 patients (35 patients with suspected aqueductal stenosis and 8 patients with third ventriculostomy) were retrospectively analyzed. PC-cine, 3 dimensional sagittal fast spin echo sequence [driven-equilibrium imaging (DRIVE) or volumetric isotrophic T2-weighted acquisition (T2 VISTA)] and steady-state coherent fast GRE sequence (balanced turbo field echo; bTFE) imaging were performed in all patients. The patency of the aqueduct or third ventriculostomy site was scored. Some pitfalls of each sequence were also analyzed in individual cases. 93% of all cases showed consistent scores in PC-cine, DRIVE/T2 VISTA, and bTFE imaging. DRIVE/T2 VISTA imaging provided functional information of cerebrospinal fluid flow with flow-related artifacts, while bTFE imaging allowed direct visualization of the aqueduct or ventriculostomy site. However, evaluation of anatomical structures was difficult in three cases with strong flow-related artifacts on DRIVE/T2 VISTA and in 2 cases with susceptibility artifacts on bTFE. Both DRIVE/T2 VISTA and bTFE imaging have complementary roles in evaluating the patency of the aqueduct and 3rd ventriculostomy site.

  10. SLC26A4 gene copy number variations in Chinese patients with non-syndromic enlarged vestibular aqueduct

    Directory of Open Access Journals (Sweden)

    Zhao Jiandong

    2012-05-01

    Full Text Available Abstract Background Many patients with enlarged vestibular aqueduct (EVA have either only one allelic mutant of the SLC26A4 gene or lack any detectable mutation. In this study, multiplex ligation-dependent probe amplification (MLPA was used to screen for copy number variations (CNVs of SLC26A4 and to reveal the pathogenic mechanisms of non-syndromic EVA (NSEVA. Methods Between January 2003 and March 2010, 923 Chinese patients (481 males, 442 females with NSEVA were recruited. Among these, 68 patients (7.4% were found to carry only one mutant allele of SLC26A4 and 39 patients (4.2% lacked any detectable mutation in SLC26A4; these 107 patients without double mutant alleles were assigned to the patient group. Possible copy number variations in SLC26A4 were detected by SALSA MLPA. Results Using GeneMapper, no significant difference was observed between the groups, as compared with the standard probe provided in the assay. The results of the capillary electrophoresis showed no significant difference between the patients and controls. Conclusion Our results suggest that CNVs and the exon deletion in SLC26A4 are not important factors in NSEVA. However, it would be premature to conclude that CNVs have no role in EVA. Genome-wide studies to explore CNVs within non-coding regions of the SLC26A4 gene and neighboring regions are warranted, to elucidate their roles in NSEVA etiology.

  11. The application of high-resolution CT in the visualization of the vestibular aqueduct (Meniere's disease) and labyrinthine otospongiosis

    International Nuclear Information System (INIS)

    Ever since the introduction of temporal bone imaging by means of high-resolution CT, it appears that the combination of high spatial resolution, high density resolution and the freedom of patient positioning for scanning of optimal otological planes may play a unique role in the diagnosis and follow-up of a number of otological disorder. Two examples are described here. The first is the possibility of determining whether the vestibular aqueduct in idiopathic Meniere's disease is obliterated or not, and if so, whether it is a bony or a fibrous obliteration. Although the results are preliminary, there are indications that all three cathegories occur and that the efficacy of drainage of the endolymphatic sac can be evaluated prior to surgery. The second example is the possibility of outlining and quantifying the bone mineral loss in cases of labyrinthine otospongiosis. Preliminary studies have outlined that there is a relationship between the degree of decalcification and the severity of sensorineural hearing loss. These examples show high-resolution, thin-section multiplanar CT to have great potential in the diagnosis and treatment of otological disorders. This will become evident as the techniques that were used here are worked out in more detail and become more widely known. (orig.)

  12. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: II. Annual plants

    Science.gov (United States)

    Berry, Kristin H.; Mack, Jeremy S.; Weigand, James F.; Gowan, Timothy A.; LaBerteaux, Denise

    2015-01-01

    We studied recovery of winter annual plants in a 97-m wide disturbed aqueduct corridor in the Mojave Desert 36 years after construction. We established plots at 0, 20, and 40 m from the road verge at the corridor center and at 100 m in undisturbed vegetation. We recorded 47 annual species, of which 41 were native and six were exotic. Exotic species composed from 64 to 91% of total biomass. We describe a bilateral process of recovery: from the road verge to the outward edge of the corridor and from undisturbed habitat into the corridor. Native annual plants significantly increased in richness from road verge to undisturbed vegetation, but not in density, biomass, or cover. In contrast, exotic annual plants increased in density, biomass, cover and richness with increasing distance from the road verge. The species of colonizing shrubs and type of canopy cover affected density, biomass, and richness of annuals. Species composition of native annuals differed significantly by distance, suggesting secondary succession. In general, native annuals were closer to achieving recovery on the 40-m plots than at the road verge. Recovery estimates were in centuries and dependent on location, canopy type, and whether considering all annuals or natives only.

  13. 大跨叠箱渡槽施工期温度场测试及数值模拟研究%Temperature Field Test and Numerical Simulation of Large Span Stacked Box Aqueduct During Construction Period

    Institute of Scientific and Technical Information of China (English)

    董国桢

    2015-01-01

    以黔中水利焦家大跨叠式箱形渡槽为例,进行了温度场分布连续测试及相应的有限元数值模拟,系统研究了叠箱渡槽的温度分布特点,为大跨度叠箱渡槽的设计与施工提供技术支持。%Taking Jiaojia large span stacked box aqueduct of Qianzhong water conservancy project in Guizhou as an exam-ple,this paper made a continuous test on temperature field distribution and corresponding finite element numerical simula-tion,and then a systematic study on the temperature distribution characteristics of the stacked box aqueduct was made, which could provide a technical support for the design and construction of large span stacked box aqueduct.

  14. Construction Discussion for the Large-span Prestressed Concrete Thin-wall U-shaped Aqueduct%大跨度预应力混凝土薄壁U型连续梁渡槽施工探讨

    Institute of Scientific and Technical Information of China (English)

    计孝龙

    2016-01-01

    结合云桂铁路横跨新哨站场连续梁薄壁 U 型渡槽(34+36+34)的施工经验,从渡槽支架系统、超长预应力的施工以及止水缝的施作来探讨此类大跨度连续梁渡槽的一些施工经验。%In this article,as the aspects of aqueduct support system,extra-long prestressed construction and the applying of sealed joint,we discussed some construction experience about these large-span continuous beam aqueducts.Some experi-ences were applied in the continuous beam thin-wall U-shaped aqueduct (34 +36 +34)of Nanning-Kunming High-speed Railway across the new whistle station.

  15. 上承式预应力拉杆拱形渡槽动力性能研究%DYNAMIC BEHAVIOR STUDY ON TOP- SUPPORTED PRE -STRESSED TIE- ARC AQUEDUCT

    Institute of Scientific and Technical Information of China (English)

    孙伟; 宋晓辉; 刘纯祥

    2011-01-01

    上承式预应力拉杆拱形渡槽是一种新型的渡槽结构形式,与传统的渡槽结构形式相比结构更紧凑、不对桥墩产生水平推力而且槽墩轻巧、施工方便,有较高的工程应用价值.通过对界河上承式预应力拉杆拱形渡槽结构动力性能的监测分析并结合ANSYS有限元软件进行模态分析,对该类型结构形式的动力性能做了详细分析.分析结果表明:渡槽的振动周期较长,属于柔性结构;渡槽结构以槽身的横向振动为主;渡槽的竖向刚度相对较强,而槽身平面外刚度较弱.%Top -supported pre -stressed tie -arc aqueduct is a new type of aqueduct ,which possesses many advantages such as compact integer structure, no horizontal force on support piers, light pier and easy construction.Therefore, the new aqueduct has very high applicable values in engineering. Through on - site monitor and ANSYS modal analysis, detailed analysis on dynamic behavior of Jiehe top - supported pre - stressed tie - arc aqueduct is performed. The results show that the aqueduct is flexible structure because of long vibration period, transverse vibration is dominating , vertical rigidity is strong while out - plane rigidity of aqueduct is weak.

  16. 基于XFEM的渡槽单向地震动作用下裂纹开展分析%Analysis of crack growth of aqueduct under effect of single dimensional earthquake force based on XFEM

    Institute of Scientific and Technical Information of China (English)

    何祥瑞; 张华; 纪爱丽

    2016-01-01

    Taking bent-type aqueduct as study object,the paper established a linear elastic calculating model with two-dimensional aqueduct of rubber bearings based on ABAQUS platform with XFEM.It calcuated the growth and extension of cracks and the equivalent stress of aqueduct structures during dynamic circulating process under different seismic waves,and analyzed the range of cracks and the damage degree of aqueduct structures.The results show that XFEM can better simulate the crack dehiscence and expansion of aqueduct structure.Both the joints between beam and column,and the bottom of column are the weak parts of anti-seismic of aqueduct structure.%以排架渡槽为研究对象,建立了基于ABAQUS平台的扩展有限元法的二维橡胶支座排架渡槽线弹性计算模型.计算了不同地震波激励下渡槽结构的裂纹开裂扩展及在动态变化循环过程中渡槽结构的等效应力,对比分析了不同地震波作用下渡槽结构的裂纹开裂范围及损伤程度.研究结果表明:XFEM能够较好地模拟渡槽结构的裂纹开裂和扩展情况;连梁与排架柱节点以及排架柱底部是排架渡槽的抗震薄弱部位.

  17. Seismic Response Study on Multi-body Aqueduct Structure Considering Water Sloshing%考虑水体晃动的多槽式渡槽结构地震反应研究

    Institute of Scientific and Technical Information of China (English)

    季日臣; 许涛; 苏小凤; 唐艳

    2012-01-01

    为分析水体晃动对多槽式渡槽结构动力特性的影响,基于流固耦合理论,以南水北调中线工程某双槽式渡槽为例进行研究.应用Westerguard水体附加质量法模拟水体与结构的动力相互作用,采用MIDAS/CIVIL计算软件对该双槽式渡槽的自振特性和地震反应进行有限元计算,分析水体对渡槽动力特性的影响.并选用具有隔震和耗能双重功能的摩擦摆支座对大型渡槽结构进行隔震研究.计算结果表明,摩擦摆支座纵横向隔震能够大幅减小墩顶位移和墩底内力,从而满足结构的抗震需求.%In order to analyse the effects of water sloshing on multi-body aqueduct dynamic characteristics , based on the fluid-structure coupling theory, the double-body aqueduct of South to North Water Diversion Project was studied. The added mass method was used to simulate the dynamic interaction between water and aqueduct structure. The free vibration characteristics and seismic response of the aqueduct were calculated by the MIDAS/CIVIL software. The effects of water sloshing on aqueduct dynamic characteristics were analyzed. Friction Pendulum Bearings ( FPB) with double function of seismic isolation and energy dissipation were adopted to study the seismic isolation of large aqueduct. The results show that the longitudinal and lateral isolation of FPB can reduce signtificantly the top displacement and bottom internal forces of piers satisfying the requirement of seismic resistance.

  18. Stress and Deformation Analysis for Yangjiaba Aqueduct with Three-dimensional Finite Element Method%杨家坝渡槽结构应力与变形三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    圣玉兰; 段亚辉

    2011-01-01

    针对杨家坝渡槽跨度较大导致的安全问题,采用初始应变法施加预应力,考虑了渡槽在运行过程中的11种工况,对渡槽结构应力与变形进行了三维有限元分析,得出了渡槽结构应力和位移的分布规律.结果表明,渡槽槽身位移和挠度较小,满足现行规范要求;槽身一般均处于压应力状态,且最大压应力小于混凝土容许值;在温降与夏季日照工况下槽身的最大拉应力明显超过混凝土容许值,建议在槽身两边各增加一束预应力钢绞线.%Aiming at the safety problem of Yangjiaba aqueduct caused by long span, the method of initial strain is a- dopted to apply the prestress force. Considering eleven combination operating conditions of the aqueduct in operation process, three-dimensional finite element method is used to analyze the stress and deformation of the aqueduct. The stress and displacement rules of the aqueduct are obtained. The results show that the deflection and displacement of aqueduct are small to meet the existing standard requirements; aqueduct body is generally in the compressive stress state and the maxi mum compressive stress is less than the allowable value of the concrete; but in the temperature drop and summer sunshine conditions, the maximum tensile stress is significantly more than the allowable value of the concrete; thus it suggests that a bunch of PC strand supplement to the slot on each side of the body.

  19. Aqueductal stenosis and mental retardation associated with O S odontoideum, "hypermobile" atlantoaxial dislocation and congenital stenosis of atlas leading to spastic quadriparesis

    Directory of Open Access Journals (Sweden)

    Rupant K Das

    2007-01-01

    Full Text Available Background: The authors report a unique concomitant occurrence of mental retardation, hydrocephalus due to aqueductal stenosis, a freely floating atlas (having anterior, posterior and transverse atlantoaxial dislocation [AAD] consequent to an orthotopic os odontoideum and stenosis of atlantal ring. There were no features of coexisting chondroskeletal dysplasias or other systemic diseases. To the best of the authors′ knowledge, this is the first reported case of its type in the literature. Case Report: This 17-year-old girl with delayed milestones had enlarging head with vomiting at 1 year of age. Her CT scan revealed hydrocephalus with aqueductal stenosis, and she underwent a ventriculoperitoneal shunt. She subsequently had progressive quadriparesis. A minor fall led to transient unconsciousness and aggravation of her symptoms. Radiology of the craniovertebral junction revealed os odontoideum with anterior, posterior and transverse C1-2 subluxation and atlantal ring stenosis with marked cervical compression. A C1 laminectomy with occipitocervical contoured rod fusion with onlay autologous bone graft under guidance of intraoperative image intensifier was performed. Conclusion: The concomitant presence of hydrocephalus due to aqueductal stenosis, mental retardation and congenital stenosis of the atlantal ring points towards a congenital origin for the os odontoideum. The free floating atlantal ring on the axis led to anteroposterior and transverse AAD, necessitating intubation and occipitocervical stabilization in absolutely neutral position of the neck since both flexion as well as extension movements would have been deleterious. Congenital stenosis of atlas is an extremely rare entity; it contributed to cervical canal compromise even in neutral position of the cervical spine when the AAD had been adequately reduced, requiring an additional C1 laminectomy. The simultaneous presence of all these anomalies merited unique management considerations.

  20. Seismic Isolation Study of Large-scale Aqueduct with Ball Bearings%球型支座应用于大型渡槽的隔震研究

    Institute of Scientific and Technical Information of China (English)

    张艳红; 胡晓; 胡选儒; 和秀芬; 欧阳先凯

    2011-01-01

    结合实际大型渡槽工程,设计球型隔震支座NKQZ15000GD,该支座具有较高的竖向承载能力、较低的水平剪切刚度,并具有一定阻尼和复位能力;对该支座进行材料性能测试,拟合支座的力学性能参数;分别采用反应谱法和动力时程法,计算隔震渡槽在设计地震与超设计地震作用下的动力反应;分析球型隔震支座应用于大型渡槽的减震效果,根据定量分析的结果得到一些规律性的结论.%For the actual large-scale aqueduct project, a ball isolation bearings NKQZ15000GD was designed, which showed a higher vertical bearing capacit, lower shear stiffness,certain damping and reset capability. Material testing was conducted on the bearings and the mechanical parameters were obtained by test data fitting. The response spectrum method and dynamic time-history method were used to analyze the seismic responses of isolation aqueduct under the designed earthquake and super-designed earthquake. Damping effect of the ball bearings set in the large-scale aqueduct was also analyzed. According to the results of quantitative analyses,some regularity conclusions were given.

  1. Analysis method of capacity spectrum of isolated aqueduct%隔震渡槽结构的能力谱分析方法

    Institute of Scientific and Technical Information of China (English)

    殷开娟; 周逸仁

    2014-01-01

    Based on the displacement of seismic design theory,this paper introduced the basic principle and implementation of capacity spectrum method.With the background of the south to north water diver-sion project,it studied the seismic performance of an aqueduct structure, and then compared with the re-sults of nonlinear time-history analysis.Considering the particularity of aqueduct structure,when calcu-lating the demand spectrum curve,it used constant ductility elastoplastic demand spectrum which based on the code for seismic design of hydraulic structures.Analysis show that capacity spectrum method can be used for seismic performance evaluation of isolated aqueduct.%基于位移的抗震设计理论,介绍了能力谱法的基本原理和实施步骤。以南水北调工程为背景,应用该方法对渡槽结构的抗震性能进行了研究,并与非线性时程分析结果作对比。考虑到渡槽结构的特殊性,在计算需求谱曲线时,采用基于水工建筑物抗震设计规范的等延性弹塑性需求谱。分析表明:能力谱法可以用于隔震渡槽结构的抗震性能评估。

  2. 排导结构中泥石流的流动形态%A Study on Flowwing Velocity in Aqueduct of Debris Flow

    Institute of Scientific and Technical Information of China (English)

    马永泰; 周富春; 陈洪凯

    2001-01-01

    根据能量守恒原理,推导出泥石流在排导槽中的能量方程。根据此方程,可求出泥石流在排导槽中任意横断面的平均流速。对方程涉及的各参数进行了深入的讨论,首次引入泥石流对一般水体的修正系数K。并把该成果应用于平川泥石流的治理。%This paper inqures into the energy equation of debis flow indrainage canal , according to the law of coservation of energy. Mean current velocity of any transverse section of the debris flow of the aqueduct can be ascertained from this equation. And this paper also gives the course of inference of the equation ,the formula of hydraulic raidius and energy loss of the debris flow in the process of flowing. Meanwhile this paper makes concrete analysis of all parameteres—α1、α2、α3、ξ1、ξ2、n1、n2, especially first leades into a revised coefficient K cotrast debris flow with water. Finally the theory is applied to the design of aqueduct of debris flow in Pinchuan. K value(K=1.3) is obtained by a model experiment,and it is revised to 1.4 by inspection of the scene,then utilizing the equation ,mean current velocity of the debis flow is reached in the exit transverse section of the aqueduct.

  3. Hybrid simulation of flow in a long aqueduct%长渡槽段水流运动的复合模拟

    Institute of Scientific and Technical Information of China (English)

    刘士和; 段蕾; 曹兵; 胡宁宁

    2011-01-01

    长渡槽内水位变化、流速流态等水力特性是工程设计部门甚为关注的问题.南水北调中线一期工程总干渠长约10 km的沙河渡槽长宽比大、过水建筑物多等,单独采用物理模型试验进行研究不太经济,单独采用二维甚至三维数学模型进行计算也存在模型参数难以确定的困难,采用复合模拟方法经济有效地解决了以上难题.在设计流量与加大流量的条件下进行计算,得到如下主要成果:沙河渡槽内3个弯道中,鲁山坡落地槽弯道段的横向水面差最大,设计和加大流量工况下分别达0.056 m和0.066 m;沙河渡槽内水流衔接良好,流态平稳.%Hydraulic characteristics such as water-level,water flow regime and flow velocity in a long aqueduct are issues of particular concern to engineering design department. The main channel of Middle Route of South-to-North Water Transfer Project in Shahe River is nearly 10 km long, which has several characteristics including large ratio of length to width and amount of water-carrying structures. It is uneconomical to adopt model test only,while it is difficult to determine model parameter when 2D or 3D mathematical model is used alone. In this paper,the hybrid simulation method will be built for the aqueduct which can tackle problems mentioned above economically and efficiently. The main results in the case of design discharge and large discharge are as follows: The transverse difference of water levels of Lushanpo Curve section is the biggest one among the three curved sections in the Shahe River Aqueduct,which is 0. 056 m in design discharge and 0.066 m in large discharge; Current joining and water flow regime are smooth in the Shahe River Aqueduct.

  4. Large Vestibular Aqueduct Syndrome of Diagnosis and Management in Recent Status%大前庭水管综合征的诊治现况

    Institute of Scientific and Technical Information of China (English)

    钱永忠; 李福军

    2005-01-01

    @@ 一、概况 大前庭水管综合征(Large vestibular aqueduct syndrome,LVAS)是较常见的先天性内耳畸形疾病.Valvassori等[1]在3 700例前庭或听功能障碍患者的CT中发现50例大前庭水管扩大异常,发病率为1.5%,其中40%是单独异常,而60%伴有其他畸形.

  5. Impacts on Natural Vibration Frequency of Aqueduct by Water Shaking%水体的晃动作用对渡槽自振频率的影响

    Institute of Scientific and Technical Information of China (English)

    彭维东; 柴军瑞

    2014-01-01

    As a water transmission structure, shaking of water in the aqueduct duct may impact the natural vibration frequency of the aq-ueduct.By application of the general large finite element software of ADINA, modal calculations on the following three operating condi-tions are performed:in aqueduct duct, no water, water of 1/2 design depth and water of design depth respectively.Frequencies under the three operating conditions are compared and analyzed.It shows that the shaking of water features the reduction of the natural vibration fre-quency of structures.%渡槽作为一种输水建筑物,槽壳中的水体晃动作用会对渡槽的自振频率产生一定的影响,文章采用大型通用有限元软件ADINA对槽壳内无水、有1/2设计水深水的槽壳和有设计水深水的槽壳3种工况进行模态计算,并将3种工况下的频率进行对比分析,可以得出水体的晃动具有降低结构自振频率的特性。

  6. 连续刚构预应力U型薄壳渡槽有限元分析%Finite element analysis of prestressed U-type continuous aqueduct

    Institute of Scientific and Technical Information of China (English)

    白新理; 黄和法; 刘琰玲; 赵新铭

    2001-01-01

    A prestressed U-type continuous aqueduct is analyzed by means of the famous nonlinear F.E. program ADINA. Static analysis results are listed and frequencies and modeshapes are described. The results show that the minus bending moment make the stresses decreased in continuous aqueduct, and that the maximum compressive stress, the maximum tensile stress and the maximum displacement are all under the design value. Finally, conclusions and suggestions are given to the original design.%使用非线性有限元程序系统ADINA,对南水北调中线穿黄连续刚构方案的预应力U型薄壳渡槽进行了结构分析.给出了静力分析结果和动力特性分析结果.结果表明,与简支方案相比,连续刚构方案结构减小了变形、应力和钢筋用量,最大压应力和最大拉应力均满足规范中的强度设计要求,最大位移也满足刚度要求.同时还对原设计方案提出了改进建议.

  7. Finite element analysis on aqueduct buckle type steel pipe bracket%渡槽扣件式钢管支架有限元分析

    Institute of Scientific and Technical Information of China (English)

    杨金龙; 晁永莲

    2012-01-01

    以引洮供水一期工程总干渠4号渡槽为工程背景,采用MIDAS有限元分析软件对扣件式钢管支架进行了有限元分析。分析结果表明,渡槽支架构件均满足强度和稳定要求,并具有足够的安全储备,对同类结构的设计与计算工作具有一定理论指导作用。%Taking No.4 aqueduct project of Yinyao water supply project 1 main canal as the background,made finite element analysis on buckle type steel pipe bracket using the MIDAS finite element analysis software,according to the analysis results,aqueduct bracket members met the strength and stability requirements,and had enough emergency capecity.Had a certain theoretical guidance to the design and calculation of similar structures.

  8. Action of fluid on aqueduct body during strong earthquake%强震下流体对渡槽槽身的作用

    Institute of Scientific and Technical Information of China (English)

    李遇春; 楼梦麟

    2000-01-01

    The boundary element method is applied to simulate nonlinear sloshing of fluid,dynamic horizontal force and overturning moment actingon the aqueduct body during earthquake.The computational results of BEM(nonlinear)are compared with that of linearized theories.The numerical results reveal that a great horizontal force acting on the aqueduct body may occurred during strong earthquake.This action must be considered in seismic resistance design.%本文应用边界元法计算了强震下流体的非线性晃动及其对槽身的水平力及翻转力矩,将所得数值结果与线性解析方法的计算结果作了比较,分析了两类结果的异同点。计算表明:强震时,流体对槽身可能会产生很大的横向水平力,建议在抗震设计时考虑这一作用因素。

  9. Increase insulation effect of polyurethane board pasting on closed aqueduct surface in cold regions%北方寒冷地区封闭渡槽粘贴聚氨酯板提高保温效果

    Institute of Scientific and Technical Information of China (English)

    刘德仁; 张东; 张世民

    2013-01-01

    Areas of northern China are mainly in the temperate monsoon climate zone and temperate continental climate zone, it is cold in winter, and the air temperature is low, which has a big influence on water diversion facilities, especially aqueduct. As for closed aqueduct water diversion projects which need to be operated in winter with non-pressure water delivery in cold regions of northern China, it is of great significance to study and research the safe operation under low temperature environment in winter. With the rapid development of the construction of water diversion projects, the original research results about aqueducts mainly lie in the structural stress of the aqueduct, then the effects of fluid-solid coupling, earthquake, wind and temperature stress, and other factors are gradually considered, seismic and reliability theory is also introduced into the design of diversion facilities. For water diversion projects in northern China, the problem of the safety of water diversion under low temperature environments in winter should also be considered. The present study in freezing disease of water diversion project and safety operation in winter is relatively less, which are mainly in the fields of monitoring analysis and numerical calculation analysis. In this paper, according to an aqueduct engineering practice with non-pressure water delivery in cold region of northern China, a scale model test of an aqueduct is undertaken in an indoor environment cabinet to study the anti-freezing and insulation effects of pasting polyurethane insulation board on the surface of the aqueduct under low temperature environment in winter. In order to study the insulation effects of polyurethane insulation board on aqueduct, the tests are mainly divided into two cases: pasting and without pasting polyurethane insulation board on the surface of the aqueduct model. By the tests, the influence of the external environment temperature and rate of flow on water flow temperature during

  10. Increase insulation effect of polyurethane board pasting on closed aqueduct surface in cold regions%北方寒冷地区封闭渡槽粘贴聚氨酯板提高保温效果

    Institute of Scientific and Technical Information of China (English)

    刘德仁; 张东; 张世民

    2013-01-01

      为了研究封闭渡槽在冬季低温环境下的安全运行状况,结合中国北方寒冷地区某无压输水渡槽工程实际,通过在室内环境箱中进行渡槽比例模型试验,研究了渡槽在冬季输水过程中,水流温度受外界环境温度及流速的影响。为保证渡槽在冬季寒冷条件下的安全运行,在渡槽模型表面粘贴聚氨酯保温材料,研究了聚氨酯保温板对渡槽的保温效果,并与不粘贴保温材料时渡槽内的水流温度进行了对比。经试验发现,渡槽外壁黏贴聚氨酯保温板在防止渡槽水流温度降低方面的作用明显,减小了约45%的水流温度降低值,研究成果可为北方寒冷地区同类型工程的设计与安全运营提供参考。%Areas of northern China are mainly in the temperate monsoon climate zone and temperate continental climate zone, it is cold in winter, and the air temperature is low, which has a big influence on water diversion facilities, especially aqueduct. As for closed aqueduct water diversion projects which need to be operated in winter with non-pressure water delivery in cold regions of northern China, it is of great significance to study and research the safe operation under low temperature environment in winter. With the rapid development of the construction of water diversion projects, the original research results about aqueducts mainly lie in the structural stress of the aqueduct, then the effects of fluid-solid coupling, earthquake, wind and temperature stress, and other factors are gradually considered, seismic and reliability theory is also introduced into the design of diversion facilities. For water diversion projects in northern China, the problem of the safety of water diversion under low temperature environments in winter should also be considered. The present study in freezing disease of water diversion project and safety operation in winter is relatively less, which are mainly in the fields of

  11. 大型灌区矩形多纵梁渡槽结构分析与优化%The Structure Analysis and Optimization Design of Rectangular Aqueduct of the Multi-longitudinal Beams in the Large Irrigation Districts

    Institute of Scientific and Technical Information of China (English)

    杜江; 王立坤; 黄勇

    2015-01-01

    为了进一步研究矩形多纵梁渡槽结构受力分布规律,以黑龙江省某大型灌区输水渡槽为例,采用ANSYS有限元分析方法对其进行受力分析。结果表明,增加渡槽侧墙及底板厚度能够有效提高渡槽整体受力条件,在满足各项应力及变形指标情况下可适当减小纵梁的高度以节省工程量。该项目的实施有效地解决了该大型灌区水资源匮乏等问题。%Further studying the structure analysis of large rectangular aqueduct bridge with multi -longitudinal beams , this paper analyses the force for an aqueduct in large irrigation districts in Heilongjiang Province which is based on the finite element software of ANSYS .The results show that increasing the aqueduct sidewall and bottom thickness can effectively improve the stress condition of the aqueduct .The height of the beam can be reduced to save the amount of work in the condition that the stress and deformation index meet the conditions .The problem of the water shortage in the large irriga-tion was solved effectively by the implementation of the project .

  12. 杨家坝大跨度简支预应力渡槽徐变效应分析%Creep Effect Analysis of Yangjiaba Longspan Simply-supported Prestressed Aqueduct

    Institute of Scientific and Technical Information of China (English)

    李柯; 段亚辉

    2011-01-01

    针对杨家坝大跨度简支预应力渡槽在长期荷载作用下单跨结构稳定、挠度是关系到渡槽安全与正常运行的问题,采用有效模量法借助有限元软件ANSYS建模,计算了渡槽槽身在假定荷载保持不变条件下由徐变引起的应力和挠度,分析了渡槽的安全稳定性.结果表明,该渡槽徐变应力和挠度均满足现行规范要求,为工程设计提供了重要参考.%In view of the situation that single span structure stability and deflection is related to safety and normal operation of Yangjiaba longspan simply-supported prestressed aqueduct, effective modulus method is applied to calculate the creep deflection and stresses change of the aqueduct under the given load by using finite element analysis software AN-SYS. At the same time, it analyzes the safety and stability of the aqueduct. The results show that the creep stresses and deflection of the aqueduct meet requirements of current specification, which provides important reference for engineering design.

  13. Analysis of Dynamic Characteristics and Seismic Response of Large-sized Multi-troughs Rectangular Aqueduct%大型多槽式矩形渡槽动力特性及地震响应分析

    Institute of Scientific and Technical Information of China (English)

    袁海军; 张静娜; 任益楼; 马文英

    2011-01-01

    基于Housner模型,考虑地震影响下晃激荡水体与槽身间的相互作用力,建立了流固耦合动力分析模型,并以南水北调中线工程为例进行了大型多槽式渡槽的动力特性与地震位移时程响应分析.结果表明,开敞式多侧墙槽身横向抗震能力起控制作用,尤其应加强边墙、中墙两端抗震防护,可为类似工程抗震设计提供参考.%Based on the Housner model, dynamic analysis model of fluid solid coupling for large-sized multi-troughs aqueduct is established by considering interaction of sloshing water and aqueduct-body under influence of earthquake.Taking the South-North Water Transfer Project in middle routes for an example, the dynamic characteristics and seismicdisplacement responses with time-history for large-sized multi-troughs aqueduct are analyzed. The result shows that the transverse seismic of the open style and multi sidewall aqueduct body play the control action, especially the seismic protection in the two ends of sidewall and midwall should be strengthen.

  14. Calculation for the Secondary Bending Moment in the Prestressed Concrete Structure of the Caohe Aqueduct%漕河渡槽预应力次生弯矩计算

    Institute of Scientific and Technical Information of China (English)

    赵军涛; 王志刚; 袁浩; 刘修水

    2013-01-01

    The secondary be nding moment from three-dimension prestressing is firstly proposed to calculate the prestress in the Caohe aqueduct of Middle Route Project of S-N water diversion. The calculation of the secondary bending moment and it’s the impact on the structure of the aqueduct body is discussed with the design examples in the Caohe aqueduct in this paper. The experience summarized in this paper can offer help and reference in calculating three-dimension prestressing in the large aqueduct.%南水北调中线漕河渡槽,首次将三向预应力次生弯矩影响考虑到结构设计当中,本文结合漕河渡槽槽身设计实例,对次生弯矩的计算及影响分析进行了论述,并总结了经验,为大型渡槽多向预应力设计提供了借鉴和参考。

  15. 宁夏引黄灌区输水渡槽安全鉴定与评价研究%Study on the Appraisal and Evaluation of Aqueduct Security in the Irrigation Area of Ningxia

    Institute of Scientific and Technical Information of China (English)

    张锋

    2016-01-01

    Based on the analysis of the management of 4 aqueducts with different construction time and service life of Qixing Canal in the irrigation area of Ningxia, it analyzed from the construction quality, the flow ability to conduct site safety inspection and quality inspection;From the aspects of structure stability, structural seismic analysis accounting. Based on hierarchy analysis of aqueduct structure safety assessment method of the various factors, the weights by using expert scoring and given, one ticket veto, such as mechanism, realized the reasonable evaluation and effective assessment of the aqueduct. Through the analysis of the field and the calculation results, the establishment of the level of security standards;old aqueduct of safety evaluation index system; form a complete system of aqueduct of safety evaluation. 4 flumes of safety appraisal conclusion has been applied to the improvement of irrigation district, for the solid and consolidate the irrigation area water aqueduct engineering design provides the technical support;using the research results can effectively reveal the cooperatives, the old safety status of water conveyance aqueduct.%在分析宁夏引黄灌区七星渠不同建设年代和运行年限的4座渡槽管理情况的基础上,从施工质量、过流能力进行现场安全检查和质量检测,从结构稳定、结构抗震等方面进行分析核算,基于层次分析的多因素渡槽结构安全评价方法,采用专家打分和赋予权重、一票否决等机制,实现对渡槽的合理评价和有效评估。通过实测和分析核算结果,建立老旧渡槽安全性的等级标准,建立渡槽安全评价的指标体系,形成完整的渡槽安全评价体系。

  16. 桩—土—渡槽—水相互作用动力特性分析%Dynamic Characteristics Analysis of Aqueduct Structure of Pile-soil Interaction and Fluid-solid Coupling

    Institute of Scientific and Technical Information of China (English)

    王博; 申金虎; 徐建国

    2012-01-01

    At present, aseismic research of aqueduct mostly focus on the fluid-solid coupling between aqueduct and water body and gives less attention to pile-soil dynamic interaction. However, the pile-soil interaction affects the aqueduct structure response to dynamic load especially seismic load. In order to study the impact of pile-soil interaction on dynamic characteristics of aqueduct structure, the large-scale finite element software ABAQUS is used to establish three-dimensional mechanical simulation model of pile-soil-aqueduct-water by taking into account fluid-solid coupling and pile-soil interaction in middle route of South-to-North Water Diversion Project. At the same time, the natural frequencies and vibration is obtained with modal analysis under different operating conditions. Compared with the consolidation model, the results indicate that the pile-soil interaction reduces the natural frequency of aqueduct under the action of earthquake load, and it changes the dynamic characteristics of the aqueduct.%目前,对渡槽抗震性能的研究多集中在槽身与水体的流固耦合问题上,对桩土间的动力相互作用则研究较少,然而桩土相互作用会影响渡槽结构对动荷载尤其是地震荷载的反应.为探究桩土相互作用对渡槽结构动力特性的影响,采用大型有限元软件ABAQUS对南水北调中线工程双洎河渡槽建立了同时考虑流固耦合和桩土相互作用的桩—土—渡槽—水三维仿真力学模型,并进行了不同工况下的自振频率及振动模态分析.结果表明,与固结模型相比,考虑桩土相互作用的渡槽结构在地震荷载作用下自振频率减小,桩土相互作用改变了渡槽结构动力特性.

  17. Intrinsic factors determining the physical behaviour and durability ofthe Miocene sandstones used to build the Zaghouan-Carthage aqueduct (Tunis

    Directory of Open Access Journals (Sweden)

    Zoghlami, K.

    2004-12-01

    Full Text Available The present paper addresses the relationship between the intrinsic factors, physical behaviour and durability of Miocene Age sandstone used to build Tunisian Heritage Monuments, and more specifically the Zaghouan-Carthage aqueduct. A petrography study (optical microscopy and mercury intrusion porosi metry was conducted to characterize the porous system of the rock. Stone hydric behaviour was also determined by finding vacuum saturation, desorption, capillary and water vapor transmission. Finally, mechanical strength (compressive strength, abrasion resistance and durability (via accelerated sodium sulfate crystallization ageing were also found. The results obtained were indicative of good hydric performance due to the macroporous nature of the stone and the connectivity of its porous system. This rock was also found to have very low mechanical strength due to its scant lithification, making it particularly susceptible to salt weathering. It was also observed to be highly resistant to chemical alteration, given the absence of chemically unstable minerals in its composition. The durability of the material was consequently found to depend directly on the presence or absence of salts in the monument.

    En este trabajo se estudia la relación entre los factores intrínsecos, el comportamiento físico y la alterabilidad de la arenisca miocénica utilizada en el Patrimonio Monumental de Túnez, en concreto, en el acueducto romano de Zaghouan-Cartago. A partir del estudio petrográfico detallado de la roca se ha caracterizado el sistema poroso mediante microscopía y porosimetría de mercurio. También se ha caracterizado su comportamiento hídrico (absorción al vacío, desorción, capilaridad, permeabilidad al vapor de agua, se ha determinado su comportamiento mecánico (resistencia a compresión, resistencia al desgaste por rozamiento y su durabilidad mediante ensayos acelerados de cristalización de sales (sulfato de sodio. Los resultados

  18. Analysis of seismic response including pounding effect for a Large-Scale aqueduct%考虑碰撞效应的大型渡槽结构地震响应分析

    Institute of Scientific and Technical Information of China (English)

    王博; 黄亮; 徐建国; 孙丽萍; 侯玉洁

    2011-01-01

    Aiming at pounding phenomenon at expansion joints of a large-scale aqueduct during earthquakes, a dynamic analysis model considering effects of collision was presented. With time history analysis method of nonlinear seismic responses, pounding effects of adjacent girders at expansion joints on seismic responses of a large-scale aqueduct were studied, and influences of two-sided and one-sided pounding on structural responses were also investigated. The results showed that the pounding changes the response states of the aqueduct to a certain extent, the relative displacements between the girders decrease, but the huge pounding force is harmful to the safe operation of the aqueduct. The results could be a reference for seismic design of large-scale aqueducts.%针对渡槽在地震作用下伸缩缝处的碰撞现象.建立考虑碰撞效应的渡槽动力分析模型,用非线性地震反应时程分析方法,研究了纵向地震作用下的碰撞效应对于渡槽地震响应的影响,分析比较了单边碰撞与双边碰撞对渡槽地震响应的影响差异,结果表明碰撞对渡槽结构的地震响应状态有所改变,渡槽槽身间的相对位移受碰撞的影响将减小,但碰撞产生的巨大撞击力对渡槽结构有较大危害,研究结果对大型渡槽结构的抗震设计具有一定的参考价值.

  19. 预应力混凝土渡槽温度影响及设计研究%Temperature Effect on Prestressed Concrete Drainage Aqueduct and Its Design Considerations

    Institute of Scientific and Technical Information of China (English)

    李晓克; 张晓燕; 张学朋; 赵顺波

    2012-01-01

    结合南水北调中线工程左岸排水预应力混凝土渡槽结构设计,针对渡槽太阳暴晒温差变化剧烈、长年处于无水状态、洪水期过流历时短且流量变化大等特点,提出了左岸排水预应力混凝土渡槽结构的设计思路.同时根据三维有限元数值模拟计算结果,对比分析各荷载工况下渡槽的受力分布规律,进一步明确了温度效应已成为排水渡槽结构设计中不可忽略的重要因素之一,验证了渡槽设计思路的合理性、有效性.研究成果对同类结构的设计与施工具有重要的工程参考价值.%The prestressed concrete drainage aqueduct on the left bank of the Middle Route of South-to-North Water Transfer Project will have no water transferred for almost a whole year while in short flood period the flow changes greatly. It will also suffer from drastic temperature difference between the sunny side and shade side in summer. Considerations for the design of drainage aqueduct are presented, and 3-D finite element calculation is performed to comparatively analyze the stresses and displacements of the aqueduct under all load cases. It' s confirmed that temperature effect on prestressed drainage concrete aqueduct could not afford to be ignored when designing the aqueduct. This research would be referential for the design and construction of similar structures.

  20. Techniques and development trends of temperature control and crack prevention of large-scale concrete aqueducts%大型渡槽温控防裂技术及发展趋势

    Institute of Scientific and Technical Information of China (English)

    陈彦玉; 黄达海

    2011-01-01

    介绍南水北调工程大型渡槽在材料性质、结构设计、施工措施等方面温控防裂的基本经验;针对渡槽薄壁结构的特点,阐述短期温度应力和温湿耦合作用下渡槽的开裂机理;从温度监测、温度场实时仿真和预报、早龄期混凝土开裂风险预报、施工信息平台搭建、限裂设计下渡槽混凝土温控标准制定等方面探讨渡槽温控防裂的发展趋势.%The temperature control experience of large-scale concrete aqueducts in China' s South-to-North Water Diversion Project was introduced, such as material properties, structural design and construction measures. The cracking mechanism of the concrete aqueducts under short-term thermal stress and coupling of heat and moisture diffusion effect was illustrated as regards the features of the aqueduct with thin-walled structure. Finally, the development trends of temperature control and crack prevention of concrete aqueducts were discussed from the aspects of temperature monitoring, real-time temperature simulation and prediction, early-age concrete cracking risk prediction, construction information platform and temperature control standards for concrete aqueducts under crack-control design.

  1. Study on structural design and foundation treatment of Chengzi aqueduct in Maliba area%云南麻栗坝城子渡槽结构设计与基础处理研究

    Institute of Scientific and Technical Information of China (English)

    张宝琼

    2016-01-01

    云南麻栗坝城子渡槽虽然设计过流量小,但槽身长,工程地质条件复杂,易产生不均匀沉降问题。结合城子渡槽的工程地质条件和建筑物特点,对槽身的结构型式及渡槽的断面型式进行了比选,在此基础上提出了渡槽结构与基础处理设计方案。桩基试验与工程实践表明,城子渡槽采用的梁式U型结构型式、钻孔钢筋混凝土灌注桩基础方案以及跨河段采用的三连拱结构、重力墩基础方案合理可靠。%The design of Chengzi aqueduct is characterized as small flow and long aqueduct body and the problem of uneven settlement exists due to the complex engineering -geologic conditions .In combination with the engineering -geologic conditions and features of the structure , structural form of the aqueduct body and cross section forms were compared and selected , and the design of aqueduct structure and foundation treatment were studied on this basis .The pile foundation tests and engineering prac-tice indicate that it is reasonable , feasible, safe and reliable to adopting the U -shaped beam structure and reinforced concrete with filling pile foundation for the aqueduct , and 3-arched structure and gravity pier foundation scheme for the cross -river sec-tion.

  2. 大型渡槽结构随机地震反应与抗震可靠度分析%Stochastic Earthquake Response and Seismic Reliability Analysis of Large-scale Aqueduct Structures

    Institute of Scientific and Technical Information of China (English)

    刘章军; 方兴

    2012-01-01

    The method of probability density evolution was employed to research the stochastic earthquake response and seismic reliability assessment for large-scale aqueduct structure under the condition of water level fluctuation and water-aqueduct interaction. Results show that the probability distribution of stochastic seismic responses of the aqueduct structure is irregular. The stochastic earthquake response and the failure probability of large-scale aqueduct structure increase obviously with the rising of water level. However, with the water level unchanged, the seismic response is apparently smaller while the seismic reliability much higher considering the water sloshing effect on the aqueduct structure.%应用概率密度演化理论,分别研究了大型渡槽结构槽内水位变化以及水体与渡槽相互作用情况下的随机地震反应与抗震可靠度问题.分析结果表明,渡槽结构随机地震反应的概率分布呈现非规则分布,大型渡槽结构的随机地震反应与失效概率随着槽体内水位上升而显著增大.当槽体内水位一定时,考虑水体晃动对渡槽结构的影响,其地震反应却明显偏小,且抗震可靠度大幅提高.

  3. 南水北调中线湍河渡槽槽身施工方案研究%Construction scheme of Tuanhe aqueduct of Middle Route Project of South-to-North Water Diversion

    Institute of Scientific and Technical Information of China (English)

    简兴昌; 梁仁强; 杨谢芸

    2014-01-01

    To meet the design requirements of quality and construction schedule of Tuanhe aqueduct of South- to-North Wa-ter Diversion, the paper compares the construction schemes and technologies by two methods of full scaffold and aqueduct fabrica-tion machine according to engineering and structural properties of the aqueduct. With the tech-economic comparison from five aspects of construction quality, period, cost, safety and construction diversion, the optimized construction scheme by aqueduct fabrication machine with 40m width of span and 1600t weight is selected and successfully applied in engineering practice. The project was totally completed on September 28, 2013. The successful experience has significant promoting effect to the construc-tion equipment, technology and techniques of large-scale aqueducts in China.%为保证南水北调中线湍河渡槽的施工质量和工期满足设计要求,结合渡槽的工程特性及槽身结构特点,对槽身满堂支架法及造槽机法的施工方案及施工工艺进行了研究。经施工质量、工期、造价、安全、施工导流等方面的技术经济比较,优选出40 m跨1600 t重的造槽机施工方案,并成功应用于工程实践。工程于2013年9月28日完成全部施工,其成功经验,对我国大型渡槽施工设备、施工工艺、施工技术具有巨大推动作用。

  4. HHT modal parameter identification for aqueduct based on secondary filtering%基于二次滤波的HHT渡槽模态参数辨识方法

    Institute of Scientific and Technical Information of China (English)

    张建伟; 江琦; 曹克磊; 朱良欢

    2015-01-01

    In order to improve the accuracy of safe operation assessment for larger aqueduct structure, a valid Hilbert –Huang Transform (HHT) modal parameter identification method based on secondary filtering under ambient excitation was proposed. For the vibration signal of large aqueduct structure, high-frequency white noise and low-frequency noise are often mixed into structure vibration information, which belongs to non-stationary and nonlinear signal in low signal to noise ratio (SNR). Wavelet threshold method can partially filter out the high-frequency white noise, and Empirical Mode Decomposition (EMD) can be used to obtain a series of intrinsic mode functions from high frequency to low frequency. So the secondary filtering combined wavelet threshold and EMD was used to process vibration signal to achieve a higher precision and a better de-nosing effect. High-frequency white noise and low-frequency water flow noise were filtered out firstly through the secondary filtering, highlighting the useful dominant dynamic characteristics of structure, which reduced the noise interference in a certain extent and avoided the phenomenon of modal frequency mixed effectively during the later modal identification. Then structure system order was determined by theory of singular entropy increment. Finally the modal parameter of large structure was identified through HHT in combination with natural excitation technique (NExT) to process the de-noised signals, which improved accuracy and precision of modal parameter identification. Taking U-shaped aqueduct of Jintai river pumping irrigation as the research object, we collected the vibration response data under normal working condition. We then used this proposed method to identify vibration response data to achieve the modal parameter of aqueduct structure. According to fluid-solid interactions theory, the three-dimensional finite element model of a cross U-shaped aqueduct structure was constructed through finite element model

  5. Comparative Study of Layout Schemes for Suohe River Culvert Aqueduct%索河涵洞式渡槽槽身方案比选

    Institute of Scientific and Technical Information of China (English)

    王美斋; 杨顺群; 宋海印; 刘许超

    2011-01-01

    针对南水北调中线工程交叉渠系建筑物索河渡槽,充分考虑渡槽跨度大、流量大、结构复杂等特点,对比各种形式后提出矩形截面渡槽作为研究重点,并针对矩形截面,对比了双槽分缝外槽壁不加肋与双槽不分缝单隔墙两种槽身布置方案,采用大型通用计算程序ANSYS平台,开展两种方案槽身结构的三维空间有限元计算分析研究,结果表明双槽不分缝单隔墙方案具有工程量省、整体性好、整体应力变形水平较双槽分缝外槽壁不加肋方案小、拉应力满足设计要求的优点,但也具有底板端部不均匀沉降大的缺点.综合各结果,双槽不分缝单隔墙可作为南水北调中线工程索河渡槽的设计方案.%The aqueduct with rectangular cross-section was put forward as the research emphasis after comparing various forms and considering some characteristics such as the large aqueduct span, large flow and complicated structure according to SuoHe culvert aqueduct of South-to-north Water Diversion Project The scheme of dual culverts with joint without ribs and the one of dual culverts with a single wall without joint were contrasted,and the latter was chosen according to three-dimensional finite element analyses by ANSYS procedure. This scheme could save quantity and its integral performance is excellent And its integral stress and deformation level is better than the other scheme and its tensile stress meets the design requirements,but the uneven sedimentation is lager at the end of the baseplate. All in all, the scheme of dual culverts with a single wall without joint was chosen as the design scheme.

  6. 大前庭水管综合征的研究进展%Research progress in large vestibular aqueduct syndrome

    Institute of Scientific and Technical Information of China (English)

    王国鹏; 龚树生

    2006-01-01

    大前庭水管综合征(large vestibular aqueduct syndrome,LVAS),又称先天性前庭水管扩大,由Valvassori等”0于1978年首先描述并正式命名。Okumura等进一步将其分为合并耳蜗畸形(如Mondini畸形)与不合并耳蜗畸形两个亚型,但前者不列入LVAS的范畴。随着影像学和分子生物学的发展,对LVAS的研究也逐渐深入。我们就LVAS的病因与发病机制、SLC26A4基因突变与LVAS、临床表现、诊断、预防与治疗作一综述。

  7. 漕河渡槽钻孔灌注桩施工及处理措施%Construction and Treatment Measures of Bored Pile in Caohe River Aqueduct

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    There are 608 bored concrete piles (1.5 meter in the diameter) in Caohe aqueduct, the problems are inevitable in the construction, such as hole wall collapse, pipe blockage and steel reinforcement cage floating,etc. The article collects the problems often encountered in the construction of the pile foundation, and puts forward the preventive measures.%  中漕河渡槽共计采用608根直径1.5m混凝土灌注桩,施工过程中曾发生孔壁坍塌、导管堵塞、钢筋笼上浮等问题,本文对发生的问题和处理方法进行了汇总,提出了预防措施。

  8. 渡槽下部结构改造置换设计与施工%Restructuring design and construction of substructure of aqueduct

    Institute of Scientific and Technical Information of China (English)

    王聪; 尤岭; 朱克兆; 史召锋

    2014-01-01

    在南水北调中线某跨渠排水渡槽施工中,由于柱墩阻水情况不满足设计要求,需对下部结构进行改造,以减少阻水影响。介绍了将该渡槽柱墩改造为板式墩的设计和施工方案,及下部结构的受力分析过程。改造中,在不中断已建渡槽使用的前提下,完成原有盖梁受力体系的转换和板墩置换,同时对盖梁进行了截面增大的改造。对类似工期紧张、空间受限的下部结构改造工程具有借鉴意义。%Substructure of a drainage aqueduct crossing main canal of South-to-North Water Diversion Project was needed to be reconstructed due to excessive water-resistance effect, the restructuring design solution that substitutes plate-piers for col-umn-piers as well as the construction scheme are presented. In the construction, the plate-piers were substituted and the sec-tion of bent cap was enlarged, so the former force system was transferred while the aqueduct functioned well. The force analysis for the restructuring process is carried out, which provides valuable references for other substructure restructuring construction characterized as limited construction schedule and restrained construction clearance.

  9. 黔中杨家坝大跨度预应力渡槽侧向稳定有限元分析%FEM Analysis of the Lateral Stability of the Large-span Prestressed Aqueduct in Yangjiaba

    Institute of Scientific and Technical Information of China (English)

    杜晶; 段亚辉

    2011-01-01

    Yangjiaba aqueduct is a part of Guizhou Water Control Project whose single span is as long as 50m,it is a large-span pre-stressed aqueduct.Affected by wind loads,lateral stability is an important index relating to the safety of buildings.ANSYS is used to simulate foundation conditions and aqueduct under complex load to check the whole aqueduct's lateral stability,including the shear-slip stability between the aqueduct body and bearing,the anti-skidding stability between the whole aqueduct and the foundation,and the bearing capacity of foundation soil.The results show that the lateral stability and the bearing capacity of foundation soil can satisfy the requirements,which serves as an important reference for the design of large-span pre-stressed aqueduct inYangjiaba.%黔中水利枢纽一期输配水工程杨家坝渡槽单孔跨度50m,是国内最大跨度的渡槽。在风荷载等作用下的侧向稳定是关系到建筑物安全的重要指标。采用ANSYS有限元软件模拟地基条件和渡槽在复杂荷载作用下的工作情况,进行了渡槽整体侧向稳定验算,包括槽身在槽墩支座的剪切滑移稳定性和渡槽整体沿基础面的抗滑稳定性以及地基承载力。结果表明,渡槽的整体侧向稳定和地基承载力均满足要求,为杨家坝大跨度预应力渡槽经济安全设计提供了重要参考。

  10. Research on design and dynamic performance of high damping rubber isolated aqueduct%高阻尼橡胶隔震渡槽的设计和动力性能研究

    Institute of Scientific and Technical Information of China (English)

    丁晓唐; 周逸仁; 颜云燕

    2013-01-01

    以南水北调工程为背景,运用高阻尼橡胶隔震技术,并借鉴建筑与桥梁相关规范及设计经验对某渡槽进行隔震设计.采用Housner模型建立渡槽流固耦合有限元动力模型,分析隔震渡槽的的动力特性和地震响应.结果表明:隔震后结构前三阶振型均为隔震振型;采用高阻尼橡胶支座隔震和铅芯橡胶支座隔震渡槽的结构振型一致,自振频率基本相同;地震动特性对地震响应结果影响很大,当地震波特征频率与结构基频越相近时,槽身和支座响应越大,采用隔震支座效果越明显;三向地震动输入下,隔震渡槽各部位响应峰值可供设计时参考.%Based on the background of the south - to - north water diversion project, the high damping rubber isolation technology was used for the isolation design of the aqueduct, the codes and design experiences of building and bridge were refered. A finite element dynamic model of the aqueduct is established , in which the fluid - structure coupling was considered by Housner model, witch was used to analyze the dynamic characteristic and seismic response of isolated aqueduct. The results show that the first three vibration modes of the isolated structure are the isolation vibration. The structural vibration modes of the high damping rubber isolated and the lead - core rubber isolated aqueduct are the same, and their natural frequencies are basically the same. The seismic characteristics of the ground motion exert a great influence on seismic response. The closer the characteristic frequency of seismic wave gets to the fundamental frequency of the structure, the greater the response of the aqueduct body and support will be, and the more obvious effects the isolation bearings will have. Under three - direction ground motion input, the peak responses of isolated aqueduct can be refered in design .

