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This paper presents the constitution of a computationally intelligent self-adaptive steering controller for a lawn-mowing robot to yield robust trajectory tracking and disturbance rejection behavior. The conventional fixed-gain proportional–integral–derivative (PID) control procedure lacks the flexibility to deal with the environmental indeterminacies, coupling issues, and intrinsic nonlinear dynamics associated with the aforementioned nonholonomic system. Hence, this article contributes to formulating a self-adaptive single-neuron PID control system that is driven by an extended Kalman filter (EKF) to ensure efficient learning and faster convergence speeds. The neural adaptive PID control formulation improves the controller’s design flexibility, which allows it to effectively attenuate the tracking errors and improve the system’s trajectory tracking accuracy. To supplement the controller’s robustness to exogenous disturbances, the adaptive PID control signal is modulated with an auxiliary fuzzy-immune system. The fuzzy-immune system imitates the automatic self-learning and self-tuning characteristics of the biological immune system to suppress bounded disturbances and parametric variations. The propositions above are verified by performing the tailored hardware in the loop experiments on a differentially driven lawn-mowing robot. The results of these experiments confirm the enhanced trajectory tracking precision and disturbance compensation ability of the prescribed control method.

Dual use of water for fish and crop production could be a promising approach to improve irrigation under arid conditions. A watercress pot study was carried out to assess the effects of irrigation by catfish and tilapia aquaculture water on the sandy soil properties as well as the growth parameters of watercress with various combinations of artificial NPK fertilizers at El-Minia Governorate of Egypt (28°18′16″ N latitude and 30°34′38″ E longitude). Catfish aquaculture water had the greatest phytoplankton abundance at 83,762 units (×104/L), while the minimum number of phytoplankton existed in tilapia aquaculture water, recorded at 14,873 units (×104/L). There were significant average changes that varied from 120 to 237 (×104 cfu/mL−1) in total bacterial counts in tilapia and catfish waters. Watercress growth quality parameters closely paralleled at all NPK application rates, indicating that the highest quality plants were produced in pots receiving 25% of the recommended levels and irrigated with catfish aquaculture water. Nitrate concentrations of watercress plants were determined under pollution levels established by the European Commission for leafy and tuber vegetables. In conclusion, the use of microbial and phytoplankton-rich aquaculture water to irrigate vegetables and as fertilizer can maintain a balanced soil ecosystem.

The external mucosal surfaces of the fish harbor complex microbial communities, which may play pivotal roles in the physiological, metabolic, and immunological status of the host. Currently, little is known about the composition and role of these communities, whether they are species and/or tissue specific and whether they reflect their surrounding environment. Co-culture of fish, a common practice in semi-intensive aquaculture, where different fish species cohabit in the same contained environment, is an easily accessible and informative model toward understanding such interactions. This study provides the first in-depth characterization of gill and skin microbiomes in co-cultured Nile tilapia (Oreochromis niloticus) and grey mullet (Mugil capito) in semi-intensive pond systems in Egypt using 16S rRNA gene-based amplicon sequencing. Results showed that the microbiome composition of the external surfaces of both species and pond water was dominated by the following bacterial phyla: Proteobacteria, Fusobacteriota, Firmicutes, Planctomycetota, Verrucomicrobiota, Bacteroidota, and Actinobacteriota. However, water microbial communities had the highest abundance and richness and significantly diverged from the external microbiome of both species; thus, the external autochthonous communities are not a passive reflection of their allochthonous communities. The autochthonous bacterial communities of the skin were distinct from those of the gill in both species, indicating that the external microbiome is likely organ specific. However, gill autochthonous communities were clearly species specific, whereas skin communities showed higher commonalities between both species. Core microbiome analysis identified the presence of shared core taxa between both species and pond water in addition to organ-specific taxa within and between the core community of each species. These core taxa included possibly beneficial genera such as Uncultured Pirellulaceae, Exiguobacterium, and Cetobacterium and opportunistic potential pathogens such as Aeromonas, Plesiomonas, and Vibrio. This study provides the first in-depth mapping of bacterial communities in this semi-intensive system that in turn provides a foundation for further studies toward enhancing the health and welfare of these cultured fish and ensuring sustainability.

