The quality monitoring of paracetamol medicament using a noninvasive microwave sensor.

Environmental conditions, including temperature, humidity, and light, can impact the quality of drugs. Microwave-based approaches offer a fast and cost-effective way to detect quality variations, providing an alternative to traditional techniques in the pharmaceutical and cosmetic industries. This article proposes the use of a microwave sensor for monitoring the quality of pharmaceutical drugs at distinct temperature levels. A small planar sensor based on three hexagonal split ring resonators (TH-SRR) is fabricated. The design is manufactured on an FR-4 dielectric substrate. The sensor is tested on a 1000 mg paracetamol tablet, at temperatures ranging from 40 to 80 [Formula: see text]C. The Variation in the permittivity that characterizes product degradation is translated into a shift in the frequency of the scattering matrix elements. To validate the microwave approach, drug quality is examined with the laser-induced breakdown spectroscopy (LIBS) technique, an optical emission laser used for both qualitative and quantitative investigations of elements contained in a sample. The existing elements are classified using the National Institute of Standards and Technology (NIST) database and categorized according to their spectral line wavelengths. The experiments show the presence of optimal wavelength values for carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) at 247.92 nm, 656.49 nm, 244.23 nm, and 777.48 nm, respectively. The microwave experimental results show a shift frequency of approximately 1 MHz on average when the tablet is heated at 80 [Formula: see text]C for 15 min. Meanwhile, the LIBS measurement shows a remarkable shift in terms of intensity of approximately 8884 and 812 for carbon and hydrogen, respectively. Understanding how paracetamol dries under high temperatures and improving the process settings of the microwave sensor are investigated and assessed in this work.

Design and development of a highly efficient reusable zeolite impregnated ZnAl2O4 catalyst for biodiesel production.

As the demand for sustainable energy sources expands, the production of biodiesel has attracted great attention. The development of effective and ecologically friendly biodiesel catalysts has become an urgent need. In this context, the goal of this study is to develop a composite solid catalyst with enhanced efficiency, reusability, and reduced environmental impact. For that, eco-friendly, and reusable composite solid catalysts have been designed by impregnating different amounts of zinc aluminate into a zeolite matrix (ZnAl2O4@Zeolite). Structural and morphological characterizations confirmed the successful impregnation of zinc aluminate into the zeolite porous structure. Catalytic experiments revealed that the catalyst containing 15 wt% ZnAl2O4 showed the highest conversion activity of fatty acid methyl esters (FAME) of 99% under optimized reaction conditions, including 8 wt% catalyst, a molar ratio of 10:1 methanol to oil, a temperature of 100 °C, and 3 h of reaction time. The developed catalyst demonstrated high thermal and chemical stability, maintaining good catalytic activity even after five cycles. Furthermore, the produced biodiesel quality assessment has demonstrated good properties in compliance with the criteria of the American Society for Testing and Materials ASTM-D6751 and the European Standard EN14214. Overall, the findings of this study could have a significant impact on the commercial production of biodiesel by offering an efficient and environmentally friendly reusable catalyst, ultimately reducing the cost of biodiesel production.

Synthesis, Experimental, and Theoretical Study of Co3-x Ni x O4 Mixed Oxides: Potential Candidates for Hydrogen Production via Solar Redox Cycles.

Recently, green hydrogen production via solar thermochemical water splitting (STWS) as a clean and sustainable method is becoming a subject of interest to many researchers. Great efforts are being made to develop materials for STWS with suitable operating conditions, low cost, and good cycling stability. In this context, the study of mixed cobalt and nickel oxides with the general formula Co3-x Ni x O4 (0 ≤ x ≤ 1) was carried out, where four mixed metal oxides Co2.75Ni0.25O4, Co2.5Ni0.5O4, Co2.25Ni0.75O4, and Co2NiO4 have been successfully synthesized through the sol-gel method modified Pechini route. The structural investigation demonstrated that pure spinel structures were obtained for 0 ≤ x ≤ 0.75. A deep study was carried out with the main goal of finding the best phase that provides low redox temperature. Interesting reduction temperatures for all the compositions have been found, and the lowest values of 675 and 710 °C have been reported for Co2.25Ni0.75O4 and Co2.5Ni0.5O4, respectively. The thermal cycling results of this latest material using TGA measurement have proven attractive cycling stability of which the complete reoxidation of the samples was achieved. In addition, thermodynamic analysis of a reduction step was performed and good agreement of the theoretical reduction temperature of Co2.25Ni0.75O4 with the experimental one has been found.

Insight into the structure-elastic property relationship of calcium silicate glasses: a multi-length scale approach.

Based on a combination of molecular dynamics simulations, and Raman and Brillouin light scattering spectroscopies, we investigate the structure and elastic properties relationship in an archetypical calcium silicate glass system. From molecular dynamics and Raman spectroscopy, we show that the atomic structure at the short and intermediate length scales is made up of long polymerized silicate chains, which adjusts itself by closing the Si-O-Si angles and leaving more space to [CaO]n edge shared polyhedra to strengthen the glass. Using Brillouin spectroscopy, we observe an increase of elastic constants of the glass with the calcium content, as the cohesion of the glass structure is enhanced through an increase of the binding between the cross-linked calcium-silicate frameworks. This result, albeit being simple in its nature, illustrates for the first time the implication of the calcium framework in the elastic behavior of the glass and will contribute substantially to the understanding of the composition-structure-property relationships in multi-component industrial glasses.

Compact Thermal Actuation by Water and Flexible Hydrophobic Nanopore.