  11. 排架渡槽-水流固耦合体隔震分析%Analysis of isolation of fluid-structure interaction system for bent-type aqueduct

    Institute of Scientific and Technical Information of China (English)

    刘亮; 张华

    2012-01-01

    Based on bent-type aqueduct structures, dynamic characteristics and isolation of aqueduct-water coupling systems were studied by using the Arbitrary Lagrangian-Eulerian (ALE) method. Three-dimensional model with fluid-structure interaction was established, and the plate rubber support was installed. Mooney-Rivlin strain energy density model simulated mechanical constitutive relations of rubber material. The natural vibration frequency, displacement, stress of aqueduct structure, and the water sloshing height were calculated in different water depth conditions under earthquake wave action. The results show that the transverse stiffness is less. The application of isolation technology can reduce stiffness of aqueduct structure and extend natural vibration period of aqueduct structure. The fluid-structure interaction increases stress of the internal wall under earthquake wave action. The seismic displacement response of aqueduct structure and the water sloshing height increase by applying the isolation technology, but the application of isolation technology remarkably reduces the seismic stress response and elevates earthquake resistance performance.%以排架渡槽为研究对象,建立3维渡槽-水流固耦合体计算模型,设置板式橡胶隔震支座,通过Mooney-Rivlin应变能密度函数模型模拟橡胶材料的本构,采用任意拉格朗日-欧拉(ALE)方法求解渡槽和水体间的耦合动力作用问题,针对不同水深工况,计算分析渡槽-水流固耦合体自振频率以及在地震作用下的位移、应力和水体晃动波高.研究结果表明:渡槽横槽方向为结构刚度最小方向,隔震支座的设置降低了渡槽结构的刚度,延长结构的自振周期;在地震作用下,槽体与水体间的流固耦合作用使得槽身内壁两侧的应力较大;隔震支座的设置增大渡槽结构的位移响应以及槽内水体晃动的幅度,但有效降低渡槽各部位的应力响应,提高渡槽结构的抗震性能.

  12. 矩形渡槽流固耦合体系风致的动力性能%Wind-induced vibration of fluid-structure interaction system for rectangular aqueduct

    Institute of Scientific and Technical Information of China (English)

    刘亮; 张华; 郜余伟

    2012-01-01

    Based on rectangular aqueduct structures, the wind response of aqueduct-water coupling systems was studied by using the arbitrary Lagrangian-Eulerian (ALE) method. Three-dimensional model with fluid-structure interaction was established. The fluctuating wind speed time series was simulated with resorting to auto-regressive moving average (ARMA) model. The transversal displacement, the dynamic water pressure and the upsetting moment of aqueduct with different depth-width ratios were calculated in different water depth conditions under stochastic wind loads. The results show that the changing regularity of the wind-induced dynamic responses of aqueduct-water coupling systems with the change of water-depth is similar. The change of depth-width ratio greatly affects the vibration and stability of aqueduct in the same water condition, which should be paid more attention to in the wind-resistant design of aqueduct structure.%以排架矩形渡槽为研究对象,建立三维渡槽水流固耦合计算模型,通过自回归滑动平均(ARMA)模型模拟脉动风,采用任意拉格朗日-欧拉(ALE)方法求解渡槽和水体的耦合相互作用问题,针对不同水深工况、不同渡槽截面高宽比,计算分析渡槽流固耦合体系在风荷载随机动力作用下的横向位移、倾覆力矩及动水压力.研究结果表明:不同高宽比的渡槽随着槽内水深的变化,其流固耦合体系风致动力性能的变化规律性相近;在等流量水深工况下,截面高宽比的变化对渡槽结构的振动和稳定性有显著影响,在渡槽抗风设计中应予以重视.

  13. 基于有限元法的渡槽排架结构性态分析%Structural Behavior Analysis of the Bent Structure of Aqueduct Based on Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    张茂林; 常周梅; 谢利云; 刘辉

    2014-01-01

    针对我国西北寒旱灌区的渡槽基础和排架易在高矿化度地下水侵蚀和冻融交替作用下出现建筑物结构稳定性和整体性态衰退的问题,采用大型数值分析软件ANSYS对受侵蚀前后渡槽排架的结构进行了计算和分析,探索渡槽在不同工况下的应力和变形规律。分析结果表明:在只有竖向荷载的情况下,侵蚀前后渡槽结构变形分布规律基本相同。x向位移最大值均出现在渡槽两端上部区域,y向变形以跨中区域最为明显,z向以渡槽排架的顶部附近变形最为明显。%The large-scale numerical analyze software ANSYS was used to calculate and analyze the aqueduct bent structures before and after the erosion,and the law of stress and deformation were obtained for aqueduct under the different conditions,which aimed at the problem of a large pile of salt were stranded and gathered in land caused by surface irrigation and alternate freezing and thawing,which resulted in erosion and destruction of the building structure and its basic structure. The analysis results show that:the law of deformation distribution of aqueduct structure is basically the same before and after the erosion only under the condition of gravity. The maximum displacement in x appears in the upper area on both ends of the aqueduct. The most obvious deformation area in y is across the central,and the most obvious deformation area in z is near the top of aqueduct bent. The analysis results can provide the theory basis for further research of the bent structure of aqueduct in the irrigation area.

  14. 渡槽支撑框架在罕遇地震下的非线性时程分析%Analysis on nonlinear time history of aqueduct support frames under rare earthquake

    Institute of Scientific and Technical Information of China (English)

    章梁; 程震宇; 张爱晖

    2012-01-01

    This paper made elastic-plastic dynamic time history analysis on a typical aqueduct support frames structure using section fiber model to south-to-north water transfer middle route project. The analysis results showed that, under rare earthquake this aqueduct had no obvious weak parts, the maximum displacement angle within the specified value, had a good seismic performance.%采用截面纤维模型对南水北调中线工程中的某典型渡槽的支撑框架结构进行了罕遇地震作用下的弹塑性动力时程分析,分析结果表明,该渡槽在罕遇地震作用下,没有明显的薄弱部位,最大层间位移角在限值以内,具有良好的抗震性能。

  15. Design and construction research for Tuanhe aqueduct of Middle Route Project of South-to-North Water Diversion%南水北调中线湍河渡槽设计与施工研究

    Institute of Scientific and Technical Information of China (English)

    郑光俊; 吕国梁; 张传健; 夏国柱

    2014-01-01

    The Tuanhe aqueduct is a key controlling project in Middle Route Project of South-to-North Water Diversion. According to its characters of long distance and large flow, the engineers firstly determine its length, layout and span, then the structural formation of double pre-stressed beam aqueduct is proposed. The structural calculation results and 1:1 model test process are presented in detail. The results show that mechanics calculation method adopted is basically correct and the calcula-tion results are in agreement with the model test, in which the aqueduct body is in compression state in general and in good work-ing situation. Finally, the construction scheme and layout using aqueduct fabrication machine is presented.%湍河渡槽是南水北调中线关键控制性工程之一,针对其长度大、流量大的特点,设计首先确定了槽身布置方式、渡槽长度及跨度,然后选定了双向预应力梁式渡槽为其结构形式。详述了渡槽结构计算分析结果和1∶1模型试验过程。分析表明,渡槽结构的计算方法选用基本正确,其计算结果与模型试验结果基本一致,槽身基本处于全受压状态,工作状态良好。介绍了造槽机的施工方案及布置情况。

  16. Model test of TLD effect on aqueduct structure subjected to strong vibration%强震作用下渡槽 TLD 效应模型试验研究

    Institute of Scientific and Technical Information of China (English)

    黄研昕; 钱向东

    2014-01-01

    通过对矩形截面渡槽的单跨模型进行动力试验研究,探讨了渡槽在刚性地基强震条件下的调谐液体阻尼器(TLD)效应;通过调节槽内水位,研究了水体横向减震作用与深宽比的关系。试验结果表明,水体的晃动及水波破碎对渡槽的横向动力响应起到了 TLD 减震作用。渡槽内水位增加会改变结构的动力特性,使渡槽结构自振频率下降。在强震作用下,TLD 横向减震效果随水位变化发生波动,当槽内水体晃动频率与渡槽结构自振频率接近时,减震作用最为显著。%Based on tests of a rectangular one-span simply supported aqueduct, the tuned liquid damper (TLD) effect on the aqueduct under the condition of a rigid foundation subjected to strong vibration was analyzed. The relationship between the transverse damping effect and the ratio of depth to width were studied by adjusting the water level. The test results demonstrated that water sloshing and wave breaking had a TLD effect on the aqueduct structure; the increase of the water level in the aqueduct changed the dynamic properties of the structure, causing the self-vibration frequency of the structure to decrease; during strong vibration, the TLD effect fluctuated with the change of water level; and the most significant TLD effect occurred when the water sloshing frequency was close to the self-vibration frequency of the structure.

  17. Design of flood discharge aqueduct of Beipai River of Middle Route Project of South-to-North Water Diversion%南水北调中线工程北排河排洪渡槽设计

    Institute of Scientific and Technical Information of China (English)

    张大勇; 陈璐; 闫海青

    2014-01-01

    According to the characteristics of flood discharge aqueduct of Beipai River of Middle Route Project of South-to-North Water Diversion, including large design discharge, high grade of loads and strict requirements for construction, we have studied the loading features of the upper and lower parts of the aqueduct, and compared the construction difficulty and schedule, the pre-stressed concrete simple supported beam scheme is adopted for the upper structure, which is a single trough in a single line. With consideration of the geological conditions of the engineering area, columnar pier was selected as lower pier of the aque-duct, and rock-socketed pile is designed as the foundation of the pier. Through analysis and calculation aiming at 3 basic cases of the aqueduct, the results meet the requirements and specifications.%针对南水北调中线一期工程北排河排洪渡槽设计流量大、荷载大、施工技术要求高等特点,通过对渡槽上、下部结构形式的受力特性、施工难度、工期等研究比选,确定了渡槽上部结构采用预应力混凝土简支梁方案,并且按单线单槽布置;在考虑了渡槽工程区地形地质条件后,渡槽下部墩身采用桩柱式桥墩,桩基础按嵌岩柱进行设计。经对北排河排洪渡槽3种基本工况进行分析计算,证明其结果满足规范要求。

  18. 杨家坝渡槽预应力合理张拉时机研究%Research on the Reasonable Stretching Time Prestress Tensioning of the Yangjiaba Aqueduct

    Institute of Scientific and Technical Information of China (English)

    万晓光; 段亚辉

    2011-01-01

    大跨度预应力渡槽在跨年度的施工中,选择在不同的季节进行预应力的张拉,对渡槽结构的稳定产生较大的影响,故对渡槽进行预应力合理张拉时机的研究是重要的。以杨家坝渡槽为计算对象,采用有限元法,通过仿真计算,比较分析了渡槽在不同季节的温度条件下,渡槽结构的应力及位移的变化情况,表明杨家坝渡槽在月平均气温10℃时张拉预应力,可以适当避免渡槽应力以及位移出现过大的情况,并可为同类工程提供参考。%The large-span prestressed aqueduct selects different seasons to stretch the prestressed strand in the year-extending construction,it has an important effect on the stability of the structures of aqueducts.Based on the Yangjiaba Dam and through simulation calculation of FEM,the change of stress and displacement of the aqueduct structures is compared and analyzed at different temperatures and different times,and the result indicates that the time of a monthly mean temperature of 10 degrees will be a reasonable time to do prestress tensioning,this can avoid the situation of the oversize stress and displacement of the aqueduct,which serves as a reference for similar projects.

  19. Analysis on Key Points for Supervision Quality Control of Aqueduct Construction, Pengshui Hydropower Project%浅析重庆彭水水电站渡槽施工监理质量控制要点

    Institute of Scientific and Technical Information of China (English)

    董团结

    2014-01-01

    渡槽上连明渠段,下接升船机,是彭水水电站通航建筑物的重要组成部分。通过参建各方努力,在监理工程师有效的质量控制下,克服了单根箱梁体型较大、结构复杂、质量要求高、安装困难、安全问题突出。安全、顺利的完成了渡槽箱梁的预制、安装、铺装层钢纤维混凝土浇筑等施工。整个渡槽施工质量良好,投入使用后,运行正常,达到了各项设计要求。%The aqueduct, which is connected the open canal at upstream and lift lock at downstream, is one important component of the navigation structures of Pengshui Hydropower Project.With the effective quality control by the Supervision Engineer, difficulties in terms of large box girder, complicated structure, high quality requirement and outstanding safety factors are overcome.The aqueduct box girder is smoothly precast , installed and steel-fiber concreted .The quality-secured construction of the aqueduct satisfies design requirements and assures its normal operation after being put into service.

  20. A Thermal Stress Finite Element Analysis of Pre-stressed Rectangle Aqueduct%预应力矩形渡槽温度应力有限元分析

    Institute of Scientific and Technical Information of China (English)

    任德记; 张超; 王刚; 郑重阳

    2011-01-01

    Taking the JIHE aqueduct for example. Using three-dimensional finite element method of the prestressed concrete rectangle aqueduct stress behavior of numerical simulation. Especially concern about the influence of temperature load and pre-stress on aq- ueduct. The thermal stress coupling adopt order coupling method to realize. The calculation results show that: the aqueduct internal force and steel bars are reasonable, distribution of stress can meet the requirements of specification, the concrete temperature load of groove body stress has greater influence.%结合南水北调沸河渡槽工程实例。通过运用三维有限单元法对预应力混凝土矩形渡槽的受力性能进行数值模拟。重点分析预应力和温度荷载对渡槽应力的影响。热应力耦合采用顺序耦合法来实现。计算结果表明:渡槽内力及预应力配筋分布合理,混凝土应力满足规范要求,温度荷载对槽身应力有较大影响。

  1. 基于深水波理论的渡槽动力响应分新%A Dynamic Response Analysis of Aqueduct Based on Theories of Deep Water Waves

    Institute of Scientific and Technical Information of China (English)

    周洪涛; 彭刚; 胡海蛟; 贺誉

    2012-01-01

    Based on the theory of fluid dynamics, the calculation formulas for the wave height and hydrodynamic pressure in aqueduct structures are derived on theories of deep water waves. Implementation method is given in the finite element analysis software AN- SYS. The dynamic response analysis has been finished on four kinds of working conditions in aqueduct structures. The results show that the damping effect of water wave has a great effect on the dynamic response of aqueduct structure.%以流体动力学理论为基础,推导了深水波理论模型在渡槽结构中的波高与动水压力的计算公式,给出了在ANSYS有限元软件中的实现方法,并对渡槽的4种工况进行了动力响应分析。结果表明,考虑液体晃动的阻尼效应对渡槽的动力响应影响较大。

  2. Dynamic Characteristics Analysis of Double-channel Aqueduct with FEM in the South-to-North Water Diversion Project%南水北调双槽渡槽结构动力特性有限元分析

    Institute of Scientific and Technical Information of China (English)

    徐建国; 张威; 王博; 陈淮

    2011-01-01

    In order to study dynamic characteristics of the large-scale double-channel aqueduct, the spatial finite clement analysis model of the Laozhangzhuang aqueduct in middle route of the South-ro-North Water Diversion Project is established with software SAP2000. The modal analysis method is applied to calculate the frequency and modal of the first 12 steps for two cases, which includes conditions of design depth of three meters and without water. The whole process and the results achieve the desired effect. which provides reference basis for the large-scale double-channel aqueduct seismic analysis.%为研究大型双槽渡槽的动力特性,采用通用有限元软件SAP2000对南水北调中线工程中的老张庄渡槽整体结构建立空间有限元分析模型,采用模态分析方法分析计算了渡槽墩体前12阶的自振频率与振动模态,得到了渡槽在3 m设计水深和无水2种工况下的振动特性,整个过程和结果均达到了预期效果,为大型双槽渡槽结构的抗震分析提供了参考依据.

  3. Three-Dimensional Finite Element seismic Analysis of Open spandrel Truss Arch Type Prestressed Aqueduct%下承式桁架拱渡槽三维有限元抗震分析

    Institute of Scientific and Technical Information of China (English)

    裴敬垚; 孙建生; 蔺彬彬; 樊盼

    2014-01-01

    In this paper,a water diversion project that with open spandrel truss arch type pre-stressed aqueduct of structure was designed under seismic by using ANSYS software in Shanxi Province,established the finite element analysis model of the spatial entities,then determining the structural natural frequency and mode shapes through the modal analysis,solved the seismic response of the aqueduct by mode-superposition re-sponse spectrum method,and achieved each component’s control section of the aqueduct equivalent and internal force with static and dynamic characteristics,providing a reliable basis for the seismic design of the project.%结合山西省某引水工程下承式桁架拱渡槽结构抗震设计,采用 ANSYS 软件,建立空间实体有限元分析模型,通过模态分析确定结构固有频率及其振型,由振型分解反应谱原理,求解渡槽整体结构的空间地震响应,并利用渡槽结构的静、动力特性,获得了渡槽各构件控制截面的等效内力,为工程抗震设计提供了可靠依据。

  4. Research on the Reliability of Aqueducts Based on Fuzzy Comprehensive Evaluation and Variable Weight Method%基于模糊变权法的渡槽可靠性评估的研究

    Institute of Scientific and Technical Information of China (English)

    夏富洲; 陈栋梁; 刘富奎

    2012-01-01

    A fuzzy comprehensive evaluation of the reliability of aqueducts based on variable weight method is presented. The criterion of the evaluation is given on the basis of the profound research on the definition and factors of aqueducts reliability evaluation; from which the index system of the evaluation is constructed and the hierarchical structure and the evaluation model are established. The fuzzy synthetic evaluation based on variable weight method is introduced into the reliability evaluation of aqueducts, which can be more efficient in improving evaluation.%提出了基于变权理论和模糊综合评估的渡槽可靠性评估方法。在研究渡槽可靠性的定义及影响因素的基础上,给出渡槽可靠性评估准则,并构造渡槽可靠性评估指标体系,建立了渡槽可靠性评估模型。在渡槽可靠性评估中引入模糊变权法,可以更加有效地提高其评估质量。

  5. Research on Shahe Culvert Aqueduct Structure Design of the Middle Route of South-to-North Water Transfer%沙河箱基渡槽结构设计研究

    Institute of Scientific and Technical Information of China (English)

    王彩玲

    2011-01-01

    南水北调中线沙河箱基渡槽过流量大、结构尺寸大、形式复杂,进行结构设计时必须考虑渡槽的空间整体性及槽身与涵洞之间的相互作用.结合有限元仿真分析,研究沙河箱基渡槽结构设计中需要解决的若干问题,提出相应的设计模式,为以后类似工程的设计提供借鉴.%Shahe box basic aqueduct in South-to-North Water Transfer Project is over-flooded and has large structure size and complex form.When designing the structure, we must consider the space integrity and the interaction between the aqueduct and culverts.This study combines finite element simulation, discusses some problems to be solved in the structure design of Shahe box basic aqueduct, puts forward corresponding design patterns, and serves as a reference for the future design and construction of similar projects.

  6. 预制装配式渡槽型农渠设计理念及实用性探究%A Probe into the Design Idea and Availability of Pre-installed Aqueduct Field Lateral

    Institute of Scientific and Technical Information of China (English)

    李存云; 王红雨; 王小东; 李晓峰

    2015-01-01

    Combined with the features of beamed aqueduct ,the type of aqueduct field lateral with pre-installed as a new design idea which adopts the flexible tenon joint structure and pier connecting in longitudinal was put forward in view of the fill-lined field lateral encountered some problems in process of constructing and operating .The structure form and detail of construction of aqueduct field lateral were introduced in this paper .And the key points of design and construction were explored at same time .The pre-installed aqueduct field lateral was compared with fill-lined field lateral including the function ,seepage-proofing effect and economical availa‐bility .The results show that the pre-installed aqueduct field lateral is smaller than the conventional filled channel in land and earth volume and the frost resistance will be improved evidently .In addition ,the cost is lower than the fill-lined field lateral when the in‐stallation cost will not be considered .%针对填方衬砌农渠在施工与运行过程中存在的问题,结合梁式渡槽的功能特性,提出了运用柔性榫结构及连接支墩实现纵向铰接式连接的预制装配式渡槽型农渠的新设计理念。详细介绍了渡槽型农渠的结构形式及细部构造,同时探讨了其设计和施工要点。通过预制装配式渡槽型农渠与填方衬砌农渠在功能、防渗效果及经济技术等方面的对比分析,得出渡槽型农渠占地面积及填筑渠道土方量较少,抗冻胀能力较高,在不考虑现场装配费用时其造价低于填方衬砌农渠。

  7. The evaluation of 3D-CISS sequence in diagnosis of midbrain aqueduct obstruction%磁共振3D-CISS 序列在中脑导水管梗阻诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    付汪星; 车英玉; 程敬亮

    2014-01-01

    目的:探讨磁共振3D-CISS 序列在中脑导水管梗阻诊断中的应用价值。方法利用3.0T 超导 MR 扫描仪对46例中脑导水管梗阻患者脑部进行 FLASH T1 WI、TSE T2 WI 和3D-CISS 序列扫描,并对3D-CISS 序列原始图像进行重建,观察3种序列对中脑导水管结构的显示情况,进行对比分析。结果 FLASH T1 WI、TSE T2 WI 及3D-CISS 序列对中脑导水管梗阻病变显示率分别为13%、71.7%、100%。3种序列两两对比均有显著差异(P <0.0167)。结论3D-CISS 序列在显示中脑导水管梗阻病变方面较常规序列存在优势。%Objective To explore the value of three-dimensional constructive inference in steady state sequence (3D-CISS se-quence)in case of midbrain aqueduct obstruction.Methods 46 cases with midbrain aqueduct obstruction were scanned with FLASH T1 WI、TSE T2 WI and 3D-CISS sequence at 3.0T superconductive MR scanner.The original images of the 3D-CISS sequence were reconstructed.The images of three sequences showing midbrain aqueduct obstruction were observed and analyzed.Results The de-tection rate of the midbrain aqueduct obstruction was 13% 、71.7% and 100% in FLASH T1 WI、TSE T2 WI and 3D-CISS sequence, respectively.The difference between the three sequences were significant (P <0.01 67).Conclusion 3D-CISS sequence shows mid-brain aqueduct obstruction more accurately.

  8. Climate Change Impacts on the Los Angeles Aqueducts Water Sources: 21st Century Hydrologic Projections for Owens Valley and Mono Lake Watershed

    Science.gov (United States)

    Costa-Cabral, M. C.; Roy, S. B.; Maurer, E. P.; Mills, W. B.; Chen, L.

    2011-12-01

    Precipitation from the Eastern Sierra Nevada watersheds of Owens Lake and Mono Lake is one of the main water sources, and the one of highest quality, for Los Angeles' more than 4 million people. Winter snow is stored in the large snowpack reservoir, and meltwater (~0.2-0.5 million acre-feet) is delivered annually to the city in the dry season by the 340-mile long Los Angeles Aqueduct system, operated by the Los Angeles Department of Water and Power. We identify plausible scenarios of future climate conditions in the Owens-Mono watersheds over the 21st century based on CMIP3 results for 16 global climate models (GCMs) statistically downscaled to 1/8° and greenhouse gas emission scenarios A2 and B1; and we evaluate the consequent hydrologic impacts using the Variable Infiltration Capacity (VIC) hydrologic model. Such climate scenarios have large and unquantifiable associated uncertainty and do not represent predictions, but are considered to be plausible under the current state of knowledge. We applied VIC to the Owens-Mono watersheds and calibrated the model using monthly streamflow records provided by LADWP. Of most interest to Los Angeles' water supply are the projections for the snowpack and the dry-season hydrograph that relies on snowmelt. Our results indicate future increases in the fraction of precipitation falling as rain rather than snow, from a historical value of about 20% to 20-30% by mid-century and 28-52% by end of century (depending on the GCM) for scenario A2. As a result, the snowpack's peak snow water equivalent (SWE) is projected to decline by most GCMs. The SWE peak is also projected to shift toward earlier dates (by a few days by mid-century and by a GCM-average of 2 weeks by end of century under emissions scenario A2). The diminished SWE, earlier SWE peak and earlier melt associated with rising temperatures result in earlier hydrograph peaks, a shift in the date marking the passage of half of the year's hydrograph volume (by more than one

  9. Research on Sequence of Prestressing Tension in Aqueduct Based on Characteristic Parameters%基于特征参量控制的渡槽预应力张拉顺序研究

    Institute of Scientific and Technical Information of China (English)

    吴泽玉; 王东炜

    2015-01-01

    为了得到合理预应力张拉顺序,提出利用特征参量指导预应力张拉的新途径。分别对矩形带肋和无肋渡槽及 U 形渡槽动力特性进行分析。结果表明:对于 U 形渡槽,竖向预应力和环向预应力明显降低结构整体刚度,但预应力效应并不改变振型出现的先后顺序;通过对矩形无肋渡槽6种预应力张拉顺序进行分析,得到合理的预应力张拉顺序为:先张拉40%纵向预应力,再张拉竖向预应力,然后张拉剩余的60%纵向预应力,最后张拉横向预应力。矩形无肋渡槽的这种张拉顺序不仅避免了竖向预应力对结构整体刚度的过大影响,而且能抵消结构早期由于自重产生的不利挠度。研究的渡槽预应力张拉顺序对构件力学性能改变的影响可降低到最小。%In order to obtain reasonable sequence of prestressing tension,we put forward a new way by using charac-teristic parameters to guide prestressing tension.Dynamic characteristics of rectangular aqueducts with rib and with-out rib,and U-shape aqueduct are respectively analyzed.The results show that,as for U-shape aqueduct,the vertical prestress and the circumferential prestress can obviously reduce the overall stiffness of the structure,but the pres-tressing effect does not change the order of mode of vibration.Through analyzing 6 kinds of sequence of prestressing tension for rectangular aqueduct without rib,we obtain a reasonable sequence:Firstly,prestress in the longitudinal direction is tensioned up to 40% of the maximum.Secondly,we tension the prestress in the vertical direction.Then, the rest of prestress in the longitudinal direction is tensioned.Finally,we tension the prestress in the transverse di-rection.This sequence of prestressing tension of rectangular aqueduct without rib can not only avoid the excessive influence of vertical prestress on the overall rigidity of the aqueduct,but also counteract the negative deflection

  10. 基于概率密度演化的渡槽结构抗震分析%Seismic Analysis of Large-scale Aqueduct Structures Based on the Probability Density Evolution Method

    Institute of Scientific and Technical Information of China (English)

    曾波; 邢彦富; 刘章军

    2014-01-01

    Using the orthogonal expansion method of random processes,the non-stationary seismic acceleration process is represented as a linear combination of the standard orthogonal basis func-tions and the standard orthogonal random variables.Then,using the random function,these stand-ard orthogonal random variables in the orthogonal expansion are expressed as an orthogonal func-tion form of the basic random variable.Therefore,this method can use a basic random variable to express the original earthquake ground processes.The orthogonal expansion-random function ap-proach was used to generate 126 representative earthquake samples,and each representative sam-ple was assigned a given probability.The 126 representative earthquake samples were combined with the probability density evolution method of stochastic dynamical systems and random seis-mic responses of large-scale aqueduct structures was investigated.In this study,four cases were considered;aqueduct without water,aqueduct with water in the central trough,aqueduct with wa-ter in a two-side trough,and aqueduct with water in three troughs,and probability information of seismic responses for these cases were obtained.Moreover,using the proposed method,the seis-mic reliability of the aqueduct structures was efficiently calculated.This method provides a new and effective means for precise seismic analysis of large-scale aqueduct structures.%应用随机过程的正交展开方法,将地震动加速度过程展开为标准正交基函数与标准正交随机变量的线性组合形式。在此基础上采用随机函数的思想,将正交展开式中的标准正交随机变量表达为基本随机变量的函数形式,从而实现用一个基本随机变量来表达原地震动过程的目的。结合地震动过程的正交展开-随机函数模型与概率密度演化方法,对某大型渡槽结构进行随机地震反应分析与抗震可靠度计算;重点研究空槽和三槽有水等四种工况下渡槽结构

  11. 大流量薄壁渡槽槽身张拉工艺仿真研究%Simulation of Tension Process for High-flow and Thin-wailed Aqueduct

    Institute of Scientific and Technical Information of China (English)

    张利; 王玉华; 王彩玲; 张玉明

    2011-01-01

    沙河渡槽工程是南水北调中线的主要控制性工程,渡槽槽身为预应力钢筋混凝土梁式结构,单跨30 m,槽身U型,直径8m,槽身壁厚35 cm,共228榀槽.槽身纵向预应力钢绞线27束,采用两端同时施加预应力方式,环向预应力初步设计119束,张拉施工量大,按老的张拉方法,待张拉全部完成后再将槽身起吊、移动,占用预制台座的时间长,必将严重制约槽身预制的施工进度,进而会影响整个渡槽工程的完工时间.研究项目通过建立张拉仿真模型,对渡槽预应力钢绞线的张拉施工顺序产生的应力场进行仿真研究分析,优化了环向预应力筋布置,优选出合适的张拉次序,采用分级、分步张拉方式,减少张拉工艺占用台座的时间,将大量张拉工作量放在存槽台座上完成,提高了预制效率及预制进度.%Shahe aqueduct is the main controlling project of the Middle Route of South-to-North Water Diversion Project. The aqueduct is the structure of prestressed reinforced concrete beam with single span of 30 m, U-typed body, diameter of 8m, wall thickness of 35cm, and 225 pieces of aqueduct body. There are 27 longitudinal prestressed steel strands within the aqueduct body, and the pre-stress shall be applied together at both ends. The aqueduct body has 119 circumferential pretressed steel strands in the preliminary design,and the tension work is heavy. According to the traditional tension method, the aqueduct could only be lifted and moved after the tension, which will take more time on precast pedestal,severely restricts the precast progress, and also affects the total completion time of the aqueduct The current research project has built a simulation model of tension to simulate and analyze the stress field caused by the tension of pretressed steel strand, to optimize the layout of circumferential prestressed reinforcement as well as the suitable tension order. The tension by grade and step by step could shorten

  12. Study on Technology for Concrete Placement of U-type Aqueduct over Shahe River, South-to-North Water Diversion Project%南水北调沙河U形渡槽混凝土浇筑施工技术研究

    Institute of Scientific and Technical Information of China (English)

    孟庆荣; 路明旭

    2013-01-01

    介绍了南水北调中线沙河Ⅰ标预制渡槽混凝土浇筑施工技术。大型预制渡槽混凝土的浇筑质量是整个渡槽预制的核心部分,渡槽预制质量的优劣直接关系到整套预制工艺的合理性,经过认真分析、现场试验、多次总结、专家咨询等多种途径优化渡槽浇筑工艺。%In this paper, technology for concrete placement of the precast aqueduct, Lot 1, the middle line of south-to north water diver-sion project , is described .The concrete placement quality of the large precast aqueduct is the core of the whole aqueduct precast .The quality of the precast aqueduct is related to the seasonality of the complete precast technology.In this project, the technology for the aq-ueduct concrete placement is optimized through a couple of manners such as careful analysis, site test, summaries and consultation, etc.

  13. Effects of hazardous pollutants on the walls of Valence Aqueduct (Istanbul) by Raman spectroscopy, SEM-EDX and Geographical Information System.

    Science.gov (United States)

    Unsalan, O; Kuzucuoglu, A H

    2016-01-01

    This study involves Raman spectroscopic (176-2900cm(-1)), SEM-EDX and Geographical Information System studies of the pollutants on the walls of Valence Aqueduct (Bozdoğan Kemeri), Istanbul, Turkey. Raman spectroscopy is a useful analytical method in characterization of painting materials and corrosion products. Especially, when it is not possible to take the samples from the place they exist, handheld Raman spectrometers play an important role to identify the materials in these samples. Furthermore, more information could be gathered when it is combined with SEM-EDX studies. On the other hand, regarding the cultural heritage, it is crucial to determine precise coordinates of the historical peninsula and the samples which have been exposed to pollutants, by Geographical Information Systems in order to study them and take precautions for the future. Handheld Raman spectrometer (NanoRam by B&WTek) allows recording of acceptable and good quality spectra of a large majority of minerals outdoors. Raman spectra of minerals and pollutants in this study were obtained using 785nm laser excitation source. Observed Raman bands are found at correct wavenumber positions within ±3cm(-1) compared to reference values in the literature. Taking into account the resolution of the spectrometer (9cm(-1)), the results are still reliable and applicable on such systems. Areas of potential applications of these instruments include all kind of common geoscience work outdoors. PMID:25687229

  14. 泲河渡槽半重力式挡土墙的稳定分析%Stability Analysis of Ji River Aqueduct Half of Gravity Retaining Wall

    Institute of Scientific and Technical Information of China (English)

    李会芬

    2013-01-01

    The Ji River aqueduct for the typical,respectively using the Kulun formula and the Rankine formula for inlet transition section of retaining wall check earth pressure, stress in soil and anti-slide stability under the condition of the structure without water. The results show that, despite the different ideas and methods, the obtained results are very close, can meet the requirements of specification. Results show that the original design section is reasonable.%以泲河渡槽为典型,分别采用库伦公式和朗肯公式对进口渐变段半重力式挡土墙进行了建成无水情况下的土压力、地基应力和抗滑稳定复核。结果表明,尽管所采用的理念和方法不同,得到的结果却非常接近,满足规范的要求。说明原设计断面合理。

  15. The Excel method for hydraulic calculation of rectangle aqueduct%矩形渡槽水力计算的 Excel 求解

    Institute of Scientific and Technical Information of China (English)

    韩红亮; 刘守宇; 王雪梅; 冯建栋

    2015-01-01

    The hydraulic calculation of rectangle aqueduct was related to developing the bottom slope and width,and calculating the normal depth,so its analysis process was complex,and its calculation quantity was overmuch. The Excel software is used to the above analysis and cal-culation. Through writing the spreadsheet program and using IF( )function,we can result this question effectively because the desult what we want could be calculated in a short time. At last,the calculation quality is reducted,and the design efficiency is improved.%针对矩形渡槽水力计算涉及到槽身底坡和底宽的拟定、正常水深计算等问题,分析过程复杂,计算量较大的现象,将常用的Excel软件应用于矩形渡槽的水力计算,通过编制试算、IF()语句等计算程序,实现了矩形渡槽水力计算的快速求解,减小了计算量,提高了设计效率。

  16. Physico-chemical characterization of mortars as a tool in studying specific hydraulic components: application to the study of ancient Naxos aqueduct

    Science.gov (United States)

    Maravelaki-Kalaitzaki, P.; Galanos, A.; Doganis, I.; Kallithrakas-Kontos, N.

    2011-07-01

    Mortars and plasters from the ancient aqueduct on the island of Naxos, Greece, were studied with regard to mineralogical and chemical composition, grain size distribution, raw materials and hydraulic properties, in order to assess their characteristics and design compatible repair mortars. The authentic materials contained lime, crushed-brick, siliceous and calcitic aggregates, in different proportions according to mortar type. Crushed-bricks fired at low temperatures and lightweight volcanic aggregates contained amorphous phases, which upon reaction with lime yielded hydraulic components capable of protecting the construction from the continuous presence of water. Hydraulic calcium silicate/aluminate hydrates, the proportions and the perfect packing of the raw materials, along with the diligent application justify the longevity and durability of the studied samples. The hydraulic properties of samples were pointed out through (a) the well-established CO2/H2O ratio derived from the thermogravimetric analysis and (b) by introducing two powerful indices issued from the chemical analysis, namely CaOhydr and soluble SiO2 hydr. These indices improved the clustering of hydraulic mortars and provided better correlation between mortars, plasters and their binders. By comparing grain size distribution and hydraulicity indices it was possible to distinguish among the construction phases. Based on this study, repair mortars were formulated by hydraulic lime, siliceous sand, calcareous and crushed-brick aggregates, with the optimal water content, ensuring optimum workability and compatible appearance with the authentic ones.

  17. Effects of hazardous pollutants on the walls of Valence Aqueduct (Istanbul) by Raman spectroscopy, SEM-EDX and Geographical Information System

    Science.gov (United States)

    Unsalan, O.; Kuzucuoglu, A. H.

    2016-01-01

    This study involves Raman spectroscopic (176-2900 cm-1), SEM-EDX and Geographical Information System studies of the pollutants on the walls of Valence Aqueduct (Bozdoğan Kemeri), Istanbul, Turkey. Raman spectroscopy is a useful analytical method in characterization of painting materials and corrosion products. Especially, when it is not possible to take the samples from the place they exist, handheld Raman spectrometers play an important role to identify the materials in these samples. Furthermore, more information could be gathered when it is combined with SEM-EDX studies. On the other hand, regarding the cultural heritage, it is crucial to determine precise coordinates of the historical peninsula and the samples which have been exposed to pollutants, by Geographical Information Systems in order to study them and take precautions for the future. Handheld Raman spectrometer (NanoRam by B&WTek) allows recording of acceptable and good quality spectra of a large majority of minerals outdoors. Raman spectra of minerals and pollutants in this study were obtained using 785 nm laser excitation source. Observed Raman bands are found at correct wavenumber positions within ±3 cm-1 compared to reference values in the literature. Taking into account the resolution of the spectrometer (9 cm-1), the results are still reliable and applicable on such systems. Areas of potential applications of these instruments include all kind of common geoscience work outdoors.

  18. Coupled thermo-mechanical analysis of a closed aqueduct of the Gansu Tao Diversion Project during operation%引洮工程封闭渡槽输水期间热力耦合分析

    Institute of Scientific and Technical Information of China (English)

    陈武; 张东; 李双洋; 张明义; 裴万胜

    2012-01-01

    The Gansu Tao Diversion Project (GTDP) is located in seasonally frozen soil regions in Gansu Province, China. Based on the environmental temperature conditions for the closed aqueduct along the GTDP under normal water running, and according to the basic theory of heat transfer and finite element, a thermo-mechanical coupling numerical model for the closed aqueduct in cold regions is established to study numerically temperature and thermal stress distributions of the aqueduct for a whole year. The results show that the horizontal, vertical and longitudinal tensile stresses on the cross-section of the closed aqueduct resulted from water and air temperature difference exceed concrete tensile strength in the long-run process. Furthermore, the temperature difference between inside and outside walls of the closed aqueduct is relatively large so that a larger tensile stress will appear in more than half a year. Therefore, a certain cracking and security risk will exist in the long run. The design, construction and operation departments should be greatly focusing on such issues. It is hoped that the analysis results in this study can provide a scientific basis for effective design and safety maintenance of water supply aqueducts in other cold regions.%引洮工程位于甘肃省季节性冻土地区,基于甘肃引洮供水工程沿线封闭渡槽在全年正常输水运行时的环境温度条件,根据传热学及有限元基本理论,建立了寒区封闭渡槽热力耦合分析的有限元数值模型,对其全年正常运行过程中的温度及热应力分布规律进行了数值研究.结果表明:在全年正常输水运行条件下,引洮工程封闭渡槽在长期运行过程中由于水温和气温所造成的温差均能在渡槽截面的横向、竖向及纵向产生很大的拉应力,其值均超过了混凝土的抗拉强度( 1.43 MPa),且全年大部分时间内渡槽壁面内外的温差都很大,在渡槽腹板和底板都将产生较大拉应力,因而

  19. 南水北调中线工程沙河渡槽充水试验研究%Research on Water-Filling Test of Shahe Aqueduct in the Middle Route Project of South-to-North Water Diversion

    Institute of Scientific and Technical Information of China (English)

    陈晓光

    2015-01-01

    为检验南水北调中线总干渠沙河渡槽结构质量、安全情况,按照预定方案开展了全段渡槽充水试验工作。试验共发现槽身裂缝、止水缝、施工缝及螺栓孔四类质量问题造成的渡槽质量缺陷72处,总体上混凝土施工与止水安装质量较好,发现的质量缺陷不影响工程结构安全,对其进行混凝土灌浆和表面封闭处理后,渡槽结构能够满足正常使用要求。充水试验期间,对渡槽变形及应力应变进行了全面监测,最大挠度2.90 mm,最大沉降量18.72 mm,最大沉降差5.53 mm;沙河渡槽预应力槽身结构在各工况下均处于受压状态,普通钢筋混凝土槽身结构应力应变均在允许范围内。充水试验证明,沙河渡槽整体结构安全稳定,在各设计工况下均处于平稳运行状态。%The entire section of aqueduct water filling test work was carried out according to the scheduled plan for checking the quality and security of Shahe aqueduct structure of South-to-North Water Diversion Project. In the test,72 quality defects were found out caused by four types of quality problems,such as groove crack,water stop seam,construction seam and bolt hole. As a whole,the quality of concrete con-struction and sealing was good and quality defects did not affect on the engineering structure safety. Aqueduct structure could meet the re-quirements of normal use after comprehensive concrete grouting and surface processing. In the overall monitoring of aqueduct deformation and the stress-strain during the water filling test,the maximum deflection was 2. 90 mm,the largest settlement was 18. 72 mm and the maximum differential settlement was 5. 53 mm. Shahe aqueduct prestressed tank body structure was in compression state under various operating condi-tions,and the stress-strain of ordinary reinforced concrete tank body structure was within the scope of the permit. Water filling test shows that the whole Shahe

  20. 强震作用下大型排架式U型渡槽的损伤破坏分析%Seismic Damage Analysis of U-shaped Aqueduct with the Bent-type Structure Subjected to Strong Earthquake

    Institute of Scientific and Technical Information of China (English)

    张社荣; 冯奕; 王高辉

    2013-01-01

    强震作用下排架式渡槽结构易发生损伤开裂破坏,使结构整体抗震性能发生改变.基于混凝土塑性损伤本构模型,采用等效弹簧模拟桩-土之间的动力相互作用及温降法模拟槽身三向预应力钢筋作用,应用时域分析法对某大型排架式U型渡槽在强震作用下的动力响应规律及损伤破坏发展过程进行分析,得到强震作用下排架式渡槽的破坏模式及抗震薄弱部位,研究排架式渡槽结构的整体抗震特性.研究表明,在强震作用下结构损伤破坏较大区域主要集中于下部排架盖梁、连系梁与排架柱交接的部位,可能出现混凝土开裂现象,是该排架式渡槽结构的抗震薄弱环节,而槽身整体破坏性较小.对于地震烈度较高地区的排架式渡槽结构,应重点关注下部支撑结构的抗震安全性.%The bent-type aqueduct structure is prone to injury under strong earthquakes, and the structure' s overall anti-seismic performance changes. Based on the concrete plastic damage constitutive model, the equivalent spring model was applied to stimulate the SSI while a temperature drop process was applied to stimulate the effect of pre-stressed steel bars in the aqueduct. In addition, the o-verall anti-seismic performance of bent-type aqueduct structure was studied through analyzing the dynamic response law and damage development process of a large bent-type U-shaped aqueduct under strong earthquakes by applying time-domain analysis. The research results indicated that under strong earthquakes, the bent frame joints are the anti-seismic weak parts of aqueduct, while overall damage of groove body is less likely. For bent-type aqueduct structures which are located in areas with high seismic intensity, main attention should be paid to the anti-seismic safety of the lower part of the support structure.

  1. Eeffect of the height of pier on horizontal seismic responses of aqueduct structure%槽墩高度对渡槽结构水平地震响应的影响

    Institute of Scientific and Technical Information of China (English)

    李正农; 周振纲; 朱旭鹏

    2013-01-01

    The purpose of this paper is to study the influence of the height of pier on the dynamic characteristics and horizontal seismic responses of rectangular aqueduct structure.A finite element method is developed for solving the horizontal seismic responses of aqueduct with fluid-structure coupling and pile-soil-structure interaction in this paper.Analysis is carried out by using this finite element model and the results are in good agreement with the pseudo-dynamic principle testing data.The proposed finite element method is verified.On this base,the rectangular aqueduct structures with different heights of piers are studied by using this method.Results show that the fundamental frequency of aqueduct structure model is significantly changed with the increase of the height of pier,however,the difference of high-order frequencies is not evident.In addition,under the excitation of E1 Centro earthquake ground motion and TAR earthquake ground motion,these is a decreasing trend of the maximum seismic responses of the key parts of aqueduct structure with the increase of the height of pier,especially for the E1 Centro earthquake ground.motion.Under the excitation of artificial earthquake ground motion,these is a certain fluctuation in the seismic responses of aqueduct structures with high piers,however,in general,the dynamic responses of low piers are larger.%为了研究槽墩高度对矩形渡槽结构系统的动力特性及水平地震动力响应的影响,本文采用Housner流-固耦合模型,提出了一种用于土-桩-渡槽-水体系统的有限元分析方法.以渡槽结构原理性拟动力试验结果为依据,对拟动力试验进行了有限元仿真计算,验证了本文所给出的计算模型的合理性.在此基础上,重点对不同槽墩高度的矩形渡槽结构系统进行了计算研究,结果表明:渡槽结构的基频随槽墩高变化显著,而其高阶模态频率则变化不大.在E1 Centro波及TAR波输入时,随着槽墩高的增大,渡槽

  2. 华北滨海地区土地整治中的管道输水灌溉工程研究%Research on Aqueduct Irrigation Project in Land Reclamation over Coastal Areas of North China

    Institute of Scientific and Technical Information of China (English)

    刘风建; 尹永红

    2012-01-01

    河北省沧州市滨海地区耕地整治潜力大,水资源严重不足,节水灌溉措施成为区域土地整治持续的重要基础.该文以沧州市南大港孔庄子南土地整治项目为例,在种植业资源环境分析的基础上,针对滨海地区土地整治项目中管道输水工程的设计,从灌溉水源情况、取水工程布置、田间管道输水灌溉工程中管道布置及保护装置的设置等方面进行了分析和探讨,认为发展管道输水灌溉工程应是滨海地区扩大土地整治规模的重要措施.%The coastal areas in Cangzhou City Hebei Province have a great potential of reclamation on cultivated land. With a serious shortage of water resources, water-saving irrigation measures become an important basis for continued regional land reclamation. Taking land reclamation project in south of Kongzhuangzi County Nandagang Region in Cangzhou City as an example, based on analysis of farming resources and environment, the situation of irrigation water, set of intake water project and arrangement of aqueduct and protection device in field aqueduct irrigation were studied. The results showed that the development of aqueduct irrigation project is an important measure to expand the scale of land reclamation.

  3. Quality control on erection measurement for Shahe River aqueduct in South - to - North Water Diversion Project%南水北调沙河渡槽预制安装测量监理质量控制

    Institute of Scientific and Technical Information of China (English)

    万建成; 刘彦杰; 余昊

    2014-01-01

    通过南水北调中线沙河渡槽工程的测量监理质量控制工作实践,针对 U 形梁式渡槽预制安装施工的特点,重点阐述了在施工测量检测环节的质量控制工作,并介绍了测量监理质量控制的重点和测量检测方法。既有对规范标准和设计要求的严格执行,又有对各项检测过程严格控制与创新,可为类似渡槽工程或桥梁工程的施工测量监理质量控制所借鉴。%Through the practice of quality control in supervision on the neasurenent of Shahe River aqueduct works of Middle Route Project of South - to - North Water Diversion,the quality control in construction neasurenent and detection links,and the nain quality control points and detection nethods in the supervision are introduced according to the characteristics of precast U -type bean aqueduct. In the practice,not only the current specifications are strictly inplenented,but also the whole detection process is strictly controlled and updated. The experiences can provide references for the quality control of construction neasure-nent supervision of sinilar aqueduct or bridge works.

  4. Numerical Simulation of Lead Rubber Bearing Effect on Aqueduct Isolation Based on ADINA%基于ADINA的铅芯橡胶支座对渡槽隔震效果的数值模拟

    Institute of Scientific and Technical Information of China (English)

    王化翠; 卢兴旺; 苑司乐

    2014-01-01

    采用有限元分析程序ADINA建立铅芯橡胶支座的有限元模型,通过施加水平循环正弦位移荷载,得出了铅芯橡胶支座的滞回曲线,与试验曲线吻合良好,验证了数值模拟方法的正确性;将铅芯橡胶支座应用到某渡槽实际工程,建立了渡槽-支座-水体的流固耦合抗震分析数值模型,并进行了计算分析;结果表明,运用铅芯橡胶支座后渡槽结构的地震响应显著降低,隔震效果明显,结构抗震性能得到提高。%The finite element model of the lead rubber bearing was established by using ADINA in this study. Through a horizontal cyclic sinusoidal displacement load,the hysteretic curve of lead rubber bearing was ob-tained, which was in good agreement with the test curve and the numerical simulation method was verified. Then the lead rubber bearing was applied to an aqueduct engineering,and a numerical model for fluid-structure coupling seismic analysis of aqueduct-bearing-water was established. The calculation results show that the seis-mic response of aqueduct structures has decreased after using lead rubber bearings, and the vibration isolation ef-fect is obvious, which means the structural seismic performance has been improved.

  5. 南水北调中线工程湍河渡槽安全监测设计%Safety monitoring design of Tuanhe Aqueduct of Middle Route Project of South to North Water Diversion

    Institute of Scientific and Technical Information of China (English)

    武方洁; 季凡

    2015-01-01

    湍河渡槽是南水北调中线干线控制性工程,合理的安全监测设计方案是确保监测成果可靠有效的基础。结合工程实际,并参照相关监测规范,提出了湍河渡槽安全监测设计的原则和思路,并在此基础上分别对渡槽进口闸室段和槽身段的监测设计内容展开介绍。主要包括变形监测,土压力监测,应力应变及温度监测、裂缝监测等,可为掌握渡槽施工期和运行期的安全性状提供合理可靠的数据。%Tuanhe Aqueduct is a controlling works of the Middle Route Project of South to North Water Diversion, so a reason-able safety monitoring scheme is important to the collection of effective and reliable monitoring data. Combining with the engineer-ing practice, the safety monitoring design principle and thought were proposed by referring to the relevant monitoring specifica-tion. On this basis, the monitoring design for entrance chamber section and aqueduct body section were introduced, including de-formation, stress-strain, earth pressure, temperature and cracks. It can provide reliable data for mastering the safety condition of Tuanhe Aqueduct in construction and operation period.

