3,287 research outputs found
The use of zoning mechanisms for growth management : downtown Boston in the 1980's
Full text linkThesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1988, and, Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1988.M.I.T. copy lacks leaf 98. Title as it appears in M.I.T. Graduate List, June 1988: Increasing the scope of activity of the private sector in urban development.Includes bibliographical references.by Vineet Kumar Gupta.M.S.M.C.P
sj-docx-1-pie-10.1177_09544089221125633 - Supplemental material for A novel conjugate heat transfer approach to determine the temperature distribution in single-point cutting tool under different conditions
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221125633 for A novel conjugate heat transfer approach to determine the temperature distribution in single-point cutting tool under different conditions by Rishish Mishra, Vineet Dubey, Rabesh Kumar Singh, Anuj Kumar Sharma and Jitendra Kumar Katiyar in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
FIGURE 2 in Notes on the identity of Persea haridasanii (Lauraceae) with typification of Machilus robusta
No full textFIGURE 2. Holotype of Persea haridasanii M.Gangop. (Acc. No. 7832). © The Director, State Forest Research Institute, Itanagar, Arunachal Pradesh. Reproduced with the permission.Published as part of Chakrabarty, Tapas, Rawat, Vineet Kumar, Kumar, Anand & Ghoshal, Partha Pratim, 2022, Notes on the identity of Persea haridasanii (Lauraceae) with typification of Machilus robusta, pp. 99-102 in Phytotaxa 571 (1) on page 101, DOI: 10.11646/phytotaxa.571.1.10, http://zenodo.org/record/727040
Yb3+ sensitized Na2Y2B2O7:Er3+ phosphors in enhanced frequency upconversion,.temperature sensing and field emission display
No full textNa2Y2B2O7:Er3+/Yb3+ crystalline phosphors with single monoclinic phase have been synthesized by urea assisted solution combustion method and characterized through X-ray diffraction and Field emission scanning electron microscopy analysis. Frequency upconversion (UC) emission study has been carried out upon 980 nm laser diode excitation and maximum enhancement of about similar to 1433 times for the UC emission intensity of the green band in the codoped phosphor compared to that of the singly Er3+ doped phosphor has been reported. Optical temperature sensing study performed in the developed codoped phosphor reveals that the material can be used temperature sensing application within 300-613K temperature range with maximum sensitivity similar to 7.9 x 10(-3)K(-1) at 300 K. The low-voltage cathodoluminescence measurements have been performed for Na2Y2B2O7:Er3+-Yb3+ phosphors as a function of accelerating voltage and filament current. The developed phosphors exhibit highly intense green emission with some weak emission bands in violet, blue and red regions upon electron beam excitation. (C) 2017 Elsevier Ltd. All rights reserved
Er3+-Yb3+ doped vanadate nanocrystals: A highly sensitive thermographic phosphor and its optical nanoheater behavior
No full textOptical temperature sensors play a vital role in biomedical and therapeutic applications due to their reliable and unique detection sensitivity. Internal self-heating in Er3+/Yb3+ doped yttrium vanadate particles is observed on optical excitation at 980 nm wavelength of a diode laser. Temperature sensing performance is investigated by exploiting the temperature dependent fluorescence intensity ratio (FIR) of two emission bands (H-2(11/2)/S-4(3/2)-> I-4(15/2)) of Er3+ ion. The calculated sensor sensitivity, 0.01169 K-1 at 380 K, is found the highest among the reported results for inorganic nanosensors. The temperature of the nanocrystalline sample particles is found to increase by a large value (315-460 K) within a short interval of excitation pump power (13.18-50.45W cm(-2)). This achievement suggests potential use of the present material as an optical nanoheater for hyper-thermal treatment. (C) 2014 Elsevier B.V. All rights reserved
Increasing the Gas Barrier Properties of Polyethylene Foils by Coating with Poly(methyl acrylate)-Grafted Montmorillonite Nanosheets
