Krishna Narayan Dewangan

Dr. Krishna Narayan Dewangan


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2018 in Applied Ergonomics
Verified
Journal Article
Closed access
KHK. Hamouda
K. Hamouda
SRSubhash Rakheja
Subhash Rakheja
KDKrishna Narayan Dewangan
Krishna Narayan Dewangan
PMP. Marcotte
P. Marcotte

31 August 2015 in Annals of Occupational Hygiene
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Journal Article
Open access
PDF file
KDKrishna Narayan Dewangan
Krishna Narayan Dewangan
MPMahesh R. Patil
Mahesh R. Patil
This study aims to quantify dust exposure among the workers in four different industrial settings: rice mills, flour mills, oil mills, and tea factories and to compare the obtained data with the permissible exposure limit (PEL) of Indian Union Ministry of Labour as well as to compare the dust exposure across activities and seasons. RespiConTM particle sampler was used for collecting dust concentration in the breathing zone of the workers. In total, 149 workers participated in the study and 204 samples were collected. Samples were collected in the vicinity of different processing operations. Samples in the rice mills were collected for two consecutive years in two seasons; however samples from other industries were collected for 1 year. The results indicate that geometric mean (GM) of dust exposure was significantly (P < 0.0001) different among industrial settings. Respirable dust were 8.22, 5.76, 2.98, and 6.34mg m−3 and total dust exposure were 81.05, 111.02, 56.68, and 39.85mg m−3 in the rice mills, oil mills, flour mills, and tea factories, respectively. Considerable variations in dust exposure were observed in different activities in the rice and oil mills; however variation was relatively less in the flour mills and tea factories. In the rice mills, dust concentration was higher in winter than those obtained in autumn and it is significantly different (P < 0.05) for inhalable dust and total dust. Positive correlation was obtained in thoracic dust (r2 = 0.94) and inhalable dust (r2 = 0.97) with total dust and thoracic dust with inhalable dust (r2 = 0.89). The results show that majority of the workers are exposed to higher level of respirable dust as compared to the PEL, while total dust exposure to all the workers were higher than the PEL; thus, immediate reduction of dust exposure among the workers is necessary for preventing respiratory system impairment.

5 December 2022 in Vibration
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Journal Article
Open access
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KDKrishna Narayan Dewangan
Krishna Narayan Dewangan
YYYumeng Yao
Yumeng Yao
SRSubhash Rakheja
Subhash Rakheja
This study investigated the seat-to-head vibration transmissibility (STHT) responses of 58 subjects (31 males and 27 females) seated on three different elastic seats with (WB) and without back support (NB) and under three levels of vertical vibration (0.25, 0.50 and 0.75 m/s2 RMS) in the 0.50–20 Hz range. The STHT responses with elastic seats were significantly different from the widely reported responses with rigid seats, irrespective of sitting and excitation conditions. The peak STHT magnitudes with elastic seats were relatively higher than those obtained with a rigid seat. Moreover, the transmission of seat vibration showed a strong dependence on the elastic properties of the body-seat coupling. The primary resonance frequencies were also significantly different among the elastic seats. Compared to NB conditions, the peak STHT magnitudes and the primary resonance frequencies obtained with WB conditions were significantly lower. An increase in excitation magnitude resulted in a statistically significant (p < 0.001) decrease in the primary resonance frequency.

8 February 2023 in Vibration
Verified
Journal Article
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YYYumeng Yao
Yumeng Yao
KDKrishna Narayan Dewangan
Krishna Narayan Dewangan
SRSubhash Rakheja
Subhash Rakheja
This study investigated the effects of gender and ten different anthropometric parameters on the vertical vibration transmission from seat to the head of the body seated on an elastic seat. The seat-to-head transmissibility (STHT) responses in the vertical and fore-aft directions of 58 participants (31 males and 27 females) were measured under three levels of vertical vibration (root mean square acceleration: 0.25, 0.50, and 0.75 m/s2) in the 0.50–20 Hz range, when sitting on a viscoelastic seat with and without a vertical back support, and with hands on a steering wheel. Apart from the important effects of elastic coupling between the body and seat, the results show distinctly different vertical and fore-aft STHT responses from the two genders. Moreover, the gender effect was strongly coupled with back support and excitation conditions. The primary resonance frequencies of male subjects were higher than those of female subjects, while the peak vertical STHT magnitudes were comparable. Owing to the strong coupled effects of gender and anthropometric dimensions, the study is designed to reduce the coupling by considering datasets for subjects with comparable chosen dimensions. Among the various anthropometric dimensions considered, the body mass and fat mass revealed strong influences on the primary resonance frequency, which was similar for male and female subjects with comparable body mass index and body fat mass. The vertical STHT magnitude of the two genders with the same lean body mass was also nearly identical. The peak fore-aft STHT magnitudes of the male subjects were notably higher than those of the female subjects with comparable anthropometric dimensions with the exception of the body mass.

22 December 2022 in Appliedchem
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Journal Article
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BCb surya kumar chhetry
b surya kumar chhetry
KDKrishna Narayan Dewangan
Krishna Narayan Dewangan
DMDipendra Mahato
Dipendra Mahato
Pradeep KumarPradeep Kumar
Pradeep Kumar
Agricultural operations and the processing sector generate dust laden with endotoxin in the workplace. Endotoxin, a pro-inflammatory agent, has adverse effects on health, especially in the lungs, as exposure to endotoxin reduces lung function capacity. Endotoxin exposure to workers and its harmful impact on the health of agricultural workers needs to be studied in detail for future interventions to reduce exposure to endotoxin. The review can help to identify the analytical methods used to determine endotoxin exposure in agriculture. A detailed study of the research articles published in the last two decades related to agriculture and allied fields was carried out. In the agricultural sector, Pantoea agglomerans, a Gram-negative bacterium, was predominantly present. The filters were stored at a temperature of −20 °C, and E. coli 055: B5 was the predominately used standard to analyze the endotoxin. The quantitative kinetic Limulus Amebocyte Lysate test was the most common detection method for quantifying endotoxin. Control strategies to reduce endotoxin exposure are also emphasized in this review.

25 July 2023
Verified
Book Chapter
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STSarju Thokchom
Sarju Thokchom
BCB. S. K. Chhetry
B. S. K. Chhetry
KDKrishna Narayan Dewangan
Krishna Narayan Dewangan