Spin-orbit-coupling induced lateral spin transport from first principles

Everything digital is currently stored in data centres on magnetic hard disk drives which are accessed at will using a magnetic read head. The spinning disks and moving read heads in the hard disks imply slow access time and high-power consumption making data centres giant sponges for electricity. At the same time, semiconductor based storage suffers from thermal dissipation with miniaturization on top of data leakage and high cost. The ideal memory for data storage would be cost-effective, non-volatile, fast and consume less power, combining desirable features of both magnetic and semiconductor storage technology. To this end, the field of “spintronics" promises a new direction towards efficient data storage using magnetic memories. The impetus for the research that has gone into realizing this thesis was fuelled by uncertainties in the reported spin transport parameters and the gap between phenomenological models and experiments in (spin)transport phenomena. The aim of the thesis is to resolve some of the uncertainties by pushing our computational capabilities in investigating microscopic details of transport. Furthermore, I attempt to improve upon existing models of interpretation or prediction used in experiments and application. I studied a number of topics in the field of electronic spin transport in transition metals. Because of their partially filled d-bands and complex Fermi surfaces with spin-orbit coupling, transition metals are rich in spin phenomena that have potential for spintronics applications. Using a density functional theory-based scattering approach, I studied the generation and diffusion of spin currents in non-magnetic 5d and ferromagnetic 3d transition metals. By including thermal disorder, I presented realistic calculations for these metals. I next studied lateral transport in finite size geometries that are encountered in spintronics experiments. This form the last three chapters of the thesis. The main focus of the thesis has been on the determination of the two most important spin-orbit coupling related spin transport properties, the spin flip diffusion length and the spin Hall angle

Operations and Supply Chain Optimization – The New Era Model

Purpose:This article is an investigative study of optimization of supply chain and hence operations in the new era of digitization and identifies scope for future studies and further development of ways to achieve operational excellence. Design/ Methodology/ Approach:This research uses literature review and case studies to highlight the evolution of supply chain in the present era. The focus is on operational modifications the took place following the disruptions caused by such factors as technological innovations and global pandemic. This study employs the method of case study to support and substantiate the knowledge.Findings:The COVID-19 pandemic has demonstrated to the world that supply chain is the true lifeline of any business operation. The manufacturers had been hitherto concentrating on long-term planning to decide their future course of action and the organizational strategy. The COVID-19 pandemic exposed the futility and vulnerability of long-term planning and the need for short-term ad-hoc decision-making ability.Recommendation Conclusion:It is necessary to optimize supply chain and operations to build in resilience and flexibility to ensure faster response to unforeseen disruptions. Short term responsiveness is gaining popularity and building resilience must overtake forecasting to ensure shocks such as Covid do not throw businesses completely out of gear

A Study on the Emergence of SMEs & e- Commerce

Abstract– The Covid-19 pandemic aggravated the effects of economic slowdown. With the closure of brick-and-mortar stores during lockdowns, restriction on physical movement of consumers and resulting rapid decline in sales businesses were force to turn digital and go online. It was this struggle for survival that forced the small and mid-sized enterprises (SMEs) to enter the international e-commerce arena. This article examines the scenario that propelled the SMEs into the global e-commerce, evaluates the present scenario and explores the way forward

Sulfate Induced Heave: Addressing Ettringite Behavior in Lime Treated Soils and in Cementitious Materials

