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1

An experimental study to evaluate musculoskeletal disorders and postural stress of female craftworkers adopting different sitting postures

Maity P., De S., Pal A., Dhara P. C.

International Journal of Occupational Safety and Ergonomics

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2016

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Vol. 22, No. 2

257--266

EN

This study aimed to evaluate musculoskeletal disorders (MSDs) and postural stress among female craftworkers. The study was carried out on 75 adult female craftworkers in different districts of West Bengal. The prevalence of MSDs, body part discomfort (BPD) rating and body joint angles of the workers were evaluated with standard methods. Electromyography (EMG) of the shoulder and back muscles was recorded with the BIOPAC system. The prevalence of MSDs, BPD rating and deviation of joint angle were comparatively lower in the case of sitting on the floor with folded legs than squatting and sitting on the floor with stretched legs postures. The EMG and rms values of the shoulder and back muscles were comparatively lower in this posture. Therefore, it was concluded that sitting on the floor with folded legs was less hazardous and it imposed less postural stress in comparison to other sitting postures.

2

Arsine-induced formation of silver nanoparticles in micellar medium : application of spectrophotometric determination of arsenic

Pal A., Maji S. K.

Chemia Analityczna

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2005

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Vol. 50, No. 6

1077-1086

EN

A new spectrophotometric method for the determination of arsenic at a μg^-1 level has been developed. The method was based on the formation of silver nanoparticies in anionie miceliar medium and consecutive reduction of Ag(I) by arsine (AsH.) generated from arsenic present in water. The magnitude of absorbance of yellow-coloured silver sol measured at λ_{max_{= 395 nm was proportional to arsenic concentration in the sample. Linear dynamic range (LDR) for arsenic determination was 0-0.5μg g^{-1^{(R^{2^{=0.998). Molar absorptivity equalled 4.98x10³:Lmol^-1 cm^{-2^{. and Sandell's sensitivity was 1.50 x 10^-2 μg cm^-2. Formation of silver sol in the sample containing 0.02 μg g^-1 arsenic could be easily detected visually. Detection limit was improved after removal of water from the sample, as well as when sample solution was preconcentrated. At 95% confidence level the determined concentration of arsenic was 0.18 &plmin; 0.01 μgg ^-1 (for 10 replicate analyses), compared to the true value of 0.2 (μg g. The proposed method is simple and provides reproducible results. Relative standard deviation varies within š5%. The method is insensitive to common interfering ions/materials, i.e. Fe²⁺³, Ca²⁺, Mg²⁺, Sb(III): Se(IV), P0₄^-3, SiO_{4_{^-3, NO_{3_{^-, Cl. SO_{4_{^-2 humicacid. pesticides/herbicides (such as 2,4-D. cndosulfan, atrazinc), etc.}}}}}}}}}}}}}}

PL

Opracowano nowąmetode spektrofotemetrycznego oznaczania arsenu na poziomic stężeń rzędu ug g-1. Metoda polega na redukcji Ag(I) za pomocą arsenowodoru (AsH3) generowanego z arsenu zawartego w wodzie w wyniku czego w anionowym środowisku micelamym powstają nanocząstki srebra. Wielkość absorbancj i żółto zabarwionego zolu srebra mierzona przy λmax= 395 nm była proporcjonalna do stężenia arsenu w próbce. Krzywa kalibracyjna była liniowa w zakresie stężeń arsenu 0-0.5 μg g-1 (R2=0.998). Molowy współczynnik absorpcji wynosił 4.98 x 3:Lmol-1 cm-1. a współczynnik Sandella 1,50 x 10-2 μg cm-2. Tworzenie się zolu srebra w próbce zawierającej 0,02 &mug g-1 arsenu można wykryć wizualnie.Granicę wykrywalności można polepszyć przez zatężanie roztworu. Analizy próbki o prawdziwej zawartości arsenu 0,2 μg g-1daty wynik 0,18 &plmin; &plmin; 0.01 μgg -1 (na podstawie 10 oznaczeń przy poziomie ufności 95%). Opisana metoda jest prosta i daje powtarzalne wyniki. Względne odchylenie standardowe mieściło się w granicach š5%. Metoda nie jest zakłócana przez zwykle przeszkadzające jony lub substancje takie jak: Fe2+3, Ca2+, Mg2+, Sb(III): Se(IV), P04-3, SiO4-3, NO3-, Cl. SO4-2, kwasy humusowe, pestycydy i herbicydy takie jak 1,4-D. endosulfan, atrazyna itd.

