Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
  1. Home
  2. Search

Refine search

Refine search

Access:
Content type:
Publication date:
Apply   From and To filters
Subject: Show more
Journals Show more
Publishers: Show more
Societies Show more
Series: Show more
Collections: Show more

Actions for selected content:

Select all | Deselect all
  • View selected items
  • Export citations
  • Download PDF (zip)
  • Save to Kindle
  • Save to Dropbox
  • Save to Google Drive

Save Search

You can save your searches here and later view and run them again in "My saved searches".

Please provide a title, maximum of 40 characters.
Cancel
×

30 results

Page 1 of 2

  • Comparing the Psychological Problems Among the Health Care Workers Across Two Waves of SARS-CoV-2 (COVID-19) Pandemic: An Observational Study from India
  • Snehil Gupta, Devendra Basera, Shashank Purwar, Lily Poddar, Abhijit R. Rozatkar, Mohit Kumar, Rahat Jahan, Disha Gautam
  • Journal: Disaster Medicine and Public Health Preparedness / Volume 17 / 2023
  • Published online by Cambridge University Press: 28 July 2022, e224
  • View abstract
    Objective:

    Literature investigating the change in psychological problems of the health care workers (HCWs) throughout the coronavirus disease (COVID-19) pandemic is lacking. We aimed at comparing the psychological problems and attitudes toward work among HCWs over two waves of the COVID-19 pandemic in India.

    Methods:

    A survey was conducted involving HCWs (n = 305, first wave, 2020; n = 325, second wave, 2021). Participants’ demographic and professional and psychological characteristics (using attitude toward COVID-19 questionnaire [ATCQ]; Depression, Anxiety, and Stress Scale – 21 Items and impact of event scale – 22) were recorded. The unpaired t-test/chi-squared test was used for comparison.

    Results:

    Significant improvements (χ 2(1) = 7.3 to 45.6, P < 0.05) in level of depression (42.2% vs 9.6%), anxiety (41.3% vs 16.3%), stress (30.1% vs 6.7%), event-related stress symptoms (31.2% vs 27%), work-related stress (89.8% vs 76.8%), and stigma (25.9% vs 22.8, though marginally significant) were found among the participants of the second wave (vs first wave). However, on subgroup analysis, allied-HCWs (housekeeping staff and security personnel) reported lesser concerns over the domains of the ATCQ vis-a-viz frontline-HCWs (doctors and nurses).

    Conclusion:

    This improvement could be attributed to greater awareness about the illness, better coping skills, vaccination, and so forth; however, more research is warranted to investigate these determinants.

  • Role of flexibility on the aerodynamic performance of a resonating hummingbird-inspired wing
  • D. Kumar, G. Singh, P.M. Mohite, E.M. Lau, Y.-C. Wang
  • Journal: The Aeronautical Journal / Volume 127 / Issue 1308 / February 2023
  • Published online by Cambridge University Press: 21 July 2022, pp. 193-212
  • View abstract

    This work investigates the role of flexibility and resonant excitation on the deformation mechanism and aerodynamic performance of flapping wings. A hummingbird-inspired wing (HIW) is considered and designed to have a bone-like stiffener made of carbon fibre/epoxy (CF/E) composite attached to a membrane made of carbon nanotubes/polypropylene (CNTs/PP) nanocomposite representing the flexible part of the natural wing. The designed HIW model is analysed through fluid-structure interaction simulations performed at frequencies near and at resonant frequency. It is found that HIW generates desired bending and twisting deformations that are coupled. These deformation mechanisms are studied in detail with the help of time-varying deflections and bending-twisting angles. Further, the simultaneous effect of these parameters on the aerodynamic performance of the wing is also investigated. It is observed that the coupled nature of bending and twisting deformations is critical in enhancing the aerodynamic performance of flapping wings. In addition to that, the resonance generates higher amplitude of desired structural deformations that further enhances thrust as well as lift generation capability of the wing. The underlying mechanism for this is also explained by studying the flow around the deflected surface of the wing. Compared to off-resonant frequencies, vorticity and pressures are substantially higher for the wing at resonance. A physical model of HIW is realised using CNTs/PP and CF/E composites to perform experimental wing motion analysis and to validate the computational results. In conclusion, the present study provides a basis to design efficient biomimetic flapping wings for micro aerial vehicles (MAVs) by exploring flexibility and resonant excitation.

