1,215 research outputs found
Phase space polarization and the topological string: a case study
We review and elaborate on our discussion in hep-th/0606112 on the interplay
between the target space and the worldsheet description of the open topological
string partition function, for the example of the conifold. We discuss the
appropriate phase space and canonical form for the system. We find a map
between choices of polarization and the worldsheet description, based on which
we study the behavior of the partition function under canonical
transformations.Comment: 18 pages, invited review for MPL
Assessment of potential future hydrogen markets in the U.S.
Potential future hydrogen markets in the United States are assessed. Future hydrogen markets for various use sectors are projected, the probable range of hydrogen production costs from various alternatives is estimated, stimuli and barriers to the development of hydrogen markets are discussed, an overview of the status of technologies for the production and utilization of hydrogen is presented, and, finally, societal aspects of hydrogen production and utilization are discussed
Potential for cogeneration of heat and electricity in California industry, phase 2
The nontechnical issues of industrial cogeneration for 12 California firms were analyzed under three categories of institutional settings: (1) industrial ownership without firm sales of power; (2) industrial ownership with firm sales of power; and (3) utility or third party ownership. Institutional issues were analyzed from the independent viewpoints of the primary parties of interest: the industrial firms, the electric utilities and the California Public utilities Commission. Air quality regulations and the agencies responsible for their promulgation were examined, and a life cycle costing model was used to evaluate the economic merits of representative conceptual cogeneration systems at these sites. Specific recommendations were made for mitigating measures and regulatory action relevant to industrial cogeneration in California
Music and anxiety in hospitalized children
Purpose: Music is a method of stress reduction and could be used as a non-invasive therapeutic tool to relieve the pain and anxiety of patient. This study is designed to evaluate the role of music therapy on the level of anxiety in children aged 912 yearsold, in an academic hospital in Gorgan, northeast of Iran. Methods: Sixty hospitalized children were categorized into the intervention (case=30) and the control groups (N=30) by using a simple randomized method. The data gathering instruments were questionnaires which included demographic information and a trait anxiety inventory for children, the Spielberger test (STAIC). For the intervention group, for 2 days, 20 minutes (3 am-6 pm), the soothing rhythmic music of Johann Sebastian Bach was released through a tape recorder which was equipped with a headphone and then, the Spielberger questionnaires were refilled by each patient. The control group did not receive any intervention. Results: The results showed that the anxiety scores between the control and the intervention groups had no significant difference before the application of the music. The mean anxiety after the application of music in the control group was 49.4±7.2 and in the intervention group, it was 30.7±7.5. The results showed a significant difference between the mean anxiety in the control and the intervention groups (p<0.05). Conclusions: Our results showed that in hospitalized children, music therapy reduced the anxiety level
The Effect Of Cellulase Supplementation And Various Wheat Bran Levels In Broiler Diets
It is a widely known fact that fibrous material is generally not well assimilated by a growing chick. Furthermore, the effect on the growth of a chick sometimes may be quite derogatory, depending on the quantity of the fibrous material used in the diet. This effect is generally considered to be attributable to a reduction in the energy intake and might be caused by a specific effect of the cellulose itself or by some cellulose composition products
Counting fermionic zero modes on M5 with fluxes
We study the Dirac equation on an M5 brane wrapped on a divisor in a
Calabi--Yau fourfold in the presence of background flux. We reduce the
computation of the normal bundle U(1) anomaly to counting the solutions of a
finite--dimensional linear system on cohomology. This system depends on the
choice of flux. In an example, we find that the presence of flux changes the
anomaly and allows instanton corrections to the superpotential which would
otherwise be absent.Comment: 14 pages. v2: reference added, typos corrected, few change
Computational Fluid Dynamics Simulations at Micro-Scale Stenosis for Microfluidic Thrombosis Model Characterization
Platelet aggregation plays a central role in pathological thrombosis, preventing healthy physiological blood flow within the circulatory system. For decades, it was believed that platelet aggregation was primarily driven by soluble agonists such as thrombin, adenosine diphosphate and thromboxane A2. However, recent experimental findings have unveiled an intriguing but complementary biomechanical mechanism—the shear rate gradients generated from flow disturbance occurring at sites of blood vessel narrowing, otherwise known as stenosis, may rapidly trigger platelet recruitment and subsequent aggregation. In our Nature Materials 2019 paper [1], we employed microfluidic devices which incorporated micro-scale stenoses to elucidate the molecular insights underlying the prothrombotic effect of blood flow disturbance. Nevertheless, the rheological mechanisms associated with this stenotic microfluidic device are poorly characterized. To this end, we developed a computational fluid dynamics (CFD) simulation approach to systematically analyze the hemodynamic influence of bulk flow mechanics and flow medium. Grid sensitivity studies were performed to ensure accurate and reliable results. Interestingly, the peak shear rate was significantly reduced with the device thickness, suggesting that fabrication of microfluidic devices should retain thicknesses greater than 50 µm to avoid unexpected hemodynamic aberration, despite thicker devices raising the cost of materials and processing time of photolithography. Overall, as many groups in the field have designed microfluidic devices to recapitulate the effect of shear rate gradients and investigate platelet aggregation, our numerical simulation study serves as a guideline for rigorous design and fabrication of microfluidic thrombosis models
Non-compact Topological Branes on Conifold
We consider non-compact branes in topological string theories on a class of
Calabi-Yau spaces including the resolved conifold and its mirror. We compute
the amplitudes of the insertion of non-compact Lagrangian branes in the A-model
on the resolved conifold in the context of the topological vertex as well as
the melting crystal picture. They all agree with each other and also agree with
the results from Chern-Simons theory, supporting the large N duality. We find
that they obey the Schr\"odinger equation confirming the wavefunction behavior
of the amplitudes. We also compute the amplitudes of the non-compact B-branes
in the DV matrix model which arises as a B-model open string field theory on
the mirror manifold of the deformed conifold. We take the large N duality to
consider the B-model on the mirror of the resolved conifold and confirm the
wave function behavior of this amplitude. We find appropriate descriptions of
non-compact branes in each model, which give complete agreements among those
amplitudes and clarify the salient features including the role of symmetries
toward these agreements.Comment: 32 pages, 9 figures, a reference added, typos fixe
Prevalence of major depression in preschool children
The prevalence of preschool major depressive disorder (MDD) was studied in the community. The whole population of children between 3 and 6 years attending preschool nurseries in three areas (one urban, one rural and one suburban) in Spain (n = 1,427) were contacted. Selection was by a two-stage procedure. At stage I, the ESDM 3-6, a screening measure for preschool depression, was used to identify a sample for more intensive interviewing. Sensitivity and specificity of the cut-off point of the ESDM 3–6 had been previously tested in a pilot study (n = 229). During the first stage, 222 preschool children (15.6%) were found to be probable depressives, because they scored 27 or more, the cut-off used. At stage II, the children were interviewed and diagnosed by the consensus of two clinicians, blind to the ESDM 3-6 results. DSM-IV diagnostic criteria were used to define caseness. A total of 16 children (1.12%) met the MDD criteria. The prevalence by areas was urban 0.87%, rural 0.88%, suburban 1.43%. Sex distribution prevalence was 1:1. This study is a contribution to the scarce epidemiology of preschool depression in the community
- …