Efficient and compact energy conversion is at the heart of the sustainable development of humanity. In this work it is demonstrated that hydrophobic flexible nanoporous materials can be used for thermal-to-mechanical energy conversion when coupled with water. In particular, a reversible nonhysteretic wetting-drying (contraction-expansion) cycle provoked by periodic temperature fluctuations was realized for water and a superhydrophobic nanoporous Cu2(tebpz) MOF (tebpz = 3,3',5,5'-tetraethyl-4,4'-bipyrazolate). A thermal-to-mechanical conversion efficiency of ∼30% was directly recorded by high-precision PVT-calorimetry, while the operational cycle was confirmed by in operando neutron scattering. The obtained results provide an alternative approach for compact energy conversion exploiting solid-liquid interfacial energy in nanoscopic flexible heterogeneous systems.

The Effect of Surface Entropy on the Heat of Non-Wetting Liquid Intrusion into Nanopores.

On-demand access to renewable and environmentally friendly energy sources is critical to address current and future energy needs. To achieve this, the development of new mechanisms of efficient thermal energy storage (TES) is important to improve the overall energy storage capacity. Demonstrated here is the ideal concept that the thermal effect of developing a solid-liquid interface between a non-wetting liquid and hydrophobic nanoporous material can store heat to supplement current TES technologies. The fundamental macroscopic property of a liquid's surface entropy and its relationship to its solid surface are one of the keys to predict the magnitude of the thermal effect by the development of the liquid-solid interface in a nanoscale environment-driven through applied pressure. Demonstrated here is this correlation of these properties with the direct measurement of the thermal effect of non-wetting liquids intruding into hydrophobic nanoporous materials. It is shown that the model can resonably predict the heat of intrusion into rigid mesoporous silica and some microporous zeolite when the temperature dependence of the contact angle is applied. Conversely, intrusion into flexible microporous metal-organic frameworks requires further improvement. The reported results with further development have the potential to lead to the development of a new supplementary method and mechanim for TES.

Tunable Redox Temperature of a Co3-xMnxO4 (0 ≤ x ≤ 3) Continuous Solid Solution for Thermochemical Energy Storage.

Heat-storage technologies are well suited to improve the energy efficiency of power plants and the recovery of process heat. A good option for high storage capacities, especially at high temperatures, is storing thermal energy by reversible thermochemical reactions. In particular, the Co3O4/CoO and Mn2O3/Mn3O4 redox-active couples are known to be very promising systems. However, cost and toxicity issues for Co oxides and the sluggish oxidation rate (leading to poor reversibility) for Mn oxide hinder the applicability of these single oxides. Considering, instead, binary Co-Mn oxide mixtures could mitigate the above-mentioned shortcomings. To examine this in detail, here, we combine first-principles atomistic calculations and experiments to provide a structural characterization and observe the thermal behavior of novel mixed-metal oxides based on cobalt/manganese metals with the spinel structure Co3-xMnxO4. We show that novel Co3-xMnxO4 phases indeed enhance the enthalpy of the redox reactions, facilitate reversibility, and mitigate energy losses when compared to pure metal oxide systems. Our results expand therefore the limited list of currently available thermochemical heat-storage materials and pave the way toward the implementation of tunable redox temperature materials for practical applications.

Effect of Flexibility and Nanotriboelectrification on the Dynamic Reversibility of Water Intrusion into Nanopores: Pressure-Transmitting Fluid with Frequency-Dependent Dissipation Capability.

In this article, the effect of a porous material's flexibility on the dynamic reversibility of a nonwetting liquid intrusion was explored experimentally. For this purpose, high-pressure water intrusion together with high-pressure in situ small-angle neutron scattering were applied for superhydrophobic grafted silica and two metal-organic frameworks (MOFs) with different flexibility [ZIF-8 and Cu2(tebpz) (tebpz = 3,3',5,5'tetraethyl-4,4'-bipyrazolate)]. These results established the relation between the pressurization rate, water intrusion-extrusion hysteresis, and porous materials' flexibility. It was demonstrated that the dynamic hysteresis of water intrusion into superhydrophobic nanopores can be controlled by the flexibility of a porous material. This opens a new area of applications for flexible MOFs, namely, a smart pressure-transmitting fluid, capable of dissipating undesired vibrations depending on their frequency. Finally, nanotriboelectric experiments were conducted and the results showed that a porous material's topology is important for electricity generation while not affecting the dynamic hysteresis at any speed.

Pore Morphology Determines Spontaneous Liquid Extrusion from Nanopores.

In this contribution we explore by means of experiments, theory, and molecular dynamics the effect of pore morphology on the spontaneous extrusion of nonwetting liquids from nanopores. Understanding and controlling this phenomenon is central for manipulating nanoconfined liquids, e. g., in nanofluidic applications, drug delivery, and oil extraction. Qualitatively different extrusion behaviors were observed in high-pressure water intrusion-extrusion experiments on porous materials with similar nominal diameter and hydrophobicity: macroscopic capillary models and molecular dynamics simulations revealed that the very presence or absence of extrusion is connected to the internal morphology of the pores and, in particular, to the presence of small-scale roughness or pore interconnections. Additional experiments with mercury confirmed that this mechanism is generic for nonwetting liquids and is rooted in the pore topology. The present results suggest a rational way to engineer heterogeneous systems for energy and nanofluidic applications in which the extrusion behavior can be controlled via the pore morphology.

A Highly Stable Nonhysteretic {Cu2 (tebpz) MOF+water} Molecular Spring.

A molecular spring formed by a hydrophobic metal-organic framework Cu2 (tebpz) (tebpz=3,3',5,5'-tetraethyl-4,4'-bipyrazolate) and water is presented. This nanoporous heterogeneous lyophobic system (HLS) has exceptional properties compared to numerous reported systems of such type in terms of stability, efficiency, and operating pressure. Mechanical and thermal energetic characteristics as well as stability of the system are discussed and compared in detail with those of other previously reported HLS.