Summer Research at Spin Physics Group 2012 in Full Swing
The summer researchers at Spin Physics Group were involved in interesting physics projects. All of the students showed keen interest in using experimental techniques for discovering and unravelling exciting natural phenomena. These phenomena range from monitoring seismic activity in a station located in the Syed Babar Ali School of Science and Engineering (SBASSE) Complex's basement, to following oscillatory chemical reactions and effusing ethanol for determining Boltzmann's constant. Another student studied plasmonic waves in gold-glass interfaces, while yet another young researcher shone X-rays on prized archeological finds from Sahiwal District.
Young researchers worked alongside Physics staff at SBASSE, which includes; Dr. Sabieh Anwar, Muhammad Wasif, Amrozia Shaheen, Hassaan Majeed and Rabiya Salman. Their research during summer term revealed interesting findings.
Usama Anwar's work demonstrated the Surface Plasmon Polariton (SPP) excitation on a gold/air interface in the so-called Kretschmann configuration. His research explored an angular scanning approach to generate curves of reflectivity versus angle of incidence to identify the resonance angle. The results correlated well with the theoretical predictions. Based on published work, he also learnt about how an SPP response curve can be quantitatively interpreted to extract information such as the dielectric constant and thickness of a thin film. The work is being extended to develop an SPR based biosensor.
Qurat ul ann Bajwa used X-Ray fluorescence for the analysis archeological samples recovered from recent excavations in Ghaneri Wala in Sahiwal District. These are important historical finds and the Physics Lab is currently involved in a scientific analysis of the extracts. Qurat also quantified the composition of various melt-spun glasses comprising gold, silver and palladium metals.
Uzair Abdul Lateef discovered the phenomenon of hysteresis in a light bulb, the project combined electricity with thermodynamics. An ordinary tungsten bulb was driven at various frequencies and amplitudes, and the resulting non-ohmic and nonlinear behavior was studied and corroborated with simulations in MATLAB, while changing filament geometries and types of incandescent bulbs.
Mustafa Afzal Saeed set up an experiment to monitor the evaporation of ethanol from a cylindrical container, blocking out air draughts, estimating the value of the Boltzmann constant from the evaporation curve, to within 10% accuracy. The experiment last nine days! In the second part, a clock chemical was designed, and repeated at different temperatures. From the cycling reaction, the activation energies were determined which were finally used to determine an independent estimate of Boltzmann's constant.
Sayeda Quratul Ain Akbar, a student from Skardu near the Siachen Glacier, obtained real time data of seismic activities (a.k.a. earthquakes) in the region. The travel time curves of the S and P waves were plotted to estimate the epicentres and smagnitudes of seismic events. A classroom demo was also prepared to demonstrate the seismic waves. The project will become a permanent feature of the Physics Lab, recording real time seismic activities as well as an educational resource for the classroom.
The vibrating sample magnetometer (VSM) is a tool used to quantify the magnetisation of nanomaterials and magnetic samples. An important work in progress is the low-cost development of this state-of-the-art technique.
Bilal Aftab Usman, a physics graduate from the 2012 batch at LUMS is working on this project. Using a mechanical vibrator oscillating a sample inside a strong magnetic field, it is possible to pick up modulated magnetic signals from giant magnetoresistive (GMR) or Hall sensors. The acquired signal, owing to its exceedingly small signal-to-noise ratio is fed into a homemade lock-in amplifier. In the picture, Bilal is shown building and testing the various components of the system.