Experimental analysis of free-standing and substrate-constrained Ga-doped ZnO nanostructured thermoelectric films.

Developing thermoelectric films without substrates-free-standing films-eliminates substrate-induced effects on performance and meets the flexibility requirements of emerging wearable thermoelectric applications. This study investigates Gallium-doped Zinc Oxide (GZO), composed of abundant and non-toxic elements, to fabricate a substrate-free GZO film via 3D printing and compares its structural, chemical, and thermoelectric properties with those of a substrate-constrained GZO film produced through chemical deposition. Both films exhibited uniform crystal structures and phase purity; however, the substrate-constrained film displayed additional diffraction peaks, suggesting potential substrate interactions.

Meta-analysis of chemistry-based interdisciplinary informal research experience program for high school students.

Research-based learning models, particularly interdisciplinary programs, are crucial in promoting STEM skills and fostering positive attitudes among students. This study presents a meta-analysis evaluating the impact of a chemistry-based interdisciplinary research experience program on high school students in Qatar. Over ten cohorts from 2010 to 2020, 230 students participated in multidisciplinary, hands-on research experiences.

Polyolefin-Based Smart Self-Healing Composite Coatings Modified with Calcium Carbonate and Sodium Alginate.

Corrosion-related damage incurs significant capital costs in many industries. In this study, an anti-corrosive pigment was synthesized by modifying calcium carbonate with sodium alginate (SA), and smart self-healing coatings were synthesized by reinforcing the anti-corrosive pigments into a polyolefin matrix. Structural changes during the synthesis of the anti-corrosive pigment were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis.

Mechanical properties of human hepatic tissues to develop liver-mimicking phantoms for medical applications.

Using liver phantoms for mimicking human tissue in clinical training, disease diagnosis, and treatment planning is a common practice. The fabrication material of the liver phantom should exhibit mechanical properties similar to those of the real liver organ in the human body. This tissue-equivalent material is essential for qualitative and quantitative investigation of the liver mechanisms in producing nutrients, excretion of waste metabolites, and tissue deformity at mechanical stimulus.

Do research experience programs promote capacity building in Qatar: Investigating the trend and participation differences.

Research Experience programs (REPs) inspire students to pursue advanced degrees and shape their research career paths. Government and commercial organizations sponsor REPs to promote the capacity building of the country. In Qatar, the national youth is reported to show concerning participation in Science, Technology, Engineering, and Mathematics (STEM) disciplines at the K-12 level.

High school students' STEM interests and career asirations in Qatar: An exploratory study.

This study sought to explore high school students' interest in science, technology, engineering, and mathematics (STEM) related disciplines and careers in the context of Qatar. Quantitative data was collected using a survey of 1492 high school students in grades 11-12. The normality tests (Shapiro-Wilk test and Kolmogorov Smirnov test) revealed the non-normal distribution of data, leading to employing non-parametric analyses, including Mann Whitney test, Kruskal Wallis H, and logistic regression.

Design and optimization of four-terminal mechanically stacked and optically coupled silicon/perovskite tandem solar cells with over 28% efficiency.

Silicon/perovskite tandem devices are believed to be a favorite contender for improving cell performance over the theoretical maximum value of single-junction photovoltaic (PV) cells. The present study evaluates the design and optimization of four-terminal (4-T) mechanically stacked and optically coupled configurations using SCAPS (solar cell capacitance simulator). Low-cost, stable, and easily processed semitransparent carbon electrode-based perovskite solar cells (c-PSCs) without hole transport material (HTM) and highly efficient crystalline silicon (c-Si) PV cells were utilized as top and bottom cells, respectively.

Comparative Study on Gas-Sensing Properties of 2D (MoS WS)/PANI Nanocomposites-Based Sensor.

NH is a highly harmful gas; when inhaled at levels that are too high for comfort, it is very dangerous to human health. One of the challenging tasks in research is developing ammonia sensors that operate at room temperature. In this study, we proposed a new design of an NH gas sensor that was comprised of two-dimensional (TMDs, mainly WS and MoS) and PANI.

A lightweight neural network with multiscale feature enhancement for liver CT segmentation.

Segmentation of abdominal Computed Tomography (CT) scan is essential for analyzing, diagnosing, and treating visceral organ diseases (e.g., hepatocellular carcinoma).

Humidity sensor based on poly(lactic acid)/PANI-ZnO composite electrospun fibers.

The electrospinning technique has been successfully used to prepared micro-fibers of the poly(lactic acid)/polyaniline-zinc oxide (PLA/PANI-ZnO) composite. The polyaniline-zinc oxide (PANI-ZnO) nanocomposites are synthesized by hydrothermal and polymerization methods. X-ray diffraction techniques are used to study the structural properties of the PLA/PANI-ZnO composite fibers and the PANI-ZnO nanocomposite.

Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells.

Perovskite solar cells (PSCs) expressed great potentials for offering a feasible alternative to conventional photovoltaic technologies. 2D/3D hybrid PSCs, where a 2D capping layer is used over the 3D film to avoid the instability issues associated with perovskite film, have been reported with improved stabilities and high power conversion efficiencies (PCE). However, the profound analysis of the PSCs with prolonged operational lifetime still needs to be described further.

Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy.

Despite the remarkable progress in perovskite solar cells (PSCs), their instability and rapid degradation over time still restrict their commercialization. A 2D capping layer has been proved to overcome the stability issues; however, an in-depth understanding of the complex degradation processes over a prolonged time at PSC interfaces is crucial for improving their stability. In the current work, we investigated the stability of a triple cation 3D ([(FAMA)Cs]Pb(IBr)) and 2D/3D PSC fabricated by a layer-by-layer deposition technique (PEAI-based 2D layer over triple cation 3D perovskite) using a state-of-art characterization technique: electrochemical impedance spectroscopy (EIS).

Capacitive type humidity sensor based on PANI decorated Cu-ZnS porous microspheres.

Porous microstructure materials are considered good candidates for the development of highly sensitive and fast humidity sensors. In this regard, we prepared polyaniline (PANI) decorated Cu-ZnS porous microsphere structures (PMSs) for the fabrication of humidity sensors. PANI coated Cu-ZnS PMSs were synthesized by a hydrothermal method and in situ polymerization process.

Investigation of the structural, optical and gas sensing properties of PANI coated Cu-ZnS microsphere composite.

Polyaniline (PANI)/Cu-ZnS composites with porous microspheres are prepared by a hydrothermal and polymerization method. The structural, optical, and morphological properties are characterized by X-ray powder diffraction, FTIR, UV-vis, scanning electron microscope, transmission electron microscope. The XRD results confirmed that the PANI/Cu-ZnS composite is formed.

Fabrication of polyaniline-graphene/polystyrene nanocomposites for flexible gas sensors.

This research work presents the fabrication of polyaniline (PANI) and graphene-polyaniline (graphene-PANI) nanocomposite-coated polystyrene (PS) nanofibre mats, as well as their application in flexible and highly sensitive gas sensors. The surface morphology of the flexible films is investigated using a number of techniques. The profilometry studies confirmed that the electrospun fibres are evenly distributed over a large surface area and there was no visible difference between coated and uncoated fibres.

Fabrication of flexible conductive films by rubbing in technology for application in elastic thermo-electric cells.

This method solves the problem of fabrication of flexible elastic conductive thin film samples for thermoelectric applications. For this purpose, rubbing in technology at room temperature condition has been used which is simple, economical and reliable. As a result, elastic thermo-electric cells have been fabricated that can be used for low power applications and for measurement of the gradient of temperature in industry, medicine and in instrumentation as well.