Jyoti Gyanchandani

The equation of state and structural stability of titanium obtained using the linear muffin-tin orbital band-structure method

Room-temperature isotherms of titanium in HCP and omega -phases are calculated by the first-principles linear muffin-tin orbital energy band method. Comparison with experimental data shows excellent agreement. Structural phase stability analysis by the Andersen force theorem shows that the omega -phase is the lowest-energy phase at 0 K and normal volume. The possibility that the s to d electronic transition is the cause of shock discontinuity at 17.5 GPa.

Structural stability of hafnium under pressure

A theoretical analysis on the structural stability of HF under pressure, using the linear muffin-tin orbital method in conjunction with the Andersen force theorem, predicts a new phase transition to a BCC phase at high pressures, in agreement with recent diamond cell experiments.

HIGH pressure structural investigations of zirconium using LMTO method

Abstract The structural energy differences have been calculated for zirconium as a function of pressure at zero temperature using the Andersen force theorem and the linear muffin tin orbital method. The structures included are the following: α (hcp), the room temperature room pressure phase, ω- a three atom simple hexagonal, bcc and fcc. Our calculations show that the bcc structure would become energetically most favourable above 11 GPa. This results is in agreement with well known correlation between the crystal structure and the d-electron population in transition metals at normal volume. The diamond anvil cell based high pressure x-ray diffraction experiments are in progress to verify this result.

A SINGLE STAGE GAS GUN FOR SHOCK WAVE STUDIES

For the last two decades, we have been investigating the equation of state and phase transitions in various materials by first principle electron theory methods. In order to confirm some of the theoretical predictions, we have now built indigenously an experimental facility for generating both static and dynamic pressures on samples. For producing shocks, we have developed a single stage 62.8 mm gas gun. It is patterned after the Washington State University gas gun. A unique feature is a remote control unit which allows firing of the projectile in manual or auto mode. Both planar and inclined impacts can be obtained. We have developed instrumentation for measuring projectile velocity, tilt of the impactor, shock velocity, particle velocity and shock pressure profiles. A comparison of the expected and measured projectile velocities shows that the gun is performing well. Some preliminary compression experiments indicating the effect of shear on the α → ω phase transition in Ti will be reported.

Women in Physics: An Indian Perspective

Understanding nature, which is what physics is all about, is a global human endeavor. However, for a variety of reasons, women are conspicuously underrepresented in physics. In the new millennium, it is certainly important to correct this underrepresentation—both for the sake of the women, who should have the same opportunities and resources to realize and fulfill all they desire to accomplish in their lives, as well as for the sake of physics, which must draw on the full potential of humankind to solve its myriad questions. Within the Indian context, the participation of women in public life has been quite high. Even before independence, thanks to an enlightened Indian leadership, especially that of Mahatma Gandhi, both men and women have been involved in the freedom struggle. This led to the emergence of strong women leaders in the subcontinent. Indian women have held most political positions of importance, such as prime minister, chief ministers of various states, and leaders of legislatures. Women have also held positions of prominence in the judiciary and in other professions. However, India is a country of many contrasts. Along with women of very high levels of accomplishment, it also has problems such as high levels of female illiteracy, female infanticide, and dowry deaths. This leads to unusual statistics. For instance, although almost half the women in India are illiterate, roughly a third of science graduates are women and a reasonable fraction of them stay on in science. It is interesting that a survey of all the working scientists in the country reveals that, unlike in the West, there is very little perception at either school or college level that women cannot do physics and math. The more standard reasons for dropping out seem to be family or marriage related. It becomes difficult for women to cope with the simultaneous time demands of their gender roles and their professional commitments. While training up to the Ph.D. level puts heavy demands on the time and commitment of women vis-a-vis the demands of society, which expects them to fulfill the commitments of marriage and raising a family during the crucial years of training, postgraduate degrees in science are common, and are even encouraged by parents. Moreover, jobs such as college teaching or working in scientific establishments after a Masters degree are perceived as highly desirable and prestigious for women. However, in graduate school and beyond, the dropout percentage of women becomes far more significant. Whether or not a woman completes a Ph.D. and/or pursues postdoctoral fellowships is completely dependent on her marital status, the employment of the spouse, and family support. The women who go ahead for a Ph.D., postponing marriage, often marry other students. This leads to the problem of finding two jobs in the same place. So either the couple has to compromise on the career of one of them (usually that of the woman), or end up with many years of a commuting marriage. Moreover, most jobs in academics require many years of postdoctoral training. This again entails commuting marriages, postponing or coping with the additional problems of child-bearing, and dealing with a great deal of family pressure. Even after all this effort, suitable academic jobs are difficult to get. Those who do manage to get suitable jobs along with their spouses still have to deal with problems of child-rearing, given the fact that suitable day-care centers and creches with educated caregivers are still relatively new concepts in India. In spite of these handicaps, women physicists in India form roughly 10% of the physics faculty in all of the universities, and have significant presence as researchers in the various government institutions and research laboratories. This is a pretty impressive achievement. Additionally, many women physicists have been working on frontier problems at the international level. In particle physics, Indian women physicists were involved in the top quark discovery and theorists have written highly cited and useful papers in phenomenology and quantum field theory. In fact, one of the most highly cited particle

Topic 1: Attracting Girls Into Physics

We discuss the problems in attracting girls into physics. We present some of the projects undertaken in various countries to ameliorate the problem, and we conclude with some follow‐up suggestions that can be implemented in all countries.