No full textLow-density polyethylene (LDPE) foils were coated with a thin film of polymer-grafted Montmorillonite (MMT) nanosheets, which form a barrier against gas diffusion due to their unique brick-and-mortar arrangement. The MMT nanosheets were grafted with poly(methyl acrylate) (PMA), a soft and flexible polymer. Already very thin films of this nanocomposite could reduce gas permeability significantly. The impact of the topology of the surface-grafted polymer on gas permeability was also studied. It was found that grafting MMT nanosheets with a mixture of star-shaped and linear PMA and with PMA that is cross-linked via hydrogen bonds further decrease gas permeability. The presented strategy is quick and simple and allows for the easy formation of effective gas barrier coatings for LDPE foils, as used in food packaging.Low-density polyethylene (LDPE) foils were coated with a thin film of polymer-grafted Montmorillonite (MMT) nanosheets, which form a barrier against gas diffusion due to their unique brick-and-mortar arrangement. The MMT nanosheets were grafted with poly(methyl acrylate) (PMA), a soft and flexible polymer. Already very thin films of this nanocomposite could reduce gas permeability significantly. The impact of the topology of the surface-grafted polymer on gas permeability was also studied. It was found that grafting MMT nanosheets with a mixture of star-shaped and linear PMA and with PMA that is cross-linked via hydrogen bonds further decrease gas permeability. The presented strategy is quick and simple and allows for the easy formation of effective gas barrier coatings for LDPE foils, as used in food packaging
The two-fluid model with interfacial area transport equation in gas-dispersed condensing flows
Full text linkThe student, Vineet Kumar, accepted the attached license on 2019-10-01 at 17:11.The student, Vineet Kumar, submitted this Dissertation for approval on 2019-10-01 at 17:33.This Dissertation was approved for publication on 2019-10-03 at 13:37.DSpace SAF Submission Ingestion Package generated from Vireo submission #14480 on 2020-02-28 at 17:12:05The interfacial area transport equation (IATE) has been proposed to satisfy the closure of the interfacial area concentration in the two-fluid model. The IATE provides a dynamic prediction of flow structure consistent with the two-fluid model and has been studied extensively for adiabatic two-phase flows. However, the IATE still requires attention in flows with phase change, specifically the benchmarking of the IATE in condensing gas-dispersed bubbly flows. Extending the analysis to condensing cap/slug flows, in the present two-group IATE model formulation, the inter-group mass transfer term, which is critical for proper accounting of the bubble groups, only considers the expansion of group-1 bubbles (spherical and distorted bubbles) to group-2 bubbles (cap, slug and churn-turbulent bubbles). In condensing flows, the inter-group mass transfer term is dominated by group-2 bubbles condensing to group-1 bubbles. Therefore, the modeling of the condensation interfacial area and volume sink term is revisited, and by coupling the IATE and continuity equations the sensitivity of modeling parameters is directly investigated.
A new annulus facility is built in which experimental adiabatic steam-water flow data is collected which includes gas-dispersed condensing flow data for validating the proposed one-group and two-group condensation model. The facility includes five instrumentation ports located in the unheated section to provide high-resolution two-phase measurements in addition to local pressure and local liquid temperature measurements. The dataset consists of a total of eighty-five conditions spanning across system pressures, mass fluxes, inlet liquid subcooling, and inlet void fractions. The new dataset is developed for validation of one-dimensional system codes and multi-dimensional fluid dynamics codes and fills an important gap in the adiabatic steam-water flow database literature.