  6. 多箱渡槽槽身静风三分力系数风洞试验研究%A wind tunnel test study on aerostatic coefficients of large scale multi-box aqueduct bridge deck

    Institute of Scientific and Technical Information of China (English)

    李遇春; 邸庆霜; 张文杰; 张婷婷

    2012-01-01

    A wind tunnel test for the six scaled multi-box aqueduct decks (including 3 two-box and 3 three-box models) was conducted. The cases with full and without water, and with different wind attack an- gles are considered respectively. The drag, lift and pitching moment coefficients of multi-box aqueduct decks were obtained by the test result analyses. The surface pressure distributions and the aerostatic coeffi- cients of the test models were displayed and discussed. The results show that: (1) The wind flow field around multi-box aqueduct deck is similar to that of blunt body; (2) The drag force is the most important wind load among the three static loads; (3) The drag coefficient decreases with the increasing of width/ height ratio of aqueduct decks in the whole tendency.%对6个多箱式渡槽槽身刚性测压模型进行了风洞试验研究,分别模拟了满槽、空槽以及不同风攻角的试验工况。根据试验结果得到了槽身模型的静风三分力(阻力、升力和扭矩)系数,讨论了模型风压分布以及三分力系数的变化规律。试验结果表明:(1)多箱式渡槽槽身绕流更趋近于钝体绕流;(2)槽身风荷载主要表现为风阻力;(3)阻力系数在总体趋势上随着槽截面宽高比的增加而减小。试验结果可为多箱渡槽的抗风研究与设计提供初步的参考。

  7. Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

    Science.gov (United States)

    Beggs, Clive B.; Magnano, Christopher; Belov, Pavel; Krawiecki, Jacqueline; Ramasamy, Deepa P.; Hagemeier, Jesper; Zivadinov, Robert

    2016-01-01

    Objectives Constricted cerebral venous outflow has been linked with increased cerebrospinal fluid (CSF) pulsatility in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy individuals. This study investigates the relationship between CSF pulsatility and internal jugular vein (IJV) cross-sectional area (CSA) in these two groups, something previously unknown. Methods 65 relapsing-remitting MS patients (50.8% female; mean age = 43.8 years) and 74 healthy controls (HCs) (54.1% female; mean age = 43.9 years) were investigated. CSF flow quantification was performed on cine phase-contrast MRI, while IJV-CSA was calculated using magnetic resonance venography. Statistical analysis involved correlation, and partial least squares correlation analysis (PLSCA). Results PLSCA revealed a significant difference (pC4. Controlling for age and cardiovascular risk factors, statistical trends were identified in HCs between: increased net positive CSF flow (NPF) and increased IJV-CSA at C5-C6 (left: r = 0.374, p = 0.016; right: r = 0.364, p = 0.019) and C4 (left: r = 0.361, p = 0.020); and increased net negative CSF flow and increased left IJV-CSA at C5-C6 (r = -0.348, p = 0.026) and C4 (r = -0.324, p = 0.039), whereas in MS patients a trend was only identified between increased NPF and increased left IJV-CSA at C5-C6 (r = 0.351, p = 0.021). Overall, correlations were weaker in MS patients (p = 0.015). Conclusions In healthy adults, increased CSF pulsatility is associated with increased IJV-CSA in the lower cervix (independent of age and cardiovascular risk factors), suggesting a biomechanical link between the two. This relationship is altered in MS patients. PMID:27135831

  8. STUDY OF VESTIBULAR AQUEDUCT WITH COMPUTED TOMOGRAPHY IN MENIERE′S DISEASE%梅尼埃病患者前庭小管CT影像观察

    Institute of Scientific and Technical Information of China (English)

    熊敏; 周定蓉; 姜泗长

    2001-01-01

    Objective To study the vestibular aqueduct(VA) with CT in Meniere,s disease(MD). Method The experiment consisted of three groups: normal ear group, non-MD vertigo group and MD group. VA in each group was examined with CT, and the width of the external aperture of VA was measured.Result VA in normal ear group and non-MD vertigo group was well visualized,and non-visualization rate was 9.1%. VA non-visualization rate in MD group was 75%, external aperture was narrowed in VA patients. Conclusion non-visualization or narrowing of the enterhal aperture can be considered as one of the diagnostic sings of MD.%分三组观察梅尼埃病(Meniere′s disease MD)患者前庭小管(Vestibular aqueduct,VA)CT影象,即正常耳组、非MD 眩晕组及MD组。每组均行头颅轴位CT扫描观察,并测量VA外口径。结果显示正常组及非MD眩晕组VA显影良好,不显影率均为9.1%。MD患者VA不显影率为75%,显影的VA外口也狭小。提示VA不显影或狭窄是其发育不良的表现,可作为诊断MD的影象学依据之一。

  9. Geologic Surface Effects of Underground Nuclear Testing, Buckboard Mesa, Climax Stock, Dome Mountain, Frenchman Flat, Rainier/Aqueduct Mesa, and Shoshone Mountain, Nevada Test Site, Nevada

    Science.gov (United States)

    Grasso, Dennis N.

    2003-01-01

    Surface effects maps were produced for 72 of 89 underground detonations conducted at the Frenchman Flat, Rainier Mesa and Aqueduct Mesa, Climax Stock, Shoshone Mountain, Buckboard Mesa, and Dome Mountain testing areas of the Nevada Test Site between August 10, 1957 (Saturn detonation, Area 12) and September 18, 1992 (Hunters Trophy detonation, Area 12). The ?Other Areas? Surface Effects Map Database, which was used to construct the maps shown in this report, contains digital reproductions of these original maps. The database is provided in both ArcGIS (v. 8.2) geodatabase format and ArcView (v. 3.2) shapefile format. This database contains sinks, cracks, faults, and other surface effects having a combined (cumulative) length of 136.38 km (84.74 mi). In GIS digital format, the user can view all surface effects maps simultaneously, select and view the surface effects of one or more sites of interest, or view specific surface effects by area or site. Three map layers comprise the database. They are: (1) the surface effects maps layer (oase_n27f), (2) the bar symbols layer (oase_bar_n27f), and (3) the ball symbols layer (oase_ball_n27f). Additionally, an annotation layer, named 'Ball_and_Bar_Labels,' and a polygon features layer, named 'Area12_features_poly_n27f,' are contained in the geodatabase version of the database. The annotation layer automatically labels all 295 ball-and-bar symbols shown on these maps. The polygon features layer displays areas of ground disturbances, such as rock spall and disturbed ground caused by the detonations. Shapefile versions of the polygon features layer in Nevada State Plane and Universal Transverse Mercator projections, named 'area12_features_poly_n27f.shp' and 'area12_features_poly_u83m.shp,' are also provided in the archive.

  10. Molecular epidemiology and functional assessment of novel allelic variants of SLC26A4 in non-syndromic hearing loss patients with enlarged vestibular aqueduct in China.

    Directory of Open Access Journals (Sweden)

    Yongyi Yuan

    Full Text Available BACKGROUND: Mutations in SLC26A4, which encodes pendrin, are a common cause of deafness. SLC26A4 mutations are responsible for Pendred syndrome and non-syndromic enlarged vestibular aqueduct (EVA. The mutation spectrum of SLC26A4 varies widely among ethnic groups. To investigate the incidence of EVA in Chinese population and to provide appropriate genetic testing and counseling to patients with SLC26A4 variants, we conducted a large-scale molecular epidemiological survey of SLC26A4. METHODS: A total of 2352 unrelated non-syndromic hearing loss patients from 27 different regions of China were included. Hot spot regions of SLC26A4, exons 8, 10 and 19 were sequenced. For patients with one allelic variant in the hot spot regions, the other exons were sequenced one by one until two mutant alleles had been identified. Patients with SLC26A4 variants were then examined by temporal bone computed tomography scan for radiological diagnosis of EVA. Ten SLC26A4 variants were cloned for functional study. Confocal microscopy and radioisotope techniques were used to examine the membrane expression of pendrin and transporter function. RESULTS: Of the 86 types of variants found, 47 have never been reported. The ratio of EVA in the Chinese deaf population was at least 11%, and that in patients of Han ethnicity reached at least 13%. The mutational spectrum and mutation detection rate of SLC26A4 are distinct among both ethnicities and regions of Mainland China. Most of the variants caused retention of pendrin in the intracellular region. All the mutant pendrins showed significantly reduced transport capability. CONCLUSION: An overall description of the molecular epidemiological findings of SLC26A4 in China is provided. The functional assessment procedure can be applied to identification of pathogenicity of variants. These findings are valuable for genetic diagnosis, genetic counseling, prenatal testing and pre-implantation diagnosis in EVA families.

  11. 大型钢筋混凝土涵洞式渡槽结构分析与试验研究%Analysis and Experimental Study of Large Scale Concrete Aqueduct Structure With Tunnel Style

    Institute of Scientific and Technical Information of China (English)

    张世宝; 解伟; 张淙皎; 赵平

    2001-01-01

    针对南水北调中线总干渠钢筋混凝土涵洞式渡槽双槽分缝结构形式进行了三维空间有限元分析,并以具有良好代表性的涵洞式渡槽的边联段为试验对象,进行了结构仿真试验。经成果整理并与有限元计算结果对比验证,两种手段所得结果基本吻合,从而为优化工程设计提供了依据。%Three dimensional finite element analysis about concrete opening separation structure double channel aqueduct of culvert type of the main channel in middle line of water diversion project from the Yangtze River into the Yellow River. The reality imitation experiment of the structure has been conducted by taking the boundary part of the tunnel type aqueduct, where is of the perfect representative to the real condition, as the experiment object. Comparison of the experiment results with finite element calculation shows that the two methods tally with each other in results, therefore provide basis for optimum design of the project.

  12. 龙滩水电站两级升船机中间渠道渡槽结构形式研究%Structural Analysis of the Middle Aqueduct in the Two-stage Ship Lift in Longtan Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    李丹梅; 孟庆峰

    2015-01-01

    龙滩升船机中间渠道在跨越冲沟处须采用渡槽结构. 鉴于渡槽结构尺寸较大,承受的荷载较大,使用时须考虑动水作用及结构防漏要求,对渡槽结构形式进行了比选及三维静、动力分析计算,以确定各工况下结构应力、应变状态,为结构体系的局部修改及结构配筋设计提供依据.%In the middle section of the two-stage ship lift in Longtan Hydropower Station , aqueduct structure is adopted to cross the gully .Due to its large dimensions and big load , the dynamic action and leakage proof requirement must be considered.Thus, structure form comparison and three dimensional static and dynamic analysis are carried out to deter-mine the structural stresses and strains , which provide references for the modification of structural design and also the re-inforcement design of the aqueduct .

  13. 夹马口节水改扩建工程渡槽接缝止水设计方案%Design Scheme for Joint Sealing of Aqueduct in Jiamakou Water-saving Reconstruction Project

    Institute of Scientific and Technical Information of China (English)

    徐睿

    2011-01-01

    Through the comparison and selection for the sealing types and sealing materials of joints of the aqueduct, the bond-type sealing plan is used in the joint sealing of the [/-shaped aqueduct in Jiamakou water-saving reconstruction project, which has good sealing effect and strong durability, and is simple in the construction and easy to guarantee the quality of the construction. After more than a year of practical application, it is demonstrated that the bond-type sealing method used in the project has a good effect and comprehensive functions, and is worth popularizing.%通过对渡槽接缝止水形式及止水材料的比选,确定夹马口节水改扩建工程U形渡槽接缝止水采用止水效果好、耐久性强、施工简单且质量容易保证的粘合式止水方案.经过一年多时间的实际运用,证明该工程所采用的粘合式止水,效果良好,功能全面,值得推广应用.

  14. Box girder vertical displacement monitoring for Xujiawan continuous rigid aqueduct water filling test%徐家湾连续刚构渡槽充水试验箱梁竖向位移监测

    Institute of Scientific and Technical Information of China (English)

    张健; 钟伟

    2016-01-01

    为了检验徐家湾连续刚构渡槽箱梁的安全性能,经过近42天5级加载充水试验,监测结果表明:徐家湾渡槽箱梁竖向位移与设计理论值一致,渡槽施工质量良好,结构安全。其成果可供类似连续刚构渡槽充水试验参考。%In order to check the safety of box girder of Xujiawan continuous rigid aqueduct,5-grade loading water filling test was conducted for nearly 45 days. The results of monitoring demonstrate the vertical displacement is identical with the design value,the construction quality is good,and the structure is safe. The results also can be reference for water filling test of similar rigid aqueduct.

  15. On analysis of reasons and treatment for expansion joint leakage of aqueduct at brick plant of Heihe channel%黑河渠道砖厂渡槽伸缩缝渗漏原因分析及治理

    Institute of Scientific and Technical Information of China (English)

    傅柯

    2014-01-01

    通过对黑河渠道工程砖厂渡槽伸缩缝渗漏问题的产生原因进行分析,提出了合理的治理措施,圆满解决了砖厂渡槽渗漏问题,取得了良好的防渗漏效果,对于黑河输水渠道管理单位的渠道工程维护工作具有一定的借鉴意义。%According to the analysis of reasons for leakages at expansion joint of aqueduct in the brick plant of Heihe channel project,the paper points out the reasonable treatment,solves the leakage at the aqueduct of the brick plant,and achieves better anti-leakage effect,so it is mean-ingful for the channel project maintenance of Heihe conveyance canal management parties.

  16. Comparison of Design Bearing Capacity and Site Static Load Test of the Cast-in-place Piles in Caohe Aqueduct%漕河渡槽灌注桩承载力与静载试验比较

    Institute of Scientific and Technical Information of China (English)

    杨胜慧

    2013-01-01

    The cast-in-place piles foundation is adopted in the Caohe aqueduct body. There is 0.5 meter of the piles foun-dation entering into the weak weathered rock, the bearing capacity of the piles foundation is calculated according to point bearing pile . The static load test is adopted to check the the bearing capacity of the cast-in-place pile foundation, the test results show that the bearing capacity of pile foundation in Caohe aqueduct meet the design requirements.%漕河渡槽槽身段采用灌注桩基础,桩基进入弱风化岩石0.5m,按纯端承桩计算桩基承载力。采用桩基静载试验检测桩基承载力,试验结果表明,漕河渡槽桩基承载力达到设计要求。

  17. 大前庭水管综合征患儿人工耳蜗植入效果分析%The Effects of Cochlear Implantation on Children with Large vestibular Aqueduct Syndrome

    Institute of Scientific and Technical Information of China (English)

    王节; 曹卫; 邱建新

    2009-01-01

    目的 比较大前庭水管综合征(large vestibular aqueduct syndrome,LVAs)和内耳结构正常人工耳蜗植入术后最大舒适阈值(most comfortable level,M值)和神经反应成像阈值(neural response imaging threshold,tNRI值),为LVAS患者进行人工耳蜗植入术的可行性提供依据.方法 将38例耳聋患儿根据CT检查结果分为A、B两组,A组32例,内耳结构正常;B组6例,双侧前庭导水管扩大,但不伴有其他内耳结构异常.所有患儿均植入美国Advanced Bionics公司生产的HiRes 90K人工耳蜗系统.术后1个月左右安装体外设备并进行测试,使用与患儿年龄相应的行为测试方法进行舒适阈的测试;同时用SoundWave 1.4调机软件行神经反应成像(neuralresponse imaging,NRI)检测,记录tNRI值.结果 两组术后1月开机时3、7、11和15号电极的M值和tNRI值的差异均无统计学意义(P>0.05).结论 LVAS息儿并非人工耳蜗植入的禁忌,且术后调试时各指标的设定可参考内耳结构正常患儿的数值.%Objective The purpose of this study is to compare the most comfortable levels and neural re-sponse imaging threshold between children of cochlear implants with large vestibular aqueduct syndrome and normal inner ears. Methods Thirty-eight implanted children participated in this study and were divided into two groups. Group A consisted of 32 patients with normal inner ears and group B 6 patients with radiographically proven large vestibular aqueduct syndrome. All of the patients were the recipients of the cochlear implants by Advanced Bionics. The initial time for the first programming session was approximately one month after surgery. The psychophysical tests included M- level tests. Programming techniques used in the test were suitable for the age of patients. Sound-Wave 1.4 software was used to test tNRI. Results Using the rank sum test, M-level and tNRI of electrode 3,7,11 and 15 did not differ significantly between group A and B(P>0. 05

  18. 3.0T MRI对中脑导水管脑脊液动力学研究%Research of 3.0 T MRI on Cerebrospinal Fluid Dynamics in the Midbrain Aqueduct

    Institute of Scientific and Technical Information of China (English)

    郭秀玲; 刘天立; 赵进学

    2016-01-01

    Objective To research on cerebrospinal fluid dynamics in the midbrain aqueduct by application of 3.0 T mag-netic resonance. Methods From September 2014 and September 2015, selected 23 patients accepted magnetic resonance cerebrospinal fluid examination in our hospital, all patients carried out magnetic resonance cerebrospinal fluid examination on the basis of routine MRI scans, sequence design includes: 3 D TSE DRIVE, cine PC sequences, Q - Flow sequence, which were used to observe the midbrain aqueduct detail anatomical structure, cerebrospinal fluid flow state, and drawing the time-signal intensity curve. Results Among 23 patients, including 2 cases were normal, 3 cases were obstructive hydro-cephalus, 16 cases were traffic hydrocephalus, 2 cases had not abnormalities by reexamining cerebrospinal fluid flow state postoperative water on the brain ventricle - peritoneal shunt. Conclusion Combination of 3 D TSE DRIVE, cine PC se-quences and Q - Flow sequence could have a comprehensive study on the cerebrospinal fluid dynamics in the midbrain aqueduct area.%目的:应用3.0T磁共振对中脑导水管脑脊液动力学进行初步研究。方法选择2014年9月-2015年9月在该院进行磁共振脑脊液检查的患者共23例,所有患者在常规MRI扫描的基础上进行磁共振脑脊液检查,序列设计包括:3D TSE DRIVE序列、cine PC序列、Q-Flow序列,分别用于观察中脑导水管细节解剖结构、脑脊液流动状态,并绘制时间-信号强度曲线。结果23例患者进行检查,其中2例正常,3例梗阻性脑积水,16例交通性脑积水,2例脑积水脑室-腹腔分流术后复查脑脊液流动状态未见异常。结论3D TSE DRIVE序列、cine PC序列和Q-Flow序列相结合能够对中脑导水管区的脑脊液动力学进行全面的观察研究。

  19. 超大体积薄壁渡槽施工温控技术及其应用%Temperature Control Technology and Applied Research of Large Volume Thin-wall Aqueduct

    Institute of Scientific and Technical Information of China (English)

    蒋俊峰

    2014-01-01

    Aqueduct engineering is an important link in the south-north water diversion project. The concrete crack control is particularly important because of the characteristic of the aqueduct thin-wall structure. In order to better preferably guide pro-duction and avoid quality problems of engineering, it was needed to analyze and research the mechanism of cracks and rea-sons by combining with the actual construction process strictly control the cracks in mass concrete and aqueduct project con-struction process of hydration heat simulation. Then, the paper was discussed taking heat preservation, water cooling, pouring and dismantles time and anti-cracking measures. Finally, the paper was purposefully put forward effective crack control scheme and measures, which improved the quality of engineering, guiding the project construction and achieved the an-ti-cracking goal of during the construction.%渡槽工程为南水北调工程的一个重要环节,由于渡槽薄壁结构的特点,其混凝土裂缝控制变得尤为重要。为了更好地指导生产,避免工程出现质量问题,需要结合实际施工过程,对大体积混凝土及裂缝需要严格控制的渡槽工程进行施工过程的水化热仿真分析,研究裂缝的机理及产生的原因。对采取保温、通水冷却、浇筑时间及拆模时间等防裂措施进行探讨,有针对性地提出行之有效的温控防裂方案和措施,提高工程质量,指导了工程施工,达到渡槽混凝土施工期防裂的目的。

  20. 设计优化对大马尼拉供水工程项目实施的重要性%Brief discussion on importance of design optimization for implementation of construction of Angat Water Utilization and Aqueduct Project

    Institute of Scientific and Technical Information of China (English)

    丁家仁; 王宗敏; 张雪峰

    2012-01-01

    就菲律宾大马尼拉供水工程在施工过程中的一系列设计优化工作,对项目安全、质量、工期、成本控制起到了重要作用,取得了良好的经济效益和社会效益.%A series of design optimizations made during the construction of Angat Water Utilization and Aqueduct Improvement Project in the Philippines is introduced herein. All of the optimizations concerned have played an important role in the project safety, quality, schedule and cost control, and then better economic and social benefits have been obtained as well.

  1. Prediction analysis on water temperature in closed aqueduct in cold regions%寒区封闭引水渡槽中水温变化预测分析

    Institute of Scientific and Technical Information of China (English)

    陈武; 刘德仁; 董元宏; 徐湘田

    2012-01-01

    Large water storages and diversion facilities can not be constructed at the ends of the two transportation lines of the Water Diversion Project from Tao River (WDP) in Gansu Province because of limit of engineering conditions. To solve this problem, water delivery time of the main channel has to be prolonged to winter. Based on the practical engineering condition and related heat and mass transfer theories, a three-dimensional numerical model for fluid-solid coupled convective heat transfer was established and validated by laboratory test result. The water temperature variation within the closed aqueduct under low-temperature condition in cold regions was predicted by solving the numerical model. The numerical results showed that the water temperature within the aqueduct was determined by the flow capacity, inlet water temperature, flow velocity, ambient temperature and et al. However, because of the effective design of the aqueduct, rational application of insulation and control of water flow time, the decrease of the water temperature was not obvious, and the water temperature in the aqueduct could be kept above 0°C, which ensured water supply in cold seasons. The study in this paper provides scientific reference for optimization design and safe operation of the other water diversion projects in cold regions.%甘肃引洮供水工程由于两条供水管线末端均不具备建设大型调蓄设施的工程条件,通过延长总干渠供水时间来解决调蓄不足的问题必须考虑冬季输水.针对这一实际问题,根据传热传质理论,建立了流固耦合对流换热三维数值模型,通过数值计算结果与室内模型试验结果进行对比研究,验证了数值模型的可靠性,表明其模型可用来对寒区封闭性渡槽内部水体在低温环境条件下的温度变化进行了预测分析.分析结果表明,虽然渡槽内水温与渡槽内的流量、入口水温、流速及环境温度等因素有关,但由于该渡槽结构及

  2. Great Aqueduct of Vestibule Syndrome and Perceptive Nerve Deafness%大前庭导水管综合征和儿童感音神经性耳聋

    Institute of Scientific and Technical Information of China (English)

    丛品; 徐飞

    2004-01-01

    大前庭水管综合征(Large Vostibular Aqueduct Syndrome LVAS)是一种近年来才认识到的先天性内耳畸形。其表现形式往往为儿童期的感音神经性耳聋,多为渐进行或波动性。自Valvassori等1978年首次报告后,国内1995年才始见报导,引起关注。作为儿童感音神经性耳聋的原因之一,本病在发病机制,诊断思路,防治方法方面具有其独特性。现将我院近年来资料完全的3例LVAS报告如下:

  3. Experiment and Analysis of the Pile-bottom Grouting Technology in Ming River Aqueduct Pile Foundation%桩底压浆技术在洺河渡槽桩基试验与分析

    Institute of Scientific and Technical Information of China (English)

    杨镇生

    2013-01-01

      洺河渡槽通过3根试验桩的桩底压浆前后静载对比试验,测定桩底压浆对桩周侧摩阻力和端承力的增强效果,为桩底压浆提供设计计算参数和施工工艺参数。%Through the static load comparative tests before and after pile-bottom grouting of three test piles in Ming River aqueduct, determining the effect of the pile bottom grouting on pile side friction resistance and end bearing capacity, pro-viding the design calculation parameters and construction process parameters for the pile bottom grouting.

  4. 高强度混凝土渡槽夏季施工防裂措施研究%Crack Prevention Measures for High Strength Concrete Aqueduct Constructed in Summer

    Institute of Scientific and Technical Information of China (English)

    张杨; 邬爱清; 何磊

    2011-01-01

    In spite of high carrying capacity, it involves great difficulty to control the temperature and prevent cracking during the construction of high strength concrete aqueduct in summer because of high heat of hydration. The finite element method for unsteady temperature field and stress field is applied to simulate the construction process in summer for a typical aqueduct structure. The cause of cracking at dangerous positions is analyzed based on the calculation results of temperature field and stress field in different cases. Corresponding measures of pipe cooling and surface thermal insulation are put forward, which will be beneficial for the design and construction of such high strength concrete structure.%高强度混凝土渡槽结构承载能力高,但水化放热量也大,在夏季浇筑时混凝土温控防裂难度较大.采用非稳定温度场及应力场的有限元计算方法,对夏季施工的典型渡槽结构进行了施工过程的仿真计算.根据不同工况的温度场和应力场计算结果,分析了易裂部位的开裂原因,提出了相应的水管冷却和表面保温措施,可为类似高强度混凝土结构的设计和施工提供有益的参考.

  5. Application of Improved Genetic Algorithm in Structural Optimization Design of Aqueduct%改进的遗传算法在渡槽结构优化设计中的应用

    Institute of Scientific and Technical Information of China (English)

    郑重阳; 彭辉; 闫秦龙; 刘帅

    2012-01-01

    传统的遗传算法存在寻优效率较低、精度不高等缺点.为了解决这些问题,对传统遗传算法进行了改进——采用Fortran语言编制结构优化程序,并将改进后的遗传算法应用于大型预应力矩形渡槽优化设计中.通过对比原设计方案与优化方案的结构安全性及经济性,验证了优化设计方案具有显著的经济效益.结果表明,改进后的遗传算法提高了计算性能和优化效果.%Traditional genetic algorithm has defects such as low optimization efficiency and low precision. We improved this algorithm by compiling a structural optimization program through Fortran language. The improved genetic algorithm was applied to the optimization of the design for a large-scale prestressed rectangular aqueduct. By comparing the original design with the optimized design in terms of safety and economy, we verified the feasibility of the optimized scheme. It' s proved that the optimized algorithm improves the convergence rate and accuracy of the solution. In the optimized design, each part of the aqueduct meets the stress and strain condition, and the three-dimensional mechanical behavior of the structure is more reasonable. The results demonstrate that the structural optimization reduces the construction costs and improves the structural behavior.

  6. Simplified Computational Method for Seismic Response of LRB-isolated Aqueduct%LRB隔震渡槽结构地震响应的简化计算方法

    Institute of Scientific and Technical Information of China (English)

    叶昆; 符蓉; 李黎

    2011-01-01

    In order to simplify the computational methods for seismic response of LRB-isolated aqueduct structure, different computational methods are compared in the course of conducting seismic response analysis of one large LRB - isolated aqueduct designed according to Intensity 7. These methods consist of 2DOF combined with bilinear model, 1DOF combined with bilinear model, improved 1DOF combined bilinear model and finite model. Effect of damping and stiffness of piers on the numerical results are investigated. It is shown that the mothod of improved 1 DOF combined bilinear model is the easiest and can meet the accuracy of engineering demand.%为探究采用铅芯橡胶隔震支座的大型渡槽结构地震响应的简化分析计算方法,本文针对某大型隔震渡槽进行了7度顺槽向地震响应分析.比较了双质点双线性模型、单质点双线性模型、改进后的单质点双线性模型和有限元模型的计算结果.分析了槽墩刚度、阻尼比对计算结果的影响.分析计算表明改进后的单质点双线性模型计算简便并能够满足精度要求,可以运用于实际工程的初步设计中.

  7. Key technologies for construction of large span arch-beam composite aqueduct%大跨度梁拱组合式渡槽关键施工技术

    Institute of Scientific and Technical Information of China (English)

    李峰; 颜志强; 任玉房

    2013-01-01

    Licun North Main Canal Aqueduct of the mid-route of the South-to-North Water Transfer Project is an arch-beam composite aqueduct; of which the construction consists of 12 phases and the process control is quite complicated. During the construction, the pre-stress stretch is completed in three stages with the application of pre-stress step by step. The bottom die support mainly consists of soil mold with the complement of steel tube scaffolding with bowl type coupler, which can fully accommodate the complicated structural features concerned. In accordance with the requirement on the system transformation, the formwork is demounted in four stages within the late-phase of the construction, and then the design intent is completely realized at last.%南水北调工程中线李村北干渠渡槽为梁拱组合式渡槽,总计分十二个阶段建成,过程控制复杂.施工期间,结合现浇梁段布置,将预应力张拉分三个阶段完成,逐步施加预应力.底模支撑以土胎膜为主,碗扣架为辅,可充分适应复杂结构特点.后期卸载时根据体系转换的要求,遵循对称均衡的原则,分四阶段完成,全面实现了设计意图.

  8. 三维快速成像稳态采集序列在中脑导水管狭窄诊断中的应用%Application of 3D-FlESTA Sequence in the Diagnosis of the Stenosis of Midbrain Aqueduct

    Institute of Scientific and Technical Information of China (English)

    冯建钜; 陈培友; 许健

    2010-01-01

    Objective To explore the evaluation of three-dimensional fast imaging employing steady-state acquisition(3D-FIESTA) sequence in the diagnosis of non-tumorous midbrain aqueduct stenosis.Methods 48 patients with non-tumorous midbrain aqueduct stenosis were performed by conventional SE sequence and 3D-FIESTA sequence on a 1.5T superconductive MR unit.Then the advantage on showing aqueduct of midbrain foramen was retrospectively analyzed.Results The detecting rate of midbrain aqueduct stenosis was 98% (47/48) on 3D-FIESTA sequence and 79% (38/48) on conventional SE sequence,3D-FIESTA was more advanced on showing the aqueduct of midbrain(P <0.01).Conclusion The combination of 3D-FIESTA with MPR can clearly show the midbrain aqueduct stenosis,and be a new MRI examination way of obstructive hydrocephalus.%目的 评价三维快速成像稳态采集(3D-FIESTA)序列诊断非肿瘤性中脑导水管狭窄的应用价值.方法 48例中脑导水管狭窄患者同时行常规自旋回波(SE)序列及3D-FIESTA序列扫描,并对中脑导水管的成像效果进行比较.结果 SE显示导水管狭窄率为79% (38/48),3D-FIESTA显示导水管狭窄病变率为98% (47/48);3D-FIESTA序列对中脑导水管狭窄显示效果有明显优越性,其组间比较,差异有统计学意义(P<0.01).结论 3D-FIESTA序列结合多平面重建技术能清晰显示中脑导水管狭窄,可作为一种非肿瘤性梗阻性脑积水成像的新方法.

  9. Reconstructing 15°oblique sagittal image of the vestibular aqueduct by MSCT、measurement and clinical application%MSCT前庭导水管15°斜状位图像的重建、径线测量及临床应用

    Institute of Scientific and Technical Information of China (English)

    王林省; 张丽红; 陈月芹; 王皆欢; 刘艳杰; 郭沐洁

    2015-01-01

    目的:利用多层螺旋CT(multislice CT ,MSCT)重组前庭导水管(vestibular aqueduct ,VA)15°斜矢状位图像,探讨径线测量值对大前庭导水管畸形(the large vestibular aqueduct ,LVA)的应用价值。方法标准化处理106例(212耳)正常人的颞骨M SC T 图像获得前庭水管标准化图像,测量V A中间径大小,建立99%医学参考值范围;对43(85耳)L V A患者V A中间径进行测量,并与正常值进行统计学分析。结果不同性别、侧别及各年龄组间VA中间径大小无统计学差异(t=0.252,P>0.05;t=1.573,P>0.05;F=0.089,P>0.05)。VA中间径(0.76±0.15)mm ;99%医学参考值范围:0.41~1.10 mm。LVA患者VA中间径最大值为3.60mm ,最小值为1.13mm ,与正常组比较有统计学差异(t=7.892,P<0.05)。结论利用MSCT 多平面重组易于获得VA15°斜状位图像;99%正常人 VA 中间径参考值范围:0.41~1.10 mm ;VA 中间径大于1畅10mm 提示LAV。%Objective To study the feasibility of measuring diameters of the mid section of the vestibular aque‐duct back limb on 15°oblique sagittal image reconstructed using multi‐slice computed tomography (MSCT )images of temporal bone for detecting large vestibular aqueduct syndrome (LVAS) .Methods Temporal bone MSCT ima‐ges from 106 normal hearing individuals (212 ears)were used to reconstruct a standarized section image of the ves‐tibular aqueduct .The diameters of the mid section of the aqueduct back limb were measured to establish 99% con‐fidence intervals .Images from different age group ,male and female individuals and from the left and right sides were measure separately and the results were compared with those from 43 patients with LVAS .Results There was no significant differences of intermediate diameters between male and female ,the left and right ,and the differ‐ent age groups( t=0 .252 ,P>0 .05 ;t=1

  10. 渡槽贝雷钢拱架稳定性及承载能力分析%Analysis for Stability and Bearing Capacity of Aqueduct Bailey Steel Arches

    Institute of Scientific and Technical Information of China (English)

    钟伟; 肖阳剑

    2014-01-01

    with some arch aqueduct which arch rings are constructed with suspended Bailey steel arches as background, this paper discloses mechanical behaviors of arches during cast-in-situ of arch rings by analyzing stability and bearing capability of arch structures, and compares changes of stability and bearing capability of arches under different constraints to draw a conclusion that consolidation constraint hinge joint adopts for arches can remarkably improve stability of arches without reduction of bearing capability of arches. This conclusion can provide a reference for design and construction of similar projects in the future.%以悬拼贝雷钢拱架施工拱圈的某拱式渡槽为背景,通过对拱架结构的稳定性及承载能力进行分析,揭示拱圈现浇过程中拱架的力学行为,并对拱架不同约束形式下其稳定性和承载力的变化进行比较,得出拱架采用固结约束较铰接能显著提高拱架稳定性且不降低拱架承载能力的结论,可为以后类似工程设计施工提供参考。

  11. The Aqueduct Hydraulic Loss Calculation and Its Influencing Factors%输水管道水力损失的计算及其影响因素分析

    Institute of Scientific and Technical Information of China (English)

    王中; 陈卓

    2012-01-01

    Objective: studing the effective optimization of the the aqueduct hydraulic loss calculation to get more accurate design parameters. Process: analysis of four commonly used hydraulic loss calculation formula to study how to select the correct formula, the optimization of the different channels in the calculation process, precau- tions along the process of water loss and local water loss calculations. Results : it is very important to consider the factor of hydraulic losses in hydracclic calculation.%目的通过研究可以有效的优化输水管道水力损失的计算,使设计参数更为准确。方法通过四种常用水力损失计算公式的计算分析,研究如何选取正确的计算公式,不同的管道在计算过程中的优化,沿程水损与局部水损的计算时注意事项。结果寻找到不同管道计算时采用的不同公式,并提出了由于水锤等原因造成的计算误差。结论考虑影响水力损失的因素对于水力计算来说,是十分必要的。

  12. Analysis of wind-induced vibration response of fluid-structure interaction system for aqueduct considering soil-structure interaction%考虑土-结构相互作用渡槽流固耦合体风振响应分析

    Institute of Scientific and Technical Information of China (English)

    张华; 纪爱丽; 徐威; 何祥瑞

    2015-01-01

    以排架渡槽为研究对象,分别建立考虑土−结构相互作用(SSI)效应和不考虑土−结构相互作用(SSI)效应下的三维渡槽−水流固耦合体风振计算模型,通过自回归滑动平均(ARMA)模型模拟脉动风,采用任意拉格朗日−欧拉(ALE)方法求解渡槽和水体的耦合相互作用问题,针对不同水深工况,分别计算分析渡槽流固耦合体系在风荷载随机动力作用下的动力响应。研究结果表明:考虑SSI效应使得渡槽结构横槽向抗风刚度降低,导致结构风振位移响应增大;渡槽结构各部位最大主应力随槽内水深增大而增大,考虑SSI效应渡槽结构主应力稍大于不考虑SSI效应渡槽结构主应力;在脉动风荷载作用下,水深是决定渡槽倾覆力矩和动水压力的控制因素,土−结构作用的影响较小。%Three-dimensional models of fluid-structure coupling system for bent-type aqueduct were established considering soil−structure interaction (SSI) and without considering soil-structure interaction respectively to simulate the wind-induced vibration response. The wind-induced vibration response of aqueduct-water coupling system was numerically computed by using the arbitrary Lagrangian-Eulerian (ALE) method. The fluctuating wind speed time series was simulated resorting to auto-regressive moving average (ARMA) model. The dynamic responses of fluid-structure interaction system with different water depth conditions under stochastic wind loads were calculated. The results show that as SSI is considered, the lateral wind stiffness of the aqueduct structure decreases, which results in the increase of the structural wind-induced vibration displacement responses. The maximum principal stress of the aqueduct structure increases with the increase of the water depth, and the principal stress of the aqueduct considering SSI is slightly greater than that of the aqueduct without considering SSI. Under the action of

  13. 输水管道水力损失的计算及其影响因素分析%The aqueduct hydraulic loss calculation and its influencing factor analysis

    Institute of Scientific and Technical Information of China (English)

    王中

    2012-01-01

      通过研究可以有效的优化输水管道水力损失的计算,使设计参数更为准确。方法:通过四种常用水力损失计算公式的计算分析,研究如何选取正确的计算公式,不同的管道在计算过程中的优化,沿程水损与局部水损的计算时注意事项。结果:寻找到不同管道计算时采用的不同公式,并提出了由于水锤等原因造成的计算误差。结论:考虑影响水力损失的因素对于水力计算来说,是十分必要的。%  The research can effectively optimize the aqueduct hydraulic loss calculation and make design pa-rameters more accuracy. By analysis of four commonly used hydraulic loss calculation formula, to study how to select the correct formula, optimize the calculation process for the different pipes and consider water loss and local water loss along the process of calculations. It found the different formulas used in the calculation of the different pipes, and provides a calculation error caused due to water hammer and other reasons. The conclu-sions is that considering the factors affecting the hydraulic loss for the hydraulic calculation is necessary.

  14. 漕河渡槽项目第Ⅱ标段基桩静载试验%Pile static load test of sectionⅡof Caohe River aqueduct project

    Institute of Scientific and Technical Information of China (English)

    刘国华

    2015-01-01

    Caohe Aqueduct is one of th e landmark buildings in the middle route of South to North Water Diversion Pro-ject,the self weight of its each cross with water weight is up to 6300t. The design requirements each pile maximum loading capacity of 13000kN,characteristics of the large tonnage static load test is not only poor safety but also high cost. How can do that is safe and can reduce the cost to complete the relative such test has received much attention.The article from the large tonnage static load test procedure and the results achieved are analyzed and summarized to provide reference for large tonnage static load test in future.%漕河渡槽是南水北调中线工程的标志性建筑物之一,其每跨自身重量加过水重量达6300t,要求每根基桩静载试验最大加载量1.3万kN。大吨位静载试验的特点是安全性差、成本高,如何能既安全又相对降低成本地完成此类试验的关键,对大吨位静载试验的过程进行了总结,对取得的成果进行了分析,可为桩基大吨位静载试验提供借鉴。

  15. Construction of precast concrete dome of installation under long-span aqueduct section of ship-lift%升船机渡槽段大跨度穹顶混凝土预制拱施工

    Institute of Scientific and Technical Information of China (English)

    杨根录; 周建兵

    2015-01-01

    向家坝水电站升船机渡槽段为大跨度穹顶结构,其下部为电站厂房安装间,穹顶施工时也正是机组安装的关键时期。为确保穹顶施工过程中不发生高空掉物和自身的施工安全,将原设计的“贝雷桥架模板支撑体系+现浇方案”改为“弧形移动支撑样架+预制弧形拱+安全防护桁架”的施工方案,有效避免了穹顶模板拼装及上部混凝土施工期间对下部安装间机组安装的干扰,确保了施工安全,缩短了直线工期。%The ship-lift′s aqueduct section of Xiangjiaba Hydropower Station is above the assembly bay of the powerhouse with long-span dome .The dome construction is in the key period of generating unit installation .In order to ensure the construc-tion safety without object falling , the construction scheme of arc -shaped mobile supporting frame plus precast arch and safety protection truss"is adopted to replace the original design of Bailey frame formwork support system plus the cast -in-place.It is proved that the new scheme effectively avoids the interference to the installation of generating units from the dome template assem -bly and the upper concrete construction , so as to ensure the construction safety and shorten the critical construction period .

  16. 兰新高速铁路戈壁区路堑段明洞渡槽排水设计研究%Study on Aqueduct Drainage Design of Lanzhou~Urumqi High-speed Railway Cutting Section in Gale Gobi District

    Institute of Scientific and Technical Information of China (English)

    于介

    2016-01-01

    以兰新高速铁路新疆境内长段落路堑段综合排水系统中的明洞渡槽为研究对象,结合其大风戈壁漫流区的特点,提出以明洞渡槽为主体的“导流堤+明洞渡槽+路堑天沟”的综合排水系统,其研究成果可为戈壁漫流区路堑地段排水工程服务,并为今后类似的工程修建提供参考依据。%Based on the gallery aqueduct comprehensive drainage system in cutting section of the High-speed Rail from Lanzhou to Urumqi in Xinjiang, an integrated drainage system including diversion dike, gallery aqueduct and cutting gutter is proposed according to the characteristics of the flow area of the gale in Gobi. The research results will service the drainage engineering of the road cutting section in Gobi and provide reference for the construction of similar projects in the future.

  17. Test Analysis of Cellulose Fiber in High-Strength Concrete of Shahe Aqueduct in the Middle Route of the South-to-North Water Diversion Project%纤维素纤维在南水北调中线沙河渡槽高强混凝土中的试验分析

    Institute of Scientific and Technical Information of China (English)

    王斌

    2012-01-01

    沙河渡槽是南水北调中线保证通水与否的重要控制工程,是目前采用预制工艺的单体自重最大的薄壁预应力输水构件,对构件的抗裂和强度及耐久性存在极高的要求.纤维素纤维是新兴的复合纤维,属于低弹模级材料.可以大幅提高混凝土及砂浆的均质性,有效抑制早期的塑性裂缝和干缩裂缝,同时改善混凝土的抗渗性、抗冻融性及耐火性,最终达到提高混凝土的耐久性.通过现场在混凝土配合比中添加纤维素纤维的试验,验证纤维素纤维对于高强度混凝土性能的影响和改善,挑选适合沙河渡槽预制槽体混凝土的纤维素纤维以及掺量,达到满足设计要求,保证沙河渡槽的工程质量.%The Shahe aqueduct is an important controlling engineering factor to ensure water running in the Middle Route of the South-to-North Water Diversion Project,and it is a thin-walled prestressed conveyance component using the prefabrication with the largest single unit weight, which has a high requirement for the crack resistance and durability of the component The cellulose fiber is a new composite fiber and a material with low-elastic modulus. The cellulose fiber can increase the homogeneity of the concrete and mortar substantially,inhibit the plastic cracks and shrinkage cracks of the concrete during the early period,improve the impermeability,freeze-thaw resistance,and fire resistance of the concrete,and improve the durability of concrete ultimately. In this paper,the in-situ test of adding the cellulose fiber into the concrete is performed, which verifies the impact and improvement of the cellulose fiber on the performance of high-strength concrete. Additionally,the cellulose fiber and its content are determined to suit the prefabricated tank concrete of the Shahe aqueduct and to meet the design requirements in order to ensure the engineering quality of the Shahe aqueduct project

  18. Numerical Simulation of Temperature Control and Anti-cracking Measures for the Ming River Aqueduct of the South-to-North Water Diversion Project%南水北调洺河渡槽施工期温控防裂仿真计算

    Institute of Scientific and Technical Information of China (English)

    夏世法; 鲁一晖; 李秀琳; 耿运生

    2012-01-01

    The Ming River aqueduct adopts the high-performance C50 concrete with high speed of heat generation and high calorific value. The surface cracks are prone to occur in the thin concrete structures such as the bottom board,side wall, longeron, and crossbeam during the early period of construction,and they may expand and thus form the throughout cracks. In addition, the aqueduct is divided into two layers. When the temperature of the concrete at the upper side walls drops, the throughout cracks may occur caused by the strong constrictions of the bottom concrete. In this paper, the three-dimensional numerical analysis is conducted to obtain the measures and indexes of temperature control for the aqueduct in different months during the construction period, which can provide the feedback for the design and guidance for the construction and thus prevent the formation of cracks in the concrete. Moreover, the results in this paper can be used as references for other similar projects.%南水北调中线洺河渡槽工程采用C50高性能混凝土,发热速度快,发热量高.对于槽身底板、侧墙、纵梁和横梁等薄壁结构来说,在浇筑早期容易产生表面裂缝,并可能进而发展成为贯穿性裂缝.另外,由于渡槽分两层浇筑,当上层新浇侧墙混凝土温度下降时,受老混凝土约束,容易产生贯穿性裂缝.利用仿真计算遴选不同月份施工时渡槽混凝土的温控措施及温度控制指标,以便反馈设计和指导施工,达到渡槽混凝土施工期防裂的目的,并可为类似工程提供参考.

  19. 南水北调中线大型预应力渡槽有限元分析%Finite Element Analysis of a Large Pre-stressed Concrete Aqueduct in the Middle Route of South-to-North Water Diversion Project

    Institute of Scientific and Technical Information of China (English)

    王刚; 任德记; 周亮; 张超

    2011-01-01

    针对南水北调中线总干渠渡槽的大流童、大跨度、大荷载、过水断面大等特性,提出了钢绞线的两种布束方案和模拟技术,为确保工程的安全和结构的优化,采用三维有限元方法,研究分析了两种布束方案下各工况底梁、底肋、边墙等控制断面的应力、应变分布规律,结果表明:采用方案一的钢绞线布束方案较为合理,且槽身满足抗裂和挠度要求.%According to the characteristics of the main canal aqueduct in the middle route of South-to-North Water Diversion Project,such as traffic flow, large span, load enough, large cross section, two prestressed strand methods and numerical simulation methods are put forward. In order to ensure the safety and the optimal design of them,a three-dimensional space calculation with the ANSYS is analyzed and the stress distribution of control section, including the bottom beam and rib, side wall, is obtained by using two methods. Results show that the first method is much more reasonable and meets the requirements of crack and deflection of the aqueduct body.

  20. Research and design of aqueduct structure over-passing Qingdao-Lanzhou Highway in South-to-North Water Diversion%南水北调中线青兰高速交叉渡槽结构设计研究

    Institute of Scientific and Technical Information of China (English)

    郑光俊; 张传健; 吕国梁; 刘磊

    2014-01-01

    The aqueduct over-passing Qingdao-Lanzhou Highway is a large type crossing structure on the main canal of Mid-dle Route Project of South-to-North Water Diversion. Because an additional water head was not designed in the planning stage and the approach road of built highway should be considered, the aqueduct design has encountered great difficulties. This paper innovatively puts forward the trapezoidal cross section with separated buttress and a flow-direction asymmetric slant parallelogram in plane. This structure layout is unique and original, and successfully solves the technical difficulties, which can be referred by similar projects.%南水北调中线青兰高速交叉渡槽工程是总干渠上的大型交叉建筑物。由于规划阶段未对其分配额外水头,且需兼顾已建高速公路引线工程布置,给渡槽的设计带来了极大困难。为此,设计创新性地提出了过水断面为梯形、槽身结构为分离式扶壁梯形、在顺流向平面上呈不对称斜平行四边形布置的渡槽结构。结构布置和设计新颖而独特,成功解决了相关技术难题,可为类似渡槽工程设计提供借鉴。

  1. 两个大前庭水管综合征家系的临床及SLC26A4基因的检测分析%Clinical and Molecular Diagnosis in Two Chinese Families with Enlargement of Vestibular Aqueduct

    Institute of Scientific and Technical Information of China (English)

    田晓丽; 崔书平; 段乃超; 马建刚; 蒋新霞; 黄爱萍; 刘艳平; 朱庆文

    2014-01-01

    Objective To elucidate the clinical diagnosis and molecular pathogenesis of LAVS in two Chinese families. Methods Clinical data and DNA samples were obtained from two LAVS families. The exons and flanking spliciding sites of SLC26A4 were screened in 6 hearing loss patients and 6 normal members in the two families by PCR and direct sequencing. Results There were 9 people and a fetus in the first family of a total of 3 generations. Among them only the third generation had 2 deafness patients. There were 14 people in the second family of a total of 3 generations. Among them the second genera-tion had 3 deafness patients and the third had one deafness patient. The clinical characteristics of patients in the two families included pre-and post-lingual sensorineural hearing loss, dysphonia and enlarged vestibular aqueduct. A total of 5 different types of SLC26A4 mutations were identified in the two families. Conclusions Hearing loss in the 6 patients of the two families are probably caused by different biallelic mutations of SLC26A4. The fetus in the first family appears to be a carrier. Enhanc-ing pre-pregnancy and prenatal screening of deafness gene is of great significance in preventing this kind of deafness in new-born children.%目的:分析两个非综合征型前庭水管扩大耳聋家系的临床特征和SLC26A4基因检测特点。方法对两个非综合征型前庭水管扩大耳聋小家系进行临床表型分析,并对两个家系中的6例耳聋患者、6例听力正常者及1例胎儿进行SLC26A4基因全编码序列的检测。结果第一个家系共3代9人,其中仅第三代2人为耳聋患者,2例均为语后感音神经性聋,颞骨CT显示均为前庭水管扩大,1例胎儿。第二个家系共三代14人,其中4人为耳聋患者,1例为语后感音神经性聋,3例为语前感音神经性聋。颞骨CT显示均为前庭水管扩大。两个家系共发现SLC26A4基因1022delC、c.919-2A>G、p.G497S、p. H723R、p.T410M五种

  2. Arsenic Geochemistry in Source Waters of the Los Angeles Aqueduct

    OpenAIRE

    Hering, Janet G; Wilkie, Jennifer A; Chiu, Van Q

    1997-01-01

    Arsenic is a widely distributed constituent of geologic materials, with an average crustal abundance of 1.8 ppm. The natural processes of weathering of arsenic-containing minerals and volcanism contribute arsenic to groundwaters, surface freshwaters, and seawater. Recently, increased attention has focused on arsenic geochemistry in natural waters. This attention has been motivated by concern over the human health effects of arsenic exposure; consumption of drinking water can be a significant,...

  3. Hydrogeological Characteristics of Hellenic Aqueducts-Like Qanats

    OpenAIRE

    Andreas N. Angelakis; Emmanouil Steiakakis; Konstantinos S. Voudouris; Yiannis Christodoulakos

    2013-01-01

    In ancient Hellas, water management began in the early Minoan Era (ca. 3200–1100 BC) and was related to the geomorphology, the geology, the topography, and the local climatic, hydrological, and socio-political conditions. Historical and archaeological evidences show that ancient Greeks had developed even qanat-related technologies since the Classical times. During democratic periods, the focus of water management was on sustainable small scale, safe, and cost effective management practices, a...

  4. The geographical information systems in the development of the municipal aqueducts

    International Nuclear Information System (INIS)

    The geographic information systems can be used at the water/wastewater systems in order to systematize and optimize these public services. This task should be accomplished by applying an organized method and many other technologies, including GPS, ground penetrating radar topography, photogrametry, remote sensing and field inspection for collecting information. The project planning while applying such kind of method must be accordingly managed with the needs, which could have been previously obtained by direct evaluation at the business organization domain. In the same way, the geographic database design and implementation must take into account this needs in order to reflect the water system reality. The project achievements can be defined in terms of the GIS effectiveness, completeness, and users thrust on it and the support granted to the water enterprise managers. The stages of application development (including analysis, design, development and implementation), such as the map and report of the water network elements at any street intersection, must be oriented to the intranet and optionally the Internet. This document is the result of the experience of a cadastral and geodetic engineer teamwork, which wants to expose the importance and benefits at the operative, administrative and economic level that GIS implementation and maintenance offers, in the Colombian water/waste-water systems

  5. IMPLEMENTATION OF QUALITY THROUGH LEADERSHIP FUNCTIONS - CASE STUDY: OLD ROMAN AQUEDUCT

    Directory of Open Access Journals (Sweden)

    Slavko Arsovski

    2012-12-01

    Full Text Available In this paper, the authors chose the specific implementation approach through quality leadership function, using, therefore, a well-known model of quality implementation in modern organizations, setting the hypothesis of its possible application in the construction of water supply in ancient Rome.

  6. Progressive fluctuant hearing loss, enlarged vestibular aqueduct, and cochlear hypoplasia in branchio-oto-renal syndrome.

    NARCIS (Netherlands)

    Kemperman, M.H.; Stinckens, C.I.C.; Kumar, S.; Huygen, P.L.M.; Joosten, F.B.M.; Cremers, C.W.R.J.

    2001-01-01

    OBJECTIVE: To study the results of petrosal bone imaging and audiometric long-term follow-up of two patients with branchio-oto-renal (BOR) syndrome and relate them to the clinical features, including caloric responses. STUDY DESIGN: Longitudinal case study. SETTING: Tertiary referral center. PATIENT

  7. Roman aqueducts and calcareous sinter deposits as a proxy for environmental changes

    OpenAIRE

    Sürmelihindi, Emine Gül

    2013-01-01

    Die im Süden der Türkei gelegen, antiken Städte Aspendos und Patara, waren in der Römerzeit zwei bedeutende Handelszentren mit hoher Bevölkerungsdichte. Aquädukte versorgten beide Städte mit carbonathaltigem Wasser, wobei sich Kalksinter (Calciumcarbonat) in der Kanalrinne ablagerte. Dabei lagern sich im Wechsel eine hellere und dunklere Kalksinterlage ab, die als Sinterpaar bezeichnet wird. Um die Entstehung dieser Sinterpaare besser zu verstehen, und die beteiligten Prozesse mit saisonalen ...

  8. Pumps, Aqueducts, and Drought Management: vascular physiology in vascular cognitive impairment

    OpenAIRE

    Marshall, Randolph S.; Lazar, Ronald M

    2010-01-01

    Vascular cognitive impairment has been traditionally defined by structural pathology – an accumulation of infarcts -- leading to progressive cognitive decline. Recent evidence, however, suggests that cognitive impairment may be independently mediated by hemodynamic dysfunction including global and hemispheral hypoperfusion and altered cerebral blood flow regulation. In this review we examine evidence for the contribution of hemodynamic impairment to cognitive dysfunction in the setting of lar...

  9. Transethmoidal encephalocele after reduction of high intracranial pressure in aqueductal stenosis.

    Science.gov (United States)

    Sharifi, Guive; Alavi, Ehsan; Jalessi, Maryam; Haddadian, Karim; Faramarzi, Faezeh

    2014-01-01

    Acquired non-traumatic transethmoidal encephaloceles are very infrequent lesions that are generally caused by a tumor or hydrocephalus. As far as we know, there is no reported case of encephalocele after CSF diversion in the literature. We present a 25-year-old woman with hydrocephalus due to aquiductal stenosis who was treated with endoscopic third ventriculostomy. Nine months later, she had developed rhinorrhea and on imaging she had a transethmoidal encephalocele. She underwent endonasal endoscopic repair of the defect and removal of herniated parenchyma. CSF diversion to parasellar cisterns is not a known iatrogenic cause of basal encephalocele and is not noted elsewhere as a complication of third ventriculostomy. However, as third ventriculostomy is performed usually for intracranial hypertension treatment and intracranial hypertension itself is a known but rare cause of lacunar skull defect and encephalocele, this co-incidence may occur. PMID:24535796

  10. Thoughts Regarding the Dimensions of Faults at Rainier and Aqueduct Mesas, Nye County, Nevada, Based on Surface and Underground Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Drellack, S.L.; Prothro, L.B.; Townsend, M.J.; Townsend, D.R.