  • Cross cultural and global uses of a digital mental health app: results of focus groups with clinicians, patients and family members in India and the United States
  • Elena Rodriguez-Villa, Abhijit R. Rozatkar, Mohit Kumar, Vikram Patel, Ameya Bondre, Shalini S. Naik, Siddharth Dutt, Urvakhsh M. Mehta, Srilakshmi Nagendra, Deepak Tugnawat, Ritu Shrivastava, Harikeerthan Raghuram, Azaz Khan, John A. Naslund, Snehil Gupta, Anant Bhan, Jagadisha Thirthall, Prabhat K. Chand, Tanvi Lakhtakia, Matcheri Keshavan, John Torous
  • Journal: Cambridge Prisms: Global Mental Health / Volume 8 / 2021
  • Published online by Cambridge University Press: 24 August 2021, e30
    • Article
      • You have access
      • Open access
    • PDF
    • HTML
    • Export citation
  • View abstract
    Background

    Despite significant advancements in healthcare technology, digital health solutions – especially those for serious mental illnesses – continue to fall short of their potential across both clinical practice and efficacy. The utility and impact of medicine, including digital medicine, hinges on relationships, trust, and engagement, particularly in the field of mental health. This paper details results from Phase 1 of a two-part study that seeks to engage people with schizophrenia, their family members, and clinicians in co-designing a digital mental health platform for use across different cultures and contexts in the United States and India.

    Methods

    Each site interviewed a mix of clinicians, patients, and their family members in focus groups (n = 20) of two to six participants. Open-ended questions and discussions inquired about their own smartphone use and, after a demonstration of the mindLAMP platform, specific feedback on the app's utility, design, and functionality.

    Results

    Our results based on thematic analysis indicate three common themes: increased use and interest in technology during coronavirus disease 2019 (COVID-19), concerns over how data are used and shared, and a desire for concurrent human interaction to support app engagement.

    Conclusion

    People with schizophrenia, their family members, and clinicians are open to integrating technology into treatment to better understand their condition and help inform treatment. However, app engagement is dependent on technology that is complementary – not substitutive – of therapeutic care from a clinician.

  • Realisation and testing of novel fully articulated bird-inspired flapping wings for efficient and agile UAVs
  • D. Kumar, T. Goyal, S. Kamle, P.M. Mohite, E.M. Lau
  • Journal: The Aeronautical Journal / Volume 125 / Issue 1294 / December 2021
  • Published online by Cambridge University Press: 23 August 2021, pp. 2114-2148
  • View abstract

    Large birds have evolved an effective wing anatomy and mechanics, enabling airborne mastery of manoeuvres and endurance. For these very reasons, they are difficult to replicate and study. The aim of the present work is to achieve active wing articulations to mimic natural bird flapping towards efficient and agile Unmanned Aerial Vehicles (UAVs). The proposed design, bio-mimicking the black-headed gull, Larus ridibundus, has three active and independent servo-controlled wing joints at the shoulder, elbow and wrist to achieve complex controls. The construction of the wing is realised through a polymeric skin and carbon fibre–epoxy composite spars and ribs. The wing movements (flapping, span reduction and twisting) envelopes of the full-scale robotic gull (Robogull) are examined using the Digital Image Correlation (DIC) technique and laser displacement sensing. Its aerodynamic performance was evaluated in a wind tunnel at various flapping parameters, wind speeds and angles of attack. It is observed that a flapping amplitude of 45 $^\circ$ is more favourable than 90 $^\circ$ for generating higher lift and thrust, while also depending on the presence of span reduction, twist and wind speed. The model performs better at a flying velocity of 4m/s as compared with 8m/s. Both lift and thrust are high at a higher flapping frequency of 2.5Hz. Combined variation of the flapping frequency and stroke ratio should be considered for better aerodynamic performance. The combination of a lower stroke ratio of 0.5 with a flapping frequency of 2.5Hz generates higher lift and thrust than other combinations. Span reduction and wing twist notably and independently enhance lift and thrust, respectively. An increase in the angle-of-attack increases lift but decreases thrust. The model can also generate a significant rolling moment when set at a bank angle of 20 $^\circ$ and operated with independently controlled flapping amplitudes for the wings (45 $^\circ$ for the left wing and 90 $^\circ$ for the right wing). Based on the optimal values for the flapping amplitude (45 $^\circ$ ), flapping frequency (2.5Hz) and flying velocity (4m/s), the Strouhal number (St) of the Robogull model is 0.24, lying in the optimal range ( $0.2 < \mathrm{St} < 0.4$ ) for natural flyers and swimmers.

  • Resistant Superbugs: Race against Time
  • Mohit Kumar
  • Journal: Infection Control & Hospital Epidemiology / Volume 37 / Issue 3 / March 2016
  • Published online by Cambridge University Press: 06 January 2016, pp. 365-366
  • Print publication: March 2016
    • Article
      • You have access
    • PDF
    • HTML
    • Export citation
  • 3 - Conservation Laws
  • Suresh Chandra, Professor & Head, Department of Physics, Lovely Professional University, Punjab, Mohit Kumar Sharma, Assistant Professor, Department of Physics, ITM University, Gwalior, Monika Sharma, Research Scholar, School of Studies, Physics, Jiwaji University, Gwalior
  • Book: Fundamentals of Mechanics
  • Published by: Foundation Books
  • Published online: 05 March 2014
  • Print publication: 02 January 2014, pp 60-119
  • View extract

    Summary

    A conservation law in the physical world is a consequence of some symmetry. A number of conservation laws exist. Some of them are exact and some are approximate. There are conservation laws pertaining to energy, momentum, angular momentum, charge, number of baryons (protons, neutrons and heavier elements), strangeness and various quantities. In this book, we are mainly interested in the conservation of energy, momentum and angular momentum. The conservation laws are powerful tools because of the following:

    1. Conservation laws are independent of the details of trajectory and often of the details of the particular force.

    2. Conservation laws may be used even when the force is not known. This applies particularly in the physics of elementary particles.