Two datasets were obtained to develop an understanding of factors characterizing the eLearning experience of secondary school teachers and university undergraduate students in Jordan. Both datasets were collected via electronic questionnaires. The secondary school teachers’ dataset was collected toward the end of the second semester of the 2019/2020 academic year, and the university undergraduate students’ dataset was collected during the summer semester of the same year. Six hundred and sixty-six participants responded to the secondary school teachers’ questionnaire, and one thousand participants responded to the university undergraduate students’ questionnaire. A structural equation modelling approach was utilized to analyze the data. Future research might extend the two data models by collecting data about other factors and examine their impact on the eLearning experience of secondary school teachers and university undergraduate students in Jordan and other countries. Moreover, the datasets can be compared with other data from different developing and developed countries.

The main objective of this study is to present a bibliometric analysis of research on e-learning accessibility at the global level. The bibliometric literature was comprised of 1,325 documents, after data pre-processing, published in Scopus database, covering the period from 1985 to 2021. First, a performance analysis was conducted to assess the publication performance of authors, institutions, countries, and other actors. Second, a science mapping analysis was performed to reveal the structure and dynamics of the e-learning accessibility field. As a result, the most productive, sources, authors, institutions, and countries were identified. Also, the collaboration patterns between particular actors were assessed. Furthermore, the e-learning accessibility research themes and their interrelationships were uncovered. This study contributes to the literature by providing useful information about the e-learning accessibility research status quo and, helps policymakers to achieve effective research planning. That is, it helps in objectively identifying strengths and gaps in e-learning accessibility research in terms of its growth, development, themes, impact, and coverage.

A new type of geopolymer with an iron–oxygen–silicon linkage is synthesized and reported for the first time. The aim was to enable the iron-rich clay material (laterite) as a raw material for the geopolymerization. Iron was used in different ratios ranging 1–3 wt. % in the raw mix designing geopolymer followed by activation with concentrated alkali solutions of NaOH and KOH in different concentrations. The bonding of Fe–O–Si was confirmed from the FTIR peaks in NaOH- and KOH-based geopolymers. X-ray diffraction studies confirmed the formation of zeolitic, sodalite, and almandite phases. The final product has shown a compressive strength of 2371.8 and 1503 kN/m2 and can be used as a construction material. [ABSTRACT FROM AUTHOR]

Recently, metallic wires have gained popularity for utilization as waveguides in propagating sub-THz and THz waves through surface plasmonic polaritons (SPPs). Single and double metallic wire waveguides have demonstrated the ability to propagate these high frequencies with minimal loss and nearly zero dispersion. However, wires typically installed commercially are often coated with dielectric material. Therefore, this paper investigated the effects of using two and four metallic copper wires, both with and without dielectric coating. The impact of various gap distances on different propagation characteristics was also analyzed. Computer Simulation Technology (CST) Microwave Studio was employed in this study for electromagnetic simulations of both uncoated and coated configurations of two and four wires. The introduction of a dielectric coating led to an enhancement in reducing conductor losses and improving energy confinement, with the goal of enhancing the overall efficiency of waveguide signal propagation. [ABSTRACT FROM AUTHOR]

Cancer is a prevalent problem in modern times and while there are available treatments, it continues to cause a significant number of deaths. Cancer is a complex anomaly of the body that is becoming increasingly difficult to control. In the field of nano medicine, nanoparticles are utilized as a drug transporter. Zinc oxide nanoparticles, in particular, offer flexible platforms for therapeutic and biomedical applications, and have the potential to act as an effective anticancerous drug. To investigate this potential, a study was conducted using Rattus Norvegicus as an animal model. The rats were administered carbon tetrachloride (CCl4) and zinc oxide (ZnO) nanoparticles for fourteen consecutive days. After euthanizing the rats, biomedical tests were performed to verify the therapeutic results of the nanoparticles. Analysis of histopathological slides and morphology revealed visible differences in the vital organ, with liver cirrhosis observed in the rats injected only with carbon tetrachloride compared to those injected with both carbon tetrachloride and zinc oxide nanoparticles. Overall, the study highlights the potential of zinc oxide nanoparticles as a promising anti-cancerous drug, with the need for continued research in the development of new and effective treatments for cancer. [ABSTRACT FROM AUTHOR]