Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

Strength enhancement of the subgrade soil of unpaved road with geosynthetic reinforcement layers

Abstract: Geosynthetic reinforcement layers are often used to improve the performance of pavement structures. The performance of an unpaved road is routinely measured in terms of the California bearing ratio (CBR), which is an index of strength of subgrade soil of unpaved road. In the present study, an experimental investigation was carried out to evaluate the performance of the subgrade soil by placing a single layer and double layers of geosynthetic reinforcements (Glasgrid, Tenax 3D grid and Tenax multimat) horizontally at varying depths from the top surface of subgrade soil. Through a series of CBR tests in the laboratory, an attempt was made to determine the optimum depth of the reinforcement layer. The single layer of reinforcement has been placed at the middle, one-third and one-fourth of the height of the CBR specimen from the top surface of the soil in the CBR mould. The double layers of reinforcement were placed at one-fourth of the specimen height from the top surface and the bottom surface. The results show the significant contribution in terms of increased CBR value of the soil, resulting in reduced design thickness of the pavement layers above the subgrade soil. It has been observed that for a single layer reinforcement the Tenax 3D grid performs better than other geosynthetics used in this study while the Tenax multimat performs best for double layers. The results indicate that for the maximum benefit, the Tenax 3D grid reinforcement should be placed in between 0.3H and 0.36H where H is the height of the soil specimen. For Glasgrid and Tenax multimat reinforcements, the maximum effect of reinforcement is obtained when they are placed between 0.41H and 0.62H.

Development of membranes by radiation grafting of acrylamide into polyethylene films: Characterization and thermal investigations

Abstract: Polyethylene-g-polyacrylamide membranes were prepared by graft polymerization of acrylamide into polyethylene films by preirradiation technique. The characterization and thermal behavior of membranes with different degrees of grafting were evaluated by density, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry measurements. Grafting led to considerable changes in the structure of polyethylene membranes. The density of the polyethylene film increased wtih the increase in the degree of grafting, although the increase beyond 100% grafting was less pronounced than at lower graft levels. The heat of fusion and the crystallinity of polyethylene decreased with the increase in the degree of grafting. The decrease in crystallinity is because of the cumulative effect of the dilution of inherent crystallinity by the incorporation of amorphous polyacrylamide grafts within the noncrystalline region of polyethylene (dilution effect) and partial disruption of the crystallites (crystal defects). X-ray diffraction measurements also revealed a decrease in the crystallinity in grafted films. Membranes behaved as a two-component system where polyethylene and polyacrylamide components underwent independent degradation irrespective of the graft levels. In general, the thermal stability of polyethylene in membranes was markedly improved by the grafting of acrylamide monomer as evident from the initial decomposition temperature increasing from 311°C for virgin PE to 390°C in grafted membranes.

ATLAS: Automatic Temporal Segmentation and Annotation of Lecture Videos Based on Modelling Transition Time

Abstract: The number of lecture videos available is increasing rapidly, though there is still insufficient accessibility and traceability of lecture video contents. Specifically, it is very desirable to enable people to navigate and access specific slides or topics within lecture videos. To this end, this paper presents the ATLAS system for the VideoLectures.NET challenge (MediaMixer, transLectures) to automatically perform the temporal segmentation and annotation of lecture videos. ATLAS has two main novelties: (i) a SVMhmm model is proposed to learn temporal transition cues and (ii) a fusion scheme is suggested to combine transition cues extracted from heterogeneous information of lecture videos. According to our initial experiments on videos provided by VideoLectures.NET, the proposed algorithm is able to segment and annotate knowledge structures based on fusing temporal transition cues and the evaluation results are very encouraging, which confirms the effectiveness of our ATLAS system.

Green route synthesis of silver nanoparticles using plants/ginger extracts with enhanced surface plasmon resonance and degradation of textile dye

Abstract: Silver nanoparticles (AgNPs) of 10–20 nm sized were synthesized via eco-friendly and cost-effective green methods using ginger (Zingiber officinale) extract and exhibit an excellent crystalline structure. The AgNPs show absorption maximum at around 407 nm at an optimal pH of 10, hence exhibits a strong surface plasmon resonance (SPR), which arises when the interaction of free electron oscillation of AgNPs is in resonance with the frequency of light interacted. AgNPs growth could be controlled by changing environmental factors such as pH, temperature, reaction time and concentration. The development of AgNPs using ginger extract is much higher as compared to tulsi (Ocimum sanctum) and neem (Azadirachta indica), plant nectar (honey), pomegranate peel extracts and fructose. In the presence of catalyst AgNPs, the absolute absorption intensity (absorbance) of textile dye, methylene blue (MB) is reduced dramatically by sodium borohydride (NaBH4). The absorbance of MB diminished 99.9% and the solution became colorless (in 10 min). Thus, the hazardous dye is degraded faster by AgNPs than the metal oxides/NPs used so far. Note that most medicinal plant extracts used in the present study are quite helpful for several diseases, including coronavirus (Covid-19).