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In this study, an extension on the previously reported status of the COllaborative Carbon Column Observing Network's (COCCON) calibration procedures incorporating refined methods is presented. COCCON is a global network of portable Bruker EM27/SUN FTIR spectrometers for deriving column-averaged atmospheric abundances of greenhouse gases. The original laboratory open-path lamp measurements for deriving the instrumental line shape (ILS) of the spectrometer from water vapour lines have been refined and extended to the secondary detector channel incorporated in the EM27/SUN spectrometer for detection of carbon monoxide (CO). The refinements encompass improved spectroscopic line lists for the relevant water lines and a revision of the laboratory pressure measurements used for the analysis of the spectra. The new results are found to be in good agreement with those reported by Frey et al. (2019) and discussed in detail. In addition, a new calibration cell for ILS measurements was designed, constructed and put into service. Spectrometers calibrated since January 2020 were tested using both methods for ILS characterization, open-path (OP) and cell measurements. We demonstrate that both methods can detect the small variations in ILS characteristics between different spectrometers, but the results of the cell method indicate a systematic bias of the OP method. Finally, a revision and extension of the COCCON network instrument-to-instrument calibration factors for XCO2, XCO and XCH4 is presented, incorporating 47 new spectrometers (of 83 in total by now). This calibration is based on the reference EM27/SUN spectrometer operated by the Karlsruhe Institute of Technology (KIT) and spectra collected by the collocated TCCON station Karlsruhe. Variations in the instrumental characteristics of the reference EM27/SUN from 2014 to 2017 were detected, probably arising from realignment and the dual-channel upgrade performed in early 2018. These variations are considered in the evaluation of the instrument-specific calibration factors in order to keep all tabulated calibration results consistent.

The aim of this paper is to study the impacts of overshooting convection at a local scale on the water distribution in the tropical UTLS. Overshooting convection is assumed to be one of the processes controlling the entry of water vapour mixing ratio in the stratosphere by injecting ice crystals above the tropopause which later sublimate and hydrate the lower stratosphere. For this purpose, we quantify the individual impact of two cases of overshooting convection in Africa observed during SCOUT-AMMA: the case of 4 August 2006 over Southern Chad which is likely to have influenced the water vapour measurements by micro-SDLA and FLASH-B from Niamey on 5 August, and the case of a mesoscale convective system over Aïr on 5 August 2006. We make use of high resolution (down to 1 km horizontally) nested grid simulations with the three-dimensional regional atmospheric model BRAMS (Brazilian Regional Atmospheric Modelling System). In both cases, BRAMS succeeds in simulating the main features of the convective activity, as well as overshooting convection, though the exact position and time of the overshoots indicated by MSG brightness temperature difference is not fully reproduced (typically 1° displacement in latitude compared with the overshoots indicated by brightness temperature difference from satellite observations for both cases, and several hours shift for the Aïr case on 5 August 2006). Total water budgets associated with these two events show a significant injection of ice particles above the tropopause with maximum values of about 3.7 ton s−1 for the Chad case (4 August) and 1.4 ton s−1 for the Aïr case (5 August), and a total upward cross tropopause transport of about 3300 ton h−1 for the Chad case and 2400 ton h−1 for the Aïr case in the third domain of simulation. The order of magnitude of these modelled fluxes is lower but comparable with similar studies in other tropical areas based on models. These two estimations exhibit significant differences and highlight variability among the cases of the impact of overshooting convection in hydrating the lower stratosphere. We show that the regional enhancement of water above the tropopause is between 0.21 to 0.67 ppmv between 380 and 400 K, generally in the range of other model estimations. The amount of water which remains in the stratosphere after the overshoot is estimated for both cases. A range of 330 to 507 tons is found for the Chad case and an upper limit of 200 tons is found for the Aïr case. Finally we emphasize that the hydrated area in the LS by overshooting convection can be advected relatively far away from the overshoot initial location, with locally mixing ratios of more than 3 ppmv higher than the background level, which is compatible with the balloon borne measurements performed above Niamey in the same air mass, 30 h after the overshoot.

The title compound, C16H11N2OF, is a member of the azo dye family. The dihedral angle subtended by the benzene ring and the naphthalene ring system measures 18.75 (7)°, indicating that the compound is not perfectly planar. An intramolecular N—H...O hydrogen bond occurs between the imino and carbonyl groups. In the crystal, the molecules are linked into inversion dimers by C—H...O interactions. Aromatic π–π stacking between the naphthalene ring systems lead to the formation of chains along [001]. A Hirshfeld surface analysis was undertaken to investigate and quantify the intermolecular interactions. In addition, energy frameworks were used to examine the cooperative effect of these intermolecular interactions across the crystal, showing dispersion energy to be the most influential factor in the crystal organization of the compound.

