Serious complication may occurred in COVID-19 patients, including Acute Respiratory Distress Synd... more Serious complication may occurred in COVID-19 patients, including Acute Respiratory Distress Syndrome (ARDS) that causes death. Currently, ARDS from COVID-19 is still an ongoing challenge. Adequate treatment in ARDS management might significantly decreases morbidity and mortality.
New measurements of photoionization cross-sections from the 7p 2P3/2 excited state of potassium n... more New measurements of photoionization cross-sections from the 7p 2P3/2 excited state of potassium near the first ionization threshold are presented using a two-step laser excitation/ionization technique in conjunction with a time-of-flight (TOF) mass spectrometer. The absolute values of photoionization cross-sections have been determined as (3.52?????0.52)?Mb, (2.21?????0.33)?Mb, (1.35?????0.22)?Mb and (0.54?????0.08)?Mb at four ionizing laser wavelengths; 1064?nm, 643.61?nm, 532?nm and 355?nm respectively whereas the number density has been determined as (1.6?????0.31)???1010?cm?3. The presently measured experimental values of photoionization cross-sections are in good agreement with the literature experimental and theoretical values.
The existence of a Cooper minimum in the experimentally measured photoionization cross sections f... more The existence of a Cooper minimum in the experimentally measured photoionization cross sections for the 7s 2 S 1/2 excited state of potassium has been reported using a two-step laser excitation technique in conjunction with a time-of-flight mass spectrometer. The photoionization cross sections for the 7s 2 S 1/2 state have been determined as (9.78 ± 0.01) × 10 −2 , (3.30 ± 0.49) × 10 −4 , (5.47 ± 0.82) × 10 −3 , and (2.06 ± 0.30) × 10 −2 Mb at the ionizing laser wavelengths 1064, 700, 532, and 355 nm, respectively, that validate the presence of a Cooper minimum at ∼ =1.25 eV above the first ionization threshold. The number density has been determined as N 0 = 2 × 10 11 cm −3. The experimentally determined absolute values of the cross sections are in qualitative agreement with the theoretical predictions.
The photoionization cross-section and number density of the 3p 2 P 1/2,3/2 excited levels of sodi... more The photoionization cross-section and number density of the 3p 2 P 1/2,3/2 excited levels of sodium have been measured as a function of the laser energy using two-step laser excitation in conjunction with a thermionic diode working in the space charge limited mode. Employing the saturation technique, the crosssections for the 3p 2 P 1/2 and 3p 2 P 3/2 levels are determined as 2.16 (43) Mb and 3.74 (74) Mb respectively.
Journal of Chromatography & Separation Techniques, 2020
A method using dispersive solid-phase extraction (d-SPE) cleanup followed by QuEChERS with High P... more A method using dispersive solid-phase extraction (d-SPE) cleanup followed by QuEChERS with High Performance Liquid Chromatography (HPLC) has been established for determination of Neonicotinoid pesticide residues in various vegetables including brinjal, salad leaves, coriander, cabbage and lady finger. Based on an assessment of the HPLC characteristics, validation experiments are conducted for three Neonicotinoid pesticides i.e. Nitenpyram, Imidacloprid and Acetamiprid. In acidified acetonitrile analytical extraction is done with NaCl and MgSO4 followed by activated neutral carbon. The method show good linearity (R2 ≥ 0.999) and relative standard deviation (RSD ≤ 3.36%). Average recoveries of three insecticides are in the range of 55% to 82% at spiking levels of 275.68 to 409.3 mg.Kg-1. LOD and LOQ of three Neonicotinoid pesticides are in the range of 2.658 - 3.761 mg.Kg-1 and 8.056 - 11.4 mg.Kg-1. This QuEChERS determination method by HPLC is precise, simple, sensitive, accurate, ea...
Serious complication may occurred in COVID-19 patients, including Acute Respiratory Distress Synd... more Serious complication may occurred in COVID-19 patients, including Acute Respiratory Distress Syndrome (ARDS) that causes death. Currently, ARDS from COVID-19 is still an ongoing challenge. Adequate treatment in ARDS management might significantly decreases morbidity and mortality.
New measurements of photoionization cross-sections from the 7p 2P3/2 excited state of potassium n... more New measurements of photoionization cross-sections from the 7p 2P3/2 excited state of potassium near the first ionization threshold are presented using a two-step laser excitation/ionization technique in conjunction with a time-of-flight (TOF) mass spectrometer. The absolute values of photoionization cross-sections have been determined as (3.52?????0.52)?Mb, (2.21?????0.33)?Mb, (1.35?????0.22)?Mb and (0.54?????0.08)?Mb at four ionizing laser wavelengths; 1064?nm, 643.61?nm, 532?nm and 355?nm respectively whereas the number density has been determined as (1.6?????0.31)???1010?cm?3. The presently measured experimental values of photoionization cross-sections are in good agreement with the literature experimental and theoretical values.
The existence of a Cooper minimum in the experimentally measured photoionization cross sections f... more The existence of a Cooper minimum in the experimentally measured photoionization cross sections for the 7s 2 S 1/2 excited state of potassium has been reported using a two-step laser excitation technique in conjunction with a time-of-flight mass spectrometer. The photoionization cross sections for the 7s 2 S 1/2 state have been determined as (9.78 ± 0.01) × 10 −2 , (3.30 ± 0.49) × 10 −4 , (5.47 ± 0.82) × 10 −3 , and (2.06 ± 0.30) × 10 −2 Mb at the ionizing laser wavelengths 1064, 700, 532, and 355 nm, respectively, that validate the presence of a Cooper minimum at ∼ =1.25 eV above the first ionization threshold. The number density has been determined as N 0 = 2 × 10 11 cm −3. The experimentally determined absolute values of the cross sections are in qualitative agreement with the theoretical predictions.
The photoionization cross-section and number density of the 3p 2 P 1/2,3/2 excited levels of sodi... more The photoionization cross-section and number density of the 3p 2 P 1/2,3/2 excited levels of sodium have been measured as a function of the laser energy using two-step laser excitation in conjunction with a thermionic diode working in the space charge limited mode. Employing the saturation technique, the crosssections for the 3p 2 P 1/2 and 3p 2 P 3/2 levels are determined as 2.16 (43) Mb and 3.74 (74) Mb respectively.
Journal of Chromatography & Separation Techniques, 2020
A method using dispersive solid-phase extraction (d-SPE) cleanup followed by QuEChERS with High P... more A method using dispersive solid-phase extraction (d-SPE) cleanup followed by QuEChERS with High Performance Liquid Chromatography (HPLC) has been established for determination of Neonicotinoid pesticide residues in various vegetables including brinjal, salad leaves, coriander, cabbage and lady finger. Based on an assessment of the HPLC characteristics, validation experiments are conducted for three Neonicotinoid pesticides i.e. Nitenpyram, Imidacloprid and Acetamiprid. In acidified acetonitrile analytical extraction is done with NaCl and MgSO4 followed by activated neutral carbon. The method show good linearity (R2 ≥ 0.999) and relative standard deviation (RSD ≤ 3.36%). Average recoveries of three insecticides are in the range of 55% to 82% at spiking levels of 275.68 to 409.3 mg.Kg-1. LOD and LOQ of three Neonicotinoid pesticides are in the range of 2.658 - 3.761 mg.Kg-1 and 8.056 - 11.4 mg.Kg-1. This QuEChERS determination method by HPLC is precise, simple, sensitive, accurate, ea...
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