Three datasets have been used for validation consisting of condensing two-phase flow data in the unheated section of a vertical annulus with conditions spanning a range of pressures, inlet subcoolings and mass fluxes. For bubbly flows, the coupled void transport - IATE simulation results in good agreement in the predictions of the void fraction and the interfacial area concentration under nearly all sixty conditions with the proposed modifications to the condensation model. Considering the two-group two-fluid IATE model formulation, the inter-group mass transfer term is modified to be applicable for all flow conditions. The group-2 Nusselt number correlation is also modified to account for the appropriate heat transfer length scale for group-2 bubbles. A second inter-group transfer coefficient is introduced for the proposed model, and a closure relation is provided. Validation of the proposed two-group two-fluid model against the new dataset shows good agreement with experimental data with the significant improvement over the one-group IATE model for conditions with substantial group-2 void fraction throughout the simulation domain.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-02-28 without embargo termsMade available in DSpace on 2020-03-02T21:58:00Z (GMT). No. of bitstreams: 3
KUMAR-DISSERTATION-2019.pdf: 14582730 bytes, checksum: ce0a7375f6601ad53d85486a4f4c9f0e (MD5)
LICENSE.txt: 4209 bytes, checksum: 30fba849219db8fbd60a5cbb358cb703 (MD5)
PROQUEST_LICENSE.txt: 4555 bytes, checksum: c47fa44e8de2b2f0f36eb93656c8b5bc (MD5)
Previous issue date: 2019-10-0
Machilus robusta Smith 1921
No full textMachilus robusta Smith (1921: 169). Type:— CHINA. Yunnan, hills to the northeast of Tengyueh, March 1913, G. Forrest 9716 (lectotype designated here, E00123812, digital image!, Fig. 1; isolectotypes, A00041882, K000778788, digital images!). Additional syntypes:— CHINA, Yunnan, Shweli valley, February 1913, G. Forrest 9594 (A00112551, E00123816, K000778789, digital images!). CHINA. Yunnan, Shweli-Salween divide, February 1914, G. Forrest 12216 (E00123817, K000778787, digital images!). CHINA, Yunnan, Shweli-Salween divide, August 1917, G. Forrest 15753 (E00123814 [wrongly databased as ‘15758’], K000778790, digital images!). Homotypic synonym:— Persea robusta (W.W.Sm.) Kostermans (1962: 193). Heterotypic synonyms:— Machilus haridasanii (M.Gangop.) Gangopadhyay (2020: 444), syn. nov. Type:— INDIA. Arunachal Pradesh, Dibang valley district, Anini, 30 March 1984, K. Haridasan 601 (holotype, Herbarium of State Forest Research Institute, Arunachal Pradesh, Itanagar!, Fig. 2). INDIA. Arunachal Pradesh, Kameng district, Saiden to Jirigoon, 4 February 1995, K. P. Singh BSI-99369 (paratype, ASSAM 0000000115, image!). Basionym:— Persea haridasanii Gangopadhyay (2006: 133). Machilus haridasanii (M.Gangop.) Kumar (2020: 30), nom. illegit.Published as part of Chakrabarty, Tapas, Rawat, Vineet Kumar, Kumar, Anand & Ghoshal, Partha Pratim, 2022, Notes on the identity of Persea haridasanii (Lauraceae) with typification of Machilus robusta, pp. 99-102 in Phytotaxa 571 (1) on pages 99-100, DOI: 10.11646/phytotaxa.571.1.10, http://zenodo.org/record/727040
YVO4:Er3+/Yb3+ phosphor for multifunctional applications
No full textThis article reports luminescence studies on wet-chemical route prepared YVO4:Er3+/Yb3+ microdisc phosphor. The 980 nm laser excited upconversion (UC) emission intensity ratio of green to red bands is found too high to neglect the contribution from the red emission band, which is not observed normally in Er3+/Yb3+-doped materials. The red emission is also found absent in the downconversion emission under excitation at 316 nm. The variation of UC intensities with external temperature exhibits a well-fashioned pattern, which suggests that the H-2(11/2) and S-4(3/2) levels of Er3+ ion are thermally coupled. The YVO4:Er3+/Yb3+ phosphor has shown outstanding temperature-sensing behavior with maximum sensitivity of 0.0117 K-1 at 400 K. This material is also employed to develop a latent fingerprint in green color. Furthermore, the present phosphor could be useful for solar cell concentrators, drug delivery, and disease therapy applications. (C) 2014 Optical Society of Americ
sj-docx-1-pie-10.1177_09544089231159834 - Supplemental material for Lean, green, and smart manufacturing: An ingenious framework for enhancing the sustainability of operations management on the shop floor in industry 4.0
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089231159834 for Lean, green, and smart manufacturing: An ingenious framework for enhancing the sustainability of operations management on the shop floor in industry 4.0 by Varun Tripathi, Somnath Chattopadhyaya, A K Mukhopadhyay, Shubham Sharma, Vineet Kumar, Changhe Li and Sunpreet Singh in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
- …
