Laboratory Model Tests on Stone Column and Pervious Concrete Columns: A Comparative Study

This study aims to perform laboratory model tests to investigate the load-deformation behavior of stone columns (SCs), pervious concrete columns (PCCs), and composite columns (CCs). Here, CC refers to the column which has the upper portion made of PCC and the lower portion made of SC. The parameters investigated in this study include column diameters, column lengths, and installation methods (pre-cast and cast-in-situ methods). The results of the model tests reveal that the axial load-carrying capacity of PCC is nearly 8 times more than that of SC with the same diameter. Moreover, it is also observed that at the top portion of SC, with the PCC length which is about 3.75 to 5 times the column diameter, the load-carrying capacity can significantly increase. It is concluded that the installation methods have marginal influence on the load-deformation behavior of PCC

Vehicle-to-Grid Integration for Enhancement of Grid: A Distributed Resource Allocation Approach

In the future grids, to reduce greenhouse gas emissions Electric Vehicles (EVs) seems to be an important means of transportation. One of the major disadvantages of the future grid is the demand-supply mismatch which can be mitigated by incorporating the EVs into the grid. The paper introduces the concept of the Distributed Resource Allocation (DRA) approach for incorporating a large number of Plug-in EV (PEVs) with the power grid utilizing the concept of achieving output consensus. The charging/discharging time of all the participating PEVs are separated with respect to time slots and are considered as strategies. The major aim of the paper is to obtain a favorable charging strategy for each grid-connected PEVs in such a way that it satisfies both grid objectives in terms of load profile smoothening and minimizing of load shifting as well as economic and social interests of vehicle owners i.e. a fair share of the rate of charging for all connected PEVs. The three-fold contribution of the paper in smoothening of load profile, load shifting minimization, and fair charging rate is validated using a representative case study. The results confirm improvement in load profile and also highlight a fair deal in the charging rate for each PEV

Diabetic foot ulcer and its surgical management

Background: Almost 80% population of diabetic foot are from low to middle income countries like India, a country with second largest number of diabetic populations. Prevalence of diabetes mellitus in India is 9.3%. Lower extremity diseases, including peripheral neuropathy, peripheral arterial disease, and foot ulceration, is twice common in diabetic subjects. the most feared consequence of diabetic foot ulcer is limb amputation, which is seen 10 to 30 times more often in person with diabetes. The objective of this study concentrates on surgical management of diabetic foot ulcer.Methods: This is an observational prospective study of 100 cases for evaluation of diabetic foot ulcer and its surgical management at P.D.U. Hospital, Rajkot from January 2017 to November 2018.Results: The average age of presentation is 55.70 year. The male to female ratio was 1.27:1. Most of the patients are from lower middle class and upper lower class according to modified kuppuswamy socioeconomic classification. Most of the patients have duration of diabetes more than 5 years.  Most common microorganism grown from culture was Staphylococcus aureus. This study has higher rate of amputations of 74% due to late presentation and neglected disease due to peripheral neuropathy causes decreased pain sensation. There was no mortality in this study.Conclusions: Management of diabetic foot ulcer is by multimodal approach with conservative and surgical approaches. Preventive measures, early diagnosis and timely surgical intervention prevents limb amputations in diabetic foot ulcer

Mudskipper fishing in the coast of Bhavnagar, Gulf of Khambhat, Gujarat, India

Coastal areas of Bhavnagar district harbors wide range of ichthyofaunal diversity and diverse fisheries resources. The fishermen in this area use wide range of fishing methods and gears, which evolved traditionally and being adept extensively in Bhavnagar coastline. Livelihood of these fishermen is almost entirely depends on mudskipper fishing and they employ three types of fishing methods to catch them i.e. direct catch through digging the burrow, stick traps around mudskipper holes, and by nylon net. Fishing by using nylon net is the most commonly used method compared to others

Multi-Agent Based Control and Reconfiguration for Restoration of Distribution Systems with Distributed Generators

Restoration entails the development of a plan consisting of opening or closing of switches, which is called reconfiguration. This dissertation proposes the design of a fast and efficient service restoration with a load shedding method for land-based and ship systems, considering priority of customers and several other system operating constraints. Existing methods, based on centralized restoration schemes that require a powerful central computer, may lead to a single point of failure. This research uses a decentralized scheme based on agents. A group of agents created to realize a specific goal by their interactions is called a Multi-Agent System (MAS). Agents and their behaviors are developed in Java Agent DEvelopment Framework (JADE) and the power system is simulated in the Virtual Test Bed (VTB). The large-scale introduction of Distributed Generators (DGs) in distribution systems has made it increasingly necessary to develop restoration schemes considering DG. The separation of utility causes the system to decompose into electrically isolated islands with generation and load imbalance that can have severe consequences. Automated load shedding schemes are essential for systems with DGs, since the disconnection of the utility can lead to instability much faster than an operator intervention can repair. Load shedding may be the only option to maintain the island when conditions are so severe as to require correction by restoration schemes. Few algorithms have been reported for the problem of maintaining the island, even though load shedding has been reported for power systems using underrequency and under-voltage criteria. This research proposes a new operational strategy for sudden generator-load imbalance due to loss of utility that dynamically calculates the quantity of load to be shed for each island and the quantity of load that can be restored. Results presented in this dissertation are among the first to demonstrate a state-of-the-art MAS for load shedding under islanded conditions and restoration of the shed loads. The load shedding and restoration schemes developed here have behaviors that can incorporate most of the distribution topologies. Achieving service restoration with DG is complicated but new automated switch technologies and communications make MAS a better scheme than existing schemes

Resilient Networked Control of Inverter-Based Microgrids against False Data Injections

Inverter-based energy resource is a fast emerging technology for microgrids. Operation of micorgrids with integration of these resources, especially in an islanded operation mode, is challenging. To effectively capture microgrid dynamics and also control these resources in islanded microgrids, a heavy cyber and communication infrastructure is required. This high reliance of microgrids on cyber interfaces makes these systems prone to cyber-disruptions. Hence, the hierarchical control of microgrids, including primary, secondary, and tertiary control, needs to be developed to operate resiliently. This paper shows the vulnerability of microgrid control in the presence of False Data Injection (FDI) attack, which is one type of cyber-disruption. Then, this paper focuses on designing a resilient secondary control based on Unknown Input Observer (UIO) against FDI. The simulation results show the superior performance of the proposed controller over other standard controllers