At least 13 times during the Pleistocene Epoch lava flowed into the inner gorge of the Grand Canyon and formed lava dams, as high as 600 m, that temporarily blocked the flow of the Colorado River. K-Ar ages on these lava dams indicate that the seven youngest formed within a short period of time between about 0.6 and 0.4 mega-annum (Ma). The physiography of the lava dam remnants within the canyo...

While most large river-deltas in the world are facing the risk of subsidence and erosion in the Anthropocene, it is suspected that the Changjiang submerged delta (CSD) could be subjected to the impacts of the world's largest dam, the Three Gorges Dam (TGD). Here we firstly indicate that the CSD went through high accumulation (1958-1978); slight accumulation (1978-1997), slight erosion (1997-200...

OBJECTIVES Use of a rubber dam during root canal treatment is considered the standard of care because it enhances patient safety and optimises the odds of successful treatment. Nonetheless, not all dentists use a rubber dam, creating disconnect between presumed standard of care and what is actually done in clinical practice. Little is known about dentists' attitudes towards use of the rubber da...

In the present article, effect of non-uniform excitation of reservoir bottom on nonlinear response of concrete gravity dams is considered. Anisotropic damage mechanics approach is used to model nonlinear behavior of mass concrete in 2D space. The tallest monolith of Pine Flat dam is selected as a case study. The horizontal and vertical components of 1967 Koyna earthquake is used to excite the s...

OBJECTIVE Rubber dam is recommended by the British Society of Paediatric Dentistry (BSPD) for various restorative and endodontic procedures. To date, there has been no report of actual usage of rubber dam within the speciality of paediatric dentistry. The aim of this study was to assess the usage of rubber dam amongst paediatric dentistry specialists within the UK. METHODS A postal questionna...

Environmental water’s corrosion evaluation of concrete (structure), steel bars and structures in reinforced is an item engineering investigation. Therefore, environmental water samples are used for chemical composition testing during the investigation carried out according to regulations. Evaluation very necessary. Taking Lai Hydropower Station dam site as example, through test results samples,...

Department of Civil Engineering, University of Colorado Denver, CO 80204, United States b International Research Institute for Climate and Society, The Earth Institute at Columbia University, Palisades, NY 10964, United States Department of Earth and Environmental Engineering, Columbia University, New York, NY 10027, United States d Lamont-Doherty Earth Observatory, Columbia University, Palisad...

The khap Tai Dam is the singing of the Tai Dam (or Black Tai) ethnic group. This paper presents the results of an ongoing research studying the relationship between spoken and sung tones in this specific repertoire. Two questions are addressed: (1) Are speech tones realised in khap Tai Dam singing? (2) Are the contours of speech and song similar or different in khap Tai Dam? The main results so...

According to the experience in construction of water conservancy and hydropower projects Mainland, RCC dam has two main advantages: rapid speed roller compacted concrete can realize early power generation, price fly ash is much lower than that cement, which reduce project cost. Tibet special geographical environment climatic conditions, generally characteristics “high altitude, low pressure, te...

DNA adenine methylation by DNA adenine methyltransferase (Dam) in Escherichia coli plays an important role in processes such as DNA replication initiation, gene expression regulation, and mismatch repair. In addition, E. coli strains deficient in Dam are hypersensitive to DNA-damaging agents. We used genome microarrays to compare the transcriptional profiles of E. coli strains deficient in Dam ...