Typhoid fever is a significant public health concern in many parts of the world, particularly in developing countries with poor sanitation and hygiene conditions. In July 2016, an outbreak of typhoid fever occurred in Ghannouche, located in the south of Tunisia. This paper reports the results of a field investigation undertaken to identify possible transmission pathways and risk factors in order to propose control and preventive measures. A retrospective cohort study including a passive and active case finding, as well as an environmental and bacteriological investigation was conducted from July to September 2016. A case was defined as a person residing or having stayed in Ghannouche and having presented from the beginning of June clinical signs suggestive of typhoid fever, with, for a confirmed case, laboratory isolation of S.Tyhi, and for a probable case, an epidemiological link with a confirmed case. Attack rates were determined, and risk ratios were estimated with respect to exposures. Unadjusted and adjusted odds ratios were estimated using binary logistic regression. Among the 628 subjects investigated, 102 cases of typhoid fever were identified (74 confirmed and 28 probable) with an overall attack rate of 16.24%. Over 56% of cases were male and those under 10 years old were most affected (38.2%% of cases) with a median age of 12 years (interquartile range 5 to 25 years). The main clinical signs were fever (95%) and diarrhea (57%). Young age (adjusted OR = 0.95 and 95% CI = 0.93–0.97), low level of education (adjusted OR = 4.76 and 95% CI = 1.34–16.81), and the habitat type Arab or rudimentary house (adjusted OR = 4.93 and 95% CI = 2.61–8.27) were the socio-demographic factors independently associated with typhoid fever. Typhoid fever was found to be associated with drinking softened water (adjusted OR = 2.64 and 95% CI = 1.16–4.82), eating raw fruit and vegetables from family gardens (adjusted OR = 6.13 and 95% CI = 3.66–11.06), and using uncontrolled waste disposal (adjusted OR = 3.52 and 95% CI = 2.03–6.94). A total of 110 drinking water samples were analyzed; out of the 38 samples of softened water, 12 were non-compliant and 5 were positive for Salmonella. The screening activity identified two asymptomatic carriers, one of whom was a softened water seller. We concluded that drinking softened water from informal or unauthorized sale units, consuming fruit and vegetables from family gardens, uncontrolled dumping of household waste, and poor socio-economic conditions increase the risk of typhoid fever in this region. Many recommendations were implemented to stop this outbreak and to prevent further episodes.

Rockfalls can cause loss of life and material damage. In Northern Morocco, rockfalls and rock avalanche-deposits are frequent, especially in the Dorsale Calcaire morpho-structural unit, which is mostly formed by Jurassic limestone and dolostone formations. In this study, we focus exclusively on its northern segment, conventionally known as “the Haouz subunit”. First, a rockfall inventory was conducted. Then, two datasets were prepared: one covering exclusively the source area and the other representing the entirety of the mass movements (source + propagation area). Two algorithms were then used to build rockfall susceptibility models (RSMs). The first one (Logistic Regression: LR) yielded the most unreliable results, where the RSM derived from the source area dataset significantly outperformed the one based on the entirety of the rockfall affected area, despite the lack of significant visual differences between both models. However, the RSMs produced using Artificial Neural Networks (ANNs) were more or less similar in terms of accuracy, despite the source area model being more conservative. This result is unexpected given the fact that previous studies proved the robustness of the LR algorithm and the sensitivity of ANN models. However, we believe that the non-linear correlation between the spatial distribution of the rockfall propagation area and that of the conditioning factors used to compute the models explains why modeling rockfalls in particular differs from other types of landslides.

Focusing on the Oued Laou watershed, this study presents an innovative approach to simulate daily precipitation over a 35-year period in northern Morocco. We used the SARIMAX (AutoRegressive Seasonal Moving Average with Exogenous Variables) model and combined its potential with the Python programming language to achieve these Predictions. The SARIMAX model is an advanced time series analysis tool that integrates exogenous, autoregressive, seasonal and integrated variables. This model is capable of accurately predicting daily, monthly and annual precipitation averages for the study period. The climate projections obtained suggest that precipitation in the study area will decrease and it’s accompanied by increasing temperatures. This could have significant impacts on ecosystems, water resources and the agricultural sector. This study provides essential information for a better understanding of the particular climatic trends in northern Morocco. It provides a sound basis for making informed decisions on the sustainable management of natural resources. This information will be essential in anticipating and mitigating the effects of climate change, particularly with regard to precipitation and its potential impacts it could have on the environment and agriculture.

