5,832 research outputs found
A smart material based approach to morphing
This presentation gives an overview of the Shape Memory Alloy (SMA) based approach to the research and13; development of adaptive/smart/morphing airframe structural technologies at the Advanced Composites13; Division, NAL. Central to this approach is the efficient integration of thermal NiTi SMA elements with13; polymeric carbon composites. The SMA elements could be either externally placed or embedded in the13; polymeric composite. The external connection could be in the form of mechanisms / devices
Active Vibration Control of Structures using an Impedance Matching Control Technique
Active vibration control of structures has gained a lot of interest in recent years. This paper presents an active vibration control methodology of a structure using piezoelectric actuators. The proposed methodology is useful in practical applications where the system to be controlled is difficult to model due to the presence of complex boundary conditions. The impedance matching control technique uses a power flow approach wherein the controller is designed such that the power flow into the structure is minimized. The system transfer function is obtained from the experimental collocated actuator/sensor pair data using Eigen Realisation Algorithm (ERA). The controller is designed for the system transfer function according to impedance matching theory. The above approach is targeted towards the vibration control of wind tunnel stings, which suffer from flow-induced vibration. A wind tunnel sting model is designed and fabricated for this study. The real time implementation of the impedance matching controller has been carried out using dSPACE® Digital Signal Processor (DSP) card. The results are encouraging and demonstrate the feasibility of applying this technique in the wind tunne
Abnormal modulation of atmospheric parameters during the tsunami of 2004
This paper discusses the abnormal changes in weather elements observed at a tropical mountain location and a coastal station in India. Abnormal changes were noticed in the atmospheric parameters at a time close to the occurrence of tsunami on the Indian coasts due to high magnitude earthquakes in the Sumatra region on 26 December 2004. Close to the time of this earthquake occurrence, uncharacteristic and large magnitude changes in weather elements were recorded at Braemore (8o45â²N, 77o05â²E, 360 m amsl), a mountain field station at Western Ghats. Abnormal changes were also recorded at Minambakkam (13oN, 80o18â²E, 16 m SLP), close to eastern coastal belts. In the Braemore field station, simultaneous changes were observed in the atmospheric parameters; decrease in pressure by 0.6 hPa, increase in relative humidity by 30 and a prominent reduction in air temperature by more than 3oC on the day of tsunami. Also, unusually the relative humidity did not reach 100 on the previous night. However, in the Minambakkam station, the relative humidity increased by 10 associated with a sharp decrease in temperature by about 2.5oC. The changes in both the stations occurred almost at the same time and duration. Therefore, it may be concluded that these changes are associated with the high magnitude earthquake and subsequent tsunami
A State-of-the-Art review on the drive of renewables in Gujarat, State of India: Present situation, barriers and future initiatives
Given the recent increasing public focus on climate change issues, the share of electricity generation by renewable energy resources is increasing day by day. Increased renewables share will give us robust, sustainable, and climate-friendly energy systems for the future. Renewable energy penetration with the current power systems needs substantial research, planning and development which are now the primary focus throughout the world. In this study, a global renewable energy scenario is explained in detail in contrast with India, considering a case study elucidating the comprehensive review of the Gujarat state in India. The primary focus is on Gujarat state’s actions plans to pertain to harvest renewable energy and maximizing its share in the energy mix. This study examines the actions and the policies adopted by the Gujarat government to overcome the potential barriers in order to support non-conventional as well as renewable energy development. It also investigates the numerous techno-economic and social constraints with possible solutions in promoting the deployment of upcoming renewable energy resources across Gujarat. This study can be used as a guideline for the government, policymakers, utilities, stakeholders and researchers to promote an increased renewable energy share in Gujarat as well as at other places around the globe
Hybrid renewable energy microgrid for a residential community: A techno-economic and environmental perspective in the context of the SDG7
Energy, being a prime enabler in achieving sustainable development goals (SDGs), should be affordable, reliable, sustainable, and modern. One of the SDGs (i.e., SDG7) suggests that it is necessary to ensure energy access for all. In developing countries like India, the progress toward SDG7 has somewhat stagnated. The aging conventional electric power system has its dominant share of energy from fossil fuels, plagued with frequent power outages, and leaves many un-electrified areas. These are not characteristics of a sustainable and modern system in the context of the SDG7. Promoting renewable-based energy systems, especially in the context of microgrids (MGs), is one of the promising advances needed to rejuvenate the progress toward the SDG7. In this context, a hybrid renewable energy microgrid (HREM) is proposed that gives assurance for energy access to all in an affordable, reliable, and sustainable way through modern energy systems. In this paper, a techno-economic and environmental modeling of the grid-independent HREM and its optimization for a remote community in South India are presented. A case of HREM with a proposed configuration of photovoltaic/wind turbine/diesel generator/battery energy storage system (PV/WT/DG/BESS) was modeled to meet the community residential electric load requirements. This investigation dealt with the optimum sizes of the different components used in the HREM. The results of this model presented numerous feasible solutions. Sensitivity analysis was conducted to identify the best solution from the four optimized results. From the results, it was established that a PV + DG + BESS based HREM was the most cost-effective configuration for the specific location. In addition, the obtained optimum solutions were mapped with the key criteria of the SDG7. This mapping also suggested that the PV + DG + BESS configuration falls within the context of the SDG7. Overall, it is understood that the proposed HREM would provide energy access to households that is affordable, reliable, sustainable, and modern