Civil engineers are at times required to stabilize sulfate bearing clay soils with calcium based stabilizers. Deleterious heaving in these stabilized soils may result over time. This dissertation addresses critical questions regarding the consequences of treating sulfate laden soils with calcium-based stabilizers. The use of a differential scanning calorimeter was introduced in this research as a tool to quantify the amount of ettringite formed in stabilized soils. The first part of this dissertation provides a case history analysis of the expansion history compared to the ettringite growth history of three controlled low strength mixtures containing fly ash with relatively high sulfate contents. Ettringite growth and measurable volume changes were monitored simultaneously for mixtures subjected to different environmental conditions. The observations verified the role of water in causing expansion when ettringite mineral is present. Sorption of water by the ettringite molecule was found to be a part of the reason for expansion. The second part of this dissertation evaluates the existence of threshold sulfate levels in soils as well as the role of soil mineralogy in defining the sensitivity of soils to sulfate-induced damage. A differential scanning calorimeter and thermodynamics based phase diagram approach are used to evaluate the role of soil minerals. The observations substantiated the difference in sensitivity of soils to ettringite formation, and also verified the existence of a threshold level of soluble sulfates in soils that can trigger substantial ettringite growth. The third part of this dissertation identifies alternative, probable mechanisms of swelling when sulfate laden soils are stabilized with lime. The swelling distress observed in stabilized soils is found to be due to one or a combination of three separate mechanisms: (1) volumetric expansion during ettringite formation, (2) water movement triggered by a high osmotic suction caused by sulfate salts, and (3) the ability of the ettringite mineral to absorb water and contribute to the swelling process

METHOD AND SYSTEM FOR INITIATING PAYMENT TRANSACTTION USING DEDICATED PAY BUTTON

The present disclosure relates to initiating a payment transaction using a dedicated pay button. The pay button is associated with the a computer hardware. The pay button includes a button, or a pad physically or digitally located on the computing hardware. The method includes receiving a link request generated from a computer hardware of a user. Further, the method includes configuring the pay button on the computer hardware to be linked with an electronic wallet of the user based on the received link request. Finally, the method includes initiating a payment transaction triggered with the Pay button of the computer hardware of the user

Value Creation Through Consolidation- Steel Sector

The recent wave of mergers and consolidation in the steel sector and the trend to globalise the companies has given me the opportunity to study the effects of merger or acquisition activity on the share price and on the mean returns of the share price over a maximum window of one year. As mega deals are signed in this sector, the strategy behind these acquisitions are analysed in this study and recommendations are given for further consolidation and globalisation in the steel sector. The majority of the gains accumulate to the targets shareholders due to the premiums required by their shareholders in order to sell their shares. Hence, the returns to acquirers are historically shown to be neutral or even negative (Bild, 1998). However, some disparity in returns around the mean is expected, and as companies choose to continue to acquire, it is of interest to investigate this further. The general purpose of this dissertation is therefore to contribute with insight into how value is created through the merger or acquisition activity. Analysis is done on the share price and also the strategy implemented by these companies under scrutiny, as to find out whether the merger/ acquisition activity has created value. Share price has been analysed with the mean equality test, using the Eview software. Graph has been plotted for the time windows and the share price trend has been analysed over a maximum period of one year

Role of epigenetic modifications in inhibitory immune checkpoints in cancer development and progression

A balance between co-inhibitory and co-stimulatory signals in the tumor microenvironment (TME) is critical to suppress tumor development and progression, primarily via maintaining effective immunosurveillance. Aberrant expression of immune checkpoints (ICs), including programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), lymphocyte-activation gene 3 (LAG-3) and T cell immunoreceptor with Ig and ITIM domains (TIGIT), can create an immune-subversive environment, which helps tumor cells to evade immune destruction. Recent studies showed that epigenetic modifications play critical roles in regulating the expression of ICs and their ligands in the TME. Reports showed that the promoter regions of genes encoding ICs/IC ligands can undergo inherent epigenetic alterations, such as DNA methylation and histone modifications (acetylation and methylation). These epigenetic aberrations can significantly contribute to the transcriptomic upregulation of ICs and their ligands. Epigenetic therapeutics, including DNA methyltransferase and histone deacetylase inhibitors, can be used to revert these epigenetic anomalies acquired during the progression of disease. These discoveries have established a promising therapeutic modality utilizing the combination of epigenetic and immunotherapeutic agents to restore the physiological epigenetic profile and to re-establish potent host immunosurveillance mechanisms. In this review, we highlight the roles of epigenetic modifications on the upregulation of ICs, focusing on tumor development, and progression. We discuss therapeutic approaches of epigenetic modifiers, including clinical trials in various cancer settings and their impact on current and future anti-cancer therapies

An evaluation of sorter induced cell stress (SICS) on peripheral blood mononuclear cells (PBMCs) after different sort conditions - are your sorted cells getting SICS?

