Designing bulk acoustic wave resonators for parametric amplification of spin waves

Spintronics is an emerging field of research dealing with devices that can potentially exploit the additional degree of freedom provided by the electron spin along with or instead of the conventional electronic charge. One of the most promising aspects of spintronics is the potential use of magnetostatic spin waves as information carriers in logic devices, where information is encoded in the electron spin. A major obstacle in making this a practically viable alternative to conventional electronics is the very large intrinsic spin wave damping in most known magnetic materials. In this work, we propose a new technique of parametrically amplifying spin waves by means of acoustic resonators. An equivalent electrical model of an acoustic resonator was developed to efficiently design the acoustic resonators for the desired frequency ranges. Backward volume magnetostatic spin waves were measured in Yttrium Iron Garnet films at frequencies of 1.7 GHz or higher, requiring acoustic resonators to be designed for at least 3.4 GHz or higher for parametric amplification. Acoustic resonators with resonance frequency of 4 GHz were fabricated

Parametric Pumping of Spin Waves Using Acoustic Waves

Spintronics is an emerging field of research wherein the electron spin instead of, or along with, the conventional electron charge may be utilized in developing next generation logic devices. One of the most promising aspects of spintronics is that information transfer may be achieved by spin waves in logic devices, which may provide a solution for power consumption related challenges in modern electronic devices. However, a major obstacle in making further progress in this field is the large intrinsic spin wave damping in most known magnetic materials which inhibits propagation of spin waves over sufficiently large distances. In this work, we investigate and experimentally demonstrate a new technique of amplifying spin waves parametrically using bulk acoustic waves. Backward volume magnetostatic spin waves in yttrium iron garnet (YIG) films have been amplified using bulk acoustic wave resonators driven at resonances at twice the spin wave frequency. The generation of idler spin waves in the parametric process have been experimentally demonstrated as well, which provides insight into fundamental physical mechanism responsible for the process of acoustic spin pumping. The variation of threshold acoustic energy for onset of parametric amplification with frequency detune has also been experimentally studied, with the results agreeing well with theoretical predictions. This work proposes a new technique to compensate for inherent losses in spin wave propagation in spin wave based logic devices

Diagnostics and Selective Nano-Therapeutics to Combat Multidrug-Resistant Bacteria

Due to extensive use of antibiotics various strains multidrug resistant bacteria are emerging rapidly. In USA alone according to CDC report 2013 more than 2 million is affected by these strains of multidrug resistant bacteria causing several deaths. Hence an effective way of diagnostics and therapeutics need to be designed which can successfully combat the menace ofmultidrug drug resistant bacteria.In the present thesis, we discuss about novel strategies for both diagnostics and therapeutics for multidrug resistant bacteria. In the 1st chapter we discuss a novel DNA sequencing technique utilizing purely optical spectroscopy techniques like surface enhanced Raman and FTIR spectroscopy using 3D plasmonic nano focusing. This technique can be effective in doing single molecular study, detecting any mutations or epigenetic influences that can result in development of multi drug resistance in bacteria. In the 2nd chapter we show that among different ROS, only superoxide was found to be bactericidal, killing a range of multidrug-resistant (MDR) pathogens without affecting the viability or growth of mammalian cells. In our in vitro studies, intracellular superoxide generation using light-activated quantum dots yielded highly selective and effective antimicrobial action. These results can pave the way for rational design of nanoscale therapies as precision medicine.In the 3rd chapter we show the design of superoxide-generating QDs using optimal QD material and size well-matched to superoxide redox potential, negatively charged ligands to modulate their uptake in cells and selective redox interventions, and core/shell structures to improve their stability for therapeutic action.In the 4th chapter we discuss about alloy quantum dots lowering cadmium content and replacing it with more benign zinc content. Using QDs with low cadmium content as alternative candidates for selective light-activated therapy, we show negligible toxicity of these QDs to mammalian cells, while maintaining high treatment efficacy against MDR pathogens. These results provide design principles for developing different QDs as selective therapeutics to counter the growing threat of antimicrobial resistant infections

Finite Element Simulation ForThermal Analysis In Laser Forming Of D36 Ship Building Steel

The laser bending process is one of the advanced bending processes which can be achieved by elasto-plastic deformation through the local introduction of thermal stresses. It is a thermo-mechanical process in which a laser heat source of suitable power is used for bending the material rather than any external force. In this work, sequential thermal analysis is carried out for SOLID70 element by using ANSYS. The deformation of a sheet, subjected to an irradiation, has been studied through a sequentially coupled thermo-mechanical elasto-plastic simulation by using the finite element model (FEM). D36 shipbuilding steel sheet has been taken as the work-piece material for the analysis. The thermal effects due to heat input into the work piece are analyzed which includes temperature distribution, thermal flux distribution, thermal gradient distribution and variation of thermal properties with time.Keywords: Laser beam forming, Gaussian distribution, FEM