    2011-02-01

    The geologic setting and history, along with observations through 50 years of detailed geologic field work, show that large-displacement (i.e., greater than 30 meters of displacement) syn- to post-volcanic faults are rare in the Rainier Mesa area. Faults observed in tunnels and drill holes are mostly tight, with small displacements (most less than 1.5 meters) and small associated damage zones. Faults are much more abundant in the zeolitized tuffs than in the overlying vitric tuffs, and there is little evidence that faults extend downward from the tuff section through the argillic paleocolluvium into pre-Tertiary rocks. The differences in geomechanical characteristics of the various tuff lithologies at Rainier Mesa suggest that most faults on Rainer Mesa are limited to the zeolitic units sandwiched between the overlying vitric bedded tuffs and the underlying pre-Tertiary units (lower carbonate aquifer–3, lower clastic confining unit–1, and Mesozoic granite confining unit).

  11. 海域输水管道工程的结构设计%Structral Design of Sea Aqueduct Project

    Institute of Scientific and Technical Information of China (English)

    汪俊池; 刘延波

    2009-01-01

    本文介绍从温州市内引水,向洞头县多个岛屿供水的工程.本输水干管沿途经过了陆域和海域多种不同的地形、地貌,因此本工程的结构设计包含了多种不同形式的穿越工程设计.本文重点介绍了海域管道的穿越工程设计.

  12. 渡槽结构优化研究及实现%The optimization design and achieve of aqueduct structure

    Institute of Scientific and Technical Information of China (English)

    刘晓文

    2001-01-01

    针对渡槽的纵坡、跨度、断面形式及结构计算方法采用优化设计,得到输水渡槽的经济、合理的结构型式和尺寸,并在深圳市东部供水水源工程中实现,获得良好的经济效果.

  13. GENERAL DESCRIPTION OF THE AQUEDUCT TUNNEL OF EUPALINOS IN ANCIENT SAMOS : New survey by use of digital measurement techniques

    OpenAIRE

    Yoshitake, Ryuichi; ヨシタケ, リュウイチ; 吉武, 隆一

    2012-01-01

    In about 540 B.C., the Greek enginieer Eupalinos dug a tunnel over 1 km long through a mountain to bring water from a spring on its far side into the city of Samos on the Greek island of the same name. The tunnel was dug from both ends to meet in the middle. Since the tunnel was rediscovered in the nineteenth century, there have been several investigations. The present article reports a new measurement of the tunnel using modern instruments and a reinvestigation of the construction strategy. ...

  14. Genetic deletion of Rnd3 results in aqueductal stenosis leading to hydrocephalus through up-regulation of Notch signaling

    OpenAIRE

    Lin, Xi; Liu, Baohui; Yang, Xiangsheng; Yue, Xiaojing; Diao, Lixia; Jing WANG; Chang, Jiang

    2013-01-01

    Rho family guanosine triphosphatase (GTPase) 3 (Rnd3), a member of the small Rho GTPase family, is involved in the regulation of cell actin cytoskeleton dynamics, cell migration, and proliferation through the Rho kinase-dependent signaling pathway. We report a role of Rnd3 in the pathogenesis of hydrocephalus disorder. Mice with Rnd3 genetic deletion developed severe obstructive hydrocephalus with enlargement of the lateral and third ventricles, but not of the fourth ventricles. The cerebral ...

  15. Community Knowledge Sharing and Co-Production of Water Services: Two Cases of Community Aqueduct Associations in Colombia

    Directory of Open Access Journals (Sweden)

    Valeria Llano-Arias

    2015-06-01

    These new forms of citizenship based on claims of sovereignty over natural, common goods are gradually transforming Colombian democratic space. The article draws on debates around active citizenship, deepening democracy, and participatory communication approaches to explain the aims of community organisations and the mechanisms by which they are self-organising and managing water at the local level.

  16. [Scanning electron microscopy studies of the structure of tissue in the cochlear opening of the cochlear aqueduct].

    Science.gov (United States)

    Galić, M; Giebel, W

    1987-01-01

    The structure of the internal and external tissue of the cochlear opening of the cochlear aquaeduct was examined by light microscopy on semithin sections and by scanning electron microscopy. The whole area is filled with a net of mesenchymal cells. The cell axes are randomly orientated inside the aquaeduct. On the outside of the cochlear aquaeduct fibrocytic tissue fills a space which is triangular in cross-section between the basal part of the cochlea wall of the tympanic scala and the middle portion of the round window membrane. In this area the direction of the net is uniform and it gives the impression of anchorage of the round window membrane on the perilymphatic side. The rim bordering the perilymphatic space is a dense net but not fully closed. The scanning electron microscopic pictures taken perpendicular to this border structure show clearly a texture of mesenchymal cells with open spaces. No closed "membrana limitans" was found. The possible function of the fixation of the round window membrane to the perilymphatic space giving rise to an asymmetric perilymph movement is discussed with regard to the physiology of sound transmission. PMID:3561119

  17. 50 CFR 17.95 - Critical habitat-fish and wildlife.

    Science.gov (United States)

    2010-10-01

    ..., roads, aqueducts, antennas, water tanks, agricultural fields, paved areas, lawns, and other urban... denning. (3) Critical habitat does not include manmade structures (such as buildings, aqueducts,...

  18. Opptimum Design of Yanjiagou Aqueduct of Yellow River Project%扬黄灌溉工程阎家沟渡槽优化设计

    Institute of Scientific and Technical Information of China (English)

    王引田; 吴恺; 王卫东

    2003-01-01

    针对阎家沟渡槽地处湿陷性黄土覆盖层厚、冲沟窄而深、沟谷地下水位较高的特点,对渡槽进行了选择、优化设计,最终选择了过流条件较合理的"U"型槽身、适应湿陷性黄土层的扩底井柱桩及转孔灌柱桩基础和经济合理的超高型"A"字型支承排架.

  19. 赵山渡渡槽伸缩缝处理方案设计%Scheme design for expansion joints treatment of Zhaoshandu aqueduct

    Institute of Scientific and Technical Information of China (English)

    张伟

    2009-01-01

    随着城市供水发展,引水工程功能的变化,对输水渡槽伸缩缝止水结构要求提高,水工建筑物的运行维护技术要求也变得更加复杂,为了满足供水功能变化,必须对伸缩缝的止水系统进行改造.

  20. An overview of construction technologies of the Liyuan River aqueduct%梨园河渡槽工程施工技术综述

    Institute of Scientific and Technical Information of China (English)

    田学义

    2009-01-01

    渡槽工程的施工方法是多种多样的,梨园河渡槽施工采用了单排架现浇和槽身现场浇筑使用混凝土预制块砌筑一定断面型式的墙体作支撑,完全是创新方法,伸缩止水缝和连接段等部位的施工也有独到之处,从而使工程建设达到了节省资金、缩短工期、保证质量及增加安全性等良好效果,是大断面单排架"U"型薄壳渡槽施工方法的有益探索.

  1. 龙场渡槽主拱圈施工支架方案设计%The Longchang aqueduct main arch construction stent design

    Institute of Scientific and Technical Information of China (English)

    刘平; 罗连生

    2013-01-01

    结合黔中水利枢纽一期工程龙场渡槽主拱圈现浇施工实际,详细介绍了主拱圈现浇施工中组合支架的设计方案,并对组合支架各组成部分的布设及注意要点进行了阐述,为今后同类桥梁的施工提供了借鉴.

  2. The Pile Base Design of Yanjiagou Aqueduct and Its Stability Analyse%闫家沟渡槽桩基设计及稳定性分析

    Institute of Scientific and Technical Information of China (English)

    崔末兰

    2003-01-01

    针对闫家沟渡槽基础位于Ⅳ级自重湿陷性黄土地区,又处于Ⅷ度地震区,且基础上部排架很高这一特殊性,根据建筑桩基技术规范,进行了渡槽桩基优化设计,保正了建筑物的设计安全可靠,且施工方便,经济合理.

  3. Application of anchorages in treatment of quality defects of aqueducts%植筋技术在渡槽质量事故处理中的应用

    Institute of Scientific and Technical Information of China (English)

    方业源

    2010-01-01

    五化灌区塘柳渡槽在施工不慎发生槽壁钢筋严重偏移的质量事故,在受到施工工期严格限制的情况下采用植筋技术,弥补了施工缺陷.本文介绍了该质量事故的处理方案、植筋的具体施工工序和需要注意的一些问题,可为工程技术人员处理类似质量事故提供参考.

  4. Songgou aqueduct design in Dongfanghong irrigation district in Xinmi city%新密市东方红灌区宋沟渡槽设计

    Institute of Scientific and Technical Information of China (English)

    高涛; 赵芮

    2008-01-01

    由于宋沟渡槽设计具有渡槽设计的代表性,因此对其进行了位置选择,水力计算等的整体布置,并进行了槽身与支撑结构的尺寸拟定,内力计算,渡槽稳定性计算,配筋,细部结构的设置等,旨在最终确保渡槽施工的顺利进行.

  5. 一大型水利渡槽爆破拆除设计与施工%DESIGN AND CONSTRUCTION OF A LARGE IRRIGATION AQUEDUCT BRIDGE'S BLASTING DEMOLITION

    Institute of Scientific and Technical Information of China (English)

    袁松

    2009-01-01

    针对湖北省大悟县一大型水利渡槽结构特征,采取了水压爆破法拆除.本文阐述了该渡槽不采取炮孔法而采取水压爆破法拆除的理由、水压爆破法设计与施工和爆破效果.重点指出了水压爆破药量计算与药包布置,可供类似工程参考.

  6. The continuous beam aqueduct design in express highway%高速公路上连续梁式渡槽的设计

    Institute of Scientific and Technical Information of China (English)

    陈亮

    2010-01-01

    针对合淮阜高速公路上的跨度较大的地面输水建筑物,普通的梁式简支渡槽难以满足要求的特点,采用了预应力连续梁式渡槽,简略介绍了该渡槽结构设计和结构静力计算方法,指出这是一种经济合理并满足耐久性的结构.

  7. HIGH ASPECTRATIO RATIO OF RECTANGULAR AQUEDUCT OPTIMIZED SUPPORT DESIGN%梁式矩形渡槽高宽比优化设计研究

    Institute of Scientific and Technical Information of China (English)

    杜新亮; 韩沛东

    2016-01-01

    采用合适的高宽比可以使渡槽的横向受力条件更好。为了优化渡槽结构,在结构稳定的基础上更加经济,有必要研究不同高宽比对渡槽的影响。论文以遂宁市三仙湖水库补水渠小香林渡槽为例,采用通用电算程序对不同高宽比下渡槽的受力情况进行分析。

  8. Ancient Rome I: Government and Politics; the Military; Trade and the Economy; Aqueducts, Baths, and Sewers; the Arena. Volume 7. Teaching with Primary Sources Series.

    Science.gov (United States)

    Baker, Rosalie F.; Baker, Charles F., III

    This unit on Ancient Rome (covering a time period from 753 B.C. until A.D. 476) contains the following elements: a list of documents, with a description of each document and a brief synopsis of its historical significance to the unit's theme; the documents; and a set of activities. The unit's documents are grouped under the five categories listed…

  9. Localising deformation along the elevation of linear structures : an experiment with space-borne InSAR and RTK GPS on the Roman Aqueducts in Rome, Italy.

    OpenAIRE

    Tapete D.; Morelli S.; Fanti R.; Casagli N.

    2015-01-01

    We map and monitor the condition of linear structures using Measurement Points (MPs) from satellite Interferometric Synthetic Aperture Radar (InSAR), and deal with the uncertainty of localising the detected deformation along the building elevation. We combine spatial information of the MPs with elevation measurements collected by Real Time Kinematic (RTK) GPS surveying to understand where structural motions occurred. The MPs are geolocated along the z-direction by exploiting their height info...

  10. Large endolymphatic sac. A congenital deformity of the inner ear shown by magnetic resonance imaging

    OpenAIRE

    Phelps, P D; Mahoney, C. F. O.; Luxon, L M

    1997-01-01

    Fluctuant and progressive hearing impairment in a patient with a wide vestibular aqueduct has been called the 'large vestibular aqueduct syndrome'. Recently reports of magnetic resonance imaging (MRI) studies describe enlargement of the endolymphatic sac and duct in patients shown to have large vestibular aqueducts by computed tomography (CT). A patient with progressive deafness was shown to have borderline or slightly enlarged vestibular aqueducts by re-formatted sagittal CT. However, MRI in...

  11. Structural Safety Analysis of Large-sized Aqueduct for South-North Water Diversion Project%南水北调大型渡槽结构抗震安全性研究

    Institute of Scientific and Technical Information of China (English)

    胡少伟; 游日

    2011-01-01

    阐述了南水北调中大型渡槽的抗震问题,分别介绍了基于常微分方程求解器(ODE)和有限元方法的大型渡槽动力计算模型、动力特性分析和设置铅芯橡胶支座(LRB)的隔震分析.研究表明,基于ODE求解器的解析和半解析方法有很好的精度和可靠性,可用于大型渡槽的初步设计.结合所得的研究成果,对南水北调的渡槽抗震提出了合理化建议.%Firstly, this study briefly explains the current situation of Chinese seismic design codes for bridge pile foundations in liquefying and lateral spreading ground. The Chinese and the Japanese seismic design method and technical detail for bridge pile foundations in liquefying and lateral spreading ground are described and compared systematically and comprehensively, and the methods to determine the reduction factor of subgrade reaction as well as the computing mode of the applied force on piles due to liquefaction-induced lateral spreading of soil in Japanese design codes are especially introduced. Finally, some key problems of current Chinese design codes including seismic design method, vertical bearing capacity, buckling stability analysis and seismic measures near the soil dividing boundary for piles in liquefying and lateral spreading ground are generalized and the corresponding improvement suggestions are proposed. These will tend to improve the seismic safety of bridge engineering and provide certain reference values for our country' s engineering talents.Firstly, this study briefly explains the current situation of Chinese seismic design codes for bridge pile foundations in liquefying and lateral spreading ground. The Chinese and the Japanese seismic design method and technical detail for bridge pile foundations in liquefying and lateral spreading ground are described and compared systematically and comprehensively, and the methods to determine the reduction factor of subgrade reaction as well as the computing mode of the applied force on piles due to liquefaction-induced lateral spreading of soil in Japanese design codes are especially introduced. Finally, some key problems of current Chinese design codes including seismic design method, vertical bearing capacity, buckling stability analysis and seismic measures near the soil dividing boundary for piles in liquefying and lateral spreading ground are generalized and the corresponding improvement suggestions are proposed. These will tend to improve the seismic safety of bridge engineering and provide certain reference values for our country' s engineering talents.

  12. Basic theory on aqueduct bridge vibration control using lsolation and energy dissipation hybrid sistem%渡槽结构隔震与耗能减振控制机理的研究

    Institute of Scientific and Technical Information of China (English)

    庄中华; 李敏霞; 陈厚群

    2002-01-01

    本文结合设计中的南泉水河渡槽结构,将隔震耗能混合减支座应用于渡槽结构,并将该控制结构与没有控制支座的常规结构进行了地震反应的比较分析.在计算分析中将渡槽槽墩结构简化为顶部具有集中质量的单柱结构,槽体作为刚体处理,槽内水体简化为Housner模型.

  13. Design of Hydraulic System for DZ30/2500 Rectangle Aqueduct Building Machine%DZ30/2500矩型渡槽造槽机液压系统设计

    Institute of Scientific and Technical Information of China (English)

    李艳; 祖国栋; 张红军

    2014-01-01

    造槽机整机分散,液压系统采用独立单元设计,使其简化和模块化.外模底模单侧8启闭液压缸、外模侧模单侧8支横移液压缸,内模侧模单侧8支旋转液压缸、内模侧模单侧8支横移液压缸,可实现同步伸缩,这是由结构件的刚度来实现的,也可进行单独调整,这是由控制阀来实现的.

  14. Design method for aqueduct piles on deep layer Loess foundation with gravity damping collapse characteristics%大厚度自重湿陷性黄土地基上渡槽桩基的设计方法

    Institute of Scientific and Technical Information of China (English)

    李敬昌

    2004-01-01

    通过对宁夏扬黄扶贫灌溉工程渠道建筑物的基础处理,阐述了在大厚度自重湿陷性黄土地基采用桩基设计的理论依据及方法,为以后类似基础处理工程提供借鉴.

  15. Review of optimize design on Caobe aqueduct in South-to-North water transfer project%南水北调中线工程漕河渡槽安全监测设计

    Institute of Scientific and Technical Information of China (English)

    张颖军

    2010-01-01

    漕河渡槽作为南水北调中线工程中标志性建筑物,具有技术难度大、安全监测复杂等特点.根据漕河渡槽的特点,对观测设计原则、观测部位的选定、观测项目设置,以及不同观测部位、项目的测点布置进行综述,以期对今后南水北调工程观测设计有所裨益.

  16. Application and Practice of Large Span Precast Aqueduct in Projects%大跨度预制渡槽在工程中的应用与实践

    Institute of Scientific and Technical Information of China (English)

    张宁; 郭春雷; 周磊

    2009-01-01

    对宁夏引黄灌渠大跨度渡槽的方案比选,水力计算,槽壳双向预应力设计,侧墙预制吊运、槽墩、槽台设计,钻孔灌注桩基础设计,预制与现浇施工控制等问题,作以概略说明,并依据施工流程进行结构分析,供设计单位在作类似结构设计时参考.

  17. Design and Construction of Large-sized Concrete Box Aqueduct for Water Delivery%大型输水混凝土箱形渡槽设计与施工

    Institute of Scientific and Technical Information of China (English)

    戴金水; 郭雁平

    2005-01-01

    现以深圳市供水网络干线工程跨越深圳水库的箱形渡槽为工程实例,介绍了大型输水渡槽在设计、施工过程中,采用预应力技术,成功地解决了大型钢筋混凝土箱形渡槽纵向应力大、易裂缝渗漏的难题,是我国水利工程渡槽建筑史上的一项新尝试,对长距离调水工程的设计、施工具有重要的技术借鉴意义.

  18. Design and Construction Technical Problems of Gravity Aqueduct under Complex Topographic and Geologic Conditions%复杂地形地质条件下自流式输水管道设计施工技术问题

    Institute of Scientific and Technical Information of China (English)

    李学志

    2013-01-01

      在基岩山区复杂地形地质条件下,怎样能使自流输水管道设计施工科学经济合理,做到投资少效果好,这是工程技术人员在设计施工中应解决的问题。只要抓住自流输水管道的水气流原理,采取适当的工程措施,使水压传递连续,问题就容易解决。%In complex terrain mountainous bedrock geological conditions, how to conduct scientific economic and rational design and construction of artesian water pipelines and achieve less investment and good effect is the issue to be addressed by engineering and technical personnel in the design and construction. Only grasping the water and gas convection law of artesian water pipelines and taking appropriate engineering measures can the problem be easily solved.

  19. 东深供水改造工程旗岭渡槽施工测量%Construction survey of Qi-ling aqueduct in the retrofit of Dong-shen water supply work

    Institute of Scientific and Technical Information of China (English)

    蔡锐武; 张小平

    2004-01-01

    本文通过东深供水改造工程旗岭渡槽施工测量工作,重点讨论旗岭渡槽施工控制网的建立、施工放样方法及施工过程中建筑物的变形观测,并对其精度进行分析,以期对从事本行业的人员有所借鉴.

  20. Design of bowl-buckle scaffloding support system in the aqueduct project along the Jiehe River%界河渡槽工程碗扣式脚手架支撑方案设计

    Institute of Scientific and Technical Information of China (English)

    卢玉强; 张海龙; 黄启胜

    2010-01-01

    近年来,大跨度的水工建筑物应用日趋增多,为保证施工安全,其支撑必须要具有足够的承载力、刚度和稳定性.以山东省胶东地区引黄调水工程界河渡槽工程中碗扣式脚手架支撑为例,介绍了如何对碗扣式支撑系统进行设计计算以及如何确定其排布形式和间距等.

  1. Design and calculation of large span aqueduct bridge of Yantian reservoir in Shenzhen municipality%深圳市雁田水库大跨度输水管桥设计与计算

    Institute of Scientific and Technical Information of China (English)

    贺晓彬

    2004-01-01

    为缩短施工工期,降低工程投资,充分利用钢管的输水和跨越能力,建造大跨度大型输水管桥,是我国水利工程建设的发展方向之一.本文以深圳市龙口--茜坑供水工程新建雁田水库管桥的工程实例,简要介绍了其设计、结构静力计算手段,为同类型工程设计与建设提供了重要的技术借鉴和实践经验.

  2. 大型核电站排水箱涵和交叉口渡槽的结构设计%Structure Design of Water Discharge Box Culvert and Crossing Aqueduct in Large Nuclear Power Station

    Institute of Scientific and Technical Information of China (English)

    廖泽球

    2001-01-01

    岭澳核电站排水箱涵和交叉口渡槽为现浇钢筋混凝土结构,是海域工程中的重要建筑物,是与核安全有关的物项.因此,箱涵和渡槽的抗震设计标准较高,其支墩均设置了橡胶支座,它对改善结构的受力状态、提高抗震性能和减少钢筋用量起到了重要作用.

  3. Hydrography, Surface water within Sedgwick County including rivers, streams, lakes, ponds and floodways. Some additional drainage ways and aqueducts are also included., Published in 2008, 1:1200 (1in=100ft) scale, Sedgwick County, Kansas.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Hydrography dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Orthoimagery information as of 2008. It is described as 'Surface...

  4. NEUROCISTICERCOSIS CON LOCALIZACION EN ACUEDUCTO DE SILVIO: DESCRIPCION DE CASO Y REVISION DE LA LITERATURA.

    Directory of Open Access Journals (Sweden)

    Leonardo Dominguez de la Ossa

    2007-01-01

    Full Text Available Neurocysticercosis (NCC is the most common parasitic disease of the central nervous system. We report a patient with neurocysticercosis in Silvio aqueduct . A ventriculoperitoneal shunt was place and there were not surgical complications the surgical procedure is described and we analized the inusual localization in Silvio aqueduct

  5. NEUROCISTICERCOSIS CON LOCALIZACION EN ACUEDUCTO DE SILVIO: DESCRIPCION DE CASO Y REVISION DE LA LITERATURA.

    OpenAIRE

    Leonardo Dominguez de la Ossa; Luis Rafael Moscote Salazar

    2007-01-01

    Neurocysticercosis (NCC) is the most common parasitic disease of the central nervous system. We report a patient with neurocysticercosis in Silvio aqueduct . A ventriculoperitoneal shunt was place and there were not surgical complications the surgical procedure is described and we analized the inusual localization in Silvio aqueduct

  6. Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI

    DEFF Research Database (Denmark)

    Gideon, P; Ståhlberg, F; Thomsen, C;

    1994-01-01

    An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal...

  7. Patofysiologiske mekanismer bag øjensymptomer ved primaere tumorer i corpus pineale

    DEFF Research Database (Denmark)

    Illum, N O; Møller, M; Garde, E

    1993-01-01

    Primary tumors of the pineal body can produce dyscoordinative movements of the eye, pupillary dilatation, paralysis of adduction during convergence and nystagmus. Obstruction of the aqueduct can cause hydrocephalus, increased intracranial pressure and papilledema. Diabetes insipidus may be a...

  8. All architecture fluctuates between the technical and the spectacle

    OpenAIRE

    Jennings, Sinead

    2011-01-01

    non-peer-reviewed TOC: Introduction / Layers of Understanding / SNN+ / The “Industrial Park” / The Colosseum: Urban Sink / Of Aqueducts and Co. Down / Statement of Intent / Thesis Drawings / Bibliography

  9. 78 FR 37846 - Resource Management Plan/General Plan and Environmental Impact Statement/Environmental Impact...

    Science.gov (United States)

    2013-06-24

    ... FR 46518). The comment period on the Draft EIS/EIR ended on October 2, 2012. The Final EIS/EIR... reservoirs, aqueducts, power plants, and pumping stations operated within the California State Water...

  10. The water-supply system in Roman Pompeii

    OpenAIRE

    Olsson, Richard

    2015-01-01

    This study focusses on the urban infrastructure for water supply in Roman Pompeii. The water distribution network of lead pipes was constructed inside the city walls, at the time when the city was connected to an aqueduct. Life for the Pompeiians changed considerably when aqueduct water started running continuously in street fountains all around the city. The study is based on previous research and on my own investigations and measurements on site in connection with the Swedish Pompeii Projec...

  11. Pendred Syndrome: study of three families

    OpenAIRE

    Bigozzi, M; Melchionda, S; R. Casano; Palladino, T; Gitti, G

    2005-01-01

    Although the textbook view of the Pendred syndrome is that of an autosomal recessive condition characterised by deafness and goitre, it is increasingly clear that not all patients present this classical clinical description. Malform-ations of the inner ear, specifically, enlargement of the vestibular aqueduct, are common in the Pendred syndrome. Mutations in the Pendred syndrome gene have been observed in patients with deafness and vestibular aqueduct dilatation, in the absence of other Pendr...

  12. Routes, dynamics, and correlates of cochlear inflammation in terminal and recovering experimental meningitis

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Worsøe, Lise; Brandt, Christian Thomas;

    2009-01-01

    inflammatory cells via cochlear aqueduct, whereas the endolymphatic space was infiltrated from the spiral ligament. Rosenthal's canal was infiltrated through osseous spiral lamina canaliculi. In the untreated group, the degree of inflammation correlated with time of death, whereas antibiotic treatment reversed...... this development. Perilymphatic inflammation correlated significantly with the CSF leukocyte count, whereas endolymphatic inflammation correlated with spiral ligament inflammation. CONCLUSIONS: Meningogenic inflammation of the rat cochlea occurs via the cochlear aqueduct and the spiral ligament...

  13. The continuity of Roman water supply systems in post-Roman Spain: the case of Valentia, a reliable example?

    OpenAIRE

    Martínez Jiménez, Javier (Archaeologist)

    2011-01-01

    Even if the general assumption is that Roman water supply systems (aqueducts in particular) ceased to function during the late Roman period, and that these were not present in medieval cities, recent archaeological research is proving that this was not always the case. Several cities in Spain show archaeological continuity in their water supply systems into the Visigothic period, and one of these seems to be Valencia. There is archaeological evidence to suggest a functioning aqueduct until th...

  14. Cerebrospinal fluid flow in patients with dilated ventricles studied with MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Parkkola, R.K.; Komu, M.E.S. [Department of Diagnostic Radiology, University Hospital of Turku (Finland); Kotilainen, E.M.; Valtonen, S.O. [Department of Neurosurgery, University Hospital of Turku (Finland); Thomsen, C. [Department of Radiology, National Danish University Hospital, Copenhagen (Denmark); Gideon, P. [Danish Magnetic Resonance Research Center, Hvidovre Hospital (Denmark)

    2000-09-01

    The purpose of this study was to measure the cerebrospinal fluid (CSF) velocity and flow in the aqueduct in patients with wide ventricles with or without signs of normal pressure hydrocephalus (NPH) before and after shunt surgery. We studied 18 patients with wide ventricles with MRI and measured the CSF velocity values in the aqueducts. Twelve patients with the clinical triad of NPH were examined. Six patients were studied only before shunt surgery and 6 patients were studied both before and after shunt surgery. Three patients with wide ventricles without clinical triad of NPH, and 3 patients with hydrocephalus following subarachnoid hemorrhage were also examined. Seven NPH patients with hyperdynamic CSF flow and three NPH patients with normal CSF velocity and flow values showed a positive clinical response to shunt surgery. Two of the three patients with hydrocephalus and hyperdynamic CSF flow values in the aqueduct secondary to subarachnoid bleeding responded to shunt surgery. One patient with same disease and low CSF velocity and flow values did not respond. No change was detected in the CSF flow values of the aqueduct when measurements before and after shunt surgery were compared. Ventriculoperitoneal shunting does not change the CSF dynamics in the aqueduct. (orig.)

  15. Menière-lignende symptomer efter meningeom

    DEFF Research Database (Denmark)

    Friis, Morten; Klokker, Mads; Fugleholm, Kåre

    2010-01-01

    A 36-year-old woman who presented with a right sided hearing loss, tinnitus and attacks of dizziness was initially diagnosed with Ménière's disease. A meningioma was found along the posterior surface of the petrosal bone, centred partly on the external aperture of the vestibular aqueduct with no ......A 36-year-old woman who presented with a right sided hearing loss, tinnitus and attacks of dizziness was initially diagnosed with Ménière's disease. A meningioma was found along the posterior surface of the petrosal bone, centred partly on the external aperture of the vestibular aqueduct...... with no relation to the meatal canal. Removal of the meningial tumour improved the hearing but Ménière's-like symptoms recurred after 18 months despite surgery. Ménière's-like symptoms could hypothetically be caused by changes of the endolymphatic duct or the vein of the vestibular aqueduct....

  16. Darcy's Public Fountains of the City of Dijon, Past and Present

    Science.gov (United States)

    Bobeck, P.; Ritzi, R. W.; Bair, E. S.

    2006-12-01

    Les Fountaines Publiques de la Ville de Dijon (Darcy, 1856) is well known for introducing the equation of ground-water motion. The monograph is a summary of Darcy's career-long study of hydraulics including water flow in canals, aqueducts, pipes, sand filters, and ground-water wells. He presented his knowledge in these areas in reviewing his construction of the public water supply system for Dijon, a system completed in 1840. The authors have recently traveled the length of Darcy's aqueduct system from its source at Rosoir spring, to the Porte Guillaume reservoir (at Jardin Darcy as it enters Dijon), through the city, to the terminal reservoir. We present the state of Darcy's original aqueduct (no longer in use) and public water supply system, and compare his design to the modern public water supply system serving Dijon.

  17. Genetic deletion of afadin causes hydrocephalus by destruction of adherens junctions in radial glial and ependymal cells in the midbrain.

    Directory of Open Access Journals (Sweden)

    Hideaki Yamamoto

    Full Text Available Adherens junctions (AJs play a role in mechanically connecting adjacent cells to maintain tissue structure, particularly in epithelial cells. The major cell-cell adhesion molecules at AJs are cadherins and nectins. Afadin binds to both nectins and α-catenin and recruits the cadherin-β-catenin complex to the nectin-based cell-cell adhesion site to form AJs. To explore the role of afadin in radial glial and ependymal cells in the brain, we generated mice carrying a nestin-Cre-mediated conditional knockout (cKO of the afadin gene. Newborn afadin-cKO mice developed hydrocephalus and died neonatally. The afadin-cKO brain displayed enlarged lateral ventricles and cerebral aqueduct, resulting from stenosis of the caudal end of the cerebral aqueduct and obliteration of the ventral part of the third ventricle. Afadin deficiency further caused the loss of ependymal cells from the ventricular and aqueductal surfaces. During development, radial glial cells, which terminally differentiate into ependymal cells, scattered from the ventricular zone and were replaced by neurons that eventually covered the ventricular and aqueductal surfaces of the afadin-cKO midbrain. Moreover, the denuded ependymal cells were only occasionally observed in the third ventricle and the cerebral aqueduct of the afadin-cKO midbrain. Afadin was co-localized with nectin-1 and N-cadherin at AJs of radial glial and ependymal cells in the control midbrain, but these proteins were not concentrated at AJs in the afadin-cKO midbrain. Thus, the defects in the afadin-cKO midbrain most likely resulted from the destruction of AJs, because AJs in the midbrain were already established before afadin was genetically deleted. These results indicate that afadin is essential for the maintenance of AJs in radial glial and ependymal cells in the midbrain and is required for normal morphogenesis of the cerebral aqueduct and ventral third ventricle in the midbrain.

  18. Mechanisms of hydrocephalus in cerebral cysticercosis: implications for therapy

    Energy Technology Data Exchange (ETDEWEB)

    Estanol, B.; Kleriga, E.; Loyo, M.; Mateos, H.; Lombardo, L.; Gordon, F.; Saguchi, A.F.

    1983-08-01

    Patients with hydrocephalus secondary to cerebral cysticercosis are a highly heterogeneous group. The mechanisms of hydrocephalus in these patients are multiple. Intraventricular cysts may be found in the 3rd and 4th ventricles, the sylvian aqueduct, and the foramen of Monro. Intraventricular cysts can be suspected when the 3rd and 4th ventricles or aqueduct remain enlarged despite shunting. Intraventricular contrast medium demonstrates the presence of the parasites. The intraventricular cysts should be removed surgically. Hydrocephalus due to cisternal cysticercosis can be diagnosed by isotope cisternography. These patients should receive shunts, but the long term prognosis is probably poor. Guidelines for the management of hydrocephalus due to cysticercosis are suggested.

  19. Mechanisms of hydrocephalus in cerebral cysticercosis: implications for therapy

    International Nuclear Information System (INIS)

    Patients with hydrocephalus secondary to cerebral cysticercosis are a highly heterogeneous group. The mechanisms of hydrocephalus in these patients are multiple. Intraventricular cysts may be found in the 3rd and 4th ventricles, the sylvian aqueduct, and the foramen of Monro. Intraventricular cysts can be suspected when the 3rd and 4th ventricles or aqueduct remain enlarged despite shunting. Intraventricular contrast medium demonstrates the presence of the parasites. The intraventricular cysts should be removed surgically. Hydrocephalus due to cisternal cysticercosis can be diagnosed by isotope cisternography. These patients should receive shunts, but the long term prognosis is probably poor. Guidelines for the management of hydrocephalus due to cysticercosis are suggested

  20. Unsteady-Flow Modeling for Emergency Shutdown of the CAP Canal

    OpenAIRE

    Clemmens, Bert; Wahlin, Brian; Shapiro, Marcus; Dent, Patrick

    2016-01-01

    The Central Arizona Project (CAP) is designed to bring about 1.9 ML of Colorado River water per year to Maricopa, Pima, and Pinal counties in Arizona. CAP carries water from the Colorado River at Lake Havasu toTucson. The CAP canal system is a 540 km long system of conveyance system aqueducts, tunnels, pumping plants,pipelines and a large reservoir (just north of Phoenix, AZ). Water is pumped uphill from the Colorado River. This study was conducted for the Hayden-Rhodes Aqueduct of the Centra...

  1. Cochlear implantation in patients with inner ear bone malformations with posterior labyrinth involvement: an exploratory study.

    Science.gov (United States)

    Palomeque Vera, Juan Miguel; Platero Sánchez-Escribano, María; Gómez Hervás, Javier; Fernández Prada, María; González Ramírez, Amanda Rocío; Sainz Quevedo, Manuel

    2016-04-01

    Inner ear bone malformations are one cause of profound sensorineural hearing loss. This investigation focused on those affecting the posterior labyrinth, especially enlarged vestibular aqueduct syndrome, which is associated with fluctuating and progressive hearing loss. The objectives of this study were to analyze the behavior of the electrical stimulation, auditory functionality and linguistic development in patients with inner ear malformations involving the posterior labyrinth. The study included ten patients undergoing cochlear implantation (cases: five with enlarged vestibular aqueduct, two with vestibular aqueduct stenosis/aplasia, and three with semicircular canal disorders). Post-implantation, data were gathered on the electrical stimulation threshold and maximum comfort levels and on the number of functioning electrodes. Evaluation of Auditory Responses to Speech (EARS) subtests were used to assess auditory functionality and language acquisition at 6, 12, and 24 months post-implantation. Results were compared with findings in a control group of 28 cochlear implantation patients without these malformations. No significant differences were found between case and control groups in electrical stimulation parameters; auditory functionality subtest scores were lower in cases than controls, although the difference was only statistically significant for some subtests. In conclusion, cochlear implantation patients with posterior labyrinth bone malformations and profound hearing loss, including those with enlarged vestibular aqueduct syndrome, showed no significant difference in electrical stimulation threshold with controls. Although some auditory functionality test results were lower in cases than in controls, cochlear implantation appears to be beneficial for all patients with these malformations. PMID:25971996

  2. Inner ear pressure changes following square wave intracranial or ear canal pressure manipulation in the same guinea pig

    NARCIS (Netherlands)

    Thalen, E; Wit, H; Segenhout, H; Albers, F

    2002-01-01

    Inner ear pressure was measured in scala tympani with a micropipette during square wave pressure manipulation of the intracranial compartment and, subsequently, of the external ear canal (EEC) in the same guinea pig. As expected, the combination of the cochlear aqueduct and the inner ear behaves as

  3. Dynamics of inner ear pressure change caused by intracranial pressure manipulation in the guinea pig

    NARCIS (Netherlands)

    Thalen, EO; Wit, HP; Segenhout, JM; Albers, FWJ

    2001-01-01

    Previous studies have shown that pressure changes in the cerebrospinal fluid compartment are transmitted to the inner ear. The main route for pressure transfer is the cochlear aqueduct, about which little is known with regard to its dynamic properties. In the present study, sudden intracranial press

  4. 78 FR 64935 - Borough of Ellwood City, Pennsylvania; Notice of Preliminary Determination of a Qualifying...

    Science.gov (United States)

    2013-10-30

    ..., canal, pipeline, aqueduct, flume, ditch, or similar manmade water conveyance that is operated for the distribution of water for agricultural, municipal, or industrial consumption and not primarily for the... of: (1) An intake from the existing 24-inch wastewater discharge pipe; (2) a proposed 20-foot-wide...

  5. Supplementary lithologic logs of selected vertical drill holes in area 12, Nevada Test Site

    International Nuclear Information System (INIS)

    Lithologic data were collected from drill holes in the Rainier and Aqueduct Mesas, Area 12, Nevada Test Site since 1970. Data presented in this report include locations and lithologies for 1 slant and 22 vertical drill holes greater than 152.4 m (500 ft) in depth in these areas. 3 figures, 1 table

  6. 75 FR 27580 - Notice of Lodging of the Consent Decree Under the Clean Water Act

    Science.gov (United States)

    2010-05-17

    ..., a proposed Consent Decree in United States v. Puerto Rico Aqueduct and Sewer Authority (``PRASA... with the Surface Water Treatment Rule (``SWTR''), at three Water Treatment Plants (``WTPs'') owned and... treatment plant improvement projects over the next 15 years valued at $195 million. These projects...

  7. Disturbances of cerebrospinal fluid (CSF) circulation - neuro psychiatric symptoms and neuroradiological contribution

    International Nuclear Information System (INIS)

    The present study aims at relating dementia, pseudo-neurasthenic and affective organic brain syndromes to underlying types of CSF flow disorder and to the subsequent alteration of anatomy. T 2*-weighted magnetic resonance imaging (MRI) in the mid sagittal plane permitted an analysis of aqueductal CSF flow phenomena and hydrocephalus-induced elevation, thinning and dorsal impingement of the corpus callosum. Furthermore, the width of the third ventricle was measured on the transverse scout images. 72 patients with communicating hydrocephalus (increased aqueductal CSF pulsations) and 26 patients with aqueductal stenosis (absence of aqueductal flow phenomena) were compared with 22 controls. Dementia and affective disorders were distributed equally among both CSF flow subgroups whereas pseudo-neurasthenic syndromes were observed more frequently in non-communicating hydrocephalus (p < 0.03). Alzheimer-type and multi infarct dementia syndromes were found more frequently in communicating hydrocephalus whereas non-classifiable dementia showed some predilection for non-communicating hydrocephalus. Callosal height, area and third ventricular width did not predict affective or pseudo neurasthenic disorder whereas third ventricular width (p < 0.01) and callosal area (p < 0.05) discriminated between demented and non-demented patients. Dorsal impingement of the corpus callosum by the falx was a non-specific finding. (author)

  8. Minimally Invasive-Endoscopic Intraventricular Neurosurgery

    Medline Plus

    Full Text Available ... the first three days I got back from school and everybody was like, “Oh, how’s your surgery ... aqueduct- That is correct. -which doesn't have flow in it. Did Richie have that? Yeah, Richie ...

  9. An Appraisal of Qualifying Role of Hydraulic Heritage Systems: A Case Study of Qanat in the Central Iran

    NARCIS (Netherlands)

    Fasihi Harandi, M.; De Vries, M.J.

    2014-01-01

    Hydraulic heritage systems, both underground and exposed, have been known to be sustainable for millennia. Persian and also Roman aqueducts are examples of such hydrosystems. Their value is often overlooked but they have undeniable advantages: they have functional interconnectedness with their surro

  10. No abnormalities of intrinsic brain connectivity in the interictal phase of migraine with aura

    DEFF Research Database (Denmark)

    Hougaard, Anders; Amin, F M; Magon, S;

    2015-01-01

    were investigated. Following advanced denoising, the data were analyzed both in a hypothesis-driven fashion, testing for abnormalities involving 27 different brain areas of potential relevance to migraine with aura including the cortical visual areas, the amygdala and peri-aqueductal grey matter, and...

  11. Wernicke's encephalopathy induced by total parenteral nutrition in patient with acute leukaemia: unusual involvement of caudate nuclei and cerebral cortex on MRI

    International Nuclear Information System (INIS)

    We report a 13-year-old girl with leukaemia and Wernicke's encephalopathy induced by total parenteral nutrition. MRI showed unusual bilateral lesions of the caudate nuclei and cerebral cortex, as well as typical lesions surrounding the third ventricle and aqueduct. After intravenous thiamine, the patient improved, and the abnormalities on MRI disappeared. (orig.)

  12. World's leading physics lab shut for poisoning water

    CERN Multimedia

    Popham, Peter

    2003-01-01

    Gran Sasso National Laboratory, the most advanced laboratory in the world for underground research into astroparticle physics, has been shut after polluting the environment. The laboratory, deep beneath the Apenninnes is said to have poisoned an aqueduct with waste from its equipment and committed numerous other infringements and ommissions (1 page)

  13. Assessment of CSF dynamics and venous flow in the superior sagittal sinus by MRI in idiopathic intracranial hypertension: a preliminary study

    DEFF Research Database (Denmark)

    Gideon, P; Sørensen, P S; Thomsen, C;

    1994-01-01

    ). We examined 12 patients with idiopathic intracranial hypertension (IIH; pseudotumour cerebri), and 10 healthy volunteers. The peak caudal and rostral CSF flow in the aqueduct during the cardiac cycle did not differ significantly between the patients and the volunteers. A significant correlation...

  14. Cerebrospinal fluid production and dynamics in normal aging: a MRI phase-mapping study

    DEFF Research Database (Denmark)

    Gideon, P; Thomsen, C; Ståhlberg, F;

    1994-01-01

    these parameters. Eight young healthy volunteers (mean age 29.8 years) and five elderly healthy volunteers (mean age 69.0 years) were examined, all were normal on conventional MRI. Slightly higher aqueductal CSF peak flow velocities and peak volume flow in both the caudal and rostral directions were found...

  15. 基于不同水体模型的渡槽结构动力特性对比分析

    Institute of Scientific and Technical Information of China (English)

    张华; 陈雯雯; 刘亮; 徐威

    2011-01-01

    The finite element method and finite volume method were used to analyse two kind depth-width radio of aqueduct with different water model such as the added mass model, Housner water model and potential-based model by considering the effect of water slashing to the modal orthogonality of aqueduct. The results contain the natural frequency and vibration mode. On this basis, the difference of the results among the different water model was analysed to reflect the fluid-solid coupling modal of aqueduct and sensitive factors of the aqueduct structure which could provide the theoretical basis and could be referenced in the design of the aqueduct structure.%考虑到渡槽槽体内水体的晃动对结构模态正交性的影响,采用有限元以及有限体积方法分析了两种不同高宽比的渡槽结构在附加质量模型、Housner水体模型以及势流体这三种水体模型下的流固耦合动力特性,包括自振频率和主振型.在此基础上,探讨了三种不同水体模型下渡槽结构流固耦合模态的差异,得到渡槽结构在不同水体模型下的动力特性敏感性因素,为渡槽抗震抗风设计提供参考依据.

  16. The petromastoid canal on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, G.A.; Schmitz-Rode, T.; Weidner, J.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany)

    2002-11-01

    The objective was to assess visibility and anatomy of the petromastoid canal in high-resolution CT. Computed tomography images of 188 patients were reviewed for delineation of the petromastoid canal. This bony canal connects the mastoid antrum with the cranial cavity and houses the subarcuate artery and vein. The diameter, obtained in the middle portion of the canal, was compared with the diameter of the vestibular and cochlear aqueduct in all patients, and absolute values measured in 20 cases. Collimation was 1 mm in 164 and 2 mm in 24 examinations. Additionally, temporal bone of a cadaver was imaged and microdissected. The petromastoid canal was identified bilaterally in all 164 scans that were obtained with a slice thickness of 1 mm. In 5 of the 24 patients imaged with a collimation of 2 mm, the canal was not visible, most probably due to partial-volume effects. The petromastoid canal had the same diameter as the cochlear aqueduct in 42/44 (right/left), exceeded it in 66/61 and was smaller in 75/78 cases. In comparison to the vestibular aqueduct it had an equal diameter in 38/41 (right/left), exceeded it in 63/61, and was rated as smaller in 82/81 temporal bones. Diameters for the canals were: petromastoid canal 0.51{+-}0.04 mm; cochlear aqueduct 0.57{+-}0.03; and vestibular aqueduct 0.63{+-}0.06 mm. Microdissection of the specimen revealed the entire course of the canal and demonstrated a similar appearance of the structure as in the images. The petromastoid canal can easily be identified on high-resolution, thin-slice CT images. Knowledge of the anatomy of this bony canal prevents misinterpretation as pathological structure, such as fracture line, which might occur if this structure is not known. (orig.)

  17. Coupling poroelasticity and CFD for cerebrospinal fluid hydrodynamics.

    Science.gov (United States)

    Tully, Brett; Ventikos, Yiannis

    2009-06-01

    This research uses a novel coupling of poroelastic theory and computational fluid dynamics to investigate acute hydrocephalus resulting from stenosis of the cerebral aqueduct. By coupling poroelastic theory with a multidimensional simulation of the cerebral aqueduct we are able to investigate, for the first time, the impact of physically relevant stenosis patterns on ventricular enlargement, accounting for the nonintuitive long time history responses of the ventricular system. Preliminary findings demonstrate clearly the importance that the fluidic-poroelastic coupling plays: ventricular enlargement is significantly smaller with local stenosis patterns and almost all of the observable pressure drop occurs across the stenosis. Short timescale effects [O(heartbeat)] are explored and their contribution to the long timescales interrogated. PMID:19304478

  18. A potential portal flow in the inner ear

    DEFF Research Database (Denmark)

    Friis, Morten; Qvortrup, Klaus

    2007-01-01

    OBJECTIVES/HYPOTHESIS: The aim of the present study was to visualize the flow direction of blood in the extraosseous part of the vein of the vestibular aqueduct (VVA) and to explore the effect of an induced obstruction in the distal part of the VVA before it merges with the sigmoid sinus. The end......OBJECTIVES/HYPOTHESIS: The aim of the present study was to visualize the flow direction of blood in the extraosseous part of the vein of the vestibular aqueduct (VVA) and to explore the effect of an induced obstruction in the distal part of the VVA before it merges with the sigmoid sinus....... The endolymphatic sac has been implicated as a potential endocrine gland, which venules drain to the VVA. A reversal of the direction of flow in the VVA toward the inner ear could, through vestibular arteriovenous anastomosis, cause portal circulation in the inner ear. STUDY DESIGN: The authors conducted...

  19. 基于CATIA设计表的水工建筑物关联设计%CATIA design table based associated design of hydraulic structure

    Institute of Scientific and Technical Information of China (English)

    王小平; 王陆; 蔺志刚

    2013-01-01

    Based on CATIA platform, combined with draft tube and aqueduct project design, the concept and method for realizing the associated design of the hydraulic structures with CATIA design table is systematically studied herein in combination with the actual engineering design cases of a draft tube and an aqueduct. The associated design can effectively avoid the errors those may occur in design, and then makes the design of the relevant hydraulic structure more reasonable and be optimized.%基于CATIA平台,结合尾水管和渡槽设计工程实例,系统地对利用设计表实现水工建筑物关联设计的思路和方法进行了研究.结果表明,关联设计能够有效避免设计中的错误,使水工建筑物设计趋于合理,得到优化.

  20. Measurement of blood velocity using laser Doppler method for the designing module

    Science.gov (United States)

    Chen, Guo-Liang; Lee, Jen-Ai; Lu, Tung-Wu; Chen, Zhao-Cheng; Chen, Chien-Ming

    2005-04-01

    We built the Dual Beam Mode of the LDA (Laser Doppler Anemometry) frame, set the photodetector at the same side with light source which collect the scattering light of blood cell. It's proper to reduce LDA optical path and convenient for our designing module. The concentration of chicken blood in this study is about 1% and we measured the relations actually between flood velocity and the angle of beams cross on particles, temperature, and the diameter of aqueduct. We found better results while the cross angle was less than 38.8 degree, diameter of aqueduct was 6 mm, and temperature of blood was set to 36 . These parameters can also provide important basis for the LDA module kit that we are designing.

  1. 大前庭导水管综合征听力学研究新进展

    Institute of Scientific and Technical Information of China (English)

    冯春; 纳玉萍

    2009-01-01

    大前庭水管综合征(large vestibular aqueduct syndrome,LVAS或enlarged vestibular aqueduct syndrome,EVAS)是一种越来越被广泛认识的临床常见的隐性遗传性听力障碍性疾病,发病率占儿童和青少年感音神经性聋的1%~12%。临床上将只有前庭水管扩大畸形,不伴有其他内耳发育异常和其他器官系统的异常(Pendred’s Syndrome,Branchiootorenal Syndrome),合并感音神经性听力损失的患者诊断为大前庭水管综合征。

  2. 大前庭水管综合征

    Institute of Scientific and Technical Information of China (English)

    李春林

    2010-01-01

    @@ 20世纪60年代Valvassori和Clemis在一次国际性会上报道了类似梅尼埃病样疾病,该作者于1978年报告在3 700例听觉或前庭功能障碍患者的颞骨多轨迹断层摄影中,有50例前庭水管扩大,并将其命名为"大前庭水管"(large vestibalar aqueduct,LVA),并将临床上伴有感音神经听力损失等症状者,称之为大前庭水管综合征(large vestibular aqueduct syndrome,LVAS)[1].

  3. A hydro-elastic model of hydrocephalus

    OpenAIRE

    Smillie, A.; Sobey, Ian; Molnar, Z

    2004-01-01

    We combine elements of poroelasticity and of fluid mechanics to construct a mathematical model of the human brain and ventricular system. The model is used to study hydrocephalus, a pathological condition in which the normal flow of the cerebrospinal fluid is disturbed, causing the brain to become deformed. Our model extends recent work in this area by including flow through the aqueduct, by incorporating boundary conditions which we believe more accurately represent the anatomy of the brain ...

  4. Computed tomographic findings of progressive supranuclear palsy compared with Parkinson's disease

    International Nuclear Information System (INIS)

    We investigated computed tomographic (CT) films of 4 pathologically documented cases of progressive supranuclear palsy (PSP) in which the clinical presentations were atypical and compared the findings with those of 15 patients with Parkinson's disease (PD). Dilatation of the third ventricle, atrophy of the midbrain tegmentum, and enlargement of the interpeduncular cistern toward the aqueduct were found to be the characteristic findings in PSP. Thus, radiological findings can be useful when the differential diagnosis between PSP and PD is clinically difficult. (author)

  5. Computed tomography of common congenital lesions of the temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, H.Y. E-mail: drhyyuen@doctors.org.uk; Ahuja, A.T.; Wong, K.T.; Yue, V.; Hasselt, A.C. van

    2003-09-01

    This pictorial review describes the application of high-resolution computed tomography to the investigation and pre-operative work-up of the common lesions of congenital hearing loss, including congenital aural dysplasia, various congenital ossicular anomalies, inner ear dysmorphology, large vestibular aqueduct syndrome, and congenital absence of cochlear nerve and labyrinthitis ossificans from previous infection. The aim is to help radiologists to provide a more accurate diagnosis of underlying aetiology and assist in surgical planning.

  6. Situational Analysis of Flood and Drought in Rwanda

    OpenAIRE

    Asumadu-Sarkodie, Samuel; Rufangura, Patrick; Jayaweera, MPC Herath; Owusu, Phebe Asantewaa

    2015-01-01

    In this paper, a situational analysis of flood and drought in Rwanda were assessed using AQUEDUCT Global Flood Analyzer based on the population, Gross Domestic Product (GDP) and urban damage for current and future projections (2030). In order to estimate future changes, three scenarios from: Representative Concentration Pathways (RCP) and Shared Socio-economic Pathways (SSP) from the Intergovernmental Panel on Climate Change 5th Assessment Report which represents climate change and socioecono...

  7. La fiebre amarilla y la creación del acueducto y alcantarillado del municipio de Socorro, Colombia (1929)

    OpenAIRE

    Aleidys Hernández Tasco; Cristina Campos

    2015-01-01

    Socorro, a municipality of Santander Colombia, was an important urban settlement during previous times, but throughout the nineteen century it lost its political important. Socorro came to be important again for the central government in 1929 amidst a yellow fever epidemic. In order to avoid the spreading of yellow fever, the central government constructed a sewage system and an aqueduct for Socorro. This paper analyzes how the yellow fever epidemic encouraged the develop...

  8. Two siblings with progressive, fluctuating hearing loss after head trauma, treated with cochlear implantation.

    OpenAIRE

    Wolf, M.J.F. de; Honings, J.; Joosten, F. B. M.; Hoefsloot, L.H.; Mylanus, E.A.M.; Cremers, C. W. R. J.

