The Emirates Mars Ultraviolet Spectrometer (EMUS) for the EMM Mission

The Emirates Mars Mission (EMM) Hope probe was launched on 20 July 2020 at 01:58 GST (Gulf Standard Time) and entered orbit around Mars on 9 Feb 2021 at 19:42 GST. The high-altitude orbit (19,970 km periapse, 42,650 km apoapse altitude, 25° inclination) with a 54.5 hour period enables a unique, synoptic, and nearly-continuous monitor of the Mars global climate. The Emirates Mars Ultraviolet Spectrometer (EMUS), one of three remote sensing instruments carried by Hope, is an imaging ultraviolet spectrograph, designed to investigate how conditions throughout the Mars atmosphere affect rates of atmospheric escape, and how key constituents in the exosphere behave temporally and spatially. EMUS will target two broad regions of the Mars upper atmosphere: 1) the thermosphere (100–200 km altitude), observing UV dayglow emissions from hydrogen (102.6, 121.6 nm), oxygen (130.4, 135.6 nm), and carbon monoxide (140–170 nm) and 2) the exosphere (above 200 km altitude), observing bound and escaping hydrogen (121.6 nm) and oxygen (130.4 nm).EMUS achieves high sensitivity across a wavelength range of 100–170 nm in a single optical channel by employing “area-division” or “split” coatings of silicon carbide (SiC) and aluminum magnesium fluoride (Al+MgF2) on each of its two optical elements. The EMUS detector consists of an open-face (windowless) microchannel plate (MCP) stack with a cesium iodide (CsI) photocathode and a photon-counting, cross-delay line (XDL) anode that enables spectral-spatial imaging. A single spherical telescope mirror with a 150 mm focal length provides a 10.75° field of view along two science entrance slits, selectable with a rotational mechanism. The high and low resolution (HR, LR) slits have angular widths of 0.18° and 0.25° and spectral widths of 1.3 nm and 1.8 nm, respectively. The spectrograph uses a Rowland circle design, with a toroidally-figured diffraction grating with a laminar groove profile and a ruling density of 936 gr mm−1 providing a reciprocal linear dispersion of 2.65 nm mm−1. The total instrument mass is 22.3 kg, and the orbit-average power is less than 15 W.

Estimating the Rate of Azithromycin Degradation Due to Increasing Temperature for Three Drug types by Spectrophotometer (UV) and Gas Chromatography-Mass Spectrometry (GC-MS)

Azithromycin is a board antibiotic that affects various gram-positive and negative bacteria, so azithromycin is used for the treatment different of bacterial infections, as well as used azithromycin as a prophylactics antibiotic after different surgery. Azithromycin is used for children and adults, so it is available in pharmacies in different dosage forms like capsules, tablets, powder for reconstituting for oral administration. The aims of the present research is to assess the azithromycin stability from different available dosage forms (bioequivalence study) against temperature in hot climate country (Saudi Arabi). Three samples in the form of three drugs in which Azithromycin acts as an active ingredient were prepared and exposed to heat. These drugs are Azithromycin® 250 mg, Az-1® 250 mg,andZirox® 250 mg. Three spectral techniques were used to study the change in concentration and chemical composition when the temperature is raised from 27Co to 60Co the spectrometers used are ultraviolet spectrometer and Gas Chromatography-Mass Spectrometry. The temperature of the three drugs was raised from 27Co to 60Co inside the water path. The ultraviolet spectrometer shows considerable degradation in Azithromycin concentration by raised the temperature from 27Co to 60Co, but the other two drugs are not affected appreciably by heating.The results obtained using the retention time technique of gas chromatography, show a change of the retention time to be (20.308- 20.396 -20.350) for Azithromycin®, Az-1®, and Zirox®scanned, respectively. This change may result from the difference in the matrix chemical composition of each drug. The mass spectrometry results show that rising temperature to 60Co district the chemical bond of the active ingredient to be decomposed to five compounds having M/Z (43-72-99-158-198), respectively.

An Improved Algorithm for Measuring Nitrate Concentrations in Seawater Based on Deep-Ultraviolet Spectrophotometry: A Case Study of the Aoshan Bay Seawater and Western Pacific Seawater

Nowadays, it is still a challenge for commercial nitrate sensors to meet the requirement of high accuracy in a complex water. Based on deep-ultraviolet spectral analysis and a regression algorithm, a different measuring method for obtaining the concentration of nitrate in seawater is proposed in this paper. The system consists of a deuterium lamp, an optical fiber splitter module, a reflection probe, temperature and salinity sensors, and a deep-ultraviolet spectrometer. The regression model based on weighted average kernel partial least squares (WA-KPLS) algorithm together with corrections for temperature and salinity (TSC) is established. After that, the seawater samples from Western Pacific and Aoshan Bay in Qingdao, China with the addition of various nitrate concentrations are studied to verify the reliability and accuracy of the method. The results show that the TSC-WA-KPLS algorithm shows the best results when compared against the multiple linear regression (MLR) and ISUS (in situ ultraviolet spectrophotometer) algorithms in the temperatures range of 4–25 °C, with RMSEP of 0.67 µmol/L for Aoshan Bay seawater and 1.08 µmol/L for Western Pacific seawater. The method proposed in this paper is suitable for measuring the nitrate concentration in seawater with higher accuracy, which could find application in the development of in-situ and real-time nitrate sensors.

Impacts of resonant magnetic perturbations on edge carbon transport and emission on EAST with EMC3-EIRENE modelling

The modelling of edge carbon transport and emission on EAST tokamak under resonant magnetic perturbation (RMP) fields has been conducted with the three-dimensional edge transport code EMC3-EIRENE. The measured vertical distribution of CVI emission by the extreme ultraviolet spectrometer system for the perturbed case shows a reduction in the CVI emission by 20 % compared to the equilibrium case. The chord-integrated CVI emission can be reconstructed by EMC3-EIRENE modelling, which presents an increase in the CVI emission with RMP fields. The discrepancy between experiments and simulations has been investigated by parameter study to examine the sensitivity of the simulation results on the edge plasma conditions and the impurity perpendicular transport. It is found that the variation of edge plasma conditions for the equilibrium case cannot resolve the discrepancy in the CVI emission between simulations and measurements. The simulations with enhanced impurity perpendicular transport coefficient allows a reasonable agreement with the measured reduction of CVI emission.