ABSTRACT
The propagation of spin waves is one of the promising ways to design nanoscale spintronic devices. The spin waves can interact with the magnetic skyrmion, a particle-like object that is topologically stabilized by Dzyaloshinskii-Moriya interaction (DMI) in thin film heterostructures. In this work, a spin wave-driven skyrmion-based diode is proposed by employing a T-shaped ferromagnetic nanotrack. The one-way motion of the skyrmion is achieved by exploiting the mid-arm at the center of the nanotrack. This prevents the reverse motion of the skyrmion owing to the skyrmion Hall effect (SkHE) and the absence of a repulsive force from the far edge in the mid-arm region. In order to facilitate the diode functionality of the spin wave-driven skyrmion, the amplitude and frequency of the excitation field should be considered in the ranges 0.07 T ≤ H0 ≤ 0.4 T and 60 GHz ≤ f ≤ 80 GHz, respectively. The micromagnetic interaction energy between the edges and the spin wave-driven skyrmion creates a potential gradient that induces the force which is responsible for the longitudinal motion of the skyrmion. The suggested spin wave driven diode exhibits a processing speed on the order of 100 m s-1 at 60 GHz frequency and 0.4 T amplitude. Hence, this device paves the way for the development of complete non-charge based magnetic devices for various spintronic applications.
ABSTRACT
BACKGROUND: The information on healthcare expenditure is crucial to know the impact of the pandemic on public health budgets, thereby correctly managing the ongoing crisis and preparing for subsequent waves. OBJECTIVE: To estimate the length of stay and cost incurred on COVID-19 patients who died in the ICU. METHODS: It is a record-based descriptive study conducted on 76 deceased COVID-19 patients admitted to the ICU of a dedicated COVID-19 hospital (DCH) between April and October 2020. Central Government Health Services (CGHS) package rate list, Delhi-NCR, was used as a reference for the cost of the ICU bed, ventilator, investigations, and procedures. RESULTS: The median duration of stay in the hospital was 12 days, and in the ICU, it was eight days. The median total cost of managing the patient was 91,235.6 INR; of this, the median total cost for ICU stay per patient was 6,904 INR. The major proportion of total expenses was contributed by personal protective equipment (PPE) kits, an average of 11,091.33 INR per month. The median cost of stay in the ICU, on the ventilator, in the ward, and mean cost of investigations were higher among those with associated co-morbidities. CONCLUSION: Most elderly male with co-morbidities lost their battle after ventilator support in the ICU. Patients with co-morbidities and severe disease not only have a long duration of hospitalization and poor survival rate but also fetch an economic burden close to one lakh on the institute.