Flow cytometry and fluorescence-activated cell sorting have become invaluable tools to analyze and isolate specific cell populations in a wide range of biomedical research and clinical applications. In countless approaches worldwide, scientists are using single cell analyses to better understand the significance and variation within different cellular populations, and fluorescence-activated cell sorting has become a major technique for cell isolation in both basic and clinical research. However, majority of available cell sorters are pressurized, droplet-based systems, which apply significant environmental pressure and shear stress to cells during sorting. Recently, the flow cytometry community has become increasingly aware about the potential negative effects this could have on sorted cells and the term "sorter induced cell stress" (SICS) has been proposed. However, up to date only a limited number of studies have investigated the effects of cell sorting on cell viability and function. Therefore, solid data on the effects of sheath pressure and nozzle size on survival and function of sorted cells are surprisingly rare. With this in mind, we sorted "CD4 " T-cells and "live" cells from human peripheral blood mononuclear cells (PBMCs) at different sort conditions and analyzed their quality before and after sorting in a series of assays. Here we present our findings in reference to cell viability and cell proliferation following sorting on different instruments (BD FACSAria III SORP and BD FACSJazz), utilizing different nozzle sizes (70 to 100 μm) and sheath pressure settings (20 to 70 psi). The results show no significant differences in cell viability and proliferation after the different tested sort conditions, but rather differences between individual experiments. These findings are evaluated and their potential significance in cell sorting experiments is discussed. [Abstract copyright: Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.

Post-operative atrial fibrillation in off pump coronary artery bypass graft: association with medication

Background: Post-operative atrial fibrillation is a common post-operative complication and has significant morbidity and mortality. This study was done with an objective to determine the association of various medication use in patients undergoing coronary artery bypass graft (CABG) with post-operative atrial fibrillation (POAF).Methods: This was a prospective observational study done in the department of cardiovascular and thoracic surgery of GMC Kottayam from December 2019 to December 2020 after obtaining institutional review board clearance. A sample size of 334 was fixed and patients undergoing off pump (OP) CABG were consecutively recruited in the study. The association of intraoperative and postoperative medication use with occurrence of POAF were analysed using the univariate analysis with a p<0.05 using the SPSS 16 software.Results: Peri-operative inotrope use was found to be significantly associated with post operative atrial fibrillation odds ratio 1.08 (95% CI 1.02-1.13). We could not find any association with preoperative use of beta blockers/agonist, antidiabetics, levothyroxine, ACE inhibitors or antiplatelet drugs. All the patients 60 (18%) who developed POAF were given amiodarone as per protocol.Conclusions: Perioperative inotrope use was found to have significant association with the development of post operative atrial fibrillation following OPCABG. More multi-institutional studies with determination of association with individual drugs and doses with POAF need to be conducted in future

Mothering and Radical Selfcare: An Autoethnography of Participating in a Facebook Parenting Group

The article documents the experiences of parenting of an urban Indian Hindu middle-class couple at the intersection of virtual and physical spaces and ideas. The experiences and ideas documented in this paper have co-evolved as the authors are parenting their four-year-old daughter and realised how their participation in a Facebook parenting group is influencing them as parents. The relational perspective in autoethnography is used to examine the mutual influences between the authors as partners, parents, and participants in the Facebook parenting group. This is done to understand how our participation in the Facebook parenting group mutually influenced our understanding of ideas of empowered mothering and self-care. The paper draws from Audre Lorde’s idea of radical self-care to analyse the interactions on the online group on empowered mothering and self-care