A Simplified Approach to Optimally Controlled Quantum Dynamics

A new formalism for the optimal control of quantum mechanical physical observables is presented. This approach is based on an analogous classical control technique reported previously[J. Botina, H. Rabitz and N. Rahman, J. chem. Phys. Vol. 102, pag. 226 (1995)]. Quantum Lagrange multiplier functions are used to preserve a chosen subset of the observable dynamics of interest. As a result, a corresponding small set of Lagrange multipliers needs to be calculated and they are only a function of time. This is a considerable simplification over traditional quantum optimal control theory[S. shi and H. Rabitz, comp. Phys. Comm. Vol. 63, pag. 71 (1991)]. The success of the new approach is based on taking advantage of the multiplicity of solutions to virtually any problem of quantum control to meet a physical objective. A family of such simplified formulations is introduced and numerically tested. Results are presented for these algorithms and compared with previous reported work on a model problem for selective unimolecular reaction induced by an external optical electric field.Comment: Revtex, 29 pages (incl. figures

Preparation of Photoactive Transition-Metal Layered Double Hydroxides (LDH) to Replace Dye-Sensitized Materials in Solar Cells

This work highlights the use of Fe-modified MgAl-layered double hydroxides (LDHs) to replace dye and semiconductor complexes in dye-sensitized solar cells (DSSCs), forming a layered double hydroxide solar cell (LDHSC). For this purpose, a MgAl-LDH and a Fe-modified MgAl LDH were prepared. X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy were used to analyze the structural properties, morphology, and success of the Fe-modification of the synthesized LDHs. Ultraviolet-visible (UV-Vis) absorption spectroscopy was used to analyze the photoactive behavior of these LDHs and compare it to that of TiO2 and dye-sensitized TiO2. Current-voltage (I–V) solar simulation was used to determine the fill factor (FF), open circuit voltage (VOC), short circuit current (ISC), and efficiency of the LDHSCs. It was shown that the MgFeAl-LDH can act as a simultaneous photoabsorber and charge separator, effectively replacing the dye and semiconductor complex in DSSCs and yielding an efficiency of 1.56%

A PROSPECTIVE STUDY OF CLINICAL PROFILE OF STROKE IN A TERTIARY CARE HOSPITAL

ABSTRACTObjective: The objective of the work was to study the clinical profile of stroke in a tertiary care hospital.Methods: A prospective observational study on stroke was carried out for a period of 6-month (May 2015 to October 2015). A total of 241 inpatientsfrom Shri Preethi Hospital were incorporated in the study. The data were collected and evaluated by reviewing case files and patient interview.Result and Conclusion: Out of 241 patients, an incidence of ischemic stroke was found to be higher. The occurrence of stroke steeply rises with agewith male predominance. The burden of stroke tends to be more in rural, illiterate, and low socioeconomic status population. The study reveals riskfactors such as sedentary lifestyle, previous and family history of stroke, underlying disease like hypertension, diabetes. The circadian pattern in onsetshowed a significant peak in morning (6 am-12 pm) for Ischemic and afternoon (12 pm-6 pm) for hemorrhagic stroke. Topographic distribution ofcerebral infract and hemorrhage was found to be in parietal lobe and periventricular white matter, respectively. Mostly prescribed medication forischemic and hemorrhagic patients was antihypertensive and mannitol, respectively. The contraindication for thrombolytic therapy was found to below economic status and average delay in time of presentation to hospital. The study highlights the need for aggressive management of traditionalrisk factors, need for extensive work up in patient to find etiologies and need for more active interventions in community for the prevention of stroke.Keywords: Ischemic, Hemorrhagic, Circadian pattern, Antihypertensive