Integrating anti-swing controller with px4 autopilot for quadrotor with suspended load

Multi-rotor flying vehicles (MRFVs) are increasingly becoming the preferred means of transportation in various civilian and military applications, such as mine detection, reconnaissance missions, agriculture, and load transfer to areas inaccessible to ground vehicles. In these applications, the payload is suspended underneath the vehicle and subjected to large oscillations because of external disturbances or the vehicle’s acceleration. This study proposes an anti-swing controller (ASC) based on time-delayed feedback of the load swing angles to be implemented in MRFVs with suspended load and operated by a PX4 autopilot. The PX4 autopilot is now widely used in commercial drones. The implementation of the proposed ASC does not require any modifications to the original PX4 firmware because it adds additional displacements to the original trajectories of MRFVs. The effectiveness of the ASC is evaluated by simulating a quadrotor as an example of MRFVs with different flight conditions.

     

Treatment of Algerian crude oil using REB09305 OS demulsifier

Algerian crude oil was submitted to a treatment procedure using REB09305 OS demulsifier. Temperature, time of contact with charge and centrifugation speed were studied. Separation of water from crude oil was observed with a demulsification ratio of 100% in ambient temperature for 20?ppm demulsifier dose, 1200?rpm and 45?min of centrifugation time. The results obtained in this study showed that REB09305 OS demulsifier can be considered a promising product for the treatment of industrial crude oil and the removal of water from it.     

Exfoliated Kidney Cells from Urine for Early Diagnosis and Prognostication of CKD: The Way of the Future?

Chronic kidney disease (CKD) is a global health issue, affecting more than 10% of the worldwide population. The current approach for formal diagnosis and prognostication of CKD typically relies on non-invasive serum and urine biomarkers such as serum creatinine and albuminuria. However, histological evidence of tubulointerstitial fibrosis is the ‘gold standard’ marker of the likelihood of disease progression. The development of novel biomedical technologies to evaluate exfoliated kidney cells from urine for non-invasive diagnosis and prognostication of CKD presents opportunities to avoid kidney biopsy for the purpose of prognostication. Efforts to apply these technologies more widely in clinical practice are encouraged, given their potential as a cost-effective approach, and no risk of post-biopsy complications such as bleeding, pain and hospitalization. The identification of biomarkers in exfoliated kidney cells from urine via western blotting, enzyme-linked immunosorbent assay (ELISA), immunofluorescence techniques, measurement of cell and protein-specific messenger ribonucleic acid (mRNA)/micro-RNA and other techniques have been reported. Recent innovations such as multispectral autofluorescence imaging and single-cell RNA sequencing (scRNA-seq) have brought additional dimensions to the clinical application of exfoliated kidney cells from urine. In this review, we discuss the current evidence regarding the utility of exfoliated proximal tubule cells (PTC), podocytes, mesangial cells, extracellular vesicles and stem/progenitor cells as surrogate markers for the early diagnosis and prognostication of CKD. Future directions for development within this research area are also identified.     

Effect of Moisture Content on Thermal Properties of Porous Building Materials

The thermal conductivity and specific heat capacity of characteristic types of porous building materials are determined in the whole range of moisture content from dry to fully water-saturated state. A transient pulse technique is used in the experiments, in order to avoid the influence of moisture transport on measured data. The investigated specimens include cement composites, ceramics, plasters, and thermal insulation boards. The effect of moisture-induced changes in thermal conductivity and specific heat capacity on the energy performance of selected building envelopes containing the studied materials is then analyzed using computational modeling of coupled heat and moisture transport. The results show an increased moisture content as a substantial negative factor affecting both thermal properties of materials and energy balance of envelopes, which underlines the necessity to use moisture-dependent thermal parameters of building materials in energy-related calculations.     

Highly porous Zr-MCM-48 immobilized Cu-porphyrin for photocatalytic reduction of CO2 to methanol in a slurry reactor

Journal of Materials Science: Materials in Electronics - This study involves the development of novel mesoporous Zr-MCM-48 photocatalyst impregnated with Cu-porphyrin (CuTPP) having Si/Zr ratio of...     