    2010-01-01

    OBJECTIVE: Description of two siblings with unexplained, progressive, perceptive hearing loss after head trauma. DESIGN: Case report. SUBJECTS: Two siblings aged six and eight years old with bilateral, intermittent but progressive hearing loss. RESULTS: These patients had a c.1172G>A (p.Ser391Asn) mutation in the SLC26A4 gene, which has not previously been reported and which caused Pendred or enlarged vestibular aqueduct syndrome. The diagnosis was based on the perceptive hearing loss, com...

  9. PRACTICAL EARTH ANCHORING TECHNOLOGY FOR STRENGTHENING SLOPE WALL PROTECTION (CASE STUDY: DG. SIRUA ROAD POST CONSTRUCTION FAILURE WITH SKYHOOK ??? GRID BEAM TECHNOLOGY IN MAKASSAR CITY ??? INDONESIA)

    OpenAIRE

    Samang, Lawalenna; Hino, Takenori; Harianto, Tri; Ramli, Muhammad Isran; Walenna, Muhammad Akbar

    2013-01-01

    The application of soil anchoring system and grid beam method of strengthening protection wall post construction failure was observed in this research. The construction of the slope wall protection is situated to suit the existence of barrier made for aqueduct. Based on the numerical simulation on scenario of potential causes of slope failure, it indicates several phenomena such as the stability of barrier foundation experiences drastic drop. Scrutinizing the result of investigation and ideal...

  10. Streptococcus pneumoniae-Induced Inhibition of Rat Ependymal Cilia Is Attenuated by Antipneumolysin Antibody

    OpenAIRE

    Hirst, Robert A; Mohammed, Bashir J.; Mitchell, Timothy J.; Andrew, Peter W.; O'Callaghan, Christopher

    2004-01-01

    Ciliated ependymal cells line the ventricular surfaces and aqueducts of the brain. In ex vivo experiments, pneumolysin caused rapid inhibition of the ependymal ciliary beat frequency and caused ependymal cell disruption. Wild-type pneumococci and pneumococci deficient in pneumolysin caused ciliary slowing, but penicillin lysis of wild-type, not pneumolysin-deficient, pneumococci increased the extent of ciliary inhibition. This effect was abolished by antipneumolysin antibody. Ependymal ciliar...

  11. Water Supply Options for the East Bay Municipal Utility District: A Critical Analysis

    OpenAIRE

    Fisher, Anthony C.

    1988-01-01

    The two main objectives of the East Bay Municipal Utility District (EBMUD) water supply management program are to cope with a failure of the aqueducts in the Delta due to earthquake and flood damage and to mitigate periodic shortages. EBMUD emphasizes construction of additional terminal storage, specifically development of a reservoir in Buckhorn Canyon, to meet both objectives. Better alternatives--cheaper and less environmentally damaging--are (to cope with failure) use of existing termin...

  12. A Interpretação do Patrimônio Histórico Romano na cidade de Mainz, Renânia-Palatinado (Alemanha)

    OpenAIRE

    Poliana Fabíula Cardozo

    2012-01-01

    Mainz was founded by the Romans two thousand years ago was an important base of the Empire. Had its rise for two centuries, when he saw his decline attacks by vandals. Today the city has reminders of that era, are exposed to elements such as aqueducts, temples, towers and gates; vessels, ornaments, and other theater. The city administration shall prepare a brochure about, and encourages its visitors. This article aims to describe how the interpretation of this heritage in light of the interpr...

  13. Preliminary finding on reconstruction of the late Roman water structure in Sinop (Turkey)Sinop (Türkiye) geç Roma dönemi su yapılarının rekonstrüksiyonuna ait ön bulgular

    OpenAIRE

    TUROĞLU, Hüseyin; BAYRAKDAR, Cihan

    2013-01-01

    Various water structures of the late Roman period are found in Sinop and its vicinity. These consist of channels, aqueducts, water collection ponds, wells and cisterns. This study has combined the results of various archeological finds with geographic data from Geographic Information Systems and Remote Sensing technologies (GIS). First findings indicate that Sinop (in the later Roman period) was supplied with water from mainly 2 sources. The routes of the main water channels have been reconst...

  14. A vertex-centered discontinuous Galerkin method for flow problems

    OpenAIRE

    Ekström, Sven-Erik

    2016-01-01

    The understanding of flow problems, and finding their solution, has been important for most of human history, from the design of aqueducts to boats and airplanes. The use of physical miniature models and wind tunnels were, and still are, useful tools for design, but with the development of computers, an increasingly large part of the design process is assisted by computational fluid dynamics (CFD). Many industrial CFD codes have their origins in the 1980s and 1990s, when the low order finite ...

  15. Alternative Tourism Opportunities in Köprü Creek Basin

    OpenAIRE

    Sağdıç, Mustafa; Bozyiğit, Recep

    2008-01-01

    Köprü River Basin has been drawing attention with its natural, historical and cultural tourism potential. In the basin, among the natural tourism values, Köprü Canyon National Park, natural monuments, plateaus, canyon valleys, resort places, beaches, mountainous places, floristic wealth are need to be mentioned. The antique cities, ramshackle houses, aqueducts, routes, bridges, old houses, handcrafts, festivals are among the historical and cultural values. Although Köprü River Basin has a gre...

  16. SLC26A4 Variations Among Graves’ Hyper-Functioning Thyroid Gland

    OpenAIRE

    Hassen Hadj-Kacem; Rihab Kallel; Salima Belguith-Maalej; Mouna Mnif; Ilhem Charfeddine; Abdelmounem Ghorbel; Mohamed Abid; Hammadi Ayadi; Saber Masmoudi

    2010-01-01

    Deleterious mutations of SLC26A4 cause Pendred syndrome (PS), an autosomal recessive disorder comprising goitre and deafness with enlarged vestibular aqueducts (EVA), and nonsyndromic hearing loss (NSHL). However, the SLC26A4 hyperactivity was recently associated with the emergence of autoimmune thyroid diseases (AITD) and asthma among human and mouse model. Here, by direct sequencing, we investigate the sequences of the 20 coding exons (2 to 21) of SLC26A4 and their flanking intron-exon junc...

  17. A review of Ancient Roman water supply exploring techniques of pressure reduction.

    OpenAIRE

    Monteleone, M. C.; Yeung, Hoi; Smith, Richard

    2007-01-01

    The Ancient Roman water supply systems still leave us astonished when admiring the solidity of the ruins of aqueducts surviving around Europe. Some parts of these systems are still in use at present and prove the practical efficiency of Roman hydraulics in the principles acquired from the populations living in the different regions of the Empire. In Pompeii the urban water supply system stands as a clear example of the Roman planning of urban complex networks by using small water towers to se...

  18. Un informe de Pedro de Ribera para Nueva España: el abastecimiento de agua a Guadalajara

    OpenAIRE

    Recio Mir, Álvaro

    2014-01-01

    The project proposed by the Franciscan architect Pedro Antonio de Buzeta to supply water to the New Spanish city of Guadalajara was sent to Madrid for review and supervision by the Council of the Indies. The Madrid architect Pedro de Ribera dealt with its technical aspects, and in 1735 he wrote an interesting critique of the plan. Among other questions, he defended the use of underground aqueducts, demonstrated his erudition and considered diverse improvements to Buzeta’s project.El proyecto ...

  19. Preliminary finding on reconstruction of the late Roman water structure in Sinop (Turkey)

    Sinop (Türkiye) geç Roma dönemi su yapılarının rekonstrüksiyonuna ait ön bulgular

    OpenAIRE

    Hüseyin Turoğlu; Cihan Bayrakdar

    2013-01-01

    Various water structures of the late Roman period are found in Sinop and its vicinity. These consist of channels, aqueducts, water collection ponds, wells and cisterns. This study has combined the results of various archeological finds with geographic data from Geographic Information Systems and Remote Sensing technologies (GIS). First findings indicate that Sinop (in the later Roman period) was supplied with water from mainly 2 sources. The routes of the main water channels have been reconst...

  20. INTEGRATION OF GEOMATIC TECHNIQUES FOR THE URBAN CAVITY SURVEY

    OpenAIRE

    M. Deidda; Sanna, G.

    2013-01-01

    Cagliari, county seat of Sardinia Region (Italy), situated in the southern part of the island, is characterized by a subsoil full of cavities. The excavations in fact, which lasted more than 4000 years, had a great development due also to the special geological characteristics of the city subsoil. The underground voids, which the city is rich in, belong to different classes such as hydraulic structures (aqueducts, cisterns, wells, etc.), settlement works (tunnels, bomb shelters, tomb...

  1. Hydropower landscapes and tourism development in the Pyrenees

    OpenAIRE

    Rodriguez, Jean-François

    2012-01-01

    Since the development of hydroelectric power at the end of the 19th century, most of the high mountain valleys in the Pyrenees have been equipped with hydropower facilities (dams, water intake structures, aqueducts, penstocks, access routes, etc.). Thus, today many landscapes in the Pyrenees bear witness to the exploitation of this renewable resource. But in the classical imaginary world, these mountain areas are seen as the archetype of the beautiful natural landscape, in accordance with aes...

  2. The engineering design of the Tua rail track : evidence from the archives

    OpenAIRE

    Martins, Lurdes; Vasconcelos, Graça; Lourenço, Paulo B.; Beira, Eduardo

    2012-01-01

    This paper intends to give a detailed overview of the different phases of the Tua line focused on the changes in the longitudinal and transversal outline and on the definition of the project of special structures (tunnels, bridges, aqueducts and stone walls). For this, a detailed investigation was carried on the archives of REFER, the company in charge of the management of the infrastructure of the national Portuguese railways. The Tua line fit the Nacional railways plan, defin...

  3. PRESTACIÓN DEL SERVICIO DE AGUA POTABLE A TRAVÉS DE COMUNIDADES RURALES, MUNICIPIO DE OCAMONTE. IMPLICACIONES SOCIOJURÍDICAS

    OpenAIRE

    Roberto Silva Fernández; Gonzalo Romero Becerra; José Valentín Pereira Rueda

    2014-01-01

    Research aimed to understanding the problems of drinking water in rural areas of the municipality of Ocamonte, Santander, in key areas such as coverage, quality and condition of the fluid delivery by the local authority. Characterizes the problematic situation and explores the legal partner of organized rural communities, traditional owners of the aqueducts, can provide for the State service possible. Was done the analysis of the rules governing the matter, background and further exploration ...

  4. Impact of Bicarbonate, Ammonium Chloride, and Acetazolamide on Hepatic and Renal SLC26A4 Expression

    OpenAIRE

    Alesutan, Ioana; Daryadel, Arezoo; Mohebbi, Nilufar; Pelzl, Lisann; Leibrock, Christina; Voelkl, Jakob; Bourgeois, Soline; Dossena, Silvia; Nofziger, Charity; Paulmichl, Markus; Carsten A Wagner; Lang, Florian

    2011-01-01

    SLC26A4 encodes pendrin, a transporter exchanging anions such as chloride, bicarbonate, and iodide. Loss of function mutations of SLC26A4 cause Pendred syndrome characterized by hearing loss and enlarged vestibular aqueducts as well as variable hypothyroidism and goiter. In the kidney, pendrin is expressed in the distal nephron and accomplishes HCO(3)(-) secretion and Cl(-) reabsorption. Renal pendrin expression is regulated by acid-base balance. The liver contributes to acid-base regulation ...

  5. Difusión de modelos técnicos romanos: particularidades del sistema de abastecimiento de agua a la ciudad de Baelo Claudia

    OpenAIRE

    Borau, Laetitia

    2015-01-01

    The water supply network of the Roman city of Baelo Claudia, in particular its aqueducts and its castellum aquae, was the focus of new investigations performed in 2013. The goal of this study was to make a first assessment of conservation status of the archaeological remains. It also allowed highlighting the originality of some types of structures, in particular bridges and steeps chutes and broadcasting of some Italic technology from the Mediterranean Sea to the Atlantic coast.A lo largo del...

  6. Marcus Agrippa’s Building Activity in Ancient Rome

    OpenAIRE

    Таривердиева, Сабина Эльмар кызы

    2014-01-01

    The author examines the ideological significance of public buildings and constructions of Marcus Agrippa in Rome, who restored all the Roman aqueducts and built new ones as well as erected a huge complex of buildings in the Campus Martius thereby completely changing its face. The main ideological purpose of the building was to glorify the princeps, his family, and at a later stage the principate regime, which is most clearly reflected in the Pantheon. But if compared with the buildings of Aug...

  7. Les aqueducs à souterazi de la Régence d'Alger

    OpenAIRE

    Kameche-Ouzidane, Dalila

    2015-01-01

    At the beginning of the Regency, the urban community is organized around the sustainability of some intramural sources. However, the new Ottoman rulers are keen to establish a true hydraulic system to satisfy the water needs of a growing city.Aqueducts are designed to provide the city with water, their ingenuity is a function of topography and how the waters of the Algerian Sahel arise. These achievements include ravines crossings, but also souterazi traps or towers toppled playing the role o...

  8. Organized Communities and Potable Water Public Utilities in Colombia: Advocacy for the Third Economic Option Based on the Common-pool Resources Theory

    OpenAIRE

    Moncada Mesa, Jhonny; Pérez Muñoz, Carolina; Valencia Agudelo, Germán Darío

    2013-01-01

    Based on the theory and institutional principles proposed by Elinor Ostrom, this paper explores whether Colombian organized communities are able to provide potable water public utility in a sustainable manner and manage it as a common-pool resource (CPR). For this purpose, a set of Colombian community aqueducts is selected and compared against the eight principles proposed by this theory. The results have shown that, in general it complies with institutional principles but it also highlights ...

  9. The behaviour of both Listeria monocytogenes and rat ciliated ependymal cells is altered during their co-culture

    OpenAIRE

    Fadaee-Shohada, Mina J.; Hirst, Robert A; Andrew Rutman; Roberts, Ian S.; Chris O'Callaghan; Andrew, Peter W.

    2010-01-01

    BACKGROUND: Ciliated ependymal cells line the cerebral ventricles and aqueducts separating the infected CSF from the brain parenchyma in meningitis. PRINCIPAL FINDINGS: Investigation of the interaction of Listeria monocytogenes with cultured rat brain ependymal cells showed that certain strains reduced the beat frequency of the cilia but all the strains studied significantly reduced the ciliary beat amplitude (the linear distance travelled by the tip of each cilium per beat cycle). CONCLUSION...

  10. The Economy of the Early Roman Empire

    OpenAIRE

    Peter Temin

    2006-01-01

    Many inhabitants of ancient Rome lived well. Tourists marvel at the temples, baths, roads and aqueducts that they built. Economists also want to understand the existence of a flourishing and apparently prosperous economy two millennia ago. Market institutions and a stable government appear to have been the combination that produced this remarkable result. This essay provides an economist's view of the Roman economy that emphasizes the role of markets. I focus on the early Roman Empire, from 2...

  11. Sources of ground movement at Vesuvius before the AD 79 eruption: Evidence from contemporary accounts and archaeological studies

    OpenAIRE

    Marturano, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia

    2008-01-01

    Historical sources have recorded earthquake shocks, their effects and difficulties that local inhabitants experienced before the AD 79 Pompeii eruption. Archaeological studies pointed out the effects of such seismicity, and have also evidenced that several water crises were occurring at Pompeii in that period. Indeed numerous sources show that, at the time of eruption, and probably some time before, the civic aqueduct, having ceased to be supplied by the regional one, was out of o...

  12. An Appraisal of Qualifying Role of Hydraulic Heritage Systems: A Case Study of Qanat in the Central Iran

    OpenAIRE

    M Fasihi Harandi; De Vries, M.J.

    2014-01-01

    Hydraulic heritage systems, both underground and exposed, have been known to be sustainable for millennia. Persian and also Roman aqueducts are examples of such hydrosystems. Their value is often overlooked but they have undeniable advantages: they have functional interconnectedness with their surrounding society and ecology, which sometimes leads to revitalization plans. By using the notion ‘qualifying role’, this paper will raise questions concerning the disregarded functions and early and ...

  13. Developmental Changes of ENaC Expression and Function in the Inner Ear of Pendrin Knock-Out Mice as a Perspective on the Development of Endolymphatic Hydrops

    OpenAIRE

    Bo Gyung Kim; Jin Young Kim; Hee Nam Kim; Jinwoong Bok; Wan Namkung; Jae Young Choi; Sung Huhn Kim

    2014-01-01

    Pendrin mutations cause enlarged vestibular aqueducts and various degrees of sensorineural hearing loss. The selective abolition of pendrin causes dilation of the membranous labyrinth known as endolymphatic hydrops, loss of the endocochlear potential, and consequently loss of hearing function. Because Na+ transport is one of the most important driving forces for fluid transport, the epithelial Na+ channel (ENaC) is believed to play an important role in fluid volume regulation in the inner ear...

  14. Novel technologies for WWTP optimization in footprint, nutrients valorization, and energy consumption

    OpenAIRE

    Morales Pereira, Nicolás

    2014-01-01

    The continuous development of the human society causes stress to natural systems: pollution increase, deforestation, global resource depletion, etc. Water resource contamination and water scarcity are among the major challenges to be confronted by humanity in the 21st century. Present wastewater treatment technologies were developed between the end of the 19th century and during 20th century. Technology evolved from simple aqueduct sewerages that dumped in waterways without treatment to a com...

  15. Cranial CT signs of the Chiari II malformation

    International Nuclear Information System (INIS)

    Serial CT scans of 32 patients with proved Chiari II malformations and 19 patients with hydrocephalus and meningomyelocele (presumed to have Chiari II malformation) were reviewed and compared with CT scans from 30 patients with non-chiari aqueductal stenosis to develop criteria for identifying the Chiari II malformation and for differentiating it from other forms of hydrocephalus. Correlation with post-mortem specimens of Chiari II brains provided a pathologic basis for the CT signs observed. (orig.)

  16. Numerical analysis of shell and spatial structures

    OpenAIRE

    Samartín, Avelino

    1991-01-01

    Since the advent of the computer into the engineering field, the application of the numerical methods to the solution of engineering problems has grown very rapidly. Among the different computer methods of structural analysis the Finite Element (FEM) has been predominantly used. Shells and space structures are very attractive and have been constructed to solve a large variety of functional problems (roofs, industrial building, aqueducts, reservoirs, footings etc). In this type of structu...

  17. Groundwater utilization through the centuries focusing οn the Hellenic civilizations

    Science.gov (United States)

    Angelakis, Andreas N.; Voudouris, Konstantinos S.; Mariolakos, Ilias

    2016-03-01

    Groundwater has been utilized since the Prehistoric times. Water supply of some Minoan settlements on the eastern side of the island of Crete (Greece) was based on groundwater. Later on, many wells were constructed in several areas of Greece and their use expanded through subsequent periods. The greatest achievement in groundwater exploitation by ancient Greeks was the construction of long underground galleries or qanats, which collected water from springs and alluvial deposits. In Classical times, most of the wells were on private properties and their owners were forced by regulations to maintain the wells in good condition and ready for use in wartime. During that period, the first scientific theories of Aristotle and Theophrastus were developed in regards to hydrological phenomena, and the processes involved in the formation of surface water and groundwater were clarified. Wells played a major part in urban water supply during the Roman period, in which famous aqueducts were constructed to transfer water; however, several regions of Greece were self-sufficient in water, supplied by many wells from the Prehistoric to the Byzantine period. People understood the local geological conditions and, according to their culture, constructed and managed their own types of wells. In addition to the wells and aqueducts, the hydraulic technology included cisterns to store rainwater, and systems to capture spring water for transport by aqueducts. The examples of hydro-technologies and water management practices described in this paper may have some relevance for water engineering even in modern times.

  18. Groundwater utilization through the centuries focusing οn the Hellenic civilizations

    Science.gov (United States)

    Angelakis, Andreas N.; Voudouris, Konstantinos S.; Mariolakos, Ilias

    2016-08-01

    Groundwater has been utilized since the Prehistoric times. Water supply of some Minoan settlements on the eastern side of the island of Crete (Greece) was based on groundwater. Later on, many wells were constructed in several areas of Greece and their use expanded through subsequent periods. The greatest achievement in groundwater exploitation by ancient Greeks was the construction of long underground galleries or qanats, which collected water from springs and alluvial deposits. In Classical times, most of the wells were on private properties and their owners were forced by regulations to maintain the wells in good condition and ready for use in wartime. During that period, the first scientific theories of Aristotle and Theophrastus were developed in regards to hydrological phenomena, and the processes involved in the formation of surface water and groundwater were clarified. Wells played a major part in urban water supply during the Roman period, in which famous aqueducts were constructed to transfer water; however, several regions of Greece were self-sufficient in water, supplied by many wells from the Prehistoric to the Byzantine period. People understood the local geological conditions and, according to their culture, constructed and managed their own types of wells. In addition to the wells and aqueducts, the hydraulic technology included cisterns to store rainwater, and systems to capture spring water for transport by aqueducts. The examples of hydro-technologies and water management practices described in this paper may have some relevance for water engineering even in modern times.

  19. Sources of ground movement at Vesuvius before the AD 79 eruption: Evidence from contemporary accounts and archaeological studies

    Science.gov (United States)

    Marturano, Aldo

    2008-11-01

    Historical sources have recorded earthquake shocks, their effects and difficulties that local inhabitants experienced before the AD 79 Pompeii eruption. Archaeological studies pointed out the effects of such seismicity, and have also evidenced that several water crises were occurring at Pompeii in that period. Indeed numerous sources show that, at the time of eruption, and probably some time before, the civic aqueduct, having ceased to be supplied by the regional one, was out of order and that a new one was being built. Since Roman aqueducts were usually built with a recommended minimum mean slope of 20 cm/km and Pompeii's aqueduct sloped from the nearby Apennines toward the town, this slope could have been easily cancelled by uplift that occurred in the area even if this was only moderate. For the crustal deformations a volcanic origin is proposed and a point source model is used to explain the observations. Simple analysis of the available data suggests that the ground deformations were caused by a < 2 km 3 volumetric change at a depth of ˜ 8 km that happened over the course of several decades.

  20. Exploring the Efficacy of Endoscopic Ventriculostomy for Hydrocephalus Treatment via a Multicompartmental Poroelastic Model of CSF Transport: A Computational Perspective

    Science.gov (United States)

    Vardakis, John C.; Tully, Brett J.; Ventikos, Yiannis

    2013-01-01

    This study proposes the implementation of a Multiple-Network Poroelastic Theory (MPET) model coupled with finite-volume computational fluid dynamics for the purpose of studying, in detail, the effects of obstructing CSF transport within an anatomically accurate cerebral environment. The MPET representation allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood, in an integral and comprehensive manner. A key novelty in the model is the amalgamation of anatomically accurate choroid plexuses with their feeding arteries and a simple relationship relaxing the constraint of a unique permeability for the CSF compartment. This was done in order to account for the Aquaporin-4-mediated swelling characteristics. The aim of this varying permeability compartment was to bring to light a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF into the blood system. This model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO). The implications of treating such a clinical condition with the aid of endoscopic third (ETV) and endoscopic fourth (EFV) ventriculostomy are considered. We observed peak CSF velocities in the aqueduct of the order of 15.6 cm/s in the healthy case, 45.4 cm/s and 72.8 cm/s for the mild and severe cases respectively. The application of ETV reduced the aqueductal velocity to levels around 16–17 cm/s. Ventricular displacement, CSF pressure, wall shear stress (WSS) and pressure difference between lateral and fourth ventricles (ΔP) increased with applied stenosis, and subsequently dropped to nominal levels with the application of ETV. The greatest reversal of the effects of atresia come by opting for ETV rather than the more complicated procedure of EFV. PMID:24391968

  1. Exploring the efficacy of endoscopic ventriculostomy for hydrocephalus treatment via a multicompartmental poroelastic model of CSF transport: a computational perspective.

    Directory of Open Access Journals (Sweden)

    John C Vardakis

    Full Text Available This study proposes the implementation of a Multiple-Network Poroelastic Theory (MPET model coupled with finite-volume computational fluid dynamics for the purpose of studying, in detail, the effects of obstructing CSF transport within an anatomically accurate cerebral environment. The MPET representation allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood, in an integral and comprehensive manner. A key novelty in the model is the amalgamation of anatomically accurate choroid plexuses with their feeding arteries and a simple relationship relaxing the constraint of a unique permeability for the CSF compartment. This was done in order to account for the Aquaporin-4-mediated swelling characteristics. The aim of this varying permeability compartment was to bring to light a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF into the blood system. This model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO. The implications of treating such a clinical condition with the aid of endoscopic third (ETV and endoscopic fourth (EFV ventriculostomy are considered. We observed peak CSF velocities in the aqueduct of the order of 15.6 cm/s in the healthy case, 45.4 cm/s and 72.8 cm/s for the mild and severe cases respectively. The application of ETV reduced the aqueductal velocity to levels around 16-17 cm/s. Ventricular displacement, CSF pressure, wall shear stress (WSS and pressure difference between lateral and fourth ventricles (ΔP increased with applied stenosis, and subsequently dropped to nominal levels with the application of ETV. The greatest reversal of the effects of atresia come by opting for ETV rather than the more complicated procedure of EFV.

  2. Progressive white-matter disease with primary cerebellar involvement: a separate entity?

    International Nuclear Information System (INIS)

    Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity. (orig.)

  3. Intracranial flow of cerebrospinal fluid

    International Nuclear Information System (INIS)

    This paper reports cerebrospinal fluid (CSF) flow in the third ventricle, aqueduct, fourth ventricle, basal cisterns, and subarachnoid spaces at the cervical-medullary junction evaluated in 25 patients and 10 normal volunteers. Information was acquired on 1.5-T magnet with a cardiac-gated, single-section, gradient-echo technique and displayed via closed-loop cine imaging. Qualitative assessment of flow patterns via magnitude reconstruction was correlated with quantitative data generated via phase reconstruction. Normal patterns of CSF flow were established. Pathologic changes involving these pathways altered the flow patterns, either causing increased turbulence and flow of CSF or decreasing the expected flow

  4. Solution of hydraulic nets, by means of the application of the pattern of balance of nodes and the method of linealization of equations

    International Nuclear Information System (INIS)

    The dimension of nets of fluids distribution is a common problem to different areas of the engineering, as the chemistry and the civil, present in the design of aqueducts, distribution systems of domiciliary gas, nets against fire and plants of chemical transformation. This work presents a model for its simulation, by means of the application of the balance of nodes and the theory of linealization of equations, it allows to know a complex net, in which they can be present, accessories, bombs, control valves, aspersion mouthpieces and process equipment. It is applicable to open, closed nets or combinations of two

  5. Large-Scale Utilization of Saline Groundwater for Irrigation of Pistachios Interplanted with Cotton

    OpenAIRE

    Sanden, Blake; Ferguson, Louise; Kallsen, Craig E.; Marsh, Brian; Hutmacher, Robert B; Corwin, Dennis

    2009-01-01

    Twelve, 19.5 acre test plots arranged in a randomized complete block design are set within two 155 acre fields to provide a realistic production environment. These blocks of welldrained Panoche clay loam were formerly irrigated with California Aqueduct water and sprinklers for the last 30 years. Overall the field electrical conductivity (EC) ranged from 0.5 to 4.5, averaging 1.57 dS/m to a 3-foot depth. Saturation extract boron was 0.6 ppm. The area is underlain by a semi-saline aquifer that ...

  6. Bacterial Invasion of the Inner Ear in Association With Pneumococcal Meningitis

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Brandt, Christian; Østergaard, Christian;

    2014-01-01

    through the cochlear aqueduct, into the scala tympani of the cochlea (perilymphatic space). From here, bacteria spreads apically toward the helicotrema and subsequently basally through the scala vestibuli, toward the vestibule and the vestibular system. When the bacteria after 5 to 6 days had reached...... scala vestibuli of the basal turn of the cochlea, hematogenous spreading occurred to the spiral ligament and into the cochlear endolymph, subsequently to the vestibular endolymph. We found no evidence of alternative routes for bacterial invasion in the inner ear. Several internal barriers to bacterial...

  7. Organized Communities and Potable Water Public Utilities in Colombia: Advocacy for the Third Economic Option Based on the Common-pool Resources Theory

    Directory of Open Access Journals (Sweden)

    Jhonny Moncada Mesa

    2013-11-01

    Full Text Available Based on the theory and institutional principles proposed by Elinor Ostrom, this paper explores whether Colombian organized communities are able to provide potable water public utility in a sustainable manner and manage it as a common-pool resource (CPR. For this purpose, a set of Colombian community aqueducts is selected and compared against the eight principles proposed by this theory. The results have shown that, in general it complies with institutional principles but it also highlights difficulties, particularly in regards to the "minimal recognition of organization rights" principle.

  8. La fiebre amarilla y la creación del acueducto y alcantarillado del municipio de Socorro, Colombia (1929

    Directory of Open Access Journals (Sweden)

    Aleidys Hernández Tasco

    2015-12-01

    Full Text Available Socorro, a municipality of Santander Colombia, was an important urban settlement during previous times, but throughout the nineteen century it lost its political important. Socorro came to be important again for the central government in 1929 amidst a yellow fever epidemic. In order to avoid the spreading of yellow fever, the central government constructed a sewage system and an aqueduct for Socorro. This paper analyzes how the yellow fever epidemic encouraged the development of sanitary actions in an urban space such as Socorro. This urban and social history allows situating Socorro and Colombia within the sanitary debated developed in Latina America in the early twentieth century.

  9. Neurologic amebiasis caused by Balamuthia mandrillaris in an Indian flying fox (Pteropus giganteus).

    Science.gov (United States)

    Crossland, Nicholas A; Ali, Ibne; Higbie, Christine; Jackson, Jonathan; Pirie, Gordon; Bauer, Rudy

    2016-01-01

    A 4-5-month-old intact male Indian flying fox (Pteropus giganteus) was presented to the Baton Rouge Zoo's veterinary hospital with an acute onset of obtundation that was diagnosed with amebic encephalitis. Histologic examination revealed numerous amebic trophozoites within necrotic foci, affecting the occipital cerebrum and surrounding the mesencephalic aqueduct. The etiologic agent, Balamuthia mandrillaris, was determined by multiplex quantitative real-time polymerase chain reaction, immunohistochemistry, and indirect fluorescent antibody test. The current report documented a case of amebic encephalitis within the order Chiroptera. PMID:26762405

  10. Serial MR imaging studies in enlarged endolymphatic duct and sac syndrome

    International Nuclear Information System (INIS)

    Large vestibular aqueduct syndrome (LVAS) is a congenital disorder characterized by progressive or fluctuating sensorineural hearing loss of unknown etiology. Serial MR examinations were performed before and after the development of hearing loss in two patients with LVAS. The signal and volume of the enlarged endolymphatic sac (EES) vary even in ears with stable hearing. In ears with fluctuating hearing, changes in EES signals were observed in only one of two patients. The finding that the EES volume and signal intensity vary dynamically independently of hearing is important for future research into the pathophysiology of hearing loss in this syndrome. (orig.)

  11. Mouse Models for Pendrin-Associated Loss of Cochlear and Vestibular Function

    OpenAIRE

    Wangemann, Philine

    2013-01-01

    The human gene SLC26A4 and the mouse ortholog Slc26a4 code for the protein pendrin, which is an anion exchanger expressed in apical membranes of selected epithelia. In the inner ear, pendrin is expressed in the cochlea, the vestibular labyrinth and the endolymphatic sac. Loss-of-function and hypo-functional mutations cause an enlargement of the vestibular aqueduct (EVA) and sensorineural hearing loss. The relatively high prevalence of SLC26A4 mutations provides a strong imperative to develop ...

  12. Isotopic hydrodynamic of the aquifer systems Jaruco and Aguacate, Cuba

    International Nuclear Information System (INIS)

    An isotopic dispersive model is applied to the Jaruco and Aguacate karstic groundwater basins of Western Cuba. The best fit of the model was validated with stable (18O and 2H) and radioactive (3H) isotopes. Modeling showed an aquifer stratification in two basic levels with turnover times of three month to upper level and close to 100 years to the lower level. The last one mainly supplies the base flow of the Ojo de agua and Bello springs and therefore, controls the dry season exploitation yields of the aqueducts of El Gato and Bello. Model results introduces an important constraint in the exploitation of groundwater resource of both aquifer systems

  13. Applications of spaceborne laser ranger on EOS

    Science.gov (United States)

    Degnan, John J.; Cohen, Steven C.

    1988-01-01

    An account is given of the design concept and potential applications in science and engineering of the spaceborne laser ranging and altimeter apparatus employed by the Geodynamics Laser Ranging System; this is scheduled for 1997 launch as part of the multiple-satellite Earth Observing System. In the retrograding mode for geodynamics, the system will use a Nd:YAG laser's green and UV output for distance determination to ground retroreflectors. Engineering applications encompass land management and long-term ground stability studies relevant to nuclear power plant, pipeline, and aqueduct locations.

  14. Hydraulic Model Studies of Upper Stillwater Dam Stepped Spillway and Outlet Works

    OpenAIRE

    Engineering Research Center; U.S. Department of the Interior, Bureau of Reclamation

    1987-01-01

    Concrete dam and part of the Bonneville Unit of the Central Utah Project, is located about 80 miles east of Salt Lake City, Utah (fig. 1). Upper Stillwater Reservoir will be used to regulate the flows of Rock Creek and South Fork of Rock Creek for release to the Strawberry Aqueduct. The reservoir water surface will be kept constant during the summer but will be lowered about 160 feet during fall and winter releases. The structural height of the dam is 285 feet. Its crest length is 2,800 feet ...

  15. Estado da arte do concretocomo material de construção

    OpenAIRE

    Paulo Roberto do Helene Lago; Salomon Levy Mony

    2003-01-01

    This paper presents a synthesis of the historical evolution of both the making and the use of concrete as a building construction material. It is shown a list of dates and works that have used this material since 5,600 b.C. Many concrete works are mentioned; its use is so widespread that it has become one of the best humans friends. For this reason, it has been used in house buildings, works of art, aqueducts, and buildings for religious purposes, aiming fundamental...

  16. Geochemistry and mineralogy approaches to characterize brick and its lake sediments sources: Antioch Roman City (Southern Turkey)

    OpenAIRE

    El Ouahabi, Meriam; Hubert, Aurelia; Benjelloun, Yacine; Chene, Grégoire; Strivay, David; De Sigoyer, Julia; Pamir, Hatice; Karabacak, Volkan; FAGEL, Nathalie

    2016-01-01

    The Roman aqueduct of Antioch-on-the-Orontes (Southern Turkey) is situated close to the Antioch city. This last is located near the Amik Lake (Lake of Antioch) and close to the junction between the active Dead Sea fault and the East Anatolian fault. During the Roman period, the Amik Plain was more densely occupied than at any time in its history [1]. The study focuses on the bricks and the lake sediments characterization in order to determine the source area as well as the technical productio...

  17. The science of structural engineering

    CERN Document Server

    Heyman, Jacques

    1999-01-01

    Structures cannot be created without engineering theory, and design rules have existed from the earliest times for building Greek temples, Roman aqueducts and Gothic cathedrals - and later, for steel skyscrapers and the frames for aircraft. This book is, however, not concerned with the description of historical feats, but with the way the structural engineer sets about his business. Galileo, in the seventeenth century, was the first to introduce recognizably modern science into the calculation of structures; he determined the breaking strength of beams. In the eighteenth century engineers move

  18. Water System Operator Training for the Central Arizona Project

    OpenAIRE

    Wahlin, Brian; Clemmens, Bert

    2016-01-01

    The Central Arizona Project (CAP) is designed to bring about 1.85 billion cubic meters (1.5 million acre-feet) of Colorado River water per year to Maricopa, Pima, and Pinal counties in Arizona. The CAP canal system is a 540-km (336-mile) long system of conveyance aqueducts, tunnels, pumping plants, and pipelines that is monitored and remotely controlled using Supervisory Control and Data Acquisition (SCADA) software from CAP headquarters in Phoenix, AZ. Because the CAP is crucial to the renew...

  19. Urban Data Center: A Architectural Celebration of Data

    OpenAIRE

    Talarico, Gui

    2011-01-01

    Throughout the last century, the popularization of the automobile and development of roads and highways has changed the way we live, and how cities develop. Bridges, aqueducts, and power plants had comparable impact in the past. I consider each of these examples to be â iconsâ of infrastructures that we humans build to improve our living environments and to fulfill our urge to become better.Fast forward to now. The last decades showed us the development of new sophisticated networks that...

  20. Ecological study on chronic kidney disease and arsenic in drinking water in districts of Guanacaste

    OpenAIRE

    Darner Mora-Alvarado; Azucena Urbina-Campos; Horacio Chamizo-García

    2015-01-01

    To analyze the association between arsenic-contaminated drinking water intake (total-As) above 10 ug/L and the Standardized Morbidity Index (SMI) for Chronic Kidney Disease (CKD) in the 59 districts of the province of Guanacaste, Costa Rica.  1600 sampling and analyses for total-As were performed on water from 421 aqueducts and population weighted averages were calculated in each of the 59 districts. SMI were established using the CKD hospital discharge data for the year 2012. Using the ab...

  1. Progressive white-matter disease with primary cerebellar involvement: a separate entity?

    Energy Technology Data Exchange (ETDEWEB)

    Yalcinkaya, C. [Division of Child Neurology, Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Arslanoglu, I. [Division of Endocrinology, Department of Paediatrics, Goeztepe Hospital, Istanbul (Turkey); Islak, C. [Division of Neuroradiology, Department of Radiology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Aydin, A. [Division of Metabolic Disease, Department of Paediatrics, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Boltshauser, E. [Division of Paediatric Neurology, University Children' s Hospital, Steinwiesstrasse 75, 8032 Zuerich (Switzerland)

    2002-09-01

    Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity. (orig.)

  2. Water in Athens Then and Now

    Science.gov (United States)

    Christaki, Maria

    2015-04-01

    The presentation examines the water sources and the water supply projects in Athens in relation to the historical, urban and demographic development since 3500 BC. Athens and the Athens basin were inhabited from the Late Neolithic period (about 5300-4500 BC.). In recent years, after thorough investigations and excavations in the north and south side of the Acropolis, the Agora and the Dipylon, conclusions were drawn regarding the historical construction and residential development of Athens. The findings show that the Athenians had settled permanently on the sides of the Acropolis from Hysteroneolithic or Final Neolithic period (3500-3000 BC.). The water provision was primarily secured by using wells and natural springs, such as the Neolithic wells near the Klepsydra spring. The climate in Attica is dry Mediterranean with sunny and dry summers and wet and mild winters. The annual precipitation in the city of Athens is about 400 mm and long dry periods are been detected in historical times all the way to today. Since prehistoric times, the city of Athens and the wider region of Attica did not contain many natural water sources so aquatic reserves were never adequate to meet the needs of residents, as these changed over time The lack of water in Attica drove its inhabitants to study the flow of rivers and penetration of rain into the earth to discover and extract hidden waters. This enabled Athenians to acquire technical expertise and develop a significant hydrotechnologic culture, as evidenced by their works. As the population of Athens and the need for water increased residents - among others - turned to obtaining water from distant sources and construct aqueducts that brought water into the city using gravity. In the mid of 6th century BC (tyranny of Peisistrateidon) and while the population was 300,000 the Peisistrateio aqueduct built. After the 6th. century BC there were, fountains, cisterns, reservoirs and aqueducts throughout the city. In Roman Athens, the

  3. Topographic relations of the high jugular fossa to the inner ear. A radioanatomic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Wadin, K.; Wilbrand, H.

    The radioanatomy of high jugular fossae and their topographic relations to the inner ear structures were investigated in 245 unselected temporal bones. One hundred and fifty specimens were submitted to multidirectional and 10 to computed tomography. After careful chemical and fermentative maceration plastic casts were made, using polyester resin and silicone rubber. With the use of vacuum, even minute structures became filled with the casting material. The specimens offered a three-dimensional view of the jugular fossae and surrounding structures. Fifty-eight (24%) of the total 245 specimens had high jugular fossae at a level above the lower border of the round window. Five casts showed a dehiscence of the peripheral portion of the vestibular aqueduct caused by the high jugular fossa. In 2 casts the proximal portion of the cochlear aqueduct was affected. In some casts the posterior semicircular canal, the facial canal, the stapedial muscle and the round window lay so close to the fossa that a dehiscence could not be excluded. In a clinical material of 102 high fossae the radiographic findings were in accordance with the experimental results. High jugular fossae were predominantly found in pyramids with low-grade mastoid bone pneumatization and sparse or no perilabyrinthine air cells.

  4. Survival and Infectivity of the Insect-Parasitic Nematode Heterorhabditis bacteriophora Poinar in Solutions Containing Four Different Turfgrass Soil Surfactants

    Directory of Open Access Journals (Sweden)

    Cale A. Bigelow

    2012-12-01

    Full Text Available This laboratory study examined viability and infectivity of the entomopathogenic nematode (EPN Heterorhabditis bacteriophora Poinar in solutions containing four different turfgrass soil surfactants: Revolution (Aquatrols Corp., Paulsboro, NJ, Aqueduct (Aquatrols Corp., Paulsboro, NJ, Cascade Plus (Precision Laboratories Inc., Waukegan, IL and OARS (Aqua-Aid Inc., Rocky Mount, NC. Infective juvenile H. bacteriophora were added to solutions containing each of the four surfactants, and nematode viability and infectivity were monitored over time. In one of two trials, nematode survival in solutions containing the surfactants Aqueduct and Cascade Plus was consistently higher compared to the water control and solutions containing Revolution or OARS. Surfactants had no significant influence on nematode infectivity in either trial. Findings indicate that most of the common turfgrass soil surfactants examined should be compatible with EPNs and that some may potentially enhance nematode survival. Results also imply that tank-mixing of EPNs with most turfgrass soil surfactants should not pose a significant risk to the nematodes. The influence of soil surfactants on EPN performance remains to be examined in the field.

  5. Application of a New Genetic Deafness Microarray for Detecting Mutations in the Deaf in China.

    Directory of Open Access Journals (Sweden)

    Hong Wu

    Full Text Available The aim of this study was to evaluate the GoldenGate microarray as a diagnostic tool and to elucidate the contribution of the genes on this array to the development of both nonsyndromic and syndromic sensorineural hearing loss in China.We developed a microarray to detect 240 mutations underlying syndromic and nonsyndromic sensorineural hearing loss. The microarray was then used for analysis of 382 patients with nonsyndromic sensorineural hearing loss (including 15 patients with enlarged vestibular aqueduct syndrome, 21 patients with Waardenburg syndrome, and 60 unrelated controls. Subsequently, we analyzed the sensitivity, specificity, and reproducibility of this new approach after Sanger sequencing-based verification, and also determined the contribution of the genes on this array to the development of distinct hearing disorders.The sensitivity and specificity of the microarray chip were 98.73% and 98.34%, respectively. Genetic defects were identified in 61.26% of the patients with nonsyndromic sensorineural hearing loss, and 9 causative genes were identified. The molecular etiology was confirmed in 19.05% and 46.67% of the patients with Waardenburg syndrome and enlarged vestibular aqueduct syndrome, respectively.Our new mutation-based microarray comprises an accurate and comprehensive genetic tool for the detection of sensorineural hearing loss. This microarray-based detection method could serve as a first-pass screening (before next-generation-sequencing screening for deafness-causing mutations in China.

  6. Application of a New Genetic Deafness Microarray for Detecting Mutations in the Deaf in China

    Science.gov (United States)

    Wu, Hong; Feng, Yong; Jiang, Lu; Pan, Qian; Liu, Yalan; Liu, Chang; He, Chufeng; Chen, Hongsheng; Liu, Xueming; Hu, Chang; Hu, Yiqiao; Mei, Lingyun

    2016-01-01

    Objective The aim of this study was to evaluate the GoldenGate microarray as a diagnostic tool and to elucidate the contribution of the genes on this array to the development of both nonsyndromic and syndromic sensorineural hearing loss in China. Methods We developed a microarray to detect 240 mutations underlying syndromic and nonsyndromic sensorineural hearing loss. The microarray was then used for analysis of 382 patients with nonsyndromic sensorineural hearing loss (including 15 patients with enlarged vestibular aqueduct syndrome), 21 patients with Waardenburg syndrome, and 60 unrelated controls. Subsequently, we analyzed the sensitivity, specificity, and reproducibility of this new approach after Sanger sequencing-based verification, and also determined the contribution of the genes on this array to the development of distinct hearing disorders. Results The sensitivity and specificity of the microarray chip were 98.73% and 98.34%, respectively. Genetic defects were identified in 61.26% of the patients with nonsyndromic sensorineural hearing loss, and 9 causative genes were identified. The molecular etiology was confirmed in 19.05% and 46.67% of the patients with Waardenburg syndrome and enlarged vestibular aqueduct syndrome, respectively. Conclusion Our new mutation-based microarray comprises an accurate and comprehensive genetic tool for the detection of sensorineural hearing loss. This microarray-based detection method could serve as a first-pass screening (before next-generation-sequencing screening) for deafness-causing mutations in China. PMID:27018795

  7. Magnetic resonance velocity mapping of 3D cerebrospinal fluid flow dynamics in hydrocephalus: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Stadlbauer, Andreas [Landesklinikum St. Poelten, MR Physics Group, Department of Radiology, St. Poelten (Austria); University of Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany); Salomonowitz, Erich [Landesklinikum St. Poelten, MR Physics Group, Department of Radiology, St. Poelten (Austria); Brenneis, Christian [Landesklinikum St. Poelten, Department of Neurology, St. Poelten (Austria); Ungersboeck, Karl [Landesklinikum St. Poelten, Department of Neurosurgery, St. Poelten (Austria); Riet, Wilma van der [European MRI Consultancy (EMRIC), Strasbourg (France); Buchfelder, Michael; Ganslandt, Oliver [University of Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany)

    2012-01-15

    To investigate the detectability of CSF flow alterations in the ventricular system of patients with hydrocephalus using time-resolved 3D MR velocity mapping. MR velocity mapping was performed in 21 consecutive hydrocephalus patients and 21 age-matched volunteers using a 3D phase-contrast (PC) sequence. Velocity vectors and particle path lines were calculated for visualisation of flow dynamics. CSF flow was classified as ''hypomotile flow'' if it showed attenuated dynamics and as ''hypermotile flow'' if it showed increased dynamics compared with volunteers. Diagnostic efficacy was compared with routine 2D cine PC-MRI. Seven patients showed hypomotile CSF flow: six had non-communicating hydrocephalus due to aqueductal stenosis. One showed oscillating flow between the lateral ventricles after craniotomy for intracranial haemorrhage. Seven patients showed normal flow: six had hydrocephalus ex vacuo due to brain atrophy. One patient who underwent ventriculostomy 10 years ago showed a flow path through the opening. Seven patients showed hypermotile flow: three had normal pressure hydrocephalus, three had dementia, and in one the diagnosis remained unclear. The diagnostic efficacy of velocity mapping was significantly higher except for that of aqueductal stenosis. Our approach may be useful for diagnosis, therapy planning, and follow-up of different kinds of hydrocephalus. (orig.)

  8. PRESTACIÓN DEL SERVICIO DE AGUA POTABLE A TRAVÉS DE COMUNIDADES RURALES, MUNICIPIO DE OCAMONTE. IMPLICACIONES SOCIOJURÍDICAS

    Directory of Open Access Journals (Sweden)

    Roberto Silva Fernández

    2014-01-01

    Full Text Available Research aimed to understanding the problems of drinking water in rural areas of the municipality of Ocamonte, Santander, in key areas such as coverage, quality and condition of the fluid delivery by the local authority. Characterizes the problematic situation and explores the legal partner of organized rural communities, traditional owners of the aqueducts, can provide for the State service possible. Was done the analysis of the rules governing the matter, background and further exploration tools were applied to understand the real situation of rural aqueducts that supply water for human consumption and agricultural development work, as well as perceptions and perspectives are made of the people with the problem. As a result of government neglect in providing the vital service and lack of policies and investments to ad- dress the problem was evident. Was evidenced the legal possibility to develop mechanisms that will allow the rural community to provide water service constituting their self as nonprofit associations or firms and fulfilling requirements that law demand to providers.

  9. Magnetic resonance imaging of the inner ear and its application to cochlear implant candidates

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) images of normal and abnormal inner ear obtained with a 1.5 T unit without the use of a surface coil were analyzed to evaluate the effectiveness of this method in the screening of cochlear implant candidates. In a series with sixteen normal adult volunteers, 22 to 45 years in age, 100% of the cochleae, vestibules, and lateral and posterior semicircular canals were clearly demonstrated in T2 weighted images. Satisfactory images were not obtained for 22% of the superior semicircular canals, 22% of the cochlear aqueduct, and 81% of the vestibular aqueduct in axial images, but coronal and sagittal reconstructed images by use of a three-dimensional Fourie transformation sequence provided better detectability of these structures. In five ear surgery patients with proven obliteration of the labyrinth, decreased signal intensity was observed in the T2 weighted images. Ten cochlear implant candidates were examined by MRI prior to implantation, and the results were compared with the surgical findings. In two ears in which the cochlea showed a decrease in signal intensity, the cochlea had been obliterated by inflammatory granulations. On the other hand, the lumens of all nine cochleae which were clearly visualized by MRI were found to be patent. (author)

  10. Phenomena of instability along the valley of the Gulch Las Perdices and their menace for Guayabetal town

    International Nuclear Information System (INIS)

    Along the valley of the gulch Las Perdices are frequent the slips. These slips have been come presenting in the permeable and porous colluviums that are on the sedimentary and metamorphic rocks that act as waterproof barrier to the flow. The deforestation, abundant precipitation and accented topographical slope, they are considered as the main causes of uncertainty in the area in study. The reforestation and the drainage are fundamental to minimize the menaces for slips, especially in the sector bordering to the lagoon or the hydrant for the Guayabetal aqueduct. The original hydrant was destroyed soon after the slips that affect the place, being this the reason so that the water consumed at the moment is characterized to be cloudy with a high concentration of silts, phenomenon this that is accentuated in the winter times. This problem will be continued presenting while slips exist in the high part and the municipal aqueduct is continued supplying of the waters of the gulch Las Perdices. The sector bordering to the lagoon is the most critical in these moments, so that a quick water movement could originate an avalanche that would affect so much to the civil works as to the inhabitants of the oriental sector of Guayabetal. In this area, it is recommended to begin with preventive measured urgency and correctives, in order to reduce the menace for flood and slips

  11. The mechanism of pathological changes of intraventricular hemorrhage in dogs

    Directory of Open Access Journals (Sweden)

    Dai Jiong

    2009-12-01

    Full Text Available Background : Intraventricular hemorrhage (IVH is an independent risk factor for both morbidity and mortality in patients with intracerebral hemorrhage and subarchnoid hemorrhage. The pathophysiological mechanisms by which blood within the ventricles causes brain damage are still poorly understood. Settings and Design : We developed a canine (dog model with long-term survival. Aims : To study the mechanisms of pathological changes associated with IVH. Materials and Methods : The neurological status, cranial computed tomographic findings, and the pathological changes were studied in the dogs with IVH and also in the control dogs, intraventiricular saline injection. Results : In all the dogs in the control group there were no abnormalities in all the three parameters studied. The dogs in the IVH group developed neurological deficits after the blood injection. There was linear relationship between the ventricular volume and blood clot volume in the first week. After the first week, there was progressive enlargement of the ventricular volume, while the clots continued to shrink. There was complete lysis of the clots within 4 weeks. Pathological studies showed distruction of the ependymal lining of the ventricular system, subependymal gliosis and ischemia of the neurons in the subependymal areas, prominently around the aqueduct. Conclusion : Ventricular dilation was the prominent feature following intraventricular injection of the blood. The other pathological features included disruption of ependymal lining, subependymal gliosis, and ischemic necrosis of neurons in the periventricular tissue of the third ventricle, aqueduct, and the fourth ventricle. These pathological may have some role in the ventricular dilatation following IVH.

  12. Case of spontaneous ventriculocisternostomy

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru (Hiroshima Univ. (Japan). School of Medicine); Kuwabara, Satoshi

    1983-05-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH/sub 2/O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

  13. The  main  East  Mountain  Drain  Aqueduct Rebuilding  Project  Suspension  Support   Construction Technology  Research%东干渠山水沟渡槽翻建工程悬挂支撑施工工艺的研究

    Institute of Scientific and Technical Information of China (English)

    张永德

    2012-01-01

      宁夏水利厅东干渠山水沟渡槽翻建工程于2008年9月开工建设,2009年4月完工。渡槽槽身采用预应力结构,两侧墙吊装就位后再进行槽底混凝土浇筑,原设计方案采用满堂脚手架作底部支撑,项目部根据现场施工情况改进施工措施,改用悬挂支撑,达到预期效果,节省了施工成本。%  Ningxia provincial water resources bureau east main canal mountain drain aqueduct rebuilding project in September 2008 to start construction, completed in April 2009. Aqueduct body using prestressed structure, two side wall hoisting in place of the reentry after tank bottom concrete pouring, the original design scheme adopts the scaffold for bottom support, the project construction according to the improved construction measures, convert suspension support, and achieved the desired results, save the construction cost.