Roman and inverse roman domination in network of triangles
In graph G (V, E), a function f : V → {0, 1 2} is said to be a Roman Dominating Function (RDF). If ∀u ∈ V, f(u) = 0 is adjacent to at least one vertex v ∈ V such that f(v) = 2. The weight of f is given by w(f) = P v∈V f(v). The Roman Domination Number (RDN) denoted by γR(G) is the minimum weight among all RDF in G. If V −D contains a RDF f 1 : V → {0, 1, 2}, where D is the set of vertices v, f(v) > 0, then f 1 is called Inverse Roman Dominating Function (IRDF) on a graph G with respect to the RDF f. The Inverse Roman Domination Number (IRDN) denoted by γ 1 R(G) is the minimum weight among all IRDF in G. In this paper we find RDN and IRDN of few triangulations graphs.Publisher's Versio
EFFECT OF GRAPE SEED EXTRACT ON REMINERALIZATION OF ARTIFICIAL CARIES: AN IN-VITRO STUDY
Objective: Grape seeds are gaining more importance because the Proanthocyanidins†present in them have excellent anticaries, remineralizing, and antibacterial properties. Although many preventive measures have been tried, dental caries remains one of the most prevalent diseases in humans.The ultimate goal of any intervention is the preservation of tooth structure, prevention of lesion progression and inducing remineralization. Thepresent in-vitro study was done to investigate the effect of grape seed extract (GSE) on artificial enamel caries in human teeth.Methods: A total of 50 sound premolars extracted from patients undergoing orthodontic treatment were used in the study. The teeth were cleanedand were immersed in a demineralizing solution for 96 hrs at 37°C and 50% relative humidity to create artificial lesions. The samples were randomlydivided into two groups of 25 each. Half of the samples were immersed in the GSE solution (test) and the other half in saline (control), respectively, for8 days. The samples were measured by microhardness tester to obtain values in Vickers hardness scale. Data were entered into Microsoft Excel andwere analyzed using independent t-test for inter-group comparison and paired t-test for intra-group comparison using SPSS version 21.Results: The mean±SD microhardness values after remineralization for the test and control groups were 357.56±5.53 and 337.60±6.38. GSE groupsignificantly increased the microhardness of the lesions (p≤0.001).Conclusion: GSE is a potential remineralizing agent and can be used to prevent progression of dental caries.Keywords: Grape seed extract, Remineralization, Dental caries
Generalised Compositional Theories and Diagrammatic Reasoning
This chapter provides an introduction to the use of diagrammatic language, or
perhaps more accurately, diagrammatic calculus, in quantum information and
quantum foundations. We illustrate the use of diagrammatic calculus in one
particular case, namely the study of complementarity and non-locality, two
fundamental concepts of quantum theory whose relationship we explore in later
part of this chapter.
The diagrammatic calculus that we are concerned with here is not merely an
illustrative tool, but it has both (i) a conceptual physical backbone, which
allows it to act as a foundation for diverse physical theories, and (ii) a
genuine mathematical underpinning, permitting one to relate it to standard
mathematical structures.Comment: To appear as a Springer book chapter chapter, edited by G.
Chirabella, R. Spekken
Three operational taxonomic units of Eimeria are common in Nigerian chickens and may undermine effective diagnosis of coccidiosis
Mapping spot blotch resistance genes in four barley populations
Bipolaris sorokiniana (teleomorph: Cochliobolus sativus) is the fungal pathogen responsible for spot blotch in barley (Hordeum vulgare L.) and occurs worldwide in warmer, humid growing conditions. Current Australian barley varieties are largely susceptible to this disease and attempts are being made to introduce sources of resistance from North America. In this study we have compared chromosomal locations of spot blotch resistance reactions in four North American two-rowed barley lines; the North Dakota lines ND11231-12 and ND11231-11 and the Canadian lines TR251 and WPG8412-9-2-1. Diversity Arrays Technology (DArT)-based PCR, expressed sequence tag (EST) and SSR markers have been mapped across four populations derived from crosses between susceptible parental lines and these four resistant parents to determine the location of resistance loci. Quantitative trait loci (QTL) conferring resistance to spot blotch in adult plants (APR) were detected on chromosomes 3HS and 7HS. In contrast, seedling resistance (SLR) was controlled solely by a locus on chromosome 7HS. The phenotypic variance explained by the APR QTL on 3HS was between 16 and 25% and the phenotypic variance explained by the 7HS APR QTL was between 8 and 42% across the four populations. The SLR QTL on 7HS explained between 52 to 64% of the phenotypic variance. An examination of the pedigrees of these resistance sources supports the common identity of resistance in these lines and indicates that only a limited number of major resistance loci are available in current two-rowed germplasm
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