Optimization of a satellite project

Improvement in technological performance by project optimizatio

Nuclear composition and heating in accreting neutron-star crusts

Nuclear reactions in accreting neutron-star crusts and the heat release accompanying them are studied, under different assumptions concerning the composition of the outermost layer formed of the ashes of X-ray bursts. Particular examples of ashes containing nuclides with A ~ 90-110 are considered and compared with a standard A=56 case. In all cases, evolution of a crust shell is followed from 10^8 g/cm^3 to a few times 10^{13} g/cm^3. The total crustal heating produced in the non-equilibrium processes in the accreting crust is 1.1-1.5 MeV per one accreted nucleon. The composition of the accreted crust at densities exceeding the threshold for the pycnonuclear fusion is essentially independent of the assumed initial composition of the X-ray burst ashes.Comment: 5 pages, 2 figures, accepted for publication in A&A Letter

Empathy and medical education.

Spiro has said, "computed tomographic scans offer no compassion and magnetic resonance imaging has no human face. Only men and women are capable of empathy." Empathy is an essential and required part of our roles as caregivers. We must enhance this natural emotion that exists in each of us; we can do so by carefully designing a curriculum, much as we would for learning about the physiology of the liver. The roots of our need for detachment and equanimity go back to Sir William Osler, but the pendulum has swung too far, and the need for retention of millions of data bits overwhelms our souls. Although excessive emotion is destructive and counter-productive, we must not suppress our passion--but control it. The best physician both feels with the patient and prescribes for the patient at the same time. To do one without the other is inadequate care. As medical educators our task is clear