This case study focuses on the area of El Plateado near the city of Loja, Ecuador, where landslides with a high impact on infrastructures require monitoring and control. The main objectives of this work are the characterization of the landslide and the monitoring of its kinematics. Four flights were conducted using a remotely piloted aerial vehicle (RPAS) to capture aerial images that were processed with SfM techniques to generate digital elevation models (DEMs) and orthoimages of high resolution (0.05 m) and sufficient accuracy (below 0.05 m) for subsequent analyses. Thus, the DEM of differences (DoD) and profiles are obtained, but a morphometric analysis is conducted to quantitatively characterize the landslide’s elements and study its evolution. Parameters such as slope, aspect, topographic position index (TPI), terrain roughness index (TRI), and topographic wetness index (TWI) are analyzed. The results show a higher slope and roughness for scarps compared to stable areas and other elements. From TPI, slope break lines have been extracted, which allow the identification of landslide features such as scarps and toe tip. The landslide shows important changes in the landslide body surface, the retraction of the main scarp, and advances of the foot. A general decrease in average slope and TRI and an increase in TWI are also observed due to the landslide evolution and stabilization. The presence of fissures and the infiltration of rainfall water in the unsaturated soil layers, which consist of high-plasticity clays and silts, contribute to the instability. Thus, the study provides insights into the measurement accuracy, identification and characterization of landslide elements, morphometric analysis, landslide evolution, and the relationship with geotechnical factors that contribute to a better understanding of landslides. A higher frequency of the RPAS surveys and quality of geotechnical and meteorological data are required to improve the instability analysis together with a major automation of the GIS procedures.

A novel electrochemically sensitive sensor has been developed based on Hydrochar derived from Phoenix dactylifera was prepared for the detection of Methylene Blue (MB). These hydrochar (HC) have been used for the modification of the glassy carbon electrode (GCE). This electrode was characterized by scanning electron microscopy (SEM). The electrochemical properties of MB in the modified electrode (HC/GCE) were studied by square-wave voltammetry (SWV) and cyclic voltammetry (CV) under optimized conditions. Owing to a synergistic effect, the HC/GCE exhibited an obvious electrocatalytic effect on positively charged MB. The influence of experimental variables (accumulation time, supporting electrolyte, pH) was studied. Under optimized conditions, the constructed sensor illustrated a linear voltammetric curve for the MB in the concentration interval from 10-4M to 10-10M, with a detection limit of 0.2nM. A study of the effect of interference on sensor functionality was carried out, as well as an analysis of MB recovery in real wastewater samples. The modified electrode offers numerous advantages, including easy preparation, low detection limit, high sensitivity, good repeatability, short response time and an effective detection platform for MB in wastewater. [ABSTRACT FROM AUTHOR]

The title compound, C9H7NO2S crystallizes with two independent molecules (A and B) in the asymmetric unit with Z = 8. Both molecules are almost planar with a dihedral angle between the isoxazole and thiophen rings of 3.67 (2)° in molecule A and 10.00 (1) ° in molecule B. The packing of molecules A and B is of an ABAB... type along the b-axis direction, the configuration about the C=C bond is Z. In the crystal, the presence of C—H...O, C—H... N and π–π interactions [centroid–centroid distances of 3.701 (2) and 3.766 (2) Å] link the molecules into a three-dimensional architecture. An analysis of Hirshfeld surfaces shows the importance of C—H...O and C—H...N hydrogen bonds in the packing mechanism of the crystalline structure.

The title compounds, 2,6-diiodo-4-nitrotoluene (DINT, C7H5I2NO2) and 2,4,6-tribromotoluene (TBT, C7H5Br3,), are trisubstituted toluene molecules. Both molecules are planar, only the H atoms of the methyl group, and the nitro group in DINT, deviate significantly from the plane of the benzene ring. In the crystals of both compounds, molecules stack in columns up the shortest crystallographic axis, viz. the a axis in DINT and the b axis in TBT. In the crystal of DINT, molecules are linked via short N—O...I contacts, forming chains along [100]. In TBT, molecules are linked by C—H...Br hydrogen bonds, forming chains along [010]. Hirshfeld surface analysis was used to explore the intermolecular contacts in the crystals of both DINT and TBT.

