Fault current limiting and protection circuit for power electronics used in a Modular Converter

The thesis objective is to safeguard power electronics used in modular converter applications. A new fault current limiting and protection circuit is proposed. The system level fault mitigation assemblies take a long time to remove a fault and within this time the IGBTs used in the Flexible AC Transmission System (FACTS) application will undergo high thermal and mechanical stress. Exposure to such conditions over a prolonged period of time will reduce the device lifetime, which is one of the major reasons why power electronics are not very popular in utility applications. Modular converter approach will reduce the device ratings required to mitigate the fault at power electronics level. The fault current limiting and protection circuit is tested using PSPICE simulation tool. The test set up is simple comprising of two IGBTs, one which acts as device under test (DUT) and another which acts as switch regulating fault seen by DUT. The test voltage is 480 Volt and R-L is varied over a range of L – 20nanoHenry, 2microHenry, and 10microHenry and R – 20Ohm, 50Ohm, and 100Ohm. The fault current limiting (FCL) and protection circuit worked accurately in each of the cases described above, thereby safely turning OFF the device within the short circuit withstand capacity (10microseconds) of IGBTs. The FCL and protection circuit can mitigate both Hard Switched Fault and Fault Under Load seen by the IGBT during short circuit condition. The circuit developed is different from the conventional protection gate drives available in the market and there is the possibility of customizing it further for modular blocks

Smart Growth and Transit Oriented Development: Financing and Execution Challenges in India

Cities today face burgeoning personalized vehicles as a consequence of neglected public transport and a spatial planning model isolated from transport planning. Transportation planning has been accorded a residual rank post spatial planning. This has prompted dispersed and automobile-centric growth of cities. The pursuit of more sustainable, liveable, congestion and pollution free cities resulted in the paradigm of New Urbanism and Smart Growth. Transit-oriented Development (TOD), an integral part of Smart Growth, has emerged as a paradigm in urban design. It aims at the concentration of development in or around a transit station or along a transit corridor. TOD could be a befitting reply to sprawl, congestion, pollution and provide an effective way to restructure existing cities. By integrating public transport and land use planning TOD provides ways to intensify agglomeration economies and weaken congestion diseconomies. TOD has several socio-economic and environmental benefits to its credit. The chapter looks at the various advantages of TOD and the challenges faced in its execution and financing. Further, several successful TOD practices from around the globe have been discussed to draw lessons for replication in India

Chilika Fisheries : a place for participatory GIS?

Coastal areas are considered rich biodiversity zones and proper exploitation of their resource bases influence the economic growth of the regions they support. But in recent times, these fragile ecosystems are under serious threat from anthropogenic influences like over-exploitation and environmental pollution. In this process a large number of coastal areas including lakes and lagoons are under serious threat and some are already highly degraded. So to maintain an ecological balance, it is important to sustain populations that live in coastal zones without endangering the resource base. In the modern era, advanced technologies provide supports to various sectors by providing information for management and development. These technologies can be used in conjunction with geographic information systems, which have been developed as a powerful tool for natural resource management, playing an important role in decision-making through the use of both spatial and attribute data. If both information technology and human responses to development - i.e., the public - can be integrated in the management process, then it is more likely that sustainable resource management and development can be achieved. This research explores the potential for participatory geospatial tools, such as a Public Participation Geographic Information System, to be used in community-based natural resource management. This thesis implements and analyses the effectiveness of a PPGIS approach through a case study of Chilika Lake, a coastal community at Orissa, India. The aim of a participatory GIS (PPGIS) is to ensure that local communities are included in the decision making and planning processes for sustainable natural resource management. This thesis provides evidence that a PPGIS approach would be useful in the Chilika context - by demonstrating that CBNRM is not really being effectively carried out in the region and showing that given the conflict that occurs over resource use, a mediating technology such as a PPGIS might be helpful in making sure everyone has both transparent information and a voice to communicate what they see happening on the ground. Expected outcomes of this research include improving resource mapping and management techniques and enhancing decision-making capabilities through local participation. Crucial for effective CBNRM, the attitudes, perceptions, needs and concerns of resource users must be factored into the resource management process. Ultimately, the data collected in this research was used to create a Chilika Resource Information Database (CRID) that can provide a platform for CBNRM and public participation. Further, this trial of making a database with unlimited public access (PPGIS) might be a solution towards achieving sustainable resource management goals. Hopefully this database, Chilika Resource Information Database (CRID) will make it easier to visualise the spatial distribution of resources, to analyse and integrate data sets and also to assess impacts of interventions, thereby enhancing the transparency of decisions regarding the resource use

Replication stress induced site-specific phosphorylation targets WRN to the ubiquitin-proteasome pathway

Faithful and complete genome replication in human cells is essential for preventing the accumulation of cancer-promoting mutations. WRN, the protein defective in Werner syndrome, plays critical roles in preventing replication stress, chromosome instability, and tumorigenesis. Herein, we report that ATR-mediated WRN phosphorylation is needed for DNA replication and repair upon replication stress. A serine residue, S1141, in WRN is phosphorylated in vivo by the ATR kinase in response to replication stress. ATR-mediated WRN S1141 phosphorylation leads to ubiquitination of WRN, facilitating the reversible interaction of WRN with perturbed replication forks and subsequent degradation of WRN. The dynamic interaction between WRN and DNA is required for the suppression of new origin firing and Rad51-dependent double-stranded DNA break repair. Significantly, ATR-mediated WRN phosphorylation is critical for the suppression of chromosome breakage during replication stress. These findings reveal a unique role for WRN as a modulator of DNA repair, replication, and recombination, and link ATR-WRN signaling to the maintenance of genome stability

A multinational Delphi consensus to end the COVID-19 public health threat

Abstract Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic 1,2 . Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches 1 , while maintaining proven prevention measures using a vaccines-plus approach 2 that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities 3 in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end

A multinational Delphi consensus to end the COVID-19 public health threat

Abstract Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic . Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches , while maintaining proven prevention measures using a vaccines-plus approach that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end

A multinational Delphi consensus to end the COVID-19 public health threat

Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic1,2. Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches1, while maintaining proven prevention measures using a vaccines-plus approach2 that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities3 in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end