  14. Sustainability of Ancient Water Supply Facilities in Jerusalem

    Directory of Open Access Journals (Sweden)

    Jamal M. Barghouth

    2009-11-01

    Full Text Available This paper presents an overview on the sustainability of ancient water supply systems in Jerusalem from the Chalcolithic period (4500–3200 B.C. until the present time. Archaeological evidences and landscape settings were applied utilizing all available and accessible literature relevant to ancient water resources management in Jerusalem. Irrigated agriculture was practiced for many centuries in this region, hence sustainable water supply facilities were erected, including well developed aqueducts, water harvesting pools and irrigation channels for water storage and landscaping purposes. To cope with seismic events, soil subsidence and water leakage, ancient water engineers and architects applied innovative construction methods for the erection of water pools, channels and aqueduct systems. Ancient water supply systems in Jerusalem are valuable treasures of past civilizations and crucial urban environmental facilities and their protection is consistent with sustainable development principles. Effective environmental assessment as a decision-making process for sustainable development can be applied to preserve threatened ancient water facilities from major development proposals and urban infrastructure projects in Jerusalem.

  15. Radionuclide cisternography in diagnostics of obstruction hydrocephalus in introduced ventricculoperitoneal shunt

    International Nuclear Information System (INIS)

    To confirm or exclude a diagnosis of internal obstruction hydrocephalus in an 8-year old girl with an introduced ventriculoperitoneal (V-P) shunt Establishing the V-P shunt is indisputably the route of choice in non-communicating hydrocephalus. The existence of a V-P shunt, however, is connected with numerous risks, especially of injuries, infection as well as increased intraabdominal pressure - e.g. in pregnancy. The development of endoscopy in neurosurgery allows the creation of communication via the bottom of the third ventricle with basal cisterns, and the subsequent cancellation of a V-P shunt. We describe the case of an 8-year old girl with congenital internal hydrocephalus with an assumed obliteration of the Sylvian aqueduct with an established V-P shunt. An MR scan described the membrane in the area of the Sylvian aqueduct, but the disproportion between the dilatation of the lateral ventricles, third ventricle and fourth ventricle led the physician to doubt as to the accuracy of the diagnosis of internal obstruction hydrocephalus. Therefore we performed a radionuclide cisternography (in a modified manner), which proved an existing communication between the third and fourth cerebral ventricle and which contradicted the clinical diagnosis of obstruction hydrocephalus. (author)

  16. Inner ear anomalies causing congenital sensorineural hearing loss: CT and MR imaging findings

    International Nuclear Information System (INIS)

    Many congenital dysplasias of the osseous labyrinth have been identified, and the differential diagnosis of these dysplasias is essential for delivering proper patient management. We retrospectively reviewed the computed tomography (CT) and magnetic resonance (MR) imaging findings of 20 children who had congenital sensorineural hearing loss. The children included cases of enlarged vestibular aqueduct and endolymphatic sac (n=8), aplasia of the semicircular canal (n=4), lateral semicircular canal-vestibule dysplasia (n=3), common cavity malformations with a large vestibule (n=1), cochlear hypoplasia (n=1), Mondini's dysplasia with large vestibular aqueduct (n=1), Mondini's dysplasia with a large vestibule (n=1), and small internal auditory canal (n=1). Six cases were unilateral. Nine cases had combined deformities, and nine cased had cochlear implants. CT was performed with a 1.0-mm thickness in the direct coronal and axial sections with using bone algorithms. MR was performed with a temporal 3D T2 FSE 10-mm scan and with routine brain images. We describe here the imaging features for the anomalies of the inner ear in patients suffering from congenital sensorineural hearing loss

  17. Central neurocytomas of uncommon locations: report of two cases Localizações incomuns do neurocitoma central: relato de dois casos

    Directory of Open Access Journals (Sweden)

    Francinaldo Lobato Gomes

    2006-12-01

    Full Text Available We report two patients with central neurocytomas at an uncommon location in the brain. The first, a 58-year-old man presenting with signs and symptoms of increased intracranial pressure, had a tumor located at the pineal region. The second, a 21-year-old woman with tumor in the aqueductal region had worsening migraine-like headaches and diplopia. Both patients had obstructive hydrocephalus treated by neuroendoscopic third ventriculostomy and biopsy of the tumors. No additional treatment was done. We conclude that neurocytomas should be considered in the differential diagnosis of tumors located in the pineal and aqueductal regions.Relatamos dois pacientes com neurocitoma central com localização incomum no sistema nervoso central. O primeiro, 58 anos, masculino, apresentava sinais e sintomas de hipertensão intracraniana, tinha um tumor na região da pineal. O segundo, feminino, 21 anos, tinha um tumor na região do aqueduto de Sylvius e apresentava cefaléia migranosa progressiva e diplopia. Ambos apresentavam hidrocefalia obstrutiva tratada com terceiroventriculostomia endoscópica e biópsia da lesão. Não foi feito tratamento adicional. Concluimos que os neurocitomas devem ser considerados no diagnóstico diferencial de tumores localizados na região da pineal e do aqueduto.

  18. Three centuries of heavy metal pollution in Paris (France) recorded by urban speleothems

    Energy Technology Data Exchange (ETDEWEB)

    Pons-Branchu, Edwige, E-mail: epons@lsce.ipsl.fr [LSCE (UMR8212, CEA/CNRS/UVSQ), Bâtiment 12, avenue de la Terrasse, 91198 Gif-Sur-Yvette (France); Ayrault, Sophie; Roy-Barman, Matthieu; Bordier, Louise [LSCE (UMR8212, CEA/CNRS/UVSQ), Bâtiment 12, avenue de la Terrasse, 91198 Gif-Sur-Yvette (France); Borst, Wolfgang; Branchu, Philippe [CEREMA, 12 rue Teisserenc de Bort, 78190 Trappes (France); Douville, Eric [LSCE (UMR8212, CEA/CNRS/UVSQ), Bâtiment 12, avenue de la Terrasse, 91198 Gif-Sur-Yvette (France); Dumont, Emmanuel [CEREMA, rue de l' égalité Prolongée, 93352, Le Bourget cedex 319 (France)

    2015-06-15

    The first record of urban speleothems used to reconstruct the history of heavy metal pollution of shallow groundwaters is presented. Two speleothems grew during the last 300 years in an underground aqueduct in the north-eastern part of Paris. They display high Pb, Mn V, Cu, Cd and Al concentrations since 1900 due to the urbanization of the site which triggered anthropogenic contamination of the water feeding the speleothems. Surprisingly, these heavy metal concentrations are also high in the oldest part. This early pollution could come from the use of Parisian waste as fertilizers in the orchards and vineyards cultivated above the aqueduct before urbanization. Lead isotopes were measured in these carbonates as well as in lead artifacts from the 17th–18th centuries ({sup 206}Pb/{sup 207}Pb = 1.180 +/− 0.003). The mean {sup 206}Pb/{sup 207}Pb ratio, for one of the speleothems is 1.181 +/− 0.003 unvarying with time. These lead signatures are close to those of coal and old lead from northern European mines, lower than the natural background signature. It confirms that the high metal concentrations found come from anthropogenic pollution. Conversely, the lead isotopic composition of the second speleothem presents two temporal trends: for the oldest levels, the mean value (1.183 +/− 0.003) is similar to the first speleothem. For the youngest part, a lower value (1.172 +/− 0.005) is recorded, evidencing the contribution of a new lead source at the beginning of the industrial revolution. Pb isotopes were also measured in recent samples from a nearby superficial site. The first sample is a recent (AD 1975 +/− 15 years) deposit ({sup 206}Pb/{sup 207}Pb = 1.148 +/− 0.003), and the second, a thin subactual layer ({sup 206}Pb/{sup 207}Pb = 1.181 +/− 0.002). These data are compatible with the adding of anthropogenic sources (leaded gasoline and industrial lead from Rio Tinto ore). - Highlights: • Urban speleothems from underground aqueduct in Paris, France were

  19. Visualisation of cerebrospinal fluid flow patterns in albino Xenopus larvae in vivo

    Directory of Open Access Journals (Sweden)

    Mogi Kazue

    2012-04-01

    Full Text Available Abstract Background It has long been known that cerebrospinal fluid (CSF, its composition and flow, play an important part in normal brain development, and ependymal cell ciliary beating as a possible driver of CSF flow has previously been studied in mammalian fetuses in vitro. Lower vertebrate animals are potential models for analysis of CSF flow during development because they are oviparous. Albino Xenopus laevis larvae are nearly transparent and have a straight, translucent brain that facilitates the observation of fluid flow within the ventricles. The aim of these experiments was to study CSF flow and circulation in vivo in the developing brain of living embryos, larvae and tadpoles of Xenopus laevis using a microinjection technique. Methods The development of Xenopus larval brain ventricles and the patterns of CSF flow were visualised after injection of quantum dot nanocrystals and polystyrene beads (3.1 or 5.8 μm in diameter into the fourth cerebral ventricle at embryonic/larval stages 30-53. Results The fluorescent nanocrystals showed the normal development of the cerebral ventricles from embryonic/larval stages 38 to 53. The polystyrene beads injected into stage 47-49 larvae revealed three CSF flow patterns, left-handed, right-handed and non-biased, in movement of the beads into the third ventricle from the cerebral aqueduct (aqueduct of Sylvius. In the lateral ventricles, anterior to the third ventricle, CSF flow moved anteriorly along the outer wall of the ventricle to the inner wall and then posteriorly, creating a semicircle. In the cerebral aqueduct, connecting the third and fourth cerebral ventricles, CSF flow moved rostrally in the dorsal region and caudally in the ventral region. Also in the fourth ventricle, clear dorso-ventral differences in fluid flow pattern were observed. Conclusions This is the first visualisation of the orchestrated CSF flow pattern in developing vertebrates using a live animal imaging approach. CSF flow

  20. Three centuries of heavy metal pollution in Paris (France) recorded by urban speleothems

    International Nuclear Information System (INIS)

    The first record of urban speleothems used to reconstruct the history of heavy metal pollution of shallow groundwaters is presented. Two speleothems grew during the last 300 years in an underground aqueduct in the north-eastern part of Paris. They display high Pb, Mn V, Cu, Cd and Al concentrations since 1900 due to the urbanization of the site which triggered anthropogenic contamination of the water feeding the speleothems. Surprisingly, these heavy metal concentrations are also high in the oldest part. This early pollution could come from the use of Parisian waste as fertilizers in the orchards and vineyards cultivated above the aqueduct before urbanization. Lead isotopes were measured in these carbonates as well as in lead artifacts from the 17th–18th centuries (206Pb/207Pb = 1.180 +/− 0.003). The mean 206Pb/207Pb ratio, for one of the speleothems is 1.181 +/− 0.003 unvarying with time. These lead signatures are close to those of coal and old lead from northern European mines, lower than the natural background signature. It confirms that the high metal concentrations found come from anthropogenic pollution. Conversely, the lead isotopic composition of the second speleothem presents two temporal trends: for the oldest levels, the mean value (1.183 +/− 0.003) is similar to the first speleothem. For the youngest part, a lower value (1.172 +/− 0.005) is recorded, evidencing the contribution of a new lead source at the beginning of the industrial revolution. Pb isotopes were also measured in recent samples from a nearby superficial site. The first sample is a recent (AD 1975 +/− 15 years) deposit (206Pb/207Pb = 1.148 +/− 0.003), and the second, a thin subactual layer (206Pb/207Pb = 1.181 +/− 0.002). These data are compatible with the adding of anthropogenic sources (leaded gasoline and industrial lead from Rio Tinto ore). - Highlights: • Urban speleothems from underground aqueduct in Paris, France were studied. • Speleothems are used to

  1. General solutions to poroviscoelastic model of hydrocephalic human brain tissue.

    Science.gov (United States)

    Mehrabian, Amin; Abousleiman, Younane

    2011-12-21

    Hydrocephalus is a well-known disorder of brain fluidic system. It is commonly associated with complexities in cerebrospinal fluid (CSF) circulation in brain. In this paper, hydrocephalus and shunting surgery which is used in its treatment are modeled. Brain tissues are considered to follow a poroviscoelastic constitutive model in order to address the effects of time dependence of mechanical properties of soft tissues and fluid flow hydraulics. Our solution draws from Biot's theory of poroelasticity, generalized to account for viscoelastic effects through the correspondence principle. Geometrically, the brain is conceived to be spherically symmetric, where the ventricles are assumed to be a hollow concentric space filled with cerebrospinal fluid. A generalized Kelvin model is considered for the rheological properties of brain tissues. The solution presented is useful in the analysis of the disorder of hydrocephalus as well as the treatment associated with it, namely, ventriclostomy surgery. The sensitivity of the solution to various factors such as aqueduct blockage level and trabeculae stiffness is thoroughly analyzed using numerical examples. Results indicate that partial aqueduct stenosis may be a cause of hydrocephalus. However, only severe occlusion of the aqueduct can cause a significant increase in the ventricle and brain's extracellular fluid pressure. Ventriculostomy shunts are commonly used as a remedy to hydrocephalus. They serve to reduce the ventricular pressure to the normal level. However, sensitivity analysis on the shunt's fluid deliverability parameter has shown that inappropriate design or selection of design shunt may cause under-drainage or over-drainage of the ventricles. Excessive drainage of CSF may increase the normal tensile stress on trabeculae. It can cause rupture of superior cerebral veins or damage to trabeculae or even brain tissues which in turn may lead to subdural hematoma, a common side-effect of the surgery. These Post

  2. Corrosiveness and treatment of the Italian natural waters. Geology of the aquifers; Corrosivita' e trattamento di acque naturali italiane. Geologia degli acquiferi

    Energy Technology Data Exchange (ETDEWEB)

    Allievi, F.; Joppi, F.; Romagnoli, M. (Italy)

    2000-12-01

    In Italy there are about 8.000 Communes and about 6.000 administrations of aqueducts. The Italian law on the field of water foresees the reorganization of water services based on suitable territorial circles in the respect for the unity of the hydro graphic basin, the overcoming management fragmentation and the achievement of suitable managerial dimensions. This law begins to be put into practice only these days. Changing is very difficult and complex if it is considered as the first measure, it is necessary to eliminate the actual about 6.000 administrations and to constitute about 200 new managers (public and private). Steel pipes internal corrosion is considered quoting 130 aqueducts, installed in 7 Regions in the North of Italy. These water steel pipings are considered not protected inside, because the internal bitumen layer is removed by the piped water, as it's a temporary protection. The risks of corrosion of these aqueducts are eliminated if an adherent ferric-calcic deposit has formed on the metallic wall. This data concern the activity, on this matter, of the Service Corrosion and Protection of an Italian producer, leader in the steel pipes manufacturing, within the span of about 30 years (1959-1987) and the activity of reporters from 1988 to day. [Italian] Sono esaminati i casi di corrosione interna riscontrati su 130 casi di acquedotti italiani in acciaio. Viene indicata la localizzazione sul territorio dell'Italia Settentrionale, Centrale ed Insulare di acque corrosive per biossido di carbonio aggressivo, insufficienza di ossigeno, presenza di ferrobatteri e di solfobatteri, in relazione alle caratteristiche geologiche degli acquiferi. Sono descritti i trattamenti anticorrosivi effettuati sull'acqua e la loro efficacia per il controllo del processo corrosivo stesso. Viene evidenziato lo stato critico dei gestori di piccoli acquedotti che non hanno le strutture per risolvere adeguatamente i problemi della corrosione interna delle

  3. [Progress in the study of syndromic hearing loss resulted from neural crest abnormalities].

    Science.gov (United States)

    Yalan, Liu; Hua, Zhang; Yong, Feng

    2014-11-01

    More than 400 types of syndromic hearing loss (SHL) have been reported so far, in which Waardenburg syndrome (WS), congenital microtia syndrome (CMS), and large vestibular aqueduct syndrome (LVAS) are the most common ones in clinic. However, it is difficult to study the genetic basis and pathogenesis of SHL in a systematical way because of the strong clinical and genetic heterogeneity of SHL. Dysfunction of neural crest cells (NCC), which are caused by the gene interaction network extended from SOX10 and PAX3, are relevant to the phenotype of WS, CMS and LVAS. Our previous study also confirmed that the gene network was involved in the pathogenesis of WS. In this review, we summarize research progress in the pathogenic mechanisms of SHL resulted from defects in neural crest decelopment, and provide the gene interaction network of neural crest abnormalities resulting in SHL, and hope to provide research ideas and theoretical basis for the systematical study on pathogenesis of common SHL. PMID:25567871

  4. Is Normal Pressure Hydrocephalus more than a mechanical disruption to CSF flow?

    Science.gov (United States)

    Tully, Brett; Byrne, James; Ventikos, Yiannis

    2010-01-01

    This work proposes a new theoretical framework for the water transport in the cerebral environment. The approach is based on Multiple-Network Poroelastic Theory (MPET) and is a natural extension of poroelasticity, a well reported technique applied to cerebrospinal fluid (CSF) transport. MPET accounts for the transport of CSF and blood simultaneously, as they permeate and deform the cerebral tissue. To demonstrate the strength of this approach, MPET is applied to one of the most paradoxical and non-intuitive cerebral pathologies, Normal Pressure Hydrocephalus (NPH). It is shown, for the first time, that clinically relevant ventricular deformations can be observed in the case of totally unobstructed, patient-specific aqueducts. Cerebral diseases are recognised as pivotal in healthcare; they relate to a whole host of unmet clinical needs. We are convinced that basic understanding of fluid transport, as provided by a validated MPET model, is the most promising way to address these needs meaningfully, in a clinical setting. PMID:21096958

  5. An axisymmetric and fully 3D poroelastic model for the evolution of hydrocephalus.

    Science.gov (United States)

    Wirth, Benedikt; Sobey, Ian

    2006-12-01

    We formulate in general terms the equations for axisymmetric and fully 3D models of a hydrocephalic brain. The model is developed using small strain poroelasticity that includes non-linear permeability. The axisymmetric model is solved for four ventricle shapes, an ellipsoid, a 'peanut' shape, a 'cross' shape and a 'bone' shape. The distribution of fluid pressure, velocity and content in the deformed parenchyma for a blocked aqueduct provides new qualitative insight into hydrocepahlus. Some observations are offered for two forms of cerebrospinal fluid flow abnormality, normal pressure hydrocephalus and idiopathic intracranial hypertension. The model is extended to include a gravitational term in the governing equations and the effect of hydrostatic pressure variation is considered. Results of a fully 3D simulations are described for two horn-like lateral ventricles and one case with two lateral ventricles and a third ventricle. PMID:16740629

  6. A Methodology to Validate the InSAR Derived Displacement Field of the September 7th, 1999 Athens Earthquake Using Terrestrial Surveying. Improvement of the Assessed Deformation Field by Interferometric Stacking

    Science.gov (United States)

    Kotsis, Ioannis; Kontoes, Charalabos; Paradissis, Dimitrios; Karamitsos, Spyros; Elias, Panagiotis; Papoutsis, Ioannis

    2008-01-01

    The primary objective of this paper is the evaluation of the InSAR derived displacement field caused by the 07/09/1999 Athens earthquake, using as reference an external data source provided by terrestrial surveying along the Mornos river open aqueduct. To accomplish this, a processing chain to render comparable the leveling measurements and the interferometric derived measurements has been developed. The distinct steps proposed include a solution for reducing the orbital and atmospheric interferometric fringes and an innovative method to compute the actual InSAR estimated vertical ground subsidence, for direct comparison with the leveling data. Results indicate that the modeled deformation derived from a series of stacked interferograms, falls entirely within the confidence interval assessed for the terrestrial surveying data.

  7. A Methodology to Validate the InSAR Derived Displacement Field of the September 7th, 1999 Athens Earthquake Using Terrestrial Surveying. Improvement of the Assessed Deformation Field by Interferometric Stacking

    Directory of Open Access Journals (Sweden)

    Ioannis Papoutsis

    2008-06-01

    Full Text Available The primary objective of this paper is the evaluation of the InSAR derived displacement field caused by the 07/09/1999 Athens earthquake, using as reference an external data source provided by terrestrial surveying along the Mornos river open aqueduct. To accomplish this, a processing chain to render comparable the leveling measurements and the interferometric derived measurements has been developed. The distinct steps proposed include a solution for reducing the orbital and atmospheric interferometric fringes and an innovative method to compute the actual InSAR estimated vertical ground subsidence, for direct comparison with the leveling data. Results indicate that the modeled deformation derived from a series of stacked interferograms, falls entirely within the confidence interval assessed for the terrestrial surveying data.

  8. Imaging assessment of profound sensorineural deafness with inner ear anatomical abnormalities

    Institute of Scientific and Technical Information of China (English)

    Wei-Jing Wu; Xin Chen; Jing-Kun Li; Tao Peng; Yun-Peng Dong; Xue-Zhong Liu; Ding-Hua Xie; Xiang-Bo He; Li-Hua Tan; Peng Hu; An-Quan Peng; Zi-An Xiao; Shu Yang; Tian Wang; Jie Qing

    2015-01-01

    Objective: :To explore the value of a combined computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating profound sensorineural deafness patients before cochlear implant (CI) surgery. Methods:A retrospective analysis of 1012 cases of profound sensorineural deafness that received CI was performed. Results:A total of 96 cases were diagnosed with inner ear abnormalities including large vestibular aqueduct syndrome (LVAS, n ¼ 61), Michel deformity (n ¼ 3), cochlear incomplete partition I (n ¼ 2), cochlear incomplete partition II (n ¼ 6), cochlear hypoplasia with vestibular malformation (n ¼ 3), cochlear ossification (n ¼ 3), bilateral internal auditory canal obstruction (n ¼ 5) and internal auditory canal stenosis (n ¼ 2). Conclusion:High resolution CT (HRCT) can display bony structures while MRI can image the membranous labyrinth in preoperative evaluation for cochlear implantation. The combination of these two modalities provides reliable anatomical information regarding the bony and mem-branous labyrinths, as well as the auditory nerve.

  9. Rilievo e ricostruzione virtuale del Ponte Sud di Hierapolis di Frigia (Turchia

    Directory of Open Access Journals (Sweden)

    Giacomo Di Giacomo

    2013-05-01

    Full Text Available The paper concerns the topographical survey and the 3D reconstruction of a Roman bridge-aqueduct located immediately to the south of Hierapolis in Phrygia (south-western Turkey, along the ancient route directed to Colosse and the internal Anatolia; only its southern abutment and scarce remains of the northern one are preserved. It is in a very difficult location, inside the narrow and deep valley, and it was never studied before. During the 2011 field work campaign of the Italian Archaeological Mission, it was surveyed using a high precision differential GPS system (for the plan documentation and its positioning in the digital archaeological map of Hierapolis and through a Motorized Robotic Total Station (for the documentation of the elevation and the creation of a 3D model of the southern side with the aim of its virtual reconstruction.

  10. The impacts of intergovernmental grants on municipal infrastructure: Evidence from the Canada-Quebec infrastructure works 2000 program.

    Science.gov (United States)

    Mehiriz, Kaddour

    2016-10-01

    This article reports the results of a study on the outcomes of the Canada-Quebec Infrastructure Works 2000 Program (CQIWP), an infrastructure grant program to Quebec municipalities. The focus of this study is on the effects of the CQIWP on municipal investment and physical conditions of drinking water systems and, as such, it goes beyond the usual emphasis on the fiscal consequences of intergovernmental grants. The study results show that the CQIWP was an efficient tool to induce municipalities to increase investment and to reduce the number of aqueduct breakdowns. In light of these findings, this study suggests that upper levels of governments can rely on infrastructure grants to fill the gap in municipal investment and, therefore, to improve the availability and quality of municipal infrastructure. PMID:27423038

  11. Completion Report for Well ER-12-4, Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (includes Errata Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Bechtel Nevada

    2006-05-01

    Well ER-12-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in May 2005, as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit in the north-central portion of the Nevada Test Site. The well is located on Rainier/Aqueduct Mesa, northwest of Yucca Flat, within Area 12 of the Nevada Test Site. The well provided information regarding the radiological and physical environment near underground nuclear tests conducted in U12t Tunnel, information on the pre-Tertiary rocks in the area, and depth to the regional water table.

  12. Under seize: neurocysticercosis in an immigrant woman and review of a growing neglected disease.

    Science.gov (United States)

    Bock, Meredith; Garcia, Hector H; Chin-Hong, Peter; Baxi, Sanjiv M

    2015-01-01

    Neurocysticercosis (NCC) is a significantly neglected tropical disease and, with increasing globalisation, a notable emerging infection in the developed world. We describe a case of ventricular NCC in a 22-year-old Mexican-American woman with a history of seizures, who presented with 2 weeks of headaches and intermittent fevers progressing to altered mental status and vomiting. Initial imaging revealed a cystic mass at the posteroinferior aspect of the third ventricle superior to the aqueduct of Sylvius, calcifications scattered throughout the parenchyma, and enlargement of the lateral and third ventricles. Initial laboratories were unrevealing and serum investigations for Taenia solium antibody were negative, but T. solium antibody was subsequently returned positive from cerebrospinal fluid. This case highlights important issues regarding the clinical presentation, diagnostic evaluation and treatment of NCC relevant to providers not only in areas with endemic disease but, importantly, in locales with diverse immigrant populations. PMID:26682841

  13. Resolution of sudden sensorineural hearing loss following a roller coaster ride.

    Science.gov (United States)

    Kumar, Aman; Sinha, Amrita; Al-Waa, Ahmad M

    2011-07-01

    We report a case of sudden unilateral sensorineural hearing loss of sudden onset during an aeroplane flight, which completely resolved during a roller coaster ride at Alton Towers theme park. A review of the literature concerning sudden idiopathic sensorineural hearing loss and spontaneous resolution are discussed. Initially, pure-tone audiometry showed a profound sensorineural hearing loss in the right ear and mild sensorineural hearing loss in the left ear (of note, the hearing was normal prior to the episode). Following resolution of the patient's symptoms during a roller coaster ride, pure-tone audiometry showed normal hearing thresholds in both ears. Sudden sensorineural hearing loss is a symptom of cochlear injury and the mechanism of the patient's symptoms was attributed to a patent cochlear aqueduct. PMID:22754856

  14. Analysis of the Pavement Drainage Design of the Right Bank in Shijin Main Canal%石津干渠右岸路面排水设计浅析

    Institute of Scientific and Technical Information of China (English)

    姚丽华

    2014-01-01

    In order to prevent the rain water of 307 national highway road on the right bank of Shijin main canal inflows the canal to polute the water delivery quality, the author plan to set the concrete retaining wal at the main canal right slope, and the retaining wal instal the drainage ditch, and through a certain spacing of transverse aqueduct to put the road surface water into the south ditch on the side of road.%为防止石津干渠右岸307国道路面雨污水入渠污染输水水质,设计在干渠右侧坡顶处设置混凝土挡护墙,挡护墙旁设排水沟。通过一定间距设置的横向导水管,将路面集水排入南侧路边沟。

  15. Thermal power systems small power systems applications project. Volume 2: Detailed report

    Science.gov (United States)

    Marriott, A. T.

    1979-01-01

    Small power system technology as applied to power plants up to 10 MW in size was considered. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Breakeven capital costs were determined for leading contenders among the candidate systems. The potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, was studied. Criteria and methodologies were developed for the ranking of candidate power plant system design concepts. Experimental power plant concepts of 1 MW rating were studied to define a power plant configuration for subsequent detail design construction, testing and evaluation. Site selection criteria and ground rules were developed.

  16. Dynamic Programming Applications in Water Resources

    Science.gov (United States)

    Yakowitz, Sidney

    1982-08-01

    The central intention of this survey is to review dynamic programming models for water resource problems and to examine computational techniques which have been used to obtain solutions to these problems. Problem areas surveyed here include aqueduct design, irrigation system control, project development, water quality maintenance, and reservoir operations analysis. Computational considerations impose severe limitation on the scale of dynamic programming problems which can be solved. Inventive numerical techniques for implementing dynamic programming have been applied to water resource problems. Discrete dynamic programming, differential dynamic programming, state incremental dynamic programming, and Howard's policy iteration method are among the techniques reviewed. Attempts have been made to delineate the successful applications, and speculative ideas are offered toward attacking problems which have not been solved satisfactorily.

  17. History of Water Cisterns: Legacies and Lessons

    Directory of Open Access Journals (Sweden)

    Larry Mays

    2013-11-01

    Full Text Available The use of water cisterns has been traced back to the Neolithic Age; this paper thus presents a brief historical development of water cisterns worldwide over the last 5500 years. This paper is not an exhaustive presentation of all that is known today about water cisterns, but rather provides some characteristic examples of cistern technology in a chronological manner extending from prehistoric times to the present. The examples of water cistern technologies and management practices given in this paper may have some importance for water resource sustainability for the present and future. Cisterns have been used to store both rainfall runoff water and aqueduct water originating in springs and streams for the purpose of meeting water needs through seasonal variations. Cisterns have ranged in construction from simple clay pots to large underground structures.

  18. Interpretation and value of MR CSF flow studies for paediatric neurosurgery

    Directory of Open Access Journals (Sweden)

    Samukelisiwe Sithembile Mbonane

    2013-03-01

    Full Text Available Imaging techniques may be underutilised when clinicians are unaware of the technique or do not recognise its potential. Phase-contrast MR imaging (PC-MRI is a rapid, simple and non-invasive technique that is sensitive to CSF flow. It demonstrates a mechanical coupling between cerebral blood and CSF flow throughout the cardiac cycle. Neurosurgeons should be able to request this procedure routinely as part of an MRI request. This paper gives an overview of the indications, technical requirements, technique and interpretation, using image examples. Indications for CSF flow studies include assessment and functionality of shunt treatment in patients with hydrocephalus; hydrocephalus associated with achondroplasia; Chiari I malformation; confirmation of aqueductal stenosis; and determining patency of a third ventriculostomy.

  19. MRI of intracranial germ cell tumours

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, M. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Uozumi, T. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Kiya, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Mukada, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Arita, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Kurisu, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Sugiyama, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Onda, J. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Satoh, H. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Ikawa, F. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan); Migita, K. [Dept. of Neurosurgery, Hiroshima Univ. School of Medicine, Hiroshima (Japan)

    1995-01-01

    We reviewed MRI findings in proven intracranial germ cell tumours in 22 cases, 12 of whom received Gd-DTPA. On T1-weighted images, the signal intensity of the tumour parenchyma was moderately low in 19 cases and isointense in 3; on T2-weighted images, it was high in all cases. Regions of different intensity thought to be cysts were found in 17 (77 %): 7 of 12 patients with germinoma (58 %) and in all other cases. Of the 13 patients with pineal lesions T1-weighted sagittal images showed the aqueduct to be obstructed in 5, stenotic in 7 and normal in 1. Strong contrast enhancement was observed in all 12 cases. Of the 14 patients with suprasellar lesions, 5 were found to have an intrasellar extension, and in 3 of these, the normal pituitary gland, which could be distinguished from the tumour, was displaced anteriorly. Ten patients (45 %) had multiple lesions. (orig.)

  20. La Popala creek: quality analysis of water from some physical - chemical, microbiological variables and aquatic macroinvertebrates

    International Nuclear Information System (INIS)

    The Popala creek supplies water to the people of Bolombolo in Venecia municipality in Antioquia, Colombia. In November 14th and 28th of 2009, four sampling station were located along the creek, to measure five sets of variables: physico- chemical, microbiological, aquatic macroinvertebrate, biological indicators and biotic index BMWP.Physico- chemical variables, aquatic macroinvertebrates and index BMWP indicate good environmental conditions in station 2, located about 150 m from the headwaters (station 1). On the other hand, Station 4, located near to the Cauca River, exhibits deterioration in water quality. Stations 3 and 4 displayed high levels of fecal coliforms. However, the samples taken from Bolombolo's water supply network indicate the water of the aqueduct is adequate for human consumption.

  1. Australasia

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-10-01

    The papers were written in celebration of the 50th anniversary of the Snowy Mountains Scheme in Australia which diverts water from the Snowy river to the Murray and Murrumbidgee river systems and generates peak demand electricity for Sydney and Melbourne. The route of the water is described in detail. The Scheme shaped the post-war construction industry in Australia: it consists of 16 major dams, seven power stations, 24 km of interconnected tunnels and 80 km of aqueducts. A table gives principal construction features of the Scheme. The construction work brought in 100,000 people from all over the world. The technical advances made during the scheme (e.g. rockbolting) and technology employed are described. In recent years the Scheme has focused on reliability-centred maintenance methods and updating of control systems. A detailed list of the principal contractors is given.

  2. A Interpretação do Patrimônio Histórico Romano na cidade de Mainz, Renânia-Palatinado (Alemanha

    Directory of Open Access Journals (Sweden)

    Poliana Fabíula Cardozo

    2012-01-01

    Full Text Available Mainz was founded by the Romans two thousand years ago was an important base of the Empire. Had its rise for two centuries, when he saw his decline attacks by vandals. Today the city has reminders of that era, are exposed to elements such as aqueducts, temples, towers and gates; vessels, ornaments, and other theater. The city administration shall prepare a brochure about, and encourages its visitors. This article aims to describe how the interpretation of this heritage in light of the interpretation tools recommended by the literature, especially in the document of ICOMOS on thesubject. The question is relevant when it intends to demonstrate the uses of heritage interpretation as a methodology for clarification of heritage with the greater interest of you and appreciates the visitor.

  3. Bãile Herculane Resort

    Directory of Open Access Journals (Sweden)

    Munteanu Constantin

    2011-09-01

    Full Text Available Baile Herculane is a balneary resort located in Caraş-Severin County, in South-Western Romania and is located 41 km to the Northwest of the city of Drobeta Turnu Severin, Mehedinti County. Resort Baile Herculane is documentary attested since 153 a.d. and is an attraction for its healing power of water. The Romans will be arriving in Dacia were impressed with the power of exceptional quality healing waters of the Cernei Vally, therefore, have made an important point of attraction here. In those times you keep bathrooms, statues, coins, culverts, signs of gratitude to the gods that were cured with water. The aqueducts, baths and hot springs from the time of the Romans. The beauty of the places where the resort Baile Herculane cannot be described in words, you have to go to see with your eyes

  4. Documentación, valorización y difusión del patrimonio hidráulico romano en el Valle medio del Ebro.

    Directory of Open Access Journals (Sweden)

    Paula Uribe

    2012-11-01

    Full Text Available Nowadays, how to focus the last geometric documentation techniques applied to cultural heritage, aiming a didactic application, is being a complex process. The development of this purpose must balance research process with the social spreading of the scientific knowledge. Based on this concern, the aim of this research project is the geometric documentation - accompanied by a highlighting and spreading on a web environment - of a representative selection of Roman hydraulic structures. The choice of the sites has been done focusing on archaeological discovers in the Ebro’s Valley, concretely in monuments located in La Rioja, Navarra and Aragon. In this way, the purpose of the project is to document the sites and spread the knowledge about Roman aqueducts, dam, sewers, tanks and cisterns, which is essential to understand the water cycle during the Roman period.

  5. The behaviour of both Listeria monocytogenes and rat ciliated ependymal cells is altered during their co-culture.

    Directory of Open Access Journals (Sweden)

    Mina J Fadaee-Shohada

    Full Text Available BACKGROUND: Ciliated ependymal cells line the cerebral ventricles and aqueducts separating the infected CSF from the brain parenchyma in meningitis. PRINCIPAL FINDINGS: Investigation of the interaction of Listeria monocytogenes with cultured rat brain ependymal cells showed that certain strains reduced the beat frequency of the cilia but all the strains studied significantly reduced the ciliary beat amplitude (the linear distance travelled by the tip of each cilium per beat cycle. CONCLUSION: The presence of the ependyma caused aggregation of some listeria strains and in some cases extracellular material also was seen in association with bacterial aggregates. These observations were dependent on the expression of genes required for invasion, intracellular survival and listerial cell to cell spread that are regulated by the transcriptional activator, positive regulatory factor A (PrfA.

  6. Estado da arte do concretocomo material de construção

    Directory of Open Access Journals (Sweden)

    Paulo Roberto do Helene Lago

    2003-01-01

    Full Text Available This paper presents a synthesis of the historical evolution of both the making and the use of concrete as a building construction material. It is shown a list of dates and works that have used this material since 5,600 b.C. Many concrete works are mentioned; its use is so widespread that it has become one of the best humans friends. For this reason, it has been used in house buildings, works of art, aqueducts, and buildings for religious purposes, aiming fundamentally to make human life more comfortable. Among all the unnumbered works mentioned, it is presented a report of the most modern buildings built with high performance concrete, which proves its versatility as a material from both the architectonic and structural viewpoints, besides its durability.

  7. Directory of Open Access Journals (Sweden)

    Luciano Lopes Furlanetti

    2013-03-01

    Full Text Available Objective Neuroendoscopic surgery in children has particular features and is associated with different success rates (SR. The aim of this study was to identify putative factors that could influence the outcome in pediatric patients. Methods Clinical data of 177 patients under 18 years of age submitted to 200 consecutive neuroendoscopic procedures from January 2000 to January 2010 were reviewed. Results The overall success rate was 77%. Out of the patients with successful outcomes, 46% were under six months, 68% were between six months and one year of age, and 85% older than one year. Neuroendoscopic techniques provide very good results for a wide number of indications in children. Tumor-related cerebrospinal fluid (CSF circulation problems and aqueductal stenosis seem to be particularly well suited to neuroendoscopic treatment regardless of the patient's age. Conclusion Patients' age and etiology of hydrocephalus were associated with a different outcome. In all cases, surgical experience is extremely important to reduce complications.

  8. Congenital sensorineural hearing loss

    International Nuclear Information System (INIS)

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems

  9. Case Report: Acute obstructive hydrocephalus associated with infratentorial extra-axial fluid collection following foramen magnum decompression and durotomy for Chiari malformation type I [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sunil Munakomi

    2016-01-01

    Full Text Available Acute obstructive hydrocephalus due to infratentorial extra-axial fluid collection (EAFC is an extremely rare complication of foramen magnum decompression (FMD and durotomy for Chiari malformation type I. Presence of infratentorial  EAFC invariably causes obstruction at the level of the fourth ventricle or aqueduct of Silvius, thereby indicating its definitive role in hydrocephalus. Pathogenesis of EAFC is said to be a local arachnoid tear as a result of durotomy, as this complication is not described in FMD without durotomy. Controversy exists in management. Usually EAFC is said to resolve with conservative management; so hydrocephalus doesn’t require treatment. However, in this case EAFC was progressive and ventriculo-peritoneal shunting (VPS was needed for managing progressive and symptomatic hydrocephalus.

  10. Discovery Mondays: 'Sensors, or the art of measuring limits'

    CERN Document Server

    2006-01-01

    The gigantic LHC machine and experiments will be teeming with minuscule sensors like this one, capable of measuring the tiniest of phenomena. In their study of the infinitesimally small, CERN's physicists, engineers and technicians work at the highest levels of precision. To ensure maximum performance, the most sensitive accelerator and detector components have to be positioned with razor-sharp precision. Detector components, for instance, sometimes need to be aligned to the nearest thousandth of a millimetre! The positioning of the LHC beam is another crucial operation requiring similarly phenomenal precision. Come to the next Discovery Monday and see how different types of sensors are used to achieve the required degrees of precision. The Hydrostatic Levelling System (HLS), for instance, relies on the same principle of communicating vessels that was already employed in antiquity for the construction of aqueducts, bridges and other edifices. You will discover the instrumentation that makes it possible to ...

  11. Cerebrospinal fluid dynamics in Chiari malformation associated with syringomyelia

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; WANG Zhen-yu; XIE Jing-cheng; HAN Hong-bin; PEI Xin-long

    2007-01-01

    Background About 50%-70% of patients with Chiari malformation I (CMI) presented with syringomyelia (SM), which is supposed to be related to abnormal cerebrospinal fluid (CSF) flow around the foramen magnum. The aim of this study was to investigate the cerebrospinal fluid dynamics at levels of the aqueduct and upper cervical spine in patients with CMI associated with SM, and to discuss the possible mechanism of formation of SM.Methods From January to April 2004, we examined 10 adult patients with symptomatic CMI associated with SM and 10 healthy volunteers by phase-contrast MRI. CSF flow patterns were evaluated at seven regions of interest (ROI): the aqueduct and ventral and dorsal subarachnoid spaces of the spine at levels of the cerebellar tonsil, C2-3, and C5-6. The CSF flow waveforms were analyzed by measuring CSF circulation time, durations and maximum velocities of cranial- and caudal-directed flows, and the ratio between the two maximum velocities. Data were analyzed by ttest using SPSS 11.5.Results We found no definite communication between the fourth ventricle and syringomyelia by MRI in the 10 patients.In both the groups, we observed cranial-directed flow of CSF in the early cardiac systolic phase, which changed the direction from cranial to caudal from the middle systolic phase to the early diastolic phase, and then turned back in cranial direction in the late diastolic phase. The CSF flow disappeared at the dorsal ROI at the level of C2-3 in 3 patients and 1 volunteer, and at the level of C5-6 in 6 patients and 3 volunteers. The durations of CSF circulation at all the ROIs were significantly shorter in the patients than those in the healthy volunteers (P=0.014 at the midbrain aqueduct, P=0.019 at the inferior margin of the cerebellar tonsil, P=0.014 at the level of C2-3, and P=0.022 at the level of C5-6). No significant difference existed between the two groups in the initial point and duration of the caudal-directed CSF flow during a cardiac cycle at

  12. Subsidence in the Central Valley, California 2007 - present measured by InSAR

    Science.gov (United States)

    Farr, T. G.; Liu, Z.; Jones, C. E.

    2015-12-01

    Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with ~cm accuracy. For this study, we have obtained and analyzed Japanese PALSAR data for 2006 - 2011, Canadian Radarsat-1 data for 2011 - 2013, Radarsat-2 data for 2012 - 2015, and ESA's Sentinel-1A for 2015 and produced maps of subsidence for those periods. High resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2015. Using multiple scenes acquired by these systems, we were able to produce the time histories of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. The high resolution maps from UAVSAR were used to identify and quantify new, highly localized areas of accelerated subsidence along the California Aqueduct that occurred in 2014. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  13. Three-dimensional cerebrospinal fluid flow within the human ventricular system.

    Science.gov (United States)

    Howden, L; Giddings, D; Power, H; Aroussi, A; Vloeberghs, M; Garnett, M; Walker, D

    2008-04-01

    Cerebrospinal fluid (CSF) is a Newtonian fluid and can, therefore, be modelled using computational fluid dynamics (CFD). Previous modelling of the CSF has been limited to simplified geometric models. This work describes a geometrically accurate three dimensional (3D) computational model of the human ventricular system (HVS) constructed from magnetic resonance images (MRI) of the human brain. It is an accurate and full representation of the HVS and includes appropriately positioned CSF production and drainage locations. It was used to investigate the pulsatile motion of CSF within the human brain. During this investigation CSF flow rate was set at a constant 500 ml/day, to mimic real life secretion of CSF into the system, and a pulsing velocity profile was added to the inlets to incorporate the effect of cardiac pulsations on the choroid plexus and their subsequent influence on CSF motion in the HVS. Boundary conditions for the CSF exits from the ventricles (foramina of Magendie and Lushka) were found using a "nesting" approach, in which a simplified model of the entire central nervous system (CNS) was used to examine the effects of the CSF surrounding the ventricular system (VS). This model provided time varying pressure data for the exits from the VS nested within it. The fastest flow was found in the cerebral aqueduct, where a maximum velocity of 11.38 mm/s was observed over five cycles. The maximum Reynolds number recorded during the simulation was 15 with an average Reynolds number of the order of 0.39, indicating that CSF motion is creeping flow in most of the computational domain and consequently will follow the geometry of the model. CSF pressure also varies with geometry with a maximum pressure drop of 1.14 Pa occurring through the cerebral aqueduct. CSF flow velocity is substantially slower in the areas that are furthest away from the inlets; in some areas flow is nearly stagnant. PMID:18297492

  14. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 6 of 6

    Energy Technology Data Exchange (ETDEWEB)

    Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

    2009-02-01

    This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

  15. Environmental and economic aspects of water kiosks: case study of a medium-sized Italian town.

    Science.gov (United States)

    Torretta, Vincenzo

    2013-05-01

    The consumption of bottled water in Italy began in the 1970s. Since then, this usage has grown considerably, also as a result of changes in habits. The environmental impact as a result of the water production chain is very significant; it would be considered, for example, the use of plastic bottles, the consumption of oil in the production of the bottles, the emission of air from the vehicles that transport the bottles, non-recycled plastic packaging, etc. In this study, considering the comparison between two situations, use of bottled water and use of water kiosk (WK), an environmental and economic impact evaluation has been done. The study considered the production of a WK in a town with 9000 inhabitants, which supplies controlled, still and sparkling water, with an organoleptic quality higher than tap water coming from the aqueduct. In particular, taking into consideration the environmental aspects, specific attention was paid both to CO2 emissions and PET bottle waste reduction. The economic impact evaluation was carried out from the consumer's point of view. In order to provide a supply service that was economically sustainable, a calculation was done with the aim of determining a specific fee for the supplied water. Moreover, a comparison has been made between quality parameters achieved with the analysis of water from aqueducts with the limits established in the Italian legislation and the parameters of several Italian water brands. The study has the aim at considering the opportunity to follow a different people's habits, closer to the concept of sustainability, reducing the environmental charge related to the realization, transport and consumption of plastic water bottles without significant reduction of the quality of the service and with convenient and interesting economic implications. In fact the results of the study show that the alternative of WKs is more efficient in economic and environmental terms respect to the use of bottled water. PMID:23465314

  16. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 1 of 6

    Energy Technology Data Exchange (ETDEWEB)

    Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

    2009-02-01

    This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

  17. A quantitative study of CSF pulsatile flow in normal pressure hydrocephalus; An analysis of flow patterns before and after a shunting procedure using cine MR phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Shinji; Makabe, Tetsuo; Itoh, Takahiko (Okayama Univ. (Japan). School of Medicine) (and others)

    1992-06-01

    In the previous report, we described the visualization and quantitative analysis of a normal CSF pulsatile flow using cine MR phase imaging. In the present study, CSF flow velocities were measured in patients with normal pressure hydrocephalus (NPH) before and after a shunting procedure. All of the healthy subjects showed a similar flow pattern in the time-velocity flow profiles (TVFP). However, patients with NPH showed a variable pattern of TVFP and could be divided into the following four types: Type 0: the CSF flow pattern was similar to that of the healthy subjects. Type I: the caudal peak flow was delayed more than 190 msec on TVFP. Type II: the caudal peak flow was not apparent, but the CSF flow through the aqueduct was remarkable on phase images. Type III: the amplitude of TVFP was very small, and no CSF flow through the aqueduct was identified. The patients with Type III TVFP showed significantly lower NPH scores. The lumbar CSF pressures tended to be high in the patients with Type III TVFP, but nevertheless failed to reach a statistically significant level. The amplitude of TVFP increased in the patients who improved clinically after the shunting procedure. Some of the Type III patients changed into Type II, I, and 0; also, one of the Type II patients changed into a Type I patients after the shunting procedure. We conclude that cine MR phase imaging is useful for analyzing the CSF flow of the patients with NPH before and after the shunting procedure as well as for evaluating shunt patency. (author).

  18. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 4 of 6

    Energy Technology Data Exchange (ETDEWEB)

    Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

    2009-02-01

    This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

  19. A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 5 of 6

    Energy Technology Data Exchange (ETDEWEB)

    Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture

    2009-02-01

    This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.

  20. Late Holocene Paleoseismic Timing and Slip History Along the Missyaf Segment of the Dead Sea Fault in Syria

    Science.gov (United States)

    Meghraoui, M.; Gomez, F.; Sbeinati, R.; Van der Woerd, J.; Mouty, M.; Hijazi, F.; Darkal, A.; Darawcheh, R.; Radwan, Y.; Al-Najjar, H.; Layous, I.; Al-Ghazzi, R.; Barazangi, M.

    2001-12-01

    We investigate the timing of Holocene earthquakes and related slip rate along the main segment of the Dead Sea fault south of the Ghab pull-apart basin in western Syria. The 60-70 km long Missyaf segment consists of a single fault branch of the north-south trending left-lateral fault at the plate boundary between Africa and Arabia. The late Quaternary tectonic activity along the fault is characterized by (1) deflected streams with consistent left-lateral displacements of different sizes (50 to 300 m), and (2) evidence of large shutter-ridge structures and small pull-apart basins. Microtopographic surveys and trenching across the fault at two sites document the size and timing of paleoseismic events and the related faulting behavior. Near El Harif village, the fault cut across a Roman aqueduct (younger than 22 AD) and induces 10.5 ±0.1 m of left-lateral displacement. Nearby trench-excavations and test pits exhibit the fault with the shear zone affecting a succession of young alluvial deposits of a terrace meander. Radiocarbon dating of the faulting events with vertical displacements reveal the occurrence of a large seismic event prior to 408-380 BC, a penultimate event between 22 - 979 AD and the most recent event between 979 - 1255 AD. The two most recent events being most likely responsible for the Roman aqueduct total displacement, it implies an average coseismic left-lateral movement of 5 m and a slip rate of about 5 mm/yr. The correlation with the historical seismicity catalogue suggests that the most recent faulting event may correspond to the well documented large earthquake of 1170 AD.

  1. Environmental and economic aspects of water kiosks: Case study of a medium-sized Italian town

    Energy Technology Data Exchange (ETDEWEB)

    Torretta, Vincenzo, E-mail: vincenzo.torretta@uninsubria.it [Department of Science and High Technology, Insubria University of Varese, Via G.B. Vico, 46, I-21100 Varese (Italy)

    2013-05-15

    The consumption of bottled water in Italy began in the 1970s. Since then, this usage has grown considerably, also as a result of changes in habits. The environmental impact as a result of the water production chain is very significant; it would be considered, for example, the use of plastic bottles, the consumption of oil in the production of the bottles, the emission of air from the vehicles that transport the bottles, non-recycled plastic packaging, etc. In this study, considering the comparison between two situations, use of bottled water and use of water kiosk (WK), an environmental and economic impact evaluation has been done. The study considered the production of a WK in a town with 9000 inhabitants, which supplies controlled, still and sparkling water, with an organoleptic quality higher than tap water coming from the aqueduct. In particular, taking into consideration the environmental aspects, specific attention was paid both to CO{sub 2} emissions and PET bottle waste reduction. The economic impact evaluation was carried out from the consumer’s point of view. In order to provide a supply service that was economically sustainable, a calculation was done with the aim of determining a specific fee for the supplied water. Moreover, a comparison has been made between quality parameters achieved with the analysis of water from aqueducts with the limits established in the Italian legislation and the parameters of several Italian water brands. The study has the aim at considering the opportunity to follow a different people’s habits, closer to the concept of sustainability, reducing the environmental charge related to the realization, transport and consumption of plastic water bottles without significant reduction of the quality of the service and with convenient and interesting economic implications. In fact the results of the study show that the alternative of WKs is more efficient in economic and environmental terms respect to the use of bottled water.

  2. Satellite remote sensing and multiscale geophysical investigations for geoarcheology: case studies from Perù

    Science.gov (United States)

    Capozzoli, Luigi; Delle Rose, Marco; Lasaponara, Rosa; Masini, Nicola; Rizzo, Enzo; Romano, Gerardo

    2013-04-01

    Satellite remote sensing as well as geophysical techniques proved to be successful tools for characterizing archaeological areas. In order to provide useful information on the presence of buried structures and the iteration between the aqueducts (Puquios) and the local hydrogeological setting, a multi-disciplinary and multi-scale approach based on the integration of satellite remote sensing and geophysical techniques was applied in different sites of Perù. Such investigations were carried out by the Italian mission ITACA, funded by the Italian Ministry Affairs and composed of researchers of two institutes of CNR (IMAA and IBAM), which provides a scientific support for archaeological research, since 2007. In detail, the archaeological Cahuachi site (0-400 AD) was investigated by geoelectrical and georadar prospecting, in order to highlight buried structures and platforms. The detection and characterization of perhispanic aqueducts and canals were the main aims in the Nasca drainage basin and in the Ceremonial Centre of Pachacamac (500-1400 ADF). Finally, the integration of all data acquired by the different remote sensing techniques allowed for spatially characterizing the archaeological features, thus providing important information for the planning of next archaeological excavations and glimpses into the use and management of water resources by prehispanic civilizations. References Lasaponara R., Masini N., Rizzo E., Orefici G. 2011. New discoveries in the Piramide Naranjada in Cahuachi (Peru) using satellite, Ground Probing Radar and magnetic investigations, Journal of Archaeological Science, 38(9), 2031-2039, doi:10.1016/j.jas.2010.12.010 Masini N., Lasaponara R., Rizzo E., Orefici G. 2012. Integrated Remote Sensing Approach in Cahuachi (Peru): Studies and Results of the ITACA Mission (2007-2010), In: Lasaponara R., Masini N. (Eds) 2012, Satellite Remote Sensing: a new tool for Archaeology, Springer, Verlag Berlin Heidelberg, ISBN 978-90-481-8800-0, doi: 10

  3. Using satellite time series for remote sensing based investigations of ancient acqueduct systems: the case of the Nasca puquios

    Science.gov (United States)

    Lasaponara, R.; Masini, N.