Fluorine is a very common element in the Earth’s crust and is present in the air, food, and in natural waters. It never meets in the free state in nature due to its high reactivity, and it comes in the form of fluorides. Depending on the concentration of fluorine absorbed, it may be beneficial or harmful to human health. Similar to any trace element, fluoride ion is beneficial for the human body at low levels, but as soon as its concentration becomes too high, it is toxic, inducing dental and bone fluorosis. The lowering of fluoride concentrations that exceed the recommended standards in drinking water is practiced in various ways around the world. The adsorption process has been classified as one of the most efficient methods for the removal of fluoride from water as it is environmentally friendly, easy to operate, and cost-effective. The present study deals with fluoride ion adsorption on modified zeolite. There are several influential parameters, such as zeolite particle size, stirring rate, solution pH, initial concentration of fluoride, contact time, and solution temperature. The maximum removal efficiency of the modified zeolite adsorbent was 94% at 5 mg/L fluoride initial concentration, pH 6.3, and 0.5 g modified zeolite mass. The adsorption rate increases accordingly with increases in the stirring rate and pH value and decreases when the initial fluoride concentration is increased. The evaluation was enhanced by the study of adsorption isotherms using the Langmuir and Freundlich models. The Langmuir isotherm corresponds with the experimental results of the fluoride ions adsorption with a correlation value of 0.994. The kinetic analysis results of the fluoride ions adsorption on modified zeolite allowed us to demonstrate that the process primarily follows a pseudo-second-order and then, in the next step, follows a pseudo-first-order model. Thermodynamic parameters were calculated, and the ΔG° value is found to be in the range of −0.266 kJ/mol up to 1.613 kJ/mol amidst an increase in temperature from 298.2 to 331.7 K. The negative values of the free enthalpy ΔG° mean that the adsorption of fluoride ions on the modified zeolite is spontaneous, and the positive value of the enthalpy ∆H° shows that the adsorption process is endothermic. The ∆S° values of entropy indicate the fluoride adsorption randomness characteristics at the zeolite-solution interface.

Microbial fuel cells (MFCs) provide new opportunities for the sustainable production of energy, converting organic matter into electricity through microorganisms. Moreover, MFCs play an important role in remediation of environmental pollutants from wastewater with power generation. This work focuses on the evaluation of ferroelectric perovskite materials as a new class of non-precious photocatalysts for MFC cathode construction. Nanoparticles of BaTiO3 (BT) were prepared and tested in a microbial fuel cell (MFC) as photocathode catalytic components. The catalyst phases were synthesized, identified and characterized by XRD, SEM, UV–Vis absorption spectroscopy, P-E hysteresis and dielectric measurements. The maximum absorption of BT nanoparticles was recorded at 285 nm and the energy gap (Eg) was estimated to be 3.77 eV. Photocatalytic performance of cathodes coated with BaTiO3 was measured in a dark environment and then in the presence of a UV–visible (UV–Vis) light source, using a mixture of dairy industry and domestic wastewater as a feedstock for the MFCs. The performance of the BT cathodic component is strongly dependent on the presence of UV–Vis irradiation. The BT-based cathode functioning under UV–visible light improves the maximum power densities and the open circuit voltage (OCV) of the MFC system. The values increased from 64 mW m−2 to 498 mW m−2 and from 280 mV to 387 mV, respectively, showing that the presence of light effectively improved the photocatalytic activity of this ceramic. Furthermore, the MFCs operating under optimal conditions were able to reduce the chemical oxygen demand load in wastewater by 90% (initial COD = 2500 mg L−1).

Unilateral right-sided varicocele is a rare and warning condition that should hint at a serious retroperitoneal disease such as renal cell neoplasm. Furthermore, its thrombosis is such an unusual entity that only a few cases have been described. We review the literature and report, to our knowledge, the second case of acute scrotal pain caused by unilateral right-sided varicocele thrombosis complicating an ipsilateral epididymo-orchitis, with no underlying coagulopathy or abdominal neoplasm, to illustrate the clinical, morphologic and therapeutic features of this entity.

