Shiv Nadar University

About: Shiv Nadar University is a education organization based out in Dadri, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Graphene. The organization has 1015 authors who have published 1924 publications receiving 18420 citations.

Effect of Nb and Ta substitution on donor electron transport and ultrafast carrier dynamics in anatase TiO2 thin films

Abstract: Ta and Nb substituted TiO2 are important transparent conducting oxides that have potential for applications in photovoltaics, photocatalysis, and water splitting/CO2 sequestration. In addition to donating electrons, what are the effects of Nb and Ta substitution? Here we observe strong experimental evidence that Ta and Nb substitution induces large and small polarons in anatase TiO2 epitaxial thin films. The degenerate donor electrons (from both Nb and Ta) show a high temperature T3 dependence on electrical resistivity, which confirms the presence of large polarons, along with room temperature metallic transport. This is further confirmed by the enhancement in the electron effective mass, which was estimated from thermopower measurements. Femtosecond transient absorption (fs-TA) reveals the life time of the Ti-t2g and eg levels and the separation of these levels are consistent with the X-ray absorption spectroscopy (XAS) measurement. In addition, fs-TA reveals the presence of small polarons with a life time substantially >1 ns, which arises from defect levels and is a consequence of Ta and Nb substitution. X-ray photoelectron spectroscopy (XPS) provides evidence of Ti3+, which may be identified as the defects responsible for the small polarons. These long-lived small polarons may provide a way to minimize recombination dynamics in TiO2-based electrodes for photo-excited devices.

The role of Ge-related oxygen-deficiency centers in controlling the blue-violet photo- and electroluminescence in Ge-rich SiO2 via Er doping

Abstract: Using combined electroluminescence (EL) and photoluminescence (PL) studies we establish that the energy transfer process from the Er3+ to the Ge-related oxygen-deficiency centers (GeODCs) plays the key role in enhancing the 404 nm EL intensity in Ge-rich SiO2. Er doping induced structural modification does not appear to be relevant, which is deduced from the 404 nm PL quenching with increasing Er concentration, implying a gradual loss of GeODCs. In contrast to PL, the 404 nm EL intensity increases by 0.3% Er doping followed by a gradual decrease in intensity for higher Er concentrations, which is described in terms of a competition between the energy transfer process and the gradual segregation of Er due to the destruction of GeODCs with Er doping. This fact is further discussed in the light of ab initio molecular orbital calculations.

Modulation of Early Neutrophil Granulation: The Circulating Tumor Cell-Extravesicular Connection in Pancreatic Ductal Adenocarcinoma

Abstract: Tumor cells dissociate from the primary site and enter into systemic circulation (circulating tumor cells, CTCs) either alone or as tumor microemboli (clusters); the latter having an increased predisposition towards forming distal metastases than single CTCs. The formation of clusters is, in part, created by contacts between cell-cell junction proteins and/or cytokine receptor pairs with other cells such as neutrophils, platelets, fibroblasts, etc. In the present study, we provide evidence for an extravesicular (EV) mode of communication between pancreatic cancer CTCs and neutrophils. Our results suggest that the EV proteome of CTCs contain signaling proteins that can modulate degranulation and granule mobilization in neutrophils and, also, contain tissue plasminogen activator and other proteins that can regulate cluster formation. By exposing naive neutrophils to EVs isolated from CTCs, we further show how these changes are modulated in a dynamic fashion indicating evidence for a deeper EV based remodulatory effect on companion cells in clusters.

Object and Currency Detection with Audio Feedback for Visually Impaired

Abstract: In recent years, orientation and navigation technologies and support for people with visually impaired disabilities have increased. This paper proposes a model for the detection of objects for visually impaired individuals. We have developed a module for blind people to identify and match items scanned to a list of objects, such as currency notes, person and bottle, and the angle and distance of the object being detected from the camera. The model is based on image recognition from a database of objects. The results of the image recognition shall be communicated to the user by system audio feedback.

AQCI: An IoT Based Air Quality and Thermal Comfort Model using Fuzzy Inference

Abstract: As humans spend around 90% of their time indoors, Indoor Air Quality (IAQ) is a subject of major concern for the physical and mental well-being of humans According to the United States Environment Protection Agency (US EPA), even in centrally air-conditioned buildings, indoor air is much more polluted than outdoor air, mainly due to changes in occupancy patterns, old or ill-maintained ventilation systems and dust Therefore, it becomes important to measure and analyze IAQ In this work, an end to end IoT system has been developed to sense and analyze indoor environmental parameters: temperature, humidity and carbon dioxide These sensed values are then used to compute Predicted Mean Vote (PMV) and Ventilation Rate (VR), which are further combined to develop an indicator of the current air quality and thermal comfort index, the Air Quality and Comfort Indicator (AQCI), using fuzzy inference