    2012-04-01

    Satellite time series can provide valuable information to reconstruct ancient environmental changes, still fossilized in the present landscape. In particular, satellite derived moisture content and moisture patter variations over the seasons and years may facilitate the identification of areas involved in early environmental manipulation. Up to now, only a few number of archaeological studies on spatial patterns of moisture have been carried out through the world using satellite optical data. We focus on Landsat and ASTER multitemporal data acquired for some areas near Nasca basin (Peru) to extract information on ancient irrigation systems and artificial wet agro-ecosystems. The study area is particularly interesting mainly because it was populated since millennia ago despite its drought and critical environment conditions presented serious obstacles to human occupation. Considering this extreme drought, which characterizes this area today as several centuries ago, ancient populations of the Nasca River valley devised an efficient system for retrieval water and to face the drought conditions. This system was based on underground aqueducts called puquios, which in part are still used today. Archaeological record put in evidence that during the Nasca flourishing period, the number and spatial distribution of puquios were larger than today. On the basis of satellite multitemporal moisture maps, Unknown puquios were identified and confirmed by ground survey. This information can be a basic The successful results achieved in the Nasca Basin area may be also rejoined in similar environmental conditions (in Meso-America, Middle East, North Africa, Asia) where ancient populations devised aqueducts to face drought and retrieve water for domestic, ritual and agricultural needs. Reference Lasaponara R., Masini N., Following the Ancient Nasca Puquios from Space, in Lasaponara R. and Masini N. (Eds), Satellite Remote Sensing: A New Tool for Archaeology (Remote Sensing and

  4. Morphometric Analysis of the Internal Auditory Canal by Computed Tomography Imaging

    International Nuclear Information System (INIS)

    Many clinical and experimental studies have been done to analyze the anatomical and functional aspects of the internal auditory canal (IAC) in human beings since there are great inter-individual variability and structural variations that may occur regarding the other adjacent structures. The purpose of this study was to characterize the morphology of the internal auditory canal (IAC) during development using high resolution computed tomography (CT) and to analyze its dimensions, which will be determined by measuring the nearby areas and structures using a system of digital image processing. CT images of the IAC of 110 normal subjects aged 1 to 92 years (mean age, 46.5 years) of both genders were reviewed to determine the shape, area, opening width (OW), longitudinal length (LL), vertical diameter (VD) and distance from the vestibular aqueduct. The shapes observed in children and adults were funnel-shaped (74% and 58.3%, respectively), cylindrical (22% and 30.9%, respectively) and bud-shaped (4% and 10.8%, respectively). The measurements by CT in children were: area= 50.30 mm2, OW = 7.53 mm, length = 11.17 mm, VD = 4.82 mm and the distance between the IAC and the vestibular aqueduct (VA) = 12.63 mm. In adults, the measurements were: area = 44.64 mm2, OW = 7.10 mm, length = 9.84 mm, VD = 4.47 mm and the distance between IAC and VA = 11.17 mm. CT images showed that the IAC has different shapes and when the measurements obtained for children were compared with those of adults, the parameters that presented statistically significant differences in either gender were length and diameter

  5. Morphometric Analysis of the Internal Auditory Canal by Computed Tomography Imaging

    Science.gov (United States)

    Marques, Sergio Ricardo; Ajzen, Sergio; D´Ippolito, Giuseppe; Alonso, Luis; Isotani, Sadao; Lederman, Henrique

    2012-01-01

    Background Many clinical and experimental studies have been done to analyze the anatomical and functional aspects of the internal auditory canal (IAC) in human beings since there are great inter-individual variability and structural variations that may occur regarding the other adjacent structures. Objectives The purpose of this study was to characterize the morphology of the internal auditory canal (IAC) during development using high resolution computed tomography (CT) and to analyze its dimensions, which will be determined by measuring the nearby areas and structures using a system of digital image processing. Patients and Methods CT images of the IAC of 110 normal subjects aged 1 to 92 years (mean age, 46.5 years) of both genders were reviewed to determine the shape, area, opening width (OW), longitudinal length (LL), vertical diameter (VD) and distance from the vestibular aqueduct. Results The shapes observed in children and adults were funnel-shaped (74% and 58.3%, respectively), cylindrical (22% and 30.9%, respectively) and bud-shaped (4% and 10.8%, respectively). The measurements by CT in children were: area= 50.30 mm2, OW = 7.53 mm, length = 11.17 mm, VD = 4.82 mm and the distance between the IAC and the vestibular aqueduct (VA) = 12.63 mm. In adults, the measurements were: area = 44.64 mm2, OW = 7.10 mm, length = 9.84 mm, VD = 4.47 mm and the distance between IAC and VA = 11.17 mm. Conclusions CT images showed that the IAC has different shapes and when the measurements obtained for children were compared with those of adults, the parameters that presented statistically significant differences in either gender were length and diameter. PMID:23329967

  6. Endoscopic third ventriculostomy

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    Yad Ram Yadav

    2012-01-01

    Full Text Available Endoscopic third ventriculostomy (ETV is considered as a treatment of choice for obstructive hydrocephalus. It is indicated in hydrocephalus secondary to congenital aqueductal stenosis, posterior third ventricle tumor, cerebellar infarct, Dandy-Walker malformation, vein of Galen aneurism, syringomyelia with or without Chiari malformation type I, intraventricular hematoma, post infective, normal pressure hydrocephalus, myelomeningocele, multiloculated hydrocephalus, encephalocele, posterior fossa tumor and craniosynostosis. It is also indicated in block shunt or slit ventricle syndrome. Proper Pre-operative imaging for detailed assessment of the posterior communicating arteries distance from mid line, presence or absence of Liliequist membrane or other membranes, located in the prepontine cistern is useful. Measurement of lumbar elastance and resistance can predict patency of cranial subarachnoid space and complex hydrocephalus, which decides an ultimate outcome. Water jet dissection is an effective technique of ETV in thick floor. Ultrasonic contact probe can be useful in selected patients. Intra-operative ventriculo-stomography could help in confirming the adequacy of endoscopic procedure, thereby facilitating the need for shunt. Intraoperative observations of the patent aqueduct and prepontine cistern scarring are predictors of the risk of ETV failure. Such patients may be considered for shunt surgery. Magnetic resonance ventriculography and cine phase contrast magnetic resonance imaging are effective in assessing subarachnoid space and stoma patency after ETV. Proper case selection, post-operative care including monitoring of ICP and need for external ventricular drain, repeated lumbar puncture and CSF drainage, Ommaya reservoir in selected patients could help to increase success rate and reduce complications. Most of the complications develop in an early post-operative, but fatal complications can develop late which indicate an importance of

  7. A quantitative study of CSF pulsatile flow in normal pressure hydrocephalus

    International Nuclear Information System (INIS)

    In the previous report, we described the visualization and quantitative analysis of a normal CSF pulsatile flow using cine MR phase imaging. In the present study, CSF flow velocities were measured in patients with normal pressure hydrocephalus (NPH) before and after a shunting procedure. All of the healthy subjects showed a similar flow pattern in the time-velocity flow profiles (TVFP). However, patients with NPH showed a variable pattern of TVFP and could be divided into the following four types: Type 0: the CSF flow pattern was similar to that of the healthy subjects. Type I: the caudal peak flow was delayed more than 190 msec on TVFP. Type II: the caudal peak flow was not apparent, but the CSF flow through the aqueduct was remarkable on phase images. Type III: the amplitude of TVFP was very small, and no CSF flow through the aqueduct was identified. The patients with Type III TVFP showed significantly lower NPH scores. The lumbar CSF pressures tended to be high in the patients with Type III TVFP, but nevertheless failed to reach a statistically significant level. The amplitude of TVFP increased in the patients who improved clinically after the shunting procedure. Some of the Type III patients changed into Type II, I, and 0; also, one of the Type II patients changed into a Type I patients after the shunting procedure. We conclude that cine MR phase imaging is useful for analyzing the CSF flow of the patients with NPH before and after the shunting procedure as well as for evaluating shunt patency. (author)

  8. Environmental and economic aspects of water kiosks: Case study of a medium-sized Italian town

    International Nuclear Information System (INIS)

    The consumption of bottled water in Italy began in the 1970s. Since then, this usage has grown considerably, also as a result of changes in habits. The environmental impact as a result of the water production chain is very significant; it would be considered, for example, the use of plastic bottles, the consumption of oil in the production of the bottles, the emission of air from the vehicles that transport the bottles, non-recycled plastic packaging, etc. In this study, considering the comparison between two situations, use of bottled water and use of water kiosk (WK), an environmental and economic impact evaluation has been done. The study considered the production of a WK in a town with 9000 inhabitants, which supplies controlled, still and sparkling water, with an organoleptic quality higher than tap water coming from the aqueduct. In particular, taking into consideration the environmental aspects, specific attention was paid both to CO2 emissions and PET bottle waste reduction. The economic impact evaluation was carried out from the consumer’s point of view. In order to provide a supply service that was economically sustainable, a calculation was done with the aim of determining a specific fee for the supplied water. Moreover, a comparison has been made between quality parameters achieved with the analysis of water from aqueducts with the limits established in the Italian legislation and the parameters of several Italian water brands. The study has the aim at considering the opportunity to follow a different people’s habits, closer to the concept of sustainability, reducing the environmental charge related to the realization, transport and consumption of plastic water bottles without significant reduction of the quality of the service and with convenient and interesting economic implications. In fact the results of the study show that the alternative of WKs is more efficient in economic and environmental terms respect to the use of bottled water

  9. Coupled decadal variability of the North Atlantic Oscillation, regional rainfall and spring discharges in the Campania region (Southern Italy

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    P. De Vita

    2011-12-01

    Full Text Available Climate change is one of the issues most debated by the scientific community with a special focus to the combined effects of anthropogenic modifications of the atmosphere and the natural climatic cycles. Various scenarios have been formulated in order to forecast the global atmospheric circulation and consequently the variability of the global distribution of air temperature and rainfall. The effects of climate change have been analysed with respect to the risks of desertification, droughts and floods, remaining mainly limited to the atmospheric and surface components of the hydrologic cycle. Consequently the impact of the climate change on the recharge of regional aquifers and on the groundwater circulation is still a challenging topic especially in those areas whose aqueduct systems depend basically on springs or wells, such as the Campania region (Southern Italy.

    In order to analyse the long-term climatic variability and its influence on groundwater circulation, we analysed decadal patterns of precipitation, air temperature and spring discharges in the Campania region (Southern Italy, coupled with the North Atlantic Oscillation (NAO.

    The time series of precipitation and air temperature were gathered over 90 yr, in the period from 1921 to 2010, choosing 18 rain gauges and 9 air temperature stations among those with the most continuous functioning as well as arranged in a homogeneous spatial distribution. Moreover, for the same period, we gathered the time series of the winter NAO index (December to March mean and of the discharges of the Sanità spring, belonging to an extended carbonate aquifer (Cervialto Mount located in the central-eastern area of the Campania region, as well as of two other shorter time series of spring discharges. The hydrogeological features of this aquifer, its relevance due to the feeding of an important regional aqueduct system, as well as the unique availability of a long-lasting time series of

  10. Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection

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    Hwang Jong-Hee

    2008-10-01

    Full Text Available Abstract Background Worldwide, approximately two billion people are chronically infected with Toxoplasma gondii with largely unknown consequences. Methods To better understand long-term effects and pathogenesis of this common, persistent brain infection, mice were infected at a time in human years equivalent to early to mid adulthood and studied 5–12 months later. Appearance, behavior, neurologic function and brain MRIs were studied. Additional analyses of pathogenesis included: correlation of brain weight and neurologic findings; histopathology focusing on brain regions; full genome microarrays; immunohistochemistry characterizing inflammatory cells; determination of presence of tachyzoites and bradyzoites; electron microscopy; and study of markers of inflammation in serum. Histopathology in genetically resistant mice and cytokine and NRAMP knockout mice, effects of inoculation of isolated parasites, and treatment with sulfadiazine or αPD1 ligand were studied. Results Twelve months after infection, a time equivalent to middle to early elderly ages, mice had behavioral and neurological deficits, and brain MRIs showed mild to moderate ventricular dilatation. Lower brain weight correlated with greater magnitude of neurologic abnormalities and inflammation. Full genome microarrays of brains reflected inflammation causing neuronal damage (Gfap, effects on host cell protein processing (ubiquitin ligase, synapse remodeling (Complement 1q, and also increased expression of PD-1L (a ligand that allows persistent LCMV brain infection and CD 36 (a fatty acid translocase and oxidized LDL receptor that mediates innate immune response to beta amyloid which is associated with pro-inflammation in Alzheimer's disease. Immunostaining detected no inflammation around intra-neuronal cysts, practically no free tachyzoites, and only rare bradyzoites. Nonetheless, there were perivascular, leptomeningeal inflammatory cells, particularly contiguous to the aqueduct of

  11. Longitudinal neuronal organization of defensive reactions in the midbrain periaqueductal gray region of the rat.

    Science.gov (United States)

    Depaulis, A; Keay, K A; Bandler, R

    1992-01-01

    In a previous study we investigated the intraspecific defensive reactions evoked by excitation of neurons in the intermediate third of the midbrain periaqueductal gray matter (PAG) of the rat. Experiments revealed that activation of neurons in this region of the PAG mediated: (i) backward defensive behavior, characterized by upright postures and backward movements, and (ii) reactive immobility ("freezing"), in which the rat remained immobile, but reacted with backward defensive behavior to investigative, non-aggressive contact initiated by the partner. In the present study, we aimed to extend our understanding of PAG mediation of defensive behavior by observing: (i) in a non-aggressive social interaction test, the behavioral effects of microinjections of low doses of kainic acid (40 pmol in 200 nl) made in the caudal third of the PAG; and (ii) the behavioral and cardiovascular effects of microinjections of D,L-homocysteic acid (5-10 nmol in 50-100 nl) made in the PAG of the unanesthetized decerebrate rat. Kainic acid injections into the area lateral to the midbrain aqueduct in the caudal third of the PAG evoked: (i) forward avoidance behavior, characterized by forward locomotion and occasional hop/jumps; (ii) reactive immobility ("freezing"), in which the rat remained immobile, but reacted with forward avoidance behavior to investigative, non-aggressive contact initiated by the partner; and (iii) 22-28 kHz ultrasonic vocalizations. These injections also evoked a dramatic increase in defensive responsiveness to tactile stimuli on the half of the body contralateral, but not ipsilateral, to the site of injection. Electroencephalographic measurements indicated that none of these effects were secondary to seizure activity. In the decerebrate rat, D,L-homocysteic acid injections in the caudal third of the PAG evoked forward running movements along with increased blood pressure and heart rate, the strongest effects being evoked from the region lateral to the midbrain

  12. Invariant properties and rotation transformations of the GPR scattering matrix

    Science.gov (United States)

    Villela, Almendra; Romo, José M.

    2013-03-01

    We analyze the properties of the scattering matrix associated with the incident and scattered electric fields used in GPR. The elements of the scattering matrix provide information produced by different polarizations of the incident wave field. Rotationally invariant quantities such as trace, determinant and Frobenius norm lead to images that combine the information contained in the four elements of the scattering matrix in a mathematically simple and sound manner. The invariant quantities remove the directional properties implicit in the dipolar field used in GPR allowing the application of standard processing techniques designed for scalar fields, such as those used in seismic data processing. We illustrate the non-directional properties of the invariants using a 3D simulation of the wavefield produced by a point scatterer. The estimation of the azimuth angle of elongated targets is also explored using rotation transformations that maximize alternatively the co-polarized or the cross-polarized responses. The angle estimation is essentially an unstable process, particularly if low amplitudes or noisy data are involved. We apply the Frobenius norm ‖S‖F as a criterion for selection of the best amplitudes to use for a more stable and significant angle estimation. The performance of our formulation was tested with synthetic data produced by a 3D model of an air-filled metal pipe buried in a homogeneous halfspace. The images resulting from the invariants show a clear diffraction hyperbola suitable for a scalar wavefield migration, while the azimuth of the pipe is neatly resolved for amplitudes selected with ‖S‖F ≥ 0.4. A field experiment conducted above an aqueduct pipe illustrates the proposed methods with real data. The images obtained from the invariants are better than those from the individual elements of the scattering matrix. The azimuth estimated using our formulation is in agreement with the probable orientation of the aqueduct. Finally, a field

  13. L’adduction d’eau à Dieppe aux XVIe et XVIIe siècles : de l’utile à l’apparat

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    Viviane Manase

    2012-05-01

    Full Text Available La ville de Dieppe a bénéficié dès le XVIe siècle d’une adduction d’eau particulièrement dense, précoce illustration d’hygiène publique et d’urbanisme. Difficilement mis en place par le fontainier Pierre Toustain, l’aqueduc gravitaire qui sur 6,7 km mena l’eau d’une source abondante jusqu’à la ville subsiste encore en partie. En 1579 il pourvoyait en eau pas moins de seize fontaines publiques soigneusement ornées, brillantes émanations du prestige de la cité. En 1617, une originale fontaine mécanique « en forme de rocher » est édifiée en l’honneur de la venue de Louis XIII. Inspirée par les travaux du célèbre ingénieur dieppois Salomon de Caus, elle charme alors les populations par ses jeux d’eau et ses oiseaux artificiels chantants.From the sixteenth century, the city of Dieppe had an important and well-developed public water system which may be seen as an early illustration of a public health service and as an aspect of town planning. Not without difficulty, a gravitational aqueduct was built by the engineer Pierre Toustain, carrying spring water to the city over a distance of some 6.7 kilometres. Part of this aqueduct still survives. In 1579, the water flowed from no fewer than sixteen decorative fountains, symbols of the city’s prestige. In 1617, an original mechanical fountain ‘in the shape of a rock’ was constructed in honour of a visit to the city by Louis XIII. Inspired by the works of the famous engineer Salomon de Caus of Dieppe, this fountain charmed the population with its dancing waters and artificial singing birds.

  14. Satellite SAR imagery for site discovery, change detection and monitoring activities in cultural heritage sites: experiments on the Nasca region, Peru

    Science.gov (United States)

    Tapete, D.; Cigna, F.; Masini, N.; Lasaponara, R.

    2012-04-01

    Besides their suitability for multi-temporal and spatial deformation analysis, the Synthetic Aperture Radar (SAR) image archives acquired by space-borne radar sensors can be exploited to support archaeological investigations over huge sites, even those partially or totally buried and still to be excavated. Amplitude information is one of the main properties of SAR data from which it is possible to retrieve evidences of buried structures, using feature extraction and texture analysis. Multi-temporality allows the reconstruction of past and recent evolution of both landscape and built-up environment, with the possibility to detect natural and/or anthropogenic changes, including human-induced damages to the conservation of cultural heritage. We present the methodology and first results of the experiments currently undertaken using SAR data in the Nasca region (Southern Peru), where two important civilizations such as Paracas and Nasca developed and flourished from 4th century BC to the 6th century AD. The study areas include a wide spectrum of archaeological and environmental elements to be preserved, among which: the archaeological site of Cahuachi and its surroundings, considered the largest adobe Ceremonial Centre in the World; the Nasca lines and geoglyphs in the areas of Palpa, Atarco and Nasca; the ancient networks of aqueducts and drainage galleries in the Puquios area, built by Nasca in the 1st-6th centuries AD. Archaeological prospection and multi-purpose remote sensing activities are currently carried out in the framework of the Italian mission of heritage Conservation and Archaeogeophysics (ITACA), with the direct involvement of researchers from the Institute for Archaeological and Monumental Heritage and the Institute of Methodologies for Environmental Analysis, Italian National Research Council. In this context, C- and L-band SAR images covering the Nasca region since 2001 were identified for the purposes of this research and, in particular, the following

  15. A Late Holocene Slip Rate Of The North Anatolian Fault, Hersek Peninsula, Izmit Bay, Turkey

    Science.gov (United States)

    Kozaci, O.; Altunel, E.; Clahan, K.; Yonlu, O.; Sundermann, S. T.; Lettis, W. R.; Turner, J.; Altekruse, J.; Gumus, I.; Lindvall, S. C.

    2010-12-01

    The Hersek Peninsula has been a strategic site for at least the last two millennia as a result of its location. It extends into Izmit Bay and creates a shortcut for the historical Bagdad Road, an important section of the spice route, between Istanbul (Constantinople) and Iznik (Nicaea). It also controls the entrance of Izmit Bay to Izmit (Nicomedia). Civilizations have been investing in this location by building harbors, fortifications, baths, roads, bridges, aqueducts, and temples. The remnants of these historical structures record evidence for past destruction of both anthropogenic and tectonic origin. From an active tectonics point of view, the Hersek Peninsula is a key locality for understanding seismic hazard in the Marmara Region. It is the last place that the North Anatolian fault can be studied on land before it enters the Marmara Sea and it has experienced strong ground shaking most recently during the M7.4 Izmit earthquake in 1999. Paleoseismic trenching as well as archeoseismologic investigations were recently performed on the Hersek Peninsula for regional and site specific seismic hazard characterization. Our paleoseismic trenches north of the Hersek Lagoon provided fault exposures confirming the location of the North Anatolian fault on the peninsula. Detailed mapping of a 6th century A.D. Byzantine aqueduct offset 14 ± 1 meters along the projection of this fault trace revealed a minimum late Holocene slip rate of 13.6 +1/-3.5 mm yr-1. Rapid fan deposition and subsidence on the delta plain across the Hersek Peninsula has resulted in the relatively recent deposition of several meters of relatively young alluvium and nearshore tidal deposits. Nearly 2 km of trench exposures revealed these deposits were continuous and contain only minor evidence of ground shaking in the form of secondary liquefaction deposits and ground fractures. The lack of primary ground surface rupture evidence in these approximately 300-year-old sediments strongly suggests that the

  16. Using open source software for the supervision and management of the water resources system of Athens

    Science.gov (United States)

    Kozanis, S.; Christofides, A.; Efstratiadis, A.; Koukouvinos, A.; Karavokiros, G.; Mamassis, N.; Koutsoyiannis, D.; Nikolopoulos, D.

    2012-04-01

    The water supply of Athens, Greece, is implemented through a complex water resource system, extending over an area of around 4 000 km2 and including surface water and groundwater resources. It incorporates four reservoirs, 350 km of main aqueducts, 15 pumping stations, more than 100 boreholes and 5 small hydropower plants. The system is run by the Athens Water Supply and Sewerage Company (EYDAP) Over more than 10 years we have developed, information technology tools such as GIS, database and decision support systems, to assist the management of the system. Among the software components, "Enhydris", a web application for the visualization and management of geographical and hydrometeorological data, and "Hydrognomon", a data analysis and processing tool, are now free software. Enhydris is entirely based on free software technologies such as Python, Django, PostgreSQL, and JQuery. We also created http://openmeteo.org/, a web site hosting our free software products as well as a free database system devoted to the dissemination of free data. In particular, "Enhydris" is used for the management of the hydrometeorological stations and the major hydraulic structures (aqueducts, reservoirs, boreholes, etc.), as well as for the retrieval of time series, online graphs etc. For the specific needs of EYDAP, additional GIS functionality was introduced for the display and monitoring of the water supply network. This functionality is also implemented as free software and can be reused in similar projects. Except for "Hydrognomon" and "Enhydris", we have developed a number of advanced modeling applications, which are also generic-purpose tools that have been used for a long time to provide decision support for the water resource system of Athens. These are "Hydronomeas", which optimizes the operation of complex water resource systems, based on a stochastic simulation framework, "Castalia", which implements the generation of synthetic time series, and "Hydrogeios", which employs

  17. Frequency analysis of CSF flow on cine-MRI in normal pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Miyati, Tosiaki; Kasuga, Toshio; Imai, Hiroshi [Kanazawa Univ. (Japan). School of Medicine; Fujita, Hiroshi; Mase, Mitsuhito; Itikawa, Katuhiro

    2001-09-01

    To clarify the flow dynamics of intracranial cerebrospinal fluid (CSF) in normal pressure hydrocephalus (NPH), frequency analyses of CSF flow measured with an ECG-gated phase contrast cine magnetic resonance imaging (MRI) were performed. The amplitude and phase in the CSF flow spectra in the aqueduct were determined in patients with NPH after a subarachnoid hemorrhage (SAH-NPH group, n=26), an idiopathic NPH (I-NPH group, n=4), an asymptomatic ventricular dilation or a brain atrophy (VD group, n=21), and in healthy volunteers (control group, n=25). The changes of CSF flow spectra were also analyzed 5 and 15 minutes after an intravenous injection of acetazolamide. Moreover, a phase transfer function (PTF) calculated from the spectra of the driving vascular pulsation and CSF flow in the aqueduct were assessed in patients with SAH-NPH and control groups before and after acetazolamide injection. There values were compared with the pressure volume response (PVR). The amplitude of the 1st-3rd harmonics in the SAH-NPH or I-NPH group was significantly larger than in the control or VD group because of a decrease in compliance (increase in PVR). The phase of the 1st harmonic in the SAH-NPH group was significantly different from that in the control or VD group, but no difference was found between the control and VD groups. The amplitude of the 0-3rd harmonics increased, and the phase of the 1st harmonic changed in all groups after an acetazolamide injection. An evaluation of the time course of the direct current of CSF flow provided further information about the compensatory faculty of the cerebrospinal cavity. A PTF of the 1st harmonic in the SAH-NPH group was significantly larger than in the control group, and a positive correlation was noted between PTF of the 1st harmonic and PVR. In conclusion, frequency analyses of CSF flow measured by cine-MRI make it possible to obtain noninvasively a more detailed picture of the pathophysiology of NPH and of changes in intracranial

  18. Fulminating midbrain irradiation injury of pediatric brain tumor

    International Nuclear Information System (INIS)

    We report two children with post radiation midbrain damage causing severe neurological symptoms. A twelve-year-old boy with a four year history of hydro-cephalus was diagnosed with tectal glioma, which endoscopic biopsy revealed to be low grade. He underwent γ knife radiation surgery (central 24 Gy/peripheral 12 Gy). Two months later bilateral ptosis followed by total oculomotor palsy and drowsiness developed. Despite pulsed-steroid therapy the tumor size increased up to 4.6 times in volume. The tumor was totally removed and was diagnosed as an early delayed radiation reaction pathologically. His symptoms disappeared except for a slight upper gaze palsy. The second patient was a six-year-old girl with a medulloblastoma. Following total resection and a VP shunt she received conventional radiation therapy along with chemotherapy. After the final irradiation she became comatose (Japan Coma Scale (JCS) II-2) and MRI revealed diffuse midbrain damage with acute aqueduct obstruction, which recovered in two weeks. Reports of irradiation injuries of the midbrain in childhood are rare but it should be considered as a possible cause of fulminant symptoms requiring emergency treatment. Because of midbrain anatomical complexity, midbrain radiation therapy requires great care, especially in children. (author)

  19. Neurovascular compression of cranial nerves: CT and MRI findings

    International Nuclear Information System (INIS)

    Purpose: The compression of a nervous structure by an aberrant vessel may be asymptomatic or produce an important symptoms, in these cases CT and MRI show relevant information. Materials and Methods: Between January 1998 and March 2001, we studied 27 patients: 8 with trigeminal neuralgia, 7 with hemi facial spasm, 4 vertigo and tinnitus, 2 hemianopsia, 1 with neuralgia of the amygdalin fossa, 1 with bitonal voice, 1 with tongue deviation with fascicular movements, 2 essential hypertension and 1 with severe headache. All of them had a neurologic evaluation from 2 specialists and 2 neuro radiologists interpreted the results. Results: The CT and RMI images with special sequences allowed to prove the compression of the entry segments of the V, VII, IX, X and XII cranial nerves, of the optic chiasma and the ventrolateral aspect of the medulla oblongata in close relation with the vasopressor centre. Also they demonstrate a rare vessel in the Silvio aqueduct avoiding the normal flow of the CSF. Of the total of patients that were studied, 37% had surgical confirmation. Conclusion: CT and RMI are sensitive and specific methods for the detection of vascular compressions of nervous structures. (author)

  20. Imaging features of rosette-forming glioneuronal tumours (RGNTs): A series of seven cases

    Energy Technology Data Exchange (ETDEWEB)

    Medhi, Gorky; Prasad, Chandrajit; Saini, Jitender; Pendharkar, Hima; Bhat, Maya Dattatraya [National Institute of Mental Health and Neurosciences, Department of Neuroimaging and Interventional Radiology, Bangalore (India); Pandey, Paritosh [National Institute of Mental Health and Neurosciences, Department of Neurosurgery, Bangalore (India); Muthane, Yasha [National Institute of Mental Health and Neurosciences, Department of Neuropathology, Bangalore (India)

    2016-01-15

    Rosette-forming glioneuronal tumours (RGNTs) are a recently described, rare, distinct nosological entity of the glioneuronal family. We describe imaging findings (CT and MRI) in seven patients with RGNTs. This retrospective study includes seven RGNT patients (4 male, 3 female; age range: 7-42 years; mean age: 25 years) diagnosed and treated at our institute. MR studies were performed on 3 T and 1.5-T clinical MR systems. All patients were reviewed by two experienced neuroradiologists and imaging findings were tabulated. Five tumours were located in the posterior fossa, and two were in the pineal region. One of the tumours demonstrated multiple satellite lesions, which involved the midbrain, pons, medulla as well as the cervical cord. Tumours located in the pineal region compressed the 3rd ventricle/aqueduct and extended below the tentorium cerebelli. All the tumours demonstrated enhancement, and susceptibility was evident in six of the seven patients. CSF dissemination was present in two patients. RGNTs are usually solid-cystic tumours and frequently demonstrate peripheral/heterogeneous enhancement upon post-contrast study. Haemorrhage is a common feature which may not be evident on CT. Cerebrospinal fluid (CSF) dissemination is a feature and appropriate imaging should be performed whenever an RGNT is suspected. (orig.)

  1. Genotypes and phenotypes of a family with a deaf child carrying combined heterozygous mutations in SLC26A4 and GJB3 genes.

    Science.gov (United States)

    Li, Yunlong; Zhu, Baosheng

    2016-07-01

    Mutations in the SLC26A4 gene have been shown to cause a type of deafness referred to as large vestibular aqueduct syndrome (LVAS), whereas mutations in the GJB3 gene have been associated with nonsyndromic deafness. However, the clinical phenotypes of these mutations vary and remain to be fully elucidated. The present study performed genetic analysis of a Chinese family, in which the child was deaf and the parents were healthy. Sanger sequencing demonstrated that the affected individual harbored three heterogeneous mutations in the SLC26A4 and GJB3 genes, as follows: SLC26A4 IVS-2 A>G, SLC26A4 c.2168 A>G and GJB3 c.538 C>T. The affected individual exhibited hearing loss and was diagnosed with LVAS by computed tomography scan. The mother and father of the affected individual harbored the heterogeneous mutations of SLC26A4 IVS-2 A>G and GJB3 c.538 C>T, and the heterozygous mutation of SLC26A4 c.2168 A>G, respectively. Neither parents exhibited any hearing loss. The results obtained from the deaf patient provided genetic and clinical evidence that carrying combined heterogeneous mutations in the GJB3 and SLC26A4 genes may be involved in the etiology of severe hearing loss, of which the mechanism requires further examination. PMID:27176802

  2. From Planck Constant to Isomorphicity Through Justice Paradox

    Science.gov (United States)

    Hidajatullah-Maksoed, Widastra

    2015-05-01

    Robert E. Scott in his ``Chaos theory and the Justice Paradox'', William & Mary Law Review, v 35, I 1, 329 (1993) wrotes''...As we approach the 21-st Century, the signs of social disarray are everywhere. Social critics observe the breakdown of core structure - the nuclear family, schools, neighborhoods & political groups''. For completions for ``soliton'' first coined by Morikazu TODA, comparing the ``Soliton on Scott-Russell aqueduct on the Union Canal near Heriot-WATT University, July 12, 1995 to Michael Stock works: ``a Fine WATT-Balance: Determination of Planck constant & Redefinition of Kilogram'', January 2011, we can concludes the inherencies between `chaos' & `soliton'. Further through ``string theory'' from Michio KAKU sought statements from Peter Mayr: Stringy world brane & Exponential hierarchy'', JHEP 11 (2000): ``if the 5-brane is embedded in flat 10-D space time, the 6-D Planck mass on the brane is infinite'' who also describes the relation of isomorphicity & ``string theory'', from whom denotes the smart city. Replace this text with your abstract body. Incredible acknowledgments to HE. Mr. Drs. P. SWANTORO & HE. Mr. Dr-HC Jakob OETAMA.

  3. Assessment of anatomic morphology of the connective structures among brain ventricles and cerebrospinal fluid movement in them by cerebrospinal fluid spin-labeling MRI

    International Nuclear Information System (INIS)

    Objective: To assess the anatomic morphology of the connective structures among brain ventricles and cerebrospinal fluid (CSF) movement in them by CSF spin-labeling MR imaging. Methods: According to the order of registration, 50 healthy volunteers were randomly selected and received cerebrospinal fluid spin-labeling MR scan with time-spatial labeling inversion recovery single-shot fast spin echo sequence (SLIR-SSFSE). The tagged CSF was used as an endogenous tracer. The anatomic morphology of the connective structures of brain ventricles and the flow direction of CSF were observed. The longitudinal diameter and transverse diameter of bilateral foramina of monro, midbrain aqueduct, and the central and bilateral lateral apertures of the fourth ventricle of each subject were measured and calculated based on multiple measurements. The flow rate of CSF was calculated based on the flow distance of CSF in the connective structures between brain ventricles during different TI time. The mean value of each indicator was acquired. Results: Two-way flow state of CSF was observed in all connective structures, including bilateral foramina of monro, midbrain aqueduct, and the central and bilateral lateral apertures of the fourth ventricle. On the coronal planes, foramen of monro appears as a 'Y'-type tubular structure locating among the both sides of the anteriomedial thalamus and fornix, which connect upward with bilateral lateral ventricles and downward with the third ventricle. The longitudinal diameter and transverse diameter of the left side of foramen of monro were 3.50-5.50 mm [mean (4.37±0.47) mm] and 1.00-1.40 mm [mean (1.21± 0.13) mm], respectively. The longitudinal diameter and transverse diameter of the right side of foramen of' monro were 4.20-4.80 mm [mean (4.42±0.20) mm] and 1.00-1.60 mm [mean (1.21± 0.19) mm], respectively. On the sagittal planes, foramen of monro appeared as an oblique fine tubular structure with the angle of 55°-58° between the both sides

  4. Study of the subarachnoid space in cerebral cysticercosis

    International Nuclear Information System (INIS)

    A total of 135 cases of cerebral cysticercosis are analysed, whereby the cisternoscintillographic and neuroradiological methods are combined. For this, in the first case a Searle model H.P. gamma camera was used; the investigation was performed 2, 6, 24, 48 and in some cases 72 h after intrathecal injection of 131I human seroalbumin by lumbar puncture. All these patients were subjected to cliniconeurological and neuroradiological examinations, routine laboratory tests (blood, seriate coproparasitological examination and cerebrospinal fluid analysis) and special tests of intradermal reactions and histopathology. The results from the 135 patients examined were as follows: 58 were normal, while blockage was indicated in 77. The sites of obstruction were identified as being in the foramina of Luschka and Magendie in most cases and also, in order of frequency, in convexities, the aqueduct of Sylvius, the fourth ventricle and the foramen of Monro. The correlation between the clinical and radiological findings was higher than that between radiological investigations and cisternography. With cisternoscintillography a total of four false negatives and seven positives was found. (author)

  5. Study on transport of powdered activated carbon using a rotating circular flume

    Institute of Scientific and Technical Information of China (English)

    尹海龙; 邱敏燕; 徐祖信

    2013-01-01

    This study employed a rotating flume to examine the Powdered Activated Carbon (PAC) transport with water flow. The initial PAC concentration was 10 mg/L-30 mg/L, and PAC concentration versus time under a specified cross-sectional averaging fluid shear was observed. Results show that compared with PAC deposition in still water, PAC is depleted to zero faster under a fluid shear of 0.02 Pa, due to PAC agglomeration with the fluid shear. However, since PAC floc size only ranges from a single particle (2mm) to approximate 6mm, an increasing of instantaneous turbulent fluctuations could counteract the force of PAC floc settling downward, and as a result the steady PAC concentration increases with the increase of shear stress. It is found that the critical shear stress for PAC deposition is about 0.60 Pa, and further the PAC deposition probability is presented according to the experimental scenarios between 0.02 Pa and 0.60 Pa. Combining the PAC transport and deposition formula with PAC-pollutant removal model provides an insight into PAC deployment in raw water aqueduct for sudden open water source pollution.

  6. Neurological complications of neurofibromatosis type 1 in adulthood.

    Science.gov (United States)

    Créange, A; Zeller, J; Rostaing-Rigattieri, S; Brugières, P; Degos, J D; Revuz, J; Wolkenstein, P

    1999-03-01

    Neurofibromatosis type 1 (NF1) is a genetic disease with a wide range of neurological manifestations. To examine these, and to evaluate neurological morbidity in adulthood of patients with NF1, we studied a hospital-based series of 158 patients that included 138 adult patients aged >18 years and 20 children. NF1 evaluation included a multidisciplinary clinical and a clinically oriented radiological investigation. Neurological events occurring during childhood (in both children and adults of the series) and adulthood were recorded. One or several neurological manifestations have been observed in 55% of patients (adults and children) (n = 87). These included: headache (28 patients); hydrocephalus (7); epilepsy (5); lacunar stroke (1); white matter disease (1); intraspinal neurofibroma (3); facial palsy (1); radiculopathy (5); and polyneuropathy (2). Tumours included: optic pathway tumours (20); meningioma (2); cerebral glioma (3); and malignant peripheral nerve sheath tumours (6). Life-threatening complications were observed in five adults and included four malignant peripheral nerve sheath tumours and one meningioma. Pain was the leading symptom in 11 adults and was related to malignant peripheral nerve sheath tumours, complications of intraspinal neurofibromas, subcutaneous neurofibromas and peripheral nerve neurofibromas. NF1 in adults was not associated with other disabling or life-threatening neurological complications. Symptomatic optic pathway tumours, cerebral gliomas, symptomatic aqueductal stenosis and spinal compression due to intraspinal NF were observed exclusively during childhood. In this series, the predominant neurological features of adults with NF1 were chronic pain and malignant peripheral nerve sheath tumours. PMID:10094256

  7. Parkinsonian syndromes associated with hydrocephalus: case reports, a review of the literature, and pathophysiological hypotheses.

    Science.gov (United States)

    Curran, T; Lang, A E

    1994-09-01

    We present nine cases of obstructive hydrocephalus (OH) associated with marked parkinsonism. Four patients had noncommunicating OH (NCOH) [three nontumoral aqueductal stenosis (AS), one tumoral AS]. The presentation was that of acute or subacute parkinsonism, usually at the time of acute recurrent ventricular obstruction. Three had a marked response to levodopa and required short-term treatment after shunting. However, one has remained levodopa dependent after 2 1/2 years. Three of the five patients with communicating OH (COH) presented with shunt-responsive normal pressure hydrocephalus (NPH), only later to develop progressive parkinsonism. One of these was found to have progressive supranuclear palsy (PSP) at autopsy and PSP was clinically suspected in one other patient. A third had an atypical course suggestive of PSP; however, autopsy demonstrated the combination of Lewy body parkinsonism and the sequelae of hydrocephalus. The remaining two COH patients presented with levodopa-responsive parkinsonism. Subsequent clinical features and imaging studies suggested the presence of NPH. The pathophysiology of hydrocephalic parkinsonism probably involves variable sites of dysfunction in the nigrostriatal pathway and/or the cortico-striato-pallido-thalamo-cortical circuit. At certain locations these pathways lie in close proximity to the ventricular system and may be subjected to mass effects and ischemic changes secondary to ventriculomegaly. The additional importance of possible associations between subcortical cerebral ischemia, NPH, and "degenerative" disorders such as PSP and Parkinson's disease is discussed. PMID:7990846

  8. Stereotactic mesencephalotomy for palliative care pain control: A case report, literature review and plea to rediscover this operation.

    Science.gov (United States)

    Ivanishvili, Zurab; Pujara, Shyam; Honey, C Michael; Chang, Stephano; Honey, Christopher R

    2016-08-01

    Introduction Stereotactic mesencephalotomy is an ablative procedure which lesions the pain pathways (spinothalamic and trigeminothalamic tracts) at the midbrain level to treat medically refractory, nociceptive, contralateral pain. Sparsely reported in contemporary English language literature, this operation is at risk of being lost from the modern-day neurosurgical practice. Methods We present a case report and brief review of the literature on stereotactic mesencephalotomy. A 17-year-old girl with cervical cord glioblastoma and medically refractory unilateral head and neck pain was treated with contralateral stereotactic mesencephalotomy. The lesion was placed at the level of the inferior colliculus, half way between the lateral edge of the aqueduct and lateral border of the midbrain. Results The patient had no head and neck pain immediately after the procedure and remained pain-free for the remainder of her life (five months). She was weaned off her pre-operative narcotics and was able to leave hospital, meeting her palliative care goals. Conclusions Cancer-related unilateral head and neck nociceptive pain in the palliative care setting can be successfully treated with stereotactic mesencephalotomy. We believe that stereotactic mesencephalotomy is the treatment of choice for a small number of patients typified by our case. The authors make a plea to the palliative care and neurosurgical communities to rediscover this operation. PMID:26760110

  9. Protocol for three-Dimensional magnetic resonance study of inner ear

    International Nuclear Information System (INIS)

    To create a protocol for the study of the labyrinthine structures of the inner ear using fast MR sequences. We studied the petrous apex in 50 healthy volunteers at 1.5 T using T2-weighted fast MR for three-dimensional analysis. We sought the series of images of the inner ear that fulfilled the following objectives: 1) representing all the structures in the inner ear and neural complex of the internal auditory canal (IAC) in several spatial planes; 2) if possible, defining each structure totally in a single image; 3) attempting to save time; 4) making the workstation tasks simple and uniform in all the patients in order to apply general guidelines for every case, and 5) providing images similar to those known so that the existing radiological semiology could be applied. We chose a radiological series consisting of 7 images: 1) an oblique coronal plane of the cochlea; 2) an axial plane at the level of the cochlea, vesicular nerve, lateral semicircular canal and IAC; 3) a para sagittal plane through the vestibular nerve, superior and posterior semicircular canals and their common branch; 4) a para sagittal plane of the cochlea representing all the spirals; 5) a para sagittal plane of the IAC; 6) an axial plane showing the neural structures within the IAC, and 7) an axial plane at the level of the cochlear aqueduct. The protocol defined in the present report is useful for the three-dimensional MR study of the membranous labyrinth. (Author) 22 refs

  10. CT findings of hereditary dentatorubral-pallidoluysian atrophy (DRPLA)

    International Nuclear Information System (INIS)

    Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) has recently been recognized as a clinicopathological entity. It may be defined as a multisystem degenerative disease of dominant inheritance, and characterized clinically by a combination of epilepsy, myoclonus, ataxia, dementia, and choreo-athetosis. This paper reports on the CT findings of ten patients (in four families) with DRPLA. In two families, the diagnosis was established on the basis of the clinicopathological findings, while in the other two, the diagnosis was made clinically. Although the CT findings were not identical in all patients, some degree of atrophic change was always observed in the cerebellum, brainstem, and cerebral cortex. Cerebellar atrophy was always accompanied by a dilatation of the fourth ventricle. Midbrain atrophy was characterized by a prominent tegmental atrophy and aqueductal dilatation, such as is seen in progressive supranuclear palsy. Of the four patients over 40 years of age, three had a diffuse hypodensity of the cerebral white matter on CT. To our knowledge, there have been no previous reports on this hypodensity in patients with spino-cerebellar degeneration or Huntington's chorea. CT may be helpful in the differential diagnosis of progressive neuro-degenerative disorders. (author)

  11. Inner ear anomalies seen on CT images in people with Down syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Intrapiromkul, Jarunee; Aygun, Nafi; Yousem, David M. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Tunkel, David E. [The Johns Hopkins Medical Institutions, Department of Otolaryngology-Head and Neck Surgery, Baltimore, MD (United States); Carone, Marco [University of California, Division of Biostatistics, School of Public Health, Berkeley, CA (United States)

    2012-12-15

    Although dysplasia of inner ear structures in Down syndrome has been reported in several histopathological studies, the imaging findings have not been widely studied. To evaluate the prevalence and clinical significance of inner ear anomalies detected on CT images in patients with Down syndrome. The temporal bone CT images of patients with Down syndrome were assessed for inner ear anomalies; clinical notes and audiograms were reviewed for hearing loss. Logistic regression models were employed to identify which CT findings were associated with sensorineural hearing loss (SNHL). Inner ear anomalies were observed in 74.5% (38/51) of patients. Malformed bone islands of lateral semicircular canal (LSCC), narrow internal auditory canals (IACs), cochlear nerve canal stenoses, semicircular canal dehiscence (SCCD), and enlarged vestibular aqueducts were detected in 52.5% (53/101), 24.5% (25/102), 21.4% (21/98), 8.8% (9/102) and 2% (2/101) of patients' ears, respectively. IAC stenosis had the highest odds ratio (OR = 5.37, 95% CI: 1.0-28.9, P = 0.05) for SNHL. Inner ear anomalies occurred in 74.5% of our population, with malformed (<3 mm) bone island of LSCC being the most common (52.5%) anomaly. Narrow IAC was seen in 24.5% of patients with Down syndrome and in 57.1% of ears with SNHL. High-resolution CT is a valuable for assessing the cause of hearing loss in people with Down syndrome. (orig.)

  12. Geologic surface effects of underground nuclear testing, Yucca Flat, Nevada Test Site, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    This report presents a new Geographic Information System composite map of the geologic surface effects caused by underground nuclear testing in the Yucca Flat Physiographic Area of the Nevada Test Site, Nye County, Nevada. The Nevada Test Site (NTS) was established in 1951 as a continental location for testing nuclear devices (Allen and others, 1997, p.3). Originally known as the ''Nevada Proving Ground'', the NTS hosted a total of 928 nuclear detonations, of which 828 were conducted underground (U.S. Department of Energy, 1994). Three principal testing areas of the NTS were used: (1) Yucca Flat, (2) Pahute Mesa, and (3) Rainier Mesa including Aqueduct Mesa. Underground detonations at Yucca Flat and Pahute Mesa were typically emplaced in vertical drill holes, while others were tunnel emplacements. Of the three testing areas, Yucca Flat was the most extensively used, hosting 658 underground tests (747 detonations) located at 719 individual sites (Allen and others, 1997, p.3-4). Figure 1 shows the location of Yucca Flat and other testing areas of the NTS. Figure 2 shows the locations of underground nuclear detonation sites at Yucca Flat. Table 1 lists the number of underground nuclear detonations conducted, the number of borehole sites utilized, and the number of detonations mapped for surface effects at Yucca Flat by NTS Operational Area

  13. [Improvement of peduncular hallucinosis by surgical resection and carbamazepin administration in a young patient with pineocytoma].

    Science.gov (United States)

    Kawabori, Masahito; Sawamura, Yutaka; Iwasaki, Yoshinobu

    2009-07-01

    Peduncular hallucinosis is a rare phenomenon characterized by visual hallucination consisting of vivid, colored image of people, animals, scenes or geometric patterns. In most of the cases the hallucination is accompanied by sleeping disorder, and is by the patient recognized as not being real. It can be observed mainly in patients with thalamic/midbrain vascular disease, and is less frequently seen in brain stem tumor. The damage of the ascending reticular activating system by brain stem compression causing dream activity releasing what is normally suppressed during wakefulness is thought to be the mechanism of peduncular hallucinosis. The authors report a 13-year-old female presenting peduncular hallucinosis due to brainstem compression by a pineocytoma. The patient had a 3-month history of complex visual hallucination and slight somnolence. The hallucination mainly consisted of TV game characters, animals, and vegetables which were colorful and vivid. She was well oriented and realized that the hallucination was not real. MRI showed a pineal mass compressing the quadrigeminal plate inferiorly. There was mild obstructive hydrocephalus due to aqueduct stenosis. The tumor was totally removed and was pathologically diagnosed as pineocytoma. After the surgery, the hallucination ameliorated remarkably. Although the administration of benzodiazepine exacerbated the hallucination and sleep disorder, oral carbamazepine was clearly effective and produced nearly complete disappearance of hallucination. To the best of our knowledge, this is the first report of peduncular hallucinosis caused by quadrigeminal plate compression by a pineal tumor. PMID:19621778

  14. Mammal-like organization of the avian midbrain central gray and a reappraisal of the intercollicular nucleus.

    Directory of Open Access Journals (Sweden)

    Marcy A Kingsbury

    Full Text Available In mammals, rostrocaudal columns of the midbrain periaqueductal gray (PAG regulate diverse behavioral and physiological functions, including sexual and fight-or-flight behavior, but homologous columns have not been identified in non-mammalian species. In contrast to mammals, in which the PAG lies ventral to the superior colliculus and surrounds the cerebral aqueduct, birds exhibit a hypertrophied tectum that is displaced laterally, and thus the midbrain central gray (CG extends mediolaterally rather than dorsoventrally as in mammals. We therefore hypothesized that the avian CG is organized much like a folded open PAG. To address this hypothesis, we conducted immunohistochemical comparisons of the midbrains of mice and finches, as well as Fos studies of aggressive dominance, subordinance, non-social defense and sexual behavior in territorial and gregarious finch species. We obtained excellent support for our predictions based on the folded open model of the PAG and further showed that birds possess functional and anatomical zones that form longitudinal columns similar to those in mammals. However, distinguishing characteristics of the dorsal/dorsolateral PAG, such as a dense peptidergic innervation, a longitudinal column of neuronal nitric oxide synthase neurons, and aggression-induced Fos responses, do not lie within the classical avian CG, but in the laterally adjacent intercollicular nucleus (ICo, suggesting that much of the ICo is homologous to the dorsal PAG.

  15. Radium isotopes in Estonian groundwater: measurements, analytical correlations, population dose and a proposal for a monitoring strategy

    International Nuclear Information System (INIS)

    In some areas of Estonia, groundwater contains a significant number of natural radionuclides, especially radium isotopes, which may cause radiation protection concern depending on the geological structure of the aquifer. Indeed, the parametric value of 0.1 mSv y-1 for the total indicative dose established by European Directive 98/83/EC, adopted as a limit value in Estonian national legislation, is often exceeded. A Twinning Project between Estonia and Italy was carried out within the framework of the Estonian Transition Facility Programme, sponsored by the European Union. Its aims were to assess the radiological situation of Estonian groundwater and related health consequences. The first step was a study of Estonian aqueducts and the population served by them, and a thorough analysis of the radiological database for drinking water, from which the relevant effective doses for the population were obtained. Particular attention was devoted to doses to children and infants. Correlations between the chemical parameters were investigated, in order to suggest the best possible analytical approach. Lastly, a monitoring strategy, i.e. sampling points and sampling frequencies, was proposed.

  16. Vulvar migration of the peritoneal end through the inguinal canal in a female infant: An unusual complication of the ventriculo-peritoneal shunt: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Mayur Sharma

    2013-01-01

    Full Text Available Migration of the peritoneal end of the ventriculo-peritoneal shunt through the patent processus vaginalis has been described in preterm male infants with 26 such cases in the literature. The occurrence of this rare complication in the female preterm infants has not yet been reported. We report a 3-month-old premature female infant who presented with a gradual increase in head size since birth. Computed tomography revealed obstructive hydrocephalous secondary to the aqueductal stenosis and ventriculo-peritoneal shunt was performed. Ten days following the procedure she presented with swelling and other signs of inflammation over the right vulvar region. X-ray abdomen confirmed the migration of the peritoneal end into the vulva. Surgical obliteration of the patent processus vaginalis and replacement of the peritoneal end was performed. The patient had no recurrence at 6 months of follow-up. This report presents the unusual complication of a common procedure in a female infant with a review of the current literature.

  17. SEASONAL DROUGHT DYNAMICS IN EL-BEHEIRA GOVERNORATE, EGYPT

    Directory of Open Access Journals (Sweden)

    Amr Mossad

    2014-01-01

    Full Text Available Drought is the most damaging climate-related hazards due to the prolonged absence of precipitation. Therefore, understanding the drought dynamics is important for irrigation water management to mitigate the negative impacts on agriculture. In this study, Standardized Precipitation Index (SPI and Standardized Precipitation Evapotranspiration Index (SPEI were used as effective tools for tracking the changes of water status occurred at five agro-meteorological stations (Etay Al Baroud, Wadi El-Natrun, Al Boseli, Badr and Nubariyah within El-Beheira governorate, Egypt. In addition, the overall water risk for agro-meteorological stations was estimated using the Aqueduct-GIS tool. The results clarified that Badr agro-meteorological station is representing the highest of water deficit by 96.6%, whereas, Al Boseli agro-meteorological station is representing the lowest water deficit by 86.9%. However, The SPI over El-Beheira region often confined in the near normal class, while the SPEI showed a notable increase of drought (SPEI = 0 to -4 in last 10 years of the analyses. The results suggested that El-Beheira governorate is moving toward the drought in general and Wadi El-Natrun and Nubariyah are the most drought affected areas in the future.

  18. Computed tomography of the petrous bone in otosclerosis and Meniere's disease

    International Nuclear Information System (INIS)

    The aim of this investigation was to examine if, in the case of otosclerosis and Meniere's disease, one could obtain more information with high resolution computer tomography than with conventional polytomography. In the first part of this thesis a brief survey of some principles of computer tomography is given and a computer tomographic atlas of the normal petrous bone in the otoradiologic planes used in this study. In the introduction of the second part some aspects of otosclerose are discussed (definition, clinical aspects). Subsequently a treatment is given of a part of the histopathology referring to the otospongiotic and otosclerotic changes in the labyrinthine capsule. A survey is given of preceding studies on the petrous bone in the case of otosclerosis; in these studies mostly classical planigraphic techniques were employed. In the third part some general aspects of Meniere's disease are discussed: definition, incidence, clinical aspects and pathophysiology. It is assumed that the symptoms of Meniere's disease are caused by an overpressure in the endolymphatic areas of the labyrinthum ('hydrops'), however till now a proof for this is still not given. The ductus endolympathicus, which passes through a channel in the petrous bone (the vestibular aqueduct), plays a role in the drainage of endolymph. Stagnation of this drainage could cause hydrops. (Auth.)