New-onset hyperglycemia: a potential clue to detect early pancreatic cancer

Pancreatic adenocarcinoma has an incidence rate nearly equal to the mortality rate and this is mostly due to late symptom onset and diagnosis. Evidence has indicated that new-onset diabetes may be a manifestation of occult pancreatic carcinoma. Authors report the case of a young female who presented with new-onset severe hyperglycemia and superficial thrombophlebitis. She was subsequently diagnosed with pancreatic cancer confirmed by histopathology. Her glycemic status evaluated 6 months prior to her presentation during institutional health check-up was entirely normal. This case report will serve to emphasize that new-onset diabetes in certain patients could be a presenting feature of pancreatic cancer.Pancreatic adenocarcinoma has an incidence rate nearly equal to the mortality rate and this is mostly due to late onset of symptoms and delay in diagnosis. Early diagnosis of this cancer gives the opportunity for total resection of pancreas and creates hope for a full recovery. Compelling evidence now indicates that new-onset diabetes may be a manifestation of occult pancreatic carcinoma. Authors report a young female who presented with new-onset severe hyperglycemia and superficial thrombophlebitis. She was subse­quently diagnosed with pancreatic cancer confirmed by histopathology. Her glycemic status evaluated 6 months prior to her presentation during institutional health check-up was entirely normal. This case report will serve to emphasize that new-onset diabetes in certain patients could be a presenting feature of pancreatic cancer. (Clin Diabetol 2017; 6, 3: 115–117

A HYPOTHETICAL DESIGN TO INHIBIT COVID 19 DISEASE DISASTER BY DIAGRAMMATIC MODEL

SARS-CoV-2 is a new entity in the globe studied vigorously in the present world. The estimated populations are around 47 million people who are affected by the virus and around 300,000 (16th May 2020) deaths resulted from the outbreak. The rate might keep on increasing due to the non-availability of a proper vaccine, following proper management with epidemiological studies, and displacement of contact individuals as a source of transmission in particular viral-prone regions. CoVID 19 is on its vigorous spread leading to a global impact on lots of sectors. The outreaching impacts play a role in international politics, scientific developments, and economic crises over the world, and global relations among the countries. This model attempts to determine the possible impacts and outcomes of the Pandemic over the international level and some possible ways to handle it effectively. An unpredictable catastrophe in the present scenario of the world is following a high range of public health hazards. Analytical plotted data assembles for imposing in multidisciplinary segments to cure and control morbidity, a mortality rate of disease clusters, and hotspots zone. The contagious outbreak was reprogrammed as a pandemic from Wuhan in China through the transmissible chain of human contacts. Currently, the infective chain is spreading day by day with high morbidity in the United States, Europe, Scandinavian countries, and India. The transmissible chain of the virus needs to break until any effective medicine or vaccine is launched

Nowo wykryta hiperglikemia: wskazówka umożliwiająca wczesne rozpoznanie raka trzustki

 W raku gruczołowym trzustki wskaźnik umieralności jest niemal równoważny ze wskaźnikiem zapadalno­ści, co jest spowodowanie głównie tym, że choroba długo przebiega bezobjawowo i zwykle zostaje późno wykryta. Wczesne rozpoznanie raka trzustki umożliwia całkowitą resekcję guza i daje nadzieję na zupełne wyleczenie. Dostępne obecnie dowody naukowe wskazują, że cukrzyca de novo może być manifestacją kliniczną utajonego raka trzustki. Autorzy opisują przy­padek młodej kobiety, która zgłosiła się z objawami ciężkiej hiperglikemii i zakrzepowym zapaleniem żył powierzchownych. Następnie u chorej rozpoznano raka trzustki, a rozpoznanie potwierdzono w badaniu histo­patologicznym. Wartość glikemii zmierzonej podczas rutynowych badań kontrolnych przeprowadzonych 6 miesięcy wcześniej mieściły się w granicach normy. Niniejszy opis przypadku zwraca uwagę na to, że u niektórych pacjentów nowo rozpoznana cukrzyca może być objawem wskazującym na obecność raka trzustki

A COMACT MICROSTRIP PATCH ANTENNA FOR WIRELESS COMMUNICATION

Abstract—A single feed compact rectangular microstrip antenna is presented in this paper. A triangular slot is introduced at the upper edge of the patch to reduce the resonant frequency. A small piece of triangular patch is added within the area of the triangular slot to improve the gain bandwidth performance of the antenna. The antenna size has been reduced by 46.2 % when compared to a conventional square microstrip patch antenna with a maximum of 160MHz bandwidth and −27.36 dB return loss. The characteristics of the designed structure are investigated by using MoM based electromagnetic solver, IE3D. An extensive analysis of the return loss, radiation pattern, gain and efficiency of the proposed antenna is shown in this paper. The simple configuration and low profile nature of the proposed antenna leads to easy fabrication and make it suitable for th