Applying and Comparison of Chaotic-Based Permutation Algorithms for Audio Encryption

This research presents, and clarifies the application of two permutation algorithms, based on chaotic map systems, and applied to a file of speech signals. They are the Arnold cat map-based permutation algorithm, and the Baker’s chaotic map-based permutation algorithm. Both algorithms are implemented on the same speech signal sample. Then, both the premier and the encrypted file histograms are documented and plotted. The speech signal amplitude values with time signals of the original file are recorded and plotted against the encrypted and decrypted files. Furthermore, the original file is plotted against the encrypted file, using the spectrogram frequencies of speech signals with the signal duration. These permutation algorithms are used to shuffle the positions of the speech files signals’ values without any changes, to produce an encrypted speech file. A comparative analysis is introduced by using some of sundry statistical and experimental analyses for the procedures of encryption and decryption, e.g., the time of both procedures, the encrypted audio signals histogram, the correlation coefficient between specimens in the premier and encrypted signals, a test of the Spectral Distortion (SD), and the Log-Likelihood Ratio (LLR) measures. The outcomes of the different experimental and comparative studies demonstrate that the two permutation algorithms (Baker and Arnold) are sufficient for providing an efficient and reliable voice signal encryption solution. However, the Arnold’s algorithm gives better results in most cases as compared to the results of Baker’s algorithm.     

Deep hybrid model-based predictive control with guarantees on domain of applicability

A hybrid model integrates a first-principles model with a data-driven model which predicts certain unknown dynamics of the process, resulting in higher accuracy than first-principles model. Additionally, a hybrid model has better extrapolation capabilities compared with a data-based model, which is useful for process control and optimization purposes. Nonetheless, the domain of applicability (DA) of a hybrid model is finite and should be taken into account when developing a hybrid model-based predictive controller in order to maximize its performance. To this end, a Control Lyapunov–Barrier Function-based model predictive controller (CLBF-based MPC) is developed which utilizes a deep hybrid model (DHM), that is, a deep neural network (DNN) combined with a first-principles model. Additionally, theoretical guarantees are provided on stability as well as on system states to stay within the DA of the DHM. The efficacy of the proposed control framework is demonstrated on a continuous stirred tank reactor.     

Pseudo bond graph model of thermal transfers sustained by ice quantity of a domestic refrigerator for energy saving application

This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Green Nanoarchitectonics of Cu/Fe3O4 Nanoparticles Using Helleborus niger Extract Towards an Efficient Nanocatalyst,Antioxidant and Anti-lung Cancer Agent

Biogenic nanoarchitectured magnetic materials have drawn serious attention throughout the last decade. We have attempted the Helleborus niger flower extract functionalized and templated biogenic synthesis of Cu nanoparticles supported Fe₃O₄ as a likewise novel material. The plant phytomolecules were deployed as a non-toxic sustainable reductant and an outstanding capping agent to stabilize the synthesized NPs. The synthesized Cu/H.niger@Fe₃O₄ nanocomposite was undergone comprehensive characterizations through Fourier transformed infrared spectroscopy (FT-IR), electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), elemental mapping, vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and inductively coupled plasma (ICP) techniques. The material was catalytically explored in the synthesis of diverse pyrano[3,2-c]chromene derivatives by coupling 4-hydroxycoumarin, malononitrile and a range of aldehydes in hot water when it afforded excellent yields. Based on its core magnetism, the catalyst was easily recovered using a magnet and reused for 8 successive times without considerable loss in catalytic activity. After the chemical application, the synthesized Cu/H.niger@Fe₃O₄ nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC₅₀ value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549 and H358 human lung cell lines in-vitro through MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of desired nanocomposite. So, these results suggest that synthesized Cu/H.niger@Fe₃O₄ as a chemotherapeutic nanomaterial have a suitable anticancer activity against lung cell lines.