A group theoretic analysis of the compressible Navier-Stokes equations of an ideal gas is carried out. The 12-dimensional Lie symmetry group is computed. The commutation table and the Levi decomposition of its Lie algebra are presented. The equations are reduced and self-similar one-, two- and three-dimensional solutions are computed. [ABSTRACT FROM AUTHOR]

In this work, we propose a generalization of the kriging interpolation procedure from Euclidean spaces to Grassmann manifolds in the context of model order reduction based on Proper Orthogonal Decomposition (POD). This generalization relies on the introduction of a so-called geodesic experimental semi-variogram which depends solely on the repartition of the interpolation values on the manifold. Here, the interpolation values are the subspaces engendered by the bases obtained by POD of the solutions associated with sampling parameters. Three CFD applications are presented: (i) the two-dimensional flow pas a cylinder in a channel, (ii) the two-dimensional Burger equation and (iii) the one dimensional wave equation. For each application, the proposed method to compute the interpolated basis associated with a given parameter proves faster than state-of-the-art method while achieving the same accuracy. [ABSTRACT FROM AUTHOR]

Abstract Background Drug resistant tuberculosis is a major public health problem in Morocco and worldwide. Treatment outcome of drug resistant tuberculosis is poor and requires a long period of treatment with many toxic and expensive antituberculosis drugs. The aim of this study is to evaluate treatment outcomes of drug resistant tuberculosis and to determine predictors of poor treatment outcomes in a large region of Morocco. Methods It is a multi-centric observational cohort study conducted from January 01, 2014 to January 01, 2016. A questionnaire was established to collect data from clinical charts of patients with confirmed resistant TB. The study was carried out in all the 11 centers located in the Rabat-Salé-Kénitra region of Morocco where drug resistant tuberculosis is treated. Treatment outcomes were reported and the definitions and classifications of these outcomes were defined according to the WHO guidelines. Univariate and multivariate logistic regression were conducted to determine factors associated with poor drug resistant tuberculosis treatment outcomes in Morocco. Results In our study, 101 patients were treated for drug resistant tuberculosis between January 01, 2014 and January 01, 2016. Patients’ age ranged from 9.5 to70 years; 72patients (71.3%) were male and 80 patients (79.2%) were living in urban areas. Thirty two patients were smokers, 74 patients had multidrug-resistant tuberculosis, 25 patients had rifampicin resistance and 2 patients had isoniazid resistance. Treatment outcomes of tuberculosis patients were as follows: 45 patients were cured (44.5%), 9 completed treatment (8.9%), 5 patients died before completing the treatment, 35 patients were lost to follow up (34.6%) and 7 patients had treatment failure. In the multivariate analysis, being a smoker is an independent risk factor for poor treatment outcomes, (p-value = 0.015, OR = 4.355, IC [1.327–14.292]). Conclusion Treatment success outcomes occurred in more than half of the cases, which is lower than the World Health Organization target of at least a 75% success rate. A significant number of patients abandoned their treatment before its completion. These dropouts are a serious public health hazard that needs to be addressed urgently.

Rockfall simulations constitute the first step toward hazard assessments and can guide future rockfall prevention efforts. In this work, we assess the impact of digital elevation model (DEM) resolution on the accuracy of numerical rockfall simulation outputs. For this purpose, we compared the simulation output obtained using 1 m, 2 m and 3 m resolution UAV-derived DEMs, to two other models based on coarser topographic data (a 5 m resolution DEM obtained through interpolating elevation contours and the Shuttle Radar Topographic Mission 30m DEM). To generate the validation data, we conducted field surveys in order to map the real trajectories of three boulders that were detached during a rockfall event that occurred on 1 December 2018. Our findings suggest that the use of low to medium-resolution DEMs translated into large errors in the shape of the simulated trajectories as well as the computed runout distances, which appeared to be exaggerated by such models. The geometry of the runout area and the targets of the potential rockfall events also appeared to be different from those mapped on the field. This hindered the efficiency of any prevention or correction measures. On the other hand, the 1m UAV-derived model produced more accurate results relative to the field data. Therefore, it is accurate enough for rockfall simulations and hazard research applications. Although such remote sensing techniques may require additional expenses, our results suggest that the enhanced accuracy of the models is worth the investment.

Abstract This article reviews some integrators particularly suitable for the numerical resolution of differential equations on a large time interval. Symplectic integrators are presented. Their stability on exponentially large time is shown through numerical examples. Next, Dirac integrators for constrained systems are exposed. An application on chaotic dynamics is presented. Lastly, for systems having no exploitable geometric structure, the Borel–Laplace integrator is presented. Numerical experiments on Hamiltonian and non-Hamiltonian systems are carried out, as well as on a partial differential equation.