3

Hall effects on MHD low and heat transfer over a stretching surface

Gupta A. S., Pal A., Pal B., Takhar H. S.

International Journal of Applied Mechanics and Engineering

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2003

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Vol. 8, no 2

219-232

EN

A magnetohydrodynamic (MHD) flow of an incompressible viscous electrically conducting fluid over a stretching surface is investigated when the fluid is permeated by a uniform transverse magnetic field and Hall effects are taken into account. It is found that for a flow at small magnetic Reynolds number past the surface which is stretched with a velocity proportional to the distance from a fixed point, velocity profiles are similar. For a fixed value of the Hall parameter m, components of velocity along and normal to the surface at a given point decrease with an increase in the magnetic parameter M. However for fixed values of m and M, the cross-flow velocity component induced by Hall currents reaches a maximum value at a certain height from the surface and the profiles for this velocity component shift towards the left with an increase in M. A novel result of the analysis is that for a fixed value of M, the primary velocity component remains positive for small values of the Hall parameter (m=<0.5) and becomes negative for m>0.5 indicating flow reversal. The region of this flow reversal increases with an increase in m. A similarity solution for temperature distribution in the above flow is also found and the rate of heat transfer at the stretching surface is computed for various values of m and M.

4

Spectrophotometric determination of silver through photochemical formation of silver sol using diphenylamine in aqueous triton X-100 medium

Pal A.

Chemia Analityczna

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1998

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Vol. 43, No. 5

853-858

EN

Silver(I) is transformed into yellow coloured silver sol (lmax=420nm;0,98x10(4) 1 mol (-1)cm (-1) in aqueous Triton X-100 medium by photochemical reaction with diphenylamine. This has been used as a basis for the spectrophotometric determination of silver(I) in the lower parts per million (ppm) range in a quick, simple and reliable way. Beer's 1aw is obeyed in the range of 0-8.5 ppm of silver. The relative standard deviation and con idence limit (95%) for 5.65 ppm of silver (10 replicates) are found to be f 1.8% and 6:00 plus minus 0.07 respectively. The Sandell sensitivity was 1.1 x 10(-2) q.g cro 2. The effects of irradiation time, Triton X-100 concentrntion and the presence pf interfering substances are discussed. The method is applied for the determination of silver in photographic print paper.

PL

Srebro(I), w wyniku reakcji fotochemicżnej z difenyloaminq w wodnym roztworze Tritonu X-100, jest przekształcane w zabarwiony na żółto zol srebra (k,,"ux 420 nm; e = 0.98 x 10(4) 1 mol (-1) cm (-1). Reakcję tę wykorzystano do prostego i szybkiego oznaczania. srebra(I) w stężeniach poniżej 10 ppm. Prawo Beera jest spełniane w zakresie 0-8.5 ppm Ag. Względne odchylenie standardowe oraz granica ufności (95%) przy oznaczaniu 5.65 ppm Ag ( 10 oznaczeń) wynosiły odpowiednio:1.8% oraz 6.00 f 0.07. Czułość Snndella wynosiła l.l x 10-z ltg cro z. Omówiono wpływ czasu naświetlania, stężenia Tritonu Xź100 oraz obecności substancji przeszkadzających. Opracowano metodę zastosowano do oznaczania srebra w papierze fotograficznym.