13 research outputs found
p-form spectra and Casimir energies on spherical tesselations
Casimir energies on space-times having the fundamental domains of
semi-regular spherical tesselations of the three-sphere as their spatial
sections are computed for scalar and Maxwell fields. The spectral theory of
p-forms on the fundamental domains is also developed and degeneracy generating
functions computed. Absolute and relative boundary conditions are encountered
naturally. Some aspects of the heat-kernel expansion are explored. The
expansion is shown to terminate with the constant term which is computed to be
1/2 on all tesselations for a coexact 1-form and shown to be so by topological
arguments. Some practical points concerning generalised Bernoulli numbers are
given.Comment: 43 pages. v.ii. Puzzle eliminated, references added and typos
corrected. v.iii. topological arguments included, references adde
Towards Optimal Design of Steel- Concrete Composite Plane Frames using a Soft Computing Tool
The use of steel – concrete composite elements in a multistoried building increases the speed of construction and reduces the overall cost. The optimum design of composite elements such as slabs, beams and columns can further reduce the cost of the building frame. In the present study, therefore, Genetic Algorithm (GA) based design optimization of steel concrete composite plane frame is addressed with the aim of minimizing the overall cost of the frame. The design is carried out based on the limit state method using recommendations of IS 11834, EC 4 and BS 5950 codes and Indian and UK design tables. The analysis is carried out using computer- oriented direct stiffness method. A GA based optimization software, with pre- and postprocessing capabilities, has been developed in Visual Basic.Net environment. To validate the implementation, examples of 2 × 3 and 2 × 5 composite plane frames are included here along with parametric study
A comparative clinical study of intrathecal bupivacaine 2.5 mg with dexmedetomidine 5 μg versus intrathecal bupivacaine 2.5 mg with fentanyl 25 μg on the duration of labor analgesia using combined spinal epidural technique
Context: Adjuvants may be added to decrease motor blockade caused by intrathecal bupivacaine and prolong labor analgesia. Aim: To study the effect of intrathecal dexmedetomidine versus fentanyl when added to bupivacaine on the duration of labor analgesia, progress of labor, block characteristics, and side effects. Settings and Design: A prospective, randomized double-blind study. Materials and Methods: Sixty parturients consenting for labor analgesia were divided into two groups. Group A (n = 30) received an intrathecal 0.5% hyperbaric bupivacaine 2.5 mg and dexmedetomidine 5 μg and Group B (n = 30) received an intrathecal 0.5% hyperbaric bupivacaine 2.5 mg and fentanyl 25 μg. Partogram, visual analog score, sensory and motor blockage, progress of labor, maternal hemodynamic variations, and fetal heart rate were noted. Statistical Analysis Used: Standard qualitative and quantitative tests were used to compare data (e.g., unpaired student t-test, ANOVA, Chi-square); P value of 0.05 was considered significant. Results: Duration of labor analgesia was significantly greater in Group A as compared to Group B (254.17 ± 4.75 min vs. 123.67 ± 6.01 min, P 0.05)