  19. Distribution of 1-(3H)methyl-4-phenyl-1,2,3,6-tetrahydropyridine (3H-MPTP) in the frog

    International Nuclear Information System (INIS)

    The nigrostriatal toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes selective destruction of pigmented monoaminergic neurons of the brain, mainly in the substantia nigra. Primates and amphibians, whose nerve cells contain melanin, have shown a higher sensitivity for the toxic effects of MPTP than species which are lacking neuromelanin, e.g. rodents. In the present study the distribution after intraperitoneal injection of 3H-MPTP in frogs (Rana temporaria) was studied by whole-body autoradiography. Histochemical staining methods for melanin were used in order to identify the pigment in various tissues. Melanin-containing nerve cells were present bilaterally in the ventral motor parts of the frog brain. Melanin was also found in the meninges, around the cerebral ventricles and the aqueducts, and in the eyes, skin and liver. The results from the autoradiographic study of 3H-MPTP revealed a high accumulation and retention in all melanin-containing structures up to 15 days after administration (the longest survival time). The pigmented tissues showed the highest concentration of radioactivity in the body at all survival times. The MPTP-induced destruction of pigmented tissues nerve cells may be related to the binding and storage of MPTP and/or its metabolities in neuromelanin, causing toxic cytoplasmic concentrations through the continuous release of substance from the melanin depot. (author)

  20. MRI findings in children with neurofibromatosis type 1: a prospective study

    International Nuclear Information System (INIS)

    To determine the frequency and nature of MRI lesions in children with neurofibromatosis type I (NF1), 50 patients aged 8 to 16 years were evaluated prospectively with cranial MRI. Forty-one children were asymptomatic with respect to central nervous system pathology, and 50% were macrocephalic. Sixteen patients (32%) had normal MRI examinations. Thirty-two patients (64%) had high intensity lesions of T2-weighted images and 16 patients (32%) had hyperintense lesions on T1-weighted images. Seven patients (14%) had ventricular dilatation (associated with increased intracranial pressure in 2) and 11 patients (22%) had optic pathway lesions (optic glioma in 7). MRI was superior to CT in differentiating optic sheath thickening and optic nerve tortuosity from optic glioma in four patients. An intracranial tumour (ependymoma) and sphenoid wing dysplasia were evident in individual patients. Findings previously unreported in NF1 included an aqueductal web resulting in hydrocephalus, intracular neurofibroma resulting in retinal detachment, and asymptomatic enlargement of the septum pellucidum. T1 and T2 signal abnormalities in isolation were not associated with neurological deficits or the occurrence of macrocephaly, and all lesions that required intervention were suspected clinically. Macrocephaly in the absence of increased intracranial pressure or accelerated head growth is not an indication for neuroimaging in children with NF1. However, the majority of children (68%) had disease-specific abnormalities and thus MRI may provide a useful adjunct to clinical evaluation in the diagnosis of equivocal cases. (orig.)

  1. Surface and groundwater Nitrate distribution in the area of Vicenza

    International Nuclear Information System (INIS)

    Public aqueducts in the Province of Vicenza (Italy) are supplied entirely by various kinds of water sources: the sub river bed strata of the mountain valleys, water-bearing aquifers of the high plan, pressurized water-bearing aquifers of the middle plain, karstic reservoirs of the mountain massifs and local springs. Progressive increase in nitrate concentration has long been detected in the underground water of many parts of the Vicenza region. The nitrates originate from various sources: human waste, industrial dumping (e.g. the tanning industry) and the use of animal and chemical fertilizers. Nitrate distribution was studied in all wells used for extracting underground water including source waters which replenishing underground aquifers. During the study period ('91-'95), water courses in the recharge areas were found to have nitrate concentrations ranging between 2.0 and 42.0 mg/l. These values remained substantially stable in time. Underground aquifers showed stable nitrate concentration between 5.0 mg/l (mountain karstic aquifers; sub-river bed strata of valley bottom) and 44.0 mg/l (water bearing strata of the high plain of Astico and Brenta rivers). The pressurized flooding aquifers of the middle plain have lower concentrations (6.0-21.0 mg/l) but tend to increase by about 0.5 mg/l per year

  2. The impact of the roman agriculture on the territory of Savaria

    Directory of Open Access Journals (Sweden)

    András Bödőcs

    2015-02-01

    Full Text Available The first reconstruction of the centuriatio of Savaria was attempted by András Mócsy, who tried to draw itwith the utilization of mid-scale topographical maps. Since his publication there were no archaeological at-tempt in the last 40 years to prove his theory. In the last recent years we tried to continue the survey of theSavarian centuriatio’s existence with support of GIS methods. Fortunately, an interesting relationship wasnoted between the informations of some archaeological excavations and the aerial archaeological phenom-ena, thus, we were able to build a predictive model-network of the assumed centuriatio. The new grid totallydiffers from the previous reconstruction. The predictive model’s agglomeration of the assumed centuriatio-traces could be refined, and the refined model was controlled with the use of archaeological field survey andgeophysical survey as well. The new reconstruction resulted new opportunities in the interpretation of exca-vated sites or former known roman roads and aqueducts, discovered in the last decades. An other interestingrelationship could be found between the water courses that ran on the former territory of the colonia andthe roman field boundary system: the probable impact of the roman agriculture on the landscape that af-fected the “premodern” (prior to the modern stream regulations watercourse system.

  3. Prevalence of Perinatal Central Nervous System Anomalies in East Azarbaijan-Iran

    Directory of Open Access Journals (Sweden)

    M. Ghavami

    2011-06-01

    Full Text Available Background/Objective: Central nervous system (CNS anomalies are the most serious congenital abnormalities. Ultrasound examination is an effective and noninvasive modality for prenatal diagnosis of these anomalies. The purpose of the current study was to determine thefrequency of CNS and associated abnormalities.Patients and Methods: A total of 22500 pregnant women who were referred by obstetricians/ gynecologists for routine work up of pregnancy were scanned over a period of 3 years by two expert sonologists in a referral center using high resolution ultrasound unit.Results: After transabdominal sonographic examination of 22500 pregnant women, 112 (0.5%fetuses were detected with CNS anomalies, some of whom had more than one anomaly. Forty-one (37% Chiari malformations, 26 (23% monro and aqueductal stenosis cases, 18 (16% anencephaly cases, nine (8% encephaloceles, seven (6% microcephalies, five (4% Dandywalker syndromes,two (2% arachnoid cysts, two (2% agenesis of corpus callosum cases, one (1% holoprosencephaly and one (1% schizencephaly were reported in our study.Conclusion: According to our results, Chiari malformation and ydrocephalus were the most prevalent anomalies of CNS congenital abnormalities in East Azarbaijan, Iran. An accurate diagnosis depends upon fetal age, amniotic fluid volume, fetal position, operator experience and careful evaluation of the associated malformations, which are often present.

  4. Malformations and abnormalities of the petrous portion of the temporal bone

    International Nuclear Information System (INIS)

    High-resolution computed tomography (HRCT) is the procedure of choice in the diagnostics of abnormalities of the middle and inner ear. It allows a detailed presentation of anatomical features and achieves the prerequisites for selection of the various therapeutic options. The highly diverse abnormalities can be described using detailed imaging analyses. Malformations with an abnormally developed modiolus are assumed to be early embryological defects, such as the classical Mondini dysplasia. The essential therapeutic option for middle ear deformities is still a cochlear implant. The domain of magnetic resonance imaging (MRI) is not only in the analysis of the cochlear nerve and for exclusion of fibrosis or ossification of the labyrinth but is also able to visualize details of isolated malformations, such as an extended vestibular aqueduct or subtle alterations to the vestibule or can visualize them better in comparison to CT. Radiological diagnostics are used not only for classification but also to recognize typical clinical problem situations and play a key role in the diagnostics of hearing disorders and selection of the optimal therapeutic procedure. (orig.)

  5. MRI findings in children with neurofibromatosis type 1: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Van Es, S. [Dept. of Radiology, Royal Alexandra Hospital for Children, Paramatta (Australia); North, K.N. [Dept. of Neurology, Royal Alexandra Hospital for Children, Paramatta (Australia); McHugh, K. [Dept. of Radiology, Royal Alexandra Hospital for Children, Paramatta (Australia); De Silva, M. [Dept. of Radiology, Royal Alexandra Hospital for Children, Paramatta (Australia)

    1996-07-01

    To determine the frequency and nature of MRI lesions in children with neurofibromatosis type I (NF1), 50 patients aged 8 to 16 years were evaluated prospectively with cranial MRI. Forty-one children were asymptomatic with respect to central nervous system pathology, and 50% were macrocephalic. Sixteen patients (32%) had normal MRI examinations. Thirty-two patients (64%) had high intensity lesions of T2-weighted images and 16 patients (32%) had hyperintense lesions on T1-weighted images. Seven patients (14%) had ventricular dilatation (associated with increased intracranial pressure in 2) and 11 patients (22%) had optic pathway lesions (optic glioma in 7). MRI was superior to CT in differentiating optic sheath thickening and optic nerve tortuosity from optic glioma in four patients. An intracranial tumour (ependymoma) and sphenoid wing dysplasia were evident in individual patients. Findings previously unreported in NF1 included an aqueductal web resulting in hydrocephalus, intracular neurofibroma resulting in retinal detachment, and asymptomatic enlargement of the septum pellucidum. T1 and T2 signal abnormalities in isolation were not associated with neurological deficits or the occurrence of macrocephaly, and all lesions that required intervention were suspected clinically. Macrocephaly in the absence of increased intracranial pressure or accelerated head growth is not an indication for neuroimaging in children with NF1. However, the majority of children (68%) had disease-specific abnormalities and thus MRI may provide a useful adjunct to clinical evaluation in the diagnosis of equivocal cases. (orig.)

  6. Modelling of the river quality in the area of Florence in order to planning the recovery interventions

    International Nuclear Information System (INIS)

    The quality of the Arno River is rater critical due to many civil, industrial and agricultural discharges (while the waste-water treatment plant supplies only the half of the decontamination demand). The area of Florence shows an heavy situation which should be improved by the start up of the centralized wastewater plant of San Colombano. The municipal aqueduct withdrawn part of the river water reserve upstream of an inhabited place (Anconella), so the problem of the river quality in the urban areas become very important, especially during the summering minimum flow with high temperature which are the cause of the peaked pollution. In this work the study of the modelling of the quality of the Arno river is described. First objective is to present the actual quality 'state' of the river in the observed reach from Nave di Rosano (upstream Florence) to S. Giovanni alla Vena: second objective is to plan of the interventions in order to improve and control the river quality

  7. Imaging features of rosette-forming glioneuronal tumours (RGNTs): A series of seven cases

    International Nuclear Information System (INIS)

    Rosette-forming glioneuronal tumours (RGNTs) are a recently described, rare, distinct nosological entity of the glioneuronal family. We describe imaging findings (CT and MRI) in seven patients with RGNTs. This retrospective study includes seven RGNT patients (4 male, 3 female; age range: 7-42 years; mean age: 25 years) diagnosed and treated at our institute. MR studies were performed on 3 T and 1.5-T clinical MR systems. All patients were reviewed by two experienced neuroradiologists and imaging findings were tabulated. Five tumours were located in the posterior fossa, and two were in the pineal region. One of the tumours demonstrated multiple satellite lesions, which involved the midbrain, pons, medulla as well as the cervical cord. Tumours located in the pineal region compressed the 3rd ventricle/aqueduct and extended below the tentorium cerebelli. All the tumours demonstrated enhancement, and susceptibility was evident in six of the seven patients. CSF dissemination was present in two patients. RGNTs are usually solid-cystic tumours and frequently demonstrate peripheral/heterogeneous enhancement upon post-contrast study. Haemorrhage is a common feature which may not be evident on CT. Cerebrospinal fluid (CSF) dissemination is a feature and appropriate imaging should be performed whenever an RGNT is suspected. (orig.)

  8. Endodermal cyst in pineal region: Rare location

    Science.gov (United States)

    Lopez-Gonzalez, Miguel Angel; Dolan, Eugen

    2016-01-01

    Background: Pineal tumors are very uncommon intracranial lesions, and endodermal cysts in this location are extremely rare. Case Description: A 49-year-old right-handed female presented with 3 weeks history of progressive dizziness and imbalance. Imaging studies showed 1.8 cm × 1.7 cm × 1.8 cm pineal lesion with small enhancing mural component displacing ventrally the quadrigeminal plate and narrowing of aqueduct of Sylvius without hydrocephalus. In addition, she was found with small interhemispheric lipoma, and small posterior falx possible meningioma. Cerebrospinal fluid markers obtained by lumbar puncture were all negative. She underwent tumor resection, and final pathology reported endodermal cyst. No new deficits were encountered, and her gait imbalance improved significantly by 3 months follow-up. Conclusions: With evidence of enlargement or symptomatic pineal lesions, surgical consideration is necessary. Among pineal lesions, endodermal cysts are extremely uncommon and although benign pathology, long-term follow-up is advised due to unknown chronic behavior. PMID:27217965

  9. Constructive interference in steady state(CISS) 3DFT MR imaging of the inner ear and adjacent structures

    International Nuclear Information System (INIS)

    To assess the value of 3 dimensional fourier transformation interference in steady state magnetic resonance imaging(3DFT CISS MRI) in depicting the inner ear and vascular structures. Using 3DFT CISS axial and coronal MRI scans of both ears with 17.1msec/8.0msec/50 degree(TR/TE/FA) and 0.9mm in nominal thickness, we studied 68 normal ears of 34 volunteers aged between 15 and 54 years. We assessed the visualization of the membranous labyrinth, and of cranial nerves VII and VIII in the inner ear canal. We analyzed the location of the vascular loop of the anterior inferior cerebellar artery in relation to cranial nerves VII and internal auditory canal. To define the three-dimensional images of the membranous labyrinth, MIP reconstruction of axial images was carried out. The very high signal of the intralabyrinth fluid enabled one hundred percent of the membranous labrynth to be seen There was a lack of contrast between soft tissue and bone such as the facial verve canal, vestibular aqueduct and canal of the subarcuate artery. In 25% of cases, the vascular loop was recognized in the porus acusticus, and in 6% of cases, inside the internal auditory canal. 3DFT CISS MRI is useful for determining the detailed anatomy of the inner ear and the nearby vascular loop. This special MR technique can be added as a routine protocol in the study of diseases of the inner ear

  10. Melanin-concentrating hormone (MCH) immunoreactivity in non-neuronal cells within the raphe nuclei and subventricular region of the brainstem of the cat.

    Science.gov (United States)

    Torterolo, Pablo; Lagos, Patricia; Sampogna, Sharon; Chase, Michael H

    2008-05-19

    Neurons that utilize melanin-concentrating hormone (MCH) as a neuromodulator are localized within the postero-lateral hypothalamus and zona incerta. These neurons project diffusely throughout the central nervous system and have been implicated in critical physiological processes such as energy homeostasis and sleep. In the present report, we examined the distribution of MCH immunoreactivity in the brainstem of the cat. In addition to MCH+ axons, we found MCH-immunoreactive cells that have not been previously described either in the midbrain raphe nuclei or in the periaqueductal and periventricular areas. These MCH+ cells constituted: 1. ependymal cells that lined the fourth ventricle and aqueduct, 2. ependymal cells with long basal processes that projected deeply into the subventricular (subaqueductal) parenchyma, and, 3. cells in subventricular regions and the midbrain raphe nuclei. The MCH+ cells in the midbrain raphe nuclei were closely related to neuronal processes of serotonergic neurons. Utilizing Neu-N and GFAP immunohistochemistry we determined that the preceding MCH+ cells were neither neurons nor astrocytes. However, we found that vimentin, an intermediate-filament protein that is used as a marker for tanycytes, was specifically co-localized with MCH in these cells. We conclude that MCH is present in tanycytes whose processes innervate the midbrain raphe nuclei and adjacent subependymal regions. Because tanycytes are specialized cells that transport substances from the cerebrospinal fluid (CSF) to neural parenchyma, we suggest that MCH is absorbed from the CSF by tanycytes and subsequently liberate to act upon neurons of brainstem nuclei. PMID:18410908

  11. Antiquity versus modern times in hydraulics - a case study

    International Nuclear Information System (INIS)

    Water supply and water management in Antiquity represent more than Modern World can imagine about how people in that period used to think about, and exploit the resources they had, aiming at developing and improving their society and own lives. This paper points out examples of how they handled different situations, and how they managed to cope with the growing number of population in the urban areas, by adapting or by improving their water supply systems. The paper tries to emphasize the engineering contribution of Rome and the Roman Empire, mainly in the capital but also in the provinces, as for instance the today territory of France, by analysing some aqueducts from the point of view of modern Hydraulic Engineering. A third order polynomial regression is proposed to compute the water flow rate, based on the flow cross-sectional area measured in quinaria. This paper also emphasizes on contradictory things between what we thought we knew about Ancient Roman civilization, and what could really be proven, either by a modern engineering approach, a documentary approach, or by commonsense, where none of the above could be used. It is certain that the world we live in is the heritage of the Greco-Roman culture and therefore, we are due to acknowledge their contribution, especially taking into account the lack of knowledge of that time, and the poor resources they had.

  12. Projecting Global Decadal Change in Water Supply for Strategic Planning: Window Size Sensitivity in CMIP5 GCMs

    Science.gov (United States)

    Luck, M.; Landis, M.; Gassert, F.; Luo, T.; Reig, P.

    2013-12-01

    Climate adaptation and strategic planning by states, corporations, and long-term investors require reliable information on the range of possible climatic changes. However, most decision makers are incapable of planning over the century-scale time horizons for which global climate models (GCMs) are developed. Even the most forward-looking actors rarely consider scenarios more than several decades into the future. The mismatch in model design and practical demands poses a challenge in extracting useful information on the decadal scale from global climate change models. Here, we explore options and limitations in generating decadal water supply change projections, as evaluated for the World Resources Institute's Aqueduct project's estimates of future change in water stress. Our approach uses an ensemble of six CMIP5 GCMs, selected to represent a broad lineage of models that best reproduce the mean and standard deviation of recent streamflow records in 18 large river basins, bias corrected to GLDAS-2.0 runoff. We examine sensitivity of point estimates of climate normal supply and water supply variability (interannual and seasonal) at the years 2020, 2030, and 2040, with a focus on using temporal windows of different lengths (11-, 21-, and 31-years) to generate the point estimates. With the aim of creating practical information for non-expert audiences, we will discuss the persistent question of 'how can we balance uncertainty and usability in designing scientific data products?'

  13. Rare association between cystic fibrosis, Chiari I malformation, and hydrocephalus in a baby: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Jea Andrew

    2011-08-01

    Full Text Available Abstract Introduction Cystic fibrosis, an epithelial cell transport disorder caused by mutations of the cystic fibrosis transmembrane conductance regulator gene, is not generally associated with malformations of the central nervous system. We review eight previously published reports detailing an infrequent association between cystic fibrosis and Chiari I malformation. Case presentation To the best of our knowledge, our report describes only the ninth case of a baby presenting with a new diagnosis of cystic fibrosis and Chiari I malformation, in this case in a 10-month-old, full-term Caucasian baby boy from the United States of America. Neurosurgical consultation was obtained for associated developmental delay, macrocephaly, bulging anterior fontanel, and papilledema. An MRI scan demonstrated an extensive Chiari I malformation with effacement of the fourth ventricle, obliteration of the outlets of the fourth ventricle and triventricular hydrocephalus without aqueductal stenosis. Our patient was taken to the operating room for ventriculoperitoneal shunt placement. Conclusions It is possible that the cystic fibrosis transmembrane conductance regulator gene may play a previously unrecognized role in central nervous system development; alternatively, this central nervous system abnormality may have been acquired due to constant valsalva from recurrent coughing or wheezing or metabolic and electrolyte imbalances that occur characteristically in cystic fibrosis.

  14. The inferior cochlear vein: surgical aspects in cochlear implantation.

    Science.gov (United States)

    Guo, Rui; Zhang, HongLei; Chen, Wei; Zhu, XiaoQuan; Liu, Wei; Rask-Andersen, Helge

    2016-02-01

    The patency of the inferior cochlear vein (ICV) may be challenged in cochlear implantation (CI) due to its location near the round window (RW). This may be essential to consider during selection of different trajectories for electrode insertion aiming at preserving residual hearing. Venous blood from the human cochlea is drained through the ICV. The vein also drains blood from the modiolus containing the spiral ganglion neurons. Surgical interference with this vein could cause neural damage influencing CI outcome. We analyzed the topographical relationship between the RW and ICV bony channel and cochlear aqueduct (CA) from a surgical standpoint. Archival human temporal bones were further microdissected to visualize the CA and its accessory canals (AC1 and AC2). This was combined with examinations of plastic and silicone molds of the human labyrinth. Metric analyses were made using photo stereomicroscopy documenting the proximal portion of the AC1, the internal aperture of the CA and the RW. The mean distance between the AC1 and the anterior rim of the RW was 0.81 mm in bone specimens and 0.67 mm assessed in corrosion casts. The AC1 runs from the floor of the scala tympani through the otic capsule passing parallel to the CA to the posterior cranial fossa. The mean distance between the CA and AC1 canal was 0.31 and 0.25 mm, respectively. PMID:25700831

  15. Phantom model of physiologic intracranial pressure and cerebrospinal fluid dynamics.

    Science.gov (United States)

    Bottan, Simone; Poulikakos, Dimos; Kurtcuoglu, Vartan

    2012-06-01

    We describe herein a novel life-size phantom model of the intracranial cavity and its validation. The cerebrospinal fluid (CSF) domains including ventricular, cysternal, and subarachnoid spaces were derived via magnetic resonance imaging. Brain mechanical properties and cranio-spinal compliance were set based on published data. Both bulk and pulsatile physiologic CSF flow were modeled. Model validation was carried out by comparisons of flow and pressure measurements in the phantom with published in vivo data of healthy subjects. Physiologic intracranial pressure with 10 mmHg mean and 0.4 mmHg peak pulse amplitude was recorded in the ventricles. Peak CSF flow rates of 0.2 and 2 ml/s were measured in the cerebral aqueduct and subarachnoid space, respectively. The phantom constitutes a first-of-its-kind approach to modeling physiologic intracranial dynamics in vitro. Herein, we describe the phantom design and manufacturing, definition and implementation of its operating parameters, as well as the validation of the modeled dynamics. PMID:22333981

  16. Thermal power systems, small power systems application project. Volume 1: Executive summary

    Science.gov (United States)

    Marriott, A. T.

    1979-01-01

    Current small power system technology as applied to power plants up to 10 MWe in size was assessed. Markets for small power systems were characterized and cost goals were established. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Economic studies were conducted and breakeven capital costs were determined for leading contenders among the candidate systems. An application study was made of the potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, estimated to be 1000 MWe by 1985. Criteria and methodologies were developed for application to the ranking of candidate power plant system design concepts. Experimental power plants concepts of 1 MWe rating were studied leading toward the definition of a power plant configuration for subsequent detail design, construction, testing and evaluation as Engineering Experiment No. 1 (EE No. 1). Site selection criteria and ground rules for the solicitation of EE No. 1 site participation proposals by DOE were developed.

  17. Thermal power systems: Small Power Systems Applications Project. Volume II. Detailed report. Annual technical report, fiscal year 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-15

    Small Power Systems Applications activities for FY 1978 are reported. Studies were conducted to address current small power system technology as applied to power plants up to 10 MWe in size. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Economic studies were conducted at JPL and under contract to Burns and McDonnell. Breakeven capital costs were determined for leading contenders among the candidate systems. An applications study was made of the potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, estimated to be 1000 MWe by 1985. Criteria and methodologies were developed for application to the ranking of candidate power plant system design concepts. Experimental power plants concepts of 1 MWe rating were studied by three contractors as a Phase I effort leading toward the definition of a power plant configuration for subsequent detail design, construction, testing and evaluation as Engineering Experiment No. 1 (EE No. 1). Site selection criteria and ground rules for the solicitation of EE No. 1 site participation proposals by DOE were developed.

  18. Thermal Power Systems, Small Power Systems Applications Project. Annual technical report. Volume I. Executive summary, Fiscal Year 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-15

    This report is a summary of the SPSA Annual Technical Report. It covers Small Power Systems Applications activities for FY 1978. Studies were conducted to address current small power system technology as applied to power plants up to 10 MWe in size. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Economic studies were conducted at JPL and under contract to Burns and McDonnell. Breakeven capital costs were determined for leading contenders among the candidate systems. An applications study was made of the potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, estimated to be 1000 MWe by 1985. Criteria and methodologies were developed for application to the ranking of candidate power plant system design concepts. Experimental power plants concepts of 1 MWe rating were studied by three contractors as a Phase I effort leading toward the definition of a power plant configuration for subsequent detail design, construction, testing, and evaluation as Engineering Experiment No. 1 (EE No. 1). Site selection criteria and ground rules for the solicitation of EE No. 1 site participation proposals by DOE were developed.

  19. Hydrocephalus in children.

    Science.gov (United States)

    Kahle, Kristopher T; Kulkarni, Abhaya V; Limbrick, David D; Warf, Benjamin C

    2016-02-20

    Hydrocephalus is a common disorder of cerebral spinal fluid (CSF) physiology resulting in abnormal expansion of the cerebral ventricles. Infants commonly present with progressive macrocephaly whereas children older than 2 years generally present with signs and symptoms of intracranial hypertension. The classic understanding of hydrocephalus as the result of obstruction to bulk flow of CSF is evolving to models that incorporate dysfunctional cerebral pulsations, brain compliance, and newly characterised water-transport mechanisms. Hydrocephalus has many causes. Congenital hydrocephalus, most commonly involving aqueduct stenosis, has been linked to genes that regulate brain growth and development. Hydrocephalus can also be acquired, mostly from pathological processes that affect ventricular outflow, subarachnoid space function, or cerebral venous compliance. Treatment options include shunt and endoscopic approaches, which should be individualised to the child. The long-term outcome for children that have received treatment for hydrocephalus varies. Advances in brain imaging, technology, and understanding of the pathophysiology should ultimately lead to improved treatment of the disorder. PMID:26256071

  20. Limited cone-beam computed tomography imaging of the middle ear: a comparison with multislice helical computed tomography

    International Nuclear Information System (INIS)

    Purpose: To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas. Material and Methods: Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen landmarks of the middle and adjacent inner ear were evaluated and compared for their conspicuity according to a modified Likert scale. Total scores and scores for subgroups including landmarks of specific clinical interest were also compared. Results: No significant differences were found between the imaging techniques or subgroups when scores of individual structures were compared. While the middle ear itself was visible in all cases with CBCT, parts of the inner ear were 'cut off' in four cases due to the limited field of view. For the same reason, the evaluation of the whole mastoid was not possible with CBCT. The cochlear and vestibular aqueducts were not visualized in either CT techniques. The contrast-to-noise ratio was more than 50% lower in CBCT than in MSCT, but still adequate for diagnostic task. Conclusion: CBCT proved to be at least as accurate as routinely used MSCT in revealing the clinically and surgically important middle-ear structures. The results show that high-quality imaging of the middle ear is possible with the current CBCT device

  1. Endoscopic Third Ventriculostomy in Previously Shunted Children

    Directory of Open Access Journals (Sweden)

    Eva Brichtova

    2013-01-01

    Full Text Available Endoscopic third ventriculostomy (ETV is a routine and safe procedure for therapy of obstructive hydrocephalus. The aim of our study is to evaluate ETV success rate in therapy of obstructive hydrocephalus in pediatric patients formerly treated by ventriculoperitoneal (V-P shunt implantation. From 2001 till 2011, ETV was performed in 42 patients with former V-P drainage implantation. In all patients, the obstruction in aqueduct or outflow parts of the fourth ventricle was proved by MRI. During the surgery, V-P shunt was clipped and ETV was performed. In case of favourable clinical state and MRI functional stoma, the V-P shunt has been removed 3 months after ETV. These patients with V-P shunt possible removing were evaluated as successful. In our group of 42 patients we were successful in 29 patients (69%. There were two serious complications (4.7%—one patient died 2.5 years and one patient died 1 year after surgery in consequence of delayed ETV failure. ETV is the method of choice in obstructive hydrocephalus even in patients with former V-P shunt implantation. In case of acute or scheduled V-P shunt surgical revision, MRI is feasible, and if ventricular system obstruction is diagnosed, the hydrocephalus may be solved endoscopically.

  2. Inner ear anomalies seen on CT images in people with Down syndrome

    International Nuclear Information System (INIS)

    Although dysplasia of inner ear structures in Down syndrome has been reported in several histopathological studies, the imaging findings have not been widely studied. To evaluate the prevalence and clinical significance of inner ear anomalies detected on CT images in patients with Down syndrome. The temporal bone CT images of patients with Down syndrome were assessed for inner ear anomalies; clinical notes and audiograms were reviewed for hearing loss. Logistic regression models were employed to identify which CT findings were associated with sensorineural hearing loss (SNHL). Inner ear anomalies were observed in 74.5% (38/51) of patients. Malformed bone islands of lateral semicircular canal (LSCC), narrow internal auditory canals (IACs), cochlear nerve canal stenoses, semicircular canal dehiscence (SCCD), and enlarged vestibular aqueducts were detected in 52.5% (53/101), 24.5% (25/102), 21.4% (21/98), 8.8% (9/102) and 2% (2/101) of patients' ears, respectively. IAC stenosis had the highest odds ratio (OR = 5.37, 95% CI: 1.0-28.9, P = 0.05) for SNHL. Inner ear anomalies occurred in 74.5% of our population, with malformed (<3 mm) bone island of LSCC being the most common (52.5%) anomaly. Narrow IAC was seen in 24.5% of patients with Down syndrome and in 57.1% of ears with SNHL. High-resolution CT is a valuable for assessing the cause of hearing loss in people with Down syndrome. (orig.)

  3. Development of Extended Period Pressure-Dependent Demand Water Distribution Models

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcpherson, Timothy N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-20

    Los Alamos National Laboratory (LANL) has used modeling and simulation of water distribution systems for N-1 contingency analyses to assess criticality of water system assets. Critical components considered in these analyses include pumps, tanks, and supply sources, in addition to critical pipes or aqueducts. A contingency represents the complete removal of the asset from system operation. For each contingency, an extended period simulation (EPS) is run using EPANET. An EPS simulates water system behavior over a time period, typically at least 24 hours. It assesses the ability of a system to respond and recover from asset disruption through distributed storage in tanks throughout the system. Contingencies of concern are identified as those in which some portion of the water system has unmet delivery requirements. A delivery requirement is defined as an aggregation of water demands within a service area, similar to an electric power demand. The metric used to identify areas of unmet delivery requirement in these studies is a pressure threshold of 15 pounds per square inch (psi). This pressure threshold is used because it is below the required pressure for fire protection. Any location in the model with pressure that drops below this threshold at any time during an EPS is considered to have unmet service requirements and is used to determine cascading consequences. The outage area for a contingency is the aggregation of all service areas with a pressure below the threshold at any time during the EPS.

  4. Can We Mitigate Climate Extremes using Managed Aquifer Recharge: Case Studies California Central Valley and South-Central Arizona, USA

    Science.gov (United States)

    Scanlon, B. R.; Reedy, R. C.; Faunt, C. C.; Pool, D. R.; Uhlman, K.

    2015-12-01

    Frequent long-term droughts interspersed with intense floods in the southwestern U.S. underscore the need to store more water to manage these climate extremes. Here we show how managed aquifer recharge can enhance drought resilience in the southwestern U.S. with ~ 70% of California under extreme drought and 75% of Arizona under moderate drought. Data on water sources, transportation, and users were compiled for managed aquifer recharge systems in the Central Valley and south-central Arizona. Groundwater depletion of 115 to 145 km3 in the 1900s created large subsurface reservoirs in thick alluvial basins in these regions. Large canals and aqueducts up to several 100 km long allow water to be imported from reservoirs, mostly in more humid regions. Imported water is either used instead of groundwater or is applied in surface spreading basins primarily during wet periods (≤1.3 km3/yr Central Valley, ≤0.7 km3/yr Arizona) and is extracted during droughts. The dominant water users include irrigators and municipalities both within and outside the managed aquifer recharge systems. Groundwater modeling indicates that recharge basins significantly increase groundwater storage in the Central Valley. Managed aquifer recharge systems significantly enhance drought resilience and increase sustainability of water resources in semiarid regions, complementing surface water reservoirs and conjunctive surface water/groundwater use by providing longer term storage.

  5. Un informe de Pedro de Ribera para Nueva España: el abastecimiento de agua a Guadalajara

    Directory of Open Access Journals (Sweden)

    Recio Mir, Álvaro

    2014-12-01

    Full Text Available The project proposed by the Franciscan architect Pedro Antonio de Buzeta to supply water to the New Spanish city of Guadalajara was sent to Madrid for review and supervision by the Council of the Indies. The Madrid architect Pedro de Ribera dealt with its technical aspects, and in 1735 he wrote an interesting critique of the plan. Among other questions, he defended the use of underground aqueducts, demonstrated his erudition and considered diverse improvements to Buzeta’s project.El proyecto que el arquitecto franciscano Pedro Antonio de Buzeta planteó para abastecer de agua a la ciudad novohispana de Guadalajara fue enviado a Madrid para que lo supervisase el consejo de Indias. De sus aspectos técnicos se ocupó el arquitecto madrileño Pedro de Ribera, que firmó una interesante crítica a la empresa en 1735. Entre otras cuestiones, hizo una defensa de los acueductos subterráneos, demostró su erudición y planteó diversas correcciones al proyecto de Buzeta.

  6. Medical practice in Graeco-Roman antiquity

    Directory of Open Access Journals (Sweden)

    L Cilliers

    2006-09-01

    Full Text Available The roots of modem medicine can be traced back to the 5th century BC when Hippocratic rational medicine originated on the Greek islands of Cos and Cnidos. In this study we examine the way in which practitioners conducted their profession in Graeco-Roman times, as well as their training. Medical training was by way of apprenticeship with recognized doctors, but no qualifying examinations existed and the standard of practice thus varied enormously. Even in the Roman era the vast majority of medical doctors were Greek and in private practice as itinerant physicians. Civic doctors in the paid service of local communities appeared in Greek society from the 5th century BC onwards, but much later in Rome - probably as late as the 4th century AD. Rome’s unique contributions to medicine lay in public health measures (e.g. their aqueducts, public baths and sewages systems and an excellent medical service for their armies and navy. Hospitals (valetudinaria were established for military purposes and for slaves on large Roman estates from the 1st century BC, but civic hospitals for the general public originated as late as the 4th century AD. The Greek medical schools of Cos and Cnidos were eventually superseded by the school of Alexandria in Egypt and towards the end of the Roman Empire by that of Carthage in northern Africa. Its gradual demise in the Christian era lowered the curtain on original medical endeavours during antiquity.

  7. Difusión de modelos técnicos romanos: particularidades del sistema de abastecimiento de agua a la ciudad de Baelo Claudia

    Directory of Open Access Journals (Sweden)

    Borau, Laetitia

    2015-12-01

    Full Text Available The water supply network of the Roman city of Baelo Claudia, in particular its aqueducts and its castellum aquae, was the focus of new investigations performed in 2013. The goal of this study was to make a first assessment of conservation status of the archaeological remains. It also allowed highlighting the originality of some types of structures, in particular bridges and steeps chutes and broadcasting of some Italic technology from the Mediterranean Sea to the Atlantic coast.A lo largo del año 2013 se llevó a cabo un nuevo trabajo de investigación sobre las redes de abastecimiento de agua de la ciudad romana de Baelo Claudia. Más concretamente, se estudiaron sus acueductos y su castellum aquae. El desarrollo de dicho proyecto tuvo como primer objetivo hacer un balance del estado de conservación de los vestigios arqueológicos. Además, permitió destacar la originalidad de ciertos dispositivos, como son los puentes y los pozos de resalto. Por ende, sirvió para mejorar nuestra comprensión acerca de cómo se realizaba la difusión de técnicas itálicas desde la cuenca mediterránea hasta la costa atlántica.

  8. Antiquity versus modern times in hydraulics - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Stroia, L [Research Department, Sangari Engineering Services SRL, 35-39 Emil Racovita, Complex Azur 1, AP 08, Voluntari, 077191 (Romania); Georgescu, S C [Hydraulics and Hydraulic Machinery Department, University ' Politehnica' of Bucharest 313 Spl. Independentei, S6, Bucharest, 060042 (Romania); Georgescu, A M, E-mail: liviu.stroia@sangari.r [Hydraulics and Environmental Protection Department, Technical University of Civil Engineering Bucharest, 124 Lacul Tei Bd, S2, Bucharest, 020396 (Romania)

    2010-08-15

    Water supply and water management in Antiquity represent more than Modern World can imagine about how people in that period used to think about, and exploit the resources they had, aiming at developing and improving their society and own lives. This paper points out examples of how they handled different situations, and how they managed to cope with the growing number of population in the urban areas, by adapting or by improving their water supply systems. The paper tries to emphasize the engineering contribution of Rome and the Roman Empire, mainly in the capital but also in the provinces, as for instance the today territory of France, by analysing some aqueducts from the point of view of modern Hydraulic Engineering. A third order polynomial regression is proposed to compute the water flow rate, based on the flow cross-sectional area measured in quinaria. This paper also emphasizes on contradictory things between what we thought we knew about Ancient Roman civilization, and what could really be proven, either by a modern engineering approach, a documentary approach, or by commonsense, where none of the above could be used. It is certain that the world we live in is the heritage of the Greco-Roman culture and therefore, we are due to acknowledge their contribution, especially taking into account the lack of knowledge of that time, and the poor resources they had.

  9. Proposed terms of reference : class environmental assessment for waterpower projects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    Ontario's waterpower resources currently make up about 27 per cent of the province's energy supply, with an installed capacity of 8,150 MW. The remainder is comprised of 39 per cent nuclear, 32 per cent fossil fuels (coal, gas, and oil), and 2 per cent renewable energy sources such as solar and wind power. Of the 200 operating waterpower facilities in Ontario, two-thirds are located south of the French and Mattawa rivers. More than half of these were constructed before 1951. The waterpower facilities in Ontario range widely in capacity and energy production. Waterpower facilities consist of a main dam, a powerhouse, an auxiliary storage dam, an auxiliary block dam, penstock, tunnels, canals, weirs, aqueducts, spillways, electrical incorporation, and other auxiliary structures. A Class Environmental Assessment (EA) provides a planning process through which potential impacts can be assessed and addressed. Class EA streamlines the environmental assessment process by focusing on defined issues. The proposed waterpower Class EA will propose that undertaking be a process for the planning, designing, establishing, constructing, operating, expanding or retiring of waterpower facilities under 200 MW. 1 tab., 2 figs.

  10. Antiquity versus modern times in hydraulics - a case study

    Science.gov (United States)

    Stroia, L.; Georgescu, S. C.; Georgescu, A. M.

    2010-08-01

    Water supply and water management in Antiquity represent more than Modern World can imagine about how people in that period used to think about, and exploit the resources they had, aiming at developing and improving their society and own lives. This paper points out examples of how they handled different situations, and how they managed to cope with the growing number of population in the urban areas, by adapting or by improving their water supply systems. The paper tries to emphasize the engineering contribution of Rome and the Roman Empire, mainly in the capital but also in the provinces, as for instance the today territory of France, by analysing some aqueducts from the point of view of modern Hydraulic Engineering. A third order polynomial regression is proposed to compute the water flow rate, based on the flow cross-sectional area measured in quinaria. This paper also emphasizes on contradictory things between what we thought we knew about Ancient Roman civilization, and what could really be proven, either by a modern engineering approach, a documentary approach, or by commonsense, where none of the above could be used. It is certain that the world we live in is the heritage of the Greco-Roman culture and therefore, we are due to acknowledge their contribution, especially taking into account the lack of knowledge of that time, and the poor resources they had.

  11. Acueducto pretensado sobre el arroyo de El Gato

    Directory of Open Access Journals (Sweden)

    Ruiz de Azúa y Murgía, M. A.

    1966-12-01

    Full Text Available This project is located on the main canal of the VII sector of the Bembézar (Seville irrigated zone. It is 512.5 m long, consisting of 25 spans, each 20.50 m long. There are, in addition, two approach aqueducts, each of them 13 m in length. The arrangement adopted was the classical one, of structural boxes, with a lower slab, and tie members between the top chords. Prestressed concrete was used, to ensure the watertightness of the canal, as well as achieving a 12% reduction in cost with respect to traditional designs in reinforced concrete.La obra que se relata está ubicada en el canal principal del sector VII de la zona regable del Bembézar (Sevilla. Tiene 513,5 m de longitud (25 vanos de 20,50 m, además de los dos acuerdos de acceso, de 13 m cada uno. La solución adoptada fue la clásica de cajeros resistentes con losa inferior de solera y tirantes entre las cabezas superiores, empleándose el hormigón pretensado por asegurarse así la impermeabilidad del conjunto, además de obtener una economía del 12 por 100 respecto a los tipos tradicionales de hormigón armado.

  12. Radium isotopes in Estonian groundwater: measurements, analytical correlations, population dose and a proposal for a monitoring strategy

    Energy Technology Data Exchange (ETDEWEB)

    Forte, M; Rusconi, R [ARPA Lombardia (Environmental Protection Agency of Lombardia), via Juvara 22, 20129 Milan (Italy); Bagnato, L [Department of Quantitative Methods for Business and Economic Sciences, University of Milan-Bicocca, Piazza dell' Ateneo Nuovo 1, 20126 Milan (Italy); Caldognetto, E; Trotti, F [ARPAV (Environmental Protection Agency of Veneto), via Dominutti 8, 37135 Verona (Italy); Risica, S, E-mail: m.forte@arpalombardia.it [Istituto Superiore di Sanita, Technology and Health Department, viale Regina Elena 299, 00161 Rome (Italy)

    2010-12-01

    In some areas of Estonia, groundwater contains a significant number of natural radionuclides, especially radium isotopes, which may cause radiation protection concern depending on the geological structure of the aquifer. Indeed, the parametric value of 0.1 mSv y{sup -1} for the total indicative dose established by European Directive 98/83/EC, adopted as a limit value in Estonian national legislation, is often exceeded. A Twinning Project between Estonia and Italy was carried out within the framework of the Estonian Transition Facility Programme, sponsored by the European Union. Its aims were to assess the radiological situation of Estonian groundwater and related health consequences. The first step was a study of Estonian aqueducts and the population served by them, and a thorough analysis of the radiological database for drinking water, from which the relevant effective doses for the population were obtained. Particular attention was devoted to doses to children and infants. Correlations between the chemical parameters were investigated, in order to suggest the best possible analytical approach. Lastly, a monitoring strategy, i.e. sampling points and sampling frequencies, was proposed.

  13. Remote sensing and archaeological survey in the Hierapolis of Phrygia territory, Turkey

    Science.gov (United States)

    Scardozzi, Giuseppe

    2007-10-01

    The paper concerns the results of a research project on the application in archaeological survey of high resolution images of the QuickBird 2 satellite. The research is carried out within the activities of the Italian Archaeological Mission at Hierapolis of Phrygia, Turkey). The use of satellite images with high geometric, radiometric and spectral resolutions has constituted an important tool for archaeological research in the city and in the surrounding area, because vertical aerial photographies and recent and detailed cartographies are non-available. In fact the exceptional spatial resolution of the images makes them comparable to aerial photos on a medium scale; this type of documentation has an enormous potential in the study of urban and territorial ancient contexts. The examination of these images has permitted to detect surface anomalies and traces linked to archaeological buried structures or to paleo-environmental elements; moreover, particulary in the territory, the panchromatic images were georeferenced and used as the base field maps for the survey, in integration with GPS systems. The study of the satellite images and the ground truth verify have made fundamental contributions to the reconstruction of the urban layout of Hierapolis. Also much interesting were the results obtained in the territory of the city, with the integration of remote sensing and archaeological survey; the researches recovered numerous and important data on necropolis, aqueducts, roads, farms, quarries and villages dependent from Hierapolis. All the data collected are integrating into a GIS to produce archaeological maps.

  14. Limited cone-beam computed tomography imaging of the middle ear: a comparison with multislice helical computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peltonen, L.I.; Aarnisalo, A.A.; Kortesniemi, M.K.; Suomalainen, A.; Jero, J.; Robinson, S. [Dept. of Otorhinolaryngology and Dept. of Radiology, Helsinki Univ. Central Hospital (Finland)

    2007-02-15

    Purpose: To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas. Material and Methods: Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen landmarks of the middle and adjacent inner ear were evaluated and compared for their conspicuity according to a modified Likert scale. Total scores and scores for subgroups including landmarks of specific clinical interest were also compared. Results: No significant differences were found between the imaging techniques or subgroups when scores of individual structures were compared. While the middle ear itself was visible in all cases with CBCT, parts of the inner ear were 'cut off' in four cases due to the limited field of view. For the same reason, the evaluation of the whole mastoid was not possible with CBCT. The cochlear and vestibular aqueducts were not visualized in either CT techniques. The contrast-to-noise ratio was more than 50% lower in CBCT than in MSCT, but still adequate for diagnostic task. Conclusion: CBCT proved to be at least as accurate as routinely used MSCT in revealing the clinically and surgically important middle-ear structures. The results show that high-quality imaging of the middle ear is possible with the current CBCT device.

  15. Reconstructing the natural hydrology of the San Francisco Bay-Delta watershed

    Science.gov (United States)

    Fox, P.; Hutton, P. H.; Howes, D. J.; Draper, A. J.; Sears, L.

    2015-10-01

    We evaluated the impact of landscape changes on the amount of delta outflow reaching San Francisco Bay. The natural landscape was reconstructed and water balances were used to estimate the long-term annual average delta outflow that would have occurred under natural landscape conditions if the climate from 1922 to 2009 were to repeat itself. These outflows are referred to as natural delta outflows and are the first published estimate of natural delta outflow. These natural delta outflows were then compared with current delta outflows for the same climate and existing landscape, including its re-engineered system of reservoirs, canals, aqueducts, and pumping plants. This analysis shows that the long-term, annual average delta outflow under current conditions is consistent with outflow under natural landscape conditions. The amount of water currently used by farms, cities, and others is about equal to the amount of water formerly used by native vegetation. Development of water resources in California's Central Valley transferred water formerly used by native vegetation to new beneficial uses without substantially reducing the long-term annual average supply to the San Francisco Bay-Delta estuary. Based on this finding, it is unlikely that observed declines in native freshwater aquatic species are the result of annual average delta outflow reductions.

  16. The Three Colorado Rivers: Comparing the Physical, Legal, and Economic Allocation of a Shared River

    Science.gov (United States)

    Rushforth, R.; Ruddell, B. L.

    2015-12-01

    : For many rivers, the legal allocation of surface water was settled decades ago. The process of apportioning surface water between multiple stakeholders is an arduous process with opposing interests competing for scarce resources. The political capital spent initially allocating a river often cannot be regained, stymieing future attempts for re-allocation. The Colorado River Compact (Compact), signed in 1922, has been "the law of the river" for over 90 years. Since its signing, the Colorado River Basin (CRB) population has increased tenfold, while average river flows have decreased due to threats unforeseeable to Compact signers, such as global climate change. Water sharing agreements, like the Compact, legally re-allocate physical river flows; however, water is increasingly shared through trade rather than aqueducts. Virtual water, or the water embodied by a good or service, is a trade adaption to resource scarcity, namely water and land. This study presents findings of a virtual water complement to the Compact. The goal of this study is to determine how the legal allocation of physical water resources are re-allocated as virtual water via economic trade in a shared river basin. Results are presented by at the sub-basin, state, and county-level, showing the geographic origin and destination of virtual water from CRB states and the Upper and Lower basins. A water stress index is calculated to show the indirect water stress of Colorado River water resources and network statistics are employed to rank the importance of virtual water sources in the CRB.

  17. Neural correlates of the empathic perceptual processing of realistic social interaction scenarios displayed from a first-order perspective.

    Science.gov (United States)

    Fehr, T; Achtziger, A; Roth, G; Strüber, D

    2014-10-01

    The neural processing of impulsive behavior is a central topic in various clinical and non-clinical contexts. To investigate neural and behavioral correlates of the empathic processing of complex social scenarios, especially considering ecological validity of the experimental procedure, we developed and investigated a video stimulus inventory. It includes realistic neutral, social-positive, and reactive-aggressive action scenarios. Short video-clips showing these social scenarios from a first-person perspective triggering different emotional states were presented to a non-clinical sample of 20 young adult male participants during fMRI measurements. Both affective interaction conditions (social-positive and reactive-aggressive) were contrasted against a neutral baseline condition and against each other. Behavioral evaluation data largely confirmed the validity of the emotion-inducing stimulus material. Reactive-aggressive and social-positive interaction scenarios produced widely overlapping fMRI activation patterns in hetero-modal association cortices, but also in subcortical regions, such as the peri-aqueductal gray. Reactive-aggressive compared to social-positive scenarios yielded a more anterior distribution of activations in pre-motor and inferior frontal brain regions associated to motor-preparation and inhibitory control processing as well as in the insula associated to pain- and/or aversion-processing. We argue that there are both principally common neural networks recruited for the processing of reactive-aggressive and social-positive scenarios, but also exclusive network parts in particular involved depending on individual socialization. PMID:24814646

  18. Evapotranspiration of applied water, Central Valley, California, 1957-78

    Science.gov (United States)

    Williamson, Alex K.

    1982-01-01

    In the Central Valley, Calif., where 57% of the 20,000 square miles of land is irrigated, ground-water recharge from agricultural lands is an important input to digital simulation models of ground-water flow. Several methods of calculating recharge were explored for the Central Valley Aquifer Project and a simplified water budget was designed where net recharge (recharge minus pumpage) equals net surface water diverted minus evapotranspiration of applied water (ETAW). This equation eliminates the need to determine pumpage from the water-table aquifer, assuming that the time lag for infiltration is not longer than the time intervals of interest for modeling. This study evaluates only the evapotranspiration of applied water. Future reports will describe the other components of the water budget. ETAW was calculated by summing the products of ETAW coefficients and respective crop areas for each 7 1/2-minute quadrangle area in the valley, for each of three land-use surveys between 1957 and 1978. In 1975 total ETAW was 15.2 million acre-feet, a 43% increase since 1959. The largest increases were in the south, especially Kern County, which had a sixfold increase, which was caused by the import of surface water in the California Aqueduct. (USGS)

  19. CT findings of hereditary dentatorubral-pallidoluysian atrophy (DRPLA)

    Energy Technology Data Exchange (ETDEWEB)

    Tokiguchi, Susumu; Kurashima, Akihiko; Tsuchiya, Toshiaki; Ito, Jusuke; Naito, Haruhiko; Nagai, Hiroko; Wakabayashi, Masatoshi; Morita, Masahiro

    1987-12-01

    Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) has recently been recognized as a clinicopathological entity. It may be defined as a multisystem degenerative disease of dominant inheritance, and characterized clinically by a combination of epilepsy, myoclonus, ataxia, dementia, and choreo-athetosis. This paper reports on the CT findings of ten patients (in four families) with DRPLA. In two families, the diagnosis was established on the basis of the clinicopathological findings, while in the other two, the diagnosis was made clinically. Although the CT findings were not identical in all patients, some degree of atrophic change was always observed in the cerebellum, brainstem, and cerebral cortex. Cerebellar atrophy was always accompanied by a dilatation of the fourth ventricle. Midbrain atrophy was characterized by a prominent tegmental atrophy and aqueductal dilatation, such as is seen in progressive supranuclear palsy. Of the four patients over 40 years of age, three had a diffuse hypodensity of the cerebral white matter on CT. To our knowledge, there have been no previous reports on this hypodensity in patients with spino-cerebellar degeneration or Huntington's chorea. CT may be helpful in the differential diagnosis of progressive neuro-degenerative disorders.

  20. Visualization of inner ear dysplasias in patients with sensorineural hearing loss. High-resolution MR imaging and volume-rendered reconstructions

    International Nuclear Information System (INIS)

    Purpose: We evaluated a data acquisition and post-processing protocol for inner ear (IE) assessment by MR imaging in patients, suffering from various labyrinth malformations. Material and Methods: MR IE studies of 158 consecutive patients (316 IEs) suffering from sensorineural hearing loss without evidence of an acoustic neurinoma were reviewed for pathologies of the IE and internal acoustic meatus. High-resolution MR data of all abnormal IE studies (n=45) were post-processed to previously standardized 3D volume rendered (VR) reconstructions. Results: In 9 patients (5.7%) the following IE dysplasias were detected: malformation of the cochlea (6 IEs), vestibulum (4 IEs), semicircular canals (12 IEs) and vestibular aqueduct/endolymphatic sac (10 IEs). One patient showed evidence of an aplasia of the vestibulocochlear nerve. In 4 patients multiple IE dysplasias were encountered. Comprehensive 3D visualization of all labyrinthine dysplasias was achieved by the use of two VR reconstructions. The overall time for bilateral IE assessment amounted to 30-35 min. Conclusion: The imaging protocol allows for rapid and comprehensive visualization of various IE dysplasias, based on a limited number of VR reconstructions