    3. Conservation laws have an intimate connection with invariance.

    4. Even when the force is known exactly, a conservation law may be a convenient help in solving for the motion of a particle.

    Elastic and inelastic collisions

    Generally, we consider collision between two bodies. A collision between two bodies may be either elastic or inelastic. In an elastic collision, total kinetic energy of the two bodies before collision is equal to the total kinetic energy of the bodies after collision. That is, in an elastic collision, the kinetic energy of the system of bodies is conserved. However, the kinetic energy may be shared among the bodies during collision. On the other hand, in an inelastic collision, the kinetic energy of the system is not conserved.

Fundamentals of Mechanics
  • Fundamentals of Mechanics
  • Suresh Chandra, Mohit Kumar Sharma, Monika Sharma
  • Published by: Foundation Books
  • Published online: 05 March 2014
  • Print publication: 02 January 2014
  • View description
    Fundamentals of Mechanics is a textbook intended for first year students of physics at undergraduate level. It deals with the principles and applications of mechanics which is taught as a core subject of physics. The range of topics covered in this book includes Galilean transformation, Newton's law of gravitation, vectors, centre of mass, moment of inertia and angular momentum. There are many review questions which are ideal for homework assignments. Moreover, the book is thoroughly illustrated with numerous figures to help demonstrate the key concepts. Key features:Provides detailed explanation of the basic concepts of mechanics; Includes solved examples and chapter-end exercises comprising both descriptive and non-descriptive questions; Contains 250 exercises of varying difficulties, from simple to difficult calculations.
  • 7 - Non-inertial Reference Frames
  • Suresh Chandra, Professor & Head, Department of Physics, Lovely Professional University, Punjab, Mohit Kumar Sharma, Assistant Professor, Department of Physics, ITM University, Gwalior, Monika Sharma, Research Scholar, School of Studies, Physics, Jiwaji University, Gwalior
  • Book: Fundamentals of Mechanics
  • Published by: Foundation Books
  • Published online: 05 March 2014
  • Print publication: 02 January 2014, pp 211-229
  • View extract

    Summary

    So far, in our discussion, we have assumed the existence of an inertial reference frame and all the experiments and theories have been developed for inertial reference frames. Reality seems to be otherwise. In fact, there is no inertial reference frame. Our laboratories are situated on the earth and any reference frame attached to the earth is not inertial reference frame, owing to its revolution around the sun and rotation about its own axis. The earth has translational motion which is not uniform and rotational motion. It is therefore doubly non-inertial. However, we cannot discard everything developed so far. We have already discussed with suitable reasoning that for practical purposes, the earth may be taken as inertial reference frame. Nevertheless, it is worth to discuss about the motions in non-inertial reference frames. An inertial reference frame moves with constant linear velocity. Thus, the deviation from non-inertial can be in two ways: (i) reference frame is moving with accelerated linear velocity and (ii) reference frame is moving with angular velocity. We shall handle the anomaly in two steps. First, we shall see how to make corrections when our reference frame is moving with linear acceleration with respect to an inertial reference frame. Next, we shall account for corrections when our reference frame is rotating with respect to an inertial reference frame.

  • 2 - Laws of Motion
  • Suresh Chandra, Professor & Head, Department of Physics, Lovely Professional University, Punjab, Mohit Kumar Sharma, Assistant Professor, Department of Physics, ITM University, Gwalior, Monika Sharma, Research Scholar, School of Studies, Physics, Jiwaji University, Gwalior
  • Book: Fundamentals of Mechanics
  • Published by: Foundation Books
  • Published online: 05 March 2014
  • Print publication: 02 January 2014, pp 36-59
  • View extract

    Summary

    Mechanics is a branch of science and technology where we deal with various kinds of motions of bodies. Based on the observations for the motions of bodies, Newton put forth three laws, often called the Newton's laws of motion. In the present chapter, we shall discuss about them. While discussing the Newton's laws of motion, we shall assume that the atmosphere around us is not imposing any force on the moving bodies. That is, we shall assume that the atmosphere is not present. For expressing the motion, we require some reference frame and a coordinate system.

    Inertial reference frame

    For describing motion of a body, we require a reference frame. Newton considered an absolute reference frame and a universal time. For an absolute reference frame, its origin as well as its axes are absolutely fixed. Distances (displacements) of bodies are measured with reference to this reference frame.

    The reference frame in which Newton's laws of motion are valid is known as an inertial reference frame. In fact such a reference frame does not exist, as no material body is at absolute rest and therefore we cannot have an absolute reference frame. Even a reference frame attached to the earth is not an absolute one, as the earth revolves around the sun, as well as it spins about its own axis. Further, sun also moves in our galaxy, the Milky Way. In fact, no body in the universe is at the absolute rest.

Page 1 of 2