Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects

The paper deals with a formation of artificial rock (clinker). Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker’s chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld). Scanning electron microscopy (SEM) was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S) and belite (C2S)), excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper

Electrical properties and Raman studies of phase transitions in ferroelectric [N(CH 3 ) 4 ] 2 CoCl 2 Br 2

International audienc

Electrical properties and Raman studies of phase transitions in ferroelectric [N(CH 3 ) 4 ] 2 CoCl 2 Br 2

International audienc

Raman studies of phase transitions in ferroelectric [C 2 H 5 NH 3 ] 2 ZnCl 4

International audienc

Raman studies of phase transitions in ferroelectric [C 2 H 5 NH 3 ] 2 ZnCl 4

International audienc

Effective Removal of Methyl Orange Dyes Using an Adsorbent Prepared from Porous Starch Aerogel and Organoclay

Intending to provide efficient and compact wastewater remediation, the present work is exploiting and introducing a novel composite prepared from porous starch aerogel (PSA) and organically modified Ca-montmorillonite (OMMT) for the removal of dyes from aqueous samples. First, potato starch components were used as a hydrolysis precursor to obtain PSA. The organoclay samples were prepared by co-intercalation of octadecylamine (ODA) into Ca-MMT using a low-temperature melting procedure. Composites with different starch-to-organoclay ratios of 10:1, 1:1, and 1:10 were then prepared by a blending process in distilled water and used for methyl orange (MO) uptake. The removal of methyl orange dyes increased with the amount of organoclay in the PSA matrix. Characterization revealed that organoclay synergy improved the PSA surface chemistry, while an important improvement in textural properties and thermal stability was also observed. The composite’s efficiency was demonstrated by high removal capabilities towards MO in most experimental runs, with a maximum adsorption capacity beyond 344.7 mg/g. The fitting result showed that MO adsorption follows a monolayer adsorption model, and chemisorption was the rate-controlling step. Nonetheless, this study proved the great potential of PSA/OMMT in dyeing wastewater treatment. Furthermore, starch modification is proven as an effective approach to enhancing the performance of starch-derived adsorbents

Viral and Bacterial Zoonotic Agents in Dromedary Camels from Southern Tunisia: A Seroprevalence Study

The rapid spread of SARS-CoV-2 clearly demonstrated the potential of zoonotic diseases to cause severe harm to public health. Having limited access to medical care combined with severe underreporting and a lack of active surveillance, Africa carries a high burden of neglected zoonotic diseases. Therefore, the epidemiological monitoring of pathogen circulation is essential. Recently, we found extensive Middle East respiratory syndrome coronavirus (MERS-CoV) prevalence in free-roaming dromedary camels from southern Tunisia. In this study, we aimed to investigate the seroprevalence, and thus the risk posed to public health, of two additional viral and two bacterial pathogens in Tunisian dromedaries: Rift Valley fever virus (RVFV), foot-and-mouth disease virus (FMDV), Coxiella burnetii and Brucella spp. via ELISA. With 73.6% seropositivity, most animals had previously been exposed to the causative agent of Q fever, C. burnetii. Additionally, 7.4% and 1.0% of the dromedaries had antibodies against Brucella and RVFV, respectively, while no evidence was found for the occurrence of FMDV. Our studies revealed considerable immunological evidence of various pathogens within Tunisian dromedary camels. Since these animals have intense contact with humans, they pose a high risk of transmitting serious zoonotic diseases during active infection. The identification of appropriate countermeasures is therefore highly desirable

Prevalence of Middle East Respiratory Syndrome Coronavirus in Dromedary Camels, Tunisia

Free-roaming camels, especially those crossing national borders, pose a high risk for spreading Middle East respiratory syndrome coronavirus (MERS-CoV). To prevent outbreaks, active surveillance is necessary. We found that a high percentage of dromedaries in Tunisia are MERS-CoV seropositive (80.4%) or actively infected (19.8%), indicating extensive MERS-CoV circulation in Northern Africa

Activated Porous Carbon Supported Pd and ZnO Nanocatalysts for Trace Sensing of Carbaryl Pesticide in Water and Food Products

Nanomaterials-based sensors are direly needed as a monitoring tool for the credible and accurate determination of pesticides in water and food samples. Herein, electrocatalysts of Pd and ZnO nanoparticles (NPs) supported on a highly porous framework of activated carbons (APC) were prepared for efficient electrochemical detection of carbaryl trace. First, activated potato starch was used as a pyrolysis precursor to obtain APC. The ZnO NPs were then grown on the APC substrate by sol–gel/impregnation methods, followed by in situ reduction of Pd NPs. The as-prepared nanocomposite of Pd/ZnO/APC was morphologically and structurally confirmed by systematic physicochemical analysis. As-fabricated Pd/ZnO/APC nanocomposites were later evaluated for the efficient sensing of carbaryl by modifying a glassy carbon electrode (GCE). Cyclic voltammetry analysis revealed the unique oxidative sensing ability of Pd/ZnO/APC for carbaryl at 0.62 V with a low ΔE (80 mV) as compared to that of bare GCE. Based on the notable sensing ability of Pd/ZnO/APC, a reliable and sensitive electrochemical method was anticipated for the quantitative and qualitative determination of carbaryl. Meanwhile, experimental parameters, including electrolyte environment and electrodeposition conditions, were carefully refined to achieve maximum sensitivity and low detection limits. Under optimized conditions, the electrochemical sensing of carbaryl was realized with an LOD of 0.01 μM and a detection range of 0.01–5.0 μM. Moreover, the sensing electrode exhibited excellent selectivity, good reproducibility, and long-term stability, which qualified the sensor to analyze real samples, where it also showed satisfactory performance