1,305 research outputs found

    Development of Self-Compacting Engineered Cementitious Composites

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84749/1/iwscc_self-c_ecc_98.pd

    Are Preoperative Kattan and Stephenson Nomograms Predicting Biochemical Recurrence after Radical Prostatectomy Applicable in the Chinese Population?

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    Purpose. Kattan and Stephenson nomograms are based on the outcomes of patients with prostate cancer recruited in the USA, but their applicability to Chinese patients is yet to be validated. We aim at studying the predictive accuracy of these nomograms in the Chinese population. Patients and Methods. A total of 408 patients who underwent laparoscopic or open radical resection of prostate from 1995 to 2009 were recruited. The preoperative clinical parameters of these patients were collected, and they were followed up regularly with PSA monitored. Biochemical recurrence was defined as two or more consecutive PSA levels >0.4 ng/mL after radical resection of prostate or secondary cancer treatment. Results. The overall observed 5-year and 10-year biochemical recurrence-free survival rates were 68.3% and 59.8%, which was similar to the predicted values by the Kattan and Stephenson nomograms, respectively. The results of our study achieved a good concordance with both nomograms (Kattan: 5-years, 0.64; Stephenson: 5-years, 0.62, 10-years, 0.71). Conclusions. The incidence of prostate cancer in Hong Kong is increasing together with the patients’ awareness of this disease. Despite the fact that Kattan nomograms were derived from the western population, it has been validated in our study to be useful in Chinese patients as well

    The failure of stellar feedback, magnetic fields, conduction, and morphological quenching in maintaining red galaxies

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    The quenching "maintenance'" and related "cooling flow" problems are important in galaxies from Milky Way mass through clusters. We investigate this in halos with masses 10121014M\sim 10^{12}-10^{14}\,{\rm M}_{\odot}, using non-cosmological high-resolution hydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model. We specifically focus on physics present without AGN, and show that various proposed "non-AGN" solution mechanisms in the literature, including Type Ia supernovae, shocked AGB winds, other forms of stellar feedback (e.g. cosmic rays), magnetic fields, Spitzer-Braginskii conduction, or "morphological quenching" do not halt or substantially reduce cooling flows nor maintain "quenched" galaxies in this mass range. We show that stellar feedback (including cosmic rays from SNe) alters the balance of cold/warm gas and the rate at which the cooled gas within the galaxy turns into stars, but not the net baryonic inflow. If anything, outflowing metals and dense gas promote additional cooling. Conduction is important only in the most massive halos, as expected, but even at 1014M\sim 10^{14}\,{\rm M}_{\odot} reduces inflow only by a factor 2\sim 2 (owing to saturation effects and anisotropic suppression). Changing the morphology of the galaxies only slightly alters their Toomre-QQ parameter, and has no effect on cooling (as expected), so has essentially no effect on cooling flows or maintaining quenching. This all supports the idea that additional physics, e.g., AGN feedback, must be important in massive galaxies.Comment: 16 pages, 12 figure

    Collapse of Randomly Self-Interacting Polymers

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    We use complete enumeration and Monte Carlo techniques to study self--avoiding walks with random nearest--neighbor interactions described by v0qiqjv_0q_iq_j, where qi=±1q_i=\pm1 is a quenched sequence of ``charges'' on the chain. For equal numbers of positive and negative charges (N+=NN_+=N_-), the polymer with v0>0v_0>0 undergoes a transition from self--avoiding behavior to a compact state at a temperature θ1.2v0\theta\approx1.2v_0. The collapse temperature θ(x)\theta(x) decreases with the asymmetry x=N+N/(N++N)x=|N_+-N_-|/(N_++N_-)Comment: 8 pages, TeX, 4 uuencoded postscript figures, MIT-CMT-

    Ground States of Two-Dimensional Polyampholytes

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    We perform an exact enumeration study of polymers formed from a (quenched) random sequence of charged monomers ±q0\pm q_0, restricted to a 2-dimensional square lattice. Monomers interact via a logarithmic (Coulomb) interaction. We study the ground state properties of the polymers as a function of their excess charge QQ for all possible charge sequences up to a polymer length N=18. We find that the ground state of the neutral ensemble is compact and its energy extensive and self-averaging. The addition of small excess charge causes an expansion of the ground state with the monomer density depending only on QQ. In an annealed ensemble the ground state is fully stretched for any excess charge Q>0Q>0.Comment: 6 pages, 6 eps figures, RevTex, Submitted to Phys. Rev.

    Natural Language Interfaces for Tabular Data Querying and Visualization: A Survey

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    The emergence of natural language processing has revolutionized the way users interact with tabular data, enabling a shift from traditional query languages and manual plotting to more intuitive, language-based interfaces. The rise of large language models (LLMs) such as ChatGPT and its successors has further advanced this field, opening new avenues for natural language processing techniques. This survey presents a comprehensive overview of natural language interfaces for tabular data querying and visualization, which allow users to interact with data using natural language queries. We introduce the fundamental concepts and techniques underlying these interfaces with a particular emphasis on semantic parsing, the key technology facilitating the translation from natural language to SQL queries or data visualization commands. We then delve into the recent advancements in Text-to-SQL and Text-to-Vis problems from the perspectives of datasets, methodologies, metrics, and system designs. This includes a deep dive into the influence of LLMs, highlighting their strengths, limitations, and potential for future improvements. Through this survey, we aim to provide a roadmap for researchers and practitioners interested in developing and applying natural language interfaces for data interaction in the era of large language models.Comment: 20 pages, 4 figures, 5 tables. Submitted to IEEE TKD

    Cosmic Rays or Turbulence can Suppress Cooling Flows (Where Thermal Heating or Momentum Injection Fail)

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    The quenching ‘maintenance’ and ‘cooling flow’ problems are important from the Milky Way through massive cluster elliptical galaxies. Previous work has shown that some source of energy beyond that from stars and pure magnetohydrodynamic processes is required, perhaps from active galactic nuclei, but even the qualitative form of this energetic input remains uncertain. Different scenarios include thermal ‘heating’, direct wind or momentum injection, cosmic ray heating or pressure support, or turbulent ‘stirring’ of the intracluster medium (ICM). We investigate these in 10¹²−10¹⁴M⊙ haloes using high-resolution non-cosmological simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model, including simplified toy energy injection models, where we arbitrarily vary the strength, injection scale, and physical form of the energy. We explore which scenarios can quench without violating observational constraints on energetics or ICM gas. We show that turbulent stirring in the central ∼100 kpc, or cosmic ray injection, can both maintain a stable low-star formation rate halo for >Gyr time-scales with modest energy input, by providing a non-thermal pressure that stably lowers the core density and cooling rates. In both cases, associated thermal-heating processes are negligible. Turbulent stirring preserves cool-core features while mixing condensed core gas into the hotter halo and is by far the most energy efficient model. Pure thermal heating or nuclear isotropic momentum injection require vastly larger energy, are less efficient in lower mass haloes, easily overheat cores, and require fine tuning to avoid driving unphysical temperature gradients or gas expulsion from the halo centre
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